To obtain high efficiency luminescent materials, the system Al2O3-B2O3 containing Ce3+ andTb3+ ions with variation of B2O3-content, has been prepared by Al2O3, H3BO3, CeO2 and Tb4O7 underreducing atmosphere at 1250i ....To obtain high efficiency luminescent materials, the system Al2O3-B2O3 containing Ce3+ andTb3+ ions with variation of B2O3-content, has been prepared by Al2O3, H3BO3, CeO2 and Tb4O7 underreducing atmosphere at 1250i . It is notable that the brightness of the sample with appropriatecomposition is similar to that of commercial phosphorous containing Ce3+ and Tb3+, indicating that a newhigh efficency green luminescent material was obtained with appropriate B2O3-content.展开更多
MnO-SiO_2-Al_2O_3-MnS oxysulfide system has been investigated by experimental phase diagram and activity measurement coupled with thermodynamic modeling.Phase equilibria of the MnO-MnS,MnO-SiO_2-MnS, MnO-Al_2O_3-MnS a...MnO-SiO_2-Al_2O_3-MnS oxysulfide system has been investigated by experimental phase diagram and activity measurement coupled with thermodynamic modeling.Phase equilibria of the MnO-MnS,MnO-SiO_2-MnS, MnO-Al_2O_3-MnS and MnO-SiO_2-Al_2O_3-MnS systems under low oxygen partial pressure have been experimentally investigated for the temperature range of 1 185 to 1 500℃using equilibration and quenching techniques. Equilibrium phases were analyzed by scanning electron microscope,electron probe X-ray microanalysis(EPMA), and differential thermal analysis(DTA ).Phase diagrams were successfully constructed for the systems investigated.Two ternary compounds in the MnO-SiO_2-MnS system were found.Activities of MnO and MnS in MnO-SiO_2-Al_2O_3-MnS liquid oxysulfide solution from very low sulfur concentration to high sulfur concentration at solid MnS saturation were investigated employing gas/liquid/Pt - Mn alloy under controlled atmosphere at 1 500℃.As X(SiO_2)/(X(MnO) + X(SiO_2)) increases in liquid oxysulfide solution,activity coefficient of MnO decreases while that of MnS increases.As X(AlO_(1.5)) increases,the activity coefficient of MnS increases while no remarkable change was observed for the activity coefficient of MnO.Quantitative analysis of the thermodynamic properties of the oxysulfide solution as well as phase diagram of the system was also earned out by employing the Modified Quasichemical Model in the quadruplet approximation.In view of inclusion utilization for free - cutting steel,it might have an advantage to decrease the Al_2O_3 content and increase the MnO/SiO_2 ratio.展开更多
High-temperature experiments were carried out for the slag systems of“FeO”−SiO_(2)−CaO−Al_(2)O_(3)and“FeO”−SiO_(2)−CaO−MgO at 1200℃and p(O_(2))of 10^(−7)kPa.The equilibrated samples were quenched,and the phase co...High-temperature experiments were carried out for the slag systems of“FeO”−SiO_(2)−CaO−Al_(2)O_(3)and“FeO”−SiO_(2)−CaO−MgO at 1200℃and p(O_(2))of 10^(−7)kPa.The equilibrated samples were quenched,and the phase compositions were measured by electron probe microanalysis(EPMA).A series of pseudo-ternary and pseudo-binary phase diagrams are constructed to demonstrate their applications in copper smelting process and evaluation of the thermodynamic database.Spinel and tridymite are identified to be the major primary phases in the composition range related to the copper smelting slags.It is found that the operating window of the smelting slag is primarily determined by w_(Fe)/w_(SiO_(2))ratio in the slag.Both MgO and Al_(2)O_(3)in the slag reduce the operating window which requires extra fluxing agent to keep the slag to be fully liquid.Complex spinel solid solutions cause inaccurate predictions of the current thermodynamic database.展开更多
Understanding the phase equilibria of the Fe_(3)O_(4)-Cr_(2)O_(3)-CaO system is essential for the efficient recycling of stainless steel pickling sludge.The isothermal section of this system at 1473 K under oxygen par...Understanding the phase equilibria of the Fe_(3)O_(4)-Cr_(2)O_(3)-CaO system is essential for the efficient recycling of stainless steel pickling sludge.The isothermal section of this system at 1473 K under oxygen partial pressure of 0.15 Pa was investigated.Key experiments on the relevant binary systems were conducted using a combination of equilibrium-quenching techniques,X-ray diffraction,high-resolution transmission electron microscope,and electron probe microanalysis.These systems were rigorously assessed using the CALPHAD(CALculation of Phase Diagram)method,incorporating the present experimental data.The liquid phase was modeled using the ionic two-sublattice model,represented as(Ca^(2+),Cr^(3+),Fe^(2+))P(O_(2)^(-),Va,FeO_(1.5))Q,where Va represents vacancy,and P and Q denote the number of sites on the cation and anion sublattices,respectively.To ensure electroneutrality,the values of P and Q adjust according to the composition of the mixture.From this,the isothermal section of the Fe_(3)O_(4)-Cr_(2)O_(3)-CaO system at 1473 K under the specified oxygen partial pressure was obtained based on the thermodynamic parameters of the binary systems.The present experimental data and calculation results hold significant implications for the comprehensive recycling of stainless steel pickling sludge.展开更多
Aqueous Zn-N_(2)batteries with unique configuration are of potential for simultaneous N_(2)electro reduction and electricity generation,in which the electrocatalysts are critical for improving the NH_(3)yield and the ...Aqueous Zn-N_(2)batteries with unique configuration are of potential for simultaneous N_(2)electro reduction and electricity generation,in which the electrocatalysts are critical for improving the NH_(3)yield and the energy efficiency.Herein,a heterostructure Nb_(2)O_(5)/Nb_(2)CT_(x)with abundant exposed Nb active sites and tuned electron density has been synthesized by in situ formation and anchoring of Nb_(2)O_(5) nanoparticles on the surface of Nb_(2)CT_(x)MXene,which shows an enhanced N_(2)adsorption/activation capacity.The heterostructure Nb_(2)O_(5/)Nb_(2)CT_(x)was used as the cathode of Zn-N_(2)battery that can deliver a peak power density of 1.25 mW cm^(-2)in 1.0 M KOH and can continuously produce NH_(3)with a yield of3.62μg h^(-1)mg_(ca)^(t-1).The NH_(3)formed in the battery system can be easily collected as a net product without circulating the electrolyte.Moreover,the Nb_(2)O_(5/)Nb_(2)CT_(x)has a long durability,evidenced by 70 h of operation at-0.4 V vs.reversible hydrogen electrode,which is the highest among the MXene-based electrocatalysts reported thus far.This work may provide a new methodology based on Zn-N_(2)battery for sustainable and large-scale NH_(3)production with minimal energy consumption.展开更多
The formation characteristics of calcium aluminates in the CaO-Al2O3-SiO2 system with sodium oxide was investigated by XRD, SEM-EDS and DSC-TG technologies. The main phases in the clinker after sintering at 1350 °...The formation characteristics of calcium aluminates in the CaO-Al2O3-SiO2 system with sodium oxide was investigated by XRD, SEM-EDS and DSC-TG technologies. The main phases in the clinker after sintering at 1350 °C are 12CaO?7Al2O3, 2CaO?Al2O3?SiO2 and 2CaO?SiO2 when the mass ratio of Al2O3 to SiO2 is 3.0 and the molar ratio of CaO to Al2O3 is 1.0. The proportion of 12CaO?7Al2O3 increases with the increase of Na2O addition when the molar ratio of Na2O to Al2O3 is from 0 to 0.4, while the proportion of 2CaO?Al2O3?SiO2 decreases with the increase of Na2O addition. Na2O forms solid solution in 12CaO?7Al2O3, which increases the volume of elementary cell of 12CaO?7Al2O3. The formation temperature of 12CaO?7Al2O3 is decreased by 30 °C when the molar ratio of Na2O to Al2O3 increases from 0 to 0.4 determined by DSC. The alumina leaching property of clinker increases obviously with the increase of Na2O addition.展开更多
The effects of Fe2O3 content on the microstructure and mechanical properties of the CaO-Al2O3-SiO2 system were investigated by differential thermal analysis（DTA）, X-ray diffraction（XRD）, scanning electron microsc...The effects of Fe2O3 content on the microstructure and mechanical properties of the CaO-Al2O3-SiO2 system were investigated by differential thermal analysis（DTA）, X-ray diffraction（XRD）, scanning electron microscopy（SEM）, electron spin resonance（ESR）, and Mssbauer spectroscopy. The results show that the addition of Fe2O3 does not affect the main crystalline phase in the prepared glasses, but it reduces the crystallisation peak temperature, increases the crystallisation activation energy, and reduces the crystal granularity. The ESR results indicate that Fe2O3 can promote crystallization, as it leads to the phase separation of the CaO-Al2O3-SiO2 system due to axial distortion. Moreover, Fe2O3 alters the network structure of the CaO-Al2O3-SiO2 system, allowing Fe3＋ to enter octahedral sites that exhibit higher symmetry than tetrahedral sites. All of these factors are favourable to increasing the bending strength. The Mssbauer results reveal that there are two types of coordination for both Fe3＋ and Fe2＋ and the bending strength of the CaO-Al2O3-SiO2 system increases with the amount of six-coordinate Fe3＋. The increasing interaction between Fe3＋ and Fe2＋ can also enhance the bending strength of the CaO-Al2O3-SiO2 system. The microhardness of the CaO-Al2O3-SiO2 system was determined to be HV 896.9 and the bending strength to be 217 MPa under the heat treatment conditions of nucleation temperature of 700 °C and nucleation time of 2 h, crystallization temperature of 910 °C and crystallization time of 3 h.展开更多
文摘To obtain high efficiency luminescent materials, the system Al2O3-B2O3 containing Ce3+ andTb3+ ions with variation of B2O3-content, has been prepared by Al2O3, H3BO3, CeO2 and Tb4O7 underreducing atmosphere at 1250i . It is notable that the brightness of the sample with appropriatecomposition is similar to that of commercial phosphorous containing Ce3+ and Tb3+, indicating that a newhigh efficency green luminescent material was obtained with appropriate B2O3-content.
文摘MnO-SiO_2-Al_2O_3-MnS oxysulfide system has been investigated by experimental phase diagram and activity measurement coupled with thermodynamic modeling.Phase equilibria of the MnO-MnS,MnO-SiO_2-MnS, MnO-Al_2O_3-MnS and MnO-SiO_2-Al_2O_3-MnS systems under low oxygen partial pressure have been experimentally investigated for the temperature range of 1 185 to 1 500℃using equilibration and quenching techniques. Equilibrium phases were analyzed by scanning electron microscope,electron probe X-ray microanalysis(EPMA), and differential thermal analysis(DTA ).Phase diagrams were successfully constructed for the systems investigated.Two ternary compounds in the MnO-SiO_2-MnS system were found.Activities of MnO and MnS in MnO-SiO_2-Al_2O_3-MnS liquid oxysulfide solution from very low sulfur concentration to high sulfur concentration at solid MnS saturation were investigated employing gas/liquid/Pt - Mn alloy under controlled atmosphere at 1 500℃.As X(SiO_2)/(X(MnO) + X(SiO_2)) increases in liquid oxysulfide solution,activity coefficient of MnO decreases while that of MnS increases.As X(AlO_(1.5)) increases,the activity coefficient of MnS increases while no remarkable change was observed for the activity coefficient of MnO.Quantitative analysis of the thermodynamic properties of the oxysulfide solution as well as phase diagram of the system was also earned out by employing the Modified Quasichemical Model in the quadruplet approximation.In view of inclusion utilization for free - cutting steel,it might have an advantage to decrease the Al_2O_3 content and increase the MnO/SiO_2 ratio.
文摘High-temperature experiments were carried out for the slag systems of“FeO”−SiO_(2)−CaO−Al_(2)O_(3)and“FeO”−SiO_(2)−CaO−MgO at 1200℃and p(O_(2))of 10^(−7)kPa.The equilibrated samples were quenched,and the phase compositions were measured by electron probe microanalysis(EPMA).A series of pseudo-ternary and pseudo-binary phase diagrams are constructed to demonstrate their applications in copper smelting process and evaluation of the thermodynamic database.Spinel and tridymite are identified to be the major primary phases in the composition range related to the copper smelting slags.It is found that the operating window of the smelting slag is primarily determined by w_(Fe)/w_(SiO_(2))ratio in the slag.Both MgO and Al_(2)O_(3)in the slag reduce the operating window which requires extra fluxing agent to keep the slag to be fully liquid.Complex spinel solid solutions cause inaccurate predictions of the current thermodynamic database.
基金supports on the Project 52274306 from the National Natural Science Foundation of China are gratefully acknowledged.
文摘Understanding the phase equilibria of the Fe_(3)O_(4)-Cr_(2)O_(3)-CaO system is essential for the efficient recycling of stainless steel pickling sludge.The isothermal section of this system at 1473 K under oxygen partial pressure of 0.15 Pa was investigated.Key experiments on the relevant binary systems were conducted using a combination of equilibrium-quenching techniques,X-ray diffraction,high-resolution transmission electron microscope,and electron probe microanalysis.These systems were rigorously assessed using the CALPHAD(CALculation of Phase Diagram)method,incorporating the present experimental data.The liquid phase was modeled using the ionic two-sublattice model,represented as(Ca^(2+),Cr^(3+),Fe^(2+))P(O_(2)^(-),Va,FeO_(1.5))Q,where Va represents vacancy,and P and Q denote the number of sites on the cation and anion sublattices,respectively.To ensure electroneutrality,the values of P and Q adjust according to the composition of the mixture.From this,the isothermal section of the Fe_(3)O_(4)-Cr_(2)O_(3)-CaO system at 1473 K under the specified oxygen partial pressure was obtained based on the thermodynamic parameters of the binary systems.The present experimental data and calculation results hold significant implications for the comprehensive recycling of stainless steel pickling sludge.
基金supported by the National Natural Science Foundation of China(Nos.U24B20198,22308139,52071171,52202248)the Natural Science Foundation of Liaoning Province(2023-MS-140)+8 种基金the Key Research Project of Department of Education of Liaoning Province(LJKZZ20220015)the Australian Research Council(ARC)through Future Fellowship(FT210100298)Discovery Project(DP220100603)Linkage Project(LP210200504,LP220100088,LP230200897)the Industrial Transformation Research Hub(IH240100009)schemesthe Australian Government through the Cooperative Research Centres Projects(CRCPXIII000077)the Australian Renewable Energy Agency(ARENA)as part of ARENA’s Transformative Research Accelerating Commercialisation Program(TM021)European Commission’s Australia-Spain Network for Innovation and Research Excellence(AuSpire)the Foundation of State Key Laboratory of Clean and Efficient Coal Utilization,Taiyuan University of Technology(MJNYSKL202301)。
文摘Aqueous Zn-N_(2)batteries with unique configuration are of potential for simultaneous N_(2)electro reduction and electricity generation,in which the electrocatalysts are critical for improving the NH_(3)yield and the energy efficiency.Herein,a heterostructure Nb_(2)O_(5)/Nb_(2)CT_(x)with abundant exposed Nb active sites and tuned electron density has been synthesized by in situ formation and anchoring of Nb_(2)O_(5) nanoparticles on the surface of Nb_(2)CT_(x)MXene,which shows an enhanced N_(2)adsorption/activation capacity.The heterostructure Nb_(2)O_(5/)Nb_(2)CT_(x)was used as the cathode of Zn-N_(2)battery that can deliver a peak power density of 1.25 mW cm^(-2)in 1.0 M KOH and can continuously produce NH_(3)with a yield of3.62μg h^(-1)mg_(ca)^(t-1).The NH_(3)formed in the battery system can be easily collected as a net product without circulating the electrolyte.Moreover,the Nb_(2)O_(5/)Nb_(2)CT_(x)has a long durability,evidenced by 70 h of operation at-0.4 V vs.reversible hydrogen electrode,which is the highest among the MXene-based electrocatalysts reported thus far.This work may provide a new methodology based on Zn-N_(2)battery for sustainable and large-scale NH_(3)production with minimal energy consumption.
基金Projects(51174054,51104041)supported by the National Natural Science Foundation of China
文摘The formation characteristics of calcium aluminates in the CaO-Al2O3-SiO2 system with sodium oxide was investigated by XRD, SEM-EDS and DSC-TG technologies. The main phases in the clinker after sintering at 1350 °C are 12CaO?7Al2O3, 2CaO?Al2O3?SiO2 and 2CaO?SiO2 when the mass ratio of Al2O3 to SiO2 is 3.0 and the molar ratio of CaO to Al2O3 is 1.0. The proportion of 12CaO?7Al2O3 increases with the increase of Na2O addition when the molar ratio of Na2O to Al2O3 is from 0 to 0.4, while the proportion of 2CaO?Al2O3?SiO2 decreases with the increase of Na2O addition. Na2O forms solid solution in 12CaO?7Al2O3, which increases the volume of elementary cell of 12CaO?7Al2O3. The formation temperature of 12CaO?7Al2O3 is decreased by 30 °C when the molar ratio of Na2O to Al2O3 increases from 0 to 0.4 determined by DSC. The alumina leaching property of clinker increases obviously with the increase of Na2O addition.
基金Project(50974090)supported by the National Natural Science Foundation of ChinaProjects(JCYJ20140418182819155,JCYJ20130329113849606)supported by the Shenzhen Dedicated Funding of Strategic Emerging Industry Development Program,China
文摘The effects of Fe2O3 content on the microstructure and mechanical properties of the CaO-Al2O3-SiO2 system were investigated by differential thermal analysis（DTA）, X-ray diffraction（XRD）, scanning electron microscopy（SEM）, electron spin resonance（ESR）, and Mssbauer spectroscopy. The results show that the addition of Fe2O3 does not affect the main crystalline phase in the prepared glasses, but it reduces the crystallisation peak temperature, increases the crystallisation activation energy, and reduces the crystal granularity. The ESR results indicate that Fe2O3 can promote crystallization, as it leads to the phase separation of the CaO-Al2O3-SiO2 system due to axial distortion. Moreover, Fe2O3 alters the network structure of the CaO-Al2O3-SiO2 system, allowing Fe3＋ to enter octahedral sites that exhibit higher symmetry than tetrahedral sites. All of these factors are favourable to increasing the bending strength. The Mssbauer results reveal that there are two types of coordination for both Fe3＋ and Fe2＋ and the bending strength of the CaO-Al2O3-SiO2 system increases with the amount of six-coordinate Fe3＋. The increasing interaction between Fe3＋ and Fe2＋ can also enhance the bending strength of the CaO-Al2O3-SiO2 system. The microhardness of the CaO-Al2O3-SiO2 system was determined to be HV 896.9 and the bending strength to be 217 MPa under the heat treatment conditions of nucleation temperature of 700 °C and nucleation time of 2 h, crystallization temperature of 910 °C and crystallization time of 3 h.
