Dynamics of arrays of legs powered by a discrete electrical model of nerve

This paper studies the dynamics of an array of legs connected through magnetic coupling at nodes of a discrete electrical model of nerve fibre or a linear electric line. Considering legs fixed on spring, it is found that they exhibit pulse like behavior when the electrical signal propagates in the array. The amplitude of the pulse like motion increases with the magnitude of magnetic field. Legs without spring undergo a step motion at the passage of the electrical signal, advancing in a given distance before they stop. The magnitude of the step also increases with the magnetic coupling. Considering a linear electrical line excited at a single node, it is found that the legs oscillate with decreasing amplitude till the center of the line and increasing amplitude from the center to the first node of the linear line.     

论灾后重建中的党内民主建设

灾后重建中党的建设特别是党内民主建设先行一步，指相对于其他重建工作，党的建设应该以新的思路及早谋划安排；相对于其他非地震灾区，灾区党的建设更应率先创新，力图走出一条新路；相对于其他一般地区，绵阳作为中国科技城，其创新的理念理应在党的建设上得到体现；相对于其他党建任务，北川等极重灾区完全可以在党的建设特别是党内民主建设上迈出更大步伐。先行一步重点在于“四个致力于”，遵循原则在于“四个着眼于”，保障条件在于“四个依赖于”。     

体操运动员踏跳动作数据的空间轨迹检索方法

检索体操运动员踏跳动作数据空间轨迹,有利于帮助运动员改善动作标准性,使其不易受伤且得分率更高。当前空间轨迹检索方法因索引机制不佳,只能检索较短的体操运动员踏跳动作数据空间轨迹,检索过程复杂且结果不可靠。提出一种新型体操运动员踏跳动作数据空间轨迹检索方法,采用层次化运动模型对体操运动员踏跳动作进行描述,将倾斜角度、最小外界矩形MER与紧密度、运动速度、外接矩形长宽和变化率等作为踏跳动作特征,对踏跳动作特征进行提取;依据提取的特征构建一个空间轨迹数据库,通过反向表技术完成索引。通过精确命中指标对相似度进行衡量,从而实现踏跳动作数据空间轨迹的匹配,完成体操运动员踏跳动作数据的空间轨迹检索。实验结果表明,所提方法索引性能强;且检索速度快、精度高,检索结果全面、稳定。     

Generalized thermo-visco-elastic problem of a spherical shell with three-phase-lag effect

This problem deals with the thermo-visco-elastic interaction due to step input of temperature on the stress free boundaries of a homogeneous visco-elastic isotropic spherical shell in the context of generalized theories of thermo-elasticity. Using the Laplace transformation the fundamental equations have been expressed in the form of vector–matrix differential equation which is then solved by eigen value approach. The inverse of the transformed solution is carried out by applying a method of Bellman et al. [R. Bellman, R.E. Kolaba, J.A. Lockette, Numerical Inversion of the Laplace Transform, American Elsevier Publishing Company, New York, 1966]. The stresses are computed numerically and presented graphically in a number of figures for copper material. A comparison of the results for different theories (TEWED (GN-III), three-phase-lag method) is presented. When the body is elastic and the outer radius of the shell tends to infinity, the corresponding results agree with the result of existing literature.     

用极限电流法求催化反应速度常数

在钛(Ⅳ)-草酸-氯酸盐体系中分别用稳态方法(慢速线性扫描电位)和暂态方法(院跃电位)测量了该体系的催化反应极限电流,从而计算出钛催化氯酸根转化为氯离子的反应速度常数k=3.6×10~4 l/mol·s。     

基于步长优化和共轭梯度法的改进BP算法

本文针对传统ＢＰ算法存在的两个常见问题进行了讨论，提出了基于步长优化和共轭梯度法的改进ＢＰ算法。新的算法避免了目前由人为经验确定迭代步长的缺陷，并能有效克服局部极小值。这样可使网络加快收敛，稳定性变好。     

一类未知系统的数字控制器设计

本文提出一类常见未知系统的数字控制器的一种设计方法。该方法仅需要对象的?跃响应数据。仿真实例说明了这种控制器的设计方法及其性能。     

Room-Temperature Near-Infrared Metastable Species Measured by Phase-Sensitive Lock-in and Fourier Transform Techniques

An ultrasensitive detecting system coupled with either a lock-in or Fourier transform technique has been used to detect near-infrared (1000-2500 nm) metastable species in room temperature solutions. These species include O₂(¹Δ_g), O₂(¹σ⁺_g), the solvent induced satellite peak of molecular singlet oxygen (¹Δ_g) emission, and the triplet state of bis(triisobutylsiloxy)silicon-2,-3-naphthalocyanine (SilNC). Using the O₂(¹Δ_g) emission in benzene as a standard, the quantum yield and radiative decay rate of SiINC triplet state have been determined. Depending on types of spectral acquisition, special techniques such as phase-distinguishing and step scan capabilities were utilized. Their advantages and disadvantages are discussed.     

数控双环直流可逆调速系统阶跃扰动动态速降分析

介绍了双环直流可逆调速DDC系统PI数字调节器设计方法的阶跃扰动动态速降分析方法及公式,给出了典型应用实例阶跃扰动实际参数仿真结果和计算结果,结论简单且实用.     

高旋仪步进电机可变微分技术

本文着重讨论新研制的高温高压泥装旋转拈度、失水仪中步进电机微分技术,用以解决低转速下仪器的测量精度问题。