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   242篇
  免费   7篇
  国内免费   17篇
安全科学   13篇
废物处理   7篇
环保管理   43篇
综合类   57篇
基础理论   73篇
环境理论   1篇
污染及防治   48篇
评价与监测   13篇
社会与环境   5篇
灾害及防治   6篇
  2023年   7篇
  2022年   5篇
  2021年   8篇
  2020年   5篇
  2019年   8篇
  2018年   6篇
  2017年   13篇
  2016年   12篇
  2015年   8篇
  2014年   11篇
  2013年   17篇
  2012年   16篇
  2011年   19篇
  2010年   15篇
  2009年   20篇
  2008年   13篇
  2007年   5篇
  2006年   17篇
  2005年   8篇
  2004年   12篇
  2003年   7篇
  2002年   5篇
  2001年   7篇
  1998年   1篇
  1996年   3篇
  1995年   2篇
  1994年   1篇
  1993年   1篇
  1991年   1篇
  1988年   2篇
  1986年   1篇
  1985年   1篇
  1984年   1篇
  1983年   1篇
  1982年   2篇
  1979年   1篇
  1961年   3篇
  1959年   1篇
排序方式: 共有266条查询结果,搜索用时 15 毫秒
201.
A three-dimensional Joint frequency distribution (3DJFD) map of Florida is developed based upon wind rose data available for 10 cities. This map may be used in conjunction with the analytic polar coordinate Gaussian Plume Model or conventional dispersion models to calculate the approximate incremental pollution concentration contours associated with an emission source at any site in Florida. Possible means of generalizing the work to other geographic regions, to stack height altitudes, and to incorporate time dependence are discussed.  相似文献   
202.
We evaluated 41 rural workers occupationally exposed to pesticides and 32 subjects as a control group, using the micronucleus (MN) and the comet assay. For the comet assay, we evaluated the peripheral blood, and for the MN, we sampled cells from the oral epithelium. Damage to DNA was measured by tail length, % DNA in tail (% tail), olive tail moment (OTM), and tail moment (TM). The exposed group presented an 8× increase in MN frequency, when compared to the control group (p <0.05). When we contrasted the MN frequencies between the individuals that use and do not use personal protective equipment, we found a mean of 7.5 MN (57 % variance) and 12.1 MN (130 % variance), respectively. The binucleated cells were 0.04 and 0.005, in the exposed and control groups, respectively, indicating 8× increase in the number of binucleated cells, when comparing the groups (p <0.05). In the comet assay, we demonstrated statistically significant differences in three parameters (% DNA, OTM, and TM) indicating that the rural workers presented high levels of genomic damages. Our results indicate that occupational exposure to pesticides could cause genome damage in somatic cells, representing a potential health risk to Brazilian rural workers that deal constantly with agrochemicals without adequate personal protection equipment.  相似文献   
203.
204.
Brockman, Ruth R., Carmen T. Agouridis, Stephen R. Workman, Lindell E. Ormsbee, and Alex W. Fogle, 2012. Bankfull Regional Curves for the Inner and Outer Bluegrass Regions of Kentucky. Journal of the American Water Resources Association (JAWRA) 48(2): 391‐406. DOI: 10.1111/j.1752‐1688.2011.00621.x Abstract: Bankfull regional curves that relate channel dimensions and discharge to watershed drainage area are useful tools for assisting in the correct identification of bankfull elevation and in stream restoration and reconstruction. This study assessed 28 stable streams located in two physiographic regions of Kentucky: the Inner Bluegrass and the Outer Bluegrass. Bankfull channel dimensions, discharge, and return period as well as average channel slope, median bed material size, sinuosity, Rosgen stream classification, and percent impervious area were determined. Significant relationships were found between drainage area and the bankfull characteristics of cross‐sectional area, width, mean depth, and discharge for both the Inner Bluegrass and Outer Bluegrass regions (α = 0.05). It was also found that the percent impervious area in a watershed had minimal effect on bankfull dimensions, which is attributed to the well‐vegetated nature of the streambanks, cohesive streambank materials, and bedrock control. No significant differences between any of the Inner Bluegrass and Outer Bluegrass regional curves were found (α = 0.05). Comparisons were made between the Inner Bluegrass and Outer Bluegrass curves and others developed in karst‐influenced areas in the Eastern United States. Although few significant differences were found between the regional curves for bankfull discharge and width, a number of the curves differed with regards to bankfull cross‐sectional area and mean depth.  相似文献   
205.
206.
The objective of this study was to determine the concentrations of trace elements in sediment samples taken from impermeable urban areas of a city with predominantly agroindustrial development characteristics. For this, samples were taken every month from paved streets in the city of Toledo, Paraná State (PR), Brazil. Thus, trace element levels were obtained through analysis performed by optical emission spectrometry with inductively coupled plasma. Levels of total organic carbon were also obtained through the dry combustion method. When compared to local background levels, the trace element levels were shown to be enriched in the following percentage proportions: barium (Ba) (45.4%), copper (Cu) (48.6%), chromium (Cr) (37.2%), manganese (Mn) (81.6%), nickel (Ni) (0%), lead (Pb) (40%), zinc (Zn) (283.7%), magnesium (Mg) (34.3%), and sodium (Na) (250.2%), whereas the carbon (C) percentages were around 1%. The most significant enrichment factors occurred for Ba, Cr, Pb, Zn, Mg, and Na. The highest rates occurred in geoaccumulation where the sediments were enriched by zinc. According to the principal guidelines, the concentrations obtained for cadmium (Cd), Cr, Cu, Ni, and Zn can cause adverse environmental impacts.  相似文献   
207.
208.
Urban water scarcity from ongoing drought and an increasing population are driving a range of water saving options to be explored in Melbourne (Australia). This paper assesses the cost effectiveness of five water treatment and industrial reuse options in the Fishermans Bend industrial area at Port Melbourne. In consultation with industrial stakeholders and the local water utility, the study design began by identifying potential water sources and sinks in the area. Treatment technologies for each option - using a combination of membrane bioreactors (MBR) and in some cases reverse osmosis (RO) technologies - were developed. In evaluating the potential for future implementation, the cost effectiveness ($/kiloLitre) was assessed relative to water supply augmentation and water demand management options available in Melbourne. Additionally, the opportunities and barriers for option implementation in Port Melbourne were contrasted with the Kwinana Industrial Area, Western Australia where many regional synergy projects have been undertaken. This research identifies that the future implementation of industrial ecology opportunities requires strong and ongoing stakeholder involvement as described in this paper.  相似文献   
209.
210.
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