六通道掠入射软X射线针孔照相技术

在对平面反射镜高能X射线截止原理分析研究的基础上,为传统的针孔照相系统配置了光学滤片加平面反射镜组成的滤波系统,消除了大部分的高能尾部的影响。介绍了六通道掠入射软X射线针孔相机的结构设计、工作原理及性能。将光源按光子能量切割成6个能段分别进行记录,滤波后各通道的出射光为窄带软X射线。在阳加速器上对六通道掠入射软X射线针孔相机系统进行考核,加速器输出电流为779 kA,电流上升时间为75 ns,使用的负载为16根环形W丝阵,成功获取了6个通道的针孔照相图像,并结合Dante谱仪相应通道测得的功率时间谱进行了对比分析,确定了部分Z箍缩辐射热点的图像与功率发射谱的对应关系。     

Z箍缩内爆过程中的能量转换机制研究

利用一维三温辐射磁流体力学程序对氖气和铝丝阵Z箍缩内爆过程中的能量转换过程进行了详细的数值研究，发现在内爆过程中离子和电子之间的碰撞能量交换是最主要的能量交换过程，其次是电子和光子之间的光电过程和轫致过程，而康普顿散射过程中的能量交换可以忽略不计；辐射出的x射线主要是在光电激发和光电复合过程中产生的，其次是在轫致辐射过程和康普顿散射过程中产生的.理论分析表明，辐射出的x射线能量可以超过，也可能小于其等离子体最大动能.数值模拟结果表明，在氖气Z箍缩中，辐射出的x射线能量没有超过其等离子体最大动能，而在铝丝阵列内爆中，辐射出的x射线能量超过了其等离子体最大动能，但小于磁压所做的功；在整个Z箍缩过程中欧姆加热能量是较小的. 关键词： Z箍缩 能量转换 x射线辐射     

近top-hat光束Z扫描理论分析

利用快速Hankel变换的方法，对薄介质的Z扫描进行了理论分析。讨论了近top-hat光束 Z扫描曲线的特征，分析了闭孔近top-hat光束下限制光阑半径与光束扩束半径之比（光 阑束腰比）对归一化透射率的影响，通过理论分析，给出了获得最佳测量灵敏度的光阑束腰 比值.在最佳灵敏度的实验配置下分析了远场光阑的大小对归一化透射率的影响. 关键词： 高精度快速Hankel变换 近top-hat光束 Gaussian光束 Z扫描     

Z衬度扫描透射电子显微术的前沿进展

文章介绍了Z衬度扫描透射电子显微术(Z-scanning transmission electron microscopy，Z-STEM，Z为原子序数)的最新进展：Z-STEM可以直接“观察”到晶体中原子的真实位置，Z衬度图像的分辨率在经过球差校正后可达0．6A；在利用Z衬度成像技术对材料的阴极荧光(cathodoluminescence，CL)性质的研究中，首次观察到了“死层”(dead layer)的存在．然后，文章以半导体与结晶氧化物界面结构、Al72Ni20Co8十角形准晶结构以及SrTiO3晶界结构为例，具体介绍了Z衬度成像在测定物质结构与化学组成方面独特的优势。     

快脉冲直线变压器气体开关技术

阐述了Z箍缩驱动惯性聚变装置对快脉冲直线变压器气体开关的需求背景,介绍了快脉冲直线变压器气体开关技术发展的基本要求及国际研究进展,归纳了近年来主要研究成果和对当前研究有重要借鉴意义的结论,给出了提高静态稳定性、降低触发阈值和延长开关寿命的措施。介绍了气体放电的汤逊和流注理论,指出:在不大于1.5106 Pacm范围内,汤逊理论完全适用于描述气体开关自击穿过程。根据巴申定律、Meek击穿判据,给出了开关气压和间距设计要点,分析了多间隙开关间隙数量和间隙的电压分布均匀性对开关自击穿电压的影响。根据触发击穿延时经验公式,归纳了降低触发电压阈值的技术途径。介绍了1维的电极熔蚀判据,并总结了减轻电极烧蚀的方法和措施最后指出开关技术研究总体策略和方法。     

三种金属酞菁配合物的非线性光学性质研究

用YAG皮秒激光器 ,利用“Z scan”方法测量了三种金属钛菁配合物苯硫基钛菁锌 (C56H3 2 N8S4Zn) ,苯硫基铝钛菁 (C56H3 2 AlClN8S4) ,烷氧基铝钛菁 (C56H3 2 AlClN8O4)二甲基甲酰胺 (DMF)溶液的非线性折射率 ,并计算了三阶非线性光学极化率Χ(3 ) 。比较发现 ,不同中心离子 ,不同取代基的金属钛菁配合物的三阶非线性系数不同。文章对引起三阶非线性光学效应的机制做了初步的探讨和分析 ,并简单分析了光动力治疗过程中能量传递的分子机制     

基于CAN总线的接口电路设计

文中介绍了CAN总线的主要性能及特点,CAN总线在实际工业应用中的总体结构,同时给出了CAN总线协议转换器的硬件设计方法和通信协议.主要研究了CAN总线接口电路设计,所设计的总线接口电路由微处理器、CAN控制器、CAN,总线收发器组成,并且详细介绍了CAN控制器、CAN收发器的功能以及CAN总线接口的硬件电路和硬件条件下的软件设计,为后续CAN总线接口电路的应用打下了基础.     

Janus MSiGeN4 (M =Zr and Hf) monolayers derived from centrosymmetric β-MA2Z4:A first-principles study

A two-dimensional (2D) MA2Z4 family with α andβ phases has been attracting tremendous interest,the MoSi2N4 and WSi2N4 of which have been successfully fabricated (Science 369,670 (2020)).Janus monolayers have been achieved in many 2D families,so it is interesting to construct a Janus monolayer from the MA2Z4 family.In this work,Janus MSiGeN4 (M =Zr and Hf)monolayers are predicted fromβ-MA2Z4,which exhibit dynamic,mechanical and thermal stabilities.It is found that they are in-direct band-gap semiconductors by using generalized gradient approximation (GGA) plus spin-orbit coupling (SOC).With biaxi-al strain a/a0 from 0.90 to 1.10,the energy band gap shows a nonmonotonic behavior due to a change of conduction band min-imum (CBM).A semiconductor to metal transition can be induced by both compressive and tensile strains,and the phase trans-formation point is about 0.96 for compressive strain and 1.10 for tensile strain.The tensile strain can change the positions of CBM and valence band maximum (VBM),and can also induce the weak Rashba-type spin splitting near CBM.For MSiGeN4 (M =Zr and Hf) monolayers,both an in-plane and out-of-plane piezoelectric response can be produced,when a uniaxial strain in the basal plane is applied,which reveals the potential as piezoelectric 2D materials.The high absorption coefficients in the visible light region suggest that MSiGeN4 (M =Zr and Hf) monolayers have potential photocatalytic applications.Our works provide an idea to achieve a Janus structure from the MA2Z4 family,and can hopefully inspire further research exploring Janus MA2Z4 monolayers.     

Fluorescent Photochromic α-Cyanodiarylethene Molecular Switches: An Emerging and Promising Class of Functional Diarylethene

Fluorescent photochromic molecules that exhibit distinct light-triggered changes in their emission colors are highly desirable for the fabrication of smart soft materials and advanced photonic devices. α-Cyanodiarylethenes, that is, α-cyano-functionalized diarylethenes, as alternative “non-azo” Z/E photochromic molecular switches, are popular choices due to their unique characteristics such as their aggregation-induced emission or aggregation-induced-enhanced emission behavior in their self-assembled states, and visible changes in fluorescence colors during Z/E photoisomerization. In recent years, the development of fluorescent photochromic α-cyanodiarylethene-based compounds including α-cyanostilbenes, dicyanodistyrylbenzenes, and diaryldicyanoethenes, has mainly focused on molecular design, photochemical and photophysical behavior in solution, and smart soft matter technologies. In this review, recent significant achievements in light-responsive systems based on the Z/E photoisomerization of fluorescent photochromic α-cyanodiarylethene switches that span the range from liquid crystals to gels and finally to self-assembled nanostructures, are highlighted. The smart soft materials constructed from α-cyanodiarylethene molecular switches find use in a plethora of areas, including display, sensing, encrypting, actuating, and biomedical imaging applications, among others. The review concludes with a brief perspective on some major challenges and opportunities for the future development of light-responsive smart soft photonic materials.     

ACPR1000多样化驱动系统的研究与实现

本文讲述了核电站仪控系统增加多样化驱动系统的必要性以及多样化驱动系统需要实现的系统功能。通过分析AP1000项目和方福项目多样化驱动系统的具体实现方案，结合ACPR1000仪控系统的特点，给出了ACPR1000多样化驱动系统的实现方案。