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Calculation of laser induced collisional energy transfer in the Sr-Ca system

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science china(Physics,Mechanics & Astronomy) 2011年第2期54卷 256-261页

作者： LU ZhenZhong1,2.CHEN DeYing1,2.FAN RongWei1,2.& XIA YuanQin1,2.1 National Key Laboratory of science and Technology on Tunable Laser,harbin {2. of Technology,harbin 150080,china 2.{2. of Opto-electronics,harbin {2. of Technology,harbin 150080,china 1. National Key Laboratory of science and Technology on Tunable Laser Harbin Institute of Technology Harbin 150080 China2. Institute of Opto-electronics Harbin Institute of Technology Harbin 150080 China

Based on the four-state model of laser-induced collisional energy transfer,the cross section of the collisional energy transfer in the Sr-Ca system is *** factors,including field intensity,relative speed,and temperature,which influence the collisional cross section,are discussed for illustrating the features of the Sr-Ca laser-induced collisional energy transfer(LICET) *** calculated results show that the LICET spectral profiles obviously become narrower when the laser field intensity *** collision cross section rises with laser intensity and tends to *** the vicinity of the spectral profile center,the cross section at fixed laser detuning becomes smaller as the relative speed and system temperature *** results indicate that the intermediate states strongly affect the spectral profile of LICET.

关键词： laser-induced collisional energy transfer collision cross section Sr-Ca system

An improved nonlinear control strategy for deep space formation flying spacecraft

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Acta Mechanica Sinica 2009年第6期25卷 847-856页

作者： Peng Li Pingyuan Cui Hutao Cui Deep Space Exploration research center,{2. institute of Technology, 150080 {2., china Deep Space Exploration research center Harbin Institute of Technology 150080 Harbin China

This paper aims to provide further study on the nonlinear modeling and controller design of formation flying spacecraft in deep space missions. First, in the Sun-Earth system, the nonlinear formation dynamics for the circular restricted three-body problem （CRTBP） and elliptic restricted three-body problem （ERTBP） are presented. Then, with the Floquet mode method, an impulsive controller is developed to keep the Chief on the desired Halo orbit. Finally, a nonlinear adaptive control scheme based on Nonzero set- point LQR and neural network is proposed to achieve high precision formation maneuver and keeping. The simulation results indicate that the proposed nonlinear control strategy is reasonable as it considers not only the orbit keeping of the Chief, but also the formation modeling inaccuracy. Moreover, the nonlinear adaptive control scheme is effective to improve the control accuracy of the formation keeping.

关键词： Spacecraft formation flying. Libration pointHalo orbit - Nonlinear control

Wrinkle-crease interaction behavior simulation of a rectangular membrane under shearing

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Acta Mechanica Sinica 2011年第4期27卷 550-558页

作者： C.-G.Wang.H.-F.Tan.X.-D.He center for Composite Materials,harbin {2. of Technology,150080 harbin,china Post-doctoral research center in Material science and Engineering,harbin {2. of Technology,150001 harbin,china center for Composite Materials Harbin Institute of Technology Harbin China Post-doctoral research center in Material {2. and Engineering Harbin Institute of Technology Harbin China

Wrinkling analysis of a rectangular membrane with a single crease under shearing is performed to understand the wrinkle-crease interaction behaviors. The crease is considered by introducing the residual stresses from creasing and the effective modulus into the baseline configuration with assumed circular cross-sectional crease geometry. The wrinkling analysis of the creased membrane is then performed by using the direct perturb-force （DP） simulation technique which is based on our modified displacement components （MDC） method. Results reveal that the crease may influence the stress transfer path in the membrane and further change the wrinkling direction. The crease appears to improve the bending stiffness of the membrane which has an effective resistance on the wrinkling evolution. The effects of the crease orientation on wrinkle-crease interaction are studied toward the end of this paper. The results show that the wrinkling amplitude, wavelength, and direction increase as the crease orientation increases, and the wrinkling number decreases with the increasing crease orientation. These results will be of great benefit to the analysis and the control of the wrinkles in the membrane structures.

关键词： Membrane structure - Wrinkle-crease interac-tion Membrane wrinkling Creased membrane

Uniqueness and stability in an inverse problem for a Poisson's equation

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science china Mathematics 2007年第7期50卷 967-976页

作者： Li-xin FENG~(1+) Yan-cheng QU~2.1 School of Mathematical sciences,Heilongjiang University,harbin {2.,china 2.research center of Control and Inertial Technology,harbin institute of Technology,harbin 150001,china 1. School of Mathematical sciences Heilongjiang University Harbin 150080 China 2. research center of Control and Inertial Technology Harbin Institute of Technology Harbin 150001 China

Consider the Poisson’s equation Ψ″ (x) = ?e v?Ψ + e Ψ?v ? N(x) with the Dirichlet boundary data, and we mainly investigate the inverse problem of determining the unknown function N(x) from a parameter function fa... 详细信息

关键词： Poisson’s equation well-posedness inverse problem 65N30 35R30

Basic solution of two parallel Mode-I cracks in functionally graded materials

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science china(Technological sciences) 2008年第9期51卷 1380-1393页

作者： LIANG Jun center for Composite Materials and Structures, harbin {2. of Technology, harbin 150080, china center for Composite Materials and Structures Harbin Institute of Technology Harbin 150080 China

The solution of two parallel cracks in functionally graded materials subjected to a tensile stress loading is derived in this paper. To make the analysis tractable, it is assumed that the shear modulus varies exponentially with coordinate parallel to the crack. The problem is formulated through Fourier transform into four pairs of dual integral equations, in which the unknown variables are jumps of displace-ments across crack surfaces. To solve the dual integral equations, the jumps of displacements across crack surfaces are directly expanded as a series of Jacobi polynomials to obtain the shielding effects of the two parallel cracks in functionally graded materials.

关键词： parallel cracks shielding effects functionally graded materials

中国政治经济学年度发展报告（2.2.）（下）

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政治经济学评论 2024年第3期 90+207-208页

作者： center for Studies of Contemporary Political Economy,research {2. for 2.st-Century Marxism,Nankai University·University of Chinese Academy of Social science center for Teaching and research on Capital,Renmin University of china National {2. of Socialist Political Economy with Chinese Characteristics,Renmin University of china 南开大学·中国社会科学院大学2.世纪马克思主义研究院当代政治经济学研究中心中国人民大学《资本论》教学与研究中心中国人民大学全国中国特色社会主义政治经济学研究中心

编者按2.2.年，高质量发展扎实推进，新质生产力加快形成，我国经济总体回升向好，圆满实现发展主要预期目标。为针对性地破解经济恢复发展中的难题，聚焦推进中国式现代化进程中的重点、难点问题，中国政治经济学界开展系统深入研究，...

编者按2.2.年，高质量发展扎实推进，新质生产力加快形成，我国经济总体回升向好，圆满实现发展主要预期目标。为针对性地破解经济恢复发展中的难题，聚焦推进中国式现代化进程中的重点、难点问题，中国政治经济学界开展系统深入研究，取得系列代表性成果。为准确刻画学界研究进展和轨迹，推动中国经济学理论体系的构建和完善，本刊精选议题如期奉上《中国政治经济学年度发展报告（2.2.）》。自2.10年起，本刊连续十四年发布《中国政治经济学年度发展报告》，“年度发展报告”专栏已成为本刊标志性特色栏目。2.2.年报告聚焦12.专题，分为（上）（下）两篇，其中专题1—6于报告（上）篇刊登，专题7—12.报告（下）篇刊登。2.2.年报告（下）选题如下：

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Finite time L_1 Approach for Missile Overload Requirement Analysis in Terminal Guidance

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Chinese Journal of Aeronautics 2009年第4期22卷 413-418页

作者： Ji Denggao,He Fenghua,Yao Yu Control and Simulation center,harbin {2. of Technology,harbin 150080,china [a]Control and Simulation center Harbin Institute of Technology Harbin 150080 China

This article analyzes the problem about the missile overload requirement in a homing terminal guidance under various engagement scenarios. An augmented proportional navigation guidance （APNG） model is introduced on the basis of linear kinematics. To analyze the peak-to-peak performance of the terminal guidance system, a new finite time L1 performance measure for a linear time-varying （LTV） continuous system is proposed. Then, according to the idea of the adjoint system, a novel method for computing the L1 norm of a linear continuous system is first derived. Within the finite time L1 framework, the quantitative relation between the guidance loop dynamics and the maximum missile-target maneuver ratio is offered. This relation is expressed in the form of graphs and formulas that can be used to synthesize some of the major subsystem specifications for the missile guidance system. The illustrative examples show that a significant performance improvement is achieved with the proposed guidance loop dynamics.

关键词： finite time Lx-induced norm performance time varying systems missile overload requirement terminal guidance

Experimental study on a transpiration cooling thermal protection system

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science china(Technological sciences) 2010年第10期53卷 2765-2771页

作者： LIU Shuang & ZHANG BoMing center for Composite Materials and Structure, harbin {2. of Technology, harbin 150080, china 1. center for Composite Materials and Structure Harbin Institute of Technology Harbin 150080 China

Transpiration cooling thermal protection systems (TPS) are investigated for potential applications in hypersonic and re-entry vehicles,which are subjected to the severe aerodynamic heating environment. In this paper a transpiration cooling thermal protection system was designed and manufactured,and an experiment platform with radiant heating at the bottom as heat source was developed. The cooling capacity of the transpiration cooling TPS was experimentally investigated. By combining transpiration cooling method with traditional TPS,the heat load capability of the TPS can be improved. The structure temperature with active cooling applied was much lower than that without active cooling applied under the same heat load as well as the heat load increased with active cooling than the one without active cooling for the same structure temperature. The experimental results showed that at 5800 s,the temperature of inner structure was 100°C with active cooling applied compared to 500°C without active cooling applied,then the temperature increased and reached to 360°C at 8300 s. Heat load of this transpiration cooling TPS can be increased by over 70% as compared to the passion one and the cooling capability of the transpiration TPS was about 1700 kJ/kg. The results can provide fundamental data for developing the transpiration cooling TPS.

关键词： thermal protection metallic thermal protection system active cooling transpiration cooling cooling capacity

Monocular vision-based iterative pose estimation algorithm from corresponding feature points

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science china(Information sciences) 2010年第8期53卷 1682-1696页

作者： ZHANG ShiJie 1 , CAO XiBin 1 , ZHANG Fan 1 & HE Liang 2.1 research center of Satellite Technology, {2. institute of Technology, harbin 150080, china 2.Shanghai Aerospace Control Engineering institute, Shanghai 2.02.3, china 1. research center of Satellite Technology Harbin Institute of Technology Harbin 150080 China2. Shanghai Aerospace Control Engineering Institute Shanghai 200233 China

To determine the relative pose between an object and a single camera using 2.-to-3D point correspondences, a kind of iterative methods based on inverse projection ray approach is proposed. An iterative algorithm which is divided into depth recovery stage and absolute orientation stage is also proposed. In the first stage, the optimal translation vector is first computed in terms of rotation matrix via least square method, then the depths of the observed points are estimated by projecting the estimated point orthogonally to the inverse projection ray defined by the image point, and finally 3D points are reconstructed using the estimated depths from previous step. In the second stage, the optimal rotation matrix is estimated by applying Umeyama algorithm to fitting of the 3D model points and 3D estimated points. The above two stages are repeated until the result converges. The global convergence of the two-stage iterative algorithm is proven based on the global convergence theorem. Finally, a spacecraft docking application is implemented to test the effectiveness and convergence of the proposed algorithm by mathematical simulation and physical simulation.

关键词： monocular vision feature point relative pose two-stage iterative algorithm global convergence