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Photocatalytic Reforming of Sugar and Glucose into H2 over Functionalized Graphene Dots
摘要： Photocatalytic reforming of biomass into H2 combining with its photosynthesis counterpart constitutes a sustainable carbon cycle that produces a clean solar fuel. This study reports the use of environmentally benign graphene-based photocatalysts to effectively reform sugar and glucose. We produce a catalyst consisting of sulfur and nitrogen codoped graphene oxide dots (SNGODs) by sequentially annealing graphite-derived graphene oxide with sulfur and ammonia, exfoliating the annealed product into dots, and autoclaving the dots in an ammonia solution. The codoping introduces quaternary nitrogen on the graphene basal plane to patch the vacancy defects and the autoclaving creates a conjugation between the nitrogen nonbonding states and the graphitic-π orbital by introducing peripheral amide and amino groups. These functionalization steps enlarge the electron resonance domain, narrowing the bandgap and inducing charge delocalization and separation. Here, when SNGODs deposited with a Pt cocatalyst effectively catalyzed H2 production from aqueous solutions of sugar and glucose under visible light irradiation for more than 80 h. The apparent quantum yields of the reforming of sugar and glucose reach 11% and 7.4%, respectively, under 420-nm monochromatic irradiation. This pioneer study demonstrates the superiority of using carbon-based photocatalysts for biomass reforming and provides a structure-tuning strategy for enhancing the catalytic activity.
关键词： Reforming of sugar,Hydrogen production,Graphene oxide,Reforming of glucose,Photocatalytic reforming
更新于2025-11-20 15:33:11
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Near-Infrared Hyperspectral Imaging Rapidly Detects the Decay of Postharvest Strawberry Based on Water-Soluble Sugar Analysis
摘要： This paper presents a novel strategy to detect the fungal decay in strawberry using reflectance near-infrared hyperspectral imaging (NIR-HSI, 1000–2500 nm). The variation of fructose, glucose, sucrose, and total water-soluble sugar (TWSS) content was analyzed using HPLC with a reference method during fungal infection in strawberry. The feasibility of quantifying sugar constituents relevant to the different stages of decay in strawberry was evaluated using NIR-HSI with key wavelengths selected via successive projection algorithm. The results showed that the predicted performance of TWSS content was acceptable within 2 and 2.603 for RPD, respectively. Five to seven key wavelengths were obtained based on sugar constituents, and excellent performance for classification accuracy among the three stages of decay was 89.4 to 95.4% for calibration and 87.0 to 94.4% for prediction, respectively. This rapid approach provides a new strategy for the selection of key wavelengths to detect the decay and sugar constituents in strawberries.
关键词： Strawberry,Key wavelength,Decay,Sugar content,Hyperspectral imaging
更新于2025-09-23 15:23:52
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Portable, visual, and nondestructive detector integrating Vis/NIR spectrometer for sugar content of kiwifruits
摘要： A portable sugar content detector for intact kiwifruits was developed using a visible/near-infrared spectrometer over the wavelength of 350–1,100 nm as spectra collector, a tablet computer as controller, a micro-halogen lamp as light source, and a self-made “Y” shape optical fiber as light transmitter and light receiver. The software applied to collect spectra, to establish sugar content prediction model, and to predict sugar content of kiwifruits was developed by Java language. Partial least square regression model was established to determine sugar content of kiwifruits. Contrasted with the sugar content obtained by digital refractometer, the root-mean-square error of the developed detector was 0.93% in soluble solids content. The obtained sugar content using the developed detector could be given in 2.5 s. The study shows that the developed portable sugar content detector is a promising tool for on-site or in field nondestructive measurement on sugar content of kiwifruits.
关键词： kiwifruits,portable detector,Vis/NIR spectrometer,nondestructive measurement,sugar content
更新于2025-09-23 15:23:52
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Classification of Sugar Beets Based on Hyperspectral and Extreme Learning Machine Methods
摘要： Sugar beet varieties were classified based on hyperspectral technology and the Extreme Learning Machine (ELM) algorithm. The influences of seven pretreatment methods, namely, Savitzky-Golay smoothing (SG), the first derivative (FD) method, SG smoothing combined with the FD method (SG-FD), logarithmic transformation (LT), LT combined with the FD method (LT-FD), the standard normal variate (SNV) method, and SNV combined with the FD method (SNV-FD), on the recognition performance of the ELM model were analyzed to select the best pretreatment method. To simplify the input variables, the standard deviation peak method was used to extract the feature bands for different preprocessed spectral data. The experimental results showed that for different pretreatment methods, the recognition rates of sugar beet varieties by ELM models were all over 80%. Additionally, the combination of different pretreatment methods and FD effectively improved the signal-to-noise ratio and enhanced the accuracy and stability of spectral models. Overall, the recognition accuracy of the ELM models established based on the feature bands was better than that established based on all bands, which suggests that the feature bands extracted by the standard deviation peak method are effective. Based on the SG-FD pretreatment method, the ELM models established using all bands and feature bands both achieved the highest recognition effect. Specifically, the recognition rates of the prediction sets were 93.94% and 95.45%, respectively.
关键词： Standard deviation peak method,ELM,Different pretreatment methods,Sugar beet variety,Hyperspectral
更新于2025-09-23 15:23:52
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Simple direct observation of polarization changes of Rayleigh scattering on sugar solution at low concentration
摘要： The direct measurement of polarization changes can be used to prove Rayleigh scattering at low concentration of sucrose and commercial sugar solution. The polarization changes of scattered light is linearly dependent on the polarization angle in the range 0° to 70°, and linearly dependent on sample concentration (number of particles). This method is able to show sugar’s relative different quality, i.e. pure sucrose and commercial sugar due to different molecular size and additional impurities in the commercial sugar.The method is simpler and easier to study the interaction of light with matter for special condition. Additionally, for other known parameters, the method can be developed to obtain the molecular size and composition information of the sample using Rayleigh scattering.
关键词： direct polarization changes,Rayleigh scattering,Sugar solution
更新于2025-09-23 15:21:01
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Natural Sugar Assisted Chemically Reinforced Highly Durable Piezo-Organic Nanogenerator with Superior Power Density for Self-Powered Wearable Electronics
摘要： Natural piezoelectric material is of increasing interest particularly for applications in biocompatible, implantable, and flexible electronic devices. In this paper we introduce a cost effective, easily available natural piezoelectric material, i.e., sugar in the field of wearable piezoelectric nanogenerator (PNG) where low electrical output, biocompatibility and performance durability are still critical issues. We report on a high performance piezo-organic nanogenerator (PONG) based on the hybridization of sugar encapsulated polyvinylidene fluoride (PVDF) nanofiber webs (SGNFW). We explore the crucial role of single crystal sugar having fascinating structure along with the synergistic enhancement of piezoelectricity during nano-confinement of sugar interfaced macromolecular PVDF chains. As a consequence, the SGNFW based PONG exhibits outstanding electricity generation capability (for example ~100V under 10 kPa human finger impact and maximum power density of 33 mW/m2) in combination with sensitivity to abundantly available different mechanical sources (such as wind flow, vibration, personal electronics and acoustic vibration). Consequently, it opens up suitability in multifunctional self-powered wearable sensor designs for realistic implementation. In addition, commercially available capacitors are charged up effectively by the PONG due to its rapid energy storage capability. The high performance or the PONG not only offers the “battery free” energy generation (several portable units of LEDs and a LCD screen are powered up without using external storage) but also promises its use in wireless signal transmitting systems that widens the potential in personal health care monitoring. Furthermore, owing to the geometrical stress confinement effect, the PONG is proven to be a highly durable power generating device validated by stability test over 10 weeks. Therefore, the organic nanogenerator would be a convenient solution for portable personal electronic devices that are expected to operate in a self-powered manner.
关键词： self-powered electronics,PVDF,organic piezoelectric nanogenerator,high performance and durability,Natural piezoelectric material,sugar
更新于2025-09-23 15:21:01
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Post-annealed graphite carbon nitride nanoplates obtained by sugar-assisted exfoliation with improved visible-light photocatalytic performance
摘要： Two-dimensional (2D) graphitic carbon nitride (g-C3N4) nanoplates (CNNP) have become a hot research topic in photocatalysis due to their small thickness and large specific surface area that favors charge transport and catalytic surface reactions. However, the wide application of 2D g-C3N4 nanoplates prepared by ordinary methods suffers from increased band gaps with a poor solar harvesting capability caused by the strong quantum confinement effect and reduced conjugation distance. In this paper, a facile approach of exfoliation and the following fast thermal treatment of the bulk g-C3N4 is proposed to obtain a porous few-layered g-C3N4 with nitrogen defects. Due to the preferable crystal, textural, optical and electronic structures, the as-obtained porous CNNP demonstrated a significantly improved photocatalytic activity towards water splitting than the bulk g-C3N4 and even the 3 nm-thick CNNP obtained by sugar-assisted exfoliation of the bulk g-C3N4. The difference in the enhancement factors between the H2O splitting and organic decomposition has revealed the effect of N defects. This study offers insightful outlooks on the scalable fabrication of a porous few-layered structure with a promoted photocatalytic performance.
关键词： Photocatalytic activity,g-C3N4 nanoplates,Co-grinding,Thermal treatment,Sugar
更新于2025-09-23 15:19:57
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Design, realization, and tests of a portable solar box cooker coupled with an erythritol-based PCM thermal energy storage
摘要： Solar radiation is a variable energy source and the mismatch between the availability of such source and the domestic energy demand is a paramount challenge to deal with. For this reason, in this work a 4.08 concentration ratio portable solar box cooker coupled with a thermal energy storage (TES) based on a phase change material (PCM) was characterized through outdoor experimental tests. The TES is a double-wall stainless steel vessel, with the annular volume filled with 2.5 kg of erythritol. The portable solar box cooker was tested under 4 different experimental conditions: without load, with water, with silicone oil, and with silicone oil inserted in the erythritol-based TES. The load tests were divided into a heating and a cooling phase, in order to evaluate the cooker performance in absence of solar radiation. Results showed that equipping the portable solar box cooker with the erythritol-based TES allowed to extend the average load cooling time, in the range 125–100 °C, of around 351.16%.
关键词： Experimental,Heating phase,Sugar alcohol,Cooling phase,Polyalcohol
更新于2025-09-23 15:19:57
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A Waveguide-Fed 35-GHz Rectifier With High Conversion Efficiency
摘要： Raman spectroscopy performed using optical fibers, with excitation at 1064 nm and a dispersive detection scheme, was utilized to measure a selection of unifloral honeys produced in the Italian region of Calabria. The honey samples had three different botanical origins: chestnut, citrus, and acacia. A multivariate processing of the spectroscopic data enabled us to distinguish their botanical origin, and to build predictive models for quantifying important nutraceutic indicators, such as the main sugars and potassium. Furthermore, the Raman spectra of chestnut honeys were compared with the taste profile measured by an electronic tongue: A good correlation to a bitter-savory taste was obtained. This experiment indicates the excellent potential of Raman spectroscopy as a modern analytical tool for the nondestructive and rapid multi-component analysis of food quality indicators.
关键词： Food products,sugar,predictive models,labeling,pattern analysis,Raman scattering
更新于2025-09-23 15:19:57
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[IEEE 2019 International Conference on Electrical, Electronics and Computer Engineering (UPCON) - ALIGARH, India (2019.11.8-2019.11.10)] 2019 International Conference on Electrical, Electronics and Computer Engineering (UPCON) - Comparative Study of MPPT Techniques for Solar Photovoltaic System
摘要： Raman spectroscopy performed using optical fibers, with excitation at 1064 nm and a dispersive detection scheme, was utilized to measure a selection of unifloral honeys produced in the Italian region of Calabria. The honey samples had three different botanical origins: chestnut, citrus, and acacia. A multivariate processing of the spectroscopic data enabled us to distinguish their botanical origin, and to build predictive models for quantifying important nutraceutic indicators, such as the main sugars and potassium. Furthermore, the Raman spectra of chestnut honeys were compared with the taste profile measured by an electronic tongue: A good correlation to a bitter-savory taste was obtained. This experiment indicates the excellent potential of Raman spectroscopy as a modern analytical tool for the nondestructive and rapid multi-component analysis of food quality indicators.
关键词： Food products,sugar,predictive models,labeling,pattern analysis,Raman scattering
更新于2025-09-19 17:13:59