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Pulse Characteristics of Cavityless Solid-State Laser

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Chinese Physics Letters 2020年第4期37卷 62-66页

作者： Rui Guo Ye-Wen jiang Ting-hao Liu qiang Liu Ma-Li Gong Department of Precision Instrument Tsinghua UniversityBeijing 100084 Key Laboratory of Photon Measurement and Control Technology Ministry of EducationTsinghua UniversityBeijing 100084 State Key Laboratory of Tribology Tsinghua UniversityBeijing 100084

We propose a theoretical model(cavityless pulsed solid-state-laser theory) to analyze the pulse characteristics of cavity-less solid-state lasers. A high gain Nd:YVO4 end-pumped cavityless laser system is adopted to verify the theoretical model. It shows that the performance of output energy and pulse width achieved in cavityless configuration is better than that in resonator configuration when the small-signal gain reaches the saturated *** simulation results calculated by our theoretical model agree very well with the experimental results. This agreement proves the validity of our theoretical model, which has great importance for theoretical analyses of high gain pulsed laser.

关键词： pumped resonator Nd:

Multi-channel blind deconvolution algorithm for multiple-input multiple-output DS/CDMA system

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Journal of Systems Engineering and Electronics 2007年第3期18卷 454-461页

作者： Cheng hao Guo Wei jiang Yi National Key Lab of Communication Univ. of Electronic Science and Technology Chengdu 610054 P. R. China

Direct sequence spread spectrum transmission can be realized at low SNR, and has low probabilityof detection. It is aly problem how to obtain the original users＇ signal in a non-cooperative context. In practicality, the DS/CDMA sources received are linear convolute mixing. A more complex multichannel blind deconvolution MBD algorithm is required to achieve better source separation. An improved MBD algorithm for separating linear convolved mixtures of signals in CDMA system is proposed. This algorithm is based on minimizing the average squared cross-output-channel-correlation. The mixture coefficients are totally unknown, while some knowledge about temporal model exists. Results show that the proposed algorithm can bring about the exactness and low computational complexity.

关键词： DS/CDMA signal non-cooperative MBD stochastic gradient algorithms for MBD.

Improved algorithms to plan missions for agile earth observation satellites

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Journal of Systems Engineering and Electronics 2014年第5期25卷 811-821页

作者： Huicheng hao Wei jiang Yijun Li Research Center of Information Management and Information Systems Harbin Institute of Technology School of Engineering Northeast Agricultural University

This study concentrates of the new generation of the agile （AEOS）. AEOS is a key study object on management problems earth observation satellite in many countries because of its many advantages over non-agile satellites. Hence, the mission planning and scheduling of AEOS is a popular research problem. This research investigates AEOS characteristics and establishes a mission planning model based on the working principle and constraints of AEOS as per analysis. To solve the scheduling issue of AEOS, several improved algorithms are developed. Simulation results suggest that these algorithms are effective.

关键词： mission planning immune clone algorithm hybrid genetic algorithm (EA) improved ant colony algorithm general particle swarm optimization (PSO) agile earth observation satellite (AEOS).

Stability analysis of switched positive nonlinear systems: an invariant ray approach

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Science China(Information Sciences) 2019年第11期62卷 174-188页

作者： hao YANG Xudong Zhao Bin jiang College of Automation Engineering Nanjing University of Aeronautics and Astronautics School of Control Science and Engineering Dalian University of Technology

This paper addresses the stability problem associated with a class of switched positive nonlinear systems in which each vector field is homogeneous, cooperative, and irreducible. Instead of using the Lyapunov function approach, we fully establish the invariant ray analysis method to establish several stability conditions that depend on the states, rays, and/or times. We illustrate the efficiency of our proposed approach using the example of a chemical reaction.

关键词： positive systems switched nonlinear systems stability

Recent progress in gold nanoparticle-based biosensing and cellular imaging

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Science China Chemistry 2016年第7期59卷 783-793页

作者： Haiyang Peng hao Tang Jianhui jiang State Key Laboratory of Chemo/Bio-Sensing and Chemometrics College of Chemistry and Chemical Engineering Hunan University

Gold nanoparticles(Au NPs) have been extensively used in optical biosensing and bioimaging due to the unique optical properties. Biological applications including biosensing and cellular imaging based on optical properties of Au NPs will be reviewed in the paper. The content will focus on detection principles, advantages and challenges of these approaches as well as recent advances in this field.

关键词： gold nanoparticle optical functionalization biosensing cellular imaging

Recent Advances in Two-dimensional Materials for Electrochemical Energy Storage and Conversion

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Chemical Research in Chinese Universities 2020年第1期36卷 10-23页

作者： YANG Chao WANG hao-Fan XU qiang AIST-Kyoto University Chemical Energy Materials Open Innovation Laboratory(ChEM-OIL) National Institute of Advanced Industrial Science and Technology(AIST)YoshidaSakyo-kuKyoto 606-8501Japan School of Materials Science Japan Advanced Institute of Science and Technology1-1 AsahidaiNomi 923-1292Japan

With the increased energy demand,developing renewable and clean energy technologies becomes more and more significant to mitigate climate warming and alleviate the environmental *** key point is design and synthesis of low cost and efficient materials for a wide variety of electrochemical *** the past ten years,two-dimensional(2D)nanomaterials that graphene represents have been paid much attention as a class of the most promising candidates for heterogeneous electrocatalysts in electrochemical storage and *** unique properties,such as good chemical stability,good flexibility,and good electronic properties,along with their nanosized thickness and large specific area,make them exhibit comprehensively good performances for energy storage and ***,we present an overview on the recent advances in electrochemical applications of graphene,graphdiyne,transition metal dichalcogenides(TMDs),and MXenes for supercapacitors(SCs),oxygen reduction reaction(ORR),and hydrogen evolution reaction(HER).

关键词： Two-dimensional material Graphene Graphdiyne Layered transition-metal dichalcogenide MXene Energy storage and conversion

Optimization methods for regularization-based ill-posed problems： a survey and a multi-objective framework

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Frontiers of Computer Science 2017年第3期11卷 362-391页

作者： Maoguo GONG Xiangming jiang hao LI Key Laboratory of Intelligent Perception and Image Understanding of Ministry of Education Xidian University Xi'an 710071 China

Ill-posed problems are widely existed in signat processing. In this paper, we review popular regularization models such as truncated singular value decomposi- tion regularization, iterative regularization, variational regularizafion. Meanwhile, we also retrospect popular optimiza- tion approaches and regularization parameter choice meth- ods. In fact, the regularization problem is inherently a multi- objective problem. The traditional methods usually combine the fidelity term and the regularization term into a single- objective with regularization parameters, which are difficult to tune. Therefore, we propose a multi-objective framework for ill-posed problems, which can handle complex features of problem such as non-convexity, discontinuity. In this framework, the fidelity term and regularization term are optimized simultaneously to gain more insights into the ill-posed prob- lems. A case study on signal recovery shows the effectiveness of the multi-objective framework for ill-posed problems.

关键词： ill-posed problem regularization multi- objective optimization evolutionary algorithm signal processing

Fault-tolerant flocking control against multiple malicious agents under geometric configuration containment

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Science China(Information Sciences) 2024年第10期67卷 261-282页

作者： Chencheng ZHANG hao YANG Bin jiang College of Automation Engineering Nanjing University of Aeronautics and Astronautics Institute of Engineering and Technology (ENTEG) University of Groningen

Flocking control in the presence of malicious decisions is a crucial research topic since agents in swarms are likely to suffer from security issues in practice. This paper considers a swarm containing malicious agents that deliberately alter their controller parameters and disrupt the swarm by causing collisions,divisions, and escapes. Two possible malicious scenarios are considered. The first is that one malicious agent acts selectively on a subset of its neighbors and the second is that multiple malicious agents are either scattered or clustered together. To achieve the flocking control objective:(1) containment conditions based on specific geometric configurations are established;(2) hierarchical fault-tolerant flocking control methods based on those containment conditions are proposed. Compared to existing research dealing with malicious agents in swarms, our approach aims to contain rather than remove them. This guarantees the completeness of the task and takes agents' motions into consideration. Simulations show the effectiveness of the proposed methods.

关键词： flocking control fault-tolerant control multiple malicious agents geometric configuration

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RESERVOIR SEDIMENTATION AND TRANSFORMATION OF MORPHO-LOGY IN THE LOWER YELLOW RIVER DURING 10 YEAR'S INITIAL OPERATION OF THE XIAOLANGDI RESERVOIR

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Journal of Hydrodynamics 2012年第6期24卷 914-924页

作者： CHEN Jian-guo ZHOU Wen-hao CHEN qiang International Research and Training Center on Erosion and Sedimentation(IRTCRS) China Institute of Water Resources and Hydropower Research(IWHR)

The Xiaolangdi Hydro-Project is one of the large projects on the main stem of the Middle Yellow River. It has been operated for more than 10 years, since its impoundment in October, 1999. The reservoir has trapped 2.833 × 10^9 m3 of sediment, and caused the total erosion of 1.891 × 10^9t in the Lower Yellow River from October, 1999 through October, 2010. Not only the serious atrophied situation of the Lower Yellow River （LYR） has been resuscitating, but also many new phenomena of sediment transport and behaviors of channel re-establishing are coming into being. They are illustrated and discussed in detail in this paper.

关键词： reservoir sedimentation density current water-sediment regulation artificial flood channel siltation and erosion,erosion efficiency river configuration