基于局域表面等离子体共振效应生物传感器的制备方法及应用

金属纳米颗粒表现出来的局域表面等离子体共振效应被广泛应用于生物传感器领域.综述了局域表面等离子体共振效应的基本原理,对比了局域表面等离子体和表面等离子体的异同,详细介绍了胶体化学平板印刷术、电子束光刻法、聚焦离子束光刻法、纳米球光刻术等多种金属纳米颗粒阵列和图形制备技术、特点及应用,分析了局域表面等离子体共振生物传感器的应用前景、现存问题及其解决途径.     

具有等离子共振效应的纳米金属在光解水中的应用

简述光催化分解水反应的基本原理、肖特基结和等离子体共振的概念、等离子体共振在光解水过程的工作机制。介绍Au和Ag等贵金属复合半导体、单一银系化合物、非贵金属等离子体光催化剂。提出具有等离子共振效应的金属纳米颗粒能提高光解水性能的原因是形成肖特基结和具有独特的局域表面等离子共振效应;相比半导体,金属的功函数较大,形成的肖特基结可实现电荷定向迁移;局域表面等离子共振效应通过共振能量转移、增强局部场强和热电子注入等方式拓宽光谱吸收,提高电荷分离效率和光催化效率。认为等离子光催化的研究目前主要集中在Au、Ag等贵金属,其原理有待深入探究,且应理论与实验相结合;开发非贵金属替代物将更有利于降低成本。     

金纳米锥阵列与金薄膜耦合结构表面等离子体折射率传感研究

设计了基于SiO₂薄膜间隔的金纳米锥与金薄膜耦合结构表面等离子体共振折射率传感器。使用时域有限差分法研究了复合结构中的表面等离子体共振模式,复合结构不仅能够激发局域表面等离子体共振,也可激发传播表面等离子体共振。入射电磁波的能量部分通过单个金纳米锥耦合到局域表面等离子体,部分通过金纳米锥阵列二维光栅耦合到传播表面等离子体。在待测物折射率1.30～1.40的范围内,对复合结构的反射光谱进行了模拟研究,发现共振波长与分析物折射率呈线性关系,且由于局域和传播表面等离子体的高效激发,反射光谱共振峰处的反射率几乎为零。此外,在最优的金纳米锥几何参数下,传播表面等离子体共振模式的半高全宽非常窄,灵敏度和品质因数分别达到770 nm/RIU和113 RIU^-1,具有良好的折射率传感性能。所设计的复合结构作为表面等离子体共振传感器有望广泛应用于生物检测领域。     

银纳米颗粒的化学还原法制备简介及其应用

银纳米颗粒的光学性能,如局域表面等离子体共振(Localized Surface Plasmon Resonance,LSPR)特性可通过其形貌、尺寸、外部介电环境的调控而实现变化。不同形貌的银纳米颗粒具有强弱不同的局域表面等离子体共振效应,从而表现出独特的光学性质。综述了利用化学还原法制备不同形貌的银纳米颗粒,主要包括柠檬酸钠还原法、多元醇法以及种子介导生长法,分析了这3种合成方法的机理和特点,将近年来不同形貌银纳米颗粒的研究进展进行了综述。最后介绍了不同形貌银纳米颗粒在表面增强拉曼散射(Surface-Enhanced Roman scattering,SERS)基底、催化、抗菌领域上的应用研究,并总结和展望了银纳米颗粒在合成和相关应用领域的发展前景。     

金属纳米粒子的量子等离子体共振效应研究取得突破

具有纳米尺度的金属纳米粒子在物理、力学等性能方面迥异于块体金属材料,其中以纳米金属粒子的量子等离子体共振效应在纳米光学、生物学、传感器、光谱仪及太阳能的收集等领域具有巨大的潜在应用价值,相关研究一直备受国内外科研人员的关注。在纳米金属粒子的量子等离子体共振效应中,人们以往的研究对象多为     

纸基GO/贵金属纳米复合材料的SERS性能研究

表面增强拉曼散射作为一种高灵敏、无损伤的分析技术,被广泛应用于物质的鉴定以及定量分析。提出一种低成本制备SERS衬底的方法,即利用浸渍-提拉法在滤纸上吸附一层均匀的氧化石墨烯(GO),并结合等离子体溅射技术在纸基GO上沉积贵金属纳米颗粒,以浓度为10~(-5) mol/L的罗丹明6G(R6G)为探针分子,分析基底的表面增强拉曼散射特性。结果表明,当Au和Ag纳米颗粒溅射时间分别为20与90 s时,吸收波长与拉曼激光波长一致,其局域表面等离子体共振效应(LSPR)达到最佳;此外,利用GO良好的消荧光效果以及滤纸的纤维结构可进一步提高衬底所具的SERS性能。     

贵金属纳米线的模板法制备及应用研究进展

贵金属纳米线因独特的光学性质吸引了人们的普遍关注,已经被广泛应用于生物传感器、太阳能电池、纳米尺度光电器件领域。其光学性能主要来源于贵金属表面的区域等离子体共振,而区域等离子体共振主要由金属纳米线的形状、尺寸、组成以及电磁常数决定。简要地回顾了模板法合成贵金属纳米线的方法,讨论了影响纳米线光学性质的因素,最后简述了应用前景。     

影响贵金属纳米颗粒表面等离子体共振因素评述

贵金属纳米颗粒具有可调的共振吸收谱,被广泛用于光能传送器、近场扫描光学显微学、表面增强谱学、化学和生物传感器等。系统地评述了颗粒尺寸、颗粒分布、颗粒形状、颗粒体积分数、颗粒组成和颗粒结构等因素对金属纳米颗粒等离子体共振吸收性能的影响,有利于深入理解等离子体共振吸收的物理实质和实现对等离子体共振频率的调控。     

前驱物和表面活性剂对等离子体电化学法制备银纳米颗粒的影响

利用等离子体电化学法成功制备出银纳米颗粒,并通过局域表面等离子共振效应对颗粒的生长过程进行实时监测,研究了表面活性剂的浓度、种类和前驱物浓度对银纳米颗粒制备的影响。研究结果表明:增大前驱物或表面活性剂浓度对Ag;还原均有促进作用;与聚乙烯吡络烷酮(PVP)和十六烷基三甲基溴化铵(CTAB)相比较,十二烷基硫酸钠(SDS)作为表面活性剂,在相同时间内,生成的银纳米颗粒数量更多,尺寸和形状分布更均匀。     

纳米光学天线研究现状及进展

基于spp共振效应的纳米天线结构能有效收集光的能量,并将它限制在亚波长尺度,其巨大的局域场增强效应为纳米光子学大范围的应用提供了广阔的前景,例如,纳米尺度内光信息的处理和传播、近场显微镜超分辨率成像、高效太阳能电池、超高密度近场光存储、纳米光刻、量子单光予源、高效率纳米电磁波集中器、高灵敏度生化传感器等。文章在介绍纳米天线的基本构造和工作原理的基础上,综述了其在多个领域的应用。     

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