全文获取类型
收费全文 | 10247篇 |
免费 | 728篇 |
国内免费 | 2566篇 |
专业分类
安全科学 | 649篇 |
废物处理 | 1278篇 |
环保管理 | 1758篇 |
综合类 | 6843篇 |
基础理论 | 812篇 |
环境理论 | 3篇 |
污染及防治 | 1650篇 |
评价与监测 | 382篇 |
社会与环境 | 138篇 |
灾害及防治 | 28篇 |
出版年
2024年 | 18篇 |
2023年 | 85篇 |
2022年 | 154篇 |
2021年 | 225篇 |
2020年 | 269篇 |
2019年 | 208篇 |
2018年 | 209篇 |
2017年 | 239篇 |
2016年 | 344篇 |
2015年 | 375篇 |
2014年 | 688篇 |
2013年 | 749篇 |
2012年 | 803篇 |
2011年 | 800篇 |
2010年 | 589篇 |
2009年 | 684篇 |
2008年 | 564篇 |
2007年 | 801篇 |
2006年 | 929篇 |
2005年 | 709篇 |
2004年 | 601篇 |
2003年 | 605篇 |
2002年 | 503篇 |
2001年 | 426篇 |
2000年 | 406篇 |
1999年 | 364篇 |
1998年 | 268篇 |
1997年 | 200篇 |
1996年 | 162篇 |
1995年 | 143篇 |
1994年 | 124篇 |
1993年 | 93篇 |
1992年 | 50篇 |
1991年 | 38篇 |
1990年 | 20篇 |
1989年 | 9篇 |
1988年 | 6篇 |
1987年 | 8篇 |
1986年 | 10篇 |
1984年 | 5篇 |
1983年 | 4篇 |
1982年 | 5篇 |
1981年 | 6篇 |
1980年 | 7篇 |
1979年 | 5篇 |
1974年 | 3篇 |
1973年 | 6篇 |
1972年 | 3篇 |
1971年 | 5篇 |
1970年 | 3篇 |
排序方式: 共有10000条查询结果,搜索用时 546 毫秒
21.
Environmental Impact Assessment of the Mining and Concentration Activities in the Kola Peninsula, Russia by Multidate Remote Sensing 总被引:4,自引:0,他引:4
Rigina O 《Environmental monitoring and assessment》2002,75(1):13-33
On the Kola Peninsula, the mining and concentration industry exerts anthropogenic impact on the environment. Tailing dumps cause airborne pollution through dusting, and waterborne pollution due to direct dumping and accidental releases. The objectives were: (1) to analyse multidate satellite imagesfor 1964–1996 to assess the environmental pollution from themining and concentration activity in the Kola in temporal perspective; (2) to evaluate remote sensing methods for integrated environmental impact assessment. The area of mining and industrial sites steadily expands and amounted to 94 km2 in 1996. The polluted water surface amounted to at least 150 km2 through dumping in 1978 and to 106 km2 in1986 due to dusting. Thus, the impact from the mining and concentration activity should be reconsidered as more significant than it was officially anticipated. In the past the main mechanism of pollution wasdirect dumping into the lakes. Currently and in future, airborne pollution after dusting storms will dominate. The effective recultivation of the tailing dumps will be a long-term process. For effective assessment of impacts from the mining and concentration industry, remote sensing methods should be complemented by in-situ measurements, fieldwork, and mathematical modelling. 相似文献
22.
23.
密切值法在污染源治理方案优选中的应用 总被引:5,自引:0,他引:5
本文采用密切值法进行污染源多个治理方案的优化决策研究,并通过实例分析获得了与实际状况相符合的优化结果。 相似文献
24.
The landfill of municipal solid waste(MSW) could be regarded as denitrification reactor and involved in ammonia nitrogen biological removal process. In this research, the process was applied to municipal solid waste collected in Shanghai, China, which was characterized by high food waste content. The NH4^ removal efficiency in the system of SBR nitrifying reactor followed by fresh and matured landfilled waste layer in series was studied. In the nitrifying reactor, above 90% of NH4^ in leachate was oxidized to NO2^- and NO3^- . Then high concentrated NO2^- and NO3^- were removed in the way of denitrification process in fresh landfilled waste layer. At the same time, degradation of fresh landfilled waste was accelerated. Up to the day 120, 136.5 gC/(kg dry waste) and 17.9 gN/(kg dry waste) were converted from waste layer. It accounted for 50.15 % and 86.89 % of the total carbon and nitrogen content of preliminary fresh waste, which was 4.42 times and 5.17 times higher than that of reference column respectively. After filtering through matured landfilled waste, BOD5 concentration in leachate dropped to below 100 mg/L, which would not affect following nitrification adversely. Because the matured landfilled waste acted as a well methanogenic reactor, 23% of carbon produced accumulatively from fresh landfilled waste degradation was converted into CH4. 相似文献
25.
1IntroductionNovelbiologicalactivatedcarbonandactivatedsludgesystemhasshownitsefectiveabilitytoreduceCODintoxicorganicwastewa... 相似文献
26.
Based on wet air oxidation (WAO) and Fenton reagent, thispaper raises a new low pressure wet catalytic oxidation(LPWCO)which requires low pressure for the treatment of highlyconcentrated and refractory organic wastewater. Compared withgeneral wet air oxidation, the pressure of the treatment(0.1-0.6MPa) is only one of tens to percentage of latter(3.5-10MPa). Inaddition, its temperature is no more than 180℃.Compared withFenton reagent, while H2O2/COD(weight ratio) less than 1.2, theremoval of COD in the treatment is over twenty percents more thanFenton's even the value of COD is more than 14000mg/L. In thispaper, we study the effect factor of COD removal and the mechanismof this treatment. The existence of synergistic effect (catalytic oxidation and carbonization) for COD removal in H2SO4-Fenton reagent system under the condition of applied pressure and heating (0.1-0.6MPa, 104-165℃) was verified. The best condition of this disposal are as follows:H2O2/COD(weight ratio)=0.2-1.0, Fe2+ 0.6×10-3 mol, H2SO4 0.5mol, COD>1×104mg/L, the operating pressure is 0.1-0.6MPa and temperature is 104-165℃. This method suit to dispose the high-concentrated refractory wastewater, especially to the wastewater containing H2SO produced in the manufacture of pesticide, dyestuff and petrochemical works. 相似文献
27.
28.
29.
Anoveralldescriptionofindustrialwastewasgivenfromgeneration;treatment,disposalandemissionandcomprehensiveutilization.Inspiteo... 相似文献
30.
对石油亚砜(PSO)萃取巯基醋酸的条件和影响进行了实验研究,确定了石油亚砜通过氢键和巯基醋酸形成的萃合物的组成.为从废水中回收巯基醋酸以及石油硫醚的综合利用提供了依据. 相似文献