全文获取类型
收费全文 | 205篇 |
免费 | 38篇 |
国内免费 | 78篇 |
专业分类
安全科学 | 9篇 |
废物处理 | 38篇 |
环保管理 | 10篇 |
综合类 | 138篇 |
基础理论 | 62篇 |
污染及防治 | 35篇 |
评价与监测 | 13篇 |
社会与环境 | 6篇 |
灾害及防治 | 10篇 |
出版年
2024年 | 1篇 |
2023年 | 3篇 |
2022年 | 4篇 |
2021年 | 11篇 |
2020年 | 6篇 |
2019年 | 13篇 |
2018年 | 38篇 |
2017年 | 3篇 |
2016年 | 11篇 |
2015年 | 15篇 |
2014年 | 10篇 |
2013年 | 14篇 |
2012年 | 18篇 |
2011年 | 16篇 |
2010年 | 14篇 |
2009年 | 18篇 |
2008年 | 6篇 |
2007年 | 3篇 |
2006年 | 6篇 |
2005年 | 18篇 |
2004年 | 12篇 |
2003年 | 11篇 |
2002年 | 8篇 |
2001年 | 6篇 |
2000年 | 12篇 |
1999年 | 6篇 |
1998年 | 4篇 |
1997年 | 4篇 |
1996年 | 10篇 |
1995年 | 7篇 |
1994年 | 7篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1988年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有321条查询结果,搜索用时 31 毫秒
21.
采用钙基吸收剂及复合氧化剂半干法脱除模拟球团烟气中的SO_2及Hg~0,考察了多因素条件对吸收效果的影响。实验结果表明,在以NaClO和NaClO_2为复合氧化剂、 NaClO与NaClO_2体积比1∶0.5、复合氧化剂质量分数3%、反应温度110℃、钙基吸收剂质量3.0 g、模拟烟气进气流量1.2 L/min的条件下,SO_2和Hg~0的脱除率分别为98%和93%,证明钙基吸收剂与复合氧化剂对污染物球团烟气中的SO_2和Hg~0有良好的脱除作用。 相似文献
22.
23.
24.
用锯木屑作为吸附材料,0#柴油为吸附对象进行室内模拟实验,研究了木屑对纯油、水中浮油的吸附以及吸油后的木屑在水中的漂浮性能;并以木屑粒径、木屑投加量、振荡频率、油膜厚度为研究指标,设计了5因素4水平的正交实验,考察了各因素对0#柴油的吸附量、去除率以及木屑漂浮率的影响并对优化条件进行了讨论。结果表明,在实验研究范围内,木屑对水中柴油的吸附速度极快,1min即可达到饱和,饱和吸附量为8.08g/g;木屑在水中漂浮性能良好,静态时经72h漂浮,漂浮率维持在92%左右;振荡频率为150r/min时,72h内漂浮率维持在68%以上;最佳吸油条件组合为吸附剂粒径10~20目,振荡频率120r/min,木屑投加量0.7g,油膜厚度1.65mm。 相似文献
25.
南京市冬季大气颗粒态汞的分布特征 总被引:2,自引:0,他引:2
采集了南京市2012年冬季4个功能区的PM2.5、PM10、TSP样品,对不同粒径大气颗粒物中的颗粒态汞测试。结果表明,南京冬季大气颗粒物TSP中汞的质量浓度为49.26 pg/m3~257.14 pg/m3,平均质量浓度为161.27 pg/m3;PM10中汞的质量浓度为44.82 pg/m3~228.29 pg/m3,平均质量浓度为147.38 pg/m3;PM2.5中汞的质量浓度为35.98 pg/m3~178.58 pg/m3,平均质量浓度为104.10 pg/m3。不同功能区大气颗粒态汞质量浓度的分布趋势为:交通综合区>旅游区>住宿综合区>商业区。大气颗粒态汞60%以上存在于可吸入肺的PM2.5中,细颗粒物富集汞的能力比粗颗粒物强。 相似文献
26.
Hugh Lehman 《Journal of Agricultural and Environmental Ethics》1988,1(2):155-162
According to a rights view it is acceptable to kill animals if they are innocent threats or shields or are in a lifeboat situation. However, according to advocates of such a view, our practices of killing animals for food or scientific research may be morally unacceptable. In this paper we argue that, even if we grant the basic assumptions of a rights view, a good deal of killing of animals for food and scientific research continues to be morally acceptable. 相似文献
27.
Hiroshi Mitomo Kazunobu Sasada Kenji Nishimura Fumio Yoshii Naotsugu Nagasawa 《Journal of Polymers and the Environment》2004,12(2):95-103
Poly(-caprolactone) (PCL) was blended with diatomaceous earth (diatomite) and irradiated with -rays to introduce cross-linking between PCL molecules or both components. The unwashed diatomite containing a little of a volatile component showed high efficiency of introduction of cross-linking, whereas that with no volatile component showed low efficiency of introduction of cross-linking. Elongational viscosity, melt viscosity, and modulus of PCL/diatomite blend irradiated at various doses were significantly improved. Enzymatic degradation of the PCL/diatomite blend became faster than that of the PCL, though that of the blend irradiated became slower. 相似文献
28.
Azotobacter vinelandii UWD, ATCC 53799, an engineered strain derived from Azotobacter vinelandii UW was used in the poly(ethylene glycol) (PEG)-modulated synthesis of poly(-hydroxybutyrate) (PHB). To the best of our knowledge, this is the first report on modulating the production of PHB by amending the fermentation broth with PEG using A. vinelandii UWD. It was determined that A. vinelandii UWD is prone to back-mutation to the parent strain; hence fermentation experiments require the use of the antibiotic rifampicin. Diethylene glycol (DEG) and PEGs with molecular weights of 400, 2000, and 3400 Da and pentaerythritol ethoxylate (PEE) were used in the modulated fermentation experiments in a concentration of 2% (w/v). The molecular weight of the resulting polymers was reduced by up to 78%. No impact on the productivity of the strain was observed. Spectroscopic evidence showed that PEG-modulated synthesis resulted in the covalent attachment of the ethylene glycol moiety only when a small molecule, DEG, was used. PEGs had the same effects on the polymer formation in terms of molecular weight reduction as DEG, but no spectroscopic evidence was found for the formation of a covalent linkage between PHB and higher molecular weight PEGs. 相似文献
29.
A simple method for the quantitative gradient analysis of a xerotermic forest-margin ecotone is described. In this method, the mean value of the coefficient of similarity between all plots of the transect is used for estimating the rate of changes in species composition. Changes in the phytosociological spectrum are analyzed. The method adequately reflects trends in the displacement of forest species by forest-margin, steppe, and meadow species. 相似文献
30.
The results of a study on morphophysiological variation in fish inhabiting a subarctic lake exposed to chronic industrial pollution are described using an example of cisco, Coregonus lavaretus. It is shown that indices of the heart, liver, kidneys, gills, and fatness in these fish are increased significantly and have retained increased values for the past 20 years. The observed changes are analyzed on the basis of biochemical data. The results of studies on the dynamics of hematological parameters in fish are used for characterizing the development of toxicosis. Adaptive rearrangements associated with an increase in the metabolic rate and the activation of protective systems in the fish are explained in the context of S.S. Schvarts' concept. The idea is proposed that the additional energy cost of detoxification may be responsible for morphophysiological variation in fish under conditions of water pollution. 相似文献