全文获取类型
收费全文 | 870篇 |
免费 | 92篇 |
国内免费 | 75篇 |
专业分类
安全科学 | 117篇 |
废物处理 | 11篇 |
环保管理 | 359篇 |
综合类 | 322篇 |
基础理论 | 74篇 |
污染及防治 | 33篇 |
评价与监测 | 45篇 |
社会与环境 | 53篇 |
灾害及防治 | 23篇 |
出版年
2024年 | 3篇 |
2023年 | 12篇 |
2022年 | 31篇 |
2021年 | 27篇 |
2020年 | 27篇 |
2019年 | 23篇 |
2018年 | 20篇 |
2017年 | 22篇 |
2016年 | 24篇 |
2015年 | 31篇 |
2014年 | 26篇 |
2013年 | 48篇 |
2012年 | 49篇 |
2011年 | 53篇 |
2010年 | 63篇 |
2009年 | 50篇 |
2008年 | 40篇 |
2007年 | 62篇 |
2006年 | 55篇 |
2005年 | 44篇 |
2004年 | 34篇 |
2003年 | 36篇 |
2002年 | 23篇 |
2001年 | 47篇 |
2000年 | 28篇 |
1999年 | 23篇 |
1998年 | 19篇 |
1997年 | 18篇 |
1996年 | 8篇 |
1995年 | 19篇 |
1994年 | 16篇 |
1993年 | 5篇 |
1992年 | 8篇 |
1991年 | 5篇 |
1989年 | 5篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 4篇 |
1980年 | 2篇 |
1979年 | 5篇 |
1978年 | 3篇 |
1976年 | 1篇 |
1973年 | 4篇 |
1972年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有1037条查询结果,搜索用时 500 毫秒
311.
Scott J. Goetz 《Journal of the American Water Resources Association》2006,42(1):133-143
Riparian buffer zone management is an area of increasing relevance as human modification of the landscape continues unabated. Land and water resource managers are continually challenged to maintain stream ecosystem integrity and water quality in the context of rapidly changing land use, which often offsets management gains. Approaches are needed not only to map vegetation cover in riparian zones, but also to monitor the changes taking place, target restoration activities, and assess the success of previous management actions. To date, these objectives have been difficult to meet using traditional techniques based on aerial photos and field visits, particularly over large areas. Recent advances in remote sensing have the potential to substantially aid buffer zone management. Very high resolution imagery is now available that allows detailed mapping and monitoring of buffer zone vegetation and provides a basis for consistent assessments using moderately high resolution remote sensing (e.g., Landsat). Laser‐based remote sensing is another advance that permits even more detailed information on buffer zone properties, such as refined topographic derivatives and multidimensional vegetation structure. These sources of image data and map information are reviewed in this paper, examples of their application to riparian buffer mapping and stream health assessment are provided, and future prospects for improved buffer monitoring are discussed. 相似文献
312.
Alan Carlin 《Journal of the American Water Resources Association》1971,7(2):221-227
The Sierra Club, which has long fought selected water resource projects that it believes would be environmentally damaging, has come to the conclusion in recent years that much more basic reforms are required in water resources development activities if the demands for environmental quality now evidenced by the American people are to be satisfied. These reforms should not be limited to those that would have a direct effect on the environmental aspects of proposed projects, but also many others long advocated by the economics profession that would have favorable indirect effects. Among the urgent reforms with indirect effects are those involving revision of the procedures used in evaluating proposed projects. These procedures should be revised so that future evaluations will much more accurately reflect the economic and environmental merits of proposed projects. Basic reforms of tax policies are also needed that will eliminate most of the private profit available to those who can persuade the government to increase the value of their land through the construction of water projects. Finally, some additional actions can be taken that will have a direct impact on lessening the adverse environmental impact of water projects beyond the provisions of the National Environmental Policy Act of 1969. 相似文献
313.
On November 13-14, 2003, a symposium on high-visibility safety belt use enforcement in Raleigh, NC: (a) celebrated the 10th anniversary of North Carolina's Click It or Ticket program; (b) documented current knowledge regarding safety belt use; (c) proposed strategies to increase use further; and (d) discussed research to support these strategies. 相似文献
314.
Bodie JR 《Journal of environmental management》2001,62(4):443-455
The regulation and management of stream ecosystems worldwide have led to irreversible loss of wildlife species. Due to recent scrutiny of water policy and dam feasibility, there is an urgent need for fundamental research on the biotic integrity of streams and riparian zones. Although riverine turtles rely on stream and riparian zones to complete their life cycle, are vital producers and consumers, and are declining worldwide, they have received relatively little attention. I review the literature on the impacts of contemporary stream management on freshwater turtles. Specifically, I summarize and discuss 10 distinct practices that produce five potential biological repercussions. I then focus on the often-overlooked use of riparian zones by freshwater turtles, calculate a biologically determined riparian width, and offer recommendations for ecosystem management. Migration data were summarized on 10 species from eight US states and four countries. A riparian zone encompassing the majority of freshwater turtle migrations would need to span 150 m from the stream edge. Freshwater turtles primarily chose high, open sandy habitats to nest. Nests in North America contained eggs and hatchlings during April through September and often through the winter. In addition, freshwater turtles utilized diverse riparian habitats for feeding, nesting, and overwintering. Additional documentation of stream and riparian habitat use by turtles is needed. 相似文献
315.
316.
317.
王彬辉 《中国环境管理干部学院学报》2000,(2)
长期以来,我国对排污或超标排污实行征收排污费制度。九届人大常委会第13次会议修订通过的《海洋环境保护法》对此进行了改革。本文对此进行了深入分析。 相似文献
318.
Alan E. Haberstock Henry G. Nichols Mark P. DesMeules Jed Wright Jon M. Christensen Daniel H. Hudnut 《Journal of the American Water Resources Association》2000,36(6):1271-1286
ABSTRACT: Successful restoration of declining anadromous species is dependent upon effective riparian buffer zone management. Natural resource managers, policy developers and local conservation groups require science‐based information concerning the width at which a given buffer will be effective for its stated purpose. This paper summarizes a method developed in 1999 to determine effective riparian buffer widths for Atlantic salmon habitat protection as part of the Atlantic Salmon Conservation Plan for Seven Maine Rivers. A major assumption of the method is that no two buffers are alike with respect to their effectiveness and that various buffer characteristics dictate the required width for a given level of effectiveness. The method uses a predictive model that generates suggested riparian buffer widths as a function of specific, measurable buffer characteristics (such as slope, soil characteristics, and plant community structure and density) that affect buffer function. The method utilizes a variable‐width, two‐zone approach and specifies land uses that are consistent with desired buffer function within the two zones. 相似文献
319.
Anna Peterson 《Journal of Agricultural and Environmental Ethics》2000,12(3):237-261
Mainstream currents within Christianity havelong insisted that humans, among all creatures, areneither fully identified with their physical bodiesnor fully at home on earth. This essay outlines theparticular characteristics of Christian notions ofhuman nature and the implications of this separationfor environmental ethics. It then examines recentefforts to correct some damaging aspects oftraditional Christian understandings of humanity'splace in nature, especially the notions of physicalembodiment and human embeddedment in earth. Theprimary goal of the essay is not to offer acomprehensive evaluation of Christian thinking aboutnature but rather to identify theological anthropologyas a crucial dimension of, and problem for, Christianenvironmental ethics. 相似文献
320.