Synthesis,phase composition and structural and conductive properties of ferroelectric microparticles based on ATiOx (A = Ba,Ca, Sr)

The paper presents the results of a study of structural, optical and conductive properties of ferroelectric microparticles based on ATiO_x (A = Ba, Ca, Sr) obtained by solid-phase synthesis. According to the data obtained, as a result of the synthesis microparticles of dendroid form were obtained. During the study, the dependences of the change in the phase composition and crystallographic characteristics on the choice of component A in the structure of a ferroelectric are established. Studies of conductive and optical characteristics of investigated microparticles were conducted. During tests of conductive characteristics of microparticles, the nonlinearity of the current – voltage characteristics was established due to the presence of impurity inclusions in the structure and a high concentration of vacancy and dislocation defects, which have a significant effect on the ballistic nature of charge transfer.     

基于遗传算法的浮法玻璃光学常数测量与分析

浮法玻璃作为镀膜产品的基片,分析其光学常数是进行产品光学设计及质量控制的基础.由于反射光无法完全体现材料吸收特征、玻璃两个界面的多次反射光产生退偏问题,使利用椭偏原理分析浮法玻璃光学常数存在局限性.本文利用分光光度计测量浮法玻璃300~2500 nm范围透射光谱,根据光谱特征,建立以高斯振子及极振子为核心的复合振子模型,共15个未知参数,利用遗传算法依据透射光谱数据分析获得最佳振子参数,得到相应的光学常数,符合浮法玻璃基本光学特性.     

氧浓度的光学探测系统及其特性的研究

介绍了一种利用荧光猝灭反应动力学原理探测氧浓度的新方法，报告了一种性能优异的荧光大分子材料，建立了相应的光学探测装置，并详细地研究了实验溶剂、荧光材料在硅橡胶膜中的浓度等因素对设备性能的影响。     

Deposition of Multifunctional Titania Ceramic Films by Aerosol Routes

Aerosol coating processes were developed to deposit titania ceramic films onto steel and silica substrates. In situ light-scattering measurements were used to understand the deposition mechanisms in different system configurations. The conditions that were necessary to obtain uniform, nonporous, and well-adhered titania films on steel substrates were established. The as-coated films had excellent anticorrosion characteristics at room temperature, as established by the standard salt-fog test. Film crystallinity and morphology were examined using X-ray diffractometry and scanning electron microscopy; these analysis methods revealed an oriented, nanocrystalline anatase phase. Film composition was established, as a function of film thickness, using Auger electron spectroscopy and was confirmed to be stoichiometric (Ti:O = 1:2). The optical band gap and optical phonons of the deposited films were probed using spectrophotometry and Raman scattering, respectively; these analysis methods revealed a blue shift of the gap, relative to bulk anatase, and a localization of carriers in the nanometer-sized crystallites.     

How to model the behaviour of organic photovoltaic cells

In this paper we discuss the optimization of various parameters which govern the behaviour of polymer based and organic photovoltaic cells. General mechanisms leading to the generation of charge carriers and the related loss factors are detailed. Theoretical electrical parameters for bilayer and interpenetrating networks of donors and acceptors (open circuit voltages) are established along with current versus voltage characteristics. An equivalent circuit to a solar cell, considering the effects of shunt resistance across the whole layer, is elaborated. After modelling optical interference and its effects on the photocurrent spectrum, orders of magnitude of the required parameters are established for an efficient solar cell. Deviations from optimal values and their effects on the current–voltage characteristics are discussed. Ageing and degradation effects, and calculations demonstrating the necessary photophysical requirements to achieve long‐term stable devices are presented. Copyright © 2006 Society of Chemical Industry     

Microscopy and laser diffraction investigation of block copolymers used as adhesives

In a previous paper, we established a relationship between the adhesive properties and the chain characteristics of ABA poly(styrene-b-isoprene) block copolymers (or SIS). Only copolymers which do not easily undergo phase separation give joints with high tensile lap-shear resistance. By optical and electron microscopy, as well as by laser diffraction, we have now studied the structure of a series of SIS copolymers. We found that a random distribution of small polyisoprene noduli in the polystyrene matrix effectively exists in SIS which show good adhesive properties.     

光学碱度及其在冶金中的应用

光学碱度的概念现已广泛用来解释和预测炉渣的化学性质．光学碱度利用探针离子的信息表示炉渣中的相对“自由”氧离子,是一种表达炉渣碱度的有效方法,炉渣的光学碱度即可通过测量而得到,也可由炉渣的化学成分计算出来．很多结果表明,在炼钢的渣剂控制模型中,利用光学碱度比一般碱度更能可靠地控制冶炼终点的化学成分;在钢包和中间包利用光学碱度的概念也有助于控制钢中的残余元素;也可以用来建立一些元素渣—金属平衡时的计算公式．本文系统介绍了光学碱度的概念,讨论和评价了其在冶金中的应用．     

Evaluation of the optical characteristics of composite films with carbon fillers in the IR range of wavelengths

The applicability of the Bouguer—Lambert—Beer law was demonstrated for determining the optical characteristics of composite films in analyzing absorption of laser radiation with introduction of the corresponding corrections. The validity of using Eq. (5) for composite films with carbon fillers was demonstrated and is very important in analyzing reflection of laser radiation from the investigated composites. The optical characteristics of the composite films with carbon fillers are not only a function of the filler content, but also of the filler type.     

Studying optical and nonlinear optical properties of synthesized azo dyes doped in polymer and liquid crystal using birefringence and Z‐ scan techniques

The authors report the effect of the structure of new synthesized photo‐responsive azo dyes, based on N‐benzyl‐N‐ethyl‐aniline on their optical and nonlinear optical properties, when doped in polymer and liquid crystal (LC) hosts. Anisotropic response of dyes doped with polymer polymethyl methacrylate is studied using photo‐induced birefringence experiment and the optical nonlinearity of dyes doped in LC 5CB is measured using z‐scan technique. A correlation is established between dipole moment and optical/nonlinear optical response, which makes it possible to develop molecular design strategies to create structures with suitable anisotropic response and nonlinearity in various host systems for different applications. It is also shown how very little change in the structure of the dye may cause severe changes in the dipole moment and its nonlinear response. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

深水油气田全电控制式水下分配单元设计

分析全电控制式水下分配单元的基本构成与功能,设计水下分配单元的总体结构,建立以光功率分配器为核心的点对多点光通信系统模型。采用光通信系统模拟软件Optisystem模拟验证设备的可行性,并分析了光信号传输质量的影响因素。     

Experimental investigation of continuous single‐phase rimming flow in a horizontal rotating cylinder

Rimming flow of water that leads to a thin film onto the inner surface of a horizontally rotating cylinder is studied in this work. At higher rotational speeds, axial flow of uniform thin film is established inside the rotating cylinder. Film thickness measurements under different flow conditions were performed in the annular flow regime using an optical interferometric technique. Dimensional analysis was also performed to understand the parametric dependence of key parameters involved in the rimming flow of water inside a horizontal rotating cylinder and expressions to determine average film thickness and average residence time are also presented. This study will provide a basis to estimate the transport characteristics in the thin film inside the horizontal rotating cylinder. © 2014 American Institute of Chemical Engineers AIChE J, 60: 3939–3950, 2014     

Influence mechanism of injection process parameters on iridescent pattern defects on optical molded parts

Iridescent patterns are insufferable molding defects during mass manufacturing of polymer optic devices by using injection molding (IM) technique and seriously affect the appearance and imaging performance of parts. However, at present, the research on the factors affecting iridescent pattern defects is lacking, resulting in the difficulty of obtaining effective methods to weaken iridescent pattern defects. This article aims to clarify the correlation mechanism between injection process parameters and iridescent patterns and provide a theoretical basis for reducing iridescent pattern defects. Based on the process characteristics of IM and the optical mechanism of iridescent patterns, the correlation between iridescent patterns and influencing factors such as optical characteristics and the material structure is established. The influence mechanism of process parameters on iridescent patterns is further clarified by experiments. The results show the iridescent pattern color is related to the retardation, while the iridescent pattern brightness is affected by the retardation and transmittance. Process parameters change the retardation and transmittance by varying factors such as the thickness, birefringence, and crystallinity. Higher mold temperature, reasonable melt temperature, injection speed, and holding pressure are conducive to reducing the colorful fringe area and iridescent pattern brightness, thereby weakening the iridescent patterns on the part.     

Thermoimpulsive synthesis of nickel aluminides

We studied the effect of explosive loading on the microstructure and phase composition of the Ni–Al system in the course of SHS interaction. X-ray diffraction, micro x-ray diffraction, and optical methods established an appreciable effect of shock-wave loading on the structural characteristics of the synthesis products. A multistage character of SHS in the system in question was noted; the nature of shock-wave action is determined by the structure which has formed by the instant of loading. It is suggested to use the method of measurement of concentration inhomogeneity for studying the effect of a shock wave on the diffusion interaction in reacting systems.RITTs PM, 614061, Perm'. Translated from Fizika Goreniya i Vzryva, Vol. 30, No. 6, pp. 83–88, November–December, 1994.     

Experimental investigation of ultrasonic-vibration polishing of K9 optical glass based on ultrasonic atomization

K9 optical glass has an important position in the field of optical material because of its excellent chemical stability and optical projection. The hard and brittle characteristics of K9 optical glass make conventional processing difficult and time-consuming. A non-conventional hybrid polishing system combining ultrasonic atomization (UA) spraying method and axial ultrasonic vibration was developed for processing K9 optical glass. This system utilizes the high-frequency vibration characteristics of ultrasonic vibration technology: On the one hand, the ultrasonic atomization spraying method is used to generate evenly distributed atomized droplets for polishing, on the other hand, the axial ultrasonic vibration of the polishing tool provides impact kinetic energy for the free abrasive particles. Mechanical polishing (MP), ultrasonic-assisted polishing (UVP), mechanical polishing under ultrasonic atomization spraying (UA-MP) and ultrasonic vibration polishing under ultrasonic atomization spraying (UA-UVP) were carried out on K9 optical glass. The material removal rate (MRR), material removal depth (MRD), surface quality and surface micromorphology of the polished workpieces were also analyzed and compared. The experimental results showed that the best surface was obtained at UA-UVP (A_Ⅰ = 9 μm) with MRR of 0.0994 mm³/min, material removal depth of 26.816 μm, the Ra and Sa values were 0.028 μm and 0.033 μm respectively. Meanwhile, no obvious pits and scratches were observed on the micromorphological surface. Ultrasonic atomization contributes to even material removal from the polished surface and axial ultrasonic vibration of the polishing tool has a significant effect in improving the polishing characteristics, which provides the experimental basis for applying ultrasonic vibration technology in polishing.     

Advanced spinel ceramics with highest VUV-vis transparency

Synthesis of optical grade spinel ceramics superior to commercially available single crystal spinel was successfully achieved through reactive sintering between high purity MgO and Al₂O₃ powders with a small amount of MgF₂ and AlF₃ as sintering aids. The average grain size of the fabricated spinel ceramics was approximately 20 μm, with residual porosity at the 10⁻¹³ level. The transmission characteristics from the visible to infrared region of the spinel ceramics (optical loss:0.1 %/cm) are equal to or higher than those of the single crystal spinel produced by the Czochralski method. Since the optical homogeneity of the ceramics is extremely high, the beam quality of the laser transmitted through the material did not degrade. The optical band gaps of spinel ceramics and single crystals are 6.81 eV and 5.51 eV respectively. However, polycrystalline ceramics showed excellent characteristics especially in the vacuum ultraviolet wavelengths below 200 nm where single crystals are difficult to transmit.     

荧光硫量子点制备及应用研究进展

硫量子点具有发光强度高、毒性低和光化学性能稳定等优势，广泛应用于细胞成像、光电转换和化学催化等领域。鉴于此，本文系统综述了硫量子点的合成方法，光学性能和应用背景。硫量子点的合成方法可分为“自下而上法”和“自上而下法”，对比发现“自上而下法”合成的硫量子点具有更高的荧光量子产率。分析了硫量子点的光学性质，表明其具有紫外吸收特性、荧光特性、光致发光、电化学发光以及光学稳定性。最后，系统介绍了硫量子点在荧光探针、生物成像以及发光器件等领域的重要应用。基于以上分析，深刻剖析了当下硫量子点在前沿应用中亟待解决的问题，展望了未来硫量子点在生物医学、光电催化等新行业、新领域的发展方向。     

Evaluation of the optical changes for a soda-lime-silicate glass exposed to radiation

A soda-lime-silicate glass is exposed to beta radiation from an ⁹⁰Sr source and gamma radiation from a ⁶⁰Co source. Under exposure to radiation of the ⁹⁰Sr and ⁶⁰Co radioisotopes, the glass changes its color depending on the irradiation doses. The effect of beta irradiation on the optical properties of the glass is compared with that of gamma irradiation. The optical properties of the irradiated glasses differ significantly from those of the unirradiated glasses. Under exposure to beta and gamma radiation, the three main optical absorption bands appear at ～380–460, ～620, and ～1050 nm. It is established that the absorption band at ～420 nm, which is attributed to Fe³⁺ ions, is very sensitive to beta and gamma irradiation.     

Tailoring the nanostructure of anodic aluminum oxide cladding on optical fiber

We report a comprehensive investigation of fabricating nanostructured anodic aluminum oxide (AAO) cladding on optical fiber. We show that the pore size and interpore distance in the AAO cladding with pore channels vertically aligned to fiber surface can be readily controlled by applied voltage, the type, and concentration of electrolytic acid during anodization of aluminum‐coated optical fiber. The structural characteristics of the AAO cladding were examined by scanning electron microscopy (SEM) and analyzed using ImageJ software. Processing maps correlating AAO growth and anodization parameters were established. Compared to planar AAO growth on aluminum foil, higher growth rate as well as larger pore diameter and interpore distance were observed for AAO cladding formation on optical fiber under identical anodization conditions due to circumferential tensile stress in the AAO growth front at the convex AAO/aluminum interface. This tensile stress also contributed to radial cracking of the AAO cladding upon exceeding some threshold thickness.     

Characterization of copper oxidation by linear potential sweep voltammetry and UV-Visible-NIR diffuse reflectance spectroscopy

The aim of this study was to characterize the compounds grown on copper during oxidation at low temperature (T<573 K) in air by electrochemical and optical methods. The following oxides have been characterized: a precursor Cu _x O of mixed valency character, a non stoichiometric cuprous oxide, CuO and its precursor. The mechanism of reduction has been established for layers containing CuO and a non stoichiometric copper(I) oxide. CuO is reduced before cuprous oxide. In complicated cases, it is impossible to draw conclusions from the characteristics of the electrochemical reduction (the first step of CuO reduction and the reduction of Cu(I) species specific of the non-stoichiometry are observed at the same potential). Nevertheless, the association of a non-destructive technique such as diffuse reflectance spectroscopy and electrochemical methods allows identification of the different species present in corrosion layers on copper surfaces.     

点聚焦透射式菲涅尔聚光器的光热性能

针对非均匀辐射造成的热均匀性不高的问题，本文基于Tracepro光学软件，采用Monte Carlo光线追迹法，设计点聚焦透射式菲涅尔聚光器，并建立聚光性能模型，研究F数、相对位置和跟踪误差3种不同设计参数对光学性能的影响规律。通过仿真模拟得到：①F数、跟踪误差对光学效率和几何聚光比影响较大，对热均匀性影响较小；②光斑能量均匀度随相对位置呈V形规律变化，聚光器在焦距位置并不一定是最好的，适当缩小间距不仅可以提高热均匀性还可以节省空间和造价；③本文设计的点聚焦透射式菲涅尔集热器光学效率82.69%，光斑能量均匀度22.06%，几何聚光比226，平均热流密度64924W/m²，聚光性能和热均匀性综合性能良好，在聚光光伏和光热利用领域有一定的适用性和应用前景。