共查询到20条相似文献,搜索用时 78 毫秒
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针对工业自动化和国防军事领域同步分解电角度量值溯源需求,提出了一种基于多盘感应比例电桥平衡原理的同步分解电角度校准方法,并组建了一套同步分解标准器校准装置。该装置通过电桥的准电压平衡和不平衡误差电压解算的方法获得同步分解电角度的标准值,并通过相对简单的接线方式,实现同步和分解两种模式下0°~360°电角度的校准。对同步模式下电角度校准装置的不确定度进行了评估,不确定度达到0.00013°(0.47″)。该方法具有准确度高、操作简单、测量速度快的特点,使同步分解电角度量值溯源到感应电压比例标准。 相似文献
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直流电桥在电学计量中占有相当重要的地位。20世纪80年代上海仪表厂推出了高准确度的XQJ-7型和QJ48型直流比较电桥检定装置 ,其测量准确度可达0 0015% ,目前仍居世界领先地位。尽管如此 ,它却不具备自动测试的条件。由于被检电桥要测量的电阻太多 ,每进行一次测量都需反复调节电桥平衡 ,所以完成一台电桥检定太费时间。如果使用不当 ,还会给测量带来干扰 ,若测试人员不熟练会造成很多人为误差。为了解决所存在的问题 ,本人设计了一套新的直流电桥半自动检定系统。一、测量原理的设计其测量原理是采用比例测量法来实现对电… 相似文献
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本文介绍了在F18高精密电桥基础上,利用Visual Basic6.0,Access2000、Microsoft Excel及水晶报表为主要开发工具,以Windows为开发平台设计了一套完善的温度计自动测量检定系统。实验验证该系统提高了测量准确度及温度计检定的工作效率。 相似文献
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变压比电桥检定装置是检定变压比电桥的专用检定装置,该装置主体部分为六位感应分压器,并在其输入,输出回路中增加了相序开关,连接组别,分接头,倍率转换等部件,使整个装置具有操作方便,能直接读取测量结果的特点。该装置设计合理,技术先进,并有可靠的计量溯源。 相似文献
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《技术监督实用技术》1999,(6)
磁性材料的自动检测装置是我国计量科研工作的一个重要成果。该装置是应用第三代ATS(自动测量系统)原理研制成功的新一代磁性材料自动测量装置,它以微机为核心,完全取代了以冲击检流计为代表的经典磁测装置和以电子积分器磁测电桥为代表的第二代磁测装置,而成为第三代磁性材料测试装置。它能够应用于硅钢、非晶、微晶稀土永磁等多种磁性材料的检测,效率很高。原先检定一个磁体要几个小时甚至半天时间,用了这个设备后只需1分钟,而且准确度很高。专家鉴定认为,该装置达到了国际先进水平,在硅钢磁性测量方面甚至居国际领先地位。… 相似文献
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为了提高耐电压测试仪自动检定的效率,减少不必要的人员误差,开发了耐电压测试仪自动检定装置。该装置采用STC89C58芯片作为CPU,AD7753作为A/D转换芯片,提高了检定准确度,实现了耐电压测试仪的自动检定。能够满足JJG795-2004《耐电压测试仪》检定规程的要求。 相似文献
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《International journal for numerical methods in engineering》2018,113(9):1488-1506
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. 相似文献
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Standards are the basis for production enterprises to organize production ex-factory inspection trade 《中国标准化(英文版)》2008,25(1):24-25
Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.…… 相似文献
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Steffen Müller-Probandt 《材料科学与工程:中英文B版...》2018,(4):161-177
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... 相似文献
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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. 相似文献
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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.…… 相似文献
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Janet Lang 《Materials and Manufacturing Processes》2017,32(7-8):857-866
ABSTRACTThe 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. 相似文献
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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. 相似文献
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C. Qihong W. Zhan‐Wen J. Yi J. Yehua L. Fei F. Hanguang 《Materialwissenschaft und Werkstofftechnik》2014,45(7):582-590
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. 相似文献
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《中国标准化(英文版)》2014,(4)
正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from 相似文献