Sn掺杂ZnO微晶的水热法制备及表征

采用水热法合成了具有不同形貌的Sn掺杂ZnO微晶.采用XRD、SEM、UV等分析手段对试样进行了表征.实验结果表明,随着Sn掺杂比例的增加,ZnO微晶的粒度增大,大的微晶达到500 nm,小的仅为100 nmm.大的ZnO微晶为六棱锥体,显露锥面P{10 (1)1},负极面O(000 (1)),并对其生长机理进行了探讨.     

Sn掺杂ZnO半导体纳米线的制备、表征及光学性能

采用化学气相沉积法获得了Sn掺杂含量约为2．4％（原子分数）的Sn掺杂ZnO半导体纳米线。X射线衍射结果表明，Sn的掺杂并没有改变ZnO的纤锌矿结构。掺杂纳米线的室温光致发光光谱在409．2nm和498．0nm处出现了蓝绿光发光峰。探讨了其发光机制，认为前者可能来源于从导带到Zn空位形成的浅受主能级的跃迁以及从氧空位形...     

Sn掺杂ZnO纳米带的制备及其光致发光性能研究

采用热蒸发法制备了单晶Sn掺杂ZnO纳米带,其中Sn的掺杂含量约为5%(原子分数).X射线衍射(XRD)结果表明Sn掺杂ZnO纳米带为单相纤锌矿结构.X射线光电子能谱(XPS)表明样品中Sn的价态为4+.样品的室温光致发光谱(PL)在445.8nm处存在较强的蓝光发射峰,对其发光机制进行了分析.     

Sn催化的Ga掺杂ZnO纳米线的制备及其光致发光性能研究

采用化学气相沉积的方法,以Sn粉为催化剂制备出大长径比的Ga掺杂ZnO纳米线。采用扫描电子显微镜观察制备的产物,发现样品为直径约25～90nm的纳米线。通过比较不同Ga掺杂含量样品的室温光致发光谱,发现一定掺杂含量的Ga可以提高ZnO纳米线的紫外发光强度,同时,Ga的掺杂也会引起ZnO紫外发光峰的蓝移。随着Ga含量的增加,蓝移程度越来越小,甚至发生红移。Sn的引入只对Ga掺杂ZnO纳米线的蓝绿光有贡献。     

Sn掺杂ZnO半导体纳米线的制备、表征及光学性能

采用化学气相沉积法获得了Sn掺杂含量约为2.4%(原子分数)的Sn掺杂ZnO半导体纳米线。X射线衍射结果表明,Sn的掺杂并没有改变ZnO的纤锌矿结构。掺杂纳米线的室温光致发光光谱在409.2nm和498.0nm处出现了蓝绿光发光峰。探讨了其发光机制,认为前者可能来源于从导带到Zn空位形成的浅受主能级的跃迁以及从氧空位形成的浅施主能级到价带的跃迁;而后者来源于从氧空位形成的浅施主能级到锌空位浅受主能级的跃迁。     

棒状和球状氧化锌微晶的控制合成及其表征

以醋酸锌和尿素为主要原料,利用微乳-溶剂热法控制合成了棒状和球状ZnO微晶.用XRD、TEM、FTIR.和SAED等技术手段对两种形状的ZnO微晶进行了表征.结果表明:棒状ZnO微晶的平均尺寸为50nm×320nm,球状ZnO微晶的平均尺寸约为200nm.     

ZnO:Sn/Ag/ZnO:Sn复合薄膜电极的防氧化性能研究

随着分辨率的提高,传统金属电极在电阻率和抗氧化性能方面已经不适合作为需要高温热处理的场致发射显示器件中的薄膜电极。本文采用5.77%(原子比)Sn掺杂的ZnO:Sn作为Ag层的保护层,利用磁控溅射法制备ZnO:Sn/Ag/ZnO:Sn复合薄膜及其电极,并采用X射线衍射、光学显微镜、扫描电子显微镜和电性能测试系统研究复合薄膜及其电极在经过不同温度退火后的晶体结构、表面形貌和电学性能的变化。ZnO:Sn膜层致密,25 nm厚的ZnO:Sn足以保护Ag层在530℃的高温中不被明显氧化,电极电阻率低达2.0×10-8Ω.m左右。     

微波辅助水热法合成的可见光响应型Sm掺杂ZnO微晶的光催化性能和抗菌活性

采用六水合硝酸锌为锌源、六水合硝酸钐为掺杂剂、十二烷基硫酸钠为诱导剂、无水乙醇和水为混合溶剂,利用微波辅助水热法制备了Sm掺杂ZnO微晶。将Sm掺杂到ZnO晶体结构中,不仅改变ZnO的晶体结构,而且Sm掺杂对ZnO的形貌有明显的影响。考察不同Sm掺杂ZnO样品对罗丹明B的降解性能和对白色念珠菌和霉菌的抗菌活性,结果表明,[Sm]/[Zn]物质的量比为1%的Sm掺杂ZnO微晶表现出最好的光催化性能和抗菌活性。在模拟可见光下(500 W氙灯)照射160min后光催化降解罗丹明B的脱色率为75.9%,TOC去除率为66.3%。由菌落计数结果可知,其对白色念珠菌和黄曲霉的抑菌率分别为81%和77%。     

ZnO∶Sn/Ag/ZnO∶Sn复合薄膜电极的防氧化性能研究

随着分辨率的提高,传统金属电极在电阻率和抗氧化性能方面已经不适合作为需要高温热处理的场致发射显示器件中的薄膜电极.本文采用5.77%(原子比)Sn掺杂的ZnO∶Sn作为Ag层的保护层,利用磁控溅射法制备ZnO∶Sn/Ag/ZnO∶Sn复合薄膜及其电极,并采用X射线衍射、光学显微镜、扫描电子显微镜和电性能测试系统研究复合薄膜及其电极在经过不同温度退火后的晶体结构、表面形貌和电学性能的变化.ZnO∶Sn膜层致密,25 nm厚的ZnO∶Sn 足以保护Ag层在530℃的高温中不被明显氧化,电极电阻率低达2.0×10-8Ω·m左右.     

微波辅助水热法合成的可见光响应型Sm掺杂ZnO微晶的光催化性能和抗菌活性

采用六水合硝酸锌为锌源、六水合硝酸钐为掺杂剂、十二烷基硫酸钠为诱导剂、无水乙醇和水为混合溶剂,利用微波辅助水热法制备了Sm掺杂ZnO微晶.将Sm掺杂到ZnO晶体结构中,不仅改变ZnO的晶体结构,而且Sm掺杂对ZnO的形貌有明显的影响.考察不同Sm掺杂ZnO样品对罗丹明B的降解性能和对白色念珠茵和霉菌的抗茵活性,结果表明,[Sm]/EZn]物质的量比为1％的Sm掺杂ZnO微晶表现出最好的光催化性能和抗菌活性.在模拟可见光下(500 W氙灯)照射160 min后光催化降解罗丹明B的脱色率为75.9％,TOC去除率为66.3％.由菌落计数结果可知,其对白色念珠茵和黄曲霉的抑茵率分别为81％和77％.     

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.