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1.
Total factor productivity (TFP) determines long‐term economic growth and is a comprehensive industry‐level productivity measure. This paper proposes Jorgenson's method as an appropriate TFP measurement for the construction industry. The method is less restrictive than the conventional Chau's approach, as it does not impose the Hick Neutral Technical Change assumption. Jorgenson's method is then applied to estimate TFP growth in the construction industry of Singapore over 1984–1998. TFP growth is found down by 1.53% per annum over this period, indicating that the performance of TFP in the construction industry lags behind the rest of economy. TFP growth is also found to be fluctuating over time and tends to move in tandem with the construction business cycle.

As a monitor of progress towards TFP achievement, factors influencing TFP growth in the construction industry of Singapore over 1984–1997 are identified. Seven factors are found to be significantly related to TFP growth. Among them, economies of scale, R&D by the industry, investment allowance granted and labour unions are leading contributors to TFP growth; while foreign worker, construction accidents and pre‐cast are major hampers.

The general methodology presented in this study can be applied to other countries. Future studies are required to find appropriate indicators for factors unquantified.  相似文献   
2.
The construction industries in many countries are starting to consider seriously the strategic use of information technology (IT). The use of information technology in construction is extending beyond the stage of piecemeal application for improving the efficiency of discrete operations by individual organizations to the advanced stage where IT is applied strategically in commercial enterprises, government agencies and professional institutions. Progress in construction in this regard appears to lag behind that in most other sectors of the economy. This paper considers the nature and the background of this progression in construction by examining proposals by Earl (1989) of nine basic prerequisites to the IT era which make a strategic approach timely. Each prerequisite is outlined and how it has been met in other sectors of the economy considered. The extent to which these prerequisites apply in construction and the scope for their application in the near future are examined. It is argued that all organizations involved in construction will ultimately have to think strategically about their use of IT, and how some are already doing so is described.

In discussing the factors which hinder the strategic application of IT in construction, the nature of the design and construction processes and initiatives that may be necessary to overcome the perceived problems are examined in detail. The strategies that are evolving at a national level in Singapore are outlined.  相似文献   
3.
The objectives of construction projects, from the client's point of view, are well known, and techniques have been developed to help practitioners achieve them. Ensuring that projects contribute towards protecting the environment is not yet one of these objectives. However, in almost all countries, issues relating to the environment are receiving attention from governments, non-governmental institutions and commercial organizations in most sectors of the economy, as well as from the general public. Statutory measures are being taken by governments to effect pollution control, resource conservation and protection of natural ecosystems. Productive enterprises are reviewing, and where necessary, changing aspects of their operations to address these concerns and comply with the increasingly more stringent requirements. Many environment-related statutes, regulations, codes and general policies have implications for the construction industry, affecting where constructed items are located, how they are planned and designed, the materials and components used, the techniques and equipment adopted, and how the completed facilities are maintained, altered and, ultimately, demolished.

After giving an overview of the factors contributing to, and the nature of, general developments relating to the environment {especially in the area of government policy), the implications of these trends for the construction industry are considered. Actions being taken by the industry in these regards are next discussed. It is suggested that the consideration of issues relating to the environment should be part of the culture of the construction industry everywhere, and that there is a case for making the environment the fourth client objective on construction projects.  相似文献   
4.
Raftery, J., Pasadilla, B., Chiang, Y. H., Hui, E. C. M. and Tang, B. S. (1998) Construction Management and Economics, 16, 729–37 review recent developments in the construction industries in Asia. They discuss the main causes and effects of key trends in globalization and their impact on the industries. This paper considers some of the points raised by Raftery et al. It starts with an overall review of their paper. It then considers construction industry development in general, technology transfer and joint ventures, and the impact of policy reform on the industries. It suggests additional relevant issues, and highlights some areas where further research would be appropriate.  相似文献   
5.
The problems of construction industries in developing countries are well researched. For over three decades, proposals have been made for action to address these difficulties. Developing countries have implemented these recommendations, and other initiatives. However, results have been disappointing and the problems have persisted. A possible reason for the lack of progress is the absence of measurable targets in construction industry development programmes to guide and assess, at intervals, the success of their implementation. This paper critically discusses the formulation of a set of indicators for measuring and monitoring progress in the effort to improve the construction industry in a developing country. Previous proposals of indicators and those used in Singapore are examined. A set of indicators is suggested and their merits and possible problems are considered. Recommendations are made on how the indicators can be most effectively implemented.

Les problèmes liés à l'industrie du bâtiment dans les pays en voie de développement sont clairement définis. Pendant plus de trois décennies, des propositions ont été formulées en vue de mener des actions visant à surmonter ces difficultés. Les pays en voie de développement ont suivi ces recommandations et pris d'autres initiatives. Néanmoins, les résultats ont été décevants et les problèmes ont persisté. L'une des raisons possibles du manque d'avancée est l'absence d'objectifs mesurables dans les programmes de développement de l'industrie du bâtiment, qui permettraient de guider et d'évaluer, par intervalles, la réussite de leur mise en oeuvre. Le présent document aborde de façon critique la formulation d'un groupe d'indicateurs destinés à mesurer et à surveiller la progression des efforts destinés à améliorer l'industrie du bâtiment dans un pays en voie de développement. Il examine également les propositions antérieures relatives à des indicateurs, ainsi que celles utilisées à Singapore. Il suggère enfin un groupe d'indicateurs et examine leurs avantages et leurs inconvénients éventuels. Des recommendations visant à optimiser l'utilisation de ces indicateurs sont également formulées.  相似文献   
6.
Blood has traditionally been used as a high protein ingredient in both human food and animal feed, with resulting economic, environmental and nutritional benefits. However, potentially serious health and safety issues related to blood consumption, particularly the risk of pathogenic or harmful metabolic materials, the infectivity of prion diseases, and the presence of identified allergens such as bovine serum albumin (BSA), are causing many consumers to shy away from any product containing either animal blood or ingredients derived from animal blood. Thus, despite the significant volumes of blood produced by slaughterhouses, blood is currently underutilized as a food ingredient. This article reviews the use of animal blood as an ingredient in food intended for human consumption or for animal feed and discusses the related consumer concerns.  相似文献   
7.
Accumulation of toxic metals in liver, a rich natural source of essential elements, can present health risks to regular consumers of liver. A total of 35 fresh liver samples of cow, sheep, goat, pig, grass-cutter (Thryonomys swinderianus), gaint rat (Cricetomys gambianus), red deer (Cervus elaphus), chicken and antelope (Antilocapra americana) were obtained from three different markets in Accra and Kumasi, Ghana. Samples were analyzed using atomic absorption spectrometry and an automatic mercury analyzer. Levels of iron in the grass-cutter and pig of 500.5–645.4 mg kg?1 were the highest in the animal livers examined. Mn concentrations were highest in grass-cutter and rat liver, ranging 16.5–30.2 mg kg?1. The safe Cu and Zn permissible limits of 20 and 50 mg kg?1 were exceeded in 70 and 75% of the liver samples, respectively. Generally, for each animal group studied, at least 50% of the sample livers exceeded the Cd permissible limit of 0.5 mg kg?1. The levels of Pb, which ranged 1.3–13.8 mg kg?1, exceeded the proposed European Commission (EC) limit of 0.5 mg kg?1. Care must be taken by regular consumers of the iron-rich animal livers of grass-cutter, pig and rat because they also had the highest levels of Pb (in grass-cutter and pig) and Cd (in grass-cutter, rat and pig). The liver samples analyzed for Hg had values far below the permissible limit of 0.5 mg kg?1.  相似文献   
8.
Construction activity is known to have a major impact on the environment. Construction is a major consumer of a wide range of naturally occurring and synthesized resources. The extraction, processing and utilization of these resources can have various negative impacts on the environment. With increased awareness and knowledge of these impacts, efforts are being made to avoid these adverse effects. Among these is the selection and specification of appropriate materials. This paper studies the level of environmental awareness and knowledge of architects in Singapore when selecting and specifying materials during the design stage. Responses to a questionnaire indicate that the architects are aware of the environmental impacts of building materials, and knowledgeable about possible measures which could help avoid the problems. However, they are not adopting green design approaches. Key policy directions for government, professional bodies, educators and clients are made to enable Singapore architects to apply their knowledge of environmental issues in their design decisions.  相似文献   
9.
Multilayer thin‐film structures in the wings of a butterfly; Papilio crino produce a colourful iridescence from reflected light. In this investigation, scanning electron microscope images show both the concave cover scales and pigmented air‐chamber ground scales. The microstructures with the concavities retroreflect incident light, thus causing the double reflection. This gives rise to both the colour mixing and polarisation conversion clearly depicted in the optical images. The result of the numerical and theoretical analysis via the CIELAB, and optical reflection and transmission of light through the multilayer stacks with the use of transfer method show that the emerging colouration on the Papilio crino is structural and is due to the combination of colours caused by multiple bounces within the concavities. The butterfly wing structure can be used as the template for designing the photonic device.Inspec keywords: bio‐optics, scanning electron microscopy, photodiodes, optical sensors, optical images, light reflection, reflectivity, colour, optical links, multilayers, optical multilayers, light polarisationOther keywords: pigmented air‐chamber ground scales, concavities, incident light, double reflection, colour mixing, polarisation conversion, optical images, numerical analysis, theoretical analysis, optical reflection, multilayer stacks, emerging colouration, butterfly wing structure, papilio crino fabricius, thin‐film structures, colourful iridescence, reflected light, electron microscope images, concave cover scales  相似文献   
10.
Corrosion product deposits formed over long periods of time could exert a considerable influence on the corrosion rate of used nuclear fuel under permanent disposal conditions. To simulate the build up of such deposits, the oxidative dissolution of UO2 (nuclear fuel) has been studied under constant current conditions in sodium chloride (pH = 9.5) solutions containing silicate. Currents in the range 1-300 nA cm−2 (normalized to the geometric area of the electrode surface) were applied in an attempt to simulate rates as close as experimentally feasible to those anticipated under disposal conditions. The deposits were characterized using scanning electron microscopy, energy dispersive X-ray spectroscopy and Raman spectroscopy. At high currents (?20 nA cm−2) very high potentials (∼0.5 V vs. SCE) were achieved and surface deposits were formed at localized sites on the electrode surface. Raman analyses indicated that these deposits were hydrated uranyl silicates. Their localization was shown to be due to the formation of acidified sites on an otherwise passive surface as a consequence of uranyl ion hydrolysis underneath the deposit. At these sites the local current density was considerably higher than the nominally applied current density. The fraction of the surface covered by a deposit increased as the applied current decreased, leading to a decrease in the extent of acidification. Measurements as a function of applied current density established a potential of ∼0.25 V (vs. SCE) as a threshold below which acidification did not occur despite the formation of a deposit. When the current was reduced to 1-2 nA cm−2, the potential (∼0.11 V (vs. SCE)) approached the range of corrosion potentials measured in aerated solutions. These values are well below the threshold potential. Since the maximum corrosion current densities anticipated under actual disposal conditions are <1 nA cm−2, the prospects for acidification leading to enhanced corrosion and radionuclide release rates are very remote.  相似文献   
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