溶液标准物质及滤光片检定/校准分光光度法化学需氧量测定仪的优缺点对比

现行化学需氧量测定仪A类仪器的检定方法存在诸多问题:检定时间较长,检定成本较高,现场检定时溶液标准物质不便于携带,检定废液对环境产生污染等.相较于溶液标准物质使用滤光片检定/校准A类化学需氧量测定仪能克服以上溶液标准物质带来的问题.本文通过对比阐述了两种方法的优缺点.     

高压天然气流量计现场在线实流检定

介绍了引进的车载移动式标准表法的天然气流量标准装置的构成、不确定度分析及验证方法;使用该标准装置开展流量计现场实流检定时,保证流量计检定结果准确可靠应采取的措施,现场检定工艺流程和检定结果;并就流量计现场检定问题对计量站的设计提出了建议.实践表明,对天然气流量计实施现场在线实流检定可以有效地提高流量测量的准确度.     

医用激光源检定中探测器的合理选择与使用

医用激光源检定中会使用各种激光辐射度探测器。在检定实践中笔者发现，一些检定员对探定器的选择和使用了解较少，造成检定结果错误或检定设备的损坏。本文就常见的激光辐射度探测器的工作原理和特点及其选择使用的原则作一简要介绍。     

非车载充电机检定装置电能误差测量不确定度分析

为了确保电动汽车非车载充电机检定装置电能计量准确性,文章依据JJF(豫)262—2019《电动汽车非车载充电机检定装置校准规范》和JJF 1059.1—2012《测量不确定度评定与表示》,使用0.01级直流电能标准装置测量某0.05级电动汽车非车载充电机检定装置在负载点750 V、100 A下的电能误差,并分析了非车载充电机检定装置的测量不确定度。该测量不确定度评定结果符合JJF(豫)262—2019《电动汽车非车载充电机检定装置校准规范》的要求,具有一定的普遍性和实用性。     

大面积多探头α、β、γ辐射监测校准方法

通过对大面积多探头α、β、γ辐射监测设备校准测试技术方法的深入研究,运用“多点法”校准测试技术,针对不同形状和面积的探测器,确定校准点的数量与布点方案,设计了由系列校准放射源、空心人体躯干模型、实心人体躯干模型和专用系列校准器具等部分组成的校准测试系统,实现了大面积多探头α、β、γ辐射监测设备的校准测试与检定.结果：活度值测量范围：0～1.6×104Bq,单位面积活度值不确定度≤10％.     

基于VBA实现黑体辐射源发射率偏离1引起有效亮度温度修正

按照最新的工作用辐射温度计检定规程和辐射测温用-10～200℃黑体辐射源校准规范要求,需要根据有效亮度温度概念,通过对黑体辐射源进行发射率影响修正和环境辐射误差修正,文章对有效亮度温度发射率影响数学模型,使用VBA语言,研究二分算法,高效实现有效亮度温度与实际温度的修正计算,从而为日常检定、校准工作提供了有力的技术保障。     

辐射温度计检定方法的浅谈

本文对检定辐射温度计所使用的标准器和检定装置的技术条件做了归纳和比较。详细介绍了检定前的准备工作、检定项目和检定步骤,总结了检定固有误差的方法和数据处理。     

检定辐射温度计过程中应该注意的问题

辐射温度计近些年来使用得越来越多,使得许多省市计量机构都建立了检定该测温仪的标准。由于影响辐射温度计的准确性的因素比较多,文章对在检定辐射温度计过程中应该注意的问题进行了论述,并给出一些计算方法。     

电动汽车非车载充电机的不确定度分析

在国家市场监管总局最新发布的《实施强制管理的计量器具目录》中,电动汽车充电桩列入其中实施周期检定,鼓励各地方对其具体强制检定方式予以探索。潍坊市计量测试所依据JJG 1149—2018 《电动汽车非车载充电机检定规程》,于2020年10月建立电动汽车非车载充电机检定装置计量标准,采用0. 05级非车载充电机现场测试仪作为主标准器,可对规程中要求的电动汽车非车载充电机的工作误差、付费金额误差和时钟示值误差等计量参数进行检定,文章根据建标情况对以上参数做出不确定度的评定和分析,结果符合相关规程要求,具有一定的参考价值。     

固定式环境γ谱仪量值溯源方法

对一台类似于固定式环境γ谱仪的自主研发Na I(Tl)γ谱仪开展基本性能测试实验。其本底计数率约为(647.1±0.4)s~(-1)(k=1),远大于JJG 417-2006《γ谱仪》检定规程要求的8 s~(-1)。在该本底计数率下,γ谱仪无法完成JJG 417-2006提出的刻度源、活度检测项目中放射性样品的测量。这表明JJG 417-2006不适用于固定式环境γ能谱仪。针对此问题,依据固定式环境γ谱仪使用环境、监测对象及技术指标,对其新的量值溯源方法进行了探讨。     

Very high-energy gamma rays from gamma-ray bursts

Very high-energy (VHE) gamma-ray astronomy has undergone a transformation in the last few years, with telescopes of unprecedented sensitivity having greatly expanded the source catalogue. Such progress makes the detection of a gamma-ray burst at the highest energies much more likely than previously. This paper describes the facilities currently operating and their chances for detecting gamma-ray bursts, and reviews predictions for VHE gamma-ray emission from gamma-ray bursts. Results to date are summarized.     

In-flight energy calibration for the X-ray and gamma-ray spectrometers on the solar-A satellite

The electronically gated in-flight energy calibration is applied to the X-ray and gamma-ray spectrometers on a SOLAR-A satellite. The NaI X-ray spectrometer covering the 20–400 keV energy band is calibrated by an ²⁴¹Am radioactive source which decays by the simultaneous emission of 60 keV X-rays and 5.48 MeV alpha-particles. The X-ray calibration spectrum is accumulated in coincidence with an event tag pulse generated by the simultaneous detection of an X-ray and an alpha-particle. The BGO gamma-ray spectrometer covering the 0.2–10 MeV energy band is calibrated by a ⁶⁰Co radioactive source which decays by the simultaneous emission of 1.17 and 1.33 MeV gamma-rays and a beta-ray (maximum energy is 313 keV). The gamma-ray calibration spectrum is accumulated in a manner similar to the X-ray spectrometer. Since the present method enables to select the calibration pulse without the disadvantage of introducing extra pulses, it is suitable for a space experiment where external conditions and background counting rates can significantly change.     

Axion searches with fermi and IACTs

Axion Like Particles (ALPs), postulated to solve the strong-CP problem, are predicted to couple with photons in the presence of magnetic fields, which may lead to a significant change in the observed spectra of gamma-ray sources such as AGNs. Here we simultaneously consider in the same framework both the photon/axion mixing that takes place in the gamma-ray source and that one expected to occur in the intergalactic magnetic fields. We show that photon/axion mixing could explain recent puzzles regarding the observed spectra of distant gamma-ray sources as well as the recently published lower limit to the EBL intensity. We finally summarize the different signatures expected and discuss the best strategy to search for ALPs with the Fermi satellite and current Cherenkov telescopes like CANGAROO, HESS, MAGIC and VERITAS.     

Galactic sources science with AGILE: The case of the Carina Region

During its first 2 years of operation, the gamma-ray AGILE satellite accumulated an extensive dataset for the Galactic plane. The data have been monitored for transient sources and several gamma-ray sources were detected. Their variability and possible association were studied. In this talk we will focus on the results of extensive observations of the Carina Region during the time period 2007 July–2009 January, for a total livetime of 130 days. The region is extremely complex, hosting massive star formation, with the remarkable colliding wind binary Eta Carinae, massive star clusters and HII regions (e.g. NGC 3324, RCW49, Westerlund II) and a giant molecular cloud extending over 150 pc (between l=284.7 and 289). The Carina Nebula itself is the largest and IR highest surface brightness nebula of the Southern emisphere. We monitored several gamma ray sources in the Carina Region. In particular we detect a gamma ray source (1AGL J1043-5931) consistent with the position of Eta Carinae and report a remarkable 2-days gamma-ray flaring episode from this source on 2008 October 11–13. If 1AGL J1043-5931 is associated with the Eta Car system, our data provide the long sought first detection above 100 MeV of a colliding wind binary.     

Suppression of gamma-ray sensitivity of liquid scintillators for neutron detection

Methods to reduce gamma-ray sensitivity of a liquid scintillator EJ309 have been studied. Zero-crossing pulse shape discrimination method was used to separate events generated by neutron and gamma radiation between 60− keVee and 4 MeVee. The measurements were carried out under irradiation from an intense ¹³⁷Cs source, yielding dose rate of 10 mR/h at the detector. A Pu-Be source was used to establish neutron integration window. Pile-up rejection (PUR) circuit was used to reduce gamma-ray induced events under irradiation from an intense gamma-ray source. Further, application of lead, tin and copper shields was done in order to decrease intrinsic gamma-neutron detection efficiency.     

浮子流量计检定装置的研制

介绍了一种型号为LB311非水液体浮子流量计检定装置,该装置基于标准表法,采用一大一小离心泵来提供稳流源,用涡轮流量计作为标准表来检定浮子流量计,测试流量范围宽;采用三阀调节系统,调节精度高.     

Effect of surface treatment of carbon fibers with gamma-ray radiation on mechanical performance of their composites

Gamma-ray radiation was used to surface treat PAN carbon fibers. The efficiency of gamma-ray radiation was compared with air oxidation in terms of variations in the surface structure of carbon fibers and the mechanical performance of their composites. It was observed that the composites reinforced with the gamma-radiated carbon fibers showed higher interfacial adhesion strength and thus better flexural and shear properties than the composites reinforced with air-treated fibers. The observed higher content of carboxyl group on the surface of the gamma-radiated carbon fibers is likely to be responsible for the stronger fiber-matrix bonding. It is concluded that gamma-ray radiation is an effective approach of tailoring surface properties of carbon fibers.     

A 6130 keV gamma-ray source using the 13C(α, n)16O reaction

A high energy gamma-ray source has been produced by mixing the alpha emitter ²³⁸Pu with ¹³C to produce the 6130 keV gamma-ray from the de-excitation of the second excited state ¹⁶O. The gamma-ray spectrum and emission rate have been measured and the neutron emission rate and mean energy have been determined.     

The EDELWEISS-III Project and the Rejection Performance of Its Cryogenic Germanium Detectors

The EDELWEISS-III experiment searches for Dark matter using cryogenic germanium detectors in the low radioactivity environment of the Laboratoire Souterrain de Modane. The experiment and the FID detector design, whereby all surfaces are covered with interleaved electrodes, are described. The performance for gamma-ray and surface event rejection of these detectors is discussed. In particular, recent calibrations with a \(^{210}\) Pb source reveals that the excellent surface event rejection already demonstrated with planar interleaved electrodes also extends to the entire surface of the large FID detectors, even on their cylindrical outer surfaces, where the electric field has a more complicated geometry. Expected results with the full exposure of the EDELWEISS-III experiment are discussed.