全文获取类型
收费全文 | 498篇 |
免费 | 64篇 |
国内免费 | 259篇 |
专业分类
安全科学 | 61篇 |
废物处理 | 42篇 |
环保管理 | 41篇 |
综合类 | 406篇 |
基础理论 | 119篇 |
污染及防治 | 132篇 |
评价与监测 | 7篇 |
社会与环境 | 8篇 |
灾害及防治 | 5篇 |
出版年
2024年 | 2篇 |
2023年 | 9篇 |
2022年 | 15篇 |
2021年 | 20篇 |
2020年 | 22篇 |
2019年 | 27篇 |
2018年 | 20篇 |
2017年 | 24篇 |
2016年 | 29篇 |
2015年 | 42篇 |
2014年 | 26篇 |
2013年 | 57篇 |
2012年 | 60篇 |
2011年 | 63篇 |
2010年 | 51篇 |
2009年 | 48篇 |
2008年 | 26篇 |
2007年 | 56篇 |
2006年 | 46篇 |
2005年 | 37篇 |
2004年 | 39篇 |
2003年 | 18篇 |
2002年 | 16篇 |
2001年 | 12篇 |
2000年 | 15篇 |
1999年 | 16篇 |
1998年 | 7篇 |
1997年 | 6篇 |
1996年 | 7篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1992年 | 1篇 |
1988年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有821条查询结果,搜索用时 15 毫秒
771.
772.
Among all the 209 kinds of polychlorinated biphenyls (PCBs) congeners, nonplanar and coplanar PCB congeners have di erent levels
of toxicity on mammal cells such as neuronal cells, but little is known about their toxicity on fish cells although PCB congeners usually
have high bioaccumulation abilities in the detected fish bodies. This study showed that 2,2’,4,4’,5,5’-hexacholorbiphenyl (PCB153,
nonplanar congener) and 3,3’,4,4’,5,5’-hexacholorbiphenyl (PCB169, coplanar congener) caused apoptosis on the isolated crucian carp
(Carassius auratus) lymphocytes and the induced cytotoxicity was structure-dependent. According to the laser confocal microscope
observations, apoptosis was clearly distinguished by condensation of nucleus, shrinkage and formation of apoptotic bodies. DNA
fragmentation was detected by agarose gel electrophoresis. These typical morphological and biochemical characteristics indicate the
occurrence of apoptosis on fish lymphocytes. According to the flow cytometry analysis, after the cells were exposed to 10 mol/L
PCBs for 3 h, the apoptotic percentage induced by PCB153 was 23.41%, while that induced by PCB169 was even higher (31.03%).
Furthermore, incubating PCBs with fish lymphocytes enhanced levels of reactive oxygen species (ROS) and malondialdehyde (MDA),
clearly indicating the presence of oxidative stress and lipid peroxidation. Our data also demonstrate that the di erent cytotoxic e ects
induced by coplanar and nonplanar PCBs were correlated with their structural characteristics and the coplanar congener was more
cytotoxic than nonplanar congener. This study suggests that cytotoxicity mechanisms of the PCB congeners on fish lymphocytes
depend on their planarity and chemical structures. 相似文献
773.
ZHAN Manjun 《环境科学学报(英文版)》2009,21(3)
Reactive oxygen species (ROS) can be produced by interactions between sunlight and light-absorbing substances in natural water environment. ROS may participate in the indirect photolysis of trace organic pollutants, therefore resulting in the changing of their environmental fates and ecological risks in natural water system. Bisphenol A (BPA), an endocrine-disrupting chemical, exits widely in natural water. The photodegradation of BPA promoted by ROS (·OH, 1O2, HO2·/O2·-) which were produced on the excitation of ubiquitous constituents (such as nitrate ion, humic substances and Fe(III)-oxalate complexes) in natural water under simulated solar radiation was investigated. Both molecular probe method and electron spin resonance (ESR) test were used for the determine the characterization of generated ROS. It was found that ·OH was photochemically produced with the presence of nitrate ion, humic substances and Fe(III)-oxalate complexes and 1O2 was produced with the presence of humic substances. The steady-state concentrations of ·OH was 1.27×10-14 mol/L in nitrate ion, and the second-order rate constant of BPA with ·OH was 1.01×1010L/( mol·s). 相似文献
774.
ZHAN Manjun 《环境科学学报(英文版)》2009,21(3):303-306
Reactive oxygen species(ROS) can be produced by interactions between sunlight and light-absorbing substances in natural water environment.ROS may participate in the indirect photolysis of trace organic pollutants,therefore resulting in changes in their environmental fates and ecological risks in natural water systems.Bisphenol A(BPA),an endocrine-disrupting chemical,exits widely in natural waters.The photodegradation of BPA promoted by ROS(.OH,1O2,HO2./O2·-),which were produced on the excitation of ubiquito... 相似文献
775.
776.
777.
采用介质阻挡放电降解二硫化碳(CS2)模拟废气,考察了外加气体空气、氮气(N2)、电源输入功率、初始浓度和停留时间对CS2转化率的影响。结果表明:CS2的去除率呈现空气>N2。在输入功率63 W,停留时间为5.34 s,CS2的初始浓度300 mg/m3,N2氛围下的去除效率为36.9%,而空气氛围下的去除效率可达62.5%。在N2与空气氛围下其产物明显不同,在空气氛围下,主要产物为SO2、COS、CO和CO2;而在N2氛围下其主要产物为大量单质硫、少量CO与CO2。对DBD降解CS2的机理分析表明,在N2条件下主要是高能电子与紫外光的作用;而在有空气条件下,O2的存在促进了CS2的深度氧化。 相似文献
778.
779.
Coupling of zero valent iron and biobarriers for remediation of
trichloroethylene in groundwater 总被引:1,自引:0,他引:1
This study attempted to construct a three series barrier system to treat high concentrations of trichloroethylene (TCE; 500 mg/L) in
synthetic groundwater. The system consisted of three reactive barriers using iron fillings as an iron-based barrier in the first column,
sugarcane bagasse mixed with anaerobic sludge as an anaerobic barrier in the second column, and a biofilm coated on oxygen carbon
inducer releasing material as an aerobic barrier in the third column. In order to evaluate the extent of removal of TCE and its metabolites
in the aquifer down gradient of the barrier system, a fourth column filled with sand was applied. Residence time of the system was
investigated by a bromide tracer test. The results showed that residence time in the column system of the control set and experimental
set were 23.62 and 29.99 days, respectively. The e ciency of the three series barrier system in removing TCE was approximately
84% in which the removal e ciency of TCE by the iron filling barrier, anaerobic barrier and aerobic barrier were 42%, 16% and 25%,
respectively. cis-Dichloroethylene (cis-DCE), vinyl chloride (VC), ethylene and chloride ions were observed as metabolites following
TCE degradation. The presence of chloride ions in the e uent from the column system indicated the degradation of TCE. However,
cis-DCE and VC were not fully degraded by the proposed barrier system which suggested that another remediation technology after
the barrier treatment such as air sparging and adsorption by activated carbon should be conducted. 相似文献
780.
The objective of the study was to investigate the presence and the activity of quantum dots nanoparticles in colored wastewaters. The special interest is devoted to the investigation of their role in the typical treatment of water or wastewater, studying their influence on the effectiveness of applied treatments methods. The standard chemical processes for water treatment and disinfection (direct UV photolysis and direct ozonation) were applied for the degradation of colored organic pollutant, reactive azo dye, in the presence/absence of CdSe/ZnS core-shells quantum dots. The obtained results indicated that investigated nanoparticles inhibit the overall efficiency of applied processes, especially in the case of direct UV photolysis, although catalytic effect might be expected in part due to the semiconductor nature of quantum dots. Such results lead to a conclusion that CdSe/ZnS nanoparticles behave as additional pollutants in the system. They should be removed from the system prior the treatment, because their presence could decrease the efficiency, i.e., prolong the time of treatment and correspondingly increase the costs of the treatment process. 相似文献