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A MAGNETO-MECHANICAL FULLY COUPLED MODEL FOR GIANT MAGNETOSTRICTION IN HIGH TEMPERATURE SUPERCONDUCTOR

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Acta Mechanica Solida Sinica 2015年第4期28卷 353-359页

作者： Zhiwen Gao Youhe zhou Key Laboratory of Mechanics on Disaster and Environment in Western China attached to the Ministry of Education of China Department of Mechanics and Engineering Sciences College of Civil Engineering and Mechanics Lanzhou University

This paper presents a fully coupled model to account for the flux pinning induced giant magnetostriction in type-Ⅱ superconductors under alternating magnetic field The superconductor E-J constitutive law is characterized by power law where the critical current density is assumed to depend exponentially on the flux density. The governing equations of the two-field problem （i.e., the interactions of elastic and magnetic effects） are formulated in a two-dimensional model. The magnetostriction curves and magnetization loops are calculated over a wide range of parameters. The effects of applied magnetic field frequency f and amplitude B0 and critical current density on magnetostriction and magnetization are discussed. Results show that the critical current density of high temperature superconductor （HTS） YBCO has a significant effect on the magnetization and magnetostriction. The pinning-induced magnetostriction which has been observed in experiment can be qualitatively simulated by this model.

关键词： high temperature superconductor (HTS) giant magnetostriction magnetization,magneto-mechanical couple alternating magnetic field

Coverage-based cooperative target acquisition for hypersonic interceptions

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Science China(Technological Sciences) 2018年第10期61卷 1575-1587页

作者： zhou Jin LEI HuMin Air Force Engineering University Air and Missile Defense College

This paper presents a novel coverage-based cooperative target acquisition algorithm for hypersonic interceptions. Firstly, the difficulties in the hypersonic trajectory prediction are introduced which invalidate the conventionally used predicted impact point based mid-course guidance and seeker acquisition. Secondly, in order to optimally estimate and predict the target trajectory information, the interacting multiple model(IMM) algorithm is used with the constant velocity(CV) model, the constant acceleration(CA) model and the Singer model serving as the model set. The target states are described with the probability density function(PDF) based on the IMM prediction. Thirdly, the interceptor seeker target acquisition model is established which considers the blur edge region of the field of view. The cooperative target acquisition algorithm is designed by maximizing the interceptor seekers cooperative coverage of the target high probability region(HPR). Finally, digital simulations prove the effectiveness of the proposed method and reveal that the real challenge in the hypersonic target acquisition is the poor trajectory prediction accuracy which may further result to the unsteadiness of the interceptor trajectories.

关键词： cooperative coverage target acquisition hypersonic interception IMM trajectory prediction midcourse guidance

TRANSIENT PHOTOLUMINESCENCE SPECTRA OF GaAs/AlGaAs QUANTUM WELLS, QUANTUM WELL WIRES, AND QUANTUM WELL BOXES

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Chinese Physics Letters 1990年第6期7卷 284-287页

作者： CHENG Wenqin HUANG Yi zhou Junming FENG Wei WANG Hezhou SHE Weilong HUANG xuguang LIN Weizhu YU Zhenxin xu Geng Institute of Physics Chinese Academy of SciencesBeijing 100080 Laboratory of Ultrafast Laser Spectrascopy Zhongshan UniversityGuangzhou 510275 Department of Physics Zhongshan UniversityGuangzhou 510275

The interaction of the electrons with the phonons in GaAs/AlGaAs quantum wells,quantum well wires,and quantum well boxes has been studied by meansuring their time resolved photoluminescence(PL)*** the quantum well(Q W)system,relaxation time of the electron energy of the narrower well is shorter than that of the wider *** is attributed to the stronger interaction of the electrons with the interface mode *** the Q W wires and Q W boxes,the shortening of the relaxation time is *** is due to the stronger electron-phonon interaction caused by the reduction of screening *** experiments also demonstrated the incident laser intensity dependence of the relaxation time.

关键词： spectra effect relaxation

Genome-wide association study and metabolic pathway prediction of barrenness in maize as a response to high planting density

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Journal of Integrative Agriculture 2022年第12期21卷 3514-3523页

作者： ZHANG xu-huan LIU Hao MA xu-hui zhou Gu-yi RUAN Hong-qiang CUI Hong-wei PANG Jun-ling KHAN Ullah Siffat ZONG Na WANG Ren-zhong LENG Peng-fei ZHAO Jun Biotechnology Research Institute Chinese Academy of Agricultural SciencesBeijing 100081P.R.China State Key Laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of SciencesBeijing 100093P.R.China

Increasing the planting density is one way to enhance grain production in ***,high planting density brings about growth and developmental defects such as barrenness,which is the major factor limiting grain *** this study,the barrenness was characterized in an association panel comprising 280 inbred lines under normal(67500 plants ha–1,ND)and high(120000 plants ha–1,HD)planting densities in 2017 and *** population was genotyped using 776254 single nucleotide polymorphism(SNP)markers with criteria of minor allele frequency>5%and<20%missing data.A genome-wide association study(GWAS)was conducted for barrenness under ND and HD,as well as the barrenness ratio(HD/ND),by applying a Mixed Linear Model that controls both population structure and relative kinship(Q+K).In total,20 SNPs located in nine genes were significantly(P<6.44×10–8)associated with barrenness under the different planting *** them,seven SNPs for barrenness at ND and HD were located in two genes,four of which were common under both ND and *** addition,13 SNPs for the barrenness ratio were located in seven genes.A complementary pathway analysis indicated that the metabolic pathways of amino acids,such as glutamate and arginine,and the mitogen-activated protein kinase(MAPK)signaling pathway might play important roles in tolerance to high planting *** results provide insights into the genetic basis of high planting density tolerance and will facilitate high yield maize breeding.

关键词： Zea mays L high planting density barrenness genome-wide association study MAPK pathway

Matrix Solid-phase Dispersion Extraction of Alkaloids from the Roots of Aconitum kusnezoffii Reichb

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Chemical Research in Chinese Universities 2011年第1期27卷 23-27页

作者： WEI Wei LI xu-wen SHI Xiao-lei zhou Hong-yu YANG Rui-jie ZHANG Han-qi JIN Yong-ri College of Chemistry Jilin University Changchun 130012 P. R. China

Matrix solid-phase dispersion（MSPD） was developed for the extraction of four alkaloids, including aconitine, mesaconitine, hypaconitine and deoxyaconitine, from the roots ofAconitum kusnezoffii Reichb. The determination of the analyte was carried out by high performance liquid chromatography with UV detection. The alkaline alumina was used as sorbent. The mixture of acetonitrile and water was used as elution solvent. Several extraction parameters, such as type of sorbent, the ratio of sample to solid support material, type of the elution solvent and the volume of the elution solvent were tested. Mean recoveries ranged from 93.16% to 102.73%, with relative standard deviations from 0.27% to 4.17%. With the extraction efficiency and time expenditure taken into account, MSPD extraction should be a comparatively good method.

关键词： Matrix solid-phase dispersion Aconitine-type alkaloid Aconitum kusnezoffii Reichb. Extraction High-performance liquid chromatography 1005-9040(2011 )-01-023-05

A vision-based navigation approach with multiple radial shape marks for indoor aircraft locating

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Chinese Journal of Aeronautics 2014年第1期27卷 76-84页

作者： zhou Haoyin Zhang Tao Department of Automation School of Information Science and TechnologyTsinghua University National Key Laboratory of Integrated Flight Vehicle Control Technology Xi'an Flight Automatic Control Research Institute

Since GPS signals are unavailable for indoor navigation, current research mainly focuses on vision-based locating with a single mark. An obvious disadvantage with this approach is that locating will fail when the mark cannot be seen. The use of multiple marks can solve this problem. However, the extra process to design and identify different marks will significantly increase system complexity. In this paper, a novel vision-based locating method is proposed by using marks with feature points arranged in a radial shape. The feature points of the marks consist of inner points and outer points. The positions of the inner points are the same in all marks, while the positions of the outer points are different in different marks. Unlike traditional camera locating methods （the PnP methods）, the proposed method can calculate the camera location and the positions of the outer points simultaneously. Then the calculation results of the positions of the outer points are used to identify the mark. This method can make navigation with multiple marks more efficient. Simulations and real world experiments are carried out, and their results show that the proposed method is fast, accurate and robust to noise.

关键词： Flexible mark Indoor aircraft Multiple marks Navigation Vision-based locating

Adaptive dynamic surface control for air-breathing hypersonic vehicle

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Journal of Systems Engineering and Electronics 2013年第3期24卷 463-479页

作者： Li zhou Shumin Fei School of Information and Control Nanjing University of Information Science and Technology School of Automation Southeast University

This paper describes an adaptive control approach for an air-breathing hypersonic vehicle. The control objective is to provide robust altitudes and velocity tracking in the presence of model uncertainties and varying disturbances. A fuzzy-neural disturbance observer is developed to estimate uncertainties and disturbances, and the adaptive controller is synthesized by the dynamic surface approach combing with the observer. The tracking error at the steady state can be guaranteed to converge to inside of a small residue set which the size of the set can be an arbitrary small value. Simulation results demonstrate the effectiveness of the presented approach.

关键词： flight control dynamic surface control fuzzy-neura system disturbance observer hypersonic vehicle.

Time-Efficient Power Allocation Scheme for Two-Way Multi-relay Cognitive Radio Networks

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Chinese Journal of Electronics 2016年第2期25卷 357-363页

作者： zhou Zhikang ZHU Qi The Key Wireless Lab of Jiangsu Province School of Telecommunication and Information EngineeringNanjing University of Posts and Telecommunications Key Lab on Wideband Wireless Communications and Sensor Network Technology of Ministry of Education

Cooperative relaying has been emerging as a key technology in Cognitive radio(CR) networks. A two-way Amplify-and-forward(AF) based multi-relay CR network is considered, where a primary user coexists with a pair of secondary users and multiple relays. A Timeefficient sub-optimal power allocation scheme(TESOPA)based on Cauchy-Schwarz inequality is provided to maximize the total end-to-end transmission rate of the secondary system. TESOPA is proposed under maximal transmission power constraints, while ensuring the quality of service of the primary user during the whole communication process. The computational complexity is sharply decreased by using the Cauchy-Schwarz inequality. Simulation results show that the proposed TESOPA scheme performs very close to the near-optimal Interior point method based power allocation(IPMPA), especially in interference dominant networks where interference constraints play a key role in determining power allocation results instead of maximal transmission power constraints.

关键词： Power allocation Relay network Cognitive radio Amplify-and-forward Two-way communication

Clinicopathologic characteristics of intrahepatic cholangiocarcinoma in patients with positive serum a-fetoprotein

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World Journal of Gastroenterology 2008年第14期14卷 2251-2254页

作者： Yan-Ming zhou Jia-Mei Yang Bin Li Zheng-Feng Yin Feng xu Bin Wang Peng Liu Zhi-Min Li Department of Hepato- Biliary-Pancreato-Vascular Surgery The First Xiamen Hospital Fujian Medical University Xiamen 361003 Fujian Province China Department of Special Treatment Eastern Hepatobiliary Surgery Hospital Second Military Medical University Shanghai 200438 China Molecular Oncology Research Laboratory Eastern Hepatobiliary Surgery Hospital Second Military Medical University Shanghai 200438 China

AIM:To explore clinicopathologic characteristics of intrahepatic cholangiocarcinoma (ICC) in patients with positive serum a-fetoprotein (AFP). METHODS:One hundred and thirty one patients who underwent surgical dissection for pathologically confirmed ICC were divided into a positive AFP (> 20 ng/mL) group (n = 32) and a negative AFP group (n = 99), whose clinicopathologic features were analyzed and compared. RESULTS:The positive rate of HBsAg and liver cirrhosis of the positive AFP group was higher than that of the negative AFP group, while the positive rate of CA19-9 (> 37 U/mL) and the lymph node metastasis rate was lower. CONCLUSION:ICC patients with positive AFP share many clinicopathologic similarities with hepatocellular carcinoma.

关键词： Intrahepatic cholangiocarcinoma A-fetopro tein Hepatitis B virus Liver cirrhosis Hepatic stem cells