全文获取类型
收费全文 | 623篇 |
免费 | 3篇 |
国内免费 | 4篇 |
专业分类
安全科学 | 10篇 |
废物处理 | 18篇 |
环保管理 | 50篇 |
综合类 | 217篇 |
基础理论 | 116篇 |
环境理论 | 1篇 |
污染及防治 | 172篇 |
评价与监测 | 20篇 |
社会与环境 | 25篇 |
灾害及防治 | 1篇 |
出版年
2023年 | 4篇 |
2022年 | 5篇 |
2021年 | 10篇 |
2020年 | 10篇 |
2018年 | 5篇 |
2017年 | 16篇 |
2016年 | 11篇 |
2015年 | 5篇 |
2014年 | 16篇 |
2013年 | 24篇 |
2012年 | 27篇 |
2011年 | 40篇 |
2010年 | 25篇 |
2009年 | 21篇 |
2008年 | 36篇 |
2007年 | 29篇 |
2006年 | 28篇 |
2005年 | 18篇 |
2004年 | 15篇 |
2003年 | 7篇 |
2002年 | 18篇 |
2001年 | 13篇 |
2000年 | 10篇 |
1999年 | 4篇 |
1998年 | 6篇 |
1997年 | 4篇 |
1996年 | 5篇 |
1995年 | 8篇 |
1994年 | 4篇 |
1993年 | 5篇 |
1990年 | 4篇 |
1981年 | 6篇 |
1980年 | 5篇 |
1977年 | 5篇 |
1973年 | 6篇 |
1972年 | 6篇 |
1971年 | 4篇 |
1970年 | 4篇 |
1967年 | 6篇 |
1965年 | 5篇 |
1963年 | 6篇 |
1962年 | 4篇 |
1961年 | 4篇 |
1960年 | 6篇 |
1959年 | 7篇 |
1957年 | 6篇 |
1956年 | 9篇 |
1955年 | 11篇 |
1934年 | 4篇 |
1913年 | 3篇 |
排序方式: 共有630条查询结果,搜索用时 15 毫秒
81.
82.
83.
84.
85.
Trine Lund Hansen Thomas H?jlund Christensen Sonia Schmidt 《Waste management & research》2006,24(2):141-152
Modelling of environmental impacts from the application of treated organic municipal solid waste (MSW) in agriculture differs widely between different models for environmental assessment of waste systems. In this comparative study five models were examined concerning quantification and impact assessment of environmental effects from land application of treated organic MSW: DST (Decision Support Tool, USA), IWM (Integrated Waste Management, U.K.), THE IFEU PROJECT (Germany), ORWARE (ORganic WAste REsearch, Sweden) and EASEWASTE (Environmental Assessment of Solid Waste Systems and Technologies, Denmark). DST and IWM are life cycle inventory (LCI) models, thus not performing actual impact assessment. The DST model includes only one water emission (biological oxygen demand) from compost leaching in the results and IWM considers only air emissions from avoided production of commercial fertilizers. THE IFEU PROJECT, ORWARE and EASEWASTE are life cycle assessment (LCA) models containing more detailed land application modules. A case study estimating the environmental impacts from land application of 1 ton of composted source sorted organic household waste was performed to compare the results from the different models and investigate the origin of any difference in type or magnitude of the results. The contributions from the LCI models were limited and did not depend on waste composition or local agricultural conditions. The three LCA models use the same overall approach for quantifying the impacts of the system. However, due to slightly different assumptions, quantification methods and environmental impact assessment, the obtained results varied clearly between the models. Furthermore, local conditions (e.g. soil type, farm type, climate and legal regulation) and waste composition strongly influenced the results of the environmental assessment. 相似文献
86.
87.
The Science of Nature - 相似文献
88.
Cosmological implications of the Machian principle 总被引:1,自引:1,他引:0
The famous idea of Ernst Mach concerning the non-absolute but relational character of particle inertia is taken up in this paper and is reinvestigated with respect to its cosmological implications. From Thirring’s general relativistic study of the old Newtonian problem of the relativity of rotations in different reference systems, it appears that the equivalence principle with respect to rotating reference systems, if at all, can only be extended to the system of the whole universe, if the mass of the universe scales with the effective radius or extent of the universe. A reanalysis of Thirring’s derivations still reveals this astonishing result, and thus the general question must be posed: how serious this result has to be taken with respect to cosmological implications. As we will show, the equivalence principle is, in fact, fulfilled by a universe with vanishing curvature, i.e. with a curvature parameter, which just has the critical density , where is the Hubble constant. It turns out, however, that this principle can only permanently be fulfilled in an evolving cosmos, if the cosmic mass density, different from its conventional behaviour, varies with the reciprocal of the squared cosmic scale. This, in fact, would automatically be realized, if the mass of each cosmic particle scales with the scale of the universe. The latter fact, on one hand, is a field-theoretical request from a general relativistic field theory which fulfills H. Weyl’s requirement of a conformal scale invariance. On the other hand, it can perhaps also be concluded on purely physical grounds, when taking into account that as source of the cosmic metrics only an effective mass density can be taken. This mass density represents the bare mass density reduced by its mass equivalent of gravitational self-binding energy. Some interesting cosmological conclusions connected with this fact are pointed out in this paper. 相似文献
89.
Bode M Haas M Faymonville T Thiede B Schuphan I Schmidt B 《Journal of environmental science and health. Part. B》2006,41(3):201-222
In the present investigation, the oxidative metabolism of 14C-labeled metamitron was examined in plant cell cultures of tobacco overexpressing human P450 enzymes CYP1A1 or CYP1A2; special interest was in the aromatic hydroxylation of the herbicide. The oxidative metabolites deaminometamitron (DAM) and 4-hydroxydeaminometamitron (4-HDAM) were found in the untransformed control culture as well as in the transgenic culture. The transgenic cultures, however, exhibited higher turnover rates after 48 h of incubation with 20 microg 14C-metamitron per assay (untransformed: 40%, CYP1A1: 80%, CYP1A2: 100%). Primary metabolite 4-HDAM was partially found in glucosylated form in the transgenic cultures. As minor oxidative metabolites, 6-hydroxyphenyl-3-methoxymethyl-1,2,4-triazine-5(4H)-one and 3-hydroxymethyl-6-phenyl-1,2,4-triazine-5(4H)-one were identified in the transgenic cultures by GC-MS, LC-MS. Additionally, it could be demonstrated that both foreign enzymes (CYP1A1, CYP1A2) also catalyzed the deamination of metamitron. In a large-scale study (up to 400 microg per assay) with the transgenic culture expressing CYP1A2, the high efficiency of this P450 system toward metamitron was demonstrated: turnover of the xenobiotic was almost complete with 400 microg. Since large portions of unglucosylated 4-H-DAM were found, the activity of foreign CYP1A2 apparently exceeded that of endogenous O-glucosyltransferases of the tobacco cell culture. We concluded that in comparison to the nontransformed cell culture, the extent of metabolism was considerably higher in the transgenic cultures. The transgenic cell cultures expressing human CYP1A1 or CYP1A2 are thus suitable tools for the production of large quantities of primary oxidized metabolites of metamitron. 相似文献
90.
Holger Borwitzky Helmut Bendig Klaus Gerhard Schmidt 《Environmental Sciences Europe》1997,9(3):127-130
Measurements show that PCN may occur in industrial waste and residues in the mg/kg range. Investigations were carried out with optimized parameters for GC and MS using two different GC/MS-systems. Chromatograms were obtained for a variety of chlorination degrees using capillary columns of different polarities. It is proposed to quantify PCN using relevant single compounds comparable to the analysis of polychlorinated biphenyls. 相似文献