A high order energy preserving scheme for the strongly coupled nonlinear Schrōdinger system

A high order energy preserving scheme for a strongly coupled nonlinear Schrōdinger system is roposed by using the average vector field method. The high order energy preserving scheme is applied to simulate the soliton evolution of the strongly coupled Schrōdinger system. Numerical results show that the high order energy preserving scheme can well simulate the soliton evolution, moreover, it preserves the discrete energy of the strongly coupled nonlinear Schrōdinger system exactly.     

球形充气液泡所带电量及系统能量变化的分析

本文分析了球形充气液泡所带的电量,推导出一个较为普遍的计算公式,并分析了整个系统的能量变化关系.     

Propagation of elliptical Gaussian beam passing through apertured paraxial optical systems

The propagation of elliptical Gaussian beam passing through paraxial optical systems with aperture is investigated analytically by using tensor method. The approximate formula for propagation of elliptical Gaussian beam through hard apertured optical systems is derived based on the fact that the circ function can be expanded into a finite sum of complex Gaussian functions. The derived formula provides a convenient tool for treating the propagation and transformation of elliptical Gaussian beam through apertured optical systems. As an application example, the propagation properties of elliptical Gaussian beam through apertured fractional Fourier systems are discussed.     

导弹逼近告警器及无源干扰设备测试软件设计

为解决导弹逼近告警器及无源干扰设备测试成本高、维护保障难的问题,研制了一套导弹逼近告警器及无源干扰设备自动检测系统;设计了系统测试软件,按照模块化设计方式,针对设备检测需求,开发不同的软件测试模块并集成;该系统集成度高,配置灵活,操作智能化,功能完整,测试项目全,测试和排故障效率高;经试用表明,该检测系统具有良好的操作性和维护性,可以为导弹逼近告警器及无源干扰设备检测维修提供技术支持,有效节省测试成本和维护保障费用。     

一种云环境下的发动机健康管理系统及其应用

针对航空公司对大量飞机发动机进行健康管理的需求,通过建立发动机健康管理云端数据中心,建立了一种云环境下的民航发动机健康管理系统,该系统对于验证发动机故障诊断方法的有效性具有突出优势,并且对于实现多种方法协同进行发动机故障诊断具有重要价值;提出了一种基于灰色关联分析的灰色故障识别方法,通过在云端平台使用灰色故障识别方法实现JT9D-7R4发动机的典型气路性能故障诊断为例,表明云环境下的发动机健康管理系统可以有效地进行航空发动机故障诊断。     

Double peaks on ac magnetization in a superconducting Pb-porous glass nanocomposite

Studies of temperature dependences of ac magnetization were carried out for a superconducting lead-porous glass nanocomposite. Double peaks were found on the imaginary part of ac magnetization which were accompanied with double steps on the real part. The lower-temperature anomalies in ac magnetization differed noticeably when they were obtained upon cooling and warming. The double peaks were treated as two phase transitions in the vortex system: the liquid-solid transition which occurs close to the onset of superconductivity and solid-solid one which is triggered by superconductivity in confined lead islands.     

Design of a multi-cusp ion source for proton therapy

The permanent magnets of the discharge chamber in a multi-cusp proton source are studied and designed. The three electrode extraction system is adopted and simulated. A method to extract different amounts of current while keeping the beam emittance unchanged is proposed.     

300～1100nm多波段成像光学系统设计及杂光分析

设计了一套300～1100nm多波段光学系统,该系统能对目标的近紫外、可见光和近红外3个波段同时成像,可满足目标多波段信息探测的要求。由于在光学系统中镜筒内壁反射和棱镜表面反射会产生杂光和鬼像,因此,利用Light—Tools软件对此系统的杂光和鬼像进行了模拟分析。模拟结果表明,视场之外11．7—18．3°和-11．7～-18．3°的入射光线被胶合棱镜上下表面反射后,会聚焦到3个探测器靶面范围内,形成鬼像;6．2°-9．8°和一6．2°--9．8°的入射光线被镜筒反射后会在3个探测器上形成杂光。利用设计的多波段光学系统进行了相关实验,结果证明了模拟分析的正确性,表明此分析能用于指导多波段光学系统的设计和研制。提出了减少杂光和鬼像的相应措施,实验结果验证了提出的措施能够减少杂光及消除鬼像,提高系统成像质量。     

考虑停靠站影响的公交运输系统模型

受停靠站影响,公共交通系统运行过程中容易产生集簇现象.本文细致地考虑了公交停靠站长度和停靠站在线路上的分布情况,构建了一个新的公交运输系统元胞自动机模型.数值模拟结果表明,在引入停靠站长度和停靠站分布两种因素后,模型在微观层面上更清晰地刻画了车辆在公交线路上的时空分布,再现了公交运行中的集簇现象,定量地评价了停靠站分布对车辆平均速度的影响.本研究对进一步认识集簇现象的形成机理和优化停靠站设计具有指导意义.     

Structural features of melts in the In-Bi system

A testing device for the resistivity of high-temperature melt was adopted to measure the resistivity of In-Bi system melts at different temperatures. The resistivity of In_xBi_100−x(x=0-100) melt is in linear relationship with temperature, which is within the temperature measuring range. The resistivity of melt lowers with the increase of the In content. Based on Nordheim law and combined with the experimental resistivity of In-Bi melts, we verified the existence of InBi atom clusters and estimated the mole fraction of the InBi atom clusters in the melt, and the estimated value shows fine consistency with the result in literature [1]. The study reveals that the structural feature of In-Bi melts can be briefly divided into two intervals: in the interval of 0-50 at% In, the structural feature of the melt is that InBi atom clusters distribute in matrices, which have similar properties of Bi; in the interval of 50 at%-100 at% In, the structural feature of the melt is that InBi atom clusters distribute in matrices, which have similar properties of In. The content of InBi atom clusters in In₅₀Bi₅₀ melts reaches a higher value when the temperature is cooled down to a point, which is 152 K above the melting point. At the same time, the melts have an obvious fluctuation of concentration, which leads to that the resistivity of the melts deviates from the linear relationship at high temperature.