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1.
IntroductionSemiconductor nanoparticles show a quantum sizeeffect and have attracted much attention because oftheir unique photochemical and photophysical proper-ties[1—4].In recent years,quantumdots of CdS and in-organic nanoparticles hybrid composites …  相似文献   

2.
The three-phase behavior in the quaternary system of an alkyl (C8/10^- or C12/14^-)polyglucoside / 1-butanol / n-octane / water has been studied at 40℃ with the modified fishlike phase diagram, which is presented by us for the first time. The mass fraction of 1-butanol in the hydrophile-lipophile balanced interfacial layer, A^S, the coordinates of the start point B and the end point E of the phase diagram, and the solubilities of alkyl polyglucoside and 1-butanol in n-octane phase were calculated. The solubilization of the microemulsion was also discussed.  相似文献   

3.
1 INTRODUCTION Interhalogen compounds have played an impor- tant role in environment and chemical engineering production. During the course of ozone exhaustion induced by sunlight in polar region, Br2, BrCl and HOBr are all precursors of Br atom[1]. Lately, scien- tists have detected that the content of BrCl in polar region sunlight was 35 ppt, larger than that of Br2 (25 ppt). Previous studies suggested that the con- centration of BrCl and O3 exhibits obvious negative correlation: w…  相似文献   

4.
A single molecule detection technique was developed by the combination of a single channel poly (dimethylsiloxane)/glass micro-fluidic chip and fluorescence correlation spectroscopy (FCS). This method was successfully used to determine the proportion of two model components in the mixture containing fluorescein and the rhodamine-green succinimidyl ester.  相似文献   

5.
从单分散二氧化硅(SiO_2)微球的合成方法、粒度表征、定值及其组装体几何比表面积的计算等几个方面对SiO_2比表面积标准物质的合成进行了总结.这种类型比表面积标准物质的合成不仅可以扩展我国比表面积标准物质的种类,而且将有助于加深人们对物质真实比表面积的进一步认识.  相似文献   

6.
By means of acid-base potentiometric titration and the advanced BEST computer program developed by Martell et al., the deprotonation constants of four inhibitors [Aminotrimethylenephosphoinic acid(ATMP), 2-phosphino-tutane-1,2, 4-tricarboxylic acid (PBTCA), polyacrylic acid (PAA, Mw=2000), poly (maleic, acrylic) acid(PMAAA, Mw=3000)], and the stability constants of the complexes of these inhibitors with Ca^2 have been determined. And the distribution curves of ATMP at different pH values in aqueous solutions have also been given out. The result of this study can be applied to explaining the inhibition mechanism.  相似文献   

7.
不同尺寸单分散PMMA/GMA/DVB聚合物荧光微球的制备   总被引:1,自引:0,他引:1  
刘宏波  汪长春 《化学学报》2008,66(10):1269-1273
采用无皂乳液聚合及种子无皂乳液聚合方法制备了200~800 nm四种不同尺寸的单分散PMMA/GMA/DVB (PMGD)复合微球. 用扫描电镜(SEM)和动态光散射(DLS)对粒径尺寸、形貌进行了表征. 实验发现单体滴加速度是影响种子无皂乳液聚合过程二次成核的关键因素. 用乙二胺对微球表面的环氧基团开环后, 通过在微球表面接枝树枝状PAMAM (d-PAMAM)达到微球表面的官能化的目的, 元素分析和红外光谱实验证明了微球表面d-PAMAM的存在. 最后利用微球表面的活性氨基与四甲基异硫氰酸罗丹明(TRITC)反应, 得到四种尺寸的水分散性的红色荧光微球.  相似文献   

8.
The nanotitanium dioxide (TiO2) photocatalytic and porous ceramic filtering technique is one of the advanced methods to effectively treat organic wastewater. The TiO2 sol doped with Fe^3+ ions was prepared by sol-gel processing. The influences of the process conditions of coating nanophotocatalytic material- Fe^3+-TiO2 film on the surface of porous ceramic filter by dipping-lift method on the performance of porous ceramic filter were studied. The porous ceramic filters have two functions at the same time, filtration and photocatalytic degradation. The results of this study showed that the pH and viscosity of the sol, amount of Fe^3+ ions doped as well as the coating times greatly affect the quality of coating film, the performance parameters and the photocatalytic activity of the porous ceramic filter. When the pH of the sol is 3-4, the viscosity is about 6 mPa.S, the amount of doped Fe^3+ ions is about 2.0 g/L, the porous ceramic filter has been shown to have the best filtering performance and photocatalytic activity. In this condition, the porosity of porous ceramic is about 42.5%, the pore diameter is 8-10μm. The degradation of methyl-orange is 74.76% under lighting for 120 rain.  相似文献   

9.
Two possible reaction mechanisms of VS^+(^3∑^-, 1^Г) with CO in the gas phase have been studied by using B3LYP/TZVP and CCSD(T)/6-311+G (3df, 3pd) methods: the O/S exchange reaction (VS^++CO→VO^++CS) and the S-transfer reaction (VS^+ + CO → V^+ + COS). The two reactions proceed via two-step and one-step mechanism, respectively. The barriers of the triplet and singlet PESs are 30.6 and 50.9 kcal/mol, respectively, for O/S exchange reaction and 7.3 and 50.2 kcal/mol, respectively, for the S-transfer reaction. The results indicate that the triplet ground state reaction is more favorable, and the S-transfer reaction is more favorable than the O/S exchange reaction, which is in good agreement with the experimental observation.  相似文献   

10.
1 INTRODUCTION The reactions between halogen and halogen are basic reactions in chemistry. Especially, in the syn- thesis of iodo-substituted aromatic hydrocarbon, the reaction Cl2 I2 = 2ICl could heighten the usage of iodine atom to 100%. So far, to the best of our know- ledge, the studies about halogen-halogen reaction mechanisms are very few. In detail, only the struc- ture and stability studies of X2Y- (X, Y = Cl, Br and I) ions by calculating reaction potential energy sur- face…  相似文献   

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