考虑线路剩余输电容量的多目标电网规划

传统输电网规划方案由于没有考虑网络中各线路的负载运行水平，得到的最小费用方案会导致部分线路负载率偏高。文中的新规划模型将线路投资费用和网络剩余输电容量作为目标函数，同时考虑优化线路负载率的分布，用以求取最少投资下具有最大网络剩余输电容量的规划方案。结合混沌变量的随机遍历特性，将混沌优化算法应用于输电网非线性混合整数规划模型的优化求解。算例表明方法的正确性和有效性。     

基于无人机图像识别技术的水利工程输电线路缺陷检测方法

水利工程输电线路缺陷故障检测受到环境和设备自身性能影响较大,维护成本较高。为了提高缺陷检测能力,提出基于无人机图像识别技术的水利工程输电线路缺陷检测方法,将GNSS/INS多传感器设备植入到无人机系统中,采用无人机图像信息采集方法,提取水利工程输电线路的点云数字图像,结合输电线路的内部几何参数和线路外观几何参数分析的方法,分析在缺陷状态下的水利工程输电线路的变形和异常参数分析部情况,根据输电线路无人机图像的点云数据分布投影点,分析缺陷故障下不连通、簇之间的空间间隔,根据中心化投影点的聚类分布,实现输电线路的缺陷检测。仿真测试结果表明,采用该方法进行水利工程输电线路缺陷检测的特征聚类性较好,提高了检测的精准度和实时性。     

基于模糊随机机会约束规划的输电可靠性裕度计算

提出了基于模糊随机机会约束规划的输电可靠性裕度的数学模型和混合智能算法。将影响输电可靠性的重要因素表述为随机变量或服从正态分布的事件，例如将发电机和线路运行状态视为服从二次型分布的离散型随机变量，将用户需求看成服从正态分布的随机事件。在不确定因素随机化的基础上，将输电可靠性裕度问题转化为等价的模糊随机优化问题，输电线路开断、发电机开断和负荷模型的等约束条件退化为随机函数、模糊函数。文中提出的求解该机会约束规划模型的混合智能算法，在IEEE 30节点系统上进行了仿真计算，验证了该方法的正确性和可行性。     

输电线路风偏故障分析及应对措施

通过对输电线路运行情况进行全面的调研分析,风偏故障是造成输电线路跳闸的一个主要因素。结合一些输电线路跳闸统计情况,从风偏机理、天气、地理环境、线路本体设计等方面综合分析了风偏故障的成因,进一步分析了风偏防治措施。在全面借鉴行业先进经验的基础上,依据风偏防治的原则和规范,给出了相应的风偏故障防范措施;并结合相关的电网事故案例,对输电线路风偏防治的现行状况提出了进一步的整改措施,从设计、施工、运维方面提出风偏反措建议。     

基于机会约束规划的输电系统规划方法

输电系统在电力市场中扮演着十分重要的角色，因为其提供了实现公平竞争的场所。输电系统的状况如容量充裕性对电力市场的竞争性有重要的影响。适当地扩展或加强输电系统对满足发电公司和用户的需要、消除或减缓输电系统阻塞具有重要作用。与传统的输电系统规划问题相比，电力市场环境下的输电系统规划更加复杂，需要处理的不确定性因素更多。机会约束规划是专门用于解决包含不确定性因素的优化问题的一类随机优化方法，适用于市场环境下的输电系统规划问题。文中将机会约束规划引入到市场环境下的输电系统规划研究中，给出了基于蒙特卡罗仿真和遗传算法的求解方法，为解决这一重要而困难的问题做了一些新的尝试，并通过一个算例系统说明了该方法的可行性。     

输电系统固定成本分摊问题(续完)

在电力市场环境下，输电固定成本需要公平、合理地分摊给所有电网使用者。合理的分摊方法可以引导对现有输电设备的有效和合理的使用，并为将来的发电规划和负荷选址提供经济信号。文中对现有的输电固定成本分摊方法进行了全面而系统的综述，按照所分摊的成本、承担成本的主体、所基于的系统状态、冗余容量成本的分摊、对反向潮流的收费、对无功功率的处理、分摊的原则与方法等方面，对现有的输电成本分摊方法进行了详细的分析，论述了每一种方法的特点，并对各种方法进行了比较和讨论。     

计及风险约束的多阶段输电系统规划方法

多阶段输电系统规划问题是一个复杂的非线性组合优化问题。与传统的输电系统规划问题相比，电力市场环境下的输电系统规划更加复杂，需要处理的不确定性因素更多。在不确定性环境下所制定的输电系统规划决策不可避免地会带有一定的风险, 包括安全风险与经济风险。因此，在制定输电系统规划方案时需要适当考虑风险的影响，亦即需要进行风险管理。在此背景下，文中利用机会约束规划可以显式描述风险的特点，构造了计及风险约束的多阶段输电系统规划的模型框架，并给出了相应的求解算法，为解决这一重要而困难的问题做了一些新的尝试。最后通过一个算例系统说明了所提出的方法的可行性。     

输电规划方法的评述

评述了输电规划的现状，分析了电力市场改革给输电规划带来的新问题。从优化问题的诸要素出发，归纳现有的输电规划求解方法。指出输电规划在考虑经济性的同时，要以量化的指标来反映系统的安全风险水平，兼顾规划方案的经济性和安全性。在此基础上讨论了输电规划的发展趋势。     

给水管网的优化布置与设计

在以往的灌溉中为了实现加压输水系统的优化设计,经建立了许多模型,这些模型主要用于水分配网络的分析和设计,其中供水管线的布局大部分是固定的,从而限制了供水管线的布局以及系统的其他特性进一步的优化。本文提出了一种混合优化方法,包括两种计算方法,线性规划(LP)和混合整数规划(MIP),前者适合于线路布局优化,后者则更适合于设计优化。将这两种算法组合起来,建立了给水管网优化布置与设计模型,并且应用于给水管网的优化设计,在所有可行路径中寻找成本最小的路径。     

500 kV集庆线压覆矿产及采空区分析与评价

电网建设中输电线路经过采空区尤其是煤矿采空区的现象已属常见，评价采空沉陷对输电线路的影响规律以及采取相应的应对措施，对保障电网的安全稳定运行，具有实践意义。文章通过对线路路径所经煤田地段的压覆矿产情况进行了实地的调查、分析，并对采空区进行了评价，为线路路径方案及铁塔基础方案提供了依据。     

地下厂房施工过程的三维非线性数值模拟分析

根据冗各电站地下厂房开挖支护的施工顺序,以隐式杆单元模拟锚杆,以壳单元模拟混凝土喷层,采用三维非线性有限元技术,对洞室群的开挖支护动态过程进行了模拟计算。通过三维非线性有限元计算分析得到:洞室群动态开挖过程中围岩应力变形的分布规律,围岩塑性区的发展规律,锚杆受力变化情况。计算结果表明:整个开挖过程中,洞周围岩位移变化规律正常,量值较小,塑性区主要分布在洞室周边,围岩稳定性较好;但在洞室交叉口处围岩的变形较大,出现较大范围的塑性区,在此基础上提出了支护措施优化方案,并对优化方案的效果进行了评价。     

Evaluation of freshwater mussel relocation as a conservation and management strategy

The relocation of unionacean mussels is commonly used as a conservation and management tool in large rivers and streams. Relocation has been used to recolonize areas where mussel populations have been eliminated by prior pollution events, to remove mussels from construction zones and to re-establish populations of endangered species. More recently, relocation has been used to protect native freshwater mussels from colonization by the exotic zebra mussel Dreissena polymorpha. We conducted a literature review of mussel relocations and evaluated their relative success as a conservation and management strategy. We found that 43% of all relocations were conducted because of construction projects that were forced to comply with the Endangered Species Act 1973 and that only 16% were monitored for five or more consecutive years. Most (43%) relocation projects were conducted from July to September, presumably a period when reproductive stress is relatively low for most species and the metabolic rate is sufficient for reburrowing in the substrate. The mortality of relocated mussels was unreported in 27% of projects; reported mortality varied widely among projects and species and was difficult to assess. The mean mortality of relocated mussels was 49% based on an average recovery rate of 43%. There is little guidance on the methods for relocation or for monitoring the subsequent long-term status of relocated mussels. Based on this evaluation, research is needed to develop criteria for selecting a suitable relocation site and to establish appropriate methods and guidelines for conducting relocation projects.     

基于模型试验的河床砂砾石层基本特性研究

为了经济可靠地确定深厚覆盖层的基本特性参数,以大渡河双江口水电站坝基河床砂砾石层基本特性研究为工程背景,进行大尺寸模型试验,研究河床砂砾石层的旁压模量和动探击数随密度、级配以及上覆压力的变化规律。根据室内模型试验结果,结合现场旁压试验及钻孔试验成果,推断出坝址区河床砂砾石相关层位的密度,并依此进行砂砾石室内力学试验,获得设计所需力学参数。研究成果可为深厚覆盖层基本特性测试提供新的方法。     

基于BP神经网络-马尔科夫链模型的隧道围岩位移预测

在隧道工程施工中,围岩位移预测起着很重要的作用。将BP神经网络-马尔科夫链模型引入到隧道围岩位移预测中来,通过对训练样本的学习,利用BP神经网络实现了对位移时间序列的滚动预测,同时得到了实测值与预测值的相对误差;在此基础上利用马尔科夫链对相对误差进行修正,有效地提高了预测结果的精度。并将该模型应用于某公路隧道拱顶下沉位移时序预测中,结果表明该模型具有精度高、科学可靠的特点,为隧道围岩变形的预测提供了新的途径。     

Short communication. Pipelines as a refuge for freshwater snails

In the lower River Murray, Australia, populations of gastropods have declined markedly over the past 40 years. Of the native fauna of about 18 species, only the ancylid Ferrissia petterdi remains common (but in patches), and another five species feature in sporadic local resurgences. Until recently the viviparid Notopala was thought to be extinct. The introduced physid Physa acuta is widespread, but in low numbers. The decline probably is associated with flow regulation, high turbidity and the introduction of common carp. Snail populations have persisted, however, in irrigation pipelines fed from the river, where they periodically cause blockages. This paper reports the discovery of the only known populaion of Notopala hanleyi in a pipeline where the inner wall accumulates microbial and other organic matter, providing high quality food for snails. In the Murray before regulation most of the periphytic biomass was probably microbial, as fluctuating water levels would have maintained littoral communities in a highly productive, early state of succession his postulated that, by stabilizing seasonal water levels, regulation has promoted the production of filamentous green algae, an inferior food source, and so displaced snail populations from the open aquatic environment.     

浙江省水域调查录入系统的设计和应用

浙江省水域调查录入系统将调查数据与电子地图相整合,对分类水域数据进行统计计算,并对输入数据进行合理性和完整性检查,得到调查范围内现有水域的详细数据,实现了水域调查数据输入、计算、统计和查询的数字化管理,提高了工作效率和工作质量,为各地下阶段水域保护规划编制和水域管理工作提供了数据支持。对该系统的设计原则、功能和技术设计等作了介绍。     

基于CT-连续加荷水泥乳化沥青混凝土细观损伤规律研究

利用CT技术对水泥乳化沥青混凝土的细观损伤过程进行实时扫描观测,获得了混凝土试件在连续加荷下的CT图像。通过采用直观分析法、CT数分析法、CT数与损伤变量关系3种方法分析表明,水泥乳化沥青混凝土的破坏过程可分为压密、扩容、裂纹扩展、破坏4个阶段,同时混凝土在受压过程中具有韧性,在极限荷载之前各断面处于压密和微扩容的强化阶段,极限荷载之后混凝土从损伤到破坏发展比较平稳。     

Automated system for removal and pneumatic transport of fly ash from electric precipitator hoppers

A system for removal and pneumatic transport of fly ash is examined, in which air pulses act on batches (pistons) of ash formed in a duct. Studies are made of the effect of several physical parameters on the force required to displace a piston of ash and these serve as a basis for choosing a system for removal and pneumatic transport of ash simultaneously from several hoppers of an electric precipitator. This makes it possible to separate the ash particles according to size without introducing additional components. Formulas are given for calculating the structural and dynamic parameters of this system and measurements of indirect dynamic parameters are used to calculate the input-output characteristics of the system. In order to optimize the system, configurations for summing several ducts into a single transport duct for pneumatic ash transport are proposed. Some variants of dry ash utilization and the advantages of producing of size-separated particles are considered. __________ Translated from élektricheskie Stantsii, No. 2, pp. 26–30 (2008).     

The flood pulse advantage and the restoration of river-floodplain systems

The ‘flood pulse advantage’ is the amount by which fish yield per unit mean water area is increased by a natural, predictable flood pulse. Evidence for this increase is presented from tropical and temperate fisheries. It is argued that increasing multispecies fish yield by restoring the natural hydrological regime is consistent with increasing production of other trophic levels and with restoration from ecological and aesthetic viewpoints. When applied to a river-floodplain system, this restoration would provide a large, self-sustaining potential for recreation, commercial exploitation, and flood control. An interim ‘natural flood pulse’ restoration approach is proposed for systems modified for navigation. This approach approximates the natural hydrological regime in a river reach and is intended as a first step in the long process of restoring the watershed.     

浅谈天湖水电站水轮机运行故障及处理措施

简述天湖水电站投运以来各种故障的表现形式，分析其原因，提出了相应的处理方法及措施，并对合理利用国内外设备提出建议。