全文获取类型
收费全文 | 7643篇 |
免费 | 133篇 |
国内免费 | 893篇 |
专业分类
安全科学 | 306篇 |
废物处理 | 490篇 |
环保管理 | 656篇 |
综合类 | 1969篇 |
基础理论 | 1518篇 |
环境理论 | 3篇 |
污染及防治 | 2698篇 |
评价与监测 | 533篇 |
社会与环境 | 364篇 |
灾害及防治 | 132篇 |
出版年
2023年 | 79篇 |
2022年 | 242篇 |
2021年 | 214篇 |
2020年 | 121篇 |
2019年 | 137篇 |
2018年 | 266篇 |
2017年 | 237篇 |
2016年 | 307篇 |
2015年 | 259篇 |
2014年 | 390篇 |
2013年 | 705篇 |
2012年 | 443篇 |
2011年 | 523篇 |
2010年 | 406篇 |
2009年 | 390篇 |
2008年 | 440篇 |
2007年 | 418篇 |
2006年 | 385篇 |
2005年 | 299篇 |
2004年 | 271篇 |
2003年 | 256篇 |
2002年 | 213篇 |
2001年 | 299篇 |
2000年 | 197篇 |
1999年 | 139篇 |
1998年 | 97篇 |
1997年 | 103篇 |
1996年 | 69篇 |
1995年 | 76篇 |
1994年 | 74篇 |
1993年 | 62篇 |
1992年 | 55篇 |
1991年 | 50篇 |
1990年 | 48篇 |
1989年 | 46篇 |
1988年 | 30篇 |
1987年 | 22篇 |
1986年 | 22篇 |
1985年 | 20篇 |
1984年 | 21篇 |
1983年 | 24篇 |
1982年 | 24篇 |
1981年 | 20篇 |
1980年 | 11篇 |
1979年 | 15篇 |
1978年 | 12篇 |
1975年 | 13篇 |
1973年 | 9篇 |
1972年 | 11篇 |
1966年 | 8篇 |
排序方式: 共有8669条查询结果,搜索用时 31 毫秒
121.
122.
杞麓湖主要污染物的动态变化特征研究 总被引:1,自引:0,他引:1
以1997年杞麓湖水质监测结果为基础,运用相关分析,双因子方差分析等方法,对杞麓湖主要污染物动态变化特征的研究结果表明,杞麓湖主要污染物的空间分布较为均匀;BOD5和TN都有较为明显的季节变化。 相似文献
123.
124.
Wu Jin Wang Anpu Huang Yanchu Ma ciguang Y. Ii S. Daishim K. Furuy T. Kikuchi H. Matsushit K. Tanabe 《环境科学学报(英文版)》1990,2(1):27-39
A study has been made on elements organic constituents, TSP, SO2,NO2 of atmospheric pollutants in Beijing. 17 elements, and some PAHs, e. g. B(a)P, B(b, j, k)P, and B(g, h, i)P, in airborne particles by X-ray fluorescence spectroscopy and HPLC, GC/MS, have been determined respectively. It has been shown that the elements Pb, Zn, S and Cu were more enriched in fine particles and different valence states of sulfur at various sites. It was found that the concentrations of S6+ and S2-were more than 85% and less than 15% of the total sulfur respectively. Concentrations of major PAHs and sulfur-containing compounds increased in winter and in urban area. High values for Pb and Zn in city, Fe and Mn at industrial area and Cu, Al rural sites were obtained respectively. This implies the functions of different elemental sources of various sites. Thus, elements can be from distingushed anthropogenic and natural sources.The main contribution of SO2 was found of to have same seasonal variation as the anthropogenic el 相似文献
125.
126.
127.
Fan Jinhong Xu Wenying Gao Tingyao Ma Luming 《Frontiers of Environmental Science & Engineering in China》2007,1(4):504-508
Iron and copper bimetallic system (catalyzed Fe-Cu process) is a promising technology for alkaline nitrobenzene-containing
wastewater treatment. However, little is currently known about the changes of treatment efficiency with time going. This research
investigated the long-term performance of the catalyzed Fe-Cu process to reduce nitrobenzene (NB) in alkaline wastewater.
In addition, the changes of the metal surfaces morphologies and matters before and after the reaction were analyzed by scanning
electron microscopy (SEM) in conjunction with energy-dispersion spectroscopy (EDS) and X-ray diffraction spectroscopy (XRD).
The results showed that the surface properties of copper almost remained unchanged after weeks of operation, which spelled
its strong chemical stability and resistance to poisoning. Moreover, the results indicated that there were two reasons for
the treatment efficiency decreasing with time. One was the gradual iron element consumption due to corrosion. The other was
iron reactivity weakened due to the precipitates accumulation on the surfaces that were mainly Fe3O4 and FeCO.
__________
Translated from Environmental Pollution & Control, 2006, 28(10): 783–785 [译自: 环境污染与防治] 相似文献
128.
涤沦仿真丝印染废水治理技术的研究及其应用 总被引:8,自引:0,他引:8
采用化学法去除对苯二甲酸,对高浓度涤纶仿真丝印染废水进行治理。结果表明:该技术对碱减量废水中CODCr的去除有显著的效果。当废水的pH值在12~14,CODCr含量在10000~33000mg/L时,将废水的pH值调节到4~6,出水CODCr能降至1000~2700mg/L之间,CODCr去除率为77%~955%。为涤纶纺真丝印染废水治理达标排放奠定了基础 相似文献
129.
The application of ultrasonic-electrolysis process for the removal of copper is studied.In the ultrasonic field cavitation acts as jets and agitates the solution and breaks the barrier layer between the cathode surface and the bulk of the solution.Thus increases metal deposition on the cathode surface.The results show that an ultrasonic field is successful for the removal of low copper concentrations in solution. 相似文献
130.
Zhang YJ Bryan ND Livens FR Jones MN 《Environmental pollution (Barking, Essex : 1987)》1997,96(3):361-367
The interactions of a range of actinide elements (Th, U, Np, Pu, Am) with humic substances from the Needle's Eye natural analogue site were studied by gel permeation chromatography. Bulk humic substances were isolated by ammonia extraction, followed by dialysis against distilled water and freeze-drying. The gel permeation results suggest that Needle's Eye humic substances can be fractionated into three incompletely resolved fractions with average molecular weights determined by analytical ultracentrifugation around 49 000 for Fraction 1, around 14 700 for Fraction 2 and around 8000 for Fraction 3. Although there are significant differences between the organic matter elution patterns in individual gel permeation experiments, presumably due to differences in column packing, these are much smaller than the differences between metal ions. The uranium that is naturally present in these humic substances is largely bound in the late-eluting fraction. Spikes of the early actinides, including Np and Pu in controlled valency states, have been added to the humic substances, and gel permeation of the spiked humic substances shows that the three humic fractions vary greatly in their effectiveness and selectivity as ligands for early actinides. 相似文献