Precision Measurement of the (e++e−) Flux in Primary Cosmic Rays from 0.5 GeV to 1 TeV with the Alpha Magnetic Spectrometer on the International Space Station

We present a measurement of the cosmic ray (e++e-) flux in the range 0.5 GeV to 1 TeV based on the analysis of 10.6 million (e++e-) events collected by AMS. The statistics and the resolution of AMS provide a precision measurement of the flux. The flux is smooth and reveals new and distinct information. Above 30.2 GeV, the flux can be described by a single power law with a spectral index &gamma;=-3.170&plusmn;0.008(stat+syst)&plusmn;0.008(energyscale).</p

Precision Measurement of the Helium Flux in Primary Cosmic Rays of Rigidities 1.9 GV to 3 TV with the Alpha Magnetic Spectrometer on the International Space Station

Knowledge of the precise rigidity dependence of the helium flux is important in understanding the origin, acceleration, and propagation of cosmic rays. A precise measurement of the helium flux in primary cosmic rays with rigidity (momentum/charge) from 1.9 GV to 3 TV based on 50 million events is presented and compared to the proton flux. The detailed variation with rigidity of the helium flux spectral index is presented for the first time. The spectral index progressively hardens at rigidities larger than 100 GV. The rigidity dependence of the helium flux spectral index is similar to that of the proton spectral index though the magnitudes are different. Remarkably, the spectral index of the proton to helium flux ratio increases with rigidity up to 45 GV and then becomes constant; the flux ratio above 45 GV is well described by a single power law.</p

Mapping Diurnal Variability of the Wintertime Pearl River Plume Front from Himawari-8 Geostationary Satellite Observations

The spatial pattern of the wintertime Pearl River plume front (PRPF), and its variability on diurnal and spring-neap time scales are characterized from the geostationary meteorological Himawari-8 satellite, taking advantage of the satellite’s unique 10-minutely sea surface temperature sequential images. Our findings suggest that the PRPF in winter consists of three subfronts: the northern one north of 22° N 20′, the southern one south of 21° N 40′, and the middle one between 22° N 20′ and 21° N 40′. The time-varying trend of the frontal intensity generally exhibits a strong-weak-strong pattern, with the weakest plume front occurring at about 06:00 UTC, which is closely associated with net surface heat flux over the region. The comparison in frontal variability between the spring and neap tides shows that the plume front during the spring tide generally tends to be more diffuse for the frontal probability, move further offshore for the frontal position, and be weaker for the frontal intensity than those found during the neap tide. These great differences largely depend on the tidally induced stronger turbulent mixing during the spring tide while the wind stress only plays a secondary role in the process. To best of our knowledge, the distinct diurnal variations in PRPF with wide coverage are observed for the first time. This study demonstrates that the Himawari-8 geostationary satellite has great potential in characterizing high-frequency surface thermal fronts in considerable detail

Mapping Diurnal Variability of the Wintertime Pearl River Plume Front from Himawari-8 Geostationary Satellite Observations

The spatial pattern of the wintertime Pearl River plume front (PRPF), and its variability on diurnal and spring-neap time scales are characterized from the geostationary meteorological Himawari-8 satellite, taking advantage of the satellite&rsquo;s unique 10-minutely sea surface temperature sequential images. Our findings suggest that the PRPF in winter consists of three subfronts: the northern one north of 22&deg; N 20&prime;, the southern one south of 21&deg; N 40&prime;, and the middle one between 22&deg; N 20&prime; and 21&deg; N 40&prime;. The time-varying trend of the frontal intensity generally exhibits a strong-weak-strong pattern, with the weakest plume front occurring at about 06:00 UTC, which is closely associated with net surface heat flux over the region. The comparison in frontal variability between the spring and neap tides shows that the plume front during the spring tide generally tends to be more diffuse for the frontal probability, move further offshore for the frontal position, and be weaker for the frontal intensity than those found during the neap tide. These great differences largely depend on the tidally induced stronger turbulent mixing during the spring tide while the wind stress only plays a secondary role in the process. To best of our knowledge, the distinct diurnal variations in PRPF with wide coverage are observed for the first time. This study demonstrates that the Himawari-8 geostationary satellite has great potential in characterizing high-frequency surface thermal fronts in considerable detail

SOC-dependent high-rate dischargeability of AB_5-type metal hydride anode: Mechanism linking phase transition to electrochemical H-desorption kinetics

The current application of nickel-metal hydride (Ni-MH) batteries places a particular emphasis on the high-rate dischargeability (HRD) at varying state-of-charges (SOCs). However, most research on the HRD of AB5-type MH anodes only considers the fully charged case but overlooks the significant impact of SOC. In this work, at first, the great SOC effect on the HRD or pulse power of AB_5-type MH anode is presented. Then, by crosschecking the SOC dependence of both ‘in situ’ polarization and ‘ex situ’ kinetic parameters, a definite SOC-dependent H-desorption kinetics for AB_5-type MH anode is acquired. Finally, a novel mechanism linking phase transition to H-desorption kinetics for AB_5-type MH anode is proposed. The HRD or pulse power of AB5-type MH anode significantly improves when SOC decreases from 100% to an appropriate range (90-60%) and suddenly deteriorates when SOC drops below ∼20%. The former improvement relates to the formation of saturated solid solution that simultaneously facilitates both charge-transfer reaction and hydrogen diffusion. The latter deterioration is due to the complete depletion of hydride causing an insufficient supply of hydrogen atoms

SOC-dependent high-rate dischargeability of AB_5-type metal hydride anode: Mechanism linking phase transition to electrochemical H-desorption kinetics

The current application of nickel-metal hydride (Ni-MH) batteries places a particular emphasis on the high-rate dischargeability (HRD) at varying state-of-charges (SOCs). However, most research on the HRD of AB5-type MH anodes only considers the fully charged case but overlooks the significant impact of SOC. In this work, at first, the great SOC effect on the HRD or pulse power of AB_5-type MH anode is presented. Then, by crosschecking the SOC dependence of both ‘in situ’ polarization and ‘ex situ’ kinetic parameters, a definite SOC-dependent H-desorption kinetics for AB_5-type MH anode is acquired. Finally, a novel mechanism linking phase transition to H-desorption kinetics for AB_5-type MH anode is proposed. The HRD or pulse power of AB5-type MH anode significantly improves when SOC decreases from 100% to an appropriate range (90-60%) and suddenly deteriorates when SOC drops below ∼20%. The former improvement relates to the formation of saturated solid solution that simultaneously facilitates both charge-transfer reaction and hydrogen diffusion. The latter deterioration is due to the complete depletion of hydride causing an insufficient supply of hydrogen atoms