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81.
A significant amount of mineral aggregates are used in constructing, rehabilitating and maintaining roads. As local (nearby) quarries get exhausted, aggregates need to be hauled from sources that are at ever-greater distances. Hence, over time the cost of trucking as well as the amount of emissions generated by trucking increases with a decrease of local natural aggregate stocks. The objectives of this study are to construct and utilize a system dynamics model of the depletion of a stock of natural aggregates due to pavement construction and maintenance, and determine the effect of using local and nonlocal aggregates, recycling and project cancellation (slowing growth) on the paving of roads. Long-term simulations are carried out with available aggregate stock, trucking distance and cost data. The quality of roads and a sustainability score, based on engineering, economic and environmental factors (emissions) are evaluated for different scenarios. An optimal combination of the use of local and nonlocal recycled aggregates, recycling and project cancellation is recommended. The proposed system dynamics model could be utilized by agencies to plan for the proper utilization of aggregate resources for road development and maintenance/rehabilitation projects.  相似文献   
82.
The Western Development Initiative (WDI), launched in 2000 by the Chinese Government, will greatly change the modes and improve the quality of life of the 355 million people living in the western region of China. This paper presents a panoramic picture of the mineral industries under the framework of the WDI. First, it gives an overview of the WDI, including a summary of the favorable and unfavorable conditions for the WDI, the objectives, priorities and key geographical areas for the WDI and the national policies and measures for implementing the WDI. Second, it describes the roles of the mineral industries in the WDI. Finally, it details the policies and actions of the Chinese Government on the exploration and development of mineral resources in the western region in support of the WDI.  相似文献   
83.
The USSR ranks as a major producer of virtually all energy and non-fuel minerals. Soviet minerals policy, a key component of national economic development, is based primarily on an unprecedented level of self-sufficiency. The author explains how recent changes in historical export-import patterns, decreasing ore grades, rising consumption, limitations imposed by the Soviet economic system, and depletion of easily accessible deposits could signify a future inability to sustain its supply independence. The apparent existence of vast, remote mineralized areas in Asia suggests self-sufficiency could remain an option available to Soviet leaders, but it would be even more expensive to maintain.  相似文献   
84.
我国矿产资源态势及发展战略的哲学思考   总被引:1,自引:0,他引:1  
本文以辩证法为指导,客观地分析了我国矿产资源的情况,指出我国矿情主要具有两个特点:矿产资源形势总量丰富,人均较少;矿产资源形势有喜有忧。基于此,提出我国矿产资源发展战略对策是:实行开源与节流并重的方针,走“资源节约型”道路;利用国内外两种资源;资源配套与发挥区域优势相结合。  相似文献   
85.
The USSR has long been regarded as a resource-rich country with no need for external sources of non-fuel mineral resources. Increasingly, however, it is beginning to appear that such an assessment of the Soviet non-fuel mineral resource picture is overly optimistic. The Soviet mineral industry is beset by a variety of problems which complicate the extraction and utilization of needed minerals. The USSR remains a resource-rich country, but the difficulties it encounters exploiting its resources are multiplying. This article examines the Soviet aluminium, chromium, cobalt, copper, gold, iron, lead, manganese, platinum, titanium and zinc industries, and offers views of the Soviet resource future in each area.  相似文献   
86.
The concept of value is central to mineral economics as it is all branches of economics. In the minerals sphere particular problems are posed for a theory of value by, firstly, the non- renewability of mineral resources, secondly the substantial effort that must be made to convert a mineral into a useful product, and finally the perception of minerals, both economically and symbolically, as peculiarly national forms of wealth. Some thoughts are offered on different approaches to mineral resource valuation and on the frequently conflicting principles of exploitation to which these various approaches give rise.  相似文献   
87.
The USA is becoming increasingly dependent on key strategic metals (such as chrome, cobalt, manganese and platinum-group metals) from politically unstable regions of the world. This dependence is the result of an inconsistent and fragmented US non-fuel minerals policy. Neglect of the US minerals industry has led to a decline in US mineral production and processing capabilities. Options for a comprehensive US non-fuel minerals policy include increased domestic production; increased substitution and recycling; a domestic stockpiling programme; and diversification of, and ensured access to, foreign sources of supply. These four options are examined and recommendations are made for increased mineral surveys of public lands, a regulatory review, domestic production of strategic minerals, tax incentives, conservation, stockpiling, and a foreign policy that will ensure security of supply.  相似文献   
88.
Available estimates of potentially recoverable world mineral and fuel resources are examined with a view to determining whether everyone likely to be living on earth next century could be raised to the material living standards people in developed countries now have. It is concluded that this goal is impossible. A number of fundamentally important implications follow, especially regarding the inappropriateness of growth strategies in general, goals for Third World development, and the need for ‘de-development’ of developed countries to much more frugal, self-sufficient and cooperative social systems.  相似文献   
89.
Political-economic events of the 1970s brought mineral resource appraisal to the focus of national policy. Estimates of and methodologies for mineral resources appraisal were scrutinized, revealing deficiencies in method and data and fostering considerable debate about the credibility of estimates and about preferred methodology. Since credibility can be increased through the acquisition of additional geoscience information, questions regarding methodology have more than one formulation and therefore more than one correct solution, depending upon the expected value of additional information and the conditional losses of relevant policy options. When existing information is meagre and the expected value of information is high, the optimum decision may be to defer all policy options until after the acquisition and analysis of- additional information. Decision theory offers an analytical framework that is sufficiently generalized to provide answers for highly varied circumstances of geoscience and resource information and policy issues. Our ability to perform any such analysis is limited by inaccuracies in both geologists' estimates of undiscovered mineral resources, and in economists' calculations of conditional losses of policy options for each of the relevant states of mineral resources.  相似文献   
90.
矿物纤维粉尘的环境健康效应研究   总被引:1,自引:0,他引:1  
研究者运用表面化学,电化学和细胞培养等生化方法,以及IR,XRF,UV等谱学和电子微束手段,通过对主要6类不同形态矿物粉尘的特征,表面官能团和活性位分析以及电化学,溶解,毒性研究等,提出了表面介体的概念并初步验证了它的存在,从表面官能团,表面综合性状探讨了矿物纤维材料的表面化学活性一生物活性-生物持久性-生物毒性-环境安全性;提出界/膜体系来研究矿物生产生物毒性的过程和所依存的条件;对矿物粉尘在Gamble溶液,血清与生物大分子,人体有机酸,氨基酸,维生素中以及动物体内行为的研究,进一步阐明了在氨基酸/蛋白质/功能膜以及含有外露蛋白质的其它有机体单元中粉尘的溶解,反应,络合与破坏,粉尘中的硅成分在体内的残留,溶解,运移方式,选择性吸附体液中的脂-醇类物质,红细胞及其残片,粉尘与体内物质交换及免疫细胞的相互作用过程,提供了降低粉尘毒性的处理方式。  相似文献   
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