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   27958篇
  免费   263篇
  国内免费   202篇
安全科学   718篇
废物处理   936篇
环保管理   3698篇
综合类   7625篇
基础理论   6241篇
环境理论   8篇
污染及防治   6810篇
评价与监测   1356篇
社会与环境   901篇
灾害及防治   130篇
  2018年   308篇
  2017年   300篇
  2016年   445篇
  2015年   345篇
  2014年   484篇
  2013年   2011篇
  2012年   632篇
  2011年   903篇
  2010年   743篇
  2009年   877篇
  2008年   950篇
  2007年   1010篇
  2006年   898篇
  2005年   746篇
  2004年   783篇
  2003年   796篇
  2002年   704篇
  2001年   985篇
  2000年   673篇
  1999年   463篇
  1998年   338篇
  1997年   308篇
  1996年   356篇
  1995年   377篇
  1994年   409篇
  1993年   365篇
  1992年   378篇
  1991年   368篇
  1990年   405篇
  1989年   397篇
  1988年   322篇
  1987年   319篇
  1986年   301篇
  1985年   312篇
  1984年   317篇
  1983年   313篇
  1982年   321篇
  1981年   337篇
  1980年   290篇
  1979年   294篇
  1978年   257篇
  1977年   231篇
  1976年   247篇
  1974年   261篇
  1973年   239篇
  1972年   229篇
  1971年   218篇
  1968年   229篇
  1967年   260篇
  1966年   222篇
排序方式: 共有10000条查询结果,搜索用时 937 毫秒
1.
This article postulates strong endogenous relationships in lower income countries between institutional quality, financial development and sustained economic growth. These associations were investigated using the vector-error correction model (VECM) and Granger causality method for a sample of 79 countries from 2005 to 2022. The findings show that (1) these variables reinforce each other in the short run. (2) In the long run, both institutional quality and financial development can fuel economic growth. (3) The positive effect of institutional quality on economic growth is greater than that of financial development. Policy implications of these findings are that careful attention should be paid to co-development policies to enhance the institutional quality and the financial system in these economies. Policies should also consider economic growth strategies to enable sustainable economic growth rates.  相似文献   
2.
Brazil hosts the largest expanse of tropical ecosystems within protected areas (PAs), which shelter biodiversity and support traditional human populations. We assessed the vulnerability to climate change of 993 terrestrial and coastal-marine Brazilian PAs by combining indicators of climatic-change hazard with indicators of PA resilience (size, native vegetation cover, and probability of climate-driven vegetation transition). This combination of indicators allows the identification of broad climate-change adaptation pathways. Seventeen PAs (20,611 km2) were highly vulnerable and located mainly in the Atlantic Forest (7 PAs), Cerrado (6), and the Amazon (4). Two hundred fifty-eight PAs (756,569 km2), located primarily in Amazonia, had a medium vulnerability. In the Amazon and western Cerrado, the projected severe climatic change and probability of climate-driven vegetation transition drove vulnerability up, despite the generally good conservation status of PAs. Over 80% of PAs of high or moderate vulnerability are managed by indigenous populations. Hence, besides the potential risks to biodiversity, the traditional knowledge and livelihoods of the people inhabiting these PAs may be threatened. In at least 870 PAs, primarily in the Atlantic Forest and Amazon, adaptation could happen with little or no intervention due to low climate-change hazard, high resilience status, or both. At least 20 PAs in the Atlantic Forest, Cerrado, and Amazonia should be targeted for stronger interventions (e.g., improvement of ecological connectivity), given their low resilience status. Despite being a first attempt to link vulnerability and adaptation in Brazilian PAs, we suggest that some of the PAs identified as highly or moderately vulnerable should be prioritized for testing potential adaptation strategies in the near future.  相似文献   
3.
4.
5.
6.
7.
8.
9.
10.
Male Baladi rabbits were acutely and sub-chronically intoxicated with cyanofenphos and profenophos. The levels of cholesterol, triglycerides, B-lipoproteins and total proteins were determined in the serum, brain, spinal cord and sciatic nerve of rabbits. Moreover, the activities of alkaline phosphatase, acid phosphatase and glutamic-pyruvic transaminase were determined in the liver of the animals. The whole studies revealed that the biochemical constituents were highly affected by the tested insecticides. Also, the liver function suffered from adverse effects of the tested insecticides.  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