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   3811篇
  免费   291篇
  国内免费   80篇
安全科学   520篇
废物处理   78篇
环保管理   988篇
综合类   1941篇
基础理论   173篇
环境理论   2篇
污染及防治   86篇
评价与监测   139篇
社会与环境   175篇
灾害及防治   80篇
  2024年   10篇
  2023年   26篇
  2022年   53篇
  2021年   92篇
  2020年   134篇
  2019年   77篇
  2018年   58篇
  2017年   95篇
  2016年   90篇
  2015年   119篇
  2014年   210篇
  2013年   170篇
  2012年   214篇
  2011年   287篇
  2010年   213篇
  2009年   188篇
  2008年   141篇
  2007年   251篇
  2006年   245篇
  2005年   200篇
  2004年   175篇
  2003年   168篇
  2002年   152篇
  2001年   160篇
  2000年   166篇
  1999年   108篇
  1998年   77篇
  1997年   75篇
  1996年   49篇
  1995年   50篇
  1994年   23篇
  1993年   45篇
  1992年   18篇
  1991年   7篇
  1990年   9篇
  1989年   2篇
  1988年   2篇
  1987年   5篇
  1986年   4篇
  1985年   1篇
  1984年   1篇
  1983年   2篇
  1982年   2篇
  1981年   2篇
  1978年   2篇
  1977年   3篇
  1975年   1篇
排序方式: 共有4182条查询结果,搜索用时 15 毫秒
991.
葡萄和葡萄酒行业与环境保护   总被引:1,自引:0,他引:1  
目前,对葡萄园质量的鉴定不再只是根据葡萄酒的质量来进行.葡萄酒的质量形象还需要其他的因素:产地美丽的风景,葡萄园及葡萄酒厂与周围环境的协调,产品的自然特色,对环境的贡献等等.所以,环境保护也对葡萄酒的形象提出了新的挑战:除传统的生态、品种、酿造以及品牌、历史和人文等因素外,环境保护和健康意识越来越成为影响消费者对葡萄酒质量的感知和理解的重要因素.显然,在葡萄与葡萄酒生产过程中的环境保护措施,将会提高产品环保形象,从而提高其在国际市场上的竞争能力.这就需要有关国家将环境保护纳入其葡萄与葡萄酒生产的有关标准或法规中.  相似文献   
992.
冷冻是工业生产中广泛的应用操作单元过程,具有易泄漏,操作压力高,易发生冻堵,设备材质易发生冷脆,冷冻剂和载冷体具有腐蚀性,工艺过程中存在引火源等火险特点。对其生产工艺进行了火灾危险性分析,并提出了针对性的防火防爆措施和技术。  相似文献   
993.
The aim of this paper is to suggest an effective procedure to eliminate a major deficiency in impressed current cathodic protection (CP). Current work describes performed activities through jetty cathodic protection troubleshooting as a case study. Although CP troubleshooting is straightforward, sometimes it is very complicated and confusing. To eliminate the appeared imperfection, different procedures were carried out; the root cause of the trouble in the system was shown to be in reversed current. Here the current which passed throughout installed junction were measured to survey reversed current. Current work offers a new approach in CP troubleshooting.  相似文献   
994.
Behavior of dust/air mixtures is very complex and difficult to predict since it depends on material properties as well as boundary conditions. Without other influences airborne particles deposit due to gravity but the time it takes for total deposition as well as easiness of resurrection depends very much on the specific dust sample and the boundary conditions. It still lacks a complete understanding of all interacting reasons and one approach is using experimentally determined characteristics, one is named dustiness.Dustiness is the tendency of dust to form clouds and to stay airborne. Dustiness is determined with two basic principles, which are light attenuation and ratio of filled-in and measured mass. Assessment of dustiness of industrial powders has been done for a long time regarding work place safety. Dustiness is used there to determine inhalable fraction and to evaluate health risks. Lately it became interesting in dust explosion protection as well. Dustiness could be used to optimize determination of zones, adaption of venting area and/or for positioning of suppression systems.Dustiness can be useful in many ways but is not a physical property of dusts, therefore it depends on material properties such as density, particle size distribution, shape and water content as well as boundary conditions or determination method. This makes it very difficult to compare dustiness for different techniques and apparatuses and determination method as well as results should be considered carefully. This work gives an overview of existing standards, recent research and suggests improvements to the new dustiness as proposed for dust explosion protection.  相似文献   
995.
橇装式LNG汽车加气站作为新型加气站的一种,其一旦发生雷击并引发火灾或爆炸将造成不可估量的损失,因此橇装式LNG汽车加气站的防雷安全十分重要。在结合橇装式LNG汽车加气站所处环境及其系统特点,雷电对其破坏机理和途径,分析了造成雷电灾害因子。通过计算分析,运用ADBSGP现代综合防雷技术从防直击雷、防闪电感应、防雷击电磁脉冲等方面入手,提出了安装外部防雷装置、采用防雷等电位连接技术作为防闪电感应措施,采取屏蔽和安装SPD作为防雷击空间电磁场和闪电电涌侵入措施。  相似文献   
996.
This paper provides a review on the following issues: the differences in injury patterns between adults and children under similar loading conditions during an automotive crash event. Because of the recent awareness and the ensuing necessity, as an example, injuries including fatalities due to airbag deployment are discussed. Biomechanical differences explain the varying injury patterns and mechanisms of injury. The commonly adopted scaling techniques for predicting pediatric tolerances are described. A comparison of the biomechanical properties of the pediatric and adult structures is given. Some insight is provided with regard to the use of these data to develop validated mathematical models of pediatric structures. The paper concludes with recommendations for further research.  相似文献   
997.
Hearing protectors attenuate both the background noise and the useful sounds embedded in noise such as the sounds of speech and warning signals. An effective hearing protector is one that attenuates background noise while leaving sufficient energy of speech and warning signals to reach the ear of the worker. At present, however, there are no established criteria for assessing effective change in speech-to-noise ratio caused by hearing protection devices (HPDs). One such criterion could be a change in most comfortable (listening) level (MCL) for speech caused by the presence of HPDs. In this study the HPD-related shift in MCL for speech presented in quiet was measured and compared with two measures of noise attenuation: Noise Reduction Rating (NRR) and high–medium–low (H–M–L). The results indicate that the MCL shift may be a sensitive measure of speech attenuation by HPDs, which together with the appropriate H–M–L may describe technical properties of HPDs.  相似文献   
998.
A few aspects of skin protection against ultraviolet (UV) light and methods of assessing efficacy of UV-protecting cream or gels have been discussed. UV-protection in cream and gels is not only a strategy of the cosmetic industry but a necessity because of human occupational activity and daily habits.  相似文献   
999.
通风设施防护效果评价指标研究   总被引:1,自引:0,他引:1  
当前我国职业病危害形势严峻,尘毒危害是职业病危害防治的重点,而通风设施是预防和控制尘毒危害的重要工程防护措施。阐述了通风设施在职业病危害预防与控制方面的作用,对我国企业现行的新风量、全面通风量、通风换气次数和职业接触限值等通风设施防护效果评价指标、国外普遍采用的控制风速防护效果评价指标以及目前有些机构使用的捕集效率评价指标进行了分析和讨论,对新风量、通风量和通风换气次数在职业病危害预评价和控制效果中的应用进行了研究,并得出了我国需建立健全通风设施防护效果评价指标和评估方法的结论。  相似文献   
1000.
提出了苯作业场所中的几点防护措施。  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