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Output feedback control of hypersonic vehicles based on neural network and high gain observer

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Science China(Information Sciences) 2011年第3期54卷 429-447页

作者： LI XinDong,XIAN Bin,DIAO chen,YU YanPing,YANG KaiYan & ZHANG yao The Tianjin Key Laboratory of Process Measurement and Control,School of Electrical Engineering and Automation,Tianjin University,Tianjin 300072,China 1. The Tianjin Key Laboratory of Process Measurement and Control School of Electrical Engineering and Automation Tianjin University Tianjin 300072 China

In this paper,the output feedback control problem for a genetic hypersonic vehicle is considered under the restriction that only the vehicle’s velocity and altitude are measurable. High gain observers (HGO) are utilized to provide estimation signals for unmeasurable derivatives of the vehicle’s velocity and altitude. Neural network based feedforward function is designed to compensate for model uncertainties. The proposed control design require less knowledge of the hypersonic vehicle’s dynamic model. A comprehensive stability analysis of the closed loop system under the output feedback control is carried to prove that the proposed control law yields semiglobal uniformly ultimately bounded tracking while keeping all the closed loop signals bounded. Numerical simulation results are presented to validate the proposed control design.

关键词： hypersonic vehicle nonlinear output feedback control neural network high gain observer

Effects of antiviral agents and HBV genotypes on intrahepaticcovalently closed circular DNA in HBeAg-positive chronichepatitis B patients

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World Journal of Gastroenterology 2008年第8期14卷 1268-1273页

作者： Hai-Ying Lu Li-Wei Zhuang Yan-Yan Yu chong-Wen Si Jun Li Jian-Jun Zhang Zheng Zeng Xin-Yue chen Zhong-Hou Han Yong chen Departnlent of Infectious Diseases Peking University First Hospital Beijing 100034 China Beijing Zhongfuyouxin Beijing 100085 China Beijing You'an Hospital Beijing 100054 China Qinhuangdao Third Hospital Qinhuangdao 066000 Hebei Province China Huai'an Infectious Disease Hospital Huai'an 223300 Jiangsu Province China

AIM： To evaluate the effects of antiviral agents and HBV genotypes on intrahepatic covalently closed circular DNA （ccc DNA） in HBeAg-positive chronic hepatitis B patients.METHODS： Seventy-one patients received lamivudine （n = 35）, or sequential therapy with lamivudine- interferon alpha 2b （IFN-α 2b, n = 24） for 48 wk, or IFN-α 2b （n = 12） for 24 wk. All subjects were followed up for 24 wk. Intrahepatic ccc DNA was measured quantitatively by PCR. HBV genotypes were analyzed by PCR-RFLP.RESULTS： Sequential lamivudine- INF-α therapy, lamivudine and INF-α monotherapy reduced ccc DNA of 1.7 log, 1.4 log and 0.8 log, respectively （P 〈 0.05）. Seventeen out of the 71 patieots developed HBeAg seroconversion, the reduction of ccc DNA in the HBeAg seroconversion patients was more significant than that in the HBeAg positive patients （3.0 log vs 1.6 log, P = 0.0407）. Twenty-four weeks after antiviral therapy withdrawal, 16 patients had a sustained virological response, the baseline intrahepatic ccc DNA in the patients with a sustained virological response was significantly lower than that in the patients with virological rebound （4.6 log vs 5.4 log, P = 0.0472）. HBV genotype C accounted for 85.9% （n = 61）, and genotype B for 14.1% （n = 10）, respectively, in the 71 patients. There was no significant difference in the change of ccc DNA level between HBV genotypes C and B （2.1 log vs 1.9 log）.CONCLUSION： Forty-eight week sequential lamivudine- INF-α therapy and lamivudine monotherapy reduce ccc DNA more significantly than 24-wk INF-α monotherapy. Low baseline intrahepatic ccc DNA level may predict the long-term efficacy of antiviral treatment. HBV genotypes C and B have no obvious influence on ccc DNA load.

关键词： Covalently closed circular DNA, Hepatitis Bvirus Sequential therapy Lamivudine Interferon

A new step-cooling process for strength and toughness matching control of vanadium-containing railway wheels:effect of intragranular ferrite

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Baosteel Technical Research 2023年第3期17卷 40-48页

作者： yao Sancheng LIU Xuehua ZHAO Hai JIANG Bo chen Gang XU Kang Technology Center Ma’anshan Iron and Steel Co.Ltd.Ma’anshan 243003China Technology Center Baowu Group Masteel Rail Transit Materials Technology Co.Ltd.Ma’anshan 243003China

To improve the competitive relationship between strength and toughness,the effect of low undercooling in austenite(γ)on the microstructure and mechanical properties of commercial vanadium-containing wheel steels was studied using an optical microscope(OM),a scanning electron microscope(SEM),a transmission electron microscope(TEM),and mechanical property *** results show that when the wheel steel is slightly cooled to an appropriate temperature above A c3 point for a short time after it has been austenitized at an elevated temperature,the solid-solved vanadium is pre-precipitated in the form of V(C,N)second phase semicoherent with the matrix in the originalγ*** phase hardly participates in matrix *** to the small mismatch between V(C,N)and ferrite(α),during the subsequent-cooling phase transformation stage,the pre-precipitated second phase becomes theαnucleation point,causing granular and ellipsoidal intragranular ferrite(IGF,with an average size of 4-6μm)to nucleate in the originalγ.The IGF production and strength loss increases with the increasing undercooling *** on this,Masteel Co.,*** developed a new heat-treatment step-cooling process that can promote the formation of IGF,considerably improving the level and uniformity of fracture toughness on the premise that the strength and hardness of the wheel are almost unchanged.

关键词： vanadium microalloyed railway wheel strength and toughness match low undercooling in austenite intragranular ferrite second phase step-cooling process

Radiation Crosslinking of Pol ysulfone-Pol ysiloxane Multiblock Copolymers

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Chemical Research in Chinese Universities 1992年第3期8卷 273-277页

作者： chen Xin-fang, ZHANG Chun-shan and CHUI Zhan-chen (Institute of Materials Science, Jilin University, Changchun)LI Bin-yao (Changchun Institute of Applied Chemistry, Academia Sinica, Changchun)

In this paper the effects of irradiation on the structures and properties of polysul-fone-polysiloxane multiblock copolymers and its important applied prospects are studied in detail.

关键词： Radiation-crosslinking Polysulfone Polydimethylsiloxane Multiblock copolymer

Enhanced Protective Efficacy of H5 Subtype Influenza Vaccine with Modification of the Multibasic Cleavage Site of Hemagglutinin in Retroviral Pseudotypes

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Virologica Sinica 2013年第3期28卷 136-145页

作者： Ling Tao JianJun chen Jin Meng yao chen Hongxia Li Yan Liu Zhenhua Zheng Hanzhong Wang State Key Laboratory of Virology Wuhan Institute of Virology Chinese Academy of Sciences chongqing Academy of Chinese Materia Medica

Traditionally, the multibasic cleavage site （MBCS） of surface protein H5-hemagglutinin （HA） is converted to a monobasic one so as to weaken the virulence of recombinant H5N1 influenza viruses and to produce inactivated and live attenuated vaccines. Whether such modification benefits new candidate vaccines has not been adequately investigated. We previously used retroviral vectors to generate wtH5N1 pseudotypes containing the wild-type HA （wtH5） from A/swine/Anhui/ca/2004 （H5N1） virus. Here, we generated mtH5N1 pseudotypes, which contained a mutant-type HA （mtH5） with a modified monobasic cleavage site. Groups of mice were subcutaneously injected with the two types of influenza pseudotypes. Compared to the group immunized with wtH5N1 pseudotypes, the inoculation of mtH5N1 pseudotypes induced significantly higher levels of HA specific IgG and IFN-y in immunized mice, and enhanced protection against the challenge of mouse-adapted avian influenza virus A/Chicken/Henardl2/2004 （H5N1）. This study suggests modification of the H5-hemagglutinin MBCS in retroviral pseudotypes enhances protection efficacy in mice and this information may be helpful for development of vaccines from mammalian cells to fight against H5N 1 influenza viruses.

关键词： Influenza H5 subtype Vaccine Pseudotype Hemagglutinin Multibasic cleavage site

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飞机除冰车专用车架拓扑优化及强度分析

制造业自动化 2013年第6期35卷 127-129页

作者：袁敏陈翀西华大学交通与汽车工程学院成都610039

本文简要介绍了拓扑优化技术,对除冰车车架建立有限元模型,进行了强度分析和拓扑优化设计。在此基础上对车架进行二次设计并进行验算,对优化前后的相关数据进行了对比分析。分析结果表明经过拓扑优化,车架强度满足要求,同时轻量化效果... 详细信息

本文简要介绍了拓扑优化技术,对除冰车车架建立有限元模型,进行了强度分析和拓扑优化设计。在此基础上对车架进行二次设计并进行验算,对优化前后的相关数据进行了对比分析。分析结果表明经过拓扑优化,车架强度满足要求,同时轻量化效果明显。

关键词：车架拓扑优化强度分析轻量化

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新三维混沌系统及其电路仿真实验

物理学报 2007年第4期56卷 1966-1970页

作者：刘凌苏燕辰刘崇新西南交通大学机械工程学院成都610031 西安交通大学电气工程学院西安710049

提出了一个混沌系统,并对该系统的基本动力学特性进行了深入研究.得到该系统的Lyapunov指数、Lyapunov维数,给出了Poincaré映射图以及时域图和相图.运用电子工作平台EWB软件对实现该新混沌系统的振荡器电路进行了仿真实验.经过数值仿... 详细信息

提出了一个混沌系统,并对该系统的基本动力学特性进行了深入研究.得到该系统的Lyapunov指数、Lyapunov维数,给出了Poincaré映射图以及时域图和相图.运用电子工作平台EWB软件对实现该新混沌系统的振荡器电路进行了仿真实验.经过数值仿真和电路系统仿真证实该系统与以往发现的混沌吸引子并不拓扑等价,属于新的混沌系统.

关键词：混沌系统动力学行为电路实现

Clinical practice guidelines for ultrasound-guided breast lesions and lymph nodes biopsy: Chinese society of breast surgery (CSBrS) practice guidelines 2021

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Chinese Medical Journal 2021年第12期134卷 1393-1395页

作者： Jin-Fei Ma Lu-Yan chen Shuang-Ling Wu Ying-Ying Xu Fan yao Feng Jin Pei-Fen Fu Bo chen Department of Breast Surgery The First Affiliated Hospital of China Medical UniversityShenyangLiaoning 110001China Department of Breast Surgery The First Affiliated HospitalZhejiang UniversitySchool of MedicineHangzhouZhejiang 310003China

With the maturation and advances of image-guided puncture biopsy technology,the proportion of open breast biopsy has gradually ***-guided biopsy is convenient in practice and supports real-time *** order to standardize the practice of ultrasound-guided breast and regional lymph node biopsy,and provide a reference for Chinese breast surgeons,based on the version of Consensus statements and operation guidelines on breast lesions and lymph nodes biopsy guided by ultrasound(2019),[1]the Chinese Society of Breast Surgery(CSBrS)has re-evaluated the quality of the evidence of relevant clinical studies referring to the Grading of Recommendations Assessment,Development,and Evaluation(GRADE)handbook and considered domestic medical condition to develop the Clinical Practice Guidelines for Ultrasound-guided Breast Lesions and Lymph Nodes Biopsy:CSBrS Practice Guidelines 2021.

关键词： biopsy breast lymph

Accelerating the Activation of NO_(x)^(−)on Ru Nanoparticles for Ammonia Production by Tuning Their Electron Deficiency

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CCS Chemistry 2022年第11期4卷 3455-3462页

作者： Guang-yao Zhai Qi-Yuan Li Shi-Nan Zhang Dong Xu Si-Yuan Xia Peng Gao Xiu Lin Yun-Xiao Lin Jin-Huan cheng Wei-yao Hu Lu-Han Sun Xin-Hao Li Jie-Sheng chen School of Chemistry and Chemical Engineering Frontiers Science Center for Transformative MoleculesShanghai Jiao Tong UniversityShanghai 200240 School of Environmental Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240

Stable and portable ammonia(NH3)is a promising,low-cost,and environment-friendly medium for energy *** to achieve the rapid production of NH3 from reducing NO_(x)^(−)in aqueous systems and industrial wastewater via electrochemical methods remains the main challenge for practical application on a large *** corresponding electrocatalysts as the key materials in electrochemical devices suffer from low activity,especially in neutral *** this work,we successfully elevated the activity of the bench-mark Ru electrocatalysts to more than 30 times via construction of rectifying contact of Ru metals and noble *** theoretically predicted and then rationally designed a new type of P-O rich carbon with large work functions as“noble”supports to attract a pronounced number of electrons from Ru metals at the rectifying *** resulting electron deficiency of Ru metals largely promotes the pre-adsorption and activation of NO_(x)^(−)anions,providing high Faradaic efficiencies(>96%)and record-high turnover frequency values for universal NO_(2)^(−)and NO_(3)^(−)reduction in neutral solution.

关键词： electrochemical NOx−reduction ammonia production energy storage P-O rich carbon electron deficiency of Ru nanoparticles