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   167篇
  免费   1篇
  国内免费   2篇
安全科学   2篇
废物处理   13篇
环保管理   15篇
综合类   34篇
基础理论   27篇
污染及防治   54篇
评价与监测   19篇
社会与环境   5篇
灾害及防治   1篇
  2023年   3篇
  2022年   10篇
  2021年   2篇
  2020年   1篇
  2019年   1篇
  2018年   7篇
  2017年   4篇
  2016年   5篇
  2015年   4篇
  2014年   5篇
  2013年   19篇
  2012年   6篇
  2011年   6篇
  2010年   7篇
  2009年   4篇
  2008年   9篇
  2007年   7篇
  2006年   10篇
  2005年   3篇
  2004年   9篇
  2003年   6篇
  2002年   8篇
  2001年   2篇
  2000年   3篇
  1999年   1篇
  1997年   1篇
  1994年   1篇
  1992年   1篇
  1991年   1篇
  1989年   3篇
  1988年   1篇
  1987年   2篇
  1975年   1篇
  1973年   1篇
  1971年   1篇
  1964年   2篇
  1963年   1篇
  1962年   1篇
  1961年   3篇
  1959年   2篇
  1958年   3篇
  1957年   2篇
  1956年   1篇
排序方式: 共有170条查询结果,搜索用时 281 毫秒
161.
This study reports source apportionment of polycyclic aromatic hydrocarbons (PAHs) in particulate depositions on vegetation foliages near highway in the urban environment of Lucknow city (India) using the principal components analysis/absolute principal components scores (PCA/APCS) receptor modeling approach. The multivariate method enables identification of major PAHs sources along with their quantitative contributions with respect to individual PAH. The PCA identified three major sources of PAHs viz. combustion, vehicular emissions, and diesel based activities. The PCA/APCS receptor modeling approach revealed that the combustion sources (natural gas, wood, coal/coke, biomass) contributed 19–97% of various PAHs, vehicular emissions 0–70%, diesel based sources 0–81% and other miscellaneous sources 0–20% of different PAHs. The contributions of major pyrolytic and petrogenic sources to the total PAHs were 56 and 42%, respectively. Further, the combustion related sources contribute major fraction of the carcinogenic PAHs in the study area. High correlation coefficient (R 2 > 0.75 for most PAHs) between the measured and predicted concentrations of PAHs suggests for the applicability of the PCA/APCS receptor modeling approach for estimation of source contribution to the PAHs in particulates.  相似文献   
162.
Transgenic Bt crops produce insecticidal Cry proteins that are released to soil in plant residues, root exudates, and pollen and that may affect soil microorganisms. As a continuation of studies in the laboratory and a plant-growth room, a field study was conducted at the Rosemount Experiment Station of the University of Minnesota. Three Bt corn varieties that express the Cry1Ab protein, which is toxic to the European corn borer (Ostrinia nubilalis Hübner), and one Bt corn variety that expresses the Cry3Bb1 protein, which is toxic to the corn rootworm complex (Diabrotica spp.), and their near-isogenic non-Bt varieties were evaluated for their effects on microbial diversity by classical dilution plating and molecular (polymerase chain reaction-denaturing gradient gel electrophoresis) techniques and for the activities of some enzymes (arylsulfatases, acid and alkaline phosphatases, dehydrogenases, and proteases) involved in the degradation of plant biomass. After 4 consecutive years of corn cultivation (2003-2006), there were, in general, no consistent statistically significant differences in the numbers of different groups of microorganisms, the activities of the enzymes, and the pH between soils planted with Bt and non-Bt corn. Numbers and types of microorganisms and enzyme activities differed with season and with the varieties of corn, but these differences were not related to the presence of the Cry proteins in soil. The Cry1Ab protein of Bt corn (events Bt11 and MON810) was detected in most soils during the 4 yr, whereas the Cry3Bb1 protein was not detected in soils of Bt corn (event MON863) expressing the cry3Bb1 gene.  相似文献   
163.
Journal of Material Cycles and Waste Management - The amount of ceramic waste being generated is increasing day by day, and ceramic waste management is one of the most challenging issues for many...  相似文献   
164.
Environmental Science and Pollution Research - The energy storage application plays a vital role in the utilization of the solar energy technologies. There are various types of the energy storage...  相似文献   
165.
166.
Environmental Science and Pollution Research - In this experimental study on self-compacting concrete (SCC), the Manufactured sand (M-sand) and Fly ash (FA) were utilised for partial replacement of...  相似文献   
167.
Environmental Science and Pollution Research - Particulate matter (PM) emitted from compression ignition (CI) engines (diesel engines) has a detrimental effect on human health and the environment....  相似文献   
168.
Journal of Material Cycles and Waste Management - This research investigation has mainly focused on the development of cementless concrete, i.e., geopolymer concrete, along with the reutilization...  相似文献   
169.
Environmental Science and Pollution Research - The successful use of solar energy for cooking requires the systems adopted not only to have technical attributes that conveniently address specific...  相似文献   
170.
Environment, Development and Sustainability - India has the largest dairy industry in the world and accounts for a significant share of the global emission of livestock methane ( $$\hbox...  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