Butyl-Xanthate Adsorption on the Surface of Sulfide Minerals under Conditions of their Preliminary Treatment with Water Electrolysis Products according to Atomic-Force Microscopy and Infrared Fourier Spectroscopy Data

The morphology of sphalerite, galena, and chalcopyrite surfaces and the features of potassium butyl xanthate (PBX) adsorption on them under conditions of preliminary mineral treatment with water electrolysis products are studied using atomic-force microscopy and diffuse reflectance IR (infrared) Fourier spectroscopy. It is revealed that practically all types of treatment with electrochemically modified water (the product of non-diafragm treatment, anolyte, and catholyte) coarsens the surface relief of the minerals due to the formation of surface aggregates with different sizes. On the contrary, after chalcopyrite is treated with anolyte, its surface relief become smoother. It is found that water electrolysis products differently affect the chemical and physical types of PBX adsorption on the surface of the minerals under investigation. The performed experiments indicate that a complex of atomic-force microscopy and IR Fourier spectroscopy techniques is an efficient ex situ approach for monitoring the surface state of sulfide minerals and the direct study of PBX adsorption products.     

CuO薄膜的三阶非线性光学特性研究

采用脉冲激光沉积技术在Si(100)和熔石英基片上制备了单相的CuO薄膜.通过X射线衍射仪,拉曼光谱仪,场发射扫描电镜和紫外可见光光度计对薄膜的结构,表面形貌和光学性质进行了表征. 场发射扫描电镜结果表明CuO薄膜中晶粒排列致密且分布均匀,其尺寸约为45nm.结合飞秒激光(800nm,50fs)和Z扫描方法测量了薄膜的三阶非线性光学特性,结果表明CuO薄膜具有超快的非线性光学响应且非线性折射率和非线性吸收系数均为负值,其大小分别为-3.96×10^-17 m^{2< 关键词： CuO薄膜 Z-扫描')" href="#">Z-扫描 三阶光学非线性}     

Investigation into the orientation of the liquid-crystal mixture E7 in composite photonic crystals based on single-crystal silicon

The orientation of the liquid crystal E7 on the surface of silicon wafers and inside the grooves of grooved silicon prepared by anisotropic etching in an alkali is investigated. The orientation of the liquid crystal is determined using IR absorbance and IR reflectance spectroscopy and the capacitance method. The specific features of IR absorption in the liquid crystal introduced into periodic matrices are analyzed. It is shown that the liquid crystal E7 in grooved silicon is characterized by a weakly pronounced planar orientation of the molecules with respect to the silicon walls.     

A compact optical parametric oscillator Raman microscope for wavelength‐tunable multianalytic microanalysis

We have developed a high‐throughput microscope for wavelength‐tunable microscopic studies of materials by Raman, surface‐enhanced Raman, fluorescence, and reflectance spectroscopy. Narrow‐band excitation over a broad tuning range (410–2200 nm) is provided by a solid‐state, compact, and relatively inexpensive new class of diode‐pumped Nd:YAG optical parametric oscillator emitting approximately 1‐mJ, 10‐ns pulses at a rate up to 100 Hz. Rayleigh rejection over the tuning range is obtained with an array of angle‐tuned custom dielectric filters. Although high‐power, low duty‐cycle light sources have so far had only very limited use for tunable Raman and surface‐enhanced Raman spectroscopy, we show that undesirable nonlinear effects that arise from the high peak power of the output can be mitigated to produce good results with the proper choice of additional microscope elements. Measurements can be performed across the visible range with 20% sample‐to‐detector throughput and 10 cm⁻¹ resolution. The system is also fitted with a fiber optic imaging system to perform fluorescence and reflectance spectroscopy measurements with a spatial resolution of 5 µm. We demonstrate the instrument's analytical capabilities by recording resonance Raman and surface‐enhanced Raman emissions from a commercial lake pigment and crystal violet, respectively, colorants of interest in cultural heritage studies and forensic science. We also isolate and measure the reflectance spectrum of a commercial lake pigment and the ultraviolet fluorescence spectrum of a single fiber of cochineal‐dyed silk. The tunability, flexibility, compactness, and spatial resolution of the device provide novel capability for multianalytic materials research in fields such as forensic science and cultural heritage studies. Copyright © 2012 John Wiley & Sons, Ltd.     

基于多维漫反射光谱技术的复杂混合溶液成分检测

为了进行复杂混合溶液的成分检测,该文提出了一种基于多维漫反射光谱技术的浓度检测方式,通过信号中携带的不同成分的多种光学性质来进行分析。实验设计了基于超连续谱激光光源、精密电控平移台和光谱仪的检测装置,选用Intralipid-20%溶液作为研究对象,用蒸馏水配制体积百分数1%～20%的溶液,分别测量距其入射点1.5～13mm(间隔0.5mm)范围内的24点漫反射光谱信号,以偏最小二乘回归算法对单点和多点漫反射光谱信号进行建模与预测。得到建模精度最高的为距离入射位置最近的1点～13点对应的光谱信号所建立的模型,预测精度最高的为距离入射位置最近的1点～7点对应的光谱信号所建立的模型。结果表明,增加不同位置信息的光谱信号,能够提高光谱的信噪比,与传统光谱技术仅利用吸光度或反射率等单一光学性质的方法相比,增加了被测物质散射特性的影响,利用被测物质多种光学性质的变化提高了建模及预测的精度,为基于多维光谱的复杂混合溶液检测提供了基础。     

纳米纤锌矿氮化硼的同步辐射真空紫外反射光谱与光学性质

对冲击波法合成的纳米纤锌矿氮化硼（ｗＢＮ）进行了同步辐射真空紫外区的反射光谱测量，得到波长范围１００一２４０ｎｍ区间的反射光谱．利用Ｋｒａｍｅｒｓ－Ｋｒｏｎｉｇ关系计算获得了它的光学常数和介电函数谱，并导出了光电导谱．获得了纳米ｗＢＮ的光学禁带宽度实验值，为８．７±０．５ｅＶ．将以上结果和最新的理论计算进行了比较．观察到了经不同退火温度处理的纳米ｗＢＮ样品结构及尺寸变化对反射光谱和光学性质的影响． 关键词：     

卷云短波反射特性的模拟计算研究

利用通用大气辐射传输(CART)软件模拟计算了0.4～2.5μm波段卷云大气反射率,分析了卷云大气的反射率随波长、光学厚度、有效尺度、卷云高度和地表类型变化情况,并模拟计算了0.55,1.38,2.75μm波段卷云大气反射率间关系。结果表明,可见光到近红外波段,卷云大气反射率随卷云光学厚度的增大而增大。可见光波段,卷云大气反射率随卷云粒子有效尺度变化很小;近红外波段,卷云大气的反射率随卷云粒子有效尺度增大而减小;近红外大气强吸收波段,卷云大气的反射率随卷云高度的增大而增大。大气窗口区卷云大气的反射率随地表类型的变化有显著的变化。通过0.55μm和2.75μm波段,1.38μm和2.75μm波段的卷云大气反射率间关系可以反演卷云光学厚度和有效尺度。     

掺Ga对ZnO电子态密度和光学性质的影响

采用密度泛函理论下的第一性原理平面波赝势方法,研究了掺Ga对纤锌矿ZnO电子态密度和光学性质的影响.从晶体配位场理论分析了掺Ga前后ZnO的成键情况及态密度的变化.计算得到掺Ga后电子浓度为2.42×10²¹ cm^-3,ZnO的载流子浓度提高了10⁴倍.比较分析掺Ga前后ZnO的介电函数、复折射率、吸收光谱和反射光谱可得,ZnO光吸收边向高能端移动,光学带隙增大.在可见光区,ZnO光吸收系数与反射率减小,光透过率显著提高,使ZnO:Ga成为 关键词： 密度泛函理论 态密度 光学性质 ZnO:Ga     

Dependence of the Silica Glass Parameters on the Fluence of Fast Neutrons

The results of comprehensive investigations into the influence of fast-neutron fluences on the silica glass parameters are presented. In particular, the dose dependences of the parameters are measured by optical (luminescence, absorption, EPR, IR, and refraction), dielectric, and x-ray spectroscopy methods over a wide range of fluences from 10¹⁷ to 10²¹ cm^–2. It is concluded that the specific features in the formation of radiation-induced defects and silica damages are most likely due to the neutron-induced phase transition.     

Radiation-induced bond switching in mixed Ge–As sulphide glasses

A mechanism for γ-ray-induced changes in the optical properties of ternary Ge–As sulphide glasses is analysed at the microstructural level. It is shown, using IR FFT spectroscopy, that these changes are associated with chemical bond switching accompanied by coordination topological defect formation.     

IR reflectance spectra and optical constants of Al-Cu-Fe quasicrystalline thin films

The optical properties of Al-Cu-Fe quasicrystalline films and, for comparison, crystalline films of similar composition are studied using middle-and far-IR reflectance spectroscopy. Measurements are performed with 0.1-to 0.3-μm-thick films on sapphire substrates. The complex dielectric function of the films is calculated from experimental data. It is found that the real part of the dielectric function is negative for the crystalline films but positive and weakly frequency dependent, except in the range near 245 cm^?1, for the quasicrystalline films. The optical conductivity of the quasicrystalline films does not feature the Drude peak observed for crystalline films and exhibits a peak at 245 cm^?1, which can be assigned to optical phonon excitations and is absent for crystalline films.     

Influence of Iodine-Containing Solutions on the Condition of a Porous Silicon Surface and Its Photoluminescent Properties

The influence of surface treatment of porous silicon in iodine-containing solutions on its photoluminescent properties has been investigated. The porous silicon samples were prepared by anodizing in HF-based electrolytes and placed in fluoride-hydrogen solutions with the addition of iodine immediately after their formation. The surface condition was controlled by IR Fourier spectroscopy methods in the 400–4000-cm^–1 range. It has been established that the result of the porous silicon treatment in iodine-containing solutions is a decrease in the intensity of Si–H _x -bonds without the appearance of additional vibrations in the range under investigation. At the same time, such a treatment substantially affects the spectrum and intensity of porous silicon photoluminescence and increases its stability in subsequent storage. The possible reasons for the revealed phenomena are discussed.     

One-step,template-free hydrothermal synthesis of CuO tetrapods

The present investigation reports one-step template-free hydrothermal synthesis of CuO tetrapods (CuO-T) and its characterization. The CuO tetrapods have been prepared in moderate condition without using any surfactant. The prepared sample was characterized by powder X-ray diffraction (PXRD), Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR) spectroscopy, UV–vis–NIR (DRS) spectroscopy and Photoluminescence (PL) spectroscopy. The X-ray diffraction and Fourier transform infrared spectrum analysis confirm clearly the formation of a pure phase high-quality CuO with monoclinic crystal structure. X-ray peak broadening analysis was used to evaluate the average crystallite size (∼30 nm) and lattice strain by the Williamson–Hall (W–H) method. Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) result reveals that the particles are tetrapods in shape with an average length ∼50 nm. Additionally the optical properties were investigated by using UV–vis reflectance spectra with considerable blue-shift in the optical band gap (Eg = 1.45 eV) due to quantum confinement effect. Photoluminescence (PL) spectrum showed both UV as well as visible emission peaks indicating their good optical properties.     

Spectroscopic properties of 2-phenylbenzothiazole and 1-phenylpyrazole luminophores metalated with platinum metals

The effect of metalation of 2-phenylbenzothiazole and 1-phenylpyrazole with Pd(II), Pt(II), and Rh(III) on the structure and optical properties of luminophore complexes is studied by ¹H NMR spectroscopy, IR spectroscopy, and electronic absorption and emission spectroscopy. It is shown that metalation of luminophores leads to the formation of five-membered {M(C??N)} fragments in the composition of square planar and octahedral complexes, which exhibit a long-wavelength charge-transfer band. The luminescence properties of the complexes are characterized by quenching of the fluorescence and by enhancement of the phosphorescence from the mainly intraligand excited state. Fluorescence quenching of complexes is attributed to the thermally activated energy transfer to metal-centered states and their efficient nonradiative decay.     

高速850 nm垂直腔面发射激光器的优化设计与外延生长

利用传输矩阵理论和TFCalc薄膜设计软件分析了分布布拉格反射镜和垂直腔面发射激光器(VCSEL)的反射率谱特性,对比了从谐振腔入射与从表面入射时反射率谱的差异,为白光反射谱表征VCSEL外延片提供了依据.利用Crosslight软件模拟了InGaAs/AlGaAs应变量子阱的增益谱随温度的变化特性及VCSEL器件内部温度分布,设计了增益-腔模调谐的VCSEL.采用金属有机物化学气相淀积设备外延生长了顶发射VCSEL,制作了氧化孔径为7.5μm的氧化限制型VCSEL器件,测试了器件的直流特性、光谱特性和眼图特性;6 mA,2.5 V偏置条件下输出光功率达5 mW,4级脉冲幅度调制传输速率达50 Gbit/s.     

Tunable structural color of anodic tantalum oxide films

Tantalum(Ta) oxide films with tunable structural color were fabricated easily using anodic oxidation.The structure,components,and surface valence states of the oxide films were investigated by using gazing incidence X-ray diffractometry,X-ray photoelectron microscopy,and surface analytical techniques.Their thickness and optical properties were studied by using spectroscopic ellipsometry and total reflectance spectrum.Color was accurately defined using L*a*b* scale.The thickness of compact Ta2O5 films was linearly dependent on anodizing voltage.The film color was tunable by adjusting the anodic voltage.The difference in color appearance resulted from the interference behavior between the interfaces of air-oxide and oxide-metal.     

Infrared vibrational spectra of l-histidinium dihydrogen orthophosphate orthophosphoric acid (LHP)

The entire vibrational spectrum of a single crystal of l-histidinium dihydrogen orthophosphate orthophosphoric acid (LHP) was studied by infrared (IR) spectroscopy from 10 up to 4000 cm⁻¹. The polarized infrared (IR) reflectivity spectra were measured between 7 and 250 K, in the frequency range 10–600 cm⁻¹. From the IR spectral analysis, the phonon modes were classified within their symmetry species, and their longitudinal (LO) and transversal (TO) optical frequencies were calculated. A tentative assignment of the various internal modes observed in the transmissivity spectrum of LHP, between 300 and 4000 cm⁻¹, is proposed. The present study did not reveal any low-temperature structural phase transition.     

Interfacial ketene via the photo‐Wolff rearrangement for the modification of monolayer protected gold nanoparticles

An interfacial diazoketone‐modified gold nanoparticle (AuNP) was prepared and characterized by ¹H NMR and IR spectroscopy, TGA and TEM. Irradiation of the diazoketone leads to loss of nitrogen and the formation an interfacial ketene–AuNP via the photo‐Wolff rearrangement, evidenced by the loss of the characteristic C = N = N signal at 2068 cm^?1 in the IR spectrum and the growth of a new signal at 2100 cm^?1 indicative of the ketene. This ketene is relatively stable in the absence of added nucleophiles, but reacts quickly with oxygen nucleophiles illustrating the potential use of this ketene–AuNP as a template for a wide range of surface modifications. Copyright © 2013 John Wiley & Sons, Ltd.     

Vibrational dynamics of fullerene molecules adsorbed on metal surfaces studied with synchrotron infrared radiation

Infrared (IR) spectroscopy of chemisorbed C₆₀ on Ag (111), Au (110) and Cu (100) reveals that a non-IR-active mode becomes active upon adsorption, and that its frequency shifts proportionally with the charge transferred from the metal to the molecule by about 5 cm^-1 per electron. The temperature dependence of the frequency and the width of this IR feature have also been followed for C₆₀/Cu (100) and were found to agree well with a weak anharmonic coupling (dephasing) to a low-frequency mode, which we suggest to be the frustrated translational mode of the adsorbed molecules. Additionally, the adsorption is accompanied by a broadband reflectance change, which is interpreted as due to the scattering of conduction electrons of the metal surface by the adsorbate. The reflectance change allows determination of the friction coefficient of the C₆₀ molecules, which results in rather small values (∼2×10⁹ s^-1 for Ag and Au, and ∼1.6×10⁹ s^-1for Cu), consistent with a marked metallic character of the adsorbed molecules. Pre-dosing of alkali atoms onto the metal substrates drastically changes the IR spectra recorded during subsequent C₆₀ deposition: anti-absorption bands, as well as an increase of the broadband reflectance, occur and are interpreted as due to strong electron–phonon coupling with induced surface states. Received: 6 June 2001 / Accepted: 23 October 2001 / Published online: 3 April 2002     

Structural and optical properties of lithium borobismuthate glasses

Glasses with compositions 25Li₂O-(75−x)Bi₂O₃-x B₂O₃, with 0?x?30 mol%, have been prepared using the melt quenching technique. The density and the molar volume have been determined. IR spectroscopy is used as a structural probe of the nearest neighbor environment in the glass network. The optical transmittance and reflectance spectrum of the glasses have been recorded in the wavelength range 400-1100 nm. The values of the optical band gap E_g^opt for indirect transition and refractive index have been determined for 0?x?30 mol%. The average electronic polarizability of the oxide ion α_o²⁻ and the optical basicity have been estimated from the calculated values of the refractive indices. Variations in the different physical parameters such as the density, molar volume, optical band gap, refractive index, average electronic polarizability of the oxide ion and optical basicity with B₂O₃ content have been analyzed and discussed in terms of the changes in the glass structure.