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Synthesis and characterization of novel star-shaped pyridine cored compounds with alternating carbazole and triphenylamine moieties

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Chinese Chemical Letters 2008年第6期19卷 647-650页

作者： Ji Bing Yuan Zhi Guo Zhang Louis Man Leung Ke Li Zhang College of Chemistry and Molecular Sciences Wuhan University Wuhan 430072 China College of Chemical and Environmental Engineering Hubei University of Technology Wuhan 430068 China Department of Chemistry Hong Kong Baptist University Hongkong China

Amorphous 2,4,6-trissubstituted pyridines containing three peripheral carbazole or two triphenylamine and one carbazole moieties, respectively, have been synthesized and characterized. The properties of the compounds are investigated by UV-vis absorption, photoluminescence spectroscopy, thermal analysis as well as cyclic voltammetry. The results show that the compounds have high thermal stability, emit blue light. Also, the compounds possess the HOMO and LUMO energy levels comparable to those of NPB. The effects of different substituents on the electronic properties of the materials have been discussed.

关键词： star-shaped Carbazole Tdphenylamine Pyridine

The self-assemblies of a newly designed star-shaped molecule end-capped with bromine atoms studied by scanning tunneling microscopy

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Chinese Chemical Letters 2020年第2期31卷 353-356页

作者： Jingfei Hou Bin Tu Qingdao Zeng Chuanlang Zhan Jiannian Yao Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of PhotochemistryInstitute of ChemistryChinese Academy of SciencesBeijing 100080China CAS Key Laboratory of Standardization and Measurement for Nanotechnology CAS Center for Excellence in NanoscienceNational Center for Nanoscience and Technology(NCNST)Beijing 100190China University of Chinese Academy of Sciences Beijing 100190China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100149China

A new star-shaped molecule StOF-Br_3 containing oligofluorenes and halogen atoms(Bromine) has been synthesized and studied by Scanning Tunneling Microscopy(STM) at the highly oriented pyrolytic graphite(HOPG) surface.We have obtained the high-resolution self-assembled STM images,from which the highly ordered and closely packed non-porous arrangements of the StOF-Br_3 molecular selfassemblies at the heptanoic acid/HOPG surface could be observed.The molecular models and selfassembled StOF-Br_3 architectures have been given in the following text.Besides,we have also figured out the surface free energy by the density functional theory(DFT) calculation,which proved that the halogen...halogen interaction was strong enough to stabilize the ordered molecular self-assemblies.This work verifies the existence of bromine...bromine interactions,and meanwhile provides a kind of effective approach for quickly building ordered molecular nanoarchitectures with large areas and different geometries.

关键词： Molecular self-assemblies star-shaped molecules Scanning tunneling microscopy(STM) Halogen...halogen interactions Bromine atoms

Synthesis and Physicochemical Characterization of Biodegradable star-shaped Poly Lactide-Co-Glycolide-<i>β</i>-Cyclodextrin Copolymer Nanoparticles Containing Albumin

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Advances in Nanoparticles 2014年第1期3卷 14-22页

作者： Soodabeh Davaran Akbar Rezaei Somayeh Alimohammadi Amir Ahmad Khandaghi Kazem Nejati-Koshki Hamid Tayefi Nasrabadi Abolfazl Akbarzadeh Department of Medical Nanotechnology Faculty of Advanced Medical Science Tabriz University of Medical Sciences Tabriz Iran Department of Medicine Tabriz University of Medical Sciences Tabriz Iran Department of Science Ahar Branch Islamic Azad University Ahar Iran

The purposes of this research were to synthesize and characterize star-shaped poly lactide-co-glycolide-β-cyclo-dextrin (PLGA-β-CD) copolymer by reacting L-lactide, glycolide and β-cyclodextrin in the presence of stannous octoate as a catalyst. The structure of PLGA-β-CD copolymer was confirmed with 1H-NMR, 13C-NMR and FT-IR spectra. Albumin as a model peptide drug was encapsulated within nanoparticles made of PLGA-β-CD with a modified double emulsion method. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) photomicrographs showed that the nanoparticles have the mean diameter within the range of 80 - 210 nm. Also they were almost spherical in shape. Effects of the experimental parameters, such as copolymer composition, copolymer concentration, and reaction temperature, on particular size and encapsulation efficiency were investigated.

关键词： Albumin star-shaped Poly Lactide-Co-Glycolide β-Cyclodextrin Nanoparticles

A CLASS OF INVERSE QUOTIENT CURVATURE FLOW IN THE ADS-SCHWARZSCHILD MANIFOLD

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Acta Mathematica Scientia 2023年第6期43卷 2553-2572页

作者：纪正超 Zhejiang Institute of Modern Physics Zhejiang UniversityHangzhou 310027China Center of Mathematical Sciences Zhejiang UniversityHangzhou 310027China

In this paper,we study the asymptotic behavior of a class of inverse quotient curvature flow in the anti-de Sitter-Schwarzschild manifold.We prove that under suitable convex conditions for the initial hypersurface,one can get the long-time existence for the inverse curvature flow.Moreover,we also get that the principal curvatures of the evolving hypersurface converge to 1 when t→+∞.

关键词： star-shaped quotient curvature support function

COMMON FIXED POINTS WITH APPLICATIONS TO BEST SIMULTANEOUS APPROXIMATIONS

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Analysis in Theory and Applications 2012年第1期28卷 1-12页

作者： Sumit Chandok T. D. Narang Guru Nanak Dev University India

For a subset K of a metric space （X,d） and x ∈ X,Px（x）={y ∈ K ： d（x,y） = d（x,K）≡ inf{d（x,k）： k ∈ K}}is called the set of best K-approximant to x. An element go E K is said to be a best simulta- neous approximation of the pair y1,y2 E ∈ if max{d（y1,go）,d（y2,go）}=inf g∈K max {d（y1,g）,d（y2,g）}.In this paper, some results on the existence of common fixed points for Banach operator pairs in the framework of convex metric spaces have been proved. For self mappings T and S on K, results are proved on both T- and S- invariant points for a set of best simultaneous approximation. Some results on best K-approximant are also deduced. The results proved generalize and extend some results of I. Beg and M. Abbas^[1], S. Chandok and T.D. Narang^[2], T.D. Narang and S. Chandok^[11], S.A. Sahab, M.S. Khan and S. Sessa^[14], P. Vijayaraju^[20] and P. Vijayaraju and M. Marudai^[21].

关键词： Banach operator pair best approximation demicompact fixed point star-shaped nonexpansive asymptotically nonexpansive and uniformly asymptot-ically regular maps

MOLECULAR WEIGHT DISTRIBUTION OF AB, A, TYPE CONDENSATION POLYMERS OBTAINED BY ADDING AB MONOMERS IN BATCHES

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Science China Chemistry 1992年第1期35卷 19-27页

作者：杨玉良陆建明骆德莘孙猛唐敖庆 Institute of Material Science Fudan University Shanghai 200433 PRC Institute of Theoretical Chemistry Jilin University Changchun 13002.3 PRC

The molecular weight distribution (MWD) and arm length distribution of AB, Ar type condensation polymers obtained by adding AB monomers in batches have been derived by statistical and kinetic methods. Calculations show the MWD of condensation polymers obtained by this process is much narrower than that of one batch reaction and agrees with the Monte Carlo results very well.

关键词： molecular weight distribution arm length distribution Flory distribution star-shaped condensation polymers Monte Carlo method.