In the present work,the turbulent mixing process of a polydisperse quartz particle flow with a plasma stream generated by a radio-frequency(RF)inductively coupled plasma torch was numerically studied.The thermobaric s...In the present work,the turbulent mixing process of a polydisperse quartz particle flow with a plasma stream generated by a radio-frequency(RF)inductively coupled plasma torch was numerically studied.The thermobaric stress in the quartz particles under dynamic heating in a heterogeneous plasma flow was determined by a two-stage approximation approach.The effect of the presence of vacuoles in natural quartz on the particle thermobaric destruction conditions was studied.It was found that the equivalent thermal and baric stresses in quartz particles may significantly increase in the presence of vacuoles within a small gas volume fraction.The influence of the regime and energetic working conditions of an RF inductively coupled plasma torch system on the particle thermobaric destruction conditions was examined,and a recommendation was given to promote the degree of thermobaric destruction of quartz particles,which is of substantial importance for improving the overall enrichment efficiency of quartz concentrates.展开更多
In thermal-structural testing of hypersonic materials and structures,deformation measurement on the front surface of an object directly heated by quartz lamps is highly necessary and very challenging.This work describ...In thermal-structural testing of hypersonic materials and structures,deformation measurement on the front surface of an object directly heated by quartz lamps is highly necessary and very challenging.This work describes a novel front-surface high-temperature deformation measurement technique,which adopts ultraviolet 3D digital image correlation(UV 3D-DIC)to observe and measure the high-temperature deformation fields on front surfaces directly heated by quartz lamps.Compared with existing blue light DIC techniques,the established UV 3D-DIC,which combines UV CCD camera,active UV illumination and bandpass filter imaging,can effectively suppress the strong disturbing light emitted by the quartz lamps and the heated sample itself during heating process.Two experiments were carried out to verify the robustness and accuracy of the developed technique:(1)direct observation of front surfaces of a hypersonic thermal structure sample heated from room temperature to 1050℃,and(2)front-surface thermal stain and coefficient of thermal expansion(CTE)measurement of an Inconel 718 sample up to 800℃.The well matched strain and CTE results with literature data show that UV 3D-DIC system is an effective technique for front-surface deformation measurement and has great potential in characterizing deformation response of hypersonic materials and structures subjected to transient aerodynamic heating.展开更多
Quartz crystal has good thermoluminescence (TL) properties which are closely related to the type, dose, method of radiation, and heating conditions before determination. Different TL peaks in the glow curve of quartz ...Quartz crystal has good thermoluminescence (TL) properties which are closely related to the type, dose, method of radiation, and heating conditions before determination. Different TL peaks in the glow curve of quartz are displayed by different types of quartz owing to their much varied environmental influences. Therefore, it is important both in methodological research and in practice to understand first the展开更多
In 1976 a new iron silicate named Laihunite was first discovered in the Archaean metamorphic iron deposits in Liaoning Province, China, and has been studied since then by many authors. Another ferrifayalite, occurring...In 1976 a new iron silicate named Laihunite was first discovered in the Archaean metamorphic iron deposits in Liaoning Province, China, and has been studied since then by many authors. Another ferrifayalite, occurring in metamorphic rocks in Hebei Province and differing from Laihunite in chemical composition, was found展开更多
The determination of thermophysical properties of rocks is a basic experimental means both in theoretical and in applied geothermal researches. Since the installation of the Geotherm-I Model steady-state rock thermal ...The determination of thermophysical properties of rocks is a basic experimental means both in theoretical and in applied geothermal researches. Since the installation of the Geotherm-I Model steady-state rock thermal conductivity meter of parallel-plate type in 1976, our geothermal lab has provided more than 2000 rock thermal conductivity values. To further extend the measurements to loose, weakly cemented, water-saturated porous展开更多
The 2,2,6,6-tetramethylpiperidine nitroxide radicals have been receiving more and more attention from people owing to their thermal stability and application for protecting polymer materials from photo-oxidation and p...The 2,2,6,6-tetramethylpiperidine nitroxide radicals have been receiving more and more attention from people owing to their thermal stability and application for protecting polymer materials from photo-oxidation and photo-degradation. In their EI mass spectra the relative intensity of the peak of the nitroxide radical with mass number (FW+1) is usually greater than that calculated according to its natural abundance of elemental composition of the FW peak, and sometimes even greater than that of the FW peak. Therefore, it was difficult to assign the formula weight (FW) of nitroxide radical by the EI method.展开更多
基金supported by National Natural Science Foundation of China(Nos.52202460,52177128)National Key R&D Program of China(Nos.2020YFC2201100,2021YFC2202804)+2 种基金China Postdoctoral Science Foundation(Nos.2021M690392,2021TQ0036)Science Foundation for Youth Scholars of the Beijing Institute of TechnologyAdvanced Space Propulsion Laboratory of BICE and the Beijing Engineering Research Centre of Efficient and Green Aerospace Propulsion Technology(No.LabASP-2021-04)。
文摘In the present work,the turbulent mixing process of a polydisperse quartz particle flow with a plasma stream generated by a radio-frequency(RF)inductively coupled plasma torch was numerically studied.The thermobaric stress in the quartz particles under dynamic heating in a heterogeneous plasma flow was determined by a two-stage approximation approach.The effect of the presence of vacuoles in natural quartz on the particle thermobaric destruction conditions was studied.It was found that the equivalent thermal and baric stresses in quartz particles may significantly increase in the presence of vacuoles within a small gas volume fraction.The influence of the regime and energetic working conditions of an RF inductively coupled plasma torch system on the particle thermobaric destruction conditions was examined,and a recommendation was given to promote the degree of thermobaric destruction of quartz particles,which is of substantial importance for improving the overall enrichment efficiency of quartz concentrates.
基金supported by the National Natural Science Foundation of China(Nos.11602011,11872009,and 11632010)the National S&T Major Project of China(No.ZX069)+1 种基金the Aeronautical Science Foundation of China(No.2016ZD51034)the Postdoctoral Science Foundation of China(No.2017M610029)。
文摘In thermal-structural testing of hypersonic materials and structures,deformation measurement on the front surface of an object directly heated by quartz lamps is highly necessary and very challenging.This work describes a novel front-surface high-temperature deformation measurement technique,which adopts ultraviolet 3D digital image correlation(UV 3D-DIC)to observe and measure the high-temperature deformation fields on front surfaces directly heated by quartz lamps.Compared with existing blue light DIC techniques,the established UV 3D-DIC,which combines UV CCD camera,active UV illumination and bandpass filter imaging,can effectively suppress the strong disturbing light emitted by the quartz lamps and the heated sample itself during heating process.Two experiments were carried out to verify the robustness and accuracy of the developed technique:(1)direct observation of front surfaces of a hypersonic thermal structure sample heated from room temperature to 1050℃,and(2)front-surface thermal stain and coefficient of thermal expansion(CTE)measurement of an Inconel 718 sample up to 800℃.The well matched strain and CTE results with literature data show that UV 3D-DIC system is an effective technique for front-surface deformation measurement and has great potential in characterizing deformation response of hypersonic materials and structures subjected to transient aerodynamic heating.
文摘Quartz crystal has good thermoluminescence (TL) properties which are closely related to the type, dose, method of radiation, and heating conditions before determination. Different TL peaks in the glow curve of quartz are displayed by different types of quartz owing to their much varied environmental influences. Therefore, it is important both in methodological research and in practice to understand first the
文摘In 1976 a new iron silicate named Laihunite was first discovered in the Archaean metamorphic iron deposits in Liaoning Province, China, and has been studied since then by many authors. Another ferrifayalite, occurring in metamorphic rocks in Hebei Province and differing from Laihunite in chemical composition, was found
文摘The determination of thermophysical properties of rocks is a basic experimental means both in theoretical and in applied geothermal researches. Since the installation of the Geotherm-I Model steady-state rock thermal conductivity meter of parallel-plate type in 1976, our geothermal lab has provided more than 2000 rock thermal conductivity values. To further extend the measurements to loose, weakly cemented, water-saturated porous
文摘The 2,2,6,6-tetramethylpiperidine nitroxide radicals have been receiving more and more attention from people owing to their thermal stability and application for protecting polymer materials from photo-oxidation and photo-degradation. In their EI mass spectra the relative intensity of the peak of the nitroxide radical with mass number (FW+1) is usually greater than that calculated according to its natural abundance of elemental composition of the FW peak, and sometimes even greater than that of the FW peak. Therefore, it was difficult to assign the formula weight (FW) of nitroxide radical by the EI method.
