Marine natural products(MNPs)are valuable resources for drug development.To date,17 drugs from marine sources are in clinical use,and 33 pharmaceutical compounds are in clinical trials.Presently the success of drug de...Marine natural products(MNPs)are valuable resources for drug development.To date,17 drugs from marine sources are in clinical use,and 33 pharmaceutical compounds are in clinical trials.Presently the success of drug development from the marine resources is higher than the industry average.It is a feasible strategy to conduct the discovery of druglead compounds based on marine chemical ecology by fully exploiting the pharmacological potential of marine chemical defense matters.In the search for bioactive MNPs,our group has constructed a biological resources library including more than 1500 strains of fungi.Focusing on the strategy of Blue Drug Library,we have discovered a series of novel MNPs with abundant biological functions.Highly efficient and scalable total synthesis of(+)-aniduquinolone A(44)and pesimquinolone I(48)have been completed,which will facilitate access to sufficient quantities of candidates for in vivo pharmacological and toxicological studies.As a nucleoprotein(NP)inhibitor,QLA(75)possesses significant anti-influenza A virus(IAV)activities both in vitro and in vivo.CHNQD-00803(76)is a potent and selective AMP-activated kinase(AMPK)activator that can effectively inhibit metabolic disorders and metabolic dysfunction-associated steatohepatitis(MASH)progression.Moreover,we identified two new candidate molecules with potent anti-hepatocellular carcinoma effects.Particularly,as a natural guanine-nucleotide exchange factors for ADP-ribosylation factor GTPases(Arf-GEFs)inhibitor prodrug,CHNQD-01255(78)is qualified to be developed as a targeted candidate anticancer drug,which may be promising to apply for cancer immunotherapy.Hence,it is evident that MNPs play an important role in drug development.展开更多
Marine science technology innovation provides power and guarantees for marine eco-civilization construction,which provides direction and material support for marine science technology innovation.Therefore,the coordina...Marine science technology innovation provides power and guarantees for marine eco-civilization construction,which provides direction and material support for marine science technology innovation.Therefore,the coordinated development of the two is of great significance to the marine economy sustainable development in China’s coastal areas.On the basis of clarifying the connotations of marine science technology innovation and marine eco-civilization in China’s coastal areas from 2006 to 2019,the mechanism for their coordinated development was analysed.A comprehensive indicator system based on the connotation of the two was constructed,and the coordinated development relationship was empirically tested using the coupled coordination model and the panel vector autoregressive(PVAR)model.The results show that:1)the level of China’s coastal marine science technology innovation continues to improve,gradually forming the core of the development of marine science technology innovation in the north,east and south of Shandong,Shanghai and Guangdong;the level of marine eco-civilization development fluctuating upward trend,showing obvious spatial differentiation characteristics.2)The degree of coordination of marine science technology innovation and marine eco-civilization is growing over time.There is no causal relationship between marine science technology innovation and marine eco-civilization in the northern marine economic circle,but there is a two-way causal relationship between the two in the eastern and southern marine economic circles.3)Marine eco-civilization shows a significant positive and continuous impact on marine science technology innovation,and marine science technology innovation shows a long-term,continuous,fluctuating,and lagging impact on marine eco-civilization.The overall role of marine eco-civilization on marine science technology innovation is dominant,and there are significant differences in the impact effects of the two major marine economic circles.展开更多
When investigating the vortex-induced vibration(VIV)of marine risers,extrapolating the dynamic response on the entire length based on limited sensor measurements is a crucial step in both laboratory experiments and fa...When investigating the vortex-induced vibration(VIV)of marine risers,extrapolating the dynamic response on the entire length based on limited sensor measurements is a crucial step in both laboratory experiments and fatigue monitoring of real risers.The problem is conventionally solved using the modal decomposition method,based on the principle that the response can be approximated by a weighted sum of limited vibration modes.However,the method is not valid when the problem is underdetermined,i.e.,the number of unknown mode weights is more than the number of known measurements.This study proposed a sparse modal decomposition method based on the compressed sensing theory and the Compressive Sampling Matching Pursuit(Co Sa MP)algorithm,exploiting the sparsity of VIV in the modal space.In the validation study based on high-order VIV experiment data,the proposed method successfully reconstructed the response using only seven acceleration measurements when the conventional methods failed.A primary advantage of the proposed method is that it offers a completely data-driven approach for the underdetermined VIV reconstruction problem,which is more favorable than existing model-dependent solutions for many practical applications such as riser structural health monitoring.展开更多
An observer-based adaptive backstepping boundary control is proposed for vibration control of flexible offshore riser systems with unknown nonlinear input dead zone and uncertain environmental disturbances.The control...An observer-based adaptive backstepping boundary control is proposed for vibration control of flexible offshore riser systems with unknown nonlinear input dead zone and uncertain environmental disturbances.The control algorithm can update the control law online through real-time data to make the controller adapt to the environment and improve the control precision.Specifically,based on the adaptive backstepping framework,virtual control laws and Lyapunov functions are designed for each subsystem.Three direction interference observers are designed to track the timevarying boundary disturbance.On this basis,the inverse of the dead zone and linear state transformation are used to compensate for the original system and eliminate the adverse effects of the dead zone.In addition,the stability of the closed-loop system is proven by Lyapunov stability theory.All the system states are bounded,and the vibration offset of the riser converges to a small area of the initial position.Finally,four examples of flexible marine risers are simulated in MATLAB to verify the effectiveness of the proposed controller.展开更多
High velocity oxygen fuel(HVOF)spraying process is commonly used to produce superalloy coatings.Inconel 625 coating was prepared on Q235B low carbon steel by HVOF.A series of experiments were conducted to examine the ...High velocity oxygen fuel(HVOF)spraying process is commonly used to produce superalloy coatings.Inconel 625 coating was prepared on Q235B low carbon steel by HVOF.A series of experiments were conducted to examine the surface and corrosion resistance properties of Inconel 625 HVOF coating.In this paper,potentiodynamic polarization tests and electrochemical impedance spectroscopy(EIS)tests were carried out to evaluate the corrosion resistance of Inconel 625 coating under simulated marine environment.The experiment-al results showed that Inconel 625 coating revealed low porosity and desired coating thickness.Shift in the corrosion potential(E_(corr))to-wards the noble direction combined with much low corrosion current density(i_(corr))indicating a significant improvement of HVOF Inconel 625 coating compared with the substrate.展开更多
Island ecosystems support diverse aquatic invertebrate communities comprising endemic taxa.Documentation of existing species is important for conservation.In this study,a checklist of marine opisthobranch from the Rep...Island ecosystems support diverse aquatic invertebrate communities comprising endemic taxa.Documentation of existing species is important for conservation.In this study,a checklist of marine opisthobranch from the Republic of Mauritius is presented.A combination of benthic surveys(50 m×5 m in triplicates),rover diving techniques and photo documentation were used over two years(2018–2020)within 35 sheltered and unsheltered lagoons.Morphological and molecular analysis were used for identification.Species composition within sheltered and unsheltered areas in Mauritius was estimated using the Bray-Curtis similarity.The checklist featured 117 species belonging to 61 genera and 28families,of which 13 are new records.The findings increased the knowledge of opisthobranch diversity from the Mauritius by 15.4%.Among the listed species,the distribution range of Cyerce nigra,Actinocyclus papillatus,and Phyllidia picta extended from the Western Pacific to the South Western Indian Ocean.Molecular analysis of the undescribed Gymnodoris sp.showed it resembled Gymnodoris sp.from Hawaii and were different by a genetic distance value of 10.6%.The species richness and evenness were higher within the sheltered regions of Mauritius which harboured the food resource of opisthobranch.These areas as compared to unsheltered regions were heavily populated,suggesting the probable influence of wave actions on opisthobranch diversity and abundance.The order Nudibranchia was reported as most speciose,with 86 species.The Sacoglossa and Nudibranchia were observed only on macroalgae and sponges respectively.High abundance was also recorded on shipwrecks which are the most common form of artificial reefs.With the inclusion of observations from previous studies,201species belonging to 94 genera and 36 families are now known from the Mauritius.展开更多
Using monthly observations and ensemble hindcasts of the Nanjing University of Information Science and Technology Climate Forecast System(NUIST-CFS1.0) for the period 1983–2020, this study investigates the forecast s...Using monthly observations and ensemble hindcasts of the Nanjing University of Information Science and Technology Climate Forecast System(NUIST-CFS1.0) for the period 1983–2020, this study investigates the forecast skill of marine heatwaves(MHWs) over the globe and the predictability sources of the MHWs over the tropical oceans. The MHW forecasts are demonstrated to be skillful on seasonal-annual time scales, particularly in tropical oceans. The forecast skill of the MHWs over the tropical Pacific Ocean(TPO) remains high at lead times of 1–24 months, indicating a forecast better than random chance for up to two years. The forecast skill is subject to the spring predictability barrier of El Nino-Southern Oscillation(ENSO). The forecast skills for the MHWs over the tropical Indian Ocean(TIO), tropical Atlantic Ocean(TAO), and tropical Northwest Pacific(NWP) are lower than that in the TPO. A reliable forecast at lead times of up to two years is shown over the TIO, while a shorter reliable forecast window(less than 17 months) occurs for the TAO and NWP.Additionally, the forecast skills for the TIO, TAO, and NWP are seasonally dependent. Higher skills for the TIO and TAO appear in boreal spring, while a greater skill for the NWP emerges in late summer-early autumn. Further analyses suggest that ENSO serves as a critical source of predictability for MHWs over the TIO and TAO in spring and MHWs over the NWP in summer.展开更多
Structure-soil interface friction characteristics is of importance to investigate the interaction between engineering structures and soils,especially for offshore structures.The interface friction behavior between mar...Structure-soil interface friction characteristics is of importance to investigate the interaction between engineering structures and soils,especially for offshore structures.The interface friction behavior between marine clay and structural materials with different roughness was studied in this paper by using 3D optical scanning tests,a modified direct shear device and numerical simulation.Relationships between the surface roughness of structures,water content and interface friction angle were presented by model tests.The increase of water contents decreased the interface friction angles.For interfaces with different roughness,the interface friction angles will be smaller than that of the soil when the water content exceeds a certain value.The roughness of the interface and the water content of the soil are mutually coupled to influence the coefficient of friction(COF).This paper proposed a Finite Element Method(FEM)to simulate the interface direct shear tests of structures with different roughness.The surface models with different roughness are established based on the structure data obtained by 3D scanning.The Coupled Eulerian-Lagrangian(CEL)approach was employed to analyse soils sheared by irregular surfaces.The interface behavior for interfaces with different roughness under cyclic shear stresses was analyzed by FEM.展开更多
The ocean is one of the essential fields of national defense in the future,and more and more attention is paid to the lightweight research of Marine equipment and materials.This study it is to develop a Machine learni...The ocean is one of the essential fields of national defense in the future,and more and more attention is paid to the lightweight research of Marine equipment and materials.This study it is to develop a Machine learning(ML)-based prediction method to study the evolution of the mechanical properties of Al-Li alloys in the marine environment.We obtained the mechanical properties of Al-Li alloy samples under uniaxial tensile deformation at different exposure times through Marine exposure experiments.We obtained the strain evolution by digital image correlation(DIC).The strain field images are voxelized using 2D-Convolutional Neural Networks(CNN)autoencoders as input data for Long Short-Term Memory(LSTM)neural networks.Then,the output data of LSTM neural networks combined with corrosion features were input into the Back Propagation(BP)neural network to predict the mechanical properties of Al-Li alloys.The main conclusions are as follows:1.The variation law of mechanical properties of2297-T8 in the Marine atmosphere is revealed.With the increase in outdoor exposure test time,the tensile elastic model of 2297-T8 changes slowly,within 10%,and the tensile yield stress changes significantly,with a maximum attenuation of 23.6%.2.The prediction model can predict the strain evolution and mechanical response simultaneously with an error of less than 5%.3.This study shows that a CNN/LSTM system based on machine learning can be built to capture the corrosion characteristics of Marine exposure experiments.The results show that the relationship between corrosion characteristics and mechanical response can be predicted without considering the microstructure evolution of metal materials.展开更多
The microstructure and precipitated phases of as-cast Mg-5Y-1.5Nd-x Zn-0.5Zr(x=0,2,4,6 wt.%)alloys were investigated by optical microscopy,scanning electron microscopy,energy-dispersive spectrometry and X-ray Diffract...The microstructure and precipitated phases of as-cast Mg-5Y-1.5Nd-x Zn-0.5Zr(x=0,2,4,6 wt.%)alloys were investigated by optical microscopy,scanning electron microscopy,energy-dispersive spectrometry and X-ray Diffraction.The exposure corrosion experiment of these magnesium alloys was tested in South China Sea and KEXUE vessel atmospheric environment.The corrosion characteristic and mechanism of magnesium alloys of Mg-5Y-1.5Nd-x Zn-0.5Zr(x=0,2,4,6 wt.%)alloys were analyzed by weight loss rate,corrosion depth,corrosion products and corrosion morphologies.The electrochemical corrosion tests were also measured in the natural seawater.The comprehensive results showed that Mg-5Y-1.5Nd-4Zn-0.5Zr magnesium alloy existed the best corrosion resistance whether in the marine atmospheric environment and natural seawater environment.That depended on the microstructure,type and distribution of precipitated phases in Mg-5Y-1.5Nd-4Zn-0.5Zr magnesium alloy.Sufficient quantity anodic precipitated phases in the microstructure of Mg-5Y-1.5Nd-4Zn-0.5Zr alloy played the key role in the corrosion resistance.展开更多
The construction of major marine infrastructure projects and the exploration and development of deep-sea mineral resources require fine imaging of seabed strata and structures.The highresolution marine seismic explora...The construction of major marine infrastructure projects and the exploration and development of deep-sea mineral resources require fine imaging of seabed strata and structures.The highresolution marine seismic exploration based on a high broadband sparker source is an important approach to reveal seabed stratum and reservoir structure,and identify geohazard.To optimize the performance of sparker seismic source,we investigated the electro-acoustic characteristics of spark discharge under conditions of different charging voltages and electrode numbers.Results show that the sound source level increased with the increase of the charging voltage,whereas the main frequency decreased when the charging voltage increases.In addition,it was found that the charging capacitance had more obvious influence on the main frequency than the sound source level did.Although the load energy decreased with increasing electrode number,the sound source level still increased but the main frequency decreased.Meanwhile,the primary to bubble(P/B)ratio increased with the increase of the electrode number.To gain a deeper insight into the electro-acoustic characteristics,we investigate the relationship between sound source level and power peak,from which a good correlation was observed.A more practical statistical analysis on the rise rate of current was processed,and a perfect logarithmic function was derived.Furthermore,we found that the main frequency was most possibly subjected to the electrical energy,especially the charging energy per electrode.The results indicate that the charging energy per electrode less than 10 J could increase the main frequency to above 300 Hz.At last,the main frequency could be reduced to 20 Hz when the charging energy of a single-electrode discharge was enhanced to over 4 kJ.This study shall be helpful in developing a sparker seismic source and improving the performance for marine engineering exploration and geohazard assessment.展开更多
The application of microorganisms as probiotics is limited due to lack of safety evaluation.Here,a novel multi-stress-tolerant yeast Meyerozyma guilliermondii GXDK6 with aroma-producing properties was identified from ...The application of microorganisms as probiotics is limited due to lack of safety evaluation.Here,a novel multi-stress-tolerant yeast Meyerozyma guilliermondii GXDK6 with aroma-producing properties was identified from marine mangrove microorganisms.Its safety and probiotic properties were assessed in accordance with phenotype and whole-genome sequencing analysis.Results showed that the genes and phenotypic expression of related virulence,antibiotic resistance and retroelement were rarely found.Hyphal morphogenesis genes(SIT4,HOG1,SPA2,ERK1,ICL1,CST20,HSP104,TPS1,and RHO1)and phospholipase secretion gene(VPS4)were annotated.True hyphae and phospholipase were absent.Only one retroelement(Tad1-65_BG)was found.Major biogenic amines(BAs)encoding genes were absent,except for spermidine synthase(JA9_002594),spermine synthase(JA9_004690),and tyrosine decarboxylase(inx).The production of single BAs and total BAs was far below the food-defined thresholds.GXDK6 had no resistance to common antifungal drugs.Virulence enzymes,such as gelatinase,DNase,hemolytic,lecithinase,and thrombin were absent.Acute toxicity test with mice demonstrated that GXDK6 is safe.GXDK6 has a good reproduction ability in the simulation gastrointestinal tract.GXDK6 also has a strong antioxidant ability,β-glucosidase,and inulinase activity.To sum up,GXDK6 is considered as a safe probiotic for human consumption and food fermentation.展开更多
Taking the Paleozoic of the Sichuan and Tarim basins in China as example,the controlling effects of the Earth system evolution and multi-spherical interactions on the formation and enrichment of marine ultra-deep petr...Taking the Paleozoic of the Sichuan and Tarim basins in China as example,the controlling effects of the Earth system evolution and multi-spherical interactions on the formation and enrichment of marine ultra-deep petroleum in China have been elaborated.By discussing the development of“source-reservoir-seal”controlled by the breakup and assembly of supercontinents and regional tectonic movements,and the mechanisms of petroleum generation and accumulation controlled by temperature-pressure system and fault conduit system,Both the South China and Tarim blocks passed through the intertropical convergence zone(ITCZ)of the low-latitude Hadley Cell twice during their drifts,and formed hydrocarbon source rocks with high quality.It is proposed that deep tectonic activities and surface climate evolution jointly controlled the types and stratigraphic positions of ultra-deep hydrocarbon source rocks,reservoirs,and seals in the Sichuan and Tarim basins,forming multiple petroleum systems in the Ediacaran-Cambrian,Cambrian-Ordovician,Cambrian-Permian and Permian-Triassic strata.The matching degree of source-reservoir-seal,the type of organic matter in source rocks,the deep thermal regime of basin,and the burial-uplift process across tectonic periods collectively control the entire process from the generation to the accumulation of oil and gas.Three types of oil and gas enrichment models are formed,including near-source accumulation in platform marginal zones,distant-source accumulation in high-energy beaches through faults,and three-dimensional accumulation in strike-slip fault zones,which ultimately result in the multi-layered natural gas enrichment in ultra-deep layers of the Sichuan Basin and co-enrichment of oil and gas in the ultra-deep layers of the Tarim Basin.展开更多
This study evaluates the performance of 16 models sourced from the coupled model intercomparison project phase 6(CMIP6)in simulating marine heatwaves(MHWs)in the South China Sea(SCS)during the historical period(1982−2...This study evaluates the performance of 16 models sourced from the coupled model intercomparison project phase 6(CMIP6)in simulating marine heatwaves(MHWs)in the South China Sea(SCS)during the historical period(1982−2014),and also investigates future changes in SCS MHWs based on simulations from three shared socioeconomic pathway(SSP)scenarios(SSP126,SSP245,and SSP585)using CMIP6 models.Results demonstrate that the CMIP6 models perform well in simulating the spatial-temporal distribution and intensity of SCS MHWs,with their multi-model ensemble(MME)results showing the best performance.The reasonable agreement between the observations and CMIP6 MME reveals that the increasing trends of SCS MHWs are attributed to the warming sea surface temperature trend.Under various SSP scenarios,the year 2040 emerges as pivotal juncture for future shifts in SCS MHWs,marked by distinct variations in changing rate and amplitudes.This is characterized by an accelerated decrease in MHWs frequency and a notably heightened increase in mean intensity,duration,and total days after 2040.Furthermore,the projection results for SCS MHWs suggest that the spatial pattern of MHWs remains consistent across future periods.However,the intensity shows higher consistency only during the near-term period(2021−2050),while notable inconsistencies are observed during the medium-term(2041−2070)and long-term(2071−2100)periods under the three SSP scenarios.During the nearterm period,the SCS MHWs are characterized by moderate and strong events with high frequencies and relatively shorter durations.In contrast,during the medium-term period,MHWs are also characterized by moderate and strong events,but with longer-lasting and more intense events under the SSP245 and SSP585 scenarios.However,in the long-term period,extreme MHWs become the dominant feature under the SSP585 scenario,indicating a substantial intensification of SCS MHWs,effectively establishing a near-permanent state.展开更多
In blood or bone marrow,leukemia is a form of cancer.A person with leukemia has an expansion of white blood cells(WBCs).It primarily affects children and rarely affects adults.Treatment depends on the type of leukemia...In blood or bone marrow,leukemia is a form of cancer.A person with leukemia has an expansion of white blood cells(WBCs).It primarily affects children and rarely affects adults.Treatment depends on the type of leukemia and the extent to which cancer has established throughout the body.Identifying leukemia in the initial stage is vital to providing timely patient care.Medical image-analysis-related approaches grant safer,quicker,and less costly solutions while ignoring the difficulties of these invasive processes.It can be simple to generalize Computer vision(CV)-based and image-processing techniques and eradicate human error.Many researchers have implemented computer-aided diagnosticmethods andmachine learning(ML)for laboratory image analysis,hopefully overcoming the limitations of late leukemia detection and determining its subgroups.This study establishes a Marine Predators Algorithm with Deep Learning Leukemia Cancer Classification(MPADL-LCC)algorithm onMedical Images.The projectedMPADL-LCC system uses a bilateral filtering(BF)technique to pre-process medical images.The MPADL-LCC system uses Faster SqueezeNet withMarine Predators Algorithm(MPA)as a hyperparameter optimizer for feature extraction.Lastly,the denoising autoencoder(DAE)methodology can be executed to accurately detect and classify leukemia cancer.The hyperparameter tuning process using MPA helps enhance leukemia cancer classification performance.Simulation results are compared with other recent approaches concerning various measurements and the MPADL-LCC algorithm exhibits the best results over other recent approaches.展开更多
Offshore carbon dioxide(CO_(2)) storage is an effective method for reducing greenhouse gas emissions. However, when using traditional seismic wave methods to monitor the migration of sequestration CO_(2) plumes, the c...Offshore carbon dioxide(CO_(2)) storage is an effective method for reducing greenhouse gas emissions. However, when using traditional seismic wave methods to monitor the migration of sequestration CO_(2) plumes, the characteristics of wave velocity changes tend to become insignificant beyond a certain limit. In contrast, the controllable source electromagnetic method(CSEM) remains highly sensitive to resistivity changes. By simulating different CO_(2) plume migration conditions, we established the relevant models and calculated the corresponding electric field response characteristic curves, allowing us to analyze the CSEM's ability to monitor CO_(2) plumes. We considered potential scenarios for the migration and diffusion of offshore CO_(2) storage, including various burial depths, vertical extension diffusion, lateral extension diffusion,multiple combinations of lateral intervals, and electric field components. We also obtained differences in resistivity inversion imaging obtained by CSEM to evaluate its feasibility in monitoring and to analyze all the electric field(Ex, Ey, and Ez) response characteristics. CSEM has great potential in monitoring CO_(2) plume migration in offshore saltwater reservoirs due to its high sensitivity and accuracy. Furthermore, changes in electromagnetic field response reflect the transport status of CO_(2) plumes, providing an important basis for monitoring and evaluating CO_(2)transport behavior during storage processes.展开更多
The phase change of CO_(2) has a significant bearing on the siting, injection, and monitoring of storage. The phase state of CO_(2) is closely related to pressure. In the process of seismic exploration, the informatio...The phase change of CO_(2) has a significant bearing on the siting, injection, and monitoring of storage. The phase state of CO_(2) is closely related to pressure. In the process of seismic exploration, the information of formation pressure can be response in the seismic data. Therefore, it is possible to monitor the formation pressure using time-lapse seismic method. Apart from formation pressure, the information of porosity and CO_(2) saturation can be reflected in the seismic data. Here, based on the actual situation of the work area, a rockphysical model is proposed to address the feasibility of time-lapse seismic monitoring during CO_(2) storage in the anisotropic formation. The model takes into account the formation pressure, variety minerals composition, fracture, fluid inhomogeneous distribution, and anisotropy caused by horizontal layering of rock layers(or oriented alignment of minerals). From the proposed rockphysical model and the well-logging, cores and geological data at the target layer, the variation of P-wave and S-wave velocity with formation pressure after CO_(2) injection is calculated. And so are the effects of porosity and CO_(2) saturation. Finally, from anisotropic exact reflection coefficient equation, the reflection coefficients under different formation pressures are calculated. It is proved that the reflection coefficient varies with pressure. Compared with CO_(2) saturation, the pressure has a greater effect on the reflection coefficient. Through the convolution model, the seismic record is calculated. The seismic record shows the difference with different formation pressure. At present, in the marine CO_(2) sequestration monitoring domain, there is no study involving the effect of formation pressure changes on seismic records in seafloor anisotropic formation. This study can provide a basis for the inversion of reservoir parameters in anisotropic seafloor CO_(2) reservoirs.展开更多
Dredged marine soils(DMS)have poor engineering properties,which limit their usage in construction projects.This research examines the application of reactive magnesia(rMgO)containing supplementary cementitious materia...Dredged marine soils(DMS)have poor engineering properties,which limit their usage in construction projects.This research examines the application of reactive magnesia(rMgO)containing supplementary cementitious materials(SCMs)to stabilize DMS under ambient and carbon dioxide(CO_(2))curing conditions.Several proprietary experimental tests were conducted to investigate the stabilized DMS.Furthermore,the carbonation-induced mineralogical,thermal,and microstructural properties change of the samples were explored.The findings show that the compressive strength of the stabilized DMS fulfilled the 7-d requirement(0.7-2.1 MPa)for pavement and building foundations.Replacing rMgO with SCMs such as biochar or ground granulated blast-furnace slag(GGBS)altered the engineering properties and particle packing of the stabilized soils,thus influencing their performances.Biochar increased the porosity of the samples,facilitating higher CO_(2) uptake and improved ductility,while GGBS decreased porosity and increased the dry density of the samples,resulting in higher strength.The addition of SCMs also enhanced the water retention capacity and modified the pH of the samples.Microstructural analysis revealed that the hydrated magnesium carbonates precipitated in the carbonated samples provided better cementation effects than brucite formed during rMgO hydration.Moreover,incorporating SCMs reduced the overall global warming potential and energy demand of the rMgO-based systems.The biochar mixes demonstrated lower toxicity and energy consumption.Ultimately,the rMgO and biochar blend can serve as an environmentally friendly additive for soft soil stabilization and permanent fixation of significant amounts of CO_(2) in soils through mineral carbonation,potentially reducing environmental pollution while meeting urbanization needs.展开更多
Climate change has led to significant fluctuations in marine ecosystems,including alterations in the structure and function of food webs and ecosystem status.Coastal ecosystems are critical to the functioning of the e...Climate change has led to significant fluctuations in marine ecosystems,including alterations in the structure and function of food webs and ecosystem status.Coastal ecosystems are critical to the functioning of the earth’s lifesupporting systems.However,temporal variations in most of these ecosystems have remained unclear so far.In this study,we employed a linear inverse model with Markov Chain Monte Carlo(LIM-MCMC)combined with ecological network analysis to reveal the temporal variations of the food web in Haizhou Bay of China.Food webs were constructed based on diet composition data in this ecosystem during the year of 2011 and 2018.Results indicated that there were obvious temporal variations in the composition of food webs in autumn of 2011 and 2018.The number of prey and predators for most species in food web decreased in 2018 compared with 2011,especially for Trichiurus lepturus,zooplankton,Amblychaeturichthys hexanema,and Loligo sp.Ecological network analysis showed that the complexity of food web structure could be reflected by comprehensive analysis of compartmentalized indicators.Haizhou Bay ecosystem was more mature and stable in 2011,while the ecosystem’s self-sustainability and recovery from disturbances were accelerated from 2011 to 2018.These findings contribute to our understanding of the dynamics of marine ecosystems and highlight the importance of comprehensive analysis of marine food webs.This work provides a framework for assessing and comparing temporal variations in marine ecosystems,which provides essential information and scientific guidance for the Ecosystem-based Fisheries Management.展开更多
UAV marine monitoring plays an essential role in marine environmental protection because of its flexibility and convenience,low cost and convenient maintenance.In marine environmental monitoring,the similarity between...UAV marine monitoring plays an essential role in marine environmental protection because of its flexibility and convenience,low cost and convenient maintenance.In marine environmental monitoring,the similarity between objects such as oil spill and sea surface,Spartina alterniflora and algae is high,and the effect of the general segmentation algorithm is poor,which brings new challenges to the segmentation of UAV marine images.Panoramic segmentation can do object detection and semantic segmentation at the same time,which can well solve the polymorphism problem of objects in UAV ocean images.Currently,there are few studies on UAV marine image recognition with panoptic segmentation.In addition,there are no publicly available panoptic segmentation datasets for UAV images.In this work,we collect and annotate UAV images to form a panoptic segmentation UAV dataset named UAV-OUC-SEG and propose a panoptic segmentation method named PanopticUAV.First,to deal with the large intraclass variability in scale,deformable convolution and CBAM attention mechanism are employed in the backbone to obtain more accurate features.Second,due to the complexity and diversity of marine images,boundary masks by the Laplacian operator equation from the ground truth are merged into feature maps to improve boundary segmentation precision.Experiments demonstrate the advantages of PanopticUAV beyond the most other advanced approaches on the UAV-OUC-SEG dataset.展开更多
基金supported by the Shandong Province Special Fund ‘Frontier Technology and Free Exploration’ from Laoshan Laboratory (No. 8-01)the National Natural Science Foundation of China (No. 42376116)+3 种基金the Special Funds of Shandong Province for Qingdao National Laboratory of Marine Science and Technology (No. 2022QN LM030003)the State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Guangxi Normal University (No. CMEMR2023-B16)the National Key Research and Development Program of China (No. 2022YFC2601305)the Innovation Center for Academicians of Hainan Province, and the Fundamental Research Funds for the Central Universities (No. 202461059)
文摘Marine natural products(MNPs)are valuable resources for drug development.To date,17 drugs from marine sources are in clinical use,and 33 pharmaceutical compounds are in clinical trials.Presently the success of drug development from the marine resources is higher than the industry average.It is a feasible strategy to conduct the discovery of druglead compounds based on marine chemical ecology by fully exploiting the pharmacological potential of marine chemical defense matters.In the search for bioactive MNPs,our group has constructed a biological resources library including more than 1500 strains of fungi.Focusing on the strategy of Blue Drug Library,we have discovered a series of novel MNPs with abundant biological functions.Highly efficient and scalable total synthesis of(+)-aniduquinolone A(44)and pesimquinolone I(48)have been completed,which will facilitate access to sufficient quantities of candidates for in vivo pharmacological and toxicological studies.As a nucleoprotein(NP)inhibitor,QLA(75)possesses significant anti-influenza A virus(IAV)activities both in vitro and in vivo.CHNQD-00803(76)is a potent and selective AMP-activated kinase(AMPK)activator that can effectively inhibit metabolic disorders and metabolic dysfunction-associated steatohepatitis(MASH)progression.Moreover,we identified two new candidate molecules with potent anti-hepatocellular carcinoma effects.Particularly,as a natural guanine-nucleotide exchange factors for ADP-ribosylation factor GTPases(Arf-GEFs)inhibitor prodrug,CHNQD-01255(78)is qualified to be developed as a targeted candidate anticancer drug,which may be promising to apply for cancer immunotherapy.Hence,it is evident that MNPs play an important role in drug development.
基金Under the auspices of the National Natural Science Foundation of China(No.42076222)。
文摘Marine science technology innovation provides power and guarantees for marine eco-civilization construction,which provides direction and material support for marine science technology innovation.Therefore,the coordinated development of the two is of great significance to the marine economy sustainable development in China’s coastal areas.On the basis of clarifying the connotations of marine science technology innovation and marine eco-civilization in China’s coastal areas from 2006 to 2019,the mechanism for their coordinated development was analysed.A comprehensive indicator system based on the connotation of the two was constructed,and the coordinated development relationship was empirically tested using the coupled coordination model and the panel vector autoregressive(PVAR)model.The results show that:1)the level of China’s coastal marine science technology innovation continues to improve,gradually forming the core of the development of marine science technology innovation in the north,east and south of Shandong,Shanghai and Guangdong;the level of marine eco-civilization development fluctuating upward trend,showing obvious spatial differentiation characteristics.2)The degree of coordination of marine science technology innovation and marine eco-civilization is growing over time.There is no causal relationship between marine science technology innovation and marine eco-civilization in the northern marine economic circle,but there is a two-way causal relationship between the two in the eastern and southern marine economic circles.3)Marine eco-civilization shows a significant positive and continuous impact on marine science technology innovation,and marine science technology innovation shows a long-term,continuous,fluctuating,and lagging impact on marine eco-civilization.The overall role of marine eco-civilization on marine science technology innovation is dominant,and there are significant differences in the impact effects of the two major marine economic circles.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.51109158,U2106223)the Science and Technology Development Plan Program of Tianjin Municipal Transportation Commission(Grant No.2022-48)。
文摘When investigating the vortex-induced vibration(VIV)of marine risers,extrapolating the dynamic response on the entire length based on limited sensor measurements is a crucial step in both laboratory experiments and fatigue monitoring of real risers.The problem is conventionally solved using the modal decomposition method,based on the principle that the response can be approximated by a weighted sum of limited vibration modes.However,the method is not valid when the problem is underdetermined,i.e.,the number of unknown mode weights is more than the number of known measurements.This study proposed a sparse modal decomposition method based on the compressed sensing theory and the Compressive Sampling Matching Pursuit(Co Sa MP)algorithm,exploiting the sparsity of VIV in the modal space.In the validation study based on high-order VIV experiment data,the proposed method successfully reconstructed the response using only seven acceleration measurements when the conventional methods failed.A primary advantage of the proposed method is that it offers a completely data-driven approach for the underdetermined VIV reconstruction problem,which is more favorable than existing model-dependent solutions for many practical applications such as riser structural health monitoring.
基金financially supported by the Sichuan Science and Technology Program(Grant No.2023NSFSC1980)。
文摘An observer-based adaptive backstepping boundary control is proposed for vibration control of flexible offshore riser systems with unknown nonlinear input dead zone and uncertain environmental disturbances.The control algorithm can update the control law online through real-time data to make the controller adapt to the environment and improve the control precision.Specifically,based on the adaptive backstepping framework,virtual control laws and Lyapunov functions are designed for each subsystem.Three direction interference observers are designed to track the timevarying boundary disturbance.On this basis,the inverse of the dead zone and linear state transformation are used to compensate for the original system and eliminate the adverse effects of the dead zone.In addition,the stability of the closed-loop system is proven by Lyapunov stability theory.All the system states are bounded,and the vibration offset of the riser converges to a small area of the initial position.Finally,four examples of flexible marine risers are simulated in MATLAB to verify the effectiveness of the proposed controller.
基金supported by Zhejiang Provincial Natural Science Foundation of China(No.LTGC23E010001)the Youth Science and Technology Project of Zhejiang Provincial Administration for Market Regulation(No.QN2023427)Science and Techno-logy Project of State Administration for Market Regulation(No.2022MK054).
文摘High velocity oxygen fuel(HVOF)spraying process is commonly used to produce superalloy coatings.Inconel 625 coating was prepared on Q235B low carbon steel by HVOF.A series of experiments were conducted to examine the surface and corrosion resistance properties of Inconel 625 HVOF coating.In this paper,potentiodynamic polarization tests and electrochemical impedance spectroscopy(EIS)tests were carried out to evaluate the corrosion resistance of Inconel 625 coating under simulated marine environment.The experiment-al results showed that Inconel 625 coating revealed low porosity and desired coating thickness.Shift in the corrosion potential(E_(corr))to-wards the noble direction combined with much low corrosion current density(i_(corr))indicating a significant improvement of HVOF Inconel 625 coating compared with the substrate.
文摘Island ecosystems support diverse aquatic invertebrate communities comprising endemic taxa.Documentation of existing species is important for conservation.In this study,a checklist of marine opisthobranch from the Republic of Mauritius is presented.A combination of benthic surveys(50 m×5 m in triplicates),rover diving techniques and photo documentation were used over two years(2018–2020)within 35 sheltered and unsheltered lagoons.Morphological and molecular analysis were used for identification.Species composition within sheltered and unsheltered areas in Mauritius was estimated using the Bray-Curtis similarity.The checklist featured 117 species belonging to 61 genera and 28families,of which 13 are new records.The findings increased the knowledge of opisthobranch diversity from the Mauritius by 15.4%.Among the listed species,the distribution range of Cyerce nigra,Actinocyclus papillatus,and Phyllidia picta extended from the Western Pacific to the South Western Indian Ocean.Molecular analysis of the undescribed Gymnodoris sp.showed it resembled Gymnodoris sp.from Hawaii and were different by a genetic distance value of 10.6%.The species richness and evenness were higher within the sheltered regions of Mauritius which harboured the food resource of opisthobranch.These areas as compared to unsheltered regions were heavily populated,suggesting the probable influence of wave actions on opisthobranch diversity and abundance.The order Nudibranchia was reported as most speciose,with 86 species.The Sacoglossa and Nudibranchia were observed only on macroalgae and sponges respectively.High abundance was also recorded on shipwrecks which are the most common form of artificial reefs.With the inclusion of observations from previous studies,201species belonging to 94 genera and 36 families are now known from the Mauritius.
基金jointly supported by the National Natural Science Foundation of China (Grant Nos.42192562 and 42030605)。
文摘Using monthly observations and ensemble hindcasts of the Nanjing University of Information Science and Technology Climate Forecast System(NUIST-CFS1.0) for the period 1983–2020, this study investigates the forecast skill of marine heatwaves(MHWs) over the globe and the predictability sources of the MHWs over the tropical oceans. The MHW forecasts are demonstrated to be skillful on seasonal-annual time scales, particularly in tropical oceans. The forecast skill of the MHWs over the tropical Pacific Ocean(TPO) remains high at lead times of 1–24 months, indicating a forecast better than random chance for up to two years. The forecast skill is subject to the spring predictability barrier of El Nino-Southern Oscillation(ENSO). The forecast skills for the MHWs over the tropical Indian Ocean(TIO), tropical Atlantic Ocean(TAO), and tropical Northwest Pacific(NWP) are lower than that in the TPO. A reliable forecast at lead times of up to two years is shown over the TIO, while a shorter reliable forecast window(less than 17 months) occurs for the TAO and NWP.Additionally, the forecast skills for the TIO, TAO, and NWP are seasonally dependent. Higher skills for the TIO and TAO appear in boreal spring, while a greater skill for the NWP emerges in late summer-early autumn. Further analyses suggest that ENSO serves as a critical source of predictability for MHWs over the TIO and TAO in spring and MHWs over the NWP in summer.
基金supported by a grant from the National Natural Science Foundations of China(No.52171282)supported by Taishan Scholars Program of Shandong Province,China(No.tsqn202306098)the Shandong Provincial Key Research and Development Plan,China(No.2021ZLGX04).
文摘Structure-soil interface friction characteristics is of importance to investigate the interaction between engineering structures and soils,especially for offshore structures.The interface friction behavior between marine clay and structural materials with different roughness was studied in this paper by using 3D optical scanning tests,a modified direct shear device and numerical simulation.Relationships between the surface roughness of structures,water content and interface friction angle were presented by model tests.The increase of water contents decreased the interface friction angles.For interfaces with different roughness,the interface friction angles will be smaller than that of the soil when the water content exceeds a certain value.The roughness of the interface and the water content of the soil are mutually coupled to influence the coefficient of friction(COF).This paper proposed a Finite Element Method(FEM)to simulate the interface direct shear tests of structures with different roughness.The surface models with different roughness are established based on the structure data obtained by 3D scanning.The Coupled Eulerian-Lagrangian(CEL)approach was employed to analyse soils sheared by irregular surfaces.The interface behavior for interfaces with different roughness under cyclic shear stresses was analyzed by FEM.
基金supported by the Southwest Institute of Technology and Engineering cooperation fund(Grant No.HDHDW5902020104)。
文摘The ocean is one of the essential fields of national defense in the future,and more and more attention is paid to the lightweight research of Marine equipment and materials.This study it is to develop a Machine learning(ML)-based prediction method to study the evolution of the mechanical properties of Al-Li alloys in the marine environment.We obtained the mechanical properties of Al-Li alloy samples under uniaxial tensile deformation at different exposure times through Marine exposure experiments.We obtained the strain evolution by digital image correlation(DIC).The strain field images are voxelized using 2D-Convolutional Neural Networks(CNN)autoencoders as input data for Long Short-Term Memory(LSTM)neural networks.Then,the output data of LSTM neural networks combined with corrosion features were input into the Back Propagation(BP)neural network to predict the mechanical properties of Al-Li alloys.The main conclusions are as follows:1.The variation law of mechanical properties of2297-T8 in the Marine atmosphere is revealed.With the increase in outdoor exposure test time,the tensile elastic model of 2297-T8 changes slowly,within 10%,and the tensile yield stress changes significantly,with a maximum attenuation of 23.6%.2.The prediction model can predict the strain evolution and mechanical response simultaneously with an error of less than 5%.3.This study shows that a CNN/LSTM system based on machine learning can be built to capture the corrosion characteristics of Marine exposure experiments.The results show that the relationship between corrosion characteristics and mechanical response can be predicted without considering the microstructure evolution of metal materials.
基金National Natural Science Foundation of China for Exploring Key Scientific Instrument(No.41827805)the Open Funds of the State Key Laboratory of Rare Earth Resource Utilization(No.RERU2021017)Hainan Province Science and Technology Special Fund(ZDYF2021GXJS210)for providing support。
文摘The microstructure and precipitated phases of as-cast Mg-5Y-1.5Nd-x Zn-0.5Zr(x=0,2,4,6 wt.%)alloys were investigated by optical microscopy,scanning electron microscopy,energy-dispersive spectrometry and X-ray Diffraction.The exposure corrosion experiment of these magnesium alloys was tested in South China Sea and KEXUE vessel atmospheric environment.The corrosion characteristic and mechanism of magnesium alloys of Mg-5Y-1.5Nd-x Zn-0.5Zr(x=0,2,4,6 wt.%)alloys were analyzed by weight loss rate,corrosion depth,corrosion products and corrosion morphologies.The electrochemical corrosion tests were also measured in the natural seawater.The comprehensive results showed that Mg-5Y-1.5Nd-4Zn-0.5Zr magnesium alloy existed the best corrosion resistance whether in the marine atmospheric environment and natural seawater environment.That depended on the microstructure,type and distribution of precipitated phases in Mg-5Y-1.5Nd-4Zn-0.5Zr magnesium alloy.Sufficient quantity anodic precipitated phases in the microstructure of Mg-5Y-1.5Nd-4Zn-0.5Zr alloy played the key role in the corrosion resistance.
基金Supported by the National Natural Science Foundation of China(No.42276195)the Natural Science Foundation of Zhejiang Province(No.LQ22D060006)the Science Foundation of Zhejiang Sci-Tech University(No.21022092-Y)。
文摘The construction of major marine infrastructure projects and the exploration and development of deep-sea mineral resources require fine imaging of seabed strata and structures.The highresolution marine seismic exploration based on a high broadband sparker source is an important approach to reveal seabed stratum and reservoir structure,and identify geohazard.To optimize the performance of sparker seismic source,we investigated the electro-acoustic characteristics of spark discharge under conditions of different charging voltages and electrode numbers.Results show that the sound source level increased with the increase of the charging voltage,whereas the main frequency decreased when the charging voltage increases.In addition,it was found that the charging capacitance had more obvious influence on the main frequency than the sound source level did.Although the load energy decreased with increasing electrode number,the sound source level still increased but the main frequency decreased.Meanwhile,the primary to bubble(P/B)ratio increased with the increase of the electrode number.To gain a deeper insight into the electro-acoustic characteristics,we investigate the relationship between sound source level and power peak,from which a good correlation was observed.A more practical statistical analysis on the rise rate of current was processed,and a perfect logarithmic function was derived.Furthermore,we found that the main frequency was most possibly subjected to the electrical energy,especially the charging energy per electrode.The results indicate that the charging energy per electrode less than 10 J could increase the main frequency to above 300 Hz.At last,the main frequency could be reduced to 20 Hz when the charging energy of a single-electrode discharge was enhanced to over 4 kJ.This study shall be helpful in developing a sparker seismic source and improving the performance for marine engineering exploration and geohazard assessment.
基金This research was supported by the Funding Project of Chinese Central Government Guiding to the Guangxi Local Science and Technology Development(GUIKEZY21195021)the Natural Science Fund for Distinguished Young Scholars of Guangxi Zhuang Autonomous Region of China(2019GXNSFFA245011)+3 种基金the Funding Project of Chinese Central Government Guiding to the Nanning Local Science and Technology Development(20231012)the Funding Projects of Guangxi Key Research and Development Plan(GUIKE AB23075173)the Funding Project of Technological Development from Angel Yeast(Chongzuo)Co.,Ltd.(JS1006020230722019)the Innovation Project of Guangxi Graduate Education(YCBZ2021012).
文摘The application of microorganisms as probiotics is limited due to lack of safety evaluation.Here,a novel multi-stress-tolerant yeast Meyerozyma guilliermondii GXDK6 with aroma-producing properties was identified from marine mangrove microorganisms.Its safety and probiotic properties were assessed in accordance with phenotype and whole-genome sequencing analysis.Results showed that the genes and phenotypic expression of related virulence,antibiotic resistance and retroelement were rarely found.Hyphal morphogenesis genes(SIT4,HOG1,SPA2,ERK1,ICL1,CST20,HSP104,TPS1,and RHO1)and phospholipase secretion gene(VPS4)were annotated.True hyphae and phospholipase were absent.Only one retroelement(Tad1-65_BG)was found.Major biogenic amines(BAs)encoding genes were absent,except for spermidine synthase(JA9_002594),spermine synthase(JA9_004690),and tyrosine decarboxylase(inx).The production of single BAs and total BAs was far below the food-defined thresholds.GXDK6 had no resistance to common antifungal drugs.Virulence enzymes,such as gelatinase,DNase,hemolytic,lecithinase,and thrombin were absent.Acute toxicity test with mice demonstrated that GXDK6 is safe.GXDK6 has a good reproduction ability in the simulation gastrointestinal tract.GXDK6 also has a strong antioxidant ability,β-glucosidase,and inulinase activity.To sum up,GXDK6 is considered as a safe probiotic for human consumption and food fermentation.
基金Supported by National Key Research and Development Program of China(2017YFC0603101)National Natural Science Foundation of China(42225303,42372162,42102146)+1 种基金Strategic Priority Research Program of the Chinese Academy of Sciences(XDA14010101)Basic and Forward-Looking Major Technology Project of China National Petroleum Corporation(2023ZZ0203)。
文摘Taking the Paleozoic of the Sichuan and Tarim basins in China as example,the controlling effects of the Earth system evolution and multi-spherical interactions on the formation and enrichment of marine ultra-deep petroleum in China have been elaborated.By discussing the development of“source-reservoir-seal”controlled by the breakup and assembly of supercontinents and regional tectonic movements,and the mechanisms of petroleum generation and accumulation controlled by temperature-pressure system and fault conduit system,Both the South China and Tarim blocks passed through the intertropical convergence zone(ITCZ)of the low-latitude Hadley Cell twice during their drifts,and formed hydrocarbon source rocks with high quality.It is proposed that deep tectonic activities and surface climate evolution jointly controlled the types and stratigraphic positions of ultra-deep hydrocarbon source rocks,reservoirs,and seals in the Sichuan and Tarim basins,forming multiple petroleum systems in the Ediacaran-Cambrian,Cambrian-Ordovician,Cambrian-Permian and Permian-Triassic strata.The matching degree of source-reservoir-seal,the type of organic matter in source rocks,the deep thermal regime of basin,and the burial-uplift process across tectonic periods collectively control the entire process from the generation to the accumulation of oil and gas.Three types of oil and gas enrichment models are formed,including near-source accumulation in platform marginal zones,distant-source accumulation in high-energy beaches through faults,and three-dimensional accumulation in strike-slip fault zones,which ultimately result in the multi-layered natural gas enrichment in ultra-deep layers of the Sichuan Basin and co-enrichment of oil and gas in the ultra-deep layers of the Tarim Basin.
基金The National Natural Science Foundation of China under contract Nos 42275024 and 42105040the Key R&D Program of China under contract No.2022YFE0203500+3 种基金the Guangdong Basic and Applied Basic Research Foundation under contract Nos 2023B1515020009 and 2024B1515040024the Youth Innovation Promotion Association CAS under contract No.2020340the Special Fund of South China Sea Institute of Oceanology of the Chinese Academy of Sciences under contract No.SCSIO2023QY01the Science and Technology Planning Project of Guangzhou under contract No.2024A04J6275.
文摘This study evaluates the performance of 16 models sourced from the coupled model intercomparison project phase 6(CMIP6)in simulating marine heatwaves(MHWs)in the South China Sea(SCS)during the historical period(1982−2014),and also investigates future changes in SCS MHWs based on simulations from three shared socioeconomic pathway(SSP)scenarios(SSP126,SSP245,and SSP585)using CMIP6 models.Results demonstrate that the CMIP6 models perform well in simulating the spatial-temporal distribution and intensity of SCS MHWs,with their multi-model ensemble(MME)results showing the best performance.The reasonable agreement between the observations and CMIP6 MME reveals that the increasing trends of SCS MHWs are attributed to the warming sea surface temperature trend.Under various SSP scenarios,the year 2040 emerges as pivotal juncture for future shifts in SCS MHWs,marked by distinct variations in changing rate and amplitudes.This is characterized by an accelerated decrease in MHWs frequency and a notably heightened increase in mean intensity,duration,and total days after 2040.Furthermore,the projection results for SCS MHWs suggest that the spatial pattern of MHWs remains consistent across future periods.However,the intensity shows higher consistency only during the near-term period(2021−2050),while notable inconsistencies are observed during the medium-term(2041−2070)and long-term(2071−2100)periods under the three SSP scenarios.During the nearterm period,the SCS MHWs are characterized by moderate and strong events with high frequencies and relatively shorter durations.In contrast,during the medium-term period,MHWs are also characterized by moderate and strong events,but with longer-lasting and more intense events under the SSP245 and SSP585 scenarios.However,in the long-term period,extreme MHWs become the dominant feature under the SSP585 scenario,indicating a substantial intensification of SCS MHWs,effectively establishing a near-permanent state.
基金funded by Researchers Supporting Program at King Saud University,(RSPD2024R809).
文摘In blood or bone marrow,leukemia is a form of cancer.A person with leukemia has an expansion of white blood cells(WBCs).It primarily affects children and rarely affects adults.Treatment depends on the type of leukemia and the extent to which cancer has established throughout the body.Identifying leukemia in the initial stage is vital to providing timely patient care.Medical image-analysis-related approaches grant safer,quicker,and less costly solutions while ignoring the difficulties of these invasive processes.It can be simple to generalize Computer vision(CV)-based and image-processing techniques and eradicate human error.Many researchers have implemented computer-aided diagnosticmethods andmachine learning(ML)for laboratory image analysis,hopefully overcoming the limitations of late leukemia detection and determining its subgroups.This study establishes a Marine Predators Algorithm with Deep Learning Leukemia Cancer Classification(MPADL-LCC)algorithm onMedical Images.The projectedMPADL-LCC system uses a bilateral filtering(BF)technique to pre-process medical images.The MPADL-LCC system uses Faster SqueezeNet withMarine Predators Algorithm(MPA)as a hyperparameter optimizer for feature extraction.Lastly,the denoising autoencoder(DAE)methodology can be executed to accurately detect and classify leukemia cancer.The hyperparameter tuning process using MPA helps enhance leukemia cancer classification performance.Simulation results are compared with other recent approaches concerning various measurements and the MPADL-LCC algorithm exhibits the best results over other recent approaches.
基金Supported by Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory (2019BT02H594)Sanya Technology Innovation Special Project (2022KJCX08)。
文摘Offshore carbon dioxide(CO_(2)) storage is an effective method for reducing greenhouse gas emissions. However, when using traditional seismic wave methods to monitor the migration of sequestration CO_(2) plumes, the characteristics of wave velocity changes tend to become insignificant beyond a certain limit. In contrast, the controllable source electromagnetic method(CSEM) remains highly sensitive to resistivity changes. By simulating different CO_(2) plume migration conditions, we established the relevant models and calculated the corresponding electric field response characteristic curves, allowing us to analyze the CSEM's ability to monitor CO_(2) plumes. We considered potential scenarios for the migration and diffusion of offshore CO_(2) storage, including various burial depths, vertical extension diffusion, lateral extension diffusion,multiple combinations of lateral intervals, and electric field components. We also obtained differences in resistivity inversion imaging obtained by CSEM to evaluate its feasibility in monitoring and to analyze all the electric field(Ex, Ey, and Ez) response characteristics. CSEM has great potential in monitoring CO_(2) plume migration in offshore saltwater reservoirs due to its high sensitivity and accuracy. Furthermore, changes in electromagnetic field response reflect the transport status of CO_(2) plumes, providing an important basis for monitoring and evaluating CO_(2)transport behavior during storage processes.
文摘The phase change of CO_(2) has a significant bearing on the siting, injection, and monitoring of storage. The phase state of CO_(2) is closely related to pressure. In the process of seismic exploration, the information of formation pressure can be response in the seismic data. Therefore, it is possible to monitor the formation pressure using time-lapse seismic method. Apart from formation pressure, the information of porosity and CO_(2) saturation can be reflected in the seismic data. Here, based on the actual situation of the work area, a rockphysical model is proposed to address the feasibility of time-lapse seismic monitoring during CO_(2) storage in the anisotropic formation. The model takes into account the formation pressure, variety minerals composition, fracture, fluid inhomogeneous distribution, and anisotropy caused by horizontal layering of rock layers(or oriented alignment of minerals). From the proposed rockphysical model and the well-logging, cores and geological data at the target layer, the variation of P-wave and S-wave velocity with formation pressure after CO_(2) injection is calculated. And so are the effects of porosity and CO_(2) saturation. Finally, from anisotropic exact reflection coefficient equation, the reflection coefficients under different formation pressures are calculated. It is proved that the reflection coefficient varies with pressure. Compared with CO_(2) saturation, the pressure has a greater effect on the reflection coefficient. Through the convolution model, the seismic record is calculated. The seismic record shows the difference with different formation pressure. At present, in the marine CO_(2) sequestration monitoring domain, there is no study involving the effect of formation pressure changes on seismic records in seafloor anisotropic formation. This study can provide a basis for the inversion of reservoir parameters in anisotropic seafloor CO_(2) reservoirs.
基金This work was supported by the Creative Groups of Natural Science Foundation of Hubei Province(Grant No.2021CFA030).Onyekwena Chikezie Chimere is an awardee for the ANSO Scholarship 2020-PhD.Ishrat Hameed Alvi is a recipient of the 2021 PhD ANSO Scholarship.
文摘Dredged marine soils(DMS)have poor engineering properties,which limit their usage in construction projects.This research examines the application of reactive magnesia(rMgO)containing supplementary cementitious materials(SCMs)to stabilize DMS under ambient and carbon dioxide(CO_(2))curing conditions.Several proprietary experimental tests were conducted to investigate the stabilized DMS.Furthermore,the carbonation-induced mineralogical,thermal,and microstructural properties change of the samples were explored.The findings show that the compressive strength of the stabilized DMS fulfilled the 7-d requirement(0.7-2.1 MPa)for pavement and building foundations.Replacing rMgO with SCMs such as biochar or ground granulated blast-furnace slag(GGBS)altered the engineering properties and particle packing of the stabilized soils,thus influencing their performances.Biochar increased the porosity of the samples,facilitating higher CO_(2) uptake and improved ductility,while GGBS decreased porosity and increased the dry density of the samples,resulting in higher strength.The addition of SCMs also enhanced the water retention capacity and modified the pH of the samples.Microstructural analysis revealed that the hydrated magnesium carbonates precipitated in the carbonated samples provided better cementation effects than brucite formed during rMgO hydration.Moreover,incorporating SCMs reduced the overall global warming potential and energy demand of the rMgO-based systems.The biochar mixes demonstrated lower toxicity and energy consumption.Ultimately,the rMgO and biochar blend can serve as an environmentally friendly additive for soft soil stabilization and permanent fixation of significant amounts of CO_(2) in soils through mineral carbonation,potentially reducing environmental pollution while meeting urbanization needs.
基金The Shandong Provincial Natural Science Foundation under contract No.ZR2023MD096the National Key R&D Program of China under contract Nos 2018YFD0900904 and 2018YFD0900906.
文摘Climate change has led to significant fluctuations in marine ecosystems,including alterations in the structure and function of food webs and ecosystem status.Coastal ecosystems are critical to the functioning of the earth’s lifesupporting systems.However,temporal variations in most of these ecosystems have remained unclear so far.In this study,we employed a linear inverse model with Markov Chain Monte Carlo(LIM-MCMC)combined with ecological network analysis to reveal the temporal variations of the food web in Haizhou Bay of China.Food webs were constructed based on diet composition data in this ecosystem during the year of 2011 and 2018.Results indicated that there were obvious temporal variations in the composition of food webs in autumn of 2011 and 2018.The number of prey and predators for most species in food web decreased in 2018 compared with 2011,especially for Trichiurus lepturus,zooplankton,Amblychaeturichthys hexanema,and Loligo sp.Ecological network analysis showed that the complexity of food web structure could be reflected by comprehensive analysis of compartmentalized indicators.Haizhou Bay ecosystem was more mature and stable in 2011,while the ecosystem’s self-sustainability and recovery from disturbances were accelerated from 2011 to 2018.These findings contribute to our understanding of the dynamics of marine ecosystems and highlight the importance of comprehensive analysis of marine food webs.This work provides a framework for assessing and comparing temporal variations in marine ecosystems,which provides essential information and scientific guidance for the Ecosystem-based Fisheries Management.
基金This work was partially supported by the National Key Research and Development Program of China under Grant No.2018AAA0100400the Natural Science Foundation of Shandong Province under Grants Nos.ZR2020MF131 and ZR2021ZD19the Science and Technology Program of Qingdao under Grant No.21-1-4-ny-19-nsh.
文摘UAV marine monitoring plays an essential role in marine environmental protection because of its flexibility and convenience,low cost and convenient maintenance.In marine environmental monitoring,the similarity between objects such as oil spill and sea surface,Spartina alterniflora and algae is high,and the effect of the general segmentation algorithm is poor,which brings new challenges to the segmentation of UAV marine images.Panoramic segmentation can do object detection and semantic segmentation at the same time,which can well solve the polymorphism problem of objects in UAV ocean images.Currently,there are few studies on UAV marine image recognition with panoptic segmentation.In addition,there are no publicly available panoptic segmentation datasets for UAV images.In this work,we collect and annotate UAV images to form a panoptic segmentation UAV dataset named UAV-OUC-SEG and propose a panoptic segmentation method named PanopticUAV.First,to deal with the large intraclass variability in scale,deformable convolution and CBAM attention mechanism are employed in the backbone to obtain more accurate features.Second,due to the complexity and diversity of marine images,boundary masks by the Laplacian operator equation from the ground truth are merged into feature maps to improve boundary segmentation precision.Experiments demonstrate the advantages of PanopticUAV beyond the most other advanced approaches on the UAV-OUC-SEG dataset.
