Scanning of skin gloss by a diffractive optical element-based handheld glossmeter

Skin specular gloss (referred to as “gloss’’) determination is important in dermatology and cosmetic industry as it gives an indication of the skin health and beauty. Its accurate determination is, therefore, necessary. Commercially available glossmeters typically employ large incidence angle geometry, large illumination area, and fixed point measurements making them impractical regarding measurement of curved and complex non-planar objects or surfaces as well as low gloss regime such as the skin. In this study, we have demonstrated the novel application of a diffractive optical element-based handheld glossmeter with scanning capability, overcoming the disadvantages of conventional glossmeters, in the accurate determination of skin gloss and gloss profile for different skin types under different measurement conditions. Different parts of the body (back of the hands, the inner part of the arm and the forehead) of four volunteers with light, dark and intermediate skin types were scanned (also in different directions) to obtain the skin gloss profile and the statistical average skin gloss. Additionally, the skin surface was modified by arm extension and scanned as well. Our preliminary results showed that the statistical average skin gloss reading increased with the increasing lightness of skin. Areas with higher sebaceous glands (forehead) showed higher gloss reading than the other body parts (inner arm and back of the hand). However, the roughness of the skin surface decreased the statistical average skin gloss reading. The handheld scanning skin glossmeter allows for the accurate determination of skin gloss with sensitivity to small variation in the skin surface roughness with high repeatability.     

基于页岩气返排液中甲烷浓度及排放速率的红外光谱反演研究

随着页岩气的开发,传统的手持式甲烷测量仪无法继续应对复杂的开采工况。针对页岩气开发过程中温室气体甲烷的浓度及排放速率难以实时在线监测的问题,利用自主设计并搭建的开放光程傅里叶变换红外光谱（FTIR）测量系统,对页岩气开采过程中各种工况下返排液进行实时在线测量。其中FTIR分辨率为1 cm-1, 光程为50 m,红外光源通过返排液正上方被光谱仪接收。对测量所得的红外光谱进行多次平均,提高光谱质量并进行反演计算。从HITRAN数据库中提取甲烷特征吸收截面,考虑环境与仪器等影响,对测量温度进行修正,选取合适的吸收波段,与水汽的吸收截面进行吸收峰叠加,合成标准光谱。使用最小二乘法对实测光谱与标准光谱进行拟合,从而反演出甲烷浓度。并根据返排液排放速率,结合光路通过返排池的距离及红外光谱反演浓度,对页岩气开采过程中甲烷排放速率进行计算。结果表明：不同开采工况下,光谱反演浓度呈明显起伏变化。更换三项分离器时,甲烷浓度有明显上升;在点燃火炬时,甲烷浓度持续低值;其红外光谱反演浓度符合页岩气开采过程中甲烷排放情况。改变测量光谱平均次数,对返排液甲烷进行单位小时和连续80小时测量并分析。在单位小时内,甲烷浓度在100～800 μmol·mol-1范围内呈现明显起伏变化;甲烷的排放速率在50～300 m3·h-1内波动。对返排液进行80小时连续测量,甲烷浓度最大值为936.4 μmol·mol-1,其最大排放速率达到535.1 m3·h-1;最低值为36.82 μmol·mol-1最小排放速率为18.63 m3·h-1。反演数据结果说明：在页岩气开发过程中,其返排液为一个无组织甲烷排放源,且排放速率在短时间内变化十分明显。红外光谱反演浓度和传统手持式甲烷测量仪测量结果具有较好一致性,相关系数为0.743 6。相对于传统手持式甲烷测量仪器,红外光谱反演法具有响应速度更快,非接触远距离,实时在线测量等优势。     

Fast handheld two-photon fluorescence microendoscope with a 475 microm x 475 microm field of view for in vivo imaging

A fast handheld two-photon fiber-optic fluorescence endoscope for three-dimensional (3D) in vivo cellular imaging is developed. The compact handheld probe of the two-photon endoscope can simply be placed into contact with the target tissue to reveal clear 3D surface and subsurface histological images without biopsy. The new system has, to the best of our knowledge, the largest field of view (FOV) of 475 microm x 475 microm and a 3D imaging volume larger than 475 microm x 475 microm x 250 microm. A real-time two-photon fluorescence image is displayed at 0.4 mm(2)/s. The lateral and axial resolutions of the two-photon fluorescence endoscope are better than 1 and 14.5 microm, respectively.     

Wavelength-dependence of double optical gating for attosecond pulse generation

Both polarization gating （PG） and double optical gating （DOG） are productive methods to generate single attosecond （as） pulses. In this paper, considering the ground-state depletion effect, we investigate the wavelength-dependence of the DOG method in order to optimize the generation of single attosecond pulses for the future application. By calculating the ionization probabilities of the leading edge of the pulse at different driving laser wavelengths, we obtain the upper limit of duration for the driving laser pulse for the DOG setup. We find that the upper limit duration increases with the increase of laser wavelength. We further describe the technical method of choosing and calculating the thickness values of optical components for the DOG setup.     

Optoelectronic instrumentation enhancement using data mining feedback for a 3D measurement system

3D measurement by a cyber-physical system based on optoelectronic scanning instrumentation has been enhanced by outliers and regression data mining feedback. The prototype has applications in (1) industrial manufacturing systems that include: robotic machinery, embedded vision, and motion control, (2) health care systems for measurement scanning, and (3) infrastructure by providing structural health monitoring. This paper presents new research performed in data processing of a 3D measurement vision sensing database. Outliers from multivariate data have been detected and removal to improve artificial intelligence regression algorithm results. Physical measurement error regression data has been used for 3D measurements error correction. Concluding, that the joint of physical phenomena, measurement and computation is an effectiveness action for feedback loops in the control of industrial, medical and civil tasks.     

三维时域散斑动态干涉测量系统的集成化设计

三维电子散斑干涉技术（3D ESPI）具有非接触、高精度、高灵敏度和全场测量等优点,被广泛应用于许多领域。为了实现非接触动态全场三维测量,设计并建立了一个紧凑、完备的三维测量系统。用一个多波长光纤耦合激光器代替3个独立光源,产生的离面、面内散斑干涉图仅用一台彩色CCD相机就能捕捉和处理;整个测量系统采用笼式结构,具有高度的灵活性和稳定性;对基于小波变换的相位展开算法进行了编程,实现了被测物体三维位移信息的完整提取。实验证明该测量系统可以实时获取被测物体的三维位移,在测量实验中,获得的三维位移值17.68 μm、36.23 μm、13.85 μm,相比于实际位移值18.1 μm、36.4 μm、14.0 μm它们的绝对误差分别为0.42 μm、0.17 μm、0.15 μm,相对误差分别为2.3%、0.5%、1.1%。     

工业园区边界污染气体定量分析及来源研究

工业园区中边界污染气体的浓度不仅受工业园区无组织污染源的排放影响,也受园区道路机动车尾气的扩散影响。利用AG-FTIR-DA3000型开放光程傅里叶变换红外光谱(Open-FTIR)测量系统,对厂区边界污染气体进行实时在线测量,确定污染气体厂界实测浓度。同时,针对机动车尾气扩散影响厂区边界污染气体浓度的问题,通过AG-FTIR-DX4000型便携式傅里叶变换红外光谱(FTIR)测量系统,确定不同排放标准下机动车尾气污染源浓度。利用便携式FTIR测量结果、风速风向、大气稳定度、车流量等变量因素建立参考坐标,给出了高斯扩散的数理模型。并结合Open-FTIR,对Open-FTIR的测量路径进行积分计算并构建点线源扩散模型,从而建立各种排放标准的烟团线源扩散表。将Open-FTIR实测浓度与构建的点线源扩散模型模拟浓度相结合,分析工业园区边界污染气体的来源。结果表明：厂区边界污染气体主要包括一氧化碳、甲烷、乙烯、乙醛、丙烯、甲醇、丙醛、异丁烯、甲醛、二氧化硫,其中一氧化碳、甲烷、乙烯浓度受机动车尾气的扩散影响。早晚高峰期时,机动车尾气的扩散对边界污染气体浓度影响较大;非高峰期,在1:00时与...     

Effect of mineralogical and microstructural properties on surface roughness and gloss of some ornamental marbles subjected to polishing process

High surface finish quality of the produced slabs is generally desirable in the stone processing industry. This paper presents the results of an experimental investigation into the effects of mineralogical‐petrographical and chemical variables on the surface roughness and glossiness of some selected ornamental marbles subjected to grinding–polishing processes. For this purpose, a series of grinding–polishing procedures were performed on the slabs of three distinct marble types. Roughness and brightness measurements were carried out on predetermined surfaces of marble samples using a stylus profilometer and a glossmeter, respectively. Thin sections were examined by a polarizing microscope for mineralogical‐petrographical characterization of the studied marbles. Scanning electron microscopy was used to aid in the identification and characterization of the slab surface morphologies at each polishing stage. X‐ray diffraction and scanning electron microscopy with energy‐dispersive X‐ray spectroscopy were used for the determination of mineralogical and chemical compositions of the samples. Mainly because of the differences in textural and chemical compositions, different levels of microroughness and gloss values were observed for the studied marble varieties. The presence of different mineral phases such as the grain (i.e. calcite to calcite) and phase contacts (i.e. calcite to epidote) greatly affected the heterogeneity of the marbles, resulting with different removal mechanisms under the action of abrasive grits. Copyright © 2013 John Wiley & Sons, Ltd.     

Handheld device for fast and non-contact optical measurement of protein films on surfaces

Thin films of bacteria, proteins and other biochemical substances are almost always found on surfaces exposed to the environment. Optical methods enable innovative tools for the study of such films. Residua of proteins exhibit fluorescence when excited in the UV. We present a specially designed handheld measuring device that can detect organic contamination levels down to 100 ng/cm² with measurement times shorter than a second. Using time-correlated spectroscopy methods the fluorescence detection of contamination levels on surfaces is possible even if the fluorescence spectra of contamination and base material overlap. The results presented in this paper show that a detection of contamination levels of bovine serum albumine (BSA) down to 100 ng/cm² is possible on non-fluorescent materials. A theoretical analysis shows the possibility to detect BSA levels down to less than 1 ng/cm² with the presented setup. Future development of handheld optical devices suitable for the detection or analysis of various compounds can be based on these results. A compact formalism is suggested that can be used to calculate the minimal concentration of a given organic contamination that can be detected with a certain measurement setup.     

线照明并行谱域光学相干层析成像系统与缺陷检测应用研究

针对玻璃缺陷在线无损检测的迫切需求,本文报道了一种基于线照明并行谱域光学相干层析成像系统的大视场检测系统.该系统采用快速面阵CMOS相机,单次拍摄即可获取完整的横截面(B-scan)图像.基于线照明面阵探测器的并行谱域光学相干层析成像系统,可以同时获取沿线照明方向各位置处的深度分辨信息,避免了横向扫描机构的应用.研制系统的轴向分辨率为17.9μm,并行方向上的横向分辨率55.7μm,扫描方向上的横向分辨率为24.8μm,轴向扫描速率为128 000 A-scan/s,横向视场为32 mm,空气中成像深度大于6 mm,成像灵敏度达到62 dB以上.利用研制的线照明并行谱域光学相干层析成像系统,开展了不同类型玻璃表面及其内部缺陷的检测应用研究.     

Qualitative and quantitative ultrashort echo time (UTE) imaging of cortical bone

We describe the use of two-dimensional ultrashort echo time (2D UTE) sequences with minimum TEs of 8 μs to image and quantify cortical bone on a clinical 3T scanner. An adiabatic inversion pulse was used for long T(2) water and fat signal suppression. Adiabatic inversion prepared UTE acquisitions with varying TEs were used for T(2) measurement. Saturation recovery UTE acquisitions were used for T(1) measurement. Bone water concentration was measured with the aid of an external reference phantom. UTE techniques were evaluated on cadaveric specimens and healthy volunteers. A signal-to-noise ratio of around 30, contrast-to-noise ratio of around 27/20 between bone and muscle/fat were achieved in tibia in vivo with a nominal voxel size of 0.23 × 0.23 × 6.0 mm(3) in a scan time of 5 min. A mean T(1) of 223 ± 11 ms and mean T(2) of 390 ± 19 μs were found. Mean bone water concentrations of 23.3 ± 1.6% with UTE and 21.7 ± 1.3% with adiabatic inversion prepared UTE sequences were found in tibia in five normal volunteers. The results show that in vivo qualitative and quantitative evaluation of cortical bone is feasible with 2D UTE sequences.     

超高分辨光学相干层析成像技术与材料检测应用

本文报道了一种超高分辨率谱域光学相干层析成像(SD-OCT)系统. 该系统基于超连续谱激光光源并截取部分光谱作为宽带光源, 其中心波长为665 nm, 光谱半高全宽(FWHM) 230 nm. 系统轴向分辨率0.9 μm, 轴向扫描速率28600行/秒, 横向分辨率3.9 μm, 横向视场1 mm, 最大成像深度0.6 mm(空气中). 利用研制的超高分辨率SD-OCT系统, 对不同型号的工业砂纸精细结构进行了成像, 并与普通SD-OCT的成像结果进行对比, 充分展示了研制系统在材料无损检测中优势.     

Development of an online X-ray fluorescence analysis system for heavy metals measurement in cement raw meal

ABSTRACT

Particulate matters, gaseous chemicals, and heavy metals emitted from industrial processes into the environment could be directly transmitted to humans through air inhalation. In order to accurately estimate health risk and control the source of pollution caused by cement raw meal, an online X-ray fluorescence analyzer system, consisting of an X-ray fluorescence analyzer with data acquisition software and a laser rangefinder, was developed to carry out the measurement of heavy metals in cement raw meal. The X-ray fluorescence analyzer was mounted on a sled, which can effectively smooth the surface of cement raw meal and reduce the impact of surface roughness during online measurement. The laser rangefinder was mounted over the sled for measuring the distance between cement raw meal sample and the analyzer. Several heavy metals and other elements in cement raw meal were online measured by the X-ray fluorescence analyzer directly above a conveyor belt. The limits of detection for Pb, Cr, Fe, Ti, Ca, and S by the analyzer were 47 ± 1, 33 ± 1, 37 ± 1, 44 ± 1, 246 ± 4, and 118 ± 1 mg kg^?1, respectively. The relative standard deviation (RSD) for the elements mentioned was less than 10.7%. By comparison with the results by inductively coupled plasma mass spectrometry (ICP-MS) and CHNS/O elemental analyzer, relative deviation (D) of the online X-ray fluorescence analyzer was less than 7.4% for Fe, Ti, Ca, and S, between 1.71% and 12.10% for Pb and Cr.     

基于二维重组和动态窗格的水质检测紫外-可见光谱去噪算法

立足于成功研制的紫外-可见光谱水质检测多参数测量系统,针对紫外-可见光谱水质多参数原位实时检测在精度、灵敏度、稳定性等方面的实际需要,开展了基于二维重组和动态窗格的水质检测紫外-可见光谱去噪算法的研究,以此提高紫外-可见光谱水质检测的测量精度。光谱法水质检测系统通常使用工业级低成本光谱仪,其输出光谱包含明显的非平稳噪声。传统去噪法难以在滤除噪声的同时保留谱线细节。而且,原位实时水质检测条件下,被测水样可能快速变化,传统去噪法中常用的多次采样求均值法将产生额外的测量误差。引入的去噪算法通过对水样光谱进行等间隙连续采样,将光谱数据张成由光谱轴和时间轴构成的二维矩阵,经过二维小波变换后,设置一个可变宽度的窗格在系数矩阵中水平滑动,使用窗格内的小波系数计算得到动态去噪阈值,并随窗格滑动构建去噪阈值向量,由此进行光谱去噪。其中,窗格宽度由相邻区域的噪声方差变化率决定,变化率较高的区域缩小窗格宽度,反之则扩大宽度。实验结果表明,这种去噪算法不仅能有效去除光谱中的非平稳噪声,而且能保留光谱的细节信息,有助于提高仪器的测量精度。与此同时,由于该算法并未使用时域平均,样本的快速变化对去噪性能的影响较小,适合在线或原位水质检测的水样本环境。     

Frequency multiplexed DOG filter

In order to improve optical correlation performance, a multiplexed DOG (MDOG) filter is constructed from two Difference of Gaussian (DOG) filters, one DOG filter is tuned for noise robustness and the other for accurate object localization. The filter's performance is compared with the CMF, POF and single DOG filter.     

X光分幅相机在黑腔等离子体填充特性研究中的应用

 在神光Ⅱ装置上2.4 ns长脉冲三倍频激光（激光能量8×300 J）与腔靶耦合实验研究中,X光分幅相机通过激光注入孔观测获得了3种腔尺寸腔内Au等离子体径向运动时空分辨图像。用MATLAB对图像进行了定量处理,结合时间分辨辐射温度测量结果分析表明：在腔内不充气、无低Z衬垫情况下,标准腔（800 μm×1 350 μm）在激光脉冲作用到约1.5 ns时出现明显的Au等离子体堵腔效应;当腔尺寸放大到1.25倍（1 000 μm×1 800 μm）和1.5倍（1 200 μm×2 100 μm）时,腔内等离子体基本不堵腔。给出了3种腔尺寸不同时期腔内Au等离子体径向聚心速度,分析表明：大腔的聚心速度比小腔的慢,后期比初期慢。     

Rotational Spectroscopy and Ring-Puckering Conformation of 3-Hydroxytetrahydrofuran

The microwave spectrum of 3-hydroxytetrahydrofuran was recorded using a Fourier transform microwave spectrometer; the rotational constants (MHz) are: A = 5581.8230(7), B = 3638.8316(7), and C = 2924.7410(7). Microwave spectra for four (13)C isotopic species were recorded in natural abundance. Stark effect measurements were used to determine the projections of the dipole moment on the principal inertial axes: μ(a) = 0.956(1) D, μ(b) = 0.875(2) D, μ(c) = 1.050(2) D, and μ(tot) = 1.667(2) D. The internal coordinates of the carbon and oxygen atoms were least-squares fit to the 15 moments of inertia, and the best-fit structure is a C(4')-endo envelope ring conformation, in good agreement with ab initio calculations (MP2/6-31Gdaggerdagger). Copyright 2000 Academic Press.     

Inhomogeneous Double Optical Gating of High-Intensity Isolated Attosecond Pulse Generation in Crossed Metal Nanostructures

We propose and investigate an effective method for obtaining high-energy and high-intensity isolated attosecond pulses (IAPs) using the inhomogeneous double optical gating (DOG) technology in specifically designed metal nanostructures. First, using the homogeneous mid-infrared DOG technology modulated by a linearly near-infrared field, we obtain a harmonic yield of 2.5 orders of magnitudes higher than that from the single polarization gating (PG) technology. Further, introducing the crossed metal nanostructures along the driven and gating components, we can extend not only the harmonic cutoff but also enhance the harmonic yield attributed to the plasmonic field enhancement near the vicinity of metal nanostructures. As a result, we find a single harmonic plateau with smaller modulations. The supercontinuum is not very sensitive to the pulse duration of the near-infrared field, and the harmonic yields can be further enhanced with increase in the pulse intensity of the near-infrared field, showing a 108 eV supercontinuum with an intensity enhancement of 4 orders of magnitudes. Finally, by superposing the selected harmonics from the inhomogeneous DOG scheme, we obtain a 33 as SAP with an intensity increase of 4 orders of magnitudes.     

Sensor for the detection of local contrast gloss of products

We introduce a sensor for providing information on the local contrast gloss (or luster) of products. The sensor also provides information of the local specular gloss of the object. The signals of this sensor are produced by diffractive optical elements from fields that are scattered in the diffuse and specular directions from the object. We present specular gloss, diffuse-reflectance factor related to the contrast gloss, and visibility maps measured from black prints on paper. High variation can be observed in the relevant gloss parameters obtained from the printed area. In addition, borders of the print can be clearly detected from the diffuse-reflectance-factor maps. The sensor also allows detection of raster points of a print. This sensor opens up entirely new means to study prints and other substances.     

T-ray topography by time-domain polarimetry

We demonstrate a method for substantially improving the axial resolution of terahertz time-of-flight measurements by analyzing the time-dependent polarization direction of an elliptically polarized single-cycle terahertz electromagnetic (T-ray) pulse. We show that, at its most sensitive, the technique has an axial resolution of ～λ/1000 (<1 μm) with a subsecond measurement time, and very clear T-ray topographic images are obtained. Such a very high axial resolution of the T-ray topography opens the way for novel industrial and biomedical applications such as fine metalworking and corneal inspection in a safe manner.