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   1865篇
  免费   48篇
  国内免费   378篇
安全科学   66篇
废物处理   116篇
环保管理   145篇
综合类   653篇
基础理论   408篇
污染及防治   672篇
评价与监测   114篇
社会与环境   86篇
灾害及防治   31篇
  2023年   12篇
  2022年   86篇
  2021年   34篇
  2020年   28篇
  2019年   31篇
  2018年   87篇
  2017年   64篇
  2016年   76篇
  2015年   74篇
  2014年   101篇
  2013年   153篇
  2012年   116篇
  2011年   127篇
  2010年   95篇
  2009年   112篇
  2008年   135篇
  2007年   132篇
  2006年   117篇
  2005年   56篇
  2004年   89篇
  2003年   73篇
  2002年   56篇
  2001年   112篇
  2000年   56篇
  1999年   46篇
  1998年   32篇
  1997年   29篇
  1996年   27篇
  1995年   31篇
  1994年   17篇
  1993年   17篇
  1992年   19篇
  1991年   11篇
  1990年   8篇
  1989年   6篇
  1988年   9篇
  1987年   2篇
  1986年   2篇
  1985年   4篇
  1984年   1篇
  1983年   1篇
  1982年   1篇
  1981年   1篇
  1980年   1篇
  1977年   1篇
  1964年   1篇
  1960年   1篇
  1951年   1篇
排序方式: 共有2291条查询结果,搜索用时 15 毫秒
71.
The servicising approach in vineyard protection is considered a valid alternative to achieve decoupling between the economic and environmental performance of viticulture. In this paper, a policy package is designed to promote the uptake of a servicised model of vineyard protection in an area of smallholding viticulture. In doing so, a specific methodology based on a step by step protocol has been followed that aims to come up with a package that is effective, implementable and socially as well as politically acceptable. The paper concludes on the importance of combining several policy instruments in a policy package to realise the political objective. The proposed viable policy package includes incentives that support the companies’ shift towards offering crop protection solutions, further development of IPM solutions and instruments that encourage farmers to reduce the use of pesticides and collectively hire crop protection services.  相似文献   
72.
The Mekong River Delta in Vietnam plays a crucial role for the region in terms of food security and socioeconomic development; however, it is one of the most low-lying and densely populated areas in the world. It is vulnerable to seawater incursion, flood risk, and shoreline change, exacerbated as a consequence of sea-level rise (SLR) related to climate change. This study examined the Kien Giang coast in the western part of the delta, comprising seven coastal districts (namely Ha Tien, Kien Luong, Hon Dat, Rach Gia, Chau Thanh, An Bien, and An Minh), the economy of which is important in terms of agriculture and aquaculture. The analytical hierarchical process (AHP) method of multi-criteria decision making was integrated directly into geographic information systems (GIS) to derive a composite vulnerability index that indicated areas most likely to be vulnerable to SLR. The hierarchical structure comprised three key components: exposure (E), sensitivity (S), and adaptive capacity (A), at level 1. At the next level, 8 sub-components were mapped: seawater incursion, flood risk, shoreline change, population characteristics, land use/land cover, and socioeconomic, infrastructure, and technological capability, beyond which a further 22 variables (level 3) and 24 sub-variables (level 4) related to vulnerability were also mapped. Variables were assigned weights for incorporation into AHP pairwise comparisons after discussion with stakeholders. Maps were generated to visualise areas where the relative vulnerability was very low, low, moderate, high, and very high. Societal data were generally only available at district level; however, several regional patterns emerged. Relatively high exposure to flooding and inundation, salinity, and moderate loss of mangroves occurred along the coastal fringe of each district. This western section of the delta, which is low-lying and remote from the distributaries that carry sediment to the coast, appears to be particularly vulnerable. The most sensitive areas tended to be ethnic households engaged in rice cultivation and with moderate population density. The least adaptable areas consisted of high numbers of poor households, with low income, and moderate densities of transport, irrigation and drainage systems. Most coastal districts were determined to be moderately to relatively highly vulnerable, with scattered hotspots along the coast.  相似文献   
73.
74.
The waterborne polyurethane (PU) prepolymer was prepared based on isophorone diisocyanate (IPDI), polyester polyol (N220), dimethylol propionic acid (DMPA) and hydroxyethyl methyl acrylate (HEMA). The modified waterborne polyurethane–acrylate (PUA) emulsions were obtained with different proportions of acrylate (butyl acrylate and methyl methacrylate) and initiating agent by in situ dispersion technique. The structures and thermal properties of prepared PU and PUA were analyzed and characterized with FT-IR, UV–Vis spectroscopy and DSC. The PUA hybrid samples had lower glass transition temperature of hard segment and higher decomposition temperatures than PU sample. Performances of the emulsion and film were studied by means of apparent viscidity, particle size and polydispersity, surface tension and mechanical properties. The results indicated that the particle sizes of the PUA dispersions were larger than those of the pure PU and the solvent resistance, mechanical properties of PUA films was improved compare with the unmodified polyurethane film. The film had the biggest hardness and the least water absorption when the BA/MMA mass ratio 5:5 modified PU. The obtained PUA have great potential application such as coatings, leather finishing, adhesives, sealants, plastic coatings and wood finishes.  相似文献   
75.
Environmental Science and Pollution Research - A large amount of biochar-derived dissolved organic matter (BDOM) will be released into the environment with biochars application into repairing...  相似文献   
76.
Environmental Science and Pollution Research - In this study, the degradation performance of nutrients in zeolite trickling filter (ZTF) with different influent C/N ratios and aeration conditions...  相似文献   
77.
Environmental Science and Pollution Research - The pollution of heavy metals (HMs) in the soil has become one of the important factors affecting the national environment and human health....  相似文献   
78.
Environmental Science and Pollution Research - The abatement of SO2 and the utilization of copper tailings are identified as two attention-attracting environmental issues in the copper smelter. In...  相似文献   
79.
<正>Arsenic(As)is a well-recognized toxicant and carcinogen.Chronic exposure to inorganic arsenic causes a range of human cancers(e.g.,skin,bladder,and lung)and increases the risk of developing diabetes,hypertension,and cardiovascular and neurological diseases.The prevalence of arsenic species and the severity of their health effects continue to drive and demand for extensive research(Carlin et al.,2016).  相似文献   
80.
张霞  蔡宗寿  陈丽红  陈颖 《环境工程》2013,(Z1):288-291
水葫芦规模化控养是"十二五"期间滇池治理的重要措施之一。首先介绍了滇池水葫芦规模化控养现状,比较了滇池草海和外海在水葫芦控养前后水质的变化情况,指出滇池水葫芦规模化控养对草海水体生态恢复效果显著,可以在滇池选择适宜水葫芦生长的水域继续扩大水葫芦控养面积,使水葫芦在滇池生态治理中发挥更大的作用。  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