Heterogeneous expression of stearoyl-acyl carrier protein desaturase genes SAD1 and SAD2 from Linum usitatissimum enhances seed oleic acid accumulation and seedling cold and drought tolerance in Brassica napus

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.

Coseismic Coulomb stress changes induced by a 2020-2021 M_(W)>7.0 Alaska earthquake sequence in and around the Shumagin gap and its influence on the Alaska-Aleutian subduction interface

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.

Efficient desorption and reuse of collector from the flotation concentrate:A case study of scheelite

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.

曲妥珠单抗和帕妥珠单抗联合不同化疗方案新辅助治疗HER-2阳性乳腺癌真实世界疗效及安全性观察

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。

Ethylenediamine tetramethylenephosphonic acid as a selective collector for the improved separation of chalcopyrite against pyrite at low alkalinity

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.

RPNet: Rice plant counting after tillering stage based on plant attention and multiple supervision network

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.

The BnTFL1–BnGF14nu–BnFD module regulates flower development and plant architecture in Brassica napus

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.

Enzootic epidemiology of Brucella in livestock in central Gansu Province after the National Brucellosis Prevention and Control Plan

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.

Role and Effects of Eucommia ulmoides Leaves in the Growth Process of Livestock and Poultry

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.

Gibberellin homeostasis and plant height control by EUI and a role for gibberellin in root gravity responses in rice

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.

Structural insights into a novel histone demethylase PHF8

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.

甘露特钠胶囊联合盐酸多奈哌齐片治疗痴呆患者的临床疗效及安全性

目的:评价甘露特钠胶囊联合盐酸多奈哌齐片治疗痴呆患者的临床疗效及安全性。方法:将60例痴呆患者按随机数表法分为对照组与联合治疗组,每组各30例。对照组患者开始每天口服1次盐酸多奈哌齐片5 mg,1个月后改为每天10 mg;联合治疗组患者开始每天口服2次甘露特钠胶囊(450 mg/次),同时口服1次盐酸多奈哌齐片5 mg,1个月后将多奈哌齐剂量升至10 mg/d,2组患者均给药治疗12个月。分别采用简易精神状态检查量表(MMSE)评分和日常生活能力量表(ADL)评分评价2组患者治疗前后的认知功能和日常生活能力,根据血脂联素、Reptin、血清淀粉样蛋白A(SAA)指标的变化评价患者治疗前后的营养指标及免疫指标水平。通过观察2组患者用药后发生的不良反应,评价2种用药方案的安全性。结果:治疗12个月后,2组患者的认知功能和日常生活能力均有不同程度的改善,但联合治疗组患者MMSE评分(20.01±4.40)、ADL评分(62.20±10.04)均明显高于治疗前(16.30±3.18)、(52.13±7.28),也明显高于对照组(17.86±3.08)、(58.08±8.98),差异均有统计学意义(P均<0.05);联合治疗组患者血脂联素(20.32±5.43)明显高于治疗前(12.30±3.26),也明显高于对照组(13.21±5.12)(P均<0.05);Reptin(4.56±0.98)、SAA(5.28±2.18)水平明显低于治疗前(22.74±6.27)、(9.1±2.10),也明显低于对照组(16.13±2.01)、(7.26±2.26)(P均<0.05)。治疗后,2组患者心电图、血尿常规、肝肾功能均无明显异常,也未发生头晕乏力、嗜睡、胃肠道等不良反应。结论:与单用盐酸多奈哌齐片相比,甘露特钠胶囊联合盐酸多奈哌齐片对痴呆具有更好的临床疗效,且安全性良好。

PARP inhibitor reduces proliferation and increases apoptosis in breast cancer cells

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.

Weaker Interactions in Zn^(2+)and Organic Ion-pre-intercalated Vanadium Oxide toward Highly Reversible Zinc-ion Batteries

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.

Concrete-Filled Steel Tube Arch Bridges in China

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.

Nest-site Use by the Chinese Alligator (Alligator sinensis) in the Gaojingmiao Breeding Farm,Anhui,China

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.

An Entropy-Based Model for Recommendation of Taxis’Cruising Route

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.

Macrobenthic communities on the continental shelf of the Prydz Bay, East Antarctica

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.

Experimental and numerical analysis of a demister with vortex generators

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.