High Precision Diamond Machining of Hybrid Sol-Gel Coatings

Flexible and economic production of complex reflective optical elements is achieved by high-precision machining of aluminum and copper with diamond tools. There is also an increasing demand for complex refractive optical elements like micro lens arrays, Fresnel lenses or prismatic surfaces on silicon wafers or metallic surfaces. For the production of these optical elements, hybrid sol-gel coatings based on methacryloxypropyltrimethoxysilane (MATMS) and zirconium (IV) tetra n-propoxide (ZTP) were deposited on aluminum substrates by spin-coating. The influence of the rotational velocity and the chemical sol composition on the coating thickness was determined. The hardness and elastic modulus of these coatings was measured as a function of the chemical composition. The machining characteristics of these coatings were investigated by high precision turning and fly cutting with diamond tools of different geometry. The resulting surface finish obtained was determined as a function of the machining parameters.     

Full-range optical pH sensor based on imaging techniques

A new colour-based disposable sensor array for a full pH range (0-14) is described. The pH sensing elements are a set of different pH indicators immobilized in plasticized polymeric membranes working by ion-exchange or co-extraction. The colour changes of the 11 elements of the optical array are obtained from a commercial scanner using the hue or H component of the hue, saturation, value (HSV) colour space, which provides a robust and precise parameter, as the analytical parameter. Three different approaches for pH prediction from the hue H of the array of sensing elements previously equilibrated with an unknown solution were studied: Linear model, Sigmoid competition model and Sigmoid surface model providing mean square errors (MSE) of 0.1115, 0.0751 and 0.2663, respectively, in the full-range studied (0-14). The performance of the optical disposable sensor was tested for pH measurement, validating the results against a potentiometric reference procedure. The proposed method is quick, inexpensive, selective and sensitive and produces results similar to other more complex optical approaches for broad pH sensing.     

Determination of trace elements in lithium niobate crystals by solid sampling and solution-based spectrometry methods

Solid sampling (SS) graphite furnace atomic absorption spectrometry (GFAAS) and solution-based (SB) methods of GFAAS, flame atomic absorption spectrometry (FAAS), inductively coupled plasma optical emission spectrometry (ICP-OES) and inductively coupled plasma mass spectrometry (ICP-MS) were elaborated and/or optimized for the determination of Cr, Fe and Mn trace elements used as dopants in lithium niobate optical crystals.     

Determination of multielement in optical waveguide and standard reference materials by instrumental neutron activation analysis

Trace amounts of transition elements (Co, Cr, Cu, Fe, Mn and V) and other seven elements in optical waveguide samples were determined by INAA. The contents of impurities in ultra-pure materials are less than those of high-purity materials and of G.R. grade. The increase of contamination of trace transition elements and iridium from furnace or crucible are observed in the production of optical glass fibers. Up to seventeen elements were determined in five NBS biological standard reference materials: Oyster Tissue: SRM-1566, Brewers Yeast: SRM-1569, Spinach: SRM-1570, Orchard Leaves: SRM-1571 and Tuna Fish, and in four Japanese biological standard reference materials: Tea Leaves B&C, Pepperbush and Shark Meat. The analytical results in NBS and Japanese standard reference materials are in good agreement with published values and certified values by NBS.     

Immobilization of scandium and other chemical elements in systems with aquatic macrophyte

The possibility of immobilization of scandium and other chemical elements by biogenic materials derived from an aquatic macrophyte was explored. The concentrations of scandium and some other chemical elements were measured in the dried biomass (mortmass) of aquatic plants Myriophyllum aquaticum. In the experiments, the mortmass was incubated in aquatic systems where some chemical elements were added to the aquatic medium. After the incubation, the concentrations of these chemical elements in the mortmass were measured using inductively coupled plasma atomic emission spectroscopy (ICP-AES), also referred to as inductively coupled plasma optical emission spectrometry (ICP-OES). Increases in the concentrations of scandium and some other chemical elements (Ce, In, Se, Ru, Pd, U, and Zr) were observed in the biogenic material.     

Three-dimensional quantum photonic crystals and quantum photonic glasses

The structure and optical properties of quantum-dot photonic crystals (quantytes) were studied. Such crystals have the so-called band gaps, which leads to a strong reflection of electromagnetic waves from the crystal surface. It was shown that in certain spectral regions the refractive index has a negative sign, and the group velocity of electromagnetic waves essentially decreases. The applications of quantytes as optical information recording and rewriting devices, negative refractive optical elements, selective mirrors, narrowband filters, and others were discussed.     

Nanocomposites based on opal matrices and silica sols doped with rare earth compounds

Ordered 3D composites based on opal matrices and silica sols doped with rare earth elements have been prepared using colloidal chemistry methods. A uniform distribution of rare earth elements (which is important for avoiding luminescence concentration quenching) was achieved by means of repeated filling of the opal matrix interstitial space with silica sols doped with salts or oxides of rare earth elements. Trace amounts (10–30 ppm) of europium in a composite were shown to strongly affect optical properties of the material.     

Optical and Chromaticity Characteristics of Ethylenediaminetetraacetates of 3d-Block Elements

Optimum conditions for the formation of mono- and mixed-ligand Cr(III), Mn(II), Fe(III), Co(II, III), Ni(II), and Cu(II) ethylenediaminetetraacetates were found. The optical and chromaticity characteristics of these complexes were determined. The prospects of using chromaticity characteristics of the studied complexes of 3d-block elements in optical methods were shown.     

Substoichiometric and non-destructive determination of trace impurities in high-purity optical glasses by neutron activation analysis

A method of radioactivation analysis has been developed for the determination of 17 elements as impurities in high-purity optical glasses. The substoichiometric extraction of platinum with dithizone was studied and a simple procedure was proposed for the determination of platinum. Copper and manganese were also determined substoichiometrically by the extractions with dithizone and with thenoyltrifluoracetone, respectively. The non-destructive γ-ray spectrometry using a Ge(Li) detector has been applied for the determination of the other 14 elements (Ag, Co, Cr, Eu, Fe, Ir, Sc, Zn, Cs, Hf, Rb, Sb, Ta and Tb). Impurity elements at the ppb level were analysed by the proposed method and it is shown that the method is reliable for the determination of trace impurities in high-purity optical glasses.     

Transformable Plasmonic Helix with Swinging Gold Nanoparticles

Control over multiple optical elements that can be dynamically rearranged to yield substantial three-dimensional structural transformations is of great importance to realize reconfigurable plasmonic nanoarchitectures with sensitive and distinct optical feedback. In this work, we demonstrate a transformable plasmonic helix system, in which multiple gold nanoparticles (AuNPs) can be directly transported by DNA swingarms to target positions without undergoing consecutive stepwise movements. The swingarms allow for programmable AuNP translocations in large leaps within plasmonic nanoarchitectures, giving rise to tailored circular dichroism spectra. Our work provides an instructive bottom-up solution to building complex dynamic plasmonic systems, which can exhibit prominent optical responses through cooperative rearrangements of the constituent optical elements with high fidelity and programmability.     

电感耦合等离子体-发射光谱分析中硫酸基体效应及抑制

研究了电感耦合等离子体-发射光谱分析中的硫酸基体效应及克服干扰的有效方法。对2%~20%范围内4种不同体积分数H2SO4溶液中30种元素的基体效应进行了观察,发现H2SO4对各元素的谱线发射强度均存在明显的抑制作用。实验证实体积分数5%乙酸可有效抑制H2SO4的基体效应,并建立了H2SO4溶液中痕量元素的电感耦合等离子体-发射光谱分析法。     

Analysis of nickel-niobium alloys by inductively coupled plasma optical emission spectrometry

Inductively coupled plasma optical emission spectrometry (ICP-OES) was applied to the analysis of major and minor elements of Ni-Nb alloys obtained by aluminothermic reduction process. Digestion of samples was made using a mixture of HF+HNO₃. Minor and trace elements were determined without matrix separation. The precision for all constituents was <3%. Recoveries for the analyte-spiked samples were 95%.     

Room Temperature Exciton-Polariton Bose-Einstein Conden-sation in Organic Single-crystal Microribbon Cavities

Thanks to the large binding energy and excellent optical properties of Frenkel excitons,organic semiconductors emerge as ideal platforms for the realization of room-temperature exciton polariton(EP)Bose-Einstein condensates(BEC),which is of great importance for developing on-chip coherent light sources and optical logic elements.     

电感耦合等离子体光谱/质谱联机同时测定多金属结核中常量、微量、痕量元素

采用电感耦合等离子体质谱(ICP-MS)与等离子体光谱(ICP-OES)联机同时测定多金属结核样品中常量、微量、痕量元素。样品经高压密封溶样弹消解后,一次气动雾化进样,ICP-OES测定常量和微量元素,ICP-MS测定微量和痕量元素。详细探讨了不同浓度范围元素的测定方式、元素分析信号的采集模式、多原子离子干扰的校正因子。采用ICP-MS与ICP-OES二种方式同时测定Co、Cu、Ni、Zn、V、Ba、Sr,分析结果表明具有较好的一致性。所建立的ICP-MS与ICP-OES联机检测技术用于多金属结核标准样品的分析(Nod-A-1,GSPN-1,GSPN-2,GSPN-3),分析结果与推荐值符合,相对标准偏差小于10％。     

等离子体发射光谱法测定茶水中无机元素的含量

采用电感耦合等离子体发射光谱法对茶水中的无机元素进行分析,对其中的Cu、Zn、Mn、P、Fe5种元素进行定量,讨论了等离子体发射光谱法最佳实验条件及影响茶叶中无机元素浸出量的因素。Cu、Zn、Mn、P、Fe的回收率为92．5％～103．5％,测定结果的相对标准偏差为1．34％-4．5％（n=5）。     

Measurements of scattered light on a microchip flow cytometer with integrated polymer based optical elements

Flow cytometry is widely used for analyzing microparticles, such as cells and bacteria. In this paper, we report an innovative microsystem, in which several different optical elements (waveguides, lens and fiber-to-waveguide couplers) are integrated with microfluidic channels to form a complete microchip flow cytometer. All the optical elements, the microfluidic system, and the fiber-to-waveguide couplers were defined in one layer of polymer (SU-8, negative photoresist) by standard photolithography. With only a single mask procedure required, all the fabrication and packaging processes can be finished in one day. Polystyrene beads were measured in the microchip flow cytometer, and three signals (forward scattering, large angle scattering and extinction) were measured simultaneously for each bead. To our knowledge this is the first time forward scattered light and incident light extinction were measured in a microsystem using integrated optics. The microsystem can be applied for analyzing different kinds of particles and cells, and can easily be integrated with other microfluidic components.     

Comparison of the evaporation processes of classical spectrography and optical spectrometry tandem technique for the determination of the relevant environmental elements

The evaporation as a part of the spectrochemical excitation process is a complicated procedure during which different thermo-chemical reactions connected mainly to the formation of carbides are overshot. This one is accelerated namely at the 4000 K on the top of the carrier electrode. The carbide creation markedly affects the evaporation process of single elements of the given matrix and modifies this process. In spite of this it is evident that the intensity of the DC arc has a significant impact on the evaporation of all elements. The evaporation capability of two optical methods, the classical non-controlled direct current (DC) arc spectrography and the PC controlled DC arc optical emission spectrometry, have been compared for the determination of some environmental important elements (Al, Cr, Ni, and V). The experiments were carried out using grating spectrograph PGS-2 and simultaneous multi-channel LECO 750 spectrometer which is connected to a separated evaporation cell and adjusted to the Marinković plasma source. Standardized evaporation curves were designed and the half-time (t_50%) values and the total (t_100%) evaporation time values were calculated. The basic statistical evaluation was done and the main figures of the merit were calculated.     

以不同的环内酰胺为手性辅助剂的烯酰基环内酰胺的立体选择环氧化反应

Asymmetric epoxidation of N-enoylsultams （1, 3-15） incorporating a variety of chiral sultams as the chiral induction elements with UHP/TFAA has been studied. Both diastereomeric isomers of epoxides （2, 16-28） were obtained in high yield and moderate to high optical purity.     

Binary optical encoding strategy for multiplex assay

A binary optical encoding strategy is proposed to meet the increasing requirements of multiplex bioassays. As illustrated in fluorescence immunodetection of multiplex antigen molecules, photonic crystal beads (PCBs) and quantum dots (QDs) can be used as biomolecular microcarriers and fluorescence labels, respectively. The categories of antigens were deciphered by the binary combination of optical spectra of PCBs and QDs as independent encoding elements. The number of categories that could be detected was theoretically m × n, where m and n represent the number of encoding PCBs and QDs, respectively. In addition, the concentrations of the antigens were determined by the fluorescence signals of the QDs. Results of sensitivity analysis indicate that a low-level detection of 58 pg/mL was achieved. Because of the special nanostructures of these two encoding elements, the binary encoding strategy demonstrated its superiority and practicability when compared with single PCB or QD encoding. This supports potential application in multiplex bioassays.     

ICP-AES和ICP-MS法测定光学玻璃中的15种稀土元素

采用Na₂O₂熔融分解样品,运用电感耦合等离子体发射光谱法（ICP-AES）和电感耦合等离子体质谱法（ICP-MS）测定光学玻璃中的稀土元素。采用该方法对国家一级标准物质GBW07158、GBW07159、GBW07160和GBW07161进行测定,其结果表明与标准值相符。方法选择性好、灵敏度好、定量准确,适用于光学玻璃中稀土元素的测定,结果令人满意。