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1.
本文试图以泰克西纳的知识领域划分对哈佛大学、芝加哥大学、香港中文大学、北京大学的通识课程进行考察。研究发现,中外大学的通识课程基本上覆盖所有的知识领域;中外大学均有数量比较多的文学、音乐和艺术评论及历史课程;不同的大学在通识课程开设中各有传统和偏重。 相似文献
2.
Phenol degradation in photochemically enhanced Fenton process was investigated in this work. UV-VIS spectra of phenol degradation showed the difference between photo-Fenton process and UV/H2O2, which is a typical hydroxyl radical process. A possible pathway diagram for phenol degradation in photo-Fenton process was proposed, and a mathematical model for chemical oxygen demand (COD) removal was developed. Operating parameters such as dosage of H2O2 and ferrous ions, pH, suitable carrier gas were found to impact the removal of COD significantly. The results and analysis of kinetic parameters calculated from the kinetic model showed that complex degradation of phenol was the main pathway for removal of COD; while hydroxyl radicals acted weakly in the photo-Fenton degradation of phenol. 相似文献
3.
INTRODUCTION For the degradation of high concentration wast- ewater with toxic and non-biodegradable pollutants, the UV/Fenton method has been proposed in recent years (Braun et al., 1991; Bossmann et al., 1998). The UV/Fenton system relies mainly on oxidative degradation reactions, where organic radicals are generated by photolysis of the organic substrate or by reaction with hydroxyl radicals. These radical intermediates are subsequently trapped by dissolved molecular oxygen and lea… 相似文献
4.
Scrubbing of NO
x
from the gas phase with Fe(II)EDTA has been shown to be highly effective. A new biological method can be used to convert
NO to N2 and regenerate the chelating agent Fe(II)EDTA for continuous NO absorption. The core of this biological regeneration is how
to effectively simultaneous reduce Fe(III)EDTA and Fe(II)EDTA-NO, two mainly products in the ferrous chelate absorption solution.
The biological reduction rate of Fe(III)EDTA plays a main role for the NO
x
removal efficiency. In this paper, a bacterial strain identified asKlebsiella Trevisan sp. was used to demonstrate an inhibition of Fe(III)EDTA reduction in the presence of Fe(II)EDTA-NO. The competitive inhibition
experiments indicted that Fe(II)EDTA-NO inhibited not only the growth rate of the iron-reduction bacterial strain but also
the Fe(III)EDTA reduction rate. Cell growth rate and Fe(III)EDTA reduction rate decreased with increasing Fe(II)EDTA-NO concentration
in the solution.
Project (No. 20176052) supported by the National Natural Science Foundation of China and the Scientific Research Foundation
for Returned Overseas Chinese Scholars, Ministry of Education 相似文献
5.
The heterogeneous UV/Fenton process with the appropriate amount of Fe-Mn-Cu-Y as catalyst was developed and various operation conditions for the degradation of phenol were evaluated. The results indicated that by using the heterogeneous UV/Fenton process, the CODcr removal rate reached almost 100% for wastewater containing phenol. Compared with the homogeneous process, the developed catalyst could be used at wider pH range in the UV/Fenton process. Comparison of various heterogeneous process showed that heterogeneous UV/Fenton process was best. The heterogeneous UV/Fenton process with Fe-Mn-Cu-Y catalyst is highly efficient in degrading various organic pollutants. 相似文献
6.
A novel fluidized electrochemical reactor that integrated advanced electrochemical oxidation with activated carbon (AC) fluidization in a single cell was developed to model pollutant p-nitrophenol (PNP) abatement. AC fluidization could enhance COD removal by 22%-30%. In such a combined process, synergetic effects on PNP and COD removal was found, with their removal rate being enhanced by 137.8% and 97.8%, respectively. AC could be electrochemically regenerated and reused, indicating the combined process would be promising for treatment of biorefractory organic pollutants. 相似文献
7.
A novel metallo-organic chemical vapor deposition (MOCVD) technique has been applied to the preparation of the photocatalytic
titanium dioxide supported on activated carbon. The effects of various condition parameters such as carrier gas flow rate,
source temperature and deposition temperature on the deposition rate were investigated. The maximum deposition rate of 8.2
mg/(g·h) was obtained under conditions of carrier gas flow rate of 400 ml/min, source temperature of 423 K and deposition
temperature of 913 K. The deposition rate followed Arrhenius behavior at temperature of 753 K to 913 K, corresponding to activation
energy E
a of 51.09 kJ/mol. TiO2 existed only in anatase phase when the deposition temperature was 773 K to 973 K. With increase of deposition temperature
from 1073 K to 1273 K, the rutile content sharply increased from 7% to 70%. It was found that a deposition temperature of
773 K and a higher source temperature of 448 K resulted in finely dispersed TiO2 particles, which were mainly in the range of 10–20 nm.
Project (No. 90206007) supported by the National Natural Science Foundation of China 相似文献
8.
A novel fluidized electrochemical reactor that integrated advanced electrochemical oxidation with activated carbon (AC) fluidization
in a single cell was developed to model pollutant p-nitrophenol (PNP) abatement. AC fluidization could enhance COD removal by 22%–30%. In such a combined process, synergetic
effects on PNP and COD removal was found, with their removal rate being enhanced by 137.8% and 97.8%, respectively. AC could
be electrochemically regenerated and reused, indicating the combined process would be promising for treatment of biorefractory
organic pollutants.
Project (No. 20306027) supported by the National Natural Science Foundation of China 相似文献
9.
Experimental study on the inhibition of biological reduction of Fe(Ⅲ)EDTA in NOx absorption solution
LI Wei WU Cheng-zhi ZHANG Shi-han SHI Yao LEI Le-cheng 《Journal of Zhejiang University. Science. B》2005,6(10)
Scrubbing of NOx from the gas phase with Fe(Ⅱ)EDTA has been shown to be highly effective. A new biological method can be used to convert NO to N2 and regenerate the chelating agent Fe(Ⅱ)EDTA for continuous NO absorption. The core of this biological regeneration is how to effectively simultaneous reduce Fe(Ⅲ)EDTA and Fe(Ⅱ)EDTA-NO, two mainly products in the ferrous chelate absorption solution. The biological reduction rate of Fe(Ⅲ)EDTA plays a main role for the NOx removal efficiency. In this paper, a bacterial strain identified as Klebsiella Trevisan sp. was used to demonstrate an inhibition of Fe(Ⅲ)EDTA reduction in the presence of Fe(Ⅱ)EDTA-NO. The competitive inhibition experiments indicted that Fe(Ⅱ)EDTA-NO inhibited not only the growth rate of the iron-reduction bacterial strain but also the Fe(Ⅲ)EDTA reduction rate. Cell growth rate and Fe(Ⅲ)EDTA reduction rate decreased with increasing Fe(Ⅱ)EDTA-NO concentration in the solution. 相似文献
10.
INTRODUCTION Nitrogen oxide (NOx) is one of the main air pol- lutants found in the flue gases from chemical and power plants belching acid rain and photochemical smog. Over 90 percent of all man-made nitrogen ox- ides that enter our atmosphere are produced by the combustion of various fuels. Compared with the ad- vanced stage of SO2 gas removal technologies devel- opment, the removal of NOx gases is still in the initial stages of development as roughly 90 to 95 percent of NOx emitted i… 相似文献