Extension of the range of resonator scanning spectrometer into submillimeter band and some perspectives of its further developments

Extension of the working frequency of modern resonator spectrometers into submillimeter wave range is described. Experimental record of atmospheric absorption spectrum covering 45-370 GHz range is demonstrated for the first time, and measured water vapor J′_{ka′, kc′}-J_{ka, kc} = 5_1,5-4_2,2 at 325 GHz line parameters are presented. For the first time pressure lineshift for the 325-GHz water vapor line is measured. Further extension of working range is discussed. New estimations of physical limits of time needed for measurements of absorption in the whole Backward Wave Oscillator (BWO) range are given for phase continuous synthesizer regime. Basic schemes of fast broadband continuous phase synthesized sources are discussed. Verification of the previous measurements of water vapor 3_1,3-2_2,0 at 183 GHz line parameters is presented. Comparisons with ringdown resonator spectrometers are given.     

光谱色散匀滑技术与衍射光学器件联用性能的空间频谱分析

基于空间频谱分析方法，建立了光谱色散匀滑技术(SSD: Smoothing by Spectral Dispersion)与衍射光学器件(DOE: Diffractive Optical Element)联用性能的简化分析模型，为SSD与DOE联用时，SSD参量的优化提供了理论依据.数值模拟了SSD各参量，包括脉冲时间、调制频率、位相调制系数、光栅线色散系数等对束匀滑性能的影响.模拟结果表明，SSD参量经过优化选取，且波前畸变随时间快速变化时，能获得良好的束匀滑性能.     

压气机非定常叶顶间隙流的数值模拟研究

利用数值方法研究了某低速轴流孤立压气机转子中非定常叶顶间隙流的流动特征和频率特性。结果显示转子顶部区域的压力脉动主要来源于叶顶泄漏涡的非定常波动。波动的具体形式表现为泄漏涡瞬态空间位置、尺度和形态的周期性变化,波动频率为1266 Hz。     

Optical modulation and digital demodulation of an in-plane moiré carrier

A rotational mismatch of gratings is used to generate a fringe carrier of an in-plane moiré pattern so that specimen deformation shows itself in the form of modulation of the carrier frequency. As both the unmodulated and modulated carriers are the patterns without fringe-loop or fringe-connection, they are automatically numbered with monotonical increasing orders by a digital image processing system without any ambiguity. The orders at every pixel of the image are determined by interpolation of the orders of the tracked fringes to establish two grey image files, from the difference of which, the orders of the in-plane displacement moiré are displayed with grey-level variation.     

CCD对高空间分辨率波前干涉检测的影响

推导并用实验验证了光强与入射波前在单位像元面积里成近似线性关系，从而得到入射波前经CCD采样后的功率谱密度（PSD）公式.根据该公式，模拟分析了影响CCD采集系统的系统传递函数的各个因素：入射波前、CCD的填充因子及CCD的曝光时间，得出了他们与系统传递函数的定性关系，并且通过实验明确CCD曝光时间对高空间分辨率波前检测不确定度的影响，为高空间分辨率干涉设计提供了理论依据.     

表面活性剂对均相沉淀法制备单晶Ce2O(CO3)2￠H2O微粉形貌及 形成机理的影响

在尿素及硝酸铈的混合溶液中分别加入表面活性剂CTAB、 PEG19000、OP-10,利用均相沉淀法合成了不同形貌的CeO2超细前驱体Ce2O(COa)2·H2O,采用X射线衍射及透射电子显微镜等测试手段,对产品的物相和形貌进行了表征．实验结果表明,所得产品均为斜方晶系的单晶Ce2O(CO3)2·H2O,且表面活性剂的加入使晶体的晶化程度明显提高;添加不同的表面活性剂得到不同形貌尺寸的产物: 阳离子型表面活性剂CTAB对Ce2O(CO3)2·H2O晶体的形貌影响不大,所得产物尺寸变小,且分散性得到一定的改善;非离子型表面活性剂对所得产物的形貌影响显著．加入PEG19000和OP-10分别得到了形状排列有序的、尺寸较均匀的、较规则无团聚的微米棒及具有紧密结合中心的发散状的花样微粒．不同形貌前驱体的形成与晶粒形成生长机理的改变有关．     

Synthesis and Properties of a Heteronuclear Ag（Ⅰ）/Ni（Ⅱ） Complex

Introduction Itiswell knownthatcyanogroupsincyanometa latessuchas[Ag(CN)2]-unitscanbeusedasbridg ingligandsandapolymericstructurecanbeformed throughsilver silver(argentophilic)interactions.This propertyhasbeenexploredintheconstructionofmany oligomericandp…     

Design of polarization retarder suitable for nonlinear optical systems

We present a design technique of retarders suitable for nonlinear optical systems. A thin sample of LiNbO₃ crystal is utilized as a retarder for wide-ranging applications. Analysis shows that the same crystal can be used for single-wave or two-wave retardations, changing the orientation of the crystal only. As an application, the retarder is used to polarize two waves orthogonal, as necessary for difference frequency mixing in an AgGaSe₂ crystal.     

退火温度对Fe基纳米晶粉芯磁致频移特性影响的研究

研究了充有不同温度退火Fe基纳米晶粉芯LC回路的磁致频移特性（MFS），发现充有不同温度退火Fe基纳米晶粉芯LC回路的磁致频移不同，充有经600℃退火Fe基纳米晶粉芯LC回路的磁致频移最灵敏。     

A compact optical heterodyne interferometer by optical integration and its application

A compact high-resolution optical heterodyne interferometer combining a two-frequency light module and a minute optical system is described. The light module, which generates two independent frequencies of light, is fabricated by proton exchange method on LiNbO₃ substrate. We report an experiment evaluating measurement accuracy using a micro-displacement measurement system which incorporates this interferometer. Results of the experiment with a standard thickness sample show high thermal stability with maximum measurement error of 1.8 nm at a temperature from 19°C to 33°C. The system was used to measure the hysteresis of a piezoelectric element for displacements of several nm, thereby making it possible to analyze the system quantitatively in practice.