二芳烯材料在重复擦写体全息存储中的应用研究

二芳烯材料是一种性能优异的光致色变材料,具有很好的抗疲劳性能,一般能重复擦写上万次,而不损失其性能。通过体全息光栅记录实验、角度复用体全息存储实验、重复擦写及强光记弱光读等实验,对二芳烯材料在重复擦写体全息存储中的应用进行了系统研究。由于二芳烯材料具有很高的折射率调制度(Δn=1.15×10-3)、可多次重复擦写、强光记弱光读的准非易失等性能,在可重复擦写的体全息存储中具有广阔的应用前景。     

一种基于差动调焦的激光共轭引导传感器

提出了一种新型基于差动调焦的激光共轭引导传感器(简称LCTS),采用共轭引导原理,避免了在调试过程中激光直接打到靶上的散射影响,提高了对不同靶型的适应性,并克服了物镜景深对监测范围的限制,能够对不同高度的靶进行定位。LCTS实现了对靶和光点的同时定位和引导,能有效地提高靶和激光的引导精度和效率。     

(Nd1－xErx)2Co15.5V1.5的结构转变与磁性

利用电弧熔炼制备了(Nd1-xErx)2Co15.5V1.5（x=0—1.0）化合物样品.通过x射线衍射分析和磁性测量研究了Er替代Nd2Co15.5V1.5中的Nd时对化合物结构和磁性的影响.研究结果表明，低Er含量（x<0.4），化合物为Th2Zn17型结构；高Er含量时(x>0.)，化合物转变为Th2Ni17结构；Er含量为x＝0.4和0.5时，两种结构共存.两种结构的晶胞参数a,c和晶胞体积V随着Er含量的增加都呈现递减的趋势.随着Er含量的增加，(Nd1-xErx)2Co15.5V1.5化合物的 关键词： (Nd1-xErx)2Co15.5V1.5 结构转变 磁性     

液固流化床流动特性的数值模拟

采用欧拉-欧拉双流体模型,结合k-ε模型模拟液相湍流流动和颗粒动理学方法模拟颗粒流动,考虑流固相间作用曳力和虚拟质量力,建立两相流动模型方程和本构关系。模拟结果表明入口速度和曳力模型对液固流动都有一定的影响。选用不同的曳力模型,对模拟结果中固含率的径向分布影响较大,甚至改变了固含率径向分布趋势,同时分析了虚拟质量力对液体-颗粒流动分布的影响。     

Sixth Harmonic of A Nd：YVO4 Laser Generation In KBBF for ARPES

We report that a deep ultraviolet （DUV） laser from the sixth harmonic of a 1064nm laser has been firstly used as light source in an ultrahigh energy-resolution angle-resolved photoemission spectroscopy （ARPES）. The wavelength is 177.3nm obtained by using the second harmonic KBe2BO3F2 crystal with a frequency tripled 1064nm Nd：YVO4 laser. The large flux （10^14 - 10^15 photons/s） and narrow line width （0.26 meV） are suitable for the ultrahigh-energy resolution ARPES. The laser-ARPES can be a powerful tool to study the electronic structure at and near the Fermi level of the superconductor and correlated materials. The laser-ARPES has worked more than 500 h already.     

基于平场全息凹面光栅的舌诊用光谱仪的研制

由于传统的望舌诊断法过于依赖中医师的经验判断,导致误诊的概率相对较大,而基于图像处理的舌诊法受光源、图像采集设备影响较大,同时对于病理不同而颜色相近的舌象识别率不高。为了克服上述缺点,利用舌光谱的“指纹效应”,通过使用光谱法来对不同性状的舌象进行诊断,为了实现这一目标,研制了一款用于舌象诊断的光谱仪,同时为了克服传统分光器件的不足,分光系统中采用了平场全息凹面光栅作为分光器件,能保证系统小型化、光通量利用率提高的同时,改善光谱成像的质量和分辨率。通过系统实验测试,该光谱仪的光谱范围达到340～850 nm, 分辨率优于2 nm,同时通过模拟实验充分验证了该系统的有效性。     

Holographic grating formation in dry photopolymer film with shrinkage

An important issue in developing applications for photopolymers in holography is the effect of shrinkage on recording properties. In this paper, we introduce a model to describe real-time formation of a single grating in photopolymers at any geometrical angle, under the assumption that the shrinkage is in proportion to the polymerization. This model combines polymerization kinetics with the coupled-wave theory, explaining the shrinkage effect on the diffraction efficiency. The model is validated by comparing its predictions with the experimental results for a film of 99μm thickness.     

一个序列的组合解释及其应用

该文给出了一个序列的组合解释，讨论了这个序列在研究两类Chebyshev多项式，广义Fibonacci序列和广义Lucas序列中的一些应用.     

Optoelectronic oscillator-based interrogation system for Michelson interferometric sensors

High-performance interrogation systems for optical fiber sensors are extensively required for environmental condition monitoring applications. In this article, we propose and demonstrate a Michelson interferometer (MI) interrogation system based on an optoelectronic oscillator (OEO). The frequency of the OEO is related to the free spectral range (FSR) of the MI. Thus, when the FSR of the MI varies with a change in external physical factors, the frequency of the OEO shifts and can be used for interrogation. We demonstrate that the temperature sensitivity and interrogation resolution are 35.35 MHz/℃ and 0.012 ℃, respectively. Such an OEO-based scheme enables wavelength-to-frequency mapping and promises a wide linear interrogation range, high resolution and high-speed interrogation.