共查询到19条相似文献,搜索用时 62 毫秒
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市场经济的出现和发展空前地拓展了人的自由和民主。市场经济全球化趋势,又使民主具有了全球化的趋势。而市场经济全球化构成了民主全球化的经济基础。在此基础上,本文还探讨了民主全球化在当代的一些主要表现。 相似文献
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航天器动力学环境试验的发展概况和趋势 总被引:7,自引:3,他引:4
文章介绍了20世纪航天器动力学环境试验技术的发展概况和趋势,特别就试验技术的发展作了较详细的阐述.文章指出,试验工作对解决实际的问题仍然是主要的和基础的手段. 相似文献
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导航卫星遥测数据趋势预测技术研究 总被引:1,自引:0,他引:1
《航天器工程》2017,(3):70-77
介绍了基于遥测数据的趋势预测方法、基于物理模型的趋势预测方法和基于知识的趋势预测方法的适用对象和特点。文章对导航卫星遥测数据进行了分类,重点研究了基于遥测数据的趋势预测方法,给出了各类算法的适用性;并针对传统SumSin模型、ARMA模型的局限,给出了改进措施和实现流程。最后搭建了验证系统,用于上述算法的验证和导航卫星参数的提前预警。 相似文献
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引言2009年民航局空管局开展航空气象服务年活动,并制定趋势预报发布率统计办法,统一评比2009年各月的趋势预报发布率。本文收集了2009年3~11月汕头外砂机场趋势预报发布资料,在分析研究2009年3~11月汕头机场趋势 相似文献
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以新型号设计所选用的集成电路(核心的数字及模拟集成电路)为依托,选取集成电路的特征参量并进行型号规格的合并,特征参量的提取,对参量逐一统计分析,通过量化分析,提出航天产品选用集成电路的趋势与对策. 相似文献
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今年欧洲各城市流动展出的家用电器展览会表明,电冰箱制造有三大趋势:电功率效率更高;价格合理;无霜并普遍采用电子控制.此外很多厂商推出了组合式厨房柜,使厨房面积利用率更高,使用更舒适.重视双门家用冷冻冰箱的节电是理所当然的,尤其在西德等国,他们一年四季连续地使用冰箱.于是AEG公司率先重新设计了机柜(例如隐藏式蒸发板).它的最新产品是240升的冰箱,耗电量为0.7度/日,比一只30瓦灯泡的耗电量还要少. 相似文献
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The issues of freedom of information and protection of national sovereignty have been brought to the fore by the global spread of satellite broadcasting. This article discusses the issues and the international legal strategies that have been adopted to deal with them. It is suggested that the European model—in which states have no right to interfere with reception but broadcasters are obliged to fill 50% of their content with European programs—presents a blueprint that others could follow. 相似文献
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Economic and commercial spacepower is about market dominance and control. The USA is still the largest investor in space in the world and the technological and commercial leader in many areas but its leadership is being challenged. When other nations have similar capabilities, control becomes a problem, assuming, as is the case with space, that control is also a critical issue in security. Moreover, exerting spacepower may be inconsistent with expanded commercial developments in space, raising investment risks and creating incentives for foreign competitors. To the extent that global market opportunity is denied by restrictive commercial policies, spacepower from a purely international economic competitive perspective is diminished. Though it is encouraging that the US commercial space policies have been in Presidential Documents over the past 20 years, they have been unintentionally undermined to a large extent by other policies, with security almost always trumping commerce. This paper examines the way globalization and commercial space developments have changed the nature of spacepower and suggests that the USA's reactions to these changes have not thus far served it well. 相似文献
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《北华航天工业学院学报》2017,(4)
随着全球化和现代化的不断发展,世界各地的文明的差异并不会消失而呈现"同质化"的面貌,相反,本地化和根源性会与之并行不悖,文明的多样性仍然存在,并构成文明对话的前提。杜维明先生针对亨廷顿所提出的"文明冲突论"指出,解决问题的唯一出路是不同文明之间的对话。他进一步探讨了文明对话的原则、方法和愿景,提出儒家思想中的"和而不同"乃是文明对话的前提,而"己所不欲,勿施于人"则可作为对话的"黄金规则"。 相似文献
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介绍了一种新的刚体转动的四元数模型。这些模型可以提高再定向控制的对边界条件的适应能力,在此基础上还介绍了这些模型的一些实际应用。 相似文献
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A. A. Davydov 《Cosmic Research》2011,49(4):335-344
A communication satellite (small spacecraft) injected into a geosynchronous orbit is considered. Flywheel engines are used
to control the rotational spacecraft motion. The spacecraft after the emergency situation has passed into a state of uncontrolled
rotation. In this case, no direct telemetric information about parameters of its rotational motion was accessible. As a result,
the problem arose to determine the rotational satellite motion according to the available indirect information: current taken
from the solar panels. Telemetric measurements of solar panel current obtained on the time interval of a few hours were simultaneously
processed by the least squares method integrating the equations of rotational satellite motion. We present the results of
processing 10 intervals of the measurement data allowing one to determine the real rotational spacecraft motion and to estimate
the total angular momentum of flywheel engines. 相似文献
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为满足航天器微振动环境模拟的需要,开展了多自由度微振动时域波形复现控制方法研究。首先,介绍了基于时域波形复现的多自由度微振动环境模拟控制理论方法。其次,针对六自由度微振动激励系统,应用MATLAB软件建立了基于实测传递函数矩阵的多输入多输出微振动激励仿真系统,针对微振动时域波形复现闭环控制过程进行了算法编程,并给出了仿真的闭环控制流程图。最后,通过算例对多自由度微振动时域波形复现进行了数值仿真,以给定的白噪声为输入,模拟对实际存在的系统非线性、测量误差等影响因素的控制效果。仿真结果验证了多自由度微振动时域波形复现控制方法的可行性及有效性,所得结论可以为研究多自由度微振动时域波形复现控制系统提供参考。 相似文献