Optical cavity coupled surface plasmon resonance sensing for enhanced sensitivity

A surface plasmon resonance (SPR) sensing system based on the optical cavity enhanced detection tech-nique is experimentally demonstrated. A fiber-optic laser cavity is built with a SPR sensor inside. By measuring the laser output power when the cavity is biased near the threshold point, the sensitivity, defined as the dependence of the output optical intensity on the sample variations, can be increased by about one order of magnitude compared to that of the SPR sensor alone under the intensity interrogation scheme. This could facilitate ultra-high sensitivity SPR biosensing applications. Further system miniaturization is possible by using integrated optical components and waveguide SPR sensors.     

Effect of Aspect Ratio Distribution on Localized Surface Plasmon Resonance Extinction Spectrum of Gold Nanorods

Gold nanorods with different aspect ratios are prepared in micells using a seeded growth method. Their extinction spectra are observed with an UV-visible spectrophotometer and analysed theoretically. It is known that there are two plasmon resonance peaks for gold nanorod corresponding to transverse and longitudinal plasmon resonance respectively. Moreover, the longitudinal plasmon resonance peak shifts to long wavelength when we increase the aspect ratio determined from TEM. Especially, we model the extinction spectrum using Gans' theory and compare it with our experimental result. Considering the aspect radios distribution of gold nanorods, it is found that longitudinal plasmon resonance peak will be wider than the nanorods with single aspect ratio, which is consistent with our experimental result. In addition, the effect of dielectric constant of surrounding medium is considered.     

Photonic Crystal Fibre SERS Sensors Based on Silver Nanoparticle Colloid

A photonic crystal fibre （PCF） surface enhanced Raman scattering （SERS） sensor is developed based on silver nanoparticle colloid. Analyte solution and silver nanoparticles are injected into the air holes of PCF by a simple modified syringe to overcome mass-transport constraints, allowing more silver nanoparticles involved in SERS activity. This sensor offers significant benefit over the conventional SERS sensor with high flexibility, easy manufacture. We demonstrate the detection of 4-mercaptobenzoic acid （4-MBA ） molecules with the injecting way and the common dipping measurement. The injecting way shows obviously better results than the dipping one. Theoretical analysis indicates that this PCF SERS substrate offers enhancement of about 7 orders of magnitude in SERS active area.     

软代数的Stone定理

对于每一个正规软代数Ｆ，对应有一个准Ｂｏｏｌｅ环Ｆ．反之，每一个准Ｂｏｏｌｅ环Ｒ，对应有一个正规软代数Ｒ，且有＝Ｆ，＝Ｒ．     

二甲苯在TFJF型催化剂上深度氧化动力学的研究

在193-225 iC温度范围内，在轴向取样的管式积分反应器中研究了二甲苯在TFJF型催化剂上深度氧化的宏观动力学，在试验条件下，该反应的速度方程为:     

偶极矩与选择性分子间引力

选择性分子间引力是指不同分子或同一分子上的两个集团之间的相互作用.两个集团之间的作用比组成两个集团的原子之间作用的总和要大,而且只有当两个集团的电子性质和空间结构都适应时,才表现出较强烈的作用.可以设想,在非极性溶剂中,两种溶质分子之间有无选择性分子间力,对体系的电性质,例如介电常数、摩尔极化度和溶质的平均偶极矩等,将发生不同影响,我们选择了由色谱法证实存在选择性分子间力的十余对分子,通过介电常数的测定和溶质分子平均偶极矩的计算,进一步证实选择性分子间力的存在及产生的影响.     

镍在酸性介质中的阳极钝化研究

在镍与镍合金的电镀生产中,镍的阳极钝化能阻滞它的正常溶解,应设法避免.但在镍的阴极电积过程中,镍表面钝化膜则有利于提高镀层的结合力,因而需将镍基体在镀前作阳极电解预处理.所以,研究镍的阳极纯化行为有其实际意义.对镍的阳极钝化虽曾有不少研究,但关于钝化膜的组成与钝化机理仍未完全清楚.本文用动电位扫描法测定了镍在硫酸介质中的钝化曲线,以及酸度、温度、阴离子等对纯化曲线的影响.从纯化曲线得到了在实验条件下致纯电位值和钝化区的电位范围;推测了在不同电位时产生的钝化膜的组成;以及在一定电位内镍溶解的动力学规律.本文用成相膜理论解释了实验结果,探讨了钝化机理,并为控制钝化过程提供了实验依据.     

Improving the luminous efficiency of quantum dot-converted LEDs by doping boron nitride nanoparticles

Optical Review - Quantum dot-converted LEDs (QCLEDs) are a new type of LED device. However, the low luminous efficiency of the QCLED cannot meet the requirements for practical applications. In this...     

B型套筒角焊缝缺陷相控阵超声检测定量方法

B型套筒修复作为油气管道修复的主要方式之一,在其修复的焊接过程中,该结构的环形角焊缝内部常常出现以气孔、夹渣为代表的孔型缺陷。这类缺陷由于角焊缝特殊的结构,在利用相控阵超声无损检测技术对其检测时,难以对其进行定量分析。通过数值模拟和实验,发现通过相控阵超声扇扫得到缺陷回波信号峰值与孔型缺陷直径呈正相关,为孔型缺陷的定量分析提供了一种可靠的手段。