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   358篇
  免费   2篇
  国内免费   6篇
安全科学   9篇
废物处理   44篇
环保管理   36篇
综合类   29篇
基础理论   47篇
环境理论   1篇
污染及防治   147篇
评价与监测   38篇
社会与环境   13篇
灾害及防治   2篇
  2023年   11篇
  2022年   35篇
  2021年   28篇
  2020年   14篇
  2019年   15篇
  2018年   17篇
  2017年   14篇
  2016年   19篇
  2015年   13篇
  2014年   18篇
  2013年   51篇
  2012年   16篇
  2011年   13篇
  2010年   7篇
  2009年   9篇
  2008年   7篇
  2007年   8篇
  2006年   9篇
  2005年   10篇
  2004年   6篇
  2003年   7篇
  2002年   6篇
  2001年   2篇
  2000年   4篇
  1999年   2篇
  1998年   2篇
  1995年   1篇
  1994年   3篇
  1993年   1篇
  1991年   1篇
  1990年   2篇
  1989年   1篇
  1988年   2篇
  1987年   1篇
  1984年   1篇
  1982年   1篇
  1980年   2篇
  1978年   1篇
  1977年   1篇
  1972年   1篇
  1966年   1篇
  1965年   1篇
  1964年   2篇
排序方式: 共有366条查询结果,搜索用时 15 毫秒
91.
Environmental Science and Pollution Research - This research paper presents the results of an experimental investigation of the degradation of three different contaminants including progesterone...  相似文献   
92.
Environmental Science and Pollution Research - Cadmium is an important widely distributed heavy metal in the environment due to its several industrial uses, while milk thistle is an important herb...  相似文献   
93.
This study investigates for the first time the feasibility of isolating nanocellulose from several selected feedstocks via a novel Ni(II)-hydrolysis process, including lignocellulosic biomasses (oil palm trunk, banana peel and coconut husk) and processed biomasses (newspaper, tissue paper and cotton linter), with an obtained gravimetric yield ranging from 59.6 to 86.2%. The isolation of nanocellulose products from these selected feedstocks was verified by the successive removal of most of their non-cellulosic components (lignin and hemicellulose) and cellulose amorphous regions, the increase in the crystallinity index and the nanoscale of the individual crystals. Most importantly, the resultant nanocellulose products rendered better thermal stability than that of corresponding original sources, which are highly potential to be utilized as the new renewable sources of reinforcement materials with potential applications in bio-nanocomposites and thermoplastics. Therefore, this work proves the viability of direct production of nanocellulose from a variety of cellulosic sources by using Ni(II)-based transition metal salt catalyst. The results suggested that the concept of waste to wealth could be well executed from the obtained nanocellulose, which are greatly potential for various industrial applications.  相似文献   
94.
The aim of this study was to determine type of response curves for seventeen woody species (10 tree and 7 shrub species) to soil factors in an intact riparian forest in Safaroud River in northern Iran using HOF function. Data were collected along transects established perpendicular to the water flow on both sides of the river. Results indicated different responses for different woody species. The most common were symmetricunimodal response curves and curves showing an increase in occurrence probability after a certain value in form of a plateau. Bimodal curves were four times more frequent in riverside than forest interior area. It seems that river flow disturbances through frequent floods effect on species tolerance and optimum in riversides.  相似文献   
95.
Environmental Science and Pollution Research - Microplastics (MP) pollution is an emerging threat to life and the environment. These particles are not restricted to human-inhabited lands but also...  相似文献   
96.
A total of two hundred and forty random samples were collected equally from mutton, liver and kidney of 40 local (Jordanian) and 40 imported Australian sheep (40 each sub sample). Fresh samples were collected from 12–18 m old sheep slaughtered in abattoirs in Jordan in 2002. Besides, 40 fresh mutton samples of imported Chinese sheep were collected from different markets. Atomic absorption spectrometry (AAS) was used to estimate the lead (Pb) content of the samples. Results indicated that Australian mutton had significantly higher (p < 0.05) mean of lead pollution than that of the local and Chinese muttons. The mean concentration of lead (mg/kg) in Australian, local and Chinese muttons was 4.30, 3.15 and 2.17, respectively. The mean concentration of lead in Australian sheep liver was significantly higher (p < 0.05) than that recorded in the local sheep liver. The mean concentration of Pb in Australian and local sheep liver was 5.69 and 4.52 mg/kg, respectively. The mean concentrations of Pb in the kidney of the Australian and local sheep were not significantly different (p > 0.05). They were 4.59 and 3.87 mg/kg, respectively.On the basis of the samples lead level, 85, 92 and 87.5% of local, Australian and Chinese mutton respectively, exceeded the international safe permissible limit of 1.0 mg/kg. Furthermore, the effect of Pb on animal and human health was discussed.  相似文献   
97.
The recycling of sewage sludge on agriculture land represents an alternative, advantageous, disposal of this waste material. The aim of the present study was to evaluate the feasibility of using industrial sewage sludge, produced in Pakistan, as a fertiliser. Agricultural soil amended with 25% (w/w) sewage sludge with or without lime treatment was used for growing a variety of sorghum (PARC-SS-1). The mobility of the heavy metals (HMs) (Cd, Cu, Cr, Ni, Pb and Zn) and metalloid (As) in the untreated industrial waste water sewage sludge (UIWS) samples were assessed by applying a modified BCR (Community Bureau of Reference) sequential extraction procedure. The single extraction procedure comprised of the application of mild extractant (CaCl2) and water for the estimation of the proportion of easily soluble metal fractions. The precision and accuracy of BCR was evaluated by using a certified reference material of soil amended with sewage sludge BCR 483. The plant available metal contents, as extracted by the deionised water and 0.01 M CaCl2 solution and exchangeable fraction of BCR sequential, decreased with lime application in the range of 10–44% for As, Cr, Ni, Pb and Zn, except in the cases of Cd and Cu, where their mobility was increased by 10% and 24%, respectively. Sludge amendment enhanced the dry weight yield of sorghum and the increase was more obvious after liming up to 25%. The uptake of HMs were lower in test samples (3.2–21.8%), except for Cu and Cd, which was higher (4%), while they were below the permissible limit of these metals. The present experiment demonstrates that liming was important in factors facilitating the growth of sorghum in sludge-amended soil.  相似文献   
98.
Pakistan has a large population of more than 150 million people with an overall carrier frequency of approximately 5.6% for β-thalassemia. Punjab is the largest province of the country having more than 50% of the population. The state of β-thalassemia is alarming as consanguinity is very high (>81%) and the literacy rate is low in South Punjab. A thalassemia prevention program is the need of the hour in this part of Pakistan. In this study, we initiated awareness, screening, and characterization of the mutations causing β-thalassemia as well as a genetic counseling program mainly in the districts of Faisalabad and D.G. Khan to establish prenatal diagnosis, a facility previously unavailable in this region for disease prevention. A total of 248 unrelated transfusion-dependent children and the available members of their families were screened to characterize the mutations and identify the carriers. Genetic counseling was provided to these families and prenatal diagnosis offered. In the samples analyzed, 11 β-thalassemia mutations and three hemoglobin variants were detected mainly by using the Monoplex and Multiplex ARMS-PCR. First-trimester prenatal diagnosis was carried out through chorionic villus sampling (CVS) in seven pregnancies at risk. As a result of our campaign, 145 carrier couples planning to have more children gave their consent to have retrospective prenatal diagnosis in every pregnancy in future. A cooperative trend and a positive attitude toward the prevention of β-thalassemia were noticed in the families with affected children and in the general population. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   
99.
100.
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