全文获取类型
收费全文 | 416篇 |
免费 | 13篇 |
国内免费 | 154篇 |
专业分类
安全科学 | 27篇 |
废物处理 | 21篇 |
环保管理 | 22篇 |
综合类 | 213篇 |
基础理论 | 60篇 |
污染及防治 | 184篇 |
评价与监测 | 14篇 |
社会与环境 | 22篇 |
灾害及防治 | 20篇 |
出版年
2023年 | 7篇 |
2022年 | 25篇 |
2021年 | 17篇 |
2020年 | 14篇 |
2019年 | 9篇 |
2018年 | 20篇 |
2017年 | 25篇 |
2016年 | 23篇 |
2015年 | 26篇 |
2014年 | 24篇 |
2013年 | 32篇 |
2012年 | 30篇 |
2011年 | 41篇 |
2010年 | 31篇 |
2009年 | 21篇 |
2008年 | 31篇 |
2007年 | 33篇 |
2006年 | 26篇 |
2005年 | 16篇 |
2004年 | 17篇 |
2003年 | 18篇 |
2002年 | 7篇 |
2001年 | 18篇 |
2000年 | 11篇 |
1999年 | 11篇 |
1998年 | 8篇 |
1997年 | 9篇 |
1996年 | 2篇 |
1995年 | 10篇 |
1994年 | 3篇 |
1993年 | 4篇 |
1992年 | 3篇 |
1991年 | 4篇 |
1990年 | 1篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有583条查询结果,搜索用时 15 毫秒
461.
462.
Guorong Zhu Guilan Di Meng Zhang Te Cao Leyi Ni Rongting Fang Gongliang Yu 《Environmental science and pollution research international》2018,25(34):34027-34045
Few studies have focused on the biomechanical responses of submerged, rosette-forming macrophytes to wave action, water depth, or their co-occurrence in naturally eutrophic systems. The plant architecture, root anchorage strength-related traits, leaf morphology, and biomechanics of Vallisneria natans inhabiting a range of water depths were examined along three transects (T1, T2, and T3) in a eutrophic lake, Lake Erhai, in Yunnan Province, China. These transects were exposed to weak wave action and hyper-eutrophication (T1), moderate wave action and eutrophication (T2), or strong wave action and eutrophication (T3). The results showed that V. natans was mainly distributed at intermediate depths, with the widest colonization depth in T1. The values of plant architecture, root anchorage strength-related traits, leaf morphology, and biomechanics were generally highest in T3 and smallest in T2. Along the depth gradient, these values were generally highest at 3.5, 2.5, and 2.5 m for the plants growing in T1, T2, and T3, respectively. These findings suggest that V. natans adopts a “tolerance” strategy to cope with the effects of strong wave action in eutrophic habitats and an “avoidance” strategy when exposed to moderate wave action in eutrophic areas. Since the absence of an avoidance strategy increases the resistance to low-light stress at the expense of increased drag forces, there is a limit to the wave action that V. natans can withstand. This study indicates that biomechanics could be important when determining the distribution pattern of V. natans in Lake Erhai. 相似文献
463.
464.
Lu SY Du Y Yan JH Li XD Ni MJ Cen KF 《Journal of the Air & Waste Management Association (1995)》2012,62(6):717-724
The distribution of polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs), in brief dioxins, has seldom been addressed systematically in fly ash from municipal solid waste incinerators (MSWIs). This study shows the amount and fingerprint of PCDD/Fs in fly ash from four different Chinese MSWIs, that is, three mechanical grate units and one circulating fluidized bed unit. In these fly ash samples, dioxins-related parameters (international toxic equivalent quantity, total amount of PCDD/Fs, individual isomer classes, and 17 toxic 2,3,7,8-substituted congeners) all tend to increase with decreasing particle size for mechanical grate incinerators, yet only for the finest fraction for fluidized bed units. Moreover, the fluidized bed incinerator seems superior to grate incineration in controlling dioxins, yet a comparison is hampered by internal differences in the sample, for example, the fluidized bed fly ash has much lower carbon and chlorine contents. In addition, the presence of sulfur from mixing coal as supplemental fuel to the MSW may poison the catalytic steps in dioxins formation and thus suppress the formation of dioxins. With more residual carbon and chlorine in the fly ash, it is easier to form dioxins during cooling. Nevertheless, there is no apparent relation between Fe, Cu, and Zn contents and that of dioxins in fly ash. 相似文献
465.
探讨了采用实验室规模的生物处理组合工艺(上流式厌氧污泥床+曝气生物滤池+缺氧反应器+膜生物反应器,UASB+BAF+ANO+MBR)处理垃圾渗滤液过程中,邻苯二甲酸二丁酯(DBP)和邻苯二甲酸二(2-乙基己基)酯(DE-HP)两种内分泌干扰物在各工艺段的去除效率和机理。测定结果表明,对于DBP和DEHP浓度分别为164.4μg/L和215.0μg/L的原水,总出水浓度分别降至11.8μg/L和10.4μg/L,去除率分别达到92.9%和95.2%,处理效果良好。其中DBP在处理工艺中逐级降解,主要是微生物的降解作用。MBR是DEHP的主要去除工艺段,去除比例达到56.6%,膜截留效果明显。采用生物处理组合工艺可实现对垃圾渗滤液中DBP和DEHP的同时高效去除。 相似文献
466.
通过水溶液聚合法制备了聚丙烯酸水凝胶(polyacrylic acid,PAA),研究了溶液酸碱度和温度对聚丙烯酸水凝胶吸附氯化1-丁基3-甲基咪唑离子液体的影响。结果表明,水凝胶对氯化1-丁基3-甲基咪唑离子液体的吸附量随溶液pH值增大而逐渐增大,pH=2~4时增幅明显,而pH大于4时变化趋于缓慢;随温度的升高而逐渐降低。该等温吸附行为基本符合Langmuir吸附等温式,由二级吸附动力学模型获得的吸附过程活化能(Ea=52.470 kJ/mol)可以看出,PAA对氯化1-丁基3-甲基咪唑的吸附属于化学吸附范畴。 相似文献
467.
通过建立2个简单的铬生物地球化学循环模型PM和CM,来说明人类工业活动对铬的生物地球化学循环的影响。通过对PM和CM的比较发现,人类的工业活动向陆地、海水和大气圈的输入通量,占其各自总输入通量的69.65%、56.96%和38.23%。 相似文献
468.
469.
Fluorescence of sediment humic substance and its effect on the sorption of selected endocrine disruptors 总被引:2,自引:0,他引:2
Humic substances (HS) have a critical influence on the sorption of organic contaminants by soils and sediments. This paper describes investigations into the sorption behavior of three representative endocrine disruptors, bisphenol A (BPA), 17beta-estradiol (E2), and 17alpha-ethynylestradiol (EE2), onto sediments and HS extracted sediments using a batch technique. The organic carbon-normalized partition coefficients (K(oc)) for the extracted HS (K(oc)(hs)) were calculated, and the fluorescence spectra of the HS extraced from different sediment samples were gained using excitation/emission matrix (EEM). Particular attention was paid to the correlations between the fluorescence characteristics of HS and the log K(oc)(hs) of selected endocrine disruptors. The results show that the log K(oc)(hs) values range from 3.14 to 4.09 for BPA, from 3.47 to 4.33 for E2, and from 3.65 to 4.32 for EE2. Two characteristic excitation-emission peaks were observed for HS samples extracted from sediments. They are located at Ex/Em=250-260 nm/400-450 nm (peak alpha') and Ex/Em=310-330 nm/390-400 nm (peak alpha) respectively. The alpha' and alpha peak relative intensities I(alpha')/I(alpha) vary from 0.46 to 1.64 for different extracted HS samples. The similarity between fulvic acids (FA) Ex/Em pairs and those observed for HS indicates that FA is the predominant fraction of HS extracted from sediments. Moreover, the log K(oc)(hs) values of BPA, E2, and EE2 have a negative linear correlation to I(alpha')/I(alpha) values. Peak alpha is often attributed to relatively stable and high molecular weight aromatic fulvic-like matter. Therefore, the result presented here reveals that the abundance of aromatic rings in HS molecular structure plays a critical role in the sorption of selected endocrine disruptors. 相似文献
470.
Liang XQ Chen YX Li H Tian GM Ni WZ He MM Zhang ZJ 《Environmental pollution (Barking, Essex : 1987)》2007,150(3):313-320
A simple but comprehensive model is developed to quantify N losses from urea applied to a near-trench paddy field, considering all the N-transformations such as urea hydrolysis, volatilization, nitrification, denitrification, and all the important transportations like runoff, lateral seepage, vertical leaching and crop uptake. Seasonal average data of field observations for three crop seasons were used for model calibration and validation, which showed that ammonia volatilization accounted for 26.5-29.4% of the applied N and N uptake by crop occupied 38.2-44.8%, while N losses via surface runoff, vertical leaching and lateral seepage varied from 5.6-7.7%, 4.0-4.9% to 5.0-5.3% of the applied N, respectively. These observed results were well predicted by our model, indicating that the model performed effectively at quantifying N losses via individual processes in a wide range of urea application rates and benefit for developing water and fertilizer management strategies for near-trench paddy fields. 相似文献