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   1764篇
  免费   34篇
  国内免费   28篇
安全科学   74篇
废物处理   89篇
环保管理   184篇
综合类   356篇
基础理论   315篇
环境理论   1篇
污染及防治   506篇
评价与监测   175篇
社会与环境   103篇
灾害及防治   23篇
  2023年   20篇
  2022年   46篇
  2021年   54篇
  2020年   27篇
  2019年   26篇
  2018年   53篇
  2017年   66篇
  2016年   55篇
  2015年   40篇
  2014年   82篇
  2013年   144篇
  2012年   66篇
  2011年   102篇
  2010年   72篇
  2009年   85篇
  2008年   100篇
  2007年   88篇
  2006年   69篇
  2005年   73篇
  2004年   72篇
  2003年   80篇
  2002年   55篇
  2001年   55篇
  2000年   33篇
  1999年   27篇
  1998年   22篇
  1997年   14篇
  1996年   11篇
  1995年   13篇
  1994年   17篇
  1993年   17篇
  1992年   20篇
  1991年   6篇
  1990年   9篇
  1989年   11篇
  1988年   6篇
  1987年   3篇
  1986年   11篇
  1985年   11篇
  1984年   4篇
  1983年   8篇
  1982年   11篇
  1981年   5篇
  1973年   3篇
  1970年   2篇
  1962年   5篇
  1961年   2篇
  1955年   2篇
  1938年   2篇
  1931年   2篇
排序方式: 共有1826条查询结果,搜索用时 62 毫秒
31.
一株硝基苯高效降解菌的筛选及其降解特性   总被引:14,自引:0,他引:14  
自南京化工厂下水道底泥和废水处理系统曝气池活性污泥中驯化分离得到一株能快速降解硝基苯的菌株,初步鉴定其为不动杆菌属菌株。该菌株降解硝基苯的最适宜环境条件为温度25℃~35℃,pH7~8,振荡速率大于120r/m。在适宜环境条件下,该菌株能够在24h内全部降解初始浓度不超过400mg/L的硝基苯,该浓度范围内硝基苯的降解过程符合零级动力学特征;当硝基苯的初始浓度超过400mg/L时,降解菌的生长受到毒害作用,该浓度范围内硝基苯的降解在开始有一个明显的停滞期,降解过程不再符合零级或一级动力学特征。  相似文献   
32.
Pork producers in Western Europe moreand more encounter a variety of societalconcerns about pork and pork production. Sofar, however, producers predominantly focusedon low consumer prices, therewith addressingjust one concern. This resulted in an intensiveand large-scale production system, decreasinglyrelated to the area of farm land, andaccompanied with increasing concerns aboutsafety and healthiness of pork, animal welfare,environmental pollution, and others.An overview was given of possible concernsabout West-European pork production with theconsumers, citizens, and producers, and thoseconcerns are traced back to the pork productionsystem. The various kinds and qualities ofinformation about the pork production system onwhich possible concerns are based have beenworked out extensively in this paper. Knowledgeabout the aspects of pork production that cangive rise to concerns can be used in two ways.First, the communication about those aspectstowards consumers and citizens can be adjustedor extended to give them better possibilitiesto make food choices or to develop their ownopinions about pork production. Second,producers could change the pork productionsystem such that it better satisfies consumersand citizens. Such adaptations are wellpossible, as three pork quality schemes, whichhave been evaluated, illustrate. However, mostof these adaptations can only be carried out atthe cost of the present low consumer prices andwill not occur spontaneously on a large scale.Therefore, accounting for the type andrelevance of the concerns, legislation isnecessary to address societal concerns in abalanced way such that pork production systemsbecome acceptable for the majority of oursociety.  相似文献   
33.
工业生态系统及其建设   总被引:10,自引:0,他引:10  
本文分析了工业生态系统的基本特征及核心内容、阐述了工业生态系统建设的基础,原则及其对策。  相似文献   
34.
塔克拉玛干沙漠腹地沙尘暴特征--以塔中地区为例   总被引:13,自引:2,他引:13  
塔克拉玛干沙漠是中国油气开发的重要区域,沙尘暴是该区域重要的灾害性天气,但以往相关的研究很少。为了了解塔克拉玛干沙漠腹地沙尘暴的发生规律,利用塔中气象站1997-2002年的气象资料,对塔中地区沙尘暴的强度、过程、类型和时间变化等特征进行了分析。研究结果表明:(1)塔中年平均沙尘暴日数为16.83d,较沙漠北缘的轮台和沙漠南缘的民丰、和田为多,体现出沙尘源对沙尘暴发生的影响;(2)沙尘暴发生之前出现明显的风速突然降低和风向转换;(3)同塔里木盆地其它区域一样,塔中沙尘暴也可分为5种类型,其主导类型为冷空气东灌型;(4)沙尘暴时间变化规律明显,且从20世纪90年代至21世纪初,塔中沙尘暴日数与持时明显下降,同全疆的变化趋势一致。  相似文献   
35.
Women and biodiversity: The long journey from users to policy-makers   总被引:1,自引:0,他引:1  
Although there has been a broad acknowledgment that women's local and traditional knowledge is fundamental to guarantee food security and conserve biological diversity, few women are represented at the managerial and decision‐making level of environmental movements and organizations. The United Nations, its agencies and agreements have long promoted the full and effective participation of women in decision‐making processes. So how can commitments contained in international agreements be translated into concrete actions? By using the case of the Convention on Biological Diversity, one of the key agreements adopted at the 1992 Earth Summit in Rio de Janeiro, this article analyses how gender‐equitable initiatives tend to assume an ad hoc character with few governments effectively involving women in their sustainable development strategies. The views expressed in this article are those of the authors and do not necessarily reflect the official position of the United Nations or its subsidiary bodies.  相似文献   
36.
The redevelopment of brownfields has become a central component of government efforts to revitalize many US cities. While the focus of these efforts has concentrated on promoting industrial and commercial redevelopment, some cities have started to also consider converting brownfields into parks and open space as part of a more comprehensive renewal strategy. Based on a survey of 20 case studies, this paper identifies and discusses: (1) the primary issues involved in brownfield greening projects; (2) the benefits of such projects; and (3) the specific planning processes involved. The overall conclusion drawn from the survey is that numerous renewal‐oriented benefits can ensue from greening projects, if there is extensive stakeholder commitment devoted to deal with its financial and development‐oriented challenges.  相似文献   
37.
38.
Abstract

The presence of diethyl-phthalate (DEP), dibutyl-phthalate (DBP), butylbenzyl-phthalate (BBP), diethylhexyl-phthalate (DEHP) and diisononyl-phthalate (DINP) was determined in 295 tequila samples. They were grouped by age of maturation (white, aged, extra aged or ultra aged) and year of production (between 2013 and 2018). Gas Chromatography coupled with Mass Spectrometry was used for identification and quantification. The results showed that 65 samples (22% of the total) were phthalate free. DEP (0.13-0.27?mg/kg), BBP (0.05–2.91?mg/kg) and DINP (1.64–3.43?mg/kg) were detected in 11 (3.73%), 37 (12.54%) and 5 (1.69%) samples, respectively. But, these concentrations did not exceed the maximum permitted limits (MPL) of phthalates for alcoholic beverages. DBP (0.01–2.20?mg/kg) and DEHP (0.03–4.64?mg/kg) were detected in 96 (32.54%) and 224 (75.93%) samples, from them only 10 (3.39%) and 15 (5.08%) samples, respectively, exceeded the MPL for alcoholic beverages and they were few tequilas produced in the year 2014 or before. DEHP was the most frequent phthalate found in tequila and observed DEHP concentrations were 2-times higher in ultra aged tequilas compared to those in white tequilas. We concluded that all tequilas produced in 2015 and after, satisfied the international standards for these compounds.  相似文献   
39.
40.
Environmental Geochemistry and Health - Lake Atamanskoye is one of the most polluted aquatic environments in the South of Russia. This water body was affected by long-term pollution by effluent...  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