全文获取类型
收费全文 | 1226篇 |
免费 | 83篇 |
国内免费 | 62篇 |
专业分类
安全科学 | 190篇 |
废物处理 | 33篇 |
环保管理 | 275篇 |
综合类 | 510篇 |
基础理论 | 125篇 |
环境理论 | 1篇 |
污染及防治 | 59篇 |
评价与监测 | 47篇 |
社会与环境 | 70篇 |
灾害及防治 | 61篇 |
出版年
2024年 | 2篇 |
2023年 | 8篇 |
2022年 | 24篇 |
2021年 | 43篇 |
2020年 | 49篇 |
2019年 | 24篇 |
2018年 | 26篇 |
2017年 | 44篇 |
2016年 | 47篇 |
2015年 | 46篇 |
2014年 | 62篇 |
2013年 | 90篇 |
2012年 | 101篇 |
2011年 | 96篇 |
2010年 | 73篇 |
2009年 | 61篇 |
2008年 | 53篇 |
2007年 | 86篇 |
2006年 | 68篇 |
2005年 | 51篇 |
2004年 | 62篇 |
2003年 | 35篇 |
2002年 | 34篇 |
2001年 | 22篇 |
2000年 | 36篇 |
1999年 | 24篇 |
1998年 | 18篇 |
1997年 | 16篇 |
1996年 | 8篇 |
1995年 | 3篇 |
1994年 | 4篇 |
1993年 | 11篇 |
1992年 | 4篇 |
1991年 | 4篇 |
1990年 | 2篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1983年 | 4篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1975年 | 1篇 |
1974年 | 3篇 |
1973年 | 2篇 |
1971年 | 3篇 |
1970年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有1371条查询结果,搜索用时 15 毫秒
991.
L. Douglas James Dean T. Larson Daniel H. Hoggan 《Journal of the American Water Resources Association》1983,19(4):595-603
ABSTRACT A conceptual framework and the systematic collection of reliable information for application within the framework are the cornerstones of effective water planning. The ideal of strengthening these cornerstones was a driving force behind formation of the Water Resources Council and Council efforts, during its life, to develop the Principles and Standards and to complete two National Water Assessments. The Assessments contained voluminous data but never really became an integral component of the national water planning process. Before being disbanded in 1982, the Council solicited several appraisals of its assessment process. This paper reports one made by the university community in which experiences and opinions were obtained from 108 water research administrators and water policy experts. 相似文献
992.
Evelyn B. Pluhar 《Journal of Agricultural and Environmental Ethics》1988,1(3):211-224
Professor Hugh Lehman has recently argued that the rights view, according to which nonhuman animals have a prima facie right to life, is compatible with the killing of animals in many circumstances, including killing for food, research, or product-testing purposes. His principle argument is an appeal to life-boat cases, in which certain lives should be sacrificed rather than others because the latter would allegedly be made worse-off by death than the former. I argue that this reasoning would apply to so-called inferior humans just as much as to animals, and that this appeal is unsuccessful in any case. I distinguish two versions of the rights view: the equal and the unequal rights views. Although the unequal rights view, unlike the equal rights view, would sanction the killing of animals (and some humans) for food under severely restricted circumstances, neither rights view sanctions the raising of animals for their meat. Moreover, neither rights view would sanction the killing of animals for research or product-testing purposes. I conclude with a brief discussion of the merits of phasing out the meat production industry. 相似文献
993.
Giovanni Giavelli 《Environmental management》1989,13(4):425-433
Environmental research is characterized in each of its successive phases by a strong interdisciplinarity. A rotational groups system (RGS) method is proposed as an instrument to encourage interaction among researchers from fields that are traditionally far apart. Meetings conducted with the RGS procedure involve all the researchers, who, in repeated and topical encounters, are able to exchange information on a wide variety of environmental subjects. These meetings can be arranged according to a special calendar, through a series of phases treating different aspects of the same subjects to be discussed, and above all, referring to specific themes and working guidelines organized on the basis of criteria designed to favor an exchange of ideas and constructive discussion. At the end, the plenary assembly edits an overall resume of the proceedings, and votes on the final resolution, which brings together all the conclusive opinions regarding the themes discussed. 相似文献
994.
James E. Kundell 《Journal of the American Water Resources Association》1986,22(5):785-789
ABSTRACT: Societal trends indicate an increased need for university water researchers to develop and improve working relationships with state legislatures to help ensure that water related legislation is based on sound water resources information. Recommendations for providing technical support to state legislatures on water resources issues include: the necessity for researchers to take the initiative; the importance of researchers capitalizing on existing linkages; the need to maintain a continuous link between key legislators, legislative staff, and researchers; and the need for researchers to provide comprehensible information in a timely manner. 相似文献
995.
996.
Edwin T. Engman William J. Gburek Leslie H. Parmele James B. Urban 《Journal of the American Water Resources Association》1971,7(3):495-505
ABSTRACT The problems encountered in estimating scale parameters in interdisciplinary watershed research are discussed. Meteorology, hydrology, geology and water quality are discussed with respect to their individual strengths and weaknesses when applied to different scale problems. Areas where incompatibilities exist are pointed out and suggestions are made for effecting compromise. A watershed scale of roughly a hundred acres may be the scale at which all disciplines can effect optimum interaction. 相似文献
997.
Marshall Gys 《Journal of the American Water Resources Association》1971,7(3):521-528
ABSTRACT The long-term effects of presently used and alternatively proposed water pricing policies were studied using some tools of operations research and economics. A discrete deterministic dynamic programming model was structured and operated to determine the optimal water supply capacity expansion paths for a hypothetical residential community with a given water pricing policy. The objective of the model was the maximization of future discounted consumers'surpluses plus producer's revenues net of the long-run cost of supply. State variables were the size of system capacity in MGD and stage variables were the times of feasible capacity increase in years. Demand curves, population sizes, and growth rates for various economic sectors of the community were assumed known, as well as short-run production and capital construction costs. Several policies, including constant unit rates, decreasing or increasing block rates and summer differential rates were tested. It was concluded that price plays a major role in the short-run allocation and long-run planning and conservation of water supplies. Conservational pricing policies were advocated as means of lowering the long-run cost of water, using the water price-demand function as a planning tool. Further research in these areas was recommended. 相似文献
998.
Warren Viessman Karen E. Stork 《Journal of the American Water Resources Association》1973,9(4):647-654
In recent years, important changes have occurred in water resources research. There have been major shifts in attitudes of Congress, state legislatures and the general public toward water and related resource issues. Future water research and development will have to be environmentally oriented. Emphasis is shifting to research productivity. To justify research expenditures, hard facts must be produced which demonstrate payoff. Technology transfer (getting research results into the hands of users in an understandable and usable form) is gaining prominence. Research projects must be designed for total problem solution and technology transfer must be incorporated as a part of project objectives. Research must be planned and conducted to meet users' needs. Guidelines for modern research design and technology transfer are presented. 相似文献
999.
废弃聚合物钻井液化学脱水处理技术的实验研究 总被引:1,自引:0,他引:1
在分析废弃聚合物钻井液组成的基础上,对采用化学固液分离无害化处理方法进行了实验研究。以部分水解聚丙烯酰胺(HPAM)、聚电解质A为絮凝剂和混合酸为凝聚剂的复合絮凝剂配方,可以彻底破坏HPAM类型废弃钻井液的胶体体系,使废浆液絮凝脱水。通过3口井废钻井液样品的絮凝试验,加药剂后废浆液自然脱水率为25%~35%,13.3kPa压差下抽滤出水率为51%~60%,絮凝残渣无再造浆能力。 相似文献
1000.
根据钻井废水的污染成分及国内外处理区域环境的敏感性采取三种方法对其进行治理,即:废水回灌、集中处理后回灌或回注、现场处理后回注。在冀东油田进行了三种处理方案的试验研究,取得了一定的效益,有望在石油行业推广应用。 相似文献