全文获取类型
收费全文 | 2231篇 |
免费 | 5篇 |
国内免费 | 41篇 |
专业分类
安全科学 | 65篇 |
废物处理 | 115篇 |
环保管理 | 132篇 |
综合类 | 582篇 |
基础理论 | 442篇 |
环境理论 | 1篇 |
污染及防治 | 643篇 |
评价与监测 | 183篇 |
社会与环境 | 100篇 |
灾害及防治 | 14篇 |
出版年
2023年 | 24篇 |
2022年 | 81篇 |
2021年 | 80篇 |
2020年 | 17篇 |
2019年 | 28篇 |
2018年 | 27篇 |
2017年 | 45篇 |
2016年 | 45篇 |
2015年 | 23篇 |
2014年 | 39篇 |
2013年 | 130篇 |
2012年 | 53篇 |
2011年 | 85篇 |
2010年 | 69篇 |
2009年 | 72篇 |
2008年 | 85篇 |
2007年 | 77篇 |
2006年 | 56篇 |
2005年 | 57篇 |
2004年 | 51篇 |
2003年 | 52篇 |
2002年 | 63篇 |
2001年 | 72篇 |
2000年 | 63篇 |
1999年 | 42篇 |
1998年 | 23篇 |
1997年 | 37篇 |
1996年 | 30篇 |
1995年 | 31篇 |
1994年 | 30篇 |
1993年 | 28篇 |
1992年 | 20篇 |
1991年 | 42篇 |
1990年 | 53篇 |
1989年 | 24篇 |
1988年 | 30篇 |
1987年 | 22篇 |
1985年 | 23篇 |
1984年 | 25篇 |
1983年 | 19篇 |
1982年 | 32篇 |
1979年 | 22篇 |
1977年 | 16篇 |
1976年 | 14篇 |
1974年 | 18篇 |
1972年 | 17篇 |
1967年 | 23篇 |
1966年 | 19篇 |
1962年 | 14篇 |
1958年 | 14篇 |
排序方式: 共有2277条查询结果,搜索用时 31 毫秒
1.
Morsheda Akhter Sagar Kumar Dutta Palash Kumar Dhar Jamil Ahmed Mohammed Nazrul Islam Khan Md. Khairul Amin Jahidul Islam 《环境质量管理》2023,32(4):149-160
Catalytic activity of spinel ferrite in breaking down toxic dye materials are promising due to their uniqueness. In this study, aluminum-doped copper zinc ferrite, Cu0.4Zn0.6-xAlxFe2O4 (x = 0.0, 0.2, 0.4, 0.6), a catalyst for toxic dye degradation is synthesized through chemical co-precipitation route. The formation of the spinel ferrite catalyst is initially confirmed by Fourier transform infrared spectra, which shows the frequency of metal-oxygen bond vibration at 539 and 427 cm−1 attributed to the tetrahedral and octahedral sites respectively. Higher intensity sharp peak of X-ray diffraction for (311) plane is the evidence for the phase purity and the formation of spinel ferrite. The crystallite size is found to decrease with the increase of Al3+ ion. The surface structure of the obtained particles is investigated using a scanning electron microscope. Analyses of the material's magnetic characteristics using a vibrating sample magnetometer (VSM) revealed that it is, in fact, a soft magnet, as evidenced by the loop of its hysteresis, which is narrow. The catalytic degradation of methylene blue dye under the mechanism of the photo-Fenton process is studied with the obtained spinel ferrites and the result is found to be as high as 96.5%. The process follows pseudo-second order kinetics and the Langmuir isotherm. 相似文献
2.
3.
4.
Jürgen Tomiuk Lutz Bachmann Michael Leipoldt Jörg U. Ganzhorn Reiner Ries Michaela Weis & Volker Loeschcke 《Conservation biology》1997,11(2):491-497
The genetic polymorphism of natural populations of Lepilemur mustelinus ruficaudatus was studied by protein electrophoresis. We sampled blood from 72 individuals from four populations separated by geographic or anthropogenic barriers from southwestern Madagascar. Six out of 22 enzyme loci showed genetic variation with a degree of polymorphism of 0.273. The expected and observed degree of genetic heterozygosity over all loci is similar to that of other primates (He = 0.058, Ho = 0.036). The F-statistics revealed that the four subpopulations were similar with respect to gene structure (FST = 0.065, p = 0.016), but the genotypic structures within subpopulations were inconsistent with random mating. For the total of the four subpopulations the proportion of heterozygous individuals was significantly smaller than expected under random mating (FIS = 0.373, FIT = 0.414, p < 0.01). These results correspond closely to what is expected considering the low migration ability of individuals of L. m ruficaudatus leading to small and rather isolated inbred populations. 相似文献
5.
Khan Syed Abdul Rehman Mathew Manoj Dominic P. D. D. Umar Muhammad 《Environment, Development and Sustainability》2022,24(9):10633-10665
Environment, Development and Sustainability - Environmental deterioration and global warming has created a substantial impact on international companies to incorporate eco-friendly, green supply... 相似文献
6.
Environment, Development and Sustainability - Public open spaces (POSs) provide a forum for social gathering, health, leisure, and recreation opportunities for city dwellers. POSs are considered... 相似文献
7.
Studies on the effects of some organic pollutants on the heavy metal transport in an Indian soil 总被引:1,自引:0,他引:1
The translocation of some heavy metals, such as Hg, Cd, Cu, Co, Ni and Zn, as affected by organic pollutants, i.e. methanol, ethanol, propanol, formaldehyde, acetaldehyde, benzaldehyde, acetone, ethyl methyl ketone and cyclo-hexanone, was studied in an Indian red soil using soil thin layer chromatography. It was observed that an increase in the concentration of organic compounds in developer enhances the heavy metal mobility, except in the case of Cu and Hg which show a decreasing trend. The results are discussed in relation to the physico-chemical characteristics of the soil and adsorption/desorption phenomena. 相似文献
8.
Stemwater running down the trunks of beech (Fagus sylvatica L.) has an acidifying effect on soil near the stem. The deposition of acidifying substances may be two to four times higher close to the stem compared to in the stand in general. To study reversibility of soil acidification, 72 stumps of beech trees were chosen from five different year classes of felling (3, 6, 9, 14-15, 25-30), representing the years when stemflow ceased to affect the soil. The H(+) concentration (pH KCl) in the topsoil (0-5 cm) differed between the distances 10-30 cm and 230-250 cm from the stumps, the soil close to the stem being more acid. The longer the time since felling the smaller the differences in H(+) concentration became. This reduction in soil acidity amounted to ca. 50% after 15 years, and only small further changes occurred over the next ten years. This indicates that soil may not recover fully from acidification, or does so at a rather slow rate after the initial 15 years of recovery. 相似文献
9.
The impact of sulphur dioxide, in two different concentrations (286 microg m(-3) and 571 microg m(-3)) for various exposure periods, on conidial germination of some powdery mildew fungi was investigated in artificial treatment conditions. SO(2) in general was inhibitory for conidial germination of all the studied powdery mildew fungi and the species did not differ much from each other in their sensitivity to SO(2). The per cent conidial germination was increasingly inhibited with an increase in the concentration of SO(2). The concentration of SO(2) and the exposure period were important determinants of the inhibitory effect. 相似文献
10.
The effects of Sphagnum and urban runoff on the bioavailability of metals were tested by adding PbCl2 and ZnCl2 to laboratory microcosms constructed of peat substrate with or without live Sphagnum spp. and planted with Acer rubrum L. seedlings or Vaccinium macrocarpon Ait. shoots. We hypothesized that Sphagnum would increase bioavailability through its acidifying action, while urban runoff would decrease availability through increases in alkalinity. Metals were more available to the test plants treated with acidic swampwater than with alkaline runoff. Sphagnum moss caused increases in tissue concentrations in V. macrocarpon, but not in A. rubrum. The latter species took up more metals when grown on substrate from sites receiving runoff, whereas the former took up more metals from substrate from undisturbed sites, despite the lower substrate metal concentrations. Differences in uptake by the two species may reflect differences in their ability to root in the Sphagnum mat. The results demonstrate that Sphagnum spp. exerts strong species-specific effects on the uptake of metals by vascular plants, and that plant species native to acidic wetlands vary widely in their response to metals in the substrate. 相似文献