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   35356篇
  免费   392篇
  国内免费   454篇
安全科学   954篇
废物处理   1357篇
环保管理   4723篇
综合类   5689篇
基础理论   9952篇
环境理论   21篇
污染及防治   9035篇
评价与监测   2193篇
社会与环境   2050篇
灾害及防治   228篇
  2022年   294篇
  2021年   268篇
  2020年   214篇
  2019年   291篇
  2018年   502篇
  2017年   500篇
  2016年   728篇
  2015年   605篇
  2014年   852篇
  2013年   2672篇
  2012年   1066篇
  2011年   1534篇
  2010年   1247篇
  2009年   1296篇
  2008年   1530篇
  2007年   1617篇
  2006年   1407篇
  2005年   1221篇
  2004年   1193篇
  2003年   1142篇
  2002年   1129篇
  2001年   1476篇
  2000年   1024篇
  1999年   624篇
  1998年   491篇
  1997年   490篇
  1996年   522篇
  1995年   559篇
  1994年   491篇
  1993年   450篇
  1992年   469篇
  1991年   436篇
  1990年   425篇
  1989年   448篇
  1988年   384篇
  1987年   351篇
  1986年   310篇
  1985年   344篇
  1984年   329篇
  1983年   363篇
  1982年   374篇
  1981年   316篇
  1980年   281篇
  1979年   302篇
  1978年   257篇
  1977年   223篇
  1976年   223篇
  1975年   215篇
  1973年   205篇
  1972年   234篇
排序方式: 共有10000条查询结果,搜索用时 796 毫秒
781.
This paper focuses on community-wide emergencies caused by war-related events in Lebanon at the beginning of June 1982. Mobilization for the "Peace for Galilee" campaign began on Friday, 4th June. Overnight, families were disrupted, husbands and sons were in danger, and within 24 hours there were notifications of casualities and deaths. Families in crisis became a widespread phenomenon. In Herzlia, as in many other communities, a new service - the Emergency Center - emerged under the auspices of the Ministry of Labor and Social Affairs and the Municipality. The authors describe this process of getting organized, the populations served, how the Center was staffed, the role of citizen volunteers, and the types of interventions used to help vulnerable families as well as soldiers home on leave. Stress is placed on the unique type of short-term co-operation achieved between social workers of the local Department of Social Welfare, the staff of the Department of Community Services (especially its Volunteer Bureau), the local liason officer of the Israel Defence Force, the municipal government, and public-spirited volunteers. Mention is made of conditions which made possible the activation of such a service within hours, of the Center's capacity to serve all segments of the population, and of how it was deactivated within a few weeks when the emergency ended. On the basis of lessons learned from this experience, the paper ends with a number of specific recommendations. The authors hope that such innovative forms of crisis-intervention will become part of the helping technology widely available at the community level in future years.  相似文献   
782.
783.
Community response to hazard information   总被引:1,自引:0,他引:1  
McKay JM 《Disasters》1984,8(2):118-123
The impact of flood hazard information on public acceptance of a selected flood mitigation strategy was assessed by an analysis of the content of newspaper reports of community reaction and letters to the editor. The impact of personal delivery of a flood hazard map on individual perception of risk and attitude to such information was assessed using personal interviews. The results indicated that media coverage of the flood hazard information reduced public criticism of the works. This result must be partially attributable to the dramatic style of media coverage and the fact that the media only emphasized the positive value of the works. The interview demonstrated that personal delivery of the information raised perception of risk, improved comprehension of flood risk, had no impact on acceptability of risk but discouraged some respondents from seeking such information in the future. Factors to explain the last negative change were identified to be the format of the map sheet and low salience of flood hazard. On the basis of all results, methods to improve community response to hazard information are provided.  相似文献   
784.
Davey  J. T.  Gee  J. M.  Moore  S. L. 《Marine Biology》1978,45(4):319-327
The population dynamics of Mytilicola intestinalis Steuer in mussels (Mytilus edulis L.) from the River Lynher, Cornwall, England, have been studied over 3 years. By transplanting uninfested mussels from the River Erme, South Devon, into the Lynher mussel bed, the study was extended to the growth and development of new infestations under natural conditions. Female Mytilicola intestinalis are shown to breed twice, and two generations of parasites coexist for most of the year, with recruitment taking place in summer and autumn. One generation contributes its first brood to the autumn recruits before overwintering and contributing its second brood to the following summer's recruits. The other generation overwinters as juvenile and immature stages to contribute its two broods successively to the summer and autumn recruits. Environmental temperatures are believed to control the rates of development at all stages rather than acting as triggers in the onset or cessation of breeding at specific times. There is no evidence to support the contention that heavily infested mussels are killed, and parasite mortality is shown to be density-independent.  相似文献   
785.
The regular day-night changes in tissues, physiologic functions, and behavior of organisms are based on endogenous rhythmic processes which under constant conditions continue with periods slightly deviating from 24h. These ‘arcadian’ rhythms have properties of self-sustained oscillators. Under natural conditions, circadian rhythms are synchronized (entrained) to 24 h by periodic factors in the environment, the so-called ‘Zeitgebers’. In the laboratory, circadian rhythms can also be entrained to periods other than 24 h within certain limits. Data on the phase relationship between the circadian rhythm and an entraining light-dark cycle for vertebrates, insects, plants, and unicellular organisms are reviewed.  相似文献   
786.
787.
788.
789.
790.
The development of traceability in low-level radioactivity measurements is discussed. The role that the development of large quantities of natural matrix standards can play is also discussed.  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