In this study,the characteristics of azimuthally asymmetric equivalent potential temperature(θ_(e))distributions in the outer core of tropical cyclones(TCs)encountering weak and strong vertical wind shear are examine...In this study,the characteristics of azimuthally asymmetric equivalent potential temperature(θ_(e))distributions in the outer core of tropical cyclones(TCs)encountering weak and strong vertical wind shear are examined using a Lagrangian trajectory method.Evaporatively forced downdrafts in the outer rainbands can transport low-entropy air downward,resulting in the lowestθ_(e)in the downshear-left boundary layer.Quantitative estimations ofθ_(e)recovery indicate that air parcels,especially those originating from the downshear-left outer core,can gradually revive from a low entropy state through surface enthalpy fluxes as the parcels move cyclonically.As a result,the maximumθ_(e)is observed in the downshear-right quadrant of a highly sheared TC.The trajectory analyses also indicate that parcels that move upward in the outer rainbands and those that travel through the inner core due to shear make a dominant contribution to the midlevel enhancement ofθ_(e)in the downshear-left outer core.In particular,the former plays a leading role in suchθ_(e)enhancements,while the latter plays a secondary role.As a result,moist potential stability occurs in the middle-to-lower troposphere in the downshear-left outer core.展开更多
In perovskite solar cells(PSCs),the light-soaking effect,which means device performance changes obviously under continuous light illumination,is potentially harmful to loaded devices as well as accurately assessing th...In perovskite solar cells(PSCs),the light-soaking effect,which means device performance changes obviously under continuous light illumination,is potentially harmful to loaded devices as well as accurately assessing their efficiency.Herein,chemically stable tungsten trioxide(WO3)with high electron mobility is used as electron transport material in methylamine(MA)-free PSCs.However,the light-soaking effect is observed apparently in our devices.A fullerene derivative,C60 pyrrolidine Tris-acid(CPTA),is introduced to modify the interface between WO3 and perovskite(PVK)layers,which can bond with WO3 and PVK simultaneously,leading to the passivation of the defect and the suppression of trap-assisted nonradiative recombination.What is more,the introduction of CPTA can enhance the built-in electric field between WO3 and PVK layers,thereby facilitating the electron extraction and inhibiting the carrier accumulation at the interface.Consequently,the lightsoaking effect of WO3-based PSCs has been eliminated,and the power conversion efficiency has been boosted from 17.4%for control device to 20.5%for WO3/CPTA-based PSC with enhanced stability.This study gives guidance for the design of interfacial molecules to eliminate the light-soaking effect.展开更多
基金jointly supported by the National Key Research and Development Program of China under Grant No. 2017YFC1501601the National Natural Science Foundation of China under Grant Nos. 42175005 and 41875054
文摘In this study,the characteristics of azimuthally asymmetric equivalent potential temperature(θ_(e))distributions in the outer core of tropical cyclones(TCs)encountering weak and strong vertical wind shear are examined using a Lagrangian trajectory method.Evaporatively forced downdrafts in the outer rainbands can transport low-entropy air downward,resulting in the lowestθ_(e)in the downshear-left boundary layer.Quantitative estimations ofθ_(e)recovery indicate that air parcels,especially those originating from the downshear-left outer core,can gradually revive from a low entropy state through surface enthalpy fluxes as the parcels move cyclonically.As a result,the maximumθ_(e)is observed in the downshear-right quadrant of a highly sheared TC.The trajectory analyses also indicate that parcels that move upward in the outer rainbands and those that travel through the inner core due to shear make a dominant contribution to the midlevel enhancement ofθ_(e)in the downshear-left outer core.In particular,the former plays a leading role in suchθ_(e)enhancements,while the latter plays a secondary role.As a result,moist potential stability occurs in the middle-to-lower troposphere in the downshear-left outer core.
基金National Natural Science Foundation of China,Grant/Award Numbers:51925206,U1932214National Key Research and Development Program of China,Grant/Award Number:2017YFA0402800。
文摘In perovskite solar cells(PSCs),the light-soaking effect,which means device performance changes obviously under continuous light illumination,is potentially harmful to loaded devices as well as accurately assessing their efficiency.Herein,chemically stable tungsten trioxide(WO3)with high electron mobility is used as electron transport material in methylamine(MA)-free PSCs.However,the light-soaking effect is observed apparently in our devices.A fullerene derivative,C60 pyrrolidine Tris-acid(CPTA),is introduced to modify the interface between WO3 and perovskite(PVK)layers,which can bond with WO3 and PVK simultaneously,leading to the passivation of the defect and the suppression of trap-assisted nonradiative recombination.What is more,the introduction of CPTA can enhance the built-in electric field between WO3 and PVK layers,thereby facilitating the electron extraction and inhibiting the carrier accumulation at the interface.Consequently,the lightsoaking effect of WO3-based PSCs has been eliminated,and the power conversion efficiency has been boosted from 17.4%for control device to 20.5%for WO3/CPTA-based PSC with enhanced stability.This study gives guidance for the design of interfacial molecules to eliminate the light-soaking effect.
