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991.
Darius H. Torchinsky David Hsieh J.L. Luo Nuh Gedik 《Journal of Physics and Chemistry of Solids》2011,72(5):519-522
We report on band-dependent quasiparticle dynamics in the hole-doped Ba-122 pnictides measured by ultrafast pump-probe spectroscopy. In the superconducting state of the optimal and over hole-doped samples, we observe two distinct relaxation processes: a fast component whose decay rate increases linearly with excitation density and a slow component whose relaxation is independent of excitation strength. We argue that these two components reflect the recombination of quasiparticles in the two hole bands through intraband and interband processes. We also find that the thermal recombination rate of quasiparticles increases quadratically with temperature in all samples. The temperature and excitation density dependence of the decays indicates fully gapped hole bands and nodal or very anisotropic electron bands. 相似文献
992.
Du‐Qiang Luo Hui‐Ying Deng Xiao‐Long Yang Bao‐Zhong Shi Jing‐Ze Zhang 《Helvetica chimica acta》2011,94(6):1041-1047
Three new triterpenoid derivatives, named (15α)‐15‐hydroxysoyasapogenol B ( 1 ), (7β,15α)‐7,15‐dihydroxysoyasapogenol B ( 2 ), and (7β)‐7,29‐dihydroxysoyasapogenol B ( 3 ), were isolated from cultures of the plant endophytic fungus Pestalotiopsis clavispora. Their structures and relative configurations were elucidated by extensive spectroscopic analysis and X‐ray crystallography. 相似文献
993.
994.
Linwang Yuan Zhaoyuan Yu Wen Luo Lin Yi Guonian Lü 《Advances in Applied Clifford Algebras》2013,23(2):497-518
Traditional Euclidean geometry-based Geographical Information System (GIS) is not multidimensional unification with weak ability to object expression and analysis of high dimensions. Geometric algebra (GA) can connect different geometric and algebra systems, and provide rigorous and elegant foundation for expression, modeling and analysis in GIS. This paper proposes the implementation methods for system construction and key components of multidimension-unified GIS. Based on such properties as multidimension-unified and coordinate-free of GA, data models, data indexes, and data analysis algorithms for multidimensional vector data, raster and vector field data are developed. This study indicates that GA provides a new mathematical tool for the development of GIS characterized as multidimension-unified expression and computation. For the development of geographical analysis methods, it can represent multidimensional spatio-temporal changes conveniently. 相似文献
995.
In this paper, a formula of the spectrum of semi-Cayley graphs over finite abelian groups will be given. In particular, the spectrum of Cayley graphs over dihedral groups and dicyclic groups will be given, respectively. 相似文献
996.
Summary An on-line flow injection-solid-phase extraction-capillary zone electrophoresis (FI-SPE-CZE) method has been developed for
determination of cimetidine in human plasma. Sodium dodecylsulfate (SDS) was used as dynamic chemical modifier for elimination
of capillary contamination by biological macromolecules. FI on-line preconcentration and cleaning of the analyte by means
of a C18 microcolumn was performed automatically and CZE separation was performed consecutively without interruption of the applied
voltage and between-run-washing of the capillary. A detection limit of 8 μgL−1 (3×σ) was achieved at a sample throughput of 12h−1. The approach was successfully used for a pharmacokinetic study of cimetidine. 相似文献
997.
In this article, based on Lyapunov–Krasovskii functional method and stochastic analysis theory, we obtain some new criteria ensuring mean square stability of trivial solution of a class of impulsive stochastic differential equations with delays. As an application, a class of stochastic impulsive neural network with delays has been discussed. One illustrative example has been provided to show the effectiveness of our results. 相似文献
998.
Broadening-independent demodulation for wavelength modulation spectroscopy based on even-order harmonics 总被引:1,自引:0,他引:1
The line broadening of gas absorption spectrum is a significant but unknown factor in traditional demodulation of wavelength modulation spectroscopy, which is a kind of tunable diode laser absorption spectroscopy in weak absorption cases. In this paper, another signal demodulation method based on some simple algebraic operations with the amplitudes of the zero-, second-, and fourth-order harmonics was proposed. With this method the effect of spectrum broadening could be selfeliminated. That makes the amplitude of the demodulated signal is irrelevant to the broadening, and enables the direct and fast measurement without complex simulations and curve fittings in traditional method. 相似文献
999.
对用稳定图识别真假模态的一点改进 总被引:1,自引:0,他引:1
利用单位样值响应矩阵和自由响应的特征值分解形式中的特征值前的系数矩阵的范数作稳定判据,结合稳定图识别真假模态,计算表明,本方法具有较好的分解能力。 相似文献
1000.
Xizhang Luo Jiancong Luo Jiayin Qin 《Journal of Infrared, Millimeter and Terahertz Waves》1999,20(6):1085-1090
The effect of buffer gas N2 on miniature optically pumped NH3 submillimeter wave (SMMW) cavity laser emission at 67.2μm was studied theoretically and experimentally. It has been found that: 1. N2 had a positive effect on laser output of 67.2μm, 2. sharp absorption in laser spectrum under certain gases mixture pressure corresponded to the threshold of 'bottleneck effect”. 相似文献