光纤中高斯型伪随机序列码偏振度的理论分析和实验研究

推导了准单色光波情况下高斯脉冲伪随机序列偏振度的简洁数学表达式.理论分析结果表明,偏振度与差分群延迟之间的关系与线路啁啾和光纤色散无关,并且此关系可以由光信号频谱半宽度Δω和分光比γ唯一确定.用10 Gbit/s 7级m序列归零码进行的实验表明:实验结果与理论推导基本一致,从而验证了推导公式的正确性.     

气管支气管树内气流和颗粒运动的大涡模拟

为更精确地描述真实人体呼吸道内的空气流动,明晰颗粒的运动沉积规律,本文从直接医学CT扫描得到的原始数据出发,利用图像辨识技术,重构了一个男性真人气管支气管树前三级的三维几何模型.采用大涡模拟的方法计算了非规则几何曲面结构内的气体流动现象,并在拉格朗日框架下跟踪颗粒的运动规律.数值计算得到了气流场的三维分布,以及颗粒的运动轨迹情况,结果表明现有基于Weibel的对称模型与真实人体的几何结构有较大的差异,而几何结构对流动影响较大;受非对称复杂结构影响,在不同截面的二次气流速度的分布规律不同;分叉后颗粒进入左右支气管的数量有明显的不同.     

考虑最佳入口温度的多股流换热器网络循环优化

针对于多股流换热器网络的应用优势,本文在衍生网络优化方法基础上,提出了考虑最佳入口温度的多股流换热器循环优化方法,即利用多股流换热器网络小面积换热器合并而不产生固定投资费用这一特点,将优化结果中存在公用工程的流体返回到另一种流体的入口并与其入口流体进行循环优化。结果表明,这种优化方法能够进一步发挥多股流换热器网络的优点,得到年综合费用更小、运行费用更低的网络结构。     

Phase Dependence of Fluorescence Spectrum of a Two-Level Atom in a Trichromatic Field

We examine the phase-dependent effects in resonance fluorescence of a two-level atom driven by a trichromatic modulated field. It is shown that the fluorescence spectrum depends crucially on the sum of relative phases of the sideband components compared to the central component, not simply on the respective phases. The appearance or disappearance of the central peak and the selective elimination of the sideband peaks are achieved simply by varying the sum phase. Once the sum phase is fixed, the spectrum keeps its features unchanged regardless of the respective relative phases.     

RIBLL终端LASCAR闪烁体阵列探测器研制进展

介绍了RIBLL终端LASCAR闪烁体阵列探测器的工作原理和结构特点. 描述了为满足放射性核束实验的要求而对阵列所作的重要改进. 给出了LASCAR构型优化改造的工作设想和实施步骤. The principles and structure characteristics of LASCAR scintillator array detector at RIBLL terminal are described. Special emphases are laid upon the latest progress for the development of LASCAR array detector to meet the requirements of the RIB experiments. The working plan and steps for optimizing configuration of the LASCAR multi unit neutron scintillator array detector are also presented.     

周视大像旋稳海天线向量角补偿算法

为使两轴周视光电探测系统在三自由度扰动和大像旋条件下搜索并跟踪水面目标,在虚拟天际线焦平面像五自由度解析表达式基础上,推导出焦平面坐标系铅直轴的方向向量和该坐标系下海天出射平面法向量夹角的余弦表达式.该式求反余弦后减π/2,得到焦平面铅直坐标轴的方向向量和海天出射平面法向量小于π/2的夹角,该夹角的0.5倍作为俯仰反射镜的净作动量,目的是克服非线性像旋使包含目标信息的虚拟海天线的像线通过焦平面中心.该算法与方位补偿算法联动能够使目标像点始终逼近焦平面原点.通过数学模型仿真和真实工况试验都验证了俯仰机构位置环海天线向量角补偿算法的合理性.     

相干多普勒测风激光雷达

 鉴于多普勒测风激光雷达在航空航天、遥感遥测、气象观测等军事及民用领域中的广泛应用,结合相干探测工作原理,介绍了国外几种典型波段相干多普勒测风激光雷达系统,重点分析了激光发射机/接收机、空间扫描、数据处理等关键技术,并对相干多普勒激光雷达的广阔应用前景进行了展望。指出国内相干多普勒测风激光雷达研究已取得的一些重要进展。     

Analysis of Nanostructural Waveguides Using Fourth-Order Accurate Finite Difference Methods with Nonuniform Scheme

We successfully apply fourth-order accurate finite difference methods with nonuniform scheme to analysis the symmetric slot waveguides. The results of numerical simulations show that the present nonuniform formula offers the results more accurate than the previously presented second order schemes.     

Antiproton-Nucleus Interaction and Coulomb Effect at High Energies

The Coulomb effect in high energy antiproton-nucleus elastic and inelastic scattering from ¹²C and ¹⁶O is studied in the framework of Glauber multiple scattering theory for five kinetic energies ranged from 0.23 to 1.83 GeV. A microscopic shell-model nuclear wave functions, Woods-Saxon single-particle wave functions, and experimental pN amplitudes are used in the calculations. The results show that the Coulomb effect is of paramount importance for filling up the dips of differential cross sections. We claim that the present result for inelastic scattering of antiproton-¹²C is sufficiently reliable to be a guide for measurements in the very near future. We also believe that antiproton nucleus elastic and inelastic scattering may produce new information on both the nuclear structure and the antinucleon-nucleon interaction, in particular the p-neutron interaction.     

Three-Party Quantum State Sharing of an Arbitrary Unknown Two-Qubit State Based on Entanglement Swapping and Bell-State Measurements

We propose a scheme for sharing an arbitrary unknown two-qubit state among three parties by using a four-qubit cluster-class state and a Bell state as a quantum channel. With a quantum controlled phase gate (QCPG) operation and a local unitaryoperation, any one of the two agents has the access to reconstruct the original state if he/she collaborates with the other one, whilst individual agent obtains no information. As all quantum resource can be used to carry the useful information, the intrinsic efficiency of qubits approaches the maximal value. Moreover, the present scheme is more feasible with present-day technique.