首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   226篇
  免费   7篇
安全科学   21篇
废物处理   5篇
环保管理   60篇
综合类   15篇
基础理论   57篇
污染及防治   51篇
评价与监测   15篇
社会与环境   5篇
灾害及防治   4篇
  2023年   2篇
  2017年   2篇
  2016年   4篇
  2015年   4篇
  2014年   2篇
  2013年   30篇
  2012年   8篇
  2011年   7篇
  2010年   3篇
  2009年   5篇
  2008年   13篇
  2007年   4篇
  2006年   9篇
  2005年   5篇
  2004年   7篇
  2003年   7篇
  2002年   9篇
  2001年   8篇
  2000年   4篇
  1999年   8篇
  1998年   4篇
  1997年   2篇
  1996年   5篇
  1995年   2篇
  1994年   1篇
  1993年   1篇
  1992年   5篇
  1991年   5篇
  1990年   2篇
  1989年   5篇
  1988年   2篇
  1987年   2篇
  1986年   7篇
  1985年   2篇
  1984年   2篇
  1983年   2篇
  1982年   4篇
  1981年   1篇
  1980年   2篇
  1979年   6篇
  1978年   4篇
  1977年   5篇
  1976年   4篇
  1975年   2篇
  1974年   3篇
  1973年   2篇
  1972年   2篇
  1971年   2篇
  1968年   1篇
  1966年   2篇
排序方式: 共有233条查询结果,搜索用时 15 毫秒
81.
Guided group discussion ( [Lewin et?al., 1952] , [Werner, 2003] and [Werner and Adams, 2001] ) was used to persuade groups to replace their toxic home and garden chemicals with nontoxic alternatives. We hypothesized that discussion would allow participants to hear others endorse the new information, and this normative information would facilitate persuasion. Approximately two months after the group discussion, we obtained questionnaires from the organizer of the meeting and a member of the group who had missed the meeting because of another obligation (i.e., not because of disinterest in the topic). Most organizers were female and analyses were limited to females. This quasi-experimental matched control group design indicated that those who attended the meeting were more favorable towards using nontoxics and more interested in sharing leftover toxic products with friends (instead of discarding them). Path and mediation analyses showed that the organizer’s evaluation of the meeting predicted her final attitude, and perceptions that the group endorsed the material (perceived group norm) partially mediated this relationship. A second mediation analysis showed that evaluation of the meeting predicted intention to share leftover toxics and this relationship was fully mediated by the organizer’s impression that the group would also share leftovers. The results support the idea that persuasion is based both on individual evaluation and normative influence, especially when people are not confident others will accept the behavior, such as sharing leftover toxic products.  相似文献   
82.
During the past several years, an increasing body of evidence and opinion has formed concerning the relationships between advancements in environmental, health, and safety (EH&S) management and the financial performance of the organization. In recent work,1 we have described a new theoretical model linking improvements in environmental management systems and environmental performance to corporate risk, stock volatility, and market value, as well as an empirical evaluation that validated our model. A number of other studies2 have documented changes in the market value of corporate equity as a function of environmental accidents, incidents, and (conversely) accomplishments. These are in addition to the numerous examples presented in the literature and at EH&S conferences and symposia that suggest that concerted efforts to reduce the organization's environmental “footprint” can yield cost savings, increased market share, reduced time to market, and perhaps other financial benefits. Some have gone so far as to proclaim that a new era has begun, in which environment-friendly corporations will increasingly be recognized and rewarded by financial market participants, and organizations that lag behind will be severely penalized.3 This article documents a new survey undertaken to identify important environmental factors, if any, investors employ in evaluating the quality and worth of equity and debt financing instruments.  相似文献   
83.
The assumption of demographic closure in the analysis of capture-recapture data under closed-population models is of fundamental importance. Yet, little progress has been made in the development of omnibus tests of the closure assumption. We present a closure test for time-specific data that, in principle, tests the null hypothesis of closed-population model M t against the open-population Jolly-Seber model as a specific alternative. This test is chi-square, and can be decomposed into informative components that can be interpreted to determine the nature of closure violations. The test is most sensitive to permanent emigration and least sensitive to temporary emigration, and is of intermediate sensitivity to permanent or temporary immigration. This test is a versatile tool for testing the assumption of demographic closure in the analysis of capture-recapture data.  相似文献   
84.
The implication of organic acids in Pb translocation was studied in two species varying in shoot lead accumulation, Sesuvium portulacastrum and Brassica juncea. Citric, fumaric, malic and α-cetoglutaric acids were separated and determined by HPLC technique in shoots, roots and xylem saps of the both species grown in nutrient solutions added with 200 and 400 μM of Pb(II). The lead content of the xylem saps was determined by ICP–MS. Results showed that S. portulacastrum is more tolerant to Pb than B. juncea. Lead concentration in xylem sap of the S. portulacastrum was significantly greater than in that of B. juncea. For both species, a positive correlation was established between lead and citrate concentrations in xylem sap. However minor relationship was observed for fumaric, malic and α-cetoglutaric acids. In the shoots lead treatment also induced a significant increase in citric acid concentration. Both observations suggest the implication of citric acid in lead translocation and shoot accumulation in S. portulacastrum and B. juncea. The relatively high accumulation of citric acid in xylem sap and shoot of S. portulacastrum could explain its high potential to translocate and accumulate this metal in shoot suggesting their possible use to remediate Pb polluted soils.  相似文献   
85.
Understanding global sea levels: past, present and future   总被引:4,自引:0,他引:4  
The coastal zone has changed profoundly during the 20th century and, as a result, society is becoming increasingly vulnerable to the impact of sea-level rise and variability. This demands improved understanding to facilitate appropriate planning to minimise potential losses. With this in mind, the World Climate Research Programme organised a workshop (held in June 2006) to document current understanding and to identify research and observations required to reduce current uncertainties associated with sea-level rise and variability. While sea levels have varied by over 120 m during glacial/interglacial cycles, there has been little net rise over the past several millennia until the 19th century and early 20th century, when geological and tide-gauge data indicate an increase in the rate of sea-level rise. Recent satellite-altimeter data and tide-gauge data have indicated that sea levels are now rising at over 3 mm year−1. The major contributions to 20th and 21st century sea-level rise are thought to be a result of ocean thermal expansion and the melting of glaciers and ice caps. Ice sheets are thought to have been a minor contributor to 20th century sea-level rise, but are potentially the largest contributor in the longer term. Sea levels are currently rising at the upper limit of the projections of the Third Assessment Report of the Intergovernmental Panel on Climate Change (TAR IPCC), and there is increasing concern of potentially large ice-sheet contributions during the 21st century and beyond, particularly if greenhouse gas emissions continue unabated. A suite of ongoing satellite and in situ observational activities need to be sustained and new activities supported. To the extent that we are able to sustain these observations, research programmes utilising the resulting data should be able to significantly improve our understanding and narrow projections of future sea-level rise and variability.  相似文献   
86.
In this paper we examine the role of community-based organisations (CBOs) in the environmental policy regime of Philadelphia, through a citywide survey (N?=?40) and interviews with leaders from three types of CBOs: community development corporations (CDCs), civic associations (CAs), and business-improvement organisations. We found that CBOs of all types have changed their organisational missions and identities in response to their pursuit of sustainability goals, but that CDCs more so than either CAs or business organisations have integrated sustainability into their governance structures. Second, we found that a growing number of CBOs have expanded their work to involve environmental policy and programming. Third, we found that the work of local non-profit organisations has become directly linked to the city's broader sustainability plan, Greenworks.  相似文献   
87.
88.
89.
90.
Hyperargininemia is a progressive neurometabolic disorder caused by deficiency of hepatic cytosolic arginase I, resulting from mutations in the ARG1 gene. We diagnosed arginase deficiency in a three-year-old male child of first-cousin Palestinian Arab parents. Prenatal diagnosis of an unaffected fetus was achieved in the second trimester of a subsequent pregnancy by cordocentesis and analysis of arginase activity in fetal erythrocytes. ARG1 mutation analysis in the proband revealed homozygosity for a deletion of 10 753 bp extending from the first intron to beyond the poly (A) site of the gene. This is the first gross deletion in the ARG1 gene to be identified and the first mutation to be described in an arginase-deficient patient of this ethnic origin. The identification of the ARG1 deletion in this family enabled first-trimester prenatal diagnosis in a subsequent pregnancy by multiplex PCR analysis performed on chorionic villous DNA. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号