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   3558篇
  免费   3篇
  国内免费   59篇
安全科学   70篇
废物处理   193篇
环保管理   345篇
综合类   471篇
基础理论   1214篇
污染及防治   842篇
评价与监测   269篇
社会与环境   208篇
灾害及防治   8篇
  2023年   51篇
  2022年   99篇
  2021年   90篇
  2020年   22篇
  2019年   31篇
  2018年   144篇
  2017年   143篇
  2016年   218篇
  2015年   70篇
  2014年   47篇
  2013年   88篇
  2012年   446篇
  2011年   235篇
  2010年   47篇
  2009年   41篇
  2008年   70篇
  2007年   85篇
  2006年   82篇
  2005年   406篇
  2004年   540篇
  2003年   410篇
  2002年   46篇
  2001年   43篇
  2000年   27篇
  1999年   32篇
  1998年   5篇
  1997年   9篇
  1996年   3篇
  1995年   11篇
  1994年   5篇
  1993年   5篇
  1992年   4篇
  1991年   9篇
  1990年   4篇
  1989年   5篇
  1984年   2篇
  1983年   5篇
  1982年   5篇
  1981年   2篇
  1979年   2篇
  1977年   2篇
  1976年   2篇
  1975年   4篇
  1974年   3篇
  1972年   2篇
  1969年   2篇
  1967年   2篇
  1966年   3篇
  1964年   2篇
  1957年   1篇
排序方式: 共有3620条查询结果,搜索用时 31 毫秒
991.
992.
Environmental Science and Pollution Research - The hydrophobicity of silica and composite aerogels has enabled them to acquire applications in a variety of fields. With remarkable structural,...  相似文献   
993.
Modern science is global. This is particularly true of environmental science, which has been guided to a considerable extent by international environmental policy. Accordingly, one might expect the standards of scientific research around the globe to have unified over the last 30 years. Yet environmental scientists from different nations and scientific schools have demonstrably dissimilar views on key environmental issues. This is the conclusion we reached after a series of in-depth interviews with prominent American and Russian environmental scientists. The greatest difference was found in the perception of two global issues—stratospheric ozone depletion and climate change.  相似文献   
994.
Few studies have been conducted on the impact of carbon emissions disclosure on firms’ financial performance in emerging economies. Furthermore, comparison between accounting-based measures and market-based ones remains limited. This article examines the effect of carbon emissions reporting on the financial value of South African companies for the period 2010–2015. Using panel regression approaches, the findings show that, in most cases, carbon emission disclosure generates a positive relationship with ROA (an accounting-based indicator) but a negative association with MVA (a market-based indicator). The article concludes that accounting-based indicators offer more explanatory power for corporate greening initiatives.  相似文献   
995.
The major problem associated with gravity dam was siltation of reservoir which reduced its effective water storage capacity. In order to maintain effective storage capacity of reservoir, dredging of deposits was required and dredged material was disposed of haphazardly causing damage to the sensitive environment. A better alternative could be the possibility of utilization of dredged deposits in construction works involving large quantities of material. The dredged material consisted of very fine sandy silt possessing poor geotechnical characteristics and was required to be stabilized with suitable additives before use as construction material. This laboratory investigation evaluated geotechnical properties of dredged reservoir material stabilized with cement, fly ash and fiber for its probable use as subbase in lightly trafficked roads. Compaction, unconfined compressive strength and tensile strength tests were performed on appropriate combinations of the constituent materials. The results of study revealed significant improvement in unconfined compressive strength and split tensile strength after stabilization with cement and fly ash. The unconfined compressive strength and split tensile strength of cement–fly ash-stabilized dredged reservoir material improved further upon addition of polypropylene fiber. The composite possessed the potential to be utilized as sustainable material in subbase of roads subject to further validation before application in the field. The dredging of sediments improved effective storage capacity of reservoir and increased its sustainable life period. The utilization of fly ash could diminish the environmental and economic concerns arising out of its haphazard disposal.  相似文献   
996.
Some of pathogenic bacteria and fungi have the ability to produce fetal toxins which may be the direct causes of cytotoxicity or cellular dysfunction in the colonization site. Biological and non-biological environmental factors, challenge and microbes influence the effect of toxins on these pathogens. Modern research mentions that many natural materials can reduce the production of toxins in pathogenic microbes. However, researches that explain the mechanical theories of their effects are meager. This review aimed to discuss the ameliorative potential role of plant-derived compounds and probiotics to reduce the toxin production of food-borne microbes either in poultry bodies or poultry feedstuff. Moreover, studies that highlight their own toxicological mechanisms have been discussed. Adding natural additives to feed has a clear positive effect on the enzymatic and microbiological appearance of the small intestine without any adverse effect on the liver. Studies in this respect were proposed to clarify the effects of these natural additives for feed. In conclusion, it could be suggested that the incorporation of probiotics, herbal extracts, and herbs in the poultry diets has some beneficial effects on productive performance, without a positive impact on economic efficiency. In addition, the use of these natural additives in feed has a useful impact on the microbiological appearance of the small intestine and do not have any adverse impacts on intestinal absorption or liver activity as evidenced by histological examination.  相似文献   
997.
Piles of steel slag, a solid waste generated from the iron and steel industry, could be seen due to no utility found for the past century. Steel slag has now gained much attention because of its new applications. The properties of slag greatly influence its use and thus had got varied applications. The chemical composition of steel slag varies as the mineral composition of raw material such as iron ore and limestone varies. This paper reviews the characteristics of steel slag and its usage. The paper reviews recent developments in well-known applications to the steel slag such as aggregate in bituminous mixes, cement ingredient, concrete aggregate, antiskid aggregate, and rail road ballast. This paper also reviews novel uses such as mechanomutable asphalt binders, building material, green artificial reefs, thermal insulator, catalyst and ceramic Ingredient. The review is also done on utilization of solid waste for waste management by the novel methods like landfill daily cover material, sand capping, carbon sequestration, water treatment and solid waste management. Review also shows recovery of pure calcium carbonate and heavy metals from slag, providing opportunity for revenue generation. Steel slag once traded as free to use by steel industries is now sold in the market at some price. Its utilization is of great economic significance as it also contributes to the reduction of solid waste.  相似文献   
998.
Environmental Science and Pollution Research - Heavy metals (HMs) constitute a group of persistent toxic pollutants, and the petroleum industry is one of the sources of these metals. This study...  相似文献   
999.
Environmental Science and Pollution Research - Cancer is a universal health issue, and many anticancer therapeutic drugs have been isolated from natural products. This study analyzed the cytotoxic...  相似文献   
1000.
Environment, Development and Sustainability - Islam emphasizes the importance of environmental care, as prescribed in its primary sources of Shariah, the Quran and the authenticated actions and...  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