材料期刊网

制备条件对用于甘油蒸汽重整反应Ni基催化剂性能的影响

M. A. Goula , N. D. Charisiou , K. N. Papageridis , G. Siakavelas

催化学报 doi:10.1016/S1872-2067(16)62518-4

研究了制备参数对用于甘油蒸汽重整反应的Ni基催化剂性能的影响。采用过量浸渍法、等体积浸渍法和改进的平衡沉积过滤(EDF)法制备了一系列Al2O3负载的8 wt%Ni催化剂,运用X射线衍射(XRD)、电感耦合等离子体光谱仪、N2吸附-脱附、扫描电镜(SEM)、透射电镜和H2程序升温还原(TPR)表征了催化剂的表面和体相性质；采用CHN分析仪和SEM表征了使用后催化剂以测定其表面沉积的碳及其形貌。结果表明,制备方法对所制催化剂的织构、结构和表面性质影响很大,导致氧化铝表面Ni物种的分散和种类的不同。即使XRD和TPR结果证实形成了铝酸镍晶相,但Ni/Al-edf催化剂中β峰的贡献大于其它两个催化剂的,表明在这种情况下铝酸镍更容易还原。在550 oC以上CO2选择性增加和CO选择性不变,表明Ni/Al-wet和Ni/Al-edf催化剂可成功催化水汽变换反应。另外,650oC时Ni/Al-edf催化剂上甘油生成气相产物的转化率、氢气产率以及烯丙醇、乙醛和乙酸选择性最高,且它在所有催化剂中的积炭量也最低。将催化剂结构性质、分散度和还原性与其催化性能相关联,发现EDF法制得的催化剂比表面积和活性相分散度更高,更易被还原,因而其活性和生成H2的选择性更高,也更抗积碳。

关键词: 甘油 , 氢气 , 蒸汽重整 , 负载型镍催化剂 , 催化剂制备

Exact solutions of nonlinear dispersive K(m, n) model with variable coefficients

Applied Mathematics and Computation

The variable-coefficient Korteweg-de Vries (KdV) equation with additional terms contributed from the inhomogeneity in the axial direction and the strong transverse confinement of the condense was presented to describe the dynamics of nonlinear excitations in trapped quasi-one-dimensional Bose-Einstein condensates with repulsive atom-atom interactions. To understand the role of nonlinear dispersion in this variable-coefficient model, we introduce and study a new variable-coefficient KdV with nonlinear dispersion (called vc-K(m, n) equation). With the aid of symbolic computation, we obtain its compacton-like solutions and solitary pattern-like solutions. Moreover, we also present some conservation laws for both vc-K(+)(n, n) equation and vc-K (n, n) equation. (C) 2011 Elsevier Inc. All rights reserved.

关键词: Vc-K(m, n) equation;Nnonlinear dispersion;Symbolic analysis;Compacton-like solutions;Solitary pattern-like solutions;Conservation;laws;compacton solutions;solitary patterns;equations;solitons

SNOEK-Ke-K■STER PEAK OF INTERNAL FRICTION IN Fe-P-N ALLOYS

Y.Y.Che , G. Y.Zeng , Y. C. Xu and J. W , Ji(College of Science , Northeastern University , Shenyang 110006 , China)

金属学报(英文版)

The internal friction and precipitate phases of the deformed Fe-P-N alloys have been investigated. It has been found that the ratio of depends on the content of P and the relation holds if the content of N is lower than 30wt.ppm and the content of P is lower than 640wt.ppm. It shows that the intercept K2 is related to the presence of the atomic pairs and clusters of P in the alloy matrix.

关键词: internal friction , null

Amorphous B-C-N semiconductor

Journal of Applied Physics

Amorphous BC2N powders were prepared by mechanical milling with hexagonal boron nitride and graphite as starting materials. A bulk amorphous BC2N compound was produced by sintering the as-milled amorphous BC2N powders in a vacuum of 10(-5) Torr at a temperature of 1470 K. The conductivity measurement for the bulk amorphous BC2N compound showed that it behaves as a semiconductor with band gap energy of 0.11 eV for temperatures ranging from room temperature to 560 K and a semimetal for temperatures between 560 and 740 K. The mechanism of the formation of the amorphous BC2N powders is discussed. (C) 1998 American Institute of Physics.

关键词: bc2n

K型和N型热电偶的性能对比

张祖力 , 王华

功能材料

N型热电偶是为了提高K型热电偶性能而研制出的一种综合性能更好、更稳定的热电偶,它在K型热电偶的基础上对其抗氧化性能、辐照嬗变、有序无序转变和磁性转变等方面进行了改进,从而提高了热电稳定性能及抗高温氧化性能.

关键词: N型热电偶 , K型热电偶 , 热电稳定性

N&K多功能薄膜分析仪在OLED失效分析中的应用

陈柳 , 俞宏坤 , 曾韡 , 彭雅芳

液晶与显示 doi:10.3969/j.issn.1007-2780.2010.04.028

使用N&K多功能薄膜分析仪对OLED的结构进行分析,对比了不同时间室温老化实验样品的反射率波谱.对反射率进行计算拟合,得到OLED的多层膜结构信息.对相同室温老化实验条件下的完好器件和失效器件的结构进行了对比,发现对于结构为ITO/NPB/Alq3/LiF/Al的器件,主要是Alq3和LiF层发生变化引起器件失效.由此也证明使用N&K多功能薄膜分析仪是OLED失效分析的有效手段.

关键词: 有机电致发光器件 , N&K多功能薄膜分析仪 , 失效分析

溶胶-凝胶法制备K-N共掺ZnO 薄膜的结构及光学特性

张振兴 , 张海军 , 廖梦舟 , 周华 , 谢二庆 , 潘孝军

功能材料 doi:10.3969/j.issn.1001-9731.2013.22.020

采用溶胶-凝胶法在 Si(100)衬底上生长了K与N共掺的ZnO 薄膜，并用 X射线衍射仪、扫描电子显微镜、荧光分光光度计、紫外-可见分光光度计对ZnO 薄膜样品的结构和光学特性进行了研究。结果表明，溶胶-凝胶法制备的 ZnO 薄膜为六方纤锌矿结构。随着K掺杂浓度的增大，薄膜的结晶性变好，组成薄膜的颗粒变大，并表现出c 轴择优生长特性，同时掺杂导致的氧空位缺陷也在增加，使得绿光发射增强，薄膜的光学带隙先增后减。

关键词: ZnO 薄膜 , K-N 共掺杂 , 光学带隙 , 光致发光谱 , 溶胶-凝胶法

Effect of pre-oxidation on the corrosion behavior of Fe-40Al sheet in a N-2-11.2O(2)-7.5CO(2)-500 ppm SO2 atmosphere at 1273 K

Intermetallics

A 200 mum thick Fe-40Al sheet, produced by powder metallurgy and hot extruding, was pie-oxidized at 1373 K in air for different times and then the pre-oxidized specimens were corroded at 1273 K for up to 360 ks in a N-2-11.2 vol.% O-2-7.4 vol.%CO2-500 ppm SO2 atmosphere. The pre-oxidation followed a parabolic rate law, forming continuous, adherent alpha-Al2O3 oxide scales, accompanied by the formation of valley-like flaws. The valley-like flaws originate from the inclusion of additives in the alloy substrate. The inclusion of additives as alpha-Al2O3 in the Fe-40Al sheet leads to some local exfoliation of the oxide scale in the SO2 containing atmosphere. The Fe-40Al pre-oxidized for longer than 14.4 ks showed very good corrosion resistance in the N-2-11.2 vol.% O-2-7.4 vol.% CO2-500 ppm SO2 atmosphere, and there is little exfoliation of the oxide scale after 360 ks oxidation at 1273 K. (C) 2003 Published by Elsevier Science Ltd.

关键词: iron aluminides (based on FeAl);corrosion;iron aluminides;hf additions;oxide scales;o-18 tracer;alloys;preoxidation;sulfidation;sulfur;ods

Ga、K双掺杂对N型Bi2Te2.7Se0.3材料热电性能的影响

段兴凯 , 胡孔刚 , 丁时锋 , 满达虎 , 林伟明 , 金海霞

稀有金属材料与工程

采用真空熔炼及热压方法制备了Ga和K双掺杂N型Bi2Te2.7Se0.3热电材料.XRD分析结果表明,Ga和K已经完全固溶到Bi2Te2.7Se0.3晶体结构中,形成了单相固溶体合金.SEM分析表明,材料组织致密且有层状结构特征.通过Ga和K部分替代Bi,在300～500 K的大部分温度范围内,Ga和K双掺杂对提高Bi2Te2.7Se0.3的Seebeck系数产生了积极的作用,同时双掺杂样品的电导率也得到明显的提高.Ga和K双掺杂样品的热导率都大于未掺杂的Bi2T2.7Se0.3,Ga0.02Bi1.94K0.04Te2.7 Se0.3合金在500 K获得ZT最大值为1.05.

关键词: 双掺杂 , 热压 , 显微结构 , 热电性能

La对Fe-P-N合金Snoek-Ke-K■ster峰的影响

戢景文 , 魏全金 , 张国福 , 赖祖涵 , 陈廷国

金属学报

研究了F? P—N合金加?对Snoek—Ke-Koster(SKK)峰的影响,发现与合金含La,P的原子浓度比(C_(La)/C_p)有关:对于C_(La)/C_p较大(例如4.56和2.6)的合金,La有明显增强SKK阻?效应:对于C_(La)/C_p=0.27的P过饱和合金,La对SKK峰无明显影响。

关键词: 内耗 , Snoek-Ke-Koster peak , Fe-P-La-N alloy