罗罗参与美国下一代军用发动机研制

罗罗公司凭借其独特的技术能力进入了美国军用航空发动机领域,不仅在F136上与GE公司展开合作,甚至在美国下一代军用发动机研制上与GE站在了同一条起跑线上,而另一家美国军用发动机巨头普惠则尚未出发。     

可变形旋翼技术

<正>伊拉克战争和阿富汗战争的经验表明,旋翼机技术亟待大幅改善。随着美国军方对速度、载荷和机动性要求的不断提高,旋翼机的使用可用性、任务可靠性和后勤保障性都成为     

2018全球MRO市场十大新发展方向

正2018年,全球民用航空售后服务市场,将是更加高效的一年。因为2018年全球将有2100架新飞机交付使用,再加上现有的机队规模,市场基本需求非常强劲,高效运营是必需的。以下是2018年值得关注的10个新发展方向。在它们的引领下,高效运营才可能实现。虚拟现实增强现实和虚拟现实将继续牵引维修培训、远程维修支援、航线维修和MRO流程改进。     

VLF electromagnetic waves observed onboard GEOS-1

This paper is concerned mainly with the information which can be extracted from frequency-time spectra in the VLF range. The instrument used is the correlator which has a good frequency resolution (50 Hz) and time resolution (30 ms) in one magnetic and one electric component simultaneously. By suitable computer analysis, it is possible for instance to distinguish between the two dominant electromagnetic emissions, hiss and chorus, as well as to display the complete spectra. This treatment is applied to the Survey periods, which are a fixed sequence of modes, repeated every hour on the hour in order to have reference data from GEOS analogous to many ground-based observatories. One result of this treatment obtained already is that hiss and chorus normally appear together, although one or the other may be dominating in intensity. The occurrence rate of these emissions in local time is also given.For continuous surveillance the filterbank data are used. There are 16 frequency filters supplying magnetic and electric amplitude at few different frequencies. Using these data, a storm sudden commencement can be followed with good time resolution (1 s), and an interesting correlation has been found in a few cases between the VLF signal amplitude and the cold plasma density (as measured by the active part of the S-300 experiment).