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   749篇
  免费   33篇
  国内免费   26篇
安全科学   204篇
废物处理   10篇
环保管理   102篇
综合类   290篇
基础理论   49篇
污染及防治   24篇
评价与监测   54篇
社会与环境   20篇
灾害及防治   55篇
  2023年   4篇
  2022年   6篇
  2021年   18篇
  2020年   11篇
  2019年   9篇
  2018年   9篇
  2017年   21篇
  2016年   22篇
  2015年   19篇
  2014年   36篇
  2013年   29篇
  2012年   36篇
  2011年   51篇
  2010年   35篇
  2009年   41篇
  2008年   33篇
  2007年   33篇
  2006年   39篇
  2005年   43篇
  2004年   49篇
  2003年   39篇
  2002年   31篇
  2001年   18篇
  2000年   22篇
  1999年   21篇
  1998年   19篇
  1997年   12篇
  1996年   18篇
  1995年   26篇
  1994年   12篇
  1993年   14篇
  1992年   11篇
  1991年   8篇
  1990年   6篇
  1987年   2篇
  1985年   1篇
  1984年   1篇
  1978年   1篇
  1977年   1篇
  1970年   1篇
排序方式: 共有808条查询结果,搜索用时 531 毫秒
61.
A set of simulation and optimization tools capable of analyzing the development and operation of a complex, multi-basin, interconnected water resource are explained. These models provide valuable information regarding the important questions: (1) “When should new projects be build?” (2) “How big should they be?” and (3) “How should the system be operated?” Since these tools were developed by and for practicing engineers, their applicability to real-world problems is mandatory. To assure this, testing was done on an actual proposed project, the Texas Water System.  相似文献   
62.
红壤丘陵区土地利用变化对土壤质量影响   总被引:3,自引:0,他引:3  
以鄂南红壤丘陵典型区的三个村为代表 ,应用地理信息系统对 1981和 1998年两个时期的土地利用变化和土壤质量进行对比研究 ,分析了土地利用变化对土壤质量的影响。结果表明 :研究区土地利用结构总体上具有农业型特点 ,17a间水田减少了 2 1% ;其余的利用方式则有不同幅度的增加 ,居民地、水域、林地、园地和旱地增加了 4 2 .2 %、99.6 %、8%、5 6 .8%和 8%。土壤质量有从优劣两端向中等靠拢的趋势 ,17a后 、 、 和 等地面积分别减少 18.6 %、12 .2 %、2 9.6 %和 2 5 % ; 等地增幅达 5 1.9%。土地利用方式及管理措施是影响土壤质量演变方向和强度的关键因子 ,园地和林地的土壤质量大多得到明显改善 ,水田的Δ SQI多数呈下降的趋势 ,旱地的土壤质量变化比较复杂 ,与土地利用结构相关。依此 ,本文探讨了定向培育土壤质量的途径  相似文献   
63.
重大事故应急救援法律法规体系建设   总被引:16,自引:6,他引:10  
重大事故应急救援法律法规体系作为生产安全应急救援体系建设的重要内容之一 ,在重特大事故多发的今天 ,已显得尤为重要。笔者结合国内外重大事故应急救援立法的现状 ,论述加强我国应急救援法律法规体系建设的必要性 ;提出重大应急救援法律法规体系建设要从法律、行政法规及部门规章、地方性法规及规章3个方面进行 ;同时提出建立联席会议制度、应急预案编制审核和备案制度、报告与信息发布制度、应急救援的分级响应制度、应急救援演习制度、应急救援资金补偿制度、应急救援的奖惩制度等急救援工作制度体系。最后 ,还强调建立重大事故应急救援体系对于提高政府对国家危机的管理能力有着深远的影响和意义。  相似文献   
64.
通才式安全工程专业课程设置的探讨   总被引:8,自引:2,他引:6  
根据安全工程专业所处的学科结构体系 ,讨论了通才式安全工程专业高等教育课程设置所考虑的因素。提出了通才式安全工程专业高等教育课程的设置思想、专业基础课和主干课的学时比以及实践与理论相结合的实习方法。  相似文献   
65.
An algorithm for assessing the risk of traffic accident   总被引:3,自引:0,他引:3  
INTRODUCTION: This study is aimed at developing an algorithm to estimate the number of traffic accidents and assess the risk of traffic accidents in a study area. METHOD: The algorithm involves a combination of mapping technique (Geographical Information System (GIS) techniques) and statistical methods (cluster analysis and regression analysis). Geographical Information System is used to locate accidents on a digital map and realize their distribution. Cluster analysis is used to group the homogeneous data together. Regression analysis is performed to realize the relation between the number of accident events and the potential causal factors. Negative binomial regression model is found to be an appropriate mathematical form to mimic this relation. Accident risk of the area, derived from historical accident records and causal factors, is also determined in the algorithm. The risk is computed using the Empirical Bayes (EB) approach. A case study of Hong Kong is presented to illustrate the effectiveness of the proposed algorithm. RESULTS: The results show that the algorithm improves accident risk estimation when comparing to the estimated risk based on only the historical accident records. The algorithm is found to be more efficient, especially in the case of fatality and pedestrian-related accident analysis. IMPACT ON INDUSTRY: The output of the proposed algorithm can help authorities effectively identify areas with high accident risk. In addition, it can serve as a reference for town planners considering road safety.  相似文献   
66.
事故致因理论的比较分析   总被引:5,自引:0,他引:5  
本文对事故致因理论进行了总结并对其优缺点进行了介绍,对一些主要的事故致因理论进行了比较,分析了其异同,提出了各自的特点和适用条件,并对其理论发展前景进行了展望。运用事故致因理论对具体事故案例进行了分析,找出了事故原因,提出了预防措施。  相似文献   
67.
本文以我国1997—2010年的消费结构数据为基础,运用灰色-马尔科夫链模型对数据进行了分析和预测,然后通过MATLAB预测了我国未来十年的能源消费结构,结合我国政府承诺的非化石能源目标对模型预测结果做了进一步的修正,最后根据能源发展趋势给出了能源消费结构的优化策略。  相似文献   
68.
The Environmental Management System (EMS) is commonly implemented in private firms. However, on the basis of a strengths, weaknesses, opportunities and threats (SWOT) analysis, our work analyzes the consequences of implementing an EMS within the context of local public administrations, particularly regarding the City Council of Ohanes in Almería (Spain). This is the first European corporation to implement an EMS according to the ISO 14001 Standard, certified by the Spanish Association of Normalization and Certification. Its analysis would be equivalent to the Shumpeterian "market innovator study", so that public administration "followers" can take advantage of the derived benefits and of minimizing the negative effects of such an experience. On the other hand, we show that the economic and environmental advantages derived from the EMS go beyond the activities that the City Council is in charge of. They have spillover effects that extend them to all economic activities in the municipality and these effects are expected to be increased in the medium and long-term perspective. In this paper, we compare the costs and benefits that the municipality obtains in two cases: the City Council implements the EMS or it does not implement it. The main objective of this article is to show the economic and environmental advantages obtained by a municipality when it is only the City Council who is implementing an EMS. It is logical to suppose that this case study can stimulate other municipalities to use this instrument, even if the economic and environmental characteristics of the municipality are different.  相似文献   
69.
EU's long-term objective is to become a recycling and resource effective society, where waste is utilized as a resource and waste generation is prevented. A system dynamics model was developed to analyze the policy mechanisms that promote packaging material efficiency in products through increased recycling rates. The model includes economic incentives such as packaging and landfill taxes combined with market mechanisms, behavioral aspects and ecological considerations in terms of material efficiency (the packaging material per product unit, recycled fraction in products). The paper presents the results of application of various policy instruments for increasing packaging material efficiency and recovery rate and reducing landfilled fraction. The results show that a packaging tax is an effective policy instrument for increasing the material efficiency. It ensures the decrease of the total consumption of materials and subsequent waste generation. The tax helps to counteract a rebound effect, which, as identified by the analysis, can be caused by reduced material costs due to eco-design. The model is applied to the case of Latvia. Yet, the elements and structure of the model developed are similar to waste management systems in many countries. By changing numeric values of certain parameters, the model can be applied to analyze policy mechanisms in other countries.  相似文献   
70.
将河南平顶山煤气公司原煤气输配系统改造成为自动恒压控制系统,从而提高安全系数,降低煤气输配电耗。  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