基于高频飞秒瞬态反射技术的Bi薄膜的相干声子振荡

以飞秒振荡器作为激发光源,使用单色泵浦-探测技术观测Bi薄膜的超快动力学和相干声子振荡。在不同泵浦能量(0.28~4.57 m J/cm2)下,可以观测到明显的相干声子振荡现象,这主要是由A1g模式的振动引的。在考虑啁啾系数的条件下使用经典阻尼振荡函数对测试结果进行拟合。实验和理论拟合结果显示,随着泵浦能量的增加,其振荡强度明显增强,经过快速傅里叶变换后,A1g模式的频率值从2.98 THz变化到2.92 THz,明显不对称,啁啾常数发生变化,A1g模式有软化趋势,这与低频高能脉冲激发下得出的结论一致。     

短波长纳米ZnO／MgO准一维光电材料的晶格振动及电子-声子相互作用耦合特性

基于介电连续模型与Loudon单轴晶体模型,研究了短波长纤锌矿氧化锌（ZnO）材料与闪锌矿氧化镁（MgO）晶体构成的准一维ZnO／MgO纳米线结构的晶格振动特性及相关的电子-声子相互作用耦合函数。结果表明,在准一维ZnO／MgO圆柱形纳米线体系中存在两种极化光学声子模,即界面模与准受限模。均给出了结构中的这两种声子模的声子态及其色散方程。而且,也导出了基于场的量子化方案,体系解析的电子一声子相互作用耦合函数。结果对进一步研究准一维ZnO／MgO纳米线体系的极化子效应对结构的光电平特,陛的影响具有鼋耍囊义     

湖北省居民消费水平与GDP的误差修正模型研究

选取湖北省居民消费水平和GDP这两个重要的经济变量做协整分析,研究表明在所选取的样本区间内(1985年~2003年),两列时间序列之间存在协整关系,进而建立了误差修正模型,并且得到了较好的拟合结果,随后验证了两变量间具有双向G ranger因果关系。     

A new linearly-combined bi-exponential model for kinetic analysis of the isometric relaxation process of <Emphasis Type="Italic">Bufo gastrocnemius</Emphasis> under electric stimulation in vitro

There was a slow-relaxing tail of skeletal muscles in vitro upon the inhibition of Ca^2＋-pump by cyclopiazonic acid （CPA）. Herein, a new linearly-combined bi-exponential model to resolve this slow-relaxing tail from the fast-relaxing phase was investigated for kinetic analysis of the isometric relaxation process of Bufo gastrocnemius in vitro, in comparison to the single exponential model and the classical bi-exponential model. During repetitive stimulations at a 2-s interval by square pulses of a 2-ms duration at 12 V direct currency （DC）, the isometric tension of Bufo gastrocnemius was recorded at 100 Hz. The relaxation curve with tensions falling from 90% of the peak to the 15th datum before next stimulation was analyzed by three exponential models using a program in MATLAB 6.5. Both the goodness of fit and the distribution of the residuals for the best fitting supported the comparable validity of this new bi-exponential model for kinetic analysis of the relaxation process of the control muscles. After CPA treatment, however, this new bi-exponential model showed an obvious statistical superiority for kinetic analysis of the muscle relaxation process, and it gave the estimated rest tension consistent to that by experimentation, whereas both the classical bi-exponential model and the single exponential model gave biased rest tensions. Moreover, after the treatment of muscles by CPA, both the single exponential model and the classical bi-exponential model yielded lowered relaxation rates, nevertheless, this new bi-exponential model had relaxation rates of negligible changes except much higher rest tensions. These results suggest that this novel linearly-combined bi-exponential model is desirable for kinetic analysis of the relaxation process of muscles with altered Ca2^＋-pumping activity.