仿壁虎刚毛阵列对卫星表面吸附能力模型与计算

壁虎脚的粘着机理对航天机器人脚掌的研制和开发具有重要启发意义.通过单根刚毛与光滑表面黏着力模型与计算、卫星粗糙表面分布模型与接触概率与计算、刚毛阵列与卫星粗糙表面黏着力模型与计算等,分析仿壁虎刚毛阵列对卫星表面的吸附能力,发现在一定条件下仿壁虎刚毛阵能够在太空失重环境中黏着在卫星表面,对航天舱内爬行机器人、管道机器人的...     

脚尖数据的研究及其分析

大部分步态研究者将注意力投入到臀部和膝盖关节的角度变化所形成的步态特征,脚的步态特征关注还较少。针对这个问题深入研究了脚的一些特征,提取了脚尖数据进行分析,并对脚尖的坐标进行变换得到时域、频域及其他信息,在中科院数据库NLPR上进行试验和研究,表明脚尖的数据可以较好的区分男女性,甚至是不同的个体。脚尖数据的表示包含了较多的属性信息,有利于步态识别的进一步研究。     

地源热泵技术在建筑节能中的应用

本文探讨如何通过地源热泵技术实现建筑节能。研究通过地源热泵来实现一机多用,使其既能用于冬季供暖,又可以用于夏季制冷。同时也讨论了如何与太阳能相配合,来实现地热平衡。文中还给出了通过插值法和曲线拟合法对测量数据进行处理获得变温带和增温带的温度-深度曲线的方法。     

示波器输入电容对上限截止频率测量的影响

单管放大电路是模拟电路中的一个经典实验。通过这个实验,学生可以更好地掌握静态工作点的调整和测试方法,并通过测量放大电路的主要性能指标,体会静态工作点对动态特性的影响。实验电路的上限截止频率仿真值和实测值存在较大差异,本文针对这个问题进行了详细的分析,指出示波器的输入电容是引起差异的主要原因,并进一步讨论了可有的改进测试方法。     

On the origin of ultrahigh energy cosmic rays

The origin of cosmic rays with energy E ? 10¹⁸ eV is a long-standing problem in astrophysics. The development of ever larger detectors has brought in key experimental results in the past decade, most particularly the detection of a cut-off at the expected position for the long sought Greisen–Zatsepin–Kuzmin suppression as well as evidence for large scale anisotropies. This paper summarizes and discusses the recent achievements in this field.     

国际空间太阳能电站的技术进展

综述了当前国际空间太阳能电站技术的研究进展与发展趋势。重点介绍了空间太阳能电站系统方案新构思“太阳塔”和“太阳盘”的特点；介绍了空间太阳能电站的主要相关技术———无线电能传输技术、太阳能转换技术和空间运输技术等的发展趋势；最后简要介绍了月球电站的进展情况。     

Grinding performance evaluation of porous composite-bonded CBN wheels for Inconel 718

For high-efficiency grinding of difficult-to-cut materials such as titanium and nickel alloys, a high porosity is expected and also a sufficient mechanical strength to satisfy the function.However, the porosity increase is a disadvantage to the mechanical strength. As a promising pore forming agent, alumina bubbles are firstly induced into the abrasive layer to fabricate porous cubic boron nitride（CBN） wheels. When the wheel porosity reaches 45%, the bending strength is still high up to 50 MPa with modified orderly pore distribution. A porous CBN wheel was fabricated with a total porosity around 30%. The grinding performance of the porous composite-bonded CBN wheel was evaluated in terms of specific force, specific grinding energy, and grinding temperature, which were better than those of the vitrified one under the same grinding conditions. Compared to the vitrified CBN wheel, clear straight cutting grooves and less chip adhesion are observed on the ground surface and there is also no extensive loading on the wheel surface after grinding.     

定向破坏复合材料层合壳体结构铺层的分析与设计

以复合材料层合板为基本材料设计了一种结构新颖的定向破坏复合材料层合壳体结构,在导弹与

该壳体结构的初始接触区域预制缺陷区,导弹发射时以四瓣形式开裂,大幅度提高了导弹的发射效率。利用ANSYS

有限元模拟分析软件,通过强度分析确定了最佳铺层设计方案,单层板厚度为0.2 mm,采用基体本身加强预

置缺陷区的[0°/90°/ ±45°]2S 铺层方式。该种铺层方式的爆破载荷为0.21 MPa,最小顶破载荷为1 kN,完全能够

满足其在工作环境下既能承受一定的压力不漏气又能在较小的顶破载荷下自行破裂的设计要求。

     

基于 VxWorks 的大容量 SATA 电子盘驱动实现

本文讲述了大容量 SATA 电子盘在 VxWorks 操作系统中的驱动设计过程.介绍了硬件系统组成,描述了 VxWorks 中 SATA 电子盘设备的驱动流程,MPC8377 CPU 自带 SATA 控制器的配置和大容量电子盘的配置,以及文件系统的建立过程     

Stability analysis of an aeroelastic system with friction

In this paper, harmonic balance method, exact formulation and numerical simulation method are adopted to study the effects of different friction stiffness on the stability of 1.5 degrees of freedom aeroelastic system. On this basis, the expressions of input energy and dissipated energy are deduced, and the energy method is used to reveal the mechanisms of the stable boundary and unstable boundary existing in the system and the effects of different friction stiffness on the stability of the system. Studies have shown that the stability region and the critical aerodynamic damping ratio of the system rise with the increase of the friction stiffness, while the friction stiffness has little effect on the stability boundary. In the analysis of the stability of system, the results of harmonic balance method, exact formulation and Newmark of numerical simulation method are in good agreement. Compared with exact formulation and numerical simulation method, the concept and conclusion of harmonic balance method are simple in the system stability analysis.