Ocean internal waves interpreted as oscillation travelling waves in consideration of ocean dissipation

Most studies of the synthetic aperture radar remote sensing of ocean internal waves are based on the solitary wave solutions of the Korteweg-de Vries （KdV） equation, and the dissipative term in the KdV equation is not taken into account. However, the dissipative term is very important, both in the synthetic aperture radar images and in ocean models. In this paper, the traveling-wave structure to characterize the ocean internal wave phenomenon is modeled, the results of numerical experiments are advanced, and a theoretical hypothesis of the traveling wave to retrieve the ocean internal wave parameters in the synthetic aperture radar images is introduced.     

5,10,15-三(五氟苯基)Corrole及其相似卟啉化合物的光物理特性

采用稳态和时间分辨的瞬态光谱技术对比研究了一种Corrole化合物5,10,15-三(五氟苯基)Corrole(FtsTPC)和一种卟啉化合物5,10,15,20-四(五氟苯基)卟啉(F20TPP)的光物理特性.结果表明:F15TPC的B带吸收峰较宽而F20TPP的强而窄,F15TPC的Q带有两个吸收峰而F20TPP有四个.F15TPC的荧光量子产率为0.15,荧光寿命为4.8 ns,F20TPP的荧光量子产率为0.05,荧光寿命为11.1 ns;与F20TPP相比F15TPC具有发光效率高、荧光寿命短的特点.F15TPC具有较大的发光速率常数和无辐射跃迁速率常数,这可能是由于F15TPC少了一个氟代苯基,致使其发色团本身的电子结构发生变化所致.另外空间结构的不对称性和非共面性也对其光物理性质有影响.     

共焦扫描显微成象系统的点扩散函数再商讨

针对共焦扫描显微成象中物体相对于被扫描点的位置矢量是反向移动的特性,探讨了物体移动后的物函数在此基础上,根据成象的理论进行了计算,得到新的系统点扩散函数表达式,最后根据计算结果分析成象的性质,得出了系统成象的相干性.     

Microstructure evolution of WC/steel composite by laser surface re-melting

WC/steel composites fabricated by electro-slag melting and casting were re-melted by transverse flow CO₂ laser. Optical microscopy, scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction and transmission electron microscopy were used to analyze the microstructure evolution in laser melted layer. It was found that the laser-affected zone has three distinguished zones, the melted, transient and heat affected zone. The phases of the melted zone were composed of WC, Fe₃W₃C, (Cr,Fe)₇C₃, martensite and retained austenite. The microstructure evolution in the melted zone was represented by the transformation of three parts including the steel matrix, WC particles cluster and dispersed carbides. A significant reactant was herringbone eutectic carbide of Fe₃W₃C. The effect of laser scanning rate was mainly behaved in affecting the melt depth, microstructure of transient zone and dissolution of medium carbides. In comparison with the substrate, the melted zone has much higher microhardness.     

Mode Distribution and Bandwidth Characteristic of Arbitrarily Trapezoidal-Groove Guide for Millimeter Waves

The modes TE and TM of arbitrarily trapezoidal-groove guide are analyzed by using the mode-matching method. The mode TE₁₁ is the dominant mode of the trapezoidal-groove guide under different conditions. The bandwidth characteristic and the operation condition for the single dominant mode are discussed. The obtained conclusions are of very important significance in theoretical study and practical application of trapeziodal-groove guides for millimeter waves.     

The magnetic properties of one-dimensional spin-1 ferromagnetic Heisenberg model in a magnetic field within Callen approximation

The effect of magnetic field h on the magnetic properties of the one-dimensional spin-1 ferromagnetic Heisenberg model is studied by the double-time Green’s function method. The magnetization and susceptibility are obtained within the Callen approximation. The zero-field susceptibility is as a decreasing function of the temperature T. The magnetization m increases in the whole field region, but the susceptibility maximum χ(T_m) decreases. The position T_m of the susceptibility maximum is both solved analytically and fits well to be a power law T_m∼h^γ at low fields and to be linear increasing at high fields. The height χ(T_m) decreases as a power law χ(T_m)∼h^−β with h increasing. The exponents (γ,β) obtained in our results agree with the other theoretical results. Our results are roughly in agreement with the results obtained in the experiment of Ni(OH)(NO₃)H₂O.     

Approximate analytical expressions of apertured broadband beams in the far field

The approximate analytical expressions of the apertured broadband beams in the far field with Gaussian and Laguerre-Gaussian spatial modes are presented.For the radially polarized Laguerre-Gaussian beam,the result reveals that the electromagnetic field in the far field is transverse magnetic.The influences of bandwidth(Γ) and truncation parameter(C 0) on the transverse intensity distribution of the Gaussian beam and on the energy flux distribution of radially polarized Laguerre-Gaussian beam are analysed.     

基于ARM的核磁共振波谱仪气动温控系统设计

提出了一种基于ARM（Advanced RISC Machine,先进精简指令计算机）的核磁共振波谱仪气动温控系统设计方案. 该控制系统以ARM为控制器,利用其内嵌的CAN控制器实现CAN总线通信,通过PID控制算法控制气流和温度,实现控制NMR实验样品的更换和旋转,检测并控制样品的温度等功能. 该设计方案具有系统控制灵活、控制精度高以及成本低的优点.      

Effects of rapid thermal annealing on the optical properties of InAs/(In)GaAs quantum dots with different areal density

The effects of rapid thermal annealing on the optical properties of InAs/(In)GaAs quantum dots (QDs) with different areal density were investigated by photoluminescence (PL) measurement. The annealing results in PL peak energy blue-shift which strongly depends on QD areal density and capping layer. It is noticeable that low-density QDs and/or InGaAs-capped QDs are more sensitive to the annealing. We attribute the larger energy blue-shift from these samples to enhanced strain-driven diffusion and/or defect-assisted diffusion.