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Experimental Study of Hypervelocity Impact on Multi-Shock Structure

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Journal of Beijing Institute of Technology 2004年第3期13卷 274-279页

作者：张庆明陈沿海黄风雷 State Key Laboratory for the Prevention and Control of Explosion Disasters Beijing Institute of Technology Beijing 100081 China

Hypervelocity impact tests on multi-shock shields are carried out in order to develop space structures (against) space debris impacts. Sheets of LY12 aluminum were used as bumpers. The total thickness of shield structure, which consists of several sheets with various thickness, is 3.0 mm or 2.0 mm. Results of the tests show that the type 0.5 mm+0.5 mm+0.5 mm+0.5 mm is a better choice of spacecraft shield structure.

关键词： hypervelocity multi-sheet structure debris cloud space debris

Clone Selection Algorithm with Niching Strategy for Computer Immune System

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Journal of Beijing Institute of Technology 2004年第2期13卷 169-173页

作者：张雅静侯朝桢薛阳 School of Information Science and Technology Beijing Institute of Technology Beijing100081 China .School of Computer Yantai University Yantai Shandong 264005 China

A clone selection algorithm for computer immune system is presented. Clone selection principles in biological immune system are applied to the domain of computer virus detection. Based on the negative selection algorithm proposed by Stephanie Forrest, combining mutation operator in genetic algorithms and niching strategy in biology is adopted, the number of detectors is decreased effectively and the ability on self-nonself discrimination is improved. Simulation experiment shows that the algorithm is simple, practical and is adapted to the discrimination for long files.

关键词： clone selection negative selection mutation computer immune system change detection

Experimental Study and Numerical Simulation of Hypervelocity Projectile Impact on Double-Wall Structure

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Journal of Beijing Institute of Technology 2004年第3期13卷 280-284页

作者：陈沿海张庆明黄风雷 State Key Laboratory for the Prevention and Control of Explosion Disasters Beijing Institute of Technology Beijing100081 China

Tests of hypervelocity projectile impact on double-wall structure were performed with the front wall ranging from 0.5 mm to 2.0 mm thick and different impact velocities. Smooth particle hydrodynamics (SPH) code in LS-DYNA was employed for the simulation of hypervelocity impact on the double-wall structure. By using elementary shock wave theory, the experimental results above are analyzed. The analysis can provide an explanation for the penetration mechanism of hypervelocity projectile impact on double-wall structure about the effect of front wall thickness and impact velocity..

关键词： hypervelocity impact double-wall structure SPH space debris spacecraft shield

Inertia Matching During Dynamic Simulation of Vehicle Drive System on Test Bench

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Journal of Beijing Institute of Technology 2004年第2期13卷 197-201页

作者：宋强孙逢春郑慕侨顾进超 School of Mechanical and Vehicular Engineering Beijing Institute of Technology Beijing100081 China

Framework and basic parameters of a test bench for motor drive system of electric vehicle (EV) are illuminated. Two kinds of electric drive models, one was for the electric vehicle drived on real road, the other was for that on test bench, are put forward. Then, dynamic analysis of these models is made in detail. Inertia matching method of the test bench is researched and some useful formulas and graphs are brought forward. The experiment of an electric bus is introduced in order to explain the usage of this inertia matching method.

关键词： electric drive test bench framework dynamic analysis inertia matching

Underwater Distribution Field of Laser Through Wavy Surface of Water

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Journal of Beijing Institute of Technology 2003年第2期12卷 216-219页

作者：马泳杨克成林锦章 Department of Electronic and Information Engineering State Key Lab of Laser Technology

Aimed at the properties of the absorption and the scattering of photons in the water, the process of simulating by Monte Carlo method is analyzed. According to the slope distribution of wavy surface of water, the distribution field of underwater laser is simulated, and some conclusions about the distribution field of laser through wavy surface in two different conditions are obtained. The characteristics of the distribution of laser in the seawater at the same depth with different water qualities and in the seawater at different depths with the same water quality are computed. The results are significant to the design of airborne oceanic lidar.

关键词： Monte Carlo simulation photon scattering absorption