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   40275篇
  免费   337篇
  国内免费   276篇
安全科学   886篇
废物处理   1895篇
环保管理   5611篇
综合类   6418篇
基础理论   10835篇
环境理论   15篇
污染及防治   9763篇
评价与监测   2682篇
社会与环境   2578篇
灾害及防治   205篇
  2022年   203篇
  2021年   253篇
  2019年   236篇
  2018年   1867篇
  2017年   1769篇
  2016年   1775篇
  2015年   620篇
  2014年   725篇
  2013年   2464篇
  2012年   1367篇
  2011年   2534篇
  2010年   1698篇
  2009年   1711篇
  2008年   2157篇
  2007年   2614篇
  2006年   1177篇
  2005年   1037篇
  2004年   982篇
  2003年   1074篇
  2002年   1054篇
  2001年   1129篇
  2000年   838篇
  1999年   514篇
  1998年   391篇
  1997年   345篇
  1996年   424篇
  1995年   431篇
  1994年   430篇
  1993年   382篇
  1992年   360篇
  1991年   350篇
  1990年   389篇
  1989年   360篇
  1988年   336篇
  1987年   315篇
  1986年   285篇
  1985年   302篇
  1984年   318篇
  1983年   323篇
  1982年   312篇
  1981年   314篇
  1980年   268篇
  1979年   287篇
  1978年   237篇
  1977年   207篇
  1976年   206篇
  1975年   191篇
  1974年   196篇
  1973年   202篇
  1972年   203篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
Ten out of the 12 new EU members, used to belong to the so-called “former eastern block”, with a post WWII environmental policy radically different from the tendencies followed in Western Europe. The lack of conservation regulations has resulted in a rather harmful industrialization, regarding natural resources and environmental quality. While air pollution transfer is a phenomenon of transboundary level, there is a particular interest in examining the contribution of the new EU member states to the environmental pressure faced by the older member states and vice versa. The current study utilises the official data for almost 20 years published by the European Monitoring and Evaluation Program concerning the transboundary transfer of NOx and SO2 in order to analyse the situation and discuss the present and future environmental policy regarding air pollution.  相似文献   
92.
Three hundred and fifty-four women who underwent midtrimester genetic amniocentesis were matched for age, parity, indication, and smoking history, with an equivalent number of women who had declined the procedure, for the purpose of comparing the neonatal respiratory status of their offspring. There was no evidence that the infants exposed to genetic amniocentesis were compromised.  相似文献   
93.
The impact of prenatal sonographic diagnosis of oesophageal and gastrointestinal obstructions has been analysed over a 10-year period. Three groups of patients were evaluated. The first group consisted of 46 newborns with abnormal prenatal sonogratns, 41 of which were confirmed to have intestinal obstruction postnatally. The second group consisted of 17 neonates with normal prenatal sonograms who had intestinal obstruction postnatally. The third group included 56 newborns who did not undergo a prenatal sonogram but who had intestinal obstruction confirmed at surgery. Polyhydramnios without the appearance of a stomach on ultrasound was diagnostic of pure oesophageal atresia. Polyhydramnios with intestinal dilation was diagnostic of intestinal obstruction. Although surgery was performed earlier in the infants diagnosed prenatally with ultrasound, mortality was no less than in the group that did not undergo a prenatal sonogram, probably because of the high incidence of associated anomalies.  相似文献   
94.
Manganese-oxidizing fungi and bacteria   总被引:1,自引:0,他引:1  
The Science of Nature -  相似文献   
95.
The lessons of history indicate that mismanagement of natural resources and the environment often leads to potentially adverse consequences.The increasing interest in economic development,particularly in the developing countries of the world coupled with increasing population pressures and the globalization of economic activity is placing noticeable stresses on the ultimate sustainability of both human and environmental systems.Sustainable development is not a new concept.It has been an area of concern for different elements of society for some time.Yet efforts to understand the implications of sustainable development have not,until recently,been formalized.We have focused singularly on economic development and environmental quality as if they were mutually exclusive.This paper focuses on the concept of concurrency as both a conceptual framework and practicable method of understanding and implementing the ecology and economy of sustainability.  相似文献   
96.
97.
98.
99.
100.
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