平面分层介质结构全波分析综述

本文综述了广义谱域导抗法，直线法及直线法的快速算法，全波离散镜象法等主要方法，并对各种方法的特点进行了比较，这些方法可有效地处理平面分层介质结构问题，文中包括作者近期的研究成果。     

Differential geometry properties of lines of curvature of parametric surfaces and their visualization

We present algorithms for computing the differential geometry properties of lines of curvature of parametric surfaces. We derive a unit tangent vector, curvature vector, binormal vector, torsion, and algorithms to evaluate their higher-order derivatives of lines of curvature of parametric surfaces. Among these quantities, it is shown that the curvature and its first derivative of the lines of curvature lend a hand for the formation of curved plates in shipbuilding. We also visualize the twist of lines of curvature, which enables us to observe how much the osculating plane of the line of curvature turns about the tangent vector.     

威信煤电一体化一期电厂“三条红线”指标分析

对云南威信煤电一体化一期电厂进行最严格水资源管理制度的三条红线控制指标定量分析和计算,选取项目用水总量和流域水资源利用率分析用水总量控制指标;取设计耗水率、新水利用率、取水指标、全厂复用水率、循环水利用率、厂区生活用水等来分析用水效率控制指标,选取水功能区水质达标率分析水功能区限制纳污指标。结果表明:项目建成后流域水资源开发利用率为7.4%;设计耗水率0.51~0.61 m3/(s·GW)、新水利用率100%、取水指标0.58 m3/(s·GW)、全厂复用水率98.3%、循环水利用率98.7%;项目要求电厂所有退水必须全部回收利用,污水零排放,所在区域水质目标为Ⅱ类。     

多分支平行双线输电线故障定位算法的研究

本文针对多分支平行双线输电线提出了一种新的故障定位方法。应用相同的算法对全部分支进行逐条搜索,故障分支和故障点位置可以一并被确定。经仿真证明,该方法是有效的。     

Weaving patterns of lines and line segments in space

Aweaving W is a simple arrangement of lines (or line segments) in the plane together with a binary relation specifying which line is above the other. A system of lines (or line segments) in 3-space is called arealization ofW, if its projection into the plane isW and the above-below relations between the lines respect the specifications. Two weavings are equivalent if the underlying arrangements of lines are combinatorially equivalent and the above-below relations are the same. An equivalence class of weavings is said to be aweaving pattern. A weaving pattern isrealizable if at least one element of the equivalence class has a three-dimensional realization. A weaving (pattern)W is calledperfect if, along each line (line segment) ofW, the lines intersecting it are alternately above and below. We prove that (i) a perfect weaving pattern ofn lines is realizable if and only ifn 3, (ii) a perfect m byn weaving pattern of line segments (in a grid-like fashion) is realizable if and only if min(m, n) 3, (iii) ifn is sufficiently large, then almost all weaving patterns ofn lines are nonrealizable.Jànos Pach has been supported in part by Hungarian NFSR Grant 1812, NSF Grant CCR-8901484, and the Center for Discrete Mathematics and Theoretical Computer Science (DIMACS), a National Science Foundation Science and Technology Center, under NSF Grant STC88-09648. Richard Pollack has been supported in part by NSA Grant MDA904-89-H-2030, NSF Grants DMS-85-01947 and CCR-8901484, and DIMACS. Emo Welzl has been supported in part by the ESPRIT II Basic Research Actions Program of the EC under Contract No. 3075 (project ALCOM) and DIMACS.     

An overview of Dynamic Software Product Line architectures and techniques: Observations from research and industry

Over the last two decades, software product lines have been used successfully in industry for building families of systems of related products, maximizing reuse, and exploiting their variable and configurable options. In a changing world, modern software demands more and more adaptive features, many of them performed dynamically, and the requirements on the software architecture to support adaptation capabilities of systems are increasing in importance. Today, many embedded system families and application domains such as ecosystems, service-based applications, and self-adaptive systems demand runtime capabilities for flexible adaptation, reconfiguration, and post-deployment activities. However, as traditional software product line architectures fail to provide mechanisms for runtime adaptation and behavior of products, there is a shift toward designing more dynamic software architectures and building more adaptable software able to handle autonomous decision-making, according to varying conditions. Recent development approaches such as Dynamic Software Product Lines (DSPLs) attempt to face the challenges of the dynamic conditions of such systems but the state of these solution architectures is still immature. In order to provide a more comprehensive treatment of DSPL models and their solution architectures, in this research work we provide an overview of the state of the art and current techniques that, partially, attempt to face the many challenges of runtime variability mechanisms in the context of Dynamic Software Product Lines. We also provide an integrated view of the challenges and solutions that are necessary to support runtime variability mechanisms in DSPL models and software architectures.     

Another test of sensor lines on control panels

In this experiment all panels had four circular displays arranged in a square on a vertical surface and four controls aligned vertically to the right of the displays. Two panels had linkages between controls and displays which earlier research had shown to be compatible, the other two had incompatible linkages. Each of these four panels was tested with and without sensor lines showing the linkages between controls and displays. Ninety-six subjects each made 128 trials on one of the eight panels. A subject's task was to respond as quickly as possible by pushing the correct control to extinguish a light when it appeared in one of the displays. Sensor lines had no effect on performance with the compatible panels but impaired performance on the incompatible panels. The results also confirm again the potency of the compatibility principle: responses were faster and fewer errors were made when using the compatible panels.     

图形电镀夹膜修理方法

图形电镀已经是PCB制造加厚铜的主要方式,夹膜问题是此工艺流程的一大顽疾,本文为各位同仁介绍一种有效、简便、实用的修理夹膜的方法.     

一种基于CSRR＿CRLH TL的带通滤波器设计

提出一种基于探针加载的互补开口谐振环(CSRR)的复合左右手传输线(CRLH TL)结构。利用CSRR+CRLH结构的谐振特性,并通过延长CRLH耦合缝隙的长度以及增加CSRR中短路探针的数量,在引入传输零点的同时缩小了滤波器的尺寸。经过仿真优化,实现了滤波器宽频带、高选择性和小型化设计。加工了基于该结构的带通滤波器样机,样机整体尺寸为30mm×15mm×1.35mm。测试结果表明,滤波器的中心频率及插入损耗分别为6.6GHz和0.65dB,3 dB带宽为9.3 GHz,在无线通信、导航等微波系统中具有良好的应用前景。     

基于PSCAD的采油区配电线路防雷研究

为提升采油区10 kV配电线路的耐雷水平,本文系统研究了10 kV配电线路的防雷现状,探讨了各项防雷措施的优劣,利用PSCAD仿真软件对“上”字型杆塔和三角型杆塔分别建模,仿真分析绝缘子类型、避雷器安装、避雷线架设等防雷措施对线路耐雷水平的影响。然后,通过对某采油区配套的一条10 kV配电线路开展实地测量与建模仿真,分析验证了多项防雷措施的可行性与有效性。最终采用对24支#3杆使用降阻剂、深埋接地极、在线路前20基杆塔上架设避雷线和在部分杆塔的三相绝缘子两端并联线路避雷器等措施进行优化。仿真结果显示,采取上述优化措施后,该线路整体耐雷水平显著提高。本文制定的防雷优化方案具有普适性,可以为其它采油区的10kV配电线路防雷提供借鉴。