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971.
Leishan Shao Yuliang Zhang Changhao Liu Jingjing Li Ailin Qin 《Liquid crystals》2013,40(12):1458-1464
In this study, a graft polymer matrix prepared by living radical polymerisation had been incorporated into polymer dispersed liquid crystals (PDLCs). The electro-optical properties of the PDLCs were investigated. The results showed that the length and density of graft chain had a great influence on the memory effect of the PDLCs. Low-driving-voltage and weak-memory-effect PDLCs could easily be obtained with a graft polymer matrix. 相似文献
972.
As a nanoparticle support material, carbon nanotubes (CNTs) provide a certain potential activation of catalysis in heterogeneous catalytic organic reactions. Herein, an efficient Ag/CNT‐catalyzed synthesis of enamines via hydroamination of activated alkynes with aromatic amines has been described. This catalyst still retains catalytic activity after being recycled and reused three times. In addition, it represents a green and environmentally friendly process for preparation of enamines. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
973.
Yi Li Xincheng Wang Jing Jing Baorong Xie 《Journal of Dispersion Science and Technology》2013,34(11):1564-1568
Giant vesicles have been of intense interest as the model system for cell membranes. To bring numerous applications of the vesicles into full play, the existence time of the vesicles becomes particularly important. In this work, we explored the existence time of the vesicles in distilled water under four kinds of representative alternative current (AC) electric fields with different energizing time. When the application time of AC electric field reached 1 hour, the existence time of the vesicles reached the maximum value. As the applied electric field time increased, the existence time of the vesicles decreased. Thus, after obtaining the best vesicles on the carbon fiber electrode, disconnecting the external electric field is very necessary. Based on the in situ observation using inverted microscope, the disappearing phenomena of the vesicles were presented. In addition, it is found that vesicles in phosphate buffer solutions (PBSs) can last about 2–3 days when the electric field was applied for 1 hour, which was much longer than that in distilled water. 相似文献
974.
P. Yi A. Aldahan G. Possnert X. L. Hou P. He B. Wang 《Journal of Radioanalytical and Nuclear Chemistry》2013,295(3):1797-1801
Iodine speciation plays a significant role in iodine volatilizing into atmosphere from the seas, as well as serving as a biological indicator. Despite this importance, the data on iodine species revealed inconclusive evidence of what factors controlling speciation transformation. We here present new data on profiles of 129I speciation in the Baltic Proper during November 2009. Along with the two earlier investigations (August 2006 and April 2007), an assessment of seasonal variation of 129I species is presented. The results show that, due to the anoxic nature of Baltic Proper, presence of 129IO3 ? in the Baltic Proper does not follow an obvious seasonal cycle, as the case with 129I?. Concentrations of 129I? in the Baltic Proper exhibit higher values in summer than the other two seasons (spring and winter), which might be associated with degrading of organic matter and release from sediment to water column that is more pronounced during summer. 129I? in surface water from the three seasons does not reflect the release function from the reprocessing facilities during the period April 2007 to November 2009. Consequently variability of 129I? in surface seawater of the Baltic Proper depends, to some extent, on local physical as well as biochemical conditions. 相似文献
975.
Suxia Li Kang Lin Huaiyu Pang Yixin Wu Jianhe Xu 《Applied biochemistry and biotechnology》2013,169(2):612-623
An organic solvent-tolerant lipase from Serratia marcescens ECU1010 (rSML) was overproduced in Escherichia coli in an insoluble form. High concentrations of both biomass (50 g cell wet weight/L culture broth) and inclusion bodies (10.5 g/L) were obtained by applying a high-cell-density cultivation procedure. Activity assays indicated that the enzymatic activity of rSML reached 600 U/L. After treatment with isopropyl ether for 12 h, the maximum lipase activity reached 6,000 U/L. Scanning electron microscopy and Fourier transform infrared microspectroscopy revealed the activation mechanism of rSML in the presence of organic solvents. rSML was stable in broad ranges of temperatures and pH values, as well as in a series of organic solvents. Besides, rSML showed the best enantioselectivity for the kinetic resolution of (±)-trans-3-(4-methoxyphenyl)glycidic acid methyl ester. These features render the S. marcescens ECU1010 lipase attractive for biotechnological applications in the field of organic synthesis and pharmaceutical industry. 相似文献
976.
Morphology development and growth process of spherulites in miscible poly(ethylene succinate)/poly(ethylene oxide) blends are studied by means of polarizing optical microscopy and atom force microscopy in this paper. Thin films with different film thicknesses were used to follow the growth processes of spherulites and dendrites. It is shown that, when one component spherulite grows, the other component in the melt is always excluded from the spherulite. The excluded component may reenter into the spherulite through diffusion depending on amorphous volume fraction of spherulite and segmental mobility of molecules, which leads to the occurrence of interpenetrated growth. This mechanism was analyzed in detail in this paper. 相似文献
977.
Considering the diffusion reaction at solid interfaces, the ignition temperature of compounds fabricated by self-propagating high-temperature synthesis (SHS) is modelled with the help of size-dependent activation energy. As reactant size decreases, ignition temperature also decreases. This is because of increased contact areas between the reactants and the lowered diffusion barrier, both of which must be calculated specifically for reactants in nanoscale. The model predictions and experimental results are consistent for some metallic compounds. 相似文献
978.
The adsorptive denitrogenation from fuels over three metal-organic frameworks(MIL-96(Al),MIL-53(Al)and MIL-101(Cr))was studied by batch adsorption experiments.Four nitrogen-containing compounds(NCCs)pyridine,pyrrole,quinoline and indole were used as model NCCs in fuels to study the adsorption mechanism.The physicochemical properties of the adsorbents were characterized by XRD,N2physical adsorption,FT-IR spectrum and Hammett indicator method.The metal-organic frameworks(MOFs),especially the MIL-101(Cr)containing Lewis acid sites as well as high specific surface area,can adsorb large quantities of NCCs from fuels.In addition,the adsorptive capacity over MIL-101(Cr)will be different for NCCs with different basicity.The stronger basicity of the NCC is,the more it can be absorbed over MIL-101(Cr).Furthermore,pore size and shape also affect the adsorption capacity for a given adsorbate,which can be proved by the adsorption over MIL-53(Al)and MIL-96(Al).The pseudo-second-order kinetic model and Langmuir equation can be used to describe kinetics and thermodynamics of the adsorption process,respectively.Finally,the regeneration of the used adsorbent has been conducted successfully by just washing it with ethanol. 相似文献
979.
Bao-Lei Wang Qing-Nan Li Yi-Zhou Zhan Li-Xia Xiong Shu-Jing Yu Zheng-Ming Li 《Phosphorus, sulfur, and silicon and the related elements》2013,188(4):483-491
Abstract A novel series of pyrazole derivatives containing substituted phenylsulfinyl/sulfonyl group have been synthesized via the oxidation of intermediate pyrazole sulfoether with H2O2 in acetic acid. The novel compounds were characterized by melting point, 1H NMR, FT-IR, MS, and elemental analysis or HRMS. The biological activity results showed that most of the title compounds exhibit significant fungicidal activities against Alternaria solani Sorauer, Phytophthora capsici, and Corynespora cassiicola. [Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental files: Additional text and figures.] 相似文献
980.
In single-slip-oriented copper single crystals, which were cyclically deformed under constant plastic shear strain amplitude control, a persistent slip band (PSB) was initiated on the persistent slip line (PSL) that first formed in the matrix vein dislocation structure. During intermediate temperature recovery (ITR) treatment in vacuum at 245 to 400°C, the variations in dislocation configurations and other defects of fatigued specimens were studied by using the scanning electron microscopy (SEM) electron channelling contrast (ECC) and the positron annihilation life (PAL) techniques. The results show that the ladders in the PSBs became curved and broken, or escaped locally until the PSBs disappeared completely during ITR treatment. The annihilation of the PSBs and other dislocation structures in the fatigued specimens prolonged the fatigue life to a certain extent. 相似文献