In order to control the accumulation of SiC ceramic particles on the wall of the rotating chamber in the frame of a dry granulation process,the effect of the wall reverse speed on the mixing process is investigated.In...In order to control the accumulation of SiC ceramic particles on the wall of the rotating chamber in the frame of a dry granulation process,the effect of the wall reverse speed on the mixing process is investigated.In particular,an Euler-Euler two-phase flow model is used to analyze the dynamics of both SiC particles and air.The numerical results show that by setting a certain reverse rotating speed of the rotating chamber,the accumulation of SiC particles on the wall can be improved,i.e.,their direction of motion in proximity to the wall can be changed and particles can be forced to re-join the granulation process.Experimental tests conducted to verify the reliability of the numerical findings,demonstrate that when the reverse rotating speed of the rotating chamber is 4 r/min,the sphericity of SiC particles in the rotating chamber is the highest and the fluidity is the best possible one.展开更多
This paper presents an innovative approach to reusing waste tile granules(TG) and ceramic polishing powder(PP) to produce high performance ceramic tiles.We studied formulations each with a TG mass fraction of 25.0% an...This paper presents an innovative approach to reusing waste tile granules(TG) and ceramic polishing powder(PP) to produce high performance ceramic tiles.We studied formulations each with a TG mass fraction of 25.0% and a different PP mass fraction between 1.0% and 7.0%.The formulations included a small amount of borax additive of a mass fracton between 0.2% and 1.2%.The effects of these industrial by-products on compressive strength,water absorption and microstructure of the new ceramic tiles were investigated.The results indicate that the compressive strength decreases and water absorption increases when TG with a mass fraction of 25.0% are added.Improvement of the compressive strength may be achieved when TG(up to 25.0%) and PP(up to 2.0%) are both used at the same time.In particular,the compressive strength improvement can be maximized and water absorption reduced when a borax additive of up to 0.5% is used as a flux.Scanning electron microscopy reveals that a certain amount of fine PP granules and a high content of fluxing oxides from borax avail the formation of glassy phase that fills up the pores in the new ceramic tiles,resulting in a dense product with high compressive strength and low water absorption.展开更多
Early research mainly studies the performance of TiO2 power condition.As a result of using power condition TiO2,its power is slight,not easy to precipitate,and creates another pollutants.Therefore,the ceramic granulat...Early research mainly studies the performance of TiO2 power condition.As a result of using power condition TiO2,its power is slight,not easy to precipitate,and creates another pollutants.Therefore,the ceramic granulated substance carrier material was used to prepare the TiO2 thin film to carry on the water treatment to obtain the good effect.The gangue of coal was used to make the ceramic granulated substance basis,then in a ceramic granulated basis place TiO2 thin film was painted,advancing together the running water processing experiment.The test result is as follows:The TOC content reduces by above 80%,and used to filter the material to be possible to replace at will,which has obtained good effect.In the testing,using the scanning electron microscope analyzer,carrying on the superficial appearance view to the TiO2 ceramic sand leach material to scratch,finally indicated,it has some turtle crack in the TiO2 ceramic granulated substance surface,has crystal boundary surface flaw,causes it to have bigger catalytic activity.展开更多
The zirconia ceramic ring was prepared using fused monoclinic zirconia as main starting material, adopting composite stabilizer of magnesia, yttria and calcium nitrate, and applying recombination technology of traditi...The zirconia ceramic ring was prepared using fused monoclinic zirconia as main starting material, adopting composite stabilizer of magnesia, yttria and calcium nitrate, and applying recombination technology of traditional refractories and ceramics. Effect of the preparation process on material properties was comparatively studied, and the microstructure and phase composition were analyzed. The results show that adopting the high-speed mixing granulation process and the appropriate heat treatment can realize the control on the phase composition and microstructure, the zirconia ceramic ring with good thermal shock resitance and mechanical properties can be prepared.展开更多
An advanced ceramic cutting tool material Al2O3/TiC/TiN (LTN) is developed by incorporation and dispersion of micro-scale TiC particle and nano-scale TiN particle in alumina matrix. With the optimal dispersing and f...An advanced ceramic cutting tool material Al2O3/TiC/TiN (LTN) is developed by incorporation and dispersion of micro-scale TiC particle and nano-scale TiN particle in alumina matrix. With the optimal dispersing and fabricating technology, this multi-scale and multi-phase nanocomposite ceramic tool material can get both higher flexural strength and fracture toughness than that of A1203/TiC (LZ) ceramic tool material without nano-scale TiN particle, especially the fracture toughness can reach to 7.8 MPa . m^0.5. The nano-scale TiN can lead to the grain fining effect and promote the sintering process to get a higher density. The coexisting transgranular and intergranular fracture mode induced by micro-scale TiC and nano-scale TiN, and the homogeneous and densified microstructure can result in a remarkable strengthening and toughening effect. The cutting performance and wear mechanisms of the advanced multi-scale and multi-phase nanocomposite ceramic cutting tool are researched.展开更多
This study focuses on the characterisation of strength, density, and size of granules produced in various scales of a high shear granulator. Calcium carbonate (Durca165) was used as the feed powder and aqueous polye...This study focuses on the characterisation of strength, density, and size of granules produced in various scales of a high shear granulator. Calcium carbonate (Durca165) was used as the feed powder and aqueous polyethylene glycol (PEG 4000) as the binder. The dried granules were analysed for their strength, density, size distribution, and wall make-up. Granules were produced in granulators with four scales, 1, 5, 50, and 250 L under three scale-up rules of constant tip speed, constant shear stress, and constant Froude number. The results show that regardless of equipment scale, increasing the impeller speed has a great effect on crushing strength and stress. The underlying cause is an increase in granule density due to more consolidation at higher impeller speeds. Wall make-up is significantly reduced to less than 5% as the scale is increased from 1 to 250 L. The results of this study corroborate our previous findings that the constant tip speed rule is the best criterion for scale-up of high shear granulators.展开更多
目的评价桑丹通络颗粒治疗阴虚血瘀证缺血性脑卒中恢复期的临床有效性与安全性。方法采用回顾性队列研究方法,通过湖南省中医药研究院附属医院门诊与住院病历系统收集2021年7月至2022年6月收治的缺血性脑卒中恢复期患者临床资料,选择应...目的评价桑丹通络颗粒治疗阴虚血瘀证缺血性脑卒中恢复期的临床有效性与安全性。方法采用回顾性队列研究方法,通过湖南省中医药研究院附属医院门诊与住院病历系统收集2021年7月至2022年6月收治的缺血性脑卒中恢复期患者临床资料,选择应用桑丹通络颗粒联合西医常规治疗的51例患者为暴露组,匹配仅应用西医常规治疗的102例患者为对照组,两组均治疗2周。比较治疗前后总有效率、美国国立卫生研究院卒中量表(National Institute of Health Stroke Scale,NIHSS)评分、日常生活活动能力(activity of daily living,ADL)评分、血脂水平、血液流变学指标和症状总积分等,并对所有患者治疗期间不良反应事件进行记录。结果暴露组临床总有效率84.31%,高于对照组的67.65%(P<0.05)。与治疗前比较,两组治疗后NIHSS、TC、LDL降低(P<0.01或P<0.05),且暴露组低于对照组(P<0.05);两组ADL升高(P<0.01),且暴露组高于对照组(P<0.01)。与治疗前比较,暴露组治疗后症状总积分、血液流变学各项指标降低(P<0.01或P<0.05),且暴露组低于对照组(P<0.01或P<0.05);HDL-C升高(P<0.01),且暴露组高于对照组(P<0.01)。结论桑丹通络颗粒联合西医常规治疗可明显改善阴虚血瘀证缺血性脑卒中恢复期患者症状,降低其神经缺损程度,改善血脂水平和血液流变学指标,有效提高其生存质量,疗效确切且安全稳定。因此,推测桑丹通络颗粒具有一定的临床应用与推广价值。展开更多
Ceramic Matrix Composite (CMC) turbine guide vanes possess multi-scale stress and strain with inhomogeneity at the microscopic scale. Given that the macroscopic distribution cannot reflect the microscopic stress flu...Ceramic Matrix Composite (CMC) turbine guide vanes possess multi-scale stress and strain with inhomogeneity at the microscopic scale. Given that the macroscopic distribution cannot reflect the microscopic stress fluctuation, the macroscopic method fails to meet the requirements of stress and strain analysis of CMC turbine guide vanes. Furthermore, the complete thermodynamic properties of 2D woven SiC/SiC-CMC cannot be obtained through experimentation, Accordingly, a method to calculate the thermodynamic properties of CMC and analyze multi-scale stress and strain of the turbine guide vanes should be established. In this study, the multi-scale thermodynamic analysis is investigated. The thermodynamic properties of Chemical Vapor Infiltration (CVI) pro- cessed SiC/SiC-CMC are predicted by a Representative Volume Element (RVE) model with porosity, leading to the result that the relative error between the calculated in-plane tensile modulus and the experimental value is 4.2%. The macroscopic response of a guide vane under given conditions is predicted. The relative error between the predicted strain on the trailing edge and the experimental value is 9.7%. The calculation of the stress distribution of micro-scale RVE shows that the maximum value of microscopic stress, which is located in the interlayer matrix, is more than 1.5 times that of macroscopic stress in the same direction and the microscopic stress distribution of the interlayer matrix is related to the pore distribution of the composite.展开更多
Abstract: Uniform Er3A15O12 spheres are of great value for fabricating optical ceramics. The highly monodisperse and size-controllable erbium aluminum garnet (EAG) precursors for transparent ceramics were successfu...Abstract: Uniform Er3A15O12 spheres are of great value for fabricating optical ceramics. The highly monodisperse and size-controllable erbium aluminum garnet (EAG) precursors for transparent ceramics were successfully synthesized through a new microwave process. The precursors constituted of ultrafine particles joining together by a hydroxyls formed compact network structure in the absence of SO42 , however, the morphologies of the precursors exhibited spheres with trace amount of SO42-. With manipulated programming of microwave irradiation parameters, narrow distributed particles of 40-50 nm were finally obtained by a separation of nu- cleation and nanocrystal growth. The mechanism behind the influence of microwave irradiation parameters on the growth of EAG precursors was preliminarily analysed. Easily dispersible and pure phase EAG were obtained at 950℃. The as-prepared EAG powders were used to fabricate transparent ceramics and transparent polycrystalline EAG ceramics were obtained under hydrogen furnace at 1750℃ for 8 h.展开更多
The photo bioreaction combined with flow and mass transfer is simulated with pore-scale lattice Boltzmann(LB) method, which is the scenario of a bioreactor filled with a porous granule immobilized photosynthetic bacte...The photo bioreaction combined with flow and mass transfer is simulated with pore-scale lattice Boltzmann(LB) method, which is the scenario of a bioreactor filled with a porous granule immobilized photosynthetic bacteria cells for hydrogen production. The quartet structure generation set(QSGS) is used to generate porous structure of the immobilized granule. The effects of porosity of the immobilized granule on flow and concentration fields as well as the hydrogen production performance are investigated. Higher porosity facilitates the substrate solution smoothly flowing through the porous granule with increasing velocity, and thus results in higher product concentration inside the immobilized granule. Additionally, the substrate consumption efficiency increases, while hydrogen yield slightly decreases with increasing porosity, and they tend to stable for the porosity larger than 0.5. Furthermore, the LB numerical results have a good agreement with the experimental results. It is demonstrated that the pore-scale LB simulation method coupling with QSGS is available to simulate the photo hydrogen production in the bioreactor with porous immobilized granules.展开更多
基金the National Natural Science Foundation of China(Grant No.51964022).
文摘In order to control the accumulation of SiC ceramic particles on the wall of the rotating chamber in the frame of a dry granulation process,the effect of the wall reverse speed on the mixing process is investigated.In particular,an Euler-Euler two-phase flow model is used to analyze the dynamics of both SiC particles and air.The numerical results show that by setting a certain reverse rotating speed of the rotating chamber,the accumulation of SiC particles on the wall can be improved,i.e.,their direction of motion in proximity to the wall can be changed and particles can be forced to re-join the granulation process.Experimental tests conducted to verify the reliability of the numerical findings,demonstrate that when the reverse rotating speed of the rotating chamber is 4 r/min,the sphericity of SiC particles in the rotating chamber is the highest and the fluidity is the best possible one.
基金Funded by a grant from the Key Technologies R & D Program of Guangzhou (No. 2004440003110013)
文摘This paper presents an innovative approach to reusing waste tile granules(TG) and ceramic polishing powder(PP) to produce high performance ceramic tiles.We studied formulations each with a TG mass fraction of 25.0% and a different PP mass fraction between 1.0% and 7.0%.The formulations included a small amount of borax additive of a mass fracton between 0.2% and 1.2%.The effects of these industrial by-products on compressive strength,water absorption and microstructure of the new ceramic tiles were investigated.The results indicate that the compressive strength decreases and water absorption increases when TG with a mass fraction of 25.0% are added.Improvement of the compressive strength may be achieved when TG(up to 25.0%) and PP(up to 2.0%) are both used at the same time.In particular,the compressive strength improvement can be maximized and water absorption reduced when a borax additive of up to 0.5% is used as a flux.Scanning electron microscopy reveals that a certain amount of fine PP granules and a high content of fluxing oxides from borax avail the formation of glassy phase that fills up the pores in the new ceramic tiles,resulting in a dense product with high compressive strength and low water absorption.
文摘Early research mainly studies the performance of TiO2 power condition.As a result of using power condition TiO2,its power is slight,not easy to precipitate,and creates another pollutants.Therefore,the ceramic granulated substance carrier material was used to prepare the TiO2 thin film to carry on the water treatment to obtain the good effect.The gangue of coal was used to make the ceramic granulated substance basis,then in a ceramic granulated basis place TiO2 thin film was painted,advancing together the running water processing experiment.The test result is as follows:The TOC content reduces by above 80%,and used to filter the material to be possible to replace at will,which has obtained good effect.In the testing,using the scanning electron microscope analyzer,carrying on the superficial appearance view to the TiO2 ceramic sand leach material to scratch,finally indicated,it has some turtle crack in the TiO2 ceramic granulated substance surface,has crystal boundary surface flaw,causes it to have bigger catalytic activity.
文摘The zirconia ceramic ring was prepared using fused monoclinic zirconia as main starting material, adopting composite stabilizer of magnesia, yttria and calcium nitrate, and applying recombination technology of traditional refractories and ceramics. Effect of the preparation process on material properties was comparatively studied, and the microstructure and phase composition were analyzed. The results show that adopting the high-speed mixing granulation process and the appropriate heat treatment can realize the control on the phase composition and microstructure, the zirconia ceramic ring with good thermal shock resitance and mechanical properties can be prepared.
基金Selected from Proceedings of the 7th International Conference on Frontiers of DesignManufacturing(ICFDM'2006)This project is supported by National Natural Science Foundation of China(No.50275086)the University of New South Wales Visiting Professorship Scheme,Australia.
文摘An advanced ceramic cutting tool material Al2O3/TiC/TiN (LTN) is developed by incorporation and dispersion of micro-scale TiC particle and nano-scale TiN particle in alumina matrix. With the optimal dispersing and fabricating technology, this multi-scale and multi-phase nanocomposite ceramic tool material can get both higher flexural strength and fracture toughness than that of A1203/TiC (LZ) ceramic tool material without nano-scale TiN particle, especially the fracture toughness can reach to 7.8 MPa . m^0.5. The nano-scale TiN can lead to the grain fining effect and promote the sintering process to get a higher density. The coexisting transgranular and intergranular fracture mode induced by micro-scale TiC and nano-scale TiN, and the homogeneous and densified microstructure can result in a remarkable strengthening and toughening effect. The cutting performance and wear mechanisms of the advanced multi-scale and multi-phase nanocomposite ceramic cutting tool are researched.
基金the EPSRC(Grant No.GR/S25029/01),Borax Europe Ltd.,Hosokawa Micron B.V.,Pfizer Global R&D,and Procter and Gamble for their financial support of this project
文摘This study focuses on the characterisation of strength, density, and size of granules produced in various scales of a high shear granulator. Calcium carbonate (Durca165) was used as the feed powder and aqueous polyethylene glycol (PEG 4000) as the binder. The dried granules were analysed for their strength, density, size distribution, and wall make-up. Granules were produced in granulators with four scales, 1, 5, 50, and 250 L under three scale-up rules of constant tip speed, constant shear stress, and constant Froude number. The results show that regardless of equipment scale, increasing the impeller speed has a great effect on crushing strength and stress. The underlying cause is an increase in granule density due to more consolidation at higher impeller speeds. Wall make-up is significantly reduced to less than 5% as the scale is increased from 1 to 250 L. The results of this study corroborate our previous findings that the constant tip speed rule is the best criterion for scale-up of high shear granulators.
文摘目的评价桑丹通络颗粒治疗阴虚血瘀证缺血性脑卒中恢复期的临床有效性与安全性。方法采用回顾性队列研究方法,通过湖南省中医药研究院附属医院门诊与住院病历系统收集2021年7月至2022年6月收治的缺血性脑卒中恢复期患者临床资料,选择应用桑丹通络颗粒联合西医常规治疗的51例患者为暴露组,匹配仅应用西医常规治疗的102例患者为对照组,两组均治疗2周。比较治疗前后总有效率、美国国立卫生研究院卒中量表(National Institute of Health Stroke Scale,NIHSS)评分、日常生活活动能力(activity of daily living,ADL)评分、血脂水平、血液流变学指标和症状总积分等,并对所有患者治疗期间不良反应事件进行记录。结果暴露组临床总有效率84.31%,高于对照组的67.65%(P<0.05)。与治疗前比较,两组治疗后NIHSS、TC、LDL降低(P<0.01或P<0.05),且暴露组低于对照组(P<0.05);两组ADL升高(P<0.01),且暴露组高于对照组(P<0.01)。与治疗前比较,暴露组治疗后症状总积分、血液流变学各项指标降低(P<0.01或P<0.05),且暴露组低于对照组(P<0.01或P<0.05);HDL-C升高(P<0.01),且暴露组高于对照组(P<0.01)。结论桑丹通络颗粒联合西医常规治疗可明显改善阴虚血瘀证缺血性脑卒中恢复期患者症状,降低其神经缺损程度,改善血脂水平和血液流变学指标,有效提高其生存质量,疗效确切且安全稳定。因此,推测桑丹通络颗粒具有一定的临床应用与推广价值。
文摘Ceramic Matrix Composite (CMC) turbine guide vanes possess multi-scale stress and strain with inhomogeneity at the microscopic scale. Given that the macroscopic distribution cannot reflect the microscopic stress fluctuation, the macroscopic method fails to meet the requirements of stress and strain analysis of CMC turbine guide vanes. Furthermore, the complete thermodynamic properties of 2D woven SiC/SiC-CMC cannot be obtained through experimentation, Accordingly, a method to calculate the thermodynamic properties of CMC and analyze multi-scale stress and strain of the turbine guide vanes should be established. In this study, the multi-scale thermodynamic analysis is investigated. The thermodynamic properties of Chemical Vapor Infiltration (CVI) pro- cessed SiC/SiC-CMC are predicted by a Representative Volume Element (RVE) model with porosity, leading to the result that the relative error between the calculated in-plane tensile modulus and the experimental value is 4.2%. The macroscopic response of a guide vane under given conditions is predicted. The relative error between the predicted strain on the trailing edge and the experimental value is 9.7%. The calculation of the stress distribution of micro-scale RVE shows that the maximum value of microscopic stress, which is located in the interlayer matrix, is more than 1.5 times that of macroscopic stress in the same direction and the microscopic stress distribution of the interlayer matrix is related to the pore distribution of the composite.
基金supported by Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘Abstract: Uniform Er3A15O12 spheres are of great value for fabricating optical ceramics. The highly monodisperse and size-controllable erbium aluminum garnet (EAG) precursors for transparent ceramics were successfully synthesized through a new microwave process. The precursors constituted of ultrafine particles joining together by a hydroxyls formed compact network structure in the absence of SO42 , however, the morphologies of the precursors exhibited spheres with trace amount of SO42-. With manipulated programming of microwave irradiation parameters, narrow distributed particles of 40-50 nm were finally obtained by a separation of nu- cleation and nanocrystal growth. The mechanism behind the influence of microwave irradiation parameters on the growth of EAG precursors was preliminarily analysed. Easily dispersible and pure phase EAG were obtained at 950℃. The as-prepared EAG powders were used to fabricate transparent ceramics and transparent polycrystalline EAG ceramics were obtained under hydrogen furnace at 1750℃ for 8 h.
基金financial support provided by the State Key Program of National Natural Science of China (51136007)National Natural Science Funds for Distinguished Young Scholars (50825602)
文摘The photo bioreaction combined with flow and mass transfer is simulated with pore-scale lattice Boltzmann(LB) method, which is the scenario of a bioreactor filled with a porous granule immobilized photosynthetic bacteria cells for hydrogen production. The quartet structure generation set(QSGS) is used to generate porous structure of the immobilized granule. The effects of porosity of the immobilized granule on flow and concentration fields as well as the hydrogen production performance are investigated. Higher porosity facilitates the substrate solution smoothly flowing through the porous granule with increasing velocity, and thus results in higher product concentration inside the immobilized granule. Additionally, the substrate consumption efficiency increases, while hydrogen yield slightly decreases with increasing porosity, and they tend to stable for the porosity larger than 0.5. Furthermore, the LB numerical results have a good agreement with the experimental results. It is demonstrated that the pore-scale LB simulation method coupling with QSGS is available to simulate the photo hydrogen production in the bioreactor with porous immobilized granules.