刍议图书馆网站监测方案

首先介绍图书馆网站建设的重要性,介绍了确保网站正常运行的一些措施,指出了对网站进行监测的迫切性,对监测方法做了对比介绍,最后介绍了手机邮和监测方案。     

混凝土防渗墙补强处理方案的选择

本文介绍了混凝土防渗墙的建造特点,分析了防渗墙质量事故的原因,重点介绍了贴墙的处理方案,以实例进行介绍。     

砼的分类、制造及在建筑工程中的应用

文章从砼字面描述了砼的来源,接着根据抗压程度详细介绍了砼的分类,还介绍了如何生产制造砼制品,最后简单介绍了砼在现实生活中的用途。     

发展中的光盘及数据存储技术

本文比较系统地介绍了光盘及光盘系统的发展历程,简要介绍了一些常见光盘,同时介绍当前数据存储技术的研究动态。     

辐射采暖实现人工环境的热舒适性

本文介绍了辐射采暖的热舒适性特点，并结合工程实例介绍了地板辐射采暖系统，介绍了国际上先进的采暖技术——柔强辐射采暖。     

基于WEB模式的高校设计大赛报名系统设计

本文介绍了基于WEB模式的高校设计大赛报名系统开发的方法,介绍了系统平台的选择,数据库的设计开发,并详细介绍了各功能模块的实现原理。     

热电偶的使用与安装技术要求

本文详细介绍了山东石横特钢集团有限公司炼铁厂在线使用的各种测温热电偶的型号规格,介绍了不同型号热电偶的不同应用场合.同时详细介绍了热电偶使用过程中的各种安装技术要求.     

德国工业设备管理公司的空间环模设备

介绍了德国工业设备管理公司的空间环模设备。着重介绍了热真空模拟试验及其设备的结构与性能。还介绍了热真空模拟试验设备的残气分析。     

淀粉的改性及其应用

本文简要介绍了淀粉的结构、特点以及几种淀粉衍生化的改性方法。介绍了几种淀粉衍生物及其应用，着重介绍了接枝共聚淀粉的合成并展望了其发展趋势。     

浅谈脱硫技术在电厂的应用

对脱硫方法进行了介绍,并介绍了国内常用的几种烟气脱硫（FGD）的技术,详细的介绍了适合于已建成的小型电厂的脱硫的技术。     

气体流量量值溯源体系探讨

介绍了气体流量量值溯源中的关键环节,并对各环节的国际发展趋势进行了简单介绍.     

钟罩式气体流量标准装置不确定度分析

介绍了钟罩式气体流量标准装置的几种检定方法,比较了各检定方法的区别、特点及要求,并结合检定数据进行了不确定度分析。     

Bell prover — calibration and monitoring of time stability

This paper is focused on the calibration and measurement of the geometric parameters of a bell prover that serves as a standard of volume of gas flow. It also includes methods for monitoring the time stability of the bell prover: intra- and inter-laboratory comparison measurements, Shewhart analysis and planned evaluation of recalibration intervals.     

电驱动双活塞式气体流量标准装置的仿真研究

设计研制了一套用于检定临界流流量计的双活塞式气体流量标准装置.该装置利用两个活塞交替运行产生连续标准流量,可有效提高检定流量上限.介绍了该双活塞式气体流量标准装置的机械结构和检定原理;然后在Simulink仿真环境下,搭建了装置系统模型,并在此基础上进行了在最大检定流量点和最小检定流量点上活塞联动过程的仿真.结果显示,压力、流量等几项重要指标均能控制在规定的范围内,该装置可用于临界流流量计的检定.     

Performance of a gas flow meter calibration system utilizing critical flow venturi standards

A set of Critical Flow Venturis (CFVs) were manufactured by Flow Systems and calibrated by NIST in Gaithersburg, MD. Subsequently these flow standards along with pressure and temperature standards have been integrated into a gas flow meter calibration (GFC) system. Performance data and an uncertainty analysis is discussed here in this paper. Calibration data on these CFV standards will be used to inter-compare the NIST and CEESI primary facilities.     

Establishment and verification of a primary low-pressure gas flow standard at NIMT

This paper presents the establishment and verification of a primary low-pressure gas flow standard with the capacity of 0.005 L/min to 24 L/min (at 23 °C and 101.325 kPa), newly established at National Institute of Metrology of Thailand (NIMT). This facility is a mercury-sealed piston prover consisting of three precision-machined glass cylinders. Flow measurement can be carried out manually or semi-automatically. The electronics were installed in a separate console to minimize their thermal impact on the gas temperature. Special care was taken in designing the facility to ensure sound and representative gas pressure and temperature measurement. The relative expanded uncertainty of mass flow measurement was evaluated to be less than 0.13%. To verify the measurement capability and performance of the new facility, a bilateral comparison with the piston prover at Center for Measurement Standards (CMS), Taiwan was conducted. The transfer standard used was a set of three critical flow venturis with dedicated thermometers. Eight flow rates of dry air ranging from 42 mL/min to 14.5 L/ min at 0 °C and 101.325 kPa (0.055 g/min to 18.87 g/min) were tested. Comparison results showed that the E _n values for the flow measurements at NIMT with reference to CMS were all well less than unity, demonstrating good agreement between the two participants.     

Uncertainty analysis of NIST’s 20 liter hydrocarbon liquid flow standard

The National Institute of Standards and Technology (NIST) uses a bi-directional 20 L-displacement piston prover as its primary standard for measuring hydrocarbon liquid flows ranging from 1.86 × 10⁻⁵ m³/s (0.3 gpm) to 2.6 × 10⁻³ m³/s (40 gpm). Our analysis shows that the prover’s uncertainty over this flow range is 0.074 % (k = 2, corresponding to a 95 % confidence interval). Using a dual rotor turbine meter as the transfer standard, we compare the new 20 L piston prover standard with NIST’s other hydrocarbon liquid standards and NIST’s water flow standard. The results are consistent with the presented uncertainty analysis.     

建立计量器具制造企业诚信体系，不断提升用户、监管机构、员工的满意度

国家取消了计量器具制造许可,将原事先审批制改为事中、事后监管制,这对计量器具制造企业提出了如何通过自律,来规范产品制造过程、提升产品质量、不断满足用户需求、确保政府放心的新课题。     

钟罩装置标准容积的数学模型研究与建立

在钟罩装置标准容积实测数据的基础上,通过描点图定性分析了钟罩罩体高度和半径的关系特性,提出采用傅里叶级数建立数学模型,借助Matlab获得理想的函数方程,并分析了其拟合标准差。实际应用中采用光栅尺测量钟罩下降的高度,运用定积分原理对函数进行积分获得钟罩下降任意高度时排出的气体容积值,在瞬时流量下限标准容积的相对扩展不确定度达到4×10^-4(k=2),相对以半径平均值为估计值的方法,降低了66.7%,同时可实现钟罩在检测过程中任意点的启停。     

主动式活塞体积管流量标准装置阶跃特性研究

动态流量测量在研发和生产过程中越来越重要,为了开展流量计的动态响应特性相关试验,使用激光干涉仪对燃油流量标准装置的活塞位移进行了动态测量,并分析了该装置的阶跃特性。试验结果表明,在一定阶跃流量范围内,该装置的时间常数在7~60 ms之间。建议进一步优化装置的传动结构和伺服控制参数,改善装置的阶跃特性。