全文获取类型
收费全文 | 33697篇 |
免费 | 316篇 |
国内免费 | 242篇 |
专业分类
安全科学 | 747篇 |
废物处理 | 1346篇 |
环保管理 | 4433篇 |
综合类 | 6528篇 |
基础理论 | 8708篇 |
环境理论 | 15篇 |
污染及防治 | 7748篇 |
评价与监测 | 2164篇 |
社会与环境 | 2399篇 |
灾害及防治 | 167篇 |
出版年
2022年 | 210篇 |
2021年 | 226篇 |
2019年 | 220篇 |
2018年 | 841篇 |
2017年 | 823篇 |
2016年 | 961篇 |
2015年 | 530篇 |
2014年 | 674篇 |
2013年 | 2253篇 |
2012年 | 989篇 |
2011年 | 1761篇 |
2010年 | 1238篇 |
2009年 | 1383篇 |
2008年 | 1671篇 |
2007年 | 1927篇 |
2006年 | 1116篇 |
2005年 | 983篇 |
2004年 | 952篇 |
2003年 | 1012篇 |
2002年 | 946篇 |
2001年 | 1075篇 |
2000年 | 764篇 |
1999年 | 502篇 |
1998年 | 379篇 |
1997年 | 376篇 |
1996年 | 403篇 |
1995年 | 417篇 |
1994年 | 415篇 |
1993年 | 391篇 |
1992年 | 376篇 |
1991年 | 374篇 |
1990年 | 365篇 |
1989年 | 320篇 |
1988年 | 298篇 |
1987年 | 268篇 |
1986年 | 289篇 |
1985年 | 284篇 |
1984年 | 319篇 |
1983年 | 314篇 |
1982年 | 305篇 |
1981年 | 290篇 |
1980年 | 263篇 |
1979年 | 248篇 |
1978年 | 219篇 |
1977年 | 212篇 |
1974年 | 203篇 |
1973年 | 170篇 |
1972年 | 181篇 |
1971年 | 174篇 |
1967年 | 169篇 |
排序方式: 共有10000条查询结果,搜索用时 187 毫秒
981.
Konstantinos C. Makris Dibyendu Sarkar Jason Salazar Pravin Punamiya Rupali Datta 《Environmental science and pollution research international》2010,17(1):195-202
Background, aim, and scope
Alum (aluminum sulfate) is the currently preferred chemical amendment for phosphorus (P) treatment in poultry litter (PL). Aluminum-based drinking-water treatment residuals (Al-WTRs) are the waste by-product of the drinking-water treatment process and have been effectively used to remove P from aqueous solutions, but their effectiveness in PL water extracts has not been studied in detail. Elevated cost associated with alum could be minimized by using the equally effective WTRs to remove soluble P from PL, and they can be obtained at a minimal cost from drinking-water treatment plants. 相似文献982.
983.
984.
985.
R. Ciccoli V. Cigolotti R. Lo Presti E. Massi S.J. McPhail G. Monteleone A. Moreno V. Naticchioni C. Paoletti E. Simonetti F. Zaza 《Waste management (New York, N.Y.)》2010,30(6):1018-1024
The use of biomass and waste to produce alternative fuels, due to environmental and energy security reasons, is a high-quality solution especially when integrated with high efficiency fuel cell applications. In this article we look into the coupling of an anaerobic digestion process of organic residues to electrochemical conversion to electricity and heat through a molten carbonate fuel cell (MCFC). In particular the pathway of the exceedingly harmful compound hydrogen sulphide (H2S) in these phases is analysed. Hydrogen sulphide production in the biogas is strongly interrelated with methane and/or hydrogen yield, as well as with operating conditions like temperature and pH. When present in the produced biogas, this compound has multiple negative effects on the performance and durability of an MCFC. Therefore, there are important issues of integration to be solved.Three general approaches to solve the sulphur problem in the MCFC are possible. The first is to prevent the formation of hydrogen sulphide at the source: favouring conditions that inhibit its production during fermentation. Secondly, to identify the sulphur tolerance levels of the fuel cell components currently in use and develop sulphur-tolerant components that show long-term electrochemical performance and corrosion stability. The third approach is to remove the generated sulphur species to very low levels before the gas enters the fuel cell. 相似文献
986.
International environmental agreements (IEAs) can coordinate abatement of transboundary pollutants. This paper investigates
how heterogeneous countries facing a stock pollutant might structure such an agreement. In particular, we examine how an IEA
might be implemented with a set of monetary transfers. The focus is on transfers that are time invariant, linear in emissions,
and consistent with budget balance. There is a range of such schemes that would induce efficient emissions. We provide a simple
and intuitive characterization of these penalties and describe how specific proposals might be chosen in order to facilitate
compliance and implementation. Our proposals are illustrated with a simple example. We show that heterogeneity reduces the
scope for penalty schemes to jointly satisfy desirable properties. 相似文献
987.
Stephanie C. Payne Mindy E. Bergman Jennifer M. Rodríguez Jeremy M. Beus Jaime B. Henning 《Journal of Loss Prevention in the Process Industries》2010,23(6):806-812
In order to evaluate the leading and lagging effects of process safety climate on incidents, we correlated safety climate survey data with organizational safety records from before and after the survey time period. We obtained data from a large, multinational organization with manufacturing operations involving a number of complex processes, chemicals, and hazardous substances. A total of 7728 employees from 62 sites responded to a safety climate survey in 2007. Individual responses were aggregated to the site-level and matched to site-level organizational records of process safety incidents 1 year before and 1 year after survey administration. Employees’ perceptions of good routine housekeeping were significantly related to environmental impact incidents as both a leading and a lagging indicator, as well as fires/explosions and property damage outcomes. Employees’ perceptions of systems to prevent backlogs and the extent to which health and safety problems are promptly corrected were also related to environmental releases and fires/explosions. Implications for process safety climate research, organizational survey strategies, and organizational climate change are discussed. 相似文献
988.
João G.R. Giovanelli Marinez Ferreira de Siqueira João Alexandrino 《Ecological modelling》2010,221(2):215-170
We here examine species distribution models for a Neotropical anuran restricted to ombrophilous areas in the Brazilian Atlantic Forest hotspot. We extend the known occurrence for the treefrog Hypsiboas bischoffi (Anura: Hylidae) through GPS field surveys and use five modeling methods (BIOCLIM, DOMAIN, OM-GARP, SVM, and MAXENT) and selected bioclimatic and topographic variables to model the species distribution. Models were first trained using two calibration areas: the Brazilian Atlantic Forest (BAF) and the whole of South America (SA). All modeling methods showed good levels of predictive power and accuracy with mean AUC ranging from 0.77 (BIOCLIM/BAF) to 0.99 (MAXENT/SA). MAXENT and SVM were the most accurate presence-only methods among those tested here. All but the SVM models calibrated with SA predicted larger distribution areas when compared to models calibrated in BAF. OM-GARP dramatically overpredicted the species distribution for the model calibrated in SA, with a predicted area around 106 km2 larger than predicted by other SDMs. With increased calibration area (and environmental space), OM-GARP predictions followed changes in the environmental space associated with the increased calibration area, while MAXENT models were more consistent across calibration areas. MAXENT was the only method that retrieved consistent predictions across calibration areas, while allowing for some overprediction, a result that may be relevant for modeling the distribution of other spatially restricted organisms. 相似文献
989.
990.
E.K. Papadimitriou 《Waste management (New York, N.Y.)》2010,30(4):572-582
Commingled household waste (HW) that had a controlled composition was autoclaved at elevated pressures in the presence of saturated steam for one hour at the nominal temperature levels of 130 °C, 160 °C and 200 °C. The focus of this study was the impact of temperature/pressure on hydrolysis of organic matter during autoclaving and the extent of its hydrolysis. The pH decreased with autoclaving temperature with which it had a linear relationship, and ranged from 7.4 and 6 in floc, and 6.7 and 3.6 in steam condensate. Overall, organic matter solubilisation, as indicated by dissolved organic carbon, biological and chemical oxygen demands, and total dissolved solids, increased with temperature. Lignin did not appear to hydrolyse. Hemicellulose hydrolysed and degraded the most, followed by cellulose. The highest recoveries of hemicellulose and cellulose in solution were achieved at 160 °C, although the latter could be due to experimental error. The largest losses of hemicellulose and cellulose were recorded at 200 °C. The performance of the system in respect to hydrolysis was inferior compared to other hydrothermal systems, particularly those employing wet oxidation. 相似文献