用测长机校准数显千分表测量结果的不确定度评定

介绍了0～25 mm数显千分表的示值误差测量结果的不确定度分析,表明了用TWIN-CHECK1200测长机进行校准的可行性.     

飞航导弹航向飞行包络计算模型及仿真分析

飞航导弹飞行包络的确定是航迹评估的重要前提,是其安全飞行的重要基础。文中基于飞航导弹的飞行过程,分析了各飞行阶段航向误差因素,建立航向飞行包络误差模型,给出了飞行包络半径大小计算的数学方程,最后进行了仿真分析。文中的研究对飞航导弹航迹评估和飞行安全维护具有重要的军事意义。     

Learning to Reach to Locations Encoded from Imaging Displays

We examined the use of hand gestures while people solved spatial reasoning problem in which they had to infer motion from static diagrams (mental animation problems). In Experiment 1, participants were asked to think aloud while solving mental animation problems. They gestured on more than 90% of problems, and most gestures expressed information about the component motions that was not stated in words. Two further experiments examined whether the gestures functioned in the mechanical inference process, or whether they merely served functions of expressing or communicating the results of this process. In these experiments, we examined the effects of instructions to think aloud, restricting participants' hand motions, and secondary tasks on mental animation performance. Although participants who were instructed to think aloud gestured more than control groups, some gestures occurred even in control conditions. A concurrent spatial tapping task impaired performance on mechanical reasoning, whereas a simple tapping task and restricting hand motions did not. These results indicate that gestures are a natural way of expressing the results of mental animation processes and suggest that spatial working memory and premotor representations are involved in mental animation. They provide no direct evidence that gestures are functional in the thought process itself, but do not rule out a role for overt gestures in this type of spatial thinking.     

市场经济学原理的研究对象与任务

市场经济学不同于西方经济学、微观经济学，也不同于把经济学置于市场经济条件下进行再考察，它的研究对象是市场在配置经济资源的进程中，与市场主体及其经济活动所发生的各种关系。市场经济学的研究任务，则是揭示市场在配置经济资源的进程中，与市场主体及其经济活动所发生的各种内在的本质的必然的联系，即市场经济运行的规律性，包括基础性的市场经济规律，也包括特定社会形态的市场经济规律。而市场经济学原理的研究任务就是提供市场经济最普遍、最一般的规律性，它在任何地域范围内、任何市场经济模式下、市场经济发展的任何阶段都是适用的。市场经济学原理可为健全完善市场经济理论体系提供基础理论，可为认识市场经济体制提供核心思想，可为发展市场经济提供基本理论依据，可为判断市场经济行为提供基本标准。     

我国电子商务应用技术与发展战略

简述了我国电子商务应用技术的选择和发展电子商务的战略，提出发展我国电子商务应注意的问题。     

某雷达模拟器的目标与杂波信号模拟强度研究

建立了雷达模拟器中目标、地物杂波、海杂波、气象杂波的信号强度计算模型,根据相对运动关系解算出各目标与杂波信号的强度,并按时间流程存储在对应的数据表中,从而信号源将产生相应强度的信号注入雷达模拟台,以便后端雷达模拟台能在雷达威力覆盖范围内准确地显示出目标与杂波强度变化。通过仿真软件在雷达训练模拟器中的功能测试,实现了目标与杂波仿真效果,满足了雷达模拟训练的要求。     

基于权衡空间探索的多约束弹道初值确定方法

运载火箭弹道设计对初值的选取敏感,需要设计人员具备相应经验,新构型或新任务下迭代设计易发散,设计过程依靠人员手动调整,效率较低。应用权衡空间探索及全局优化思想,给出了多约束弹道设计初值确定方法,并在此基础上重新建立了弹道设计流程,自动完成初值选取及精确设计,降低了设计过程对人员经验的依赖性,提升了弹道设计方法的智能化程度,提高了论证及设计效率。     

船载卫通站单脉冲跟踪接收机典型故障分析

描述了某船载卫通站天线跟踪丢失目标的故障现象,从天线跟踪系统的设备组成和工作原理入手,结合设备工作环境和条件,详细说明了故障排查与定位过程。针对接收机中频信号频带内发现的主信号漂移及杂散频率干扰现象,分析了C-L频段变频器本振频率漂移产生的原因,以及设备环境温度、振动等外部因素和器件老化等内部因素对本振频率参数的综合影响,给出了通过调节C-L变频器本振单元微调元件进行频率修正来规避杂散信号对主信号干扰的方法。结果表明,该方法能有效解决天线跟踪的故障问题。     

Dynamic modeling and simulation of a pressurized system used in flight vehicle

For a typical pressurized system with a novel dual-stage gas pressure reducing regulator, a system model is established with modular models of various typical components. The simulation study on the whole working period shows that the general trends and magnitudes of simulation curves are in agreement with experimental measured curves. As the key component in the pressurized system, the regulator is studied by a series of numerical simulations to reveal the influences of various structure parameters on its stability. Furthermore, the variable ranges which can guarantee the stability of regulator and system are obtained to provide guidance for design. The modeling and analysis approach can be applied to other systems and components.