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Lateral scale calibration for focus variation microscopy
摘要： Areal surface texture measuring instruments can be calibrated by determining a set of metrological characteristics currently in the final stages of standardisation. In this paper, amplification, linearity and perpendicularity characteristics have been determined to calibrate the lateral performance of a focus variation microscope. The paper presents a novel and low-cost material measure and procedures that are used to determine the characteristics. The material measure is made of stainless steel with a cross-grating grid of hemispherical grooves. The design, manufacture and calibration of the material measure are discussed. The 20 × 20 mm grid is measured with and without image stitching. The results show that the proposed material measure and procedures can be used to determine the error of the amplification, linearity and perpendicularity characteristics. In addition, the lateral stage error can be significantly reduced by measurement with image stitching.
关键词： focus variation microscopy,amplification coefficient,lateral calibration,metrological characteristics,linearity deviation,perpendicularity deviation
更新于2025-09-19 17:15:36
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[ASME ASME 2018 International Mechanical Engineering Congress and Exposition - Pittsburgh, Pennsylvania, USA (Friday 9 November 2018)] Volume 8A: Heat Transfer and Thermal Engineering - Infrared Thermography to Measure Heat Transfer of a Heated Curved Thin Sheet
摘要： Heat transfer measurements on a heated curved thin sheet are performed by infrared thermography. The evolution of the temperature field is recorded to calculate the heat flux by using the two-dimensional unsteady heat balance equation. The thermal conduction term is estimated by the projection relationship between the curved surface of the thin sheet and the horizontal plane. Natural convection is neglected during the estimation of this heat flux. Unlike the traditional means of heat flux measurement, this method is non-intrusive and can measure the heat flux distribution within a curved space, allowing an easier evaluation of the errors due to radiation and tangential conduction. An electrical resistance foil with known power are applied as the heating source to compare the calculated heating power with the actual recorded power, the max relative error for different heating powers is about 10 %, which verified of the feasibility of the method. Considering possible applications, three different domestic gas cookers are used to heat three different curved thin pans, and then, in each case, the heat flux of the burners is analyzed. From the heat flux distribution of the three gas cookers, some heating characteristics such as heating power, maximum and average heating flux are investigated to help optimize the designs of the gas cookers, avoiding local over-heating and low uniformity of heat distribution.
关键词： Heat transfer measurements,infrared thermography,heating characteristics,gas cookers,curved thin-sheet
更新于2025-09-19 17:15:36
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Effects of MgO Nanocrystal Powder on Long-Term Sustain and Address Discharge Characteristics in ac-Plasma Display Panel
摘要： We investigated the characteristics of MgO surface with MgO nanocrystal powders due to the long-term (500 hours) ion bombardment comparing with the conventional MgO surface in this study. When the MgO nanocrystal powders were coated on the conventional MgO surface, it was observed that the sputtered Mg particles from MgO surface were re-deposited on the MgO nanocrystal powders, which was able to significantly suppress the re-crystallization on the phosphor layers. We confirm that the MgO nanocrystal powders play a significant role in suppressing the degradation of the MgO surface and phosphor layer after long-term severe ion bombardments. Accordingly, when the MgO nanocrystal powers were applied to the conventional MgO surface, the variations of discharge characteristics, such as address discharge delay time, firing voltage of sustain and address discharge, and luminance, were significantly reduced comparing with the conventional MgO surface.
关键词： Plasma Display Panel,Long-Term Discharge Characteristics,Plasma Application,MgO Surface,MgO Crystal Powder
更新于2025-09-19 17:15:36
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Influence of an Insulator Layer on the Charge Transport in a Metal/Insulator/n-AlGaN Structure
摘要： In this work, a parametric study revealing the impact of metal-insulator-semiconductor (MIS) structure in improving the electron injection between the n-AlGaN layer and the electrode metal is conducted. After inserting an insulator at the surface between the n-AlGaN layer and the electrode metal, the energy band bending of the thin insulator manipulates the conduction band barrier height between the electrode and the n-AlGaN layer, which enables the electrons to more efficiently tunnel through the thin insulator barrier. As a result, the electrical characteristics for the devices are significantly improved if the MIS structure is optimized. Furthermore, the impact of the affinity, the relative dielectric constant, and the bandgap for the insulator on the electron injection is investigated. Meanwhile, it is found that the electron injection is sensitive to the thickness and the length for the insulator. Detailed analysis regarding the electron transport and the device physics are reported in this work.
关键词： insulators,semiconductors,electrical characteristics,electron transport,n-AlGaN
更新于2025-09-19 17:15:36
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The electron–hole overlap in the parabolic quantum well light emitting diode is much superior to the rectangular: even to that of a staggered quantum well
摘要： The strong piezoelectric field in the InxGa1?xN/GaN quantum well (QW) LEDs, separates the electrons and holes spatially, which decreases the luminescence. Various shapes and compositions of such QWs are studied to improve the performance. We have studied the transition energy (TE), overlap of electron and hole wave functions, band structures and field distributions of the parabolic QWs (PQW) through the self consistent solutions of Schr?dinger and Poisson equations. The shape of the PQW is varied along with the compositions and dopings. The square of the overlap of electron and hole wave functions i.e. the transition probability (TP) is strikingly increased, compared to the rectangular QW and it is even higher than the symmetrically staggered QW. At a particular current density, for the same TE, the TP of the PQW increases more than two times that of the rectangular QWs. An important feature, desirable for the QW LEDs emerge. The change of the TE with increase in the current density is minimized. A brief theory, computational procedures and the results will be presented in details with suitable discussions.
关键词： Light emitting diodes,J–V characteristics,Transition probability,Transition energy,InGaN/GaN parabolic QWs
更新于2025-09-19 17:15:36
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Rapid identification of wood species by near-infrared spatially resolved spectroscopy (NIR-SRS) based on hyperspectral imaging (HSI)
摘要： Conventional near-infrared (NIR) spectroscopy has shown its potential to separate wood species non-destructively based on the aggregate effect of light absorption and scattering values. However, wood has an aligned microstructure, and there is a large refractive index (RI) mismatch between the wood cell wall substance (n≈1.55) and the cell lumen (air≈1.0, water≈1.33). Light scattering is dominant over absorption μ′ (cid:31)( ) a in wood, and this fact can be utilized for complex classification purposes. In this study, an NIR hyperspectral imaging (HSI) camera combined with one focused halogen light source (? 1 mm) was designed to evaluate the light scattering patterns of five softwood (SW) and 10 hardwood (HW) species in the wavelength range from 1002 to 2130 nm. Several parameters were combined to improve the data quality, such as image histogram plots of defined spaced bins (associated with diffuse reflectance values of light), variance calculation on the frequency (the number of pixels in each bin) of each histogram and the principal component analysis (PCA) of all the variance values at each wavelength. The identification accuracy of the quadratic discriminant analysis (QDA) under the five-fold cross-validation method was 94.1%, based on the first three principal component (PC) scores.
关键词： spatially resolved spectroscopy,light scattering characteristics,wood species identification,hardwood,quadratic discriminant analysis (QDA),near-infrared hyperspectral imaging camera,principal component analysis (PCA),softwood,halogen spot-light source
更新于2025-09-19 17:15:36
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Electromodulation of the Negative Differential Resistance in an AlGaAs/GaAs Resonant Tunneling Diode
摘要： In this work, we investigate the impact of the width of the AlGaAs right barrier and the doping concentration in the contact layers on the negative differential resistance (NDR) and the device performance of a double-barrier AlGaAs/GaAs resonant tunneling diode (RTD). Our simulation is performed using a non-equilibrium Green's formalism (NEGF). The obtained results show that increasing the width Lb2 of the right barrier, strongly reduces the peak-to-valley current ratio (PVCR. Especially, it reduces from 2.5 for symmetric RTD AlGaAs (5 nm) / GaAs (5 nm) to 1.1 when the right barrier AlGaAs is equal to 8 nm. Our findings show that a specific width of the right barrier Lb2 = 9 nm exists for which the NDR disappears completely. In addition, an increase in the doping concentration in the contact layers is found to reduce the (PVCR) and, consequently, the (NDR). These results open the door for designing resonant tunneling diodes with suitable negative differential resistances. The simulation of the RTD is performed with the use of Nanohub tools which confirms the various results presented in this paper.
关键词： Schrodinger equation,Resonant tunneling diode,Peak to valley ratio,Current-voltage characteristics,Negative differential resistance
更新于2025-09-19 17:15:36
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Formation, Charge Transfer, Structural and Morphological Characteristics of ZnO Fractal-Percolation Nanosystems
摘要： Structural and morphological characteristics of ZnO nanosystems in the form of three-dimensional network-like systems have been investigated. Current–voltage (I–V) characteristics and charge transfer parameters of ZnO fractal-percolation nanosystems have been studied both in air and in vacuum at different temperatures and voltage sweep rates. The charge transfer characteristics show the presence of RaCiCai chains in the nanosystems. The RC chains are formed because the Debye screening length has the same order of magnitude as the local values of ZnO nanowires radii. Gas-sensing tests based on I–V characteristics investigation have shown a possibility of distinguishing between reducing gases such as CH4 or C2H5OH.
关键词： current–voltage characteristics,gas sensor,ZnO nanowires,charge transfer,reducing gas
更新于2025-09-19 17:15:36
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Optimized properties of innovative ElectroChromic Device using ITO / Ag / ITO electrodes
摘要： The "Dielectric/Metal/Dielectric" (DMD) stacked films being used as transparent and conductive (TC) electrodes, have demonstrated excellent application in the ElectroChromic (EC) process and devices. In this work, multilayers (IAI) made of 50 nm of Indium Tin Oxide (ITO) / 5 nm of metallic silver (Ag) / 30 nm of ITO that exhibit band-gap, low resistance of 7.4 ? and the high figure of merit of 9.9×10-3 ?-1 were introduced in a complete five-layer Glass / IAI / NiOx / LiClO4-PC-PMMA / WO3 / IAI / Glass ElectroChromic Device (ECD). The single IAI electrode as well as the two actives EC layers Glass / IAI / NiOx and Glass / IAI / WO3 were firstly characterized for their TC and EC properties respectively. Then, the EC properties of the complete five-layer ECD were analyzed. Fast response time (2.02 s for the bleaching and 2.25 s for complete coloration), wide optical modulation in the visible light region (~55% at 550 nm), long lifetime (more than 6000 s), large capacity and good stability as well as high coloration efficiency (31.7 cm2 C–1) were obtained. The improved EC performance of ECD were related to the good electrical and optical properties of IAI electrode.
关键词： Electrochromic characteristics,Electrochromic devices,Multilayer,Polymer gel electrolyte,Transparent conductive materials
更新于2025-09-19 17:15:36
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P‐9.9: Research on The New Display Technology ‐ Inkjet‐Printed Quantum Dot Display with Blue OLEDs
摘要： Direct discharge of aquaculture wastewater in coastal areas could increase concentrations of antibiotics in coastal mangrove forests. This study focused on the Gaoqiao Mangrove Nature Reserve in Zhanjiang City, Guangdong Province. Norfloxacin (NOR) residues in rhizosphere sediments, plant roots, branches, and leaves of two dominant mangrove communities, Rhizophora stylosa and Avicennia marina, the correlation between physical properties of rhizosphere deposition and residual NOR in sediments, and NOR accumulation in the root system were analyzed. Significant differences were noted in NOR residues in rhizosphere sediments of R. stylosa and A. marina, with higher NOR concentrations than those in other wetland sediments locally and abroad. NOR accumulation in R. stylosa was higher in the branches than in the roots and was also significantly higher than that in A. marina. Thus, both species could accumulate NOR from the environment with R. stylosa showing a stronger potential to purify the environment. Cation exchange capacity and total organic carbon could affect NOR distribution in the rhizosphere sediment, and total organic carbon content could reduce NOR uptake by mangrove roots. This study contributes to research on the migration and adsorption characteristics of antibiotics in mangrove wetlands.
关键词： mangrove ecosystems,migration characteristics,aquaculture wastewater,norfloxacin,residual characteristics
更新于2025-09-19 17:13:59