小型太阳模拟器设计研究

太阳模拟器是一种模拟太阳辐射特性的测量仪器,其在航空航天领域中用来检测卫星热设计的热平衡试验和用来检测卫星姿态测量,并完成地面标定与测试试验。本文在突出太阳模拟器小型化的特点下,详细论述了太阳模拟器的设计要点,给出了详细设计方案。本文设计的太阳模拟器设计方法简单可靠,具有很大的推广价值。     

空间辐射制冷器用小型环境模拟器的研制

研制了一台试验和检测辐射制冷器的小型空间环境模拟器,系统采用闭循环小型制冷机作冷源,模拟冷背景温度20K,功率8瓦,黑度0.98,容器压力1.8×10~(-5)帕.系统配有巡回检测装置对实验数据自动进行采集.图1是模拟器结构示意图.对于模拟误差估算利用航天器模拟误差理论,推广至辐射制冷器冷黑、真空环境模拟,只能较近似地估算模拟误差的来源和大小,作为模拟器的设计依据。经过调试,符合设计要求,系统操作简便,清洁无油,不污染制冷器光学镜面,运转费用低廉.图3,参考文献4.     

平面精密工作台的性能测试和控制

要实现平面工作台的精密定位,需要对其运动进行检测,并设计相应的控制方案.为同步检测平面工作台三自由度位移,研制了图像处理位移检测系统.以CCD相机为核心结合显微镜放大、图像采集和图像处理构成检测系统.系统的位移检测不受工作台大幅转动的影响.检测系统既有较高的位移分辨率,又有一定的位移检测范围.使用图像处理位移检测系统,对清华大学制造的平面精密工作台的运动性能进行了测试.工作台干涉运动均小于主运动,通过合理的开环控制对各个运动方向上的干涉运动进行补偿,获得了工作台在平面任意方向上的运动.工作台小范围定位能力的检测表明工作台具有很高的定位分辨率.     

一种太阳模拟器检测装置的研制

本文介绍了一种太阳模拟器检测装置,以太阳电池模块作为太阳模拟器的辐照度检测模块,数据采集卡作为数据采集模块,所采集的数据经上位机处理,可对太阳模拟器的不稳定度、不均匀度等参数进行现场检测,使得检测流程更为便捷、可靠。     

日光模拟器对试验室内传热影响的数值分析

应用CFD技术对沙漠环境模拟试验室内的传热过程进行了模拟,分别比较了日光模拟器的高度和开启组数对室内温度场和地面辐射分布的影响。研究发现随着日光模拟器高度升高热气流越难被带走,地面太阳辐射值明显减小。随着灯的数量增加,室内上升气流的趋势越明显,地面太阳辐射值明显增大。将灯布置成“梅花状”,有利于辐射照度的均匀。     

无标准信号输出仪表动态多路同步检测技术

针对无标准信号输出仪表检测存在的效率低、误差大、成本高等问题,开展了仪表动态多路同步检测技术的研究,较系统地介绍了该技术的原理、系统结构、图像处理与识别方法、装置硬件及软件构成.该技术是工业视觉系统在计量检测领域研究和应用的发展,具有经济适用、快速准确的特点,有着重要的推广价值.     

线纹标准工作台的研制

文章介绍了公司自主开发的线纹标准工作台的设计思想和理论依据、各部件的制作方法及其性能测试,对由工作台为主体建成的线纹标准装置的测量不确定度、测量重复性进行了论证。线纹标准工作台的研制成功,对公司健全量值溯源系统,完善计量检测体系,创造经济效益具有深远的意义。     

日照辐射对天然气超声波流量计流场修正系数的影响

2021年我国天然气消耗量为三千多亿立方,天然气测量的微小差异就会对经济效益产生巨大的影响,而目前市场上所使用的天然气流量计的可靠性却较差。天然气超声波流量计是应用最为广泛的非接触式天然气流量计量设备,其计量精度受到诸多因素的影响。基于ANSYS计算仿真平台,根据西安市地理位置及季节性特点,建立DN300管道的四声道超声波流量计数值模型,对天然气输运环境中的太阳辐射因素进行耦合研究。天然气超声波流量计的时差法计量原理是通过超声波顺逆流时间差来计量管道流体流量,其中流量修正系数是超声波流量计计量的关键参数,其定义是声道线平均速度与管道截面平均速度的比值。通过仿真结果分析得出以下结论：随着太阳辐射能变化,流场修正系数相对误差变化较小;考虑太阳辐射耦合进气速度时,对比有太阳辐射时的流场修正系数与不考虑辐射时的流场修正系数,冬季时的相对误差范围是0.005%～0.091%,夏季的相对误差范围是0.048%～0.27%。夏季的变化幅度较冬季明显,为提高超声波流量计计量精度,可以在夏季温度较高的中午对超声流量计仪表进行二次修正。     

合理布局 科学选型 及时修正参数 唐钢提高能源计量准确度的“三件法宝”

一、合理布局1.原来的能源计量系统主要是由一次检测元件、变送器、安全栅、数显仪表几个部分组成。计量设施不完善,设备老化,遍布全公司的二级厂矿,不利于集中管理和宏观控制。为了保障计量系统的准确性,在健全计量设施方面,我们做了如下工作:在转炉煤气计量中,二钢厂和棒材厂都没有单独的计量装置,只是在总的管道上安装了一套流量表,两家的煤气使用量要靠经验值人为分配,这样势必会引起争议,造成误差;再如高线厂既烧转炉煤气又烧高炉煤气,一套计量系统不可能把二者分开计量。在结算时,也需要人为平衡,这样也势必会造成较大误差。我们针对…     

计量在太阳能光伏产业上的应用

太阳能光伏作为新兴行业,相关的光伏产品种类和性能变化非常快,因使用的计量测试仪器和测试条件的不同,测量的偏差较大,同时与之相适应的计量测试技术也没有跟上。该文简要介绍了与太阳能光伏参数测量密切相关的,包括太阳模拟器、IV测试仪、总辐射表和太阳电池量子效率测量装置在内的各项计量研究工作。     

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.     

Brainstorming for ISO Strategy 2016-2020

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