新型偶氮苯硫醇衍生物自组装膜的制备与结构表征

自组装单分子膜(ＳＡＭｓ)是近年来引起广泛注意的一种稳定的、二维有序的、致密的有机超薄膜体系,由于其优越的性能,在润滑、吸附、防腐、电化学及微电子等领域中显示出广阔的应用前景[1～4].自组装单分子膜是使用含有各种活性官能团(如-ＣＯＯＨ,-ＳＨ,-Ｓ-Ｓ-,-ＯＨ,-ＣＮ等)的分子,以化学键的形式与相应的基底(如Ａｕ,Ａｇ,Ｃｕ,Ｐｔ,Ｓｉ,Ｍｉｃａ等)相互作用从而自发地形成自组装膜.根据不同的研究或应用目的合理设计组装分子的结构及基底表面,从而得到具有所需功能的自组装单分子膜是近年来界面科学和材料科学等领域研究的热点之一.…     

Non-destructive study of lead glasses’ alteration by reflectance spectroscopy

Non-destructive detection of the early stages of glass deterioration is important for stopping the degradation and for restoring works of art. With this aim, two sets of reference glasses, with varying amounts of lead, have been damaged using a defined and controlled degradation process. The measurements of the reflectance spectra of the samples, implemented with a portable fiber-optics goniospectrophotometer in a back-scattered configuration, underline very fine levels of deterioration. For glasses containing a low amount of lead, an increase in the roughness of the upper surface with the duration of the deterioration is observed and can be quantified by an upward vertical translation of the spectra. For glasses containing an important amount of lead, an increase followed by a decrease in the roughness is observed during the alteration. Moreover in the latter set, the reflectance spectra present oscillations, due to interferences inside a superficial layer created by the loss of lead during the deterioration and involving an iridescent appearance. The analysis of these oscillations leads to the quantification of the thickness of the altered layer and to its evolution with time. The obtained results have been validated by RBS analysis. The same measurements have been implemented on archeological samples that have been damaged by naturally occurring reactions while being buried in soil. Comparisons of features and oscillations of the reflectance spectra discriminate non-weakly and strongly altered areas of the glasses, no matter the amount of lead in the samples.     

Research of reflectance photometer based on optical absorption

Gold-labeled lateral flow (LF) assay has been studied extensively due to its sensitiveness, simpleness, and rapidness. In this paper, scattering properties of nanogold particles and LF strip were analyzed. Based on the above analysis, a reflectance photometer has been developed for LF strip labeled by nanogold particles. The integration of reflection optical density was used to indicate the signal of T line and C line. A quantitative equation for cardiac troponin I (cTnI) was deduced to realize quantification of the real cTnI sample, whose correlation of coefficient (R²) was 0.989. The variation coefficient (CV) of repetitive experiments was less than 5%. The reflectance photometer was simple, sensitive, stable, and suitable for field detection.     

Partially coherent bidirectional reflectance distribution data computation for modeling periodic plasmonic structures at infrared wavelengths

A series of methods for employing Rigorous Coupled Wave Analysis (RCWA) to predict bidirectional reflectance distributions for periodic plasmonic surface structures, under partial longitudinal spatial coherence conditions, is presented. Two new methods are presented, which accurately represent the effects of directionally dependent absorption on the profiles of reflected diffraction lobes. Bidirectional reflectance distribution functions may be fit to the resulting bidirectional reflectance distributions, allowing plasmonic structures to be accurately incorporated into infrared scene-rendering and component modeling tools.     

A novel pyrophosphate BaCr2(P2O7)2 as green pigment with high NIR solar reflectance and durable chemical stability

A novel pyrophosphate BaCr₂(P₂O₇)₂ was synthesized by the conventional solid-state reaction. The X-ray diffraction (XRD), FTIR spectrum, scanning electron microscopy (SEM) and ultraviolet–visible (UV–Vis) near infrared (NIR) reflectance spectra were applied to characterize the powders. The refractive indexes and nature of the VB and CB were determined. The structure, color properties and application were investigated. The results reveal that the anomalist bodies with smooth surfaces were obtained at 1200 °C with a mean size of 3 μm. A high reflectance peak at 535 nm was observed in the visible region, which is associated with the brilliant and deep green color of this pigment. With all the acids, alkali and deionized water treatment, the polycrystalline pigment BaCr₂(P₂O₇)₂ was found to be durable in chemical stability. The significantly high NIR solar reflectance of BaCr₂(P₂O₇)₂ is 90.0%, a higher cooling ability, so it has been selected to be tested as cool green pigment in ceramics. Moreover, this novel pyrophosphate pigment has great potential as cool pigment for surface coating applications.     

聚苯乙烯胶态晶体的合成

近年来 ,胶态晶体引起物理学家和化学家的共同关注 [1] .占据晶格点的纳米或微米级微粒自组装行为 [2 ] 在光学显微镜和扫描电子显微镜下可被清晰地观察到 ,因此能作为研究晶体相变的模型 [3 ] ,并有助于人们加深对晶体中点缺陷、晶界及位错等现象的了解 .胶态晶体所具有的周期性结构更使其在光学研究领域具有特殊意义 .与半导体中电子的能带结构类似 [4 ] ,胶态晶体中传播的光波色散曲线为不连续的带状结构 ,被称为“光子晶体”(photonic crystal) .在禁带区 (photonic band gap) ,光被禁止传播 ,而光散射加强 ,可将其应用于光电开关及光催…     

Investigations on non-stoichiometric zirconium nitrides

Non-stoichiometric zirconium nitride thin films were prepared by reactive dc magnetron sputtering. Structural, optical and electrical properties were investigated with respect to nitrogen gas flow. The film characterization was obtained through various techniques: Rutherford back scattering (RBS), X-ray diffraction (XRD), reflectometry and a four probe method. We found that the deposition rate decreases while the nitrogen flow increases. Also it was shown that a stoichiometric compound (ZrN) is formed at a 4 sccm nitrogen flow. It has a rock-salt structure and presents a minimum of resistivity and a gold-like color. As nitrogen flow increases, films become more and more amorphous, semi-transparent and electrically resistive. Furthermore, at a nitrogen flow of 9 sccm, the nitrogen to zirconium atomic concentration ratio is near 1.33 and the film exhibits properties close to those of a Zr₃N₄ phase.     

Silicon as a standard material for infrared reflectance and transmittance from 2 to 5 μm

We have investigated the specular reflectance and transmittance of polished, high-resistivity single-crystal Si in the spectral range from 2 to 5 μm. Measurements were performed with a nearly collimated (≈0.7° divergence) beam at angles of incidence from 12° to 80°, and a spectral resolution of 16 cm⁻¹. The measured values agree with the expected values obtained from the published index of refraction of Si to within 0.002. This represents a substantial reduction in experimental uncertainty compared to previous results and demonstrates the usefulness of Si as a standard material for infrared reflectance and transmittance.     

具有挡光环的遮光筒的等效反射率

讨论具有多个挡光环的漫射遮光筒的等效反射率，在比较了文献中已介绍的几种等效反射率后，提出了一种更为合理的算法，它不仅考虑了挡光环边缘的直接散射和衍射，同时也考虑了为提高杂光估计可靠性作遮光筒分块计算时挡光环结构的实际影响。并用实例计算了作了比较。     

Propagation of electrons in linear atomic arrays

In this paper a new approach to the problem of electron propagation in one-dimensional arrays is developed. The approach is based on the concept of reflectance defined in the paper and propagation or non-propagation is determined by the single question of the reflectances being unity or not. This notion throws fresh insight into the localized state in one-dimensional systems and here the notion that all electrons in one-dimensional systems are localized is discussed.