Fabrication of the beam splitters for soft X-ray laser application

The electron densities of a laser-produced plasma near the critical surface can be measured by using soft X-ray laser interferometry because the soft X-ray laser has shorter wavelength, higher brightness and better coher-ence and so on. It has obvious dominance in the experi-mental research of diagnosing the distribution of electron densities in a laser-produced plasma. The experimental results can not only give the information correlated with plasmas, which cannot be described accurately in t…     

Design and fabrication of soft X-ray multilayer for broadband reflection

A random method used for improving light throughput of a soft X-ray multilayer has been developed in the 18–20 nm spectral region, based on the traditional theory of periodic multilayer, and an 8% gain in integrated reflectance is obtained. The ensemble calculation is presented at the same time, and the multilayer is fabricated by magnetron sputtering. Finally low-angle X-ray diffraction and reflectance comparative measurement are used for testing the multilayer. The results demonstrate that layer thickness disorder yields band broadening and increased integrated reflectance in the spectral range with respect to periodic multilayer, but is accompanied by a reduction in reflectance peak. Layer thickness disorder makes it more difficult to fabricate broadband multilayer, and improving the techniques of layer thickness control is the keystone of experiments.     

Aging effect of Co/C soft X-ray multilayer mirrors

Conclusion We have investigated the aging effect of Co/C soft X-ray multilayers prepared by dualfacing-target sputtering. It was found that phase-separation phenomena exist in the Co/C multilayers, which causes the reflectivity at grazing incidence to increase with time, and can be interpreted as positive enthalpy of Co-C mixing. It is evident that oxidation of the outermost layer of Co/C multilayers with Co deposited last is a potential problem in applications where the highest possible reflectivity is required.     

一种用于GPS的微带天线

利用微带天线理论,研究和分析了美国SENSOR系统公司的GPS微带天线,并找出了结构特点,为该天线的改进提供了理论依据。     

基于边缘增强模板匹配的PTZ主动目标跟踪系统

为实现对运动目标的动态跟踪,设计了基于PTZ摄像机的主动实时跟踪系统,实现对高关注度目标进行持续跟踪。该系统采用背景建模方法检测当前视野中的运动目标并进行跟踪,针对感兴趣目标采用基于边缘增强模板匹配(EETM)方法进行主动跟踪,并提出了一种简单有效的PTZ摄像机控制方法。采用海康威视球机进行测试,测试结果表明:该系统利用低成本PTZ摄像机可以实现对静态场景和动态场景中目标的检测和跟踪,对感兴趣目标进行主动跟踪,PTZ摄像机控制平稳,能够满足实时性的要求。     

自复位耗能摇摆架加固软弱底层框架抗震性能

为改善软弱底层框架的层间变形和能量耗散模式,提出一种结合预应力钢绞线和装配式BRB的自复位耗能(SCED)摇摆架加固方案.对加固后体系进行受力性能分析,并建立有限元模型对SCED摇摆架-软弱底层框架的性能进行研究.结果表明,SCED摇摆架能明显改善软弱底层框架的破坏模式、 抗震性能、 自复位性能和变形模式,但是钢绞线和...     

Ways to produce and measure atto- and femtosecond soft X-ray pulses

The ways to produce and measure atto-and femtosecond soft X-ray pulses are reported. The laser phase relation of high-order harmonic generation(HHG) shows two different radiation energy distribu-tions in time(or laser phase) domain. These energy-phase relations are helpful for realizing the dy-namic processes of HHG. Two presented parameterized formulas can be used to calculate the durations of the energy distributions with a bandwidth of the pulse. These formulas are useful in calculating and simulating pulses transports and interactions with mediums. The time structures of atto-and femto-second soft X-ray pulses can be directly measured with photoelectron spectrum transfer equations and the related laser phase determination methods without any previous pulse shape and the instantane-ous frequency assumptions. These equations and methods can be used to evaluate and improve the technical parameters of the ultra-short X-ray sources. They have wide measurement ranges and high time resolutions,which may enable ultra-fast measurements to reach metrological precisions,and lead to a new tide of scientific researches in physics,chemistry,biochemistry,etc. The application of atto-and femtosecond X-rays as well as the theoretical and technical problems in measurements are briefly discussed.     

广义框架的近似对偶框架的构造及扰动

框架的对偶框架与框架本身一样在表示信号时起着重要的作用.本文首先基于线性算子理论提出广义框架的近似对偶框架概念,然后构造广义框架的一系列近似对偶框架.最后,建立广义框架的近似对偶框架的扰动结果.     

LD侧面泵浦全固态声光锁模激光器

采用热补偿环形径向侧面泵浦Nd:YAG模块进行了连续主动声光锁模激光的实验研究, 利用自行设计的锁相环反馈电路,获得脉冲宽度为488 ps,输出功率达10 W的稳定锁模脉冲输出.     

一种计算屏蔽微带线的近似方法

提出了一种计算屏蔽微带线特性阻抗的近似方法,同精确方法的计算结果相比,偏差并不大,具有一定的工程意义。     

合肥国家同步辐射实验室软X射线磁性圆二色实验站建设及其初步应用

介绍了软X射线磁性圆二色谱的基本原理，合肥国家同步辐射实验室软X射线磁性圆二色实验站的主要装置，及其采用的相关技术，包括通过斩波器的同步光圆偏振度的计算及其与光通量的折中处理方法、光束线的主要组成和针对本储存环通量低所作的设计、与该实验站兼容的磁铁设计和采用的样品电流采集方式等，并介绍了各部分达到的性能指标．最后用该实验装置对不同厚度的Co多晶薄膜的自旋磁矩与轨道磁矩进行了初步研究，发现随薄膜厚度增加，样品自旋磁矩逐渐增大，而轨道磁矩逐渐减小．     

具有阻带抑制特性的微带带通滤波器设计

应用传输线理论分析了并联微带开路线产生传输零点的原理,设计了一个基于双模谐振器结构,中心频率为1.9 GHz、分数带宽为2%的改进型微带发夹式带通滤波器.仿真和实验结果较为一致,表明该类型的滤波器具有显著的上边阻带抑制特性,可以应用于高性能微波滤波器和双工器的设计中.     

一种用于回波增强的无源微带阵列

回波增强器在小目标探测等领域有着广泛的应用。为了增加小目标的可探测距离,本文通过使用带有微带传输线的无源正方形微带贴片阵元设计了一个无源阵列式回波增强器。其实现方法包含两部分：一是通过改变微带传输线长度进而改变电流分布来控制阵元贴片的回波方向;二是通过改变阵元间距控制阵列的回波方向。仿真结果显示一个二元阵列与同样尺寸的金属板相比,在指定方向上的RCS增强显著,很好的实现了回波增强。     

宽阻带缺陷地结构微带线

根据光子晶体和等效电路理论在微波波段的应用,针对50Ω微带线提小了一种新型一维周期缺陷地结构（DGS）,不同于以前文章的有关周期DGS,该新型的DGS单元品格是非均匀的．理论分析、仿真和实验表明：新型的DGS电路的阻带较宽,通带的波纹较小,并且阻带的中心频率和阻带的宽度可以根据设计的要求人为地改变。     

应用于便携设备的新型多频微带缝隙天线

提出一种新型微带缝隙天线,通过在辐射贴片上开倒T形单极子槽得到覆盖WiFi和GPS频段的多频天线;通过适用相位延迟双微带馈线实现天线的宽带特性,研究不同天线参数对天线性能的影响.采用商业仿真软件CST2009得到的仿真结果与实验测得的结果比较符合.     

有限维Hilbert空间中等模紧框架的一类构造方法

利用H_n中已有的等模紧框架构造H_(n+1)中的等模紧框架;并利用H-_n中已有的紧框架来构造H_(n+1)中的Parseval框架.最后给出了在这种方法下构造R~n中框架元素个数为n+1的比较稀疏的单位模紧框架的具体表达式.     

微微秒光电导采样技术及应用

本文介绍了微微秒光电导采样技术的原理，应用自己研制的微微秒光电导采样系统测量了自制的ｐｓ光电导开关、超高速光电探测器、同轴电缆线的色散展宽、锁模Ａｒ激光的脉冲宽度和ＧａＡｓ场效应晶体管的响应时间等。