This study introduces the representation of natural number sets as row vectors and pretends to offer a new perspective on the strong Goldbach conjecture. The natural numbers are restructured and expanded with the incl...This study introduces the representation of natural number sets as row vectors and pretends to offer a new perspective on the strong Goldbach conjecture. The natural numbers are restructured and expanded with the inclusion of the zero element as the source of a strong Goldbach conjecture reformulation. A prime Boolean vector is defined, pinpointing the positions of prime numbers within the odd number sequence. The natural unit primality is discussed in this context and transformed into a source of quantum-like indetermination. This approach allows for rephrasing the strong Goldbach conjecture, framed within a Boolean scalar product between the prime Boolean vector and its reverse. Throughout the discussion, other intriguing topics emerge and are thoroughly analyzed. A final description of two empirical algorithms is provided to prove the strong Goldbach conjecture.展开更多
The environmental hazards and"carbon footprint"of oil and gas drilling can be significantly reduced by replacing traditional petroleum-based chemical additives with natural materials derived from plants and ...The environmental hazards and"carbon footprint"of oil and gas drilling can be significantly reduced by replacing traditional petroleum-based chemical additives with natural materials derived from plants and animals.This paper explored for the first time the interaction mechanism between natural rubber latex(NRL)and bentonite suspensions(BTs)through a series of characterization experiments,as well as the potential applications in water-based drilling fluids(WBDF).The gel viscoelasticity experiments showed that NRL could decrease the consistency coefficient(k)and flow index(n)of BTs,and enhance the shear thinning performance of BTs as pseudo-plastic fluids.In addition,0.5 w/v%NRL not only increased the critical yield stress and strengthened the structural strength between the bentonite particles,but also facilitated the compatibility of pressure loss and flow efficiency.The evaluation of colloidal stability and WBDF performance indicated that NRL particles could promote the hydration and charge stability on the surface of BTs particles,and optimize the particle size distribution and flow resistance of WBDF under the"intercalation-exfoliation-encapsulation"synergistic interaction.Moreover,NRL can improve the rheological properties of WBDF at high temperatures(<150.C),and form a dense blocking layer by bridging and sealing the pores and cracks of the filter cake,which ultimately reduces the permeability of the cake and the filtration loss of WBDF.展开更多
Biomimetic materials have emerged as attractive and competitive alternatives for tissue engineering(TE)and regenerative medicine.In contrast to conventional biomaterials or synthetic materials,biomimetic scaffolds bas...Biomimetic materials have emerged as attractive and competitive alternatives for tissue engineering(TE)and regenerative medicine.In contrast to conventional biomaterials or synthetic materials,biomimetic scaffolds based on natural biomaterial can offer cells a broad spectrum of biochemical and biophysical cues that mimic the in vivo extracellular matrix(ECM).Additionally,such materials have mechanical adaptability,micro-structure interconnectivity,and inherent bioactivity,making them ideal for the design of living implants for specific applications in TE and regenerative medicine.This paper provides an overview for recent progress of biomimetic natural biomaterials(BNBMs),including advances in their preparation,functionality,potential applications and future challenges.We highlight recent advances in the fabrication of BNBMs and outline general strategies for functionalizing and tailoring the BNBMs with various biological and physicochemical characteristics of native ECM.Moreover,we offer an overview of recent key advances in the functionalization and applications of versatile BNBMs for TE applications.Finally,we conclude by offering our perspective on open challenges and future developments in this rapidly-evolving field.展开更多
Zeolite catalysts have found extensive applications in the synthesis of various fine chemicals.However,the micropores of zeolites impose diffusion limitations on bulky molecules,greatly reducing the catalytic efficien...Zeolite catalysts have found extensive applications in the synthesis of various fine chemicals.However,the micropores of zeolites impose diffusion limitations on bulky molecules,greatly reducing the catalytic efficiency.Herein,we explore an economic and environmentally friendly method for synthesizing hierarchical NaX zeolite that exhibits improved catalytic performance in the Knoevenagel condensation reaction for producing the useful fine chemical 2-cyano-3-phenylacrylate.The synthesis was achieved via a low-temperature activation of kaolinite and subsequent in-situ transformation strategy without any template or seed.Systematic characterizations reveal that the synthesized NaX zeolite has both intercrystalline and intra-crystalline mesopores,smaller crystal size,and larger external specific surface area compared to commercial NaX zeolite.Detailed mechanism investigations show that the inter-crystalline mesopores are generated by stacking smaller crystals formed from in-situ crystallization of the depolymerized kaolinite,and the intra-crystalline mesopores are inherited from the pores in the depolymerized kaolinite.This synthesis strategy provides an energy-saving and effective way to construct hierarchical zeolites,which may gain wide applications in fine chemical manufacturing.展开更多
Alzheimer’s disease is a progressive neurodegenerative disorder and the most common cause of dementia that principally affects older adults.Pathogenic factors,such as oxidative stress,an increase in acetylcholinester...Alzheimer’s disease is a progressive neurodegenerative disorder and the most common cause of dementia that principally affects older adults.Pathogenic factors,such as oxidative stress,an increase in acetylcholinesterase activity,mitochondrial dysfunction,genotoxicity,and neuroinflammation are present in this syndrome,which leads to neurodegeneration.Neurodegenerative pathologies such as Alzheimer’s disease are considered late-onset diseases caused by the complex combination of genetic,epigenetic,and environmental factors.There are two main types of Alzheimer’s disease,known as familial Alzheimer’s disease(onset<65 years)and late-onset or sporadic Alzheimer’s disease(onset≥65 years).Patients with familial Alzheimer’s disease inherit the disease due to rare mutations on the amyloid precursor protein(APP),presenilin 1 and 2(PSEN1 and PSEN2)genes in an autosomaldominantly fashion with closely 100%penetrance.In contrast,a different picture seems to emerge for sporadic Alzheimer’s disease,which exhibits numerous non-Mendelian anomalies suggesting an epigenetic component in its etiology.Importantly,the fundamental pathophysiological mechanisms driving Alzheimer’s disease are interfaced with epigenetic dysregulation.However,the dynamic nature of epigenetics seems to open up new avenues and hope in regenerative neurogenesis to improve brain repair in Alzheimer’s disease or following injury or stroke in humans.In recent years,there has been an increase in interest in using natural products for the treatment of neurodegenerative illnesses such as Alzheimer’s disease.Through epigenetic mechanisms,such as DNA methylation,non-coding RNAs,histone modification,and chromatin conformation regulation,natural compounds appear to exert neuroprotective effects.While we do not purport to cover every in this work,we do attempt to illustrate how various phytochemical compounds regulate the epigenetic effects of a few Alzheimer’s disease-related genes.展开更多
Landslides occurring in sensitive clay often result in widespread destruction,posing a significant risk to human lives and property due to the substantial decrease in undrained shear strength during deformation.Assess...Landslides occurring in sensitive clay often result in widespread destruction,posing a significant risk to human lives and property due to the substantial decrease in undrained shear strength during deformation.Assessing the consequences of these landslides is challenging and necessitates robust numerical methods to comprehensively investigate their failure mechanisms.While studies have extensively explored upward progressive landslides in sensitive clays,understanding downward progressive cases remains limited.In this study,we utilised the nodal integration-based particle finite element method(NPFEM)with a nonlinear strain-softening model to analyse downward progressive landslides in sensitive clay on elongated slopes,induced by surcharge loads near the crest.We focused on elucidating the underlying failure mechanisms and evaluating the effects of different soil parameters and strainsoftening characteristics.The simulation results revealed the typical pattern for downward landslides,which typically start with a localised failure in proximity to the surcharge loads,followed by a combination of different types of failure mechanisms,including single flow slides,translational progressive landslides,progressive flow slides,and spread failures.Additionally,inclined shear bands occur within spread failures,often adopting distinctive ploughing patterns characterised by triangular shapes.The sensitive clay thickness at the base,the clay strength gradient,the sensitivity,and the softening rate significantly influence the failure mechanisms and the extent of diffused displacement.Remarkably,some of these effects mirror those observed in upward progressive landslides,underscoring the interconnectedness of these phenomena.This study contributes valuable insights into the complex dynamics of sensitive clay landslides,shedding light on the intricate interplay of factors governing their behaviour and progression.展开更多
Natural disaster risk monitoring is an important task for disaster prevention and reduction.In the case of immovable cultural relics,however,the feedback mechanism,risk factors,monitoring logic,and monitoring indicato...Natural disaster risk monitoring is an important task for disaster prevention and reduction.In the case of immovable cultural relics,however,the feedback mechanism,risk factors,monitoring logic,and monitoring indicators of natural disaster risk monitoring are complex.How to achieve intelligent perception and monitoring of natural disaster risk for immovable cultural relics has always been a focus and a challenge for researchers.Based on the analysis of the concepts and issues related to the natural disaster risk of immovable cultural relics,this paper proposes a framework for natural disaster risk monitoring for immovable cultural relics based on the digital twin.This framework focuses on risk monitoring,including the physical entities of natural disaster risk for immovable cultural relics,monitoring indicators,and virtual entity construction.A platform for monitoring the natural disaster risk of immovable cultural relics is proposed.Using the Puzhou Ancient City Site as a test bed,the proposed concept can be used for monitoring the natural disaster risk of immovable cultural relics at different scales.展开更多
DNA guanine(G)-quadruplexes(G4s)are unique secondary structures formed by two or more stacked Gtetrads in G-rich DNA sequences.These structures have been found to play a crucial role in highly transcribed genes,especi...DNA guanine(G)-quadruplexes(G4s)are unique secondary structures formed by two or more stacked Gtetrads in G-rich DNA sequences.These structures have been found to play a crucial role in highly transcribed genes,especially in cancer-related oncogenes,making them attractive targets for cancer therapeutics.Significantly,targeting oncogene promoter G4 structures has emerged as a promising strategy to address the challenge of undruggable and drug-resistant proteins,such as MYC,BCL2,KRAS,and EGFR.Natural products have long been an important source of drug discovery,particularly in the fields of cancer and infectious diseases.Noteworthy progress has recently been made in the discovery of naturally occurring DNA G4-targeting drugs.Numerous DNA G4s,such as MYC-G4,BCL2-G4,KRAS-G4,PDGFR-b-G4,VEGF-G4,and telomeric-G4,have been identified as potential targets of natural products,including berberine,telomestatin,quindoline,sanguinarine,isaindigotone,and many others.Herein,we summarize and evaluate recent advancements in natural and nature-derived DNA G4 binders,focusing on understanding the structural recognition of DNA G4s by small molecules derived from nature.We also discuss the challenges and opportunities associated with developing drugs that target DNA G4s.展开更多
Natural gas hydrate(NGH)can cause pipeline blockages during the transportation of oil and gas under high pressures and low temperatures.Reducing hydrate adhesion on pipelines is viewed as an efficient way to prevent N...Natural gas hydrate(NGH)can cause pipeline blockages during the transportation of oil and gas under high pressures and low temperatures.Reducing hydrate adhesion on pipelines is viewed as an efficient way to prevent NGH blockages.Previous studies suggested the water film can greatly increase hydrate adhesion in gas-dominant system.Herein,by performing the molecular dynamics simulations,we find in water-dominant system,the water film plays different roles in hydrate deposition on Fe and its corrosion surfaces.Specifically,due to the strong affinity of water on Fe surface,the deposited hydrate cannot convert the adsorbed water into hydrate,thus,a water film exists.As water affinities decrease(Fe>Fe_(2)O_(3)>FeO>Fe_(3)O_(4)),adsorbed water would convert to amorphous hydrate on Fe_(2)O_(3)and form the ordered hydrate on FeO and Fe_(3)O_(4)after hydrate deposition.While absorbed water film converts to amorphous or to hydrate,the adhesion strength of hydrate continuously increases(Fe<Fe_(2)O_(3)<FeO<Fe_(3)O_(4)).This is because the detachment of deposited hydrate prefers to occur at soft region of liquid layer,the process of which becomes harder as liquid layer vanishes.As a result,contrary to gas-dominant system,the water film plays the weakening roles on hydrate adhesion in water-dominant system.Overall,our results can help to better understand the hydrate deposition mechanisms on Fe and its corrosion surfaces and suggest hydrate deposition can be adjusted by changing water affinities on pipeline surfaces.展开更多
Microcirculatory disturbances are complex processes caused by many factors,including abnormal vasomotor responses,decreased blood flow velocity,vascular endothelial cell injury,altered leukocyte and endothelial cell i...Microcirculatory disturbances are complex processes caused by many factors,including abnormal vasomotor responses,decreased blood flow velocity,vascular endothelial cell injury,altered leukocyte and endothelial cell interactions,plasma albumin leakage,microvascular hemorrhage,and thrombosis.These disturbances involve multiple mechanisms and interactions among mechanisms that can include energy metabolism,the mitochondrial respiratory chain,oxidative stress,inflammatory factors,adhesion molecules,the cytoskeleton,vascular endothelial cells,caveolae,cell junctions,the vascular basement membrane,neutrophils,monocytes,and platelets.In clinical practice,aside from drugs that target abnormal vasomotor responses and platelet adhesion,there continues to be a lack of multi-target drugs that can regulate the complex mechanistic links and interactions underlying microcirculatory disturbances.Natural products have demonstrated obvious positive therapeutic effects in treating ischemia/reperfusion(I/R)-and lipopolysaccharide(LPS)-induced microcirculatory disturbances.In recent years,numerous research papers on the improvement of microcirculatory function by natural products have been published in international journals.In 2008 and 2017,the first listed author of this review was invited to publish reviews in the journal of Pharmacology&Therapeutics on the improvement of microcirculatory disturbances and organ injury induced by I/R using Salvia miltiorrhiza ingredients and other natural components of compounded Chinese medicine,respectively.This review systematically summarizes the effects,targets of action,and mechanisms of natural products regarding improving I/R-and LPSinduced microcirculatory disturbances and tissue injury.Based on this summary,scientific proposals are suggested for the discovery of new drugs to improve microcirculatory disturbances in disease.展开更多
The isolation of minor components from complex natural product matrices presents a significant challenge in the field of purification science due to their low concentrations and the presence of structurally similar co...The isolation of minor components from complex natural product matrices presents a significant challenge in the field of purification science due to their low concentrations and the presence of structurally similar compounds.This study introduces an optimized twin-column recycling chromatography method for the efficient and simultaneous purification of these elusive constituents.By introducing water at a small flowing rate between the twin columns,a step solvent gradient is created,by which the leading edge of concentration band would migrate at a slower rate than the trailing edge as it flowing from the upstream to downstream column.Hence,the band broadening is counterbalanced,resulting in an enrichment effect for those minor components in separation process.Herein,two target substances,which showed similar peak position in high performance liquid chromatography(HPLC)and did not exceed 1.8%in crude paclitaxel were selected as target compounds for separation.By using the twin-column recycling chromatography with a step solvent gradient,a successful purification was achieved in getting the two with the purity almost 100%.We suggest this method is suitable for the separation of most components in natural produces,which shows higher precision and recovery rate compared with the common lab-operated separation ways for natural products(thin-layer chromatography and prep-HPLC).展开更多
In most practical engineering applications,the translating belt wraps around two fixed wheels.The boundary conditions of the dynamic model are typically specified as simply supported or fixed boundaries.In this paper,...In most practical engineering applications,the translating belt wraps around two fixed wheels.The boundary conditions of the dynamic model are typically specified as simply supported or fixed boundaries.In this paper,non-homogeneous boundaries are introduced by the support wheels.Utilizing the translating belt as the mechanical prototype,the vibration characteristics of translating Timoshenko beam models with nonhomogeneous boundaries are investigated for the first time.The governing equations of Timoshenko beam are deduced by employing the generalized Hamilton's principle.The effects of parameters such as the radius of wheel and the length of belt on vibration characteristics including the equilibrium deformations,critical velocities,natural frequencies,and modes,are numerically calculated and analyzed.The numerical results indicate that the beam experiences deformation characterized by varying curvatures near the wheels.The radii of the wheels play a pivotal role in determining the change in trend of the relative difference between two beam models.Comparing the results unearths that the relative difference in equilibrium deformations between the two beam models is more pronounced with smaller-sized wheels.When the two wheels are of equal size,the critical velocities of both beam models reach their respective minima.In addition,the relative difference in natural frequencies between the two beam models exhibits nonlinear variation and can easily exceed 50%.Furthermore,as the axial velocities increase,the impact of non-homogeneous boundaries on modal shape of translating beam becomes more significant.Although dealing with non-homogeneous boundaries is challenging,beam models with non-homogeneous boundaries are more sensitive to parameters,and the differences between the two types of beams undergo some interesting variations under the influence of non-homogeneous boundaries.展开更多
In order to study the hydrocarbon generation(HCGE)characteristics of coal-bearing basins,the coal-measure source rocks of the Middle Jurassic-Lower Jurassic(MLJ)of the piedmont thrust belt in the southern margin of th...In order to study the hydrocarbon generation(HCGE)characteristics of coal-bearing basins,the coal-measure source rocks of the Middle Jurassic-Lower Jurassic(MLJ)of the piedmont thrust belt in the southern margin of the Junggar Basin in Northwest China are taken as research objects.More than 60 MLJ samples were collected from outcrops and wells.Total organic carbon(TOC),rock pyrolysis(Rock-Eval),organic petrological,vitrinite reflectance(%Ro),and hydrous pyrolysis were performed to analyze the relevant samples.The pyrolysis gases and liquid products were measured,and then the chemical composition,as well as carbon isotopes of the gases,were analyzed.The results indicate that the MLJ source rocks have the capacity for large-scale gas generation.In addition,for coal-measure source rocks,the heavier the carbon isotope of kerogen(δ^(13)C_(kerogen)),the lower the liquid hydrocarbon and hydrocarbon gas yield,and the easier it is to produce non-hydrocarbon gas.It is worth noting that when theδ^(13)C_(kerogen)in organic matter(OM)is relatively heavier,the fractionation of its products may become weaker in the evolutionary process.The vital contribution of the MLJ source rock to natural gas resources in the study area was further confirmed by comparing it with the Jurassic source gas.展开更多
Non-degradable polymers cause serious environmental pollution problem,such as the widely-used while unrecyclable coatings which significantly affect the overall degradation performance of products.It is imperative and ...Non-degradable polymers cause serious environmental pollution problem,such as the widely-used while unrecyclable coatings which significantly affect the overall degradation performance of products.It is imperative and attractive to develop biodegradable functional coatings.Herein,we proposed a novel strategy to successfully prepare biodegradable,thermoplastic and hydrophobic coatings with high transparence and biosafety by weakening the interchain interactions between cellulose chain.The natural cellulose and cinnamic acid were as raw materials.Via reducing the degree of polymerization(DP)of cellulose and regulating the degree of substitution(DS)of cinnamate moiety,the obtained cellulose cinnamate(CC)exhibited not only the thermalflow behavior but also good biodegradability,which solves the conflict between the thermoplasticity and biodegradability in cellulose-based materials.The glass transition temperature(T_(g))and thermalflow temperature(T_(f))of the CC could be adjusted in a range of 150–200℃ and 180–210℃,respectively.The CC with DS<1.2 and DP≤100 degraded more than 60%after an enzyme treatment for 7 days,and degraded more than 80%after a composting treatment for 42 days.Furthermore,CC had no toxicity to human epidermal cells even at a high concentration(0.5 mg mL^(-1)).In addition,CC could be easily fabricated into multifunctional coating with high hydrophobicity,thermal adhesion and high transparence.Therefore,after combining with cellophane and paperboard,CC coating with low DP and DS could be used to prepare fully-biodegradable heat-sealing packaging,art paper,paper cups,paper straws and food packaging boxes.展开更多
Potential natural vegetation(PNV)is a valuable reference for ecosystem renovation and has garnered increasing attention worldwide.However,there is limited knowledge on the spatio-temporal distributions,transitional pr...Potential natural vegetation(PNV)is a valuable reference for ecosystem renovation and has garnered increasing attention worldwide.However,there is limited knowledge on the spatio-temporal distributions,transitional processes,and underlying mechanisms of global natural vegetation,particularly in the case of ongoing climate warming.In this study,we visualize the spatio-temporal pattern and inter-transition procedure of global PNV,analyse the shifting distances and directions of global PNV under the influence of climatic disturbance,and explore the mechanisms of global PNV in response to temperature and precipitation fluctuations.To achieve this,we utilize meteorological data,mainly temperature and precipitation,from six phases:the Last Inter-Glacial(LIG),the Last Glacial Maximum(LGM),the Mid Holocene(MH),the Present Day(PD),2030(20212040)and 2090(2081–2100),and employ a widely-accepted comprehensive and sequential classification sy–stem(CSCS)for global PNV classification.We find that the spatial patterns of five PNV groups(forest,shrubland,savanna,grassland and tundra)generally align with their respective ecotopes,although their distributions have shifted due to fluctuating temperature and precipitation.Notably,we observe an unexpected transition between tundra and savanna despite their geographical distance.The shifts in distance and direction of five PNV groups are mainly driven by temperature and precipitation,although there is heterogeneity among these shifts for each group.Indeed,the heterogeneity observed among different global PNV groups suggests that they may possess varying capacities to adjust to and withstand the impacts of changing climate.The spatio-temporal distributions,mutual transitions and shift tendencies of global PNV and its underlying mechanism in face of changing climate,as revealed in this study,can significantly contribute to the development of strategies for mitigating warming and promoting re-vegetation in degraded regions worldwide.展开更多
Urea-assisted natural seawater electrolysis is an emerging technology that is effective for grid-scale carbon-neutral hydrogen mass production yet challenging.Circumventing scaling relations is an effective strategy t...Urea-assisted natural seawater electrolysis is an emerging technology that is effective for grid-scale carbon-neutral hydrogen mass production yet challenging.Circumventing scaling relations is an effective strategy to break through the bottleneck of natural seawater splitting.Herein,by DFT calculation,we demonstrated that the interface boundaries between Ni_(2)P and MoO_(2) play an essential role in the selfrelaxation of the Ni-O interfacial bond,effectively modulating a coordination number of intermediates to control independently their adsorption-free energy,thus circumventing the adsorption-energy scaling relation.Following this conceptual model,a well-defined 3D F-doped Ni_(2)P-MoO_(2) heterostructure microrod array was rationally designed via an interfacial engineering strategy toward urea-assisted natural seawater electrolysis.As a result,the F-Ni_(2)P-MoO_(2) exhibits eminently active and durable bifunctional catalysts for both HER and OER in acid,alkaline,and alkaline sea water-based electrolytes.By in-situ analysis,we found that a thin amorphous layer of NiOOH,which is evolved from the Ni_(2)P during anodic reaction,is real catalytic active sites for the OER and UOR processes.Remarkable,such electrode-assembled urea-assisted natural seawater electrolyzer requires low voltages of 1.29 and 1.75 V to drive 10 and600 mA cm^(-2)and demonstrates superior durability by operating continuously for 100 h at 100 mA cm^(-2),beyond commercial Pt/C||RuO_(2) and most previous reports.展开更多
During the operational process of natural gas gathering and transmission pipelines,the formation of hydrates is highly probable,leading to uncontrolled movement and aggregation of hydrates.The continuous migration and...During the operational process of natural gas gathering and transmission pipelines,the formation of hydrates is highly probable,leading to uncontrolled movement and aggregation of hydrates.The continuous migration and accumulation of hydrates further contribute to the obstruction of natural gas pipelines,resulting in production reduction,shutdowns,and pressure build-ups.Consequently,a cascade of risks is prone to occur.To address this issue,this study focuses on the operational process of natural gas gathering and transmission pipelines,where a comprehensive framework is established.This framework includes theoretical models for pipeline temperature distribution,pipeline pressure distribution,multiphase flow within the pipeline,hydrate blockage,and numerical solution methods.By analyzing the influence of inlet temperature,inlet pressure,and terminal pressure on hydrate formation within the pipeline,the sensitivity patterns of hydrate blockage risks are derived.The research indicates that reducing inlet pressure and terminal pressure could lead to a decreased maximum hydrate formation rate,potentially mitigating pipeline blockage during natural gas transportation.Furthermore,an increase in inlet temperature and terminal pressure,and a decrease in inlet pressure,results in a displacement of the most probable location for hydrate blockage towards the terminal station.However,it is crucial to note that operating under low-pressure conditions significantly elevates energy consumption within the gathering system,contradicting the operational goal of energy efficiency and reduction of energy consumption.Consequently,for high-pressure gathering pipelines,measures such as raising the inlet temperature or employing inhibitors,electrical heat tracing,and thermal insulation should be adopted to prevent hydrate formation during natural gas transportation.Moreover,considering abnormal conditions such as gas well production and pipeline network shutdowns,which could potentially trigger hydrate formation,the installation of methanol injection connectors remains necessary to ensure production safety.展开更多
Natural minerals,such as kaolinite,halloysite,montmorillonite,attapulgite,bentonite,sepiolite,forsterite,and wollastonite,have considerable potential for use in CO_(2) capture and mineralization due to their abundant ...Natural minerals,such as kaolinite,halloysite,montmorillonite,attapulgite,bentonite,sepiolite,forsterite,and wollastonite,have considerable potential for use in CO_(2) capture and mineralization due to their abundant reserves,low cost,excellent mechanical prop-erties,and chemical stability.Over the past decades,various methods,such as those involving heat,acid,alkali,organic amine,amino sil-ane,and ionic liquid,have been employed to enhance the CO_(2) capture performance of natural minerals to attain high specific surface area,a large number of pore structures,and rich active sites.Future research on CO_(2) capture by natural minerals will focus on the full utiliza-tion of the properties of natural minerals,adoption of suitable modification methods,and preparation of composite materials with high specific surface area and rich active sites.In addition,we provide a summary of the principle and technical route of direct and indirect mineralization of CO_(2) by natural minerals.This process uses minerals with high calcium and magnesium contents,such as forsterite(Mg_(2)SiO_(4)),serpentine[Mg_(3)Si_(2)O(OH)_(4)],and wollastonite(CaSiO_(3)).The research status of indirect mineralization of CO_(2) using hydro-chloric acid,acetic acid,molten salt,and ammonium salt as media is also introduced in detail.The recovery of additives and high-value-added products during the mineralization process to increase economic benefits is another focus of future research on CO_(2) mineralization by natural minerals.展开更多
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
Solution processability significantly advances the development of highly-efficient perovskite solar cells.However,the precursor solution tends to undergo irreversible degradation reactions,impairing the device perform...Solution processability significantly advances the development of highly-efficient perovskite solar cells.However,the precursor solution tends to undergo irreversible degradation reactions,impairing the device performance and reproducibility.Here,we utilize a reductive natural amino acid,Nacetylcysteine(NALC),to stabilize the precursor solution for printable carbon-based hole-conductorfree mesoscopic perovskite solar cells.We find that I_(2) can be generated in the aged solution containing methylammonium iodide(MI) in an inert atmosphere and speed up the MA-FA^(+)(formamidinium) reaction which produces large-size cations and hinders the formation of perovskite phase.NALC effectively stabilizes the precursor via its sulfhydryl group which reduces I_(2) back to I^(-)and provides H^(+).The NALC-stabilized precursor which is aged for 1440 h leads to devices with a power conversion efficiency equivalent to 98% of that for devices prepared with the fresh precursor.Furthermore,NALC improves the device power conversion efficiency from 16.16% to 18.41% along with enhanced stability under atmospheric conditions by modifying grain boundaries in perovskite films and reducing associated defects.展开更多
文摘This study introduces the representation of natural number sets as row vectors and pretends to offer a new perspective on the strong Goldbach conjecture. The natural numbers are restructured and expanded with the inclusion of the zero element as the source of a strong Goldbach conjecture reformulation. A prime Boolean vector is defined, pinpointing the positions of prime numbers within the odd number sequence. The natural unit primality is discussed in this context and transformed into a source of quantum-like indetermination. This approach allows for rephrasing the strong Goldbach conjecture, framed within a Boolean scalar product between the prime Boolean vector and its reverse. Throughout the discussion, other intriguing topics emerge and are thoroughly analyzed. A final description of two empirical algorithms is provided to prove the strong Goldbach conjecture.
基金supported by the National Natural Science Foundation of China (Grant No.51991361 and Grant No.51874329)。
文摘The environmental hazards and"carbon footprint"of oil and gas drilling can be significantly reduced by replacing traditional petroleum-based chemical additives with natural materials derived from plants and animals.This paper explored for the first time the interaction mechanism between natural rubber latex(NRL)and bentonite suspensions(BTs)through a series of characterization experiments,as well as the potential applications in water-based drilling fluids(WBDF).The gel viscoelasticity experiments showed that NRL could decrease the consistency coefficient(k)and flow index(n)of BTs,and enhance the shear thinning performance of BTs as pseudo-plastic fluids.In addition,0.5 w/v%NRL not only increased the critical yield stress and strengthened the structural strength between the bentonite particles,but also facilitated the compatibility of pressure loss and flow efficiency.The evaluation of colloidal stability and WBDF performance indicated that NRL particles could promote the hydration and charge stability on the surface of BTs particles,and optimize the particle size distribution and flow resistance of WBDF under the"intercalation-exfoliation-encapsulation"synergistic interaction.Moreover,NRL can improve the rheological properties of WBDF at high temperatures(<150.C),and form a dense blocking layer by bridging and sealing the pores and cracks of the filter cake,which ultimately reduces the permeability of the cake and the filtration loss of WBDF.
基金supported by the National Natural Science Foundation of China(52003113,31900950,82102334,82002313,82072444)the National Key Research&Development Program of China(2018YFC2001502,2018YFB1105705)+6 种基金the Guangdong Basic and Applied Basic Research Foundation(2021A1515010745,2020A1515110356,2023A1515011986)the Shenzhen Fundamental Research Program(JCYJ20190808120405672)the Key Program of the National Natural Science Foundation of Zhejiang Province(LZ22C100001)the Natural Science Foundation of Shanghai(20ZR1469800)the Integration Innovation Fund of Shanghai Jiao Tong University(2021JCPT03),the Science and Technology Projects of Guangzhou City(202102020359)the Zigong Key Science and Technology Plan(2022ZCNKY07).SXC thanks the financial support under the Startup Grant of the University of Chinese Academy of Sciences(WIUCASQD2021026).HW thanks the Futian Healthcare Research Project(FTWS2022013)the financial support of China Postdoctoral Science Foundation(2021TQ0118).SL thanks the financial support of China Postdoctoral Science Foundation(2022M721490).
文摘Biomimetic materials have emerged as attractive and competitive alternatives for tissue engineering(TE)and regenerative medicine.In contrast to conventional biomaterials or synthetic materials,biomimetic scaffolds based on natural biomaterial can offer cells a broad spectrum of biochemical and biophysical cues that mimic the in vivo extracellular matrix(ECM).Additionally,such materials have mechanical adaptability,micro-structure interconnectivity,and inherent bioactivity,making them ideal for the design of living implants for specific applications in TE and regenerative medicine.This paper provides an overview for recent progress of biomimetic natural biomaterials(BNBMs),including advances in their preparation,functionality,potential applications and future challenges.We highlight recent advances in the fabrication of BNBMs and outline general strategies for functionalizing and tailoring the BNBMs with various biological and physicochemical characteristics of native ECM.Moreover,we offer an overview of recent key advances in the functionalization and applications of versatile BNBMs for TE applications.Finally,we conclude by offering our perspective on open challenges and future developments in this rapidly-evolving field.
基金The financial supports from the National Natural Science Foundation of China (22178059, 22208054 and 22072019)Natural Science Foundation of Fujian Province, China (2020J01513)+1 种基金Sinochem Quanzhou Energy Technology Co., Ltd. (ZHQZKJ-19-F-ZS0076)Qingyuan Innovation Laboratory (00121002)
文摘Zeolite catalysts have found extensive applications in the synthesis of various fine chemicals.However,the micropores of zeolites impose diffusion limitations on bulky molecules,greatly reducing the catalytic efficiency.Herein,we explore an economic and environmentally friendly method for synthesizing hierarchical NaX zeolite that exhibits improved catalytic performance in the Knoevenagel condensation reaction for producing the useful fine chemical 2-cyano-3-phenylacrylate.The synthesis was achieved via a low-temperature activation of kaolinite and subsequent in-situ transformation strategy without any template or seed.Systematic characterizations reveal that the synthesized NaX zeolite has both intercrystalline and intra-crystalline mesopores,smaller crystal size,and larger external specific surface area compared to commercial NaX zeolite.Detailed mechanism investigations show that the inter-crystalline mesopores are generated by stacking smaller crystals formed from in-situ crystallization of the depolymerized kaolinite,and the intra-crystalline mesopores are inherited from the pores in the depolymerized kaolinite.This synthesis strategy provides an energy-saving and effective way to construct hierarchical zeolites,which may gain wide applications in fine chemical manufacturing.
文摘Alzheimer’s disease is a progressive neurodegenerative disorder and the most common cause of dementia that principally affects older adults.Pathogenic factors,such as oxidative stress,an increase in acetylcholinesterase activity,mitochondrial dysfunction,genotoxicity,and neuroinflammation are present in this syndrome,which leads to neurodegeneration.Neurodegenerative pathologies such as Alzheimer’s disease are considered late-onset diseases caused by the complex combination of genetic,epigenetic,and environmental factors.There are two main types of Alzheimer’s disease,known as familial Alzheimer’s disease(onset<65 years)and late-onset or sporadic Alzheimer’s disease(onset≥65 years).Patients with familial Alzheimer’s disease inherit the disease due to rare mutations on the amyloid precursor protein(APP),presenilin 1 and 2(PSEN1 and PSEN2)genes in an autosomaldominantly fashion with closely 100%penetrance.In contrast,a different picture seems to emerge for sporadic Alzheimer’s disease,which exhibits numerous non-Mendelian anomalies suggesting an epigenetic component in its etiology.Importantly,the fundamental pathophysiological mechanisms driving Alzheimer’s disease are interfaced with epigenetic dysregulation.However,the dynamic nature of epigenetics seems to open up new avenues and hope in regenerative neurogenesis to improve brain repair in Alzheimer’s disease or following injury or stroke in humans.In recent years,there has been an increase in interest in using natural products for the treatment of neurodegenerative illnesses such as Alzheimer’s disease.Through epigenetic mechanisms,such as DNA methylation,non-coding RNAs,histone modification,and chromatin conformation regulation,natural compounds appear to exert neuroprotective effects.While we do not purport to cover every in this work,we do attempt to illustrate how various phytochemical compounds regulate the epigenetic effects of a few Alzheimer’s disease-related genes.
基金support provided by the UK Engineering and Physical Sciences Research Council(EP/V012169/1).
文摘Landslides occurring in sensitive clay often result in widespread destruction,posing a significant risk to human lives and property due to the substantial decrease in undrained shear strength during deformation.Assessing the consequences of these landslides is challenging and necessitates robust numerical methods to comprehensively investigate their failure mechanisms.While studies have extensively explored upward progressive landslides in sensitive clays,understanding downward progressive cases remains limited.In this study,we utilised the nodal integration-based particle finite element method(NPFEM)with a nonlinear strain-softening model to analyse downward progressive landslides in sensitive clay on elongated slopes,induced by surcharge loads near the crest.We focused on elucidating the underlying failure mechanisms and evaluating the effects of different soil parameters and strainsoftening characteristics.The simulation results revealed the typical pattern for downward landslides,which typically start with a localised failure in proximity to the surcharge loads,followed by a combination of different types of failure mechanisms,including single flow slides,translational progressive landslides,progressive flow slides,and spread failures.Additionally,inclined shear bands occur within spread failures,often adopting distinctive ploughing patterns characterised by triangular shapes.The sensitive clay thickness at the base,the clay strength gradient,the sensitivity,and the softening rate significantly influence the failure mechanisms and the extent of diffused displacement.Remarkably,some of these effects mirror those observed in upward progressive landslides,underscoring the interconnectedness of these phenomena.This study contributes valuable insights into the complex dynamics of sensitive clay landslides,shedding light on the intricate interplay of factors governing their behaviour and progression.
基金National Natural Science Foundation of China(Nos.42171444,42301516)Beijing Natural Science Foundation Project-Municipal Education Commission Joint Fund Project(No.KZ202110016021)Beijing Municipal Education Commission Scientific Research Project-Science and Technology Plan General Project(No.KM202110016005).
文摘Natural disaster risk monitoring is an important task for disaster prevention and reduction.In the case of immovable cultural relics,however,the feedback mechanism,risk factors,monitoring logic,and monitoring indicators of natural disaster risk monitoring are complex.How to achieve intelligent perception and monitoring of natural disaster risk for immovable cultural relics has always been a focus and a challenge for researchers.Based on the analysis of the concepts and issues related to the natural disaster risk of immovable cultural relics,this paper proposes a framework for natural disaster risk monitoring for immovable cultural relics based on the digital twin.This framework focuses on risk monitoring,including the physical entities of natural disaster risk for immovable cultural relics,monitoring indicators,and virtual entity construction.A platform for monitoring the natural disaster risk of immovable cultural relics is proposed.Using the Puzhou Ancient City Site as a test bed,the proposed concept can be used for monitoring the natural disaster risk of immovable cultural relics at different scales.
基金supported by the National Institutes of Health(R01CA177585,U01CA240346,and R01CA153821)(DY)the Purdue Center for Cancer Research(P30CA023168)+2 种基金the National Natural Science Foundation of China(82173707 and 82322065)the Program for Jiangsu Province Innovative Research Scholar(JSSCRC2021512)the“Double First-Class”University Project(CPUQNJC22_08).
文摘DNA guanine(G)-quadruplexes(G4s)are unique secondary structures formed by two or more stacked Gtetrads in G-rich DNA sequences.These structures have been found to play a crucial role in highly transcribed genes,especially in cancer-related oncogenes,making them attractive targets for cancer therapeutics.Significantly,targeting oncogene promoter G4 structures has emerged as a promising strategy to address the challenge of undruggable and drug-resistant proteins,such as MYC,BCL2,KRAS,and EGFR.Natural products have long been an important source of drug discovery,particularly in the fields of cancer and infectious diseases.Noteworthy progress has recently been made in the discovery of naturally occurring DNA G4-targeting drugs.Numerous DNA G4s,such as MYC-G4,BCL2-G4,KRAS-G4,PDGFR-b-G4,VEGF-G4,and telomeric-G4,have been identified as potential targets of natural products,including berberine,telomestatin,quindoline,sanguinarine,isaindigotone,and many others.Herein,we summarize and evaluate recent advancements in natural and nature-derived DNA G4 binders,focusing on understanding the structural recognition of DNA G4s by small molecules derived from nature.We also discuss the challenges and opportunities associated with developing drugs that target DNA G4s.
基金This work was supported by the National Natural Science Foundation of China(51874332,51991363)the CNPC's Major Science and Technology Projects(ZD2019-184-003)+1 种基金the Fundamental Research Funds for Central Universities(20CX05008A)“14th Five-Year plan”forward-looking basic major science and technology project of CNPC(2021DJ4901).
文摘Natural gas hydrate(NGH)can cause pipeline blockages during the transportation of oil and gas under high pressures and low temperatures.Reducing hydrate adhesion on pipelines is viewed as an efficient way to prevent NGH blockages.Previous studies suggested the water film can greatly increase hydrate adhesion in gas-dominant system.Herein,by performing the molecular dynamics simulations,we find in water-dominant system,the water film plays different roles in hydrate deposition on Fe and its corrosion surfaces.Specifically,due to the strong affinity of water on Fe surface,the deposited hydrate cannot convert the adsorbed water into hydrate,thus,a water film exists.As water affinities decrease(Fe>Fe_(2)O_(3)>FeO>Fe_(3)O_(4)),adsorbed water would convert to amorphous hydrate on Fe_(2)O_(3)and form the ordered hydrate on FeO and Fe_(3)O_(4)after hydrate deposition.While absorbed water film converts to amorphous or to hydrate,the adhesion strength of hydrate continuously increases(Fe<Fe_(2)O_(3)<FeO<Fe_(3)O_(4)).This is because the detachment of deposited hydrate prefers to occur at soft region of liquid layer,the process of which becomes harder as liquid layer vanishes.As a result,contrary to gas-dominant system,the water film plays the weakening roles on hydrate adhesion in water-dominant system.Overall,our results can help to better understand the hydrate deposition mechanisms on Fe and its corrosion surfaces and suggest hydrate deposition can be adjusted by changing water affinities on pipeline surfaces.
基金supported by the National Natural Science Foundation of China(81873217 and 82074310)the State Key Laboratory of Core Technology in Innovative Chinese Medicine(20221108).
文摘Microcirculatory disturbances are complex processes caused by many factors,including abnormal vasomotor responses,decreased blood flow velocity,vascular endothelial cell injury,altered leukocyte and endothelial cell interactions,plasma albumin leakage,microvascular hemorrhage,and thrombosis.These disturbances involve multiple mechanisms and interactions among mechanisms that can include energy metabolism,the mitochondrial respiratory chain,oxidative stress,inflammatory factors,adhesion molecules,the cytoskeleton,vascular endothelial cells,caveolae,cell junctions,the vascular basement membrane,neutrophils,monocytes,and platelets.In clinical practice,aside from drugs that target abnormal vasomotor responses and platelet adhesion,there continues to be a lack of multi-target drugs that can regulate the complex mechanistic links and interactions underlying microcirculatory disturbances.Natural products have demonstrated obvious positive therapeutic effects in treating ischemia/reperfusion(I/R)-and lipopolysaccharide(LPS)-induced microcirculatory disturbances.In recent years,numerous research papers on the improvement of microcirculatory function by natural products have been published in international journals.In 2008 and 2017,the first listed author of this review was invited to publish reviews in the journal of Pharmacology&Therapeutics on the improvement of microcirculatory disturbances and organ injury induced by I/R using Salvia miltiorrhiza ingredients and other natural components of compounded Chinese medicine,respectively.This review systematically summarizes the effects,targets of action,and mechanisms of natural products regarding improving I/R-and LPSinduced microcirculatory disturbances and tissue injury.Based on this summary,scientific proposals are suggested for the discovery of new drugs to improve microcirculatory disturbances in disease.
基金supported by the National Natural Science Foundation of China(22078281)。
文摘The isolation of minor components from complex natural product matrices presents a significant challenge in the field of purification science due to their low concentrations and the presence of structurally similar compounds.This study introduces an optimized twin-column recycling chromatography method for the efficient and simultaneous purification of these elusive constituents.By introducing water at a small flowing rate between the twin columns,a step solvent gradient is created,by which the leading edge of concentration band would migrate at a slower rate than the trailing edge as it flowing from the upstream to downstream column.Hence,the band broadening is counterbalanced,resulting in an enrichment effect for those minor components in separation process.Herein,two target substances,which showed similar peak position in high performance liquid chromatography(HPLC)and did not exceed 1.8%in crude paclitaxel were selected as target compounds for separation.By using the twin-column recycling chromatography with a step solvent gradient,a successful purification was achieved in getting the two with the purity almost 100%.We suggest this method is suitable for the separation of most components in natural produces,which shows higher precision and recovery rate compared with the common lab-operated separation ways for natural products(thin-layer chromatography and prep-HPLC).
基金Project supported by the YEQISUN Joint Funds of the National Natural Science Foundation of China(No.U2341231)the National Natural Science Foundation of China(No.12172186)。
文摘In most practical engineering applications,the translating belt wraps around two fixed wheels.The boundary conditions of the dynamic model are typically specified as simply supported or fixed boundaries.In this paper,non-homogeneous boundaries are introduced by the support wheels.Utilizing the translating belt as the mechanical prototype,the vibration characteristics of translating Timoshenko beam models with nonhomogeneous boundaries are investigated for the first time.The governing equations of Timoshenko beam are deduced by employing the generalized Hamilton's principle.The effects of parameters such as the radius of wheel and the length of belt on vibration characteristics including the equilibrium deformations,critical velocities,natural frequencies,and modes,are numerically calculated and analyzed.The numerical results indicate that the beam experiences deformation characterized by varying curvatures near the wheels.The radii of the wheels play a pivotal role in determining the change in trend of the relative difference between two beam models.Comparing the results unearths that the relative difference in equilibrium deformations between the two beam models is more pronounced with smaller-sized wheels.When the two wheels are of equal size,the critical velocities of both beam models reach their respective minima.In addition,the relative difference in natural frequencies between the two beam models exhibits nonlinear variation and can easily exceed 50%.Furthermore,as the axial velocities increase,the impact of non-homogeneous boundaries on modal shape of translating beam becomes more significant.Although dealing with non-homogeneous boundaries is challenging,beam models with non-homogeneous boundaries are more sensitive to parameters,and the differences between the two types of beams undergo some interesting variations under the influence of non-homogeneous boundaries.
基金financially supported by Xinjiang Oilfield Company of China(Grant No.2020-C4006)。
文摘In order to study the hydrocarbon generation(HCGE)characteristics of coal-bearing basins,the coal-measure source rocks of the Middle Jurassic-Lower Jurassic(MLJ)of the piedmont thrust belt in the southern margin of the Junggar Basin in Northwest China are taken as research objects.More than 60 MLJ samples were collected from outcrops and wells.Total organic carbon(TOC),rock pyrolysis(Rock-Eval),organic petrological,vitrinite reflectance(%Ro),and hydrous pyrolysis were performed to analyze the relevant samples.The pyrolysis gases and liquid products were measured,and then the chemical composition,as well as carbon isotopes of the gases,were analyzed.The results indicate that the MLJ source rocks have the capacity for large-scale gas generation.In addition,for coal-measure source rocks,the heavier the carbon isotope of kerogen(δ^(13)C_(kerogen)),the lower the liquid hydrocarbon and hydrocarbon gas yield,and the easier it is to produce non-hydrocarbon gas.It is worth noting that when theδ^(13)C_(kerogen)in organic matter(OM)is relatively heavier,the fractionation of its products may become weaker in the evolutionary process.The vital contribution of the MLJ source rock to natural gas resources in the study area was further confirmed by comparing it with the Jurassic source gas.
基金supported by the National Natural Science Foundation of China(No.52173292)the National Key Research and Development Project of China(No.2020YFC1910303)the Youth Innovation Promotion Association CAS(No.2018040).
文摘Non-degradable polymers cause serious environmental pollution problem,such as the widely-used while unrecyclable coatings which significantly affect the overall degradation performance of products.It is imperative and attractive to develop biodegradable functional coatings.Herein,we proposed a novel strategy to successfully prepare biodegradable,thermoplastic and hydrophobic coatings with high transparence and biosafety by weakening the interchain interactions between cellulose chain.The natural cellulose and cinnamic acid were as raw materials.Via reducing the degree of polymerization(DP)of cellulose and regulating the degree of substitution(DS)of cinnamate moiety,the obtained cellulose cinnamate(CC)exhibited not only the thermalflow behavior but also good biodegradability,which solves the conflict between the thermoplasticity and biodegradability in cellulose-based materials.The glass transition temperature(T_(g))and thermalflow temperature(T_(f))of the CC could be adjusted in a range of 150–200℃ and 180–210℃,respectively.The CC with DS<1.2 and DP≤100 degraded more than 60%after an enzyme treatment for 7 days,and degraded more than 80%after a composting treatment for 42 days.Furthermore,CC had no toxicity to human epidermal cells even at a high concentration(0.5 mg mL^(-1)).In addition,CC could be easily fabricated into multifunctional coating with high hydrophobicity,thermal adhesion and high transparence.Therefore,after combining with cellophane and paperboard,CC coating with low DP and DS could be used to prepare fully-biodegradable heat-sealing packaging,art paper,paper cups,paper straws and food packaging boxes.
基金funded by the National Natural Science Foundation of China(grants No.30960264,31160475 and 42071258)Open Research Fund of TPESER(grant No.TPESER202208)+2 种基金Special Fund for Basic Scientific Research of Central Colleges,Chang’an University,China(grant No.300102353501)Natural Science Foundation of Gansu Province,China(grant No.22JR5RA857)Higher Education Novel Foundation of Gansu Province,China(grant No.2021B-130)。
文摘Potential natural vegetation(PNV)is a valuable reference for ecosystem renovation and has garnered increasing attention worldwide.However,there is limited knowledge on the spatio-temporal distributions,transitional processes,and underlying mechanisms of global natural vegetation,particularly in the case of ongoing climate warming.In this study,we visualize the spatio-temporal pattern and inter-transition procedure of global PNV,analyse the shifting distances and directions of global PNV under the influence of climatic disturbance,and explore the mechanisms of global PNV in response to temperature and precipitation fluctuations.To achieve this,we utilize meteorological data,mainly temperature and precipitation,from six phases:the Last Inter-Glacial(LIG),the Last Glacial Maximum(LGM),the Mid Holocene(MH),the Present Day(PD),2030(20212040)and 2090(2081–2100),and employ a widely-accepted comprehensive and sequential classification sy–stem(CSCS)for global PNV classification.We find that the spatial patterns of five PNV groups(forest,shrubland,savanna,grassland and tundra)generally align with their respective ecotopes,although their distributions have shifted due to fluctuating temperature and precipitation.Notably,we observe an unexpected transition between tundra and savanna despite their geographical distance.The shifts in distance and direction of five PNV groups are mainly driven by temperature and precipitation,although there is heterogeneity among these shifts for each group.Indeed,the heterogeneity observed among different global PNV groups suggests that they may possess varying capacities to adjust to and withstand the impacts of changing climate.The spatio-temporal distributions,mutual transitions and shift tendencies of global PNV and its underlying mechanism in face of changing climate,as revealed in this study,can significantly contribute to the development of strategies for mitigating warming and promoting re-vegetation in degraded regions worldwide.
基金supported by the Vietnam National University,Ho Chi Minh City (Grant No.TX2024-50-01)partial supported by National Natural Science Foundation of China (Grant No.22209186)。
文摘Urea-assisted natural seawater electrolysis is an emerging technology that is effective for grid-scale carbon-neutral hydrogen mass production yet challenging.Circumventing scaling relations is an effective strategy to break through the bottleneck of natural seawater splitting.Herein,by DFT calculation,we demonstrated that the interface boundaries between Ni_(2)P and MoO_(2) play an essential role in the selfrelaxation of the Ni-O interfacial bond,effectively modulating a coordination number of intermediates to control independently their adsorption-free energy,thus circumventing the adsorption-energy scaling relation.Following this conceptual model,a well-defined 3D F-doped Ni_(2)P-MoO_(2) heterostructure microrod array was rationally designed via an interfacial engineering strategy toward urea-assisted natural seawater electrolysis.As a result,the F-Ni_(2)P-MoO_(2) exhibits eminently active and durable bifunctional catalysts for both HER and OER in acid,alkaline,and alkaline sea water-based electrolytes.By in-situ analysis,we found that a thin amorphous layer of NiOOH,which is evolved from the Ni_(2)P during anodic reaction,is real catalytic active sites for the OER and UOR processes.Remarkable,such electrode-assembled urea-assisted natural seawater electrolyzer requires low voltages of 1.29 and 1.75 V to drive 10 and600 mA cm^(-2)and demonstrates superior durability by operating continuously for 100 h at 100 mA cm^(-2),beyond commercial Pt/C||RuO_(2) and most previous reports.
基金supported by 111 Project (No.D21025)Open Fund Project of State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation (Nos.PLN2021-01,PLN2021-02,PLN2021-03)+2 种基金High-end Foreign Expert Introduction Program (No.G2021036005L)National Key Research and Development Program (No.2021YFC2800903)National Natural Science Foundation of China (No.U20B6005-05)。
文摘During the operational process of natural gas gathering and transmission pipelines,the formation of hydrates is highly probable,leading to uncontrolled movement and aggregation of hydrates.The continuous migration and accumulation of hydrates further contribute to the obstruction of natural gas pipelines,resulting in production reduction,shutdowns,and pressure build-ups.Consequently,a cascade of risks is prone to occur.To address this issue,this study focuses on the operational process of natural gas gathering and transmission pipelines,where a comprehensive framework is established.This framework includes theoretical models for pipeline temperature distribution,pipeline pressure distribution,multiphase flow within the pipeline,hydrate blockage,and numerical solution methods.By analyzing the influence of inlet temperature,inlet pressure,and terminal pressure on hydrate formation within the pipeline,the sensitivity patterns of hydrate blockage risks are derived.The research indicates that reducing inlet pressure and terminal pressure could lead to a decreased maximum hydrate formation rate,potentially mitigating pipeline blockage during natural gas transportation.Furthermore,an increase in inlet temperature and terminal pressure,and a decrease in inlet pressure,results in a displacement of the most probable location for hydrate blockage towards the terminal station.However,it is crucial to note that operating under low-pressure conditions significantly elevates energy consumption within the gathering system,contradicting the operational goal of energy efficiency and reduction of energy consumption.Consequently,for high-pressure gathering pipelines,measures such as raising the inlet temperature or employing inhibitors,electrical heat tracing,and thermal insulation should be adopted to prevent hydrate formation during natural gas transportation.Moreover,considering abnormal conditions such as gas well production and pipeline network shutdowns,which could potentially trigger hydrate formation,the installation of methanol injection connectors remains necessary to ensure production safety.
基金supported by the Beijing Natural Science Foundation,China(No.2242055).
文摘Natural minerals,such as kaolinite,halloysite,montmorillonite,attapulgite,bentonite,sepiolite,forsterite,and wollastonite,have considerable potential for use in CO_(2) capture and mineralization due to their abundant reserves,low cost,excellent mechanical prop-erties,and chemical stability.Over the past decades,various methods,such as those involving heat,acid,alkali,organic amine,amino sil-ane,and ionic liquid,have been employed to enhance the CO_(2) capture performance of natural minerals to attain high specific surface area,a large number of pore structures,and rich active sites.Future research on CO_(2) capture by natural minerals will focus on the full utiliza-tion of the properties of natural minerals,adoption of suitable modification methods,and preparation of composite materials with high specific surface area and rich active sites.In addition,we provide a summary of the principle and technical route of direct and indirect mineralization of CO_(2) by natural minerals.This process uses minerals with high calcium and magnesium contents,such as forsterite(Mg_(2)SiO_(4)),serpentine[Mg_(3)Si_(2)O(OH)_(4)],and wollastonite(CaSiO_(3)).The research status of indirect mineralization of CO_(2) using hydro-chloric acid,acetic acid,molten salt,and ammonium salt as media is also introduced in detail.The recovery of additives and high-value-added products during the mineralization process to increase economic benefits is another focus of future research on CO_(2) mineralization by natural minerals.
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financial support from the National Natural Science Foundation of China(grant nos.52172198,51902117,and 91733301)。
文摘Solution processability significantly advances the development of highly-efficient perovskite solar cells.However,the precursor solution tends to undergo irreversible degradation reactions,impairing the device performance and reproducibility.Here,we utilize a reductive natural amino acid,Nacetylcysteine(NALC),to stabilize the precursor solution for printable carbon-based hole-conductorfree mesoscopic perovskite solar cells.We find that I_(2) can be generated in the aged solution containing methylammonium iodide(MI) in an inert atmosphere and speed up the MA-FA^(+)(formamidinium) reaction which produces large-size cations and hinders the formation of perovskite phase.NALC effectively stabilizes the precursor via its sulfhydryl group which reduces I_(2) back to I^(-)and provides H^(+).The NALC-stabilized precursor which is aged for 1440 h leads to devices with a power conversion efficiency equivalent to 98% of that for devices prepared with the fresh precursor.Furthermore,NALC improves the device power conversion efficiency from 16.16% to 18.41% along with enhanced stability under atmospheric conditions by modifying grain boundaries in perovskite films and reducing associated defects.
