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311.
Kale VD Walunj AR Battu RS Sahoo SK Singh B Paramasivam M Roy S Banerjee T Banerjee H Rao CS Reddy DJ Reddy KN Reddy CN Tripathy V Jaya M Pant S Gupta M Singh G Sharma KK 《Environmental monitoring and assessment》2012,184(7):4267-4270
Supervised field trials were conducted at the research farms of four agricultural universities located at different agro-climatic zones of India to find out the harvest time residues of flubendiamide and its des-iodo metabolite on pigeon pea (Cajanus cajan) during the year 2006-2007. Two spray applications of flubendiamide 20 WDG at 50 g (T(1)) and 100 g (T(2)) a.i./ha were given to the crop at 15-days interval. The foliage samples at different time intervals were drawn at only one location, however, the harvest time samples of pigeon pea grain, shell, and straw were drawn at all the four locations. The residues were estimated by HPLC coupled with UV-VIS variable detector. No residues of flubendiamide and its des-iodo metabolite were found at harvest of the crop at or above the LOQ level of 0.05 μg/g. On the basis of the data generated, a pre-harvest interval (PHI) of 28 days has been recommended and the flubendiamide 20 WDG has been registered for use on pigeon pea by Central Insecticide Board and Registration Committee, Ministry of Agriculture, Government of India and the MRL has been fixed by Ministry of Health and Family Welfare, Government of India under Prevention of Food and Adulteration as 0.05 μg/g on pigeon pea grains. 相似文献
312.
Factors controlling the salinity in groundwater in parts of Guntur district, Andhra Pradesh, India 总被引:1,自引:0,他引:1
Subba Rao N 《Environmental monitoring and assessment》2008,138(1-3):327-341
Groundwater chemistry has been studied to examine the associated hydrogeochemical processes operating for the development
of salinity in the groundwater in parts of Guntur district, Andhra Pradesh, India. The study area is underlain by charnockites
and granitic gneisses associated with schists of the Precambrian Eastern Ghats. Groundwater is the main resource for irrigation
besides drinking. Chemical parameters, pH, EC, TDS, Ca2+, Mg2+, Na+, K+, , , Cl−, , , F− and SiO2, are taken into account. Groundwater is of brackish type. Na+−Cl− facies dominates the groundwater. Examination of compositional relations and mineral saturation states shows that the ion
exchange of Ca2+ for adsorbed Na+, evapotranspiration, dissolution of soil salts, dissolution of NaCl and CaSO4, and precipitation of CaCO3 are the dominant hydrogeochemical processes associated with the groundwater composition in the area. Evapotranspiration causes
accumulation of salts in the soil/weathered zone. These salts reach the water table by leaching through infiltrating recharge
water. A positive relation between depth to water table and TDS with season supports this inference. The effects of human
activities, such as intensive and long-term irrigation, irrigation-return-flow, application of unlimited agricultural fertilizers
and recycling of saline groundwater, act to further increase the salinity in the groundwater. Therefore, the groundwater quality
increases towards the flow path, while the post-monsoon groundwater shows higher concentrations of TDS, Na+, Mg2+, Cl−, , , F− and SiO2 ions. The study could help to understand the hydrogeochemical characteristics of the aquifer system for taking effective
management measures to mitigate the inferior groundwater quality for sustainable development. 相似文献
313.
Khaparde VV Pipalatkar PP Pustode T Rao CV Gajghate DG 《Environmental monitoring and assessment》2012,184(2):903-911
Influence of burning of fireworks on particle size distribution of PM10 and associated barium (Ba) were studied at a congested residential cum commercial area of Nagpur city, India. Sampling was
carried out by cascade impactor having 50% cut-off aerodynamic diameters of <10, 9, 5.8, 4.7, 3.3, 2.1, 1.1, 0.7, and <0.4 μm,
2 days before diwali, during diwali, celebrations of marriage functions, and New Year’s Eve. Noticeably, increased levels
of PM10 and Ba were observed during diwali as compared to days before diwali and other activities. PM10 levels were increased by four to nine times whereas Ba levels were increased by eight to 20 times higher in alveolar region,
when compared with the levels observed before diwali. Probability of deposition of Ba mass in alveolar region varied between
14 and 27 ng/h with higher deposition when the burning of fireworks activity was lower near the site. Trimodal distribution
of Ba was observed on the first 2 days of diwali at 0.4–2.1, 2.1–4.7, and 4.7 to less than PM10 micrometer range. While on the third day, it appeared bimodal with 70% contribution in coarse fraction whereas on the fourth
day, distribution appeared unimodal with 66% contribution in alveolar region (<0.4–1.1 μm). Distribution of Ba varied with
respect to particle size, in accordance with the intensity of the fireworks used on different days and distance between the
burning of firecrackers from the monitoring site. 相似文献
314.
India's Unnao region is home to many leather-treatment facilities and related industries. Industrial and agricultural waste leads to heavy metal contamination that infiltrates groundwater and leads to human health hazards. This work measured the amount of heavy metal in groundwater at specific sites near the industrial facilities in Unnao and identified potential sources of contamination as anthropogenic or lithogenic. Groundwater samples were taken from 10 bore well sites chosen for depth and proximity to industry. Data obtained from sample sites was interpreted using a multivariate statistical analytical approach, i.e., principal component analysis, clustering analysis, and correlation analysis. The results of the multivariate analysis showed that cadmium, copper, manganese, nickel, lead, and zinc were correlated with anthropogenic sources, while iron and chromium were associated with lithogenic sources. These findings provide information on the possible sources of heavy metal contamination and could be a model for assessing and monitoring heavy metal pollution in groundwater in other locales. This study analyzed a selection of heavy metals chosen on the basis of industries located in the study area, which might not provide a complete range of information about the sources and availability of all heavy metals. Therefore, an extended investigation on heavy metal fractions will be developed in further studies. 相似文献
315.
Subba Rao N 《Environmental monitoring and assessment》2008,136(1-3):437-447
Trace elements are essential for human health. However, excess concentrations of these elements cause health disorders. A
study has been carried out in Visakhapatnam environs, Andhra Pradesh, India to ascertain the causes for the origin and distribution
of iron content in the groundwaters. Fifty groundwater samples are collected and analyzed for iron. The content of iron ranges
from 400 to 780 μg/l. A comparison of groundwater data with rock and soil chemistry suggests that the concentration of iron
(400–530 μg/l) in the groundwaters is derived from the rocks and soils due to geogenic processes. This concentration is taken
as a natural occurrence of iron in the groundwaters of the study area for assessing the causes for its next higher content
(>530 μg/l). Relatively higher concentration of iron (540–550 μg/l) is observed at some well waters, where the wells are located
nearby municipal wastewaters, while the very high concentration of iron (610–780 μg/l) is observed in the industrially polluted
groundwater zones, indicating the impact of anthropogenic activities on the groundwater system. These activities mask the
concentration of iron caused by geogenic origin. Hence, both the geogenic and anthropogenic activities degrade the groundwater
quality. Drinking water standards indicate that the iron content in all the groundwater samples exceeds the permissible limit
(300 μg/l) recommended for drinking purpose, causing the health disorders. Necessity of close monitoring of groundwater quality
for assessing the impact of geogenic and anthropogenic sources with reference to land use/land cover activities is emphasized
in the present study area to protect the groundwater resources from the pollution. 相似文献
316.
用SOS/Umu生物测试评价北方某自来水厂对遗传毒性物质的去除效果 总被引:2,自引:0,他引:2
大量研究表明,饮用水中存在着能导致遗传毒性的物质,在我国许多水厂水质检测能力有限的前提下,生物毒性指标作为反映有毒物质综合指标具有重要的现实意义.本研究应用SOS/Umu生物毒性测试评价了北方某市一自来水厂的A、B、C、D 4套试验工艺在不同的季节(冬春两季)各工艺段出水的遗传毒性效应.结果显示,冬春两季地表水加氯后遗传毒性效应均显著增加,冬季间接遗传毒性效应高于春季;活性炭吸附对去除遗传毒性物质效果显著,但后期加氯使遗传毒性效应增加;冬春两季比较,以及地下水和地表水比较,各工艺出水的遗传毒性效应差别很大.通过研究表明,本研究所应用的生物毒性测试SOS/Umu能够快速、准确地对水厂工艺过程中致突变物质的处理效果进行评价,能对工艺改进提出指导,是自来水质安全性评价的重要补充手段. 相似文献
317.
Aruna Palanisamy B. S. Rao Shaik Mehazabeen 《Journal of Polymers and the Environment》2011,19(3):698-705
Castor oil was chemically modified into a diethanolamide by a two step process. The first step was the hydroxylation of double
bonds in castor oil and second step was the transamidation using diethanolamine to increase the hydroxyl value. Water blown
polyurethane foams were developed with this castor oil based polyol using polypropylene glycol of molecular weight 1,000 as
the copolyol and polymeric MDI. The density and mechanical properties namely compression and flexural strength depended on
the composition of the foam formulation. The hydroxyamide content and molecular weight of commercial polyol had significant
effect on the micro structure as observed by optical microscopy. 相似文献
318.
Luo SL Chen L Chen JL Xiao X Xu TY Wan Y Rao C Liu CB Liu YT Lai C Zeng GM 《Chemosphere》2011,85(7):1130-1138
This study investigates the heavy metal-resistant bacterial endophytes of Cd-hyperaccumulator Solanum nigrum L. grown on a mine tailing by using cultivation-dependent technique. Thirty Cd-tolerant bacterial endophytes were isolated from roots, stems, and leaves of S. nigrum L. and classified by amplified ribosomal DNA-restriction analysis into 18 different types. Phylogenetic analysis based on 16S rDNA sequences showed that these isolates belonged to four groups: Actinobacteria (43%), Proteobacteria (23%), Bacteroidetes (27%) and Firmicutes (7%). All the isolates were then characterized for their plant growth promoting traits as well as their resistances to different heavy metals; and the actual plant growth promotion and colonization ability were also assessed. Four isolates were re-introduced into S. nigrum L. under Cd stress and resulted in Cd phytotoxicity decrease, as dry weights of roots increased from 55% to 143% and dry weights of above-ground from 64% to 100% compared to the uninoculated ones. The total Cd accumulation of inoculated plants increased from 66% to 135% (roots) and from 22% to 64% (above-ground) compared to the uninoculated ones. Our research suggests that bacterial endophytes are a most promising resource and may be the excellent candidates of bio-inoculants for enhancing the phytoremediation efficiency. 相似文献
319.
The evaluation and assessment of monitoring data generated over a period of 1983-2007 (25 years) of a nuclear facility is presented. Time trends of particulate radioactivity, correlation between 137Cs in discharge canal seawater and station discharged activity and correlation of 137Cs, 60Co, and 131I in marine species such as sponge and Nerita (gastropod) and corresponding discharged activity are discussed. The concentration of 137Cs and 131I in seawater versus biota are discussed. A good correlation between 137Cs in seawater and 137Cs in liquid waste discharged was observed (R2 = 0.8, p < 0.001). Similarly, correlation was good for Nerita and discharged concentration of 137Cs, 131I and 60Co (R2 = 0.55-0.73 and p < 0.001). The measurements over the years indicated that there is no accumulation of radionuclides in either the terrestrial or aquatic environments. The mean 137Cs decreased from the pre-operational levels: 7.0-3.6 Bq kg−1 in soil, 0.91-0.016 Bq L−1 in milk and 0.28-0.036 Bq kg−1 in vegetation. Similarly, the mean 90Sr in these matrixes decreased from 3.9 to 0.26 Bq kg−1; 0.37-0.011 Bq L−1 and 0.34-0.022 Bq kg−1 respectively. Cesium-137 of about 700 μBq m−3 was measured in the air filter disks during 1986 and there was a decrease of three orders of magnitude in concentration over the 25 years. The evaluation of environmental data indicated that the radionuclide concentrations and potential impacts, in terms of effective dose to the members of public, have significantly reduced since 1969. 相似文献
320.