An effective regulation of the magnetism and interface of ferromagnetic materials is not only of great scientific significance,but also has an urgent need in modern industry.In this work,by using the first-principles ...An effective regulation of the magnetism and interface of ferromagnetic materials is not only of great scientific significance,but also has an urgent need in modern industry.In this work,by using the first-principles calculations,we demonstrate an effective approach to achieve non-volatile electrical control of ferromagnets,which proves this idea in multiferroic heterostructures of ferromagnetic La TiO_(3)and ferroelectric Bi FeO_(3).The results show that the magnetic properties and two-dimensional electron gas concentrations of La TiO_(3)films can be controlled by changing the polarization directions of Bi FeO_(3).The destroyed symmetry being introduced by ferroelectric polarization of the system leads to the transfer and reconstruction of the Ti-3 d electrons,which is the fundamental reason for the changing of magnetic properties.This multiferroic heterostructures will pave the way for non-volatile electrical control of ferromagnets and have potential applications.展开更多
BACKGROUND Swelling after apical microsurgery is a postoperative reaction and may reduce quality of life during healing.AIM To evaluate periapical swelling after apical microsurgery and determine potential risk factor...BACKGROUND Swelling after apical microsurgery is a postoperative reaction and may reduce quality of life during healing.AIM To evaluate periapical swelling after apical microsurgery and determine potential risk factors.METHODS Ninety-eight apical microsurgery patients were selected for this study.Before surgery,bone shadow volume and density of pathological tissue were measured by cone beam computed tomography.The other variables(age,gender,operative teeth number,fistula,preoperative swelling,drug use and preoperative root canal treatments)were assessed during examination.Swelling degree was confirmed by questionnaires for patients on postoperative days 1,7,14 and 21.Statistical analyses were performed to identify predictors for swelling.RESULTS Majority of patients reported moderate(45.9%)or severe(34.7%)swelling on day 1,and moderate(44.9%)or mild(45.9%)on postoperative day 7.Ninety-nine percent of patients had no or mild swelling on postoperative day 14.The average swelling level peaked on day 1 postoperatively and gradually decreased.Of statistical significance,age,bone shadow volume and density of pathological tissue acted as predictors of swelling(P<0.05).However,there was no significant difference in gender,tooth number,fistula,preoperative swelling,drug use,or preoperative root canal treatments(P>0.05).CONCLUSION Younger patients with larger shadow volume and density were significantly more likely to develop swelling after apical microsurgery.展开更多
Ti-stabilized 321 stainless steel was prepared using an electric arc furnace, argon oxygen decarburization (AOD) furnace, ladle furnace (LF), and continuous casting processes. In addition, the effect of refining proce...Ti-stabilized 321 stainless steel was prepared using an electric arc furnace, argon oxygen decarburization (AOD) furnace, ladle furnace (LF), and continuous casting processes. In addition, the effect of refining process and utilization of different slags on the evolution of inclusions, titanium yield, and oxygen content was systematically investigated by experimental and thermodynamic analysis. The results reveal that the total oxygen content (TO) and inclusion density decreased during the refining process. The spherical CaO–SiO2–Al2O3–MgO inclusions existed in the 321 stainless steel after the AOD process. Moreover, prior to the Ti addition, the spherical CaO–Al2O3–MgO–SiO2 inclusions were observed during LF refining pro-cess. However, Ti addition resulted in multilayer CaO–Al2O3–MgO–TiOx inclusions. Two different samples were prepared by conventional CaO–Al2O3-based slag (Heat-1) and -TiO2-rich CaO–Al2O3-based slag (Heat-2). The statistical analysis revealed that the density of inclusions and the -TiOx content in CaO–Al2O3–MgO–TiOx inclusions found in Heat-2 sample are much lower than those in the Heat-1 sample. Furthermore, the TO content and Ti yield during the LF refining process were controlled by using -TiO2-rich calcium aluminate synthetic slag. These results were consistent with the ion–molecule coexist-ence theory and FactSage?7.2 software calculations. When -TiO2-rich CaO–Al2O3-based slag was used, the -TiO2 activity of the slag increased, and the equilibrium oxygen content significantly decreased from the AOD to LF processes. Therefore, the higher -TiO2 activity of slag and lower equilibrium oxygen content suppressed the undesirable reactions between Ti and O.展开更多
A critical challenge for initiating many applications of the carbon nanotubes(CNTs) is their dispersion in organic solvent or in polymer melt. In the present study, we described a novel strategy for fabricating carbon...A critical challenge for initiating many applications of the carbon nanotubes(CNTs) is their dispersion in organic solvent or in polymer melt. In the present study, we described a novel strategy for fabricating carbon nanotubes(CNTs)-reinforced epoxy nanocomposite by utilizing aniline trimer(AT) as the noncovalent dispersant. Tensile testing showed that the tensile modulus of the CNTs-reinforced epoxy composites was considerably improved by adding a small amount of AT functionalized CNTs. Additionally, the as-prepared CNTs-epoxy nanocomposites exhibited superior tribological properties with much lower frictional coefficients and wear rates compared to those of neat epoxy resin. The well dispersed AT-functionalized CNTs in epoxy matrix played an important role in enhancing the mechanical properties, as well as acting as a solid lubricant for improving the tribological performance of epoxy/CNTs nanocomposite.展开更多
In this study, monoglycidyl silyl etherated eugenol(GSE) was synthesized as reactive epoxy diluent, and the chemical structure of GSE, intermediates, and products were characterized by Fourier transform infrared spect...In this study, monoglycidyl silyl etherated eugenol(GSE) was synthesized as reactive epoxy diluent, and the chemical structure of GSE, intermediates, and products were characterized by Fourier transform infrared spectroscopy(FTIR) and nuclear magnetic resonance(~1 H-NMR). GSE existed as a potential bio-based reactive diluent for petroleum-based epoxy resin. The curing kinetics of EP/HHPA/GSE system was studied by non-isothermal DSC method. The kinetics parameters were calculated by using the Kissinger model, Crane model, Ozawa model, and β-T(temperature-heating rate) extrapolation, respectively. In addition, the effects of GSE on the thermo-mechanical properties and thermal stability of EP/HHPA/GSE systems were studied, indicating that GSE can effectively improve the toughness and thermal decomposition temperature of the epoxy system.展开更多
基金the National Natural Science Foundation of China(Grant No.12047517)the International Cooperation Project of Science and Technology of Henan Province,China(Grant No.182102410096)+1 种基金the Natural Science Foundation of Henan Province,China(Grant No.202300410069)the China Postdoctoral Science Foundation(Grant Nos.2020M682274 and 2020TQ0089)。
文摘An effective regulation of the magnetism and interface of ferromagnetic materials is not only of great scientific significance,but also has an urgent need in modern industry.In this work,by using the first-principles calculations,we demonstrate an effective approach to achieve non-volatile electrical control of ferromagnets,which proves this idea in multiferroic heterostructures of ferromagnetic La TiO_(3)and ferroelectric Bi FeO_(3).The results show that the magnetic properties and two-dimensional electron gas concentrations of La TiO_(3)films can be controlled by changing the polarization directions of Bi FeO_(3).The destroyed symmetry being introduced by ferroelectric polarization of the system leads to the transfer and reconstruction of the Ti-3 d electrons,which is the fundamental reason for the changing of magnetic properties.This multiferroic heterostructures will pave the way for non-volatile electrical control of ferromagnets and have potential applications.
基金Supported by Natural Science Foundation of Zhejiang Province,China,No. LQ21H270001
文摘BACKGROUND Swelling after apical microsurgery is a postoperative reaction and may reduce quality of life during healing.AIM To evaluate periapical swelling after apical microsurgery and determine potential risk factors.METHODS Ninety-eight apical microsurgery patients were selected for this study.Before surgery,bone shadow volume and density of pathological tissue were measured by cone beam computed tomography.The other variables(age,gender,operative teeth number,fistula,preoperative swelling,drug use and preoperative root canal treatments)were assessed during examination.Swelling degree was confirmed by questionnaires for patients on postoperative days 1,7,14 and 21.Statistical analyses were performed to identify predictors for swelling.RESULTS Majority of patients reported moderate(45.9%)or severe(34.7%)swelling on day 1,and moderate(44.9%)or mild(45.9%)on postoperative day 7.Ninety-nine percent of patients had no or mild swelling on postoperative day 14.The average swelling level peaked on day 1 postoperatively and gradually decreased.Of statistical significance,age,bone shadow volume and density of pathological tissue acted as predictors of swelling(P<0.05).However,there was no significant difference in gender,tooth number,fistula,preoperative swelling,drug use,or preoperative root canal treatments(P>0.05).CONCLUSION Younger patients with larger shadow volume and density were significantly more likely to develop swelling after apical microsurgery.
基金The authors gratcfully acknowledge the sup-port of the National Natural Science Foundation of China(Grant No.51374020)the State Key Laboratory of Advanced Metallurgy at theUniversity of Science and Technology Beijing(USTB)the JiuquanIron and Steel Group Corporation.
文摘Ti-stabilized 321 stainless steel was prepared using an electric arc furnace, argon oxygen decarburization (AOD) furnace, ladle furnace (LF), and continuous casting processes. In addition, the effect of refining process and utilization of different slags on the evolution of inclusions, titanium yield, and oxygen content was systematically investigated by experimental and thermodynamic analysis. The results reveal that the total oxygen content (TO) and inclusion density decreased during the refining process. The spherical CaO–SiO2–Al2O3–MgO inclusions existed in the 321 stainless steel after the AOD process. Moreover, prior to the Ti addition, the spherical CaO–Al2O3–MgO–SiO2 inclusions were observed during LF refining pro-cess. However, Ti addition resulted in multilayer CaO–Al2O3–MgO–TiOx inclusions. Two different samples were prepared by conventional CaO–Al2O3-based slag (Heat-1) and -TiO2-rich CaO–Al2O3-based slag (Heat-2). The statistical analysis revealed that the density of inclusions and the -TiOx content in CaO–Al2O3–MgO–TiOx inclusions found in Heat-2 sample are much lower than those in the Heat-1 sample. Furthermore, the TO content and Ti yield during the LF refining process were controlled by using -TiO2-rich calcium aluminate synthetic slag. These results were consistent with the ion–molecule coexist-ence theory and FactSage?7.2 software calculations. When -TiO2-rich CaO–Al2O3-based slag was used, the -TiO2 activity of the slag increased, and the equilibrium oxygen content significantly decreased from the AOD to LF processes. Therefore, the higher -TiO2 activity of slag and lower equilibrium oxygen content suppressed the undesirable reactions between Ti and O.
基金financially supported by “One Hundred Talented People” of the Chinese Academy of Sciences(No.Y60707WR04)National Basic Research Program(973 Program,No.2015CB654705)Natural Science Foundation of Zhejiang Province(No.LY16B040004)
文摘A critical challenge for initiating many applications of the carbon nanotubes(CNTs) is their dispersion in organic solvent or in polymer melt. In the present study, we described a novel strategy for fabricating carbon nanotubes(CNTs)-reinforced epoxy nanocomposite by utilizing aniline trimer(AT) as the noncovalent dispersant. Tensile testing showed that the tensile modulus of the CNTs-reinforced epoxy composites was considerably improved by adding a small amount of AT functionalized CNTs. Additionally, the as-prepared CNTs-epoxy nanocomposites exhibited superior tribological properties with much lower frictional coefficients and wear rates compared to those of neat epoxy resin. The well dispersed AT-functionalized CNTs in epoxy matrix played an important role in enhancing the mechanical properties, as well as acting as a solid lubricant for improving the tribological performance of epoxy/CNTs nanocomposite.
基金the financial support provided by "One Hundred Talented People" of the Chinese Academy of Sciences–China (No. Y60707WR04)Natural Science Foundation of Zhejiang Province (No. Y16B040008)
文摘In this study, monoglycidyl silyl etherated eugenol(GSE) was synthesized as reactive epoxy diluent, and the chemical structure of GSE, intermediates, and products were characterized by Fourier transform infrared spectroscopy(FTIR) and nuclear magnetic resonance(~1 H-NMR). GSE existed as a potential bio-based reactive diluent for petroleum-based epoxy resin. The curing kinetics of EP/HHPA/GSE system was studied by non-isothermal DSC method. The kinetics parameters were calculated by using the Kissinger model, Crane model, Ozawa model, and β-T(temperature-heating rate) extrapolation, respectively. In addition, the effects of GSE on the thermo-mechanical properties and thermal stability of EP/HHPA/GSE systems were studied, indicating that GSE can effectively improve the toughness and thermal decomposition temperature of the epoxy system.
基金supported by the National Natural Science Foundation of China(Nos.30470763,81470931,and 31401188)the China Medical Board of New York(No.98-861)the Youth Foundation of Sichuan University(No.2014SCU11042),China
