光栅传感器及在轮毂椭圆度测量中的应用

阐述了光栅传感器的测量原理,并利用光栅精密测量的特性,开发了车轮毂椭圆度的测量装置。该装置应用光栅传感器采集位移信号,采用光栅莫尔条纹和光电转换原理将被测位移量转换成数字脉冲信号输出,采用脉冲辨向及四倍频细分电路以实现信号方向识别及提高测量精度,将产生的脉冲信号通过单片机控制程序实现数字显示。     

三维弹塑性分析的弹性试验模型

本文以弹塑性力学的模型理论和塑性力学形变理论为基础,提出一个三维弹塑性分析的弹性试验模型。以已知的三维弹性应力状态为原始数据,用本文所介绍的模型,可以将之转换为对应的弹塑性解答。     

微控抗张试验机的改进

抗张试验机是用来测量纸张、塑料薄膜等材料抗张强度的一种工具，文中详细介绍了对当前市场现有的微控抗张试验机的一些改进方法，这些改进已经在实际应用中证明是可行的。     

线接触等温弹流润滑问题的数值解

应用复合直接迭代法求得了弹流润滑问题的数值解。算例表明，所得的油膜形状和压力曲线具有弹流润滑问题的全部特征，最小油膜厚度与Ｄｏｗｓｏｎ公式的计算值十分接近。同时，求解方法简单，求解范围大，最大赫兹压力可达１．２ＧＰａ，适用于各种载荷、各种速度状况。     

机器人抓取工件时手部夹持器驱动力的分析

本文研究的是机器人爪操作器手部突持器抓取工件时，与“手爪开闭自由度”有关的问题．例如：相对这个自由度，必须配备一个驱动系统，因此如何确定该系统的驱动力成了机器人手部夹持器设计中一个至关重要的问题．本文以ＲＲＰＲＲ操作器抓取圆柱齿轮为例，分析如何确定机器人手部夹持器的驱动力．     

基于89C51 和28F512的现场可编程系统

由89C51单片机、28F512存储器、373数据锁存器和工作状态切换电路组成的基本单片机系统,与PC机串口相关,在PC机上运行自编的下载程序,就可控制工作状态切换器,将系统切换到编程状态,并把新的程序代码写到28F512存储器中,从而实现系统的再编程能力,该系统具有成本低,设计容易,实用性强等优点。     

中心消波自相关法语音基音检测

采用非线性中心消波与自相关/AMDF相结合的算法提取语音基音周期,有效去除声道共振峰的影响和噪声的干扰,实现语音的基音检测;绘制了周期轨迹平台图,使周期/频率读取更加直观.MATLAB仿真实验结果表明,该方法有效、准确地提取了基音周期,并且对噪声有一定的鲁棒性.     

Characteristics of lateral heterogeneities with thermal and chemical origins in the pyrolitic lower mantle

The relative changes between shear and compressional velocities (R_SP = ∂ ln V_S/∂ ln V_P), bulk sound and shear velocities (R_CS = ∂ ln V_C/∂ ln V_S), and density versus shear wave velocity (R_ρS = ∂ ln ρ/∂ ln V_S) in response to thermal and chemical variations were investigated for the pyrolitic lower mantle. For heterogeneities with thermal origins, R_SP increases from 1.7 to 2.0 together with R_ρS decreasing from 0.4 to 0.2 and R_CS = ∼0.27 from the top to the bottom of the lower mantle. In comparison, chemical variations (bulk iron or silica contents) are characterized by R_SP < 1.5 and R_CS > 0.5 at lower mantle depths. Negative values of R_ρS and R_CS are indicative of chemical anomalies in the lower mantle, but a combination of thermal and chemical heterogeneities may be required to produce velocity and density anomalies at the magnitudes observed in seismic data. Further refinement of these characteristics requires data on the higher order pressure and temperature derivatives of the elastic moduli of the constituent phases.     

弹性力学通解的构造和完备性

对任意向量本文构造了两种分解形式,从而构造性地给出了Boussinesq-Galerkin解和Papkovich-Neuber解中的势函数,由此直接证明了它们的完备性。文中也讨论了这两种通解之间的关系。     

Methimazole treatment reduces cardiac hypertrophy and mortality without a concomitant reduction in blood pressure in established Goldblatt two-kidney one clip hypertension

The effects of methimazole, and antithyroid drug, on blood pressure and other parameters were evaluated in the established phase of Goldblatt two-kidney one clip (G2K-1C) hypertension. Methimazole was administered via drinking water for five weeks, starting five weeks after hypertension had been induced. After this period of treatment, similarly high blood pressures were observed in methimazole-treated and non-treated G2K-1C rats, despite the fact that a hypothyroid state had been achieved in methimazole-treated rats. Methimazole-treated G2K-1C rats showed reductions in heart rate, ventricular weight, ventricular/body weight ratio and mortality in comparison with rats not treated with methimazole. These results clearly demonstrate that hypothyroidism induced by methimazole: a) does not reverse G2K-1C hypertension, but b) improves the rate of survival and c) reduces relative cardiac hypertrophy, possibly by the reduction in cardiac work observed in Goldblatt hypothyroid rats.