市场经济全球化趋势与民主全球化趋势

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。     

中国航天提供全球化服务

4月8日．在西昌举行的“长征”火箭用户大会上获悉．中国航天利用资源卫星数据．提供全球化服务．展示出了中国航天积极承担国际义务与责任的形象。     

基于灰色关联模型的遥测数据趋势异常分析

为分析和判断火箭遥测数据的趋势异常,提出一种基于改进关联模型的趋势异常分析方法.针对遥测数据量大、局部特征时轴偏移及幅值偏差累积、不同时段重要程度不同等特点,对文献[11]中关联模型进行了适应性改进,引入均衡度概念,根据权重系数和关联度定义分段异常度、异常均衡度和异常关联度,用以综合评价遥测数据与历史数据的整体趋势一致...     

航天器动力学环境试验的发展概况和趋势

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.     

导航卫星遥测数据趋势预测技术研究

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。     

基于新型经验模分解的激光陀螺漂移趋势项提取

为了提高激光陀螺建模精度进而提高惯件导航系统的精度,需要对激光陀螺漂移时间序列的趋势项进行精确提取.针对陀螺漂移时间序列非线性、非平稳的特点,提出一种基于自适应正弦延拓的新型经验模分解方法对其趋势项进行提取.该方法根据信号端点附近数据变化趋势,在其两端加上适当相位、幅值和频率的正弦延拓函数,从而抑制端点效应,提高分解精度.数字仿真和实例应用结果表明该方法具有筛选次数少,自适应能力强,分解精度高的优点,是提取趋势项的一种有效方法.     

提高趋势预报发布率的方法分析

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     

基于新息趋势的纳卫星地磁定轨

针对地磁定轨系统受地磁偏差影响精度不高的问题,提出了一种基于新息趋势的自适应地磁定轨算法(AKF).该算法将地磁偏差建模为随机游走模型,使之参与滤波.在滤波器运行过程中,依据新息的变化趋势,实时调整滤波器状态.以Swarm-A卫星的观测数据的实验表明,该算法和传统滤波器相比具有计算量低,收敛速度快,定位精度高等优点.通...     

集成电路选用趋势研究

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.     

欧洲电冰箱的三大技术趋势

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.     

Globalization and commercialization of satellite broadcasting: current issues

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.     

Globalization, commercial space and spacepower in the USA

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.     

“文明对话”与“全球伦理”:全球化进程中儒学的可能贡献

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"。     

基于刚体转动四元数模型的航天器再定向方案

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。     

Determination of parameters of attitude motion of a small communication satellite using the data of measurements of current of solar panels

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.     

攻角变化对超音速进气道再起动特性的影响

以二维非定常可压缩流的N-S方程为控制方程,采用SST k-ω湍流模型对攻角变化引起的超音速进气道再起动过程进行了数值模拟,研究了攻角变化对超音速进气道再起动特性的影响.结果表明,当超音速进气道不起动时,可通过合理改变攻角实现进气道的再起动工作;超音速进气道的再起动攻角随攻角变化速率的增大近似呈线性增加;攻角变化速率较...     

On solving the problems of optimization of trajectories of many-revolution orbit transfers of spacecraft

The problem of optimal control over many-revolution spacecraft orbit transfers between circular coplanar orbits of satellites is considered. The spacecraft flight is controlled by a thrust vector of a jet engine with restricted thrust (JERT). The mass expenditure is minimized at a limited time of flight. The optimal control problem is solved based on the maximum principle. The boundary value problem of the maximum principle is solved numerically using the shooting method. A modified computation scheme of the shooting method is suggested (multi-point shooting), as well as a method (correlated with the scheme) of choosing the initial approximation with the use of a solution to the optimization problem in the impulse formulation. The scheme and method allow one to construct many-revolution spacecraft orbit transfers.     

热变形对一种天线指向机构指向精度的影响分析

热变形对天线指向机构的指向精度具有重要影响,但利用传统的设计方法很难实现对指向精度的准确计算,尤其是热变形对指向精度影响的研究工作更是少见。为此建立了机构的三维实体热-结构耦合有限元分析模型,根据有限元分析结果并结合机构的运动链关系,构建了各关键运动副运动误差的计算方法;在此基础上实现了机构指向误差的计算,研究了运动副名义、最大以及最小配合间隙条件下,温度载荷对各关键运动副运动误差和指向精度的影响。研究结果表明,温度载荷对关键运动副的运动误差以及机构的指向精度具有重要影响,随着温度载荷偏离常温数值的增加,指向误差不断增大,名义配合间隙条件下的指向误差最大。