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351.
352.
关于高职高专数控专业实训与实训基地建设探讨 总被引:2,自引:0,他引:2
数控专业人才是国家级紧缺人才,为了能更好、更快地培养满足社会需求的有用人才,必须重视和加强实训建设,本文就实训环节的安排、实训基地的建设及师资队伍的建设等问题进行了探讨。 相似文献
353.
零春 《桂林航天工业高等专科学校学报》2005,10(3):61-63
论文对雅思考试的特点及其对大学英语考试的影响进行分析,并阐述了雅思考试对大学英语教学改革的启示。 相似文献
354.
Leung-Pong Wong Yim-Shu Lee Ki-Wai Cheng D. Chow M.H.L. 《IEEE transactions on aerospace and electronic systems》2004,40(4):1294-1310
An interleaved two-phase forward converter using an integrated magnetic component is proposed for telecommunication and computer applications. The integrated magnetic component consists of two step-down transformers and two output-filtering inductors on a single magnetic core. The z-parameter (gyrator) model and the equivalent-circuit model of the integrated magnetic component are presented. The circuit operation and design criteria of the proposed converter are described. All theoretical analyses are verified by simulated and experimental results. 相似文献
355.
Honeycomb sandwich materials have been widely used in aerospace industry as secondary structural materials or interior panels. Recently the research of full thermoplastic honeycomb sandwich materials has been of interest due to their recyclability. In their production, they usually demand an adhesive-free process, namely fusion bonding, to connect thermoplastic honeycomb core and face sheets. It is a heat induced process where a parameter of temperature should be well controlled to guarantee the product quality. This article presents a mathematical model of heat conduction to analyze the transient temperature distribution from heating tools towards inner part of the core under fusion bonding conditions. In order to simplify the complexity of 3D honeycomb geometry, a homogenization method is used to obtain average thermal properties of the honeycomb along the major heat flux direction. The model is validated by comparing with the results of in-situ temperature measurement during fusion bonding. The presented model can also be applied to analyzing general out-of-plane heat conduction through honeycomb sandwich structures made from other materials. 相似文献
356.
C.-H. Chun 《Acta Astronautica》1978,5(9):681-686
An experimental verification of Marangoni convection in the liquid inter-space between two-coaxial discs is carried out at reduced gravity effect using small Bond's number obtained by choice of small characteristical diameter. Silicon oil is used as working fluid. The upper or lower disc can be heated electrically. The flow is visualized by illuminating fine powder of Titandioxide in the fluid with a vertical “light cut” of about 0.1 mm thickness, which is produced by a laser with a cylindrical glass rod and a microscope objective. Photographs and moving pictures are taken from a TV monitor. From these the vortex configuration and the velocity distribution can be determined, which would be expected for the Marangoni convection in the zero-g condition, for example in the spacelab. 相似文献
357.
Ch.-H. Chun 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1983,3(5):183-186
During a 6-minutes free flight of a sounding rocket an experiment on the thermal Marangoni convection in a right circular cylindric floating zone was carried out to verify the thermal Marangoni convection by flow visualisation for the first time at 10?4 g. From the motion picture analysis the velocity distributions are obtained. The interdependence between the two velocity maxima and the S-shaped temperature distribution on the free surface is discussed. The influence of the heat transfer caused by the flow of the surrounding air induced by the thermal Marangoni convection itself is considered briefly. 相似文献
358.
分布式内存数据库的恢复 总被引:1,自引:0,他引:1
对分布式内存数据库的恢复进行了讨论,内容包括:转储、分布式事务提交及日志。在最后提出了一个日志生成算法,该算法针对机群式环境下的应用,对两阶段提交协议(2-Phase-CommitmentProtocol)进行了改进,有着良好的实用前景。 相似文献
359.
360.
IMM(Interacting Multiple Model)滤波算法以混合状态系统的观点为基础,利用一个连续状态的微分方程来描述目标的运动,利用一个离散差分方程来描述目标的机动出现,从而建立了更为准确的目标运动模型。本文对该滤波算法进行了进一步的研究,总结了该算法的特点,指出了影响该算法性能的因素,并进行了细致的分析。 相似文献