材料期刊网

固体氧化物电化学装置用高温 SiO2-Al2O3-BaO-MgO 和SiO2-Al2O3-ZrO2-CaO-Na2O 玻璃陶瓷密封剂

S. QI , N. M. POROTNIKOVA , M. V. ANANYEV , A. V. KUZMIN , V. A. EREMIN , A. A. PANKRATOV , N. G. MOLCHANOVA , O. G. REZNITSKIKH , A. S. FARLENKOV , E. G. VOVKOTRUB , Yu. P. ZAIKOV

中国有色金属学报(英文版) doi:10.1016/S1003-6326(16)64421-7

制备了在燃料电池中作为密封剂使用的操作温度可达700~900°C 的 SiO2?Al2O3?BaO?MgO 和SiO2?Al2O3?ZrO2?CaO?Na2O 系玻璃陶瓷。采用同步热分析和高温膨胀测量技术，对所研究的玻璃陶瓷的热性能和其与燃料电池用材料(YSZ 电解质，合金连接器 Crofer22APU,15Х25Т)的匹配性能进行研究。采用原子发射光谱对玻璃陶瓷的元素成分进行分析。结果表明，45%SiO2?15%Al2O3?25%BaO?15%MgO 陶瓷的线膨胀系数为10.0×10?6°C?1，60%SiO2?10%Al2O3?10%ZrO2?5%CaO?15%Na2O 的为9.5×10?6°C ?1。采用扫描电镜对 YSZ/玻璃陶瓷/Crofer22APU 的界面结构进行分析。SiO2?Al2O3?BaO?MgO 玻璃中的硅酸盐相发生了晶化，采用拉曼光谱和X 射线衍射对晶化产物进行了分析。与非晶玻璃相比，所研究的玻璃陶瓷作为电化学或氧传感器中的密封剂使用时具有更佳的性能指标。而 SiO2?Al2O3?ZrO2?CaO?Na2O 低温非晶陶瓷可以作为燃料电池中的密封剂使用。

关键词: 玻璃陶瓷密封剂 , 燃料电池 , YSZ , Crofer22APU , 硅酸镁

EFFECT OF PHOTOOXIDATION ON PHOTOLUMINESCENCE OF N, N'-DIPHENYL-N, N'-DI(M-TOLYL)-BENZIDINE AND RUBRENE CODOPED PMMA THIN FILMS

Y.B. Hou

金属学报(英文版)

In this paper, the PMMA films doped with N,N'-diphenyl-N,N'-di(m-tolyl)-benzidineand rubrene were fabricated by spin coating, and the effect of photooxidation onthe photoluminescence of the doped PMMA thin films was investigated. The resultsshowed that under the irradiation of 350nm UV light, N,N'-diphenyl-N,N'-di(m-tolyl)-benzidine can sensitized rubrene and results in the enhancement in the photooxrationof rubrene. The effect of photooxidation on the photoluminescence from rubrene w asmore obvious. Both lifetime measurement and in situ measurement of photolumines-cence showed that rubrene molecules exist in two chemical surroundings.

关键词: photoluminescence , null

ELECTRONIC STRUCTURES OF (CdSe)_n/(ZnSe)_m STRAINED-LAYER SUPERLATTICES

HL. Huang , J.H Xing , G.L. Liu and G.Y Zhang(Department of Electrouic Science and Engineering , Liaoning University Shenyang 110036 , China)(Department of Physics , Liaoning University Shenyang 110036 , China)(Shenyang Polytechnic University Shenyan 110023 , China)(Northeast Microelectronic Institute of Ministry of Electronic Industry Shenyang 110032 , China)

金属学报(英文版)

The electronic structures of (CdSe)n/(ZnSe)m strained-lager soperfattice (SLS) were investigated by the recursion method in the tight-bindiop opproximation. The total,local, and partial density of states were calculated for n=1, m=5.The total density of states (TDOS) for bulk CdSe, ZnSe and n=1, 3, m=1, 3, 5, for SLS were investigated.Fermi energy, the band gap, the valence of an atom, and the ionization potential and the electron affinity were discassed.

关键词: density of state , null , null , null , null

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

通过J/Ψ→N(N-)M衰变研究N*时的核子极点效应

沈彭年 , 梁伟红 , 邹冰松

原子核物理评论 doi:10.3969/j.issn.1007-4627.2004.02.009

研究了J/Ψ→ p(p-)π衰变过程中核子极点图的贡献,特别是由离壳效应带来的贡献.发现衰变宽度对形状因子是敏感的.在通过用J/Ψ→ p(p-)π衰变研究N*时,核子极点图作为背景道的贡献是非常重要的; 在通过J/Ψ→ p(p-)η和 p(p-)η研究N*时,核子极点图的贡献可忽略不计; 在通过J/Ψ→ p(p-)ω研究N*时,核子极点图有明显的贡献.

关键词: J/Ψ衰变 , 核子激发态

Inter-conversion of M(n+1)AX(n) phases in the Ti-Al-C system

Journal of the American Ceramic Society

It is demonstrated that the M(n+1)AX(n) phase Ti3AlC2 may be readily synthesized by sintering a stoichiometric mixture of the lower order MAX phase Ti2AlC mixed with a stoichiometric amount of TiC in the temperature range 1350 degrees-1450 degrees C. High-quality Ti3AlC2 was readily produced using sintering times in the range 2-5 h. In general, < 2% of unwanted or remnant phases were found to be present and in some samples none could be detected at all.

关键词: resolved neutron-diffraction;ti3sic2 synthesis;mechanical-properties;powder diffraction;crystal-chemistry;ti3alc2;temperature;ceramics;carbide;ti2alc

Equilibrium Geometries, Stabilities, and Electronic Properties of the Bimetallic M(2)-doped Au(n) (M = Ag, Cu; n=1-10) Clusters: Comparison with Pure Gold Clusters

Journal of Physical Chemistry A

The density functional method with relativistic effective core potential has been employed to investigate systematically the geometrical structures, relative stabilities, growth-pattern behaviors, and electronic properties of small bimetallic M(2)Au(n) (M = Ag, Cu; n = 1-10) and pure gold Au(n) (n <= 12) clusters. The optimized geometries reveal that M(2) substituted Au(n+2) clusters and one Au atom capped M(2)Au(n-1) structures are dominant growth patterns of the stable alloyed M(2)Au(n) clusters. The calculated averaged atomic binding energies, fragmentation energies, and the second-order difference of energies as a function of the cluster size exhibit a pronounced even odd alternation phenomenon. The analytic results exhibit that the planar structure Ag(2)Au(4) and Cu(2)Au(2) isomers are the most stable geometries of Ag(2)Au(n) and Cu(2)Au(n) clusters, respectively. In addition, the HOMO-LUMO gaps, charge transfers, chemical hardnesses and polarizabilities have been analyzed and compared further.

关键词: effective core potentials;transition-metal atoms;density-functional;theory;photoelectron-spectroscopy;molecular calculations;silver;clusters;fluorescence spectroscopy;polarizability;anions;adsorption

Ferromagnetic properties, electronic structure, and formation energy of Ga(0.9375)M(0.0625)N (M=vacancy, Ca) by first principles study

Journal of Applied Physics

Using the full potential linearized augmented plane wave method based on the spin density functional theory, we investigate the ferromagnetic properties, the electronic structure, and the formation energy of Ga(0.9375)M(0.0625)N (M=vacancy, Ca). The calculations indicate that both cases prefer ferromagnetic ground state. The magnetic moments mainly come from the N atoms surrounding the defect centers, which are different from the conventional diluted magnetic semiconductor. High formation energy for the Ga vacancy Suggests that the defect concentration is too low to result in the ferromagnetic GaN. The formation energy for the two substitutional (Ca(Ga),Ca(N)) and two interstitial sites (tetrahedral T, Ca(i-T) and octahedral O, Ca(i-O)) doped configurations indicates that Ca prefers the substitutional Ga in GaN. The defect concentrations for the Ga(0.9375)Ca(0.0625)N under thermal equilibrium N-rich and N-realistic growth conditions are also discussed, respectively. The calculations show that defect concentration under N-rich condition can readily reach 7%, while under N-realistic growth condition, the maximum defect concentration is as low as 1.71% when the growth temperature increases to 1100 K (melting point of GaN). These results suggest that it would be a little difficult to achieve ferromagnetic state for Ga(0.9375)Ca(0.0625)N using the chemical-equilibrium fabrication method, such as chemical precipitation. Using the same method as that for Cu-doped ZnO [L. H. Ye et al., Phys. Rev. B 73, 033203 (2006)], the transition temperature of Ga(0.9375)Ca(0.0625)N may be close to room temperature. (C) 2008 American Institute of Physics.

关键词: generalized gradient approximation;doped zno;gan;semiconductors;calcium;systems;origin

塑性和超塑性材料m-n-δ关系的简化表达式

连建设 , 张吉人

金属学报

以Hart的微分型本构关系为基础,本文推导出了一个既包含应变硬化效应(n)又包含应变速率敏感效应(m)的m-n-δ关系式δ=[1/(1-(1-α(0))~(1/m))]~m×e~n-1当n=0时,它吻合于Ghosh和Ayres的现代分析,当m=0时,吻合于Considère的经典分析.该公式的计算结果和实验结果一致.

关键词:

Precipitation Behavior of M2N in a High-Nitrogen Austenitic Stainless Steel During Isothermal Aging

F. Shi , L.J. Wang , W.F. Cui , C.M. Liu

金属学报(英文版)

The precipitation behavior of M2N and the microstructural evolution in a Cr-Mn austenitic stainless steel with a high nitrogen content of 0.43mass% during isothermal aging has been investigated using optical microscopy (OM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The aging treatments have led to the decomposition of nitrogen supersaturated austenitic matrix through discontinuous cellular precipitation. The precipitated cells comprise alternate lamellae of M2N precipitate and austenitic matrix. This kind of precipitate morphology is similar to that of pearlite. However, owing to the non-eutectoidic mechanism of the reaction, the growth characteristic of the cellular precipitates is different from that of pearlite in Fe-C binary alloys. M2N precipitate in the cell possesses a hexagonal crystal structure with the parameters a = 0.4752nm and c = 0.4429nm, and the orientation relationship between the M2N precipitates and austenite determined from the SADP is [0110]M2N∥ [101]γ，［2110］M2N∥ ［010］γ.

关键词: austenitic stainless steel , null , null