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Debris falling forecast method for spacecraft disintegrating separation

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Astrodynamics 2023年第4期7卷 455-463页

作者： Dun Li Zhi-Hui Li Yue-Long He Jing-Jiang Chu Yu Jiang China Academy of Aerospace Aerodynamics Beijing 100074China China Aerodynamics Research&Development center Mianyang 621000China National Laboratory for CFD Beihang UniversityBeijing 100191China State Key Laboratory of Astronautic Dynamics Xi'an Satellite Control CenterXi'an 710043China

Large spacecraft fall out of orbit and re-enter the atmosphere at the end of their lifetime,and they can break up into small debris upon *** spacecraft debris generated by the disintegration may lead to high risk when the surviving debris reaches the *** way to reduce the damage risk of spacecraft is to simulate the spacecraft disintegration process and accurately predict the falling *** seriously affects the reentering process,especially in the continuous flow *** force and heat are the main factors leading to debris *** dynamic pressure leads to sharp changes in attitude and complex trajectories during debris fall.A numerical method based on an unstructured Cartesian grid was developed to simulate the disintegrating separation problem by coupling the Navier-Stokes equation and the six-degree-of-freedom trajectory equation.A method combining the numerical method for dynamic processes with numerical simulation based on a static aerodynamic/dynamic characteristic database was developed for forecasting the falling *** disintegrating separation from 60 km was simulated using the method,and the multibody aerodynamic interference and the separation trajectory were *** falling process was forecast by a numerical simulation method based on the static aerodynamic database/dynamic characteristic database when the debris went out of the influence *** method has good forecasting efficiency while considering the aerodynamic interference,making it a valuable method for forecasting disintegrating separation and falling debris.

关键词： disintegrating separation numerical simulation separation trajectory falling forecast

Investigation of iodine concentration in salt,water and soil along the coast of Zhejiang,China

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2005年第12期6卷 1200-1205页

作者：陆颖理王宁荐朱岚王国兴吴晖匡琳朱文明 Department of Endocrinology Sir Run Run Shaw Hospital School of Medicine Zhejiang University Hangzhou 310016 China disease control center Hangzhou 310006China

Objective: We aim to describe the environment iodine concentration in salt, water and soil along Zhejiang Province coast in the China foreland. It will be helpful for us to judge whether this area is insufficient in iodine and universal iodized salt is necessary or not. Methods: We collected iodized salt samples, drinking water samples (tap water in the towns, and well water or spring water in the villages), water samples from different sources (ditches, lakes, rivers) and soil samples through random sampling in June, 2005. Salt, water and soil iodine was detected by arsenic-cerium redox method. Statistical analysis was expressed as mean±SEMby Windows SPSS 13.0. Results: (1) The iodine concentration in salt was 27.9±4.33 mg/kg (n=108). (2) Seventy-five water samples were collected. The water iodine value was 0.6～84.8 μg/L (mean of 11.66 μg/L). The watershed along the Qiantang River has significantly higher iodine content than the water in Lin'an in mountain area (P＜0.01). The iodine content and mean iodine content of tap water, well or spring water and natural water sources were 4.30±2.43 μg/L (n=34), 23.59±27.74 μg/L (n=19)and 12.72±10.72 μg/L (n=22) respectively. This indicated that among environmental water sources, the ditch iodine content was the highest with river water iodine being the lowest (P＜0.01). (3) Soil iodine value was 0.11～2.93 mg/kg (mean of 1.32 mg/kg).Though there was no statistical difference of soil iodine in different districts (P=0.131), soil iodine content correlated positively with water iodine content. Conclusion: Iodine concentration in salt accords with national policy of adding iodine in salt. Foreland has more iodine in water than mountain area. The data reflected that water and soil iodine in foreland area was not high, which suggests universal iodized salt should be necessary. Environment iodine has relatively close association with pollution.

关键词：甲状腺疾病症状预防措施碘盐含碘量

QSAR Models for Predicting Additive and Synergistic Toxicities of Binary Pesticide Mixtures on Scenedesmus Obliquus

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Chinese Journal of Structural Chemistry 2022年第3期41卷 166-177,I0011页

作者：莫凌云袁柏康朱杰覃礼堂代俊峰 College of Environmental Science and Engineering Guilin University of TechnologyGuilin 541004China Guangxi Key Laboratory of Environmental Pollution control Theory and Technology Guilin University of TechnologyGuilinGuangxi 541004China Technical Innovation center of Mine Geological Environmental Restoration Engineering in Southern Karst Area MNRNanning 530023China Guangxi Collaborative Innovation center for Water Pollution control and Water Safety in Karst Area Guilin University of TechnologyGuilin 541004China

Pesticides released into the environment may pose potential risks to the ecological system and hu-man ***,existing toxicity data on pesticide mixtures still lack,especially regarding the toxic interac-tions of their *** study aimed to determine the toxic interactions of binary mixtures of pesticides on Scenedesmus Obliquus(***)and to build quantitative structure-activity relationship models(QASR)for predicting the mixture *** applying direct equipartition ray method to design binary mixtures of five pes-ticides(linuron,dimethoate,dichlorvos,trichlorfon and metribuzin),the toxicity of a single pesticide and its mix-ture was tested by microplate toxicity analysis on *** QASR models were built for combined toxicity of binary mixtures of pesticides at the half-maximal effective concentration(EC_(50)),30%maximal effective concen-tration(EC_(30))and 10%maximal effective concentration(EC_(10)).The results showed that the single toxicity follows:metribuzin>linuron>dichlorvos>trichlorfon>*** mixtures of linuron and trichlorfon,dichlorvos and metribuzin,dimethoate and metribuzin induced synergetic effects,while the remaining binary mixtures exhib-ited *** developed QSAR models were internally validated using the leave-one-out cross-validation(LOO),leave-many-out cross-validation(LMO),bootstrapping,and y-randomization test,and externally validated by the test *** three QSAR models satisfied well with the experimental values for all mixture toxicities,and presented high internally(R^(2)and Q^(2)>0.85)and externally(Q^(2)_(F1),Q^(2)_(F2),and Q^(2)_(F3)>0.80)predictive *** developed QSAR models could accurately predict the toxicity values of EC_(50),EC_(30)and EC_(10)and were superior to the concentration addition model's results(CA).Compared to the additive effect,the QSAR model could more ac-curately predict the binary mixture toxicities of pesticides with synergistic effects.

关键词： pesticide QSAR toxicity prediction binary mixture algae

Genetic Analysis of the Entire Genome of a A/duck/Shanghai/Y20/2006 (H4N6) Avian Influenza Virus

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Animal Husbandry and Feed Science 2013年第2期5卷 68-72页

作者： YANG De-quan GE Fei-fei LIU Jian JU Hou-bin WANG Jian LIU Pei-hong ZHOU Jin-ping Shanghai Animal disease control center

[ Objective] This paper aimed to investigate the origin, characteristics and molecular evolution of duck derived H4N6 subtype avian influ- enza virus （DK/SH/Y20/06） and enrich the epidemiologic data of the waterfowl origin AIV. [Method] The entire genome of DK/SH/Y20/06 was amplified and subjected to genome sequencing. The molecular software was used for sequence analysis and phylogenetic tree construction of DK/ SH/Y20/06 with some other reference sequences in GenBank. [Result] The results indicated that the amino acid sequence adjacent to HA cleav- age site was PEKASR ↓ GLF, which was the typical characteristics of the LPAIV. The phylogenetic analysis indicated that the HA gene of the isolate was derived from the Eurasian lineage in the eastern hemisphere. The NA gene was at the same branch with A/rnallard/Yan chen/2005（ H4N6）, sharing 98.3% sequence identity. The PB2, PB1, NP and PA gene of this isolate had genetically close relationships with H6 subtype AIV which is epidemic in China at present. The M gene fell into the same branch with A/environment/Korea/CSM05/2004（ H3N1 ）. The NS segment had the highest similarity with A/wild duck/Korea/YS44/2004（H1N2）. The eight genes were not at the same branch and shared a low similarity with other H4N6 subtype avian influenza viruses isolated in North America. [Condusion] These data showed that DK/SH/Y20/06（H4N6） was possibly a re- combinant virus derived from H4N6 subtype, H6N2, H6N5, H3N1 and H1 N2 subtype AIV by complex gene recombination in duck.

关键词： Duck derived avian influenza virus H4N6 subtype Whole genome sequence Gene tic evolution analysis Gene recombination.

A new visual investigation into nanogold-based genechip assay by atomic force and scanning tunneling microscope

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Chinese Optics Letters 2010年第10期8卷 964-965页

作者：顾大勇谢伟东李震鲁卫平周元国季明辉 Research Institute of disease control and Prevention Shenzhen Internation Travel Healthcare Center Shenzhen Entry-Exit Inspection and Quarantine Bureau Life Science Division Graduate School at Shenzhen Tsinghua University Department of Chemical Defence Navy Submarine Academy PLA Department 7 Research Institute of Surgery and Daping Hospital The Third Military Medical University Research Institute of disease control and Prevention Shenzhen Entry-Exit Inspection and Quarantine Bureau

Conformations of surface atoms in various stages of nanogold-based genechip testing are scanned by the atomic force and scanning tunneling microscope. We intuitively observe the process and differences in probe combination, nucleic acid hybridization, and silver staining, which might be useful to validate the assay method of genechip. We hope to use this technology to make the other invisible chemical or biochemical reaction become visible and convincible in the future.

关键词： Microscopes Nucleic acids Surface testing

Genetic diversity of Plasmodium vivax revealed by the merozoite surface protein-1 icb5-6 fragment

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Infectious diseases of Poverty 2017年第1期6卷 801-809页

作者： Wei Ruan Ling-ling Zhang Yan Feng Xuan Zhang Hua-liang Chen Qiao-yi Lu Li-nong Yao Wei Hu Department of Communicable diseases of control and Prevention Zhejiang Provincial Centre for Disease Control and PreventionHangzhouChina School of Life Sciences FuDan UniversityShanghaiChina

Background:Plasmodium vivax remains a potential cause of morbidity and mortality for people living in its endemic *** the genetic diversity of *** from different regions is valuable for studying population dynamics and tracing the origins of *** PvMSP-1 gene is highly polymorphic and has been used as a marker in many *** population *** aim of this study was to investigate the genetic diversity of the PvMSP-1 gene icb5-6 fragment and to provide more genetic polymorphism data for further studies on *** population structure and tracking of the origin of clinical ***:Nested PCR and sequencing of the PvMSP-1 icb5-6 marker were performed to obtain the nucleotide sequences of 95 *** isolates collected from Zhejiang province,*** investigate the genetic diversity of PvMSP-1,the 95 nucleotide sequences of the PvMSP-1 icb5-6 fragment were genotyped and analyzed using DnaSP v5,MEGA ***:The 95 *** isolates collected from Zhejiang province were either indigenous cases or imported cases from different regions around the world.A total of 95 sequences ranging from 390 to 460 bp were *** 95 sequences were genotyped into four allele-types(Sal I,Belem,R-III and R-IV)and 17 unique haplotypes.R-III and Sal I were the predominant *** haplotype diversity(Hd)and nucleotide diversity(Pi)were estimated to be 0.729 and 0.062,indicating that the PvMSP-1 icb5-6 fragment had the highest level of polymorphism due to frequent recombination processes and single nucleotide *** values of dN/dS and Tajima’s D both suggested neutral selection for the PvMSP-1icb5-6 *** addition,a rare recombinant style of R-IV type was ***:This study presented high genetic diversity in the PvMSP-1 marker among *** strains from around the *** genetic data is valuable for expanding the polymorphism information on ***,which could be helpful for further study on populat

关键词： Plasmodium vivax PvMSP-1 Genetic diversity Malaria

富Fe层状材料FeOCl的低热导率(英文)

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Science China Materials 2024年

作者：汪琳周天培台晓琳王铭浩王文杰王纯林岳郭宇桥谢毅吴长征 Key Laboratory of Precision and Intelligent Chemistry University of Science and Technology of China National Synchrotron Radiation Laboratory University of Science and Technology of China Hefei National Research center for Physical Sciences at the Microscale University of Science and Technology of China Institute of Energy Hefei Comprehensive National Science center

层状无机材料的弱层间耦合和大面积表面为构建低导热性无机固体材料提供了基本框架.合成具有足够散射和非谐波性的稳定层状材料,从而降低热导率,仍是一项挑战.本文在层状无机FeOCl材料体系中,通过一步氧化还原反应成功获得了一种结构稳...

层状无机材料的弱层间耦合和大面积表面为构建低导热性无机固体材料提供了基本框架.合成具有足够散射和非谐波性的稳定层状材料,从而降低热导率,仍是一项挑战.本文在层状无机FeOCl材料体系中,通过一步氧化还原反应成功获得了一种结构稳定的富含Fe2+的层状材料,实现了表面和界面的同步改性,并实现了超低的热导率.具体而言,系统的X射线吸收精细结构(XAFS)分析和电子能量损失光谱(EELS)分析表明,碱金属原子的层间插层和表面缺陷的引入诱导了大量Fe2+的存在,从而增强了其非谐波性和声子散射.此外,声子态密度(PDOS)分布也提供了确凿的证据,证明了散射概率的提高和声子模式整体的软化.所制得的层状无机材料Fe(III)1-nFe(II)nO1-xCl[K+]m不仅结构稳定,而且在298 K时的热导率比原始FeOCl降低了近60%,低至0.29 W m-1K-1,这在层状无机材料中是极低的.这项研究为低导热层状材料的设计提供了新的视角.

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Impact of Herbal Preparations on Outcomes of Highly Active Antiretroviral Therapy: A One-Year Prospective Cohort Study

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Chinese Journal of Integrative Medicine 2020年第7期26卷 497-501页

作者： SU Qi-jian SONG Ce LU Zhen-zhen LIU Zhen-wei XIAO Jian WU Fa-sheng center for AIDS Research Ruikang Hospital Affiliated to Guangxi University of Chinese MedicineNanning(530011)China Departme nt of Chronic Non comm un icable disease Prevention and control Guangxi Center for Disease Prevention and ControlNanning(530028)China School of Basic Medical Science Guangxi University of Chinese MedicineNanning(530200)China Department of Oncology Ruikang Hospital Affiliated to Guangxi University of Chinese MedicineNanning(530011)China

Objective:To investigate the impacts of two herbal preparations for human immunodeficiency virus/aquired immune deficiency syndrome(HIV/AIDS)patients,Shenling Fuzheng Capsule(参灵扶正胶囊,SLFZC)and Qingdu Capsule(清毒胶囊,QDC),on the efficacy of highly active antiretroviral therapy(HAART).Methods:HIV/AIDS patients met the criteria were all enrolled in a 1-year cohort study,in which patients receiving HAART alone were designated as Group A,those receiving HAART in combination with SLFZC were designated as Group B,and those receiving HAART in combination with QDC were designated as Group C,100 cases in each *** dose of SLFZC was 1.48 g(4 capsules),3 times daily,and QDC 1.56 g(4 capsules),3 times daily.T cell subsets,HIV RNA and HIV-1 drug resistance were detected at enrollment and 1 year after *** were followed up every 3 months,during which side-effects and other clinical data were ***:After 1-year treatment,the median increment in CD4 counts was 165.0,178.0 and 145.0 cells/μL for Group A,B and C,*** RNA was undetectable in 94%of patients in Group A,96%in Group B and 92%in Group *** were no differences regarding the increment in CD4 counts,HIV RNA and frequency of HIV-1 drug resistance *** of the 14 suspected side-effect symptoms,*** and dizziness,were lower in Groups B and C than in Group A(P<0.05,respectively).Conclusion:SLFZC and QDC do not have a negative impact on immunological and virological response to HAART;however,these preparations are not as potent in reducing HAART-associated side-effects as anticipated.

关键词： human immunodeficiency syndrome aquired immune deficiency syndrome Chinese medicine Shenling Fuzheng Capsule Qingdu Capsule

Detection of Stealthy False Data Injection Attacks Against Cyber-Physical Systems:A Stochastic Coding Scheme

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Journal of Systems Science & Complexity 2022年第5期35卷 1668-1684页

作者： GUO Haibin PANG Zhonghua SUN Jian LI Jun State Key Lab of Intelligent control and Decision of Complex Systems School of AutomationBeijing Institute of TechnologyBeijing 100081China Beijing Institute of Technology Chongging Innovation center Chongqing 401120China Key Laboratory of Fieldbus Technology and Automation of Beijing North China University of TechnologyBeijing 100144China China Industrial control Systems Cyber Emergency Response Team Beijing 100040China

This paper,from the view of a defender,addresses the security problem of cyber-physical systems(CPSs)subject to stealthy false data injection(FDI)attacks that cannot be detected by a residual-based anomaly detector without other defensive *** detect such a class of FDI attacks,a stochastic coding scheme,which codes the sensor measurement with a Gaussian stochastic signal at the sensor side,is proposed to assist an anomaly detector to expose the FDI *** order to ensure the system performance in the normal operational context,a decoder is adopted to decode the coded sensor measurement when received at the controller *** this detection scheme,the residual under the attack can be significantly different from that in the normal situation,and thus trigger an *** design condition of the coding signal covariance is derived to meet the constraints of false alarm rate and attack detection *** minimize the trace of the coding signal covariance,the design problem of the coding signal is converted into a constraint non-convex optimization problem,and an estimation-optimization iteration algorithm is presented to obtain a numerical solution of the coding signal covariance.A numerical example is given to verify the effectiveness of the proposed scheme.

关键词： Attack detection cyber-physical systems(CPSs) stealthy FDI attacks stochastic coding