Design of broadband achromatic metasurface device based on phase-change material Ge2Sb2Te5

Based on the phase-change material Ge₂Sb₂Te₅ (GST), achromatic metasurface optical device in the longer-infrared wavelength is designed. With the combination of the linear phase gradient GST nanopillar and the adjustment of the crystalline fraction m value of GST, the polarization insensitive achromic metalenses and beam deflector metasurface within the longer-infrared wavelength 9.5 μm to 13 μm are realized. The design results show that the achromatic metalenses can be focused on the same focal plane within the working waveband. The simulation calculation results show that the full-width at half-maximum (FWHM) of the focusing spot reaches the diffraction limit at each wavelength. In addition, the same method is also used to design a broadband achromatic beam deflector metasurface with the same deflection angle of 19°. The method proposed in this article not only provides new ideas for the design of achromatic metasurfaces, but also provides new possibilities for the integration of optical imaging, optical coding and other related optical systems.     

3－乙酰基卓酚酮还原新途径的研究

３－乙酰基卓酚酮还原新途径的研究高文涛，张宝田，于会文（锦州师范学院化学系１２１００３）天然产物中存在着许多酮系化合物，目前已分离出８０种以上合有酮骨架的化合物。如桧科松柏类树中的具有抗真菌活性的日柏醇，绿霉代谢产物中的细柄酸以及秋水仙球根的成份秋水...     

一类带等式约束非光滑最优化问题的逐次二次规划方法

本文对一类带等式的非光滑最优化问题给出了一种逐次二次规划方法。这类问题的目标函数是非光滑合成函数，约束函数是非线性光滑函数。该方法通过逐次解二阶规划寻找搜索方向，使用ｌ１－罚函数的非精确线搜索得到新的迭代点。我们证明了算法的全局收敛性并给出了数值试验结果。     

Y（F4‘）条件与加强形式的停止定理

首次提出了Ｙ（Ｆ４＇）条件，给出了Ｙ（Ｆ４＇）条件的两个等价关系，得到了加强形式的停止定理和强鞅的一个等价关系。     

方程x~((n))+f_1(t)x~((n-1))+f_2(t)x~((n-2))+…+f_(n-1)(t)■+f_n(t)x=0解的稳定性

考虑方程z~((n))+f_1(t)x~((n-1))+f_2(t)x~((n-2))+……+f_(n-1)(t)x+f_n(t)=0 (1)在现有文献中,对方程(1)的研究几乎能集中在二阶,对于 n>2的情形,很少见到。本文应用变换技巧以及.直接方法,特别利用文[9]的推广了的方法研究了 n 为任意正整数的方程(1)的平凡解的稳定性,得到了其平凡解全局一致渐近稳定性的充分条件。特别当 n=2时所得的结果包含了文献[1-8]的有关结果。有些结果就非文[8]的条件所能得到,如本文定理4、5及其推论1。     

下料问题的优化模型及其快速算法

结合生产实际中具体的下料问题,本文建立了该类问题的优化模型,并提出下料方式的遴选三准则,即高利用率优先准则,长度优先准则和时间优先准则.运用本文的算法对一维下料的利用率高达99.6%,机器时间4秒.对二维的利用率为98.9%,机器时间约7秒.     

What Is Its Real Existing Form?——Theoretical and Experimental Studies on 2-Mercaptobenzothiazole

1 INTRODUCTION The study of heterocyclic molecules with aroma- tic rings and their absorptions on metals is of con- siderable importance from both theoretical and te- chnological points of view. These molecules are in- teresting because of their applications as corrosion inhibitors and flotation collectors, and their abilities to form self-assembly layers[1]. 2-Mercaptobenzo- thiazole (C7H5NS2, in the following MBT) is an important heterocyclic molecule, which can be used as corrosion …     

激光自混频干涉效应中相位噪声的测量

本文研究了半导体激光器的自混频干涉效应,使用法布里-珀罗腔将输入场的相位噪声转换为强度噪声,完成了不同反馈以及不同外部距离下相位噪声的测量,并与自由运转时量子阱半导体激光器的相位噪声进行了比较.理论与实验基本一致.     

Multiparty Quantum Secret Sharing of Key Using Practical Faint Laser Pulses

Based on a bidirectional quantum key distribution protocol [Phys. Rev. A 70 (2004)012311], we propose a (m-1, m-1)-threshold scheme of m (m≥3)-party quantum secret sharing of key by using practical faint laser pulses. In our scheme, if all the m-1 sharers collaborate, they can obtain the joint secret key from the message sender. Our scheme is more feasible according to the present-day technology.