高性能超级电容器电极材料的研究进展

超级电容器即电化学电容器,是近年来发展起来的一种新型储能元件,通过离子吸附(双电层电容)或氧化还原法拉第反应(赝电容)导致电荷在电极中的储存,电荷储存机理和纳米材料的快速发展使得超级电容器的性能得到显著提高。介绍了近些年超级电容器电极材料的研究进展,从炭素材料、过渡金属氧化物和导电聚合物这3类基础材料出发,结合纳米技术并由此制得的纳米材料,综合分析了高性能超级电容器及其电极材料的发展趋势。     

太阳能光伏发电监控系统的研究和设计

社会和经济的高速发展,使得以常规能源为基础的能源结构越来越难以适应可持续发展的要求,加快开发利用太阳能等可再生能源已经成为人们的共识,但太阳能利用效率低这一问题一直影响和阻碍着太阳能技术的普及。在这种背景下,文章在设计太阳能光伏发电系统的基础上,开发了基于计算机编程语言和数据库的光伏发电监控系统,以期促进太阳能发电技术的应用。     

光伏发电系统智能检测与自适应跟踪技术的研究

针对当前光伏发电系统跟踪技术中常用的视日跟踪法和光电跟踪法存在的问题,充分结合两种方法的优势,提出一种切实可行的智能检测与自适应跟踪技术.通过给太阳光照强度模糊分级的方式,随时切换对太阳方位的跟踪方法,从而排除非太阳光照等其他因素的影响,该技术不仅可以大大提高跟踪太阳方位的精确程度,还有效降低系统运行过程中的能源消耗.     

我国光伏发电产业存在的问题及对策建议

太阳能是重要的可再生能源。积极发展光伏发电,既缓解能源供需矛盾、优化能源结构,又有利于产业结构调整。对我国光伏发电产业现状、发展趋势、存在的问题等进行了分析,提出了我国光伏发电产业健康有序发展的对策和措施建议。     

光伏发电的四大关键问题

光伏发电技术 当前世界上主要的光伏发电技术一个是晶体硅电池，包括单晶硅太阳电池和多晶硅太阳电池。单晶硅太阳电池的实验室最高转换效率可达24．7％，批量生产已超过17％，无锡尚德的冥王星技术则超过了18％。多晶硅太阳电池的实验室最高效率也超过了20％，平均效率达到16％以上。晶体硅电池中还有一种背接触高效电池，实验室最高效率已达26．8％。另一种主要光伏发电技术是薄膜太阳电池，其中已商业化的主要是非晶硅薄膜电池，     

关于推进分布式光伏发电应用的四点意见

充分认识推进分布式光伏发电应用的重大意义 推进分布式光伏发电应用是落实中央、国务院决策部署的重要举措 光伏产业是我国为数不多的具有国际竞争优势的战略性新兴产业。目前,我国光伏电池产量占全球市场份额的70％,晶体硅光伏电池转换效率达到20％,处于世界领先水平．已经形成了包括硅材料、光伏电池、逆变器等较为完整的制造体系。     

我国发展光伏发电存在的问题面临的形势及建议

光伏发电是新能源发电的一个重要组成部分。分析了我国光伏发电面临的国内外发展形势,阐述了光伏装备制造业及光伏发电的发展现状,剖析了当前我国光伏发电发展面临的主要问题,有针对性地提出了相关建议。     

光伏发电——永不枯竭的能源——多氟多科技大厦光伏发电项目建成侧记

登上多氟多科技大厦东配楼楼顶,一片好似蓝色海洋的光伏发电板熠熠生辉,正源源不断地为国家电网输送着“血液”。这是啥？这就是多氟多通过自主研发、焦作市首家业已建成的屋顶分布式光伏发电项目。多氟多董事长李世江介绍说,这一项目总投资100多万元,面积728平方米,装机容量90kW,日发电量350度。     

A production rate control policy for stochastic repair and remanufacturing systems

We consider the control of a manufacturing system responding to planned demand at the end of the expected life of each individual piece of equipment and unplanned demand triggered by a major equipment failure. The difficulty of controlling this type of production system resides in the variable nature of the remanufacturing process. In practice, remanufacturing operations for planned demand can be executed at different rates, referring to different component replacement and repair strategies. We formulate this problem as a multi-level control problem and propose a suboptimal control policy. The proposed control policy is described by inventory thresholds triggering the use of different execution modes. Determination of the control policy parameters is based on parameter optimization of analytical cost expressions. A numerical example based on a real case is presented. Our analysis demonstrates that the use of the proposed control approach can lead to a significant reduction in the total average cost, as compared to current practices.     

Matching management control systems to product strategies

A framework for management control of new product development projects is presented. Five mechanisms which comprise a management control system are identified. These mechanisms include:—
1. The control climate.
2. Management involvement.
3. Supervision.
4. The selection and socialization of individuals.
5. Organization structure.
These mechanisms are key not only because they have a significant influence on the control of new product development projects, but also because they are amenable to manipulation by management.
It is proposed that there is no one best management control system for all situations. Rather, the management control system that will be most successful is the one that is best suited to a particular product strategy. A discussion of the characteristics of two distinctly different product strategies is presented, followed by a discussion of each of the five control mechanisms mentioned above. Finally, we discuss the integration of each product strategy with its respective management control system.     

Strategic orientation and top management attention to control systems

Management control systems are viewed typically as management-by-exception tools for implementing intended strategies. This study provides a different perspective by focusing on the way that top managers use specific control systems to focus organizational attention on strategic uncertainties and thereby guide the development of new strategic initiatives. Analysis of field-based data from 30 businesses in the U.S. health care products industry is used to develop a model and propositions that distinguish between interactive and diagnostic control systems, and illustrate the selective use of these systems in different strategic contexts.     

A comparison of budgetary control systems in American and Japanese manufacturing firms

This article examines and compares some variables considered important in budgetary preparation and performance evaluation by American and Japanese executives of manufacturing firms. The literature asserts that American executives employ management styles and performance evaluation criteria that tend to overemphasise short-term goals, while Japanese executives prefer management philosophy and performance evaluation criteria that emphasise long-term goals. The survey research method is employed to gather evidence to test hypotheses pertaining to such an assertion. The research results provide empirical evidence that supports most of the assertions in the literature.The author expresses his sincere gratitude to Drs James Don Edwards of the J M Tull School of Accounting — University of Georgia, Ato Ghartey of Southeastern Massachusetts University, R S O Wallace of Exter University and annonymous reviewers for their helpful comments and suggestions.     

变流量供热控制系统的设计与实现

在分析了供热系统中变量间的耦合关系的基础上,根据变流量供热系统的控制要求,提出了在有效解耦的前提下,将供热系统分解为几个子系统分别控制的基本控制策略,设计了供热系统的控制方案。介绍了以工控机为上位机、PLC为下位机的硬件配置和软件设计方法,给出了程序流程图,详细说明了PID控制程序和定时中断程序的设计。     

A methodology for constructing expert systems

Construction of Expert Systems has so far been seen as a craft or an art, not a science. This paper attempts to improve this situation by deducing some aspects of a methodology for constructing Expert Systems from a model of an expert's expertise. It suggests that the traditional methods, based on extracting problem-solving rules from an expert and encoding them directly into a suitable knowledge representation have certain disadvantages, while attempting to extract a causal model from the expert overcomes many of these. The simple Plausible Inference Expert System shell, of which several are now commercially available, is often very suited to the construction of causal models, and some practical issues concerning the construction of causal models are discussed.
The suggested methodology has been found to work in several Expert System projects in I.C.I., though it is still being developed in the light of experience. In particular, the importance of the top-down design of an Expert System is stressed, though it is not yet based on theoretical considerations.     

长低坝水利除险加固工程防渗处理方案的探索与实践

既能满足施工技术的要求和达到防渗处理的目的,又能达到节省投资是选择施工工艺的关键。本文通过对各种施工工艺的对比和优化,最终选择了深层搅拌桩施工工艺,并在本工程除险加固工程实施与应用,取得较好的效果,达到了设计的目的与要求。     

炼厂锁定进口燃料油成本方案初探

理论上,炼厂的套期保值(Hedging)主要是通过卖出原油与成品油之间的裂解差合约(Crack)来控制炼油利润的收窄.但是,这种操作要求炼厂的原料和产品都是市场化的商品,而且都有对应的期货(或衍生品)交易工具.我国炼厂原料价格随国际市场价格波动,但油品价格尚未市场化,并相对稳定.针对这种业务结构特征,笔者提出了"选择性买入保值"(Optional Long Hedging)方案.该方案是指在某一时期汽柴油销售价格波动较小的前提下,当原料与成品油价格之间已经出现锁定炼厂利润的机会时入市,以买入期货(或衍生品)的手段建立对基本利润的保护机制,并在持仓过程中通过多种技巧增加盈利."选择性买入保值"使用的对冲工具以新加坡场外市场交易的纸货为主.对于具体的"买入保值"入市点,需要结合炼厂的盈亏平衡点来确定.套期保值综合盈利的技巧包括纸货头寸(Swaps Position)的滚动操作、敞口(Risk Exposure)的调整和保值工具的切换.     

A systems approach for developing high technology products

Product development for high technology products is comprised of the three stages of assessment, development, and execution. In addition, all three stages consist of information and decisions involving technological, product, and market dimensions. This article presents a systematic approach for integrating these three dimensions by which a go—no-go decision can be reached prior to the expenditure of large amounts of funds for research and development.