全文获取类型
收费全文 | 212篇 |
免费 | 26篇 |
国内免费 | 117篇 |
专业分类
安全科学 | 20篇 |
废物处理 | 31篇 |
环保管理 | 8篇 |
综合类 | 165篇 |
基础理论 | 31篇 |
污染及防治 | 81篇 |
评价与监测 | 15篇 |
社会与环境 | 4篇 |
出版年
2023年 | 1篇 |
2022年 | 3篇 |
2021年 | 7篇 |
2020年 | 11篇 |
2019年 | 10篇 |
2018年 | 16篇 |
2017年 | 11篇 |
2016年 | 19篇 |
2015年 | 30篇 |
2014年 | 16篇 |
2013年 | 22篇 |
2012年 | 19篇 |
2011年 | 31篇 |
2010年 | 21篇 |
2009年 | 17篇 |
2008年 | 13篇 |
2007年 | 15篇 |
2006年 | 17篇 |
2005年 | 18篇 |
2004年 | 11篇 |
2003年 | 8篇 |
2002年 | 5篇 |
2001年 | 7篇 |
2000年 | 5篇 |
1999年 | 5篇 |
1998年 | 6篇 |
1996年 | 3篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1991年 | 1篇 |
排序方式: 共有355条查询结果,搜索用时 15 毫秒
101.
Kim JW Isobe T Ramaswamy BR Chang KH Amano A Miller TM Siringan FP Tanabe S 《Chemosphere》2011,82(5):751-758
Methyl methacrylate (MMA) is grafted on multiwalled carbon nanotubes (MWCNTs) by using N2 plasma technique. The MMA grafted MWCNTs (MWCNT-g-pMMA) are characterized by using Raman spectroscopy, powder X-ray diffraction, X-ray photoelectron spectroscopy, thermo gravimetric analysis-differential thermal analysis (TGA-DTA), and potentiometric acid-base titration method. The application of MWCNT-g-pMMA in the removal of 4,4′-dichlorinated biphenyl (4,4′-DCB) from large volumes of aqueous solutions is investigated under ambient conditions. The results indicate that the adsorption of 4,4′-DCB on MWCNT-g-pMMA is much higher than that of 4,4′-DCB on MWCNTs, and the adsorbed 4,4′-DCB is difficult to be thermally decomposed from MWCNT-g-pMMA according to the TGA-DTA analysis. MWCNT-g-pMMA are suitable materials in the preconcentration and immobilization of polychlorinated biphenyls (PCBs) from large volumes of aqueous solutions in environmental pollution cleanup. 相似文献
102.
The inhibitory effect of CH3F on methanogenesis in mesophilic anaerobic granules was tested at different concentrations (0-10% v/v, in the gas phase) and verified by the stable carbon isotopic signatures of CH4 and CO2. The results showed that the inhibitory effect increased with the initial CH3F concentration up to 5%. The CH3F concentration causing 50% metabolic inhibition was 0.32%. Complete inhibition of acetoclastic methanogenesis with a 91% reduction in total methanogenic activity was achieved when 5% CH3F was initially added to the headspace, which resulted in 870 μM dissolved CH3F in the liquid. It was much higher than that applied in other natural anoxic non-granular systems, indicating that the layered granular structure influenced the inhibitory effect. The obvious increase in hydrogen content indicated that high concentrations of CH3F (?5%) suppressed hydrogenotrophic methanogenesis as well. The stable inhibition lasted for at least 6 d as the CH3F concentration decreased slowly with incubation time. These results suggested that CH3F could be used for investigating methanogenic processes in anaerobic granular systems after the CH3F concentration and incubation time for specific inhibition of acetoclastic methanogenesis were carefully determined. In the present system, CH3F concentration of 5% was suggested to be optimal. 相似文献
103.
以陶瓷为载体,采用溶胶-凝胶法制备了银离子和铈离子共掺杂TiO2的负载型光催化剂——T-AC/陶瓷,研究了pH值、双氧水用量、催化剂用量、紫外灯强度、废水的初始浓度等因素对T-AC/陶瓷光催化剂降解甲基橙染料废水的影响。结果表明,当pH为2、双氧水用量为0.5 mL/100 mL、催化剂用量为3 g/L、紫外灯功率为20 W、废水初始浓度为10mg/L时,甲基橙的降解率可达85.9%,并且甲基橙的光催化降解属于一级动力学方程,T-AC/陶瓷催化剂有较高的活性和稳定性,在废水处理中具有较好的应用前景。 相似文献
104.
以多壁碳纳米管(MWNTs)为载体,在煅烧温度200~900℃、煅烧时间1~7 h、溶胶体系pH值为2~10的工艺条件下,采用溶胶-凝胶法制备复合光催化剂(MWNTs/TiO2)。通过其对甲基橙的光催化降解效果对比,评价各种复合光催化剂催化活性之间的差异,结果表明,随着煅烧温度的升高,复合光催化剂中纳米TiO2的晶型由锐钛型逐渐向金红石型转变,500℃时为2种晶型的混合相;pH值为2的强酸性条件有利于形成金红石晶型,pH值为5的中性及弱酸性条件则有利于形成锐钛型,而pH值为3时为2种晶型的混合相;在煅烧温度500℃、煅烧时间3 h、溶胶凝胶体系pH值为3的最佳制备工艺条件下,复合光催化剂催化活性最高,借助扫描电镜发现其TiO2均匀地包覆在多壁碳纳米管管壁上。 相似文献
105.
We investigated seasonal variability of essential fatty acids (EFA) and methyl mercury (MeHg) concentrations in four size categories of planktonic organisms in two coastal lakes. MeHg concentrations increased significantly with increasing plankton size and were independent of plankton taxonomy. However, total EFA increased from seston to mesozooplankton, but decreased in the cladoceran-dominated macrozooplankton size-class. Analysis of EFA patterns revealed that linoleic, alpha-linolenic, arachidonic, and eicosapentaenoic acids increased with increasing zooplankton size, but docosahexaenoic acid (DHA) in the cladoceran-dominated macrozooplankton was generally lower than in seston. This consistent pattern demonstrates that cladocerans, although bioaccumulating MeHg, convey less DHA than similar-sized copepods to their consumers. It is thus evident that fish consuming cladocerans have restricted access to DHA, yet unrestricted dietary access to MeHg. Thus, the structure of planktonic food webs clearly affects the composition of EFA and regulates dietary supply of these essential nutrients, while MeHg bioaccumulates with increasing zooplankton size. 相似文献
106.
Selvendiran P Driscoll CT Bushey JT Montesdeoca MR 《Environmental pollution (Barking, Essex : 1987)》2008,154(1):46-55
The transport and fate of mercury (Hg) was studied in two forest wetlands; a riparian peatland and an abandoned beaver meadow. The proportion of total mercury (THg) that was methyl mercury (% MeHg) increased from 2% to 6% from the upland inlets to the outlet of the wetlands. During the growing season, MeHg concentrations were approximately three times higher (0.27ng/L) than values during the non-growing season (0.10ng/L). Transport of Hg species was facilitated by DOC production as indicated by significant positive relations with THg and MeHg. Elevated concentrations of MeHg and % MeHg (as high as 70%) were found in pore waters of the riparian and beaver meadow wetlands. Groundwater interaction with the stream was limited at the riparian peatland due to the low hydraulic conductivity of the peat. The annual fluxes of THg and MeHg at the outlet of the watershed were 2.3 and 0.092microg/m2-year respectively. 相似文献
107.
108.
109.
Acetylcholinesterase activity was determined for midge larvae (Chironomus tentans) exposed to either organophosphorus insecticides (OPs) alone or OP insecticides in binary combination with atrazine (200 μg/l). Although atrazine by itself did not reduce the level of acetylcholinesterase activity, atrazine in combination with chlorpyrifos significantly decreased acetylcholinesterase activity as compared to chlorpyrifos only treatments. Although similar trends existed for malathion and methyl parathion, differences were not statistically significant. These results match previously published toxicity data where atrazine, although not acutely toxic even at much higher levels, decreased EC50 values for chlorpyrifos by a magnitude of 4, decreased methyl parathion values by a magnitude of 2, and did not decrease values for malathion. 相似文献
110.
An experimental research into the aqueous photocatalytic oxidation (PCO) of organic groundwater pollutants, methyl-tert-butyl ether (MTBE), tert-butyl alcohol, phenol, humic substances, 2-ethoxy ethanol and ethylene glycol was undertaken using visible light-sensitive
nitrogen-doped titanium dioxide photocatalysts. Nitrogen-doped titania proved to be an effective photocatalyst for MTBE with
its action comparable to and even surpassing that of Degussa P25. In contrast, with the other substances the photocatalysts
showed negligible activity. This difference was explained by the poor adsorption properties of N-doped catalysts. The predominance
of different PCO mechanisms dependent of the surface properties of N-TiO2 catalysts was elucidated. 相似文献