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13 results on '"Yu, Shangzhi"'

1. Secure transmission of simultaneous wireless information and power transfer system for Internet of things

Author

Yu Shangzhi and Zhu Hongxing

Subjects
iot, information-energy, swipt, secure transmission, Mathematics, QA1-939
Abstract

Due to the excellent broadcasting characteristics of radio signals, simultaneous wireless information and power transfer (SWIPT) can transmit both information and energy, and provide users with stable power supply. Wireless channel has the characteristics of openness, which will lead to the leakage of information in the SWIPT system. It is one of the research hotspots in the industry to ensure the secure transmission of information in SWIPT system where there are differences in the transmission of energy and information. This paper proposes an ‘information-energy’ dynamic switching opportunistic secure transmission scheme. First, a model considering three factors of multi-cell, multi-user and multiple eavesdropper is established which assumes that the user adopts a time-domain switching receiver that collects energy in a nonlinear model. Then, combined with the time-varying wireless channel, a dynamic information energy switching transmission scheme based on signal-to-interference noise ratio threshold is proposed. Finally, the energy and information transmission performance of the scheme are comprehensively analysed.

Published
2023
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7. Utilization of biodiesel and glycerol for the synthesis of epoxidized acyl glycerides and its application as a plasticizer.

Author

Wu, Zhenyu, Cai, Jinjin, Liu, Zhonghui, Liang, Xiaojiang, Yu, Shangzhi, and Nie, Yong

Subjects
GLYCERIDES, FATTY acid methyl esters, GLYCERIN, DIETHYLHEXYL phthalate, PLASTICIZERS, PETROLEUM waste
Abstract

In many regions, even if waste vegetable oil is used as raw material, the profits of biodiesel (fatty acid methyl ester, FAME) enterprises still remain restricted, and they are facing environmental problems caused by the by‐product glycerol. Hence, value‐added utilization of FAME and glycerol is a promising alternative to improve the competitiveness of biodiesel enterprises in the economy and environmental protection. In this paper, FAME and glycerol were utilized to prepare epoxidized acyl glycerides by transesterification and epoxidation. In the transesterification, acyl glycerides were prepared by reacting FAME and glycerol catalyzed by K2CO3. The contents of monoacyl glyceride, diacyl glyceride, and triacyl glyceride in the acyl glycerides were about 50%, 40%, and 10%, and the optimal conditions were a temperature of 200°C and the molar ratio of FAME to glycerol of 1:1. In the epoxidation, selectivity of epoxides was significantly affected by monoacyl glyceride content, and a treatment method was developed to control the monoacyl glyceride content <5%. In addition, the plasticity of epoxidized acyl glycerides to partially substitute dioctyl phthalate in polyvinyl chloride was studied, the overall mechanical properties, thermal stability, and extraction resistance were improved. In this work, FAME and glycerol were utilized to prepare epoxidized acyl glycerides with higher value‐added, which provide a potential solution for improving the market competitiveness of biodiesel enterprises. [ABSTRACT FROM AUTHOR]

Published
2023
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11. Microwave-assisted catalytic dehydration of glycerol for sustainable production of acrolein over a microwave absorbing catalyst

Author

Ruchao Gong, Duan Ying, Yong Nie, Jianbing Ji, Qinglong Xie, Meizhen Lu, Shanshan Li, Pan Xu, Wang Yilei, Ji Weirong, Yu Shangzhi, and Gaoji Zheng

Subjects
Materials science, Process Chemistry and Technology, Acrolein, 02 engineering and technology, Coke, 010402 general chemistry, 021001 nanoscience & nanotechnology, medicine.disease, 01 natural sciences, Catalysis, 0104 chemical sciences, chemistry.chemical_compound, Chemical engineering, chemistry, medicine, Glycerol, Dehydration, 0210 nano-technology, Selectivity, Microwave, General Environmental Science, Space velocity
Abstract

Uniform temperature distribution within solid catalyst particles is important to achieving low coke formation in a high-temperature reaction. However, the issue of uneven temperature distribution exists in most fixed-bed catalytic reaction systems. Here, we developed a microwave-assisted system and used it in catalytic dehydration of glycerol for sustainable production of acrolein. A coated microwave absorbing catalyst WO3/ZrO2@SiC was prepared and employed in the catalytic reactions. The effects of reaction temperature, ZrO2/SiC ratio, and weight hourly space velocity (WHSV) on glycerol conversion and arcolein selectivity were examined. Experimental results showed that the microwave heating proved to be more effective than the conventional electric heating for glycerol dehydration to acrolein at lower temperature. The acrolein selectivity reached over 70% with complete glycerol conversion at 250 oC by microwave heating. The catalyst acidity was greatly influenced by ZrO2/SiC ratio, which in turn determined the acrolein selectivity. More importantly, much better catalyst stability was obtained in the microwave-heating process than the electric-heating process. In addition, the microwave-heating system was effective for the in-situ regeneration of deactivated catalyst.

Published
2019

12. Pyrolysis of methyl ricinoleate by microwave-assisted heating coupled with atomization feeding

Author

Yong Nie, Duan Ying, Qinglong Xie, Yu Shangzhi, Jianbing Ji, Gaoxiang Zeng, Meizhen Lu, and Xiaoning Mao

Subjects
Methyl ricinoleate, Materials science, 020209 energy, Analytical chemistry, 02 engineering and technology, Mass spectrometry, Analytical Chemistry, Heptanal, chemistry.chemical_compound, Fuel Technology, chemistry, Yield (chemistry), Scientific method, Undecylenic acid, 0202 electrical engineering, electronic engineering, information engineering, medicine, Gas chromatography, Pyrolysis, medicine.drug
Abstract

A stable high-temperature reaction site and the uniformity and speed of heating the feedstocks play a key role in pyrolysis processes. In this study, microwave-assisted heating coupled with atomization feeding was used to pyrolyze methyl ricinoleate (MR) for the efficient, continuous production of undecylenic acid methyl ester (UAME) and heptanal (HEP). The effects of feed mode, reaction temperature and preheating temperature on microwave-assisted pyrolysis (MAP) were examined. The maximum selectivities of HEP and UAME could reach 91.4 wt.% and 76.6 wt.%, respectively, at the reaction and preheating temperatures of 500 °C and 150 °C, respectively, using atomization feeding. The gas, liquid and solid products were determined by gas chromatography (GC), GC-mass spectrometry (MS) and Fourier transform infrared (FT-IR), and the gas, liquid and solid yield reached 7.0 wt.%, 89.0 wt.% and 0.1% wt.%, respectively, with an error of 3.9 wt.% at 500 °C. The pyrolysis of MR via microwave-assisted heating coupled with atomization feeding was found to be more efficient than the conventional pyrolysis process. In addition, the theoretical and actual heat for MAP of MR was 1461 kJ/kg and 2629 kJ/kg at 500 °C, respectively. The material balance and heat analysis results can be used to guide the design of an amplifying device.

Published
2018

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