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211.
NASA research programs offer many opportunities for productive partnerships with investigators in other countries. While spacecraft projects are complex and very expensive, there are other, lower-cost partnerships that can yield important scientific results and offer excellent opportunities for building up new space and Earth science programs and for training new researchers.  相似文献   
212.
综述了量子光谱成像技术的发展概况,简述了量子光谱成像原理的理论,详细介绍了纠缠双光子源的鬼成像,亚波长干涉以及热光的无透镜成像和热光的非定域双缝干涉实验及其原理。最后对量子光谱成像技术在未来的军用和民用对地观测的应用方面做出了展望。  相似文献   
213.
On 11 March 2011, an undersea earthquake of magnitude 9.0, the largest ever recorded in Japan, occurred off the Oshika Peninsula on the Pacific coast of the Tohoku region. The hypocentral region extended for 500 km in the north–south direction from Iwate Prefecture to Ibaraki Prefecture, and for 200 km in east–west direction. The earthquake generated a tsunami with a height of more than 10 m and a run-up height of up to 40.0 m in certain places, which inflicted devastating damage on the coastal areas of the Tohoku and Kanto regions. In addition to the tsunami, the earthquake caused shaking, liquefaction, subsidence, and the collapse of dams, causing major damage to vast areas in the Tohoku and Kanto regions and disrupting various types of infrastructure, including communication. In light of this unprecedented damage, satellite communications were important from various perspectives while terrestrial communications systems were damaged, and an objective evaluation of the role played by satellite communications is relevant to its future installation, adoption and use as a standalone or backup system. Furthermore, satellite communications can help reduce the extent of damage, particularly damage to communications systems, inflicted by strong earthquakes in the future. Accordingly, we report a preliminary quantitative evaluation of the role of satellite communications in the Great East Japan Earthquake, of the role of satellite communications if it becomes widespread, and of its expected role in future large-scale earthquakes in terms of the economic effect converted into cost.  相似文献   
214.
如何解决异地异构网络环境下的数据资源共享,是实现网络化制造的一个关键问题.提出了基于WebServices技术的数据资源共享系统.介绍了WebServices技术及其优势,对系统的总体架构与逻辑结构进行了方案设计,对各层的功能进行了阐述,在方案设计的基础上,对所涉及的关键技术进行了论述,最后对下一步的工作进行了描述与展望.  相似文献   
215.
系统阐述了数值模拟技术这一新兴手段在钻地武器研制中的主要算法及应用,比较了算法之间的优缺点,介绍了当今流行的各种主要计算程序。作为算例,运用非线性动力有限元LS-DYNA计算程序,对一个防空建筑在弹头侵彻下的动态响应及应力变化情况作了计算,图像形象显示了战斗部在侵彻过程中的形变及其速度,质量随时间的变化情况,最后阐述了数值模拟技术在武器设计等领域的应用。  相似文献   
216.
激励理论与人力资源管理中员工的有效激励   总被引:8,自引:1,他引:7  
激励作为一种组织内部的管理手段,对组织内部发展和员工的积极性提高方面有着不可估量的作用.结合传统的激励理论对组织内部激励策略的解释,分析了激励对提高组织绩效、优化组织管理、增强组织向心力等方面的作用,以及如何依据组织内部条件对员工进行有效激励.  相似文献   
217.
为了提高保障系统的能力,本文对备件和保障设备的组合优化方法进行了研究。首先建立反映备件和保障设备之间复杂定量关系的备件短缺量模型;其次以上述模型为优化目标,考虑经济性约束,建立组合优化模型;并通过考虑重要度等级的边际效应分析法进行求解;最后通过实例验证了上述方法和模型的有效性。该项研究可为备件和保障设备的组合优化提供技术手段,进一步为多种保障资源的综合优化提供指导。  相似文献   
218.
针对如何部署光学探测设备才能更好实现对空间目标的高精度高频度监视问题,考虑光照条件、相对关系及探测性能,构建了天/地基空间目标探测与成像仿真模型;按照轨道特征选取了94颗LEO(Low Earth Orbit,低地球轨道)卫星、63颗GEO(Geosynchronous Earth Orbit,地球同步轨道)卫星和18颗大椭圆轨道卫星,选用春夏秋冬典型季节的特定时间长度,仿真分析了国内地基、南北极科考站、LEO卫星、准GEO卫星等多平台光电手段的位置探测和成像观测能力;比对分析地基平台纬度和季节、天基平台轨道高度和倾角对探测能力的影响得出:南北极科考站相比于国内站点可提高重点季节的探测时效性,98°倾角LEO平台对低轨目标成像时效性方面更具优势,等.在此基础上,提出了我国空间目标光电观测设备天地一体的布局构想.  相似文献   
219.
In this study, the impact of Earth’s magnetic field on total electron content (TEC) was studied by using statistical multiple linear regression model and co-integration method. TEC values were measured over the Turkey-Istanbul (ista) station using date of global positioning system (GPS), and the magnetic field components of the Earth were measured from Boğaziçi University, Kandilli Observatory and Earthquake Research Institute, Geomagnetic observatory Istanbul (ISK) station. This examination has been carried out during the dates of March 14–19, 2015 covering the dates of March 17–18, 2015 known in the literature as St. Patrick's Day geomagnetic storm. The three days before the storm (March 14–16) were named as quiet days, whereas the other days (March 17–19) were named as disturbed days after which the two periods were examined separately. It was observed as a result of the examination that the x-component (south-north direction) of the magnetic field had a negative impact on TEC on quiet days, whereas the impact was positive on disturbed days. However, the y-component (east–west direction) of the magnetic field had an inverse relationship of the x-component on the quiet and disturbed days. In addition, it was deduced that the impact coefficient of the x and y-component of the magnetic field was higher on disturbed days in comparison with those on quiet days. The correlation coefficient between the TEC and the components of the Earth’s magnetic field was 0.11 on quiet days and 0.95 on disturbed days. Therefore, it can be stated that the relationship of the TEC values with the geomagnetic field are higher on disturbed days.  相似文献   
220.
Time variations of the magnetic field of the Sun, seen as a star (the data 1968–2018, with more than 27 thousand daily measurements of the solar mean magnetic field), allowed to specify the rotation period of the gravitating solar mass: 27.027(6)?days, synodic. This indicates a presumably unknown physical connection between motions of the Sun and the Earth: in the course of a year our star accomplishes nearly 27 half-revolutions, while the planet itself performs an identical number of its spinnings during one complete axial revolution of the Sun. True origin of this strange Sun–Earth resonance is unknown, but it is supposed the phenomenon might be caused by slight coherent perturbations of gravity within the solar system.  相似文献   
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