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111.
Cu nanotube arrays were fabricated by electroless deposition using porous anodic aluminium oxide membranes as templates. This was accomplished by a four-step procedure, i.e. pore-wall modification, polishing treatment, sensitization-activation and electroless deposition. The as-synthesized Cu nanotubes possess controllable inner diameter and open ends. 相似文献
112.
Y.X. Yin 《Applied Surface Science》2006,253(3):1584-1589
Wear resistant Cu-based solid solution (Cuss) toughened Cr5Si3 metal silicide composite coatings were fabricated on austenitic stainless steel AISI321 by laser cladding process. Due to the rapidly solidified microstructural characteristics and the excellent toughening effect of Cuss on Cr5Si3, the Cuss/Cr5Si3 coatings have outstanding wear resistance and low coefficient of friction under room temperature dry sliding wear test conditions coupling with hardened 0.45% C steel. 相似文献
113.
Yan Yin Otoo Yamada Shunsuke Hayashi Kazuhiro Tanaka Hidetoshi Kita Ken‐Ichi Okamoto 《Journal of polymer science. Part A, Polymer chemistry》2006,44(12):3751-3762
A series of branched/crosslinked sulfonated polyimide (B/C‐SPI) membranes were prepared and evaluated as proton‐conducting ionomers based on the new concept of in situ crosslinking from sulfonated polyimide (SPI) oligomers and triamine monomers. Chemical branching and crosslinking in SPI oligomers with 1,3,5‐tris(4‐aminophenoxy)benzene as a crosslinker gave the polymer membranes very good water stability and mechanical properties under an accelerated aging treatment in water at 130 °C, despite their high ion‐exchange capacity (2.2–2.6 mequiv g?1). The resulting polymer electrolytes displayed high proton conductivities of 0.2–0.3 S cm?1 at 120 °C in water and reasonably high conductivities of 0.02–0.03 S cm?1 at 50% relative humidity. In a single H2/O2 fuel‐cell system at 90 °C, they exhibited high fuel‐cell performances comparable to those of Nafion 112. The B/C‐SPI membranes also displayed good performances in a direct methanol fuel cell with methanol concentrations as high as 50 wt % that were superior to those of Nafion 112. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3751–3762, 2006 相似文献
114.
Amphiphilic biodegradable block copolymers [poly(sebacic anhydride)–poly(ethylene glycol)–poly(sebacic anhydride)] were synthesized by the melt polycondensation of poly(ethylene glycol) and sebacic anhydride prepolymers. The chemical structure, crystalline nature, and phase behavior of the resulting copolymers were characterized with 1H NMR, Fourier transform infrared, gel permeation chromatography, and differential scanning calorimetry. Microphase separation of the copolymers occurred, and the crystallinity of the poly(sebacic anhydride) (PSA) blocks diminished when the sebacic anhydride unit content in the copolymer was only 21.6%. 1H NMR spectra carried out in CDCl3 and D2O were used to demonstrate the existence of hydrophobic PSA domains as the core of the micelle. In aqueous media, the copolymers formed micelles after precipitation from water‐miscible solvents. The effects on the micelle sizes due to the micelle preparation conditions, such as the organic phase, dropping rate of the polymer organic solution into the aqueous phase, and copolymer concentrations in the organic phase, were studied. There was an increase in the micelle size as the molecular weight of the PSA block was increased. The diameters of the copolymer micelles were also found to increase as the concentration of the copolymer dissolved in the organic phase was increased, and the dependence of the micelle diameters on the concentration of the copolymer varied with the copolymer composition. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1271–1278, 2006 相似文献
115.
116.
Baijun Liu Gilles P. Robertson Michael D. Guiver Yi‐Ming Sun Yin‐Ling Liu Juin‐Yih Lai Serguei Mikhailenko Serge Kaliaguine 《Journal of Polymer Science.Polymer Physics》2006,44(16):2299-2310
A series of sulfonated poly(aryl ether ether ketone ketone)s statistical copolymers with high molecular weights were synthesized via an aromatic nucleophilic substitution polymerization. The sulfonation content (SC), defined as the number of sulfonic acid groups contained in an average repeat unit, could be controlled by the feed ratios of monomers. Flexible and strong membranes in sodium sulfonate form could be prepared by the solution casting method, and readily transformed to their proton forms by treating them in 2 N sulfuric acid. The polymers showed high Tgs, which increased with an increase in SC. Membranes prepared from the present sulfonated poly(ether ether ketone ketone) copolymers containing the hexafluoroisopropylidene moiety (SPEEKK‐6F) and copolymers containing the pendant 3,5‐ditrifluoromethylphenyl moiety (SPEEKK‐6FP) had lower water uptakes and lower swelling ratios in comparison with previously prepared copolymers containing 6F units. All of the polymers possessed proton conductivities higher than 1 × 10?2 S/cm at room temperature, and proton conductivity values of several polymers were comparable to that of Nafion at high relative humidity. Their thermal stability, oxidative stability, and mechanical properties were also evaluated. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2299–2310, 2006 相似文献
117.
Degradation of 4-chlorophenol in aqueous solution by γ-radiation and ozone oxidation 总被引:5,自引:2,他引:3
HU Jun WANG Jianlong & CHEN Rong . Laboratory of Environmental Technology Institute of Nuclear Energy Technology Tsinghua University Beijing China . State Key Joint Laboratory of Environmental Simulation Pollution Control Tsinghua University Beijing China Correspondence should be addressed to Wang Jianlong 《中国科学B辑(英文版)》2006,(2)
The application of radiation technology in the en-vironmental protection was listed as one of the mostimportant research fields by the International AtomicEnergy Agency (IAEA) for the peaceful use of nuclearenergy. It has great research value and potential appli-cation. Because of their broad-spectrum antimicrobialproperties, Cholophenols (CPs) have been used aspreservative agents for wood, paints, vegetable fibersand leather and as disinfectants. In addition, they havebeen widely employed… 相似文献
118.
Two novel dithienylethenes with ferrocene units were synthesized by Wittig reaction. The structure of 2a has been established by X‐ray diffraction studies. They could reversibly interconvert between two thermally stable forms, an open and a closed one, using light of different wavelengths as triggers. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
119.
120.
分别采用功率密度为1.7W/cm2、照射剂量为2000J/cm2的Ar+激光与LD激光辐照高耐药性的志贺氏福氏痢疾杆菌,波长较短的Ar+激光(488nm)所引起细菌的致死率与药敏实变率明显高于波长较长的LD激光(808nm),即波长较短的Ar+激光的辐照导致细菌耐药性显著降低. 相似文献