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   256篇
  免费   9篇
  国内免费   4篇
安全科学   7篇
废物处理   23篇
环保管理   33篇
综合类   17篇
基础理论   47篇
污染及防治   80篇
评价与监测   38篇
社会与环境   21篇
灾害及防治   3篇
  2023年   5篇
  2022年   18篇
  2021年   16篇
  2020年   3篇
  2019年   10篇
  2018年   11篇
  2017年   6篇
  2016年   14篇
  2015年   9篇
  2014年   9篇
  2013年   37篇
  2012年   9篇
  2011年   16篇
  2010年   23篇
  2009年   7篇
  2008年   13篇
  2007年   11篇
  2006年   7篇
  2005年   10篇
  2004年   5篇
  2003年   6篇
  2002年   5篇
  2001年   1篇
  2000年   2篇
  1999年   1篇
  1998年   1篇
  1994年   4篇
  1993年   1篇
  1992年   1篇
  1988年   1篇
  1985年   2篇
  1976年   1篇
  1963年   3篇
  1962年   1篇
排序方式: 共有269条查询结果,搜索用时 15 毫秒
111.
Geographic information system (GIS) has become one of the leading tools in the field of hydrogeological science that helps in assessing, monitoring, and conserving groundwater resources. Groundwater is a finite resource, which is being overexploited due to increase in demand over the years leading to decrease in its potentiality. In the present study, DRASTIC model has been used to prepare groundwater vulnerable zone in hard rock aquifer of granitic terrain. The main objective is to determine susceptible zone for groundwater pollution by integrating hydrogeological layers in GIS environment. The layers such as depth of aquifer, recharge, aquifer yield, soil type, topography, vadose zone, and transmissivity are incorporated in the DRASTIC model. The final output of the map shows that around 60% of the area falls under low to no risk of pollution zone. The high risk of pollution zones are mostly present towards the margin of southeastern periphery. The lower part of the basin as well as small area on northern side falls under moderate risk of pollution zone. For the assessment of groundwater pollution zone, 24 groundwater samples have been collected from different vulnerable zones. The chemical analysis of sample shows that the southeastern margin of basin has relatively high concentration of nitrate as compared to other parts of the basin. It is present in high pollution zone as well as moderate pollution zone. The present model can be used for assessment and management of groundwater.  相似文献   
112.
The study explains water quality of three important tributaries of the Ganga River in the middle Gangetic plains in India. Seasonal changes in the water quality of the studied rivers: Gandak, Ghaghra, and Sone were observed. During monsoon, several water quality parameters show considerable changes due to increased runoff from the catchments and other seasonal factors. Multivariate discriminant analysis delineated a few parameters responsible for temporal variation in water quality. Seasonal variation in water quality of the Gandak River was rendered by seven parameters??turbidity, sulfate, pH, phosphate, water temperature, total alkalinity, and sodium, while total alkalinity and water temperature were responsible for seasonal discrimination in water quality of Ghaghra River. Water temperature, turbidity, total dissolved solids, total suspended solids, calcium, and phosphate were important for seasonal discrimination in water quality of Sone River. The seasonal changes in water quality of the rivers were due to seasonal effects and catchment characteristics. The discriminant functions classified most of the cases correctly.  相似文献   
113.
Mesozoic deposits of the former Gondwanaland are depauperate in early mammals, in general, and multituberculate mammals, in particular. Until now, the oldest multituberculate mammals known from the Gondwanan continents come from the Early Cretaceous of Morocco, NW Africa. Here, we report the presence of a new multituberculate mammal, Indobaatar zofiae gen. et sp. nov., from the Lower/Middle Jurassic Kota Formation, Pranhita-Godavari valley in peninsular India. This is the first record of a multituberculate from the Mesozoic rocks of India and possibly predates the oldest known multituberculates from Gondwanan continents. The new specimen, representing an upper premolar (P4), compares well with the upper premolar morphology of Eobaatariinae multituberculates known from the Early Cretaceous of Mongolia, China, England, and Spain. Together with the recent findings of cimolodontan multituberculates from the Early Cretaceous of Australia and Late Cretaceous of South America, the new discovery indicates a wide temporal and spatial distribution for multituberculate mammals in the former Gondwanaland.  相似文献   
114.
Environmental Science and Pollution Research - In the present study, fermentative production of bacterial nanocellulose (BNC) by using Komagataeibacter xylinus strain SGP8 and characterization of...  相似文献   
115.
Environmental Science and Pollution Research - The photovoltaic (PV) for irrigation system is an emerging technology to harness the solar energy. The performance of the PV modules depends on the...  相似文献   
116.
Environmental Science and Pollution Research - The present work aims to investigate seasonal variations in air pollution levels in Lucknow and assess the ambient air quality of the city together...  相似文献   
117.
Environmental Science and Pollution Research - Chromite ore processing residues (COPR) are real environmental threats, leading to CrO42-, i.e., Cr (VI) leaching into groundwater. It is of serious...  相似文献   
118.
119.
120.
The electrocoagulation studies of distillery spentwash using copper anodes were utilized to demonstrate the usefulness of Box–Behnken experimental design of response surface analysis to derive a statistical model and the optimum parameters for color removal. The current intensity (1.5 A), dilution (10%) and time of electrolysis (5 h) had been found to be the optimum conditions for maximum 77.11% color removal. The actual color removal at optimized conditions was found to be 78.26%, which is to the predicted response using response surface methodology. The energy consumption and current efficiency were determined from reduction in chemical oxygen demand.  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