The spinel LiNi_(0.5)Mn_(1.5)O_(4)(LNMO)has been attracted great attention as lithium ion cathode material due to its high voltage and large energy density.However,the practical application of LNMO is still limited by...The spinel LiNi_(0.5)Mn_(1.5)O_(4)(LNMO)has been attracted great attention as lithium ion cathode material due to its high voltage and large energy density.However,the practical application of LNMO is still limited by poor cycling stability.Herein,to improve the cycling stability of spinel LNMO,it was treated with anneal process at 900℃for 2 h after prepared by traditional solid-state method(LNMO-A).LNMO-A sample presented better electrochemical property especially under high rate,with capacity of 91.2 mAhg^(-1) after 1000 cycles under 10 C.Its superior electrochemical property was ascribed to the anneal process,resulting a stable crystal structure,indicated by XRD and Raman results of electrodes after 1000 cycles under 10 C and the longer solid-solution reaction,revealed by in-situ XRD.In addition,the optimized particle size,micro morphology and the larger BET area surface induced by the recrystallization in anneal process also contributes to its superior electrochemical property.What's more,the thin layer,which interacted LNMO-A particles with each other,induced by particles remelting in anneal process is also beneficial for its excellent electrochemical property.This study not only improved the electrochemical properties by anneal process,but also revealed the origins and mechanisms for its improvement.展开更多
The Ni9.3W alloy with no ferromagnetism and high yield strength is one of the most promising textured substrate materials for coated conductors, but its low stacking fault energy makes it difficult to obtain a strong ...The Ni9.3W alloy with no ferromagnetism and high yield strength is one of the most promising textured substrate materials for coated conductors, but its low stacking fault energy makes it difficult to obtain a strong cube texture by traditional rolling methods and recrystal- lization anneals. This paper introduces four-time static recoveries during the rolling process. Rolled tapes with 80 μm in thickness were obtained by applying various deformation sequences between static recoveries to study their effects on the cube texture formation in Ni9.3W alloy substrates. The results show that rising gradient deformation sequence is an advantageous way to obtain a higher amount of cube texture, its content increases by 29.2% compared to that of traditional deformation sequence. The effect of the new recrystallization annealing process on the cube texture formation was analyzed. It is shown that the cube texture content increases with anneal temperature increasing in one-step anneal, but decreases again at higher anneal temperature. Two-step anneal could effectively improve the cube texture content, which could be further enhanced by extending holding time during the first-step anneal. However, too long holding time leads to the decrease in cube texture content. Finally, Ni9.3W alloy substrates with a cube texture content of -90.0 vol% （〈15°） are obtained by optimized two-step anneal.展开更多
The effects of the annealing process on the mechanical properties and crystallization behaviors of polypropylene random copolymer（PP-R） composites were investigated using differential scanning calorimetry（DSC）, wi...The effects of the annealing process on the mechanical properties and crystallization behaviors of polypropylene random copolymer（PP-R） composites were investigated using differential scanning calorimetry（DSC）, wide-angle X-ray diffraction（WAXD）, and dynamic mechanical analysis（DMA）, and scanning electron microscopy（SEM）. The experimental results indicated that the annealing process significantly influenced the comprehensive properties of PP-R composites. At temperatures below 23 ℃, the impact strength of the PP-R composites annealed at 120 ℃ for 6 h was relatively high at 74.73 k J/m^2, which was 16.8% higher than that of the samples annealed at 80 ℃ for 6 h. At low temperatures（-30-0 ℃）, the impact strength ranged from approximately 13.31 k J/m^2 to 54.4 k J/m^2. In addition, the annealing process conducted at 120 ℃ for 6 h improved the crystalline structure and low-temperature toughness of the PP-R composites and induced α-form to β-form crystal transformation. The work provides a possible method to reinforce and toughen the semicrystalline polymer at low temperatures（-30-0 ℃） by annealing.展开更多
We investigated the effect of annealing process on microstructures and optical properties of the sol-gel derived Ba0.9Sr0.1TiO3 （BST） films. The BST films, fabricated by layer-by-layer high-temperature （≥ 650 ℃）...We investigated the effect of annealing process on microstructures and optical properties of the sol-gel derived Ba0.9Sr0.1TiO3 （BST） films. The BST films, fabricated by layer-by-layer high-temperature （≥ 650 ℃） annealing process, had laminated structures consisting of alternating dense and porous BST layers, and exhibited excellent optical performance as Bragg reflectors. The Bragg reflection characteristic can be enhanced with increasing annealing temperature. Those BST films fabricated at temperatures lower than 650 ℃ displayed uniform cross-sectional morphologies even treated at a higher temperature. The difference in the microstructures of the BST thin films was also discussed.展开更多
The annealing time is an important affecting factor in the performance of many furnaces.The present work deals with the transient simulation of annealing process in a cubic furnace in which a solid element is placed i...The annealing time is an important affecting factor in the performance of many furnaces.The present work deals with the transient simulation of annealing process in a cubic furnace in which a solid element is placed in its center.As the working gas can have some radiating features,a set of governing equations including the energy balance with the radiative transfer equation(RTE)for the gray radiating medium and the conduction equation inside the solid product are numerically solved with progressing in time.Numerical results which are validated against both analytical and theoretical findings in the literature demonstrate that during the starting period,a high rate of radiant energy transfers into the solid body even at small optical thickness.This behavior which hastens the rate of heat transfer at low values of the radiation conduction parameter,causes a fast annealing process in which the solid body warms up to its maximum temperature.Moreover,it is revealed that the rate of heat transfer is an increasing function of radiation-conduction parameter.展开更多
Ca0.4Sr0.6Bi3.95Nd0.05Ti4O15 （C0.4S0.6BNT） ferroelectric thin films were prepared on Pt/Ti/SiO2/Si substrates by sol-gel method. Effect of annealing process （time and temperature） on structures and ferroelectric p...Ca0.4Sr0.6Bi3.95Nd0.05Ti4O15 （C0.4S0.6BNT） ferroelectric thin films were prepared on Pt/Ti/SiO2/Si substrates by sol-gel method. Effect of annealing process （time and temperature） on structures and ferroelectric properties of C0.4S0.6BNT thin film was investigated. The relative intensity of （200） peak increased first then decreased with annealing temperature and became predominant at 800 ℃. In contrast, no evident change could be observed in the （001） peak. The remnant polarization （Pr） and coercive field （Ec） for C0.4S0.6BNT film annealed at 800℃ for 5 min were 21.6μC/cm2 and 68.3 kV/cm, respectively.展开更多
Portland cement is the most common type of cement in general use around the world as a basic ingredient of concrete, mortar, stucco, and non-speciality grout. Dicalcium silicate （Ca2SiO4） is the primary constituent ...Portland cement is the most common type of cement in general use around the world as a basic ingredient of concrete, mortar, stucco, and non-speciality grout. Dicalcium silicate （Ca2SiO4） is the primary constituent of a number of different types of cement. The β-Ca2SiO4 phase is metastable at room temperature and will transform into β-Ca2SiO4 at 663K. In this work, Portland cement is annealed at a temperature of 950K under pressures in the range of 0-5.5 CPa. The high pressure experiments are carried out in an apparatus with six anvil tops. The effect of high pressure on the obtaining nano-size β-Ca2SiO4 （C2S） process is investigated by x-ray diffraction and transmission electron microscopy. Experimental results show that the grain size of the C2S decreases with the increase of pressure. The volume fraction of the C2S phase increases with the pressure as the pressure is below 3 CPa, and then decreases （P 〉 3 GPa）. The nano-effect is very important to the stabilization of β-Ca2SiO4. The mechanism for the effects of the high pressure on the annealing process of the Portland cement is also discussed.展开更多
In this paper,the effect of different annealing processes on the microstructure,texture,and formability of ferritic stainless steel was studied in detail.The results showed that the grain size in the final sheet was l...In this paper,the effect of different annealing processes on the microstructure,texture,and formability of ferritic stainless steel was studied in detail.The results showed that the grain size in the final sheet was larger and the recrystallization texture was more uniform after the final recrystallization annealing of hot-rolled steel with continuous annealing than that without annealing or with batch annealing.In addition,the final sheet had a higher average r-value and the lowest planar anisotropy.展开更多
In this study,indium oxide（In2O3） thin-film transistors（TFTs） are fabricated by two kinds of low temperature solution-processed technologies（Ta ≤ 300℃）,i.e.,water-based（DIW-based） process and alkoxide-based...In this study,indium oxide（In2O3） thin-film transistors（TFTs） are fabricated by two kinds of low temperature solution-processed technologies（Ta ≤ 300℃）,i.e.,water-based（DIW-based） process and alkoxide-based（2-ME-based）process.The thickness values,crystallization properties,chemical structures,surface roughness values,and optical properties of In2O3 thin-films and the electrical characteristics of In2O3 TFTs are studied at different annealing temperatures.Thermal annealing at higher temperature leads to an increase in the saturation mobility（μsat） and a negative shift in the threshold voltage（VTH）.The DIW-based processed In2O3-TFT annealed at 300℃ exhibits excellent device performance,and one annealed at 200℃ exhibits an acceptable μsat of 0.86 cm^2/V·s comparable to that of a-Si：H TFTs,whereas the 2-ME-based TFT annealed at 300℃ exhibits an abundant μsat of 1.65 cm^2/Vs and one annealed at 200℃ is inactive.The results are attributed to the fact that the DIW-based process induces a higher degree of oxidation and less defect states than the 2-ME-based process at the same temperature.The DIW-based process for fabricating the In2O3 TFT opens the way for the development of nontoxic,low-cost,and low-temperature oxide electronics.展开更多
基金Natural Science Foundation of Shandong Province(ZR2018MEM017)。
文摘The spinel LiNi_(0.5)Mn_(1.5)O_(4)(LNMO)has been attracted great attention as lithium ion cathode material due to its high voltage and large energy density.However,the practical application of LNMO is still limited by poor cycling stability.Herein,to improve the cycling stability of spinel LNMO,it was treated with anneal process at 900℃for 2 h after prepared by traditional solid-state method(LNMO-A).LNMO-A sample presented better electrochemical property especially under high rate,with capacity of 91.2 mAhg^(-1) after 1000 cycles under 10 C.Its superior electrochemical property was ascribed to the anneal process,resulting a stable crystal structure,indicated by XRD and Raman results of electrodes after 1000 cycles under 10 C and the longer solid-solution reaction,revealed by in-situ XRD.In addition,the optimized particle size,micro morphology and the larger BET area surface induced by the recrystallization in anneal process also contributes to its superior electrochemical property.What's more,the thin layer,which interacted LNMO-A particles with each other,induced by particles remelting in anneal process is also beneficial for its excellent electrochemical property.This study not only improved the electrochemical properties by anneal process,but also revealed the origins and mechanisms for its improvement.
基金financially supported by the National Municipal Natural Science Foundation (Nos.51571002,51171002)the Beijing Municipal Natural Science Foundation (Nos.2132011,2172008)+2 种基金the Doctoral Program of Higher Education of Special Research Fund (No.20121103110012)Beijing Municipal Natural Science Foundation B Type(No.KZ201310005003)the Project of Construction of Innovative Teams and Teacher Career Development for Universities and Colleges under Beijing Municipality (No.IDHT20130510)
文摘The Ni9.3W alloy with no ferromagnetism and high yield strength is one of the most promising textured substrate materials for coated conductors, but its low stacking fault energy makes it difficult to obtain a strong cube texture by traditional rolling methods and recrystal- lization anneals. This paper introduces four-time static recoveries during the rolling process. Rolled tapes with 80 μm in thickness were obtained by applying various deformation sequences between static recoveries to study their effects on the cube texture formation in Ni9.3W alloy substrates. The results show that rising gradient deformation sequence is an advantageous way to obtain a higher amount of cube texture, its content increases by 29.2% compared to that of traditional deformation sequence. The effect of the new recrystallization annealing process on the cube texture formation was analyzed. It is shown that the cube texture content increases with anneal temperature increasing in one-step anneal, but decreases again at higher anneal temperature. Two-step anneal could effectively improve the cube texture content, which could be further enhanced by extending holding time during the first-step anneal. However, too long holding time leads to the decrease in cube texture content. Finally, Ni9.3W alloy substrates with a cube texture content of -90.0 vol% （〈15°） are obtained by optimized two-step anneal.
基金the Science and Technology Cooperation Program of Guizhou Province of China([2016]5673)the Excellent Youth and Science&Technology Talent Foundation of Guizhou Province of China([2015]29)
文摘The effects of the annealing process on the mechanical properties and crystallization behaviors of polypropylene random copolymer（PP-R） composites were investigated using differential scanning calorimetry（DSC）, wide-angle X-ray diffraction（WAXD）, and dynamic mechanical analysis（DMA）, and scanning electron microscopy（SEM）. The experimental results indicated that the annealing process significantly influenced the comprehensive properties of PP-R composites. At temperatures below 23 ℃, the impact strength of the PP-R composites annealed at 120 ℃ for 6 h was relatively high at 74.73 k J/m^2, which was 16.8% higher than that of the samples annealed at 80 ℃ for 6 h. At low temperatures（-30-0 ℃）, the impact strength ranged from approximately 13.31 k J/m^2 to 54.4 k J/m^2. In addition, the annealing process conducted at 120 ℃ for 6 h improved the crystalline structure and low-temperature toughness of the PP-R composites and induced α-form to β-form crystal transformation. The work provides a possible method to reinforce and toughen the semicrystalline polymer at low temperatures（-30-0 ℃） by annealing.
基金Funded by the National Natural Science Foundation of China(No.61106126)
文摘We investigated the effect of annealing process on microstructures and optical properties of the sol-gel derived Ba0.9Sr0.1TiO3 （BST） films. The BST films, fabricated by layer-by-layer high-temperature （≥ 650 ℃） annealing process, had laminated structures consisting of alternating dense and porous BST layers, and exhibited excellent optical performance as Bragg reflectors. The Bragg reflection characteristic can be enhanced with increasing annealing temperature. Those BST films fabricated at temperatures lower than 650 ℃ displayed uniform cross-sectional morphologies even treated at a higher temperature. The difference in the microstructures of the BST thin films was also discussed.
文摘The annealing time is an important affecting factor in the performance of many furnaces.The present work deals with the transient simulation of annealing process in a cubic furnace in which a solid element is placed in its center.As the working gas can have some radiating features,a set of governing equations including the energy balance with the radiative transfer equation(RTE)for the gray radiating medium and the conduction equation inside the solid product are numerically solved with progressing in time.Numerical results which are validated against both analytical and theoretical findings in the literature demonstrate that during the starting period,a high rate of radiant energy transfers into the solid body even at small optical thickness.This behavior which hastens the rate of heat transfer at low values of the radiation conduction parameter,causes a fast annealing process in which the solid body warms up to its maximum temperature.Moreover,it is revealed that the rate of heat transfer is an increasing function of radiation-conduction parameter.
基金supported by the Natural Science Foundation of Shandong Province (Y2007F36)the National Natural Science Foundation of China (50872075)
文摘Ca0.4Sr0.6Bi3.95Nd0.05Ti4O15 （C0.4S0.6BNT） ferroelectric thin films were prepared on Pt/Ti/SiO2/Si substrates by sol-gel method. Effect of annealing process （time and temperature） on structures and ferroelectric properties of C0.4S0.6BNT thin film was investigated. The relative intensity of （200） peak increased first then decreased with annealing temperature and became predominant at 800 ℃. In contrast, no evident change could be observed in the （001） peak. The remnant polarization （Pr） and coercive field （Ec） for C0.4S0.6BNT film annealed at 800℃ for 5 min were 21.6μC/cm2 and 68.3 kV/cm, respectively.
基金Supported by the National Natural Science Foundation of China under Grant No 11674274
文摘Portland cement is the most common type of cement in general use around the world as a basic ingredient of concrete, mortar, stucco, and non-speciality grout. Dicalcium silicate （Ca2SiO4） is the primary constituent of a number of different types of cement. The β-Ca2SiO4 phase is metastable at room temperature and will transform into β-Ca2SiO4 at 663K. In this work, Portland cement is annealed at a temperature of 950K under pressures in the range of 0-5.5 CPa. The high pressure experiments are carried out in an apparatus with six anvil tops. The effect of high pressure on the obtaining nano-size β-Ca2SiO4 （C2S） process is investigated by x-ray diffraction and transmission electron microscopy. Experimental results show that the grain size of the C2S decreases with the increase of pressure. The volume fraction of the C2S phase increases with the pressure as the pressure is below 3 CPa, and then decreases （P 〉 3 GPa）. The nano-effect is very important to the stabilization of β-Ca2SiO4. The mechanism for the effects of the high pressure on the annealing process of the Portland cement is also discussed.
基金funded by Shanghai Youth Science and Technology Development Star Project ( No. 15QB1400200)
文摘In this paper,the effect of different annealing processes on the microstructure,texture,and formability of ferritic stainless steel was studied in detail.The results showed that the grain size in the final sheet was larger and the recrystallization texture was more uniform after the final recrystallization annealing of hot-rolled steel with continuous annealing than that without annealing or with batch annealing.In addition,the final sheet had a higher average r-value and the lowest planar anisotropy.
基金Project supported by the National Natural Science Foundation of China(Grant No.61675024)the National Basic Research Program of China(Grant No.2014CB643600)
文摘In this study,indium oxide（In2O3） thin-film transistors（TFTs） are fabricated by two kinds of low temperature solution-processed technologies（Ta ≤ 300℃）,i.e.,water-based（DIW-based） process and alkoxide-based（2-ME-based）process.The thickness values,crystallization properties,chemical structures,surface roughness values,and optical properties of In2O3 thin-films and the electrical characteristics of In2O3 TFTs are studied at different annealing temperatures.Thermal annealing at higher temperature leads to an increase in the saturation mobility（μsat） and a negative shift in the threshold voltage（VTH）.The DIW-based processed In2O3-TFT annealed at 300℃ exhibits excellent device performance,and one annealed at 200℃ exhibits an acceptable μsat of 0.86 cm^2/V·s comparable to that of a-Si：H TFTs,whereas the 2-ME-based TFT annealed at 300℃ exhibits an abundant μsat of 1.65 cm^2/Vs and one annealed at 200℃ is inactive.The results are attributed to the fact that the DIW-based process induces a higher degree of oxidation and less defect states than the 2-ME-based process at the same temperature.The DIW-based process for fabricating the In2O3 TFT opens the way for the development of nontoxic,low-cost,and low-temperature oxide electronics.
