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   435篇
  免费   2篇
  国内免费   16篇
安全科学   16篇
废物处理   30篇
环保管理   30篇
综合类   70篇
基础理论   66篇
污染及防治   166篇
评价与监测   44篇
社会与环境   27篇
灾害及防治   4篇
  2023年   9篇
  2022年   28篇
  2021年   26篇
  2020年   10篇
  2019年   9篇
  2018年   16篇
  2017年   22篇
  2016年   30篇
  2015年   18篇
  2014年   24篇
  2013年   70篇
  2012年   14篇
  2011年   22篇
  2010年   16篇
  2009年   14篇
  2008年   18篇
  2007年   20篇
  2006年   12篇
  2005年   9篇
  2004年   12篇
  2003年   11篇
  2002年   8篇
  2001年   2篇
  2000年   2篇
  1998年   1篇
  1997年   2篇
  1996年   1篇
  1995年   1篇
  1990年   1篇
  1989年   1篇
  1988年   2篇
  1987年   1篇
  1985年   4篇
  1984年   1篇
  1983年   2篇
  1979年   1篇
  1975年   1篇
  1970年   1篇
  1969年   1篇
  1967年   1篇
  1965年   2篇
  1964年   1篇
  1963年   2篇
  1962年   1篇
  1956年   2篇
  1955年   1篇
排序方式: 共有453条查询结果,搜索用时 15 毫秒
1.
Egyptian Blue, a multicomponent synthetic blue pigment has been recorded in ancient Egypt since the Fourth Dynasty of the Old Kingdom (2600–2480 B.C.). The pigment consisting of cuprorivaite (CaCuSi4O10) with variable amounts of wollastonite (CaSiO3), Cu-rich glass and cuprite (Cu3O) or tenorite (CuO) was prepared by melting the copper-rich ingredient with lime and desert sand. Low melting temperatures (below 742 °C) were achieved by addition of flux-like plant ashes. The high quality of the pigments collected from monuments of the Fifth Dynasty (2480–2320 B.C.) may indicate that the first manufacture was in early dynastic or perhaps predynastic eras. During the reign of Thutmosis III (18th Dynasty, 1490–1436 B.C.) probably bronze filings were first applied as starting material, thus indicating a technological innovation. This new method was employed till the Roman times.  相似文献   
2.
3.
4.
5.
Environmental Science and Pollution Research - It has recently been proven that epigenetic dysregulation is importantly involved in cell transformation and therefore induces cancerous diseases. The...  相似文献   
6.
Environmental Science and Pollution Research - Phthalate esters (PAEs) are endocrine disrupters and can disrupt the functioning of different hormones, causing adverse effects on human health. Due...  相似文献   
7.

Natural products may be applied in a wide range of domains, from agriculture to food and pharmaceutical industries. In this study, the antioxidant properties and the capacity to inhibit some enzymatic activities of Euphorbia resinifera and Euphorbia officinarum aqueous extracts and honeys were assessed. The physicochemical characteristics were also evaluated. Higher amounts of iron, copper and aluminium were detected in E. officinarum honey, which may indicate environmental pollution around the beehives or inadequate storage of honey samples. This honey sample showed higher amounts of total phenols and better capacity for scavenging superoxide anion free radicals and DPPH free radicals as compared with E. resinifera honey, but poorer capacity for inhibiting lipoxygenase, acetylcholinesterase, tyrosinase and xanthine oxidase. The ratio plant mass:solvent volume (1:100) and extraction time (1 - 2 h) were associated with higher total phenols and better antioxidant activities and lipoxygenase, acetylcholinesterase and tyrosinase inhibitory activities, regardless of the plant species. The aqueous extracts had systematically higher in vitro activities than the respective honey samples.

  相似文献   
8.
Environmental Science and Pollution Research - Groundwater resources are the main supply of freshwater for human activities. Nevertheless, during the last 50 years, groundwater has become very...  相似文献   
9.
A recent fieldwork in the Ka??zman-Tuzluca Basin in northeastern Turkey led us to the discovery of three vertebrate localities which yielded some limb bones of the giant rhino Paraceratherium, a crocodile tooth, and some small mammals, respectively. These discoveries allowed, for the first time to date some parts of the sedimentary units of this basin. This study also shows that the dispersal area of Paraceratherium is wider than it was known before. Eastern Turkey has several Cenozoic sedimentary basins formed during the collision of the Arabian and Eurasian plates. They are poorly documented for vertebrate paleontology. Consequently, the timing of tectonic activities, which led to the formation of the East Anatolian accretionary complex, is not constrained enough with a solid chronological framework. This study provides the first biostratigraphic evidences for the infill under the control of the compressive tectonic regime, which built the East Anatolian Plateau.  相似文献   
10.
Fallout from the Chernobyl reactor accident due to the transport of a radioactive cloud over Lebanon in the beginning of May 1986 was studied 12 years after the accident for determining the level of (137)Cs concentration in soil. Gamma spectroscopy measurements were performed by using coaxial high sensitivity HPGe detectors. More than 90 soil samples were collected from points uniformly distributed throughout the land of Lebanon in order to evaluate their radioactivity. The data obtained showed a relatively high (137)Cs activity per surface area contamination, up to 6545Bqm(-2) in the top soil layer 0-3cm. The average activity of (137)Cs in the top soil layer 0-3cm in depth was 59.7Bqkg(-1) dry soil ranging from 15 to 119Bqkg(-1) dry soil. The horizontal variability was found to be about 45% between the sampling sites. The depth distribution of total (137)Cs activity in soil showed an exponential decrease. Estimation of the annual effective dose due to external radiation from (137)Cs contaminated soil for selected sites gave values ranging from 19.3 to 91.6 micro Svy(-1).  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