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21.
Influences of adding easily degradable organic waste on the minimization and humification of organic matter during straw composting 总被引:2,自引:0,他引:2
Yi N. Shan Jin H. Chen Lei Wang Fan Li Xiao H. Fu Yi Q. Le 《Journal of environmental science and health. Part. B》2013,48(5):384-392
To find a better composting process with low greenhouse gas emission and high humus production, the effect of adding kitchen waste on reduction and humification of organic matter during straw composting was studied. Three processes were compared, consisting of different ratios of straw and kitchen waste (1:2, 1:1, and 2:1). At four time points over a 62-d incubation, the reduction and humification of compost was evaluated by measuring the total mass, carbon content, and humic material content of the compost. Treatment 1 (straw/kitchen waste ratio of 1:2) reduced the total mass of compost the most. Treatment 2 (straw/kitchen waste ratio of 1:1) reduced the total carbon content the most, reflecting the highest emission of greenhouse gas. Treatment 3 produced the most humic acid material and released the lowest amount of carbon. Hence, from the point of view of reducing greenhouse gas emissions and increasing stable organic matter such as humus and humic acid during composting, treatment #3 was optimal. The three treatments resulted in significant differences in microbial biomass and enzyme activity during composting. The highest amount of active microbial biomass was associated with the largest reduction in compost mass (treatment 1). Higher proportions of straw (treatments 2 and 3), which contains more lignin, were associated with greater β-glycosidase activity, which may generate more humus that can improve soil quality. Dehydrogenase activity seemed to be the most important microbial factor in organic carbon catabolism or humification. 相似文献
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Fang J Shan XQ Wen B Lin JM Owens G Zhou SR 《Environmental pollution (Barking, Essex : 1987)》2011,159(5):1248-1256
The effects of TiO2 nanoparticles on the transport of Cu through four different soil columns were studied. For two soils (HB and DX), TiO2 nanoparticles acted as a Cu carrier and facilitated the transport of Cu. For a third soil (BJ) TiO2 nanoparticles also facilitated Cu transport but to a much lesser degree, but for a fourth soil (HLJ) TiO2 nanoparticles retarded the transport of Cu. Linear correlation analysis indicated that soil properties rather than sorption capacities for Cu primary governed whether TiO2 nanoparticles-facilitated Cu transport. The TiO2-associated Cu of outflow in the Cu-contaminated soil columns was significantly positively correlated with soil pH and negatively correlated with CEC and DOC. During passage through the soil columns 46.6-99.9% of Cu initially adsorbed onto TiO2 could be “stripped” from nanoparticles depending on soil, where Cu desorption from TiO2 nanoparticles increased with decreasing flow velocity and soil pH. 相似文献
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Quantifying air pollution attenuation within urban parks: an experimental approach in Shanghai, China 总被引:2,自引:0,他引:2
Yin S Shen Z Zhou P Zou X Che S Wang W 《Environmental pollution (Barking, Essex : 1987)》2011,159(8-9):2155-2163
Parks with various types of vegetations played an important role in ameliorating air quality in urban areas. However, the attenuation effect of urban vegetation on levels of air pollution was rarely been experimentally estimated. This study, using seasonal monitoring data of total suspended particles (TSP), sulfur dioxide (SO(2)) and nitrogen dioxide (NO(2)) from six parks in Pudong District, Shanghai, China, demonstrated vegetations in parks can remove large amount of airborne pollutants. In addition, crown volume coverage (CVC) was introduced to characterize vegetation conditions in parks and a mixed-effects model indicated that CVC and the pollution diffusion distance were key predictors influencing pollutants removal rate. Therefore, it could be estimated by regression analysis that in summer, urban vegetations in Pudong District could contribute to 9.1% of TSP removal, 5.3% of SO(2) and 2.6% of NO(2). The results could be considered for a better park planning and improving air quality. 相似文献
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这是发生在100年前一种特殊战斗,但许多人都觉得好像是发生在昨天的故事。一个夏日的早晨,亚马逊河畔的一个农场。场长西蒙,站在他办公室的窗前,一边凝望着窗外的绿树红花,一边细心地倾听着。正在这时,警察前来通知说:"根据邻近地区得来的消息,有一个长约10公里、宽约5公里的褐色 相似文献
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Shen Yanru Zhao Wenyan Zhang Chunling Shan Yujie Shi Junxian 《Environmental science and pollution research international》2017,24(16):14337-14345
Environmental Science and Pollution Research - Streptomycin used in human and veterinary medicine is released into the environment mainly through excretions. As such, its elimination in water... 相似文献
29.
漆酶和纤维素酶在反胶束水核中心具有较强的催化活性。为了对反胶束酶体系中油酸酯化反应深入研究,采用生物表面活性剂鼠李糖脂构建反胶束体系作为漆酶与纤维素酶酯化油酸的催化反应场所。通过实验研究了反胶束体系的不同条件对酯化产物含量的影响。对于反胶束漆酶体系,最佳酯化条件为:含水量W0 40%,鼠李糖脂临界胶束浓度20 mmol·L-1,pH值4,温度40 ℃;对于反胶束纤维素酶体系,最佳酯化条件为:含水量20%,鼠李糖脂临界胶束浓度80 mmol·L-1,pH值4,温度30 ℃。综合考虑几个因素,漆酶比纤维素酶更适合应用于反胶束中油酸的酯化。研究同时采用荧光光谱法对漆酶和纤维素酶在反胶束体系中结构性能的变化进行研究,结果表明,当反胶束体系处于最佳酯化反应条件时,荧光强度最高。 相似文献
30.
Comparison between fractionation and bioavailability of trace elements in rhizosphere and bulk soils 总被引:16,自引:0,他引:16
Rhizosphere is a microbiosphere and has quite different chemical, physical and biological properties from bulk soils. A greenhouse experiment was performed to compare the difference of fractionation and bioavailability of trace elements Cr, Ni, Zn, Cu, Pb and Cd between rhizosphere soil and bulk soil. In the meantime, the influence of air-drying on the fractionation and bioavailability was also investigated by using wet soil sample as a control. Soils in a homemade rhizobox were divided into four zones: rhizosphere, near rhizosphere, near bulk soil and bulk soil zones, which was designated as S1, S2, S3 and S4. Elemental speciations were fractionated to water soluble, exchangeable and carbonate bound (B1), Fe-Mn oxide bound (B2), and organic and sulfide bound (B3) by a sequential extraction procedure. Speciation differences were observed for elements Cr, Ni, Zn, Cu, Pb and Cd between the rhizosphere and bulk soils, and between the air-dried and wet soils as well. The concentrations of all six heavy metals in fraction B1 followed the order of S2 > S3 > S1 > S4 and for B2, the order was S2 > S3 S4 > S1. For B3, the order was S1 > S3 S4 > S2, while for Cd the order was S2 > S3 approximately/= S4 > S1. The air-drying increased elemental concentration in fractions B1 and B2 by 20-50% and decreased in fraction B3 by about 20-100%. Correlation analysis also indicated that the bioavailability correlation coefficient of fraction B1 in rhizosphere wet soil to plants was better than that between either air-dried or nonrhizosphere soils. Therefore, application of rhizosphere wet soils should be recommended in the future study on the speciation analysis of trace elements in soils and bioavailability. 相似文献