平衡机最小可达剩余不平衡度测试方法的研究

本对平衡机最小可达剩余不平衡度emar测试数据的相位一幅值曲线进行分析，提出了最小可达剩余不平衡度emar与emar的计算值e估的数学关系式，为提高平衡机现场测试效率，更为客观地评价被测平衡机性能指标提供了依据。     

利用Excel进行动平衡机评定

阐述了利用Excel进行动平衡机的检验与评定的设计流程，通过计算机软件对数据进行分析处理，最终得到最小可达剩余不平衡量Umar。和不平衡量减少率URR的评定图，以实现对动平衡机是否满足使用要求的判定。     

平衡机不平衡量减少率评定方法的研究

本文对国标规定的平衡机不平衡量减少率URR评定方法进行了较深入的分析和研究 ,提出了一种基于矢量合成理论的数学计算方法。此法便于用程序实现 ,简化了原极坐标图解法的计算步骤 ,为更直观、准确地评价平衡机的性能指标提供了依据     

动不平衡及车轮动平衡机不平衡量的测量

本文叙述了高速旋转体客观存在的动不平衡现象、产生的原因、危害、平衡原理及消除的方法 ,并着重在动不平衡量的数学表征和测量方法、车轮动平衡机的不平衡量及最小可达剩余不平衡量的测量等方面进行了探讨     

航天器推进系统漏率测试不确定度评定

基于常压氦质谱累积检漏,提出了航天器推进系统漏率测试不确定度评定方法,建立了一元一次线性数学模型,运用最小二乘法理论对比分析了氦气累积过程和漏率标定过程的A类和B类不确定度计算结果,试验验证检漏不确定度评定的影响因素,认为氦气累积过程B类不确定度对航天器推进系统漏率测试结果的不确定度评定影响较大,而B类不确定度主要来源于检测仪器的固有测试误差,同时总结了检漏仪测试数据变化量与漏率测试不确定度的关系,为提高航天器推进系统漏率计算结果精准性指明了方向。     

用间歇流动化学分析仪分析水中的总氰化物浓度的不确定度评定

本文通过对间歇性流动分析仪测定水样过程的分析，采用线性最小二乘法拟合标准曲线不确定度的评定方法对总氰化物的不确定度进行了评定。     

液相色谱仪检测器的最小检测浓度的测量值的不确定度评定

本文依据JJF 1059.1-2012测量不确定度评定与表示和JJG 705-2014液相色谱仪检定规程,评定了液相色谱仪不同检测器的最小检测浓度测量值的不确定度。分析了各不确定度分量,建立了评定最小检测浓度不确定度的测量模型。对最主要的参数进行了不确定度的分析和评定。     

标准玻璃量器容量测量结果的不确定度分析与评定

根据JJF1059—1999《测量不确定度评定与表示》中规定的测量不确定度的分析步骤和方法，并借助于实际测试数据，分析了风速传感器的测试结果的不确定度。利用比较法，对风速传感器测试结果的不确定度的分析结果进行验证。     

圆柱度误差评定的最小面积准则及其应用

本文提出圆柱面形状误差评定的一个新准则──“最小面积准则”，以此建立空间一般位置圆柱度误差评定的数学模型，用有较集法方便地求得理想圆柱面的描述参数和圆柱度误差。文章从理论上证明了在小误差条件下，最小面积准则等价于ＩＳＯ关于形状误差评定的最小区域准则，因而本文方法为圆柱度误差评定实现最小条件提供了一个有效方法。     

HPLC法测定奶粉中VA含量的不确定度评定分析

目前，我国在计量测试和疫病控制分析领域，进行测量不确定度评定已较普遍，但在化学分析领域，尤其在食品分析领域，对测试结果进行测量不确定度表述和评定的尚不多见。维生素A（以下简称“VA”）又称视黄醇，具有促进机体生长，维持视觉等功能。本文根据《测试实验中测量不确定度评定》（曹志军著，吉林科学技术出版社2007年出版）对HPLC法测定奶粉中VA含量进行测量不确定度评定。并对其不确定度来源及各分量进行量化分析和表述。     

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.……     

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.     

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.     

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 ...