用原位漫反射红外光谱研究升温速率对HMX炸药热分解过程的影响

传统研究材料热稳定性的方法包括热失重（TG）（热介电法、热电阻）、真空安定性（VST）、差热分析（DTA）、差示扫描量热法（DSC）等。其中，TG是测量炸药重量变化与温度的函数关系，ST是测量真空状态下炸药热分解所产生的气体量，DTA和DSC是测量炸药在不同温度下，由于发生相变所表现出的变化（吸热或放热）。以上这些方法得到的是炸药热性质的宏观信息，而无法反映炸药在不同温度下的微观化学变化。原位红外光谱法是一种新兴的动态研究方法。该方法结合ir原位实时监控和红外光谱精确分析物质化学结构的优点，通过实时跟踪材料在不同温度下的化学变化，测定材料的微观结构与温度的关系。     

大气光学湍流测量中平均时间和原始数据的筛选

 在使用温度脉动仪测量温度结构常数时，平均时间长度的选择会影响其测量结果。通过实际测量数据的分析和讨论，确定平均时间应该为10s左右，以得到真实可靠的结构常数。由于温度脉动仪在测量时会受到各种因素的影响，为了筛选掉不可靠的测量结果，提出了一种用温度脉动原始数据来对测量结果进行筛选的方法。该方法首先排除了实验纪录中的错误测量数据，其次对于异常的实验数据，如某一层结构常数数据的异常偏大或偏小，需要根据双点温差原始数据的频谱分析来确认数据是否正常，以进一步排除异常的测量结果，尽可能保证用以统计分析的数据真实可靠。     

BOXCARS测量燃烧场的温度

 介绍了用BOXCARS技术测量CH₄/air火焰的温度。给出了甲烷气体不同流量下和火焰不同高度处的温度测量结果，分析了温度随甲烷气体流量变化和火焰高度变化的变化趋势，根据实际的实验参数计算了相应的空间分辨率。实验结果表明：利用BOXCARS技术可进行高精度、高空间分辨的温度测量。     

基于小波变换的蓝宝石荧光光纤温度计

采用激光加热小基座法生长出掺Cr3+的蓝宝石光纤荧光温度传感头，它具有结构紧凑，耐高温等特点，测温范围从室温到450℃。使用基于小波变换的数据处理方法，有效去除信号中的噪声，提高了信噪比。在对荧光测温机理和有关光纤技术进行分析的基础上，采用与调制荧光信号相关的双参考源相位锁定测量方案，可在无激励光干扰的情况下对荧光寿命进行实时测量。根据噪音和信号在小波变换下表现出的不同性质，提出以小波变换为基础的温度信号特征提取及消噪方法。与其它处理方法相比，小波变换方法可以克服傅里叶变换对突变信号不起作用的缺点，同时又比Gabor变换具有可变窗口的优点。该方法可以缩短测量时间，提高测量分辨率。     

自来水电阻率的测定

给出了自来水电阻率测量的一种方法,并做了具体测量;通过测量不同温度下的电阻率,研究它的温度系数α.     

减压氩气下基体对激光微等离子体电子温度的影响

以激光微区发射光谱分析仪结合CCD光栅光谱仪为装置，采用二谱线法，以FeⅠ356.54nm和FeⅠ358.12 nm为分析线，在减压氩气下，测量了镁基体、铝基体、硅基体和低碳钢标样6-0中的激光微等离子体的电子温度及其空间分布，给出了相同基体中微等子体电子温度的空间变化趋势和不同基体中相同空间位置处的电子温度的差异并进行了分析.利用测量的结果，以CuⅠ324.75 nm和ZnⅠ334.50 nm为分析线，从电子温度角度探索了两分析谱线相对强度的基体效应，给出了合理的解释. 关键词： 激光微等离子体 电子温度 减压氩气 基体     

由电感测量铁氧体材料的居里温度

为测量铁氧体磁芯材料的居里温度，将含有铁氧体磁芯的螺绕环置于自制的可变温度的样品室中，用电感测量仪测量螺绕环在不同温度下电感量．得到电感随温度的变化曲线，从而确定磁芯的居里温度．     

薄带非晶态磁性材料晶化温度的测量

利用普通电学测量方法，通过不同加热率和保温温度测量了非晶态磁性材料的电阻率随温度变化情况，找到了非晶体磁性材料的晶化温度及其变化规律．     

基于控温系统的超声光栅测量透明液体浓度

浓度是描述溶液特性的重要物理量,随温度的改变而发生变化.基于超声光栅测量透明液体中声速的方法,以透明溶液氯化钠溶液为例,通过控制变量法研究了声速、浓度、温度三者之间的关系,最终定量得出三者所满足的方程,实现了不同温度下浓度的测量.结果表明,该方法测量液体浓度置信度高,相对误差小,且广泛适用于透明液体浓度的测量,具有时效性高、反映时间短、精度高等优点。     

DOAS烟气测量系统的温度非线性补偿方法

基于紫外差分吸收光谱技术,针对温度对烟气浓度测量的影响,提出一种非线性补偿方法.在紫外波段200-230nm波长范围内,以SO2和NO标准气体为研究对象,从50℃到90℃间隔10℃变化测量其吸收光谱,利用多项式拟合的方法计算气体差分吸收截面,研究温度与吸收截面的定性和定量关系.实验结果显示,不同波长点的两种气体吸收截面随温度变化呈非线性关系.采用非线性补偿修正后,SO2和NO的测量误差明显减小,该方法可提高烟气测量的准确度.     

Guided-Wave Two-Dimensional Acousto-Optic Scanner Using Proton-Exchanged Lithium Niobate Waveguide

Two-dimensional scanning of a 0.6328 mum guided-light beam has been realized using noncolinear acousto-optic (AO) coplanar Bragg diffraction together with colinear AO guided-mode to substrate radiation-mode conversion in a Z-cut Xpropagation LiNbO3 proton-exchanged (PE) waveguide. The two surface acoustic (SAW) waves utilized are at the center frequencies of 500 and 200 MHz, propagating in the Y and X axes, respectively. Two-dimensional scanning of approximately 720 resolvable light beam spots, namely, 18 40 (horizontal vertical) scanning, has been demonstrated using a light beam of 1.0 mm aperture. The total number of resolvable beam spots can be greatly increased from 720 by simply utilizing SAW transducers of larger bandwidth and a light beam of greater aperture. It should also be possible to significantly increase the diffraction efficiency from 3 % by optimizing the parameters of the PE waveguide and the SAWs.     

Hybrid Wavelength and Code Division Multiple Access in Optical Networks

A review of schemes for multiple access in fiber optic networks shows that a hybrid of wavelength and code division multiple access (WCDMA) combines the best features of both. In particular, the hybrid scheme retains the large information carrying capacity of wavelength division multiple access (WDMA) and flexibility of code division multiple access (CDMA). In this paper WDMA, optical CDMA (OCDMA), and WCDMA networks are discussed. In OCDMA networks, concept of incoherent and coherent coding including inverse decoding and matched filter is introduced. The delay performance of both WDMA and WCDMA networks, under the simple suboptimum access protocols based on cyclic search, is computed. It has been shown quantitatively that tuning delay significantly affects the delay performance of both WDMA and WCDMA networks. Futhermore, delay performance of WCDMA networks is always better than the WDMA networks for the same tuning delay, load, and number of users.     

Effect ofγ-radiation on the spectral luminescence characteristics of impure cadmium tungstate crystals

Results of a study of the effect of γ-radiation on the spectral luminescence properties of cadmium tungstate crystals doped with silver, bismuth, and molybdenum cations are presented. Spectral characteristics of the nondnnnoped crystals are briefly described. Absorption and photo and X-ray luminescence spectra of the crystals taken before and after exposure to γ-radiation (5.5·10⁴ Gy) are compared. It is found that the spectral characteristics of the crystals doped with silver, bismuth, and molybdenum cations do not change markedly after the exposure. The relation between the type of impurity-induced defects, individual characteristics of the impurity cations, and the character of the effect of γ-radiation on the spectral luminescence properties of impure crystals is analyzed (preliminarily). Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 1, pp. 55–60, January–February, 1997.     

Femtosecond Transform-Limited Pulse Generation by Compensating for the Linear Chirp of SPM Spectra in Dispersion Shifted Fibers

A simple technique of pulse compression, based on the linear chirp compensation of self-phase modulation (SPM) spectra in dispersion shifted fibers, is demonstrated. The optimization procedure is carried out, for a short span of a single-mode fiber, using a parabolic law, which describes the behavior of the squared output pulse width versus the pump peak power in the case of Gaussian pulses. The experimental results give a minimum pulse duration of 233 fs, which is in good agreement with the model. Shorter and coherent pulses, down to 90 fs, have been obtained by inserting an interference filter at the optical output.     

Sorting of bending magnets for the SSRF booster

The Shanghai Synchrotron Radiation Facility(SSRF)booster ring,a full energy injector for the storage ring,is deigned to accelerate the electron beam energy from 150MeV to 3.5GeV that demands high extraction efficiency at the extraction energy with low beam loss rate when electrons are ramping.Closed orbit distortion(COD)caused by bending magnet field uniformity errors which affects the machine performance harmfully could be effectively reduced by bending magnet location sorting.Considering the affections of random errors in measurement,both ideal sorting and realistic sorting are studied based on measured bending magnet field uniformity errors and one reasonable combination of bending magnets which can reduce the horizontal COD by a factor of 5is given as the final installation sequence of the booster bending magnets in this paper.     

Measurement of nonlinear coefficient of optical fiber based on small chirped soliton transmission

We measure the waveform and phase curves of short optical pulses before and after transmission over different lengths of fibers by use of the pulse analyzer with the frequency-resolved optical gating (FROG),and numerically simulate pulse evolution under the experimental conditions.The nonlinear coefficient of the fiber is given by comparing the experimental results with the numerical ones.Difference between the experiment and numerical simulation is analyzed.     

Resonance scattering of canonical elastic shells in absorbing fluid medium

Resonance scattering of elastic spherical shell and cylindrical shell while the surrounding fluid medium has absorption is studied. The normal mode solution derived using exact elastic theory and the separation of variables is still applicable. However, the scattering form function has to be modified for the absorbing medium, otherwise the unreasonable result would be obtained. The backscattering form function in the absorbing medium is redefined, and the form function of elastic spherical and cylindrical shell with vacuum or solid matter filled is calculated in various absorption conditions. The results show that the absorption of surrounding fluid leads to notable attenuation of the coincidence resonances in the mid-frequency, but it has a little influence on the low-frequency resonance scattering induced by the filler inside the shell.     

Single-beam self-referenced phase-sensitive surface plasmon resonance sensor with high detection resolution

A versatile and low-cost single-beam self-referenced phase-sensitive surface plasmon resonance(SPR)sensing system with ultra-high resolution performance is presented.The system exhibits a root-mean-square phase fluctuation of ±0.0028.over a period of 45 min.i.e.a resolution of±5.2×10-9 refractive index units.The enhanced performance has been achieved through the incorporation of three design elements:a true single-beam configuration enabling complete self-referencing so that only the phase change associated with SPR gets detected,a differential measurement scheme to eliminate spurious signals not related to the sensor response,and the elimination of retardation drifts by incorporating temperature stabilization in the liquid crystal phase modulato .Our design should bring the detection sensitivity of non-labeling SPR biosensing closer to that achievable by conventional fluorescence-based techniques.     

Influences of SiO2 protective layers and annealing on the laser-induced damage threshold of Ta2O5 films

Ta2O5 films are prepared on BK7 substrates with conventional electron beam evaporation deposition.The effects of SiO2 protective layers and annealing on the laser-induced damage threshold (LIDT) of the films are investigated.The results show that SiO2 protective layers exert little influence on the electric field intensity(EFI)distribution,microstructure and microdefect density but increase the absorption slightly.Annealing iS effective on decreasing the microdefect density and the absorption of the films.Both SiO2 protective layers and annealing are beneficial to the damage resistance of the films and the latter is more effective to improve the LIDT.Moreover,the maximal LIDT of Ta2O5 films is achieved by the combination of SiO2 protective layers and annealing.