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   92篇
  免费   1篇
  国内免费   4篇
安全科学   5篇
废物处理   7篇
环保管理   11篇
综合类   10篇
基础理论   14篇
污染及防治   28篇
评价与监测   11篇
社会与环境   9篇
灾害及防治   2篇
  2023年   5篇
  2022年   8篇
  2021年   5篇
  2020年   1篇
  2019年   1篇
  2018年   2篇
  2017年   4篇
  2016年   4篇
  2015年   6篇
  2014年   2篇
  2013年   17篇
  2012年   6篇
  2011年   5篇
  2010年   4篇
  2009年   4篇
  2008年   5篇
  2007年   4篇
  2006年   3篇
  2005年   1篇
  2004年   4篇
  2003年   1篇
  2002年   1篇
  1998年   1篇
  1992年   1篇
  1981年   1篇
  1976年   1篇
排序方式: 共有97条查询结果,搜索用时 468 毫秒
21.
In the current study, the bioaccumulation of essential and nonessential metals and related antioxidant activity were analyzed in three organs (muscle, gills, and liver) of herbivorous (HF) and carnivorous (CF) edible fish of Chenab River. The comparative analysis revealed a more heterogeneous accumulation of metals in the muscles of HF fish than that of CF fish [chromium (Cr, 3.4 μg g?1), cobalt (Co, 1.7 μg g?1), copper (Cu, 3 μg g?1), and iron (Fe, 45 μg g?1) versus Cr (1.3 μg g?1), Co (0.1 μg g?1), Cu (1.1 μg g?1), and Fe (33 μg g?1), respectively, P?<?0.001]. These results implied an organ-specific accumulation of metals at different trophic levels. According to logistic regression analysis, the bioaccumulation of metals had marked differences in HF and CF. The antioxidant activity was significantly related to the tissue type and the metals to which the organs are exposed to. The liver of CF fish had a higher activity of antioxidant superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), and lipid peroxidase (LPO) than that of HF (P?<?0.05). LPO and guaiacol peroxidase (POD) in both groups were associated with a number of metals, but in HF, cadmium (Cd), Cr, Pb, and Zn were more related with the LPO and SOD activities. Moreover, Cd, Co, Fe, Pb, Ni, Cu, and Zn were above the permissible limits set by various agencies. In numerous cases, our results were even higher than those previously reported in the literature. The results provide an insight into the pollution pattern of Chenab River. These results may be helpful in the future to identify biomarkers of exposure in aquatic organisms.
Figure
?  相似文献   
22.
In this paper, variability in precipitation pattern of Pakistan due to environmental and climatic changes has been studied. Maps have been generated to depict global precipitation variation. Precipitation data of 25 stations of Pakistan have been used. These data were taken from Meteorological Department, Islamabad, Pakistan. The results of two global climate models, namely Australia’s Commonwealth Scientific and Industrial Research’s third generation general circulation model and National Center for Atmospheric Research’s first generation precipitation circulation model for A2 scenario have been applied to investigate the changes. It is observed that precipitation pattern will change significantly in the future. The occurrence of precipitation in all seasons for Pakistan is expected to increase with almost uniform distribution across a season. Average annual precipitation of the country will undergo an increase in the range of +57 to +71 % as compared to average of the base period.  相似文献   
23.
24.
The amount of solid waste in the vicinity of the river Ganga increased rapidly during the festive days of Ardh-Kumbh. The initial amount of solid waste was 775.0 kg, observed on 30th January 2004 in the Har Ki Pauri area, which increased to 4,550.0 kg on the main bathing day of 4th May 2004, showing nearly a six-fold increase. The total amount of solid waste collected during nine days of observations was 23,865.0 kg. The rate of solid waste generation fell sharply during the following week, after the main bathing day, and was found to be 1,155.0 kg, which is still about 14.90% higher than the initial value.  相似文献   
25.
26.
27.
Chlorophenols, typically 4-chlorophenols are highly toxic and non-biodegradable organic contaminants which pose serious threat to the environment, particularly when released into aqueous medium. The removal of these pollutants by efficient method has received worldwide concern in recent past. A new Fe_3O_4–Cr_2O_3 magnetic nanocomposite was synthesized by wet chemical method under ultrasonic irradiation. Microstructure and morphology of the nanocomposite were characterized by powder X-ray diffraction(XRD),Fourier transform infrared(FT-IR), and a transmission electron microscope(TEM). Magnetic and optical properties were studied by a vibrating sample magnetometer(VSM) and an ultraviolet–visible(UV–Vis) spectrophotometer respectively. The magnetic nanocomposite(MNC) was used as photocatalyst for effective decomposition of 4-chlorophenol in water under ultraviolet(UV) irradiation.  相似文献   
28.
The implementation and maintenance of an air pollution monitoring program can be expensive and time consuming, especially when the aim is for long-term monitoring over a significant area. Consequently, it is essential that sites are optimized to provide the best representative cover while minimizing costs. In the past, there has been a tendency to locate sampling stations at pollution hot-spots. While this is acceptable for determining a maximum potential exposure or identifying the extent of a risk, there are limitations to this approach when assessing the potential impact of any future abatement strategies or determining the level of exposure outside the vicinity. This paper presents an approach in which representative air quality assessments can be undertaken for an urban area using the minimum number of measurement sites. A novel methodology is described that involves site selection to capture the maximum variance in measured pollutants, while minimizing spatiotemporal autocorrelation between the selected sites. A case study is presented for Yazd, Iran. Overall, the results show that the proposed methodology can be effective and enable the long-term monitoring of air pollution to be undertaken on a cost-effective basis in urban areas. In addition, there is the potential for the methodology to be utilized for other forms of pollution (e.g., water, soil, and noise).  相似文献   
29.
This paper presents anthropometric data on elderly people in Australia. Data were collected in the metropolitan city of Sydney, NSW, Australia. In all 171 elderly people (males and females, aged 65 years and above) took part in the study. Mean values, standard deviations, medians, range, and coefficients of variation for the various body dimensions were estimated. Correlation coefficients were also calculated to determine the relationship between different body dimensions for the elderly population. The mean stature of elderly Australian males and females were compared with populations from other countries. The paper discusses design implications for elderly people and provides several examples of application of the anthropometric data.  相似文献   
30.
Environmental Science and Pollution Research - Global warming and climate change have become one of the most embarrassing and explosive problems/challenges all over the world, especially in...  相似文献   
[首页] « 上一页 [1] [2] 3 [4] [5] [6] [7] [8] [9] [10] 下一页 » 末  页»
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