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91.
Zhang H Liang C Liu J Tian Z Wang G Cai W 《Langmuir : the ACS journal of surfaces and colloids》2012,28(8):3938-3944
A novel strategy was designed to prepare Ag cluster-doped TiO(2) nanoparticles (Ag/TiO(2) NPs) without addition of any chemical reducing agent and/or organic additive. A defect-rich TiO(x) species was generated by laser ablation in liquid (LAL) of a Ti target. The silver ions could be reduced and deposited on the surface of TiO(2) NPs through the removal of oxygen vacancies and defects; the TiO(x) species evolved into anatase NPs in a hydrothermal treatment process. The derived Ag/TiO(2) NPs are approximately 25 nm in size, with narrow size distribution. The Ag clusters are highly dispersed inside TiO(2) and less than 3 nm in size. The doped amount can be tuned by changing the concentration of Ag(+) ions. The as-synthesized Ag/TiO(2) NPs display improved photocatalytic efficiency toward pentachlorophenol (PCP) degradation. 相似文献
92.
Haiyang Wang Zhenhua Li Erdong Wang Can Lin Yuguang Shang Guozhong Ding Xinbin Ma Shaodong Qin Qi Sun . 《天然气化学杂志》2012,(6):767-773
The effects of composite supports of CeO2-Al2O3,MgO-Al2O3,TiO2-Al2O3 or ZrO2-Al2O3 on the methanation activity of supported Co-Mo-based sulphur-resistant catalysts were investigated.The catalysts were further characterized by nitrogen adsorption measurement,X-ray diffraction and X-ray photoelectron spectroscopy.The catalyst of 5%CoO-15%MoO3 supported on CeO2-Al2O3,MgO-Al2O3,TiO2-Al2O3 or ZrO2-Al2O3 composite oxides,respectively,showed different catalytic performances of syngas methanation in the presence of hydrogen sulphide as compared with that of the 5%CoO-15%MoO3/Al2O3 catalyst.The Co-Mo/CeO2-Al2O3 catalyst shows the highest methanation activity among the tested catalysts.The enhanced methanation activity may be attributed to the improvement of the dispersion of active metal species and the inhibition of the formation of S6+. 相似文献
93.
Ming Gao Guozhong Xing Jinghai Yang Lili Yang Yongjun Zhang Huilian Liu Hougang Fan Yingrui Sui Bo Feng Yunfei Sun Zhiqiang Zhang Shanshan Liu Sean Li Hang Song 《Mikrochimica acta》2012,178(3-4):315-321
We introduce a novel voltammetric method, so-called sinusoidal envelope voltammetry, for use in electronic tongues. Fourier transformation was used to transform the data of the signal from the time domain to the frequency domain. The four taste substances, acesulfame potassium, monosodium glutamate, potassium chloride and tartaric acid, are shown to exhibit abundant frequency characteristics in the power spectrum of a Fourier transformation. This indicates that the power spectrum from sinusoidal envelope voltammetry can be used as fingerprints of samples for classification. Principal component analysis along with discrimination index and multi-frequency large amplitude pulse voltammetry as a reference technique is used to evaluate the separation ability of sinusoidal envelope voltammetry. The score plots of the method for the four taste substances and for the five brands of Jiafan rice wine show better discrimination ability than multi-frequency large amplitude pulse voltammetry. Sinusoidal envelope voltammetry is considered to be a promising technique for use in voltammetric electronic tongues. Figure
The sketch of the electronic tongue with sinusoidal envelope voltammetry (SEV) and multi‐frequency large amplitude pulse voltammetry (MLAPV) 相似文献
94.
N—烷氧甲基取代丙烯酰胺的制备 总被引:1,自引:0,他引:1
N—烷氧甲基取代丙烯酰胺的制备张志成,吴国忠,王胜,徐相凌(中国科学技术大学应用化学系合肥230026)关键词丙烯酰胺,阻聚剂,醚化N-烷氧甲基取代丙烯酰胺的结构通式为:CH_2=C-CONHCH_2OR_2R_1=H.CH_3;R_2=H,Me,E... 相似文献
95.
96.
By using upper and lower solutions and fixed point theorem we give the existence theorem of non-linear second order ordinary differential equation with discontinuous terms in Banach Space. 相似文献
97.
构造一类求解三种类型偏微分方程的间断Petrov-Galerkin方法.求解的方程分别含有二阶、三阶和四阶偏导数,包括Burgers型方程、KdV型方程和双调和型方程.首先将高阶微分方程转化成为与之等价的一阶微分方程组,再将求解双曲守恒律的间断Petrov-Galerkin方法用于求解微分方程组.该方法具有四阶精度且具有间断Petrov-Galerkin方法的优点.数值实验表明该方法可以达到最优收敛阶而且可以模拟复杂波形相互作用,如孤立子的传播及相互碰撞等. 相似文献
98.
黄酮类化合物抑制MMP-9的定量结构-活性关系和结构修饰的理论研究 总被引:3,自引:0,他引:3
运用密度泛函理论(DFT)和线性回归分析等方法研究了黄酮类化合物抑制MMP-9的定量结构-活性关系(QSAR)和结构修饰. 研究发现, 黄酮类化合物抑制MMP-9的实验生物活性数据-lg EC50值与计算获得的黄酮类化合物的最低空分子轨道能量及分子水合能之间均存在着良好的线性关系|留一法交叉验证结果表明, 所建立的两个相应的QSAR模型都具有良好的稳定性和预测能力. 进一步研究发现, 在黄酮类化合物分子的A环、B环和C环上的合适部位选用供电子能力较强、能降低分子水合能的取代基团对其进行结构修饰, 有利于提高修饰后的分子抑制MMP-9的生物活性. 根据对木犀草素(Luteolin)分子进行结构修饰的结果(共33种化合物), 我们提出了黄酮类化合物抑制MMP-9可能的作用机理, 并设计出8种经结构修饰后生物活性有显著提高的MMP-9抑制剂, 希望将来得到实验的证实. 相似文献
99.
证明了一个矩阵对策问题的解等价于一个线性规划问题的最优解.提出了求解矩阵对策的一种新方法,即直接线性规划法.该方法根据所给问题建立一个特殊的线性规划模型,然后求解,可直接得到矩阵对策的值和两个局中人的最优策略,不需作变量变换,也不要求对策值大于零.给出了直接线性规划法在求解对称对策问题中的应用. 相似文献
100.
We study the extension of canonical correlation from pairs of random vectors to the case where a data sample consists of pairs of square integrable stochastic processes. Basic questions concerning the definition and existence of functional canonical correlation are addressed and sufficient criteria for the existence of functional canonical correlation are presented. Various properties of functional canonical analysis are discussed. We consider a canonical decomposition, in which the original processes are approximated by means of their canonical components. 相似文献