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51.
Ping Li Fei Rong Yibing Xie Van Hu Chunwei Yuan 《Journal of Analytical Chemistry》2004,59(10):939-944
S-naproxen imprinted polymer was prepared with acrylamide as a functional monomer, 1,4-butanediyl diacrylate as a new kind of crossliner, and 2,4,6-trimethylbenzoylphenyl-phosphinic acid ethyl ester as photoinitiator. Their UV and IR spectra were applied to study the interactions between the template and the monomer. Binding experiments showed that the S-naproxen imprinted polymer had better recognition capability for the template than that of a blank polymer. The adsorption distribution coefficient KD of S-naproxen on molecularly-imprinted polymer was 153.2 g/mL, and the separation factor was 1.95 when the initial concentration of substrate was 2.0 mmol/L. Scatchard curves suggested that there were two classes of binding sites in the imprinted polymer and only one class in the blank polymer. Computer simulation using Hyperchem showed the existence of the interactions between the template and the functional monomer as well as the models of the complexes formed by the template and the monomer. 相似文献
52.
Chun‐Yan Hong Ye‐Zi You Cai‐Yuan Pan 《Journal of polymer science. Part A, Polymer chemistry》2004,42(19):4873-4881
Well‐defined diblock and triblock copolymers composed of poly(N‐isopropylacrylamide) (PNIPAM) and poly(ethylene oxide) (PEO) were successfully synthesized through the reversible addition–fragmentation chain transfer polymerization of N‐isopropylacrylamide (NIPAM) with PEO capped with one or two dithiobenzoyl groups as a macrotransfer agent. 1H NMR, Fourier transform infrared, and gel permeation chromatography instruments were used to characterize the block copolymers obtained. The results showed that the diblock and triblock copolymers had well‐defined structures and narrow molecular weight distributions (weight‐average molecular weight/number‐average molecular weight < 1.2), and the molecular weight of the PNIPAM block in the diblock and triblock copolymers could be controlled by the initial molar ratio of NIPAM to dithiobenzoate‐terminated PEO and the NIPAM conversion. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4873–4881, 2004 相似文献
53.
Jaedong Cho John Blackwell Sergei N. Chvalun Morton Litt Yuan Wang 《Journal of Polymer Science.Polymer Physics》2004,42(13):2576-2585
As‐cast films of poly(2,5‐benzimidazole) exhibit uniplanar orientation in which the planes of the aromatic rings lie parallel to the film surface. Upon doping with phosphoric acid, the original crystalline order is lost, but the doped film can be stretched to produce films with uniaxial orientation. After thermal annealing at 540 °C, nine Bragg reflections are resolved in the fiber diagram, and these are indexed by an orthorhombic unit cell with the dimensions a = 18.1 Å, b = 3.5 Å, and c = 11.4 Å, containing four monomer units of two chains. The absence of odd‐order 00l reflections points to a 21 chain conformation, which is probably planar so that the aromatic units can be stacked along the b axis. The water and phosphoric acid contents of the crystalline structure cannot be determined exactly because of the presence of extensive amorphous regions that probably have different solvation. The best agreement between the observed and calculated intensities is for an idealized structure containing two phosphoric acids and two water molecules per unit cell. However, the phosphoric acid is probably present mainly in the form of pyrophosphoric acid and its higher oligomers. In addition, the X‐ray data are consistent with a more disordered structure containing chains with random (up and down) polarity and a lack of c‐axis registry. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2576–2585, 2004 相似文献
54.
A hybrid cluster complex, formed by chelating a chromogenic ligand to a [2Fe-2S] cluster, sensitively exhibited differential colorimetric responses towards Hg2+, Cd2+, Cr3+, Pb2, Sn2+, Cu2+, Zn2+, Fe3+ and Co2+ in water at physiological pH. Speciation of some of these metal elements, such as Cr(III) and Sn(IV), was also studied by UV/Vis absorption. 相似文献
55.
The adsorption of human serum albumin onto hydroxyapatite-modified silver electrodes has been in situ investigated by utilizing the piezoelectric quartz crystal impedance technique. The changes of equivalent circuit parameters were used to interpret the adsorption process. A kinetic model of two consecutive steps was derived to describe the process and compared with a first-order kinetic model by using residual analysis. The experimental data of frequency shift fitted to the model and kinetics parameters, k1, k2, psi1, psi2 and qr, were obtained. All fitted results were in reasonable agreement with the corresponding experimental results. Two adsorption constants (7.19 kJ mol(-1) and 22.89 kJ mol(-1)) were calculated according to the Arrhenius formula. 相似文献
56.
57.
基于可压缩的全Naiver-Stokes方程,利用PHOENICS程序对由会聚 辐射阳极形状等离子体炬产生的超声速等离子体射流进行了数值模拟.考虑了等离子体的黏性、可压缩性以及变物性对等离子体射流特性影响.研究了超声速等离子体射流的流场结构特性以及不同环境压力对等离子体射流产生激波结构的影响.结果表明,超声速等离子体射流在喷口附近形成的周期性激波结构是其和环境气体相互作用的结果.
关键词:
等离子体炬
超声速等离子体射流
PHOENICS 相似文献
58.
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60.
NianYuanTAN XiaoMingXIAO ZeLinLI TakekoMATSUMURA-INOUE 《中国化学快报》2004,15(6):687-690
A new cobalt(Ⅱ) complex with tridentate ligand 2, 6-bis (benzimidazol-2-yl)pyridine has been synthesized by microwave irradiation method and characterized by elemental analysis,electrochemical and spectral methods. The binding of the complex with calf thymus DNA has also been investigated by absorption and fluorescence spectra. 相似文献