全文获取类型
收费全文 | 1375篇 |
免费 | 68篇 |
国内免费 | 526篇 |
专业分类
安全科学 | 80篇 |
废物处理 | 81篇 |
环保管理 | 85篇 |
综合类 | 812篇 |
基础理论 | 237篇 |
污染及防治 | 534篇 |
评价与监测 | 49篇 |
社会与环境 | 47篇 |
灾害及防治 | 44篇 |
出版年
2023年 | 29篇 |
2022年 | 76篇 |
2021年 | 81篇 |
2020年 | 43篇 |
2019年 | 47篇 |
2018年 | 53篇 |
2017年 | 71篇 |
2016年 | 73篇 |
2015年 | 72篇 |
2014年 | 119篇 |
2013年 | 119篇 |
2012年 | 110篇 |
2011年 | 132篇 |
2010年 | 88篇 |
2009年 | 104篇 |
2008年 | 101篇 |
2007年 | 91篇 |
2006年 | 62篇 |
2005年 | 49篇 |
2004年 | 50篇 |
2003年 | 50篇 |
2002年 | 29篇 |
2001年 | 39篇 |
2000年 | 40篇 |
1999年 | 37篇 |
1998年 | 34篇 |
1997年 | 23篇 |
1996年 | 27篇 |
1995年 | 21篇 |
1994年 | 18篇 |
1993年 | 16篇 |
1992年 | 8篇 |
1991年 | 17篇 |
1990年 | 15篇 |
1989年 | 6篇 |
1988年 | 10篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1983年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有1969条查询结果,搜索用时 31 毫秒
81.
针对城市垃圾箱最佳间距的研究不够精细的现状,本文通过建立排队论模型得到了可供不同城市参考的城市垃圾箱最佳间距参数表。通过对部分城市街道的垃圾箱摆放间距情况进行实地调查,运用层次分析法将影响垃圾箱间距分布的多重因素转化为单因素;建立了基于指数分布的教学模型,利用排队论分析单因素状态下的垃圾箱间距分布,得到了求解城市垃圾箱最佳间距的一般方法。 相似文献
82.
Biosorption of silver ions onto Bacillus cereus biomass was investigated. Overall kinetic experiments were performed for the
determination of the necessary contact time for the attainment of equilibrium. It was found that the overall biosorption process was
best described by pseudo second-order kinetic model. The crystals detected by scanning electron microscope and X-ray photoelectron
spectroscopy suggested the precipitation was a possible mechanism of biosorption. The molecular genetics of silver resistance of B.
cereus biomass was also detected and illustrated by a whole cell sensor tool. 相似文献
83.
The Cu2+-loaded montmorillonite clays (MMT-Cu) may be a good material for the adsorbed and eliminated pathogenic bacteria from aqueous solution. 相似文献
84.
Xinxin Wang Zhen Han Zhihui Bai Jingchun Tang Anzhou M Jizheng He Guoqiang Zhuang 《环境科学学报(英文版)》2011,23(11):1858-1864
The impact of petroleum on archaeal community in salinealkali soils was investigated, which will expand the knowledge of the archaeal population involved in the natural attenuation of hydrocarbons in extreme environments. 相似文献
85.
86.
随着我国向工业型国家转型的进程加快,我国作为一个水资源贫乏的国家,水污染的问题日益突出。因此,对于我国城市污水处理问题进行研究探讨,对于实现我国可持续发展战略有着重大的意义。本文主要对目前我国城市污水处理中存在的问题进行了分析研究,并在此基础上,对我国的城市污水处理提出了一些有针对性地对策与措施。 相似文献
87.
88.
为了研究软土地区地震作用下高墩先简支后桥面连续梁桥的支座选型及横桥向抗震约束问题,选取了普通板式橡胶支座、钢阻尼滑板支座、LNR 橡胶支座和 HDR 高阻尼支座四种支座类型,以软土地区某(4×30)m 跨径高墩先简支后桥面连续梁桥为例,进行了延性抗震体系和减隔震体系抗震设计对比以及设置挡块的横桥向抗震约束效果研究。结果表明:软土地区高墩先简支后桥面连续梁桥墩柱配筋率主要由 E1 地震作用下墩底截面偏心受压检算工况决定,采用减隔震体系并不能降低桥墩配筋率。通过对采用四种不同支座桥梁的内力、墩梁相对位移以及配筋率方面综合分析可知,软土地区高墩先简支后桥面连续梁桥的周期较长,这类桥梁抗震关键问题是防止落梁、减小墩顶位移。采用普通板式橡胶支座并合理的设计纵横向防落梁装置的延性抗震体系更适宜于软土地区高墩梁式桥,合理设计抗震挡块可以起到很好的横向约束作用,避免横向落梁的发生。 相似文献
89.
Photocatalytic ozonation of phenol and oxalic acid (OA) was conducted with a Ag^+/TiO2 catalyst and different pathways were found for the degradation of different compounds. Ag^+ greatly promoted the photocatalytic degradation of contaminants due to its role as an electron scavenger. It also accelerated the removal rate of OA in ozonation and the simultaneous process for its complex reaction with oxalate. Phenol could be degraded both in direct ozonation and photolysis, but the TOC removal rates were much higher in the simultaneous processes due to the oxidation of hydroxyl radicals resulting from synergetic effects. The sequence of photo-illumination and ozone exposure in the combined process showed quite different effects in phenol degradation and TOC removal. The synergetic effects in different combined processes were found to be highly related to the properties of the target pollutants. The color change of the solution and TEM result confirmed that Ag+ was easily reduced and deposited on the surface of Tit2 under photo-illumination, and dissolved again into solution in the presence of ozone. This simple cycle of enrichment and distribution of Ag^+ can greatly benefit the design of advanced oxidation processes, in which the sequences of ozone and photo-illumination can be varied according to the needs for catalyst recycling and the different properties of pollutants. 相似文献
90.
Experimental study on filtration and continuous regeneration of a particulate filter system for heavy-duty diesel engines 总被引:1,自引:0,他引:1
This study investigated the filtration and continuous regeneration of a particulate filter system on an engine test bench, consisting of a diesel oxidation catalyst(DOC) and a catalyzed diesel particulate filter(CDPF). Both the DOC and the CDPF led to a high conversion of NO to NO2 for continuous regeneration. The filtration efficiency on solid particle number(SPN) was close to100%. The post-CDPF particles were mainly in accumulation mode. The downstream SPN was sensitively influenced by the variation of the soot loading. This phenomenon provides a method for determining the balance point temperature by measuring the trend of SPN concentration. 相似文献