纳米粒子表面修饰与改性--SiO2纳米粒子表面接枝聚合

通过硅烷偶联剂处理SiO2纳米粒子并向其表面引入双键使其功能化，采用溶液聚合方法在SiO2纳米粒子表面进行接枝聚合实现高分子对SiO2纳米粒子的表面包覆处理，制得SiO2／PMMA复合纳米粒子，采用IR、XPS对SiO2纳米粒子表面结构进行了表征研究。     

聚苯乙烯-金纳米复合材料的可控组装及表面增强拉曼散射性能

无皂乳液聚合制备单分散聚苯乙烯(PS)微球,经过阳离子化后,在其表面通过界面可控自组装方法修饰金纳米粒子(Au NPs)制备PS-Au复合物SERS基底,通过调制组装体系中Au NPs数量控制PS微球表面金纳米粒子密度。采用紫外-可见吸收光谱、扫描电子显微镜、热重分析和拉曼光谱对PS微球及PS-Au复合物的表面形貌、组成及性能进行了表征。结果显示,金纳米粒子尺寸为40 nm、体积为3 mL时,组装得到的PS-Au复合材料具有较好的分散性和稳定性,并展现出较好的表面增强拉曼散射(SERS)活性,其增强因子达到10~5。该复合物材料作为增强基底进一步被应用于农药福美双的SERS检测,其灵敏度达到0.1×10~(-6)。     

纳米粒子表面改性研究

由于纳米粒子易团聚,对其进行表面改性是很必要的。本文综述了纳米粒子表面改性的主要方法,介绍了国内外表面改性的一些实例,并对纳米粒子表面改性的一些新发展和应用前景作了说明。     

具有核-壳结构的金纳米包覆磁性纳米复合颗粒的研究进展

具有核-壳结构的金纳米包覆的磁性纳米粒子,既具有磁性纳米粒子的特点又增加了金纳米的表面化学性质,近年来受到研究人员的广泛关注。简要综述了近年来国内外制备2类核-壳结构的金包铁磁性纳米复合材料的研究进展及相关应用,并对其应用前景进行了展望。     

超疏水表面制备工艺的研究进展

根据荷叶效应形成的2个条件——表面微纳米结构和蜡状薄膜,总结了国内外制备超疏水表面的2种主要途径,即构建微纳米粗糙表面和修饰表面活性物质;分析了超疏水表面的2种模型,即卡西尔模型和文策尔模型,发现所制备的超疏水表面为卡西尔模型;展望了其研究趋势和应用前景。     

纳米粒子在打印和印刷领域的应用

纳米粒子是一类重要的纳米材料。经过多年的研究发展,不同纳米粒子的制备方法、性质和应用研究都取得了突破性进展。基于纳米粒子独特的表面效应、量子尺寸效应等,发展出了很多新颖的功能纳米材料[1-2],这些材料在信息存储、催化、发光、医药等领域展现了广泛的应用前景[3]。近年来,纳米粒子也被越来越多地应用到打印和印刷领域,并有效推动了这一领域的发展进步。本文针对纳米粒子     

纳米材料在SPR生物传感器中的应用进展

目的研究纳米材料在SPR生物传感器中的应用进展。方法介绍表面等离子共振(SPR)原理和近几年来纳米材料在SPR生物传感器中的应用研究现状,并重点综述常见的几种纳米材料(包括金纳米粒子、金纳米棒、银纳米粒子、磁纳米粒子、石墨烯和量子点)在SPR生物传感器中的应用新进展。结果 SPR生物传感器是对表面折射率变化敏感的一项分析技术,然而,传统的SPR传感器无法检测极小的折射率变化,这就阻碍了其在超灵敏检测中的应用。结论采用纳米材料提高SPR检测灵敏度和特异性是SPR技术发展的必然趋势。     

石墨烯-金纳米复合物的制备及应用研究进展

石墨烯-金纳米复合物由于融合了石墨烯以及金纳米粒子的优良性质,具有良好的光热效应、电学特性及催化效应。近年来,石墨烯-金纳米复合物在生物医药、催化剂、光学等领域都有着广阔的应用。阐述了几种石墨烯-金纳米复合物的制备方法,分析了各种合成方法的优缺点,讨论了石墨烯-金纳米复合物的应用进展以及开发前景。     

纳米SiO_2的表面改性及作为润滑油添加剂的研究进展

纳米SiO2用作润滑油添加剂的研究尚处于起步阶段,但从研究结果看出,它具有优良的摩擦学性能。本文中简单介绍了纳米SiO2表面改性方法,总结了它作为润滑油添加剂的研究现状;并对作用机理进行了探讨;最后提出其作为润滑油添加剂的发展趋势,即纳米SiO2粒子的制备和表面修饰的“一体化”,制备高聚物-纳米SiO2杂化粒子以及对其摩擦学机理进行研究。     

纳米金属颗粒的湿化学制备

纳米金属颗粒在光电子、磁性材料和器件上具有表面增强Raman效应,量子点效应和高密度存储等重要特性.综述了在光电子、磁性材料和器件有着应用前景的金、银、铜、钴、镍、铋等金属纳米颗粒的湿化学制备,探讨了金属纳米颗粒湿化学制备控制颗粒大小、形状的一些因素和一般性特点,为制备颗粒大小、形状可控的其它种类的金属纳米颗粒作参考.     

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.