Chemical Constituents of Ligusticum sinensis Oliv.

The new phenylpropanoid diglycoside ligusinenoside A ( 1 ), and the two new 8,4′‐oxyneolignan(‘8‐O‐4′‐neolignan’) diglycosides ligusinenosides B ( 2 ) and C ( 3 ), together with nine known compounds, were isolated from the rhizomes of Ligusticum sinensis Oliv. The structures of 1 – 3 were elucidated on the basis of spectroscopic analyses.     

Separate Polarization Modes Synchronization and Synchronization Switches between Vertical-Cavity Surface-Emitting Lasers

For vertical-cavity surface-emitting lasers (VCSELs) with polarization-rotated feedback, there exist several synchronization types such as synchronizations between total powers and synchronizations between separate polarization modes. Based on the two-mode rate equations, we study and compare numerically the performances of different synchronization types. Our results show that three synchronization types exhibit good performances when their synchronization conditions are satisfied. They are the complete synchronization between total powers, complete synchronization between x-polarized modes, and generalized synchronization between x-polarized and y-polarized modes. The former two types are sensitive to the injection rate and spontaneous emission, while the third type is contrary. Synchronization type with the best performance may switch from one to another, with changing of injection rate and spontaneous emission factor.     

Monte Carlo方法研究低能电子束曝光沉积能分布规律

建立一个描述低能电子在多元多层介质中散射的物理模型,运用MonteCarlo方法模拟低能电子在靶体胶衬底中的复杂散射过程,在此基础上通过大量计算研究入射束能、胶层厚度、衬底材料等不同曝光条件对抗蚀剂沉积能密度分布的影响,获得沉积能分布规律:适量的低束能、薄胶层、低原子序数衬底可以使前散射电子对胶中沉积能密度分布的贡献增大、背散射电子的贡献减小,从而提高曝光分辨率. 关键词： 电子束曝光 MonteCarlo方法 低能电子散射 能量沉积     

Performance Analysis for Mobile Ad Hoc Network in Random Graph Models with Spatial Reuse

In this paper,we present a random graph model with spatial reuse for a mobile ad hoc network(MANET) based on the dynamic source routing protocol.Many important performance parameters of theMANET are obtained,such as the average flooding distance (AFD),the probability generating function of theflooding distance,and the probability of a flooding route to be symmetric.Compared with the random graphmodel without spatial reuse,this model is much more effective because it has a smaller value of AFD and alarger probability for finding a symmetric valid route.     

Dynamical Convergence Trajectory in Networks

It is well known that topology and dynamics are two major aspects to determine the function of a network. We study one of the dynamic properties of a network： trajectory convergence, i.e. how a system converges to its steady state. Using numerical and analytical methods, we show that in a logical-like dynamical model, the occurrence of convergent trajectory in a network depends mainly on the type of the fixed point and the ratio between activation and inhibition links. We analytically proof that this property is induced by the competition between two types of state transition structures in phase space： tree-like transition structure and star-like transition structure. We show that the biological networks, such as the cell cycle network in budding yeast, prefers the tree-like transition structures and suggest that this type of convergence trajectories may be universal.     

三量子位Heisenberg XX 链中杂质对纠缠的影响

研究了有杂质时三量子位Heisenberg-XX链中正常格点之间的热纠缠情况，给出了Concurrence的解析表达式.进一步的讨论发现，杂质对正常格点的热纠缠有着重要的影响，甚至能够改变纠缠在反铁磁区的特性.理论表明，可以通过调节温度和杂质参数来控制纠缠. 关键词： Heisenberg -XX链 热纠缠 杂质格点     

Writing Fiber Grating of Different Wavelength Using the Same Phase Mask

Chirped fiber grating was used in dispersion compensator. We tried to use the same phase mask to write fiber grating of different wavelength with two methods to reduce the price of the fiber grating.     

纳米流体介质导热机理初探

纳米流体导热行为具有许多奇异的特性，结合纳米流体的特点和微尺度传热学原理，研究了 热流在纳米颗粒内波动式及非限域的热传导特性、纳米颗粒在悬浮液内的布朗运动、颗粒- 液体界面上液膜层原子的有规则排列、以及纳米颗粒的团簇形成及移动等四方面因素对纳米 流体导热系数的影响. 关键词： 纳米流体 导热     

广义线性模型(六)

本讲座是广义线性模型这个题目的一个比较系统的介绍。主要分 3部分 :建模、统计分析与模型选择和诊断。写作时依据的主要参考资料是L .Fahrmeir等人的 :《MultivariateStatisticalModel ingBasedonGeneralizedLinearModles》。