形变热处理对引线框架用铜合金组织与性能的影响

采用金相显微镜、X射线衍射仪、维氏硬度计及力学试验机等研究了冷轧及时效处理对Cu-Ni-Co-Si合金带材组织和性能的影响。结果表明:冷轧使合金带材内晶粒组织被压扁拉长并形成变形织构,增加显微硬度,降低断后伸长率和电导率;时效使冷轧后合金带材的显微硬度降低,断后伸长率和电导率上升,但350℃时效处理使合金带材的显微硬度出现先升后降现象;合金带材经冷轧和时效处理后获得了多组不同的显微硬度、断后伸长率和电导率组合,其中综合性能较好组合的工艺主要有60%压下率冷轧后进行350℃×0.5 h、350℃×1 h或400℃×0.5 h时效处理。     

桩-软岩复合地基流变机理缩尺模型试验研究

桩-软岩复合地基承受上部载荷时,时效变形预测依赖于对其流变机理的认识以及对流变模型的合理描述,为分析其流变机理,通过桩-软岩复合地基缩尺模型载荷试验,研究了桩身应力、桩底压力、承台下软岩压力以及软岩深部变形时效特征,对桩-软岩复合地基流变机理进行了系列试验研究。桩底压力以及桩间软岩变形时效特征明显,桩-软岩复合地基在工程荷载作用下的衰减蠕变可采用5参量广义开尔文模型进行描述,其流变参数为E_H=1.1 GPa,E₁=7.05 GPa,η₁=929 GPa·h,E₂=9.03 GPa,η₂=28 GPa·h,与软岩地基比较,桩-软岩复合地基流变参数明显提高。     

20Cr1Mo1VTiB螺栓钢长期时效的组织演变及其力学性能

20Cr1Mo1VTiB螺栓钢常用于钠冷快堆蒸汽发生器紧固件,服役温度约530℃。该钢在530℃时效100～10 000 h的组织演变结果显示,时效过程中碳化物尺寸未见明显增大。随时效时间延长,MC相增多,贝氏体板条边界逐渐模糊,板条宽度逐渐增加。时效过程中力学性能未见大幅度下降,表明其在530℃服役环境下可长期使用。     

大跨度空间网架金属闸门残余应力静载负荷时效试验

针对曹娥江大闸挡潮泄洪闸工作闸门大跨度空间网架的特殊门型结构，设计了先进行90d夏季高温曝晒的自然时效，再利用钱塘江小潮汛实施残余应力静载负荷时效的试验。采用盲孔法测量残余应力，跟踪分析自然时效、静载负荷时效的消应效果，实现了门叶整体安全时效。     

钢材冲击韧性和应变时效敏感性问题的探讨

对国内外水电站压力钢管设计规范及有关钢材标准和压力容器规范关于钢材的冲击韧性和应变时效敏感性的有关规定进行了分析与比较。鉴于我国现行钢材标准对钢材在不同温度下的冲击功指标均已有明确规定，因而建议在钢管规范修订稿中可不必重复列出钢材在不同温度下的冲击功指标的要求，只需指出钢材的冲击韧性要求应按我国现行钢材标准的有关规定执行即可；鉴于我数国家的水电站压力钢管设计规范对钢材的应变时效冲击韧性均未单独提出此项要求，且我国除个别钢材标准尚列有应变时效冲击韧性的要求外，其它钢材标准则均未提应变时效冲击韧性的要求，因而建议钢管规范修订稿也暂不提钢材的应变时效冲击韧性指标为宜。如果一定要提，则建议用应变时效敏感性系数表达。     

河流自然模型试验时效的研究

在概述河流自然模型试验定义和前人众多试验研究的基础上，讨论了试验时间的确定对河流自然模型试验的意义。结合对概化水槽试验的分析，论述了河流自然模型试验时效的定义、实质及其影响因素，初步得出试验时效与河床组成、河谷比降以及流量的关系，并提出时效的判定指标。通过相似理论以及河段裁弯概化模型试验与天然河流的对比，对其合理性进行了初步验证。最后，引入“空代时”假说，分析了该假说在时效验证中的可行性。     

混凝土坝观测设计中的若干问题

（上接本刊1999年第5期第44页）7．4从趋势性变形谈保证基点的稳定性7．4．1趋势性变形是当前研究中的薄弱环节与温度分量、水压分量相比，各工程对趋势性变形的研究迄今还是很不够的。对时效分量大都停留在描绘其变化过程的阶段，用数学方法尽量从测值中如实地分解出呈趋势性变化部分的数值，以及给出其收敛率，这样做很有必要。具体工程中对时效变形产生的机理与影响因素的成果分析至今很少，但在工程的时效量较大时，上述问题就无法回避。像黄河中上游几个梯级，其时效位移都很大而且均指向上游。例如八盘峡，坝高33m，蓄水14年后时效位…     

紧水滩拱坝平面变形控制网稳定分析

介绍了边角网布置及监测，通过７期资料分析确定了基准点，且对变形点的位移量进行显著性检验及估计，为监测坝体时效位移可靠性提供了参考依据。     

水工金属结构的残余应力及时效方法

介绍了残余应力的分类、产生原因和不同作用；从水工金属结构的角度分析了应力腐蚀、脆性断裂、疲劳抗力降低或内应力松弛变形等残余应力危害的作用机理及工业预防措施。从钢的时效性引出，阐明了自然时效、热时效、振动（随焊捶击）时效、静态过载时效的工艺原理及现代工业价值。     

振动时效消除焊接应力的可行性

介绍了振动时效的工作原理及振动时效工艺的编制，列举实例，给出了残余应力测试结果、从振动的结果看，个别有焊接缺陷的焊缝，通过振动时效，检验了焊缝的综合质量，发现了原始静态下不易发现的焊接缺陷，提高了焊接质量，增加了构件的使用寿命。     

Call for Papers

正As the eldest and most distributed professional journal of water industry,Water Wastewater Engineering(W WE)gained very wide acceptance from the colleagues working in this field in this country since start publication in 1964.Now it is administrated by the Ministry of Construction of the People’s Republic of China and sponsored by the China Civil Engineering Society etc.     

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.     

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。     

Impacts of Microcystis on algal biodiversity and use of new technology to remove Microcystis and dissolved nutrients

Cyanobacteria often dominate eutrophic lakes, outcompeting green algae that are required by fish and zooplankton. This study was undertaken to ascertain the impact of the cyanobacterium, Microcystis, on algal biodiversity. Under laboratory conditions, we found that the presence of Microcystis decreased phyla richness by 58%, phyla evenness by 47%, genera richness by 66% and genera evenness by 51%. Analysis by mixed anova s demonstrated a significant interaction between treatment and time and confirmed a significant reduction in richness and evenness of phyla and genera. We also conducted a phosphate restriction assay on the algae in Mason Lake (Irvine, CA, USA) and found that the threshold needed for algal growth there was 0.02 mg L^?1 PO₄. A pilot study was then conducted to test the effectiveness of the Blue Pro? water treatment facility in removal of this colonial organism from Mason Lake, in addition to removal of dissolved nutrients required for its growth. We measured a 97% reduction in Microcystis cells, a 72% reduction in chlorophyll‐a, and a 96% reduction in phosphate after just one 10 min cycle through the unit. Our study demonstrated that removal of Microcystis colonies may allow green algae to increase in numbers. This may improve algal biodiversity, which will benefit zooplankton and fishes.     

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。     

库水波动下库岸边坡地下水浸润线解析解及误差分析

解析法是库岸边坡地下水浸润线计算中便于实际应用的方法,但该方法须基于若干假定并对潜水运动基本方程线性化后才能求解。针对各假定和线性化过程建立不同的地下水渗流数学模型,用解析法和有限元法解答上述数学模型,分析各误差大小及其规律。结果表明：库岸垂直处理带来的误差要小于方程线性化处理和不考虑非饱和渗流带来的误差,而且它们都随渗透系数变大而减小;在三峡库区库水调度情况下,假定库水位等速变化带来的误差对大多岸坡而言可以忽略;计算库岸边坡地下水浸润线时,解析法只适用于水位变化幅度相比含水层厚度较小,且几何边界规则、岩土结构简单、岩土体渗透性较好时的情况。     

SPATIAL AND TEMPORAL WATER QUALITY VARIABILITY IN AQUATIC HABITATS OF A CULTIVATED FLOODPLAIN

The floodplains of lowland rivers contain diverse aquatic habitats that provide valuable ecosystem services but are perturbed when intensively cultivated. Hydrologic, water chemistry and biological (fish) conditions in five aquatic habitats along the Coldwater River, Mississippi, were measured for more than 4 years: the river, two severed meanders that functioned as backwaters, a managed wetland and an ephemeral channel draining cultivated fields. Off‐channel habitats were connected to downstream regions 0.10% to 32% of the dry season and 24% to 67% of the wet season. The median temperatures for the five monitored sites ranged from 18°C to 23°C, the median total solids concentration for all sites was 135 mg L^?1, the median total phosphorus was 0.29 mg L^?1 and the median total nitrogen was 1.56 mg L^?1. Chemical and physical water quality displayed strong seasonal differences between the wet winter/spring and the dry summer/fall periods so that temporal variation consisted of gradual seasonal trends superimposed on strong diurnal variations. All off‐channel habitats exhibited periods of hypoxia and temperatures >30°C during the dry season. Between‐site gradients of water and habitat quality were strongly coupled to water depth and runoff loading. The rehabilitation of one backwater by increasing water depth and diverting agricultural runoff was associated with improved water quality and fish species richness relative to an adjacent untreated backwater. The diversion of polluted runoff and the use of water control structures to maintain greater water depth were observed to be effective management tools, but the former reduces the water supply to habitats that tend to dry up and the latter reduces connectivity. Published in 2011 by John Wiley & Sons, Ltd.     

簸箕李引黄灌区水沙分布及优化调度的经验

灌区利用水沙观测所取得的资料和试验数据，运用水沙运动力学理论，总结分析和揭示了灌区水沙分布的规律和特点。在此基础上，结合灌区的实际运行情况，围绕减少骨干渠道的淤积进行探讨、研究，进而，优化水沙调度方案。该方案实施后，骨干渠道减旅伴效果明显，取得了成功的经验。     

小湾水库大坝防渗面板及其裂缝的加固处理

小湾水库大坝防渗面板整体抗渗性能差,且存在多条裂缝,通过对面板钢丝网喷涂丙乳砂浆加固处理及其裂缝修补,大坝渗漏量明显减少,且左岸上灌浆廊道内及大坝下游坝面92～93 m高程下廊道入口处原有小股射流全部消失.