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研究了偶联剂改性的廉价填料级γ-Al_2O_3直接催化偏三甲苯(TMB)氧化为2,3,5-三甲基苯醌(TMBQ)性能的影响。结果表明,γ-(2,3-环氧丙基)丙基三甲氧基硅烷(KH560)改性后的填料γ-Al_2O_3催化氧化活性较高。考察了KH560用量、水解时间、吸附时间及吸附温度对催化效果的影响。在优化条件下(2mL KH560/Et OH溶液(体积比1∶25),水解1h,吸附4h,吸附温度50℃),偶联剂对填料γ-Al_2O_3表面产生一定的包覆,在催化氧化TMB时较温和,副反应较少,TMB转化率和TMBQ选择性分别为14.3%和72.4%。 相似文献
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随着科技的飞速发展 ,计算机在化学化工中的应用越来越广泛深入 ,其中一个重要方面就是用计算机来绘制各种化学、化工的专业图形。在众多的化学制图软件中 ,ISIS Draw以其完善的制绘多种化学分子结构式、化学反应方程式及化工流程图的功能 ,引起了广大化学工作者的注意。ISIS Draw是 1 990年由MDL公司开发的一个化学制图软件 ,它的较新版本为 2 2 1 ,是 1 999年4月升级后的第五代产品。该软件可从下列网址方便地免费下载 :http : www .mdli.com cgi dynamic downloadsecthtm… 相似文献
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In this paper, the authors consider the range of a certain class of ASH algebras in [An, Q., Elliott, G. A., Li, Z. and Liu, Z., The classification of certain ASH C*-algebras of real rank zero, J. Topol. Anal., 14(1), 2022, 183–202], which is under the scheme of the Elliott program in the setting of real rank zero C*-algebras. As a reduction theorem, they prove that all these ASH algebras are still the AD algebras studied in [Dadarlat, M. and Loring, T. A., Classifying C*-algebras via ordered, m... 相似文献
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When a surface is illuminated by laser, the field of diffusing reflective light can be described by Fresnel-Kirchhoff integration
in the region of Fresnel. If the correlation, before and after the change of intensity field, is analysed by statistical method,
three governing equations for variations of intensity field and speckle movement formulas can be obtained. In these equations,
the surface motion, deformation and wavelength change are all considered to cause the speckle movement.
The project supported by National Natural Science Foundation of China 相似文献
28.
Zhi Zhu Zhichao Guan Dan Liu Shasha Jia Jiuxing Li Zhichao Lei Shuichao Lin Tianhai Ji Zhongqun Tian Chaoyong James Yang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(36):10594-10599
Herein, we demonstrate that a very familiar, yet underutilized, physical parameter—gas pressure—can serve as signal readout for highly sensitive bioanalysis. Integration of a catalyzed gas‐generation reaction with a molecular recognition component leads to significant pressure changes, which can be measured with high sensitivity using a low‐cost and portable pressure meter. This new signaling strategy opens up a new way for simple, portable, yet highly sensitive biomedical analysis in a variety of settings. 相似文献
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Chen Z Shuai Q Eppink AT Jiang B Dai D Yang X Parker DH 《Physical chemistry chemical physics : PCCP》2011,13(18):8531-8536
The SH + CH(3) product channel for the photodissociation of CH(3)SH at 204 nm was investigated using the sliced velocity map ion imaging technique with the detection of CH(3) products using state selective (2+1) resonance enhanced multiphoton ionization (REMPI). Images were measured for CH(3) formed in the ground and excited vibrational states (v(2) = 0, 1, and 2) of the umbrella mode from which the correlated SH vibrational state distributions were determined. The vibrational distribution of the SH fragment in the SH + CH(3) channel at 204 nm is clearly inverted and peaks at v = 1. The highly negative anisotropy parameter of the CH(3) (v(2) = 0, 1, and 2) products is indicative of a fast dissociation process for C-S bond cleavage. Two kinds of slower CH(3) products were also observed (one of which was partly vibrationally resolved) that are assigned to a two-step photodissociation processes, in which the first step is the production of the CH(3)S (X(2)E) radical via cleavage of the S-H bond in CH(3)SH, followed by probe laser photodissociation of nascent CH(3)S radicals yielding CH(3)(X(2)A(1), v(2) = 0-2) + S((3)P(j)/(1)D) products. 相似文献
30.
Hepatocellular carcinoma (HCC) may metastasize to many organs. The survival rate is almost zero for metastatic HCC patients. Molecular mechanisms of HCC metastasis need to be understood better and new therapies must be developed. We have developed the "in vivo microscopy" to study the mechanisms that govern liver tumor cells spreading through the microenvironment in vivo. A recently developed "in vivo flow cytometer" combined with real-time confocal fluorescence imaging is used to assess spreading and the circulation kinetics of liver tumor cells. We measure the depletion kinetics of two related human HCC cell lines, high-metastatic HCCLM3 cells and low-metastatic HepG2 cells, which are from the same origin and obtained by repetitive screenings in mice. More than 60% of the HCCLM3 cells are depleted within the first hour. Interestingly, the low-metastatic HepG2 cells possess noticeably slower depletion kinetics. In comparison, less than 40% of the HepG2 cells are depleted within the first hour. The differences in depletion kinetics might provide insights into early metastasis processes. 相似文献