The mass production and quality control of RPCs for the Daya Bay experiment

Resistive plate chambers will be used in the Daya Bay reactor neutrino experiment to help veto backgrounds created by cosmic-ray muons. The mass production of RPCs began in 2008 and by the end of 2009, 1600 RPCs (3500 m²) had been produced and tested. This paper describes the production and quality control procedures, and quality assurance using cosmic-ray testing.     

平衡环境型房间量热计凝结水量测量设计

量热计法室内侧制冷量计算公式,未考虑测量中小冷量空调器制冷量时空气处理柜除湿造成的误差。为排除此误差对测试结果的影响,采用称重法分别测量量热计内、外室加湿水及被测机的凝结水。利用基于称重法设计的量热计测得5台被测机的2组数据并进行分析,结果表明,当空调器的额定制冷量低于测试室输入功率时,空气处理柜的除湿量会增大测量偏差,且随着空调器制冷量的降低偏差增大。并对室内侧制冷量计算公式进行修正,以提高计算精确度。     

吸收剂量基准石墨量热计基本性能分析

作为吸收剂量基准的石墨量热计,对于量值复现有很高要求。分析说明了NIM的石墨量热计系统的主要技术性能,包括:温度控制,电能（功率）测量,电能-辐射能量转换关系,以及吸收剂量基准值复现测量,并给出得到的结果 。对有关的技术性能指标进行说明,同时给出其随时间的变化（稳定性）。作为基准绝对测量旁证检验,对石墨比热容进行测定,与BIPM测定的结果进行比较,偏差在0.1%以内。     

Thermal Radiation Calorimeter for Measuring the Specific Heat Capacity of Liquid Samples

A new thermal radiation calorimeter for measuring the specific heat capacity of liquid samples continuously in the temperature range from 280 to 360 K is described. The heat input to the sample cell from the heater by thermal radiation is estimated using the effective emissivity, which is the apparatus constant. The heat capacity of a sample can be calculated from the temperatures of the sample and the heater, and the temperature change rate of the sample. The present sample cell was made of Pyrex glass; therefore most liquid samples do not react with the sample cell, and blackening of the surface of the sample cell is not necessary in the present temperature range. The specific heat capacities for ethanol, ethylene glycol, n-heptane, n-valeric acid, and water+ethanol mixtures were measured to confirm the reliability of the present calorimeter.     

Hadron energy reconstruction for the ATLAS calorimetry in the framework of the non-parametrical method ATLAS

This paper discusses hadron energy reconstruction for the ATLAS barrel prototype combined calorimeter (consisting of a lead-liquid argon electromagnetic part and an iron-scintillator hadronic part) in the framework of the non-parametrical method. The non-parametrical method utilizes only the known e/h ratios and the electron calibration constants and does not require the determination of any parameters by a minimization technique. Thus, this technique lends itself to an easy use in a first level trigger. The reconstructed mean values of the hadron energies are within ±1% of the true values and the fractional energy resolution is

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. The value of the e/h ratio obtained for the electromagnetic compartment of the combined calorimeter is 1.74±0.04 and agrees with the prediction that e/h>1.66 for this electromagnetic calorimeter. Results of a study of the longitudinal hadronic shower development are also presented. The data have been taken in the H8 beam line of the CERN SPS using pions of energies from 10 to 300 GeV.     

GERG Project: Development and Setup of a New Combustion Reference Calorimeter for Natural Gases

Natural gas plays an important role for worldwide energy supply. For billing purposes precise metering of volume and superior calorific value are very important. At present, only a few institutions worldwide are able to determine the superior calorific value (SCV) of gases and their mixtures with an uncertainty of less than 0.2%. Calculations of SCV’s of natural gases using the data of ISO 6976 provides a similar uncertainty as experimental approaches. For this reason a GERG (Groupe Européen de Recherches Gazières) project was initiated to develop a new reference calorimeter for determining the SCV of flammable gases (natural gases), based on the principle of Rossini for a combustion calorimeter. The purpose of such a reference calorimeter is to determine the SCV of pure gases and gas mixtures with an uncertainty of less than 0.05%. The overall uncertainty budget for the SCV is mainly influenced by the mass determination and temperature measurement. An automated weighing and calibration device is used to measure the mass of the combusted gas with an experimental uncertainty of approx. 0.015%. In addition to the experiment, the flow and temperature field in the calorimeter were simulated. These simulations help to reduce each of the combined uncertainties for the combustion and calibration experiment resulting from the temperature measurement. The determination of the adiabatic temperature rise is performed analytically. The assumptions made by early investigators were carefully reconsidered for the first time. The analysis of the temperature–time curves considers (a) the method of evaluation, (b) the interval length of the main period, (c) the location of the heat release during the calibration experiment, and (d) the temperature sensor location.     

水量热法加速器光子水吸收剂量绝对测量与国际比对

为实现加速器光子水吸收剂量绝对测量,研制了水量热计系统,在此基础上取得国际互认并建立加速器光子水吸收剂量基准,进一步提高了我国放疗剂量量值传递能力。通过水浴与半导体制冷系统二级控温,将量热计水模体的温度漂移控制在0.5μ℃/s。利用惠斯通交流电桥测量辐射所致的热敏探针阻值变化,逐次校准热敏探针和交流电桥,实现了医用加速器光子水吸收剂量的绝对测量,合成标准不确定度为0.30%。参加了国际计量局加速器光子水吸收剂量关键比对,复现的6MV和10MV光子水吸收剂量值与比对参考值之比分别为0.9917和0.9949,在不确定度允许的范围内一致。     

A Modernized Calorimeter for Measuring the Isobaric Heat Capacity of Hydrocarbons by a Continuous-Flow Method in the Critical Region

A method is described for the precision measurements of the isobaric heat capacity C_p of hydrocarbons of the normal series in a wide neighborhood of the critical point, characterized by anomalously high values of C_p, the presence of maxima and high temperatures, for which thermal decomposition of the products investigated is possible. Modernization of the method was undertaken in order to increase the accuracy of measurements of the absolute temperatures (the reference temperatures) and small differences in temperature (ΔT < 0.1 K) with original “ignoble” thermocouples. In order to minimize heat loss in the calorimeter and to increase the reliability of the experimental equipment, a new construction of the heat meter was developed and a metrological estimate of it was carried out. __________ Translated from Izmeritel'naya Tekhnika, No. 8, pp. 43–48, August, 2005.     

数字调制质量参数的校准和量值溯源

在数字移动通信中，描述数字调制质量的参数是一组新出现的重要参数。用实验数据证明国外仪器制造厂商给出的数字调制质量参数校准方法存在的缺陷，并研究出了新的校准方法；提出了数字调制质量参数量值溯源方案。     

数字心电图机计量发展及数字心电图标准波形评定方法

随着心电检测设备的发展,原有的计量标准已经不能全面评定其计量性能,波形一致性、波形失真度等参数正在成为新的计量检定规程和工作标准中主要考虑的内容.通过回顾数字心电图机计量法规和标准的发展,探讨了数字心电图标准波形的评定方法.结果表明,波形总失真度能够作为评定数字心电标准波形的有效参数.     

动态数字视频实时记录

:介绍一种基于计算机的数字视频实时记录系统。它可将每秒 2 5帧 ,格式为 51 2× 51 2× 8bit的图象实时地记录在 SCSI硬盘上 ,并且无信息损失 ,为事后的分析判断提供了良好的基础。     

数字化家庭图像监控系统

根据家庭安全防范的需要，设计实现了经济实用的数字化家庭图像监控系统。该系统以Windows、Java2为开发平台，以廉价的USB摄像头为图像采集设备。针对USB摄像头采集图像效果差，提出了一种快速有效的运动对象检测和分类算法，并能在异常发生时快速报警。同时利用媒体的流化技术和RTP／RTCP协议，实现了视频流的实时播放、传输和存储。     

1种热敏电阻温度传感器数字接口电路的研究

在一些用单片机组成的测试仪表或控制器中，常常需要一两路温度输入信号，如环境温度、水温的测量，而若仅为一两个温度信号的测量而增加1个硬件A／D转换器，则势必增加仪表的成本。这里所要介绍的热敏电阻温度传感器的数字接口电路，每路温度测量包括传感器在内仅10元左右的成本，在－20℃～＋70℃的测温范围内测温精度可达±0.2℃。并且性能稳定，抗干扰能力较强。已成功地应用在工业测控仪表中。     

序列图象目标的一种特殊数字跟踪方法

介绍了在数，模检测相结合的电视跟踪器的一项关键技术－指寅区域的位置和大小的序列图象的实时捕获和处理，并以ＡＤＳＰ２１８１为核心实现了一实际的系统，分析了其中的关键硬件技术介绍了可编程器件ＥＰＬＤ在其中的应用，给出了实时采集处理的结果。     

一种数字测图中的自动曝光控制技术

数字测图可提供高质量的数字图象 ,控制好测量系统中数字相机的曝光量是获取最佳数字图象的重要因素之一。论述了如何利用自动曝光控制技术控制曝光时间获取较为理想的数字图象     

一种科氏流量计的数字信号处理与驱动方法研究

数字信号处理和数字驱动是科里奥利质量流量计的发展趋势。研究了基于同步调制的数字信号处理方法，进行公式推导、性能分析和计算机仿真。研究数字驱动方法并利用数字控制方法提高流量管的起振性能，给出了数字驱动方案。     

改善数字随动系统过渡过程方法

对控制系统阶跃响应的过渡过程进行研究,提出在计算机控制系统中改善过渡过程的新方 法,把过渡过程分成不同的阶段,各个阶段的传递函数不变而初始条件变化。从仿真结果看出,利用新方法可使控制系统获得快速无纹波无超调的过渡特性。     

光纤准白光干涉信号数字化处理方法

提出一种光纤准白光干涉信号数字化处理方法。该方法采用干涉条纹脉冲实现干涉包络信 号同步采集,克服了导轨移动速度不均匀造成的影响;通过高斯函数曲线拟合方法高精度确定干涉信号零光程差点;大大提高了准白光干涉信号定位精度。为消除包络信号采样边界点不确定性带来的误差,采用外插法进行补偿。实验表明,采用该方法对光纤准白光干涉信号零光程差位置的定位精度优于0.5个干涉条纹。     

The Digital Revolution: A New Paradigm for Microfluidics

The digital revolution has come to microfluidics. In digital microfluidics (DMF), discrete droplets are manipulated by applying electrical fields to an array of electrodes. In contrast to microchannels, in DMF each sample and reagent is individually addressable, which facilitates exquisite control over chemical reactions. Here, we review the state‐of‐the‐art in DMF, with a discussion of device formats, actuation physics, and biological and nonbiological applications. Along the way, we identify the key players in the field, and speculate on the advances and challenges that lie ahead. As with other fronts in the digital revolution, there have been and will be unexpected developments as DMF matures, but we posit that the future is bright for this promising technology.     

数字视频系统开发测试平台及其实现

报告了自主研制的基于ＰＣ计算机ＰＣＩ总线的数字视频产品的开发测试平台。该系统以其功能强、通用性好、便于扩充、使用方便等伏良性能已成功地应用在高清晰度电视（ＨＤＴＶ）信源解码器的演示、视频编码器和复用器的研制以及标准清晰度数字电视（ＳＤＴＶ）的开发过程中，具有广阔的应用前景。