Simultaneous multichannel mass-specific detection for high-performance liquid chromatography using an array detector sector-field mass spectrometer

The use of a separation step, such as liquid chromatography, prior to inductively coupled plasma mass spectrometry (ICP–MS) has become a common tool for highly selective and sensitive analyses. This type of coupling has several benefits including the ability to perform speciation analysis or to remove isobaric interferences. Several limitations of conventional instruments result from the necessity to scan or pulse the mass spectrometer to obtain a complete mass spectrum. When the instrument is operated in such a non-continuous manner, duty cycle is reduced, resulting in poorer absolute limits of detection. Additionally, with scanning instruments, spectral skew can be introduced into the measurement, limiting quantitation accuracy. To address these shortcomings, a high-performance liquid chromatograph has been coupled to an ICP–MS capable of continuous sample introduction and simultaneous multimass detection. These features have been realized with a novel detector array, the focal plane camera. Instrument performance has been tested for both speciation analysis and for the elimination of isobaric interferences. Absolute limits of detection in the sub picogram to tens of picograms regime are obtainable, while the added mass dimension introduced by simultaneous detection dramatically increases chromatographic peak capacity.     

Real‐time lock‐in energy loss imaging with a novel high‐speed image processing CCD video camera

We have developed a high‐speed image processing CCD video camera for real‐time energy‐loss imaging using a conventional electron microscope with an energy‐loss imaging facility. As an initial demonstration of real‐time lock‐in energy‐loss imaging, a background‐subtracted energy‐loss image was observed by attaching the high‐speed image processing CCD video camera to an analytical electron microscope equipped with a floating‐type energy‐loss imaging analyser. Copyright © 2003 John Wiley & Sons, Ltd.     

Integrated Digital Image Correlation considering gray level and blur variations: Application to distortion measurements of IR camera

The acquisition of images with different modalities may involve different alterations with respect to an ideal model. Inhomogeneous brightness and contrast, blur due to non-ideal focusing, distortions are common. It is proposed herein to account for such effects for instance by registering a calibration target image with an actual optical image to measure lens distortions. An Integrated Digital Image Correlation (I-DIC) algorithm is proposed to account for the above artifacts and the algorithm is detailed. The resolution and uncertainty of the technique are first investigated on synthetic images, and then applied to the measurement of distortions for infrared (IR) images. The procedure is shown to reduce drastically the residual level assessing the validity of the image formation model, but more importantly allowing for a much improved registration of images.     

航天相机热实验测试系统设计

为了检测航天相机在高低温环境中的电子学性能及可靠性,针对某型号航天相机地面热实验测试需求,设计开发出了一种热实验测试系统,详细介绍了系统的软硬件设计方案及控温策略。系统使用人机交互界面实现热控策略,能实时完成最高80个测试点(160个温度传感器及80路加热器)的控温任务,可以在－30℃～＋50℃范围内对航天相机进行全方位的温度监控,最高控温精度达到0.5℃。经过实际测试验证,系统具有很好的稳定性,能满足航天相机地面热实验的测试需求,工程应用价值高。     

Characteristic X-ray detector: In-situ imaging of radioactive contaminant distributions

The characteristic X-ray detector (CXRD), a CsI(Tl) scintillator with a 50-mm diameter, is a directional X-ray sensor that measures characteristic X-rays from radioactive material, such as ¹³⁷Cs, and identifies the direction of radioactive contamination. We evaluated a CXRD and visualized the distribution of radioactivity in the contaminated area near the Fukushima Dai-ichi nuclear power station, where the ambient dose equivalent rate was 2.1 μSv/h at 1 m above ground level. We found a good correlation between the characteristic X-ray fluxes and the distribution of radioactive contaminants with a 0.823 Pearson product–moment correlation coefficient.     

Observation of radially polarized terahertz radiation generated by a sub-picosecond electron beam

The fundamental property of radially polarized terahertz radiation, which is axial symmetry of the polarization state in the radial direction, was measured with a Schottky diode detector and with a terahertz camera and wire-grid linear polarizer. Radially polarized terahertz radiation was generated from coherent transition radiation using a 30-MeV sub-picosecond electron beam. Bow-tie intensity distributions, aligned along the polarization direction, were clearly observed with the terahertz camera and could be rotated by changing the direction of the linear polarizer. The measured intensity distribution agreed with the calculated value. A video of the data can be found online.     

Evaluation of radiation damage behavior in polyimide aerogel by infrared camera and photoacoustic spectroscopy

In this work, the optical absorption and thermal properties of polyimide aerogel have been investigated by Infrared Camera, ultraviolet–visible and photoacoustic spectroscopy under low energy proton irradiation. The characterization method of the infrared camera can obtain the optical absorption ratio, and meanwhile get the information of specific heat capacity. Moreover, it can acquire the nature information of damaged area rather than the overall performance. The results show an increase in optical absorption after proton irradiation, which is in good coincidence with Ultraviolet–visible spectroscopy analysis. And the specific heat capacity decreased linearly with proton fluences, which can be attributed to the irradiation damage and carbonization in polyimide aerogel. The Raman spectra suggested the cleavage of chemical bonds and carbonization in polyimide aerogel. This work provides the novel, non-destructive and sensitive methods to characterize irradiation damage of aerogel.     

基于两平行线及其线上三点的摄像机标定方法

在大视场交通监控摄像机的标定中,由于不便于放置大尺寸标定靶标,常采用交通标线构成的特定几何图形替代标定靶标,但许多交通场景仅有一组平行的车道分界交通标线,难以获得传统标定方法所需的标定约束条件。针对此类交通场景,选取两平行交通标线和其中一条线上的三点作为标定参考物,依靠其中一条线上三点在单幅图像中的像素坐标、三点间的两个距离值及平行线间距作为约束条件来完成摄像机的标定。建立了图像坐标系与世界坐标系之间新的换算关系,推导出了摄像机内外参数的求解公式,探讨了旋转角对测量误差的影响。实验结果表明,在约束条件不足的情况下能够获得较好的摄像机参数近似解,沿道路方向上的测距精度优于对比文献的结果,具有标定参考物选取容易、操作简便、几何约束条件少等优点,适用于交通监控系统中大视场摄像机的快速标定场合。     

Flexible sheet with radiophotoluminescence glass beads for remotely monitoring high beta-surface-contamination

A flexible sheet was made with radiophotoluminescence (RPL) glass beads on an experimental basis for visualization of high beta-surface-contamination. A simple RPL observation system for remote contamination monitoring was constructed with a homemade UV floodlight and a commercially available digital camera with supplementary optical lenses and filters. In preliminary experiments, RPL images were well observed with the digital camera of the present system. Their precise RPL intensity was determined after the correction of nonlinear response of the camera. It was expected from experiments that RPL images of beta-surface-contamination could be quantitatively evaluated through calibration, i.e., the conversion of camera images to dose data on the sheet-type glass dosimeter.