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21.
纳米氧化铜的制备及常温脱硫效能研究 总被引:3,自引:0,他引:3
采用硝酸铜为原料、氢氧化钠溶液为沉淀剂、使用体积比为1∶1的乙醇-水溶液为分散剂的直接沉淀法制备,通过改变工艺条件得到了三种纳米氧化铜产品,平均粒径分别为25.63,10.74和7.57 nm。采用TG-DTA、FIR、XRD和TEM等对纳米氧化铜进行表征。对产品的常温脱硫活性进行了穿透试验,并与已开发的其他常温精脱硫产品进行了比较,结果表明纳米氧化铜应用于H2S脱硫,可在常温条件下具有优异的脱硫活性,对H2S的脱除精度可以达到0.05 mg·m-3以下。经过优选,产品在3 000 h-1空速下穿透硫容达到25.3%,高于同类型的其他脱硫剂产品。 相似文献
22.
A new simple and rapid electrochemical method for the determination of hydroxyl radical generated by Fenton reaction and its application 总被引:3,自引:0,他引:3
A simple and rapid electrochemical method to detect the hydroxyl radical is described. This method employed the reaction between.OH and dimethyl sulfoxide (DMSO) to generate quantitatively formaldehyde, which then reacted with hydrazine hydrochloride at pH 6.2. The product showed a second-order derivative cathodic wave with the peak potential of -1.08 V( vsSCE) by single sweep oscillopolarography. The electrochemical behavior of the product was investigated by single sweep oscillopolarography and cyclic voltammetry. The experimental conditions for the measurement were optimized and the scavenging activity of some flavonoids on hydroxyl radicals was studied. 相似文献
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在甲醇溶液中合成了一系列IIB过渡金属Zn(II), Cd(II)的二羟乙基二硫代氨基甲酸[(EtOH)2dtc]的配合物, 并对配合物M[(EtOH)2dtc]2L [M=Zn (1), Cd (2), L=2,2'-联吡啶; M=Zn (3), Cd (4), L=邻菲啰啉]进行了红外光谱、元素分析、热重分析表征工作. 热重分析表明配合物1~4中DTC配体比中性配体更易失去, 热分解最终产物为相应的氧化物. 对化合物1, 2做了X-ray单晶衍射分析, 1为单斜晶系, P21/c空间群, 晶胞参数a=0.72146(5) nm, b=2.61720(18) nm, c=1.59438(11) nm,b=97.899(2)°, V=2.9820(4) nm3, Z=4, m=1.133 mm-1, Dc=1.297 Mg•m-3; 2为三斜晶系, P-1空间群, 晶胞参数a=1.0075(2) nm, b=1.1580(2) nm, c=1.1777(2) nm, a=70.92(3)°, b=85.71(3)°, γ=81.02(3)°, V=1.2822(4) nm3, Z=2, m=2.118 mm-1, Dc=1.630 Mg•m-3. 相似文献
26.
Liancai Wang Xiangjun Bi Aiying Zhang Jianye Zhou 《Polymer Degradation and Stability》2006,91(9):2220-2228
A series of biodegradable aliphatic/aromatic copolyesters, poly(butylene terephthalate)-co-poly(butylene cyclohexanedicarboxylate)-b-poly(ethylene glycol) (PTCG), were prepared by a two-step melt polycondensation method and characterized by means of GPC, FTIR, NMR, DSC, TGA, etc. The effects of aliphatic ester content on the physical, mechanical and thermal properties, as well as in vitro and in vivo degradation behaviors were investigated. The decrease in mechanical strength was observed with an increase in poly(butylene cyclohexanedicarboxylate) (PBC) molar fraction. DSC results showed one melting point and two glass transition temperatures in all samples, and the melting temperature was found to go down gradually as more cyclohexanedicarboxylic acid (CHDA) was added. During the in vitro and in vivo degradation processes, erosion of the surface was dominant as evidenced by scanning electron microscopic observations. The copolyesters containing many CHDA units were featured by the higher water uptake and faster degradation due to much richer amorphous phase within them. 相似文献
27.
The adsorption behavior of p-hydroxybenzoic acid on a silver-coated filter paper by surface enhanced Raman scattering 总被引:3,自引:0,他引:3
On dried filter paper coated with silver nanoparticles, surface-enhanced Raman scattering (SERS) spectra of p-hydroxybenzoic acid (PHBA) were studied, and high-quality SERS spectra were obtained, indicating that the silver-coated filter paper is a highly SERS-active substrate. The analysis showed that the adsorption behavior of PHBA molecules on silver nanoparticles coated on filter paper was different from that in silver aqueous colloids. On the filter paper, it was found that the SERS spectra of PHBA changed with the proportion of PHBA molecules and silver nanoparticles, indicating that the adsorption behavior of PHBA molecules changed with the proportion. The probable reasons are given. 相似文献
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A method was developed for the determination of rare earth impurities in high purity Gd(2)O(3) by inductively coupled plasma mass spectrometry (ICP-MS). The matrix suppression effect of Gd(2)O(3) on signals of rare earth impurities was compensated for by Re internal standardization. The spectra overlap interferences from GdH, GdO, GdOH(n) (n=1-3) on Tb, Tm, Yb and Lu were eliminated by 2-thylhexylhydrogen-2-ethylhexy phosphonate (EHEHP) extraction chromatographic separation. The detection limits for REEs were 0.005-0.017 ng ml(-1) in solution and 0.002-0.05 mug g(-1) in solid. Recoveries of spiked sample for REEs were from 88 to 121% with the precision of 1.0-7.5% RSD. Determination of trace REEs in two Gd(2)O(3) samples were performed. The method can be applied to analysis of 99.99-99.9999% high purity Gd(2)O(3). 相似文献
29.
The potential-dependent surface-enhanced Raman spectrum of adsorbed p-nitrobenzoic acid (PNBA) on the roughened Au electrode has been obtained by using ultraviolet (UV) excitation at 325 nm. The surface-enhanced Raman spectra of PNBA intensely changed when the voltage was in the rang of negative value, and the electrode potential at which the resonance (potential of maximum intensity) occurs varied when the vibrational mode changes, indicating that the PNBA molecules were chemisorbed on the roughened Au surface. The charge transfer (CT) mechanism could probably explain the experiment results in the present work. 相似文献
30.
人类第七大营养素——膳食纤维 总被引:3,自引:0,他引:3
膳食纤维被称为人类第七大营养素,本文介绍了膳食纤维的有关化学问题,如其结构特点、理化性质、生理功能和检测方法,以及膳食纤维的应用与开发现状。 相似文献