上海光源储存环真空系统

上海光源储存环真空系统已于2007年底建成并开始运行.这个真空系统采用了双室结构的薄壁不锈钢真空室,其尺寸公差都小于1mm,真空室安装位置公差都小于2mm;分散的吸收器有序排列在抽气室内,把同步辐射光准直并引入光束线,同时吸收废弃的同步辐射光,把热量转移到真空室外;波纹管内的高频屏蔽机构为单指型,避免了指间接触力和磨擦;(SIP+NEG)复合泵、SIP和TSP共用,采用合理的激活NEG泵和升华钛丝的工艺程序,提供了强大的抽速和容量.真空预调试时各段真空室内的极限真空都达到5×10 -9Pa.全环真空室安装并连通后,大部分真空室不烘烤,只烘烤全环真空泵的情况下,极限真空达到2×10 -8Pa.储存环运行在束流剂量260Ah、能量3.5GeV、流强220mA时,动态压强为0.8×10 -7Pa,束流寿命21h,达到了真空系统的设计指标1.33×10 -7Pa.     

SSRF电子储存环铝合金超高真空室研制

上海光源3.5GeV电子储存环超高真空室采用铝合金材料,经数控加工后焊接而成,其结构复杂,精度要求高.在预制研究中成功地完成了一段6 m长典型真空室的设计、制造与调试.该真空室的平面度达到0.23 mm,横向偏移量1.4mm,内表面单位面积出气率4.1×10-10 Pa·m/s.在研制中暴露出结构设计和加工工艺等方面的多种问题,并找到了妥善解决的方法,为工程批量生产准备了条件.     

SSRF储存环预研制铝合金真空室的机械加工

上海同步辐射装置（SSRF）储存环铝合金超高真空室已研制成功，该机加真空室的尺寸大、尺寸精度、形位公差及粗糙度要求极高，不同于常规的大型超高真空室。在预研件加工中，成功地解决了一系列问题，如光洁度提高困难，加工成型后变形大；加工尺寸和精度受环境温度影响较大等。本文详细阐述了储存环真空室材料和热处理状态的选择依据，为了保证尺寸精度和形位公差所采取的工艺措施，分析了粗糙度的形成机理和影响因素，从刀具材料、几何角度、切削参数、冷却液选型等多方面提出了解决办法。     

上海光源首期Wiggler真空室材料选择及测试

本文对上海同步辐射光源(Shanghai Synchrotron Radiation Facility,SSRF)首期两台扭摆器(Wiggler)真空室研制中材料的选择进行了阐述,在国内首次采用不锈钢真空室内壁镀铜的工艺来减小束流尾场效应,并对SS304镀铜材料相关真空性能进行了测试,为将来加速器设备真空室设计提供了参考.     

不锈钢的同步辐射光致脱附

电子储存环真空室壁及相连光束线的同步辐射光致脱附 (PSD)严重影响着束流质量和寿命。不锈钢是加速器真空室最常用的材料 ,合肥光源的真空系统即为不锈钢结构。合肥光源在B6a光出口建立了PSD光束线 ,选用长 12 1cm ,内径8 6cm的 30 4L不锈钢真空室作为首件样品 ,用于测试不锈钢不同表面状态的脱附情况 ,结果表明经辉光放电处理的表面脱附系数最低。     

不锈钢的同步辐射光致脱附

电子储存环真空室壁及相连光束线的同步辐射致脱附（ＰＳＤ）严重影响着束流质量和寿命。不锈钢是加速器真空室最常用的材料,合肥光源的真空系统即为不锈钢结构。合肥光源在Ｂ６ａ光出口建立了ＰＳＤ光束线,选用长１２１ｃｍ,内径８．６ｃｍ的３０４Ｌ不锈钢真空室作为首件样品,用于测试不锈钢不同表面状态的脱附情况,结果表明经辉光放电处理的表面脱附系数最低。     

用于超高真空的铝合金──兰宝石密封窗

KEK TRISTANe+e-存储加速器(1)的真空系统中采用了观察官,采用了全铝合金的真空系统(包括真空室、波纹管、法兰、离子泵等)。市场上可以买到的窗玻璃为科伐-兰宝石或科伐-7056玻璃。真空系统的铝合金法兰和这种玻璃窗之间需要铝-不锈钢过渡。而使用任何铝-不锈钢过渡都是昂贵的,”不太可靠的。在TRISTAN的设计中尽量避免了使用普通不锈钢和不锈钢-铝的过渡,因而设计和制作了铝合金-兰宝石密封窗用于超高真空系统。 如图1所示,观察窗由铝合金筒(A3003)和主宝石片(A12O(2)3单晶)组成。铝合金筒和金属化兰宝石是用铝合金焊条BA4047(10…     

SSRF增强器真空系统设计和真空室研制

为减少增强器弯转磁铁的交变磁场在真空室内感应的涡流对主磁场的干扰，SSRF增强器采用了椭圆截面的薄壁不锈钢真空室，并成功研制出样机，本文描述了增强器真空系统总体设计、真空室的材料选择、结构设计和物理计算（如涡流对主磁场的影响、真空室的真空负载变形、同步辐射光对真空室温升影响和真空室内压强分布），介绍了加工工艺。     

不锈钢、无氧铜和铝合金的升温脱附谱研究

研究超高真空材料的升温脱附谱对于获得超高真空、提高极限真空度和指导真空系统的烘烤除气有重要的意义.作者设计并加工了研究超高真空升温脱附谱的实验设备,并用此设备测量了真空系统结构材料不锈钢、无氧铜和铝合金的升温脱附谱.     

上海光源(SSRF)输运线真空系统设计

本文介绍了上海光源高能输运线和低能输运线真空系统设计,包括总体布局,真空盒的结构和真空获得系统.低能输运线由两个弯段和三个直线段组成,高能输运线由五个弯段和四个直线段组成.用有限元方法分析计算了输运线弯段真空盒的大气负载变形,以确定真空盒的形状和尺寸,结果变形量小于0.15 mm.通过模拟输运线全段真空盒的压强分布来优化泵系统的布局,结果表明全线压强小于6×10-6 Pa.因此真空系统的设计方案能满足物理指标和实际工程要求.     

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.……     

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 ...     

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     

CNAS Passes APLAC's PTP Review

正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively.