Based on the actual hot zone structure of an AlN crystal growth resistance furnace, the global numerical simulation on the heat transfer process in the AlN crystal growth was performed. The influence of different heater structures on the growth of AlN crystals was investigated. It was found that the top heater can effectively reduce the axial temperature gradient, and the side heater 2 has a similar effect on the axial gradient, but the effect feedback is slightly weaker. The axial temperature gradient tends to increase when the bottom heater is added to the furnace, and the adjustable range of the axial temperature gradient of the side 1 heater + bottom heater mode is the largest. Our work will provide important reference values for AlN crystal growth by the resistance method.
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http://dx.doi.org/10.3390/ma14237441 | DOI Listing |
Background/objective: Little is known about the rates of rheumatic disease diagnosis among children during the COVID-19 pandemic. We examined the impact of the pandemic on the diagnosis of juvenile idiopathic arthritis (JIA) in the United States.
Methods: We performed a historical cohort study using US commercial insurance data (2016-2021) to identify children aged <18 years without prior JIA diagnosis or treatment in the prior ≥12 months.
ACS Appl Mater Interfaces
December 2024
Faculty of Chemical and Process Engineering, Warsaw University of Technology, Waryńskiego 1, 00-645 Warsaw, Poland.
The optical centers in AlN can frequently exist in various charge states and can be accompanied by many coexisting defect species, creating a complex environment where mutual interactions are inevitable. Therefore, it is an immediate quest to design AlN crystal growth protocols that can target a specific optical center of interest and tune its concentration while preventing the formation of other unwanted point defects. Here, we provide a powerful workflow for point defect engineering in wide band gap, binary semiconductors that can be readily used to design optimal crystal growth protocols through combining CALPHAD-based phase analysis, and defect calculations.
View Article and Find Full Text PDFJ Environ Manage
January 2025
Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, Zhejiang Engineering Research Center of Non-Ferrous Metal Waste Recycling, School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310012, China. Electronic address:
Ammonia (NH), as a hydrogen energy carrier, is advantageous for mitigating energy consumption and carbon emission; however, the current Haber process for NH synthesis requires harsh conditions with a low conversion rate. To address these challenges, chemical looping ammonia synthesis (CLAS) has been proposed for utilizing aluminum dross (AD)-a hazardous waste containing sufficient active Al and N as a nitrogen carrier-involving carbon conversion without emissions. AD samples were employed to investigate the performance of CLAS, and the evolution of nitrogen carrier.
View Article and Find Full Text PDFPhys Chem Chem Phys
December 2024
Advanced Research Institute of Multidisciplinary Sciences, Qufu Normal University, Qufu, Shandong Province, 273165, China.
Microsyst Nanoeng
November 2024
The Institute of Technological Sciences, Hubei Key Laboratory of Electronic Manufacturing and Packaging Integration, Wuhan University, 430072, Wuhan, China.
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