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351.
为了有效去除地下水中抗生素等有机污染物,本文首次提出有序介孔氧化锰(O-MnOx)为活性催化剂和过硫酸钠(Na2S2O8)为氧化剂制备活化过硫酸钠缓释剂,并将其用于地下水中四环素的降解修复过程.通过有序O-MnOx与H2O2和Na2S2O8构建的两种类芬顿催化反应体系,明确了O-MnOx对过硫酸钠的活化及其对水中四环素优异的降解性能.以O-MnOx与Na2S2O8为活性组分制备的缓释剂在地下水中可以缓慢释放过硫酸根离子.缓释剂中O-MnOx加入比例增加,其释放性能减弱,而Na2S2O8加入比例减少,过硫酸根释放速率就会加快.O-MnOx可以活化过硫酸根溶... 相似文献
352.
将废利乐包热解并对获得的热解炭和铝箔进行分拣,再以热解炭为原料,K2CO3为活化剂制备活性炭。通过热重/差热-傅里叶变换红外光谱(TG/DTA-FTIR)联用对废利乐包的热解特性进行分析,采用自动气体吸附仪测定活性炭的氮气吸附/脱附曲线,采用FTIR对活性炭的表面官能团进行表征,利用TG-FTIR联用研究了活性炭的活化机理。结果表明,废利乐包中的纸和聚乙烯分别在365和490 ℃发生热解,铝箔则在664 ℃时熔化,填充剂CaCO3在720 ℃发生分解。活性炭的比表面积和总孔体积分别为1 215 m 2/g和0.768 cm 3/g,其表面官能团主要为C=O、C—O—C和脂肪族C—H。热解炭本身含有的CaCO3在740 ℃分解生成CO2,CO2会氧化刻蚀炭基体进行造孔;820 ℃之后熔融的K2CO3也会与炭基体反应生成CO并造成炭的损耗,上述2个过程均参与了活性炭的活化造孔。 相似文献
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354.
Abstract Wheat (Triticum aestivum L.) seedlings grown from seeds produced in “organic”; (non‐chemical) and “conventional”; cropping systems are characterized by a) similar rates of root and shoot growth, b) equal sensitivity to phytotoxicity by the herbicide glyphosate, and c) equivalent basal activity of the enzyme glutathione S‐transferase (both in the roots and in the shoots). In addition, treatment of these seedlings with glyphosate leads to significantly higher contents of this enzyme both in the shoots and in the roots. However, time‐course and dose‐response investigations indicate significant differences in the induction pattern of glutathione S‐transferase: the response of “conventional”; wheat seedlings takes place earlier and with higher efficiency, than that of the “organic”; ones. 相似文献
355.
Jun Yang Yutong Xue Yuxi Liu Jiguang Deng Xiyun Jiang Huan Chen Hongxing Dai 《环境科学学报(英文版)》2020,32(4):170-179
Mesoporous Co_3 O_4(meso-Co_3 O_4)-supported Pt(0.53 wt.% Pt/meso-Co304) was synthesized via the KIT-6-templating and polyvinyl alcohol(PVA)-assisted reduction routes.Mesoporous CoO(meso-CoO) was fabricated through in situ reduction of meso-Co304 with glycerol,and the 0.18-0.69 wt.% Pt/meso-CoO samples were generated by the PVA-assisted reduction method.Meso-Co_3 O_4 and meso-CoO were of cubic crystal structure and the Pt nanoparticles(NPs) with a uniform size of ca.2 nm were well distributed on the mesoCo_3 O_4 or meso-CoO surface.The 0.56 wt% Pt/meso-CoO(0.56 Pt/meso-CoO) sample performed the best in benzene combustion(T_(50%)=156℃and T_(90%)=186℃at a space velocity of 80,000 mL/(g h)).Introducing water vapor or C02 with a certain concentration led to partial deactivation of 0.56 Pt/meso-CoO and such a deactivation was reversible.We think that the superior catalytic activity of 0.56 Pt/meso-CoO was intimately related to its good oxygen activation and benzene adsorption ability. 相似文献
356.
Culicov OA Mocanu R Frontasyeva MV Yurukova L Steinnes E 《Environmental monitoring and assessment》2005,108(1-3):229-240
Active moss biomonitoring using the species Sphagnum girgensohnii was tested at a strongly polluted site in Romania (Baia Mare) according to a novel sampling design. Nine moss transplants from each of the two background areas (Dubna, Russia and Vitosha Mountain, Bulgaria) were deployed in parallel on balconies about 24 m above street level for 4 months. The samples were analyzed for 36 elements using instrumental neutron activation analysis (INAA). Based on the results obtained the sampling variability is discussed in relation to the analytical variability, and the relative uptake of the different elements is assessed. The moss-bags using Sphagnum girgensohnii demonstrate a high or a very high relative uptake for a majority of the 36 investigated elements, but the values depend on the initial element concentration in the moss. Moss leaves analyzed separately showed somewhat higher levels than stems for many elements. Practical considerations however still speak in favor of using the whole moss for transplants. 相似文献
357.
358.
通过试验,改进和验证了污水中硫化物、亚硫酸盐及硫代硫酸盐共存时S_2O_3~(2-)和SO_3~(2-)的测定方法。S_2O_3~(2-)和S_2O_3~(2-)的回收率分别为95.6%~103%和93.5%~100%;变异系数为0.7%~1.8%和1.0%~2.5%。适用于污水中硫代硫酸盐和亚硫酸盐共存时的分析。 相似文献
359.
G.M. Kolesov 《环境科学学报(英文版)》1994,6(3):337-346
ApplicationofneutronactivationanalysisingeochemistryandcosmochemistryG.M.Kolesov(VernadskyInstituteofGeochem&AnalChem.,Russia... 相似文献
360.
Shelley E. R. Hoover Mark L. Winston Benjamin P. Oldroyd 《Behavioral ecology and sociobiology》2005,59(2):278-284
In most social insect colonies, workers do not attempt to lay eggs in the presence of a queen. However, in the honey bee (Apis mellifera), a rare phenotype occurs in which workers activate their ovaries and lay large numbers of male eggs despite the presence of a fecund queen. We examined the proximate mechanisms by which this ‘anarchistic’ behaviour is expressed. We tested the effects of brood and queen pheromones on retinue attraction and worker ovary activation using caged worker bees. We found no difference between the anarchistic and wild type queen pheromones in the retinue response elicited in either wild type or anarchistic workers. Further, we found that anarchistic queens produce a pheromone blend that is as effective at inhibiting ovary activation as the wild type queen pheromone. However, anarchistic workers are less inhibited by queen pheromones than their wild type counterparts, in a dose-dependent manner. These results show that the anarchistic phenomenon is not due to changes in the production of queen pheromones, but rather is due in part to a shift in the worker response to these queen-produced signals. In addition, we demonstrate the dose-dependent nature of the effect of queen pheromones on honey bee worker ovary activation. 相似文献