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排序方式: 共有104条查询结果,搜索用时 15 毫秒
1.
The development of renewable technologies in the last decade has been exceptional. In photovoltaic (PV) for example, efforts were not only limited to merely improving their efficiency but also to the reduction of the cost of cells and modules via volume production for commercial markets. There are many national schemes promoting the use of PV technology and regional targets for a share of renewable energy production. This paper attempts to relay to the reader a journey, based on experience, approaches for enhancing the prospect of utilising solar energy within the society we live in. The issue of expansion or enhancing the utilisation of solar energy can be undertaken by individuals, groups, institutions and governments. The aim of this paper is to provide some examples, which could serve as a framework in which action could be taken to promote solar technology.  相似文献   
2.
Utility conservation programmes are designed to benefit both participants and non-participants. This article outlines the issues involved in designing conservation programmes for utilities and determining the appropriate amount of incentives that can be provided to participants without harming non-participants. More importantly, the article discusses the issue of access to the programmes by utility customers. It concludes that it is the existing restrictions to participation, and not the level of compensation, that are of greatest concern to non-participants. A number of utility programmes designed to eliminate the problem of non-participation are reviewed.  相似文献   
3.
The HIV/AIDS pandemic poses a substantial long‐term threat to economic development in South Africa. A questionnaire survey explored the perceptions of a sample of construction firms in the Western Cape regarding HIV/AIDS policy and treatment programmes. The findings show that there is no universal view about the long‐term threat of HIV/AIDS. Most organizations have awareness policies in place but prevention and treatment policies are less common. Treatment programmes are the least implemented of all intervention services due to insufficient resource capacity, the potential stigmatization of infected persons, and low take‐up rates. Despite an acknowledgement of the benefits flowing from mounting treatment programmes, doubt exists as to their financial viability.  相似文献   
4.
The recent article in Canadian Psychology by Carleton, Peluso, and Asmundson (2010) assessing the research activity of Canadian psychology departments with graduate programmes has generated substantial feedback. We are very pleased to have provided not only an initial data set for review by departments and individuals, but also to have prompted what we believe is an important discussion. The current article responds to a thoughtful critique and extension of our initial work (Symons, 2011). Herein we address and expand on each of the comments raised by Symons in an attempt to fully delineate the successes and challenges for our profession as we take the next steps in this area of research. Also, in light of the review and other anecdotal feedback received to date, we make further recommendations for using the data available from the Web of Knowledge, the rankings we provided, and the data provided by Symons. We conclude with directions for future research that we believe will help further the area. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   
5.
The structure of CFC use in Western Europe is different from that in the USA and Japan, with the highest percentage use of CFCs in Europe in aerosols. The use of CFCs in automotive air conditioning in the EEC is much less than elsewhere and this, together with the fact that R-12 and R-22 already have similar market shares, means that the refrigeration industry in Western Europe will not be as greatly affected by CFC reduction as elsewhere. More stringent reduction programmes than those imposed by the Montreal Protocol are in force in most Western European countries, to some extent due to consumer and environmental pressure group influences. Some countries, especially in Scandinavia, are introducing additional legislation to restrict CFC use. The strongest stand has been taken by the Federal Republic of Germany, which requires a 95% reduction in CFC use by 1995, with a voluntary ban from 1992. This paper discusses in detail European research programmes into CFC replacements. Many projects have been proposed, including work on refrigerants [fundamentals (four projects), thermophysical properties (18 projects) and lubricants and materials (five projects)] and cycles and components (17 projects).  相似文献   
6.
An investigation into the training of project managers in Denmark is presented, from the early days of basic school education in the form of project work, through to university and postgraduate training and finally on to on-the-job specific training. Examples are given of typical training programmes encountered throughout a project manager's education and future developments are assessed.  相似文献   
7.
三轴蠕变试验中云母石英片岩蠕变参数的研究   总被引:4,自引:0,他引:4  
 通过三轴蠕变试验得到云母石英片岩蠕变参数--弹性模量与黏滞系数的变化规律,弹性模量在屈服点前后的变化规律不同,对应不同应力水平的黏滞系数–时间关系有3种类型。采用电子显微镜对云母石英片岩三轴蠕变的3个阶段--未受力阶段、即将出现加速蠕变阶段和破坏阶段的径向切片、轴向切片进行观测,获得云母石英片岩中主要矿物在三轴蠕变过程的微观结构变化。根据云母石英片岩三轴蠕变过程的微观结构变化对蠕变参数的变化规律进行合理解释。研究表明,云母石英片岩三轴蠕变过程中蠕变参数的变化规律与其微观结构变化之间有良好的对应性,蠕变参数在宏观上的变化是其内部微观结构变化的外在表现。最后,建立能真实反映蠕变参数变化规律的函数形式,并以此为基础得出蠕变模型,可作为描述岩石加速蠕变阶段的途径之一。  相似文献   
8.
This paper considers computer programs that purport to do inference. It finds the essence of their reasoning ability to reside in a particular relationship which exists between the computations described by the texts of those programs and machine-independent formal representations of the theories in which they are said to reason. The principal novelties in the treatment of this question are the use of explicit “abstraction functions” between states of a computation and sets of sentences of a theory, and the notion of global “inference relations” which characterize the set of all inferences of which a system is capable. The central result of the paper is an “arrow-theoretic” characterization of the concept of a knowledge representation, along with the related concept of a knowledge representation realization. The notions of equivalence and subsumption for knowledge representations are defined, as well as equivalence of knowledge representation realizations. Finally, important issues of expression evaluation and control are addressed. The paper concludes with a slogan: “The AI is in the arrows.” Cet article traite des programmes informatiques qui prétendent faire de ľinférence. Ľauteur constate que ľessentiel de leur capacityé de raisonnement réside dans la relation particulière qui existe entre les calculs décrits par les textes de ces programmes et les représentations formelles non liées à un type de machine des théories dans le cadre desquelles ils sont supposés raisonner. Les principales nouveautés dans le traitement de cette question sont ľutilisation de fonctions ?abstraction explicites éntre les etats ?un calcul et les ensembles de phrases ?une théorie, et la notion de relations ?inférence globales qui caractérisent ľensemble de toutes les inférences dont un système est capable. Le principal résultat de cet article est une caractérisation du concept de la représentation des connaissances, ainsi que du concept connexe de la réalisation de la représentation des connaissances. Les notions ?équivalence et de sous-somption pour la représentation des connaissances sont définies, ainsi que ľéquivalence des réalisations de la représentation des connaissances. Enfin, des questions importantes comme ľanalyse et le contrǒle ?expressions sont traitées.  相似文献   
9.
As part of several groundwater investigations of the Permo-Triassic Sandstone aquifers in north west England, a detailed measurement of piezometric heads and groundwater flow within observation boreholes was made which showed that vertical differences of groundwater heads persist within aquifers. A number of case histories of these studies are presented, which are used to consider the impact of head variations on typical groundwater level and groundwater quality measurements taken in observation boreholes, with a view to recommending design criteria for observation boreholes and groundwater monitoring programmes.  相似文献   
10.
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