高温超导微带滤波器的研究

参照有关文献编制了高温超导体微带带通滤波器设计ＣＡＤ软件，文中介绍了编制的方法和流程图，并与有关实验结果进行比较，表明该软件具有较好的正确性和实用性，此外用软件对ＧｄＢａＣｕＯ／Ａｇ微带滤波器进行设计和实验，得到滤波器性能较大幅度的结果。     

原子簇产生的统计规律与结构分析（Ⅲ）

多元原子簇的形成受统计规律所控制。由统计规律描述的原子簇通式为ＡＢｎ或ＡＢｎＣｍ，其中Ｂ，Ｃ为构成原子簇的可变的活性单元，它可能是单个原子，也可以是由几种元素组成的化合物集团，Ａ是同一系列原子簇的核心，由不同的Ａ加减Ｂ，Ｃ所生成的原子簇系列由不贩统计分布曲线来描述，从统计学观点来看，多元原子簇中的所胆ＡＢｎ和大部分（ＡＢｎ）Ｃｍ都可归为一类，具有与二元原子簇相似的规律，还有一些多元簇ＡＢｎＣｍ包含     

Ag／YB12Cu3O7—x,Al／YBa2Cu3O7—x界面特性分析

利用电学测量方法结合二次离子质谱（ＳＩＭＳ）技术对金属Ａｇ与Ａｌ与ＹＢａ２Ｃｕ３Ｏ７－ｘ（ＹＢＣＯ）超导薄膜接触界面电学性质和扩散特征进行了测试分析，分析结果显示由于Ａｇ和Ａｌ具有不同的化学性质，二与ＹＢＣＯ界面的互扩散特性有明显不同，这些不同影响到接触界面的电学性质和接触窗口下ＹＢＣＯ超导性能，在Ａｇ／ＹＢＣＯ样品中，在高于３５０℃以上的温度下氧气氛中退火将引起Ａｇ和Ｏ的界面互扩散，但对ＹＢＣ     

Ag／YBa_2Cu_3O（7－x）、Al／YB_2Cu_3O（7－x）界面特性

利用电学测量方法结合二次离子质谱（ＳＩＭＳ）技术对金属Ａｇ和Ａｌ与ＹＢａ２Ｃｕ３Ｏ（７－ｘ）（ＹＢＣＯ）超导薄膜接触界面电学性质和互扩散特征进行了测试分析．分析结果显示由于Ａｇ和Ａｌ具有不同的化学性质，二者与ＹＢＣＯ界面的互扩散特性有明显不同．这些不同影响到接触界面的电学性质和接触窗口下ＹＢＣＯ的超导性能．在Ａｇ／ＹＢＣＯ样品中，在高于３５０℃以上的温度下氧气氛中退火将引起Ａｇ和Ｏ的界面互扩散，但对ＹＢＣＯ体内Ｏ的分布及ＹＢＣＯ的超导性能影响不大，且有利于在界面形成好的电学接触；在Ａｌ／ＹＢＣＯ样品中，在高于３５０℃以上的温度下氧气氛中退火后，界面则主要发生Ｏ向Ａｌ膜体内的扩散，并在Ａｌ和ＹＢＣＯ界面生成一不导电的氧化层，这些将影响到ＹＢＣＯ体内Ｏ的分布和接触窗口下的ＹＢＣＯ的超导性能．在合适的退火条件（约５００℃氧气氛中）下退火，Ａｇ与ＹＢＣＯ将形成小的接触电阻，利用剥离工艺制备的样品，其界面接触电阻率ρ（ρｃ＝Ｒ×Ａ）高于是１０（－６）Ωｃｍ２．     

动态MOCVD法在Ag／Ni复合基体上连续制备YBCO超导带

本报道用ＭＯＣＶＤ方法在以１５ｃｍ／ｈｒ速度连续走带的Ａｇ／Ａｉ复合基体上制备ＹＢＣＯ超导带的结果。所有ＹＢＣＯ超导带的Ｊｃ值为１．３×１０＾４Ａ／ｃｍ＾２；样品主相为ＹＢＣＯ１２３，呈强烈ｃ－轴取向，其衍射峰的摇摆曲线半高宽约为２．８°；另外，还含有少量Ｙ２ＢａＣｕＯ５和ＢａＣｕＯ２杂相，本还用ＳＥＭ和ＥＤＸ对样品沉积层进行了观测分析。     

激光电离飞行时间质谱法研究Al原子与卤代甲烷气相化学反应

利用分子束和飞行时间质谱技术研究了激光烧蚀金属Ａｌ原子与４种不同的卤代甲烷：ＣＣｌ４，ＣＦ３Ｃｌ，ＣＦ３Ｂｒ，ＣＦ４的气相反应，由激光电离飞行时间质谱检测的结果表明，Ａｌ与ＣＦ３Ｃｌ反应生成ＡｌＣｌ，而与ＣＦ３Ｂｒ反应生成ＡｌＢｒ，与ＣＣｌ４及ＣＦ４反应分别生成ＡＣｌ及ＡｌＦ。     

激光等离子体相互作用中超热电子输运过程的蒙特卡罗模拟

利用蒙特卡罗（Ｍｏｎｔｅ－Ｃａｒｌｏ）方法模拟了激光等离子体相互作用中所产生的超热电子在固体物质中的输运过程，模拟运算采用连续慢化（ＣＳＤＡ）和玻恩（Ｂｏｒｎ）近似的单一散射模型。文中给出了具有单能，束状分布的超热电子在双层固体靶中产生的Ｋα射线强度随表面靶层厚度的变化曲线。     

粉末套管BPSCCO／Ag复合带载流各向异性特征的研究

本工作采用直流传输电流和直流磁化行为的测量研究了经恰当热－机制处理后的ＢＰＳＣＣＯ／Ａｇ复合带的临界电流特性，表明：由于ＢＰＳＣＣＯ晶粒的强ｃ轴择优取向，传输和磁化临界电流密度呈现大的各向异性，磁场在ｃ轴的分量起有主要作用，因传输和磁人监蚧电流密度相应于各向异性临界电流密度的不同主分量，故它们随角度变化的行为不同，传输电流的Ｉ－Ｖ曲线入磁驰豫Ｍ－ｔ曲线都呈现幂指数关系，即分别为Ｖ∝ＡＩ和Ｍ∝Ｂｔ，     

Nd∶LMA自锁模飞秒激光器腔结构最佳化设计

Ｎｄ∶ＬＭＡ晶体相对低的非线性折射率ｎ２，使得针对Ｔｉ∶Ｓａｐｐｈｉｒｅ自锁模激光器设计的腔，对Ｎｄ∶ＬＭＡ介质而言并没有提供足够的自幅度调制（ＳＡＭ）为了在Ｎｄ∶ＬＭＡ激光器上实现自锁模，在腔内引入一个具有大的非线性系数ｎ２、快的响应时间的ＳＦ５７介质，这样就使得激光腔的结构比较特殊在这篇文章里利用ＡＢＣＤ传输矩阵对该激光器的结构从理论上进行了分析和计算，使腔结构达到了最佳化设计     

不同气氛退火对Tl2Ba2CaCu2Ox超导电性的影响

本研究了Ａｒ气和Ｈ２／Ａｒ混合气体退火对Ｔｌ２Ｂａ２ＣａＣｕ２Ｏｘ（２２１２）超导体超导电性的影响。实验表明，在Ａｒ气中４００℃退火１至１２小时后Ｔｌ２Ｂａ２ＣａＣｕ２Ｏｘ的Ｔｃ（Ｒ＝０）随退火时间的增长明显降低。Ｘ－光衍射分析证实，在Ａｒ气或Ｈ２／Ａｒ混合气体中退火前后，Ｔｌ２Ｂａ２ＣａＣｕ２Ｏｘ超导体的结构没有发生变化。     

Design of broadband beamformers based on an expected response interpolation technique

A method for designing broadband beamformers based on an expected response interpolation technique was proposed, with the aim of reducing the heavy optimization burden in the broadband beamformer design problem. In the method, some typical frequencies in the designing frequency band are selected and the optimal array weights are designed on these typical frequencies, based on which a broadband expected response function is constructed. Then, FIR filters are designed to realize the broadband beamforming over the whole designing frequency band, via the interpolation technique which is utilized to the expected responses of the FIR filters. Broadband beamforming can be fulfilled by applying these filters to each of the sensors in the array. By using the proposed method, designers need not to divide the whole designing frequency band into narrow subbands so as to make the narrow band assumption valid, which not only reduces the heavy designing burden, but also releases the requirement for measurements at fine frequency grids in the robust beamformer design. Results of both computer simulations and watertank experiments verify the effectiveness of the proposed method.     

偏心和倾斜光学系统的像差特性

运用一种新的分析偏心和倾斜光学系统初级像差特性的方法—矢量像差理论,分析了具有较大交叉倾斜角的平行平板光学系统和具有较大倾斜角的光楔光学系统的像差特性.通过ZEMAX光学设计软件像差分析功能中的垂轴像差曲线、场曲曲线和点列图加以比较,两者非常吻合,证明该理论可以对具有较大倾斜元件的非共轴光学系统设计起指导作用.     

全光通信网的计算机仿真设计

为了规范、设计、仿真和优化全光通信网,开发一套功能强大的光网用计算机辅助设计软件(OCAD)是十分必要的.在本文里,我们总结了两种用来设计、优化WDM全光网O-CAD的方法:频域分析法(FDA)和时域分析法(TDA).最后基于SHAONET全光通信试验平台,开展了初步的OCAD设计工作,结果表明它对于设计和分析全光网的性能是十分有用和有效的.     

夫琅禾费衍射自动演示仪

介绍了夫琅禾费衍射自动演示仪的功能和实现方法.该仪器由光源、PASCO公司制作的狭缝盘、探测器、液晶显示器、计算机、单片机及步进电机等硬件组成.通过对单片机和计算机上的软件设计实现演示夫琅禾费衍射现象.该仪器还既可实现由计算机控制操作,也可以脱机独立操作.     

Applied validity of effortless method for design of sinusoidal surface microstructure

With the purpose of easily analyzing and designing the transmittance performance of a sinusoidal surface microstructure, the validity of effortless methods including scalar diffraction theory and effective medium theory has been evaluated quantitatively by the comparison of diffraction efficiencies predicted from scalar theory and effective indices theory, respectively, with exact results calculated with the rigorous vector method of Fourier modal method. Generally speaking, when the normalized period of surface microstructure is less than ten wavelengths of the incident light the scalar diffraction theory is believed to be inaccurate for designing and analyzing the diffraction efficiency of surface microstructure. But, in this paper, it is found that scalar diffraction theory can be used for predicting transmittance of the optical elements when the normalized period is more than three wavelengths of incident light within the error less than 5% at normal incidence. In addition, it is generally recognized that the effective medium theory is inaccurate for analyzing periodic surface microstructure when the normalized period is more than a tenth of the wavelength of incident light. However, the results in this study shows that effective medium theory is accurate as only zero-order waves are to propagate through the surface profiles, which the maximum difference between zero-order effective indices method and rigorous vector method reaches to 1%. Besides, the limitation of both simplified theories is dependent on not only the normalized period of a surface microstructure but also the normalized groove depth. Therefore, the range of applied validity of scalar theory and effective medium theory is expanded quantitatively compared to that of previous inaccuracy application for more easily designing and analyzing a sinusoidal surface microstructure.     

Design of one-dimensional Lambertian diffusers of light

We describe a method for designing a one-dimensional random surface that acts as a Lambertian diffuser. The method is tested using rigorous computer simulations and is shown to yield the desired scattering pattern.     

Arduino控制器CAN驱动模块的设计

随着Arduino控制器在测控系统和通信系统中的广泛应用,其CAN总线模块的开发技术日益关键,故将Arduino控制器的CAN驱动设备创建作为研究对象,从硬件电路设计到底层驱动开发进行了详细研究,以Simulink作为开发环境,采用嵌入式Matlab函数模块创建CAN驱动模块,并以实际电机应用例子的通信实验验证模型的准确性和可靠性。通过CANoe测试软件采集的传输通信数据,结果表明基于Simulink开发的CAN通信模块调试成功。这不仅为后续系统级的开发奠定了良好的通信基础,也给其他驱动模块的开发带来了启发。     

A fast algorithm for DC design of millimeter wave impatts

Computation of steady state I-V characteristics combined with the expression of dc to rf conversion efficiency in terms of voltages across avalanche and drift regions can be used for profile optimisation of mm-wave Impatts. This provides a faster design when compared to using comprehensive simulation programmes for the same purpose. The algorithm developed for faster computation of dc I-V characteristics of Impatts is described here with some specific example where the results of the present computation are compared with those obtained by other method. A good agreement, within ±0.2%, has been observed. Since the method involved here does not require large computer memory, a desk top computer with modest capabilities is good enough for designing the profiles for Impatts efficiently. The method is general in nature and can easily be adopted for device designs for lower frequencies as well.     

Design of one-dimensional Lambertian diffusers of light

Abstract

We describe a method for designing a one-dimensional random surface that acts as a Lambertian diffuser. The method is tested using rigorous computer simulations and is shown to yield the desired scattering pattern.     

分数阶Lorenz系统的分析及电路实现

频域传递函数近似方法不仅是常用的 分数阶混沌系统相轨迹的数值分析方法之一, 而且也是设计分数阶混沌系统电路的主要方法. 应用该方法首先研究了分数阶Lorenz系统的混沌特性, 通过对Lyapunov指数图、分岔图和数值仿真分析, 发现了其较为丰富的动态特性, 即当分数阶次从0.7到0.9以步长0.1变化时, 该分数阶Lorenz系统既存在混沌特性, 又存在周期特性, 从数值分析上说明了在更低维的Lorenz系统中存在着混沌现象. 然后又基于该方法和整数阶混沌电路的设计方法, 设计了一个模拟电路实现了该分数阶Lorenz系统, 电路中的电阻和电容等数值是由系统参数和频域传递函数近似确定的. 通过示波器观测到了该分数阶Lorenz系统的混沌吸引子和周期吸引子的相轨迹图, 这些电路实验结果与数值仿真分析是一致的, 进一步从物理实现上说明了其混沌特性. 关键词： 分数阶系统 Lorenz系统 分岔分析 电路实现