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   38篇
  免费   3篇
安全科学   1篇
环保管理   8篇
综合类   5篇
基础理论   6篇
污染及防治   6篇
评价与监测   9篇
社会与环境   6篇
  2022年   1篇
  2021年   1篇
  2018年   3篇
  2017年   1篇
  2016年   4篇
  2015年   1篇
  2014年   6篇
  2013年   2篇
  2012年   2篇
  2009年   1篇
  2008年   3篇
  2007年   1篇
  2004年   1篇
  2003年   4篇
  2002年   1篇
  2000年   1篇
  1999年   1篇
  1997年   2篇
  1988年   1篇
  1980年   1篇
  1964年   1篇
  1962年   1篇
  1958年   1篇
排序方式: 共有41条查询结果,搜索用时 203 毫秒
31.
Presence of pesticide residues in tobacco increases health risk of both active and passive smokers, apart from the imminent potential health problems associated with it. Thus, monitoring of pesticide residue is an important issue in terms of formulating stringent policies, enabling global trade and safeguarding the consumer’s safety. In this study, a gas chromatography-single quadrupole mass spectrometry (GC-MS) method based upon quantifier-qualifier ions (m/z) ratio was employed for detecting and assessing ten organochlorine pesticide residues (α-HCH, β-HCH, γ-HCH, δ-HCH, 2,4-DDT, 4,4-DDT, endrin, α-endosulfan, β-endosulfan and endosulfan sulphate) in 152 flue-cured (FC) tobacco leave samples from two major tobacco growing states, Karnataka and Andhra Pradesh, of India. In the majority of samples, pesticide residue levels were below the limit of quantification (LOQ). In few samples, pesticide residues were detected and they found to comply with the guidance residue levels (GRL) specifications of the Cooperation Center for Scientific Research Relative to Tobacco (CORESTA). Detection of the phase out pesticides like DDT/HCH might be due to transfer of persistent residues from the environmental components to the plant. This is the first report on these ten organochlorine pesticide residues in Indian FC tobacco.  相似文献   
32.
This paper, reports for the first time, an extensive study of alpha activity of all widely used building materials (plaster of Paris, stone chips, marble, white cement, mosaic stone, limestone, sand, granite, cement brick, asbestos, red brick, cement tile, ceramic tile and ceramics) in West Bengal, India. The alpha activities have been measured using Solid State Nuclear Track Detector (SSNTD), a very sensitive detector for alpha particles. The samples were collected from local markets of Kolkata. The measured average alpha activities ranged from 22.7+/-2.5 to 590.6+/-16.8Bqkg(-1). The alpha activity of ceramic tiles was highest and provides additional data to estimate the effect of environmental radiation exposure on human health.  相似文献   
33.
Treatment with Aldrin, an organochlorine insecticide, for 13 and 26 days caused suppression of 3beta-hydroxysteroid dehydrogenase (3beta-HSD) and 17beta-hydroxysteroid dehydrogenase (17beta-HSD) activities, along with accumulation of cholesterol in the testicular tissues of adult rats. The same treatment also resulted in a reduction in the nuclear diameter of Leydig cells (LCND) and diameter of seminiferous tubules. A decrease in the weight of testes, seminal vesicles and ventral prostate was also noted. HCG administration in the long-term (26 days) treatment restored the steroidogenic enzymes activity and the nuclear diameter of the Leydig cells. It also reduced the accumulation of tissue cholesterol towards the vehicle-injected controls. The inhibition of steroidogenesis in the testes possibly reflects a decrease in pituitary gonadotrophin release after the treatment with Aldrin.  相似文献   
34.
35.
36.
The concentration levels of major (Al, Ca, Fe, K, Mg, Mn, Na, Si, Ti) and some trace (Be, Se, Tl) elements were determined by atomic absorption spectrometry for the coal fly ashes emitted in the combustion of anthracite and soft coals. Total contents and concentration profiles were established for all elements studied as a function of the mean particle size. The content of those elements volatilized during coal combustion (Se, Tl) decreases with increasing particle size, while the unvolatilized elements show small changes in their concentration profiles. The content of aluminium shows a minimum level at a mean particle size of about 25 μm.  相似文献   
37.
We studied trends in food production and nitrous oxide emissions from India's agricultural sector between 1961 and 2000. Data from Food and Agricultural Statistics (FAO) have been gathered covering production, consumption, fertilizer use and livestock details. IPCC 1996 revised guidelines were followed in studying the variations in N2O-N emissions. Results suggest that total N2O-N emissions (direct, animal waste and indirect sources) increased ~6.1 times from ~0.048 to ~0.294 Tg N2O-N, over 40 years. Source-wise breakdown of emissions from 1961–2000 indicated that during 1961 most of the N2O-N inputs were from crop residues (61%) and biological nitrogen fixation (25%), while during 2000 the main sources were synthetic fertilizer (~48%) and crop residues (19%). Direct emissions increased from ~0.031 to ~0.183 Tg. It is estimated that ~3.1% of global N2O-N emissions comes from India. Trends in food production, primarily cereals (rice, wheat and coarse grains) and pulses, and fertilizer consumption from 1961–2000 suggest that food production (cereals and pulses) increased only 3.7 times, while nitrogenous fertilizer consumption increased ~43 times over this period, leading to extensive release of nitrogen to the atmosphere. From this study, we infer that the challenge for Indian agriculture lies not only in increasing production but also in achieving production stability while minimizing the impact to the environment, through various management and mitigation options.  相似文献   
38.
The dust fall-out rate, distribution pattern andconcentration of lead in the particulate fall-outmatters in urban Raipur city covering an area of 160 km2 during one hydrological year i.e. November1996–June 1997, has been described. The entire cityhas been divided into 6 zones comprising ofindustrial, commercial, residential and heavy trafficareas. A monthly collection and analysis of dustfall-out rate between 3.0(±0.1) and91.3(±1.2) metric tonnes km-2 month-1 wereobserved at all 6 sampling sites. The total annualflux of lead in the fall-out of the city at differentzones is in the range 0.0065–0.4304 kg km-2yr-1. The results show that dust fall-out and thelead levels both are at higher magnitudes in winterand autumn. These large levels of air pollutants havealso been correlated with some meteorological parameters like relative humidity and temperature, and strong positive correlations have been observed.  相似文献   
39.
The Soil and Water Assessment Tool (SWAT) is widely used in the United States (U.S.) to simulate hydrology and water quality simulation. Process‐based models like SWAT require a great deal of data to accurately represent the natural world, including topography, land use, soils, weather, and management. With the exception of management, all these data are available nationally from multiple sources. To date, credible SWAT studies in the U.S. have assembled suitable management data (operation scheduling, fertilization application rates, and plant growth parameterization). In this research, we develop a national management database for SWAT using existing U.S. Department of Agriculture data sources. These data are compatible with existing SWAT interfaces and are relatively easy to use. Although management data from local sources is preferred, these data are not always available. This work is intended to fill this void with more reasonable management data than the existing defaults. This national database covers all major cultivated crops and should facilitate improved SWAT applications in the U.S. These data were tested in two case studies and found to produce satisfactory SWAT predictions. The database developed in this research is freely available on the web.  相似文献   
40.
We assessed the association between arsenic intake through water and diet, and arsenic levels in first morning-void urine under variable conditions of water contamination. This was done in a 2-year consecutive study in an endemic population. Exposure of arsenic through water and diet was assessed for participants using arsenic-contaminated water (≥50 μg L?1) in a first year (group I) and for participants using water lower in arsenic (<50 μg L?1) in the next year (group II). Participants with and without arsenical skin lesions were considered in the statistical analysis. Median dose of arsenic intake through drinking water in groups I and II males was 7.44 and 0.85 μg kg body wt.?1 day?1 (p <0.0001). In females, it was 5.3 and 0.63 μg kg body wt.?1 day?1 (p <0.0001) for groups I and II, respectively. Arsenic dose through diet was 3.3 and 2.6 μg kg body wt.?1 day?1 (p?=?0.088) in males and 2.6 and 1.9 μg kg body wt.?1 day?1 (p?=?0.0081) in females. Median arsenic levels in urine of groups I and II males were 124 and 61 μg L?1 (p?=?0.052) and in females 130 and 52 μg L?1 (p?=?0.0001), respectively. When arsenic levels in the water were reduced to below 50 μg L?1 (Indian permissible limit), total arsenic intake and arsenic intake through the water significantly decreased, but arsenic uptake through the diet was found to be not significantly affected. Moreover, it was found that drinking water mainly contributed to variations in urine arsenic concentrations. However, differences between male and female participants also indicate that not only arsenic uptake, but also many physiological factors affect arsenic behavior in the body and its excretion. As total median arsenic exposure still often exceeded 3.0 μg kg body wt.?1 day?1 (the permissible lower limit established by the Joint Expert Committee on Food Additives) after installation of the drinking water filters, it can be concluded that supplying the filtered water only may not be sufficient to minimize arsenic availability for an already endemic population.  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