FJZ-250型高速分幅相机时间测量不确定度分析

FJZ-250型高速转镜分幅相机因转镜速度的不可重复性，光机结构的构造原理和控制系统各路高压触发时间的漂移，导致了时间测量的不确定度。为此，须对相机测量数据进行校正。阐述了校正方法、提供了逐幅校正位置误差的修正系数。若以预置转速对应的名义周期值去处理测量结果，则相机的时间测量合成小确定度将达1％，对名义周期值和名义幅间间隔时间值进行修正后，则可降至0.3％。     

WKB Wave Function of the General Time-Dependent Quadratic Hamiltonian System

We derived the WKB wave function for the general time-dependent quadratic Hamiltonian system using a unitary transformation method. We applied our research to sinusodially drived Caldirola–Kanai oscillator and confirmed that the time evolution of our approximated WKB wave function is similar to that of the exact one. This wave function can be used to analyze the interference between the probability amplitudes contributed by the area of overlap in phase space of quantum states.     

首次穿过边界概率及其在金融中的应用

本文把数学和管理科学有机结合,为数学应用提出问题,得出新结果,推广了J.Michel Harrison(1985)[1]第43页的命题27,并给出了在金融中的应用.     

Time Series Prediction Based on Chaotic Attractor

A new prediction technique is proposed for chaotic time series. The usefulness of the technique is thatit can kick off some false neighbor points which are not suitable for the local estimation of the dynamics systems. Atime-delayed embedding is used to reconstruct the underlying attractor, and the prediction model is based on the timeevolution of the topological neighboring in the phase space. We use a feedforward neural network to approximate thelocal dominant Lyapunov exponent, and choose the spatial neighbors by the Lyapunov exponent. The model is testedfor the Mackey-Glass equation and the convection amplitude of lorenz systems. The results indicate that this predictiontechnique can improve the prediction of chaotic time series.     

Group Representation of Relativistic Quantum Crystal Optics

A group representation of radiation propagation in an anisotropic medium is developed. The system of wave equations for electromagnetic potentials, obtained from the Maxwell equations with account for the constitutive equations, has been factorized. It is shown that the linear differential operator of the factorized system is orthogonal in transparent crystals and unitary in gyrotropic ones and is represented through the momentum operator. On the basis of the commutation relations for the components of this operator, the eigenvalue problem has been solved and the expression for the change in the radiant energy in the crystal in the form of spherical waves has been obtained. The dependences of the ray and phase velocities and the polarization vectors of waves on the birefringence anisotropy and gyrotropy as well as on the angular momentum, displacement current, and bound charge determining them have been analyzed. It has been established that in the general case of gyrotropic crystals where the nonreciprocity phenomenon takes place and in magnetoelectrics Maxwell equations are represented in a form similar to the Dirac equations and the electromagnetic radiation is correctly described by means of bispinors and is quantized as fermions.     

Scheduling data transfers in a network and the set scheduling problem

In this paper we consider the online ftp problem. The goal is to service a sequence of file transfer requests given bandwidth constraints of the underlying communication network. The main result of the paper is a technique that leads to algorithms that optimize several natural metrics, such as max-stretch, total flow time, max flow time, and total completion time. In particular, we show how to achieve optimum total flow time and optimum max-stretch if we increase the capacity of the underlying network by a logarithmic factor. We show that the resource augmentation is necessary by proving polynomial lower bounds on the max-stretch and total flow time for the case where online and offline algorithms are using same-capacity edges. Moreover, we also give polylogarithmic lower bounds on the resource augmentation factor necessary in order to keep the total flow time and max-stretch within a constant factor of optimum.     

Cu~+、Ag~+、Au~+与乙硫醇的气相化学反应

利用激光溅射 分子束的技术 ,结合反射飞行时间质谱计 ,研究了Cu+、Ag+、Au+与乙硫醇的气相化学反应。结果显示这三种金属离子与 (CH3 CH2 SH) n 反应形成一系列团簇离子M+(CH3 CH2 SH) n,且团簇离子尺寸不一样。Ag+、Au+与乙硫醇的反应还生成了 (CH3 CH2 SH) +n ,由此推测Cu+、Ag+、Au+与乙硫醇团簇的反应存在两种通道 ,一种通道是生成M+(CH3 CH2 SH) n,另一种是生成 (CH3 CH2 SH) +n 。Cu+、Au+与乙硫醇的反应还生成了M+(H2 S) (M =Cu、Au) ,但是实验中没有观察到Ag+(H2 S) ,理论计算表明Ag+(H2 S)很不稳定。另外 ,分析产物离子M+(CH3 CH2 SH) n 的强度发现 ,n =1～ 2之间存在明显的强度突变现象     

资源有限的加权总完工时间单机排序问题

本讨论资源有限的加权总工时间单机排序问题，对现在仍为OPEN问题1｜pj=bj-ajuj，∑uj≤U｜∑wjCj给出了一个有关最优解中最优资源分配的重要性质，并利用该性质分别给出了三种情况bj=b,wj=w,aj=a；bj=b,wj=w,uj=u；aj=a,wj=w,uj=u的最优算法。     

多重休假的带启动--关闭期的Geom/G/1排队

本研究多重休假的带启动——关闭期的Geom／G／1离散时间排队，给出稳态队长，等待时间分布的母函数及其随机分解结果，推导出忙期的全假期的母函数，给出该模型的几个特例。     

Effects of diamines and their fluorinated groups on the color lightness and preparation of organosoluble aromatic polyimides from 2,2‐bis[4‐(4‐amino‐2‐trifluoromethylphenoxy)phenyl]‐hexafluoropropane

To investigate the position and amount of the CF₃ group affecting the coloration of polyimides (PIs), we prepared 2,2‐bis[4‐(4‐amino‐2‐trifluoromethylphenoxy)phenyl]hexafluoropropane ( 2 ) with four CF₃ groups with 2‐chloro‐5‐nitrobenzotrifluoride and 2,2‐bis(4‐hydroxyphenol)hexafluoropropane. A series of soluble and light‐colored fluorinated PIs ( 5 ) were synthesized from 2 and various aromatic dianhydrides ( 3a – 3f ). 5a – 5f had inherent viscosities ranging from 0.80 to 1.19 dL/g and were soluble in amide polar solvents and even in less polar solvents. The glass‐transition temperatures of 5 were 221–265 °C, and the 10% weight‐loss temperatures were above 493 °C. Their films had cutoff wavelengths between 343 and 390 nm, b* values (a yellowness index) ranging from 5 to 41, dielectric constants of 2.68–3.01 (1 MHz), and moisture absorptions of 0.03–0.29 wt %. In a comparison of the PI series 6 – 8 based on 2,2‐bis[4‐(4‐aminophenoxy)phenyl]hexafluoropropane, 2,2‐bis[4‐(4‐amino‐2‐trifluoromethylphenoxy)phenyl]propane, and 2,2‐bis[4‐(4‐aminophenoxy)phenyl]propane, we found that the CF₃ group close to the imide group was more effective in lowering the color; this means that CF₃ of 5 , 7 , and 8f was more effective than that of 6c . The color intensity of the four PI series was lowered in the following order: 5 > 7 > 6 > 8 . The PI 5f , synthesized from diamine 2 and 4,4′‐hexafluoroisopropylidenediphthalic anhydride, had six CF₃ groups in a repeated segment, so it exhibited the lightest color among the four series. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 922–938, 2003