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51.
Toru Ikegami Hideyuki Negishi Dai Kitamoto Keiji Sakaki Tomohiro Imura Masayoshi Okamoto Yasushi Idemoto Nobuyuki Koura Tsuneji Sano Kenji Haraya Hiroshi Yanagishita 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2005,80(4):381-387
In order to produce highly concentrated bioethanol by pervaporation using an ethanol‐permselective silicalite membrane, techniques to suppress adsorption of succinic acid, which is a chief by‐product of ethanol fermentation and causes the deterioration in pervaporation performance, onto the silicalite crystals was investigated. The amount adsorbed increased as the pH of the aqueous succinic acid solution decreased. The pervaporation performance also decreased with decreasing pH when the ternary mixtures of ethanol/water/succinic acid were separated. Using silicalite membranes individually coated with two types of silicone rubber, pervaporation performance was significantly improved in the pH range of 5 to 7, when compared with that of non‐coated silicalite membranes in ternary mixtures of ethanol/water/succinic acid. Moreover, when using a silicalite membrane double‐coated with the two types of silicone rubber, pervaporation performance was stabilized at lower pH values. In the separation of bioethanol by pervaporation using the double‐coated silicalite membrane, removal of accumulated substances having an ultraviolet absorption maximum at approximately 260 nm from the fermentation broth proved to be vital for efficient pervaporation. Copyright © 2005 Society of Chemical Industry 相似文献
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53.
研究了铸造WCP/Ni基合金梯度复合涂层组织与摩擦磨损特性。结果表明,梯度复合涂层与基材实现了良好的冶金结合,涂层内有γ-Ni枝晶组织,γ-Ni+M23C 6共晶组织以及凝固结晶析出的M6C、M23C6、M7C3等块状或条状组织;随着铸造WCP体积分数的增加,复合涂层摩擦系数减小,耐磨性增加。19-4试样的耐磨性最高值为4.61,是基材的3倍以上。梯度涂层的磨损机理为磨粒磨损与粘着磨损的复合作用。 相似文献
54.
Lyashenko B. A. Soroka E. B. Rutkovskii A. V. Lipinskaya N. V. 《Strength of Materials》2002,34(4):402-406
The authors suggest that the dimensions of a discrete section of a coating should be chosen on the basis of calculation of the critical crack spacing in cohesion cracking. This approach allows for residual stresses in the coating. The reliability of the calculation method has been verified experimentally by direct measurement of the crack spacing. 相似文献
55.
东河塘至轮南输油管道,经过12年的运行,钢管外石油沥青玻璃布防腐层已严重老化甚至剥离。在不停输的情况下,对输油管道防腐层大修,特别像东—轮线输油管道,地处沙漠边缘、戈壁地带,没有成熟的施工经验可以借鉴。文章根据东—轮线输油管道防腐层大修的施工实践,详细介绍了长输管道不停输防腐层大修的施工工艺和质量保证措施。 相似文献
57.
Dario Pasini Luigi Garlaschelli Elza Bontempi Laura E. Depero 《Fullerenes, Nanotubes and Carbon Nanostructures》2007,15(5):367-378
The synthesis of a series of polymers and cyclopolymers bearing crown ethers of differing structure and affinities towards primary ammonium ions is discussed. These polymers have been tested in their efficiency to form structurally homogeneous thin films when blended with an amphiphilic C60 compound containing a primary ammonium ion functional group. The X-ray reflectivity characterization of the films revealed that the polymer bearing the crown ether with the least affinity for primary ammonium ions, but having the highest degree of polymerization, is the most effective in forming structurally homogeneous thin films. 相似文献
58.
59.
A. J. Slifka B. J. Filla 《Journal of research of the National Institute of Standards and Technology》2003,108(2):147-150
An industrial ceramic thermal-barrier coating designated PWA 266, processed by electron-beam physical-vapor deposition, was measured using a steady-state thermal conductivity technique. The thermal conductivity of the mass fraction 7 % yttria-stabilized zirconia coating was measured from 100 °C to 900 °C. Measurements on three thicknesses of coatings, 170 μm, 350 μm, and 510 μm resulted in thermal conductivity in the range from 1.5 W/(m·K) to 1.7 W/(m·K) with a combined relative standard uncertainty of 20 %. The thermal conductivity is not significantly dependent on temperature. 相似文献
60.
Ideally selective diisocyanate building blocks: New perspectives for dendrimers and coating binders 总被引:3,自引:0,他引:3
R. A. T. M. van Benthem A. Hofland H. W. I. Peerlings E. W. Meijer 《Progress in Organic Coatings》2003,48(2-4):164-176
Using zirconium (IV) salts as catalyst, the reaction of a diisocyanate carrying one tertiary and one primary isocyanate group (IMCI, DIMP) with alcohols can be conducted with complete regioselectivity. This unique selectivity enables the use of a diisocyanate building block in unprecedented ways. Incomplete regioselectivity of diisocyanates, as commonly encountered in currently commercial ones like IPDI and TDI, inevitably leads to polydisperse products in reaction with polyols. The ultimate monodisperse polymer architecture, dendrimers, can now be made in a facile, straightforward manner using IMCI as the ideal diisocyanate building block. Coating applications of this unique building block are not restricted to these perfect branching polymers, but also include isocyanate-functional coating resins. Without any increase in polydispersity, a hydroxyl-functional polyester can be end-capped with the IMCI diisocyanate and subsequently serve as a crosslinker in powder coatings. 相似文献