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
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null
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
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null
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null
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null
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null
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
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
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:
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
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null
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null
