Flax(Linum usitatissimum L.)is a versatile crop and its seeds are a major source of unsaturated fatty acids.Stearoyl-acyl carrier protein desaturase(SAD)is a dehydrogenase enzyme that plays a key role in oleic acid bi...Flax(Linum usitatissimum L.)is a versatile crop and its seeds are a major source of unsaturated fatty acids.Stearoyl-acyl carrier protein desaturase(SAD)is a dehydrogenase enzyme that plays a key role in oleic acid biosynthesis as well as responses to biotic and abiotic stresses.However,the function of SAD orthologs from L.usitatissimum has not been assessed.Here,we found that two LuSAD genes,LuSAD1 and LuSAD2,are present in the genome of L.usitatissimum cultivar‘Longya 10’.Heterogeneous expression of either LuSAD1 or LuSAD2 in Arabidopsis thaliana resulted in higher contents of total fatty acids and oleic acid in the seeds.Interestingly,ectopic expression of LuSAD2 in A.thaliana caused altered plant architecture.Similarly,the overexpression of either LuSAD1 or LuSAD2 in Brassica napus also resulted in increased contents of total fatty acids and oleic acid in the seeds.Furthermore,we demonstrated that either LuSAD1 or LuSAD2 enhances seedling resistance to cold and drought stresses by improving antioxidant enzyme activity and nonenzymatic antioxidant levels,as well as reducing membrane damage.These findings not only broaden our knowledge of the LuSAD functions in plants,but also offer promising targets for improving the quantity and quality of oil,and the abiotic stress tolerance of oil-producing crops,through molecular manipulation.展开更多
Three M_(W)>7.0 earthquakes in 2020-2021 occurred in the Shumagin seismic gap and its adjacent area of the Alaska-Aleutian subduction zone,including the Mw7.8 Simeonof thrust earthquake on July 22,2020,the M_(W)7.6...Three M_(W)>7.0 earthquakes in 2020-2021 occurred in the Shumagin seismic gap and its adjacent area of the Alaska-Aleutian subduction zone,including the Mw7.8 Simeonof thrust earthquake on July 22,2020,the M_(W)7.6 Sand Point strike-slip earthquake on October 19,2020,and the M_(W)8.2 Chignik thrust earthquake on July 29,2021.The spatial and temporal proximity of these three earthquakes prompts us to probe stress-triggering effects among them.Here we examine the coseismic Coulomb stress change imparted by the three earthquakes and their influence on the subduction interface.Our results show that:(1)The Simeonof earthquake has strong loading effects on the subsequent Sand Point and Chignik earthquakes,with the Coulomb stress changes of 3.95 bars and 2.89 bars,respectively.The Coulomb stress change caused by the Sand Point earthquake at the hypocenter of the Chignik earthquake is merely around 0.01 bars,suggesting the negligible triggering effect on the latter earthquake;(2)The triggering effects of the Simeonof,Sand Point,and Chignik earthquakes on aftershocks within three months are not well pronounced because of the triggering rates of 38%,14%,and 43%respectively.Other factors may have played an important role in promoting the occurrence of these aftershocks,such as the roughness of the subduction interface,the complicated velocity structure of the lithosphere,and the heterogeneous prestress therein;(3)The three earthquakes caused remarkable coseismic Coulomb stress changes at the subduction interface nearby these mainshocks,with an average Coulomb stress change of 3.2 bars in the shallow region directly inwards the trench.展开更多
Flotation is the most common method to obtain concentrate through the selective adsorption of collectors on target minerals to make them hydrophobic and floatable.In the hydrometallurgy of concentrate,collectors adsor...Flotation is the most common method to obtain concentrate through the selective adsorption of collectors on target minerals to make them hydrophobic and floatable.In the hydrometallurgy of concentrate,collectors adsorbed on concentrate can damage ion-exchange resin and increase the chemical oxygen demand(COD)value of wastewater.In this work,we proposed a new scheme,i.e.,desorbing the collectors from concentrate in ore dressing plant and reusing them in flotation flowsheet.Lead nitrate and benzohydroxamic acid(Pb-BHA)complex is a common collector in scheelite flotation.In this study,different physical(stirring or ultrasonic waves)and chemical(strong acid or alkali environment)methods for facilitating the desorption of Pb-BHA collector from scheelite concentrate were explored.Single-mineral desorption tests showed that under the condition of pulp pH 13 and ultrasonic treatment for 15 min,the highest desorption rates of Pb and BHA from the scheelite concentrate were 90.48%and 63.75%,respectively.Run-of-mine ore flotation tests revealed that the reuse of desorbed Pb and BHA reduced the collector dosage by 30%for BHA and 25%for Pb.The strong alkali environment broke the chemical bonds between Pb and BHA.The cavitation effect of ultrasonic waves effectively reduced the interaction intensity between Pb-BHA collector and scheelite surfaces.This method combining ultrasonic waves and strong alkali environment can effectively desorb the collectors from concentrate and provide“clean”scheelite concentrate for metallurgic plants;the reuse of desorbed collector in flotation flowsheet can reduce reagent cost for ore dressing plants.展开更多
目的:比较曲妥珠单抗和帕妥珠单抗(trastuzumab plus pertuzumab,HP)联合紫杉类+铂类(TCbHP)、紫杉类单药(THP)、蒽环类序贯紫杉类(AC-THP)三种化疗方案在真实世界临床实践中新辅助治疗HER-2阳性乳腺癌的疗效、安全性及耐受性。方法:回...目的:比较曲妥珠单抗和帕妥珠单抗(trastuzumab plus pertuzumab,HP)联合紫杉类+铂类(TCbHP)、紫杉类单药(THP)、蒽环类序贯紫杉类(AC-THP)三种化疗方案在真实世界临床实践中新辅助治疗HER-2阳性乳腺癌的疗效、安全性及耐受性。方法:回顾性分析2019年6月至2021年12月于保定市第一中心医院等河北省共11家三级甲等医院接受三种方案新辅助治疗并完成后续手术的180例HER-2阳性乳腺癌患者的临床病理资料,其中TCbHP组78例、THP组70例、AC-THP组32例,比较三种治疗方案的疗效、安全性及耐受性,并采用统计学方法分析临床病理因素对总体病理完全缓解(total pathologic complete response,tpCR)率的影响。结果:总人群tpCR率为58.9%(106/180)。TCbHP组的tpCR率为64.1%(50/78),高于THP组的54.3%(38/70)和AC-THP组的56.3%(18/32),差异无统计学意义(P=0.454)。TCbHP组的3级及以上不良反应发生率为12.8%(10/78),高于THP组的4.3%(3/70)和AC-THP组的9.4%(3/32),差异无统计学意义(P=0.255)。THP组的既定方案完成率为98.6%(69/70),高于TCbHP组的92.3%(72/78)和AC-THP组的90.6%(29/32),差异无统计学意义(P=0.147)。180例患者中绝经后组与绝经前组的tpCR率分别为65.4%(70/107)与49.3%(36/73),HER-2免疫组织化学法(IHC)3+组与HER-2 IHC2+且荧光原位杂交(FISH)+组的tpCR率分别为65.0%(102/157)与17.4%(4/23),激素受体(HR)阴性组与HR阳性组的tpCR率分别为78.0%(64/82)与42.9%(42/98),白蛋白结合型紫杉醇组与其他紫杉类药物组的tpCR率分别为66.3%(65/98)与50.0%(41/82),组间进行比较差异均具有统计学意义(均P<0.05)。Logistic回归多因素分析表明,HER-2 IHC3+、HR阴性、使用白蛋白结合型紫杉醇为tpCR率的独立影响因素。结论:TCbHP、THP、AC-THP方案新辅助治疗HER-2阳性乳腺癌在真实世界临床实践中疗效确切,安全性及耐受性良好。TCbHP方案可考虑作为HER-2阳性乳腺癌新辅助治疗的优选方案。展开更多
Chalcopyrite is the main Cu-containing mineral and cannot be separated well from pyrite using traditional xanthate collectors with large amounts of lime depressant, resulting in difficulties of the tailing treatment a...Chalcopyrite is the main Cu-containing mineral and cannot be separated well from pyrite using traditional xanthate collectors with large amounts of lime depressant, resulting in difficulties of the tailing treatment and associated precious metals recovery. Therefore, in this study, the green and odourless ethylenediamine tetramethylenephosphonic acid(EDTMPA) was introduced as a novel chalcopyrite collector. Flotation results from the binary mineral mixture and real ore demonstrated that EDTMPA could realize the selective separation of chalcopyrite from pyrite relative to ethyl xanthate(EX) without any depressants within the wide p H range of 6.0–11.0, and might replace the traditional high-alkaline lime process. Electrochemical and Fourier transform infrared spectra measurements indicated that the difference in adsorption performance of EDTMPA on chalcopyrite and pyrite was larger than that of EX, suggesting a better selectivity for EDTMPA. Density functional theory calculations demonstrated that there were stronger chemical bonds between P—O groups of EDTMPA and the Fe/Cu atoms on chalcopyrite in the form of a stable six-membered ring. Crystal chemistry calculations further revealed that the activity of metal atoms of chalcopyrite was higher than that of pyrite. Therefore, these basic theoretical results and practical application provide a guidance for the industrial application of EDTMPA in chalcopyrite flotation.展开更多
Rice is a major food crop and is planted worldwide. Climatic deterioration, population growth, farmland shrinkage, and other factors have necessitated the application of cutting-edge technology to achieve accurate and...Rice is a major food crop and is planted worldwide. Climatic deterioration, population growth, farmland shrinkage, and other factors have necessitated the application of cutting-edge technology to achieve accurate and efficient rice production. In this study, we mainly focus on the precise counting of rice plants in paddy field and design a novel deep learning network, RPNet, consisting of four modules: feature encoder, attention block, initial density map generator, and attention map generator. Additionally, we propose a novel loss function called RPloss. This loss function considers the magnitude relationship between different sub-loss functions and ensures the validity of the designed network. To verify the proposed method, we conducted experiments on our recently presented URC dataset, which is an unmanned aerial vehicle dataset that is quite challenged at counting rice plants. For experimental comparison, we chose some popular or recently proposed counting methods, namely MCNN, CSRNet, SANet, TasselNetV2, and FIDTM. In the experiment, the mean absolute error(MAE), root mean squared error(RMSE), relative MAE(rMAE) and relative RMSE(rRMSE) of the proposed RPNet were 8.3, 11.2, 1.2% and 1.6%, respectively,for the URC dataset. RPNet surpasses state-of-the-art methods in plant counting. To verify the universality of the proposed method, we conducted experiments on the well-know MTC and WED datasets. The final results on these datasets showed that our network achieved the best results compared with excellent previous approaches. The experiments showed that the proposed RPNet can be utilized to count rice plants in paddy fields and replace traditional methods.展开更多
Flower development and plant architecture determine the efficiency of mechanized harvest and seed yield in Brassica napus.Although TERMINAL FLOWER 1(AtTFL1)is a regulator of flower development in Arabidopsis thaliana,...Flower development and plant architecture determine the efficiency of mechanized harvest and seed yield in Brassica napus.Although TERMINAL FLOWER 1(AtTFL1)is a regulator of flower development in Arabidopsis thaliana,the function and regulatory mechanism of TFL1 orthologs in B.napus remains unclear.Six BnTFL1 paralogs in the genome of the B.napus inbred line‘K407’showed steadily increasing expression during vernalization.CRISPR/Cas-induced mutagenesis of up to four BnTFL1 paralogs resulted in early flowering and alteration of plant architecture,whereas seed yield was not altered in BnTFL1 single,double,or triple mutants.Six BnTFL1 paralogs,but not BnaA02.TFL1,showed an additive and conserved effect on regulating flowering time,total and terminal flower number,and plant architecture.BnaA10.TFL1 regulates flower development by interacting with BnaA08.FD through the protein BnaA05.GF14nu,resulting in the transcriptional repression of floral integrator and floral meristem identity genes.These findings about the regulatory network controlling flower development and plant architecture present a promising route to modifying these traits in B.napus.展开更多
Brucellosis remains one of the most common zoonoses spread worldwide,inducing enormous economic losses to the livestock industry and posing serious health threats to humans.Brucellosis re-emerged in China in the mid-1...Brucellosis remains one of the most common zoonoses spread worldwide,inducing enormous economic losses to the livestock industry and posing serious health threats to humans.Brucellosis re-emerged in China in the mid-1990s and reached a historically high level in 2015.The National Brucellosis Prevention and Control Plan(NBPCP)was initiated from 2016 to 2020.However,the present epidemiological status in livestock has not been elucidated,and whether Brucella variation occurred remains unclear.This study performed an extensive serological investigation in ruminant livestock from 2019 to 2021 in central Gansu Province,China.In total,11,296 samples from 337 farms were collected to detect the specific antibodies of Brucella.The yearly average serological prevalence of Brucella at the flock level and individual level declined from 11.32%to 8.26%and 1.17%to 0.57%,respectively.The apparent individuallevel seroprevalence of small and large ruminants was 0.89%and 0.52%,respectively.The brucellosis distribution has shifted from pastoral areas to agro-pastoral areas.Flock size and gender may be major risks of Brucella infection.Then,the B.melitensis TZ strain was isolated from female Tibetan sheep blood cell lysates.Phonotypical characterization demonstrated that it belongs to B.melitensis.biovar 3,and multilocus sequencing typing results indicated that it belongs to ST8.The whole genome and subsequent phylogenetic analysis demonstrated that the B.melitensis TZ strain is genetically more closely related to the B.melitensis QH61 strain.The B.melitensis TZ strain has similar growth characteristics to the B.melitensis 16 M strain.Overall,our study suggests that after strengthening control and prevention measures based on the NBPCP,there is a very low prevalence or absence of B.melitensis in the central Gansu Province of China,and the genotype of an epidemic strain of Brucella in Northwest China is relatively stable.展开更多
Substitutes of feed antibiotics have been a key research topic in the new stage of animal husbandry.Chinese veterinary medicine refers to decoction pieces and their preparations processed from natural plants,animals,a...Substitutes of feed antibiotics have been a key research topic in the new stage of animal husbandry.Chinese veterinary medicine refers to decoction pieces and their preparations processed from natural plants,animals,and minerals and used for animal disease prevention and improvement of animal production performance under the guidance of Chinese veterinary pharmacy theory.Eucommia ulmoides leaf extract has many active functional components such as chlorogenic acid,E.ulmoides polysaccharides and flavonoids,which have many biological properties such as antibacterial,antioxidant,immune-regulation,sugar ester-and bone metabolism-regulation effects.This paper explored active ingredients and biological properties of E.ulmoides leaf extract,as well as its role and effects in livestock and poultry breeding,providing a scientific basis for the use of E.ulmoides leaves in livestock and poultry breeding.展开更多
The rice Eui （ELONGATED UPPERMOST INTERNODE） gene encodes a cytochrome P450 monooxygenase that deactivates bioactive gibberellins （GAs）. In this study, we investigated controlled expression of the Eui gene and its...The rice Eui （ELONGATED UPPERMOST INTERNODE） gene encodes a cytochrome P450 monooxygenase that deactivates bioactive gibberellins （GAs）. In this study, we investigated controlled expression of the Eui gene and its role in plant development. We found that Eui was differentially induced by exogenous GAs and that the Eui promoter had the highest activity in the vascular bundles. The eui mutant was defective in starch granule development in root caps and Eui overexpression enhanced starch granule generation and gravity responses, revealing a role for GA in root starch granule development and gravity responses. Experiments using embryoless half-seeds revealed that RAmylA and GAmyb were highly upregulated in eui aleurone ceils in the absence of exogenous GA. In addition, the GA biosynthesis genes GA3oxl and GA20ox2 were downregulated and GA2oxl was upregulated in eui seedlings. These results indicate that EUI is involved in GA homeostasis, not only in the internodes at the heading stage, but also in the seedling stage, roots and seeds. Disturbing GA homeostasis affected the expression of the GA signaling genes GID1 （GIBBERELLIN INSENSITIVE DWARF 1）, GID2 and SLR1. Transgenic RNA interference of the Eui gene effectively increased plant height and improved heading performance. By contrast, the ectopic expression of Eui under the promoters of the rice GA biosynthesis genes GA3ox2 and GA2Oox2 significantly reduced plant height. These results demonstrate that a slight increase in Eui expression could dramatically change rice morphology, indicating the practical application of the Eui gene in rice molecular breeding for a high yield potential.展开更多
Dynamic regulation of histone methylation/demethylation plays an important role during development. Mutations and truncations in human plant homeodomain （PHD） finger protein 8 （PHF8） are associated with X-linked m...Dynamic regulation of histone methylation/demethylation plays an important role during development. Mutations and truncations in human plant homeodomain （PHD） finger protein 8 （PHF8） are associated with X-linked mental retardation and facial anomalies, such as a long face, broad nasal tip, cleft lip/cleft palate and large hands, yet its molecular function and structural basis remain unclear. Here, we report the crystal structures of the catalytic core of PHF8 with or without α-ketoglutarate （α-KG） at high resolution. Biochemical and structural studies reveal that PHF8 is a novel histone demethylase specific for di- and mono-methylated histone H3 lysine 9 （H3K9me2/1）, but not for H3K9me3. Our analyses also reveal how human PHF8 discriminates between methylation states and achieves sequence specificity for methylated H3K9. The in vitro demethylation assay also showed that the F279S mutant observed in clinical patients possesses no demethylation activity, suggesting that loss of enzymatic activity is crucial for pathogenesis of PHF8 patients. Taken together, these results will shed light on the molecular mechanism underlying PHF8-associated developmental and neurological diseases.展开更多
Objective： Apoptosis is a reliable marker of chemotherapeutic efficacy. Olaparib and paclitaxel inhibit proliferation and induce apoptosis in a variety of cancers. We investigated the effects of paclitaxel combined w...Objective： Apoptosis is a reliable marker of chemotherapeutic efficacy. Olaparib and paclitaxel inhibit proliferation and induce apoptosis in a variety of cancers. We investigated the effects of paclitaxel combined with olaparib on apoptosis in breast cancer Bcap37 cells. Methods： Proliferation and apoptosis were detected by MTT assay and PI staining. Degradation of procaspase-3 and poly（ADP-ribose） polymerase （PARP） was analyzed by Western blotting. Results： Compared with paclitaxel alone, paclitaxel combined with 100 mg olaparib significantly reduced survival in Bcap37 cells at all tested treatment durations （P〈0.05）; inhibition increased with increasing olaparib dose and treatment time （P〈0.01）. Combined treatment yielded significantly higher rates of apoptosis （P〈0.05）, which also increased with time （P〈0.01）. Fluorescence micrographs showed that early and late apoptotic cells increased with treatment time. Pro-caspase-3 and PARP degradation was induced by paclitaxel and enhanced by olaparib in a dose-dependent manner. Thus, combined treatment was substantially more effective than treatment with paclitaxel alone. Conclusions： Our findings suggest that paclitaxel and olaparib inhibit breast cancer Bcap37 cell proliferation and induce apoptosis. Combined treatment further reduced cell growth and enhanced apoptosis, suggesting that this combination therapy may be a promising treaunent for breast cancer.展开更多
Driven by safety issues,environmental concerns,and high costs,rechargeable aqueous zinc-ion batteries(ZIBs)have received increasing attention in recent years owing to their unique advantages.However,the sluggish kinet...Driven by safety issues,environmental concerns,and high costs,rechargeable aqueous zinc-ion batteries(ZIBs)have received increasing attention in recent years owing to their unique advantages.However,the sluggish kinetics of divalent charge Zn^(2+)in the cathode materials caused by the strong electrostatic interaction and their unsatisfactory cycle life hinder the development of ZIBs.Herein,organic cations and Zn^(2+)ions co-pre-inserted vanadium oxide([N(CH_(3))_(4)]_(0.77),Zn_(0.23))V_(8)O_(20)·3.8H_(2)O are reported as the cathode for ultra-stable aqueous ZIBs,in which the weaker electrostatic interactions between Zn^(2+)and organic ion-pinned vanadium oxide can induce the high reversibility of Zn^(2+)insertion and extraction,thereby improving the cycle life.It is demonstrated that([N(CH_(3))_(4)]_(0.77),Zn_(0.23))V_(8)O_(20)·3.8H_(2)O cathodes deliver a discharge capacity of 181 mA h g^(-1)at8 A g^(-1)and ultra-long life span(99.5%capacity retention after 2000 cycles).A reversible Zn^(2+)/H^(+)ions(de)intercalation storage process and pseudocapacitive charge storage are characterized.The weaker interactions between organic ion and Zn^(2+)open a novel avenue for the design of highly reversible cathode materials with long-term cycling stability.展开更多
In the past 20 years, great progress has been achieved in China in the construction of concrete-filled steel tube （CFST） arch bridges and concrete arch bridges with a CFST skeleton. The span of these bridges has bee...In the past 20 years, great progress has been achieved in China in the construction of concrete-filled steel tube （CFST） arch bridges and concrete arch bridges with a CFST skeleton. The span of these bridges has been increasing rapidly, which is rare in the history of bridge development. The large-scale construction of expressways and high-speed railways demands the development of long-span arch bridges, and advances in design and construction techniques have made it possible to construct such bridges. In the present study, the current status, development, and major innovative technologies of CFST arch bridges and concrete arch bridges with a CFST skeleton in China are elaborated. This paper covers the key con- struction technologies of CFST arch bridges, such as the design, manufacture, and installation of steel tube arch trusses, the preparation and pouring of in-tube concrete, and the construction of the world＇s longest CFST arch bridge-the First Hejiang Yangtze River Bridge. The main construction technologies of rein- forced concrete arch bridges are also presented, which include cable-stayed fastening-hanging cantilever assembly, adjusting the load by means of stay cables, surrounding the concrete for arch rib pouring, and so forth. In addition, the construction of two CFST skeleton concrete arch bridges-the Guangxi Yongning Yong River Bridge and the Yunnan-Guangxi Railway Nanpan River Bridge--is discussed. CFST arch bridges in China have already gained a world-leading position; with the continuous innovation of key technologies, China will become the new leader in promoting the development of arch bridges.展开更多
Nest-site and nesting material used by the Chinese alligator （Alligator sinensis） was studied at the Gaojingmiao Breeding Farm, Langxi County, Anhui, China from May to September 2009. In this study, artificial nesti...Nest-site and nesting material used by the Chinese alligator （Alligator sinensis） was studied at the Gaojingmiao Breeding Farm, Langxi County, Anhui, China from May to September 2009. In this study, artificial nesting materials were placed in 43 potential nesting sites before the nesting season, 11 of which were used. Additionally, eight nests were built at natural sites without artificial nesting materials provided. Seven environmental variables were measured at each nest site： distance from water, height from water surface, sunlight duration, nearest bank slope, nest site slope, vegetation coverage and concealment. Statistical analyses indicated that concealment was significantly different between used and unused nest sites, with concealment being significantly correlated to the use of materials- placed sites. In comparing the nests at artificial vs. natural sites, only the nearest bank slope differed significantly. Further, principal component analysis of natural nests indicated that the duration of nest exposure to sunlight and vegetation coverage were more influential than the other factors studied.展开更多
Cruising route recommendation based on trajectory mining can improve taxi-drivers'income and reduce energy consumption.However,existing methods mostly recommend pick-up points for taxis only.Moreover,their perform...Cruising route recommendation based on trajectory mining can improve taxi-drivers'income and reduce energy consumption.However,existing methods mostly recommend pick-up points for taxis only.Moreover,their performance is not good enough since there lacks a good evaluation model for the pick-up points.Therefore,we propose an entropy-based model for recommendation of taxis'cruising route.Firstly,we select more positional attributes from historical pick-up points in order to obtain accurate spatial-temporal features.Secondly,the information entropy of spatial-temporal features is integrated in the evaluation model.Then it is applied for getting the next pick-up points and further recommending a series of successive points.These points are constructed a cruising route for taxi-drivers.Experimental results show that our method is able to obviously improve the recommendation accuracy of pick-up points,and help taxi-drivers make profitable benefits more than before.展开更多
To explore the spatial pattern of macrobenthic communities and their response to environmental factors in the Prydz Bay,samples were collected using a 0.25-m2 box corer at 10 stations from November 2012 to April 2013....To explore the spatial pattern of macrobenthic communities and their response to environmental factors in the Prydz Bay,samples were collected using a 0.25-m2 box corer at 10 stations from November 2012 to April 2013.A total of 50 species of macrobenthos belonging to 8 phyla and 33 families were identified,of which polychaetes(e.g.,Maldane sarsi)and sponges(e.g.,Halichondria sp.and Leucosolenia sp.)were the most prominent groups.The macrobenthos in study area were categorized into five functional groups based on the feeding type,and the detritivorous group represented by polychaetes showed the highest average abundance,while the planktophagous group represented by sponges showed the highest average biomass.Macrobenthos abundance(0–592 ind./m2)and biomass(0–1155.5 g/m2)in the Prydz Bay were relatively lower than those of other Antarctic shelf soft-bottom waters,although the compositions of the dominant species and functional feeding groups were similar.The results of the Spearman rank correlation analysis indicated that the average biomass of the macrobenthos and the biomass of the planktophagous group in the study area were negatively correlated with the water depth,sediment grain size and silt percentage.However,these variables were clearly not strong determinants of macrobenthos assemblage structure.Many factors not measured in the study,e.g.,sediment organic matter and iceberg interference,have probably influenced the spatial distribution of macrobenthic community structure in the Prydz Bay.展开更多
An improved wave-plate demister equipped with vortex generators(VGs)has been proposed for wet flue gas desulfurization systems(WFGD)in this work.Numerical and experimental methods were used to evaluate the effect of V...An improved wave-plate demister equipped with vortex generators(VGs)has been proposed for wet flue gas desulfurization systems(WFGD)in this work.Numerical and experimental methods were used to evaluate the effect of VGs on the separation of small droplets.Five types of wave-plate demister with different VGs were analyzed.The vortex generators in question included rectangular plates,semi-elliptical plates,square tubes,round tubes,and triangular tubes,respectively.In order to explain the strengthening mechanism,the distribution of flow field,secondary flow,and droplet trajectory were shown,and the effect of VGs on the flow field in the demister was discussed in depth.The simulation results show that the separation performances of the demisters with VGs were significantly improved over that of the initial demister,and the accompanying pressure drop was small.For the vortex generators studied,the rectangular plate fully demonstrated its superior separation performance,followed by semi-elliptical plate.The strengthening effect of VGs was tested through experiments.Experimental data reveal that the average droplet diameter(D_(50))at the outlet of the demister with a vortex generator can be reduced to 23.13μm,whereas this value for the initial demister can be maintained at 32.07μm.Moreover,compared with the original demister 0.81,the overall separation efficiency of the improved demister was improved to 0.92.展开更多
基金supported by the National Science and Technology Innovation 2030 of China(2022ZD04010)the National Key Research and Development Program of China(2022YFD1200400)+2 种基金the Key Research and Development Program of Shaanxi Province,China(2022NY-158)the Ph D Start-up Fund of Northwest A&F University,China(Z1090121052)a grant from the Yang Ling Seed Industry Innovation Center,China(K3031122024).
文摘Flax(Linum usitatissimum L.)is a versatile crop and its seeds are a major source of unsaturated fatty acids.Stearoyl-acyl carrier protein desaturase(SAD)is a dehydrogenase enzyme that plays a key role in oleic acid biosynthesis as well as responses to biotic and abiotic stresses.However,the function of SAD orthologs from L.usitatissimum has not been assessed.Here,we found that two LuSAD genes,LuSAD1 and LuSAD2,are present in the genome of L.usitatissimum cultivar‘Longya 10’.Heterogeneous expression of either LuSAD1 or LuSAD2 in Arabidopsis thaliana resulted in higher contents of total fatty acids and oleic acid in the seeds.Interestingly,ectopic expression of LuSAD2 in A.thaliana caused altered plant architecture.Similarly,the overexpression of either LuSAD1 or LuSAD2 in Brassica napus also resulted in increased contents of total fatty acids and oleic acid in the seeds.Furthermore,we demonstrated that either LuSAD1 or LuSAD2 enhances seedling resistance to cold and drought stresses by improving antioxidant enzyme activity and nonenzymatic antioxidant levels,as well as reducing membrane damage.These findings not only broaden our knowledge of the LuSAD functions in plants,but also offer promising targets for improving the quantity and quality of oil,and the abiotic stress tolerance of oil-producing crops,through molecular manipulation.
基金supported by grants from the National Natural Science Foundation of China(Grant No.sU2139205,41774011,41874011)the National Key Research and Development Program of China(Grant No.2018YFC1503605)。
文摘Three M_(W)>7.0 earthquakes in 2020-2021 occurred in the Shumagin seismic gap and its adjacent area of the Alaska-Aleutian subduction zone,including the Mw7.8 Simeonof thrust earthquake on July 22,2020,the M_(W)7.6 Sand Point strike-slip earthquake on October 19,2020,and the M_(W)8.2 Chignik thrust earthquake on July 29,2021.The spatial and temporal proximity of these three earthquakes prompts us to probe stress-triggering effects among them.Here we examine the coseismic Coulomb stress change imparted by the three earthquakes and their influence on the subduction interface.Our results show that:(1)The Simeonof earthquake has strong loading effects on the subsequent Sand Point and Chignik earthquakes,with the Coulomb stress changes of 3.95 bars and 2.89 bars,respectively.The Coulomb stress change caused by the Sand Point earthquake at the hypocenter of the Chignik earthquake is merely around 0.01 bars,suggesting the negligible triggering effect on the latter earthquake;(2)The triggering effects of the Simeonof,Sand Point,and Chignik earthquakes on aftershocks within three months are not well pronounced because of the triggering rates of 38%,14%,and 43%respectively.Other factors may have played an important role in promoting the occurrence of these aftershocks,such as the roughness of the subduction interface,the complicated velocity structure of the lithosphere,and the heterogeneous prestress therein;(3)The three earthquakes caused remarkable coseismic Coulomb stress changes at the subduction interface nearby these mainshocks,with an average Coulomb stress change of 3.2 bars in the shallow region directly inwards the trench.
基金financially supported by the National Natural Science Foundation of China(Nos.52304314 and U23A20602)the Leading Talents of S&T Innovation of Hunan Province,China(No.2021RC4002)+2 种基金the Open Foundation of State Key Laboratory of Mineral Processing(No.BGRIMM-KJSKL-2024-16)the Open Foundation of Key Laboratory of Green Separation and Enrichment of Strategic Metal Mineral Resources(No.2023-02)the Fundamental Research Funds for the Central Universities of Central South University(No.2024ZZTS0008).
文摘Flotation is the most common method to obtain concentrate through the selective adsorption of collectors on target minerals to make them hydrophobic and floatable.In the hydrometallurgy of concentrate,collectors adsorbed on concentrate can damage ion-exchange resin and increase the chemical oxygen demand(COD)value of wastewater.In this work,we proposed a new scheme,i.e.,desorbing the collectors from concentrate in ore dressing plant and reusing them in flotation flowsheet.Lead nitrate and benzohydroxamic acid(Pb-BHA)complex is a common collector in scheelite flotation.In this study,different physical(stirring or ultrasonic waves)and chemical(strong acid or alkali environment)methods for facilitating the desorption of Pb-BHA collector from scheelite concentrate were explored.Single-mineral desorption tests showed that under the condition of pulp pH 13 and ultrasonic treatment for 15 min,the highest desorption rates of Pb and BHA from the scheelite concentrate were 90.48%and 63.75%,respectively.Run-of-mine ore flotation tests revealed that the reuse of desorbed Pb and BHA reduced the collector dosage by 30%for BHA and 25%for Pb.The strong alkali environment broke the chemical bonds between Pb and BHA.The cavitation effect of ultrasonic waves effectively reduced the interaction intensity between Pb-BHA collector and scheelite surfaces.This method combining ultrasonic waves and strong alkali environment can effectively desorb the collectors from concentrate and provide“clean”scheelite concentrate for metallurgic plants;the reuse of desorbed collector in flotation flowsheet can reduce reagent cost for ore dressing plants.
基金financial supports from the Key Program for International S&T Cooperation Projects of China (No. 2021YFE0106800)the National Natural Science Foundation of China (No. U2067201)+3 种基金the Leading Talents of S & T Innovation of Hunan Province, China (No. 2021RC4002)the Science Fund for Distinguished Young Scholars of Hunan Province, China (No. 2020JJ2044)the Key Research and Development Program of Hunan Province, China (No. 2021SK2043)the National 111 Project, China (No. B14034)。
文摘Chalcopyrite is the main Cu-containing mineral and cannot be separated well from pyrite using traditional xanthate collectors with large amounts of lime depressant, resulting in difficulties of the tailing treatment and associated precious metals recovery. Therefore, in this study, the green and odourless ethylenediamine tetramethylenephosphonic acid(EDTMPA) was introduced as a novel chalcopyrite collector. Flotation results from the binary mineral mixture and real ore demonstrated that EDTMPA could realize the selective separation of chalcopyrite from pyrite relative to ethyl xanthate(EX) without any depressants within the wide p H range of 6.0–11.0, and might replace the traditional high-alkaline lime process. Electrochemical and Fourier transform infrared spectra measurements indicated that the difference in adsorption performance of EDTMPA on chalcopyrite and pyrite was larger than that of EX, suggesting a better selectivity for EDTMPA. Density functional theory calculations demonstrated that there were stronger chemical bonds between P—O groups of EDTMPA and the Fe/Cu atoms on chalcopyrite in the form of a stable six-membered ring. Crystal chemistry calculations further revealed that the activity of metal atoms of chalcopyrite was higher than that of pyrite. Therefore, these basic theoretical results and practical application provide a guidance for the industrial application of EDTMPA in chalcopyrite flotation.
基金supported by the National Natural Science Foundation of China (61701260 and 62271266)the Postgraduate Research&Practice Innovation Program of Jiangsu Province (SJCX21_0255)the Postdoctoral Research Program of Jiangsu Province(2019K287)。
文摘Rice is a major food crop and is planted worldwide. Climatic deterioration, population growth, farmland shrinkage, and other factors have necessitated the application of cutting-edge technology to achieve accurate and efficient rice production. In this study, we mainly focus on the precise counting of rice plants in paddy field and design a novel deep learning network, RPNet, consisting of four modules: feature encoder, attention block, initial density map generator, and attention map generator. Additionally, we propose a novel loss function called RPloss. This loss function considers the magnitude relationship between different sub-loss functions and ensures the validity of the designed network. To verify the proposed method, we conducted experiments on our recently presented URC dataset, which is an unmanned aerial vehicle dataset that is quite challenged at counting rice plants. For experimental comparison, we chose some popular or recently proposed counting methods, namely MCNN, CSRNet, SANet, TasselNetV2, and FIDTM. In the experiment, the mean absolute error(MAE), root mean squared error(RMSE), relative MAE(rMAE) and relative RMSE(rRMSE) of the proposed RPNet were 8.3, 11.2, 1.2% and 1.6%, respectively,for the URC dataset. RPNet surpasses state-of-the-art methods in plant counting. To verify the universality of the proposed method, we conducted experiments on the well-know MTC and WED datasets. The final results on these datasets showed that our network achieved the best results compared with excellent previous approaches. The experiments showed that the proposed RPNet can be utilized to count rice plants in paddy fields and replace traditional methods.
文摘Flower development and plant architecture determine the efficiency of mechanized harvest and seed yield in Brassica napus.Although TERMINAL FLOWER 1(AtTFL1)is a regulator of flower development in Arabidopsis thaliana,the function and regulatory mechanism of TFL1 orthologs in B.napus remains unclear.Six BnTFL1 paralogs in the genome of the B.napus inbred line‘K407’showed steadily increasing expression during vernalization.CRISPR/Cas-induced mutagenesis of up to four BnTFL1 paralogs resulted in early flowering and alteration of plant architecture,whereas seed yield was not altered in BnTFL1 single,double,or triple mutants.Six BnTFL1 paralogs,but not BnaA02.TFL1,showed an additive and conserved effect on regulating flowering time,total and terminal flower number,and plant architecture.BnaA10.TFL1 regulates flower development by interacting with BnaA08.FD through the protein BnaA05.GF14nu,resulting in the transcriptional repression of floral integrator and floral meristem identity genes.These findings about the regulatory network controlling flower development and plant architecture present a promising route to modifying these traits in B.napus.
基金the National Key Research and Development Program(2021YFC2600204 and 2021YFD1800403)the Science and Technology Program of Gansu,China(20YF8NH153).
文摘Brucellosis remains one of the most common zoonoses spread worldwide,inducing enormous economic losses to the livestock industry and posing serious health threats to humans.Brucellosis re-emerged in China in the mid-1990s and reached a historically high level in 2015.The National Brucellosis Prevention and Control Plan(NBPCP)was initiated from 2016 to 2020.However,the present epidemiological status in livestock has not been elucidated,and whether Brucella variation occurred remains unclear.This study performed an extensive serological investigation in ruminant livestock from 2019 to 2021 in central Gansu Province,China.In total,11,296 samples from 337 farms were collected to detect the specific antibodies of Brucella.The yearly average serological prevalence of Brucella at the flock level and individual level declined from 11.32%to 8.26%and 1.17%to 0.57%,respectively.The apparent individuallevel seroprevalence of small and large ruminants was 0.89%and 0.52%,respectively.The brucellosis distribution has shifted from pastoral areas to agro-pastoral areas.Flock size and gender may be major risks of Brucella infection.Then,the B.melitensis TZ strain was isolated from female Tibetan sheep blood cell lysates.Phonotypical characterization demonstrated that it belongs to B.melitensis.biovar 3,and multilocus sequencing typing results indicated that it belongs to ST8.The whole genome and subsequent phylogenetic analysis demonstrated that the B.melitensis TZ strain is genetically more closely related to the B.melitensis QH61 strain.The B.melitensis TZ strain has similar growth characteristics to the B.melitensis 16 M strain.Overall,our study suggests that after strengthening control and prevention measures based on the NBPCP,there is a very low prevalence or absence of B.melitensis in the central Gansu Province of China,and the genotype of an epidemic strain of Brucella in Northwest China is relatively stable.
基金Supported by Agricultural Society Field Science and Technology Innovation Policy Guidance Program of Binzhou City (2023KTPY001).
文摘Substitutes of feed antibiotics have been a key research topic in the new stage of animal husbandry.Chinese veterinary medicine refers to decoction pieces and their preparations processed from natural plants,animals,and minerals and used for animal disease prevention and improvement of animal production performance under the guidance of Chinese veterinary pharmacy theory.Eucommia ulmoides leaf extract has many active functional components such as chlorogenic acid,E.ulmoides polysaccharides and flavonoids,which have many biological properties such as antibacterial,antioxidant,immune-regulation,sugar ester-and bone metabolism-regulation effects.This paper explored active ingredients and biological properties of E.ulmoides leaf extract,as well as its role and effects in livestock and poultry breeding,providing a scientific basis for the use of E.ulmoides leaves in livestock and poultry breeding.
基金Abbreviations： double-stranded RNA （dsRNA） ELONGATED UPPER- MOST INTERNODE （Eui）+5 种基金 gibberellin （GA） GIBBERELLIN INSENSI- TIVE DWARF （GID） overexpression （OX） RNA interference （RNAi） slender rice （SLR） wild type （WT） We are grateful to Dr Shinjiro Yamaguchi （RIKEN, Ja- pan） for critical reading of the manuscript, and to Professor Yinong Yang （Penn. State University, USA） for the rice RNAi vector. This work was supported by grants from the National Natural Science Foundation of China （30670186 and 30421001）, and the Ministry of Science and Technology of China （2006AA10A102） to ZH.
文摘The rice Eui （ELONGATED UPPERMOST INTERNODE） gene encodes a cytochrome P450 monooxygenase that deactivates bioactive gibberellins （GAs）. In this study, we investigated controlled expression of the Eui gene and its role in plant development. We found that Eui was differentially induced by exogenous GAs and that the Eui promoter had the highest activity in the vascular bundles. The eui mutant was defective in starch granule development in root caps and Eui overexpression enhanced starch granule generation and gravity responses, revealing a role for GA in root starch granule development and gravity responses. Experiments using embryoless half-seeds revealed that RAmylA and GAmyb were highly upregulated in eui aleurone ceils in the absence of exogenous GA. In addition, the GA biosynthesis genes GA3oxl and GA20ox2 were downregulated and GA2oxl was upregulated in eui seedlings. These results indicate that EUI is involved in GA homeostasis, not only in the internodes at the heading stage, but also in the seedling stage, roots and seeds. Disturbing GA homeostasis affected the expression of the GA signaling genes GID1 （GIBBERELLIN INSENSITIVE DWARF 1）, GID2 and SLR1. Transgenic RNA interference of the Eui gene effectively increased plant height and improved heading performance. By contrast, the ectopic expression of Eui under the promoters of the rice GA biosynthesis genes GA3ox2 and GA2Oox2 significantly reduced plant height. These results demonstrate that a slight increase in Eui expression could dramatically change rice morphology, indicating the practical application of the Eui gene in rice molecular breeding for a high yield potential.
基金Supplementary information is linked to the online version of the paper on the Cell Research website.Acknowledgments We thank Dr Dawei Li （China Agricultural University） for generously providing us with the experimental conditions during the early stages of this project. We thank Dr Ruiming Xu （Institute of Biophysics, Chinese Academy of Sciences） for critical reading of this manuscript and advice. We thank Dr Pinchao Mei （Chinese Academy of Medical Sciences and Peking Union Medical College）, Xinqi Liu （Nankai University） and Jiemin Wong （East China Normal University） for discussions and advice. The synchrotronradiation experiments were performed at Shanghai Synchrotron Radiation Facility （SSRF） and NE3A in the Photon Factory. Z.C. is supported by the National Basic Research Program of China （973 Program, 2009CB825501）, the National Natural Science Foundation of China （30870494 and 90919043）, the New Century Excellent Talents in University （NCET-07-0808） and the Innovative Project of SKLAB. S. H. is supported by the National Key Laboratory Special Fund 2060204. Z. D. is supported by the National Natural Science Foundation of China （J0730639）.
文摘Dynamic regulation of histone methylation/demethylation plays an important role during development. Mutations and truncations in human plant homeodomain （PHD） finger protein 8 （PHF8） are associated with X-linked mental retardation and facial anomalies, such as a long face, broad nasal tip, cleft lip/cleft palate and large hands, yet its molecular function and structural basis remain unclear. Here, we report the crystal structures of the catalytic core of PHF8 with or without α-ketoglutarate （α-KG） at high resolution. Biochemical and structural studies reveal that PHF8 is a novel histone demethylase specific for di- and mono-methylated histone H3 lysine 9 （H3K9me2/1）, but not for H3K9me3. Our analyses also reveal how human PHF8 discriminates between methylation states and achieves sequence specificity for methylated H3K9. The in vitro demethylation assay also showed that the F279S mutant observed in clinical patients possesses no demethylation activity, suggesting that loss of enzymatic activity is crucial for pathogenesis of PHF8 patients. Taken together, these results will shed light on the molecular mechanism underlying PHF8-associated developmental and neurological diseases.
文摘Objective： Apoptosis is a reliable marker of chemotherapeutic efficacy. Olaparib and paclitaxel inhibit proliferation and induce apoptosis in a variety of cancers. We investigated the effects of paclitaxel combined with olaparib on apoptosis in breast cancer Bcap37 cells. Methods： Proliferation and apoptosis were detected by MTT assay and PI staining. Degradation of procaspase-3 and poly（ADP-ribose） polymerase （PARP） was analyzed by Western blotting. Results： Compared with paclitaxel alone, paclitaxel combined with 100 mg olaparib significantly reduced survival in Bcap37 cells at all tested treatment durations （P〈0.05）; inhibition increased with increasing olaparib dose and treatment time （P〈0.01）. Combined treatment yielded significantly higher rates of apoptosis （P〈0.05）, which also increased with time （P〈0.01）. Fluorescence micrographs showed that early and late apoptotic cells increased with treatment time. Pro-caspase-3 and PARP degradation was induced by paclitaxel and enhanced by olaparib in a dose-dependent manner. Thus, combined treatment was substantially more effective than treatment with paclitaxel alone. Conclusions： Our findings suggest that paclitaxel and olaparib inhibit breast cancer Bcap37 cell proliferation and induce apoptosis. Combined treatment further reduced cell growth and enhanced apoptosis, suggesting that this combination therapy may be a promising treaunent for breast cancer.
基金supported by the funding from the National Natural Science Foundation of China(grant nos.51902187,52072224,and 51732007)the Natural Science Foundation of Shandong Province(ZR2018BEM010)+3 种基金the Science Fund for Distinguished Young Scholars of Shandong Province(ZR2019JQ16)the Fundamental Research Funds of Shandong UniversityYoung Elite Scientist Sponsorship Program by CAST(YESS)the support from Collaborative Innovation Center of Technology and Equipment for Biological Diagnosis and Therapy in Universities of Shandong
文摘Driven by safety issues,environmental concerns,and high costs,rechargeable aqueous zinc-ion batteries(ZIBs)have received increasing attention in recent years owing to their unique advantages.However,the sluggish kinetics of divalent charge Zn^(2+)in the cathode materials caused by the strong electrostatic interaction and their unsatisfactory cycle life hinder the development of ZIBs.Herein,organic cations and Zn^(2+)ions co-pre-inserted vanadium oxide([N(CH_(3))_(4)]_(0.77),Zn_(0.23))V_(8)O_(20)·3.8H_(2)O are reported as the cathode for ultra-stable aqueous ZIBs,in which the weaker electrostatic interactions between Zn^(2+)and organic ion-pinned vanadium oxide can induce the high reversibility of Zn^(2+)insertion and extraction,thereby improving the cycle life.It is demonstrated that([N(CH_(3))_(4)]_(0.77),Zn_(0.23))V_(8)O_(20)·3.8H_(2)O cathodes deliver a discharge capacity of 181 mA h g^(-1)at8 A g^(-1)and ultra-long life span(99.5%capacity retention after 2000 cycles).A reversible Zn^(2+)/H^(+)ions(de)intercalation storage process and pseudocapacitive charge storage are characterized.The weaker interactions between organic ion and Zn^(2+)open a novel avenue for the design of highly reversible cathode materials with long-term cycling stability.
文摘In the past 20 years, great progress has been achieved in China in the construction of concrete-filled steel tube （CFST） arch bridges and concrete arch bridges with a CFST skeleton. The span of these bridges has been increasing rapidly, which is rare in the history of bridge development. The large-scale construction of expressways and high-speed railways demands the development of long-span arch bridges, and advances in design and construction techniques have made it possible to construct such bridges. In the present study, the current status, development, and major innovative technologies of CFST arch bridges and concrete arch bridges with a CFST skeleton in China are elaborated. This paper covers the key con- struction technologies of CFST arch bridges, such as the design, manufacture, and installation of steel tube arch trusses, the preparation and pouring of in-tube concrete, and the construction of the world＇s longest CFST arch bridge-the First Hejiang Yangtze River Bridge. The main construction technologies of rein- forced concrete arch bridges are also presented, which include cable-stayed fastening-hanging cantilever assembly, adjusting the load by means of stay cables, surrounding the concrete for arch rib pouring, and so forth. In addition, the construction of two CFST skeleton concrete arch bridges-the Guangxi Yongning Yong River Bridge and the Yunnan-Guangxi Railway Nanpan River Bridge--is discussed. CFST arch bridges in China have already gained a world-leading position; with the continuous innovation of key technologies, China will become the new leader in promoting the development of arch bridges.
基金supported by the National Natural Science Foundation of China (NSFC, No.30770312)
文摘Nest-site and nesting material used by the Chinese alligator （Alligator sinensis） was studied at the Gaojingmiao Breeding Farm, Langxi County, Anhui, China from May to September 2009. In this study, artificial nesting materials were placed in 43 potential nesting sites before the nesting season, 11 of which were used. Additionally, eight nests were built at natural sites without artificial nesting materials provided. Seven environmental variables were measured at each nest site： distance from water, height from water surface, sunlight duration, nearest bank slope, nest site slope, vegetation coverage and concealment. Statistical analyses indicated that concealment was significantly different between used and unused nest sites, with concealment being significantly correlated to the use of materials- placed sites. In comparing the nests at artificial vs. natural sites, only the nearest bank slope differed significantly. Further, principal component analysis of natural nests indicated that the duration of nest exposure to sunlight and vegetation coverage were more influential than the other factors studied.
基金funded by the National Natural Science Foundation of China(61872139,41871320)Provincial and Municipal Joint Fund of Hunan Provincial Natural Science Foundation of China(2018JJ4052)+2 种基金Hunan Provincial Natural Science Foundation of China(2017JJ2081)the Key Project of Hunan Provincial Education Department(17A070,19A172)the Project of Hunan Provincial Education Department(17C0646).
文摘Cruising route recommendation based on trajectory mining can improve taxi-drivers'income and reduce energy consumption.However,existing methods mostly recommend pick-up points for taxis only.Moreover,their performance is not good enough since there lacks a good evaluation model for the pick-up points.Therefore,we propose an entropy-based model for recommendation of taxis'cruising route.Firstly,we select more positional attributes from historical pick-up points in order to obtain accurate spatial-temporal features.Secondly,the information entropy of spatial-temporal features is integrated in the evaluation model.Then it is applied for getting the next pick-up points and further recommending a series of successive points.These points are constructed a cruising route for taxi-drivers.Experimental results show that our method is able to obviously improve the recommendation accuracy of pick-up points,and help taxi-drivers make profitable benefits more than before.
文摘To explore the spatial pattern of macrobenthic communities and their response to environmental factors in the Prydz Bay,samples were collected using a 0.25-m2 box corer at 10 stations from November 2012 to April 2013.A total of 50 species of macrobenthos belonging to 8 phyla and 33 families were identified,of which polychaetes(e.g.,Maldane sarsi)and sponges(e.g.,Halichondria sp.and Leucosolenia sp.)were the most prominent groups.The macrobenthos in study area were categorized into five functional groups based on the feeding type,and the detritivorous group represented by polychaetes showed the highest average abundance,while the planktophagous group represented by sponges showed the highest average biomass.Macrobenthos abundance(0–592 ind./m2)and biomass(0–1155.5 g/m2)in the Prydz Bay were relatively lower than those of other Antarctic shelf soft-bottom waters,although the compositions of the dominant species and functional feeding groups were similar.The results of the Spearman rank correlation analysis indicated that the average biomass of the macrobenthos and the biomass of the planktophagous group in the study area were negatively correlated with the water depth,sediment grain size and silt percentage.However,these variables were clearly not strong determinants of macrobenthos assemblage structure.Many factors not measured in the study,e.g.,sediment organic matter and iceberg interference,have probably influenced the spatial distribution of macrobenthic community structure in the Prydz Bay.
基金This work was supported by the Foundation of key Laboratory of Space Utilization,Technology and Engineering Center for Space Utilization,Chinese Academy of Sciences(CSU-QZKT-2018-09)Open Project of Beijing Key Laboratory of Measurement and Control of Mechanical and Electrical System under Grant No.KF20181123205.
文摘An improved wave-plate demister equipped with vortex generators(VGs)has been proposed for wet flue gas desulfurization systems(WFGD)in this work.Numerical and experimental methods were used to evaluate the effect of VGs on the separation of small droplets.Five types of wave-plate demister with different VGs were analyzed.The vortex generators in question included rectangular plates,semi-elliptical plates,square tubes,round tubes,and triangular tubes,respectively.In order to explain the strengthening mechanism,the distribution of flow field,secondary flow,and droplet trajectory were shown,and the effect of VGs on the flow field in the demister was discussed in depth.The simulation results show that the separation performances of the demisters with VGs were significantly improved over that of the initial demister,and the accompanying pressure drop was small.For the vortex generators studied,the rectangular plate fully demonstrated its superior separation performance,followed by semi-elliptical plate.The strengthening effect of VGs was tested through experiments.Experimental data reveal that the average droplet diameter(D_(50))at the outlet of the demister with a vortex generator can be reduced to 23.13μm,whereas this value for the initial demister can be maintained at 32.07μm.Moreover,compared with the original demister 0.81,the overall separation efficiency of the improved demister was improved to 0.92.
