二极管阵列检测器波长校准方法研究及评价

波长校准是二极管阵列检测器研制过程中一个重要的环节,可直接影响到光谱定性定量的准确度。利用原位光源——氘灯的特征光谱结合氧化钬玻璃的透过光谱对二极管阵列检测器进行波长校准,比较波长标准值的取值方式以及校准方程的拟合方式对校准结果的影响,并使用偏差平均值、偏差标准差、均方根误差对校准结果进行评价。结果表明,多点高次函数拟合的校准结果更准确,其中多点三次函数校准结果的偏差平均值、偏差标准差、均方根误差分别是–2.97×10~(–3) nm、0.47 nm、0.44 nm。对自制光电二极管阵列检测器进行波长校准,波长误差在±1 nm以内。     

基于参量振荡探测对流层CO2的差分吸收雷达

设计了一种新颖探测对流层二氧化碳气体的 1572nm 差分吸收雷达,它的发射系统基于脉冲的种子注入 KTP 参量振荡器(OPO)。OPO 由 1064nm Nd:YAG 多模激光泵浦,转换效率 10%,重复频率 20Hz,OPO 的腔长由 PZT 单元和二氧化碳多通道吸收池精确控制,种子注入时,它可以产生单模窄带的信号光脉冲输出, 对应的空闲光输出仍然是多模。窄带 on 光源(线宽小于600MHz)对应于二氧化碳光谱的强吸收线,宽带 off 光源(150GHz)对应于光谱的弱吸收线。on 和off 双波长工作是通过对种子光的 10Hz 开关来得到的。雷达接收系统的核心是近红外光电倍增管和光子计数器,光电倍增管制冷到-60℃以降低其噪声。实验表明,该雷达的信噪比在 6km 以内大于 10 :1(10 分钟 6000 个脉冲累加)。     

近红外Mg2Si/Si异质结光电二极管的结构设计与仿真

本工作设计了近红外Mg_2Si/Si异质结光电二极管的器件结构,并采用Silvaco-TCAD对器件主要性能参数(包括光谱响应、暗电流等)进行模拟仿真,优化了器件的结构参数和工艺参数。仿真结果表明:所设计的pin型光电二极管在波长为0. 6～1. 5μm时比pn型光电二极管具有更高的响应度,峰值波长为1. 11μm时,响应度最高达到0. 742 A·W~(-1),1. 31μm处响应度为0. 53 A·W~(-1)。pin型光电二极管的暗电流密度较pn型光电二极管略大,约为1×10~(-6)A·cm~(-2)。Mg2_Si/Si异质结中间界面态密度也不宜超过1×10~(11)cm~(-2)。     

宽光谱光电折射仪

本文报导了宽光谱光电折射仪的设计原理和结构性能。仪器采用三种接收器和多种光源,可在0.2～12μm广阔波长范围内精密测定固体材料的折射率。通过计算机控制实现了自准直角的自动寻的和测量过程的自动化。在上述光谱范围,折射率的测量准确度可达第五位小数(±6×10~(-6)～±5×10~(-5))。     

液相色谱仪最小检测浓度测量值的不确定度评定

本文介绍了2014年8月14开始实施的JJG705-2014《液相色谱仪检定规程》中涉及的液相色谱仪紫外-可见检测器、二极管阵列检测器、荧光检测器、示差折光率检测器、蒸发光散射检测器最小检测浓度测量不确定的评定方法。     

高效液相色谱法测定家用装饰材料中甲醛、乙醛的含量

考察了甲醛、乙醛、2,4-二硝基苯肼的最佳衍生化条件,建立了高效液相色谱法同时测定内墙涂料中的甲醛、乙醛含量的方法。选用EclipseXDB-C18色谱柱(150mm×4.6mmi.d,5μm),以甲醇-水溶液(80:20,v/v)作为流动相进行洗脱,利用二极管阵列检测器,检测波长350nm。该方法具有较好的重现性和线性关系,相关系数均达到0.995以上,加标回收率分别为93.7%和95.9%,检测限分别为2.5×10-4mg·L-1和2.2×10-4mg·L-1。该方法简便、准确、灵敏度高。     

非线性频率电压变换器在光声检测中的应用

一、引言 光声效应是物质吸收了调制光能转变为声能的效应[1]。由于光声检测技术具有测量范围广,辐射波长宽,灵敏度高及试样要求低等优点,因此光声检测技术不仅可用于检测物质的弱吸收,而且可广泛用于进行物质的物理[2]、化学[3]及生物过程[4]的研究,以及物质特性的检测。采用非线性频率电压变换器制成的速度可调式斩光器,以其高度的稳定性,并配以锁定放大器,可以测量极其微弱的信号,在光产检测中有着广泛的应用前景。 二、工作原理 非线性频率电压变换器的线路图如图1所示。输入信号为一个连续方波信号,经过CC4069的整形后送往D触发器CC4…     

基于p-Se/Al2O3/n-ZnO纳米棒阵列异质结的自驱动紫外-可见光探测器

自驱动光探测器能够在无外加偏压的情况下将光信号转化为电信号, 在工业和军事领域有着广泛的应用。本研究报道了p型Se薄膜和n型ZnO纳米棒阵列异质结的可控合成以及它们作为自驱动紫外-可见光探测器的应用。由于在ZnO和Se的界面处形成的内建电场将光生电子-空穴对分离, 促使它们向相反方向传输, 最终被电极收集, 在0偏压下获得了较高的光电流(435 pA), 从而实现无线的自驱动光电探测。并且, 在Se和ZnO界面处沉积的Al₂O₃层有效降低了暗电流。最终, 此器件在500 nm的单色光下显示了高响应率55 μA·W ^-1和大比探测率5×10 ¹⁰Jones, 并表现出了极快的响应速度(上升时间0.9 ms, 衰减时间0.3 ms)。     

SANOA长光程差分吸收光谱仪故障维修1例

SANOA长光程差分吸收光谱仪用于空气污染地面自动监测子站的二氧化硫，一氧化氮，氮氧化物，甲醛，氨，臭氧等的测量。它的工作原理是用差分吸收原理，测量从紫外线光源发出的透过大气的光，根据每种气体成分对紫外光的特征吸收谱线，计算大气中该气体的浓度。SANOA由一个固定光源(150W紫外灯)，接收器，数据处理系统组成。紫外灯发射一光束，穿过一定距离的空气后到达接收器，经分光后，由512象素的光电二极管阵列接收(每个象素对应一个波长)，经14位A／D转换器送人CPU进行分析计算。     

使用硅光电二极管测量激光功率时的几个问题

由于硅光电二极管在测量光信号时响应快、线性好、灵敏度高、噪声低、性能稳定,故近年来在激光功率测量中获得了广泛的应用,尤其是在测量微瓦级以下的激光信号时更显得重要。随着硅光电二极管自校准技术的发     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Brainstorming for ISO Strategy 2016-2020

正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from     

CNAS Passes APLAC's PTP Review

正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively.     

新闻(英文)

正China and Greece Sign the Standardization Cooperation Agreement Witnessed by Chinese Premier Li Keqiang and Greek Prime Minister Antonis Samaras,AQSIQ Minister Zhi Shuping and ELOT Chairman and Executive Director Angelos Tolkas signed the SAC-ELOT Standardization Cooperation Agreement.The Agreement is one of the critical cooperation documents signed during Li Keqiang’s visit in Greece,encouraging China and Greece to