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.     

动态流量法超高真空标准装置

研制成功的动态流量法超高真空标准装置是一台用来校准真空规的绝对真空计量标准。装置由校准系统、微流量计系统、抽气系统和计算机控制系统组成。校准系统采用四球结构 ,校准球室直径为50 0mm。极限真空度为 6 5× 10 - 9Pa ,校准范围为 10 - 2 ～ 10 - 7Pa ,不确定度为 3% (10 - 2 ～ 10 - 6 Pa)和10 % (10 - 7Pa)。     

超导扭摆磁铁光束线前端真空系统

6T单周期超导扭摆磁铁是合肥同步辐射光源的一个插入件，用于将可用光范围扩展到X射线波段。由该磁铁引出的光束线的前端已调试完毕，其中静态真空达2．46×10－8Pa。主要介绍了该前端超高真空系统的计算设计及调试。     

北京同步辐射装置1B3前端区真空设计

北京同步辐射装置新建设的1B3前端区位于储存环1区隧道内,下游建设两条光束线1B3A光刻束线和1B3B测试束线。前端区是同步辐射实验装置的一部分,上接光源下连光束线,起到承上启下的作用。由于空气对同步辐射有着强烈的吸收效应,因此为了保证实验能够获得足够的光通量,在包括前端区的整个光束线内部都要维持超高真空环境。前端区的真空设计对同步辐射实验装置有着重要意义。前端区真空设计工作主要包含真空设备布局和真空计算两部分。1B3前端区经过安装调试后,静态真空度达到4.4×10-8Pa,在北京同步辐射装置专用模式和兼用模式下的动态真空度高于6.7×10-7Pa。从测试结果中可以看出,1B3前端区真空度达到真空设计指标,满足束线使用要求。     

超导波荡器热负荷测试装置超高真空系统

介绍了超导波荡器热负荷测试装置超高真空系统的设计、调试。通过离子泵、吸气剂泵以及系统低温冷凝面的联合抽气作用,使系统在常温下获得7.8×10-8Pa的真空度,在低温下能够获得1.7×10-8Pa的真空度,满足光源储存环真空系统1.3×10-7Pa的真空度要求。     

分流法超高/极高真空校准装置性能研究

分流法超高／极高真空校准装置由极高真空（XHV）系统、超高真空（UHV）系统、流量分流系统三部分组成。使用磁悬浮涡轮分子泵和非蒸散型吸气剂泵组合抽气在XHV校准室获得了10^-10 Pa的极高真空；采用的分流法真空规校准方法，使压力校准下限延伸到了10^-10 Pa；利用非蒸散型吸气剂泵对惰性气体无抽速的特性，使用惰性气体校准时，减小了校准下限的不确定度；校准装置的校准范围为（10^4～10^-10）Pa，合成标准不确定度为1．5％～3．5％。     

北京正负电子对撞机储存环真空系统运行和改进

目前BEPC储存环真空系统已经运行了十五年,系统运行良好,当有束流存在时,储存环的平均动态压强低于2.6×10-7Pa,束流寿命大于10 h。尽管真空系统部件多,结构复杂,但由于真空泄漏造成停机的次数并不多,大多数的泄漏能在抽真空和系统检漏期间排除。为了提高北京正负电子对撞机的性能,BEPC储存环真空系统进行了一系列的改进,例如,重新改造铝真空盒用来引出同步辐射光束线,在正负电子对撞区安装NEG泵来提高真空度。特别是真空内的扭摆磁铁被安装到储存环真空系统,通过在永久磁块表面镀氮化钛和合理的排气技术,静态压强已经达到了2.6×10-8Pa。     

快速阀控制系统

为了使北京正负电子对撞机电子贮存环的真空系统不受同步辐射光束线灾难性真空事故的破坏,在同步辐射实验室,已经为每一条光束线建造了一个真空保护系统,快速阀控制系统就是其中的一个组成部分。本文详细介绍了快速阀的机械构造及其控制系统的设计。     

三级差分抽气分子束质谱装置的设计和研究

研制了具有三级涡轮分子泵差分抽气系统的分子束质谱装置 ,该装置在 1330 0Pa典型气体采样压力下 ,三级差分抽气区的压力分别达到 5× 10 - 1,3× 10 - 3,1 2× 10 - 4Pa。利用该装置 ,已成功地实现了对活性离子物种N 和N 2 的“原位”检测     

现场真空校准装置性能研究

研制了一台校准范围为10~(-5)~10~5Pa的现场真空校准装置。将不同种类单一成分的校准气体引入装置上游室,通过几何尺寸为微米量级激光小孔的衰减,建立校准用标准压力p_(std)。上游室压力变化范围为1~10~3Pa,相应地,校准室内对应的标准压力范围10~(-5)~10~(-2)Pa(N2),测量不确定度为2.4%。另外,该装置可采用与标准真空计直接比较进行动态或静态校准,其极限真空度为10~(-6)Pa量级。对装置暴露大气后的抽气性能、静态压升及其主要计量特性进行了实验研究。实验结果表明,该装置外形尺寸以及质量分别为475 mm×420 mm×800 mm、37.8 kg,校准范围为1.9×10~(-5)~1.0×10~5Pa,相对合成标准不确定度为2.8%~0.40%。     

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.     

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...     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

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.     

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.     

Synthesis of Alumina-Zirconia Nanocomposites by Solgel Process

Al₂O₃-ZrO₂ nanocomposites were developed starting with the solgel process. Composite alumina-zirconia nanopowders were synthesized from metallorganic precursors (Aluminium secondary butoxide and zirconium Iso propoxide) using the solgel process. The parameters affecting the synthesis—solvent, concentration of precursor, R/H ratio (i.e., dilution of water in solvent)—were varied as also the temperature and pH. BET and TEM were used to measure nanosize. Diffuse reflectance spectroscopy and also qualitative optical absorption led to identical particle size estimate. The variation of process parameters was used to study the effect and interdependence of process parameters. Artificial Neural Networks was used to rigorously analyze the process. Although this led to confirmation of interdependence of parameters, the presence of a single overwhelming solvent variable was also established. Then the optimal process was used to synthesize more nanopowder. To produce bulk nanocomposite the nanopowders were sintered by varying the temperature and time period. The sintered lithoids were probed with a vickers hardness tester to measure elastic modulus, hardness, and fracture toughness. The results showed high elastic modulus, modest hardness, and very high fracture toughness.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.