利用GPS确定方位

导航导全球定位系统是军队用于定位，导航和精确定时的一种工具，美国陆军测绘工程中心目前正在研究ＧＰＳ用于陆军装备的定向，这项研究是陆军空技术研究办公室资助的。     

支线运输机的发展

文章是根据2001年5月在多伦多举行的加拿大航空与航天研究所年会鲁珀特特恩布尔演讲大会整理的，文章主要论述了支线飞机从开始至今的发展情况，今天是支线喷气式飞机占主导地位的时期，文中强调了其成功的关键因素，并且讨论了当今交通拥挤，机且成本和适用条款范围的问题，对比了在研新支线喷气飞机与现役客机，同时还和将来的实际需求进行了对比。为了避免交通拥挤以及使支线服务不断扩大，此文认为下一代支线喷气机应该考虑小机场和降低噪音。     

高压涡轮工作叶片叶型设计研究

针对高压涡轮工作叶片叶栅型面特征,采用可压燃气黏性流2维计算方法对高压涡轮工作叶片叶型进行了气动研究,并通过试验验证了优化设计,得到了叶栅气动设计参数。经与初始叶型对比,优化叶型在各状态下损失特性变化更为平缓,在超临界状态下效率更高,在λ2is=1.20状态下的损失减少了2.8%。该方法缩短了设计时间,并且节省了平面叶栅吹风试验的成本。     

美国导弹试验的组织指挥

介绍了20世纪60年代的洲际弹道导弹试验、20世纪70年代的巡航导弹试验和21世纪初的弹道导弹防御系统试验,由此推衍出美国不同时期导弹试验的组织指挥情况。从导弹武器试验模式的角度,总结出美军导弹试验任务组织指挥从独立试验阶段、联合试验阶段到一体化试验阶段的发展历程,为导弹武器系统试验组织指挥的建设提供借鉴与参考。     

Near Earth Vortices Driving of Field Aligned Currents Based on Magnetosphere Multiscale and Swarm Observations

A long-standing mystery in the study of Field-Aligned Currents (FACs) has been that:how the currents are generated and why they appear to be much stronger at high altitudes than in the ionosphere.Here we present two events of magnetotail FACs observed by the Magnetospheric Multiscale Spacecraft (MMS) on 1st July and 14th July 2016,to show how the Substorm Current Wedges (SCW) were formed.The results show that particles were transferred heading towards the Earth during the expansion phase of substorms. The azimuthal flow formed clockwise (counter-clockwise) vortex-like motion,and then generated downward (upward) FACs on the tailward/poleward side of the distorted field with opposite vorticity on their Earthward/equatorward side.We also analyzed the Region 1 FACs observed by the Earth Explorer Swarm spacecraft on 1st July 2016 and found that they were associated with FACs observed by MMS,although differing by a factor of 10.This difference suggests that either there was the closure of the currents at altitudes above 500 km or the currents were not strictly parallel to B and closed at longitudes away from where they were generated.      

Rapid and Asymmetric Response of the Earth's Bow Shock:Multipoint Observations

We analyze observations of three bow shock crossings which occurred during 2007, using upstream data from STEREO A/B, ACE and WIND, combined with multi-point THEMIS and Cluster data, and TC-1 data located near noon. During the crossing of 7 May 2007, we find that following a rapid reduction in solar wind ram pressure and subsequent pressure pulse seen by ACE and WIND upstream, the bow shock responds asymmetrically from dawn to dusk. Cluster data on the dawn-side suggest the bow shock is significantly flared and responds rapidly to the pulse arrival, while TC-1 at noon, and THEMIS on the dusk-side, are well matched to the model bow shock, but show a delayed response. The crossings observed on 21 May and 2 June show contrasting response matching the model boundary for northward Interplanetary Magnetic Field (IMF). The IMF and solar wind plasma data suggest that the bow shock crossing at dawn-dusk side and subsolar point were mainly caused by large and smaller scale features of the solar wind ram pressure rise rather than the influence of IMF.