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721.
DONG Heng-Ping YAN Shi-Lei 《理论物理通讯》2008,49(2):511-515
Within the effective field theory (EFT), staggered quadrupolar phase and bicritical point of spin-1 bond and anisotropy dilution Blume-Emery-Griffiths model is studied on simple cubic lattice in the restricted range of biquadratic interaction and bilinear interaction ratio α≤-1. The phase diagrams present a line of staggered
quadrupolar-paramagnetic (SQ-P) phase and a line of ferromagnetic-paramagnetic (F-P) phase, separated by a bicritical point (BCP). A large negative ratio and two different dilution factors magnify the
range of the SQ phase and reduce range of ferromagnetic phase in T-α
or T-D plane. These parameters can assist the reentrant behavior of
the SQ-P line and suppress that of the F-P line. The influence of bond
dilution on the BCP is dissimilar to that of anisotropy dilution. There is a
degenerate pattern at ground state in T-D plane. Some results obtained
by the pure BEG model is in qualitative agreement with the results of Monte
Carlo simulations. 相似文献
722.
Qiu Li-Hua Zhou Wei-Qun Shen Zong-Xuan Zhang Ya-Wen 《Journal of chemical crystallography》2007,37(3):181-186
The title compound (C23H30N2O), a chiral ligand, has been successfully synthesized from a natural proline. FTIR spectrum has been discussed. DFT (B3LYP)
method has been used to determine the structure. With the basis set of the 6–311G* quality, the DFT calculated bond parameters and harmonic vibrations are predicted in very good agreement with experimental
data.
相似文献
Zhou Wei-QunEmail: |
723.
724.
《Electrochemistry communications》2000,2(6):382-385
Synthesis and cyclic voltammetry data of novel copolymers containing difluorenyl-ethylene units in the conjugated backbone are reported. 相似文献
725.
本文引进单位圆盘内亚纯p叶凸函数的新子类C(n,p,A,B)和K(n,p,A,B),分别研究其包含关系与类中函数的积分变换等性质. 相似文献
726.
A new route for the synthesis of coordination compounds with dimethyl sulfide ligand is reported; the prepared compound is a novel 2-D framework with a 1-D right-handed and left-handed helical structure, which is unique in the sense that the fundamental units are unusual Cu4I4 clusters. 相似文献
727.
The electronic transport properties of single-walled ZnO nanotubes with different chiralities are investigated by nonequilibrium Green's function combined with density functional theory. In this paper we consider three representative ZnO nanotubes, namely (3, 3) armchair, (5, 0) zigzag, and (4, 2) chiral, with a similar diameter of about 5.4 Å. Short nanotubes exhibit good conductance behavior. As the tube length increases, the conductance decreases at low bias and the nanotubes indicate semiconducting behavior. The current-voltage characteristics of the nanotubes longer than 3 nm depend weakly on the length of the tubes. The armchair and chiral ZnO nanotubes with the same length and diameter have almost overlapped current-voltage curves. The electron transport behaviors are analyzed in terms of the transmission spectra, density of states and charge population of these nanotubes. The results indicate that the resonant peaks above the Fermi level are responsible for electric currents. However, the zigzag ZnO nanotubes exhibit asymmetric current-voltage curves attributed to the built-in polarization field and give larger current than the armchair and chiral nanotubes at the same bias. The features explored here strongly suggest that the ZnO nanotubes are stable, flexible structures, which are valuable in Nano-Electromechanical System. 相似文献
728.
Effect of driving frequency on the structure of silicon grown on Ag(111) films by very-high-frequency magnetron sputtering 下载免费PDF全文
The effect of driving frequency on the structure of silicon grown on Ag(111) film is investigated, which was prepared by using the very-high-frequency(VHF)(40.68 MHz and 60 MHz) magnetron sputtering. The energy and flux density of the ions impinging on the substrate are also analyzed. It is found that for the 60-MHz VHF magnetron sputtering, the surface of silicon on Ag(111) film exhibits a small cone structure, similar to that of Ag(111) film substrate, indicating a better microstructure continuity. However, for the 40.68-MHz VHF magnetron sputtering, the surface of silicon on Ag(111) film shows a hybrid structure of hollowed-cones and hollowed-particles, which is completely different from that of Ag(111)film. The change of silicon structure is closely related to the differences in the ion energy and flux density controlled by the driving frequency of sputtering. 相似文献
729.
Initial growth and microstructure feature of Ag films prepared by very-high-frequency magnetron sputtering 下载免费PDF全文
The initial growth and microstructure feature of Ag films formation were investigated, which were prepared by using the very-high-frequency(VHF)(60 MHz) magnetron sputtering. Because of the moderate energy and very low flux density of ions impinging on the substrate, the evolutions of initial growth for Ag films formation were well controlled by varying the sputtering power. It was found that the initial growth of Ag films followed the island(Volmer—Weber, VW) growth mode, but before the island nucleation, the adsorption of Ag nanoparticles and the formation of Ag clusters dominated the growth. Therefore, the whole initial stages of Ag films formation included the adsorption of nanoparticles, the formation of clusters, the nucleation by the nanoparticles and clusters simultaneously, the islands formation, and the coalescence of islands. 相似文献
730.
采用喷雾干燥法制备了xLi[Li1/3Mn2/3]O2-(1-x)LiNi5/12Mn5/12Co2/12O2(0≤x≤0.8)系列富锂层状固溶体正极材料, 并通过X射线衍射(XRD)、高分辨透射电子显微镜(HRTEM)、X射线光电子能谱(XPS)、电化学阻抗测试(EIS)以及充放电测试等多种手段研究了样品组分中Li2MnO3 含量变化对材料结构及电化学性能的影响.研究发现, 材料的微观结构随着Li2MnO3含量的增加而逐渐发生转变.当x≤0.2时, 样品的微观结构与其母体材料LiNi5/12Mn5/12Co2/12O2相似; 而当x≥0.4时, 样品的微观结构与Li2MnO3有很高的相似性.当x=0.3时, 材料表现出两相共存的特征.HRTEM结果显示, 随着Li2MnO3含量的增加, 样品中过渡金属原子的排列逐渐由长程有序转变为长程无序而短程有序, 并且在高Li2MnO3含量的样品中观察到了金属阳离子混排的现象.充放电测试结果表明, 当x≤0.6时, 材料的放电比容量随着x的增加而增加; 当x>0.6时, 其放电比容量则随着x的增加而下降; 当x=0.6时, 放电比容量最高, 室温及高温(50℃)下分别为260 和304 mA·h/g.EIS研究结果表明, 这种微观结构上由有序向无序的转变会导致材料电荷转移阻抗的增加, 进而影响材料的电化学性能. 相似文献