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   165篇
  免费   4篇
  国内免费   9篇
废物处理   23篇
环保管理   18篇
综合类   18篇
基础理论   42篇
污染及防治   52篇
评价与监测   17篇
社会与环境   8篇
  2023年   8篇
  2022年   10篇
  2021年   10篇
  2020年   1篇
  2019年   4篇
  2018年   12篇
  2017年   7篇
  2016年   7篇
  2015年   4篇
  2014年   7篇
  2013年   25篇
  2012年   3篇
  2011年   12篇
  2010年   3篇
  2009年   19篇
  2008年   9篇
  2007年   9篇
  2006年   5篇
  2005年   7篇
  2004年   3篇
  2002年   4篇
  2001年   1篇
  2000年   2篇
  1998年   1篇
  1996年   1篇
  1994年   1篇
  1992年   1篇
  1982年   1篇
  1971年   1篇
排序方式: 共有178条查询结果,搜索用时 15 毫秒
41.
A new sensitive analytical procedure has been developed for the determination of residues of endosulfan in human blood samples. The method involves the extraction of residues of endosulfan from blood samples by the addition of 60% sulfuric acid at 10 degrees C, liquid/liquid partitioning by using hexane and acetone mixture (9:1) and quantification by using GC-ECD. Residues of endosulfan in blood samples were quantified as the sum of alpha-endosulfan, beta-endosulfan, endosulfan sulfate and endosulfandiol. The influence of temperature during the extraction has been studied. Recovery experiments were conducted over the concentration range 1.0-50 ng ml(-1) and the relative standard deviation calculated. The method was found to be sufficiently sensitive to quantify the residue of total endosulfan up to the 1.0 ng ml(-1) level. The recovery was 92% with a calculated relative standard deviation of 1.96%. Conversion of endosulfan to endosulfandiol is found to be less than 0.5% under the defined conditions. The method was applied to the analysis of residue contents of endosulfan and its metabolites in blood samples collected from the exposed population. The data obtained has been confirmed by GC-MS-EI in selective ion monitoring (SIM) mode.  相似文献   
42.
Efforts to develop multipollutant control strategies have demonstrated that adding certain oxidants to different classes of Ca-based sorbents leads to a significant improvement in elemental Hg vapor (Hg0), SO2, and NOx removal from simulated flue gases. In the study presented here, two classes of Ca-based sorbents (hydrated limes and silicate compounds) were investigated. A number of oxidizing additives at different concentrations were used in the Ca-based sorbent production process. The Hg0, SO2, and NOx capture capacities of these oxidant-enriched sorbents were evaluated and compared to those of a commercially available activated carbon in bench-scale, fixed-bed, and fluid-bed systems. Calcium-based sorbents prepared with two oxidants, designated C and M, exhibited Hg0 sorption capacities (approximately 100 microg/g) comparable to that of the activated carbon; they showed far superior SO2 and NOx sorption capacities. Preliminary cost estimates for the process utilizing these novel sorbents indicate potential for substantial lowering of control costs, as compared with other processes currently used or considered for control of Hg0, SO2, and NOx emissions from coal-fired boilers. The implications of these findings toward development of multipollutant control technologies and planned pilot and field evaluations of more promising multipollutant sorbents are summarily discussed.  相似文献   
43.
The present study reported for the first time on the effect of isopod parasite, Cymothoa indica infestation on Oxyurichthys microlepis an ecologically important gobiid fish from Parangipettai coastal environment (South-east coast of India). The loss of weight in host fishes (male 20.47 and female 32.84%) were observed due to parasitism. The weight of uninfested female fish was found to be higher than that of infested one. The calus like thickening developed on the gill arch and gill filaments of host fish due to the persistent irritation caused by the appendages of the parasite. The reduction of gill surface area was observed due to the attachment of the parasites. The maximum reduction noticed in the first gill arch is mainly due to the heavy pressure exerted by the parasite. Details of gross lesions observed in the branchial chamber, buccal cavity and body surface was enumerated. Heavy infestations of parasitic juveniles have the potential to kill small fingerlings. The swimming capacity of the fish was also found to be affected.  相似文献   
44.
Journal of Material Cycles and Waste Management - Maize straw- and rice husk-derived biochars were produced in a simple metal kiln without automated control. Their characteristics and effects on...  相似文献   
45.
Mehta, Vikram M., Norman J. Rosenberg, and Katherin Mendoza, 2011. Simulated Impacts of Three Decadal Climate Variability Phenomena on Water Yields in the Missouri River Basin. Journal of the American Water Resources Association (JAWRA) 47(1):126‐135. DOI: 10.1111/j.1752‐1688.2010.00496.x Abstract: The Missouri River Basin (MRB) is the largest river basin in the United States (U.S.), and is one of the most important crop and livestock‐producing regions in the world. In a previous study of associations between decadal climate variability (DCV) phenomena and hydro‐meteorological (HM) variability in the MRB, it was found that positive and negative phases of the Pacific Decadal Oscillation (PDO), the tropical Atlantic sea‐surface temperature gradient variability (TAG), and the west Pacific warm pool (WPWP) temperature variability were significantly associated with decadal variability in precipitation and 2‐meter air temperature in the MRB, with combinations of various phases of these DCV phenomena associated with drought, flood, or neutral HM conditions. Here, we report on a methodology developed and applied to assess whether the aforementioned DCVs directly affect the hydrology of the MRB. The Hydrologic Unit Model of the U.S. (HUMUS) was used to simulate water yields in response to realistic values of the PDO, TAG, and WPWP at 75 widely distributed, eight‐digit hydrologic unit areas within the MRB. HUMUS driven by HM anomalies in both the positive and negative phases of the PDO and TAG resulted in major impacts on water yields, as much as ±20% of average water yield in some locations. Impacts of the WPWP were smaller. The combined and cumulative effects of these DCV phenomena on the MRB HM and water availability can be dramatic with important consequences for the MRB.  相似文献   
46.
Traditionally, the identification and characterization of microbial communities in contaminated soil and water has previously been limited to those microorganisms that are culturable. The application of molecular techniques to study microbial populations at contaminated sites without the need for culturing has led to the discovery of unique and previously unrecognized microorganisms as well as complex microbial diversity in contaminated soil and water which shows an exciting opportunity for bioremediation strategies. Nucleic acid extraction from contaminated sites and their subsequent amplification by polymerase chain reaction (PCR) has proved extremely useful in assessing the changes in microbial community structure by several microbial community profiling techniques. This review examines the current application of molecular techniques for the characterization of microbial communities in contaminated soil and water. Techniques that identify and quantify microbial population and catabolic genes involved in biodegradation are examined. In addition, methods that directly link microbial phylogeny to its ecological function at contaminated sites as well as high throughput methods for complex microbial community studies are discussed.  相似文献   
47.
A systematic study on the natural radionuclides such as 210Po and 210Pb in the environmental matrices of Point Calimere ecosystem has been undertaken to establish a baseline data on the radiation profile of Point Calimere environment. The environmental samples such as water, sediment and biota (seaweeds, crustaceans, molluscs and fish) have been subjected to analyses. It has been observed that the concentration of 210Po and 210Pb in the water samples of Point Calimere to be 0.5 mBq/l and 1.3 mBq/l, respectively. The soft tissues of the organisms accumulated higher 210Po content while shells and bones contained more 210Pb. The bivalve molluscs Meretrix casta have been identified to accumulate higher concentration of 210Po suggesting that they could serve as bio-indicator of radionuclides like 210Po in the Point Calimere ecosystem. The concentration factor of 210Po for the biotic components ranged from approximately 10(3) to 10(6) while for 210Pb it ranged from approximately 10(3) to 10(5).  相似文献   
48.
Soil samples were collected with distance at 5, 20, 40, 80, 160 and 320 m from the Shen-Ha Highway, Northeast China, to investigate the effect of heavy metals of highway origin on soil nematode guilds. The contents of soil Pb, Cu and Zn and the nematode community structure in this investigation were analyzed. The results showed that the contents of total and available Pb, Cu and Zn varied significantly with the different distances from the highway. Pb was the main pollutant in the soils in the vicinity of Shen-Ha Highway and the zone from 20 to 40 m away from the highway was the most polluted area. The highest abundance of soil nematodes was found at 5 m while the lowest at 20 m away from the highway. Thirty six genera of nematodes belonging to 23 families were identified. Nematode guilds having different responses to soil heavy metals were classified into four types. Soil nematode guilds may act as a prominent indicator to heavy metal pollution of highway origin.  相似文献   
49.
Environmental Science and Pollution Research - Mining and extraction of stones and minerals play a significant role in many countries economic growth in the world. The production of dolomite...  相似文献   
50.
Amyotrophic lateral sclerosis (ALS), a progressive disorder that usually runs a fatal course within 2–5 years of onset, is characterized by loss of motor neurons in the cortex, brain stem, and spinal cord. In this study mercury (Hg) concentrations were determined in blood samples of 40 ALS patients, of whom 24 ALS patients were from the Ganga plain region and their metal levels were found to be significantly higher. In contrast, Hg levels in the 16 ALS patients from non-Ganga plain regions whose levels were similar to those of the control subjects. Mercury in stream water samples and freshly deposited stream sediment were determined in the locations of patients’ native residences along the Ganga plain region and metal levels were found to be higher than the threshold guideline values for Hg in stream waters recommended by WHO. The geo-accumulation index in selected sites of freshly deposited stream sediment ranged from moderate to highly polluted. The high levels of Hg observed in ALS patients may potentially alter the redox status of neuronal cell components and induce cell-death pathways.  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