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排序方式: 共有757条查询结果,搜索用时 15 毫秒
671.
The Pathway to Sustainable Resource Management 总被引:1,自引:0,他引:1
672.
Mark A. Snyder Lisa C. Sloan Jason L. Bell 《Journal of the American Water Resources Association》2004,40(3):591-601
ABSTRACT: Using a regional climate model (RegCM2.5), the potential impacts on the climate of California of increasing atmospheric CO2 concentrations were explored from the perspective of the state's 10 hydrologic regions. Relative to preindustrial CO2 conditions (280 ppm), doubled preindustrial CO2 conditions (560 ppm) produced increased temperatures of up to 4°C on an annual average basis and of up to 5°C on a monthly basis. Temperature increases were greatest in the central and northern regions. On a monthly basis, the temperature response was greatest in February, March, and May for nearly all regions. Snow accumulation was significantly decreased in all months and regions, with the greatest reduction occurring in the Sacramento River region. Precipitation results indicate drier winters for all regions, with a large reduction in precipitation from December to April and a smaller decrease from May to November. The result is a wet season that is slightly reduced in length. Findings suggest that the total amount of water in the state will decrease, water needs will increase, and the timing of water availability will be greatly perturbed. 相似文献
673.
对西部欠发达地区环保投入机制的思考 总被引:1,自引:0,他引:1
以长江上游地区为例,分析了西部欠发达地区环保投入机制存在的问题及原因,认为西部欠发达地区构建环保投入机制的基本思路是:畅通现有的环保投入渠道,开辟新的环保投入渠道,增加环保投入的供给;加强对环保投入资金、环保项目及工程的管理,提高环保投入资金的使用效果,压缩环保投入的需求。 相似文献
674.
This article focuses on the somewhat ambiguous concept of scarce water, or, more accurately stated, on the rather more ambiguous concept of scarcity. Still today, water scarcity in a region is defined largely in physical terms, typically gallons or cubic metres per capita if a stock or per capita-year if a flow. However useful purely physical measures may be for broad comparisons, they cannot adequately reflect the variety of ways in which human beings use water — neither to their wastefulness when water is perceived as abundant nor to their ingenuity when it is not. This article argues that water scarcity should be defined according to three orders of scarcity that require, respectively, physical, economic and social adaptations. It goes on to demonstrate that perceiving scarcity mainly in physical terms limits opportunities for policy-making and approaches for capacity building. 相似文献
675.
Richard Frye James W. McFarland 《Journal of the American Water Resources Association》1980,16(1):31-35
ABSTRACT: The traditional “requirements” approach to water system planning presumes perfectly inelastic demand and arbitrarily selects a fixed water requirement per capita per day as a planning target. Economists have often pointed out that such a policy leads to over-investment in water supply facilities; a superior approach would maximize some measure of net benefits incorporating price-sensitive demand. Using a dynamic programming model to depict an investment problem in Rhode Island, we find that ambiguities about how to incorporate price-sensitive demand into a decision framework may make such an approach as arbitrary as the requirements approach. Water conservation responses may be a function of other social parameters than water price; if so, variations in these social parameters should be regarded as economic alternatives to water supply investments. 相似文献
676.
J. Ernest Flack 《Journal of the American Water Resources Association》1980,16(1):139-141
ABSTRACT: Increasing costs and competition for water have resulted in pressure to manage urban water demand through conservation programs. Metering, pricing, devices, restrictions, building code changes, and horticultural practices have all been effective in reducing average residential water use. Some conservation means are specifically aimed at reducing peak demands but these usually reduce average usage as well. Combined programs of conservation can be expected to reduce urban demand by as much as 25–30 percent over the long term. Restrictions can reduce water usage on the short term even further. The success of conservation programs is as dependent on the effectiveness of public education and information dissemination as on the conservation practices themselves. 相似文献
677.
Ung Soo Kim 《Journal of the American Water Resources Association》1980,16(5):804-812
ABSTRACT: The reduction of regional unemployment requires a sufficient demand for regional labor and the demand pattern must parallel that of supply. Due to the interdependency of Appalachian economy with the rest of the Nation, the leakage of the final demand imposed on a subregion of Appalachia is substantial. The more capital intensive the investment the higher the leakage which will lead to less demand for labor in Appalachia. While water resource projects are generally longterm projects which aim at structural changes in a regional economy, consumption expenditures induced by welfare payments or public employment programs are basically temporary measures for the rescue of unemployment. Average consumption and private investment programs may impose on Appalachia a larger material demand but the demand for the total regional labor, off-site and on-site combined, is estimated to be less than that from water resource investments. The public expenditure program for combating regional unemployment must be discretionary based on its purpose and its potential to generate optimum demand for labor which will be created by the pattern of regional resource distribution and interindustrial and interregional interactions. An interregional I/O model is best suited for analysis of this type. 相似文献
678.
Alexander E. Cassuto Stuart Ryan 《Journal of the American Water Resources Association》1979,15(2):345-353
ABSTRACT: This paper develops a model that can be used to forecast the residential elasticity of demand for water within a district. Long-term water conservation programs and revenue and cost decisions hinge crucially on a determination of this elasticity. This study then pools cross-sectional (census) and time series data to generate elasticity forecasts for the Oakland urban area. 相似文献
679.
E. L. Michalson J. R. Hamilton 《Journal of the American Water Resources Association》1975,11(6):1149-1156
ABSTRACT: A methodology is developed for examining the environmental and developmental conflicts inherent in the classification process of a wild river. The Salmon River in Idaho is used as an example of the methodology. The steps were: 1. a resource inventory, 2. an evaluation methodology, and 3. an economic comparison of resource use tradeoffs. Alternatives for the Salmon were examined, following generally the procedures outlined in the United States Water Resources Council's Establishment of Principles and Standards for Planning Water and Related Land Resources Final comparisons showed that hydroelectric development had greater net benefits than outdoor recreation at up to a three percent recreation growth rate. When recreation use grew at a faster rate, recreation had a considerable margin of net benefits in its favor. 相似文献
680.
R. Sabzehgar M. A. Kazemi M. Rasouli P. Fajri 《International Journal of Green Energy》2020,17(2):127-136
ABSTRACTIn this paper, an effective objective function is proposed to minimize the cost of operation of a microgrid with large-scale plug-in electric vehicles and renewable energy resources. The profit of consumers is taken into account by utilizing the incentives in the demand response programs, and vehicle-to-grid feature of the plug-in-electric vehicles integrated into the grid. The optimization is performed using genetic algorithms. Also, reliability indices of the economically optimized microgrid are computed for various operation configurations in both the grid-tied and islanded modes. Numerical studies are conducted on a microgrid testbed to validate the performance of the proposed strategy. 相似文献