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315 results on '"Ren, Guangxin"'

58. Regulating the Electronic Structure of Ni Sites in Ni(OH)2by Ce Doping and Cu(OH)2Coupling to Boost 5-Hydroxymethylfurfural Oxidation Performance

Author

Ren, Guangxin, Liu, Baocang, Liu, Liang, Hu, Minghao, Zhu, Junpeng, Xu, Xuan, Jing, Peng, Wu, Jinfang, and Zhang, Jun

Abstract

Biomass is a sustainable and renewable resource that can be converted into valuable chemicals, reducing the demand for fossil energy. 5-Hydroxymethylfurfural (HMF), as an important biomass platform molecule, can be converted to high-value-added 2,5-furandicarboxylic acid (FDCA) viaa green and renewable electrocatalytic oxidation route under mild reaction conditions, but efficient electrocatalysts are still lacking. Herein, we rationally fabricate a novel self-supported electrocatalyst of core–shell-structured copper hydroxide nanowires@cerium-doped nickel hydroxide nanosheets composite nanowires on a copper mesh (CuH_NWs@Ce:NiH_NSs/Cu) for electrocatalytically oxidizing HMF to FDCA. The integrated configuration of composite nanowires with rich interstitial spaces between them facilitates fast mass/electron transfer, improved conductivity, and complete exposure of active sites. The doping of Ce ions in nickel hydroxide nanosheets (NiH_NSs) and the coupling of copper hydroxide nanowires (CuH_NWs) regulate the electronic structure of the Ni active sites and optimize the adsorption strength of the active sites to the reactant, meanwhile promoting the generation of strong oxidation agents of Ni3+species, thereby resulting in improved electrocatalytic activity. Consequently, the optimal CuH_NWs@Ce:NiH_NSs/Cu electrocatalyst is able to achieve a HMF conversion of 98.5% with a FDCA yield of 97.9% and a Faradaic efficiency of 98.0% at a low constant potential of 1.45 V versus reversible hydrogen electrode. Meanwhile, no activity attenuation can be found after 15 successive cycling tests. Such electrocatalytic performance suppresses most of the reported Cu-based and Ni-based electrocatalysts. This work highlights the importance of structure and doping engineering strategies for the rational fabrication of high-performance electrocatalysts for biomass upgrading.

Published
2023
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60. The global biogeography of soil priming effect intensity

Author

Ren, Chengjie, primary, Mo, Fei, additional, Zhou, Zhenghu, additional, Bastida, Felipe, additional, Delgado‐Baquerizo, Manuel, additional, Wang, Jieying, additional, Zhang, Xinyi, additional, Luo, Yiqi, additional, Griffis, Timothy J., additional, Han, Xinhui, additional, Wei, Gehong, additional, Wang, Jun, additional, Zhong, Zekun, additional, Feng, Yongzhong, additional, Ren, Guangxin, additional, Wang, Xiaojiao, additional, Yu, Kailiang, additional, Zhao, Fazhu, additional, Yang, Gaihe, additional, and Yuan, Fenghui, additional

Published
2022
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70. Wheat straw mulching with fertilizer nitrogen: An approach for improving soil water storage and maize crop productivity

Author

Feng YongZhong, Wang Weiyu, Afridi Muhammad Zahir, Ren GuangXin, Khan Ahmad, Yang GaiHe, and Akhtar Kashif

Subjects
Soil Science, 04 agricultural and veterinary sciences, 010501 environmental sciences, Straw, 01 natural sciences, Crop productivity, Nitrogen fertilizer, Agronomy, Soil water, 040103 agronomy & agriculture, 0401 agriculture, forestry, and fisheries, Environmental science, Mulch, 0105 earth and related environmental sciences
Published
2018

83. Hyperspectral imaging for discrimination of Keemun black tea quality categories: Multivariate calibration analysis and data fusion.

Author

Ren, Guangxin, Liu, Ying, Ning, Jingming, and Zhang, Zhengzhu

Subjects
*MULTISENSOR data fusion, *SPECTRAL imaging, *HYPERSPECTRAL imaging systems, *MULTIVARIATE analysis, *TEA, *DATA analysis, *GREEN tea, *SUPPORT vector machines
Abstract

Summary: Food fraud causes significant economic losses for the industry and generates distrust between the consumers and traders. Tea is one of the most valued beverages throughout the world, being vulnerable to economically motivated cheat. The objective of the study was to develop the potential of hyperspectral imaging (HSI) allying multivariate analysis and data fusion to identify the authenticity of Keemun black tea quality categories. Data fusion that integrated of texture characteristics based on grey level co‐occurrence matrix and visible and near‐infrared spectral features via competitive adaptive reweighted sampling (CARS) was as the target data for modelling. Support vector machine (SVM) and random forest (RF) were utilised for the classification of tea samples of seven grades. The RF model using fused data gave the best performance with the correct discriminant rate of 92.70% for the prediction set. This study demonstrated that HSI coupled with RF was effective in identifying tea sample rank. [ABSTRACT FROM AUTHOR]

Published
2021
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84. Evaluation of Dianhong black tea quality using near‐infrared hyperspectral imaging technology.

Author

Ren, Guangxin, Wang, Yujie, Ning, Jingming, and Zhang, Zhengzhu

Subjects
*INFRARED imaging, *SUPPORT vector machines, *MACHINE learning, *IMAGE fusion, *EXTRACTION techniques, *TEA, *GREEN tea
Abstract

BACKGROUND Tea (Camellia sinensis L) is a highly nutritious beverage with commercial value globally. However, it is at risk of economic fraud. This study aims to develop a powerful evaluation method to distinguish Chinese official Dianhong tea from various other categories, employing hyperspectral imaging (HSI) technology and chemometric algorithms. RESULTS: Two matrix statistical algorithms encompassing a gray‐level co‐occurrence matrix (GLCM) and a gradient co‐occurrence matrix (GLGCM) are used to extract HSI texture data. Three novel spectral variable screening methods are utilized to select wavenumbers of near‐infrared (NIR) spectra: iteratively retaining informative variables (IRIV), interval random frog, and variable combination population analysis. Feature fusion of image texture characteristics and spectra data are the eigenvectors for model building. Authentic classification models are constructed using the extreme learning machine approach and the least squares support vector machine (LSSVM) approach, coupling them with features from wavelength extraction techniques for assessing the quality of Dianhong black tea. The results demonstrate that the LSSVM model using fused data (IRIV + GLGCM) provides the best results and achieves a predictive precision of 99.57%. CONCLUSION: This study confirms that HSI coupled with LSSVM is effective in differentiating authentic Dianhong black tea samples. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Published
2021
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93. Applicability of multifunctional preprocessing device for simultaneous estimation of spreading of green tea, withering of black tea and shaking of oolong tea.

Author

Ren, Guangxin, Fan, Qiye, He, Xuejun, Li, Wencui, and Tang, Xiaolin

Subjects
*GREEN tea, *TEA, *ANALYSIS of variance, *SENSORY evaluation, *AMINO acids, *RAW materials
Abstract

BACKGROUND: Preprocessing technologies of fresh tea leaves have a great influence on tea quality. A multifunctional preprocessing device for tea raw materials has been designed and utilized as a novel item of equipment to synchronously meet the process needs of spreading of green tea, withering of black tea and shaking of oolong tea. RESULTS: The preprocessing parameters of fresh tea leaves for spreading of green tea, withering of black tea and shaking of oolong tea were optimized by orthogonal experiments. Sensory assessment combined with statistical tools was employed as an analytical method to evaluate the pretreatment effect of processing different sorts of tea. The range analysis and variance analysis of tea sensory evaluation combined with chemical components (total polyphenols, free amino acids and soluble sugar) showed that A3B2C3 (70%, 25 °C, 8 h), A1B3C1 (60%, 28 °C, 18 h) and A1B1C3 (5 min, 20 °C, discontinuous leaf turning c) were considered to be the optimum schemes for the best pretreatment conditions of the above three major processing types of tea, respectively. The verification experiment of the proposed schemes was performed with satisfactory performance. CONCLUSION: This study demonstrated that a multifunctional preprocessing device for fresh tea leaves can be successfully applied to simultaneously estimate spreading of green tea, withering of black tea and shaking of oolong tea. © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Published
2020
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100. Changes in the material characteristics of maize straw during the pretreatment process of methanation

Author

Feng, Yongzhong, Zhao, Xiaoling, Guo, Yan, Yang, Gaihe, Xi, Jianchao, and Ren, Guangxin

Subjects
Corn -- Physiological aspects, Methane -- Production processes, Straw -- Chemical properties -- Identification and classification, Chemical processes -- Research, Biotechnology industry, High technology industry
Abstract

Pretreatment technology is important to the direct methanation of straw. This study used fresh water, four bacterium agents (stem rot agent, 'result' microbe decomposition agent, straw pretreatment composite bacterium agent, and complex microorganism agent), biogas slurry, and two chemical reagents (sodium hydroxide and urea) as pretreatment promoters. Different treatments were performed, and the changes in the straw pH value, temperature, total solid (TS), volatile solid (VS), and carbon-nitrogen ratio (C/N ratio) under different pretreatment conditions were analyzed. The results showed that chemical promoters were more efficient than biological promoters in straw maturity. Pretreatment using sodium hydroxide induced the highest degree of straw maturity. However, its C/N ratio had to be reduced during fermentation. In contrast, the C/N ratio of the urea-pretreated straw was low and was easy to regulate when used as anaerobic digestion material. The biogas slurry pretreatment was followed by pretreatments using four different bacterium agents, among which the effect of the complex microorganism agent (BA4) was more efficient than the others. The current study is significant to the direct and efficient methanation of straw., 1. Introduction The rural household biogas in China has rapidly developed in recent years. By 2010, the number of rural household biogas users had reached 41.8 million in China [1, [...]

Published
2012
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