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排序方式: 共有1702条查询结果,搜索用时 31 毫秒
971.
This paper provides baseline information about the total annual dust fall, and its constituents and seasonal variation, from a sub-tropical opencast coalmine area in Bina, India. Dust samples were collected monthly for 2 years (June 2002-May 2004) from five sampling sites in the region and analyzed in the laboratory for water-soluble and -insoluble matter. Water-insoluble components constituted the major fraction of the total annual dust fall. Two-way ANOVA indicated significant variations in dust fall at different sites, over the months and in their interactions. The dust deposition rate was highest during summer (March-June), followed by winter (November-February) and lowest in the rainy season (July-October). Maximum dust fall was observed near the coal handling plant (at site 2) followed by the receiving pit of the coal handling plant (site 3), near the main sub-station (site 4), Jawahar colony (site 1) and Gharasari village (site 5). An inverse and significant relation was observed between dust fall and precipitation. Our studies have shown that the main residential areas are experiencing higher levels of dust fall which makes them unsuitable for living. We suggest that residential areas should be moved farther away from the mining area in the opposite direction of prevalent winds. 相似文献
972.
Sulfamethazine uptake by plants from manure-amended soil 总被引:12,自引:0,他引:12
Animal manure is applied to agricultural land as a means to provide crop nutrients. However, animal manure often contains antibiotics as a result of extensive therapeutic and subtherapeutic use in livestock production. The objective of this study was to evaluate plant uptake of a sulfonamide-class antibiotic, sulfamethazine, in corn (Zea mays L.), lettuce (Lactuca sativa L.), and potato (Solanum tuberosum L.) grown in a manure-amended soil. The treatments were 0, 50, and 100 microg sulfamethazine mL(-1) manure applied at a rate of 56 000 L ha(-1). Results from the 45-d greenhouse experiment showed that sulfamethazine was taken up by all three crops, with concentrations in plant tissue ranging from 0.1 to 1.2 mg kg(-1) dry weight. Sulfamethazine concentrations in plant tissue increased with corresponding increase of sulfamethazine in manure. Highest plant tissue concentrations were found in corn and lettuce, followed by potato. Total accumulation of sulfamethazine in plant tissue after 45 d of growth was less than 0.1% of the amount applied to soil in manure. These results raise potential human health concerns of consuming low levels of antibiotics from produce grown on manure-amended soils. 相似文献
973.
Critical review of EPS production, synthesis and composition for sludge flocculation 总被引:1,自引:0,他引:1
Klai Nouh Ram Saurabh Kumar Sellamuthu Balasubramanian Rajeshwar Dayal Tyagi 《环境科学学报(英文版)》2018,30(4):225-245
Extracellular polymeric substances(EPS) produced by microorganisms represent biological macromolecules with unfathomable potentials and they are required to be explored further for their potential application as a bioflocculant in various wastewater sludge treatment. Although several studies already exist on biosynthetic pathways of different classical biopolymers like alginate and xanthan, no dedicated studies are available for EPS in sludge. This review highlights the EPS composition, functionality, and biodegradability for its potential use as a carbon source for production of other metabolites. Furthermore, the effect of various extraction methods(physical and chemical) on compositional, structural, physical and functional properties of microbial EPS has been addressed. The vital knowledge of the effect of extraction method on various important attributes of EPS can help to choose the suitable extraction method depending upon the intended use of EPS. The possible use of different molecular biological techniques for enhanced production of desired EPS was summarized. 相似文献
974.
Revised algorithm for estimating light extinction from IMPROVE particle speciation data 总被引:14,自引:0,他引:14
Pitchford M Maim W Schichtel B Kumar N Lowenthal D Hand J 《Journal of the Air & Waste Management Association (1995)》2007,57(11):1326-1336
The Interagency Monitoring of Protected Visual Environments (IMPROVE) particle monitoring network consists of approximately 160 sites at which fine particulate matter (PM2.5) mass and major species concentrations and course particulate matter (PM10) mass concentrations are determined by analysis of 24-hr duration sampling conducted on a 1-day-in-3 schedule A simple algorithm to estimate light extinction from the measured species concentrations was incorporated in the 1999 Regional Haze Rule as the basis for the haze metric used to track haze trends. A revised algorithm was developed that is more consistent with the recent atmospheric aerosol literature and reduces bias for high and low light extinction extremes. The revised algorithm differs from the original algorithm in having a term for estimating sea salt light scattering from Cl(-) ion data, using 1.8 instead of 1.4 for the mean ratio of organic mass to measured organic carbon, using site-specific Rayleigh scattering based on site elevation and mean temperature, employing a split component extinction efficiency associated with large and small size mode sulfate, nitrate and organic mass species, and adding a term for nitrogen dioxide (NO2) absorption for sites with NO2 concentration information. Light scattering estimates using the original and the revised algorithms are compared with nephelometer measurements at 21 IMPROVE monitoring sites. The revised algorithm reduces the underprediction of high haze periods and the overprediction of low haze periods compared with the performance of the original algorithm. This is most apparent at the hazier monitoring sites in the eastern United States. For each site, the PM10 composition for days selected as the best 20% and the worst 20% haze condition days are nearly identical regardless of whether the basis of selection was light scattering from the original or revised algorithms, or from nephelometer-measured light scattering. 相似文献
975.
Sanjena Narayanasamydamodaran Jian e Zuo Haiteng Ren Nawnit Kumar 《Frontiers of Environmental Science & Engineering》2021,15(4):66
976.
An eco-sustainable green approach for heavy metals management: two case studies of developing industrial region 总被引:2,自引:0,他引:2
Rai PK 《Environmental monitoring and assessment》2012,184(1):421-448
Multifaceted issues or paradigm of sustainable development should be appropriately addressed in the discipline of environmental
management. Pollution of the biosphere with toxic metals has accelerated dramatically since the beginning of the Industrial
Revolution. In present review, comparative assessment of traditional chemical technologies and phytoremediation has been reviewed
particularly in the context of cost-effectiveness. The potential of phytoremediation and green chemicals in heavy metals management
has been described critically. Further, the review explores our work on phytoremediation as green technology during the last
6 years and hand in hand addresses the various ecological issues, benefits and constraints pertaining to heavy metal pollution
of aquatic ecosystems and its phytoremediation as first case study. Second case study demonstrates the possible health implications
associated with use of metal contaminated wastewater for irrigation in peri-urban areas of developing world. Our researches
revealed wetland plants/macrophytes as ideal bio-system for heavy metals removal in terms of both ecology and economy, when
compared with chemical treatments. However, there are several constraints or limitations in the use of aquatic plants for
phytoremediation in microcosm as well as mesocosm conditions. On the basis of our past researches, an eco-sustainable model
has been proposed in order to resolve the certain constraints imposed in two case studies. In relation to future prospect,
phytoremediation technology for enhanced heavy metal accumulation is still in embryonic stage and needs more attention in
gene manipulation area. Moreover, harvesting and recycling tools needs more extensive research. A multidisciplinary research
effort that integrates the work of natural sciences, environmental engineers and policy makers is essential for greater success
of green technologies as a potent tool of heavy metals management. 相似文献
977.
Jinal Hardik Naik Gopi Kachhadiya Kumar Krishna Amaresan Natarajan 《Environmental science and pollution research international》2021,28(6):6540-6548
Environmental Science and Pollution Research - Soil contamination by heavy metals is one of the major abiotic stresses that cause retarded plant growth and low productivity. Among the heavy metals,... 相似文献
978.
Verma Anushka Giri Arun Kumar Debata Byomakesh 《Environmental science and pollution research international》2023,30(6):14518-14532
Environmental Science and Pollution Research - This study intends to examine the impact of ICT diffusion, globalization, financial development, government effectiveness, and economic growth on... 相似文献
979.
Hussain Mahamed Sahed Mostafa Mazarbhuiya Agnimitra Biswas Kaushal Kumar Sharma 《International Journal of Green Energy》2020,17(2):171-179
ABSTRACTVertical axis wind turbine (VAWT) is an economic and widely used energy converter for converting wind energy into useful form of energy, like mechanical and electrical energy. For efficient energy conversion in low wind speed and to have improved power coefficient of asymmetric blade VAWT, selection of optimum blade thickness is needed thus entailing its detailed investigation with respect to different operating wind speed conditions. Present study methodically explores the impact of thickness to chord (t/c) ratio on aerodynamic performance of a three bladed asymmetrical blade H-Darrieus VAWT at different low wind speed conditions by using 2D unsteady CFD simulations. The optimal t/c is obtained on the basis of maximum power coefficient and average moment coefficient of the turbine. The aerodynamic performance curves are obtained at different operating and t/c conditions and the performance insights are corroborated with the findings from the flow physics study to come to some concrete conclusions on the effects of the thickness to chord ratio. The present study identifies large blade curvature to create a large diverging passage on the blade suction surface as the prominent reason for aerodynamic performance drop at a high t/c ratio. 相似文献
980.
R. Srinivas Ajit Pratap Singh Ayush Aman Gupta Piyush Kumar 《Environmental monitoring and assessment》2018,190(12):720
Global scarcity of freshwater has been gearing towards an unsustainable river basin management and corresponding services to the humans. It needs a holistic approach, which exclusively focuses on effective river water quality monitoring and quantification and identification of pollutant sources, in order to address the issue of sustainability. These days, rivers are heavily contaminated due to the presence of organic and metallic pollutants released from several anthropogenic sources, such as industrial effluents, domestic sewage, and agricultural runoff. It is astonishing to note that even in many developing countries, most of these contaminants are carried through open drains, which enter river premises without proper treatment. Such practice not only devastates riverine ecosystem but also gives rise to deadly diseases, such as minimata and cancer in humans. Considering these issues, the present study develops a novel approach towards simultaneous identification of major sources of pollution in the rivers, along with critical pollutants and locations using an advanced hierarchical cluster and multivariate statistical analysis. A systematic approach has been developed by agglomerating both R-mode and Q-mode analysis, which develops monoplots, two-dimensional biplots, rotated component matrices, and dendrograms (using “SPSS” and “Analyse It” software) to reveal relationships among various quality parameters to identify the pollutant sources along with clustering of critical sampling sites and pollutants. A case study of the Ganges River Basin of India has been considered to demonstrate the efficacy and usefulness of the model by analyzing 85 open drains. Both organic and metallic pollutants are analyzed simultaneously as well as separately to get a holistic understanding of all the relationships and to broaden the perspective of water characterization. Results provide a comprehensive guidance to the policy makers and water managers to optimize corrective efforts, minimize further damage, and improve the water quality condition to ensure sustainable development of the river basin. 相似文献