全文获取类型
收费全文 | 116篇 |
免费 | 13篇 |
国内免费 | 122篇 |
专业分类
安全科学 | 4篇 |
废物处理 | 7篇 |
环保管理 | 2篇 |
综合类 | 152篇 |
基础理论 | 46篇 |
污染及防治 | 39篇 |
评价与监测 | 1篇 |
出版年
2023年 | 5篇 |
2022年 | 4篇 |
2021年 | 6篇 |
2020年 | 3篇 |
2019年 | 10篇 |
2018年 | 6篇 |
2017年 | 7篇 |
2016年 | 11篇 |
2015年 | 8篇 |
2014年 | 7篇 |
2013年 | 28篇 |
2012年 | 22篇 |
2011年 | 10篇 |
2010年 | 8篇 |
2009年 | 10篇 |
2008年 | 12篇 |
2007年 | 15篇 |
2006年 | 17篇 |
2005年 | 13篇 |
2004年 | 12篇 |
2003年 | 9篇 |
2002年 | 2篇 |
2001年 | 3篇 |
2000年 | 2篇 |
1999年 | 7篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 5篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
排序方式: 共有251条查询结果,搜索用时 15 毫秒
101.
以Suwannee River NOM(SRNOM)和Upper Mississippi River NOM(UMRNOM)两种水源溶解性有机质(DOM)为代表,利用500W高压氙灯作为光源模拟太阳光,进行室内光解实验.考察了冻融前后两种DOM在不同pH条件下的光谱特性参数及其与苊的结合常数(KDOC),同时通过苊的表观光解速率常数(KOBS)研究冰相与水相中不同pH条件下DOM对苊的光解影响,并进行了相关性分析.结果表明,无论在冰相还是水相中,苊都可以直接进行光降解,同时两种DOM均能促进苊的光解.在水相中,随着pH的升高,两种DOM的SUVA254、E2/E3、a254、a350与苊的KOBS均有上升,而KDOC则呈现下降趋势.同时KOBS与KDOC、a350及SUVA254均具有显著相关性.而冰相中,KOBS和KDOC随pH的变化趋势与水相一致,但SUVA254、E2/E3、a254、a350没有明显变化趋势.KOBS和KDOC相比于水相也有明显下降.此外.冰相中的KOBS仅与KDOC存在显著相关,而与其他参数均无相关性,这也说明冰中的光化学反应可能具有更加复杂的机制. 相似文献
102.
Water samples were taken from Lake Dianchi, on the Yungui Plateau of southwest China, and experiments were conducted to simulate the photochemical degradation characteristic of chromophoric dissolved organic matter (CDOM) in the lake water. Three groups of experiments under different light conditions: ultraviolet (UV) light, visible light, and dark, were done and variations of fluorescence properties, UV absorbance, and dissolved organic carbon (DOC) concentrations during the experiments were analyzed to study the photodegradation process of CDOM with time. The result showed that light irradiation led to significant photochemical degradation of CDOM, resulting in changes in florescent properties, absorbance losses, decreases in aromaticity and average molecular weight, as well as decline in DOC concentration in the water. It was also observed that UV irradiation had greater effect than visible light did. However, various fluorophores had different sensitivities to the same irradiation condition, that is, protein-like fluorophore at the low excitation wavelengths is more sensitive to UV irradiation than the other fluorophores, and is more readily to undergo photo-degradation. In addition, visible light irradiation did not have significant impact on DOC in the water, with DOC concentration decrease by 5.57% –59.9% during the experiment time. These results may provide new knowledge on the environment behavior of CDOM in the water of Lake Dianchi. 相似文献
103.
104.
黄河水体颗粒物对3种多环芳烃光化学降解的影响 总被引:2,自引:0,他引:2
研究了、苯并(a)芘、苯并(ghi)3种多环芳烃在黄河水体中的光化学降解规律,探讨了黄河泥沙和黄土2种颗粒物对多环芳烃光化学降解的影响.结果表明:①当水体不含任何颗粒物时,多环芳烃的光降解符合一级反应动力学规律,且反应动力学常数随污染物初始浓度的降低而增加;3种多环芳烃的光降解速率与分子的吸收光谱相关.②黄土通过对光强的阻碍作用和其中所含腐殖质的光敏化作用影响多环芳烃的光化学降解,这2方面的共同作用导致不同浓度黄土所产生的影响不同.黄土浓度为0.1g/L或5g/L时促进了和苯并(a)芘的光降解;黄土浓度为5g/L时促进了苯并(ghi)的降解.当水体含有黄土时,多环芳烃的光降解符合二级动力学规律.③对多环芳烃光化学降解起主要作用的是黄土中存在的溶解性腐殖质,非溶解性腐殖质的作用不大.④由于黄河泥沙在河水中长期存在,泥沙中的溶解性腐殖质都已溶于水中,泥沙主要通过对光强的阻碍作用影响水体中多环芳烃的光降解,使光降解速率随泥沙浓度的增加呈幂指数降低. 相似文献
105.
106.
水中萘普生的紫外光降解机制及其产物毒性研究 总被引:1,自引:3,他引:1
以120 W汞灯为紫外光光源,通过活性氧物种(ROS)的淬灭实验和溶解氧(DO)浓度实验和发光菌毒性实验,对水中萘普生(NPX)的降解机制、反应动力学及其产物毒性进行了研究.结果表明,NPX的紫外光降解过程包括了直接光解和ROS参与的自敏化光解两个过程,同时.OH、1O2、O.2-的自敏化光解贡献率分别为0.1%、80.2%、35.7%;溶解氧浓度实验表明,溶解氧对萘普生的降解具有抑制作用,而且浓度越大,抑制效果越明显;发光菌毒性实验表明,萘普生光降解生成了具有较萘普生更高风险的中间产物.本研究中萘普生的所有光解实验过程均符合准一级动力学方程. 相似文献
107.
水质对UV/H2O2降解邻苯二甲酸二甲酯反应动力学的影响 总被引:2,自引:0,他引:2
研究了不同初始pH值、浊度与常见阴离子浓度等水质条件对UV/H2O2工艺降解邻苯二甲酸二甲酯(DMP)反应速率的影响,并进一步比较了去离子水和自来水中DMP的降解速率.结果表明,UV/H2O2对DMP的光降解过程符合一级反应动力学模型,不同水质条件对降解速率有不同程度的影响.酸性条件较碱性条件更有利于DMP降解; 水的浊度大于7 NTU时,光降解速率常数迅速下降; NO3-、Cl3-、HCO3-等阴离子对DMP降解有抑制作用,且随离子浓度增大,抑制作用增强,3种离子对DMP光降解的抑制程度顺序为HCO3->NO3->Cl3-.在5个30 W低压汞灯照射下,当H2O2的浓度为20 mg·L-1时,DMP在去离子水和自来水中光降解速率常数分别为0.042 8 min-1和0.031 5 min-1,自来水中的光降解速率常数较去离子水中的低,这可能是水中多种离子影响的结果. 相似文献
108.
The direct photolysis of nitrobenzene and nitrophenols in aqueous solutions irradiated by polychromatic light were investigated. Several aromatic intermediates were identified as three nitrophenol isomers, nitrohydroquinone, nitrosobenzene, nitrocatechol, catechol and phenol. Nitrite and nitrate ions were also detected in the irradiated solution indicating direct photolysis of nitrobenzene or nitrophenols. The degradation of nitrobenzene and nitrophenols and the formation of three nitrophenol isomers were observed to follow zero-order kinetics. The quantum yields for nitrobenzene and nitrophenols removal are about 10^-3 and 10^-3—10^-4 respectively. The mechanism for nitrobenzene degradation was suggested to follow mainly nitro-nitrite intramolecular arrangement. 相似文献
109.
Bingbing Xu Zhonglin Chen Fei Qi Jimin Shen Fengchang Wu 《Frontiers of Environmental Science & Engineering in China》2009,3(1):91-97
In order to provide basic data for practical application, photodegradation experiment of N-nitrosodimethylamine (NDMA) in aqueous solution was carried out with a low-pressure Hg lamp. Effects of the initial concentration
of NDMA, solution pH, dissolved oxygen, and the presence of humic acid on NDMA photodegradation were investigated. NDMA at
various initial concentrations selected in this study was almost completely photodegraded by UV irradiation within 20 min,
except that at 1.07 mmol/L, NDMA could be photodegraded almost completely in the acidic and neutral solutions, while the removal
efficiency decreased remarkably in the alkaline solution. Dissolved oxygen enhanced the NDMA photodegradation, and the presence
of humic acid inhibited the degradation of NDMA. Depending on the initial concentration of NDMA, NDMA photodegradation by
UV obeyed the pseudo-first-order kinetics. Dimethylamine, nitrite, and nitrate were detected as the photodegradation products
of NDMA. 1O2 was found to be the reactive oxygen species present in the NDMA photodegradation process by UV, based on the inhibiting experiments
using tert-butanol and sodium azide. 相似文献
110.
The extensive use of antibiotics has been a worldwide environmental issue.In this study the fate of oxytetracycline (OTC),under photoirradiation,was investigated.The results showed that OTC photolysis followed first order model kinetics.Direct photolysis rate was found to be dependent on the initial OTC concentration,with k value ranging from 0.0075 to 0.0141 min~(-1),in the OTC concentration from 40 to 10 mg/L.OTC photolysis was highly pH-dependent and strongly enhanced at a high pH value,with a k value... 相似文献