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   278篇
  免费   5篇
安全科学   12篇
废物处理   1篇
环保管理   66篇
综合类   56篇
基础理论   63篇
污染及防治   65篇
评价与监测   14篇
社会与环境   4篇
灾害及防治   2篇
  2023年   1篇
  2022年   2篇
  2021年   4篇
  2020年   1篇
  2019年   5篇
  2018年   10篇
  2017年   7篇
  2016年   6篇
  2015年   5篇
  2014年   11篇
  2013年   27篇
  2012年   11篇
  2011年   14篇
  2010年   12篇
  2009年   9篇
  2008年   17篇
  2007年   10篇
  2006年   16篇
  2005年   16篇
  2004年   5篇
  2003年   13篇
  2002年   8篇
  2001年   4篇
  2000年   5篇
  1999年   9篇
  1998年   5篇
  1997年   3篇
  1996年   2篇
  1995年   5篇
  1993年   4篇
  1992年   1篇
  1991年   4篇
  1990年   4篇
  1989年   4篇
  1988年   1篇
  1987年   1篇
  1986年   2篇
  1985年   3篇
  1984年   1篇
  1983年   8篇
  1980年   1篇
  1979年   1篇
  1976年   1篇
  1973年   2篇
  1972年   1篇
  1956年   1篇
排序方式: 共有283条查询结果,搜索用时 15 毫秒
131.
In two cases of prenatally detected cystic hygroma with oligohydraminos, successful cytogenetic diagnosis of Turner syndrome was achieved using cells obtained from direct aspiration of the cystic hygroma. Exceptionally high levels of alpha-fetoprotein were found in the cystic hygroma fluid, as might be expected. However, the maternal serum alpha-fetoprotein levels were within normal limits. Elevated alpha-fetoprotein levels in ‘amniotic fluid’ noted previously in the literature may have resulted because of inadvertent tapping of the cystic hygroma. It is clear from our cases that maternal serum levels of alpha-fetoprotein will not necessarily be elevated and will not serve as a screening mechanism for cystic hygromas.  相似文献   
132.
The impact of high environmental lead levels on public health is currently under much debate. Such a situation exists in two former lead mining villages set in the Southern Uplands of Scotland, where the environment is heavily contaminated through past mining activity. A survey was conducted based on representative samples of male and female adults and of all children living in the area, to examine the distribution of blood lead levels and to compare this with the distribution in residents in a control area. Possible routes of exposure including the determination of lead in domestic water, in house dust, in airborne dust, on food preparation surfaces, on hands, in garden soils and through home grown vegetable consumption were investigated. The results indicate that there is a general increase in lead exposure in environmental variables in the contaminated area, while blood lead levels show an excess of between 45 and 70 percent compared with the control. The determinants of blood lead are discussed through correlation and multiple regression analysis.  相似文献   
133.
In 1988, the Iowa Department of Natural Resources, along withthe University of Iowa conducted the Statewide Rural WellWater Survey, commonly known as SWRL. A total of 686private rural drinking water wells was selected by use of aprobability sample and tested for pesticides and nitrates. Sixty-eight of these wells, the 10% repeat wells, were additionallysampled in October, 1990 and June, 1991. Starting inNovember, 1991, the University of Iowa, with sponsorshipfrom the United States Environmental Protection Agency,revisited these wells to begin a study of the temporalvariability of atrazine and nitrates in wells. Other wells, whichhad originally tested positive for atrazine in SWRL but werenot in the 10% repeat population, were added to the studypopulation. Temporal sampling for a year-long period beganin February of 1992 and concluded in January of 1993. Allwells were sampled monthly, one subset was sampled weekly,and a second subset was sampled for 14-day consecutiveperiods. Two unique aspects of this study were the use of animmunoassay technique to screen for triazines before gaschromatography/mass spectrometry (GC/MS) analysis andquantification of atrazine, and the use of well owners to samplethe wells. A total of 1771 samples from 83 wells are in thefinal data base for this study. This paper reviews the studydesign, the analytical methodologies, and development of thedata base. A companion paper (Pinsky et al., 1997) discussesthe analysis of the data from this survey.  相似文献   
134.
This paper examines the spread and development of ‘environmental impact assessment’ (EIA) since the enactment of the U.S. Environmental Policy Act on January 1, 1970, which established for the first time under any jurisdiction the formal requirement that an EIA be made and that an ‘environmental impact statement’ (EIS) be filed prior to implementation of certain major development projects. The paper is divided into three parts. In the first part, we briefly review the forms of EIA introduced in the western industrial countries and contrast these with developments in the socialist countries of Eastern Europe, and in the Third World. The approaches to EIA adopted by five countries — the United States, Australia, Canada, the Federal Republic of Germany, and the Soviet Union — are used to illustrate the types of national approaches that have been followed. In the second part of the paper, we use some questions raised by impact assessments as codified in legislation or regulations at the national level to highlight some of the limitations of impact assessment. Finally, we turn to international impact assessments and describe the modest progress made to date. Key impediments to the development of appropriate conceptual and institutional frameworks and methodologies for international EIAs are noted. In conclusion, we offer some suggestions about needed actions at both the national and international levels.  相似文献   
135.
We examine issues to consider when reframing conservation science and practice in the context of global change. New framings of the links between ecosystems and society are emerging that are changing peoples’ values and expectations of nature, resulting in plural perspectives on conservation. Reframing conservation for global change can thus be regarded as a stage in the evolving relationship between people and nature rather than some recent trend. New models of how conservation links with transformative adaptation include how decision contexts for conservation can be reframed and integrated with an adaptation pathways approach to create new options for global‐change‐ready conservation. New relationships for conservation science and governance include coproduction of knowledge that supports social learning. New processes for implementing adaptation for conservation outcomes include deliberate practices used to develop new strategies, shift world views, work with conflict, address power and intergenerational equity in decisions, and build consciousness and creativity that empower agents to act. We argue that reframing conservation for global change requires scientists and practitioners to implement approaches unconstrained by discipline and sectoral boundaries, geopolitical polarities, or technical problematization. We consider a stronger focus on inclusive creation of knowledge and the interaction of this knowledge with societal values and rules is likely to result in conservation science and practice that meets the challenges of a postnormal world.  相似文献   
136.
137.

Survey techniques such as contingent valuation and opinion polls are used to develop an understanding of consumer preferences for the environment in the context of environmental decision-making. However, the exposure of weaknesses in such methods has led researchers to look to other information-gathering approaches which might enhance, complement or replace survey-based approaches. One such approach is that of the citizens' jury. A citizens' jury consists of a small group of people, selected to represent the general public rather than any interest-group or sector, which meets to deliberate upon a policy question. The paper critically evaluates the role that the citizens' jury might play in aiding environmental decision-making. Two case studies are reported where the citizens' jury process is used: first, to make recommendations on rural environmental projects in the Borders Region of Scotland; and, secondly, on meeting air quality targets in Edinburgh, Scotland. The paper concludes with recommendations on how the citizens' jury might complement other methods of environmental decision support and indicates the role that citizens' juries may play in future environmental and rural decision-making.  相似文献   
138.
ABSTRACT: Riparian zones perform a variety of biophysical functions that can be managed to reduce the effects of land use on instream habitat and water quality. However, the functions and human uses of riparian zones vary with biophysical factors such as landform, vegetation, and position along the stream continuum. These variations mean that “one size fits all” approaches to riparian management can be ineffective for reducing land use impacts. Thus riparian management planning at the watershed scale requires a framework that can consider spatial differences in riparian functions and human uses We describe a pilot riparian zone classification developed to provide such a framework for riparian management in two diverse river systems in the Waikato region of New Zealand. Ten classes of riparian zones were identified that differed sufficiently in their biophysical features to require different management. Generic “first steps” and “best practical” riparian management recommendations and associated costs were developed for each riparian class. The classification aims to not only improve our understanding of the effectiveness of riparian zone management as a watershed management tool among water managers and land owners, but to also provide a basis for deciding on management actions.  相似文献   
139.
An odor of unknown origin described as a “tar” or “asphalt” smell has become unbearable for many of Globeville, CO, residents over the past few years. Residents report during odor events burning eyes and throat, headaches, skin irritation, and problems sleeping. This study was undertaken to identify the potential sources of the odor and the concentrations of air pollutants making up the odor by conducting meteorological correlations and sampling for a panel of volatile organic compounds (VOCs), sulfur gases, and polycyclic aromatic hydrocarbons (PAHs) in the neighborhood and near suspected sources. Wind speed and direction data collected every 1 min in the neighborhood indicate that when the odor is noticed, the community is directly downwind of a wood preservation facility and an asphalt roofing facility. Air samples collected during high-intensity odor events have shown concentrations of methylene chloride, hexane, toluene, naphthalene, dibenz[a,h]anthracene, benzo[g,h,i]perylene, and indeno[1,2,3-cd]pyrene, each at least two times higher than background concentrations. Naphthalene and the other PAHs are known pollutants emitted from wood treatment processes, and are known to have a coal tar odor. Naphthalene was present in a sample collected directly adjacent to the Koppers facility and was not present in any background samples. Single-compound odor and health thresholds, however, were never surpassed. Given the technical and regulatory challenges of sampling odors and controlling emissions, it is recommended that Globeville residents and neighboring industry pursue a “good neighbor policy” to solve the odor issue. Specific offending industrial processes could be identified for which there exist cost-effective control technologies that would reduce exposure to odors and air toxics in Globeville.

Implications: Meteorological correlations and samples of volatile organic compounds (VOCs), sulfur gases, and polycyclic aromatic hydrocarbons (PAHs) in the Globeville, CO, neighborhood and near suspected sources during odor events indicate potential industrial sources of a transient and noxious odor. Legislative approaches have proven unfruitful and no health or odor thresholds were typically violated. New approaches are warranted to address odor mixture effects in neighborhoods near industrial facilities.  相似文献   
140.
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