全文获取类型
收费全文 | 3968篇 |
免费 | 104篇 |
国内免费 | 1348篇 |
专业分类
安全科学 | 219篇 |
废物处理 | 218篇 |
环保管理 | 333篇 |
综合类 | 1888篇 |
基础理论 | 727篇 |
环境理论 | 1篇 |
污染及防治 | 1570篇 |
评价与监测 | 167篇 |
社会与环境 | 132篇 |
灾害及防治 | 165篇 |
出版年
2023年 | 64篇 |
2022年 | 185篇 |
2021年 | 128篇 |
2020年 | 96篇 |
2019年 | 93篇 |
2018年 | 148篇 |
2017年 | 165篇 |
2016年 | 167篇 |
2015年 | 214篇 |
2014年 | 303篇 |
2013年 | 381篇 |
2012年 | 334篇 |
2011年 | 320篇 |
2010年 | 237篇 |
2009年 | 282篇 |
2008年 | 273篇 |
2007年 | 241篇 |
2006年 | 214篇 |
2005年 | 152篇 |
2004年 | 119篇 |
2003年 | 148篇 |
2002年 | 132篇 |
2001年 | 110篇 |
2000年 | 122篇 |
1999年 | 131篇 |
1998年 | 145篇 |
1997年 | 89篇 |
1996年 | 78篇 |
1995年 | 74篇 |
1994年 | 62篇 |
1993年 | 57篇 |
1992年 | 48篇 |
1991年 | 20篇 |
1990年 | 20篇 |
1989年 | 11篇 |
1988年 | 13篇 |
1987年 | 6篇 |
1986年 | 8篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 7篇 |
1979年 | 2篇 |
1977年 | 2篇 |
1975年 | 1篇 |
1974年 | 2篇 |
1972年 | 1篇 |
1971年 | 2篇 |
1930年 | 1篇 |
排序方式: 共有5420条查询结果,搜索用时 31 毫秒
451.
The role of condensed organic matter in the nonlinear sorption of hydrophobic organic contaminants by a peat and sediments 总被引:2,自引:0,他引:2
This study examines the effect of soil organic matter heterogeneity on equilibrium sorption and desorption of phenanthrene, naphthalene, 1,3,5-trichlorobenzene (1,3,5-TCB), and 1,2-dichlorobenzene (1,2-DCB) by soils and sediments. Two estuary sediments, a Pahokee peat (PP; Euic, hyperthermic Lithic Haplosaprist), and two subsamples (base- and acid-treated peat [TP] and acid-treated peat [FP]) of the peat were used as the sorbents. The contents of black carbon particles were quantified with a chemical extraction method. Petrographical examinations revealed the presence of the condensed soil and sediment organic matter (SOM) in Pahokee peat. The Freundlich isotherm model in two different forms was used to fit both sorption and desorption data. The results show that the sorption and desorption isotherms are generally nonlinear and that the apparent sorption-desorption hysteresis is present for phenanthrene and TCB. Detailed analysis of sorption data for the tested sorbent-sorbate systems indicates that black carbon is probably responsible for sorption isotherm nonlinearity for the two sediments, whereas the humic substances and kerogen may play the dominant role in nonlinear sorption by the peat. This investigation suggests that the microporosity of SOM is important for the hydrophobic organic contaminant (HOC) sorption capacity on the peat. 相似文献
452.
Joseph C. Rode Christine H. Mooney Marne L. Arthaud‐Day Janet P. Near Timothy T. Baldwin Robert S. Rubin William H. Bommer 《组织行为杂志》2007,28(4):399-421
We examined the direct and moderated effects of an ability‐based measure of emotional intelligence (MSCEIT© V2.0) on individual performance in a sample of business undergraduates. Controlling for general mental ability and personality, emotional intelligence explained unique incremental variance in performance ratings on only one of two measures of interpersonal effectiveness (public speaking effectiveness). However, the interaction of emotional intelligence with conscientiousness explained unique incremental variance both in public speaking and group behavior effectiveness, as well as academic performance (cumulative GPA). We conclude that the effects of emotional intelligence on performance are more indirect than direct in nature. Individuals must not only have emotional intelligence, but also must be motivated to use it. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
453.
清代在水土资源、林木资源、矿产资源的保护与利用等方面采取了积极有效的措施,包括开垦土地、兴修水利、发展生态农业、植树造林、加强法制、设立环保机构等。 相似文献
454.
ABSTRACT. Planning an optimal system of activities for generating economic goods and services within an existing natural resource capacity is a difficult problem to solve. A mathematical programming model with the capacity to check multiple resource demand and supply compatibility over many time periods was developed for the solution to this type of problem. The characteristics of natural resource supply and the demand of activities were utilized to reduce the number of time periods and to minimize the loss of the dynamic reality of the problem. Reduction in the number of time periods extended the capability of the model to the solution of complex resource planning problems without oversimplification. 相似文献
455.
Janet K. Baker Norbert Dee James R. Finley 《Journal of the American Water Resources Association》1974,10(1):10-21
The parameters and the measurement procedures described in this paper are seen as being part of the first stage in development of the human environment assessment process. Additional parameters need to be identified, and methods of measuring impacts reflected by the parameters must be developed and refined. Considerations of the human environment and those elements of the natural environment that are of importance to people must be included as an integral part of the environmental impact assessment process. Therefore, there is a need for continuing to identify parameters of the human environment and to develop methods of measuring impacts so that these considerations will become a well-integrated part of the environmental impact assessment process. 相似文献
456.
457.
458.
Chiang Hung-Lung Huang Yao-Sheng 《Atmospheric environment (Oxford, England : 1994)》2009,43(26):4014-4022
Particulate matter, including coarse particles (PM2.5–10, aerodynamic diameter of particle between 2.5 and 10 μm) and fine particles (PM2.5, aerodynamic diameter of particle lower than 2.5 μm) and their compositions, including elemental carbon, organic carbon, and 11 water-soluble ionic species, and elements, were measured in a tunnel study. A comparison of the six-hour average of light-duty vehicle (LDV) flow of the two sampling periods showed that the peak hours over the weekend were higher than those on weekdays. However, the flow of heavy-duty vehicles (HDVs) on the weekdays was significant higher than that during the weekend in this study. EC and OC content were 49% for PM2.5–10 and 47% for PM2.5 in the tunnel center. EC content was higher than OC content in PM2.5–10, but EC was about 2.3 times OC for PM2.5. Sulfate, nitrate, ammonium were the main species for PM2.5–10 and PM2.5. The element contents of Na, Al, Ca, Fe and K were over 0.8 μg m?3 in PM2.5–10 and PM2.5. In addition, the concentrations of S, Ba, Pb, and Zn were higher than 0.1 μg m?3 for PM2.5–10 and PM2.5. The emission factors of PM2.5–10 and PM2.5 were 18 ± 6.5 and 39 ± 11 mg km?1-vehicle, respectively. The emission factors of EC/OC were 3.6/2.7 mg km?1-vehicle for PM2.5–10 and 15/4.7 mg km?1-vehicle for PM2.5 Furthermore, the emission factors of water-soluble ions were 0.028(Mg2+)–0.81(SO42?) and 0.027(NO2?)–0.97(SO42?) mg km?1-vehicle for PM2.5–10 and PM2.5, respectively. Elemental emission factors were 0.003(V)–1.6(Fe) and 0.001(Cd)–1.05(Na) mg km?1-vehicle for PM2.5–10 and PM2.5, respectively. 相似文献
459.
Viachaslau Filimonau Janet Dickinson Derek Robbins Mark A.J. Huijbregts 《Journal of Cleaner Production》2011,19(17-18):1917-1930
This study discusses the potential for Life Cycle Assessment (LCA) to be utilized for the environmental assessment of tourism accommodation facilities, and their contribution to global carbon footprint. To demonstrate the viability of employing LCA in the hotel sector, its simplified derivative, Life Cycle Energy Analysis (LCEA), is applied to two tourism accommodation facilities in Poole, Dorset (UK) to quantify their CO2 emissions. The results indicate that the reviewed hotels are less energy and carbon-intense than the tourism accommodation establishments reported in the literature. This may indirectly imply the continuous progress of hotel’s energy efficiency over time. The implications of the current energy use practices in the reviewed hotels are discussed and suggestions are made on how to further improve the energy performance and therefore cut the carbon footprint. Recommendations for hotel management and policy-making are developed to reduce the energy and carbon intensity of the hotel industry. A method for energy and carbon footprint analysis of outsourced laundries and breakfast services is also proposed. 相似文献
460.
武钢三烧区域改建了二台大连三洋蒸汽型双效溴化锂吸收式制冷机。叙述了该改建项目的主机选型、参数选定、设计特点等。 相似文献