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   7728篇
  免费   535篇
  国内免费   2854篇
安全科学   714篇
废物处理   459篇
环保管理   606篇
综合类   4544篇
基础理论   1281篇
环境理论   2篇
污染及防治   2460篇
评价与监测   381篇
社会与环境   329篇
灾害及防治   341篇
  2024年   28篇
  2023年   153篇
  2022年   450篇
  2021年   430篇
  2020年   390篇
  2019年   317篇
  2018年   359篇
  2017年   442篇
  2016年   405篇
  2015年   460篇
  2014年   630篇
  2013年   826篇
  2012年   708篇
  2011年   692篇
  2010年   529篇
  2009年   491篇
  2008年   518篇
  2007年   491篇
  2006年   387篇
  2005年   267篇
  2004年   207篇
  2003年   238篇
  2002年   197篇
  2001年   173篇
  2000年   181篇
  1999年   198篇
  1998年   174篇
  1997年   165篇
  1996年   147篇
  1995年   100篇
  1994年   105篇
  1993年   73篇
  1992年   49篇
  1991年   37篇
  1990年   22篇
  1989年   18篇
  1988年   10篇
  1987年   7篇
  1986年   7篇
  1985年   3篇
  1984年   7篇
  1983年   6篇
  1982年   7篇
  1981年   7篇
  1980年   1篇
  1978年   2篇
  1977年   1篇
  1975年   1篇
  1957年   1篇
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
221.
The present paper focuses on the role of emotion in intragroup conflict processes. We propose that how group members handle emotion affects intragroup interactions and has implications for task and relationship conflict. Three types of variables—collective emotional intelligence, intragroup relational ties, and conflict‐relevant interactional norms—constrain negative emotionality and may determine whether task conflict results in damaging relationship conflict. The moderating influence of these variables is discussed, as are compositional issues associated with measuring them. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   
222.
More than 50,000 tons of hazardous waste are imported and exported worldwide each year. Over 50% of hazardous waste is exported to Southeast Asia, of which leather waste is the major component. The exportation quantities of hazardous waste to Organization of Economic Cooperation and Development (OECD) countries are decreasing while they are on the increase to non-OECD countries. Some of these wastes are intended for recycling purposes but the usage of some others is not stipulated. The hazardous waste importation quantity kept fairly steady from 1997 to 2000, of which ash or residues containing copper or copper compounds were the major component. Under existing regulations and measures, the transboundary movement of hazardous waste cannot be effectively controlled and monitored. In order to ensure environmentally sound hazardous waste management, EPA-Taiwan revised the Waste Disposal Act in 2001 and cooperated with the Industrial Development Bureau (IDB) to promote industrial waste reduction and recycling projects. Strategies were proposed based on evaluation according to the 3Es Principles and the site investigation in this study.  相似文献   
223.
事故应急救援预案是防止事故发生,减少事故损失,控制事故不良后果蔓延的直接而有效的方式,也是贯彻“预防为主”方针的具体体现,企业建立健全应急救援体系必将为国家预防控制事故的发生,减少事故发生所造成的损失。产生较大而深远的影响。  相似文献   
224.
为解决皮带运输的防尘问题,通过现场调查、尘源分析、工程实验,对皮带运输设备的防尘措施进行研究,研制成密闭、无动力减压、自动加湿防尘装置,经现场试用,使作业场所空气中粉尘浓度降到国家标准以下,取得良好防尘效果.  相似文献   
225.
化学消毒法与医疗废物处理   总被引:1,自引:0,他引:1  
本文介绍了医疗废物化学消毒处理技术和标准要求,并对采用该方法处理医疗废物在我国的应用提出了相关建议。  相似文献   
226.
Emission inventory is one of the required inputs to air quality models. To assist in the urban and regional modeling efforts, United States Environmental Protection Agency (EPA) has compiled a National Emission Inventory (NEI) for criterion pollutants, and the precursors of ozone and particulate matter (PM). In December 2002, EPA released the 1999 NEI estimates (NEI99), which represent the most recent national emission data. However, the data sets are not in model-ready format for air quality simulations. This present work converts the NEI99 Final Version 2 data sets into Inventory Data Analyzer (IDA) format and processes the data using the Sparse Matrix Operator Kernel Emissions (SMOKE) modeling system to generate a gridded emission inventory in a domain covering the west Gulf Coast Region, USA. The spatial and diurnal emission characteristics of the gridded emission inventories are then assessed and compared with those of the National Emission Trend 1996 (NET96). The NEI99 database contains more complete emission records in both area and point sources. It is also found that NEI99 data exhibit greater emissions with respect to point and mobile sources but smaller emissions with respect to area sources when compared to the corresponding gridded NET96 data in the same study domain. The most distinct differences between the NEI99 and NET96 databases are CO emission of mobile sources, SO2 emissions of point sources, and VOC/PM/NH3/NOx emissions of area and non-road sources. The gridded NEI99 data show low VOC/NOx ratios (<2-5) in the urban areas of the study domain.  相似文献   
227.
彭俊豪  施式亮  刘勇  王阳  曹建 《安全》2019,40(8):28-31
为了准确探究城乡接合部居民楼火灾事故致因机理,预防与控制城乡接合部日常生产与生活过程中引发火灾事故的有效途径,建立信息面更全、实际性更强的火灾风险评估模型是目前行之有效的手段。基于湖南省某地发生火灾事故的实际情况,根据事故树分析法,以城乡接合部居民楼火灾事故为顶事件构建事故树,计算得到事故树的最小割集、最小径集和结构重要度,研究城乡接合部居民楼火灾事故的发生模式、致因因素及影响程度,为改善城乡接合部居民楼火灾安全提供重要的理论依据,并提出相应的防控措施及对策。  相似文献   
228.
Management activities such as law enforcement and community outreach are thought to affect conservation outcomes in protected areas, but their importance relative to intrinsic environmental characteristics of the parks and extrinsic human pressures surrounding the parks have not been explored. Furthermore, it is not clear which is more related to conservation outcomes—the management itself or local people's perceptions of the management. We measured objective (reports by park staff) and subjective (reports by local people) levels of community outreach and law enforcement based on responses to 374 questionnaires. We estimated mammal abundance and diversity of 6 protected areas based on data from 115 camera traps in Xishuangbanna, southwest China, a biodiversity hotspot with high hunting and land-conversion pressures. We then examined correlations among them and found that local people's perception of law enforcement was positively related to the local abundance of 2 large, hunted species, wild boar (Sus scrofa) (β = 15.22) and muntjac (Muntiacus vaginalis) (β = 14.82), but not related to the abundance of smaller mammals or to objective levels of enforcement. The subjective frequency of outreach by park staff to local communities (β = 3.42) and park size (β = 3.28) were significantly and positively related to mammal species richness, whereas elevation, human population density, and subjective frequency of law enforcement were not. We could not conclude that community outreach and law enforcement were directly causing increased mammal abundance and diversity. Nevertheless, the patterns we detected are some of the first empirical evidence consistent with the idea that biodiversity in protected areas may be more positively and strongly related to local perceptions of the intensity of park management than to either intrinsic (e.g., elevation, park size) or extrinsic (e.g., human population density) environmental factors.  相似文献   
229.

The optimal allocation of sediment resources needs to balance three objectives including ecological, economic, and social benefits so as to realize sustainable development of sediment resources. This study aims to apply fuzzy programming and bargaining approaches to solve the problem of optimal allocation of sediment resources. Firstly, Pareto-optimal solutions of multi-objective optimization were introduced, and the multi-objective optimal allocation model of sediment resources and fuzzy programming model was constructed. Then, from the perspective of multiplayer cooperation, the optimal allocation model of sediment resources was transformed into a game model by using Nash bargaining, and Nash bargaining solution was obtained as the optimal equilibrium strategy. Finally, the influence of different disagreement utility points and bargaining weights on the results was discussed, and the results of Nash bargaining and fuzzy programming methods were compared and analyzed. Results corroborate that Nash bargaining can achieve the cooperative optimization of multiple objectives with competitive relationship and obtain satisfactory scheme. Disagreement utility points and bargaining weights have a certain impact on the optimization results. The solution of fuzzy programming is close to that of Nash bargaining, which provides different ideas for multi-objective optimization problem.

  相似文献   
230.
Environmental Science and Pollution Research - In this study, the immature mice were taken to assess the potential neurological toxicity of lead (Pb) and di (n-butyl) phthalates (DBP) combination...  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