Existing studies contend that latent heating(LH)will replace sensible heating(SH)to become the dominant factor affecting the development of the Tibetan Plateau vortex(TPV)after it moves off the Tibetan Plateau(TP).How...Existing studies contend that latent heating(LH)will replace sensible heating(SH)to become the dominant factor affecting the development of the Tibetan Plateau vortex(TPV)after it moves off the Tibetan Plateau(TP).However,in the process of the TPV moving off the TP requires that the airmass traverse the eastern slope of the Tibetan Plateau(ESTP)where the topography and diabatic heating(DH)conditions rapidly change.How LH gradually replaces SH to become the dominant factor in the development of the TPV over the ESTP is still not very clear.In this paper,an analysis of a typical case of a TPV with a long life history over the ESTP is performed by using multi-sourced meteorological data and model simulations.The results show that SH from the TP surface can change the TPV-associated precipitation distribution by temperature advection after the TPV moves off the TP.The LH can then directly promote the development of the TPV and has a certain guiding effect on the track of the TPV.The SH can control the active area of LH by changing the falling area of the TPV-associated precipitation,so it still plays a key role in the development and tracking of the TPV even though it has moved out of the main body of the TP.展开更多
The effect of heat treatment on microstructure,equilibrium hydrogen sorption pressure and plateau slope of LaNi_(3.8)Al_(0.75)Mn_(0.45) alloy was investigated.X-ray diffraction(XRD)analysis indicates that annealed all...The effect of heat treatment on microstructure,equilibrium hydrogen sorption pressure and plateau slope of LaNi_(3.8)Al_(0.75)Mn_(0.45) alloy was investigated.X-ray diffraction(XRD)analysis indicates that annealed alloys have single phase and the same hexagonal structure as that of LaNi_(5) alloy(CaCu_(5) type,P6/mmm).The cell parameters of alloys fluctuate with the increasing annealing temperature.The equilibrium hydrogen pressure and plateau slope are a parabola function with annealing temperature for LaNi_(3.8)Al_(0.75)Mn_(0.45) alloy.By this relationship,an appropriate heat treatment temperature for LaNi_(3.8)Al_(0.75)Mn_(0.45) alloy is determined to about 1220-1230 K by mathematic simulation process.However,the maximum hydrogen storage capacity of alloys does not affected by the annealing temperature.展开更多
The effect of Mn substitution on phase structure,hydrogen hydriding/dehydriding properties(plateau pressure and slope)and reaction heat enthalpy of LaNi_(4.25-x)Al_(0.75)Mn_(x)alloys(x=0,0.25,0.35,0.45,0.55 and 0.65)w...The effect of Mn substitution on phase structure,hydrogen hydriding/dehydriding properties(plateau pressure and slope)and reaction heat enthalpy of LaNi_(4.25-x)Al_(0.75)Mn_(x)alloys(x=0,0.25,0.35,0.45,0.55 and 0.65)were studied.The experimental results show that all LaNi_(4.25-x)Al_(0.75)Mn_(x)alloys have single phase and have the same hexagonal structure as that of LaNi5 alloy(CaCu_(5)type,P6/mmm).With increasing Mn substitution content,the cell parameters of LaNi_(4.25-x)Al_(0.75)Mn_(x)alloy greatly increase,but the maximum hydrogen storage capacity and the equilibrium absorption pressure of LaNi_(4.25-x)Al_(0.75)Mn_(x)alloy decrease from 1.38 wt.%to 1.18 wt.%and from 1.61 to 0.0712 MPa,respectively.Moreover,the hydrogen pressure plateau slope factorσincreases from 0.014 to 0.18,but the hysteresis factor is nearly constant.The heat enthalpy absolute value|ΔH_(plat)|increases from 46.7 kJ·mol^(-1)H2 to 56.1 kJ·mol^(-1)H_(2)as the Mn content x increases from 0 to 0.65.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.42175002,42030611,42075013)the Natural Science Foundation of Sichuan,China(Grant No.2023NSFSC0242)the Innovation Team Fund of Southwest Regional Meteorological Center,China Meteorological Administration(Grant No.XNQYCXTD-202202)。
文摘Existing studies contend that latent heating(LH)will replace sensible heating(SH)to become the dominant factor affecting the development of the Tibetan Plateau vortex(TPV)after it moves off the Tibetan Plateau(TP).However,in the process of the TPV moving off the TP requires that the airmass traverse the eastern slope of the Tibetan Plateau(ESTP)where the topography and diabatic heating(DH)conditions rapidly change.How LH gradually replaces SH to become the dominant factor in the development of the TPV over the ESTP is still not very clear.In this paper,an analysis of a typical case of a TPV with a long life history over the ESTP is performed by using multi-sourced meteorological data and model simulations.The results show that SH from the TP surface can change the TPV-associated precipitation distribution by temperature advection after the TPV moves off the TP.The LH can then directly promote the development of the TPV and has a certain guiding effect on the track of the TPV.The SH can control the active area of LH by changing the falling area of the TPV-associated precipitation,so it still plays a key role in the development and tracking of the TPV even though it has moved out of the main body of the TP.
文摘The effect of heat treatment on microstructure,equilibrium hydrogen sorption pressure and plateau slope of LaNi_(3.8)Al_(0.75)Mn_(0.45) alloy was investigated.X-ray diffraction(XRD)analysis indicates that annealed alloys have single phase and the same hexagonal structure as that of LaNi_(5) alloy(CaCu_(5) type,P6/mmm).The cell parameters of alloys fluctuate with the increasing annealing temperature.The equilibrium hydrogen pressure and plateau slope are a parabola function with annealing temperature for LaNi_(3.8)Al_(0.75)Mn_(0.45) alloy.By this relationship,an appropriate heat treatment temperature for LaNi_(3.8)Al_(0.75)Mn_(0.45) alloy is determined to about 1220-1230 K by mathematic simulation process.However,the maximum hydrogen storage capacity of alloys does not affected by the annealing temperature.
文摘The effect of Mn substitution on phase structure,hydrogen hydriding/dehydriding properties(plateau pressure and slope)and reaction heat enthalpy of LaNi_(4.25-x)Al_(0.75)Mn_(x)alloys(x=0,0.25,0.35,0.45,0.55 and 0.65)were studied.The experimental results show that all LaNi_(4.25-x)Al_(0.75)Mn_(x)alloys have single phase and have the same hexagonal structure as that of LaNi5 alloy(CaCu_(5)type,P6/mmm).With increasing Mn substitution content,the cell parameters of LaNi_(4.25-x)Al_(0.75)Mn_(x)alloy greatly increase,but the maximum hydrogen storage capacity and the equilibrium absorption pressure of LaNi_(4.25-x)Al_(0.75)Mn_(x)alloy decrease from 1.38 wt.%to 1.18 wt.%and from 1.61 to 0.0712 MPa,respectively.Moreover,the hydrogen pressure plateau slope factorσincreases from 0.014 to 0.18,but the hysteresis factor is nearly constant.The heat enthalpy absolute value|ΔH_(plat)|increases from 46.7 kJ·mol^(-1)H2 to 56.1 kJ·mol^(-1)H_(2)as the Mn content x increases from 0 to 0.65.
