三维面形测量中基于模版匹配的变形条纹修复

在基于条纹投影和相位分析的三维面形测量中,由于被测物体表面标志点或复杂面形的阴影遮挡存在,会造成变形条纹局部区域的条纹数据缺失,影响相位和高度信息的最终重建,需要人为地对缺失图像信息进行修复。提出了一种新的缺失条纹数据修复方法——基于模版匹配的图像修复算法,通过图像中已有条纹信息(特别是与待修复区域周围相位信息相似度较高的已知条纹信息)对缺失的变形条纹信息进行估算,实现数据修复。该方法修复效果好,运算过程无需人为参与,便于计算机自动实现,尤其适合于待修复图像整体结构明显、纹理清晰图像的数据修复,有助于提高被测物体相位计算质量和在此基础上的三维面形重建质量。     

A Criterion for Stability of Synchronization and Application to Coupled Chua＇s Systems

We investigate synchronization in an array network of nearest-neighbor coupled chaotic oscillators. By using of the Lyapunov stability theory and matrix theory, a criterion for stability of complete synchronization is deduced. Meanwhile, an estimate of the critical coupling strength is obtained to ensure achieving chaos synchronization. As an example application, a model of coupled Chua＇s circuits with linearly bidirectional coupling is studied to verify the validity of the criterion.     

正常金属-分子量子点-超导耦合系统的介观输运研究

运用非平衡格林函数理论、正则变换以及BCS平均场理论研究了正常金属-分子量子点-超导耦合系统（N-MQD-S）的介观输运,得到了系统的电流公式并选择适当的参数进行了数值计算。数值计算结果表明：电声子耦合强度 与线宽函数 对系统的输运行为有较大影响。当 增大时,由声子辅助隧穿所产生的共振峰将高于分子量子点自身能级产生的共振峰;当线宽函数 增大时,在Andreev反射共振峰的两侧将出现新的边峰。     

The beam-based calibration of an X-ray pinhole camera at SSRF

A pinhole camera for imaging X-ray synchrotron radiation from a dipole magnet is now in operation at the Shanghai Synchrotron Radiation Facility (SSRF) storage ring. The electron beam size is derived by unfolding the radiation image and the point spread function (PSF) with deconvolution techniques. The performance of the pinhole is determined by the accuracy of the PSF measurement. This article will focus on a beam-based calibration scheme to measure the PSF system by varying the beam images with different quadrupole settings and fitting them with the corresponding theoretical beam sizes. Applying this method at SSRF, the PSF value of the pinhole is revised from 37 to 44 μm. The deviation in beam size between the theoretical value and the measured value is minimized to 4% after calibration. This optimization allows us to observe the horizontal disturbance due to injection down to as small as 0.5 μm.     

Detrended cross-correlation analysis of electroencephalogram

In the paper we use detrended cross-correlation analysis (DCCA) to study the electroencephalograms of healthy young subjects and healthy old subjects. It is found that the cross-correlation between different leads of a healthy young subject is larger than that of a healthy old subject. It was shown that the cross-correlation relationship decreases with the aging process and the phenomenon can help to diagnose whether the subject's brain function is healthy or not.     

数字域时间延迟积分时间CMOS相机高分“凝视”成像设计分析

为实现凝视卫星高分跟踪成像,设计了数字域时间延迟积分(TDI)互补金属氧化物半导体(CMOS)传感器在凝视姿态下的成像匹配模型,推导了卫星凝视跟踪成像时相对轨道坐标系的姿态变化,采用坐标变换方法实时计算其在凝视过程中随姿态变化的行转移时间,利用蒙特卡罗方法统计计算了凝视模式下姿态指向精度和稳定度对成像的影响。利用数字域TDI CMOS原理样机和小卫星姿态控制系统全物理仿真平台对成像进行了仿真分析。结果表明,卫星的姿态控制精度在成像过程中会引起纵向的像移速度失配和横向匹配的残余像移,成像积分级数越高,图像信噪比越大。积分级数的增加对卫星姿态提出较高要求,仿真平台姿态角和姿态角速度控制精度分别优于0.05°,0.005°/s时,采用积分级数为48级能较好地满足成像质量要求。     

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.     

用于太赫兹光源的准等时性储存环的设计

介绍了一种获得准等时性储存环的方案,即调节Lattice参数,在色散段引入负色散函数从而降低线性滑相因子,获得短束团。根据此方案设计了用于相干太赫兹光源的准等时性储存环,结果给出了线形光学函数曲线以及粒子的动力学孔径,表明了通过调节四极铁参数可以达到降低束团长度获得准等时性储存环的目的。还设计了用于准等时性储存环弯铁处的真空室的3维模型,并对其类腔体部分的本征模进行了计算,得到特性阻抗与品质因数的比值在10-3量级以下,表明类腔体部分对束流的影响很小。     

Estimating the bound for the generalized Lorenz system

A chaotic system is bounded, and its trajectory is confined to a certain region which is called the chaotic attractor. No matter how unstable the interior of the system is, the trajectory never exceeds the chaotic attractor. In the present paper, the sphere bound of the generalized Lorenz system is given, based on the Lyapunov function and the Lagrange multiplier method. Furthermore, we show the actual parameters and perform numerical simulations.