Preparation and optical properties of poly（vinylidene difluoride）/（Y0.97Eu0.03）2O3 rare-earth nanocomposite

In this letter, poly（vinylidene difluoride） （PVDF）/（Y0.97Eu0.03）2O3 rare-earth nanocomposites were prepared by a simple co-precipitation method, and their morphology, structure, and optical properties were investigated. The scanning electron microscope （SEM） images showed that the （Y0.97Eu0.03）2O3 rare- earth nanoparticles formed 50 nm - 2 μm aggregates in PVDF matrices. X-ray diffraction （XRD） curves indicated the incorporation and structure preserving of （Y0.97Eu0.03）2O3 nanoparticles in PVDF matrices. Photoluminescence （PL） spectra of the nanocomposite showed a characteristic red light emission at 612 nm, which was attributed to the intrinsic emission of （Y0.97Eu0.03）2O3 nanoparticles. Optical band gap （Eg） of the nanocomposite exhibited a decreasing trend with the increase of （Y0.97Eu0.03）2O3 content in PVDF matrices within the experimental dosage range.     

The two photorefractive centres in iron doped nearly stoichiometric lithium niobate crystals

This paper investigates the photorefractive properties of iron doped lithium niobate with different [Li]/[Nb] ratios The experimental results show two photorefractive centres for iron doped near-stoichiometric lithium niobate crystal Besides Fe^2＋ and Fe^3＋ ions, small polarons and bipolarons are considered as another photoactive centre.     

Light-Induced Domain Inversion in Mg-Doped near Stoichiometric Lithium Niobate Crystals

We investigate the influence of visible light on domain inversion in Mg-doped near stoichiometric lithium niobate crystals and find that the switching electric field decreases about 70% above a threshold light intensity. This effect helps us optically control domain switching and produce bulk domain structures on the micrometre scale. Finally, we introduce a model of photo-induced carriers to explain the origin of the reduction of switching electric field.     

稳态法测量冰的导热系数

基于保护热板法原型,使用干冰-乙醇和乙二醇混合浴制造不同温度稳定低温环境之间的传热代替传统的加热传热,设计了冰的导热系数测量装置,在较大的温度范围(-70～-30℃)内实现了冰的导热系数稳定可靠的测量.同时充分借助电子式温度计高效测量数据,测得了冰在不同温度下和含有不同杂质情况下的导热系数变化规律,实验结果与参考值符合较好.利用杂质对冰的导热系数的影响规律,可以按需求调节冰的导热系数.     

近化学计量比钽酸锂晶体的拉曼光谱研究

本文研究了不同组分钽酸锂晶体的拉曼散射光谱,我们发现,在谱线的形状和数量方面,近化学计量比晶体与同成分晶体存在明显差异.通过实验,我们得到了钽酸锂晶体完整的长波长光学模式,并首次给出了钽酸锂晶体拉曼线宽和晶体组分的定量关系.另外,我们还发现了两个与本征缺陷相关的局域模,278cm-1和750cm-1峰,它们的强度与晶体中本征缺陷的数量成正比.     

大直径、高掺镁铌酸锂晶体的生长及其紫外光折变性能研究

我们生长了掺镁量分别为3.0mol;、5.0mol;、7.8mol;、9.0mol;的76mm高掺镁铌酸锂晶体,检测了这些晶体的生长条纹情况,并利用双光耦合配置测试了这些晶体在351nm紫外光下的光折变性能.从实验结果看,采用同成分共熔点铌锂配比的高掺镁铌酸锂晶体生长条纹比较多;虽然高掺镁铌酸锂晶体在可见光波段有很好的抗光折变能力,但是在紫外光下具有良好的光折变性能,可以作为优良的紫外光折变材料使用.同时,实验结果表明,掺镁量在5.0mol;的铌酸锂晶体具有最佳的紫外光折变性能.     

THE TWO-BOSON SCATTERING PHASE SHIFTS IN THE GENERAL φ6 THEORY WITH THE GAUSSIAN WAVE-FUNCTIONAL APPROACH

The two-particle scattering phase shifts with a λφ⁴ +ξφ⁶ interaction are com-puted in (1 + 1) and (2 + 1) dimensions using the Gaussian wave-functional approach.Through numerical analysis, we give the phase-shift curves with respect to the scat-tering energy for most cases of this theory. In (1 + 1) and (2 + 1 ) dimensions, for the symmetry vacuum the phase shifts are positive or negative depending on the signs of the renormalized parameter, while for the asymmetric vacuum the phase shifts are negative.     

商业综合体空间布局的句法量化研究—–以宁波市“印象奉化”为例

城市商业综合体迅速发展的同时, 也存在着空置率高、商业选址定位脱离实际、内部空间布局不合理、人流动线设计缺少人性化等问题. 本文基于空间句法理论, 利用整合度、协同度、连接值、穿行度等量化指标, 对印象奉化商业综合体内外空间进行数字化模拟, 为以后商业综合体的选址、规划和空间布局及其空间关系量化提供借鉴.     

以DSD理论和LS方法为基础的程序燃烧法

给出了二维弯曲爆轰波后产物流场计算方法。爆轰波阵面传播规律满足Detonation Shock Dynamics (DSD)理论并用level set (LS)方法计算,波阵面传播规律与波后流场的耦合通过程序燃烧法实现,反应进程变量可作为LS函数的函数给出。爆轰波从刚性细管道向粗管道传播产生绕射的二维计算结果表明,化学反应速率不影响波后流场分布,只影响反应区结构。此方法可用于钝感炸药的驱动计算问题。     

VLSI中高温超导耦合互连线的电特性研究

本文采用二维时域有限差分（ＦＤＴＤ）法分析ＶＬＳＩ中的高温超导（ＨＴＳ）耦合互连线的传输特性。对耦合互连线奇偶模分别给定一系列的实传输常数β后,求出盯应场值并有杉时间序列预测模型及参数优化方法得到其对应的频率和实际的复传输常数γ,在此基础上提取出频变等效电路ＲＬＧＣ参数。通过与常规导体铝互连线的ＲＬＧＣ参数进行比较,可以看出超导出连线具有相当低的色数。通过与常规导体铝互连线的ＲＬＧＣ以数进行比较。