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Detection of parameters in solid state fermentation of Monascus by near infrared spectroscopy
摘要： The prediction model was constructed using the near-infrared spectroscopy combined with the interval least squares support vector machine method (siLS-SVM) of moisture content and pH value change during the solid fermentation of Monascus. The predictive model was established with partial least squares regression (PLS), and the comprehensive performance of the model was evaluated by cross-validating the mean square error, absolute error value and relative error value. The findings suggest that the LS-SVM model established by siLS-SVM algorithm owns superior predictability and stability for the changes of water content and pH value in the solid fermentation of Monascus (the average relative error is 1.52% and 1.55%, respectively), which can be used for the accurate quantitative prediction. The results showed that near infrared spectroscopy could be used for rapid and non-destructive determination of water content and PH value in solid-state fermentation of Monascus, which provided a new way for optimization of solid-state fermentation process of Monascus under bran substrate.
关键词： Near-infrared spectroscopy,Prediction model,Monascus,Solid state fermentation
更新于2025-09-10 09:29:36
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One-step hydrothermal synthesis of carbon dots-polymer composites with solid-state photoluminescence
摘要： Carbon dots (CDs) and CDs-polymer composites were one-step synthesized in a hydrothermal process using hexamethylenetetramine and polycarbonate as precursors. Their optical properties and the application as solid-state phosphors towards white light-emitting diodes (LEDs) were thoroughly investigated. CDs solutions exhibit strong yellow emission under blue illumination and possess excitation-independent luminescent behavior. Owing to precursor polymerization, CDs-polymer composites were synthesized in one step. The dried CDs-polymer composite powders exhibit excellent optical stability and no luminescence quenching was observed. Under light blue illumination, the powders show broad yellow luminescence with the peak wavelength centered at 550 nm and PL quantum yield of 14.86%. For their practical applications, stable white light emission was demonstrated by coating a 455nm blue LED with the powders. Our research offers a valuable reference for growing CDs-polymer composites in a facile, low-cost and low-temperature hydrothermal process and developing white LEDs with light blue LEDs and metal-free phosphors.
关键词： white light-emitting diodes (LEDs),phosphors,solid-state photoluminescence,hydrothermal method,carbon materials,luminescence
更新于2025-09-10 09:29:36
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From EBIC images to qualitative minority carrier diffusion length maps
摘要： A novel method is presented with the aim to perform minority carrier di?usion length map on cross-sectional samples. The method is based on one Electron-Beam Induced Current (EBIC) acquisition and on the analyze of the EBIC signal slope variation on each scanned points. This method is applied on a pinned photodiode array realized on a low doped silicon epitaxy, and the electron di?usion length map which is extracted is in good accordance with our expectation taking into account the doping distribution of the device. A TCAD simulation also con?rms quantitatively the measured di?usion length map. Advantages and drawbacks of this method are discussed in this study.
关键词： CMOS image sensors,CMOS,Scanning electron microscopy (SEM),Simulation,Electron-beam-induced current (EBIC),Deep submicron process,Solid-state image sensor,Semiconductor material measurements
更新于2025-09-10 09:29:36
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Determination of polaronic conductivity in disordered double perovskite La2CrMnO6
摘要： Double perovskite La2CrMnO6 ceramics was sintered using standard high temperature route in ambient air. The orthorhombic Pbnm cell characterized by a total disorder between Cr and Mn ions was determined using an XRD powder test. The grain morphology, porosity and chemical composition were determined using scanning electron microscopy. The X-ray photoemission spectroscopy showed several contributions to O 1 s, La 3d, Mn 2p, and Cr 2p core lines related to the occurrence of multiple ionic states. The electrical permittivity, modulus, AC and DC conductivity were measured in ranges of f = 20 Hz – 1 MHz and 76–440 K. The electrical transport mechanism was attributed to the small polarons. The nearest neighbor hopping occurred in the range 170 to 440 K. The variable range hoping, attributed to the Fermi glass features and disorder, was detected in the range 100 to 160 K. The relaxation process related to the temperature-independent activation energy was deduced from the electric modulus scaling.
关键词： La2CrMnO6 ceramics,Sintering,Electrical properties,Solid state synthesis
更新于2025-09-10 09:29:36
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Implementation of a Hyperspectral X-ray Camera control and processing software chain
摘要： Hyperspectral X-ray detectors, which provide the full energy spectrum detected by each individual pixel, have become available for use in lab-based facilities. The addition of spectral information currently comes at the cost of low overall acceptable ?ux rates, and can introduce countrate nonlinearity at higher energies. Neither of these drawbacks are desirable for transmission imaging and tomography. In this paper a new data processing software chain is presented for the SLcam, a pnCCD-based hyperspectral camera prototype, allowing for more control over the conversion from raw frames to hyperspectral images. Complementary to the processing software, a set of live data visualisations was developed to aid in monitoring ongoing experiments and to allow for preliminary data processing on-the-?y. The combination of these software elements forms the ?rst step towards general applicability of hyperspectral imaging at laboratory tomography setups.
关键词： Data acquisition concepts,Detector control systems,X-ray detectors,Solid state detectors
更新于2025-09-10 09:29:36
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Comparison of UV-Irradiation and Sintering on Mesoporous Sponge-like ZnO Films Prepared from PS-b-P4VP Templated Sol-Gel Synthesis
摘要： Mesoporous ZnO films with large surface-area-to-volume-ratio show great promise in multiple applications, among which solid-state dye-sensitized solar cells (ssDSSCs) have attracted great attention in the field of photovoltaics. An appropriate mesopore size in the nanostructured ZnO films significantly plays an indispensable role in improving the device efficiency resulted from an efficient penetration of dye molecules and solid hole transport material. In the present work, mesoporous sponge-like ZnO films are prepared using sol-gel synthesis templated by a diblock copolymer polystyrene-block-poly(4-vinylpyridine). Two different template removal techniques, UV-irradiation and high temperature sintering, are used to compare their respective impact on the pore sizes of the final ZnO thin films. Both, the surface morphology and the inner morphology show that mesopores obtained via UV-irradiation are smaller as compared to their sintered counterparts. Moreover, increasing the template-to-ZnO precursor ratio is found to further enlarge present mesopores. Accordingly, a strong correlation between the pore sizes of sol-gel synthesized ZnO films and photovoltaic performance of fabricated ssDSSCs is demonstrated. In contrast with the devices fabricated from the UV-irradiated ZnO films, those obtained from sintered samples show more than two times higher efficiency.
关键词： sintering,mesopores,grazing-incidence small-angle X-ray scattering,UV-irradiation,solid-state DSSCs
更新于2025-09-10 09:29:36
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Enhanced dielectric properties of BaTiO3 ceramics with cerium doping, manganese doping and Ce-Mn co-doping
摘要： Ba1?xCexTi1?yMnyO3 (where x and y varies from 0.00 to 0.03) ceramic samples are synthesized by conventional solid state reaction technique. The samples are sintered at 1473 K for 4 h. The grain size is observed to increase with increasing dopant and co-dopant concentration. The X-ray diffraction confirmed the cubic phase of these BaTiO3-based ceramics with a small amount of secondary phase. The current density shows a nearly linear relationship with voltage, and the AC resistivity of the samples is observed to decrease with increasing frequency and doping concentration. The dielectric constant and dielectric loss were observed to decrease with frequency in the lower frequency range (0.2–10 kHz), but remained almost the same at the high-frequency region (>10 kHz). Though Ce-doped samples shows better dielectric properties than Mn-doped samples, the Ce-Mn co-doped samples, having improved their dielectric properties, can be used to fabricate different optoelectric devices.
关键词： resistivity,SEM,solid state reaction,dielectric properties,XRD,grain size
更新于2025-09-09 09:28:46
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Design and development of in-situ temperature dependent diffuse reflectance spectroscopy setup
摘要： Recent advancements in the commercialization of In-situ temperature dependent optical spectrophotometer have shown potential not only for the recording of optical absorption spectra but also towards the exploration of physical insights and the understanding of instrument handling. Measurement on the effect of the variation of temperature onto optical properties mainly for semi-conducting oxides helps to explore the functioning and play a crucial role towards the development of optoelectronic devices. Being a non-contact, non-destructive technique temperature dependent DRS Setup can be used as a primary tool for the in-situ characterization of optical properties. This appreciation prompts us to design and develop an instrument that can add the ability of in-situ temperature dependent DRS above room temperature. The setup, developed and reported here, is able to accurately characterize the samples from room temperature to 500 K, which is most suitable range for the characterization of semiconducting materials, which is in the heard of current materials’ research. The present study provides the economical alternatives to the existing designs used for this purpose without compromising on the reliability of the obtained data. The in-house developed set up is found to be efficiently used for the analysis of various properties of the samples and will open up the instrumental development and commercialization of the temperature dependent DRS technique.
关键词： Detection of defects,Photon detectors for UV, visible and IR photons (solid-state),Overall mechanics design (support structures and materials, vibration analysis etc),Spectrometers
更新于2025-09-09 09:28:46
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A gauge-invariant formulation of interband and intraband currents in solids
摘要： Experiments and simulations in solid-state high harmonic generation often make use of the distinction between interband and intraband currents. These two contributions to the total current have been associated with qualitatively different processes as well as physically measurable signatures, for example, in the spectral phase of harmonic emission. However, it was recently argued [P. F?ldi, Phys. Rev. B 96, 035112 (2017)] that these quantities can depend on the gauge employed in calculations. Since physical quantities are expected to have gauge-independent values, this raises the question of whether the decomposition of the total current into interband and intraband contributions is physically meaningful or merely a feature of a particular mathematical representation of nature. In this article, we explore this apparent ambiguity. We show that a closely related issue arises when calculating instantaneous band populations. In both the case of inter/intraband currents and the case of instantaneous band populations, we propose definitions that are gauge invariant and thus allow these quantities to be calculated consistently in any gauge.
关键词： gauge invariance,solid-state,interband currents,band populations,intraband currents,high harmonic generation
更新于2025-09-09 09:28:46
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A solid (state) success
摘要： James McKenzie reflects on the impact of the solid-state laser, a device in its infancy when it became the subject of one of the first articles in Physics World. The article discusses the evolution of solid-state lasers from their early days to their widespread use in various applications such as compact discs, DVDs, Blu-ray discs, and optical communications. It also speculates on the future of solid-state lasers and their continued relevance in emerging technologies.
关键词： compact discs,DVDs,Blu-ray discs,solid-state laser,optical communications,diode laser
更新于2025-09-09 09:28:46