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排序方式: 共有8785条查询结果,搜索用时 171 毫秒
31.
J. Weise Dr.‐Ing. O. Yezerska M. Busse M. Haesche V. Zanetti‐Bueckmann M. Schmitt 《Materialwissenschaft und Werkstofftechnik》2007,38(11):901-906
Micro‐porous syntactic foams were produced by means of integration of glass bubbles into aluminium and zinc matrices. Preforms of glass bubbles were pressure infiltrated with the alloys AlSi9Cu9 ans ZnAl4Cu using squeeze casting. The preforms were sintered thermically without the use of bonding agents. Using the combination of different sintering steps syntactic foams with locally different densities could be produced. The mechanical properties of the foams were tested indicating a high compression strength of the foams and a very good compression energy absorption. Furthermore, corrosion behaviour and behaviour at higher temperatures were investigated. 相似文献
32.
Hari B. Goyal M. O. Garg K. R. Rao R. D. Srivastava 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1985,35(2):49-56
The kinetics of the reaction of acetic acid and acetylene over zinc acetate-activated carbon catalyst was investigated over a wide range of process variables in a pilot reactor. Although various catalytic reaction mechanisms were postulated, the rate of reaction was most satisfactorily correlated by a mechanism of surface reaction between charged adsorbed acetic acid and acetylene, which assumes that the rate controlling step was the irreversible charged adsorption of acetylene and acetic acid. 相似文献
33.
低碳钢热浸Zn-0.15%Ni合金镀层组织及第二相粒子 总被引:1,自引:0,他引:1
采用热浸Zn-Ni合金镀锌方法,在含0.03%-0.36%Si的低碳钢上获得Zn-Ni合金镀层,研究了镀浴中Ni含量和钢中Si含量对镀层中δ相和ζ相生长速率的影响,以及Zn-Ni合金镀层η相中的第二相粒子即Zn-Fe-Ni三元化合物Γ2相粒子的形成和长大过程,结果表明,在Zn-0.15%Ni镀浴中,含硅0.03%-0.215%钢镀层的ζ相明显受到抑制,δ相厚度略有增加,Γ2相粒子的形成和长大过程包括ζ相的溶解,Γ2相的形核和成比例吸收铁,镍而长大。 相似文献
34.
镀锌层银盐黑色钝化工艺 总被引:1,自引:0,他引:1
在含AgNO30.5~1g/L,CrO35~10g/L,H2SO40.5~1ml/L,光泽控制剂10~25mL/L的钝化液中处理镀锌层,可获得结合力良好、光亮的黑色钝化膜。 相似文献
35.
换热器防腐蚀方法介绍 总被引:3,自引:0,他引:3
文章对换热器的不同保护方法进行了介绍 ,重点讨论了渗铝、渗锌两种方法。在室温~ 80℃自来水和 3.5 %NaCl水溶液中 ,与碳钢基体相比 ,渗铝层的电位发生了反转 ,因而在针孔部位会形成大阴极小阳极的局面 ,易发生点蚀 ;而在相同条件下渗锌层不出现上述点蚀现象 ,更适宜在换热器的应用 相似文献
36.
37.
研究了用于催化卤素置换反应后的氯化锌催化剂的再生方法。其过程包括:用石灰乳中和,沉淀出氢氧化锌,用氢氧化锌中和氯化锌废液至pH值为5—6,通入氯气氧化氯化锌废液中的有机物,蒸发至必要的浓度。 相似文献
38.
Ruey-Shin Juang 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1992,54(1):75-80
The extraction of zinc from chloride solutions with tri-n-octylphosphine oxide (TOPO) dissolved in benzene has been thermodynamically studied based on the law of mass action. A model employing the simplified Pitzer equations for stoichiometric activity coefficient estimations is found to be effective for the explanation and prediction of the distribution data, and the thermodynamic extraction constant is determined as log Ket = 5.16 ± 0.11 at 20°C. 相似文献
39.
Fengqiu Tang Tetsuo Uchikoshi Yoshio Sakka 《Journal of the American Ceramic Society》2002,85(9):2161-2165
The rheological behavior and electrophoretic deposition (EPD) of ZnO nanopowder (nano-ZnO) in aqueous media have been described. A cationic polyelectrolyte (polyethylenimine, PEI) was used to disperse and modify the surfaces of the ZnO nanoparticles. The rheological properties of the ZnO aqueous suspension were investigated by measuring the viscosity versus the pH and amount of dispersant. The EPD processing was conducted via cathodic electrodeposition, using stable suspensions with low viscosity, and the depositional behavior was investigated. Bubble-free nano-ZnO deposits with uniform microstructures were successfully obtained, which was an indication of good sintering behavior. 相似文献
40.
The effects of soaking of whole, dehulled and ground millet and soybean seeds on phytate degradation and Phy/Fe and Phy/Zn molar ratios 总被引:1,自引:0,他引:1
Isabelle Lestienne Claire Mouquet-Rivier Christèle Icard-Vernière Isabelle Rochette & Serge Trèche 《International Journal of Food Science & Technology》2005,40(4):391-399
The degradation and leaching of phytates, phytase activity and iron and zinc concentrations have been studied after soaking of whole seeds, dehulled seeds and flours of millet and soybean, in order to investigate the efficiency of soaking on reducing Phy/Fe and Phy/Zn molar ratios. When using millet grains, dehulling and milling before soaking facilitated the leaching of phytates and phytases in the aqueous medium and hence phytate degradation. Dehulling of soybean seeds led to a marked increase in phytate content, whereas milling favoured reactions between phytases and phytates. The Phy/Fe and Phy/Zn molar ratios decreased only slightly during soaking. The highest decreases for millet were obtained after soaking of flour for 8 h (Phy/Fe: 10.8–7.7 and Phy/Zn: 20.3–15.1), and after soaking of whole seeds for 24 h for soybean (Phy/Fe: 10.4–9.4 and Phy/Zn: 23.8–19.1). Cooking of flours with water used for soaking did not increase phytate degradation. 相似文献