全文获取类型
收费全文 | 558篇 |
免费 | 9篇 |
国内免费 | 59篇 |
专业分类
安全科学 | 7篇 |
废物处理 | 28篇 |
环保管理 | 53篇 |
综合类 | 128篇 |
基础理论 | 116篇 |
污染及防治 | 190篇 |
评价与监测 | 78篇 |
社会与环境 | 23篇 |
灾害及防治 | 3篇 |
出版年
2023年 | 5篇 |
2022年 | 16篇 |
2021年 | 16篇 |
2020年 | 15篇 |
2019年 | 11篇 |
2018年 | 10篇 |
2017年 | 20篇 |
2016年 | 27篇 |
2015年 | 16篇 |
2014年 | 25篇 |
2013年 | 66篇 |
2012年 | 13篇 |
2011年 | 24篇 |
2010年 | 26篇 |
2009年 | 24篇 |
2008年 | 27篇 |
2007年 | 25篇 |
2006年 | 24篇 |
2005年 | 25篇 |
2004年 | 21篇 |
2003年 | 13篇 |
2002年 | 19篇 |
2001年 | 21篇 |
2000年 | 11篇 |
1999年 | 9篇 |
1998年 | 4篇 |
1996年 | 6篇 |
1995年 | 9篇 |
1994年 | 6篇 |
1993年 | 8篇 |
1992年 | 3篇 |
1991年 | 4篇 |
1990年 | 2篇 |
1989年 | 4篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1982年 | 5篇 |
1979年 | 2篇 |
1975年 | 3篇 |
1974年 | 2篇 |
1971年 | 4篇 |
1966年 | 4篇 |
1965年 | 5篇 |
1964年 | 4篇 |
1963年 | 5篇 |
1961年 | 6篇 |
1960年 | 2篇 |
1958年 | 2篇 |
1955年 | 2篇 |
排序方式: 共有626条查询结果,搜索用时 125 毫秒
31.
C. K. Jain V. V. S. Gurunadha Rao B. A. Prakash K. Mahesh Kumar Mitsuo Yoshida 《Environmental monitoring and assessment》2010,166(1-4):57-67
Hussainsagar Lake in the heart of Hyderabad City (India) receives toxic substances through five streams draining from a catchment area of 245 km2. Of particular interest are heavy metals received from urban runoff as well as municipal sewage and industrial effluents. Heavy metals entering the lake get adsorbed onto the suspended sediments, which eventually settle down in the bottom of the lake. In this study, fractionation of metal ions has been studied on the bed sediments of Hussainsagar Lake in order to determine the ecotoxic potential of metal ions. Comparison of sediments with average shale values indicated anthropogenic enrichment with copper, nickel, lead, cadmium, and zinc. The risk assessment code as applied to the present study reveals that 10–17% of manganese, 10–18% of nickel, 14–24% of chromium, 10–19% of lead, 21–30% of cadmium, and 18–28% of zinc exist in exchangeable fraction and, therefore, comes under medium risk category and may enter into food chain. The association of these metals with the exchangeable fraction may cause deleterious effects to aquatic life. The present database will help in formulating guidelines for carrying out dredging operations under restoration programs in the Hussainsagar Lake. 相似文献
32.
Hydrogeochemical characterization of fluoride rich groundwater of Wailpalli watershed, Nalgonda District, Andhra Pradesh, India 总被引:1,自引:0,他引:1
A. G. S. Reddy D. V. Reddy P. N. Rao K. Maruthy Prasad 《Environmental monitoring and assessment》2010,171(1-4):561-577
The groundwater of Nalgonda district is well known for its very high fluoride content for the past five decades. Many researchers have contributed their scientific knowledge to unravel causes for fluoride enrichment of groundwater. In the present paper, an attempt has been made to relate the high fluoride content in the groundwater to hydrogeochemical characterization of the water in a fracture hard rock terrain—the Wailpally watershed. Groundwater samples collected from all the major geomorphic units in pre- and post-monsoon seasons were analyzed for its major ion constituents such as Ca2?+?, Mg2?+?, Na?+?, K?+?, CO $_{3}^{-}$ , HCO $_{3}^{-}$ , Cl???, SO $_{4}^{-2}$ , NO $_{3}^{-}$ , and F???. The groundwaters in the watershed have the average fluoride content of 2.79 mg/l in pre-monsoon and 2.83 mg/l in post-monsoon. Fluoride concentration in groundwater does not show perceptible change neither with time nor in space. The ionic dominance pattern is in the order of Na?+? > Ca2?+??> Mg2?+??> K??? among cations and HCO $_{3}^{-}\:\,>$ Cl????> SO $_{4}^{-2} >$ NO $_{3}^{-} >$ F??? among anions in pre-monsoon. In post-monsoon, Mg replaces Ca2?+? and NO $_{3}^{-}$ takes the place of SO $_{4}^{-2}$ . The Modified Piper diagram reflect that the water belong to Ca?+?2–Mg?+?2–HCO $_{3}^{-}$ to Na?+?–HCO $_{3}^{-}$ facies. Negative chloralkali indices in both the seasons prove that ion exchange between Na?+? and K?+? in aquatic solution took place with Ca?+?2 and Mg?+?2 of host rock. The interpretation of plots for different major ions and molar ratios suggest that weathering of silicate rocks and water–rock interaction is responsible for major ion chemistry of groundwater in Wailpally watershed. Chemical characteristics and evolution of this fluoride-contaminated groundwater is akin to normal waters of other hard rock terrain; hence, it can be concluded that aquifer material play an important role in the contribution of fluoride in to the accompanying water. High fluoride content in groundwater can be attributed to the continuous water–rock interaction during the process of percolation with fluorite-bearing country rocks under arid, low precipitation, and high evapotranspiration conditions. 相似文献
33.
Serum profiles of PCDDs and PCDFs, in individuals near the Escambia Wood Treating Company Superfund site in Pensacola, FL 总被引:3,自引:0,他引:3
The Escambia Wood Treating Company (ETC) Superfund site, Pensacola, FL, is contaminated with polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/F), benzo(a)pyrene, lead and arsenic from pentachlorophenol (PCP), creosote, and other compounds used to treat utility poles and foundation pilings. Although ETC's operations ceased in 1982, soils in the areas surrounding the facility continue to exhibit elevated levels of contaminants attributable to ETC operations. In July 2000, individuals who may have been affected by contamination from the ETC site, including current and former residents and former workers and their household members were invited to participate in a study, which included a health and exposure history and routine blood analysis. We also conducted a toxicological health evaluation of a subset of these eligible workers/residents by analyzing serum levels of 17 PCDD/F congeners. Members of the ETC cohort exhibited elevated serum PCDD/F relative to the general population, and congener profiles in members of the cohort reflected patterns commonly observed in persons exposed to PCP. Hypertension prevalence in the cohort was found to correlate with PCDD/F levels, although no other significant relationships were identified with monitored health indices. 相似文献
34.
Chandrasekharan H Sarangi A Nagarajan M Singh VP Rao DU Stalin P Natarajan K Chandrasekaran B Anbazhagan S 《Journal of environmental management》2008,89(1):63-72
In this study, the Tsunami-caused deterioration of soil and groundwater quality in the agricultural fields of coastal Nagapattinam district of Tamilnadu state in India is presented by analyzing their salinity and sodicity parameters. To accomplish this, three sets of soil samples up to a depth of 30cm from the land surface were collected for the first six months of the year 2005 from 28 locations and the ground water samples were monitored from seven existing dug wells and hand pumps covering the study region at intervals of 3 months. The EC and pH values of both the soil and ground water samples were estimated and the spatial and temporal variability mappings of these parameters were performed using the geostatistical analysis module of ArcGIS((R)). It was observed that the spherical semivariogram fitted well with the data set of both EC and pH and the generated kriged maps explained the spatial and temporal variability under different ranges of EC and pH values. Further, the recorded EC and pH data of soil and ground water during pre-Tsunami periods were compared with the collected data and generated variability soil maps of EC and pH of the post-Tsunami period. It was revealed from this analysis that the soil quality six months after the Tsunami was nearing the pre-Tsunami scenario (EC< 1.5dSm(-1); pH<8), whereas the quality of ground water remained highly saline and unfit for irrigation and drinking. These observations were compared with the ground scenarios of the study region and possible causes for such changes and the remedial measures for taking up regular agricultural practices are also discussed. 相似文献
35.
A. V. M. Subba Rao Arun K. Shanker V. U. M. Rao V. Narsimha Rao A. K. Singh Pragyan Kumari C. B. Singh Praveen Kumar Verma P. Vijaya Kumar B. Bapuji Rao Rajkumar Dhakar M. A. Sarath Chandran C. V. Naidu J. L. Chaudhary Ch. Srinivasa Rao B. Venkateshwarlu 《Environmental Modeling and Assessment》2016,21(1):17-30
36.
S. Neogi P. Bhattacharyya K. S. Roy B. B. Panda A. K. Nayak K. S. Rao M. C. Manna 《Environmental monitoring and assessment》2014,186(7):4223-4236
In order to identify the viable option of tillage practices in rice–maize–cowpea cropping system that could cut down soil carbon dioxide (CO2) emission, sustain grain yield, and maintain better soil quality in tropical low land rice ecology soil respiration in terms of CO2 emission, labile carbon (C) pools, water-stable aggregate C fractions, and enzymatic activities were investigated in a sandy clay loam soil. Soil respiration is the major pathway of gaseous C efflux from terrestrial systems and acts as an important index of ecosystem functioning. The CO2–C emissions were quantified in between plants and rows throughout the year in rice–maize–cowpea cropping sequence both under conventional tillage (CT) and minimum tillage (MT) practices along with soil moisture and temperature. The CO2–C emissions, as a whole, were 24 % higher in between plants than in rows, and were in the range of 23.4–78.1, 37.1–128.1, and 28.6–101.2 mg m?2 h?1 under CT and 10.7–60.3, 17.3–99.1, and 17.2–79.1 mg m?2 h?1 under MT in rice, maize, and cowpea, respectively. The CO2–C emission was found highest under maize (44 %) followed by rice (33 %) and cowpea (23 %) irrespective of CT and MT practices. In CT system, the CO2–C emission increased significantly by 37.1 % with respect to MT on cumulative annual basis including fallow. The CO2–C emission per unit yield was at par in rice and cowpea signifying the beneficial effect of MT in maintaining soil quality and reduction of CO2 emission. The microbial biomass C (MBC), readily mineralizable C (RMC), water-soluble C (WSC), and permanganate-oxidizable C (PMOC) were 19.4, 20.4, 39.5, and 15.1 % higher under MT than CT. The C contents in soil aggregate fraction were significantly higher in MT than CT. Soil enzymatic activities like, dehydrogenase, fluorescein diacetate, and β-glucosidase were significantly higher by 13.8, 15.4, and 27.4 % under MT compared to CT. The soil labile C pools, enzymatic activities, and heterotrophic microbial populations were in the order of maize?>?cowpea?>?rice, irrespective of the tillage treatments. Environmental sustainability point of view, minimum tillage practices in rice–maize–cowpea cropping system in tropical low land soil could be adopted to minimize CO2–C emission, sustain yield, and maintain soil health. 相似文献
37.
近年来,水污染问题备受关注。生物式水质监测成为目前国家环境保护工作的重要任务之一。为准确监测水质污染情况,本文以青鳉鱼(Oryzias latipes)为研究对象,采用非接触式的机器视觉监测技术,提取青鳉鱼的生理特征(呼吸频率)和运动特征(胸鳍和尾鳍的摆动频率),并分析这些特征与水质之间的关系。本文采用支持向量机(Support Vector Machine,SVM)准确提取鱼鳃,并根据鱼鳃呼吸面积大小变化计算出鱼的呼吸频率。基于形态学细化算法提取青鳉鱼骨架,求出胸鳍和尾鳍的摆动频率。结果显示:不同浓度铜离子暴露实验测得的青鳉鱼生理特征和运动特征与实际情况一致;通过对不同铜离子浓度下的毒性实验数据对比,发现了青鳉鱼的生理特征和运动特征会随不同的铜离子浓度发生相应变化,可以作为水质监测的评价标准。 相似文献
38.
S.S. Mayakaduwa Indika Herath Yong Sik Ok Dinesh Mohan Meththika Vithanage 《Environmental science and pollution research international》2017,24(29):22755-22763
Biochar has been considered as a potential sorbent for removal of frequently detected pesticides in water. In the present study, modified and non-modified rice husk biochars were used for aqueous carbofuran removal. Rice husk biochars were produced at 300, 500, and 700 °C in slow pyrolysis and further exposed to steam activation. Biochars were physicochemically characterized using proximate, ultimate, FTIR methods and used to examine equilibrium and dynamic adsorption of carbofuran. Increasing pyrolysis temperature led to a decrease of biochar yield and increase of porosity, surface area, and adsorption capacities which were further enhanced by steam activation. Carbofuran adsorption was pH-dependant, and the maximum (161 mg g?1) occurred in the vicinity of pH 5, on steam-activated biochar produced at 700 °C. Freundlich model best fitted the sorption equilibrium data. Both chemisorption and physisorption interactions on heterogeneous adsorbent surface may involve in carbofuran adsorption. Langmuir kinetics could be applied to describe carbofuran adsorption in a fixed bed. A higher carbofuran volume was treated in a column bed by a steam-activated biochar versus non-activated biochars. Overall, steam-activated rice husk biochar can be highlighted as a promising low-cost sustainable material for aqueous carbofuran removal. 相似文献
39.
Gawhane Ranjeeta D. Rao Pasumarthi Surya Prakasa Budhavant Krishnakant B. Waghmare Vinayak Meshram Dhananjay C. Safai Pramod D. 《Environmental science and pollution research international》2017,24(26):21065-21072
Environmental Science and Pollution Research - Particulate matter with size less than or equal to 2.5 μm (PM2.5) samples were collected from an urban site Pune, India, during April... 相似文献
40.
Huilun Chen Honghao Rao Pengzhen He Yongxiang Qiao Fei Wang Haijun Liu Minmin Cai Jun Yao 《Environmental science and pollution research international》2014,21(19):11340-11348
Antibiotics are widely used in daily life but their abuse has posed a potential threat to human health. To evaluate the toxicity of chloramphenicol (CAP) at the protein level, the interaction between CAP and human serum albumin (HSA) was investigated by fluorescence, Ultraviolet–visible (UV–Vis) absorption, Fourier transform infrared (FT-IR) spectroscopy and molecular docking methods. Fluorescence data revealed that the fluorescence quenching of HSA by CAP was the result of the formation of CAP–HSA complex, and the binding constant was determined to be 3.196?×?104 L mol?1 at 310 K. The thermodynamic determination indicated that the interaction was driven by enthalpy change and entropy change together, where the multiple hydrogen bonds (CAP and the residues Arg 222 and His 242 of HSA) and van der Waals forces were the dominant binding force. The site marker competition revealed that CAP bound into sub-domain IIA of HSA. The binding of CAP induced the drastic reduction in α-helix conformation and the significant enhancement in β-sheet conformation of HSA. Molecular docking study further confirmed the binding mode obtained by experimental study. This work provides a new quantitative evaluation method for antibiotics to cause the protein damage. 相似文献