Time-varying networks based on activation and deactivation mechanisms

A class of models for activity-driven networks is proposed in which nodes vary in two states: active and inactive.Only active nodes can receive links from others which represent instantaneous dynamical interactions. The evolution of the network couples the addition of new nodes and state transitions of old ones. The active group changes with activated nodes entering and deactivated ones leaving. A general differential equation framework is developed to study the degree distribution of nodes of integrated networks where four different schemes are formulated.     

RF and field measurements of the SSC-LINAC RFQ

The 53.667 MHz continuous-wave heavy ion RFQ has been designed and manufactured for the SSC-LINAC project.This four-rod RFQ accelerates ions with maximum mass to charge ratio of 7 from 3.728 keV/u to 143 keV/u.Measurements have been carried out to check the RF performance of the cavity and the quality of the electric field.The S11 of the power coupler is adjusted to better than-44 dB,and the Q0 of the cavity is 6440.The quality of the electric field is evaluated by the perturbation method.The measurement procedure and data analysis will be discussed in detail.The error due to gravity of the perturbation bead has been corrected by averaging the fields in different quadrants.As a result,the unflatness of the electric field is±2.5%,and the dipole field component distributes from 0%to 20%in different longitudinal positions,which indicates the asymmetry of the quadrupole field.The unflatness of the quadrupole field distribution represents a good agreement with the simulation results.High power RF test and beam commissioning of the RFQ are on schedule in early 2014.     

光子回声量子存储器中非均匀展宽频谱对存储效率的影响

本文提出了一个利用光子回声技术探究非均匀展宽频谱线形(如高斯、洛伦兹分布)对存储效率影响的简捷方法。我们发现当信号光脉冲的持续时间与介质频谱线宽的乘积远大于1时,可将分布函数的傅里叶变换近似成狄拉克函数,使得研究非均匀展宽频谱对存储效率的影响变得非常容易;通过计算发现不同线形分布达到最佳存储效率的光学深度有所不同,频谱线形趋于均匀时达到最优存储效率的存储介质光学深度最小。该研究对实验上实现最优化光量子态存储具有指导意义。     

无箔二极管强流电子束空间密度分布初步研究

通过在强磁场条件下,利用环形刀口石墨阴极(刀口尺寸38~39mm)开展电子束轰击收集极内表面铜箔和垂直轰击金属靶片实验,对无箔二极管中电子束的空间密度分布进行了初步研究,并对其产生原因进行了分析。研究结果表明,电子束径向分布在37.2~40.2mm,存在密度较高区域(38.8~39.4mm)和密度最大值点(39.2mm),且均偏向于阴极外侧。无箔二极管环形阴极爆炸发射产生电子束的径向密度分布可用偏态分布近似。     

Evolution analysis of the states of the EZ model

Based on suitable choice of states, this paper studies the stability of the equilibrium state of the EZ model by regarding the evolution of the EZ model as a Markov chain and by showing that the Markov chain is ergodic. The Markov analysis is applied to the EZ model with small number of agents, the exact equilibrium state for N = 5 and numerical results for N=18 are obtained.     

星-地量子密钥分发链路持续时间分析与仿真

链路持续时间是影响卫星量子密钥分发量子比特率的重要参数.文章分析了影响星-地单光子和纠缠光子量子密钥分发链路持续时间的若干因素,并且进行了数值仿真研究.结果表明,随着轨道高度的增加或者地面最小通信仰角的减小,单光子和纠缠光子链路的持续时间有较大的改善;单光子链路时地面站同卫星星下点轨迹间的距离和纠缠光子链路时两地面站之间的距离也均是影响链路持续时间的重要参数;纠缠光子链路持续时间的影响因素较单光子链路更为复杂,其最终决定于卫星星下点轨迹同两地面站之间的位置关系.     

AC susceptibility of magnetic markers in suspension for liquid phase immunoassay

AC susceptibility of magnetic markers in solution was studied for biosensor applications. First, frequency dependence of the susceptibility was measured, and size distribution of the markers was estimated by analyzing the experimental result with the so-called singular value decomposition (SVD) method. The size distribution estimated with the magnetic measurement agreed with that obtained from conventional optical measurement. Next, susceptibility measurement was applied to the liquid-phase immunoassay without bound/free (B/F) separation. We performed the detection of biotin-coated polymer beads in suspension using avidin-coated magnetic markers. Changes of the susceptibility and the size distribution caused by the binding reaction were shown.     

水平管油水分散流液滴粒径及其分布规律研究

油水两相分散流是油水混输管道常见的流型之一,液滴是油水分散流的主要特征,液滴在油水两相管路中受到湍流惯性力、剪切力、界面张力、黏性力等多种力的作用而发生聚结和破裂,从而形成不同的液滴粒径及其分布。本研究采用高速摄像和显微照相两种方法研究了水平管中油水分散流的液滴粒径随混合流量、温度和含油率等参数的变化规律,并利用三种概率分布函数研究了液滴粒径的分布特性。研究结果表明:分散相液滴的Sauter平均直径随混合流量的增加而逐渐减小、随温度升高而逐渐增大、随含油率的增大而增大;液滴粒径的分布规律与Log-Normal和Frechet概率分布函数符合较好。     

超燃冲压发动机等截面隔离段中流动的LBM模拟

采用耦合的双分布函数格子Boltzmann方法模拟超燃冲压发动机中隔离段的流动.计算结果反映了隔离段内流场的基本结构,表明LBM在隔离段的模拟中是-种具有潜力的数值计算方法.