一种新颖的镀膜玻璃可见光透射比测量方法

镀膜玻璃可见光透射比是其光学特性的重要指标之一.本文提出一种玻璃透射比光电积分测量法.与传统光电积分法相比,该方法一次性解决了实验光源与CIE标准照明体、光探测器的光谱灵敏度与CIE光谱光视函数不匹配的问题.给出了该方法中设计校正滤色器光谱透射比的基本算式,并用相对误差最小对校正滤色器进行优化设计,得到了较为满意的结果.实验表明,该方法测量误差为±1%,小于国标标准要求的±2%.利用该方法所设计的测量装置结构简单,测量速度快,开发成本低,有可能应用于在线快速的质量检测.     

光谱规则透射比标准装置的建立

本文介绍了中国计量科学研究院建立的光谱规则透射比标准装置，它是由日立340型分光光度计的基本部件和一台微型计算机组成的，用原子线谱灯检验了它的波长准确度，用截止波长滤光器法检验了它的杂散幅射比率，用双孔径法检验了它的光度非线性，经详细分析，该标准装置的决不确定度为2×10^-4透射比单位，与美国标准技术研究院结比对结果表明，在0．1－0．3透射比范围内的一致性优于6×10^-4.     

高透钻面玻璃在线连续镀膜技术研究

使用立式连续直线镀膜生产线,采用真空磁控溅射技术在玻璃表面设计并镀制了Nb2O5/Si O2/Nb2O5/Si O2/CNx多层纳米硬质增透薄膜,并研究其透过率、硬度及理化性能。结果表明:通过引入线性阳极层离子源,控制并形成新的磁控溅射镀膜工艺,钻面玻璃产品的表面硬度达994.8 HV,是普通玻璃的2倍以上;在可见光透过率≥94%,具有一定的增透效果;经过酸/碱/溶剂/热处理后的透过率衰减ΔT0.1%,理化性能优良。     

Holmium Oxide Glass Wavelength Standards

Holmium oxide glass has been used as a wavelength standard for over four decades. These standards have shown insignificant spectral variation from batch to batch and from one manufacturer to another. The National Institute of Standards and Technology (NIST) has certified and recertified holmium oxide glass samples for over four decades. Over this period of time there has been no recorded instance of a spectral shift of the certified bands for any of the samples measured. Moreover, these samples are known to be robust and relatively insensitive to a normal range of temperature and humidity. Based on the extensive experience that NIST has with this material and its long-term stability, NIST will no longer recommend the recertification of these standards. Furthermore, traceability may be established either through the supplier or by the end user without the need for NIST involvement.     

高可见光透过、高紫外截止镀膜玻璃的制备

为了提高镀膜玻璃的可见光透过率, 本研究通过反胶束溶液刻蚀法制备出一种新型玻璃基板, 即表面多孔玻璃。玻璃表面形成了蜂窝状的多孔膜层, 减小了对可见光的反射率, 从而使可见光平均透过率提高了7%。通过一系列射频磁控溅射实验, 探索了可见光平均透过率高, 紫外阻隔率最高的最佳工艺条件。在此条件下, 分别在制备的表面多孔玻璃和普通玻璃上镀CeO₂/TiO₂防紫外线膜, 并采用紫外-可见分光光度计、SEM、XRD、XPS等测试手段对样品进行了分析表征。结果表明, 在相同的镀膜条件下, 当镀膜后表面多孔玻璃与镀膜普通玻璃的紫外光阻隔率均为99%时, 表面多孔玻璃镀膜后的可见光平均透过率为85%, 而普通玻璃镀膜后的可见光平均透过率仅为79%。此外, 玻璃表面上的孔结构还提高了薄膜与基板的接触面积, 使膜基结合力提高2倍左右。     

Massic Activity Ratios of the NBS/NIST Tritiated-Water Standards Issued Between 1954 and 1999

As part of the preparation and calibration of three new National Institute of Standards and Technology (NIST) tritiated-water radioactivity Standard Reference Materials (SRMs), the massic-activity (activity of the sample divided by the mass of the sample) ratios of all of the available NBS/NIST tritiated-water SRMs issued between 1954 and 1999 were measured using liquid-scintillation (LS) counting. Four of the tritiated-water standards (SRMs 4361, 4926B, 4927C, and 4927D) were not available for measurement. All of the other tritiated-water standards (SRMs 4361B, 4361C, 4926, 4926C, 4926D, 4926E, 4927, 4927B, 4927E, and 4927F) were available, having been stored in flame-sealed glass ampoules. Where possible, massic-activity ratios measured by liquid-scintillation counting are compared with massic-activity ratios calculated from gravimetric dilution factors. The agreement is well within the stated uncertainties. For two of the tritiated-water standards that were not available for measurement (SRMs 4361 and 4926B), massic-activity ratios calculated from gravimetric dilution factors are available.     

用双光路自动测量光谱透过率和彩色贡献指数

本文叙述用双光路自动测量镜头的光谱透过率和彩色贡献指数的控制电路,及利用微机算出和打印光谱透过率和彩色贡献指数的程序流程图。     

Considerations for the Use of Semi-Transparent Metallic Thin Films as Potential Transmittance Standards in Spectrophotometry

Various characteristics of evaporated metal-on-fused silica filters are discussed in relation to their optical transmission properties. Special metal holders provided with shutters were designed to be used with these filters, and are described in detail. Transmittance measurements, performed in various conditions, are reported and indicate that the evaporated metal-on-fused silica filters might present an acceptable material as transfer standards in spectrophotometry.     

硫气氛下热处理后太阳能玻璃减反膜的透过率稳定性

太阳能镀减反膜玻璃作为太阳能电池盖板玻璃,需要长期暴露于室外,因此了解太阳能玻璃减反膜的透过率及其稳定性具有重要意义。本文主要研究了在一定湿度和一定温度环境下,硫气氛下和未通入硫气氛下热处理后的太阳能玻璃减反膜透过率的变化。通过岛津UV-3600测定了玻璃的透过率;利用Nexus傅里叶变换红外光谱仪和INVIA显微共焦拉曼光谱仪测定了太阳能玻璃减反膜的结构。研究结果表明:太阳能玻璃减反膜的透过率稳定性与不同气氛下热处理后的结构有关;在水侵蚀作用下,减反膜的透过率与水的结合类型有关。     

Uncertainty Propagation for NIST Visible Spectral Standards

Uncertainties in the NIST spectral standards for detectors and sources in the visible wavelength range are propagated from the high accuracy cryogenic radiometer measurements, taking correlations into account at every stage. Partial correlations between spectral values at different wavelengths, important for subsequent radiometric calculations, are estimated. Uncertainty propagation through fitting and through transfer spectral measurements is described in detail. Detector uncertainties are propagated through the spectral comparator facility for external calibrations and for internal photometric quantities. Uncertainties in spectral irradiance are derived for the detector-based temperature determination, then propagated through working standards to calibrated artifacts. Spectral irradiance calibrations are generally provided at a limited number of wavelengths. Interpolation, rather than fitting, is recommended for the interpolation of NIST-provided spectral irradiance values.     

石英玻璃上生长表面光滑高光透射率的金刚石膜

石英玻璃衬底在金刚石粉和丙酮形成的悬浮液中超声波预处理,有效提高了金刚石成核密度.在最佳预处理和热丝化学气相沉积条件下,成核密度高达1010 cm-2以上.采用HFCVD中四步法生长工艺,制备出了表面粗糙度小于10 nm、膜厚300 nm、晶粒直径100 nm～150 nm、致密、均匀、高质量和高光透射率的金刚石膜,其1 μm～5 μm波段的光透射率达74%～85%.金刚石膜与石英玻璃衬底结合牢固,膜中无裂纹.     

Nd：碲酸盐玻璃的光谱和激光性质

对比了各种激光玻璃的光谱性质，指出碲酸盐玻璃是一咱理想的激光介质，并资产在室温下实现了钛宝石激光器泵浦了Ｎｄ：碲酸盐块体玻璃的激光发射，激光阈值４．２０ｍＪ，斜率效率１４．７％。     

Frequency Offset Due to Spectral Impurities in Cesium-Beam Frequency Standards

Theoretical expressions for the frequency offset due to spectral impurities in beam-tube frequency standards are given for the case of small sideband to carrier power ratios. They are valid for any value of the separation between the extraneous sideband and the carrier which interrogates the atomic transition, as well as for any value of the power in the carrier. Useful approximations are given in special cases of interest. The effects of the velocity distribution of the detected atoms and of the frequency modulation technique (sine or square wave) are considered.     

The Realization of the Ampere at NBS

We present a method for the realization of the ampere based on Faraday's induction law and using a modification of the classic Pellat balance. A preliminary apparatus has been constructed and initial measurements have been obtained. This balance is also compared with a balance similar to one proposed earlier.     

Filter Transmittance Measurements in the Infrared

We have set up a novel direct detection system to measure filter transmittances over an attenuation range of at least 5 decades, with relative combined standard uncertainties as low as 0.5% (1σ) per decade, in the 9 μm to 11 μm spectral region. This system, using an apparatus originally designed for a heterodyne measurement of transmittance, achieves higher accuracy at the expense of a reduced dynamic range. This independent measurement of transmittance allows verification of the heterodyne technique. Our system uses a source modulated at 30 MHz and a specially constructed high dynamic range and high accuracy lock-in amplifier capable of operation at the modulation frequency. The high modulation frequency and narrow bandwidth of the system allow thermal background radiation to be suppressed and high accuracy to be achieved. We correct for the non-ideal natures of the detector and attenuators. In particular, the detector position is scanned to reduce the effect of its spatial nonuniformity and the deflection of the transmitted beam caused by the nonparallel surfaces of the filter. We discuss the sources of systematic errors and the methodology to reduce their contribution.     

Developments for a New Spectral Irradiance Scale at the National Institute of Standards and Technology

Recent developments for a new spectral irradiance scale realization at the National Institute of Standards and Technology have been targeted to reduce the present relative expanded uncertainties of 0.67 % to 4.34 % (coverage factor of k = 2 and thus a 2 standard deviation estimate) in the spectral irradiance scale to 0.17 % for the range from 350 nm to 1100 nm. To accomplish this goal, a suite of filter radiometers calibrated using NIST’s high accuracy cryogenic radiometer have been used to measure the temperature of a high-temperature black-body. A comparison of the filter radiometer calibrations with the spectral irradiance scale along with an evaluation of the black-body calibration technique have been performed. With the aid of a monochromator, the calibrated filter radiometers will then be utilized to calibrate primary and secondary spectral irradiance standard lamps at NIST.     

铝合金与锌合金牺牲阳极光谱分析内控标样研制

设计研制了铝阳极和锌阳极的光谱分析内控标样。对内控标样进行了化学成份分析，用内控标样建立的工作曲线，对铝阳极和锌阳极的样品进行了光谱分析，与化学分析相比，结果令人满意。     

Control system for the NBS microtron accelerator

As various subsystems of the National Bureau of Standards/Los Alamos racetrack microtron accelerator are being brought on-line, experience has been gained with some of the innovations implemented in the control system. Foremost among these are the joystick-based operator controls, the hierarchical distribution of control system intelligence, and the independent secondary stations, permitting sectional stand-alone operation. The result of the distributed database philosophy and parallel data links has been very fast data updates, permitting joystick interaction with system elements. The software development was greatly simplified by using the hardware arbitration of several parallel processors in the Multibus system to split the software tasks into independent modules.