The crystallization behavior and transparent property of MgO-A1203-SiO2 (MAS) glasses with TiO2 and TiO2+ZrO2 as nucleating agents were discussed by differential thermal analysis, X-ray diffraction, field emission-...The crystallization behavior and transparent property of MgO-A1203-SiO2 (MAS) glasses with TiO2 and TiO2+ZrO2 as nucleating agents were discussed by differential thermal analysis, X-ray diffraction, field emission-environment scanning electron microscope, energy dispersive spectrum and UV-VIS-NIR scanning spectrophotometer. It was found that the glass crystallized at 950 ℃ with ZrO2 less than 3% could obtain transparent glass ceramic, which presented purple to colorless. With the nucleating agent additives (5% TIO2+3% ZrO2), the colorless transparent glass-ceramics with spinel as the main crystal phase could be prepared, and the transmittance reached about 80%. As the crystallized temperature increase to 1 000 ℃, besides spinel(MgA1204), sapphirine (Mg3.5A19Si1.5O20) and ZrTiO4 precipitated from matrix glass, and the transmitance of glass-ceramic decreased.展开更多
The effect of a novel active nucleating agent(TBC8-eb) on the isothermal crystallization of poly(L-lactic acid) (PLLA) was studied by differential scanning calorimetry(DSC) and Fourier transform infrared spectroscopy(...The effect of a novel active nucleating agent(TBC8-eb) on the isothermal crystallization of poly(L-lactic acid) (PLLA) was studied by differential scanning calorimetry(DSC) and Fourier transform infrared spectroscopy(FTIR) . The analysis on kinetics demonstrates that TBC8-eb can not only accelerate the crystallization rate but also transform most of the original spherulite crystals of PLLA into sheaf-like crystals. Furthermore,the free energy of folding(σe) of PLLA and PLLA with TBC8-eb is 0.15 and 0.06 J·m-2,respectively,which suggests that the addition of TBC8-eb favors the regular folding of molecule chains in the crystallization of PLLA,improv-ing its crystallization rate. The FTIR results show that TBC8-eb can accelerate the conformational ordering of PLLA in the isothermal crystallization. The conformational ordering of PLLA nucleated with TBC8-eb begins with the interchain interaction of CH3,and then a short helix emerges where a couple of CH3 groups interact.展开更多
It is deduced from thermodynamic relations and confirmed by experiment results that the nucleation rate and nucleation temperature of nucleating agents in the glass are dependent upon their melting entropy Delta S//m ...It is deduced from thermodynamic relations and confirmed by experiment results that the nucleation rate and nucleation temperature of nucleating agents in the glass are dependent upon their melting entropy Delta S//m melting temperature T//m and crystal - type transition in terms of some mathematical expressions. (Author abstract) 10 Refs.展开更多
The melting behavior of polypropylene (PP) and low ethylene content polypropylenecopolymer with and without nucleating agent samples crystallized under both isothermal and non-isothermal conditions were studied by Dif...The melting behavior of polypropylene (PP) and low ethylene content polypropylenecopolymer with and without nucleating agent samples crystallized under both isothermal and non-isothermal conditions were studied by Differential Scanning Calorimeter (DSC) and X-raydiffraction. Multiple melting behavior were observed depending on the existence of nucleatingagent and crystallization conditions. The observed phenomena have been discussed by the effect ofnucleating agent on perfection of crystal and the melting and recrystallization of imperfect crystalto a more perfect crystal during the heating process of samples.展开更多
Impregnation of isotactic polypropylene (iPP) with nucleating agent (NA21) using supercritical carbon dioxide as the swelling agent at different temperature and pressure and its non-isothermal crystallization kinetics...Impregnation of isotactic polypropylene (iPP) with nucleating agent (NA21) using supercritical carbon dioxide as the swelling agent at different temperature and pressure and its non-isothermal crystallization kinetics were investigated. The results showed that NA21 was dispersed at a nanometer-scale in the PP matrix, resulting in the formation of different typesof crystal phases of iPP and the enhancement of its mechanical properties.展开更多
The influence of aryl amide compounds(TMB)as b-nucleating agents, on the non-isothermal crystallization of a wood-flour/polypropylene composite(WF/PP)prepared by compression molding was investigated by wide-angle ...The influence of aryl amide compounds(TMB)as b-nucleating agents, on the non-isothermal crystallization of a wood-flour/polypropylene composite(WF/PP)prepared by compression molding was investigated by wide-angle X-ray diffraction and differential scanning calorimetry. TMB was proved to be an effective b-crystalline nucleating agent for WF/PP. The DSC data showed that the crystallization peak temperature(Tp) increased and the half-time(t1/2) decreased with the addition of TMB.Three theoretical models were used to analyze the nonisothermal crystallization process. The modified Avrami method and Mo method successfully explained the nonisothermal crystallization behavior of PP and its composites. Their activation energies for non-isothermal crystallization were determined basing on the Kissinger method.展开更多
A novel polypropylene random(PPR)composite materials with optimized properties was developed by addingβ-nucleating compound agents(rare earth complex WBG-2 and aryl amide derivative TMB-5)and ternary compound modifie...A novel polypropylene random(PPR)composite materials with optimized properties was developed by addingβ-nucleating compound agents(rare earth complex WBG-2 and aryl amide derivative TMB-5)and ternary compound modifier(TPE/WBG-2/CaCO_(3)).The effects of differentβ-nucleating agents and ternary compound modifier on the mechanical properties and crystallization behavior of PPR were analyzed.The results show that,compared with pure PPR materials,both WBG-2 and TMB-5 could significantly improve the impact strength of PPR.The crystallization temperature of PPR increased with the addition ofβ-nucleating agent.The modified PPR prepared with ternary compound modifier showed the most excellent comprehensive properties.展开更多
Glass ceramics was made by the one-time sintering method using the main raw material of iron tailings. On the basis of quaternary system of CaO-MgO-Al2O3-SiO2, using DTA, XRD and SEM, the effects of different nucleati...Glass ceramics was made by the one-time sintering method using the main raw material of iron tailings. On the basis of quaternary system of CaO-MgO-Al2O3-SiO2, using DTA, XRD and SEM, the effects of different nucleating agents and mixing amounts as well as heat treatment on the crystallization of railings glass ceramics were studied. The experimental results show that, nucleating agent and heat treatment are two necessary conditions for one-time sintering preparation of tailings glass ceramics namely, only adding nucleating agent or experiencing heat treatment, the quaternary system can not crystallize. The composite nucleating agent consisting of Cr2O3 and TiO2 can further lead to the crystallization of the CaO-MgO-A1203-SiO2 quaternary system at the lower temperature, with the major phase of diopside. In the range of mass content, 0%-4%, crystal intensity and crystal content grow. But when mass content is more than 4%, the crystal size will become coarser and the crystal distribution will be less regular. Different heat treatment regimes do not change the composition of the crystalline major phase in the glass ceramics crystallization of CaO-MgO-Al2O3-SiO2 system. In the range of 30-60 minutes, with the extension of nucleation and crystallization, crystallization degree enhanced, but if the holding time surpasses 60 minutes, the crystallization is worse.展开更多
The reference test methods are carried out parallelly, by means of chemical analysis, X-ray diffraction, differential scanning calorimetry-thermogravimetry, scanning electron microscopy and polarized optical microscop...The reference test methods are carried out parallelly, by means of chemical analysis, X-ray diffraction, differential scanning calorimetry-thermogravimetry, scanning electron microscopy and polarized optical microscope to study the formation of C4A3S in the presence and absence of nucleating agent. The results show that nucleating agent with high calcium and low heat consumption as tricalcium silicate (C3S) promotes the formation of C4A3S and increases desulfurization degree obviously. During calcining raw meals doped with C3S, the grain sizes of C4A3S are larger compared with that without C3S. And at the same calcining level, the mass loss and the heat consumption belonged to CaCO3 decomposition is reduced.展开更多
Glass-ceramics obtained from the electric arc furnace molten slag of incinerator fly ash was produced by applying nucleation and crystallization through heat treatment process. The effects of nucleating agent (TiO2 a...Glass-ceramics obtained from the electric arc furnace molten slag of incinerator fly ash was produced by applying nucleation and crystallization through heat treatment process. The effects of nucleating agent (TiO2 and Cr2O3) on the crystallization kinetics and heat treatment schedule of the slag were investigated. The results show that the nucleating agents changed the crystallization phase and morphology of the obtained glass-ceramics. The optimum heat treatment schedule of the glass with TiO2 was determined as nucleation at 952 K for 1.5 h and crystal growth at 1 258 K for 1.5 h, while those values with Cr203 were estimated at 971 K for 2 h and at 1 238 K for 2 h. TiO2 acting as nucleating agent could decrease the activation energy of the slag and shorten the total thermal treatment time in comparison with Cr2O3. The glass-ceramics obtained under the optimum heat treatment condition was environmentfriendly and had remarkable physical/mechanical properties and chemical durability.展开更多
Melatonin(N-acetyl-5-methoxytryptamine)is known as the hormone of darkness because it is synthesized at night and involved in regulating the circadian clock.The hormone is primarily synthesized by the vertebrate pinea...Melatonin(N-acetyl-5-methoxytryptamine)is known as the hormone of darkness because it is synthesized at night and involved in regulating the circadian clock.The hormone is primarily synthesized by the vertebrate pineal gland,but is ubiquitous among invertebrates,unicellular organisms,plants,and even cyanobacteria(Hattori and Suzuki,2024).Melatonin is well-conserved evolutionarily and possesses several physiological functions,such as immune response,bone and glucose metabolism,and memory formation besides regulating the circadian rhythm.展开更多
未来6G网络将内生支持通信和AI一体化服务,赋能丰富多彩的新业务,支撑社会高效可持续发展。为此,借鉴了IT行业AI Agent的应用范式,基于电信应用场景创新地提出了6G AI Agent技术框架的三大设计理念,包括多模型融合、定制化Agent和插件...未来6G网络将内生支持通信和AI一体化服务,赋能丰富多彩的新业务,支撑社会高效可持续发展。为此,借鉴了IT行业AI Agent的应用范式,基于电信应用场景创新地提出了6G AI Agent技术框架的三大设计理念,包括多模型融合、定制化Agent和插件式环境交互,并基于该理念构建了6G AI Agent技术框架。通过环境交互层、Agent引擎层、模型调度层、模型基座层交互协同,实现了自主环境感知、自主任务生成和自主执行任务的能力。此外,以移动网络的智能感知任务为例,探索了AI Agent的使用场景及价值,为AI新技术在电信领域发展提供了新的思路和技术支撑。展开更多
基金Funded by the National Natural Science Foundation of China(No.50472309)
文摘The crystallization behavior and transparent property of MgO-A1203-SiO2 (MAS) glasses with TiO2 and TiO2+ZrO2 as nucleating agents were discussed by differential thermal analysis, X-ray diffraction, field emission-environment scanning electron microscope, energy dispersive spectrum and UV-VIS-NIR scanning spectrophotometer. It was found that the glass crystallized at 950 ℃ with ZrO2 less than 3% could obtain transparent glass ceramic, which presented purple to colorless. With the nucleating agent additives (5% TIO2+3% ZrO2), the colorless transparent glass-ceramics with spinel as the main crystal phase could be prepared, and the transmittance reached about 80%. As the crystallized temperature increase to 1 000 ℃, besides spinel(MgA1204), sapphirine (Mg3.5A19Si1.5O20) and ZrTiO4 precipitated from matrix glass, and the transmitance of glass-ceramic decreased.
基金Supported by the National Natural Science Foundation of China (20876042) Program of Shanghai Subject Chief Scientist (10XD1401500) Research Fund for the Doctoral Program of Higher Education of China
文摘The effect of a novel active nucleating agent(TBC8-eb) on the isothermal crystallization of poly(L-lactic acid) (PLLA) was studied by differential scanning calorimetry(DSC) and Fourier transform infrared spectroscopy(FTIR) . The analysis on kinetics demonstrates that TBC8-eb can not only accelerate the crystallization rate but also transform most of the original spherulite crystals of PLLA into sheaf-like crystals. Furthermore,the free energy of folding(σe) of PLLA and PLLA with TBC8-eb is 0.15 and 0.06 J·m-2,respectively,which suggests that the addition of TBC8-eb favors the regular folding of molecule chains in the crystallization of PLLA,improv-ing its crystallization rate. The FTIR results show that TBC8-eb can accelerate the conformational ordering of PLLA in the isothermal crystallization. The conformational ordering of PLLA nucleated with TBC8-eb begins with the interchain interaction of CH3,and then a short helix emerges where a couple of CH3 groups interact.
文摘It is deduced from thermodynamic relations and confirmed by experiment results that the nucleation rate and nucleation temperature of nucleating agents in the glass are dependent upon their melting entropy Delta S//m melting temperature T//m and crystal - type transition in terms of some mathematical expressions. (Author abstract) 10 Refs.
文摘The melting behavior of polypropylene (PP) and low ethylene content polypropylenecopolymer with and without nucleating agent samples crystallized under both isothermal and non-isothermal conditions were studied by Differential Scanning Calorimeter (DSC) and X-raydiffraction. Multiple melting behavior were observed depending on the existence of nucleatingagent and crystallization conditions. The observed phenomena have been discussed by the effect ofnucleating agent on perfection of crystal and the melting and recrystallization of imperfect crystalto a more perfect crystal during the heating process of samples.
基金an International Cooperation Research Program,key project from National Science Foundation of China for multiscale methodology,SINOPEC supported fundamental research project,an Association Franco-Chinoise pour la Recherche Scientifique et Technique(AFCRST) supported project
文摘Impregnation of isotactic polypropylene (iPP) with nucleating agent (NA21) using supercritical carbon dioxide as the swelling agent at different temperature and pressure and its non-isothermal crystallization kinetics were investigated. The results showed that NA21 was dispersed at a nanometer-scale in the PP matrix, resulting in the formation of different typesof crystal phases of iPP and the enhancement of its mechanical properties.
基金financially supported by‘‘the Fundamental Research Funds for the Central Universities’’(2572015AB07)the Forestry Industry Research of China(No.201204802)the National Natural Science Foundation of China(No.31100425)
文摘The influence of aryl amide compounds(TMB)as b-nucleating agents, on the non-isothermal crystallization of a wood-flour/polypropylene composite(WF/PP)prepared by compression molding was investigated by wide-angle X-ray diffraction and differential scanning calorimetry. TMB was proved to be an effective b-crystalline nucleating agent for WF/PP. The DSC data showed that the crystallization peak temperature(Tp) increased and the half-time(t1/2) decreased with the addition of TMB.Three theoretical models were used to analyze the nonisothermal crystallization process. The modified Avrami method and Mo method successfully explained the nonisothermal crystallization behavior of PP and its composites. Their activation energies for non-isothermal crystallization were determined basing on the Kissinger method.
基金Funded by the Natural Science Foundation of Liaoning Province of China(No.20180550432)Natural Science Foundation for Young Doctoral Research(No.2020-BS-158)Basic Scientific Research Project of Colleges and Universities of Liaoning Provincial Department of Education(No.LJKQZ2021060)。
文摘A novel polypropylene random(PPR)composite materials with optimized properties was developed by addingβ-nucleating compound agents(rare earth complex WBG-2 and aryl amide derivative TMB-5)and ternary compound modifier(TPE/WBG-2/CaCO_(3)).The effects of differentβ-nucleating agents and ternary compound modifier on the mechanical properties and crystallization behavior of PPR were analyzed.The results show that,compared with pure PPR materials,both WBG-2 and TMB-5 could significantly improve the impact strength of PPR.The crystallization temperature of PPR increased with the addition ofβ-nucleating agent.The modified PPR prepared with ternary compound modifier showed the most excellent comprehensive properties.
基金Funded by The National Key Technology R & D Program of China for the 11th Five-Year Plan(2006BAJ04A04)
文摘Glass ceramics was made by the one-time sintering method using the main raw material of iron tailings. On the basis of quaternary system of CaO-MgO-Al2O3-SiO2, using DTA, XRD and SEM, the effects of different nucleating agents and mixing amounts as well as heat treatment on the crystallization of railings glass ceramics were studied. The experimental results show that, nucleating agent and heat treatment are two necessary conditions for one-time sintering preparation of tailings glass ceramics namely, only adding nucleating agent or experiencing heat treatment, the quaternary system can not crystallize. The composite nucleating agent consisting of Cr2O3 and TiO2 can further lead to the crystallization of the CaO-MgO-A1203-SiO2 quaternary system at the lower temperature, with the major phase of diopside. In the range of mass content, 0%-4%, crystal intensity and crystal content grow. But when mass content is more than 4%, the crystal size will become coarser and the crystal distribution will be less regular. Different heat treatment regimes do not change the composition of the crystalline major phase in the glass ceramics crystallization of CaO-MgO-Al2O3-SiO2 system. In the range of 30-60 minutes, with the extension of nucleation and crystallization, crystallization degree enhanced, but if the holding time surpasses 60 minutes, the crystallization is worse.
基金the National Natural Science Foundation of China (No. 50972116)
文摘The reference test methods are carried out parallelly, by means of chemical analysis, X-ray diffraction, differential scanning calorimetry-thermogravimetry, scanning electron microscopy and polarized optical microscope to study the formation of C4A3S in the presence and absence of nucleating agent. The results show that nucleating agent with high calcium and low heat consumption as tricalcium silicate (C3S) promotes the formation of C4A3S and increases desulfurization degree obviously. During calcining raw meals doped with C3S, the grain sizes of C4A3S are larger compared with that without C3S. And at the same calcining level, the mass loss and the heat consumption belonged to CaCO3 decomposition is reduced.
基金Supported by the National Natural Science Foundation of China(No.51378332 and No.20806051)Science and Technology Project of Housing and Urban-Rural Ministry(No.2014-K4-014)Chinese Postdoctoral Science Foundation(No.2013M530872)
文摘Glass-ceramics obtained from the electric arc furnace molten slag of incinerator fly ash was produced by applying nucleation and crystallization through heat treatment process. The effects of nucleating agent (TiO2 and Cr2O3) on the crystallization kinetics and heat treatment schedule of the slag were investigated. The results show that the nucleating agents changed the crystallization phase and morphology of the obtained glass-ceramics. The optimum heat treatment schedule of the glass with TiO2 was determined as nucleation at 952 K for 1.5 h and crystal growth at 1 258 K for 1.5 h, while those values with Cr203 were estimated at 971 K for 2 h and at 1 238 K for 2 h. TiO2 acting as nucleating agent could decrease the activation energy of the slag and shorten the total thermal treatment time in comparison with Cr2O3. The glass-ceramics obtained under the optimum heat treatment condition was environmentfriendly and had remarkable physical/mechanical properties and chemical durability.
基金supported by JSPS KAKENHI Grant Number JP22K11823 to AH and JP22J01508 to KW。
文摘Melatonin(N-acetyl-5-methoxytryptamine)is known as the hormone of darkness because it is synthesized at night and involved in regulating the circadian clock.The hormone is primarily synthesized by the vertebrate pineal gland,but is ubiquitous among invertebrates,unicellular organisms,plants,and even cyanobacteria(Hattori and Suzuki,2024).Melatonin is well-conserved evolutionarily and possesses several physiological functions,such as immune response,bone and glucose metabolism,and memory formation besides regulating the circadian rhythm.
文摘未来6G网络将内生支持通信和AI一体化服务,赋能丰富多彩的新业务,支撑社会高效可持续发展。为此,借鉴了IT行业AI Agent的应用范式,基于电信应用场景创新地提出了6G AI Agent技术框架的三大设计理念,包括多模型融合、定制化Agent和插件式环境交互,并基于该理念构建了6G AI Agent技术框架。通过环境交互层、Agent引擎层、模型调度层、模型基座层交互协同,实现了自主环境感知、自主任务生成和自主执行任务的能力。此外,以移动网络的智能感知任务为例,探索了AI Agent的使用场景及价值,为AI新技术在电信领域发展提供了新的思路和技术支撑。