稀土正硼酸盐Ln_(1-x)BO_3:Eu_x(Ln=Y,Gd)的结构与发光特性

用溶胶－凝胶法和高温固相反应分别制备了纳米量级和常规尺度的稀土正硼酸盐荧光粉ＬｎＢＯ３：Ｅｕ（Ｌｎ＝Ｙ,Ｇｄ）,测量了它们的激发光谱并首次观察到了ＹＢＯ３：Ｅｕ中Ｅｕ３＋的７Ｆ０→５Ｄ０跃迁的 Ｎｅｐｈｅｌａｕｘｅｔｉｃ效应．根据低温下的激发光谱,发射光谱以及变温条件对发光光谱的影响,ＹＢＯ３中Ｌｎ３＋所占据的两种格位的对称性被修正为Ｃ３和Ｄ３在不同方法制备的样品中观察到了不同的发光强度和猝灭浓度,缺陷的影响是产生这种不同的原因,退火样品的发光和拉曼散射谱的变化反映出掺杂的杂质Ｅｕ３＋的团聚化是可能的缺陷来源．     

用溶胶—凝胶法制备的Y2SiO5：Gd,Eu荧光粉的发光性能

用溶胶－凝胶法合成了Ｙ２ＳｉＯ５：Ｇｄ,Ｅｕ红色荧光粉。探讨了烧结工艺对粉体的结构及发光性能的影响。首次报道了搀杂Ｇｄ的Ｙ２ＳｉＯ５：Ｅｕ红色荧光粉的发光性能。研究结果表明,搀杂适当浓度的Ｇｄ,可以显著提高ＹｓＳｉＯ５：Ｅｕ红色荧光粉的发光强度,在Ｙ２ＳｉＯ５基质中,Ｇｄ＾３＋是Ｅｕ＾３＋的优良敏化剂。     

（Y，Zn，Sr）_3（P，VO_4）_2：Eu~（3＋），Bi~（3＋）发光性

合成了组成为（Ｙ，Ｚｎ，Ｓｒ）３（Ｐ，ＶＯ４）２：Ｅｕ３＋，Ｂｉ３＋的荧光材料，经射线结构分析确定为Ｚｎ３（ＰＯ４）２结构，属于单斜晶系，空间群为Ｐ２１／ｎ讨论了基质组成对Ｅｕ３＋离子发光性质的影响，用Ｙ３＋取代了一部分Ｚｎ２＋，用ＶＯ取代了一部分ＰＯ．由于基质的４３６ｎｍ发射与Ｅｕ３＋的激发态能级的能量重叠，Ｅｕ３＋产生较强的５９８ｎｍ和６１８ｎｍ发射．另外，掺入少量Ｂｉ３＋能增强Ｅｕ３＋发射．     

PDP荧光粉GdBO3:Eu格位选择激发下的光致发光及其相变研究

用溶胶－凝胶法制备了PDP用荧光粉LT－GdBO3:Eu,并用常规的手段,包括XRD,拉曼散射谱,发光光谱等研究了它的晶体结构和光谱性质,利用染料激光系统,选择激光荧光粉中不同格位上的Eu3 的5D0能级,得到了对应于不同格位的两套发射谱,并根据发射谱分析了Eu^3 的格位对称性,以及对这两种格位之间的能量传递过程产生影响的一些因素,在1000－1100度之间,发生了LT－GdBO3向另一种Vaterite结构的GdBO3的相轩9变,相变的过程伴随着因GdBO3晶体结构发生重排而引起的热吸收,荧光粉LT－GdBO3:Eu有很高的亮度,同时其猝灭浓度高达20mol%。     

（Y,Zn,Sr）3（P,VO4）：Eu^3＋,Bi^3＋发光性质的研究

合成了组成为（Ｙ，Ｚｎ，Ｓｒ）３（Ｐ，ＶＯ４）：Ｅｕ＾３＋，Ｂｉ＾３＋的荧光材料，经Ｘ射线结构分析确定为Ｚｎ３（ＰＯ４）２结构，属于单斜晶系，空间群为Ｐ２１／ｎ。讨论了基质组成对Ｅｕ＾３＋离子发光性质的影响，用Ｙ＾３＋取代了一部分Ｚｎ＾２＋；用ＶＯ４取代了一部分ＰＯ４由于基质的４３６ｎｍ发射与Ｅｕ＾３＋的激发态能级的能量重叠，Ｅｕ＾３＋产生较强的５９８ｎｍ和６１８ｎｍ发射。另外，掺入少量Ｂｉ＾３＋     

高温高压合成的硅酸锶铕铋的发光特性

用高温高压方法合成了Ｓｒ２ＳｉＯ４：Ｅ３＋ｕ，Ｂｉ３＋和ＳｒＳｉＯ３：Ｅｕ３＋，Ｂｉ３＋研究了合成压力对其发光性能的影响，与用溶胶－凝胶共沉淀法和常压高温法合成的产品作比较．常压制备的ＳｒＳｉＯ３：Ｅｕ３＋，Ｂｉ３＋为六角结构，而在２．３４—４．１０ＧＰＳ的合成压力范围内，它转变为反正交结构；常压下Ｓｒ２ＳｉＯ４：Ｅｕ３＋，Ｂｉ３＋为单斜结构，在４．２ＧＰａ的合成压力下，未发现其结构相变．高压合成产物的发光强度和相对量子发光效率降低，半宽度明显增加，且伴有红移发生．发光强度的改变是压致晶场的变化引起的     

PbF2：Gd,Eu晶体X射线激发的发射光谱

用脱氧剂非真空环境下、Ｓｔｏｃｋｂａｒｇｅｒ方法生长未掺和掺钆和铕的、浓度范围在０．１￣０．２ｗｔ％的ＰｂＦ２：β晶体。本文报导Ｘ射线激发ＰｂＦ２：Ｇｄ晶体的Ｇｄ＾３＋发射。揭示了分别来自＾６Ｐ和＾６Ｉ多重态３１２．５和２７７．４ｎｍ发射带，而＾６Ｄ→＾８Ｓ发射被点阵再吸收。＾６Ｉ的发射强度低于＾６Ｐ，说明＾６Ｐ能级优先占据。室温下以Ｘ射线激发在３６８．９和８１４．５ｎｍ之间观察到１４条Ｅｕ＾３＋     

高密度发光材料γ-Bi_2WO_6:Pr~(3 )的发光性质研究

研究了用固相法制备的高密度发光材料γ－Ｂｉ２ＷＯ６：Ｐｒ３＋的结构、光致发光光谱、激发谱和γ－Ｂｉ２ＷＯ６的漫反射谱．由实验测得它的晶格参数为α＝５．４５Ａ,ｂ＝１６．４２Ａ,ｃ＝５．４３Ａ,密度Ｄｘ＝９．５３ｇ／ｃｍ３．它的光致发光光谱主发射峰位于６００、６０８、６１１、６２９ｎｍ,分别来自于Ｐｒ３＋的１Ｄ２→３Ｈ４、２Ｐｏ→３Ｈ６、３Ｐｏ→３Ｈ６、３Ｐｏ→３Ｆ２跃迁的发射．其激发谱由位于约２２５～４３０ｎｍ范围内、最大值约在３７２ｎｍ的主激发带和４５０ｎｍ的激发峰组成;主激发带来自于基质,可能是基质的带间吸收、Ｗ－Ｏ间电荷迁移吸收和缺陷能级的吸收;４５０ｎｍ的激发峰来自于 Ｐｒ３＋的３Ｈ４→３Ｐ２跃迁吸收．ＢＷＯ：Ｐｒ３＋的最佳掺杂浓度为 ０．８ｍｏｌ％左右．     

高温高压合成的硅酸锶有铕铋的发光特性

用高温高压方法合成了Ｓｒ２ＳｉＯ４Ｅ＾３＋ｕ，Ｂｉ＾３＋和ＳｒＳｉＯ３Ｅｕ＾３＋＿，Ｂｉ＾３＋，研究了合成压力对其发光性能的影响，与用溶胶－凝胶共沉淀法和常压高温法合成的产品作比较，常压制备的ＳｒＳｉＯ３Ｅｕ＾３＋，Ｂｉ＾３＋为六角结构，而在２．３４－４．１０ＧＰａ的合成压力范围内，它转变为赝正交结构；常压下Ｓｒ２ＳｉＯ４；Ｅｕ＾３＋，Ｂｉ＾３＋，为单斜结构，在４．２ＧＰａ的合成压力下，未发现其结     

TiN／n—GaAs体系界面的研究

利用二次离子质谱（ＳＩＭＳ）深能级瞬态谱（ＤＬＴＳ）研究了ＴｉＮ／ｎ－ＧａＡｓ体系。ＳＩＭＳ结果表明，退火后Ｔｉ的浓度剖面向胂化镓衬底略有移动，Ｎ则基本救济为；ＤＬＴＳ观察到的Ｅｃ＝０．２１ｅＶ处的Ｔｉ＾３＋＊３ｄ）／Ｔｉ＾３＋（３ｄ＾２）单受主中心，但其浓度较ＥＬ２要小得多。根据实验结果，探讨了退火后难熔金属氮化物／ｎ－ＧｓＡｓ体系电学特性改善的原因。     

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