风力发电机组变速恒频控制系统研究

全面介绍了一种最新应用于风力发电中的新型电机—无刷双馈电机，并分析了这种新型电机作变速恒频运行的原理并对这种电机进行了动态特性仿真研究，给出了形式简洁的控制方程和易于实现的控制方案。     

Goldbach猜想在N3[12,22,32,……]中的推广

文[1]已将Goldbach猜想推广到N2[1^2，2^2，3^2，……]中去，本文除了仿[1]将此猜想推广到N3[1^2，2^2，3^2，……]，此外，还引进与Goldbach猜想对偶的另一猜想．借以研究N3[1^2，2^2，3^2，……]中之偶数表示为不同奇数的线性组合问题，得到可以补救[1]中所用方法之缺陷的新的结果．并由此提出另外的有意义的猜想．     

数字全息图变频采样研究

根据Whittaker-Shannon抽样定理,对菲涅耳全息图进行变频率采样,保证整个全息图各部分采样频率为该处相应空间频率的两倍,从而完全消除数字全息图由于采样冗余而带来全息图的信息冗余.并且,对变频采样后的全息图进行线性插值恢复即可获得良好的再现像质.实验和理论均证明了该方法的有效性和可行性,为全息图的信息存贮与传输提出一条新的思路.     

重力场与静电场特点的比较

“场”是一种客观存在的物质，但由于“场”具有不易直接感受的特殊存在形态，同学们对“场”的物质性的理解不够深刻，解决“场”的相关问题时也感到棘手．笔者就高中阶段最典型的两种场——“重力场”和“静电场”的力学性质与能量特点进行比较，使同学们对“场”的概念有更深刻的认识．     

Phase modulation in dipolar-coupled A2 spin systems: effect of maximum state mixing in H NMR in vivo

Coupling constants of nuclear spin systems can be determined from phase modulation of multiplet resonances. Strongly coupled systems such as citrate in prostatic tissue exhibit a more complex modulation than AX connectivities, because of substantial mixing of quantum states. An extreme limit is the coupling of n isochronous spins (A_n system). It is observable only for directly connected spins like the methylene protons of creatine and phosphocreatine which experience residual dipolar coupling in intact muscle tissue in vivo. We will demonstrate that phase modulation of this “pseudo-strong” system is quite simple compared to those of AB systems. Theory predicts that the spin-echo experiment yields conditions as in the case of weak interactions, in particular, the phase modulation depends linearly on the line splitting and the echo time.     

MCSCF calculation of response properties of Argon

Summary Analytic equations of the multiconfigurational SCF (MCSCF) response theory are combined with the finite-field (FF) approach to compute static and frequency dependent electric and magnetic properties of the Argon atom. A complete active space (CAS SCF) function including the 3s, 3p, 3d, 4s and 4p orbitals in the active space and a large (17s 13p 7d 5f 3g) basis set are employed. This permits an accurate determination of various linear and non-linear response properties such as e.g. electric dipole polarisability and second hyperpolarisability, Verdet constant, magnetisability and second hyperpolarisability. The results, both for the static values and for the frequency dependence of these properties, compare well with other most recent experimental and theoretical data.Dedicated to Jan Linderberg on the occasion of his 60th birthday     

甲基多烯醛共轭体系电子光谱及线性关系的MHMO法研究

甲基多烯醛共轭体系电子光谱及线性关系的ＭＨＭＯ法研究马生元（青海民族学院化学系西宁８１０００７）关键词甲基多烯醛，电子光谱，线性关系，ＭＨＭＯ法有机共轭同系物的电子光谱有广泛的线性关系［１－３］，这是分子周期性结构的必然结果。分子电子光谱则是分子中轨...     

Optimum design of vibrating cantilevers: A classical probem revisited

Optimum design of vibrating cantilevers is a classical problem widely used in the literature and textbooks in structural optimization. The problem, originally formulated and solved by Karihalloo and Niordson (Ref. 5), was to find the optimal beam shape that will maximize the fundamental vibration frequency of a cantilever. Upon reexamination of the problem, it has been found that the original analysis and solution procedure can be simplified and improved substantially. Specifically, the time-consuming inner loop devised for solving the Lagrange multiplier in the original work has been proved to be tolally unnecessary and thus should not be considered in the problem solution. This conclusion has led to a new set of simplified equations for the construction of iteration schemes. New asymptotic expressions for the optimum design solution have been obtained and verified by numerical results. Numerical analysis has shown a significant improvement in convergence rate by the proposed new procedure. Also some obvious numerical errors in the original paper have been identified and corrected.This work was suppoted in part by the University of Arizona Foundation and the Office of the Vice President for Research. The author is grateful to the reviewers for their valuable comments.     

基于经典控制理论的控制系统计算机辅助设计软件

频率法和根轨迹法是经典控制理论的两个基本的控制系统设计与分析方法。本文主要介绍的两个计算机辅助设计（ＣＡＤ）软件，分别建立在频率法和根轨迹法的基础上。通过这两个ＣＡＮ软件，可以根据给定的单输入单输出（ＳＩＳＯ）控制系统数学模型，进行各种计算，从而得到我们所需要的结果．     

尾波场与相对论效应对激光脉冲自相位调制及频移影响的比较研究

对共振和非共振情形下尾波场效应与相对论效应对强激光脉冲在稀薄等离子体中传输的影响 作了详细比较.尾波场效应导致脉冲自相位调制的不对称性，其大小与初始脉冲形状和脉宽 大小有关.在长脉冲极限下，尾波场效应远小于相对论效应，从而可以忽略；在短脉冲极限 下，尾波场效应可以抵消相对论效应.在共振情况下，尾波场效应导致脉冲内大部分光子减 速. 关键词： 脉冲传输 等离子体 相对论效应 尾波场效应 自相位调制