全文获取类型
收费全文 | 213篇 |
免费 | 10篇 |
国内免费 | 2篇 |
专业分类
安全科学 | 16篇 |
废物处理 | 12篇 |
环保管理 | 51篇 |
综合类 | 38篇 |
基础理论 | 41篇 |
污染及防治 | 44篇 |
评价与监测 | 15篇 |
社会与环境 | 5篇 |
灾害及防治 | 3篇 |
出版年
2023年 | 5篇 |
2022年 | 5篇 |
2021年 | 3篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 3篇 |
2017年 | 7篇 |
2016年 | 13篇 |
2015年 | 10篇 |
2014年 | 8篇 |
2013年 | 14篇 |
2012年 | 13篇 |
2011年 | 11篇 |
2010年 | 8篇 |
2009年 | 11篇 |
2008年 | 12篇 |
2007年 | 15篇 |
2006年 | 13篇 |
2005年 | 11篇 |
2004年 | 5篇 |
2003年 | 9篇 |
2002年 | 8篇 |
2001年 | 6篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1997年 | 4篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 6篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1983年 | 3篇 |
1981年 | 1篇 |
1941年 | 1篇 |
排序方式: 共有225条查询结果,搜索用时 679 毫秒
151.
152.
Thomas A. Gasiewicz Ellen C. Henry Raymond B. Baggs George Rucci Arnold Schecter 《Chemosphere》1986,15(9-12)
The temporal - and dose-related characteristics of hepatic enzymes induced and toxic responses elicited in the hamster by 2,3,7,8-tetrachlorodibenzo-
-dioxin were examined. The results demonstrate a dissociation of the induction of these hepatic enzymes from TCDD-elicited lethality, but not necessarily hepatic damage, in this species. Furthermore, the hyperthyroidism observed is suggestive of a role of these hormones in the relatively insensitive nature of this species to TCDD treatment. 相似文献
153.
The dugong is classified as vulnerable to extinction by the World Conservation Union on the basis of declines in area or extent
of occupancy, habitat quality, and actual or potential levels of exploitation. In Thailand, the largest groups of dugongs
are found near islands off the Andaman coast. The authors conducted a 2-year project that included dugong population and habitat
assessment as well as interviews with local fishers. The results indicate declining populations of dugongs. The largest threat
to dugongs is incidental catch in fishing nets. The numbers of deaths reported place the dugong population along the Andaman
Sea in danger of extirpation. Other threats include seagrass destruction both from fishing and coastal development and the
use of dugong parts for medicinal purposes. Villagers still show strong ties with dugongs, and the majority favor establishing
more large protected areas for the species. These should arise from an integrated national dugong and seagrass conservation
strategy formulated by concerned stakeholders from government, nongovernmental organizations, scientists, and local communities.
The strategy needs to be both top down and bottom up in its formation to balance existing and potential uses as well as conflicts
between artisanal and commercial fishers. The strategy should include the development of educational materials and enforceable
regulations, as well as the designation of community-protected seagrass beds and a system of dugong sanctuaries along the
Andaman coast. An integrated management plan is needed urgently, with the continued input of concerned scientists, to monitor
and increase knowledge of dugong behavior and distribution. 相似文献
154.
A field investigation conducted on Boulder Creek in Boulder, Colorado evaluated impacts of flood control maintenance activities on flood conveyance, water quality, and fish habitat. Thirty-nine transects were monitored at one control site and two maintenance sites over a period of eight months. Each site was visited on more than 50 occasions in order to characterize pre- and post-maintenance conditions, and to monitor maintenance activities. Measurements along the transects included substrate composition, flow depth, velocity, and elevation. Reach-average values were assigned to variables such as in-stream vegetation, streambank stability, and woody vegetation before and after maintenance. Water temperature, dissolved oxygen, pH, specific conductance, and turbidity were sampled, and habitat suitability indices were developed pre- and post-maintenance for seven indicator fish species. Water quality impacts during maintenance consisted of high turbidity levels (> 400 NTU), which returned to background levels (0.1–15 NTU) overnight, as well as changes in mean temperature and pH. Alteration of physical channel characteristics as a result of maintenance had limited effects on habitat quality for four of seven fish species, but caused improvements in habitat quality for three fish species. The main implications of this study for floodplain management are that: (1) Flood control maintenance practices can be in direct conflict with water quality and fish habitat objectives, and should be carefully designed and implemented by an interdisciplinary team. (2) Physical habitat for some fish species can be improved as well as reduced by maintenance activities. Habitat suitability curves may be useful tools for evaluating limiting factors of the habitat and for identifying opportunities for habitat improvements as part of maintenance. 相似文献
155.
Catherine G. Palmer Judith H. Miles Patricia N. Howard-Peebles R. Ellen Magenis Shivanand Patil Jan M. Friedman 《黑龙江环境通报》1987,7(8):551-555
Data pooled from contributors to a Registry for Cytogenetic Abnormalities and PKU (ReCAP) shows an unbalanced chromosome abnormality rate of 27 per cent (29 fetuses) for 107 fetuses with ultrasonically diagnosed fetal anomalies. Of the abnormal, 12 were trisomic, 6 were monosomy X and 6 were structural abnormalities, 4 were mosaics and one triploid. 相似文献
156.
Michelle Casey Chris Gennings W Hans Carter Jr Virginia C Moser Jane Ellen Simmons 《Environmental and Ecological Statistics》2006,13(1):11-23
Response surface methodology, often supported by factorial designs, is the classical experimental approach that is widely
accepted for detecting and characterizing interactions among chemicals in a mixture. In an effort to reduce the experimental
effort as the number of compounds under study is increased, ray designs have been proposed to study combinations of chemicals.
When interest is restricted to relevant mixing ratios, we are only interested in making inference along the specific rays
of interest, as opposed to methods which use designs that require more experimental effort to support the estimation of a
response surface over a broader experimental region. Methods have been developed for the test of additivity along multiple
fixed-ratio rays. Of primary importance is the detection of interactions with reasonable power. The objective of this paper
is to address power and sample size issues related to the hypothesis of no interaction. 相似文献
157.
158.
Industries presently face a challenge to maintain competitiveness while creating minimal adverse impacts on the environment. The conventional concerns of product functionality, quality, and cost are further complicated by environmental considerations. Thus, corporate environmental strategies are evolving toward a life-cycle approach by implementing life-cycle analysis (LCA), design for environment (DFE), and environmentally conscious design and manufacturing (ECDM) practices. These life-cycle concepts provide a tool for industry to identify and evaluate opportunities to minimize environmental burdens from cradle to grave. A mail survey administered by Vanderbilt University's U.S.-Japan Center for Technology Management was sent to 175 U.S. corporations from the 1994 Fortune 500 list. The results show that more than half of the 56 respondents are using life-cycle concepts for environmental assessments, with marketing and cost issues as the primary motivation factors. Hi-tech and personal care firms are more active in implementing LCAs while chemical and intermediate companies are more involved with maintaining databases and utilizing LCA tools. The survey and this article show how life-cycle thinking has not been adequately integrated throughout corporate organizations, and most environmental efforts are initiated by the environmental affairs department. However, the percentage of top management involvement has increased since 1992 and is now at moderate levels. LCA methods need to be further developed in order to expand their industrial acceptability. 相似文献
159.
Mary Ellen Harris 《Journal of the American Water Resources Association》1983,19(6):921-928
ABSTRACT: This paper addresses the recent interest in management of the Missouri River. Interstate issues in the river basin include interbasin water diversions, riverbed and shoreline degradation, loss of recreational and natural areas, reduction in navigation capacity, the status of the Pick-Sloan Missouri Basin Program in terms of general river development, and the elimination of river basin commissions, An attempt to develop a comprehensive interstate water compact failed in the 1950s. The new efforts towards establishing a compact are discussed, as well as other available mechanisms for resolution of the current political and legal differences among the ten river basin states. 相似文献
160.
The predictability of turnover was compared for part-time versus full-time workers. This was accomplished using variables (1) that were hypothesized by Mobley (1977) to precede the turnover decision and (2) that have been shown in previous research to be significantly related to turnover. Measures of these variables were assessed via questionnaires following the second month of employment. Turnover was assessed directly from company records for a period of up to twelve months following employment. None of the hypothesized antecedent variables were significantly related to turnover within the part-time group. However, within the full-time group, all of the hypothesized precursors to turnover were found to be at least marginally related to actual turnover. Further, there was evidence to suggest differential predictability of turnover across full-time and part-time employment status groups, suggesting that the two groups may have a different ‘psychology of work’. These results are discussed in terms of the supportive evidence provided. 相似文献