静态调制的光谱偏振成像系统

针对传统光谱偏振成像系统普遍存在的系统结构复杂、需要动态调制、光通量低等问题,提出一种基于静态调制的光谱偏振成像系统,将静态调制偏振探测方法与Savart偏光镜干涉成像原理相结合,可在成像过程中实时获取目标的光谱信息和全部四个Stokes偏振信息。与传统系统相比较,该系统具有无运动部件、无需动态电控调制、没狭缝限制、光通量大等优点。介绍了系统组成和基本原理,搭建了实验装置,实验装置包括二次成像光学系统、偏振调制模块、干涉成像模块、CCD图像采集及数据处理模块等,成像谱段范围为可见光近红外(480~950 nm)。利用实验装置对白板、飞机玩具模型进行了成像实验,验证了该系统的光谱偏振成像数据获取能力。对静态调制的偏振测量精度进行了验证,偏振测量统计误差小于5%。实验结果验证了系统原理的正确性和可行性,获取的光谱偏振成像数据在目标识别、目标分类、遥感探测等方面具有较高的应用价值。     

一类或决策模型及其应用

提出了一类特殊类型的数学规划模型并给出了一种新的分枝定界算法.这类数学模型尽管可以转化为0-1规划模型,但它相对于转化后的0-1规划模型:①决策意义明确,表达形式相对简单;②不需要引入参数M并在求解前确定其上界;③相对于求解转化后的0-1规划模型的分枝定界法,新分枝定界算法在最好情形下计算量最多为原算法的八分之一.作为本模型的一个应用,可以用来解决一些要么不实施要么有一定数量下限限制才可以实施的决策问题.     

螺旋光束经过振幅型衍射光学元件的传输特性及其拓扑电荷数的测量

本文提出了一种利用空间光调制器生成杨氏双缝和三角孔等振幅型衍射光学元件的方法. 利用平面波角谱衍射公式和柯林斯公式研究了螺旋光束经过这两种衍射元件后的传输特性, 并利用杨氏双缝和三角孔实现了螺旋光束拓扑电荷数的测量. 由于空间光调制器可以方便和高精度地改变光学器件的几何尺寸和所在的空间位置, 因此可便捷地实现螺旋光束拓扑电荷数的测量.     

非接触法测量距离的研究

本文设计制作了用可闻声波和超声波测距离的两种实验装置,比较了这两种测量方法的优缺点。     

基于软件无线电技术的核四极矩共振谱仪设计

介绍了软件无线电技术的基本原理， 分析了全数字化核四极矩共振谱仪的设计要求，讨论了设计时在软件、硬件方面的一些考虑，给出了基于软件无线电技术的全数字化核四极矩共振谱仪设计一个实例.     

Self-assembly of lamella-forming diblock copolymers confined in nanochannels: Effect of confinement geometry

The self-assembly of symmetric diblock copolymers confined in the channels of variously shaped cross sections(regular triangles, squares, and ellipses) is investigated using a simulated annealing technique. In the bulk, the studied symmetric diblock copolymers form a lamellar structure with period LL. The geometry and surface property of the confining channels have a large effect on the self-assembled structures and the orientation of the lamellar structures. Stacked perpendicular lamellae with period LLare observed for neutral surfaces regardless of the channel shape and size, but each lamella is in the shape of the corresponding channel’s cross section. In the case of triangle-shaped cross sections, stacked parallel lamellae are the majority morphologies for weakly selective surfaces, while morphologies including a triangular-prism-shaped B-cylinder and multiple tridentate lamellae are obtained for strongly selective surfaces. In the cases of square-shaped and ellipse-shaped cross sections, concentric lamellae are the signature morphology for strongly selective surfaces, whereas for weakly selective surfaces, stacked parallel lamellae, and several types of folding lamellae are obtained in the case of square-shaped cross sections, and stacked parallel lamellae are the majority morphologies in the case of ellipse-shaped cross sections when the length of the minor axis is commensurate with the bulk lamellar period. The mean-square endto-end distance, the average contact number between different species and the surface concentration of the A-monomers are computed to elucidate the mechanisms of the formation of the different morphologies. It is found that the resulting morphology is a consequence of competition among the chain stretching, interfacial energy, and surface energy. Our results suggest that the self-assembled morphology and the orientation of lamellae can be manipulated by the shape, the size, and the surface property of the confining channels.     

基于高斯模糊的摔倒自检测算法设计与应用

随着智能设备的普及,如何快速准确地检测、识别人体摔倒已逐渐成为研究的热点。然而现阶段对摔倒动作识别与检测仍然存在很多问题。为此,以智能设备的传感器系统采集的三轴加速度与角加速度为基础,结合经过高斯过滤后形成人体活动的信号幅度向量和陀螺仪信号幅度向量特征曲线与摔倒检测的模糊隶属函数特征模型,提出一种基于模糊的摔倒自检测算法。算法重点针对急速跑动、上下楼梯、手机平抛和自由落体等摔倒检测中的干扰动作进行了分析与区分,经过实验测试表明该算法有较快的反馈速度、较好的区分度以及较低的误判率。     

集成数据环境下装备IETM数据查询研究

针对集成数据环境下装备IETM内部所包含数据无法完全满足用户需求的问题,以装备IETM内部所包含的数据模块信息为样本数据,结合扩展查询以及Hopfield神经网络等相关技术,通过对查询扩展词与查询词之间的领域权值、关联权值以及距离权值的计算,科学合理的实现对查询扩展词的选取,并提出了基于Hopfield神经网络的装备IETM数据查询方法;在实验环境下,采用某型坦克的IETM系统对所提出方法进行验证;结果表明,该方法在数据查询率与查准率等方面都要明显高于传统的数据查询方法。     

Terahertz magnetic resonance in MnCr2O4 under high magnetic field

Terahertz (THz) time-domain spectroscopy (THz-TDS) of polycrystalline MnCr₂O₄ was performed at <9 T and low temperatures. A resonance absorption in the sub-THz range with linear blueshifts was observed as the magnetic field was increased from 4 T to 9 T. These magnetism-driven absorptions originated from a ferromagnetic resonance, which agrees with low-field electron spin resonance measurements and ferromagnetic resonance theory. The low-temperature g-factors of MnCr₂O₄ were also obtained using THz-TDS. This work provides new insights into the spin dynamics of chromite spinel compounds in the THz region.