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Multiple metallic dopants in nickel nanoparticles for electrocatalytic oxygen evolution

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Progress in Natural Science:Materials International 2023年第1期33卷 67-73页

作者： Yan Huang Jingrui Han Haibin Wang Lihua Liu Hongyan Liang School of Materials Science and Engineering Tianjin University Key Laboratory of Efficient Utilization of Low and Medium Grade Energy Ministry of Education Tianjin University College of Innovation and Entrepreneurship Shanghai Jianqiao University

Developing efficient oxygen evolution reaction(OER) electrocatalysts is of great importance for sustainable energy conversion and storage. Ni-based catalysts have shown great potential as OER electrocatalysts, but their performance still needs to be improved. Herein, we report the multiple metal doped nickel nanoparticles synthesized via a simple oil phase strategy as efficient OER catalysts. The FeMnMoV–Ni exhibits superior OER performance with an overpotential of 220 mV at 10 mA cm-2and a long-term stability of 250 h in 1 M KOH solution. In situ Raman analysis shows that the NiOOH site works as the active center and multiple metallic dopants facilitate the formation of NiOOH. Mo and V dopants promote the formation of high-valence state of Ni sites, and Mn dopants increase the electrochemical active surface area and expose more active sites. This work provides a novel strategy for catalyst design, which is critical for developing multiple metal doped catalysts.

关键词： Multiple metallic dopants Oxygen evolution Electrocatalysts In situ Raman Nickel

Impact of air pressure variations on electrical vehicle motor insulation

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High Voltage 2023年第5期8卷 1011-1019页

作者： Peng Wang Chaofan Yu Shakeel Akram Ziyuan Fan Wenhuan Zhao National Demonstration Base for innovation entrepreneurship New Energy and Electrical Insulation LaboratorySichuan UniversityChengduChina college of Electrical Engineering and Control Science Nanjing Tech UniversityNanjingChina

Variation in air pressure severely affects the insulation of electric vehicle(EV)motors,hence weakening the reliability of EVs for safe operation.Nomex‐polyimide‐Nomex,a typical insulation material for EV motors,was used to investigate the motor insulation performance under different air pressures.The results show that the partial discharge inception voltage is significantly reduced for EV motors operated at lower air pressures,and the probability of partial discharge(PD)occurrence is increased.The macroscopic results reveal that the active area of the PD expands at low pressure,while the non‐corroded ring appears in the centre.Additionally,although the number and amplitude of the PD increase significantly with decrease in air pressure,the active area of the PD expands and electrical stress on the insulation per unit area increases slowly.Therefore,when the pressure decreased from 60 to 40 kPa,the endurance life does not show a significant downward trend.Furthermore,the dielectric constant and loss of the low‐pressure samples significantly change during the ageing process,which further indicates critical degradation of the insulation.The aforementioned investigations reveal that the air pressure at different altitudes has a significant impact on the performance of insulation materials.

关键词： insulation electrical Impact

N-heterocyclic carbene-catalyzed radical reactions

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Science China Chemistry 2021年第1期64卷 7-16页

作者： Kun-Quan Chen He Sheng Qiang Liu Pan-Lin Shao Xiang-Yu Chen School of Chemical Sciences University of the Chinese Academy of SciencesBeijing 100049China College of Innovation and Entrepreneurship Southern University of Science and TechnologyShenzhen 518055China

While N-heterocyclic carbene(NHC)catalyzed electron-pair-transfer processes have been developed into an important tool for synthetically important bond formations during the past decades,the corresponding radical reactions via NHC catalysis have only received growing attention in the past six years.Taking into account the advantages NHC-catalyzed radical reactions might bring,such as creating new activation modes that were previously unobtainable,it is worthwhile to provide a conceptual understanding of this emerging area.Therefore,herein we give an overview of NHC-catalyzed radical reactions via different synthetic techniques.

关键词： N-heterocyclic carbene radical one-electron oxidant photochemistry electrochemistry

Scalable synthesis of nanoporous high entropy alloys for electrocatalytic oxygen evolution

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Rare Metals 2022年第1期41卷 125-131页

作者： Li-Hua Liu Ning Li Mei Han Jing-Rui Han Hong-Yan Liang college of innovation&entrepreneurship Shanghai Jianqiao UniversityShanghai 201306China School of Materials Science and Engineering Tianjin UniversityTianjin 300350China

High entropy alloys(HEAs)containing five or more equimolar components have shown promising catalytic performance due to their unique chemical and mechanical properties.However,it is still challenging to prepare scalable and efficient nanoporous HEAs as catalysts.Here,we present a facile strategy to synthesize largescale nanoporous HEAs particles by combing vacuum induction melting,gas atomization,and acidic etching procedure.The application of HEAs to energy conversion is evaluated with electrocatalytic oxygen evolution reaction(OER)on AlCrCuFeNi HEAs.The HEAs exhibit a low OER overpotential of 270 mV to achieve a current density of 10 mA·cm^(-2),a small Tafel slope of 77.5 mV·dec^(-1),and long-term stability for over 35 h in 1 mol·L^(-1) KOH,which is comparable to the state-of-the-art OER electrocatalyst RuO2.The findings in this paper not only provide an industrial approach to produce nanoporous HEAs powder but also inspire the applications of HEAs as catalysts.

关键词： High entropy alloys Gas atomization Acidic etching Nanoporous AlCrFeNiCu structures Oxygen evolution reaction

Molecular dynamics simulation of thermal conductivity of silicone rubber

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Chinese Physics B 2020年第4期29卷 385-390页

作者：徐文雪吴雁艳祝渊梁新刚 School of Aerospace Engineering Key Laboratory for Thermal Science and Power Engineering of Ministry of EducationTsinghua UniversityBeijing 100084China College of Innovation and Entrepreneurship Southern University of Science and TechnologyShenzhen 518055China

Silicone rubber is widely used as a kind of thermal interface material(TIM)in electronic devices.However few studies have been carried out on the thermal conductivity mechanism of silicone rubber.This paper investigates the thermal conductivity mechanism by non-equilibrium molecular dynamics(NEMD)in three aspects:chain length,morphology,and temperature.It is found that the effect of chain length on thermal conductivity varies with morphologies.In crystalline state where the chains are aligned,the thermal conductivity increases apparently with the length of the silicone-oxygen chain,the thermal conductivity of 79 nm-long crystalline silicone rubber could reach 1.49 W/(m·K).The thermal conductivity of amorphous silicone rubber is less affected by the chain length.The temperature dependence of thermal conductivity of silicone rubbers with different morphologies is trivial.The phonon density of states(DOS)is calculated and analyzed.The results indicate that crystalline silicone rubber with aligned orientation has more low frequency phonons,longer phonon MFP,and shorter conducting path,which contribute to a larger thermal conductivity.

关键词： silicone rubber chain length thermal conductivity molecular dynamics simulation

Smart control system for the precision cultivation of black fungus

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International Journal of Agricultural and Biological Engineering 2023年第1期16卷 193-202页

作者： Yongcheng Jiang Jianjun Li Yang Li Shide Li Xin Song Haiyun Wu Shiwei Zhu college of Engineering and Technology Tianjin Agricultural UniversityTianjin 300392China college of Mechanical Engineering Jiamusi UniversityJiamusi 154007HeilongjiangChina School of innovation and entrepreneurship/School of E-Business Yangzhou Polytechnic InstituteYangzhou 225000JiangsuChina college of Basic Science Tianjin Agricultural UniversityTianjin 300392China

Black fungus,with high nutritional and medicinal value,has been cultivated in China for a long time,and Heilongjiang alone accounts for about 40%of the global output.At present,the cultivation of black fungus derives mainly from the inheritance of relatively primitive practices and experience of farmers,resulting in inconsistent quality of fungus.In this study,a smart control system for the precision cultivation of black fungus was designed by using intelligent detection and control technology.The system includes a precision culture test environment and remote control system.The precision cultivation environment contains four sub-independent environments.The key parameters such as temperature,humidity,and light behavior were collected and can be adjusted individually,according to the precision cultivation stages.The intelligent remote control system included a controller cabinet,sensors unit,temperature control unit,humidity control unit,light control unit,and information transmitting unit.The controller cabinet includes a key controller which can auto-control the temperature,humidity,and lightly adjust components according to the precision cultivation conditions and processing.The temperature sensors were installed in a 3D array close to the fungus bags about 5 cm in rooms.The light tape was installed on the six walls and also had three colors(Red,Blue,and Green)which could be controlled independently in each room.The control strategy through the analysis of the data collected by all sensors,the current cultivate situation of the cultivation environment was obtained,and the heater,fan,light,and nozzle were regulated according to the strategy to maintain a suitable precision cultivation environment for fungus.To verify the feasibility of the precision cultivation processing and control system,the test result shows that the error of temperature control was about 0℃-1℃,the error of humidity control was about 1%-4%,and the error of illuminance control was about 0-50 lx;All the verification results show that the cont

关键词： black fungus precision cultivation smart control system growth environment remote control system sensor

Design and Optimization of Heat Dissipation and Cooling Device for the Open 3D Printer

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Design and Optimization of Heat Dissipation and Cooling Devi...

The Path Planning Study of Autonomous Greeting Robot based on Ant Colony Algorithm

第32届中国控制与决策会议

作者： Cui Qingquan Yin Xunhe Ning Jing School of innovation and entrepreneurship Yunnan Land and Resources Vocational College School of Electronics and Information Engineering Beijing Jiaotong University School of Economics and Management Yunnan Agricultural University

ISBN: (数字)9781728158556

ISBN: (纸本)9781728158563

The 3D printer is a machine for cumulative manufacturing, which is a digital model file, and three-dimensional objects are made of printing layer adhesive material. At present, the items printed out by a 3D printer will have a higher amount of heat, and taking out the printed items directly will cause burns to their hands. In addition, in the moment of picking up the print, the sudden release of the heat will also cause damage to the print. In the process of printing, the main control board will increase the environment of the printing area because of the working heat and the temperature of the print head, which will seriously affect the printing quality and the service life of the printer. Therefore, the open 3D printer is designed in the paper. The heat dissipation and cooling device of the machine is optimized to reduce the temperature of the main control board, and the extrusion head temperature of the printer reaches the printing working temperature without affecting the surrounding structure. Through the experimental verification and analysis, the effectiveness of the heat dissipation and cooling device of 3D printer designed in this paper is proved, which provides an effective solution for the heat dissipation research of 3D printer.

关键词： 3D printer Heat Dissipation and Cooling Device Main control board Printer extrusion head

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The Path Planning Study of Autonomous Greeting Robot based o...

Effect of substrate preset temperature on crystal growth and microstructure formation in laser powder deposition of single-crystal superalloy

第32届中国控制与决策会议

作者： Cui Qingquan Ning Jing Yin Xunhe School of innovation and entrepreneurship Yunnan Land and Resources Vocational College School of Economics and Management Yunnan Agricultural University Kunming School of Electronics and Information Engineering Beijing Jiaotong University

ISBN: (数字)9781728158556

ISBN: (纸本)9781728158563

In order to realize the autonomous greeting and greeting of the field guests,the autonomous greeting robot needs to collect and analyze the environmental data.Through the optimization algorithm,an optimal autonomous moving path from the starting point of greeting to a certain guest is found.In this paper,aiming at the autonomous greeting robot,the path planning problem of the autonomous greeting robot based on ant colony algorithm is proposed,and the related design scheme is given.The simulation example shows that the greeting robot can visit specific guests in the shortest path and time.It can effectively ensure that the robot avoids obstacles and other guests in the process of moving.It verifies the feasibility and validity of the path planning proposed in this paper,and lays a theoretical foundation for the further application of the autonomous greeting robot in non-specific environment.

关键词： Autonomous Greeting Robot Path planning Ant colony algorithm Environment map Coordinate

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Journal of Materials Science & Technology 2018年第11期34卷 2116-2124页

作者： Zhaoyang Liu Zi Wang College of Innovation and Entrepreneurship Southern University of Science and Technology Shenzhen Key Laboratory for Additive Manufacturing of High Performance Materials Southern University of Science and Technology State Key Laboratory of Powder Metallurgy Central South University

A successful repair of single-crystal components needs to avoid the stray grain formation and achieves continuous epitaxial growth of columnar dendrites in the repaired zone. In this study, the effect of substrate preset temperature on crystal growth and microstructure formation in laser powder deposition of single-crystal superalloy was studied through an improved mathematical model and corresponding experimental approaches. The results indicated that the variation of substrate preset temperature between-30℃ and ＋210℃ changes the molten pool morphology little, but obviously affects the columnar-to-equiaxed transition conditions. The preheating of substrate facilitates the stray grain formation and enlarges the primary columnar dendrite arm spacing, while the situation for precooling of substrate is opposite. Under the specific processing conditions, the critical condition for continuous epitaxial growth is that the substrate preset temperature Tsub≤ ＋90℃. When the substrate preset temperature Tsubis below ＋90℃, the height ratio of melting depth to total height of the molten pool is larger than that of stray grain, ensuring that stray grains can be completely remelted and the continuous columnar dendrites during the multi-layer laser powder deposition process on（001） surface of single-crystal substrate can be achieved.

关键词： Single-crystal superalloy Crystal growth Laser powder deposition