Because of its superior safety and excellent processability,solid polymer electrolytes(SPEs)have attracted widespread attention.In lithium based batteries,SPEs have great prospects in replacing leaky and flammable liq...Because of its superior safety and excellent processability,solid polymer electrolytes(SPEs)have attracted widespread attention.In lithium based batteries,SPEs have great prospects in replacing leaky and flammable liquid electrolytes.However,the low ionic conductivity of SPEs cannot meet the requirements of high energy density systems,which is also an important obstacle to its practical application.In this respect,escalating charge carriers(i.e.Li^(+))and Li^(+)transport paths are two major aspects of improving the ionic conductivity of SPEs.This article reviews recent advances from the two perspectives,and the underlying mechanism of these proposed strategies is discussed,including increasing the Li^(+)number and optimizing the Li^(+)transport paths through increasing the types and shortening the distance of Li^(+)transport path.It is hoped that this article can enlighten profound thinking and open up new ways to improve the ionic conductivity of SPEs.展开更多
A central research topic in condensed matter physics is the understanding of the evolution of various phases and phase transitions under different tuning parameters such as temperature, magnetic field and pressure. To...A central research topic in condensed matter physics is the understanding of the evolution of various phases and phase transitions under different tuning parameters such as temperature, magnetic field and pressure. To explore the pressure-induced evolution of the magnetism and Fermi surface of the heavy fermion antiferromagnet Yb Pt Bi, we performed tunnel diode oscillator based measurements under pressure at low temperatures in high magnetic fields. Our results reveal that the magnetic order strengthens and the Fermi surface shrinks as the pressure increases, which are consistent with typical observations for Yb-based heavy fermion compounds. In addition, an anomalous change in the quantum oscillation amplitudes is observed above 1.5 GPa, and determining the origin requires further study.展开更多
The purpose of this work is to investigate experimentally the pressure drop of drag-reducing polymer solutions in the fully developed flow region in a periodically sudden converging-diverging tube as well as in a stra...The purpose of this work is to investigate experimentally the pressure drop of drag-reducing polymer solutions in the fully developed flow region in a periodically sudden converging-diverging tube as well as in a straight tube.Testing fluids were aqueous polyacrylamide solutions with concentration ranged from 200 to 1400 w.p.p.m.,and the Reynolds number ranged from 5 x 103 to 7 x 104.Drag-reducing phenomenon is found to exist in the straight tube flow with the viscoelastic fluid,while in the periodically sudden converging-diverging tube the friction factor is insensitive to the concentration of solution展开更多
基金supported by the National Natural Science Foundation of China(51872196)the Natural Science Foundation of Tianjin,China(17JCJQJC44100)the National Postdoctoral Program for Innovative Talents,China(BX20190232)。
文摘Because of its superior safety and excellent processability,solid polymer electrolytes(SPEs)have attracted widespread attention.In lithium based batteries,SPEs have great prospects in replacing leaky and flammable liquid electrolytes.However,the low ionic conductivity of SPEs cannot meet the requirements of high energy density systems,which is also an important obstacle to its practical application.In this respect,escalating charge carriers(i.e.Li^(+))and Li^(+)transport paths are two major aspects of improving the ionic conductivity of SPEs.This article reviews recent advances from the two perspectives,and the underlying mechanism of these proposed strategies is discussed,including increasing the Li^(+)number and optimizing the Li^(+)transport paths through increasing the types and shortening the distance of Li^(+)transport path.It is hoped that this article can enlighten profound thinking and open up new ways to improve the ionic conductivity of SPEs.
基金supported by the National Key Research and Development Program of China(Grant No.2017YFA0303100)the National Natural Science Foundation of China(Grant Nos.11974306 and 12034017)the Natural Science Foundation of Zhejiang Province(Grant No.2021C01002)。
文摘A central research topic in condensed matter physics is the understanding of the evolution of various phases and phase transitions under different tuning parameters such as temperature, magnetic field and pressure. To explore the pressure-induced evolution of the magnetism and Fermi surface of the heavy fermion antiferromagnet Yb Pt Bi, we performed tunnel diode oscillator based measurements under pressure at low temperatures in high magnetic fields. Our results reveal that the magnetic order strengthens and the Fermi surface shrinks as the pressure increases, which are consistent with typical observations for Yb-based heavy fermion compounds. In addition, an anomalous change in the quantum oscillation amplitudes is observed above 1.5 GPa, and determining the origin requires further study.
文摘The purpose of this work is to investigate experimentally the pressure drop of drag-reducing polymer solutions in the fully developed flow region in a periodically sudden converging-diverging tube as well as in a straight tube.Testing fluids were aqueous polyacrylamide solutions with concentration ranged from 200 to 1400 w.p.p.m.,and the Reynolds number ranged from 5 x 103 to 7 x 104.Drag-reducing phenomenon is found to exist in the straight tube flow with the viscoelastic fluid,while in the periodically sudden converging-diverging tube the friction factor is insensitive to the concentration of solution
