共查询到20条相似文献,搜索用时 62 毫秒
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
JSF是美国有史以来与其国际伙伴之间开展的规模最大的一宗重大武器系统采办项目.其中,洛克希德·马丁(简称洛马)公司是项目主承包商,英宇航系统公司和诺斯罗普·格鲁门(简称诺格)公司为项目的主要合作伙伴.目前由这3家组成的JSF项目团队正就JSF的售后持续保障问题,对该项目的8个国际工业参与国逐一进行游说,其目的是使这些国家在接收JSF的同时也接受由JSF项目合作团队提供的长达40年的综合售后持续保障服务. 相似文献
12.
Otto Schneider 《Space Science Reviews》1967,6(5):655-704
The general characteristics and dimensions of the earth's magnetosphere, turbulent transition region, and shock wave are reviewed and examined with regard to their possible active or passive interaction with the moon. The moon may, in turn, have a wake either detectable by space experiments outside the terrestrial shock wave or capable of interacting with the earth's shock wave, wake, or magnetospheric tail. The length and detectability of such a lunar wake depend, among other factors, on the selenomagnetic field and flow characteristics of the solar wind. Direct experimental information on a lunar wake is scanty, being, in fact, limited to one supposed case recorded by the IMP-1 satellite. Some evidence has been claimed, on the other hand, for statistical relationships between geomagnetic disturbance observed at the surface and the age of the moon. These results, however, are partly conflicting with each other as regards the phase of the supposed monthly variations, and partly are lacking statistical significance or merely grazing the significance level. The proximity of the lunar period with the length of the solar rotation, as well as a yearly and half-yearly modulation of the quasi-persistent 27-day fluctuations of geomagnetic disturbance contribute to encumber the question, rendering it very difficult, with the records presently available, to free the supposed lunar effects from solar interference. It seems, therefore, recommendable to postpone a judgement on the reality of such effects.Contribución del Instituto Antártico Argentino No. 109. 相似文献
13.
14.
15.
《Aerospace and Electronic Systems Magazine, IEEE》1988,3(1):8-10
Around 1890, the mining industry of Telluride, Colorado, was going broke because of the high cost of fuel for steam power, and alternative sources of power had to be found. The author describes the transition that was made to AC power. A 133 Hz, 3000 V generator was installed with a 6 foot Pelton water wheel at Ames, Colorado, that transmitted power for a distance of 2.65 miles. This was followed by a number of additional installations, and by 1896, the original system of 133 Hz was replaced by the Tesla system that used 60 Hz 相似文献
16.
在现今社会飞速发展,行业竞争日趋激烈,手工绘制机械图早已被设计人员所淘汰的日子里,机械设计人员必须使用大幅面打印机来完成多项工作. 相似文献
17.
The magnetopause is in continuous motion and shock waves and impulsive acceleration events can occur. As an example, we show
that the interaction of an interplanetary shock with the bow shock can generate a shock wave that after passing through the
magnetosheath can interact with the magnetopause. In fluid dynamics, when a shock wave encounters a fluid discontinuity, the
interface may become unstable and form bubbles and spikes. We consider this Richtmyer-Meshkov instability in magnetohydrodynamics.
At the dayside magnetopause, the instability tends to be stabilized by the magnetic field. However, the shock wave interaction
can initiate magnetic field reconnection for the southward IMF, which may be important in strong interplanetary shock events.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
18.
W. I. Axford 《Space Science Reviews》1973,14(3-4):582-590
The possibilities for making observations of the region of interaction between the solar wind and the interstellar medium, and of the interstellar medium itself, are discussed. It is emphasized that missions to the outer planets undertaken in 1977–1979 are ideally suited for making such observations.This is one of the publications by the Science Advisory Group. 相似文献
19.
20.
高职院校目前面临着多方面生存与发展的压力。运用波特模型对高职教育进行分析,有利于全面而客观地认识高职院校面临竞争的现状,并有助于找到高职院校生存和发展之路。 相似文献