新型干涉高光谱成像系统的光束剪切特性分析

提出了一种基于新型双折射横向剪切分束器的高光谱成像方法,采用的横向剪切分束器主要由Wollaston棱镜和角锥反射体组成.在分析双折射分束器的偏光结构和分光机理的基础上,利用光线追迹方法分析了光束在Wollaston棱镜中的传播特性,通过计算光束在双折射分束器中的传播方向及出射位置,推导出调制光程差的理论表达公式.根据理论推导结果,分别仿真分析了系统在不同扫描模式下光程差与入射光视场角以及角锥顶点偏移量的调制关系.基于理论分析结果搭建了实验装置,对光程差分析结果进行验证,实验结果与理论分析结果匹配较好.所提方法可以提高剪切光束的平行性,保证干涉条纹的高调制度,降低了复原光谱准确度对光学装调精度和元件加工精度的依赖性,具有结构稳定、复杂度低的显著特点.     

Strength and equation of state of molybdenum triboride under 80 GPa pressure,using radial X-ray diffraction

The strength and equation of state of molybdenum triboride have been determined under nonhydrostatic compression up to 80?GPa, using an angle-dispersive radial X-ray diffraction technique in a diamond anvil cell (DAC). The RXD data yield a bulk modulus and its pressure derivative as K_0?=?342(6)?GPa with K₀′?=?2.11(17) at ψ?=?54.7°. Analysis of diffraction data using the strain theory indicates that the ratio of differential stress to shear modulus (t/G) ranges from 0.002 to 0.050 at pressures of 4–80?GPa. Together with theoretical results on the high pressure shear modulus, our results here show that molybdenum triboride sample under uniaxial compression can support a differential stress of ～10?GPa when it started to yield with plastic deformation at ～30?GPa. In addition, we draw a conclusion that MoB₃ is not a superhard material but a hard material.     

A catadioptric infrared dual band optically passive athermal optical system

The paper proposes a catadioptric infrared dual band optical system based on catadioptric configuration and optically passive athermal design method. The system shares primary mirror, secondary mirror and collimating lens group, and achieves abruption in longwave infrared and midwave infrared using a dichroic beam splitter. The influence of temperature on optical parameters, the design theory and design method are analyzed. A design example is presented. The detailed optimization design method and some considering factors in engineering design moment are discussed. The design results illustrate that the system can obtain good image quality in environment temperature of 10–40?°C, which could satisfy the design requirement. The actual test result not only satisfies the design requirement, but also validates the availability of the method in the paper.     

微通道板固定图案噪声及测试研究

叙述微通道板的噪声,着重介绍微通道板固定图案噪声及其简便新颖而又实用的一种测试方法,给出测试结果并进行分析。     

X波段高功率微波选模定向耦合器

高功率、长脉冲是高功率微波技术发展的趋势,提高微波器件的功率容量成为一项重要的任务,使用过模器件可以有效提高微波源的功率容量,然而却会带来微波源中同时存在多种模式的问题。为了识别一个X波段长脉冲过模高功率微波源的输出主模TM01模式,设计了一种在线选模定向耦合器,进行了理论分析和模拟优化设计。当频率范围为9.2~9.6 GHz时,模拟结果显示该选模耦合器对TM01模的耦合度为-54 dB,在400 MHz带宽内定向性大于35 dB,对TM02模的抑制度大于15 dB,功率容量可达到3 GW以上。     

Processing of Fluorescence Lifetime Image Using Modified Phasor Approach: Homo-FRET from the Acceptor

As the hardware of FLIM technique becomes mature, the most important criterion for FLIM application is the correct interpretation of its data. In this research, first of all, a more orthogonal phasor approach, called as Modified Phasor Approach (MPA), is put forward. It is a way to calculate the lifetime of the complex fluorescent process, and a rule to measure how much the fluorescence process deviates from single exponential decay. Secondly, MPA is used to analysis the time-resolved fluorescence processes of the transfected CHO-K1 Cell lines expressing adenosine receptor A₁R tagged by CYP and YFP, measured in the channel of the acceptor. The image of the fluorescence lifetime and the multiplication of the fluorescence lifetime and deviation from single exponential decay reveal the details of the Homo-FRET. In one word, MPA provides the physical meaning in its whole modified phasor space, and broadens the way for the application of the fluorescence lifetime imaging.     

非线性发展方程的Riemann theta 函数等几种新解

为了构造非线性发展方程的复合型无穷序列精确解, 获得了第二种椭圆方程的Riemann theta 函数等几种新解.在此基础上,利用第二种椭圆方程与Riccati方程的Bäcklund变换和解的非线性叠加公式, 借助符号计算系统 Mathematica, 以mKdV方程为应用实例, 构造了该方程的复合型无穷序列新精确解.这里包括Riemann theta 函数、Jacobi椭圆函数、双曲函数、 三角函数和有理函数,通过几种形式构成的复合型无穷序列新精确解. 关键词： 第二种椭圆方程 Riccati方程 非线性发展方程 Riemann theta 函数无穷序列解     

Direct observation of surface‐enhanced Raman scattering in ZnO nanocrystals

We have been able to observe the surface‐enhanced Raman scattering (SERS) from 4‐mercaptopyridine (4‐Mpy) molecules adsorbed on ZnO nanocrystals, which display 10³ enhancement factors (EFs). An excitation wavelength‐dependent behavior is clearly observed. Another molecule BVPP is also observed to have surface‐enhanced Raman signals. The chemical enhancement is most likely responsible for the observed enhancement, since plasmon resonances are ruled out. The research is important not only for a better understanding of the SERS mechanism, but also for extension of the application of Raman spectroscopy to a variety of adsorption problems on a semiconductor surface. Copyright © 2009 John Wiley & Sons, Ltd.     

Focused ion beam Moiré method

A focused ion beam (FIB) Moiré method is proposed to measure the in-plane deformation of object in a micrometer scale. The FIB Moiré is generated by the interference between a prepared specimen grating and FIB raster scan lines. The principle of the FIB Moiré is described. The sensitivity and accuracy of deformation measurement are discussed in detail. Several specimen gratings with 0.14 and 0.20 μm spacing are used to generate FIB Moiré patterns. The FIB Moiré method is successfully used to measure the residual deformation in a micro-electro-mechanical system structure after removing the SiO₂ sacrificial layer with a 5000 lines/mm grating. The results demonstrate the feasibility of this method.