定容式气体微流量标准装置的不确定度分析

定容式气体微流量标准装置采用定容法工作原理 ,用于校准热容式质量流量计 ,测量范围为1×10 -3～10Pa·m3·s -1 ,不确定度(1σ)小于1.20 %。主要分析了标准装置的不确定度     

金属膨胀式真空计量标准

介绍了新研制的金属膨胀式真空计量标准及其起始压力和体积比的测量方法，讨论了实际气体特性、温度变化和气体吸附等干扰效应，分析了标准装置的不确定度（1σ）。该标准的校准范围为105～10-4Pa，校准电容薄膜规和磁悬浮转子规时不确定度为0．01％～1．0％。     

定容式流导法气体微流量校准装置测量不确定度的评定

介绍了定容式流导法气体微流量校准装置的组成及校准方法，并着重对测量不确定度进行了评定。通过评定在定容式流量计的校准范围（1×10^-3～5×10^-6）Pa·m^3／s内，其合成标准不确定度为1，O％；在固定流导法流量计的校准范围（5×10^-4～5×10^-11）Pa·m^3／s内，其合成标准不确定度为1．4％～1.8％。     

比对法漏率校准装置

比对法漏率校准装置是计量气体漏率的一种装置 ,可绝对法和相对法对真空漏孔进行校准。绝对法的校准范围为 10 - 4～ 10 - 9Pa· m3/s;相对合成标淮不确定度为小于 10 %。相对比对法的校准范围为 10 - 6～10 - 1 0 Pa· m3/s,相对合成标准不确定度为小于 2 5 %。     

一种对射式可燃气体报警器校准装置

依据对射式可燃气体报警器的工作原理,文章研究了一种可对其进行校准的便携装置,该装置可通过长度的精确测量和其所使用有证气体标准物质进行有效溯源。文章分析了使用该装置进行校准过程中的不确定度来源,并给出了不确定度评定过程和结果,证明了该装置用以校准对射式可燃气体报警器的准确性和可靠性。     

用标准物质校准泄漏检测装置现场校验系统

利用气相色谱仪,用六氟化硫气体标准物质对RA104E型气体泄漏检测装置现场校验系统进行校准,评定校准结果的不确定度,并作出六氟化硫物质的量分数范围为1~3mmol/mol的量值传递框图,讨论进一步减小校准结果不确定度的途径以及此校准方法应用于其他气体稀释装置的发展前景。     

紧凑式标准表法气体流量标准装置的应用

介绍了紧凑式标准表法气体流量标准装置的组成及工作原理。通过分析装置的不确定度和进行测量结果的验证,证实了这种紧凑式标准表法气体流量标准装置可应用于气体流量计的检定或校准。     

定容式气体微流量标准装置

介绍 工气体微流量标准装置及其性能，讨论了温度变化，气体吸附和系统汛放等干扰效应，分析了标准装置的不确定度。该标准的校准范围为１＊１０＾－３１０Ｐ．ｍ＾３／ｓ，不确定度小于１．２％，用于校准热容式质量流量计。     

气体流量计在线校准装置的研究

研制了一套以活塞作为标准器的气体流量计在线校准装置。该装置采用主动式活塞原理,以伺服电机作为动力源驱动盘型活塞以恒定速度移动从而产生标准流量的气体。在装置机械结构上采用了“偏心”的设计,大幅度减小了标准装置的体积和质量,并且使得装置结构更为紧凑,适宜移动。装置流量范围0. 016～6m3/h,体积相对扩展不确定度Urel优于0. 02%(k=2),适用于临界流文丘里喷嘴、钟罩式气体流量标准装置和湿式气体流量计等的在线校准。     

用定容式气体流量计进行真空规校准方法的研究

提出了一种采用定容式气体流量计校准真空规的方法,并对校准装置进行了不确定度的分析。定容式气体流量计有2种工作模式:采用定容法模式可以提供(10-8～10-2)Pa.m3/s的流量,采用固定流导法模式可以提供(10-6～10-11)Pa.m3/s的流量,2种方法组合提供的标准流量范围变宽,延伸了流量下限。定容式气体流量计相对于恒压式气体流量计,有结构简单、操作方便等特点。采用定容式气体流量计校准真空规的范围为(10-6～10-2)Pa,合成标准不确定度为(0.67～1.74)%。并用恒压式气体流量计校准同一分离规进行了比较,2个校准结果一致性好于5.7%。     

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.……     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

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.……     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

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.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...