纳米ZnO镶嵌SiO2薄膜的光学特性研究

采用射频反应磁控溅射法在玻璃衬底上成功制备出纳米ZnO镶嵌SiO2非晶薄膜,利用X射线衍射仪、场发射扫描电子显微镜、X射线光电子能谱仪和紫外-可见分光光度计研究了纳米Zn0镶嵌SiO2薄膜相比纯ZnO纳米薄膜结构的变化及镶嵌结构对其光学特性的影响.研究发现与纯ZnO纳米薄膜相比,纳米ZnO镶嵌SiO2薄膜结构样品呈非晶结构,在紫外区光吸收系数以及光学带隙明显增大,光吸收以及光学带隙的变化与样品制备的衬底温度有关.研究结果表明,由于SiO2的特殊结构实现了对纳米ZnO的束缚,减少了ZnO纳米粒子的集聚,使得量子限制效应变得显著,导致复合膜光学带隙的明显增大以及吸收边的蓝移.     

纳米SiO2在钢结构防火涂料中的应用

本文将纳米SiO2应用在水性超薄型钢结构防火涂料中,经耐火实验发现适量的添加可以明显提高涂料燃烧后炭质层的强度,延长其耐火极限;同时纳米SiO2的紫外屏蔽光谱和涂料的人工老化实验表明纳米SiO2具有特殊的光学性能,可以屏蔽大部分紫外光,将其使用在钢结构防火涂料中可以有效延缓涂料的老化进程,保持防火性能的稳定.     

Au@SiO2@LaF3：Eu纳米核壳结构的制备及其发光性能

本文利用化学法合成了Au纳米颗粒、Au@SiO2、以及Au@SiO2@LaF3：Eu的纳米核壳结构,并利用透射电镜、紫外可见吸收谱以及荧光光谱对它们的形貌、吸收和发光性能进行了表征。研究表明：通过控制柠檬酸和氯金酸以及正硅酸乙酯和氨水比例可以对Au纳米颗粒的尺寸以及SiO2层的厚度分别进行调控。当Au纳米颗粒的尺寸和SiO2层厚度增加时,Au表面等离子体共振吸收峰发生红移。在Au@SiO2@LaF3：Eu纳米核壳结构中,Au表面等离子体共振对LaF3：Eu纳米颗粒的发光产生减弱作用。另外,Eu掺杂浓度对Au@SiO2@LaF3：Eu纳米核壳结构的5D0→7F2和5D0→7F1跃迁强度比有很大的影响。     

纳米纯丙胶乳制备TiO2-SiO2杂化材料的研究

用溶胶-凝胶法制得的纳米TiO2-SiO2溶胶，与纳米级的纯丙微胶乳直接共混，制备了聚丙烯酸酯／TiO2—SiO2纳米复合胶乳。用红外光谱（FT—IR）、热重分析仪（TGA）和紫外-可见光谱仪（UV—Vis）分别表征了纳米复合胶膜的化学结构及形态、热学和光学性能。实验证实，该纳米杂化材料具有优异的紫外线屏蔽作用和热稳定性。     

退火对Ag-SiO2复合薄膜形貌和光学特性的影响

使用磁控溅射制备Ag和SiO2相间的多层膜，系统研究了退火对复合薄膜形貌和光学特性的影响。实验发现退火时间越长，Ag颗粒直径越大，吸收谱峰位相对较短的退火时间有红移现象，并且吸收谱峰比较宽，比较强。在退火时间足够长的情况下，随着每层SiO2厚度的减小，Ag颗粒直径也减小，吸收峰强度变小，峰宽变窄，峰位有蓝移现象。我们做了大量实验，总结出了退火时间的计算公式。薄膜经过合适的退火时间，放置20d后发现出现小平面结构，Ag颗粒分裂，吸收谱峰宽变窄，吸收峰位蓝移。不同退火温度下的吸收谱表明500℃是一个比较理想的退火温度。     

Pd/SiO2有机-无机薄膜的制备及其在N2气氛中的热稳定性

采用溶胶-凝胶法,在甲基化改性SiO2溶胶中掺杂PdCl2,制备Pd/SiO2有机-无机薄膜.通过XRD、红外光谱、TG-DTG分析、接触角以及SEM测试,考察该样品在N2气氛中的热稳定性.结果表明,Pd/SiO2膜材料经200℃以上温度焙烧后,样品中即出现了少量纳米金属Pd粒子,这些金属Pd为PdCl2还原所得.随着焙烧温度的升高,金属Pd粒子的衍射峰强度增加,膜材料中的Si-CH3吸收峰和Si-OH吸收峰减弱.样品中的Si-CH3吸收峰在750℃时完全消失.金属Pd的掺杂对SiO2膜材料的化学结构基本没影响.保持Pd/SiO2有机-无机薄膜及分离膜疏水性的最适宜焙烧温度为350℃.     

聚烯烃/纳米SiO2复合材料研究进展

论述了纳米SiO2的表面处理方法、复合材料的制备技术及其力学和光学性能。表明纳米SiO2分散于聚烯烃(PP、HDPE)中,可以提高基体的韧性、强度和模量。以纳米SiO2作为填料的聚乙烯棚膜,呈现优良的红外线吸收性能和可见光透过性能。为此,纳米SiO2可作为一种聚乙烯农膜的新型保温剂。     

革用聚氨酯/SiO2纳米复合材料的制备与物性研究

采用溶胶-凝胶反应制备纳米SiO2颗粒，然后通过超声分散机将SiO2纳米颗粒分散到聚氨酯树脂中制备出聚氨酯／SiO2纳米复合材料。利用透射电子显微镜(TEM)、傅里叶红外分光光度计(FTIR)、万能电子试验机、动态力学分析仪(DMA)、量热示差扫描仪(DSC)分别表征了纳米复合树脂材料的结构和形态、力学性能和热稳定性。实验结果表明，纳米SiO2颗粒均匀分布在聚氨酯中，并与聚氨酯的基团发生了反应；聚氨酯／SiO2纳米复合材料具有较纯聚氨酯树脂更高的模量和内耗峰强度。拉伸强度和拉伸模量得到了很大的提高，并具有一个最佳值；而断裂伸长率有所下降，但随SiO2含量的进一步增加又有所提高；纳米SiO2掺杂对聚氨酯树脂的耐低温的性能影响不大，却提高了树脂的耐热性能，从而使聚氨酯树脂使用温度更宽。     

低对称性SiO2/Ag核壳复合纳米结构的银镜反应制备及表面增强拉曼散射活性研究

利用银镜反应在自组装的SiO2纳米粒子单层膜上制备了低对称性的SiO2/Ag核壳复合纳米结构.通过透射电镜(TEM)、扫描电镜(SEM)和紫外-可见分光光度计(UV-Vis)对核壳复合纳米结构的表面形貌和光学性质进行了表征.以亚甲基蓝作为探针分子,研究了低对称性SiO2/Ag核壳复合纳米结构的表面增强拉曼散射(SERS)活性.     

ZnO纳米复合粒子的制备及紫夕吸收性能研究

利用乙醇辅助水热法制备出ZnO／TiO2和ZnO／SnO2两种纳米复合粒子,采用X射线衍射（XRD）、扫描电子显微镜（SEM）及x射线能谱（EDS）分析方法对其结构进行表征,并通过紫外-可见漫反射光谱（uvvis）分析探讨了其紫外可见吸收性能,研究结果表明,在紫外-可见漫反射吸收光谱图中,ZnO／TiO2和ZnO／SnO2纳米复合粒子的最大吸收峰较纯纳米ZnO蓝移。同时,在可见光波段也有较弱吸收,拓展了其紫外吸收光谱。     

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.