Hyperspectral mapping-combining cathodoluminescence and X-ray collection in an electron microprobe

An optical spectrometer has been integrated into a JEOL 8900R electron microprobe, which allows simultaneous collection of light, X-ray, and electron signals. The cathodoluminescence signal is collected from a monocular eyepiece, which is integrated into the electron optics of the electron microprobe. The optical acquisition is synchronized with the stage motion. X-ray lines of major elements are collected using an energy dispersive spectrometer, X-ray lines of minor elements are collected using wavelength dispersive spectrometers, and the secondary and backscattered electron signals are collected using standard detectors. In mapping mode of operation the different signals are collected at each pixel with map sizes typically ranging from 1 million to 10 million pixels. This represents a significant amount of data from which the major correlations and associations in the map can be determined. Summing over a small number of channels and examining only a subset of the complete wavelength range are the strategies that have been developed to reduce the size of the data handled. The application of this mapping technique is demonstrated with two examples, zircons and refractory bricks. Zircons with various degrees of metamictization have been characterized, and inclusions differentiated using a combination of cathodoluminescence and X-ray maps. Examination of refractory bricks reveals subtle chemical changes in the spinel grains.     

A new algorithm to align three-dimensional maps of helical structures

By subtracting one three-dimensional (3-D) map from another, one can calculate a difference map that can reveal structural changes, such as conformational changes, not detectable by eye. Furthermore, statistical significances can be assigned to such differences. The validity of the features in the difference map, however, depends on the alignment of the two maps; that is, one needs to align the two 3-D maps so that densities corresponding to equivalent parts of the structures are at the same coordinates. An existing method using the Fourier-Bessel coefficients Gn,1(R) is commonly used for the alignment of maps of helical structures. This procedure works well if the two maps have most features in common. But if they do not, it is difficult to control which features are used in the alignment procedure since the contributions from different features in the map are not easy to separate. We devised a procedure using the radial transform of Gn,1(R) (i.e., g(n),1(r)), which retains the powerful mathematical advantage of the Fourier-Bessel representation of the data and which provides the ability to select the radial features used in the alignment procedure. We applied the new method to 3-D maps of F-actin and F-actin decorated with various myosin motor constructs. Whereas the procedure using G(n),1(R) failed to align myosin-S1 decorated actin to undecorated actin, the new procedure accurately aligned maps.     

Acoustic source localization in a reverberant environment by average beamforming

This paper presents a strategy for the application of acoustic beamforming to locate noise sources in a reverberant field.In the hypothesis of stationary phenomena, the average amplitude and standard deviation of the output of beamforming, obtained from different array locations, are calculated.The standard deviation, normalized by the maximum value, can be used for beamforming output weighting, so as to enhance the source contribution, which is space invariant, and to attenuate the mirrors and sidelobe peaks, whose spatial position changes with changes in array position.The availability of microphone signals acquired when moving the array to a different position also allows a super-array to be obtained, i.e. an array obtained considering all the data as coming from a unique array. In this way, the capability of the averaging procedure to reject mirrors effects and disturbances is combined with high resolution beamforming for application in reverberant fields. These improvements are extended to the entire frequency range, since the procedure is not greatly affected by signal wavelength.     

极紫外（EUV）单色仪波长定标

本文给出了一种新的EUV单色仪定标方法：通过测量标准气体He空阴极光源的30.38nm和58.43nm两条发射光谱和标定过的中心波长为13.90nm Mo/Si多层膜反射镜的反射率峰值位置,对Mcpherson247型EUV单色仪进行波长定标,将所定的标准点在单色仪的运动轨迹上作了相应的标识,并用Origin软件进行处理,利用一元二次方程得出拟合曲线。对标定结果作了分析,得出了在1nm～120nm波段内,用激光等离子体光源软X射线反射率计测量多层膜反射镜反射率时,测量准确度为0.08nm,测量重复性为±0.04nm。     

A novel laser wavelength meter based on the measurement of synthetic wavelength

The accuracy of the current wavelength meter using optical interferometry is limited by the numbers of fringe counted. To solve this problem, a novel laser wavelength meter based on the measurement of synthetic wavelength is proposed. The unknown wavelength is obtained by measuring the value of synthetic wavelength produced by the unknown and reference wavelengths, and half of this value corresponds to 2π variation of the phase difference between the interference signals of the unknown and reference wavelengths. The optical configuration of the wavelength meter is designed and the measurement principle is analyzed theoretically. To verify its feasibility, three helium-neon lasers' wavelengths were determined experimentally, and a relative uncertainty on the unknown wavelength of the order of 10(-8) was realized. Accuracy analysis shows that this wavelength meter has the advantage of high accuracy when the unknown wavelength is around the standard laser wavelength recommended by CIPM.     

电感耦合等离子体发射光谱法(ICP-AES)测定矿石中钼

本文报道了电感耦合等离子体发射光谱(ICP-AES)快速测定矿石中钼的方法 ,为了消除矿石的基体干扰,溶解国家一级标准样品制备成标准系列的标准溶液,制作校准曲线。钼的测定波长为202.030nm。本法检出限为0.094μg/mL,实际测定矿石中大于0.005%以上的钼。相对标准偏差(RSD)的范围:0.12%～1.4%。标样测定结果与国家标准样品值结果一致,矿石样品测定值与分光光度法测定结果一致。     

Irradiance-based emissivity correction in infrared thermography for electronic applications

This work analyzes, discusses, and proposes a solution to the problem of the emissivity correction present in infrared thermography when coatings with known emissivity cannot be deposited on the inspected surface. It is shown that the conventional technique based on two reference thermal images and the linearization of the blackbody radiation dependence on temperature is not a reliable and accurate solution when compared with the coating procedure. In this scenario, a new approach based on the direct processing of the output signal of the infrared camera (which is proportional to the detected irradiance) is proposed to obtain an accurate emissivity and surrounding reflections map, perfectly compensating the thermal maps. The results obtained have been validated using a module as a test vehicle containing two thermal test chips which incorporate embedded temperature sensors.     

Absolute intensity calibration of flat-field space-resolved extreme ultraviolet spectrometer using radial profiles of visible and extreme ultraviolet bremsstrahlung continuum emitted from high-density plasmas in Large Helical Device

A precise absolute intensity calibration of a flat-field space-resolved extreme ultraviolet (EUV) spectrometer working in wavelength range of 60-400 ? is carried out using a new calibration technique based on radial profile measurement of the bremsstrahlung continuum in Large Helical Device. A peaked vertical profile of the EUV bremsstrahlung continuum has been successfully observed in high-density plasmas (n(e) ≥ 10(14) cm(-3)) with hydrogen ice pellet injection. The absolute calibration can be done by comparing the EUV bremsstrahlung profile with the visible bremsstrahlung profile of which the absolute value has been already calibrated using a standard lamp. The line-integrated profile of measured visible bremsstrahlung continuum is firstly converted into the local emissivity profile by considering a magnetic surface distortion due to the plasma pressure, and the local emissivity profile of EUV bremsstrahlung is secondly calculated by taking into account the electron temperature profile and free-free gaunt factor. The line-integrated profile of the EUV bremsstrahlung continuum is finally calculated from the local emissivity profile in order to compare with measured EUV bremsstrahlung profile. The absolute intensity calibration can be done by comparing measured and calculated EUV bremsstrahlung profiles. The calibration factor is thus obtained as a function of wavelength with excellent accuracy. It is also found in the profile analysis that the grating reflectivity of EUV emissions is constant along the direction perpendicular to the wavelength dispersion. Uncertainties on the calibration factor determined with the present method are discussed including charge-coupled device operation modes.     

Generation of Tool Paths for Machining Free-Form Pockets with Islands Using Distance Maps

In this paper, we present a new procedure for generating tool paths using discrete distance maps, especially for dealing with free-form shaped pockets with multiple islands. In this procedure, a discrete distance map is computed by shading a right circular cone having the height of a given offset distance, while moving its apex along the boundary curve segments. Using the discrete distance maps, the proposed algorithm effectively extracts the characteristic points or the valid self-intersection points of offset curve segments. For an offset distance, one or more offset profiles are constructed without the topological problems by offsetting the boundary curve segments within the parameter values specified by these chararteristic points, and connecting them into closed profiles using the topological information contained in the distance map. The gouging-free tool path is constructed by connecting these offset profiles, starting from the innermost offset profile. In the proposed method, we do not need any artificial bridges for a pocket with multiple islands to merge the pocket profile and the island profiles into a single boundary profile.     

三坐标测量机在阀体检测中的应用研究

运用三坐标测量机及配套软件In Spec,对阀体零件进行测量,得到零件的完整测量数据,并通过In Spec测量软件导出数据为CAD图纸,得到测量图。对测量结果进行初步数据分析,检测零件是否合格。     

Instability map based on specific plastic work criterion for hot deformation

Estimating workability is very important to complete the hot or cold working process successfully without making any crack. Instability map was developed by utilizing conventional plastic work criterion in the current study. Hot compression tests were conducted using Gleeble 3800 simulator to obtain flow stress curves as a function of temperature and strain rate. Based on the compression results, new instability map based on the specific plastic work was developed for estimating the instability during the hot deformation process. The critical specific plastic work value was determined by investigating the surface irregularity and shear band formation in the compressed specimens. Then, the instability map determined was applied for predicting surface wrinkle defect during the multi-pass hot bar rolling in combination with the finite element analysis. The predicted results using new instability map suggested matched well with the observations obtained from the industry. The developed approach is easy to apply to the available simulation tools to determine necessary processing parameters.     

A setup for measuring spatial and waveguide characteristics of periodic metal-dielectric structures

An experimental setup and procedure for measuring electrodynamic characteristics of planar periodic metal-dielectric structures, which can be used for manufacturing practical equipment operating in millimeter, submillimeter, and terahertz wavelength ranges. Serviceability of the setup is checked by comparing the waveguide and spatial characteristics obtained experimentally and by numerical methods in a 4-mm wavelength range.     

双波长激光全息干涉测量技术研究

本文研究出了一种双波长激光全息干涉测量技术。论述了双波长激光全息干涉技术的基本测量原理,解决了全息图反演计算,测量光路布置和实验方法等一系列技术问题。本文的工作为火箭发动机,燃气轮机,柴油机,锅炉以及其他动力机构中的液体燃料蒸发这一耦合的传热传质过程的研究提供了一项新的测试手段。     

亚四分之一波长宽波段多层膜的设计

简要阐述了强吸收波段亚四分之一波长多层膜的设计方法。这种膜系是由强吸收材料叠加而成,每层膜光学厚度小于四分之一个波长。与常规周期多层膜相比,这种膜系更适用于提高强吸收波段的反射率。利用该方法设计了50nm~110nm波段宽带高反膜的初始膜系,通过Levenberg-M arquart方法对初始膜系进行优化,从而得到宽波段的平坦反射率,其平均反射率达到45%。     

METHOD FOR PRECISION CALIBRATION OF ROTARY SCALE ERRORS AND PRECISION DETERMINATION OF GEAR TOOTH INDEX ERRORS

A method using the ‘closure principle’ is developed for precision calibration of rotary scale errors of gear measurement machines and precision calibration of gear tooth index errors (accumulated tooth-spacing errors) after ‘removal’ of rotary scale errors. The method uses the standard machine procedure for measuring gear tooth index errors applied to a spur gear artifact mounted between machine centers. Therefore, the rotary scale calibrations include consistent effects arising from eccentricities of machine gear-mounting centers and scale-mounting center relative to the instantaneous axis of table rotation, wobble of the instantaneous axis of table rotation, as well as scale graduation errors, etc. Gear-artifact index errors are referenced to the axis connecting the mounting centers located on the gear. Successful implementation of the method does not require super precision of the gear artifact. A method for obtaining approximate uncertainties (standard deviations) of both scale and index error calibrations is developed that utilises the same measurement data required for the scale and index error calibrations. The developed methods are illustrated by applications to scale and index error calibrations obtained from multiple sets of measurements. Typical standard deviations achieved are under 0.05 μm (1/10th of the wavelength of light). Good consistency is achieved between predicted and measured results. The general methods developed should be useful for other types of rotary axis calibrations.     

Fast stereo matching based on edge energy information

A new improvement is proposed for stereo matching which gives a solution to disparity map in terms of edge energy.We decompose the stereo matching into three parts:sparse disparity estimation for image-pairs,edge energy model and final disparity refinement.A three-step procedure is proposed to solve them sequentially.At the first step,we perform an initial disparity model using the ordering constraint and interpolation to obtain a more efficient sparse disparity space.At the second step,we apply the energy function by the edge constraints that exist in both images.The last step is a kind of disparity filling.We determine disparity values in target regions based on global optimization.The proposed three-step simple stereo matching procedure yields excellent quantitative and qualitative results with Middlebury data sets in a fast way.     

Single Shot Dual-Wavelength Digital Holography: Calibration Based on Speckle Displacements

We present a calibration method which allows single shot dual wavelength online shape measurement in a disturbed environment. Effects of uncontrolled carrier frequency filtering are discussed as well. We demonstrate that phase maps and speckle displacements can be recovered free of chromatic aberrations. To our knowledge, this is the first time that a single shot dual wavelength calibration is reported by defining a criteria to make the spatial filtering automatic avoiding the problems of manual methods. The procedure is shown to give shape accuracy of 35 µm with negligible systematic errors using a synthetic wavelength of 1.1 mm.     

Simultaneous confocal recording of multiple fluorescent labels with improved channel separation

Confocal microscopes are often used to study specimens labelled with fluorophores. A commonly used method for simultaneous recording of the distribution of multiple fluorophores is to divide the fluorescent light emitted by the specimen into different wavelength regions using dichroic and bandpass filters. These different wavelength regions are then distributed to multiple detectors. However, the broad and overlapping spectra of commonly used fluorophores often result in considerable crosstalk between channels. A new technique, intensity-modulated multiple-beam scanning (IMS) microfluorometry, can be used to reduce this cross-talk substantially. The IMS technique is implemented with two laser beams of different wavelengths, intensity-modulated at different frequencies, which illuminate the specimen simultaneously. The two laser wavelengths predominantly excite one fluorophore each. Fluorescent light from the specimen is divided into two wavelength regions (red and green) which are detected by two photomultiplier tubes. The output signals from the photomultiplier tubes are connected to lock-in amplifiers. The effect of using modulated laser beams, in combination with lock-in amplifiers, is strongly to reduce cross-talk between the channels. The performance of the IMS technique using various types of specimen is compared with the results obtained using the conventional multi-detector method.     

恒波长同步扫描固体基质室温磷光法测定水样中的咔唑

本文采用同步扫描固体基质室温磷光(SS-RTP)法测定水样中的咔唑。以β-环糊精修饰滤纸为固体基质,KI为重原子,考查咔唑在芴,7,8-苯并喹啉,苊,蒽等多环芳烃(PAHs)存在下同步扫描的最优条件,选择最佳的△λ值为150nm,建立咔唑的恒波长同步扫描固体基质室温磷光分析方法。咔唑的线性范围是6.30ng.mL-1~1.67μg.mL-1,检出限为6.30ng.mL-1,相对标准偏差(RSD)为3.67%,回收率为94%~109%。该方法简便快速,无需预分离,与常规激发和发射光谱相比分辨力显著提高。