全文获取类型
收费全文 | 2599篇 |
免费 | 228篇 |
国内免费 | 947篇 |
专业分类
安全科学 | 239篇 |
废物处理 | 97篇 |
环保管理 | 216篇 |
综合类 | 1712篇 |
基础理论 | 502篇 |
污染及防治 | 552篇 |
评价与监测 | 148篇 |
社会与环境 | 157篇 |
灾害及防治 | 151篇 |
出版年
2024年 | 10篇 |
2023年 | 37篇 |
2022年 | 160篇 |
2021年 | 148篇 |
2020年 | 144篇 |
2019年 | 106篇 |
2018年 | 122篇 |
2017年 | 132篇 |
2016年 | 110篇 |
2015年 | 165篇 |
2014年 | 235篇 |
2013年 | 243篇 |
2012年 | 240篇 |
2011年 | 235篇 |
2010年 | 162篇 |
2009年 | 182篇 |
2008年 | 192篇 |
2007年 | 193篇 |
2006年 | 156篇 |
2005年 | 109篇 |
2004年 | 85篇 |
2003年 | 65篇 |
2002年 | 100篇 |
2001年 | 86篇 |
2000年 | 59篇 |
1999年 | 49篇 |
1998年 | 54篇 |
1997年 | 38篇 |
1996年 | 34篇 |
1995年 | 30篇 |
1994年 | 26篇 |
1993年 | 12篇 |
1992年 | 13篇 |
1991年 | 13篇 |
1990年 | 11篇 |
1989年 | 3篇 |
1988年 | 7篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1982年 | 1篇 |
排序方式: 共有3774条查询结果,搜索用时 359 毫秒
111.
The effects of the annealing and partial substitution of Y for La on the structural and electrochemical properties of La1-xYxNi3.55Mno.4Alo.3Cro.75 (x = 0, 0.1 and 0.2) alloys were reported in the present work. The single-phased CaCu5-type structure was retained after La was partially substituted by Y. However, the increase of Y content leads to decrease of the lattice parameters and the unit-cell volume. The annealed Lao.9Yo.1Ni3.55Mno.4Alo.3Coo.75 alloys shows typical isometric microstructure, indicating that the composition segregation is improved by annealing. Y substitution for La in the alloys is effective to improve the electrochemical properties at both room temperature and high temperature. A critical substitution content of Y is found at x = 0.1. 相似文献
112.
NOx是我国十二五期间重点控制的污染物,燃煤工业锅炉是其重要来源。为了研究燃煤工业锅炉NOx的形成与释放规律,在实验室模拟了不同煤种的燃烧过程。采用原煤/焦炭燃烧法分别研究挥发分氮和焦炭氮生成NOx的反应,探讨燃料型NOx的形成与释放规律,并解释试验模拟条件下燃煤NOx产污系数和现场实测值的差异。结果表明,试验中烟煤、无烟煤、煤焦的NO转化率平均值分别为25.77%,22.17%和11.98%,产污系数平均值分别为4.31,5.08和2.00kg/t,高于现场实测结果核算值。燃煤工业锅炉NOx以燃料型为主,燃料型NOx的形成和释放是一个复杂的多相反应过程,由挥发分氮的氧化还原反应和焦炭氮的氧化还原反应组成,煤种、温度、空气流量、粒径、氧含量等因素对4种反应各自影响及影响程度并不相同。 相似文献
113.
114.
115.
116.
117.
Catalytic bubble-free hydrogenation reduction of azo dye by porous membranes loaded with palladium (Pd) nanoparticles was studied for the first time. The effects of Pd loading, dye concentration and reuse repetitions of membranes were investigated. In reduction, the dye concentration decreased whereas the pH rose gradually. An optimal Pd loading was found. The catalytic membranes were able to be reused more than 3 times. 相似文献
118.
Jun Bai Xiuhong Yang Ruiying Du Yanmei Chen Shizhong Wang Rongliang Qiu 《环境科学学报(英文版)》2014,26(10):2056-2064
Mechanisms of soil Pb immobilization by Bacillus subtilis DBM, a bacterial strain isolated from a heavy-metal-contaminated soil, were investigated. Adsorption and desorption experiments with living bacterial cells as well as dead cells revealed that both extracellular adsorption and intracellular accumulation were involved in the Pb2+removal from the liquid phase. Of the sequestered Pb(II), 8.5% was held by physical entrapment within the cell wall, 43.3% was held by ion-exchange, 9.7% was complexed with cell surface functional groups or precipitated on the cell surface, and 38.5% was intracellularly accumulated.Complexation of Pb2+with carboxyl, hydroxyl, carbonyl, amido, and phosphate groups was demonstrated by Fourier transform infrared spectroscopic analysis. Precipitates of Pb5(PO4)3OH, Pb5(PO4)3Cl and Pb10(PO4)6(OH)2that formed on the cell surface during the biosorption process were identified by X-ray diffraction analysis. Transmission electron microscopy–energy dispersive spectroscopic analysis confirmed the presence of the Pb(II)precipitates and that Pb(II) could be sequestered both extracellularly and intracellularly.Incubation with B. subtilis DBM significantly decreased the amount of the weak-acid-soluble Pb fraction in a heavy-metal-contaminated soil, resulting in a reduction in Pb bioavailability, but increased the amount of its organic-matter-bound fraction by 71%. The ability of B.subtilis DBM to reduce the bioavailability of soil Pb makes it potentially useful for bacteria-assisted phytostabilization of multi-heavy-metal-contaminated soil. 相似文献
119.
The brominated products, formed in chlorination treatment of benzophenone-4 in the presence of bromide ions, were identified, and the formation pathways were proposed.Under disinfection conditions, benzophenone-4 would undertake electrophilic substitution generating mono- or di-halogenated products, which would be oxidized to esters and further hydrolyzed to phenol derivatives. The generated catechol intermediate would be transformed into furan-like heterocyclic product. The product species were p H-dependent,while benzophenone-4 elimination was chlorine dose-dependent. When the chlorination treatment was performed on ambient water spiked with benzophenone-4 and bromide ions, most of brominated byproducts could be detected, and the acute toxicity significantly increased as well. 相似文献
120.
Characteristics of atmospheric particles and heavy metals in winter in Chang-Zhu-Tan city clusters, China 总被引:1,自引:0,他引:1
Kai Zhang Fahe Chai Zilong Zheng Qing Yang Juansheng Li Jing Wang Yujie Zhang 《环境科学学报(英文版)》2014,26(1):147-153
To understand the pollution characteristics of atmospheric particles and heavy metals in winter in Chang-Zhu-Tan city clusters, China, total suspended particulate(TSP) and PM10samples were collected in cities of Changsha, Zhuzhou and Xiangtan from December 2011 to January 2012, and heavy metals of Cd, Pb, Cr, and As were analyzed. It shows that the average TSP concentration in Changsha, Zhuzhou and Xiangtan were(183 ± 73),(201 ± 84) and(190 ± 66) μg/m3respectively, and the average PM10 were(171 ± 82),(178 ± 65) and(179 ± 55) μg/m3respectively. The lowest TSP and PM10concentrations occurred at the background Shaping site of Changsha. The average ratio of ρ(PM10)/ρ(TSP) was 91.9%, ranging from 81.3% to 98.9%. Concerning heavy metals, in TSP samples, the concentration of Cr, As, Cd and Pb were 28.8–56.5, 18.1–76.3, 3.9–26.1 and 148.0–460.9 ng/m3, respectively, while in PM10samples, were 16.4–42.1, 15.5–67.9, 3.3–22.2 and 127.9–389.3 ng/m3, respectively. The enrichment factor of Cd was the highest, followed by Pb and As, while that of Cr was the lowest. 相似文献