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An Approximate Maximum Likelihood Algorithm for Target Localization in Multistatic Passive Radar

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Chinese Journal of Electronics 2019年第1期28卷 195-201页

作者： WANG jun QIN Zhaotao GAO fei WEI Shaoming School of Electronics and Information Engineering Beihang University

This paper addresses the problem of target localization using Bistatic range(BR) measurements in a distributed multistatic passive radar system. The rangebased positioning technique employs multiple transmitterreceiver pairs, which provide separate BR *** on the Maximum likelihood(ML) function,an efficient algebraic Approximate maximum likelihood(AML) algorithm for single target localization is *** closed-form AML solution has neither initial condition requirements nor convergence difficulty. Simulations are included to compare its performance to that of the CramerRao lower bound(CRLB) and the Two-step Weighted least squares(TS-WLS) algorithm. The proposed method is shown to be able to achieve the CRLB accuracy under Gaussian measurement noise. It is more robust to noise than the TS-WLS method, and presents relative insensitivity to target-sensor geometry.

关键词： Bistatic range(BR) measurement Multistatic passive radar Target localization Approximate maximum likelihood(AML) algorithm Maximum likelihood(ML) function

Mechanical properties and microstructure of multilayer graphene oxide cement mortar

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Frontiers of Structural and Civil Engineering 2021年第4期15卷 1058-1070页

作者： jun LIU Luxi ZHAO fei CHANG Lin CHI School of Environment and Architecture University of Shanghai for Science and TechnologyShanghai200093China

This study reports on the effects of multilayer graphene oxide(MGO)on compressive strength,flexural strength,and microstructure of cement *** cement mortar was prepared with type ***.52.5 Portland cement,standard sand,and *** mixes were prepared with inclusion of MGO(0%,0.02%,0.04%,and 0.06%by weight of cement).The testing result shows that the compressive of GO-cement mortar increased by 4.84%–13.42%,and the flexural strength increased by 4.37%–8.28%at 3 ***-cement mortar’s compressive strength and flexural strength at 7 d increased by 3.84%–12.08%and 2.54%–13.43%,*** made little contribution to the increases of compressive strength and flexural strength of cement mortar at 28 *** results of X-ray diffraction(XRD),scanning electron microscope(SEM),and nitrogen(N2)adsorption/desorption tests show that the types of hydration products and crystal grain size did not change after adding ***,it can help to improve the microstructure of the cement mortar via regulating hydration products and can provide more condensed cores to accelerate ***,the regulating action of MGO for the microstructure of cement mortar at an early age was better than that at 28 d.

关键词： graphene oxide cement mortar mechanical properties microstructure

Practical Survey on Design and Testing of Flight Control Laws for Helicopter Engineering Simulators

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Transactions of Nanjing University of Aeronautics and Astronautics 2017年第5期34卷 465-476页

作者： gu Hongbin Hu Jinshuo Fu jun Research Center of Flight Simulation and Advanced Engineering Training College of Civil Aviation Nanjing University of Aeronautics and Astronautics Nanjing 210016 P. R. China

A practical survey on engineering implementation of flight control laws on helicopter engineering simulators is *** of helicopter engineering simulators are *** flight control technologies are reviewed,with an emphasis on discussing the corresponding engineering simulation ***,the difficulties of implementing advanced control technologies are addressed,and the future development of helicopter engineering simulators are highlighted.

关键词： helicopter helicopter engineering simulator flight control law flight control technology

Review on Key Techniques of Dynamics Modeling for Helicopter Simulator

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Transactions of Nanjing University of Aeronautics and Astronautics 2016年第6期33卷 -页

作者： gu Hongbin Fu jun Hu Jinshuo Research Center of Flight Simulation and Advanced Engineering Training College of Civil AviationNanjing University of Aeronautics and Astronautics

We review the state of the art of dynamic modeling methods for helicopter *** dynamic models,including ARMCOP,GENHEL,FLYRT,BEMAP,F-B412 and UTIAS,are *** address off-axis response problem by focusing on flexible blade model,Pitt-Peters dynamic inflow model,Peters-He finite state inflow model and free wake model which are integrated with the baseline *** the advances in computing power,efficient free-vortex algorithms and parallel processing,free wake model can be used to simulate in real-time and significantly improves the effectiveness of solving off-axis response problem.

关键词： helicopter dynamic model off-aixs response

单纯性支气管扩张症与支气管扩张症-慢性阻塞性肺疾病重叠综合征患者的病原菌对比研究

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中国全科医学 2025年第6期28卷 729-736页

作者：吴俊张玲顾东伟郑磊赵祝香赵子文安徽省马鞍山市人民医院呼吸与危重症医学科 243000 安徽省马鞍山市人民医院检验科 243000 华南理工大学附属第二医院广州市第一人民医院呼吸与危重症医学科广东省广州市510180

背景我国慢性阻塞性肺疾病(简称慢阻肺)及支气管扩张症(简称支扩)患者数量庞大,均为高发病率、高病死率的慢性呼吸系统疾病。支气管扩张症-慢性阻塞性肺疾病重叠综合征(BCOS)作为一种特殊临床亚型虽常见但易被忽略。感染常是其急性恶化... 详细信息

背景我国慢性阻塞性肺疾病(简称慢阻肺)及支气管扩张症(简称支扩)患者数量庞大,均为高发病率、高病死率的慢性呼吸系统疾病。支气管扩张症-慢性阻塞性肺疾病重叠综合征(BCOS)作为一种特殊临床亚型虽常见但易被忽略。感染常是其急性恶化的诱因,但相关病原学研究相对匮乏。目的分析单纯性支气管扩张症(BE)与BCOS患者病原菌分布、耐药性特点,比较两者差异。为临床合理使用抗菌药物提供参考。方法选取2016年1月—2023年1月在马鞍山市人民医院呼吸与危重医学科住院的支扩患者584例为研究对象,根据是否合并慢阻肺将患者分为两组:BE组(未合并慢阻肺,335例)和BCOS组(合并慢阻肺,249例)。回顾性分析患者病原菌构成、药敏结果及变迁,分析两组病原菌分布及耐药性差异。结果584例支扩患者共分离299株病原菌,BE组分离病原菌146株,其中革兰阴性菌87株(59.59%),革兰阳性菌3株(2.05%),分枝杆菌9株(6.16%),真菌47株(32.19%);BCOS组分离病原菌153株,其中革兰阴性菌80株(52.29%),革兰阳性菌1株(0.65%),分枝杆菌2株(1.31%),真菌70株(45.75%);BCOS组患者白色念珠菌构成比高于BE组(χ^(2)=5.274,P=0.022)。两组铜绿假单胞菌耐药率分别为:亚胺培南10.64%、25.53%,哌拉西林他唑巴坦6.98%、15.91%,环丙沙星12.77%、21.28%,阿米卡星2.13%、2.13%;两组肺炎克雷伯菌耐药率分别为:亚胺培南0、14.29%,哌拉西林他唑巴坦0、14.29%,环丙沙星15.38%、35.71%,阿米卡星0、7.14%;BCOS组铜绿假单胞菌对氨苄西林舒巴坦耐药率低于BE组(P=0.026)。BCOS组患者产超广谱β内酰胺酶肠杆菌科(χ^(2)=4.357,P=0.037)及耐碳青霉烯类铜绿假单胞菌分离率均高于BE组(χ^(2)=5.593,P=0.018)。2016—2022年支扩患者分离铜绿假单胞菌株数均最高,呈先降后升趋势;分离肺炎克雷伯菌株数在2021、2022年明显升高,仅次于铜绿假单胞菌;2020—2022年分离分枝杆菌株数及2021—2022年分离曲霉菌株数均呈上升趋势。结论BCOS作为一种特殊表型,其病原菌分布、耐药性有其自身特点,值得关注。铜绿假单胞菌目前是BE及BCOS患者常见分离致病菌,近年来分离肺炎克雷伯菌株数仅次于铜绿假单胞菌。分离分枝杆菌、曲霉菌株数较前亦明显上升,应引起重视,尤其是BE患者。

关键词：支气管扩张症肺疾病,慢性阻塞性支气管扩张症-慢性阻塞性肺疾病重叠综合征铜绿假单胞菌肺炎克雷伯菌抗药性

Almost global smooth solutions of the 3D quasilinear Klein-Gordon equations on the product space R^(2)×T

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Science China Mathematics 2024年第12期67卷 2713-2752页

作者： jun Li fei Tao Huicheng Yin Department of Mathematics Nanjing UniversityNanjing 210093China School of Mathematical Sciences and Mathematical Institute Nanjing Normal UniversityNanjing 210023China

In this paper,for the 3D quadratic nonlinear Klein-Gordon equation on the product space R^(2)×T,we focus on the lower bound of the lifespan of the smooth solution with slowly decaying initial *** the size of initial data is bounded by ε_(0)>0,it is shown that a smooth solution exists up to the time C_(0)/20 with0 being sufficiently small and e^(c0)/ε_(0)^(2)>0 being some suitable *** that the solution of the corresponding 3D linear homogeneous Klein-Gordon equation on R^(2)×T only admits the optimal time-decay rate(1+t)−1,from which we generally derive the lifespan of the nonlinear Klein-Gordon equation up to e^(c0/ε0)rather than the more precise e^(c0/ε^(2)0) here.

关键词： quasilinear Klein-Gordon equation almost global solution Z-norm Littlewood-Paley decomposition space-time resonance method energy estimate

Deformation behavior and processing maps during isothermal compression of TC21 alloy

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Rare Metals 2017年第2期36卷 86-94页

作者： jun Gao Miao-Quan Li Ge-jun Liu Shao-fei Liu School of Materials Science and Engineering Northwestern Polytechnical UniversityXi'an 710072China

In this study,isothermal compression tests were conducted at a Gleeble-1500 simulator at deformation temperatures ranging from 1073 to 1283 K,strain rates ranging from 0.01 to 5.00 s^（-1）,and height reductions ranging from 20%to 60%.The flow stress and apparent activation energy for deformation and constitutive equation were used to characterize the deformation behavior of TC21 alloy during the isothermal *** processing maps combined microstructure observations were established based on dynamic material model（DMM） over a range of strain rates and *** results show that an initial yield drop is observed above 1203 K or at higher strain rates ranging from 1.00 to 5.00 s^-1,and oscillatory flow curves are presented particularly at a strain rate of 5.00 s^-*** has some influence on the apparent activation energy for deformation during the isothermal compression of TC21 *** Q-values and microstructure observation confirm that dynamic recrystallization（DRX） occurs in the β single-phase *** constitutive equation during the isothermal compression of TC21 alloy is developed using the Zener-Hollomon parameter in the exponent-type *** maximum and minimum relative errors between the calculated and the experimental flow stress are 14.1%and 0.3%,*** peak efficiency of power dissipation at a strain of 0.7 is about 0.51 occurring at a deformation temperature of 1073 K and strain rate of 0.01 s^-1,corresponding to an optimal deformation condition of TC21 alloy.

关键词： TC21 alloy Flow stress Apparent activation energy for deformation Constitutive equation Processing Maps

In Vitro Protein Expression Profile of Campylobacter jejuni Strain NCTC11168 by Two-dimensional Gel Electrophoresis and Mass Spectrometry

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Biomedical and Environmental Sciences 2013年第1期26卷 48-53页

作者： ZHANG Mao jun gu Yi Xin DI Xiao ZHAO fei YOU Yuan Hai MENG Fan Liang ZHANG Jian Zhong Key Laboratory for Infectious Disease Prevention and Control National Institute for Communicable Disease Control and PreventionChinese Center for Disease Control and Prevention

Objective To investigate the protein expression profiles of the major food‐borne pathogen Campylobacter jejuni *** Membrane and soluble cellular proteins were extracted from the genome‐sequenced *** strain *** expression profiles were determined using two‐dimensional gel electrophoresis（2‐DE）.All the detected spots on the 2‐DE map were subjected to matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry（MALDI‐TOF/TOF） *** A total of 537 and 333 spots were detected from the whole cell and membrane‐associated proteins of *** NCTC11168 cultured on Columbia agar medium at 42 ℃ by 2‐DE and Coomassie Brilliant Blue staining,*** of whole cell and membrane‐associated proteins included 399 and 133 spots,respectively,which included 182 and 53 functional proteins identified by MALDI‐TOF/TOF *** The comprehensive expression protein profiles of *** NCTC11168 obtained in this study will be useful for elucidating the roles of these proteins in further pathogenesis investigation.

关键词： Campylobacter jejuni Two‐dimensional gel electrophoresis MALDI‐TOF Soluble cellular protein Membrane protein

The study of proto-magnetar winds

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Research in Astronomy and Astrophysics 2010年第3期10卷 244-252页

作者： Yan-jun Chen Ye-fei Yuan Department of Physics and Electronic Science Changsha University of Science and Technology Changsha Hunan 410114 Center for Astrophysics University of Science and Technology of China Hefei 230026 China

The velocity profiles and properties of proto-magnetar winds are investigated. It is found that the corotation of wind matter with magnetic field lines significantly affects r-process nucleosynthesis and could lead to... 详细信息

关键词： stars: neutron -- stars: winds outflows -- supernovae: general -- stars magnetic fields -- nuclear reactions nucleosynthesis abundances