钢混组合结构大跨越输电塔主柱和节点的试验研究

为了给工程设计提供参考依据,对钢混组合结构大跨越输电塔中的格构式角钢-钢管混凝土主管和钢管混凝土-钢管相贯节点等关键技术进行了试验研究,获得了格构式角钢-钢管混凝土主管的整体稳定性能、破坏模式和承载力以及钢管混凝土-钢管相贯节点的管壁变形、应力集中系数和承载力数据,并提出了承载力计算方法,可用于类似结构的设计中。     

变压器升高座壁与油箱箱壁的相贯计算及其展开图CAD

给出了变压器升高座壁与油箱箱壁相贯线上交界点坐标和若干个点坐标的计算方程式，指出采用CAD技术不但可以精确计算求得相贯线上各点的坐标和展开后的尺寸，并且通过计算软件和绘图软件的连接，可绘出符合要求的展开图。     

输电铁塔用插接式钢管杆(塔)CAD

根据多边形插接式钢管杆的变形和强度计算方法 ,用C语言编写了插接式钢管杆的变形与强度设计计算软件。该软件可以计算多种工况下任意横截面处的挠度和应力 ,并输出相应的挠度曲线和应力曲线。算例表明 ,所用方法和软件正确可行 ,可供工程设计参考。     

输电铁塔用插接式钢管杆（塔）CAD

根据多边形插接式钢管杆的变形和强度计算方法，用C语言编写了插接式钢管杆的变形与强度设计软件，该软件可以计算多种工况下任意横截面处的挠度和应用，并输出相应的挠度曲线和应力曲线，算例表明，所用方法和软件正确可行，可供工程设计参考。     

立式除氧器补强相贯结构的应力计算研究

电厂压力式除氧器相贯结构引起局部应力集中,是爆炸事故的易发点,也是结构设计、强度计算的疑难点,给设备安全运行带来了隐患.本文根据除氧器结构特征和试验,首次推导了立式除氧器补强相贯的近似理论计算方法,计算结果和试验测试值相当接近.     

用解析法辅助求解相贯线极限位置点

本文利用解析的方法求解相贯线极限位置点,解决了图解法不易确定的某些极限点的位置.     

用解析法分析两圆柱相交的相贯线

机械制图中，相贯线的求解是一个重点。一般作相贯线主要采用表面取点法和辅助平面法。理论上相贯线是由无数个点组成，但作图时只作几个相贯点，然后由点连成线，因此作出的相贯线不准确。本以两相交圆柱为例，探讨用数学方程式精确求解相贯线。     

一种有效的无拓扑关系矢量多边形叠置算法

为了提高土地调查数据处理的效率，实现土地利用数据库中图斑的自动更新，本文提出一种有效的非拓扑关系矢量多边形叠置算法。本算法采用矩阵形式表达叠置多边形与底图多边形的空间关系，以减少参与叠置运算的数据量，构建每个底图多边形对应的叠置弧段链表，把复杂的多边形与多边形叠置过程转换为简单的线与多边形叠置，重新划分空间区域。通过实际应用表明，本算法能够计算出正确的叠置结果，避免了Weiler-Atherton算法中由于出入点配置出错引起的算法失败，具有较好的一般性。     

220kV单回路电缆终端钢管杆设计分析

根据220kV浔妙Ⅰ线改接电厂三期工程终端钢管杆的设计案例,首先分析了钢管杆杆段,导、地线横担及连接的设计思路,再采用NSA钢管杆设计系统软件进行有限元计算,优化结构,分析设计合理性,然后进行电缆终端支架的设计分析,最后完善了钢管杆附属设施的设计。     

多边形转子磁轭永磁同步电机空载气隙磁场解析计算

该文利用分区域方法对多边形转子磁轭永磁同步电机的空载气隙磁场进行了解析推导。该方法基于磁场连续性定理,将磁场的边界条件和交界条件相结合,在忽略磁饱和的条件下,利用不规则磁轭半径函数和偏心永磁体半径函数求解空载气隙磁场。将该方法的计算结果与有限元计算结果相对比,两者吻合较好,证明了该方法可以准确有效地计算多边形转子磁轭永磁同步电机的空载气隙磁场。     

核线几何关系解析的探讨

核线几何关系的解析是摄影测量中一个重要的研究问题。本文回顾了摄影测量中核线几何关系解析的研究现状,着重讨论了基于共面条件确定同名核线中应该注意的几个问题。     

A NEW METHOD FOR SOLVING IONIZED FIELDS OF UNIPOLAR HVDC LINES INCLUDING EFFECT OF WIND. PART II: ITERATIVE TECHNIQUES AND NUMERICAL TESTS

The modified Gaussian algorithm is introduced for solving the ionized fields of unipolar HVDC lines including the effect of wind. Specific techniques of incorporating in the algorithm the special structure of the optimization problem of the ionized field have been developed to economize the requirements for the computer memory and CPU time. Numerical tests are carried out on a coaxial cylindrical geometry and on a line-plane geometry both in the absence and in the presence of wind. Comparison with available experimental data shows good agreement. © 1997 by John Wiley & Sons, Ltd.     

Microwave bandpass filters consisting of rectangular waveguides with 1-dimensional offsets

The computer-aided analysis and design of direct-coupled and quarter-wave-coupled bandpass filters utilizing monomode rectangular waveguides with 1-dimensional offset discontinuities are described. The equivalent networks of these discontinuities, which consist of a shunt reactance and additional transmission lines connected at both sides, have been derived from the rigorous field-theoretical investigations of E-plane and H-plane displacements in rectangular waveguide. Both network elements are tabulated in terms of geometry and wavelength with fine steps to allow accurate interpolation by means of computational methods, Simple design formulae for the filter geometry as a function of the electrical specifications are given which are based upon narrow-band approximations. The analytical relationships required for a computer simulation of the filter's wide-band performance are summarized. The predicted frequency characteristics showed such close agreement with the experimental results obtained on two X-band filter models that neither tuning elements in the waveguide sections nor final adjustments of the offset widths had to be provided.     

磁光式电流互感器相对误差影响因素分析

通过对基于改进型双光路检测法的磁光式电流互感器(MOCT)工作原理的研究,指出MOCT输出信号受工作波长波动及起偏器与检偏器透光轴交角误差的影响。分析了MOCT输出信号满足IEC60044-8标准中0.2级和0.5级准确度要求时,不同工作中心波长情况下工作波长改变量和透光轴交角误差的变化范围和趋势,分析表明,MOCT可承受的工作波长变化范围随着工作中心波长的增大而增大;一次侧额定电流为100 A小电流时,工作中心波长的改变对MOCT可承受的透光轴交角误差范围影响不明显,一次侧额定电流为2000 A大电流时,影响较明显。研究了输出信号相对误差与工作波长改变量及交角误差的关系,研究表明输出信号相对误差与工作波长改变量呈线性关系,与交角误差呈非线性关系。     

1000 kV特高压输电线路防绕击问题的探讨

绕击是1000 kV特高压输电线路雷击跳闸的主要原因,为探讨此问题,分析并比较了目前输电线路绕击计算方法—规程法与电气几何模型法,指出电气几何模型将雷电的放电特性与线路的结构尺寸结合起来,很好解释了线路屏蔽失效现象,用于特高压的绕击计算中,并依据电气几何模型的原理提出减小1000kV线路绕击跳闸率的措施:减小避雷线保护角、安装可控放电避雷针、架设旁路屏蔽地线。     

Analytic solutions for some basic problems in electricity involving intersecting sphere and circular cylinder pairs

The method of electrical inversion in classical electrostatics is employed to obtain exact solutions for basic electrostatic problems pertaining to overlapping spheres/cylinders. The problems considered here include (1) a pair of overlapping conducting spheres, intersecting at a vertex angle ??/n, n an integer, placed in a constant potential field; (2) a pair of infinitely long conducting circular cylinders, intersecting at a vertex angle ??/n, n an integer, placed in a uniform field; and (3) a composite hybrid geometry consisting of two orthogonally intersecting infinitely long circular cylinders whose boundary is a combination of conducting and dielectric surfaces (with mixed boundary conditions) submerged in a uniform field. Applying the basic idea of Kelvin??s inversion repeatedly, solutions for the electric potentials are derived in each case. An exact expression for the capacitance in terms of the two radii, center-to-center distance, and the vertex angle is found for the twin sphere geometry. The capacity is then used to find the steady-state rate coefficient of a perfectly absorbing body placed in a thermally conducting environment of lower temperature. The equipotentials are plotted using the exact solutions of the two-dimensional problems and their features are discussed as well. The simple method illustrated here can be useful both as a teaching tool and as a building block for further computations.     

基于车底阴影的前方运动车辆检测

实时准确检测前方运动车辆的位置信息是车辆安全驾驶的前提,提出了一种在不依赖车道线检测情况下,基于车底阴影的前方运动车辆检测。阴影算法采用两次自适应阈值分割图像从而提取车底与路面的交线,生成目标假设区域,对建筑物或树的投影、光照强弱等干扰能初步有效的排除,提高检测效率;接着,利用熵值归一化的对称性测度来验证,排除虚假车辆。实验结果显示,该算法的正确识别率达到97.2%,平均处理速度为22.5帧/秒,对白天中多种环境能满足实时准确地要求。     

基于嵌入式系统的输电线舞动在线监测系统

本文研究了一套基于嵌入式系统的输电线舞动在线监测系统的设计原理与实现,该系统是由USB摄像头,嵌入式计算机系统和GPRS模块构成。在嵌入式计算机系统中实现了嵌入式Linux的裁减,定制和移植,并在此基础上实现了基于Qtopia的应用监测程序的编写。该监测系统是以嵌入式计算机为载体,以USB摄像头采集到的图像数据为基础。实现了基于无线GPRS的电力设备的输电线的远程实时在线监测。     

基于MPI的电力系统潮流的并行算法研究及其实现

提出了一种不受进程个数限定的电力系统潮流并行算法,算法按机器的个数划分进程,并用等间隔跳跃与指定相结合的方式将系数矩阵的各行分配给各个进程,最后利用并行消息传递接口MPI在计算机机群上实现了该算法.计算结果表明,对于规模较大的电力系统,该算法能有效地提高潮流计算速度.     

On a fundamental physical principle underlying the point locationalgorithm in computer graphics [for EM field theory]

The issue of point location is an important problem in computer graphics and the study of efficient data structures and fast algorithms is an important research area for both computer graphics and computational geometry disciplines. When filling the interior region of a planar polygon in computer graphics, it is necessary to identify all points that lie within the interior region and those that are outside. Sutherland and Hodgman are credited for designing the first algorithm to solve the problem. Their approach utilizes vector construction and vector cross products, and forms the basis of the “odd parity” rule. To verify whether a test point is within or outside a given planar polygon, a ray from the test point is drawn extending to infinity in any direction without intersecting a vertex. If the ray intersects the polygon outline an odd number of times, the region is considered interior. Otherwise, the point is outside the region. In three-dimensional space (3-space), Lee and Preparata propose an algorithm but their approach is limited to point location relative to convex polyhedrons with vertices in 3-space. Although it is rich on optimal data structures to reduce the storage requirement and efficient algorithms for fast execution, a proof of correctness of the algorithm, applied to the general problem of point location relative to any arbitrary surface in 3-space, is absent in the literature. This paper argues that the electromagnetic field theory and Gauss's Law constitute a fundamental basis for the “odd parity” rule and shows that the “odd parity” rule may be correctly extended to point location relative to any arbitrary closed surface in 3-space