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   78篇
  免费   2篇
安全科学   1篇
环保管理   10篇
综合类   4篇
基础理论   36篇
污染及防治   26篇
评价与监测   2篇
灾害及防治   1篇
  2015年   2篇
  2014年   2篇
  2013年   27篇
  2012年   1篇
  2011年   1篇
  2007年   1篇
  2006年   5篇
  2005年   5篇
  2004年   3篇
  2003年   3篇
  2002年   1篇
  2001年   3篇
  2000年   2篇
  1999年   2篇
  1998年   1篇
  1997年   2篇
  1995年   3篇
  1992年   1篇
  1991年   2篇
  1990年   4篇
  1988年   2篇
  1986年   2篇
  1983年   1篇
  1982年   2篇
  1981年   1篇
  1970年   1篇
排序方式: 共有80条查询结果,搜索用时 15 毫秒
21.
The particle and gas properties that profoundly affect design and performance of fly ash precipitators are discussed and evaluated in this section. Relation of the coal burned to these properties and to the precipitator gas cleaning problem is broadly examined. The need for a high order of technology consistently applied to cope successfully with the wide and often uncertain variations in coal and ash properties encountered in precipitation practices is emphasized.  相似文献   
22.
This article compares, contrasts and analyzes energy use data in five worldwide manufacturing subsectors. It documents the differences in energy input/production output ratios among industries and among countries, and outlines areas of opportunity for implementing energy conservation measures. Special attention is given to the energy use record in developing countries and to assessing their particular problems and limitations in reducing industrial energy demand.
Cet article établit des comparaisons, fait ressortir des contrastes et présente une analyse des données sur l'utilisation de l'énergie dans cinq sous-secteurs industriels mondiaux. Il explique les différences qui existent dans le taux de rendement relatif aux entrées-sorties dans les industries et les pays. Il désigne des secteurs où peuvent s'appliquer des mesures de conservation d'énergie. Une attention toute particulière est accordée aux tendances d'utilisation de l'énergie dans les pays en développement et à revaluation des problèmes et limitations qu'ils confrontent à réduire la demande d'énergie industrille.
Este artículo analiza comparativamente la información sobre uso de energía en cinco ramas industriales. Documenta los ratios insumo/producto en varios países e indica las oportunidades para establecer medidas para la conservacón de energa. Se da especial atención a los patrones de uso de energía en los países en desarrollo y evalúa los problemas particulares y limitaciones para la reducción del uso de energía en la indústria.  相似文献   
23.
A divergence of values has become apparent in recent debates between conservationists who focus on ecosystem services that can improve human well‐being and those who focus on avoiding the extinction of species. These divergent points of view fall along a continuum from anthropocentric to biocentric values, but most conservationists are relatively closer to each other than to the ends of the spectrum. We have some concerns with both positions but emphasize that conservation for both people and all other species will be most effective if conservationists focus on articulating the values they all share, being respectful of divergent values, and collaborating on common interests. The conservation arena is large enough to accommodate many people and organizations whose diverse values lead them to different niches that can, with good will and foresight, be far more complementary than competitive. Los Nichos Complementarios de los Conservacionistas Antropocéntricos y Biocéntricos  相似文献   
24.
This paper examines the ‘range of choice’ concept in water management. Although many efforts have been made to design policies that broaden the consideration of water resources alternatives, the experiences gained from these policy experiments have not been adequately assessed. What insights might American policy approaches offer for developing countries? To address this question, four general policy types were identified and compared: (1) comprehensive single-objective policies; (2) comprehensive multiple-objective policies; (3) specific non-structural policies; and (4) specific technological policies. Case studies of each approach revealed that effective institutional development occurs when policies are: (1) stated in clear and specific language; (2) modified as experience is gained; (3) adequate in terms of statutory and administrative authority; and (4) subject to an orderly process of public and judicial review. The most successful policy efforts to date have involved specific alternatives, while multiple-objective policies have encountered the most difficulties. Common institutional problems are identified, and their potential relevance for developing countries is discussed.  相似文献   
25.
26.
27.
A survey of academic programs in air pollution control was made. Results from the 127 schools reporting are tabulated by state. Faculty involved in air pollution instruction are identified. Some conclusions and recommendations are presented.  相似文献   
28.
The principle of fabric filtration has only recently been accepted for fossil fuel fired boiler particulate emissions control. Information on design criteria is, therefore, limited. The paper provides data on the few installations where baghouses have been installed and successfully operated. The general conclusion is that a strong relationship exists between air to cloth ratio and bag life.  相似文献   
29.
This study was undertaken to identify seasonal and source effects on the par-ticulate contaminants of the New York City atmosphere and ultimately to relate the concentrations of these contaminants to the tissue concentrations in residents of New York City. Continual weekly samples of particulates have been collected at three stations in the New York area on 8 by 10 in. glass fiber filters at a flow rate of 20 cfm.

The sample is ashed with a Tracerlab Low Temperature Asher and leached with nitric acid. Metals analyzed by the Atomic Absorption method include Pb, V, Cd, Cr, Cu, Mn, Ni, and Zn. Lead-210, total particulate, and benzene and acetone soluble organic material are also determined.

The data have been related to various meteorological parameters over a one year period to define significant seasonal and source influences, as well as site to site variations. Very significant inverse correlations to temperature are obtained for suspended particulates, vanadium, and nickel at both Manhattan and Bronx sites. Particulates show a less significant inverse correlation to temperature In lower Manhattan. Oil-fired space heating sources appear to account for as much as 50% of the particulates in the Bronx at the peak demand period.

Lead, copper, and cadmium show a general inverse correlation to average wind speed, and a direct correlation to temperature. The latter is most likely due to an inverse relation between wind speed and temperature. The heating season input for particulates, vanadium, and nickel is so great as to overcome most of the dilution effect due to winds. The other elements having more constant nonseasonal inputs, definitely reflect the effects of the wind.

The most significant site effect occurs with cadmium, which has a concentration in lower Manhattan three times that of the Bronx over a period of six to seven months in the summer and fall. The differences observed for cadmium and particulates may be explained by emission source factors which have not as yet been studied.  相似文献   
30.
Typical air quality effect levels of photochemical oxidants on specific plant substrates are illustrated. These include ambient oxidant exposure data measured as “total oxidant” as well as laboratory exposures to individual pure oxidants, ozone, or PAN compounds, since these oxidants are identified in photochemical smog. New terms, “PaNs” and “PAN-type” oxidant, have been proffered for purposes of clarification of the terminology. PAN-type oxidant more precisely defines the phytotoxicant complex causing silvering or bronzing of the lower leaf surfaces in lieu of the older term “oxidant.” Due to the recognition of several oxidizing phytotoxicants in recent years, it is recommended that the term oxidant be reserved for use as a generic term. A tabular classification of the oxidizing phytotoxicants found in community photochemical smog and the specific syndromes produced is provided.  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