A Continuation Method of Parameter Inversion for Non-Equilibrium Convection-Dispersion Equation

Based on the homotopy mapping, a globally convergent method of parameter inversion for non-equilibrium convection-dispersion equations （CDEs） is developed. Moreover, in order to further improve the computational efficiency of the algorithm, a properly smooth function, which is derived from the sigmoid function, is employed to update the homotopy parameter during iteration. Numerical results show the feature of global convergence and high performance of this method. In addition, even the measurement quantities are heavily contaminated by noises, and a good solution can be found.     

High-Average-Power Nanosecond Quasi-Phase-Matched Single-Pass Optical Parametric Generator in Periodically Poled Lithium Niobate

A pulsed nanosecond optical parametric generator (OPG) in periodically poled lithium niobate (PPLN) crysal is presented. The pump laser is an acousto-optically Q-switched Nd:YVO4 laser with the maximum average power of 6.58 W. When the repetition rate is 50kHz and the pulse width of the pump source is 80ns, the maximum average total output power of the single-pass PPLN OPG is about 1.9 W, which includes 1.322 W of 1.536μm signal radiation. The length of the PPLN crystal is only 38.7mm (at room temperature) with a grating period of 28.93μm (at room temperature). The 1.502-1.536μm signal radiation and 3.652-3.465μm idler radiation are obtained by adjusting the PPLN crystal temperature from 155℃ to 250℃.     

同步电机定子绕组不对称状态的分析方法——Ⅱ.参数的计算方法

参数计算是分析电机绕组不对称状态的关键问题。用多回路法分析同步电机定子绕组不对称状态时所用的参数,与绕组正常时的参数不同,它包括定子绕组每个支路、转子各阻尼回路和励磁绕组的自感系数和互感系数。定子支路参数可以由单个线圈参数组成。本文在考虑铁心饱和的情况下,研究了参数计算的两种方法,即气隙磁导分析法和磁场数值分析法,并将它们应用于实际电机的计算,验证和比较了两种计算方法。     

标准体系的比例型寿命使用期模型与分析

本文在基于标准被废除按比例进行时的标准体系使用期的两个新模型。首先给出了模型假设条件,然后定义了标准使用期。根据假设给出了两个模型条件下的标准使用期公式,最后通过数值示例说明了标准使用期的公式使用。     

一类半参数回归模型的估计理论

考虑半参数回归模型Y=X’β+g(T)+e,其中(X,T)为取值于R^p×[0,1]上的随机向量,β为p×1未知参数向量,g为定义于[0,1]上的未知函数,e为随机误差,Ee=0,Ee²=σ²>0,且(X,T)与e独立。本文综合最近邻和最小二乘的方法定义了β,g和σ²的估计量,g_n^*和。在适当条件下证明了和的渐近正态性,并得到了g_n^*的最优收敛速度。     

Evolving Networks with Nonlinear Assignment of Weight

We propose a weighted evolving network model in which the underlying topological structure is still driven by the degree according to the preferential attachment rule while the weight assigned to the newly established edges is dependent on the degree in a nonlinear form. By varying the parameter a that controls the function determining the assignment of weight, a wide variety of power-law behaviours of the total weight distributions as well as the diversity of the weight distributions of edges are displayed. Variation of correlation and heterogeneity in the network is illustrated as well.     

Global Parametric Sufficient Optimality Conditions for Semi-infinite Discrete Minmax Fractional Programming Problems Involving Generalized （η,ρ）-invex Functions

In this paper,we discuss a large number of sets of global parametric sufficient optimality condi-tions under various gcneralized (η,ρ)-invexity assumptions for a semi-infinite minmax fractional programmingproblem.     

多发弹丸发射系统阀门电源及可编程发射控制器的研制

多发弹丸发射系统是我院20世纪90年代从俄罗斯引进的设备，用于发射弹丸的快阀门电源属于非标产品，其备件缺乏，维修困难。为保证HL-2A装置弹丸注入实验顺利进行，根据设计要求，研制了这套弹丸快阀电源和可编程发射控制器。它们之间的连接如图1所示。