抽水蓄能电站及其系统的概率模拟与运行优化

为满足实际应用的要求，在随机生产模拟中运用负荷曲线分解技术和动态规划，提出了抽水蓄能电站及其系统的概率模拟与运行优化模型。模型以系统发电运行成本与缺电损失最小为目标，满足电站水库蓄水及库容限制条件，满足日或周的抽水—发电循环电力电量平衡条件，并考虑了抽水蓄能电站在抽水和发电方式下随机停运的影响。可应用于电源规划、发电计划和系统运行优化，可以更准确地模拟、分析和优化抽水蓄能电站及其系统的运行状况。通过算例对模型和应用进行了说明。     

基于故障模式分析的抽水蓄能电站事故备用效益评估

提出了一种定量计算抽水蓄能电站事故备用效益的故障模式分析法，通过分析故障后各类电源的事故反应过程，采用经济评价中的等效替代法和有无对比分析法，建立抽水蓄能电站的事故备用效益评估模型。该模型考虑了故障时刻系统以及在运机组的相互影响，以系统运行的整体经济性和可靠性为目标，同时兼顾了能源消耗、污染物排放等方面。应用该方法对某省抽水蓄能电站事故备用效益进行了实例计算，结果表明所述模型和方法的有效性与实用性。     

抽水蓄能电站在电网中静态和动态效益的工程实用算法

从系统观点出发对抽水蓄能电站的调峰填谷静态效益及事故备用、负荷跟踪动态效益进行了分析．文中充分考虑了电站的各种运行方式及不同机组承担不同功能时在模型和计算方法上的差别，用边际效益法优化抽水蓄能电站的工作位置，用新算法对具有不同煤耗特性的火电机组进行最优分配，在此基础上得到静态效益．各种机组以不同容量承担事故各用功能时，从新的角度计算电量损失，即将电量损失分为由于系统增行速度不够快引起的电量损失和由于备用容量不足引起的电量损失两部分，得出事故备用效益．机组承担负荷跟踪功能时，从调度运行角度出发，根据负荷情况调整机组出力．并计算由于调整速度不够快而引起的电量损失，得到负荷跟踪效益．工程实践证明该算法合理并可行．     

抽水蓄能电站日调节与周调节方式运行优化模型

提出了抽水蓄能电站的日调节与周调节方式运行优化模型。按电站抽水 — 发电循环效益最大化，满足电力电量平衡条件，满足库容、发电出力及抽水功率等限制条件，建立了基于混合整数线性规划的算法模型，可应用于电源规划的系统运行模拟，优化抽水蓄能电站的运行方式和发电计划;分析了系统发电成本、电站规模、负荷特性等对电站运行的影响。通过计算实例对算法模型的实用性、有效性做了说明。     

抽水蓄能电站备用效益研究综述

随着电力体制改革及电力系统的不断完善,抽水蓄能电站在电力系统中的动态作用越来越显著,但如果其动态作用体现的价值得不到合理的收益,将严重影响抽水蓄能电站自身的财务生存能力。通过对抽水蓄能电站动态效益的主要组成部分——备用效益进行的研究,对抽水蓄能电站承担备用容量的特点以及备用效益的研究现状、量化理论及方法进行的综合分析,为抽水蓄能电站动态效益的合理量化提供了参考依据。     

蓄能电站静动态效益的定量评估

介绍一种基于概率模拟技术的蓄能电站效益定量评估方法和所得的主要结论。所讨论的效益涉及静态效益（容量效益、调峰填谷效益）、动态效益（爬坡效益、事故备用效益、负荷备用效益和可靠性效益）以及静动态综合效益；数学建模考虑了电力系统的实际运行工况和约束条件，其结论具有实际参考意义。根据本文模型编制的软件可用于工程评估     

快速响应抽水蓄能电站系统的运行效益

抽水蓄能电站的动态运行效益远远超过人们熟悉的容量和是量效益，动态运动效益是指立即响应备用，待机快速备用，旋转备用、负荷跟踪、调频、同步发电、调压及快速起动等方面的效益。基于美国一座大型抽水蓄能电站的运行经验，论述了抽水蓄能电站的动态运行特性，并列举了３个运行实例作为动态运行效益的说明。     

抽水蓄能电站综合效益评估综述

介绍当前抽水蓄能电站效益评估的研究现状,包括静态效益、动态效益以及静、动态效益的综合评估;总结了各种效益评估方法的优缺点和适用范围,并针对抽水蓄能电站动态效益现有分类方法的不足,对动态效益重新进行界定和分类,提出了今后抽水蓄能电站效益评估的研究方向.     

抽水蓄能电站运行优化的动态规划模型

按照电站抽水-发电循环效益最大化，满足电力电量平衡条件，满足库容、发电出力及抽水功率等限制条件，将抽水蓄能电站的运行优化表达为基于日或周运行优化的多阶段优化决策过程，即抽水蓄能电站运行优化的动态规划模型，并通过算例对算法及应用做了进一步说明。     

抽水蓄能电站的作用和效益

<正>抽水蓄能电站的作用抽水蓄能电站在电网中调峰填谷、紧急事故备用、调频、调相等作用以及静态效益、动态效益和技术经济上的优越性,使其在电网中越来越不可缺少。     

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。     

Serial discontinuities in a Rocky mountain river. I. Distribution and abundance of plecoptera

Samples were taken year-round at eleven sites along the altitudinal profile (2900-1400 m a.s.l.) of the Gunnison River, a 329 km tributary of the Colorado River, to document the distribution of the Plecoptera and to evaluate responses to hypolimnial-release dams in the headwaters and middle reaches. Twenty-two species were present, with the greatest species richness occurring in an unregulated segment upstream of the middle reach dams; average nymphal biomass over the study period (175 organisms, 395 mg dry mass m^?2) was also greatest in this segment. Only four species (58 organisms, 48 mg m^?2) were present in the tailwaters of the headwater dam and values were greatly reduced (nine species; 35 organisms, 180 mg m^?2) below the middle reach dams. The stonefly community recovered ca. 80 km downstream from the last dam (15 species; 244 organisms, 250 mg m^?2), apparently in response to natural resetting of environmental conditions corresponding to those above the middle reach dams. At the most downstream site (11) only four species (four organisms, 16 mg m^?2) were present. The observed distributional pattern is a classic serial discontinuity in response to hypolimnial stream regulation in a temperate latitude river.     

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.