Effect of oxygen deficiency (δ) on transition temperature of yttrium cuprate superconductors

The nature of pairing mechanism as well as transition temperature of yttrium cuprates is discussed using the strong coupling theory. An interaction potential has been developed for the layered structure with two conducting CuO₂(a–b) layers in a unit cell. The interaction potential properly takes care of electron-electron, electron-phonon and electron-plasmon interactions. Furthermore, the electron-phonon coupling parameter (λ), the modified Coulomb repulsive parameter (μ*) and the 2D acoustic phonon (plasmon) energy as a function of oxygen deficiency is worked out. Finally, the superconducting transition temperature (T _c) is then evaluated by using these coupling parameters and obtainedT _c = 95(92)K for Y(Yb)Ba₂Cu₃O_7−δ superconductors withδ = 0·0. The model parameters estimated from the layered structure approach are consistent with the strong coupling theory. The result deduced on the variation ofT _c withδ are in fair agreement with the earlier reported data on yttrium cuprates. The analysis of the above results are discussed.     

停棒子系统与控制棒组操作范围监测试验

本文叙述了反应堆保护系统停棒与汽轮机降功率子系统的系统功能、保护参数和秦山核电站控制棒组插入监测器的设计与参数选择,确定了控制棒提升上极限值和在不同工况下棒插入低位、低-低位整定值,并在热态零功率条件下加以验证。试验证明参数选择是合理的,为功率运行阶段提供了数据。     

一种新的线性分布参数系统辨识方法

本文应用块脉冲函数（ＢＰＦ）将含有未知参数的线性分布参数系统偏微分方程转换为矩阵方程，通过最小二乘法辨识线性分布参数系统的参数，辨识结果表明，ＢＰＦ辨识法具有原理简捷，实现方便，辨识精度高等优点。     

一种实时心电图数据压缩算法

提出了一种实时心电图ＥＣＧ数据压缩算法。它是将自适应变门限算法与转折点算法相结合。自适应变门限算法是对ＡＺＴＥＣ算法的改进．它计算ＥＣＧ信号的几个统计参数来确定可变门限值。转折点算法是分析采样点的趋势并只存储每对连续的采样点中的一个。它保留信号的斜坡标志发生变化的峰点和谷点。本文算法兼有这两种算法的优点。这种算法在较高压缩比的情况下重建心电图信号失真较小．     

Neural networks for nonlinear state estimation

Estimating the state of a nonlinear stochastic system (observed through a nonlinear noisy measurement channel) has been the goal of considerable research to solve both filtering and control problems. In this paper, an original approach to the solution of the optimal state estimation problem by means of neural networks is proposed, which consists in constraining the state estimator to take on the structure of a multilayer feedforward network. Both non-recursive and recursive estimation schemes are considered, which enable one to reduce the original functional problem to a nonlinear programming one. As this reduction entails approximations for the optimal estimation strategy, quantitative results on the accuracy of such approximations are reported. Simulation results confirm the effectiveness of the proposed method.     

存在噪声和未建模动态系统传递函数的渐近无偏估计

存在未建模动态时，如何去除系统传递函数估计中噪声引起的偏差是系统辨识关心的重要问题。本文将我们已提出的ＢＥＬＳ方法进行推广得出：当系统未建模动态可用－ＦＩＲ模型描述时，应用本文的方法可得到系统传递函数的无偏辨识，而不需知道有关噪声和未建模动态概率分布函数的先验知识。     

空间机器人遥控、自主与协同操作的软件基础

空间机器人控制语言是实现空间机器人三种控制方式:遥控操作,自主操作和协同操作的软件基础,本文描述了该语言的基本结构,对于自主方式,给出了编程示例;对于遥控方式,运用程序辅助的方法,解决了操作员单独进行主/从操作时难以解决的问题.     

Stabilization of uncertain boundary control systems

We consider a class of linear infinite-dimensional systems subject to boundary uncertainties, which are linear and time-invariant. Using a deterministic approach to the design of stabilizing feedback controls, uniform exponential stability of the zero state is achieved. Lyapunov techniques are combined with Datko or Ichikawa theory. Three illustrative examples are presented.     

地地战术导弹飞行可靠性指标评定方法

在小子样情况下 ,利用系统和分系统试验数据对导弹的飞行可靠性指标进行评定 ,从数学上说是系统可靠性综合问题 .运用MML SR方法对新型号地地战术导弹的飞行可靠性指标进行评定 ,避免了MML方法在遇到无失败单元时不适用的缺陷 ,在利用地面试验信息方面有其明显优势 ;运用Bayes方法对改进型导弹的飞行可靠性指标进行评定 ,将不同试验阶段的多源试验信息作为验前信息 ,扩大了信息量 .最后 ,对两种方法在工程应用上遇到的问题进行了讨论 ,并给出了解决方法 .     

应用德国PAR88挤出机生产PVC异型材的工艺研究

从控制PVC异型材挤出机的工艺参数的角度，分析并论述了挤出机工艺参数对PVC异型材低温落锤性能的影响。