智能式微机调速器特性试验装置研究

介绍了以ＳＴＤ工控机和３８６－ＰＣ机构成的水轮机组微机调速器综合试验装置．该装置可完成电液转换器静特性、水轮机调节系统静特性及动特性的试验和试验结果分析．实用表明，装置能满足微机调速器性能测试的要求．     

Encapsulation of PV modules using ethylene vinyl acetate copolymer as a pottant: A critical review

The primary purpose of this work is to review the literature about what is and is not known about using ethylene vinyl acetate (EVA0 copolymer as the encapsulant (or pottant) material in photovoltaic (PV) modules. Secondary purposes include elucidating the complexity of the encapsulation problem, providing an overview about encapsulation of PV cells and modules, providing a historical overview of the relevant research and development on EVA, summarizing performance losses reported for PV systems deployed since ca. 1981, and summarizing the general problems of polymer stability in a solar environment. We also provide a critical review of aspects of reported work for cases that we believe are important.Failure modes resolved in the early work to establish reliability of deployed modules and the purposes and properties of pottants, are summarized. Typical performance losses in large field-deployed, large-scale systems ranging from 1% to 10% per year are given quantitatively, and qualitative reports of EVA discoloration are summarized with respect to ultraviolet (UV), world-wide location and site dependence.The general stability of polymers and their desirable bulk properties for solar utilization are given. The stabilization formulation for EVA, its effectiveness, and changes in it during degradation are discussed. The degradation mechanisms for the base resin, e.g., unstabilized Elvax 150^TM, and stabilized EVA are indicated for literature dating to the early 1950s, and the role played by unsaturated chromophores is indicated. The limited number of studies relating discoloration and PV cell efficiency are summarized.Observed degradation of EVA or the unstabilized base resin in the laboratory and examples used to measure the degradation are summarized in sections entitled: (1) thermally-induced degradation; (2) photodegradation and photothermal degradation of EVA in different temperature regimes; (3) photobleaching and photodegradation of the UV absorber and cross-linking agent; (4) acetic acid and metal and metal-oxide catalyzed oxidative degradation; and (5) discolaration and PV cell efficiency losses.Processing effects/influences on EVA stability are discussed in sections entitled: (1) EVA raw materials and extruded, uncured films; (2) thermal encapsulation processes; (3) effects of lamination, curing, and curing peroxide on gel content and chromophores formed; and (4) incomplete shielding of curing-generated chromophores. A summary is given for the limited number of accelerated lifetime testing efforts and examples of erroneous service lifetime predictions for EVA are discussed. The known factors that effect the discoloration rate of several EVA formulations are discussed in which the reduction in rate by using UV-absorbing superstrates is a prime example. A summary is given of what is and is not known about EVA degradation mechanisms, degradation from exposures in field-deployed modeules and/or laboratory testing, and factors that contribute to EVA stability or degradation. Finally, conclusions about using Elvax 150 in EVA formulations are summarized, and future prospects for developing the next-generation pottant for encapsulating PV modules are discussed.     

沥青混凝土低温性能试验和工程应用

本文主要介绍了研究沥青混凝土低温性能的试验装置—自动补偿式沥青混凝土冻断试验系统,以及结合实际工程,利用该系统进行的沥青混凝土低温性能试验研究成果。自动补偿式沥青混凝土冻断试验系统的特点是能模拟实际温度变化,采用测量—比较—补偿的方法进行试验控制,实现试件在长度L内的零位移,以消除试验机架、试件夹具等联结处因温度应力产生的变形对试验结果的影响。沥青混凝土低温性能试验研究表明：(1)沥青品种对沥青混凝土冻断温度有显著影响;(2)沥青含量在±0.3%范围内变化时对冻断温度影响不显著;(3)添加适量的聚酯纤维在改善沥青混凝土高温性能的同时,没有降低其低温性能。     

冲击回波法检测隧洞混凝土衬砌厚度

冲击回波法是通过接收、分析在混凝土中传播的回波信号，判断结构混凝土厚度和内部质量的新型无损检测技术。室内试验和工程应用研究表明，该方法为隧洞混凝土衬砌厚度检测提供了一个有效的测试手段。     

洪门水电站溢洪道基础排水廊道排水孔析出物分析

本文简要分析了排水廊道析出物及与之相关的基本资料,对析出物的成因进行了探讨。分析认为,廊道析出物成因复杂,可能来自上游粘土铺盖、左侧副坝粘土和基础岩体节理裂隙的充填物,或是三者的混合物,并认为必须对工程缺陷进行及时处理。     

澄碧河水库溢洪道闸门启闭机设备改造及考核测试

澄碧河水库溢洪道闸门控制系统部分设备陈旧老化已超过使用年限。为此,对相应控制部分进行改造,在对原有的液压系统和配电改造的同时,新建闸门计算机自动监控系统。实践证明,澄碧河水库溢洪道闸门控制设备的更换改造,实现了多种方式操作和计算机自动监控,具有闸门开度指示及各种运行状态或事故记录与查询、泄洪水量统计、打印和保护动作报警等多种功能,为澄碧河水库防洪度汛提供了安全保障。     

水工混凝土碱-骨料反应研究综述

自从1940年美国T.E.Stanton首先发现混凝土碱-骨料反应问题以来,碱-骨料反应已成为全球性混凝土工程毁坏的重要原因之一。针对这个问题,已经开展了大量的研究工作。概述了水工混凝土碱－骨料反应的危害和研究的重要性,系统阐述了混凝土碱－骨料反应原理和分类、碱－骨料反应试验方法及创新,以及使用非活性骨料、控制混凝土总碱量、控制湿度、掺入抑制材料和化学外加剂等预防碱－骨料反应的综合措施,提出了碱－骨料反应研究方面有待进一步解决的问题并给出了相关建议。     

1960-2015年洞庭湖水资源演变特征分析

洞庭湖是我国第二大淡水湖,也是长江流域重要的调蓄湖泊。由于受下垫面变化、人类活动和气候变化等的影响,洞庭湖流量、水位呈现新的变化趋势,研究洞庭湖水资源演变特征可为洞庭湖保护提供依据。采用Mann-Kendall突变检验方法对洞庭湖出口控制水文站城陵矶（七里山）及长江干流水文站枝城站、螺山站的1960-2015年流量、水位的年际和年内变化趋势进行分析。结果表明：洞庭湖上游长江枝城站在2000年以前径流量变化不大,但从2001年起呈现下降的趋势,水位呈现先上升后下降的趋势,洞庭湖出口城陵矶（七里山）站整体径流量呈现下降的趋势,而平均水位呈现上升的趋势,洞庭湖下游长江螺山站径流量整体上变化不显著,平均水位则呈现上升的趋势;三峡枢纽运行后,3个水文站汛期（4-10月）的径流量和水位均呈现下降趋势,枯水期（1-3月）则出现水位上升趋势;长江上水利工程尤其是三峡工程的修建,对洞庭湖水资源的调节影响明显。     

燃烧器检测用标准气体制取方法与控制过程

探讨了几种单一组分气体混合制取燃烧器检测用标准气体的方法和控制过程,分析了混气精度的影响因素和采取的措施,分析了该方法的局限性。     

变电站GPS授时装置实时定时标检测方法探讨

变电站自动化系统大多采用全球定位系统（GPS）授时装置保障智能电子设备（IED）之间的时间同步,通常通过时频的方式检测其输出信号的准确性。文中提出了一种新的检测方法作为补充和完善,其核心是:应用可控的实时GPS对时脉冲,控制指定时刻的时标脉冲输出和开关的动作,检测GPS授时装置输出信号的准确性和正确性,既可检测GPS授时装置输出信号的实时准确性,也可检测输出信号携带的时间编码信息的正确性。