航天测量船试验文书标准化模式研究

在分析航天测量船试验文书现状的基础上,从标准化要求出发,提出航天测量船试验文书两级两类四综合标准化模式及其基本框架和实现途径。     

交换环上的"下降"问题和"上升"问题

本文的目的是基于域上高层序的“下降”问题与“上升”问题的有关结论，在含单位元的交换环上，通过取序的特殊化以及整环的商域，将此结论加以推广。同时指明，与一个给定的赋值对相容的所有n层序对于C—R拓扑组成Rn—SpecK的一个闭子集。     

基于SolidEdge的组合夹具设计管理柔性化平台研发与应用

以组合夹具设计管理柔性化定制平台为研究对象,基于业务流程特点,形成了柔性化定制平台的系统架构,进行了零组件规格参数的定义与配置、功能定制与配置、流程定制与配置等的研究与设计。实践证明,该系统有效解决了组合夹具组装的模拟性、资料的保留性、经验的继承性、使用和管理的数字化等问题,从而提高组合夹具的生产效率和柔性化水平。     

GPS data processing of networks with mixed single- and dual-frequency receivers for deformation monitoring

In order to obtain crustal deformations of higher spatial resolution, existing GPS networks must be densified. This densification can be carried out using single-frequency receivers at moderate costs. However, ionospheric delay handling is required in the data processing. We adapt the Satellite-specific Epoch-differenced Ionospheric Delay model (SEID) for GPS networks with mixed single- and dual-frequency receivers. The SEID model is modified to utilize the observations from the three nearest dual-frequency reference stations in order to avoid contaminations from more remote stations. As data of only three stations are used, an efficient missing data constructing approach with polynomial fitting is implemented to minimize data losses. Data from large scale reference networks extended with single-frequency receivers can now be processed, based on the adapted SEID model. A new data processing scheme is developed in order to make use of existing GPS data processing software packages without any modifications. This processing scheme is evaluated using a sub-network of the German SAPOS network. The results verify that the new scheme provides an efficient way to densify existing GPS networks with single-frequency receivers.     

Laser Shock Peening of Aluminum Alloy 7050 for Fatigue Life Improvement

The effects of laser shock peening (LSP) on improving fatigue life of aluminum alloy 7050 are investigated.Surface hardness is increased corresponding to a high dislocation density induced by LSP.The X-ray diffraction stress measurement shows that LSP results in prominent increase of surface compressive stress,quasi-symmetrically distributed in the laser peened region.The fatigue life of the alloy 7050 in rivet fastener hole structure is notably improved owing to LSP.The sequence of LSP and fastener hole preparation also influence the fatigue cycle life of the alloy.     

回转表面上非测地线缠绕方程及其解

本文利用微分几何推导了回转表面上的非测地线缠绕方程,并用Runge-Kutta-Fehlberg法求解。此法与文献的分段圆锥法对比,两者计算结果很一致,说明在工程中都是可用的。     

固体火箭复合结构喷管传热的隐式计算方法

采用适用于多层复合结构的当量热容瞬态热传导方程,通过坐标变换解决多个移动边界问题,用ADI方法推导了二维隐式求解格式,在与烧蚀相耦合的情况下获得了复合结构喷管的温度分布。用隐式方法计算有效地减少了计算机时,对工程设计大有裨益。     

遥测电池自动检测装置设计

介绍运用计算机检测和控制技术的遥测电池的自动检测装置,及其主要功能、硬件结构及软件流程,简述设计中所采用的关键技术。     

模态参数识别的小波变换方法

系统地研究了使用调频高斯小波变换识别结构系统模态参数，闻基于系统脉冲响应函数的小波变换的模态参数识别方法，讨论了影响识别精度的因素以及提高识别精度的途径，并针对两自由度问题给出了方法的验证与分析。     

关于加强空管安全培训工作的探讨

“君欲善其事,必先利其器,企业要发展,人才必先行”。安全是空管行业的立足之本,而我国民航运输业的快速发展对空管服务质量和安全保障水平不断提升提出了新的要求,如何培养员工的安全素质以适应航空运输高速发展所带来的安全压力,便越来越受到民航界的关注。为此,系统、科学地