修车大队一品楼qm论坛51一品茶楼论坛,栖凤楼品茶全国楼凤app软件 ,栖凤阁全国论坛入口,广州百花丛bhc论坛杭州百花坊妃子阁

oe1(光电查) - 科学论文

过滤筛选

出版时间
  • 2018
研究主题
  • electropolymerization
  • polyporphyrin films
  • quartz crystal microbalance method
  • oxygen electroreduction.
应用领域
  • Applied Chemistry
机构单位
  • G.A. Krestov Institute of Solution Chemistry of RAS
  • University Union Nicola Tesla
  • Ivanovo State University of Chemistry and Technology
61 条数据
?? 中文（中国） ▾

  • Characterization of the morphology of titanium and titanium (IV) oxide nanolayers deposited on different substrates by application of grazing incidence X-ray diffraction and X-ray reflectometry techniques

    摘要： X-ray diffraction (XRD), grazing incidence X-ray diffraction (GIXRD) and X-ray reflectometry (XRR) techniques were applied for analysis of titanium (Ti) and titanium (IV) oxide (TiO2) nanolayers with thickness of 25 nm, 50 nm and 75 nm deposited on silicon, quartz and BK7 glass substrates. The aim of studies was investigating the crystal structure and morphology of the nanolayers in dependence on the substrate type. The chemical phases of nanolayers and substrates were determined by using the XRD and GIXRD measurements. The benefits of applying low angle GIXRD and XRR analytical techniques, both for substrate and nanofilm analysis, is discussed based on theoretical calculations and simulations. Additional, analytical capabilities of the XRR technique to nanolayer and substrate morphology analysis are presented. Simulated XRR curves for titanium (Ti) and titanium (IV) oxide nanolayers are discussed depending on the substrate type as well as the substrate and nanolayer roughnesses. Experimental reflectometry curves are presented for all titanium and titanium (IV) oxide nanolayers deposited on the different substrates. As the result of the XRR analysis, the nanolayer thickness and roughness together with substrate roughness are estimated. The mean values of the Ti and TiO2 layer thickness and roughness are presented for all studied samples. The largest roughness, both for nanolayers and for substrates, is obtained for BK7 glass material. In the manuscript, sample properties, experimental setups and measurement conditions are presented in details.

    关键词： Titanium nanolayers,Titanium (IV) oxide nanolayers,Layer ion modification,X-ray reflectometry,Grazing incidence X-ray diffraction,Silicon, quartz substrates

    更新于2025-09-23 15:22:29

  • Light Transmission of Glasses Synthesized on the Basis of Quartz Sand of Different Deposits

    摘要： Container and sheet glass are synthesized from various batches with the equivalent addition of complexing decolorizers. The effect of ceria and potassium nitrate on the light transmission coefficient is investigated. Measurement of optical characteristics of the glasses shows that light transmittance increases up to 90–93% (λ = 500–750 nm). It is determined that an increase in the concentration of ceria and potassium nitrate up to particular values in the case of each composition results in the increase in hydrolytic stability, TLCE, and the light transmission coefficient.

    关键词： discoloration,iron oxide,light transmission coefficient,chemical stability,quartz sand,synthesis of glass,raw materials

    更新于2025-09-23 15:22:29

  • Study on supercritical water oxidation of o-dichlorobenzene in a quartz micro-reactor with in situ microscope and Raman spectroscopy

    摘要： The supercritical water oxidation (SCWO) of o-dichlorobenzene (o-DCB) in a fused quartz capillary reactor was studied by in situ microscope combined with Raman spectroscopy. The influence of oxidant dosage, reaction temperature and time on the o-DCB degradation efficiency was investigated and the reaction kinetics for CO2 yield was explored as well. The obvious phase change of o-DCB-H2O/H2O2 system was observed during the heating and cooling process. The increase in H2O2 dosage, temperature and time enhanced the o-DCB degradation efficiency. The degradation of o-DCB could be attributed to the simultaneous oxidation induced by HO· and O2. The effect of temperature on the o-DCB degradation efficiency and the CO2 yield was not significant at the lower temperature stage but turned to be important at the higher temperature stage. When the oxidant dosage was twice that of chemometry and the temperature and time were 440.0 °C and 4 min, respectively, the o-DCB degradation efficiency reached approximately 100%. Under the same conditions, the CO2 yield was lower than the o-DCB degradation efficiency, indicating that the degradation of o-DCB was a multi-step reaction. The reaction kinetics showed that the kinetics of CO2 production in SCWO followed the pseudo-first order and the apparent activation energy was 172.4 kJ mol?1.

    关键词： Microscope,Supercritical water oxidation,O-dichlorobenzene,Fused quartz micro-reactor,Raman spectroscopic

    更新于2025-09-23 15:22:29

  • [IEEE 2018 IEEE 15th International Conference on Group IV Photonics (GFP) - Cancun (2018.8.29-2018.8.31)] 2018 IEEE 15th International Conference on Group IV Photonics (GFP) - Enhanced Tensile Strain in Ge Epitaxitial Layers Grown on Si-on-Quartz Wafers

    摘要： Ge epitaxial layers grown on Si-on-“quartz” wafers reveal an enhanced in-plane tensile strain of 0.36±0.03%, which is 2–3 times larger than those grown on ordinary Si-on-insulator wafers. The enhancement is derived from an increased thermal expansion mismatch.

    关键词： Si-on-quartz wafer,Ge,tensile strain

    更新于2025-09-23 15:22:29

  • [IEEE 2017 International Renewable and Sustainable Energy Conference (IRSEC) - Tangier (2017.12.4-2017.12.7)] 2017 International Renewable and Sustainable Energy Conference (IRSEC) - Mapping of the Composition of Soils Naturally Deposited on PV Modules Anywhere in Morocco

    摘要： This article constitutes a preliminary phase for the performance of a national cartography of the composition of soils naturally deposited on photovoltaic modules installed in sites of different climates. To do this, a climatic zoning of Morocco according to the De Martonne index was adopted in order to select representative sites concerned with the collection of samples. For the moment, four samples have been collected in Rabat, Errachidia, Agadir and Oujda. These samples were prepared and analyzed. Several analyzes were carried out to determine the physical, chemical and mineralogical composition of these samples. The mineralogical composition was determined via X-Ray Diffraction (XRD) and X-Ray Fluorescence analysis (XF), while characterization of the physical and chemical composition was identified using Differential Scanning Calorimetry (DSC) and Spectroscopy Infrared (IR). The results show the existence of the same abundant constituents namely: Quartz, Calcite, Dolomite, Kaolinite whose percentages differ from a climate to another.

    关键词： Soils,Quartz,Calcite,Differential Scanning Calorimetry (DSC),Kaolinite,Climatic zoning,Infrared spectroscopy (IR),X-Ray Diffraction,Photovoltaic modules,Dolomite,Cartography,X-Ray Fluorescence

    更新于2025-09-23 15:22:29

  • Resonant frequency shifts related to the elastic constants near the α-β transition in quartz

    摘要： The resonant frequency shifts of vibrational modes are related to the elastic constants at various temperatures for the a-b transition in quartz (Tc ? 573.0 (cid:2)C for a-quartz and 574.3 (cid:2)C for b-quartz). This correlation is constructed on the basis of the spectroscopic modi?cations of the Pippard relations near the a-b transition in quartz by using the observed data from the literature. Our results indicate that the elastic properties can be described from the spectroscopic parameters (frequency shifts) as we have studied here for the a-b transition in quartz. Using those relations, elastic constants can also be obtained from the frequency shifts near the phase transitions of various crystalline systems.

    关键词： Resonance frequency shifts,a-b transition,Quartz,Elastic constants

    更新于2025-09-23 15:22:29

  • Effective SEM Analytical Techniques for the Cathodoluminescence Visualization of Intergranular Cements in Saint Peter Sandstone: A Round Robin Exercise

    摘要： The use of Cathodoluminescence (CL) as an analytical tool for geoscience and materials research is well established. Many minerals exhibit CL when activated by the high-energy electron beam bombardment of the Scanning Electron Microscope (SEM) [1]. CL imaging capabilities vary among laboratories due to the differences in detector type, sample preparation (epoxy, polish, coating), SEM type (W, LaB6, FE) and analytical conditions (kV, pA/nA, sample temperature). An interlaboratory comparison was initiated to assess the optimal conditions for obtaining high resolution CL imagery [2]. Quartz (and its polymorphs) are often difficult to image by CL due to low CL response and thus it was chosen as a test material. Composed of fine to medium-grained silicon dioxide, St. Peter Sandstone is used extensively as a proppant in hydraulic formation fracture (fracking) [3]. Appropriate sample preparation is necessary for optimal CL imaging results, varying from lab to lab. In the case of the porous St. Peter Sandstone with incomplete and fragile intergranular cement structures, producing a polished sample surface without plucking grains and removing the cements is imperative. For this interlaboratory comparison, polished samples were prepared from a single St. Peter Sandstone sample that was cored perpendicular to the bedding. Samples were imbedded in Epoxy and polished to a sub micron finish. Six of these samples were shared with other SEM-EPMA laboratories with the goal of refining SEM-CL conventions for cement study and imagery. As of abstract deadline time, we have 3 examples of CL images to present, and expect to have others by the M&M conference.

    关键词： intergranular cements,SEM,quartz,St. Peter Sandstone,Cathodoluminescence

    更新于2025-09-23 15:21:21

  • Flexible and reusable cap-like thin Fe2O3 film for SERS applications

    摘要： Cap-like α-Fe2O3 films are fabricated and deposited onto quartz fabric by using radio frequency magnetron sputtering and annealing. The treated fabric sample in this study shows highly sensitive surface-enhanced Raman scattering (SERS) and excellent flexibility, reproducibility and stability. In addition, the sample can be recovered after a washing process with an organic solvent and repeatedly used. The sensitive SERS performance is attributed to chemical enhancement through a charge transfer process. Moreover, the SERS performance is also found to be dependent on the light coupling effect. When the light absorbance rate of the α-Fe2O3 films increases at a wavelength near that of laser light, the film shows excellent sensitivity due to light coupling effect.

    关键词： α-Fe2O3,Raman sensor,flexible,quartz fabric,SERS

    更新于2025-09-23 15:21:21

  • Simple and ultrafast resonance frequency and dissipation shift measurements using a fixed frequency drive

    摘要： A new method for determination of resonance frequency and dissipation of a mechanical oscillator is presented. Analytical expressions derived using the Butterworth-Van Dyke equivalent electrical circuit allow the determination of resonance frequency and dissipation directly from each impedance datapoint acquired at a fixed amplitude and frequency of drive, with no need for numerical fitting or measurement dead time unlike the conventional impedance or ring-down analysis methods. This enables an ultrahigh time resolution and superior noise performance with relatively simple instrumentation. Quantitative validations were carried out successfully against the impedance analysis method for inertial and viscous loading experiments on a 14.3 MHz quartz crystal resonator (QCR). Resonance frequency shifts associated with the transient processes of quick needle touches on a thiol self-assembled-monolayer functionalised QCR in liquid were measured with a time resolution of 112 μs, which is nearly two orders of magnitude better than the fastest reported quartz crystal microbalance. This simple and fast fixed frequency drive (FFD) based method for determination of resonance frequency and dissipation is potentially more easily multiplexable and implementable on a single silicon chip delivering economies of scale.

    关键词： Quartz crystal microbalance,Dissipation shift,Realtime monitoring,Acoustic sensor,Resonance frequency shift,Time resolution of biomolecular process measurement

    更新于2025-09-23 15:21:21

  • Highly sensitive and selective estimation of aspartame by chitosan nanoparticles–graphene nanocomposite tailored EQCM-MIP sensor

    摘要： Here, a molecularly imprinted electrochemical quartz crystal microbalance (MIP-EQCM) sensor for aspartame is developed by grafting the aspartame-imprinted polymeric matrix of chitosan on gold-coated quartz crystal electrode. Chitosan nanoparticles being biocompatible, biodegradable and also having large surface area provide a better platform by forming a well-dispersed composite suspension with graphene. Additionally graphene facilitates direct electron transfer to electrode surface for electrochemical study because of having enhanced electrical conductivity. This EQCM-MIP sensor was characterized by atomic force microscopy, contact angle measurements, cyclic voltammetry and differential pulse voltammetry (DPV). The obtained MIP showed high affinity to aspartame. A reliable method for analysis of aspartame in real and commercial samples was achieved by coupling EQCM-MIP with DPV. Linear relationship with R2 = 0.9749 (EQCM) and R2 = 0.9760 (DPV) on binding of aspartame at various concentrations was observed. Detection limit of 0.45 μg mL?1 (EQCM) and 0.07 μg mL?1 (DPV) of the fabricated sensor shows that high sensitivity and high selectivity among various structural analogues of aspartame were also achieved. The improved detection limit is promising for determination of trace amount of aspartame. This demonstrates good memory capacity of this EQCM sensor. High recovery percentage and applicability of EQCM-MIP sensor in real matrices and commercial samples offers good potential for various applications.

    关键词： Electrodeposition,Aspartame,Quartz crystal microbalance,Graphene,Chitosan nanoparticles,Molecular imprinting

    更新于2025-09-23 15:21:21