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   29594篇
  免费   277篇
  国内免费   271篇
安全科学   787篇
废物处理   1326篇
环保管理   3791篇
综合类   4449篇
基础理论   7797篇
环境理论   11篇
污染及防治   7752篇
评价与监测   2168篇
社会与环境   1864篇
灾害及防治   197篇
  2022年   278篇
  2021年   283篇
  2020年   201篇
  2019年   251篇
  2018年   454篇
  2017年   434篇
  2016年   705篇
  2015年   516篇
  2014年   765篇
  2013年   2435篇
  2012年   943篇
  2011年   1243篇
  2010年   1103篇
  2009年   1145篇
  2008年   1285篇
  2007年   1356篇
  2006年   1205篇
  2005年   1027篇
  2004年   962篇
  2003年   989篇
  2002年   929篇
  2001年   1261篇
  2000年   864篇
  1999年   551篇
  1998年   377篇
  1997年   375篇
  1996年   415篇
  1995年   429篇
  1994年   408篇
  1993年   365篇
  1992年   345篇
  1991年   346篇
  1990年   341篇
  1989年   353篇
  1988年   292篇
  1987年   258篇
  1986年   228篇
  1985年   212篇
  1984年   261篇
  1983年   242篇
  1982年   287篇
  1981年   228篇
  1980年   201篇
  1979年   249篇
  1978年   179篇
  1977年   168篇
  1976年   152篇
  1975年   152篇
  1974年   139篇
  1973年   139篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
Environment, Development and Sustainability - Sugarcane is an industrial crop globally used for producing biofuels and bioproducts and is the only source of white sugar in Bangladesh. However,...  相似文献   
2.
Russian Journal of Ecology - Climate change entails shifts in the ranges of woody plants along both latitudinal and altitudinal gradients in the boreal forest biome. In this study,...  相似文献   
3.
Environmental Science and Pollution Research - Lake Mariut Main Basin (MB) is not only one of the three basins composing Lake Mariut (LM) but is also the main source of the popular tilapia fish to...  相似文献   
4.
The Science of Nature - We present the first study that compares phenological variation in parasite load and inflammatory response in a lizard with asynchronous male and female gonadal cycles....  相似文献   
5.
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   
6.
Russian Journal of Ecology - Changes in the distribution of broadleaf tree species—Tilia cordata Mill., Quercus robur L., Acer platanoides L., and Ulmus glabra Huds.—in the central part...  相似文献   
7.
Environmental Science and Pollution Research - Nutrient source and transport study in tropical creeks adjacent to megacities are sparse on a regional and global scale. High-frequency chemical data...  相似文献   
8.
The High Plains aquifer (HPA) is the primary water source for agricultural irrigation in the US Great Plains. The water levels in many locations of the aquifer have declined steadily over the past several decades because the rate of water withdrawals exceeds recharge, which has been a serious concern to the water resources management in the region. We evaluated temporal trends and variations in agricultural water use and hydroclimatic variables including precipitation, air temperature, reference evapotranspiration, runoff, groundwater level, and terrestrial water storage across the HPA region for different periods from 1985 to 2020 at the grid, county, or region scale. The results showed that water withdrawals decreased from 21.3 km3/year in 1985 to 18.2 km3/year in 2015, while irrigated croplands increased from 71,928 km2 in 1985 to 78,464 km2 in 2015 in the entire HPA. The hydroclimatic time-series showed wetting trends in most of the northern HPA, but drying and warming trends in the southern region from 1985 to 2020. The groundwater level time-series indicated flat trends in the north, but significant declining in the central and southern HPA. Trends in irrigation water withdrawals and irrigation area across the HPA were controlled by the advancement of irrigation systems and technologies and the management of sustainable water use, but also were affected by dynamical changes in the hydroclimatic conditions.  相似文献   
9.
Environmental Science and Pollution Research - With the use of different multivariate statistical analysis methods, spatio-temporal fluctuations in the water parameters of Tiru reservoir located at...  相似文献   
10.
Environmental Science and Pollution Research - The Fundão Dam collapsed, on November 5th, 2015, dumping more than 50 million/m3 of iron ore tailings, enriched with metals, into the Doce River...  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