全文获取类型
收费全文 | 362篇 |
免费 | 44篇 |
国内免费 | 287篇 |
专业分类
安全科学 | 30篇 |
废物处理 | 20篇 |
环保管理 | 15篇 |
综合类 | 366篇 |
基础理论 | 75篇 |
污染及防治 | 165篇 |
评价与监测 | 20篇 |
社会与环境 | 1篇 |
灾害及防治 | 1篇 |
出版年
2023年 | 14篇 |
2022年 | 22篇 |
2021年 | 25篇 |
2020年 | 19篇 |
2019年 | 19篇 |
2018年 | 30篇 |
2017年 | 29篇 |
2016年 | 43篇 |
2015年 | 37篇 |
2014年 | 19篇 |
2013年 | 47篇 |
2012年 | 48篇 |
2011年 | 35篇 |
2010年 | 33篇 |
2009年 | 39篇 |
2008年 | 29篇 |
2007年 | 34篇 |
2006年 | 30篇 |
2005年 | 20篇 |
2004年 | 27篇 |
2003年 | 15篇 |
2002年 | 15篇 |
2001年 | 15篇 |
2000年 | 10篇 |
1999年 | 5篇 |
1998年 | 10篇 |
1997年 | 8篇 |
1996年 | 7篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1983年 | 1篇 |
排序方式: 共有693条查询结果,搜索用时 15 毫秒
391.
392.
Potential for microbially mediated redox transformations and mobilization of arsenic in uncontaminated soils 总被引:1,自引:0,他引:1
Shigeki Yamamura Mirai Watanabe Norio Yamamoto Kazunari Sei Michihiko Ike 《Chemosphere》2009,77(2):169-174
Surface soil samples, which had no significant As contamination, were examined for As(V) reduction, As(III) oxidation and As mobilization capability. All five soil samples tested exhibited microbial As(V)-reducing activities both in aerobic and anaerobic conditions. Under aerobic conditions when As(V) reduction had almost ceased, oxidation of As(III) to As(V) occurred, whereas only As(V) reduction was observed under anaerobic conditions. In cultures incubated with As(III), As(III) was oxidized by indigenous soil microbes only under aerobic conditions. These results indicate that microbial redox transformations of As are ubiquitous in the natural environment regardless of background As levels. Mobilization through microbially mediated As(V) and Fe(III) reduction occurred both in the presence and absence of oxygen. Significant variation in dissolved As occurred depending on the Fe contents of soils, and re-immobilization of As arose in the presence of oxygen, presumably as a consequence of dissolved As(III) and Fe(II) oxidation. There was no apparent correlation between dissolved Fe(II) and As, suggesting that reductive dissolution of Fe(III) minerals does not necessarily determine the extent of As release from soils. 相似文献
393.
In this study, the dechlorination of chlorinated hydrocarbons including trichloroethylene (TCE), tetrachloroethylene (PCE) and carbon tetrachloride (CT) by bimetallic Ni/Fe nanoparticles immobilized on four different membranes was investigated under anoxic conditions. Effects of several parameters including the nature of membrane, initial concentration, pH value, and reaction temperature on the dechlorination efficiency were examined. The scanning electron microscopic images showed that the Ni/Fe nanoparticles were successfully immobilized inside the four membranes using polyethylene glycol as the cross-linker. The agglomeration of Ni/Fe were observed in poly(vinylidene fluoride), Millex GS and mixed cellulose ester membranes, while a relatively uniform distribution of Ni/Fe was found in nylon-66 membrane because of its hydrophilic nature. The immobilized Ni/Fe nanoparticles exhibited good reactivity towards the dechlorination of chlorinated hydrocarbons, and the pseudo-first-order rate constant for TCE dechlorination by Ni/Fe in nylon-66 were 3.7-11.7 times higher than those in other membranes. In addition, the dechlorination efficiency of chlorinated hydrocarbons followed the order TCE > PCE > CT. Ethane was the only end product for TCE and PCE dechlorination, while dichloromethane and methane were found to be the major products for CT dechlorination, clearly indicating the involvement of reactive hydrogen species in dechlorination. In addition, the initial rate constant for TCE dechlorination increased upon increasing initial TCE concentrations and the activation energy for TCE dechlorination by immobilized Ni/Fe was 34.9 kJ mol−1, showing that the dechlorination of TCE by membrane-supported Ni/Fe nanoparticles is a surface-mediated reaction. 相似文献
394.
腐殖酸和铁对阿特拉津光降解影响的研究 总被引:2,自引:0,他引:2
为考察除草剂在水体中的自净性能,对模拟太阳光(λ> 290 nm)下腐殖酸和铁元素对阿特拉津的光化学降解进行了研究。结果表明,单独辐照阿特拉津几乎不降解。在分别加入3、5和10 mg/L的腐殖酸时,阿特拉津的降解率分别为34.36 %、40.74%和15.66 %;在Fe(Ⅲ)投加量从0.01 mmol/L增加到0.2 mmol/L时,阿特拉津的降解率从24.36 %增加到34.97 %。而在当腐殖酸与铁共存时,阿特拉津降解率则进一步提高。紫外可见光谱和荧光光谱均表明,腐殖酸-铁络合物的形成及其光化学作用,促进了阿特拉津的降解。 相似文献
395.
396.
实验定量研究了存在Ca2+、Mg2+和Fe3+时,应用高碘酸钾分光光度法测定Mn2+的准确性,旨在探讨应用该方法准确测定电解锰渣中Mn(Ⅱ)的可行性。结果发现Ca2+浓度超过320 mg/L时,测定过程中会产生大量絮状乳白色沉淀,对Mn2+的测定结果产生干扰。经过16 h的自然沉降,干扰被彻底消除。Mg2+在浓度为0~192 mg/L范围内对Mn2+浓度的测定不产生干扰。同时,Fe3+的存在对Mn2+浓度的测定产生灵敏的干扰,使用掩蔽剂氟化钾可以减少Fe3+的干扰,但却不能彻底消除Fe3+的干扰。提出了在电解锰行业中,没有彻底地消除Ca(Ⅱ)或Fe(Ⅲ)的干扰因素前,需要更为精确地测定Mn(Ⅱ)的浓度,不建议使用高碘酸钾分光光度法。 相似文献
397.
Shrestha RA Lama B Joshi J Sillanpää M 《Environmental science and pollution research international》2008,15(4):303-307
Goal, scope, and background Arsenic contamination in groundwater creates severe health problems in the world. There are many physiochemical and biological
methods available for remediation of arsenic from groundwater. Among them, microbial remediation could be taken as one of
the least expensive methods, though it takes longer treatment time. The main objective of this research was to study the improvement
on remediation by addition of some essential ion salts such as Mn and Fe.
Materials and methods
Staphylococcus aureus, Bacillus subtilis, Klebsiella oxytoca, and Escherichia coli were taken as model microbes from Dhulikhel, 30 km east from Kathmandu, Nepal.
Results and discussion Microbes used in this study showed different abilities in their removal of As(III) with and without addition of Mn and Fe
salts. The trend of remediation increased with time. S. aureus was found to be the best among the microbes used. It showed almost 100% removal after 48-h culture, both with and without
Fe and Mn salts. Rate of removal of As increased with addition of Fe and Mn for all microbes. Removal efficiency was found
to increase by about 32% on average after addition of salts in 24-h cultures of S. aureus. 相似文献
398.
Flament P Mattielli N Aimoz L Choël M Deboudt K de Jong J Rimetz-Planchon J Weis D 《Chemosphere》2008,73(11):1793-1798
A study on tropospheric aerosols involving Fe particles with an industrial origin is tackled here. Aerosols were collected at the largest exhausts of a major European steel metallurgy plant and around its near urban environment. A combination of bulk and individual particle analysis performed by SEM–EDX provides the chemical composition of Fe-bearing aerosols emitted within the factory process (hematite, magnetite and agglomerates of these oxides with sylvite (KCl), calcite (CaCO3) and graphite carbon). Fe isotopic compositions of those emissions fall within the range (0.08‰ < δ56Fe < +0.80‰) of enriched ores processed by the manufacturer (−0.16‰ < δ56Fe < +1.19‰). No significant evolution of Fe fractionation during steelworks processes is observed. At the industrial source, Fe is mainly present as oxide particles, to some extent in 3–4 μm aggregates. In the close urban area, 5 km away from the steel plant, individual particle analysis of collected aerosols presents, in addition to the industrial particle type, aluminosilicates and related natural particles (gypsum, quartz, calcite and reacted sea salt). The Fe isotopic composition (δ56Fe = 0.14 ± 0.11‰) measured in the close urban environment of the steel metallurgy plant appears coherent with an external mixing of industrial and continental Fe-containing tropospheric aerosols, as evidenced by individual particle chemical analysis. Our isotopic data provide a first estimation of an anthropogenic source term as part of the study of photochemically promoted dissolution processes and related Fe fractionations in tropospheric aerosols. 相似文献
399.
Comparison of Diuron degradation by direct UV photolysis and advanced oxidation processes 总被引:1,自引:0,他引:1
The rates of Diuron elimination by some advanced oxidation processes (AOPs) such as Fe(III)/UV, Ferrioxalate/UV, Fe(III)/H(2)O(2)/UV, Ferrioxalate/UV/H(2)O(2) and Fe(III)/H(2)O(2) have been compared. Experiments have been conducted at pH=2.3+/-0.1 with a batch reactor equipped with a low-pressure mercury lamp emitting mainly at 253.7nm. Data obtained under the following experimental conditions ([H(2)O(2)](0)=10(-3)M, [Diuron](0)=5x10(-5)M and [Fe(III)](0)=10(-3)M) have shown that rates of Diuron oxidation were higher with the systems Fe(III)/H(2)O(2)/UV and Ferrioxalate/UV/H(2)O(2) than with Fe(III)/UV and Fe(III)/H(2)O(2). On the other hand, Fe(III)/UV was found to be very efficient in mineralization of Diuron solution in comparison to direct UV photolysis. The experimental results showed that radical ()OH is the major pathway in the process of Diuron degradation. 相似文献
400.
Xiaoge Huang Lihao Chen Ziqi Ma Kenneth C. Carroll Xiao Zhao Zailin Huo 《Frontiers of Environmental Science & Engineering》2022,16(12):151