多媒体课件中心系统的开发与管理

介绍了多媒体课件中心信息系统的分析、设计、运行等开发与管理的全过程。通过对系统结构、功能和数据流程的分析及对系统总体结构的设计等 ,开发了以SQLServer为后台数据库 ,基于ASP网络编程的web界面的信息系统 ,为课件的保存提供了安全空间 ,为课件的上传提供了安全平台 ,使得现代信息技术在课堂领域广泛应用 ,为传统课堂的教学带来变革     

铜、铝导体生产的发展趋向及有关问题的探讨

本文综合分析了我国铜、铝及它们的合金导体在品种、质量和生产装备方面的现状和国外在该领域的进展及发展趋向,并指出:我国铜、铝导体的年用量已名列世界前茅,但导体的品种少,工艺装备落后。其中铝连铸连轧生产线比铜的更落后,主要差距在计算机监控系统,由此也限制了品种的发展;废铜在导体上的应用,要提高质量关键在于所用废铜原材料的级别、熔炼炉及熔炼工艺;铜杆质量不能满足电缆工业发展的需要,修订电工用铜杆国标或制订行业标准,实行铜杆分等使用已是势在必行;我国电缆工业需要建立真正意义上的从金属材料、镀层、导体结构到绝缘材料特种的电缆厂;行业协会在组织行业内部带有共性问题的科技攻关,与产业界、行业间的协调和科技合作方面应起到更大的作用;应发挥综合优势,加强材料、工艺、产品与设备的联合攻关,实现科技与生产的创新。     

我国直升机电力作业的现状与发展

文章介绍了国内外直升机电力作业的技术发展情况,着重阐述了我国直升机电力作业的历史、现状、需求及存在的问题,提出了我国直升机电力作业今后在开发模式、项目归口、作业机型的选择、与国内外的合作等方面的发展思路,并对今后我国开展直升机电力作业提出了几点建议。     

景洪电站高气温条件下大坝碾压混凝土连续施工研究

景洪电站地处亚热带,高气温时间长,大坝碾压混凝土施工温控难度高。本文通过对原材料及配合比、混凝土出机口温度控制、运输过程温度控制、浇筑过程的温度控制以及混凝土浇筑后的养护和冷却通水等一系列研究,提出景洪电站高气温条件下大坝碾压混凝土连续施工的综合措施,并在计算和已有经验的基础上给出具体实施方法。     

辐射沙脊群海域深槽摩阻流速特性研究

基于夏冬两季南黄海辐射沙脊群海域实测流速垂向分布资料,利用卡曼-普朗特公式估算深槽摩阻流速并分析了该海域摩阻流速分布特征,并提出摩阻流速快速估算方法。结果表明,辐射沙脊群海域涨落急时刻流速垂向分布较符合卡曼-普朗特对数流速分布。夏季平均摩阻流速为7.4cm/s,呈现北大南小、近岸大远岸小的格局;冬季平均摩阻流速为6.0cm/s,呈现中部大南北小、近岸大远岸小的格局。该海域摩阻流速呈现夏季大于冬季、大潮大于小潮的规律,涨落急摩阻流速的差异呈现出夏季小、冬季大的特点。夏冬两季涨落急时刻的摩阻流速可用近表层流速进行估算,该海域深槽摩阻流速约为近表层流速的0.06倍。     

中国与美国发电机组可靠性指标对比分析

不同国家在发电机组的可靠性指标及统计数据分析方面存在一定的差异,这对发电机组可靠性技术交流造成障碍。基于此,首先从中、美两国发电机组可靠性术语定义和指标计算公式两方面比较两国发电机组的可靠性评价方法;再从运行系数、等效可用系数、等效强迫停运率以及非计划停运次数等方面对两国各类型机组在2006-2010年的可靠性指标数据进行对比,分析两国发电机组可靠性管理和统计数据存在差异的根本原因。通过差异原因分析,促进我国电源侧规划建设和电网运行管理水平。     

气候变化和人类活动对灞河流域径流情势的影响分析

灞河径流决定其下游浐灞生态区的用水安全,开展其变化情势研究对有效管理区域水资源具有重要意义。基于灞河上游罗李村和中游马渡王水文站1959—2010年实测径流及流域降水、蒸发资料,采用肯德尔秩次相关法检验径流序列变化趋势、Mann-Kendall非参数检验法和累积距平法辨识各水文气象要素的突变点,并将累积量斜率变化率比较法用于定量计算气候变化和人类活动对灞河径流的影响程度。结果表明:11959—2010年间上游径流量相对稳定,但中游径流量有减少趋势,且在1988年发生突变后呈现出显著的减小趋势。2气候变化和人类活动对灞河上游径流变化的贡献率分别约为97%和3%,对中游径流变化的贡献率分别约为37%和63%。未来只有合理开发、开源节流并举,才能保障区域可持续发展。     

城市居住区供配电系统设计研究

在执行城市居住区供配电系统设计的有关标准中,会出现一些难以满足供配电实际要求的情况。针对江苏省启东地区城市居住区配电设施建设、运行中遇到的问题,根据居住区供配电系统设计的标准和规范,结合建设、运行、维护三个技术环节的实践,提出了相应的建设选型原则与设计建议。     

区块链技术在电力交易中的应用与展望

区块链技术作为分布式记账技术,为能源互联网中的多方协作场景提供了信任基础,在能源互联网中的电力交易等领域已有一些应用尝试。首先,文中回顾了区块链技术在电力交易中的理论研究情况,总结了其在分布式能源交易、产权登记、商品溯源、交易信息共享等方面的工程应用现状。然后,基于区块链的应用价值模型和中国电力市场的发展需求,展望了区块链技术在电力批发市场、电力零售市场、分布式发电市场化交易、电力衍生品交易、源荷互动电力交易、市场主体信用评价等中的应用。最后,分析了区块链技术在实际应用中面临的运算性能、存储容量和信任构建等潜在问题,给出了针对性的解决思路。     

高岭背靠背换流变压器安装

在高岭背靠背换流站的换流变压器安装过程中,通过设计科学、合理的换流变压器安装工艺保障系统。提高了换流变压器安装工艺的准确性、科学性,提高了工作效率,解决了换流变压器施工中耗时多、浪费大(电能、人工、材料等)等问题,并对安装中遇到的气密性问题、套管介质损耗偏大、套管与本体接口处漏油等提出了解决措施。     

Exploring the Basic Principles of Electric Motors and Generators With a Low-Cost Sophomore-Level Experiment

In order to meet changing curricular needs, an electric motor and generator laboratory experience was designed, implemented, and assessed. The experiment is unusual in its early placement in the curriculum and in that it focuses on modeling electric motors, predicting their performance, and measuring efficiency of energy conversion. While subfractional-horsepower electric motors and a primitive, but unique, small-scale dynamometer were used, experimental results proved to be reliable, accurate, and repeatable. The change in student knowledge and confidence in the application of that knowledge was assessed and shown to have increased significantly in both cases.      

添加复合固硫剂后炉内固硫试验研究

在实验室水平管式炉及1 000MW机组锅炉上对添加以碱土金属Ca、Ba、Sr盐为主的复合固硫剂后炉内的固硫效果进行了研究,分析了复合固硫剂添加比例对固硫效率、灰分中SO3含量、硫分布特性和锅炉燃烧的影响。结果表明:复合固硫剂添加比例分别为0.5%、1%、2%时,在水平管式炉内固硫效率分别达到9.2%、22.4%、52.4%,在1 000MW机组锅炉的固硫效率分别达到6.6%、15.8%、23.6%。随复合固硫剂添加比例的增大,烟气中含硫量占炉前煤总硫量比例减小,灰分中含硫量占炉前煤总硫量比例加大,固硫效果显著。     

Technology, policy, ethics, and public health: a selectbibliography

The enclosed bibliography, which includes nearly 400 entries, is organized into two main parts. Part One, consisting of Sections 1 and 2, identifies sources that examine technology and policy issues associated with public health. Among the topics considered in the works cited in Part One are risk assessment, genetic and genomic research, and privacy and confidentiality. Part Two, made up of Sections 3 and 4, includes sources that examine ethical issues in public health. Whereas Section 3 lists sources that consider ethical issues in occupational health and safety as well as in environmental health and ecological sustainability, ethical issues related to professional codes of conduct are considered in sources listed in Section 4. Also listed in Section 4 are selected sources on ethical theory and its application. Although the bibliography is fairly comprehensive, it is by no means intended as an exhaustive work     

Low-temperature fuel cells: Outlook for application in energy storage systems and materials for their development

Low-temperature fuel cells (FCs) are perspective alternative energy sources. They cannot, however, be considered as a primary energy source, because no hydrogen in pure form, used in their operation, exists in nature. The development of devices to autonomously supply and store energy can be considered as one of the most promising applications of low-temperature FCs. In the latter case, the primary purpose is to compensate differences in peaks of producing and consuming energy both in the seasons and time of day. The first part of the review describes this problem. The second part involves analyzing nanomaterials used in FCs, so that hybrid membranes, including inorganic nanoparticles, are high priority in this regard. Their incorporation into the pores of the membranes leads to an improvement in transport properties in many cases, including an increase in ionic conductivity and selectivity of transport processes. These properties of the hybrid membranes are discussed by using a model of limited elasticity of walls of the pores. Catalysts, being platinum nano-size particles, play an important role in the FC. To reduce their costs and increase activity, some approaches, implying decrease in particle sizes or using two-component particles, for example, alloys and ‘core-shell’ particles, are used. In the latter case, platinum, localized on the surface, determines activity of the catalyst, whereas the second metal increases surface area and catalyst activity. The main reasons for changes in properties of the materials and effect of the catalyst support on electrochemical processes in FCs are also considered.     

Methods of optimising tariff regulation in the electric power industry

Tariff regulation is a fiscal method of managing economic processes with the help of taxes, requiring constant development, which is directly related to the development of the electric power industry and technological progress in general. The relevance of the study is conditioned by the need to find and implement methods for optimising tariff regulation in such an economically important industry as the electric power industry. In this regard, the purpose of the study is to identify problem areas in tariff regulation in the electric power industry, consider and analyse optimisation methods used in other countries, and reveal the positive impact of these methods on the electric power industry and the economy as a whole. The primary method in this study is a system analysis, which was used for a detailed consideration of the subject matter, with the aim of a deeper and more comprehensive understanding of tariff regulation in the electric power industry as a system with many related and interacting elements. This study also applied the following research methods: logical analysis, comparison, synthesis, deduction, and classification. The study presents the results of tariff setting mechanisms in the industry, examines the existing types of regulated prices and tariffs in the consumer electricity market, and considers the state, private, and public levels of tariff regulation in the Russian Federation. The methods of improving and developing tariff regulation in other countries, which have been successfully applied and have already shown a positive result, were also considered. The study materials are of practical value for teachers and students in the field of electric power industry, managers of tariff regulation bodies.     

非洲四大流域水电开发状况及建议

尽管非洲经济发展面临诸多挑战,但增长趋势仍在继续。伴随着各国电力需求的增加,非洲电力基础设施建设充满机遇。非洲水电资源丰富,开发潜力巨大,且80%的可开发水电资源潜能集中在赞比西河、刚果河、尼罗河和尼日尔河四大流域。在“一带一路”倡议下,已有大批中国企业“走出去”投资开发非洲水电项目,推动中非电力基础设施合作。本研究通过大量的数据和资料,总结了四大流域水电资源量与开发程度,对流域内重点已建和规划的水电项目进行了详细介绍。最后,深入分析中国企业目前在非洲水电项目开发中面临的主要问题和挑战,并从战略规划、合作模式、风险防范和人才培养四个方面提出相应建议。     

Determination of the mass-transfer coefficient in liquid phase in a stream-bubble contact device

One of the most effective energy saving technologies is the improvement of existing heat and mass exchange units. A stream-bubble contact device is designed to enhance the operation efficiency of heat and mass exchange units. The stages of the stream-bubble units that are proposed by the authors for the decarbonization process comprise contact devices with equivalent sizes, whose number is determined by the required performance of a unit. This approach to the structural design eliminates the problems that arise upon the transition from laboratory samples to industrial facilities and makes it possible to design the units of any required performance without a decrease in the effectiveness of mass exchange. To choose the optimal design that provides the maximum effectiveness of the mass-exchange processes in units and their intensification, the change of the mass-transfer coefficient is analyzed with the assumption of a number of parameters. The results of the study of the effect of various structural parameters of a stream-bubble contact device on the mass-transfer coefficient in the liquid phase are given. It is proven that the mass-transfer coefficient increases in the liquid phase, in the first place, with the growth of the level of liquid in the contact element, because the rate of the liquid run-off grows in this case and, consequently, the time of surface renewal is reduced; in the second place, with an increase in the slot diameter in the downpipe, because the jet diameter and, accordingly, their section perimeter and the area of the surface that is immersed in liquid increase; and, in the third place, with an increase in the number of slots in the downpipe, because the area of the surface that is immersed in the liquid of the contact element increases. Thus, in order to increase the mass-transfer coefficient in the liquid phase, it is necessary to design the contact elements with a minimum width and a large number of slots and their increased diameter; in this case, the filling degree of contact elements by the liquid must be maximum.     

北京电网2004年设备故障情况分析

电网中运行的电气设备会发生各种故障，这些故障有的是人为原因造成，有的则是设备自身问题或自然因素引起。为防止、减少设备故障的发生，对已发生的故障情况进行统计和分析，是研究故障发生规律，采取预防措施所做的不可缺少的工作。2004年，随着北京经济的快速增长，北京电网用电最大负荷逃到9.4GW，电网运行方式调整频繁，设备经受了大负荷的冲击，全年发生了多次电网和设备故障。通过对2004年北京电力公司管辖的输电、变电、配电设备故障情况的综合分析，总结出在技术因素与部件、原因与责任方面存在的主要问题，并提出针对性的防范措施。     

The Teaching of High Voltage and High Current Engineering in Relation to Practical Engineering and Research

Technological developments in electrical engineering in recent years include substantial progress in the power fields of transmission, distribution, and utilization. Consequently, in common with other disciplines of electrical engineering, these advances make necessary some changes in existing tertiary courses if they are to keep abreast of developing technology. This is the case both in the undergraduate and graduate programs and is generating an increasing need for continuing education courses. This paper describes changes made in the power courses, at all levels, at the University of New South Wales in response to these pressures. Particular emphasis is given to laboratory developments in the high voltage and high current field, as this is seen as one area in particular need of development.     

Sir Jagadis Chunder Bose: Traversing the interdisciplinary gap between physics and biology [Reverberations]

Sir Jagadis Chunder Bose was a prolific and inventive experimental scientist. Born in what is now Bangladesh in 1858, his scientific career spanned more than 30 years and included a degree in natural sciences from Christ College, Cambridge, and a doctorate from the University of London in 1884. He studied under the likes of Lord Rayleigh, Sir James Dewar, and the great naturalist, Francis Balfour. In 1885, under great controversy, Bose assumed a faculty post in physics at Presidency College, Calcutta, India and remained there until his retirement in 1915. In 1917, he founded the institute which still bears his name and stayed technically active well into his 70s. At first, working with his own funds and only a tin smith, he managed to assemble the most sophisticated Hertzian wave apparatus of his day, and in only ten years, his fame had spread throughout Europe.