全文获取类型
收费全文 | 562篇 |
免费 | 3篇 |
国内免费 | 5篇 |
专业分类
安全科学 | 5篇 |
废物处理 | 36篇 |
环保管理 | 58篇 |
综合类 | 43篇 |
基础理论 | 134篇 |
污染及防治 | 158篇 |
评价与监测 | 108篇 |
社会与环境 | 27篇 |
灾害及防治 | 1篇 |
出版年
2023年 | 15篇 |
2022年 | 48篇 |
2021年 | 31篇 |
2020年 | 10篇 |
2019年 | 11篇 |
2018年 | 18篇 |
2017年 | 14篇 |
2016年 | 27篇 |
2015年 | 18篇 |
2014年 | 28篇 |
2013年 | 54篇 |
2012年 | 27篇 |
2011年 | 30篇 |
2010年 | 35篇 |
2009年 | 22篇 |
2008年 | 33篇 |
2007年 | 26篇 |
2006年 | 20篇 |
2005年 | 14篇 |
2004年 | 11篇 |
2003年 | 13篇 |
2002年 | 15篇 |
2001年 | 7篇 |
2000年 | 3篇 |
1999年 | 5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 |
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570条查询结果,搜索用时 15 毫秒
401.
D.R. Rudnick S. Irmak C. West J.L. Chvez I. Kisekka T.H. Marek J.P. Schneekloth D. Mitchell McCallister V. Sharma K. Djaman J. Aguilar M.E. Schipanski D.H. Rogers A. Schlegel 《Journal of the American Water Resources Association》2019,55(1):38-55
Irrigated agriculture is a major economic contributor of the High Plains Region and it primarily relies on the High Plains Aquifer as a source of water. Over time, areas of the High Plains Aquifer have experienced drawdowns limiting its ability to supply sufficient water to sustain fully irrigated crop production. This among other reasons, including variable climatic factors and differences in state water policy, has resulted in some areas adopting and practicing deficit irrigation management. Considerable research has been conducted across the High Plains Aquifer region to identify locally appropriate deficit irrigation strategies. This review summarizes and discusses research conducted in Nebraska, Colorado, Kansas, and Texas, as well as highlights areas for future research. Editor's note : This paper is part of the featured series on Optimizing Ogallala Aquifer Water Use to Sustain Food Systems. See the February 2019 issue for the introduction and background to the series. 相似文献
402.
Pramod Kumar Sharma Vilas Warudkar Siraj Ahmed 《International Journal of Green Energy》2019,16(2):152-166
This paper investigates the accuracy of the wind resource estimation for a site in a central India region using a latest licensed version of WAsP 11 and windPRO 3.1. Whole one year measured met mast wind data has been taken using anemometer and wind vane at 10 m and 25 m height, respectively above ground level. The digitized elevation and roughness model of the corresponding site shows the roughness class 4 (roughness length 1.2525 m). The wind data has been extrapolated up to 80 m height by using power and log law models which provide the power density near about 120 W/m2. As per the micro sitting guidelines for the virtual wind farm installation 5D X 7D mapping has been selected which Indicates the total power output by installing 8 Vestas V-90 1.8 MW wind turbine from WAsP is 31.561 GWh and from windPRO is 28.083 GWh. 相似文献
403.
Papiya Mandal T. Saud R. Sarkar A. Mandal S. K. Sharma T. K. Mandal J. K. Bassin 《Environmental Chemistry Letters》2014,12(1):225-230
The highly populated Indian regions are currently in a phase of rapid economic growth resulting in high emissions of carbonaceous aerosols. This leads to poor air quality and impact on climate. The chemical composition of carbonaceous aerosols has rarely been studied in industrial areas of India. Here, we investigated carbonaceous aerosols in particulate matter (PM) monthly in the industrial area of Delhi in 2011. The concentrations of organic C and elemental C in PM10 fraction were analyzed. Results show a clear seasonal variability of organic and elemental C. PM10 ranged 95.9–453.5 μg m?3, organic C ranged 28.8–159.4 μg m?3, and elemental C ranged 7.5–44.0 μg m?3; those values were higher than reported values. Organic and elemental C were correlated with each other in pre-monsoon and winter seasons, implying the existence of similar emission sources such as coal combustion, biomass burning and vehicular exhaust. The annual average contribution of total carbonaceous aerosols in PM10 was estimated as 62 %. 相似文献
404.
This paper explores the impact of violent conflict in Nepal on the functioning of community forestry user groups (CFUGs), particularly those supported by the Livelihoods and Forestry Programme, funded by the United Kingdom's Department for International Development (DFID). The key questions are: (i) what explains the resilience of CFUGs operating at the time of conflict?; (ii) what institutional arrangements and strategies allowed them to continue working under conflict conditions?; and (iii) what lessons can be drawn for donor‐supported development around the world? The study contributes to other research on the everyday experiences of residents of Nepal living in a period of conflict. It suggests that CFUG resilience was the result of the institutional set up of community forestry and the employment of various tactics by the CFUGs. While the institutional design of community forestry (structure) was very important for resilience, it was the ability of the CFUGs to support and use it effectively that was the determining factor in this regard. 相似文献
405.
406.
Administrative divisions in the Great Southern Watershed of the Himalaya are diverse in terms of population density and forest cover. This study analyzed the spatial patterns of different attributes in the different Indian states and Himalayan kingdoms, and explored the extent and patterns of forest fragmentation in a Himalayan landscape as a case study. Of the total landscape in the case study area (3167 km2), 41% was fragmented. Homogenous landscape (59%) includes either continuous natural vegetation or a village landscape. Presence of two forest patches (38% of the total fragmented area) at a unit scale of about 0.5 km2 (525 × 525 m) was the most commonly occurring pattern but, in some parts, up to 13 patches were observed. Fragmentation of vegetation was visible even at smaller scales of landscape analysis. At a scale of 75 × 75 m, land division into three patches was observed. With an increase in the unit area of landscape analysis the number of patches per unit land area and the total fragmented area also increased. The forests that escaped fragmentation were either inaccessible to humans or had rigorous legal protection. Anthropogenic activities appeared to be one of the factors responsible for fragmentation but, natural factors also contributed. 相似文献
407.
Anil Sharma PC 《Journal of environmental biology / Academy of Environmental Biology, India》2010,31(4):399-402
Studies on bioefficacy of insecticides against brinjal shoot and fruit borer, Leucinodes orbonalis Guenee on brinjal were carried out during 2007 and 2008. The results on bioefficacy of insecticides showed that in terms of shoot infestation, emamectin benzoate (0.002%), endosulfan (0.05%), novaluron (0.01%) and lambda-cyhalothrin (0.004%) were found superior. The total number of drooping shoots was minimum (4.17) in emamectin benzoate followed by endosulfan (6.83) and novaluron (7.00), as compared to spinosad (9.17), deltamethrin (11.67) and Bacillus thuringiensis (13.17). In terms of reduction in fruit infestation, emamectin benzoate (0.002%) was highly effective followed by endosulfan (0.05%), agrospray oil T (0.2%) and spinosad (0.0024%). However, cost benefit ratio was highest in agrospray oil T (0.2%) followed by lambda-cyhalothrin (0.004%), endosulfan (0.05%) and deltamethrin (0.0028%). 相似文献
408.
Pratap V Sharma YK 《Journal of environmental biology / Academy of Environmental Biology, India》2010,31(5):721-726
An experiment was conducted to see the impact of osmotic stress as it is one of the main cause in various soil and water disorders in agricultural field crops, speciallythe seed germination and seedling growth. The osmotic stress was generated using PEG-6000 and the seed germination, seedling growth were evaluated including the status of pigments i.e. chlorophyll (a, b and total), total carotenoids, pheophytin (a, b and total) and different enzymes like amylase, peroxidase, catalase and superoxide dismutase. The various osmotic potentials generated (-2, -5 and -10 bars) showed significant decrease in germination percentage as at the osmotic potential of -10 bars it was observed 70 in comparison to 90% of control. All the seedling growth parameter also showed inhibition with increase in osmotic potential. Increase in osmotic stress decreased Chlorophyll 'a', while Chlorophyll 'b' was increased in -5 bars while total chlorophyll showed decrease in -5 bars osmotic potential. Total carotenoids and pheophytin (a, b and total) were highly increased in -5 bars and decreased in -10 bars osmotic concentration. Enzymatic activity was found to be decreased in amylase while peroixidase, catalase and SOD were increased at different osmotic gradients in comparison to control. The data observed in the experiment can be helpful to assess the impact of any kind of osmotic stress on plant growth and development in crops. 相似文献
409.
Ajay Kumar Sumit Sharma Rohit Mehra Priya Kanwar Rosaline Mishra Inderpreet Kaur 《Environmental geochemistry and health》2018,40(2):815-831
Radon concentration was measured in water samples of 41 different locations from Udhampur district of Jammu & Kashmir, India, by using RAD7 and Smart RnDuo monitor. The variation of radon concentration in water ranged from 1.44 ± 0.31 to 63.64 ± 2.88 Bq L?1, with a mean value of 28.73 Bq L?1 using RAD7 and 0.64 ± 0.28 to 52.65 ± 2.50 Bq L?1, with a mean value of 20.30 Bq L?1 using Smart RnDuo monitor, respectively. About 17.07% of the studied water samples recorded to display elevated radon concentration above the reference range suggested by United Nation Scientific Committee on the Effects of Atomic Radiations (UNSCEAR). The mean annual effective dose of these samples was determined, and 78.95% samples were found to be within the safe limits set by World Health Organisation (WHO) and European Council (EU). The study revealed good agreement between the values obtained with two methods. Heavy metals (Zn, Cd, Fe, Cu, Ni, As, Hg, Co, Pb and Cr) were determined in water samples by microwave plasma atomic emission spectrometer, and their correlation with radon content was also analysed. 相似文献
410.
Nath K Singh D Sharma YK 《Journal of environmental biology / Academy of Environmental Biology, India》2007,28(3):577-582
Under the reutilization and recycling strategy of industrial effluents, treated distillery and sugar factory mixed effluent was used in petridish culture experiments to investigate its effect on seed germination and seedling growth in wheat, garden pea, black gram and mustard. The seed germination and seedling growth were significantly reduced with increase in concentration of the effluent. The fresh matter was found significantly increased in barley (1.16 g per seedling in 25% dilution level of effluents in comparison to 0.93 in control), while other higher dilution levels reduce it. Wheat, garden pea, black gram, mustard invariably showed inhibition in fresh weight. Dry weight was found consistently reduced or unchanged in different treatments. Total chlorophyll contents in barley were significantly increased in different treatments (2.351 and 2.721 mg/g fresh weight of tissue at 25, 50% dilution levels in comparison to 1.781 of control) while in other crop it was reduced alloverthe treatments. Amylase activity in wheat, garden pea, black gram and mustard was reduced in all the treatments. Only in barley its level was enhanced from 0.76 to 0.85, 0.96, 0.81 in 25, 50, 75% dilution levels of the effluent mixture respectively Based on the data of different crops barley was found to be highly tolerant as the 25 and 50% dilution levels of combined effluents. It showed no change in germination %, while seedling growth was increased in lower dilution levels of combined effluent as compared to control Barley>garden pea>wheat>black gram>mustard gradually showed increased level of sensitivity respectively Most detrimental effects were seen in mustard. This toxicity might be due to excess of nutrients, beyond the limits of tolerance. Therefore, the higher concentration of mixed effluent was not advisable for irrigation purpose, however it could be used for irrigation purpose after proper treatment and dilution (one part treated effluent and five parts of available irrigation water), as this dilution level was found growth and yield promotory 相似文献