质量矩导弹的神经网络及自适应非线性控制

本文对质量矩控制导弹的动力学方程简化和控制系统的设计进行了研究。详细阐述了所提出的控制方法，介绍了径向基单隐层神经网络进行误差补偿的算法原理，用Lyapunov理论证明了所采用方法的稳定性。在给出了质量矩导弹的六自由度动力学方程和简化后的方程后，用所提出的方法设计控制系统。通过仿真分析，得出了本文所提出的方法具有较好的误差补偿能力的结论。     

飞机超差结构疲劳寿命量化评定

依据美机实用手册介绍的疲劳寿命S-N方程,对超差结构疲劳寿命推导出了一个量化评定方程。并应用该方程对一些典型结构超差形式具体地进行了疲劳寿命量化评定。实践证明,用本文介绍的方法对超差结构疲劳寿命进行定量评定,不仅简捷明快,而且结果可靠。     

飞机主操纵系统疲劳试验载荷谱小操纵位移频次问题研究

针对飞机全机主操纵系统疲劳试验载荷谱中小操纵位移频次影响问题进行了分析和讨论,确定了某机全机主操纵系统小操纵位移频次的级别。同时,在原某机全机主操纵系统疲劳试验载荷谱的基础上再次对其小操纵位移频次进行了计算,去掉了这一级别以下对全机主操纵系统疲劳试验无影响的小操纵位移频次,从而完善了主操纵系统疲劳试验载荷谱。另外,对小操纵位移频次问题研究结果在其全机主操纵系统疲劳试验中的实施效果进行了阐述。     

What Determines the Composition of SEPs in Gradual Events?

Gradual solar energetic particle (SEP) events are evidently accelerated by coronal/interplanetary shocks driven by coronal mass ejections. This talk addresses the different factors which determine the composition of the accelerated ions. The first factor is the set of available seed populations including the solar wind core and suprathermal tail, remnant impulsive events from preceding solar flares, and remnant gradual events. The second factor is the fractionation of the seed ions by the injection process, that is, what fraction of the ions are extracted by the shock to participate in diffusive shock acceleration. Injection is a controversial topic since it depends on the detailed electromagnetic structure of the shock transition and the transport of ions in these structured fields, both of which are not well understood or determined theoretically. The third factor is fractionation during the acceleration process, due to the dependence of ion transport in the turbulent electromagnetic fields adjacent to the shock on the mass/charge ratio. Of crucial importance in the last two factors is the magnetic obliquity of the shock. The form of the proton-excited hydromagnetic wave spectrum is also important. Finally, more subtle effects on ion composition arise from the superposition of ion contributions over the time history of the shock along the observer’s magnetic flux tube, and the sequence of flux tubes sampled by the observer.     

Broad-band spectral properties of accreting X-ray binary pulsars

Broad-band spectra of accreting X-ray binary pulsars can be fitted by a phenomenological model composed of a power law with a high energy rollover above 10 keV, plus a blackbody component with a temperature of few hundred eV. While, at least qualitatively, the hard tail can be explained in terms of (inverse) Compton scattering, the origin of the soft component cannot find a unique explanation. Recently, a qualitative picture able to explain the overall broad-band spectrum of luminous X-ray pulsars was carried out by taking into account the effect of bulk Comptonization in the accretion column. After a review of these recent theoretical developments, I will present a case study of how different modeling of the continuum affect broad features, in particular the cyclotron resonance features in Vela X-1.     

The double-pulsar binary J0737–3039

A recent multibeam pulsar survey of the outer Galactic plane at Parkes has discovered the first-known double-pulsar binary, a very compact double neutron star system in which both stars are observable as radio pulsars. In this review, we briefly describe the discovery and the studies which have been enabled by the unique properties of the system. These range from the most precise confirmation yet of the theory of general relativity, with the possibility of even more new tests and the measurement of second-order post-Newtonian effects, to studies of the magnetospheres and emission properties of the two pulsars. The discovery also results in a significant increase in the expected rate of occurrence of the mergers of double neutron star systems, and hence the rate of detection of such events by the new ground-based gravitational wave detectors.     

四维下降飞行技术的研究与仿真：定常航迹角法下降剖面解算

本文研究的是四维飞行性能管理系统的核心环节－飞机在终端区域内的四维下降技术，首先探讨了基于常值航迹角的定常Ｍ数／指示空速下降飞行技术，论述了其高度剖面的构成与特点，通过尤拉积分方法求解飞机运动方程，实现了高度冲面的解算。其次开发了对速度剖面的迭代过程，选取原则及方法。本文在进行理论分析的同时，还开发了满意的仿真软件，一了其应用价值。     

卫星定位导航系统中各因素对D-R定位算法精度的影响

D- R定位算法在理论上可以用于定位。在实际工作中 ,用户的定位精度是进行定位时首先需要考虑的问题。文中主要讨论 D- R算法本身固有的定位误差。首先根据 D- R算法的定位公式推导出算法的精度误差因子。然后根据卫星定位导航系统的工作过程 ,确定了影响用户定位精度误差因子的因素并对这些因素对精度误差因子的影响进行了计算机仿真。仿真结果证明 D- R定位算法在一定条件下可以满足用户对定位精度的要求 ,用户精度误差因子可与现有的 GPS系统相当。     

一个简单有效的磁记录纠错系统

介绍一种简单有效的纠错编码方法 ,用于资源卫星高密度数字磁记录器 ,使误码率由 10 -6降低到 10 -11,同时介绍它的基本工作原理、实现方案及试验结果。     

基于损伤力学的概率疲劳曲线获取方法

文章基于损伤力学方法获得满足疲劳试验的损伤演化方程,推导出一般条件下的理论疲劳曲线以及相对应的理论中值疲劳曲线与理论理想疲劳曲线；然后根据试验数据即可确定理论疲劳曲线中的参量,从而获取疲劳曲线计算公式。通过此计算公式,可以方便地得到一组以初始损伤为参数的疲劳曲线族,继而得到以失效概率为参数的疲劳曲线族,大大降低了所需试验的数量,并为结构抗疲劳设计和寿命估算提供了依据。