全文获取类型
收费全文 | 1982篇 |
免费 | 171篇 |
国内免费 | 59篇 |
专业分类
安全科学 | 50篇 |
废物处理 | 26篇 |
环保管理 | 921篇 |
综合类 | 472篇 |
基础理论 | 295篇 |
环境理论 | 45篇 |
污染及防治 | 62篇 |
评价与监测 | 39篇 |
社会与环境 | 231篇 |
灾害及防治 | 71篇 |
出版年
2024年 | 8篇 |
2023年 | 46篇 |
2022年 | 34篇 |
2021年 | 56篇 |
2020年 | 64篇 |
2019年 | 100篇 |
2018年 | 80篇 |
2017年 | 152篇 |
2016年 | 122篇 |
2015年 | 87篇 |
2014年 | 67篇 |
2013年 | 127篇 |
2012年 | 86篇 |
2011年 | 114篇 |
2010年 | 60篇 |
2009年 | 101篇 |
2008年 | 85篇 |
2007年 | 69篇 |
2006年 | 79篇 |
2005年 | 73篇 |
2004年 | 53篇 |
2003年 | 46篇 |
2002年 | 61篇 |
2001年 | 55篇 |
2000年 | 56篇 |
1999年 | 46篇 |
1998年 | 31篇 |
1997年 | 25篇 |
1996年 | 25篇 |
1995年 | 32篇 |
1994年 | 17篇 |
1993年 | 18篇 |
1992年 | 12篇 |
1991年 | 8篇 |
1990年 | 14篇 |
1989年 | 9篇 |
1988年 | 7篇 |
1987年 | 7篇 |
1986年 | 10篇 |
1985年 | 17篇 |
1984年 | 8篇 |
1983年 | 9篇 |
1982年 | 6篇 |
1981年 | 5篇 |
1979年 | 4篇 |
1978年 | 4篇 |
1977年 | 5篇 |
1973年 | 2篇 |
1972年 | 2篇 |
1971年 | 4篇 |
排序方式: 共有2212条查询结果,搜索用时 0 毫秒
71.
The historical and regional context to the development of a planning strategy for Barcelona is examined, providing an explanation of the obstacles to development of new towns in the region, and that of Riera de Caldes in particular. The paper analyses the reasons for the failure to develop the new town, and its subsequent reversion to rural uses and a place of pilgrimage for environmentalists. 相似文献
72.
Lawrence J. MacDonnell David H. Getches William C. Hugenberg 《Journal of the American Water Resources Association》1995,31(5):825-836
ABSTRACT: The waters of the Colorado River are divided among seven states according to a complex ‘Law of the River’ drawn from interstate compacts, international treaties, statutes, and regulations. The Law of the River creates certain priorities among the states and the Republic of Mexico, and in the event of a severe sustained drought, the Law of the River dictates the distribution of water and operation of the elaborate reservoir system. Earlier work indicated that there is remarkable resilience in the system for established uses of water in the Lower Basin of the Colorado River. This work shows, based on an application of the Law of the River using computer modeling of operations of facilities on the Colorado River, that there may be serious environmental consequences and related legal restraints on how the water is used in times of shortage and that the existing legal and institutional framework governing the Colorado River does not adequately address all the issues that would be raised in a severe sustained drought. Several possible legal options for dealing with drought in the context of the Law of the River are identified. 相似文献
73.
Taiye B. Sangoyomi Benjamin L. Harding 《Journal of the American Water Resources Association》1995,31(5):925-938
ABSTRACT: We evaluated the effects of institutional responses developed for coping with a severe sustained drought (SSD) in the Colorado River Basin on selected system variables using a SSD inflow hydrology derived from the drought which occurred in the Colorado River basin from 1579–1616. Institutional responses considered are reverse equalization, salinity reduction, minimum flow requirements, and temporary suspension of the delivery obligation of the Colorado River Compact. Selected system variables (reservoir contents, streamflows, consumptive uses, salinity, and power generation) from scenarios incorporating the drought-coping responses were compared to those from Baseline conditions using the current operating criteria. The coping responses successfully mitigated some impacts of the SSD on consumptive uses in the Upper Basin with only slight impacts on consumptive uses in the Lower Basin, and successfully maintained specified minimum streamflows throughout the drought with no apparent effect on consumptive uses. The impacts of the coping responses on other system variables were not as clear cut. We also assessed the effects of the drought-coping responses to normal and wet hydrologic conditions to determine if they were overly conservative. The results show that the rules would have inconsequential effects on the system during normal and wet years. 相似文献
74.
Lester Ross 《Journal of the American Water Resources Association》1983,19(1):69-72
ABSTRACT: Ideology has predisposed the People's Republic of China against the use of prices to allocate water. Prolonged drought in north China has made the Chinese more aware of their unfavorable water resource inventory and the expense of expanding supply. Therefore, as part of the economic liberalization commenced since the death of Mao Zedong, China has started to make more active use of pricing to regulate demand and reduce the need for supply expansion. 相似文献
75.
Donald M. Anderson Mark W. Rodney 《Journal of the American Water Resources Association》2006,42(5):1391-1403
ABSTRACT: Efforts are under way to recover habitat for several threatened and endangered species in and along the Platte River in central Nebraska. A proposed recovery program for these species requires a means of characterizing “wet” versus “normal” versus “dry” hydrologic conditions in order to set corresponding Platte River instream flow targets. Methods of characterizing hydrologic conditions in real time were investigated for this purpose. Initially, 10 watershed variables were identified as potentially valuable indicators of hydrologic conditions. Ultimately, six multiple linear regression equations were developed for six periods of the year using a subset of these variables expressed as frequencies of nonexceedence. The adequacy of these equations for characterizing conditions was assessed by evaluating their historic correlation to subsequent flow in the central Platte River (1947–1994). These equations explained 54 to 82 percent of variability in the observed flow exceedences in the validation datasets, depending upon the period of year evaluated. These equations will provide initial criteria for setting applicable flow targets to determine, in real time, whether water regulation projects associated with the species recovery effort can divert or store flows without conflicting with recovery objectives. 相似文献
76.
排污收费政策失灵分析 总被引:1,自引:0,他引:1
李克国 《中国环境管理干部学院学报》2002,12(1):8-11
在市场经济体制下,经常会出现政策失灵。本文首先介绍了政策失灵的基本理论,然后对我国的排污收费政策失灵进行了深入分析,最后提出了完善我国排污收费政策的对策。 相似文献
77.
K. K. Chatterjee 《Resources Policy》2002,28(3-4)
In India, the mineral resource inventory and the production of a large number of important minerals have registered significant increases during the last few decades. Yet the country continues to be a net importer of many high value and scarce minerals and metals, like gold, diamond, and several base metals. Exploration and development of the resources of these minerals are technology- and capital-intensive. To bring technology and capital through foreign direct investment (FDI) into the Indian mineral sector, it is imperative to lay stress on: accurate resource estimation and categorization, as well as realistic projection of the true values; rationalization of legislative measures based on R&D studies and reorganization of the implementation machinery; conducive tax structure; notification of acts and rules applicable to offshore mineral resources; time-frames for granting licences and leases; encouragement to labor productivity by rationalizing labor laws; reforms in the monetary system to increase market competitiveness of Indian minerals; and judicial reforms. FDI in the Indian mineral sector is important to firm up the knowledge-base of mineral resources and their optimum exploitation. 相似文献
78.
Harold L. Stone 《Journal of the American Water Resources Association》2002,38(4):1019-1026
ABSTRACT: This study was designed to give insight into the values considered in environmental policy and illustrate the respondents' personal constructions related to creating policy through the development of a graphic tool. Using both qualitative and quantitative methods, this study anonymously captured the intensity of values currently held by decision makers and tracked changes in values over time. Data were acquired through observations of and interviews with stakeholders in a five‐year wetland mitigation bank permitting process at the Galveston District of the U.S. Army Corps of Engineers. The study included public and private sector respondents in both governmental and nongovernmental roles. The resulting representations of professional and personal stakeholders' values can be used as a tool for improving information exchange in policy negotiation and provides insight into the complexity of individual and corporate perceptions of a policy issue. 相似文献
79.
ELLISON BA 《Environmental management》1999,23(4):429-439
/ This paper explores the new politics of western water policy through an examination of the Animas-La Plata water project and implementation of the Endangered Species Act. It is suggested that the focus of western water programming has shifted from the source of distributed funds, the United States Congress, to the agencies originally created to deliver federal benefits because funding for new project construction has not been forthcoming. Under this new system, members of Congress continue to excite their constituents with promises of money for new project starts, while the administrative agencies perform the myriad duties needed to keep these projects alive. The result is that political objectives have replaced operational/management objectives in administrative processes. In this case, the author demonstrates how resource managers in the Bureau of Reclamation manipulated hydrological analysis to control administrative process, why their manipulation was unfair, and perhaps illegal, and why biologists from the US Fish and Wildlife Service accepted the analysis. While ostensibly protecting all interests, the result is that none of the objectives of federal water programming are achieved. KEY WORDS: Environmental management; Administrative politics; Water policy; Endangered Species Act; Animas-La Plata, Bureau of Reclamation 相似文献
80.
Prompted by the calls in recent years to link relief practice to peace-building, development, or both, several conferences and papers have recently mounted a strong critique, seeing these 'broadenings' of relief as 'eroding' or 'corrupting' core humanitarian principles and playing into neo-isolationist agendas to slash humanitarianism. This paper argues that whereas these critiques have important goals in mind when they encourage a concentration on the basics of relief, there has been a loss of subtlety in the ensuing debate. Considering each element of the debate in turn, the paper argues that there is more common ground between 'new' and 'old', 'broadened' and 'basics' relief than at first appears. In concluding, it is argued that further research on key questions, and an openness to hear all perspectives will get us further than entrenched positions and rallying cries. 相似文献