济钢板坯连铸机智能扇形段(ASTC)电气控制系统的应用

济南钢铁集团总公司第三炼钢厂1#连铸机由奥钢联公司设计制造,其扇形段共14段,其中水平段(7-14段)采用智能扇形段(ASTC)。智能扇形段电气控制系统具有严密的控制逻辑及可靠的控制精度,通过对水平段辊缝的实时动态控制,可有效提高扇形段辊缝的控制精度,提高了铸坯质量。     

带有区间约束的产品设计参数模糊推理法及其在继电器智能设计中的应用

在产品设计规则和计算式中,常存在一些只能在某一范围内取值的待定系数(设为a,且a∈[aL,aH]).a的取值通常受到多种因素的影响和约束,而这种约束往往带有模糊性.为此,首先根据设计规则中各种影响因素对a的模糊约束关系,分别构造两者的备择集以及备择集元素在其论域上的模糊集合,然后基于模糊综合决策方法来确定a.本方法剔除了以往在解决这一问题时,由人来决定a取值的主观性,适用于产品的智能化设计.     

Calculations of the Elastic Scattering Properties of Ultra-cold Francium Isotopes

The calculations of the elastic scattering properties of ultra-cold francium isotopes are reported in detail. A parametric model potential for the triplet molecular states of the Fr₂ is represented, and the scattering lengths a_t and the effective range r_e are calculated using WKB and Numerov methods for Fr--Fr in the triplet state. The convergence of these scattering properties depending on a K⁰ parameter and core radius is also investigated using two methods: Quantum Defect Theory and analytical formula of Symskoviski.     

Classical Approach to Analyzing the Influence of Edge Boundary Conditions on Stresses and Flexibility of Pipe Elastic Bend

A new analytical method is proposed for the analysis of boundary effect in a pipe bend portion loaded by bending moment combined with internal pressure. The proposed method is based on the simplifying hypotheses, which make possible to represent all deformation- and force-related parameters in terms of the tangential displacement assumed in the form of the Fourier series expansion by the circumferential coordinate. A set of quadric differential equations by axial coordinate containing unknown displacement expansion coefficients is derived. We obtained an analytical approximate solution for a pipe bend portion and precise solution for a straight pipe, which are expressed via Krylov functions. We formulate the application procedure for the method of initial parameter, where the values of tangential and longitudinal displacements, axial and tangential forces are used as boundary conditions. We present the equations relating the above-mentioned parameters in the initial and end sections of the pipe bend portion. The results obtained are compared with the available published data. __________ Translated from Problemy Prochnosti, No. 4, pp. 64 – 94, July – August, 2005.     

Structure study on the thermoelectric materials CexCo4Sb12 (x = 0.5, 1.0) by neutron diffraction

In order to understand the relationship between crystal structure and thermoelectric properties, the neutron diffraction patterns of the thermoelectric materials with the nominal composition Ce_xCo₄Sb₁₂ (x = 0.5, 1.0) were measured at room temperature, the data were fitted by the Rietveld profile refinement method using the Fullprof2k program. It is found that the sample Ce_0.5Co₄Sb₁₂ is composed of two phases, its major phase is CoSb₃ with skutterudite-structure and the Ce atom is not incorporated into the lattice, the impurity is monoclinic CoSb₂. In the case of Ce_1.0Co₄Sb₁₂, the major phase is filled skutterudite, about 10% of the 2a site is occupied by Ce atom, the second phase is monoclinic CoSb₂.     

USB2.0技术在光电测量系统中的应用

针对光电测量系统的特点，介绍了一种基于外设控制器CY7C68013的光电测量系统运用USB2．0接口技术实现通讯的方案；文中详细给出了硬件原理图、数据传输方式以及软件设计内容。仿真实验表明该设计方案是合理可行的。     

多群中子散射角分布L阶截断出负的改进

蒙特卡罗方法或离散纵标法模拟多群中子输运方程，散射角分布通常按Legendre级数展开，取L阶截断近似。当L较小时，近似角分布在[-1，1]定义域的多处出负，面积不归一，进而导致非物理解。文章针对这一问题，利用矩和Legendre系数等价关系，给出离散广义Gauss求积组，并用该求积组作节点构造等概率阶梯函数，逼近实际角分布，从而消除非物理解。计算取得了与实验和连续截面蒙特卡罗MCNP程序一致的结果。     

Dynamic anti-windup based control method for state constrained systems

Based on the dynamic anti-windup strategy, an alternative control methodology for state constrained systems is presented. The proposed method is an a posteriori approach for state constrained systems, which is differentiated from the usual a priori approach. That is, first a linear controller is designed to show a desirable nominal performance by ignoring state constraints. Then, an additional compensator is introduced to account for state constraints. By minimizing a reasonable performance index, a dynamic compensator is derived explicitly, which is expressed in plant and controller parameters. The proposed method not only provides a graceful performance degradation, but it also guarantees the total stability of the resulting systems. An illustrative example is given to show the effectiveness of the proposed method.     

Software Process and Product Improvement: A Historical Perspective

In this paper, a historical overview of significant attempts to get over the software crisis is presented. In particular, we trace the development of lifecycle models and information systems development methodologies during the last four decades. Finally, we explore the role of measurements and outline current and future works leading to process and product improvement.     

反应堆堆芯热功率测量方法及其误差分析

通过建立精确的数学模型 ,提出了一种测量核电站压水反应堆堆芯热功率的方法 ,并对该方法进行了误差分析。基于上述方法的KME系统与校验SAPEC系统的比较结果表明 ,该方法完全可以用于核电站堆芯热功率的测量