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   589篇
  免费   3篇
  国内免费   6篇
安全科学   5篇
废物处理   37篇
环保管理   60篇
综合类   46篇
基础理论   138篇
污染及防治   166篇
评价与监测   111篇
社会与环境   34篇
灾害及防治   1篇
  2023年   17篇
  2022年   48篇
  2021年   35篇
  2020年   11篇
  2019年   11篇
  2018年   19篇
  2017年   16篇
  2016年   28篇
  2015年   17篇
  2014年   27篇
  2013年   59篇
  2012年   28篇
  2011年   30篇
  2010年   36篇
  2009年   22篇
  2008年   33篇
  2007年   28篇
  2006年   20篇
  2005年   16篇
  2004年   11篇
  2003年   17篇
  2002年   16篇
  2001年   7篇
  2000年   4篇
  1999年   6篇
  1998年   3篇
  1997年   1篇
  1996年   2篇
  1995年   2篇
  1994年   4篇
  1992年   4篇
  1991年   1篇
  1989年   2篇
  1984年   1篇
  1982年   1篇
  1980年   1篇
  1978年   1篇
  1976年   1篇
  1974年   1篇
  1973年   1篇
  1972年   1篇
  1969年   1篇
  1966年   1篇
  1964年   1篇
  1961年   3篇
  1960年   1篇
  1958年   1篇
  1957年   1篇
排序方式: 共有598条查询结果,搜索用时 15 毫秒
1.
Waste accumulation is a grave concern and becoming a transboundary challenge for environment. During Covid-19 pandemic, diverse type of waste were collected due to different practices employed in order to fight back the transmission rate of the virus. Covid-19 was proved to be capricious catastrophe of this 20th century and even not completely eradicated from the world. The havoc created by this imperceptible quick witted, pleomorphic deadly virus can't be ignored. Though a number of vaccines have been developed by the scientists but there is a fear of getting this virus again in our life. Medical studies prove that immunity drinks will help to reduce its reoccurrences. Coconut water is widely used among all drinks available globally. Its massive consumption created an incalculable pile of green coconut shells around the different corners of the world. This practice generating enormous problem of space acquisition for the environment. Both the environment and public health will benefit from an evaluation of quantity of coconut waste that is being thrown and its potential to generate value added products. With this context, present article has been planned to study different aspects like, coconut waste generation, its biological properties and environmental hazards associated with its accumulation. Additionally, this review illustrates, green technologies for production of different value added products from coconut waste.  相似文献   
2.
One hundred forty seven samples of bovine milk were collected from 14 districts of Haryana, India during December 1998–February 1999 and analysed for the presence of organochlorine pesticide (OCPs) residues. ∑HCH, ∑DDT, ∑endosulfan and aldrin were detected in 100%, 97%, 43% and 12% samples and with mean values of 0.0292, 0.0367, 0.0022 and 0.0036 μg/ml, respectively. Eight percent samples exceeded the maximum residue limit (MRL) of 0.10 mg/kg as recommended by WHO for ∑HCH, 4% samples of 0.05 mg/kg for α-HCH, 5% samples of 0.01 mg/kg for γ-HCH, 26% samples of 0.02 mg/kg for β-HCH as recommended by PFAA and 24% samples of 0.05 mg/kg as recommended by FAO for ∑DDT. Concentrations of β-HCH and p,p′-DDE were more as compared to other isomers and metabolites of HCH and DDT.  相似文献   
3.
The Singrauli region in the southeastern part of Uttar Pradesh, India is one of the most polluted industrial sites of Asia. It encompasses 11 open cast coalmines and six thermal power stations that generate about 7,500 MW (about 10% of India’s installed generation capacity) electricity. Thermal power plants represent the main source of pollution in this region, emitting six million tonnes of fly-ash per annum. Fly-ash is deposited on soils over a large area surrounding thermal power plants. Fly-ashes have high surface concentrations of several toxic elements (heavy metals) and high atmospheric mobility. Fly ash is produced through high-temperature combustion of fossil fuel rich in ferromagnetic minerals. These contaminants can be identified using rock-magnetic methods. Magnetic susceptibility is directly linked to the concentration of ferromagnetic minerals, primarily high values of magnetite. In this study, magnetic susceptibility of top soil samples collected from surrounding areas of a bituminous-coal-fired power plant were measured to identify areas of high emission levels and to chart the spatial distribution of airborne solid particles. Sites close to the power plant have shown higher values of susceptibility that decreases with increasing distance from the source. A significant correlation between magnetic susceptibility and heavy metal content in soils is found. A comparison of the spatial distribution of magnetic susceptibility with heavy-metal concentrations in soil samples suggests that magnetic measurements can be used as a rapid and inexpensive method for proxy mapping of air borne pollution due to industrial activity.  相似文献   
4.
The migration pathways for polyaromatic hydrocarbons (PAH) and the associated active attenuating mechanisms within the urban environment are examined. The interest in developing an improved understanding of PAH migration/attenuation is focused toward quantification of the cost-effectiveness of urban runoff control strategies for mitigation of PAH inputs to receiving water bodies.A case study application to the City of Sault Ste Marie demonstrates that snow removal from sub-basins with the largest deposition rates, and relatively small wet and/or dry stormwater management ponds, are the most cost-effective remediation strategies.  相似文献   
5.
6.
7.
 The ubiquity of circadian rhythms suggests that they have an intrinsic adaptive value (Ouyang et al. 1998; Ronneberg and Foster 1997). Some experiments have shown that organisms have enhanced longevity, development time or growth rates when maintained in environments whose periodicity closely matches their endogenous period (Aschoff et al. 1971; Highkin and Hanson 1954; Hillman 1956; Pittendrigh and Minis 1972; Went 1960). So far there has been no experimental evidence to show that circadian rhythms per se (i.e. periodicity itself, as opposed to phasing properties of a rhythm) confer a fitness advantage. We show that the circadian eclosion rhythm persists in a population of the fruitfly Drosophila melanogaster maintained in constant conditions of light, temperature, and humidity for over 600 generations. The results suggest that even in the absence of any environmental cycle there exists some intrinsic fitness value of circadian rhythms. Received: 2 November 1998 / Accepted in revised form: 22 April 1999  相似文献   
8.
 This paper deals with the present scenario of hazardous waste management practices in Thailand, and gives some insights into future prospects. Industrialization in Thailand has systematically increased the generation of hazardous waste. The total hazardous waste generated in 2001 was 1.65 million tons. It is estimated that over 300 million kg/year of hazardous waste is generated from nonindustrial, community sources (e.g., batteries, fluorescent lamps, cleansing chemicals, pesticides). No special facilities are available for handling these wastes. There are neither well-established systems for separation, storage, collection, and transportation, nor the effective enforcement of regulations related to hazardous wastes management generated from industrial or nonindustrial sectors. Therefore, because of a lack of treatment and disposal facilities, these wastes find their way into municipal wastewaters, public landfills, nearby dump sites, or waterways, raising serious environmental concern. Furthermore, Thailand does not have an integrated regulatory framework regarding the monitoring and management of hazardous materials and wastes. In addition to the absence of a national definition of hazardous wastes, limited funding has caused significant impediments to the effective management of hazardous waste. Thus, current waste management practices in Thailand present significant potential hazards to humans and the environment. The challenging issues of hazardous waste management in Thailand are not only related to a scarcity of financial resources (required for treatment and disposal facilities), but also to the fact that there has been no development of appropriate technology following the principles of waste minimization and sustainable development. A holistic approach to achieving effective hazardous waste management that integrates the efforts of all sectors, government, private, and community, is needed for the betterment of human health and the environment. Received: February 26, 2001 / Accepted: October 11, 2002  相似文献   
9.
Activated carbon, developed from fertilizer waste, has been used for the removal of Hg2+, Cr6+, Pb2+, and Cu2+. Mass transfer kinetic approach has been successfully applied for the determination of various parameters necessary for designing a fixed-bed absorber. Parameters selected are the length of the (PAZ) primary adsorption zone (δ), total time involved for the establishment of primary adsorption zone (tx), mass rate of flow to the absorber (Fm), time for primary adsorption zone to move down its length (tδ), amount of adsorbate adsorbed in PAZ from breakpoint to exhaustion (Ms), fractional capacity (f), time of initial formation of PAZ (tf) and per cent saturation of column at break point. Chemical regeneration has been achieved with 1 M HNO3.  相似文献   
10.
Behaviour of forchlorfenuron residues in grape,soil and water   总被引:3,自引:0,他引:3  
Sharma D  Awasthi MD 《Chemosphere》2003,50(5):589-594
Persistence of forchlorfenuron residues in grape berries at harvest following its dip application as single or split doses to grape berry clusters and periodic dissipation of forchlorfenuron residues in grape berries following foliar spray application were studied. Periodic dissipation of forchlorfenuron residues following its fortification in soil and water were also studied. Splitting the dip application concentration of forchlorfenuron to grape berries reduced its residues in the berries at harvest, which persisted for more than 65 days from all treatments. In case of foliar application, however, the residues of forchlorfenuron in/on the grape berries persisted for 15-20 days only from three treatment concentrations of 2, 3 and 4 ml/l and dissipated with half-lives of 3.4-4.5 days. The residues of forchlorfenuron dissipated faster in soils maintained at field capacity moisture condition than in air dry soils. There was wide variation in its residue persistence in soil (DT50 = 15.1-121.3 days) depending on soil type and moisture condition. Forchlorfenuron residues persisted for more than 30 days in water and its dissipation was fastest at a water salinity level of 3.85 mmho/ cm although the rate of dissipation was not significantly affected by the change in salinity level from <0.04 to 5.90 mmho/cm.  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