Effects of the laser surface treatment on the mechanical properties of CuZr-based bulk metallic glasses

Surfaces of three types of CuZr-based bulk metallic glasses (BMGs) were modified by laser surface treatment (LST), and the influence of the treatment on structure and mechanical properties of these alloys was investigated. The phase structure of as-cast and laser-treated samples was characterized by XRD and the morphology of the alloys after fracture was examined by SEM. The compressive plasticity of treated Cu47.5Zr47.5Al5 and Cu46.5Zr47.5Al5Co1 BMGs can be improved from 0.5% to 2.0% and from 1.2% to 5.7% respectively compared with the as-cast ones, while (Cu0.55Zr0.40Al0.05)99Er1 BMG shows insignificant change of plasticity. The improvement in plasticity is attributed to induced crystallization of B2 CuZr phase in the treated surface zone of selected metallic glasses.     

Optical bistability based on surface plasmon coupled between two noble metal films involving Kerr materials

We successfully investigate an optical bistability phenomenon in a layered structure consisting of Kretschmann configuration involving the Kerr-type nonlinear and the silver film. Pure theoretical approaches are employed to investigate that the surface plasmon could easily be coupled and both the reflection and transmission curves versus the incident intensity forms optical bistability. The transmission curves are greatly influenced by the thickness of the second silver film. These results may be useful for designing novel surface plasmon-based optical devices and will be essential for future classical and quantum information processes.     

Legendre函数加权的声纳宽频带恒定束宽波束特性分析*

为了处理水声信号,声纳阵列通常需要形成宽频带恒定束宽的波束。采用两种阵元加权方法分析二维圆弧形恒定束宽换能器声纳阵列:球面Legendre函数加权方法和柱面Legendre函数加权方法。分别对球面阵、柱面阵和平面阵这三种几何结构的声纳阵列进行分析,并且计算波束宽度和波束方向。结果表明,在宽频带范围内,除了柱面Legendre函数加权的球面阵之外,其余Legendre函数加权的声纳阵列均能利用简单的、不随频率变化的阵元权重和阵元延时,形成恒定束宽的波束,并且具有较小的旁瓣,此外波束方向与预设方向也较为一致。相对于其他恒定束宽波束形成方法,Legendre函数加权方法能利用较低的计算复杂度来实现良好的宽频带恒定束宽的波束特性。     

中德化学启蒙教材有机内容比较

就化学启蒙教育阶段有机化学教学内容,将德国的《今日化学SⅠ》、国内的沪教版、人教版、鲁教版4套教材,从知识内容的选取、组织呈现等角度进行了比较,并在实验设计、作业设计、拓展学习3方面向教材编写和教学实践提出了建议。     

SYSTEMATIC STUDY OF POLARIZATION OF TWO-PHOTON ABSORPTION IN SYMMETRY ASSIGNMENTS

In this paper, we have systematically analyzed the degenerate and nondegenerate two-photon polarization ratios of various point groups. We present the maximum of symmetry assignments of two-photon transition with the combination of degenerate and nondegenerate two-photon absorption. These results provide the theoretical basis for the experimental assignments.     

Pr3+在SBN晶体中的发光特性

通过测量Ｐｒ：ＳＢＮ晶体的吸收光谱和荧光光谱来确定Ｐｒ³⁺在ＳＢＮ晶体中的能级位置。由于Ｐｒ³⁺离子占据晶体中的不同格位而引起荧光带呈现双峰结构。测量荧光寿命随温度的变化关系，表明Ｐｒ³⁺在ＳＢＮ晶体中 ³Ｐ₀态的无辐射弛豫主要是 ³Ｐ₀→¹Ｄ₂多声子弛豫过程。 关键词：     

KTiOPO4晶体纵横模劈裂的喇曼谱

在室温下测量了ＫＴｉＯＰＯ₄单晶的偏振喇曼散射谱，应用９０°散射及背散射得到了各模的峰位值，其中Ｂ₁（ＬＯ）模、Ｂ₂（ＬＯ）模的喇曼谱测量尚未见报道过。根据ＬＯ－ＴＯ劈裂的实验结果，计算出该晶体极化模的有效电荷、振子强度及沿对称轴方向的静态介电常数。 关键词：     

Traveling－Wave Electrooptical Modulator on Polymeric Film with Reversal Poling Structure

Ｔｒａｖｅｌｉｎｇ－ＷａｖｅＥｌｅｃｔｒｏｏｐｔｉｃａｌＭｏｄｕｌａｔｏｒｏｎＰｏｌｙｍｅｒｉｃＦｉｌｍｗｉｔｈＲｅｖｅｒｓａｌＰｏｌｉｎｇＳｔｒｕｃｔｕｒｅ￥ＺＨＯＵＹｉ；ＣＨＥＮＹｉｘｉｎ（ＤｅｐａｒｔｍｅｎｔｏｆＡｐｐｌｉｅｄＰｈｙｓｉｃｓ，Ｓ...     

Hybrid Optical-Electronic Implementation of Morphological Edge Detection

ＨｙｂｒｉｄＯｐｔｉｃａｌ－ＥｌｅｃｔｒｏｎｉｃＩｍｐｌｅｍｅｎｔａｔｉｏｎｏｆＭｏｒｐｈｏｌｏｇｉｃａｌＥｄｇｅＤｅｔｅｃｔｉｏｎ￥ＹＵＡＮＳｈｉｆｕ；ＺＨＡＮＧＸｕｅｒｕ；ＺＨＡＯＳｈｉｊｉｅ；ＬＩＹａｎ；ＣＨＥＮＬｉｘｕｅ（Ｄｅｐａｒｔｍｅｎｔ...     

关于虚拟激励法的一个注记

从具有随机频率与随机相位的随机谐和函数出发,证明了当随机频率与相位均为均匀分布而随机幅值与功率谱密度平方根成正比时,该随机过程的功率谱即精确地等于目标功率谱.进而表明:只需遍历频率区间,即可由单一谐和函数激励下的响应幅值给出响应的功率谱密度,从而揭示了虚拟激励法的物理意义.研究还表明:为了给出结构响应的功率谱密度,实际...