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Identification of vortex boundaries in two-dimensional incompressible flows based on the Liutex-shear interaction

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Journal of Hydrodynamics 2023年第5期35卷 825-831页

作者： Bi-yu Pang Zhang-dan Yu Bo-wen Yan Yi-qian wang Chaoqun Liu School of Mathematical Sciences Soochow UniversitySuzhou215006China Department of Computer Science and Technology Tsinghua UniversityBeijing100084China Department of Mathematics University of Texas at ArlingtonArlington76019USA

According to the Liutex-shear decomposition,vorticity can be decomposed into a rotational part,i.e.,the Liutex vector,and a residual shear *** this decomposition,the vorticity transport equation can be used to formulate a governing equation for Liutex easily for two-dimensional incompressible flows with a source term depending on the residual *** dynamics of Liutex-identified structures is then studied in a Taylor-Green vortex flow and a flow past a cylinder at Reynolds number of *** is revealed that such boundaries exist outside which the shear has trivial impact on the evolution of Liutex and inside which enhancing and weakening effects of shear on Liutex can be *** addition,there is a strong dissipation effect upon Liutex on these *** on the interaction mechanism between Liutex and shear,we argue that the vortex boundaries can be identified by these highly dissipative *** contrast,traditional methods use iso-surfaces of arbitrarily selected thresholds to represent vortex *** current method of identifying vortex boundaries based on the Liutex-shear interaction has a clearer theoretical base and avoids the arbitrary selection of *** to three-dimensional incompressible flows can be made in future following the same procedure but with a slightly more complex vorticity transport equation which includes the velocity gradient induced stretching or tilting term.

关键词： Vortex boundary identification Liutex residual shear Taylor-Green vortex cylinder flow

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Geoscience Frontiers 2022年第1期13卷 217-229页

作者： Liang Han Lin wang Xuanming Ding Haijia wen Xingzhong Yuan wengang Zhang School of Civil Engineering Chongqing UniversityChongqing 400045China Key Laboratory of New Technology for Construction of Cities in Mountain Area Chongqing UniversityChongqing 400045China National Joint Engineering Research Center of Geohazards Prevention in the Reservoir Areas Chongqing UniversityChongqing 400045China

This paper presents a confidence ellipse-based method to evaluate the similarity of soil parametric data using the database from the site investigation ***,the obtained similarity assessment results of parametric data are used to further estimate the site similarity via two proposed strategies,namely the mean and weighted mean *** former referred to the average of parametric data similarity degrees,while the latter was the weighted average,and the weight was calculated using the coefficient of variation(COV)of each *** illustration,the liquidity index(LI)dataset was firstly used to explore the performance of the presented method in the evaluation of parametric data ***,the site similarity was assessed and the effects of numbers and weights of selected parameters for study were systematically ***,the transformation models about the relationships between Cc and x as well as between Cc and e0 were constructed to illustrate the application of the similarity analysis in reduction of transformation *** show that the greatest site similarity degree is at about 0.76 in this study,and the maximum decrease of transformation uncertainty can reach up to 18%and 25.5%as union parametric data similarity degree ***,the site similarity degree represents the whole similarity between two different sites,and the presented union parameter similarity degree maintains a good agreement with transformation uncertainty.

关键词： Soil parameters Site Confidence ellipse Similarity

Preparation of SiO_2 microspheres with sodium ions and self-assembly of photonic crystals

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Chinese Science Bulletin 2010年第8期55卷 766-770页

作者： LIU LiYing wang XiuFeng ZHANG ChunXiang cheng Bing School of Materials Science and Engineering Shaanxi University of Science and Technology Xi' an 710021 China

SiO2 microspheres were prepared via a novel co-precipitation *** Na + ions were introduced by adding sodium chloride and metal sodium in solution systems for improving surface charge of the SiO2 *** then SiO2 photonic crystals were fabricated by the vertical deposition *** electrical properties,micromorphology and optical properties were characterized by zeta potential instrument,scanning electron microscope (SEM) with energy dispersive X-ray spectroscopy and Uv-Vis-Nir *** potential of the SiO2 microspheres modified by sodium chloride and metal sodium were averagely heightened 11.39 mV and 13.52 mV respectively in ethanol *** spectra showed that there was Na element in the SiO2 *** images showed that the average size of the SiO2 microspheres modified by sodium chloride and metal sodium were 380 nm and 354 nm respectively,larger than that of the unmodified ones,and their distribution standard deviation was less than 5%,and the sample of SiO2 photonic crystals was face-centered cubic structure with their (111) planes parallel to the *** addition,absorption spectra showed that photonic band gap of the SiO2 photonic crystals was modified by sodium chloride and metal sodium located in 856 nm and 798 nm ***,their absorption peaks became narrower and higher and exhibited a red-shift phenomenon.

关键词：二氧化硅微球光子晶体钠离子自我组装制备扫描电子显微镜红外分光光度计 X射线光谱

Nanobodies with cross-neutralizing activity provide prominent therapeutic efficacy in mild and severe COVID-19 rodent models

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Virologica Sinica 2023年第5期38卷 787-800页

作者： Qiuxue Han Shen wang Zhenshan wang cheng Zhang Xinyue wang Na FengTiecheng wang Yongkun Zhao Hang Chi Feihu Yan Xianzhu Xia Institute of Laboratory Animal Sciences Chinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing100021China Changchun Veterinary Research Institute Chinese Academy of Agricultural SciencesChangchun132122China Jiangsu Co-innovation Centre for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses Yangzhou225009China

The weakened protective efficacy of COVID-19 vaccines and antibodies caused by SARS-CoV-2 variants presents a global health emergency,which underscores the urgent need for universal therapeutic antibody intervention for clinical ***,we screened three alpacas-derived nanobodies(Nbs)with neutralizing activity from twenty RBD-specific *** three Nbs were fused with the Fc domain of human IgG,namely aVHH-11-Fc,aVHH-13-Fc and aVHH-14-Fc,which could specifically bind RBD protein and competitively inhibit the binding of ACE2 receptor to *** effectively neutralized SARS-CoV-2 pseudoviruses D614G,Alpha,Beta,Gamma,Delta,and Omicron sub-lineages BA.1,BA.2,BA.4,and BA.5 and authentic SARS-CoV-2 prototype,Delta,and Omicron BA.1,BA.2 *** mice-adapted COVID-19 severe model,intranasal administration of aVHH-11-Fc,aVHH-13-Fc and aVHH-14-Fc effectively protected mice from lethal challenges and reduced viral loads in both the upper and lower respiratory *** the COVID-19 mild model,aVHH-13-Fc,which represents the optimal neutralizing activity among the above three Nbs,effectively protected hamsters from the challenge of SARS-CoV-2 prototype,Delta,Omicron BA.1 and BA.2 by significantly reducing viral replication and pathological alterations in the *** structural modeling of aVHH-13 and RBD,aVHH-13 binds to the receptor-binding motif region of RBD and interacts with some highly conserved *** together,our study illustrated that alpaca-derived Nbs offered a therapeutic countermeasure against SARS-CoV-2,including those Delta and Omicron variants which have evolved into global pandemic strains.

关键词： COVID-19 SARS-CoV-2 Nanobody Broad-spectrum Therapeutic Rodent models

Healing Behavior of Micropores in Powder Metallurgy 316L Stainless Steel during Hot Forging and Heat Treatment

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Journal of Iron and Steel Research International 2014年第9期21卷 862-868页

作者： Ying KAN Shi-hong ZHANG Li-wen ZHANG Ming cheng Hong-wu SONG Hong-wei LU School of Materials Science and Engineering Dalian University of Technology Institute of Metal Research Chinese Academy of Sciences Forge Plant Angang Heavy Machine Co.Ltd.

The healing behavior of micropores in powder metallurgy （P/M） 316L stainless steel during hot forging and subsequent heat treatment was studied. The results showed that hot forging can improve the homogeneity of the pore size and enhance the relative density of material in varying degree due to different forging temperatures. As a re- sult of deformation and diffusion bonding at high temperature, the irregular pores were spheroidized and finally turned into stable inner grain pores. The comparison of compression behavior between P/M and wrought dense mate rials has shown that the pores can either be the obstacles of dislocation movement or be the nucleation sites accelera- ting the reerystallization according to the difference of deformation temperatures.

关键词： powder metallurgy 316L stainless steel microstructural evolution densification behavior micropore

A Nomogram Model for Prediction of Mortality Risk of Patients with Dangerous Upper Gastrointestinal Bleeding:A Two-center Retrospective Study

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Current Medical Science 2023年第4期43卷 723-732页

作者： Zhou LIU Liang ZHANG Guang LI wen-hui BAI Pei-xue wang Gui-jun JIANG Ji-xiang ZHANG Li-ying ZHAN Li cheng Wei-guo DONG Department of Intensive Care Unit Renmin Hospital of Wuhan UniversityWuhan 430060China Department of Radiology Renmin Hospital of Wuhan UniversityWuhan 430060China Department of Hepatobiliary Surgery Renmin Hospital of Wuhan UniversityEastern CampusWuhan 430200China Department of Gastroenterology The First People's Hospital of JingzhouJingzhou 434000China Department of Gastroenterology Renmin Hospital of Wuhan UniversityWuhan 430060China Department of Intensive Care Unit Renmin Hospital of Wuhan UniversityEastern CampusWuhan 430200China

Objective:This study aimed to establish a nomogram model to predict the mortality risk of patients with dangerous upper gastrointestinal bleeding(DUGIB),and identify high-risk patients who require emergent ***:From January 2020 to April 2022,the clinical data of 256 DUGIB patients who received treatments in the intensive care unit(ICU)were retrospectively collected from Renmin Hospital of Wuhan University(n=179)and the Eastern Campus of Renmin Hospital of Wuhan University(n=77).The 179 patients were treated as the training cohort,and 77 patients as the validation *** regression analysis was used to calculate the independent risk factors,and R packages were used to construct the nomogram *** prediction accuracy and identification ability were evaluated by the receiver operating characteristic(ROC)curve,C index and calibration *** nomogram model was also simultaneously externally *** curve analysis(DCA)was then used to demonstrate the clinical value of the ***:Logistic regression analysis showed that hematemesis,urea nitrogen level,emergency endoscopy,AIMS65,Glasgow Blatchford score and Rockall score were all independent risk factors for *** ROC curve analysis indicated the area under curve(AUC)of the training cohort was 0.980(95%CI:0.962-0.997),while the AUC of the validation cohort was 0.790(95%CI:0.685-0.895).The calibration curves were tested for Hosmer-Lemeshow goodness of fit for both training and validation cohorts(P=0.778,P=0.516).Conclusion:The developed nomogram is an effective tool for risk stratification,early identification and intervention for DUGIB patients.

关键词： acute upper gastrointestinal bleeding mortality risk factors nomogram model prognosis

Combination of western medicine and Chinese traditional patent medicine in treating a family case of COVID-19

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Frontiers of Medicine 2020年第2期14卷 210-214页

作者： Li Ni Ling Zhou Min Zhou Jianping Zhao Dao wen wang Division of Cardiology Department of Internal Medicine and Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological DisordersTongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China Division of Respiration Department of Internal Medicine and Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological DisordersTongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China

In December 2019,an outbreak of novel coronavirus(2019-nCoV)occurred in Wuhan,Hubei Province,*** February 14,2020,it has led to 66492 confirmed patients in China and high mortality up to^2.96%(1123/37914)in *** we report the first family case of coronavirus disease 2019(COVID-19)confirmed in Wuhan and treated using the combination of western medicine and Chinese traditional patent medicine Shuanghuanglian oral liquid(SHL).This report describes the identification,diagnosis,clinical course,and management of three cases from a family,suggests the expected therapeutic effects of SHL on COVID-19,and warrants further clinical trials.

关键词： novel coronavirus(2019-nCoV) COVID-19 Chinese traditional patent medicine Shuanghuanglian oral liquid

Particle transport behavior in air channel flow with multi-group Lagrangian tracking

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Chinese Physics B 2017年第1期26卷 267-277页

作者： Hao Lu wen-Jun Zhao Hui-Qiang Zhang Bing wang Xi-Lin wang School of Aerospace Engineering Tsinghua University Beijing 100084 China Faculty of Architecture The University of Hong Kong Hong Kong China

The particle motions of dispersion and transport in air channel flow are investigated using a large eddy simulation（LES） and Lagrangian trajectory method. The mean and fluctuating velocities of the fluids and particles are obtained,and the results are in good agreement with the data in the literature. Particle clustering is observed in the near-wall and low-speed regions. To reveal the evolution process and mechanism of particle dispersion and transport in the turbulent boundary layer, a multi-group Lagrangian tracking is applied when the two-phase flow has become fully developed： the fluid fields are classified into four sub-regions based on the flow characteristics, and particles in the turbulent region are divided accordingly into four groups when the gas–particle flow is fully developed. The spatiotemporal transport of the four groups of particles is then tracked and analyzed. The detailed relationship between particle dispersion and turbulent motion is investigated and discussed.

关键词： particle-laden flows channel flow large-eddy simulations coherent structures

Differences of Physicochemical Properties Between Chalky and Translucent Parts of Rice Grains

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Rice science 2022年第6期29卷 577-588,I0036-I0038页

作者： wang Cuili GUO wen HU Peisong WEI Xiangjin TANG Shaoqing JIAO Guiai State Key Laboratory of Rice Biology China National Rice Research InstituteHangzhou 310006China

Rice grain chalkiness is an important characteristic,but the difference between chalky and translucent parts in grains is still ***,we investigated the differences of flour made from the chalky or translucent part of rice grains in three indica and three japonica rice *** chalky flour had significantly lower amylose and protein contents and looser starch granule morphology,and starches in the chalky flour had higher relative crystallinity,higher short chain content but lower long chain content than those in the translucent *** water states,determined with nuclear magnetic resonance,differed between the chalky and translucent flour after soaking,cooking and retrograding,and the chalky flour had more bound and free water but less constructural water than the translucent ***,the chalky flour had lower viscosity and shorter gel consistency,but higher onset temperature and gelatinization enthalpy than the translucent *** results indicated that starch granule morphology would be more indicative than other attributions on pasting and gelatinization properties of chalky and translucent parts of rice grains.

关键词： chalkiness starch structure water state pasting property gelatinization characteristic