考虑分布式电源调峰的配电网规划

基于最大负荷的传统配电网规划方法往往需要投入大量资金建设配电网架，带来较大投资风险，并且供配电设备得不到充分利用。对此提出引入分布式电源（DG）调峰的配电网规划方法。该方法从供电公司的角度，以线路投资、网络损耗和DG投资以及DG调峰所增加的附加费用之和最小为目标，规划未来配电网络。文中充分利用配电网正常运行时呈放射状的网络结构特点，提出一种操作简单的启发式方法确定DG的位置和容量，以消除配电网架在最大负荷水平下的支路过载。此外，还讨论了不同类型DG对网架规划方案的影响。算例分析结果验证了所提出的方法的可行性和有效性。     

含分布式发电的配电网检修负荷转移方案

分布式发电（DG）的接入对配电网的规划和运行产生了深远影响，由于DG的存在，配电网检修负荷转移方案有了更多的选择。文中通过对DG运行方式和负荷转移优化问题的研究，给出了制定含DG的配电网检修负荷转移方案的3条原则，并建立了相应的数学模型。该模型以降低供电企业综合检修成本为目标，包括降低供电企业额外购买的DG电量费用、售电损失和开关操作费用，并在传统负荷转移模型约束条件的基础上增加了其他约束，保证利用可再生能源发电的DG以最大发电能力上网发电和保证利用化石能源发电的DG至少按照正常发电计划发电，以反映DG对负荷转移方案的影响。仿真结果证明了所提出的模型的正确性和有效性。     

具有模糊约束的多阶段多目标系统模糊优化理论与模型

本文将文献[1,2]提出的模糊优选理论与模型,拓展到具有模糊约束的多阶段多目标决策系统,建立了一般的有模糊约束的多阶段多目标系统的模糊优化理论与模型及其求解方法,本文模型既可求解模糊约束问题,又可求解清晰约束问题,常规单目标动态规划模型为本文模型的特例。     

基于Bender''s分解的含DG配电系统网络重构

提出了一种含分布式电源（DG）的配电系统网络重构算法，用于在配电网出现故障时，由DG构成孤岛系统以实现关键负荷的不间断供电，同时保证这一过程中整个配电系统网损最小。基于Bender's分解技术，该优化过程被分解为容量和重构2个问题:容量问题用于解决DG给定时孤岛系统最优供电容量的确定;重构问题用于在孤岛确定后对整个系统网损进行优化。重构问题的开关 — 网损相关因子反馈到容量问题，实现整个网络重构方案的优化。由IEEE 33节点系统和PG&E 69节点系统验证了所述方法的正确性。     

联网分布式发电系统规划运行研究

分布式发电（DG）与输电网联合供电成为电力系统发展趋势。输电系统与DG联合供电的规划、运行分析对满足可靠性条件下的经济供电尤为重要。文中针对远离发电中心、与输电系统弱连接的配电系统，为了满足负荷增长要求，以DG投资费用和向输电网购电费用最小为优化目标，分别对输电网正常运行且价格固定、考虑停运状态和实时电价3种典型输电网情况下联网DG系统进行规划。通过应用启发式算法，得到了各种情况下系统最优供电方案。根据不同情况下系统运行性能分析，定量讨论了输电网停运、实时电价以及可再生能源随机发电对分布式电源类型、容量等规划运行结果的影响，优化结果体现了联网DG系统联合供电优势。     

基于过程状态特征化的电容器动态规划与控制

研究了电容器规划与动态控制问题，首先建立了给定时段内配电网有功能量损耗的评估模型，并在考虑负荷变化的情况下，依靠过程状态特征化的概念构造了一个以系统能量损耗最小为目标的无功优化策略，适当的线性化处理和逐步修正思想大大简化了电容器规划与动态控制问题的数学模型，降低了求解难度，运用静态计算方法解决了动态优化问题，有效降低了动态无功优化所需的计算量。应用所提出的策略对IEEE-69节点配电系统进行了仿真计算，验证了所述方法的合理性和有效性。     

含间歇式分布电源配电网的可靠性评估

智能电网是现代电网的发展方向,它要求未来的配电网能够自由接纳分布式电源（DG）。但DG（尤其是问歇性可再生能源分布式电源）具有分散、随机变动等特性,大量接入将对系统的安全、稳定运行产生极大的影响。提出了对风力、光伏发电等DG配电网系统的可靠性进行全面准确评估的新方法。建立了间歇式分布式电源（IDG）的可靠性模型,引入关联矩阵来处理孤岛的划分问题,介绍了含IDG配电网可靠性的评估方法。通过算例分析DG对配电网可靠性的影响机制,为多种能源互补的配电网扩展规划提供一定的参考。     

多目标优化分段竞标电力市场的研究

提出了一种兼顾污染物排放量最小和购电费用最小等多目标综合优化的电力市场分段竞标新模型。采用2种算法求解该模型：一是模糊算法，即首先分别求解各单目标分段竞标模型，接着将各目标函数模糊化，然后采用最大满意度法将多目标问题转化为新的单目标分段竞标问题，由此求得兼顾多目标的竞标结果；二是目标函数转化为约束算法，即将污染物排放量作为约束构成新的购电费用最小分段竞标模型。算例仿真结果表明了该模型的有效性，也表明该模型不仅具有分段竞标的优点，还可使经济、环保等多目标综合优化，从而体现竞标机组多因素贡献的公平性。     

配电网模糊优化规划(Ⅰ)——模型与方法

配电网规划的特点和难点是不确定性的处理，以往对配电网规划不确定性的研究大多是对某一步骤进行。文中应用模糊数学理论，形成了贯通的配电网模糊规划方法。可以考虑负荷、投资、电价等相关因素的不确定性，建立相应的模糊优化规划数学模型。结合配电网的特点，提出了配电网的模糊负荷预测方法、模糊潮流算法和模糊优化方法。采用L-R型模糊数进行负荷预测和潮流计算，提出了简便实用的边界法，即用负荷模糊预报值的左、右边界和中心值分别进行潮流计算，再综合计算结果。这在输电网的模糊潮流计算中是不可行的，但配电网的辐射状结构决定了这种模糊潮流算法的简单性，可以满足模糊规划的需要。算例表明，模糊规划方法可以得到鲁棒性强的规划方案。     

计及气候、含风力发电的配电系统可靠性评估研究

分布式电源（distributed generation,DG）的接入使配电系统从辐射型的网络变为遍布中小电源和用户的互联网络,将对传统配电系统产生巨大的影响。而风力发电机（wind turbine generation,WTG）凭借其无污染、建造费用低、发电灵活等优势越来越多地被作为分布式电源接入配电网。但由于其自身功率输出随机性强的特点,对传统的分布式电源接入配电网带来了一定的影响。在充分考虑了气候因素对WTG功率输出和配电网馈线故障率的影响的同时,结合WTG的多状态模型与配电网孤岛运行方式,对含有气候因素并以风力发电机作为分布式电源的配电系统的可靠性评估情况进行了阐述,希望电网规划人员在选择最优方案时能够考虑由上述因素带来的影响。     

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。     

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.     

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。