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921.
Steven A. Primm 《Conservation biology》1996,10(4):1026-1035
Progress in grizzly bear ( Ursus arctos horribilis ) conservation in the Rocky Mountains of Canada and the United States is urgently needed. Human-caused mortality is the appropriate focal point for understanding the problem. This issue has a number of dimensions, but the human dimensions are by far the most complex and difficult to analyze. Conducting analyses and implementing conservation plans at the site or local level makes optimal use of humans' limited cognitive capabilities. Neither maintaining the status quo in grizzly bear conservation nor relying solely on major reform is a viable strategy. Instead, concerned people should take a pragmatic approach to developing innovative processes for forming reason-based public opinions that in turn inform effective public policies. There are many benefits to such an approach and, given the lack of viable alternatives, it should be tested with a pilot project by the appropriate people and organizations. 相似文献
922.
By mid-1990 the National Park Service (NPS) must present to Congress recommendations for managing overflights of at least ten national parks. The authors examine the potential role of formal negotiation in setting overflight policy in these parks by reviewing the overflight controversy at Grand Canyon National Park (GCNP). Regulations controlling overflights of the GCNP are only now being implemented after a 17-year conflict that culminated in a congressionally mandated solution. The authors review this controversy and find that, contrary to common perception, the number of park visitors bothered by overflights is not small but roughly equals the number of airborne visitors (up to 450,000 per year). On the basis of this investigation, the authors determine that formal negotiation would have been an appropriate policy-making process because of the clearly defined and limited number of parties and issues involved. Considering the number of park visitors that will continue to be affected by this issue, the authors conclude that formal negotiations should be considered for overflight problems involving other parks. Such negotiations should be park-specific. Differences in park size, extent of the problem, and parties involved would prohibit park-wide negotiations.This article has been adapted from Tourist Flights over the Grand Canyon: The Potential for Negotiated Solutions to Similar Problems, Analysis and Management, October 30, 1987. The opinions expressed in this article are those of the authors; they are not meant to represent the views of the organizations with which the authors are associated. 相似文献
923.
Steven Buskirk 《Conservation biology》2002,16(5):1443-1444
924.
This paper describes two studies conducted to test selected warning variables for their influence on the use of personal protective equipment. Both of the studies were field demonstrations; one conducted in a recreational setting and the other as part of a consumer product scenario. Each of the studies involved manipulations that could be practically implemented in many warning situations. Both studies showed that cost strongly influenced the use of personal protective equipment. “Cost” was shown to include parameters of time and difficulty with obtaining the equipment. The results indicate that a small increase in cost can devastate equipment use rates. Additional factors that were shown to positively influence equipment use under at least some circumstances include: (1) the addition of “specific consequence” information, including accident frequency and severity data, to standard warning signs/labels; and (2) product labels requiring physical manipulation by the consumer for product use. 相似文献
925.
926.
Wang-Hsien Ding Herman Valente David Spink Kenneth Aldous David Hilker Steven Connor 《Chemosphere》1989,18(9-10):1935-1942
Total concentrations of PCDDs and PCDFs were predicted from the concentrations of specifically identified dioxin and furan isomers of each congener group by partial least-squares (PLS). The accuracy of this prediction can be used to evaluate results from different data sets or different sources which were calculated by an automatic identification and quantification program-TASQR. 相似文献
927.
Daniel L. Leedy Carl D. Monk J. G. Warren Viessman Jr. Harold D. Foster EL James R. Brindell John B. Williams Paul E. Miller Harley J. Speir Richard McLean James Uphoff Worrall R. Carter Mark M. Bundy R. Steven Early SCW Eugene Meyer Y. J. Kim Charles Grigalauski Laurence Steinman Mohan K. Wali 《Environmental management》1982,6(1):73-86
928.
Steven W. Effler David L. Johnson 《Journal of the American Water Resources Association》1987,23(1):73-79
ABSTRACT: Calcium carbonate precipitate, known as “whiting,” forms in a large number of hard water lakes and reservoirs, and thus contributes to turbidity measurements in these systems. Here we document the occurrence of “whitings,” and the associated impact on turbidity, in Otisco Lake, New York. A simple, potentially broadly applicable, technique, measurement of turbidity before and after acidification, successfully quantified this component of turbidity in the lake. Calcium carbonate represented 32 percent of the turbidity in the upper waters of Otisco Lake for a three-month period, and at times was as much as 70 percent. Routine monitoring of this component of turbidity in raw water sources, where it is significant, should provide insight into water quality management and treatment plant operations. 相似文献
929.
930.
Chester C. Watson Steven R. Abt David Derrick 《Journal of the American Water Resources Association》1997,33(2):293-300
ABSTRACT: Harland Creek, in east-central Mississippi, is a rapidly migrating, meandering stream that is experiencing severe bank erosion. More than 9,000 willow (Salix nigra) posts were emplaced in February 1994 by the U.S. Army, Corps of Engineers in an effort to stabilize eroding stream banks using an experimental bioengi-neering technique. Monitoring of this stream reach and the willow post bank stabilization has resulted in a data base to assess willow mortality as related to bank aspect, post diameter, cover, and base elevation above low water. Monitoring has also resulted in the development of revised construction guidelines. Survivability of the posts, a necessary condition for long-term success, was found to average 81 percent in May 1994, 43 percent in October 1994, and 41 percent in August 1995. Even with survivability as low as 29 percent to 34 percent at specific bend reaches, willow posts are documented to be successful in bank stabilization for the period of monitoring, in comparison with more traditional riprap stabilization methods. Guidelines for improved survivability and recommended site selection are presented. Cost of willow post bank stabilization is less than traditional riprap, and willow posts can be emplaced using readily available equipment and materials. 相似文献