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   84篇
  免费   0篇
  国内免费   2篇
安全科学   6篇
废物处理   4篇
环保管理   27篇
综合类   8篇
基础理论   18篇
污染及防治   18篇
评价与监测   4篇
社会与环境   1篇
  2023年   1篇
  2022年   3篇
  2021年   1篇
  2020年   1篇
  2019年   1篇
  2015年   2篇
  2014年   2篇
  2013年   11篇
  2011年   7篇
  2010年   1篇
  2008年   3篇
  2007年   2篇
  2006年   2篇
  2005年   1篇
  2004年   3篇
  2002年   4篇
  2001年   4篇
  2000年   4篇
  1998年   2篇
  1995年   2篇
  1993年   1篇
  1992年   1篇
  1991年   3篇
  1990年   1篇
  1989年   2篇
  1988年   1篇
  1986年   1篇
  1985年   1篇
  1984年   2篇
  1983年   2篇
  1980年   1篇
  1979年   1篇
  1978年   2篇
  1977年   2篇
  1975年   2篇
  1974年   1篇
  1973年   1篇
  1971年   1篇
  1969年   1篇
  1960年   2篇
排序方式: 共有86条查询结果,搜索用时 17 毫秒
71.
Less than four years after publication of ISO 14001, thousands of organizations worldwide have adopted the standard. In this article, researchers working with the National Database on Environmental Management Systems (NDEMS) review some preliminary data on organizations' experiences with EMS adoption and implementation. Their findings indicate that, although organizations may face hurdles in implementing EMSs, the majority believes the benefits outweigh the drawbacks. © 2000 John Wiley & Sons, Inc.  相似文献   
72.
ABSTRACT: Delineation of contributing areas for wellhead protection around supply wells drilled into bedrock in Maine, USA, is currently achieved by assigning a fixed radius circle around the well. This project develops a methodology that incorporates hydrogeologic processes and ground water modeling (MODFLOW) and accounts for variable data availability to estimate the areas that contribute water to 26 bedrock supply wells. Outcrop fracture mapping and lineament analysis are used to characterize the fracture system. Multiple simulations are constructed of each site using ranges of values for recharge, hydraulic conductivity, and anisotropy. Uncertainty in the delineation process is accounted for by portraying the delineated areas as confidence zones that are constructed by overlapping the capture zones from the multiple simulations. The results are variable and depend on the ability to characterize a site in a way that can be easily modeled. Sites with complex hydrogeology tend to have larger contributing areas that reflect the greater uncertainty in the parameters. The majority of the sites, however, produce reasonable results that provide a much more accurate depiction of the area likely to contribute to a bedrock well than the fixed radius circle.  相似文献   
73.
74.
75.
76.
We summarize the results from the various measurements and the inter-sampler comparisons from Southeastern Aerosol and Visibility Study (SEAVS), a study with one of its objectives to test for closure among chemical, gravimetric and optical measurements of atmospheric aerosol particles. Sulfate and organics are the dominant components of the SEAVS fine particles (nominally, particles with aerodynamic diameter < or = 2.5 microns) but between 28 and 42% (range over various samplers) of the gravimetrically measured total fine particle concentration is unidentified by the chemical measurements. Estimates of water associated with inorganic components and measurement imprecision do not totally explain the observed difference between gravimetric and chemical measurements. We examine the theoretical and empirical basis for assumptions commonly made in the published literature to extrapolate total fine particle concentration on the basis of chemical measurements of ions, carbon and elements. We then explore the more general question of closure using the SEAVS data as well as data from other, similar studies reported in the literature. In so combining the SEAVS measurements with other similar studies, we find a strong association between organic carbon and the unidentified component, that is, the fraction of the total fine particle concentration not identified by chemical measurements. We offer several tenable hypotheses for the relationship between the organic and unidentified components that deserve to be tested in future work. Specifically, we hypothesize that (1) errors in the sampling and analysis of organic carbon; (2) estimates of organic mass from measurements of organic carbon; and/or (3) water absorption by organics may all contribute to the observed relationship.  相似文献   
77.
The article analyzes mining company partnerships in terms of four main counterparts, namely: the sovereign, owners and financial backers, the workforce, and local communities. The main characteristics of mining partnerships under the four aspects are discussed. Taxation and financial aspects are also considered. Case studies from the British coal industry and examples from Latin America are part of the article. Downsizing and labour relations are also discussed, as well as indigenous peoples' issues. The article concludes that, successful minerals companies in the future will be those that work with communities, applying the highest standards of social responsibility. This includes safety, environmental management and good business ethics.  相似文献   
78.
The distribution and abundance of the littorinid gastropod Cenchritis (Tectarius) muricatus were determined on an exposed shore at Lee Stocking Island, Bahamas in July/August 1995 and June 1999. Activity patterns were observed on two occasions shortly before a hurricane passed near the island in 1995. C. muricatus extended from the low water mark to 3.6 m vertical height above it. Highest densities (20/m2) were found just above the high tide mark but the animal remained relatively abundant (8/m2) at the highest point. Small animals were only found at high shore levels. With the exception of animals very near to the water's edge C. muricatus was inactive by day and on dry nights. Many individuals of the high shore populations became active at night during periods of high humidity and rainfall, moving distances of up to 4 m overnight. At lower levels, extensive pairing and copulation was associated with these periods of rainfall. Abundance changed dramatically after the passage of the hurricane. At the level of maximum abundance numbers were reduced from 20/m2 to 2.8/m2. Long-term experimental studies of water loss rate and haemolymph concentration showed that both water loss rate and increase in haemolymph concentration are greatest in the early period of desiccation. The concentration of the blood after 20 weeks is 250% of the original and the water lost is of the order of 22.5%. After an initial increase there appears to be evidence of regulation of haemolymph concentration possibly by exchange with free water in the shell itself. The considerable reserve capacity in tolerance is no doubt in part due to the structure and functioning of the kidney. Adaptive features of the excretory system identified from ultrastructural examination include the replacement of podocyte-containing filtration chambers in the auricle by extracellular tubules permeating the walls of both auricle and ventricle, which suggests a reduction in the rate of primary urine formation. This is also indicated by a reduced surface area of the nephridial gland, which resorbs organic solutes from the urine. Excretory cells contain single large vacuoles in which arise large multi-layered concretions composed of phospholipids and calcium salts typical of prosobranchs in which excretory products may be stored for long periods.  相似文献   
79.
Matched data collected from 143 employees and their immediate supervisors of a private sector organization indicated that employee perceptions of procedural justice were only related to supervisor-rated affective commitment among employees with a strong exchange ideology. That is, individuals motivated by a fair exchange exhibited fewer affective commitment behaviors when they viewed the environment as unfair than when they perceived it to be fair. Individuals comparatively indifferent to a fair exchange did not alter their affective commitment behaviors regardless of the level of perceived environmental fairness. These results illustrate the importance of considering individual differences in exchange ideology when attempting to alter the work environment for the purpose of increasing commitment. Implications for research and management practice are presented. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   
80.
The discriminant validity of perceptions of organizational politics, organizational support, and procedural and distributive justice was examined as the distinctions between these variables have been blurred in past research. Results from a sample of 418 full‐time employees provided evidence of discriminant validity for these variables. First, structural equation modelling was used to isolate the best structural representation of these four variables. Then, six theoretically relevant predictors (i.e., leader–member exchange, centralization, formalization, co‐worker cooperation, role conflict, and locus of control) were examined in an effort to provide further conceptual separation. Five of the six antecedents distinguished among politics, justice, and support. Suggestions for additional research that can shed light on the distinctions and similarities of these variables are offered based on the results of this study. Copyright © 2001 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