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41.
A novel bipolar conjugated polymer containing triphenylamine and 1,3,4-oxadiazole units was synthesized by Suzuki reaction.Its structure and properties were characterized by NMR,IR,UV-Vis,PL spectroscopy and electrochemical measurement. The photoluminescent spectroscopy and cyclic voltammograms measurement demonstrated that the resulting polymer shows blue emission (477 nm) and possesses both electron and hole-transporting property. 相似文献
42.
Preparation and characterization of Al2O3-MgO mixed oxides 总被引:1,自引:0,他引:1
A new catalyst system V-Cs-Cu-Tl/TiO2·SiC for vapor-phase selective oxidation reaction of p-tert-butyltoluene to p-tert-butylbenzaldehyde were studied. It was found that the addition of thallium promoted the reaction. After 365 hours stability test, the V-Cs-Cu-Tl/TiO2·SiC catalyst still kept excellent result that conversion of p-tert-butyltoluene and the selectivity of p-tert-butylbenzaldehyde reach 10 mol% and 80 mol%. The catalyst was characterized by XRD, TEM, FT-IR and ICP measurements. 相似文献
43.
利用改进了MacDiarmid氧化偶联方法合成了苯/胺封端的苯胺四聚体,通过对循环伏安曲线的分析,给出二聚体经由电化学氧化-化学偶联成为四聚体的机理,利用基质辅助激光解吸质谱和红外光谱对产物进行了表征。 相似文献
44.
Yumeng Xing Zunkai Xu Tao Liu Prof. Linqi Shi Prof. Daniel Kohane Prof. Shutao Guo 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(18):7302-7306
While poly(acyclic orthoester)s (PAOEs) have many appealing features for drug delivery, their application is significantly hindered by a lack of facile synthetic methods. Reported here is a simple method for synthesizing acyclic diketene acetal monomers from diols and vinyl ether, and their polymerization with a diol to first synthesize PAOEs. The PAOEs rapidly hydrolyze at lysosomal pH. With the help of a cationic lipid, ovalbumin, a model vaccine antigen was efficiently loaded into PAOEs nanoparticles using a double emulsion method. These nanoparticles efficiently delivered ovalbumin into the cytosol of dendritic cells and demonstrated enhanced antigen presentation over poly(lactic-co-glycolic acid) (PLGA) nanoparticles. PAOEs are promising vehicles for intracellular delivery of biopharmaceuticals and could increase the utility of poly(orthoesters) in biomedical research. 相似文献
45.
Ji Shan WU Chun Yan CHI Xian Hong WANG* Xiao Jiang ZHAO Ji LI Fo Song WANG State Key Laboratory of Polymer Physics Chemistry Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun 《中国化学快报》2001,(5)
IntroductionFerrocene-containing compounds have been widely used as important probes to investigate the electron transfer/transport properties of the molecular materials1. Recently, this technique was employed in molectronics research, where the ferrocenes were incorporated on the ends of conjugated molecular wires, and the electron transfer/transport abilities of the molecular wires were conveniently studied by electrochemical method2. Ethynylferrocene and iodoethynylferrocene were two import… 相似文献
46.
47.
Aequationes mathematicae - In this note we prove that every Jordan derivation on a triangular ring is a derivation. Moreover, we show that, under some conditions, every Jordan derivation on a... 相似文献
48.
??In this paper, we study a class of stochastic Volterra equations, which include the stochastic differential equation driven by fractional Brownian motion. By using a maximal inequality due to It\^o (1979), we establish the central limit theorem for stochastic Volterra equation on the continuous path space, with respect to the uniform norm. 相似文献
49.
A simple method for the determination of sub ppm amounts of mercury in various biological materials by neutron activation
analysis is described. Irradiated samples were decomposed with H2SO4-fuming HNO3 mixture and mercury selectively isolated by ion exchange chromatography using Dowex 50WX2 [H+] and Dowex 1X4 [Br−] columns in HBr medium. Finally the activity of197Hg fixed on an anion exchange resin was measured either with a Ge(Li) or a NaI (Tl) detector. Both the high radiochemical
purity of mercury and the practically quantitative recovery were achieved thus eliminating the necessity of determining the
chemical yield. The method was used for the determination of mercury in flour, milk, butter, margarine, fish, etc. 相似文献
50.
Electron-beam irradiation on poly(propylene carbonate) in the presence of polyfunctional monomers 总被引:1,自引:0,他引:1
Yu Sheng Qin Qing Wei Ma Xian Hong Wang Jia Zhen Sun Xiao Jiang Zhao Fo Song Wang 《Polymer Degradation and Stability》2007,92(10):1942-1947
Poly(propylene carbonate) (PPC) showed predominantly degradation under electron-beam irradiation, accompanied by deterioration of its mechanical performance due to sharp decrease of the molecular weight. Crosslinked PPC was prepared by addition of polyfunctional monomer (PFM) to enhance the mechanical performance of PPC. When 8 wt% of PFM like triallyl isocyanurate (TAIC) was added, crosslinked PPC with a gel fraction of 60.7% was prepared at 50 kGy irradiation dose, which showed a tensile strength at 20 °C of 45.5 MPa, whereas it was only 38.5 MPa for pure PPC. The onset degradation temperature (Ti) and glass transition temperature (Tg) of this crosslinked PPC was 246 °C and 45 °C, respectively, a significant increase related to pure PPC of 211 °C and 36 °C. Therefore, thermal and mechanical performances of PPC could be improved via electron-beam irradiation in the presence of suitable PFM. 相似文献