全文获取类型
收费全文 | 30664篇 |
免费 | 766篇 |
国内免费 | 4760篇 |
专业分类
安全科学 | 1462篇 |
废物处理 | 1583篇 |
环保管理 | 3619篇 |
综合类 | 9905篇 |
基础理论 | 6700篇 |
环境理论 | 14篇 |
污染及防治 | 9155篇 |
评价与监测 | 1521篇 |
社会与环境 | 1538篇 |
灾害及防治 | 693篇 |
出版年
2023年 | 285篇 |
2022年 | 750篇 |
2021年 | 645篇 |
2020年 | 534篇 |
2019年 | 507篇 |
2018年 | 778篇 |
2017年 | 827篇 |
2016年 | 941篇 |
2015年 | 1043篇 |
2014年 | 1435篇 |
2013年 | 2760篇 |
2012年 | 1640篇 |
2011年 | 2102篇 |
2010年 | 1544篇 |
2009年 | 1645篇 |
2008年 | 1741篇 |
2007年 | 1582篇 |
2006年 | 1392篇 |
2005年 | 1114篇 |
2004年 | 1010篇 |
2003年 | 1036篇 |
2002年 | 947篇 |
2001年 | 1017篇 |
2000年 | 891篇 |
1999年 | 734篇 |
1998年 | 549篇 |
1997年 | 549篇 |
1996年 | 524篇 |
1995年 | 543篇 |
1994年 | 391篇 |
1993年 | 372篇 |
1992年 | 301篇 |
1991年 | 284篇 |
1990年 | 251篇 |
1989年 | 242篇 |
1988年 | 203篇 |
1987年 | 158篇 |
1986年 | 179篇 |
1985年 | 161篇 |
1984年 | 208篇 |
1983年 | 163篇 |
1982年 | 185篇 |
1981年 | 164篇 |
1980年 | 135篇 |
1979年 | 153篇 |
1978年 | 97篇 |
1977年 | 99篇 |
1975年 | 96篇 |
1974年 | 102篇 |
1972年 | 107篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Alexis Laurent Julie Clavreul Anna Bernstad Ioannis Bakas Monia Niero Emmanuel Gentil Thomas H. Christensen Michael Z. Hauschild 《Waste management (New York, N.Y.)》2014,34(3):589-606
Life cycle assessment (LCA) is increasingly used in waste management to identify strategies that prevent or minimise negative impacts on ecosystems, human health or natural resources. However, the quality of the provided support to decision- and policy-makers is strongly dependent on a proper conduct of the LCA. How has LCA been applied until now? Are there any inconsistencies in the past practice? To answer these questions, we draw on a critical review of 222 published LCA studies of solid waste management systems. We analyse the past practice against the ISO standard requirements and the ILCD Handbook guidelines for each major step within the goal definition, scope definition, inventory analysis, impact assessment, and interpretation phases of the methodology. Results show that malpractices exist in several aspects of the LCA with large differences across studies. Examples are a frequent neglect of the goal definition, a frequent lack of transparency and precision in the definition of the scope of the study, e.g. an unclear delimitation of the system boundaries, a truncated impact coverage, difficulties in capturing influential local specificities such as representative waste compositions into the inventory, and a frequent lack of essential sensitivity and uncertainty analyses. Many of these aspects are important for the reliability of the results. For each of them, we therefore provide detailed recommendations to practitioners of waste management LCAs. 相似文献
992.
993.
Ari Z. Zivotofsky 《Journal of Agricultural and Environmental Ethics》2012,25(5):747-763
Human beings have engaged in animal husbandry and have slaughtered animals for food for thousands of years. During the majority of that time most societies had no animal welfare regulations that governed the care or slaughter of animals. Judaism is a notable exception in that from its earliest days it has included such rules. Among the Jewish dietary laws is a prohibition to consume meat from an animal that dies in any manner other than through the rigorously defined method of slaughter known as shechita. In recent decades more and more attempts have been initiated by governments around the world to either outright ban or to control and modify the practice of shechita. This paper presents the requisite background about shechita and then analyzes the ethics of some of the recent legislation. The analysis includes a rebuttal of the assertion that shechita is an inhumane method of slaughter. It further presents the consequences on the Jewish community of legislation to impose pre-slaughter stunning and explains why such legislation is unethical. The actual effect of labeling laws is discussed and it is shown why such laws are also un-ethical. 相似文献
994.
Environmentally Friendly Polyurethane Composites: Preparation, Characterization and Mechanical Properties 总被引:1,自引:0,他引:1
J. L. Zhang D. M. Wu D. Y. Yang F. X. Qiu 《Journal of Polymers and the Environment》2010,18(2):128-134
The waterborne polyurethane (PU) prepolymer was prepared based on isophorone diisocyanate (IPDI), polyester polyol (N220), dimethylol propionic acid (DMPA) and hydroxyethyl methyl acrylate (HEMA). The modified waterborne polyurethane–acrylate (PUA) emulsions were obtained with different proportions of acrylate (butyl acrylate and methyl methacrylate) and initiating agent by in situ dispersion technique. The structures and thermal properties of prepared PU and PUA were analyzed and characterized with FT-IR, UV–Vis spectroscopy and DSC. The PUA hybrid samples had lower glass transition temperature of hard segment and higher decomposition temperatures than PU sample. Performances of the emulsion and film were studied by means of apparent viscidity, particle size and polydispersity, surface tension and mechanical properties. The results indicated that the particle sizes of the PUA dispersions were larger than those of the pure PU and the solvent resistance, mechanical properties of PUA films was improved compare with the unmodified polyurethane film. The film had the biggest hardness and the least water absorption when the BA/MMA mass ratio 5:5 modified PU. The obtained PUA have great potential application such as coatings, leather finishing, adhesives, sealants, plastic coatings and wood finishes. 相似文献
995.
996.
Li-Ming Shao Zhong-He Ma Hua Zhang Dong-Qing Zhang Pin-Jing He 《Waste management (New York, N.Y.)》2010,30(7):1165-1170
Bio-drying can enhance the sortability and heating value of municipal solid waste (MSW), consequently improving energy recovery. Bio-drying followed by size sorting was adopted for MSW with high water content to improve its combustibility and reduce potential environmental pollution during the follow-up incineration. The effects of bio-drying and waste particle size on heating values, acid gas and heavy metal emission potential were investigated. The results show that, the water content of MSW decreased from 73.0% to 48.3% after bio-drying, whereas its lower heating value (LHV) increased by 157%. The heavy metal concentrations increased by around 60% due to the loss of dry materials mainly resulting from biodegradation of food residues. The bio-dried waste fractions with particle size higher than 45 mm were mainly composed of plastics and papers, and were preferable for the production of refuse derived fuel (RDF) in view of higher LHV as well as lower heavy metal concentration and emission. However, due to the higher chlorine content and HCl emission potential, attention should be paid to acid gas and dioxin pollution control. Although LHVs of the waste fractions with size <45 mm increased by around 2× after bio-drying, they were still below the quality standards for RDF and much higher heavy metal pollution potential was observed. Different incineration strategies could be adopted for different particle size fractions of MSW, regarding to their combustibility and pollution property. 相似文献
997.
Patrick L. Hanrahan 《Journal of the Air & Waste Management Association (1995)》2013,63(11):1332-1338
ABSTRACT A previous paper1 discusses the methodology for a new method for deriving the nitrogen dioxide/nitrogen oxide (NO2/NOx) ratio in plumes that originally are composed mainly of (NOx). It is called the Plume Volume Molar Ratio Method (PVMRM). This paper documents its performance against six different data sets. These performance evaluations show that the PVMRM can realistically predict the NO2 fraction at close-in receptors yet still provide conservative estimates so that the air quality standards can be protected. 相似文献
998.
999.
A. P. Altshuller S. L. Kopczynski D. Wilson W. Lonneman F. D. Sutterfield 《Journal of the Air & Waste Management Association (1995)》2013,63(10):791-794
Effects associated with photochemical air pollution were measured during irradiation of n-butane-nitrogen oxide or n-butane-ethane-nitrogen oxide mixtures, with small amounts of propylene or toluene added. The effects measured including nitrogen dioxide and oxidant dosages, yields of formaldehyde and peroxy-acetyl nitrate, and eye irritation response. The results obtained clearly show that beneficial effects result from selective changes in hydrocarbon composition as well as from reduction of total hydrocarbon concenfration. Exclusion of olefins and alkylbenzenes was highly effective in reducing oxidant dosage, formaldehyde and peroxyacetyl nitrate concentrations, and eye irritation response. The only penalty was a modest increase in nitrogen dioxide dosage. A large reduction in nitrogen oxide concentration reduced nitrogen dioxide dosage and eye irritation response, but with the penalty of a large increase in oxidant dosage. The desirability of preferentially reducing olefins and alkylbenzenes rather than paraffinic hydrocarbons, acetylene, and benzene is strongly supported by this study. Research and development efforts should be directed toward preferential hydrocarbon control by mechanical or catalytic control 相似文献
1000.