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   5335篇
  免费   40篇
  国内免费   24篇
安全科学   84篇
废物处理   335篇
环保管理   402篇
综合类   834篇
基础理论   1098篇
环境理论   4篇
污染及防治   1804篇
评价与监测   495篇
社会与环境   330篇
灾害及防治   13篇
  2023年   54篇
  2022年   161篇
  2021年   146篇
  2020年   61篇
  2019年   73篇
  2018年   180篇
  2017年   134篇
  2016年   242篇
  2015年   146篇
  2014年   279篇
  2013年   469篇
  2012年   314篇
  2011年   345篇
  2010年   254篇
  2009年   209篇
  2008年   295篇
  2007年   301篇
  2006年   264篇
  2005年   196篇
  2004年   161篇
  2003年   142篇
  2002年   129篇
  2001年   102篇
  2000年   68篇
  1999年   48篇
  1998年   30篇
  1997年   21篇
  1996年   11篇
  1995年   50篇
  1994年   45篇
  1993年   20篇
  1992年   25篇
  1991年   15篇
  1990年   14篇
  1989年   20篇
  1988年   13篇
  1985年   10篇
  1983年   13篇
  1966年   13篇
  1965年   15篇
  1964年   30篇
  1963年   13篇
  1962年   18篇
  1961年   13篇
  1960年   10篇
  1959年   26篇
  1958年   29篇
  1957年   19篇
  1956年   13篇
  1955年   19篇
排序方式: 共有5399条查询结果,搜索用时 15 毫秒
101.
102.
103.
104.
The use of recurrence plots have been extensively used in various fields. In this work, recurrence plots investigate the changes in the non-linear behaviour of urban air pollution using large datasets of raw data (hourly). This analysis has not been used before to extract information from large datasets for this type of non-linear problem. Two different approaches have been used to tackle this problem. The first approach is to show results according to monitoring network. The second approach is to show the results by particle type. This analysis shows the feasibility of using recurrence analysis for pollution monitoring and control.  相似文献   
105.
The Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method was applied to the extraction of 14 organochlorine pesticides (OCPs) residues from commercial fruit pulps available in supermarkets in Fortaleza, Northeastern Brazil. The analyses were carried out by gas chromatography (GC), coupled to an electron-capture detector (ECD), and were confirmed by GC-tandem mass spectrometry (MS). The parameters of the analytical method, such as accuracy, precision, linear range, limits of detection and quantification, were determined for each pesticide. The results showed good linearity (R2 ≥ 0.9916) and the overall average recoveries were considered satisfactory obtaining values between 69 and 110%, RSD of 2–15 %, except for hexachlorobenzene (HCB) in açai, acerola and guava pulp samples. The OCPs were detected in guava (α–HCH; lindane) and soursop (α, β–HCH isomers) samples. The QuEChERS method and GC–ECD were successfully used to analyze OCPs in commercially available Brazilian fruit pulps and can be applied in routine analytical laboratories.  相似文献   
106.
The addition of lipid wastes to the digestion of swine manure was studied as a means of increasing biogas production. Lipid waste was obtained from a biodiesel plant where used cooking oil is the feedstock. Digestion of this co-substrate was proposed as a way of valorising residual streams from the process of biodiesel production and to integrate the digestion process into the biorefinery concept.Batch digestion tests were performed at different co-digesting proportions obtaining as a result an increase in biogas production with the increase in the amount of co-substrate added to the mixture. Semi-continuous digestion was studied at a 7% (w/w) mass fraction of total solids. Co-digestion was successful at a hydraulic retention time (HRT) of 50 d but a decrease to 30 d resulted in a decrease in specific gas production and accumulation of volatile and long chain fatty acids. The CH4 yield obtained was 326 ± 46 l/kg VSfeed at an HRT of 50 d, while this value was reduced to 274 ± 43 l/kg VSfeed when evaluated at an HRT of 30 d. However these values were higher than the one obtained under batch conditions (266 ± 40 l/kg VSfeed), thus indicating the need of acclimation to the co-substrate. Despite of operating at low organic loading rate (OLR), measurements from respirometry assays of digestate samples (at an HRT of 50 d) suggested that the effluent could not be directly applied to the soil as fertiliser and might have a negative effect over soil or crops.  相似文献   
107.
108.
Abstract

The presence of diethyl-phthalate (DEP), dibutyl-phthalate (DBP), butylbenzyl-phthalate (BBP), diethylhexyl-phthalate (DEHP) and diisononyl-phthalate (DINP) was determined in 295 tequila samples. They were grouped by age of maturation (white, aged, extra aged or ultra aged) and year of production (between 2013 and 2018). Gas Chromatography coupled with Mass Spectrometry was used for identification and quantification. The results showed that 65 samples (22% of the total) were phthalate free. DEP (0.13-0.27?mg/kg), BBP (0.05–2.91?mg/kg) and DINP (1.64–3.43?mg/kg) were detected in 11 (3.73%), 37 (12.54%) and 5 (1.69%) samples, respectively. But, these concentrations did not exceed the maximum permitted limits (MPL) of phthalates for alcoholic beverages. DBP (0.01–2.20?mg/kg) and DEHP (0.03–4.64?mg/kg) were detected in 96 (32.54%) and 224 (75.93%) samples, from them only 10 (3.39%) and 15 (5.08%) samples, respectively, exceeded the MPL for alcoholic beverages and they were few tequilas produced in the year 2014 or before. DEHP was the most frequent phthalate found in tequila and observed DEHP concentrations were 2-times higher in ultra aged tequilas compared to those in white tequilas. We concluded that all tequilas produced in 2015 and after, satisfied the international standards for these compounds.  相似文献   
109.
Environmental Science and Pollution Research - Methylmercury (MeHg) is a well-known environmental pollutant associated with neurological and developmental deficits in animals and humans. However,...  相似文献   
110.
Environmental Science and Pollution Research - This paper investigates the relationship between income inequality and environmental degradation for the case of Turkey between 1987 and 2017 through...  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