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1.
通过对大直径平底负压容器平底板的设计计算,平底板计算厚度很厚。通过分析,提出了对平底板采取加强措施,从而减薄平底板计算厚度的方法。该容器在实际生产过程中性能可靠、稳定,对类似设备设计具有借鉴意义。 相似文献
2.
为了提高采油树平板闸阀密封圈的密封性能,在泛塞封的基础上,设计一种密封圈本体唇边开有锯齿状凸起的新型柔性密封结构;运用有限元分析方法模拟密封圈的工作状况,分析柔性密封结构特性参数对密封圈密封性能的影响,获得不同柔性密封圈结构参数下密封面间接触应力分布规律,并对新型密封结构进行优化。结果表明:密封面间最大接触应力随唇边锯齿数量、唇边夹角度数的增大而增大,随唇谷夹角度数的增大而减小;新型密封结构选择锯齿数量为3、唇边夹角为20°、唇谷夹角为30°的特性参数时,其最大接触应力比常规Y形密封圈提高了15倍;新型柔性密封结构的密封圈与阀杆、阀盖壁面间接触应力比常规Y形密封圈有显著提高,提高了密封圈的密封性能。 相似文献
3.
Dynamics of liquid-filled spacecraft 总被引:1,自引:0,他引:1
A method is presented for simulating coupled liquid-solid dynamics. An important example of a coupled liquid-solid system is a satellite carrying fuel. The dynamics of the satellite and the onboard fuel influence each other, which may lead to satellite motion that is uncontrollable. For better understanding of the complex dynamics of coupled systems, a numerical model is developed. The model consists of two parts. The first part that solves the liquid motion is only briefly discussed here. The focus in this paper is on the way in which the dynamics of the liquid and the solid body are coupled. For this, the governing equations are presented in which terms appear that represent the force and torque on the solid body due to the sloshing liquid. The governing equations are rewritten such that the discrete approximation of these equations can be integrated in a stable manner for arbitrary liquid/solid mass ratios. Results are presented demonstrating the stability of the present model. A grid-refinement study and a time-step analysis are performed. Finally, the flat-spin motion of a satellite, partially filled with liquid, that flew in 1992 as part of the Wet Satellite Model experiment is studied. Results from the simulation are compared with the actual flight data. 相似文献
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5.
介绍了平板显示控制芯片TO944的特点、功能、原理,并给出了基于T0944芯片的新型平板显示接口卡的软硬件实现方案,该方案具有电路简单、高可靠性、高性价比、高显示质量等优点,可用于各种不同类型与不同尺寸的平板显示器的显示。 相似文献
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Costas Chaikalis 《Wireless Personal Communications》2007,41(1):77-97
Reconfiguration concept represents reconfigurable functionalities of the radio interface for mobile radio systems. Particularly
for the physical layer, some possible reconfigurable architectures can be identified. We focus on outer interleaving for turbo
codes, which can improve their performance in flat Rayleigh fading environment. The larger the number of columns in the outer
interleaver, the better is the performance, but with the penalty of more complexity and delay. Furthermore, an incorrect choice
of the number of columns can increase the bit and frame error rates. Therefore, it would be advantageous to reconfigure the
outer interleaver in different operating environments with the optimum number of columns. Using two different data frame lengths,
in this contribution simulation results are presented for the four possible outer block interleaver configurations specified
for the 3GPP mobile standard in the case of flat Rayleigh fading channel. It is shown that different operating environments
require an optimum number of columns in terms of bit error rate and frame error rate performance. Finally, frame fade duration
is considered and the effect of the product of the Doppler frequency with the frame duration on the performance for the four
different 3GPP outer block interleaver configurations is discussed.
Costas Chaikalis was born in Athens, Greece, on March 7, 1973. He received the B.Sc. degree in electrical engineering in 1995 from Technological
Educational Institute of Lamia, Greece. He also received the M.Sc. and Ph.D. degrees from Department of Electronics and Telecommunications,
University of Bradford, Bradford, UK in 1999 and 2003, respectively. During his doctoral studies he worked as a Research Assistant
for Mobile Virtual Center of Excellence (Mobile VCE), Terminals Group, UK. Since 2003, he is a lecturer in the Department
of Electrical Engineering, Technological Educational Institute of Lamia, Greece. His research interests are in all areas of
mobile communications but especially in forward error correction coding, reconfigurable (software radio) architectures, cross
layer architectures and DSP applications. 相似文献
8.
冲切成槽法施工薄壁砼防渗墙,是一种新型防渗墙施工方法,它是利用特制的扁钻头对风化基岩或卵石层进行冲切成槽的施工方法,在工艺上有着较强的优越性. 相似文献
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Fan Jing yu Wang Dao zeng Zhong Bao chang Shanghai Institute of Applied Mathematics Mechanics Shanghai University Shanghai China 《水动力学研究与进展(B辑)》2003,15(2)
1 . INTRODUCTIONUndertheinfluenceofnaturaltides,theinterac tionsbetweenflowfeaturesandpollutantlongitudinaldiffusionintidalriversareimportantforwaterenvi ronmentrectificationinestuarineregions.Thediffu sionandtransportofpollutantinnaturalriversfallin tom… 相似文献