Transforming materials with evolving microstructures is one of the most important classes of smart materials that have many potential technological applications, and an unconventional phase field approach based on the...Transforming materials with evolving microstructures is one of the most important classes of smart materials that have many potential technological applications, and an unconventional phase field approach based on the characteristic functions of transforming variants has been developed to simulate the formation and evolution of their microstructures. This approach is advantageous in its explicit material symmetry and energy well structure, minimal number of ma- terial coefficients, and easiness in coupling multiple physical processes and order parameters, and has been applied successfully to study the microstructures and macroscopic prop- erties of shape memory alloys, ferroelectrics, ferromagnetic shape memory alloys, and multiferroic magnetoelectric crys- tals and films with increased complexity. In this topical re- view, the formulation of this unconventional phase field approach will be introduced in details, and its applications to various transforming materials will be discussed. Some ex- amples of specific microstructures will also be presented.展开更多
In this paper, an in situ metallographic video system was used to study the morphology in Cu-Zn-Al shape memory alloy (SMA) during thermal cycling phase tmnsforma-tion. There are seven different types of martensite mo...In this paper, an in situ metallographic video system was used to study the morphology in Cu-Zn-Al shape memory alloy (SMA) during thermal cycling phase tmnsforma-tion. There are seven different types of martensite morphology in Cu-Zn-Al SMA,i.e. plate, spean bamboo, noose, round-spot, line and dot-like martensites. During transformation and inverse-transformation, the thermoelastic martensites were rising and falling, growing and shrinking, splitting and merping. The growth patterns of thermoelastic martensite were divided into three types: fast growing, very slow ex-pansion and uniform automatic growth. Automatic growth appeared when ageing at a temperature below Ms. The result, for the first time, coofirmed Olson and Cohen,s suggestion that thermoelastic martensite may be automatically grown when ageing be-low Ms. With increasing numbers of thermal cycling, both the memory recovery ratio (% )and memory recoverp degradation (%) degraded logarithmically. The degrada-tion was steep in the initial stage and then became more and more gradual in the middle and the final stages caused by the stabilisation of martensite. In the initial stage, vacancies assumed the controlling role, while dislocations took the major role in other stages. The martensite transformation caused the intedeces to become bent and blurmd, but with increasing cycling numbers, the movements of interface had the same degradation effects as the memory recovery ratio curves. Under these conditions, we also found the martensites on one side of the intedece became reorientated and par-allel to the intedece. It was therefore concluded that the movement degradation of the interface and the appearance of bamboo like martensite induced the degradation of two way shape memory effect (TWMP).展开更多
his paper deals with the phase trans formation of austenite to ferrite within the critical temperature region(between Ac1 and Ac3).The results show that the volume fraction of trans formation of ferrite formed isother...his paper deals with the phase trans formation of austenite to ferrite within the critical temperature region(between Ac1 and Ac3).The results show that the volume fraction of trans formation of ferrite formed isothermally from austenite is mainly varied with the austenitizing temperature.The higher the austenitizing temperature,the more volume fraction of the ferrite formed isothermally from austenite.Besides,the phase trans formation of austenite to ferrite within the critical temperature region was checked by austenitizing isothermal time.The volume fraction of ferrite formed isothermally from austenite within the critical temperature region for different isothermal time has heen examined experimen tally.The lglg(l-fv)-1 vs lgt relation does not follow the Avrami equation strictly and consists of two straight lines.展开更多
Nowadays,researchers are becoming increasingly concerned about developing a highly efficient emission free transportation and energy generation system for addressing the pressing issue of environmental crisis in the fo...Nowadays,researchers are becoming increasingly concerned about developing a highly efficient emission free transportation and energy generation system for addressing the pressing issue of environmental crisis in the form of pollution and climate change.The introduction of Electric Vehicles(EVs)solves the challenge of emission-free transportation while the necessity for decarbonized energy production is fulfilled by the installation and expansion of solar-powered Photovoltaic(PV)systems.Hence,this paper focuses on designing an effective PV based EV charging system that aids in stepping towards the achievement of a pollution free future.For overcoming the inherent intermittency associated with PV,a novel DC-DC converter is designed by integrating both Trans Z-source con-verter and Luo converter,which offers remarkable benefits of high conversion range,lesser voltage stress and excellent efficiency.A novel robust Lion Grey Wolf Optimized Proportional Integral(LGWO-PI)controller is designed for sig-nificantly strengthening the operation of the integrated converter in terms of peak overshoot,Total Harmonic Distortion(THD)and settling time.A 3’Voltage Source Inverter(VSI)is employed to convert the stable DC output from the PV sys-tem to AC,which is then used for driving the Brushless Direct Current Motor(BLDC)motor of EV.The speed of the BLDC is regulated using a PI controller.The BLDC motor gets the power supply from the grid during the unavailability of PV based power supply.The grid is integrated with the designed EV charging system through a 1’VSI and the process of grid voltage synchronization is carried out with the application of PI controller.The simulation for evaluating the operation of the presented EV charging system is done using MATLAB and the attained out-comes have validated that this introduced methodology delivers enhanced perfor-mance with optimal efficiency of 97.6%and lesser THD of 2.1%.展开更多
We propose a novel mechanism for the production of gravitational waves in the early Universe that originates from the relaxation processes induced by the QCD phase transition. While the energy density of the quark-glu...We propose a novel mechanism for the production of gravitational waves in the early Universe that originates from the relaxation processes induced by the QCD phase transition. While the energy density of the quark-gluon mean-field is monotonously decaying in real time, its pressure undergoes a series of violent oscillations at the characteristic QCD time scales that generate a primordial multi-peaked gravitational waves signal in the radio frequencies’ domain. The signal is an echo of the QCD phase transition that is accessible by planned measurements at the FAST and SKA telescopes.展开更多
Unsymmetrical dimesogenic compounds with cholesteryl and 4-（trans-4-n-alkylcyclohexyl）phenoxy parts were synthesized by condensation of cholester-3-yl 6-bromohexanoate with appropriate 4-（trans-4-n-alkylcyclohexyl...Unsymmetrical dimesogenic compounds with cholesteryl and 4-（trans-4-n-alkylcyclohexyl）phenoxy parts were synthesized by condensation of cholester-3-yl 6-bromohexanoate with appropriate 4-（trans-4-n-alkylcyclohexyl）- phenols. Structures and thermal phase behaviour of these dimesogenic compounds have been confirmed by IR, IH NMR, elemental analysis, DSC, polarity microscopy and XRD measurements. Their thermal phase behaviour was significantly different with that of other cholesterol-based dimesogens while they exhibited low and wide phase transition temperature.展开更多
The electrochemical behavior of ionizable drugs (Amitriptyline, Diphenhydramine and Trihexyphene- dyl) at the water/1,2-dichloroethane interface with the phase volume ratio (r = Vo/Vw) equal to 1 are investigated by c...The electrochemical behavior of ionizable drugs (Amitriptyline, Diphenhydramine and Trihexyphene- dyl) at the water/1,2-dichloroethane interface with the phase volume ratio (r = Vo/Vw) equal to 1 are investigated by cyclic voltammetry. The system is composed of an aqueous droplet supported at an Ag/AgCl disk electrode and it was covered with an organic solution. In this manner, a conventional three-electrode potentiostat can be used to study the ionizable drugs transfer process at a liquid/liquid interface. Physicochemical parameters such as the formal transfer potential, the Gibbs energy of transfer and the standard partition coefficients of the ionized forms of these drugs can be evaluated from cyclic voltammograms obtained. The obtained results have been summarized in ionic partition diagrams, which are a useful tool for predicting and interpreting the transfer mechanisms of ionizable drugs at the liquid/liquid interfaces and biological membranes.展开更多
trans 1,4 Polybutadiene(PTBD) was synthesized by rare earth catalyst system. The effect of electron radiation on phase transition from monoclinic phase to hexagonal phase was observed by TEM. Electron diffraction patt...trans 1,4 Polybutadiene(PTBD) was synthesized by rare earth catalyst system. The effect of electron radiation on phase transition from monoclinic phase to hexagonal phase was observed by TEM. Electron diffraction patterns of monoclinic phase, hexagonal phase and two coexistent phases were recorded. The mechanism of phase transition was also discussed in this paper.展开更多
基金supported by the NSF (DMR-1006194 and CMMI1100339)NSFC (10972189 and 11102175)NSC(100-2628-E-002-034-MY3)
文摘Transforming materials with evolving microstructures is one of the most important classes of smart materials that have many potential technological applications, and an unconventional phase field approach based on the characteristic functions of transforming variants has been developed to simulate the formation and evolution of their microstructures. This approach is advantageous in its explicit material symmetry and energy well structure, minimal number of ma- terial coefficients, and easiness in coupling multiple physical processes and order parameters, and has been applied successfully to study the microstructures and macroscopic prop- erties of shape memory alloys, ferroelectrics, ferromagnetic shape memory alloys, and multiferroic magnetoelectric crys- tals and films with increased complexity. In this topical re- view, the formulation of this unconventional phase field approach will be introduced in details, and its applications to various transforming materials will be discussed. Some ex- amples of specific microstructures will also be presented.
文摘In this paper, an in situ metallographic video system was used to study the morphology in Cu-Zn-Al shape memory alloy (SMA) during thermal cycling phase tmnsforma-tion. There are seven different types of martensite morphology in Cu-Zn-Al SMA,i.e. plate, spean bamboo, noose, round-spot, line and dot-like martensites. During transformation and inverse-transformation, the thermoelastic martensites were rising and falling, growing and shrinking, splitting and merping. The growth patterns of thermoelastic martensite were divided into three types: fast growing, very slow ex-pansion and uniform automatic growth. Automatic growth appeared when ageing at a temperature below Ms. The result, for the first time, coofirmed Olson and Cohen,s suggestion that thermoelastic martensite may be automatically grown when ageing be-low Ms. With increasing numbers of thermal cycling, both the memory recovery ratio (% )and memory recoverp degradation (%) degraded logarithmically. The degrada-tion was steep in the initial stage and then became more and more gradual in the middle and the final stages caused by the stabilisation of martensite. In the initial stage, vacancies assumed the controlling role, while dislocations took the major role in other stages. The martensite transformation caused the intedeces to become bent and blurmd, but with increasing cycling numbers, the movements of interface had the same degradation effects as the memory recovery ratio curves. Under these conditions, we also found the martensites on one side of the intedece became reorientated and par-allel to the intedece. It was therefore concluded that the movement degradation of the interface and the appearance of bamboo like martensite induced the degradation of two way shape memory effect (TWMP).
文摘his paper deals with the phase trans formation of austenite to ferrite within the critical temperature region(between Ac1 and Ac3).The results show that the volume fraction of trans formation of ferrite formed isothermally from austenite is mainly varied with the austenitizing temperature.The higher the austenitizing temperature,the more volume fraction of the ferrite formed isothermally from austenite.Besides,the phase trans formation of austenite to ferrite within the critical temperature region was checked by austenitizing isothermal time.The volume fraction of ferrite formed isothermally from austenite within the critical temperature region for different isothermal time has heen examined experimen tally.The lglg(l-fv)-1 vs lgt relation does not follow the Avrami equation strictly and consists of two straight lines.
文摘Nowadays,researchers are becoming increasingly concerned about developing a highly efficient emission free transportation and energy generation system for addressing the pressing issue of environmental crisis in the form of pollution and climate change.The introduction of Electric Vehicles(EVs)solves the challenge of emission-free transportation while the necessity for decarbonized energy production is fulfilled by the installation and expansion of solar-powered Photovoltaic(PV)systems.Hence,this paper focuses on designing an effective PV based EV charging system that aids in stepping towards the achievement of a pollution free future.For overcoming the inherent intermittency associated with PV,a novel DC-DC converter is designed by integrating both Trans Z-source con-verter and Luo converter,which offers remarkable benefits of high conversion range,lesser voltage stress and excellent efficiency.A novel robust Lion Grey Wolf Optimized Proportional Integral(LGWO-PI)controller is designed for sig-nificantly strengthening the operation of the integrated converter in terms of peak overshoot,Total Harmonic Distortion(THD)and settling time.A 3’Voltage Source Inverter(VSI)is employed to convert the stable DC output from the PV sys-tem to AC,which is then used for driving the Brushless Direct Current Motor(BLDC)motor of EV.The speed of the BLDC is regulated using a PI controller.The BLDC motor gets the power supply from the grid during the unavailability of PV based power supply.The grid is integrated with the designed EV charging system through a 1’VSI and the process of grid voltage synchronization is carried out with the application of PI controller.The simulation for evaluating the operation of the presented EV charging system is done using MATLAB and the attained out-comes have validated that this introduced methodology delivers enhanced perfor-mance with optimal efficiency of 97.6%and lesser THD of 2.1%.
基金support by the NSFC(11875113)the Shanghai Municipality(KBH1512299)+5 种基金Fudan University(JJH1512105)supported by the Swedish Research Council,contract numbers 621-2013-428 and 2016-05996CONICYT grant MEC80170112(Chile)the European Research Council(ERC)under the European Union’s Horizon 2020 research and innovation programme(668679)supported in part by the Ministry of Education,Youth and Sports of the Czech Republic,project LT17018the framework of COST Action CA15213 “Theory of hot matter and relativistic heavy-ion collisions”(THOR)
文摘We propose a novel mechanism for the production of gravitational waves in the early Universe that originates from the relaxation processes induced by the QCD phase transition. While the energy density of the quark-gluon mean-field is monotonously decaying in real time, its pressure undergoes a series of violent oscillations at the characteristic QCD time scales that generate a primordial multi-peaked gravitational waves signal in the radio frequencies’ domain. The signal is an echo of the QCD phase transition that is accessible by planned measurements at the FAST and SKA telescopes.
基金Project supported by the National Natural Science Foundation of China （No. 20462001）.
文摘Unsymmetrical dimesogenic compounds with cholesteryl and 4-（trans-4-n-alkylcyclohexyl）phenoxy parts were synthesized by condensation of cholester-3-yl 6-bromohexanoate with appropriate 4-（trans-4-n-alkylcyclohexyl）- phenols. Structures and thermal phase behaviour of these dimesogenic compounds have been confirmed by IR, IH NMR, elemental analysis, DSC, polarity microscopy and XRD measurements. Their thermal phase behaviour was significantly different with that of other cholesterol-based dimesogens while they exhibited low and wide phase transition temperature.
文摘The electrochemical behavior of ionizable drugs (Amitriptyline, Diphenhydramine and Trihexyphene- dyl) at the water/1,2-dichloroethane interface with the phase volume ratio (r = Vo/Vw) equal to 1 are investigated by cyclic voltammetry. The system is composed of an aqueous droplet supported at an Ag/AgCl disk electrode and it was covered with an organic solution. In this manner, a conventional three-electrode potentiostat can be used to study the ionizable drugs transfer process at a liquid/liquid interface. Physicochemical parameters such as the formal transfer potential, the Gibbs energy of transfer and the standard partition coefficients of the ionized forms of these drugs can be evaluated from cyclic voltammograms obtained. The obtained results have been summarized in ionic partition diagrams, which are a useful tool for predicting and interpreting the transfer mechanisms of ionizable drugs at the liquid/liquid interfaces and biological membranes.
文摘trans 1,4 Polybutadiene(PTBD) was synthesized by rare earth catalyst system. The effect of electron radiation on phase transition from monoclinic phase to hexagonal phase was observed by TEM. Electron diffraction patterns of monoclinic phase, hexagonal phase and two coexistent phases were recorded. The mechanism of phase transition was also discussed in this paper.
