氮(空气)中二氧化硫气体标准物质的研制

采用称量法制备了氮(空气)中二氧化硫气体标准物质,采用化学法进行均匀性、稳定性考察并进行了比对分析。结果表明用称量法制备的浓度范围为1×10-6~10×10-2(mol/mol)的氮(空气)中二氧化硫气体标准物质其均匀性良好,稳定性可靠,符合气体标准物质制备的要求。该气体标准物质相对扩展不确定度为2%。     

氮(空气)中氢气体标准物质的研制

采用称量法制备了氮(空气)中氢气体标准物质,采用气相色谱法进行了均匀性、稳定性考察并进行了比对分析。结果表明用称量法制备的浓度范围为10×10-6~98×10-2(mol/mol)的氮(空气)中氢气体标准物质均匀性良好,稳定性可靠,符合气体标准物质制备的要求。该气体标准物质相对扩展不确定度为2%。     

氮中硫化氢气体浓度测定方法研究

运用紫外法在测定气体分析仪器线性和示值稳定性变化规律的基础上,研究了测定氮中硫化氢气体浓度的方法。结果表明仪器在(10～200)×10~(-6)mol/mol范围内有很好的线性,对不同浓度的氮中硫化氢气体,示值稳定性时间不同。运用不同浓度氮中硫化氢气体标准物质校准仪器72min时,测定值变化相对偏差分别达5.5%、-3.2%、-1.1%和-2.3%。当以102×10~(-6)mol/mol氮中硫化氢气体标准物质作为外标,采用单点外标法测定10.9×10~(-6)mol/mol氮中硫化氢气体标准物质浓度时,测定相对偏差可达5.4%。需选择浓度非常接近的气体标准物质作为标准采用单点外标法对氮中硫化氢气体浓度进行赋值。     

空气中一氧化碳气体标准物质的研制

采用一氧化碳纯度标准物质、高纯氮气和高纯氧气,以称重法制备了浓度为(10. 0～10. 0×10~2)×10~(-6)mol/mol的空气中一氧化碳气体标准物质。运用气相色谱仪测定了高纯氮气、高纯氧气中一氧化碳的空白含量,并基于一氧化碳红外气体分析仪对研制的标准物质进行了压力均匀性和时间稳定性检验。运用方差分析可得均匀性引入的相对标准不确定度为0. 42%,运用直线拟合分析稳定性引入的相对标准不确定度为0. 44%。结果表明,研制的空气中一氧化碳气体标准物质具备很好的均匀性和稳定性,标准值为(10. 0～10. 0×10~2)×10~(-6)mol/mol(Urel=2%,k=2),可用于测量仪器的校准、测量过程质量控制及分析方法确认和评价。     

甲烷中硫化氢气体标准物质的研制

以高纯硫化氢和高纯甲烷为原料,采用称重法制备甲烷中硫化氢气体标准物质。采用气相色谱法(FPD)进行均匀性、稳定性考察。结果表明用称量法制备的浓度为10μmol/mol的甲烷中硫化氢气体标准物质均匀性良好,稳定性可靠,符合气体标准物质制备的要求。该气体标准物质相对扩展不确定度Urel=2%,k=2。     

氮中硫化氢气体标准物质稳定性研究

采用硫化氢纯度标准物质和高纯氮气,采用称重法制备了浓度为(10. 0～200)×10~(-6)mol/mol的氮中硫化氢气体标准物质。考察了气瓶涂层处理对量值稳定性的影响,对研制的标准物质进行了压力均匀性和时间稳定性检验。运用方差分析可得均匀性引入的相对标准不确定度为0. 45%,运用直线拟合分析稳定性引入的相对标准不确定度为0. 34%。结果表明,研制的氮中硫化氢气体标准物质具备很好的量值稳定性。     

六氟化硫中六氟乙烷气体标准物质的研制

采用称量法制备并计算定值,研制(10~100)×10-6(mol/mol)六氟化硫中六氟乙烷气体标准物质。采用自主研制的钢瓶自动清洗系统、配气系统和优化的配气工艺流程保证了研制水平。对气体标准物质进行了制备方法的研究、均匀性与稳定性检验试验,结果表明研制的气体标准物质定值的扩展不确定度优于1.5%(k=2),符合气体标准物质制备要求。     

氮中二氧化硫气体标准物质的研制

正一、引言目前,烟气分析仪和二氧化硫气体检测仪广泛应用于二氧化硫暴露的检测和报警。据不完全统计,仅山东省的烟气分析仪和二氧化硫气体检测仪就有5000余台,这些仪器的原理和生产厂家多样,需要用到大量的二氧化硫气体标准物质实现其量值溯源。本研究通过选取适当的标准物质候选物,制备(100~5000)×10-6mol/mol的二氧化硫气体标准物质     

氮中43组分TO-14VOCs标准气体的研制

研制了浓度约为1×10~(-6)(mol/mol)氮中43组分TO-14 VOCs标准气体[GBW(E)062376]。该标准气体根据GB/T 5274严格按照配制气体标准物质的基本方法称量法制备及定值。利用研究开发的气质联用法对其进行了均匀性和稳定性检验。还将其与国际公认的同类标准气体进行了比对,并经国内最具权威性部门中国计量科学研究院进行检测验证。     

氮中一氧化碳气体标准物质的研制

介绍了氮中一氧化碳气体标准物质的研制过程。以高纯一氧化碳气体、高纯氮气为原料,采用称量法制备了浓度为100、500、1 000μmol/mol、0.5%mol/mol的氮中一氧化碳气体标准物质,采用与国家一级标准物质比较的方法定值。对原料气中的杂质进行了分析,对制备的气体标准物质进行了均匀性和稳定性评估。结果表明：研制的氮中一氧化碳气体标准物质均匀性和稳定性良好,标准值为100、500、1 000μmol/mol、0.5%mol/mol(U_r=2%k=2)。     

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.……     

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...     

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.     

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.     

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 ...