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91.
Xiaoping Chen Neil Ayres 《Journal of polymer science. Part A, Polymer chemistry》2011,49(14):3030-3037
The synthesis of a molecular brush was accomplished by combining step‐growth polymerization and reversible addition fragmentation chain transfer (RAFT) polymerization in a “grafting from” methodology. A symmetrical N‐alkyl urea peptoid sixmer containing alkyne functional groups was prepared using a divergent strategy, and the structure of the product was confirmed using NMR spectroscopy and mass spectrometry. A step‐growth process was used to prepare a linear poly(N‐alkyl urea peptoid) by reacting the diamine‐functionalized N‐alkyl urea peptoid sixmer with a diisocyanate. RAFT chain transfer agents were coupled to the poly(N‐alkyl urea peptoid) backbone through a copper‐catalyzed azide/alkyne cycloaddition reaction. The afforded macro‐RAFT agent was used to sequentially polymerize styrene and tert‐butyl acrylate block copolymer arms from the poly(N‐alkyl urea peptoid) backbone. The tert‐butyl groups were removed using dilute trifluoroacetic acid affording hydrophilic polyacrylic acid segments. The molecular brushes were observed to generate micelles in aqueous solution. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 相似文献
92.
Hua Zhu Xiaoping Xu Wei Cui Yuanqing Zhang Huaping Mo Yu‐Mei Shen 《Journal of polymer science. Part A, Polymer chemistry》2011,49(8):1745-1752
This article describes the synthesis and characterization of hydroxyl tailored, molecularly defined biodegradable cooligomers capable of chelating rhenium for potential radiopharmaceuticals. New insights were gained during the synthesis of lactide based on dimethylaminopyridine‐catalyzed transesterification. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 相似文献
93.
Spline wavelet transform is used to resolve overlapping voltammetric peaks. A suitable resolving factor is chosen to multiply the filters of spline wavelet and make it a peak resoluter. Simulated overlapping voltammetric peaks are processed by the peak resoluter and satisfactory results are obtained. Base-line separation can be achieved, the relative errors of peak position are less than 3.0%, and the relative errors of peak area are less than 5.0%. The effect of different resolving factors and spline wavelet basis are discussed. To test the procedure, two systems, cadmium (Ⅱ)-indium (Ⅲ) and lead (Ⅱ)-thallium (Ⅰ), are used. 相似文献
94.
线路方案比选多目标决策分析 总被引:6,自引:0,他引:6
本文通过对线路方案比选的多目标决策分析,建立了线路方案比选的 TOPSIS模型,对线路方案非劣解集进行排序,提供方案的优先顺序. 相似文献
95.
Wan Chaozhi He Tianjing Gao Xiaoping Li Jungqing Xin Houwen Liu Fan-Chen 《Journal of Molecular Structure》1986,140(3-4):227-234
In this paper, the SERS spectra of a series of compounds C6H5(CH2)nCOOH (n = 0, 1, 2) adsorbed on colloidal silver are recorded and compared with each other. The relation between the SERS intensities and the electronic structures of the compounds are discussed. The results support the molecular enhancement mechanism on SERS, especially the charge transfer idea. 相似文献
96.
In this paper, a new concept called α-inverse Lipschitz function is introduced. Based on the topological degree theory and Lyapunov functional method, we investigate global convergence for a novel class of neural networks with impulses where the neuron activations belong to the class of α-inverse Lipschitz functions. Some sufficient conditions are derived which ensure the existence, and global exponential stability of the equilibrium point of neural networks. Furthermore, we give two results which are used to check the stability of uncertain neural networks. Finally, two numerical examples are given to demonstrate the effectiveness of results obtained in this paper. 相似文献
97.
In this article,the authors obtain an integral representation for the relaxation of the functional
F(x,u,Ω):={∫^f(x,u(x),εu(x))dx Ω if u∈W^1,1(Ω,R^N), +∞ otherwise, in the space of functions of bounded deformation,with respect to L^1-convergence.Here Eu represents the absolutely continuous part of the symmetrized distributional derivative Eu.f(x,p,ξ)satisfying weak convexity assumption. 相似文献
F(x,u,Ω):={∫^f(x,u(x),εu(x))dx Ω if u∈W^1,1(Ω,R^N), +∞ otherwise, in the space of functions of bounded deformation,with respect to L^1-convergence.Here Eu represents the absolutely continuous part of the symmetrized distributional derivative Eu.f(x,p,ξ)satisfying weak convexity assumption. 相似文献
98.
用ICPOES法检测了54例男性少精、弱精不育者精液中Ca、Cd、Cu、Fe、Mg、Mn、Ni、Zn元素的含量,并对相关含量进行数据分析。结果表明,精液中微量元素含量的改变是影响精液质量的重要原因之一。 相似文献
99.
100.
Photo-induced surface grafting with glycidyl methacrylate (GMA) as monomer in association with a pad-curing treatment by using a flame retardant (FR) solution which contains 1-hydroxy ethylidene-1,1-diphosphonic acid (HEDP) and sulfamic acid (H2NSO3H) has been used to improve the fire performance of PET fabric in this study. The effects of initiator concentration, monomer concentration and the irradiation time on the grafting percentage were investigated. The chemical structure of grafted surface of the PET fabric was characterized by an attenuated total reflection-infrared (ATR-IR) spectroscopy. The fire performance was evaluated by the LOI and the vertical flammability tests, and the results indicate that the photo grafting treatment could improve the flame retardancy and dripping resistance of PET fabric. Thermal behaviour of treated PET fabric samples was investigated by thermogravimetric (TG) and differential scanning calorimetric (DSC). The morphology of the sample char residue was also investigated by scanning electron microscope (SEM). 相似文献