全文获取类型
收费全文 | 1097篇 |
免费 | 107篇 |
国内免费 | 378篇 |
专业分类
安全科学 | 152篇 |
废物处理 | 81篇 |
环保管理 | 91篇 |
综合类 | 651篇 |
基础理论 | 143篇 |
污染及防治 | 282篇 |
评价与监测 | 169篇 |
社会与环境 | 9篇 |
灾害及防治 | 4篇 |
出版年
2024年 | 12篇 |
2023年 | 20篇 |
2022年 | 46篇 |
2021年 | 40篇 |
2020年 | 43篇 |
2019年 | 33篇 |
2018年 | 35篇 |
2017年 | 60篇 |
2016年 | 64篇 |
2015年 | 70篇 |
2014年 | 81篇 |
2013年 | 127篇 |
2012年 | 105篇 |
2011年 | 109篇 |
2010年 | 58篇 |
2009年 | 69篇 |
2008年 | 52篇 |
2007年 | 79篇 |
2006年 | 82篇 |
2005年 | 51篇 |
2004年 | 42篇 |
2003年 | 49篇 |
2002年 | 46篇 |
2001年 | 37篇 |
2000年 | 33篇 |
1999年 | 29篇 |
1998年 | 31篇 |
1997年 | 25篇 |
1996年 | 18篇 |
1995年 | 5篇 |
1994年 | 7篇 |
1993年 | 5篇 |
1992年 | 7篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1983年 | 2篇 |
1978年 | 1篇 |
排序方式: 共有1582条查询结果,搜索用时 15 毫秒
51.
The amount, location, and form of NAPL in contaminated vadose zones are controlled by the spatial distribution of water saturation and soil permeability, the NAPL spill scenario, water infiltration events, and vapor transport. To evaluate the effects of these processes, we used the three-phase flow simulator STOMP, which includes a new permeability-liquid saturation-capillary pressure (k-S-P) constitutive model. This new constitutive model considers three NAPL forms: free, residual, and trapped. A 2-D vertical cross-section with five stratigraphic layers was assumed, and simulations were performed for seven cases. The conceptual model of the soil heterogeneity was based upon the stratigraphy at the Hanford carbon tetrachloride (CT) spill site. Some cases considered co-disposal of NAPL with large volumes of wastewater, as also occurred at the Hanford CT site. In these cases, the form and location of NAPL were most strongly influenced by high water discharge rates and NAPL evaporation to the atmosphere. In order to investigate the impact of heterogeneity, the hydraulic conductivity within the lower permeability layer was modeled as a realization of a random field having three different classes. For six extreme cases of 100 realizations, the CT mass that reached the water table varied by a factor of two, and was primarily controlled by the degree of lateral connectivity of the low conductivity class within the lowest permeability layer. The grid size at the top boundary had a dramatic impact on NAPL diffusive flux just after the spill event when the NAPL was present near the ground surface. NAPL evaporation with a fine grid spacing at the top boundary decreased CT mass that reached the water table by 74%, compared to the case with a coarse grid spacing, while barometric pumping had a marginal effect for the case of a continuous NAPL spill scenario considered in this work. For low water infiltration rate scenarios, the distribution of water content prior to a NAPL spill event decreased CT mass that reached the water table by 98% and had a significant impact on the formation of trapped NAPL. For all cases simulated, use of the new constitutive model that allows the formation of residual NAPL increased the amount of NAPL retained in the vadose zone. Density-driven advective gas flow from the ground surface controlled vapor migration in strongly anisotropic layers, causing NAPL mass flux to the lower layer to be reduced. These simulations indicate that consideration of the formation of residual and trapped NAPLs and dynamic boundary conditions (e.g., areas, rates, and periods of different NAPL and water discharge and fluctuations of atmospheric pressure) in the context of full three-phase flow are needed, especially for NAPL spill events at the ground surface. In addition, NAPL evaporation, density-driven gas advection, and NAPL vertical movement enhanced by water flow must be considered in order to predict NAPL distribution and migration in the vadose zone. 相似文献
52.
Thacker NP Nitnaware VC Das SK Devotta S 《Environmental science and pollution research international》2007,14(4):225-226
Samples of effluents, sludge, pulp, final products (paper) and soil were collected from the identified pulp and paper mills
in India. The samples were analysed for 2,3,7,8-tetrachloro-dibenzo-p-dioxin (2,3,7,8-TCDD) and other dioxin congeners and
precursors. Pulp and paper mills using chlorine for the bleaching process showed the presence of 2,3,7,8-TCDD in effluent
samples. In the effluent and pulp samples from mills where chlorine dioxide was used as a bleaching agent, the 2,3,7,8-TCDD
congener ranged from below the detection limit 0.05 to 0.12 ngL−1/ngg−1. The relative standard deviation of reproducibility and the percent recovery of 2,3,7,8-TCDD were 2.07 and 82.4% in pulp
and 2.8 and 92% in effluent, respectively. The 1,3,6,8-TCDD was the only other major dioxin congener found in the treated
and untreated effluent and sludge samples. However, dichlorobenzene, trichlorophenyl, and hexachlorobiphenyl were detected
in all samples. The formation of dioxins can be minimised by replacing chlorine with chlorine dioxide in bleaching processes
in pulp and paper mills. 相似文献
53.
This investigation conducted a full-scale survey the drinking water distribution system in Kaohsiung city, Taiwan. The aim
was to investigate whether the distribution system was capable of maintaining high water quality from the water treatment
facilities through to the end user. The results showed that the distribution system can maintain high water quality, except
for suitable chlorine residuals. The authors plotted chlorine residual contour maps to identify areas with low chlorine residuals,
helping them prioritize sections that must be flushed or renewal. The contour maps also provide sufficient and clear information
for locating booster chlorination stations. Contour maps enable water facilities to identify how water quality decays in the
distribution systems and the locations of such decay. Water quality decay can be caused by properties of pipeline materials,
hydraulic conditions, and/or biofilm thickness. However, understanding the exact reasons is unnecessary because the contour
maps provide sufficient information for trouble-shooting the distribution systems. 相似文献
54.
生物滤池对气相与液相中污染物质的净化 总被引:4,自引:0,他引:4
通过实验室研究探讨了生物滤池同时处理废水和废气的可行性。试验结果表明:在25℃-37℃条件下,甲苯废气的流量为90L/h,甲苯浓度为500mg/m^3;废水的流量为0.4L/h,CODcr浓度为400-750mg/L,甲苯与CODcr的去除率分别是70%-72%和86%-89%。 相似文献
55.
Highly efficient conversion of sugarcane bagasse pretreated with liquid hot water into ethanol at high solid loading 总被引:1,自引:0,他引:1
Wen Wang Xinshu Zhuang Qiang Yu Jingliang Xu Wei Qi 《International Journal of Green Energy》2016,13(3):298-304
Liquid hot water (LHW), an environmental-friendly physico-chemical treatment, was applied to pretreat the sugarcane bagasse (SCB). Tween80, a non-ionic surfactant, was used to enhance the enzymatic hydrolysis of the pretreated SCB. It found that 0.125 mL Tween80 /g dry matter could make the maximum increase (33.2%) of the glycan conversion of the LHW-pretreated SCB. A self-designed laboratory facility with a plate-and-frame impeller was applied to conduct batch hydrolysis, fed-batch hydrolysis, and the process of high-temperature (50°C) fed-batch hydrolysis following low-temperature (30°C) simultaneous saccharification and fermentation (SSF) which was adopted to overcome the incompatible optimum temperature of saccharification and fermentation in the SSF process. After hydrolyzing LHW-pretreated SCB for 120 h with commercial cellulase, the total sugar concentration and glycan conversion obtained from fed-batch hydrolysis were 91.6 g/L and 68.3%, respectively, which were 9.7 g/L and 7.3% higher than those obtained from batch hydrolysis. With Saccharomyces cerevisiae Y2034 fermenting under the non-sterile condition, the ethanol production and theoretical yield obtained from the process of SSF after fed-batch hydrolysis were 55.4 g/L and 88.3% for 72h, respectively, which were 15.5 g/L and 24.7% higher than those from separate fed-batch hydrolysis and fermentation. The result of this work was superior to the reported results obtained from the LHW-pretreated SCB. 相似文献
56.
P204为载体的微乳液膜处理焦化厂含酚废水的研究 总被引:4,自引:1,他引:3
研究了以P204为载体的Span80/煤油/NaOH微乳液膜配方及其稳定性,通过该液膜体系萃取废水中酚的研究,考察了P204与Span80的质量比、乳水比、萃取时间、油相的重复使用次数等对除酚率的影响。实验结果表明,在优化条件下,采用P204/Span80/煤油/NaOH微乳液膜处理焦化厂中高浓度的含酚废水,一次性除酚率均高于99%,且对高浓度含酚废水的除酚效果更佳;微乳液膜不仅稳定性好,传质速率高,除酚效率高,而且可自动破乳,油相可重复使用。 相似文献
57.
58.
液体旋流分离器分离效率的研究 总被引:1,自引:0,他引:1
液体旋流分离器是水环境污染治理的主要设备之一.分离效率是衡量液体旋流分离器分离过程进行完善程度的最重要的技术指标,它能从质与量两方面反映出设备性能的优劣.当前液体旋流分离器设计过程还缺少具体量化的理论依据,为了给液体旋流分离器的设计提供理论依据,通过液体旋流分离器从水中分离固体粒子的性能实验,得出了液体旋流分离器各部结构尺寸、形状、相对比例对分离效率的不同影响程度,提出了结构参数的最佳取值范围.按照本研究提出的设计原则和方法,可以制造出性能优良的液体旋流分离器. 相似文献
59.
在碱性条件下,ClO2氧化罗丹明染料发生荧光猝灭可选择性地测定ClO2的含量,而ClO2-不干扰测定;在酸性条件下可测量ClO2与ClO2-共同产生的荧光猝灭强度,利用差减法可求出ClO2-的含量.对于罗丹明S,罗丹明G,罗丹明B及丁基罗丹明B四体系,ClO2浓度分别在0.00840-0.53μg·ml-1,0.0930-3.15μg·ml-1,0.215-2.610μg·ml-1及0.0825-1.096μg·ml-1范围内,与四体系的荧光猝灭强度呈线性关系;亚氯酸根浓度分别在0.00950-0.711μg·ml-1,0.0940-2.36μg·ml-1,0.473-4.73μg·ml-1及0.473-2.36μg·ml-1范围内,与四体系的荧光猝灭强度呈线性关系.另外,选择罗丹明S荧光猝灭法分别测定了饮用水中ClO2及ClO2-,获得了满意的结果. 相似文献
60.
环境监测实验室废液的管理与处理方法 总被引:2,自引:0,他引:2
徐根红 《环境监测管理与技术》2007,19(6):50-51
环境监测实验室的废液处理常常被忽视,提出建立有效的废液管理制度的必要性.有针对性地介绍了环境监测实验室中常见废液的处理方法. 相似文献