Ti离子辐照诱发焦绿石Gd2Zr2O7相变的电子显微研究

通过高分辨和剖面电子显微技术研究了离子注入在单晶焦绿石Gd2Zr2O7中的产生的结构相变.在单晶Gd2Zr2O7中注入200keV Ti+离子,注量为1×1017ions/cm2,注入温度为常温.电子显微研究表明,1×1017ions/cm2的Ti+离子注入没有使样品非晶化,而是诱发了单晶Gd2Zr2O7从焦绿石结构转变成萤石结构.从高分辨像和选区电子衍射花样发现Gd3+和Zr3+发生了阳离子无序.重离子入射产生的级联碰撞致使阳离子无序被认为是相变发生的物理机制.     

Ag离子注入石英玻璃光学透射率研究

用Mevva离子源,将Ag离子注入到石英玻璃中形成纳米晶粒。离子注入的能量为90keV,剂量分别为5×1015、1×1016、3×1016、5×1016、1×1017ions/cm2。X光电子能谱(XPS)分析纳米Ag颗粒没有发生化学反应,说明Ag仍以金属态形式存在。光学透射率测试表明,吸收峰的位置在400nm,当剂量大于5×1016ions/cm2时,发现在440nm左右有一伴峰。分析表明400nm的峰来源于表面等离子体共振吸收,而440nm的伴峰是注入离子形成了少数非常大的纳米颗粒以及纳米颗粒之间相互作用引起的。样品退火后,表面等离子体共振吸收峰红移,而伴峰消失。随着退火的温度升高,峰位红移越大,说明纳米颗粒尺寸增大。     

双离子束沉积Zr-O薄膜的组成分析

离子束溅射沉积锆的同时以氧离子轰击形成Zr－O薄膜，经RBS及XPS分析表明薄膜由3部分组成：表面碳沾污层；Zr－O膜体；膜与基体的界面过渡层。氧离子束流密度从0.8μA／cm2增至30μA／cm2，膜体的[O]／[Zr]原子比值由略大千零升至2，最后稳定于2，碳沾污层及界面过渡层的厚度并不随氧离子束流密度的增加而变化。还讨论了Zr的化学位移情况。     

Ta和Ag离子双注入Ti6Al4V合金抗Hank's溶液腐蚀性能研究

采用Ta和Ag离子双注入对医用Ti6Al4V合金进行表面改性,以Ta离子1.5×1017 ions/cm2先注入,Ag离子1×1017 ions/cm2后注入合金样品表面.采用动电位极化曲线研究Ta+Ag离子双注入前后Ti6Al4V合金抗Hank’s溶液腐蚀性能,利用小角掠射X射线衍射技术研究离子双注入前后Ti6Al4V合金表面物相组成,以X射线光电子能谱技术分析离子双注入样品表面、离子注入合金腐蚀样品表面元素存在的化合态.结果表明,Ta+Ag离子双注入改善了Ti6Al4V合金抗Hank’s溶液腐蚀性能,离子双注入合金的腐蚀电流密度与对照样相比降低了94.6％.离子双注入Ti6Al4V合金表面生成的耐蚀合金层、少量单质Ta和Ag、合金表面的氧化物腐蚀阻挡层有利于合金抗Hank’s溶液腐蚀性能的改善.     

聚(2,5-二丁氧基)对苯乙炔的制备及其离子注入改性研究

通过双醚化反应、氯甲基化反应以及在强碱性条件下进行的脱氯化氢反应,制备出新型光电功能材料聚(2,5 二丁氧基)对苯乙炔(PDBOPV)。采用能量为10～35keV,剂量为3.0×1015～4.8×1017ions/cm2的氮离子(N+)对PDBOPV进行离子注入改性。PDBOPV薄膜的电导率随注入离子能量和剂量的增加而提高。当注入N+的能量为35keV,剂量为4.8×1017ions/cm2时,PDBOPV薄膜的电导率为0.136S/cm,比本征态的电导率提高了8个数量级。通过超高阻测试仪研究了PDBOPV薄膜表面电导率与温度的关系,发现N+注入PDBOPV薄膜的电导活化能为0.155eV。离子注入PDBOPV薄膜的电导率的环境稳定性能优于Br2、I2和FeCl3掺杂的PDBOPV。对离子注入PDBOPV薄膜的导电机理进行了初步探讨。     

氦离子注入对Ti6Al4V合金组织和力学性能的影响

在室温和400～700℃条件下,采用 1×1017ions/cm2注入剂量和200keV加速电压对 Ti6Al4V合金进行了氦离子注入.分别采用纳米硬度仪和X射线衍射方法对Ti6Al4V合金的氦离子注入表面层(≤700nm)进行了纳米硬度、弹性模量测试和物相分析.结果表明:在室温至600℃范围内,氦离子注入温度越高,Ti6Al4V合金注入层的硬度也越高,而其弹性模量则变小.氦离子注入温度为700℃时,Ti6Al4V合金发生了软化,其弹性模量也有所提高.氦离子注入引起的硬化现象与点缺陷和Ti6Al4V合金中β相的析出有关,而软化现象则与β相的粗化和γ-TiH相的形成有关.     

铌离子注入改善铝表面的力学性能

利用金属蒸气真空弧离子源,将大束流Nb离子注入到铝中,改善了铝表面的力学性能。在离子注入过程中直接形成了金属间化合物Al3Nb。金属间化合物的形成与离子注入的剂量有关。当Nb离子剂量达到3×10     

氮离子注入对纯铁表面显微形貌的影响

铁基材料由于其可降解性和无毒性,在血管支架材料领域具有潜在的应用前景.采用40kV的氮离子注入工业纯铁,注入剂量为1×1017～7×1017ions/cm2, X射线衍射表征了材料表面的物相结构,采用原子力显微镜研究了离子注入剂量对材料表面形貌的影响,并用Ra、RMS和Rz定量研究了离子注入后的表面粗糙度.结果表明,氮离子注入对纯铁表面形貌产生了一定的影响,随着注入离子剂量的增加,材料表面的粗糙度也随之增加.     

钼离子注入束流大小对H13钢表层结构与耐磨性能的影响

利用金属蒸汽真空弧离子源引出的强束流钼离子，对H13钢进行了高剂量的离子注入。测量了注入试样的磨损性能，发现在注入剂量为3×1017cm－2、注入束流密度低于47μA·cm－2时，其耐磨性得到不同程度的改善。分别利用卢瑟福背散射谱（RBS）、X射线衍射（XRD）和X光电子能谱（XPS）测试了注入试样的表面成分及其微观结构。讨论了H13钢耐磨性的影响因素。     

低能离子注入对聚吡咯甲烯的改性

利用低能氮离子对聚[(3乙酰基吡咯-2,5-二)对二甲氨基苯甲烯](Papdmabeq)薄膜进行了离子注入改性(注入能量为10～35 keV、剂量为1.2×1016～2.2×1017ions/cm2),研究了与材料三阶非线性极化率相关的物理量的变化规律.结果表明,氮离子注入使Papdmabeq薄膜的光电特性都发生了显著变化.适当能量和剂量的氮离子注入Papdmabeq薄膜后,薄膜中导电岛的数量增加,在聚合物分子链间形成了大的导电区域,导致其电导率显著提高.当注入离子的能量为25 keV、剂量为2.2×1017ionS/cm2时,Papdmabeq薄膜的电导率为9.2×10-4S/cm,比本征态Papdmabeq的电导率提高了5个数量级,且离子注入后薄膜电导率的环境稳定性优于经碘掺杂的Papdmabeq.氮离子注入可以使这种聚合物薄膜在可见光范围内的光吸收大幅度提高,使共轭程度得到显著增强.当注入离子的能量为35 keV、剂量为2.2×1017ions/cm2时,Papdmabeq的光学禁带宽度(Eg)由1.626 eV降低到1.340 eV.     

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.     

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.     

新闻(英文)

正China and Greece Sign the Standardization Cooperation Agreement Witnessed by Chinese Premier Li Keqiang and Greek Prime Minister Antonis Samaras,AQSIQ Minister Zhi Shuping and ELOT Chairman and Executive Director Angelos Tolkas signed the SAC-ELOT Standardization Cooperation Agreement.The Agreement is one of the critical cooperation documents signed during Li Keqiang’s visit in Greece,encouraging China and Greece to