全文获取类型
收费全文 | 970篇 |
免费 | 64篇 |
国内免费 | 293篇 |
专业分类
安全科学 | 52篇 |
废物处理 | 70篇 |
环保管理 | 76篇 |
综合类 | 547篇 |
基础理论 | 177篇 |
污染及防治 | 288篇 |
评价与监测 | 39篇 |
社会与环境 | 29篇 |
灾害及防治 | 49篇 |
出版年
2024年 | 1篇 |
2023年 | 9篇 |
2022年 | 39篇 |
2021年 | 22篇 |
2020年 | 27篇 |
2019年 | 21篇 |
2018年 | 33篇 |
2017年 | 42篇 |
2016年 | 31篇 |
2015年 | 49篇 |
2014年 | 63篇 |
2013年 | 73篇 |
2012年 | 54篇 |
2011年 | 65篇 |
2010年 | 57篇 |
2009年 | 48篇 |
2008年 | 72篇 |
2007年 | 51篇 |
2006年 | 57篇 |
2005年 | 47篇 |
2004年 | 28篇 |
2003年 | 40篇 |
2002年 | 37篇 |
2001年 | 51篇 |
2000年 | 41篇 |
1999年 | 43篇 |
1998年 | 45篇 |
1997年 | 31篇 |
1996年 | 28篇 |
1995年 | 27篇 |
1994年 | 22篇 |
1993年 | 21篇 |
1992年 | 10篇 |
1991年 | 8篇 |
1990年 | 5篇 |
1989年 | 4篇 |
1988年 | 4篇 |
1987年 | 4篇 |
1986年 | 4篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 3篇 |
1973年 | 1篇 |
排序方式: 共有1327条查询结果,搜索用时 375 毫秒
251.
252.
253.
254.
255.
256.
257.
258.
Jingyu Su Guanping Jin Changyong Li Xiaohui Zhu Yan Dou Yong Li Xin Wang Kunwei Wang Qianqian Gu 《环境科学学报(英文版)》2014,26(11):2355-2361
Ni was effectively recovered from spent electroless nickel (EN) plating baths by forming a nano-nickel coated activated carbon composite. With the aid of ultrasonication, melamine- formaldehyde-tetraoxalyl-ethylenediamine chelating resins were grafted on activated carbon (MFT/AG). PdC12 sol was adsorbed on MFT/AC, which was then immersed in spent electroless nickel plating bath; then nano-nickel could be reduced by ascorbic acid to form a nano-nickel coating on the activated carbon composite (Ni/AC) in situ. The materials present were carefully examined by Fourier transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy, X-ray photoelectron spectroscopy and electro- chemistry techniques. The resins were well distributed on the inside and outside surfaces of activated carbon with a size of 120 ± 30 nm in MFT/AC, and a great deal of nano-nickel particles were evenly deposited with a size of 3.8 ± 1.1 nm in Ni/MFT. Moreover, Ni/AC was successfully used as a catalyst for ultrasonic degradation of 2.6-dichloronhenol. 相似文献
259.
260.
Xiaojian Zhang Zilong Mi Yang Wang Shuming Liu Zhangbin Niu Pinpin Lu Jun Wang Junnong Gu Chao Chen 《Frontiers of Environmental Science & Engineering》2014,8(3):417-426
A red water phenomenon occurred in several communities few days after the change of water source in Beijing, China in 2008. In this study, the origin of this problem, the mechanism of iron release and various control measures were investigated. The results indicated that a significant increase in sulphate concentration as a result of the new water source was the cause of the red water phenomenon. The mechanism of iron release was found that the high-concentration sulphate in the new water source disrupted the stable shell of scale on the inner pipe and led to the release of iron compounds. Experiments showed that the iron release rate in the new source water within pipe section was over 11-fold higher than that occurring within the local source water. The recovery of tap water quality lasted several months despite ameliora- tive measures being implemented, including adding phosphate, reducing the overall proportion of the new water source, elevating the pH and alkalinity, and utilizing free chlorine as a disinfectant instead of chloramine. Adding phosphate was more effective and more practical than the other measures. The iron release rate was decreased after the addition of 1.5 mg. L-1 orthophosphate- P, tripolyphosphate-P and hexametaphosphate-P by 68%, 83% and 87%, respectively. Elevating the pH and alkalinity also reduced the iron release rate by 50%. However, the iron release rate did not decreased after replacing chloramine by 0.5-0.8 mg. L-1 of free chlorine as disinfectant. 相似文献