Using data of airborne particle measurement system, weather radar and Ka-band millimeter wave cloud-meter, physical structure characteristics of a typical stable stratiform cloud in Hebei Province on February 27, 2018...Using data of airborne particle measurement system, weather radar and Ka-band millimeter wave cloud-meter, physical structure characteristics of a typical stable stratiform cloud in Hebei Province on February 27, 2018 was analyzed. Research results showed that the detected cloud system was the precipitation stratiform cloud in the later stage of development. The cloud layer developed stably, and the vertical structure was unevenly distributed. The concentration of small cloud particles in high-level clouds was low, and it fluctuated greatly in space, and presented a discontinuous distribution state. The concentration of large cloud particles and precipitation particles was high, which was conducive to the growth of cloud droplets and the aggregation of ice crystals. The concentration of small cloud particles and the content of supercooled water were high in the middle and low-level clouds. The precipitation cloud system had a significant hierarchical structure, which conformed to the "catalysis-supply" mechanism. From the upper layer to the lower layer, the cloud particle spectrum was mainly in the form of single peak or double peak distribution, which showed a monotonic decreasing trend in general. The spectral distribution of small cloud particles in the cloud was discontinuous, and the high-value areas of spectral concentration of large cloud particles and precipitation particles were concentrated in the upper part of the cloud layer, and the particle spectrum was significantly widened. There was inversion zone at the bottom of the cloud layer, which was conducive to the continuous increase of particle concentration and the formation of large supercooled water droplets.展开更多
A new frequency domain method for charged particle identification, called Frequency Ratio Analysis（FRA）, is proposed by analyzing the frequency spectra of proton pulses and alpha pulses acquired from a totally deple...A new frequency domain method for charged particle identification, called Frequency Ratio Analysis（FRA）, is proposed by analyzing the frequency spectra of proton pulses and alpha pulses acquired from a totally depleted Si detector. Identification performance of the FRA method is evaluated and compared with two time domain methods, the current pulse amplitude method and the second moment method. The results show that the FRA method is not only feasible and effective but also superior to the two time domain methods, as it achieves an obvious increase in value of the figure-of-merit（FOM）.展开更多
A 2-D slab-symmetric model of mixed convective-stratiform cloud is developed by superimposing convective cloud-size field on the convergence field,in order to simulate and study the mixed clouds consisting of stratifo...A 2-D slab-symmetric model of mixed convective-stratiform cloud is developed by superimposing convective cloud-size field on the convergence field,in order to simulate and study the mixed clouds consisting of stratiform cloud and convective cloud.A deep convective,anelastic and conservative system of equations with basic variables(V,θ,π')is solved by a new method to calculate dynamic field.The water substance in the cloud is divided into 6 categories and the microphysical processes are described in spectrum with two variable parameters and more reasonable particle number/size distributions.To compare with measured radar echo intensity and structure,the model may calculate echo intensity of the model cloud observed by radar.展开更多
Extensive Air Showers(EAS)induced by cosmic ray particles of very low energies,owing to the significantly steep cosmic ray energy spectrum,dominate the secondary particle flux measured by single detectors and small sh...Extensive Air Showers(EAS)induced by cosmic ray particles of very low energies,owing to the significantly steep cosmic ray energy spectrum,dominate the secondary particle flux measured by single detectors and small shower arrays.Such arrays connected in extended networks can be used to determine potentially interesting spatial correlations between showers,which may shed new light on the nature of ultra high-energy cosmic rays.The quantitative interpretation of showers recorded by small local arrays requires a methodology that differs from that used by ordinary large EAS arrays operating in the"knee"region and above.We present"small EAS generator,"a semi-analytical method for integrating cosmic ray spectra over energies of interest and summing over the mass spectra of primary nuclei in arbitrary detector configurations.Furthermore,we provide results on the EAS electron and muon fluxes and particle density spectra.展开更多
基金Supported by National Key R&D Plan Projects (2018YFC1507900)Hebei Province Science and Technology Plan Program(20375402D)。
文摘Using data of airborne particle measurement system, weather radar and Ka-band millimeter wave cloud-meter, physical structure characteristics of a typical stable stratiform cloud in Hebei Province on February 27, 2018 was analyzed. Research results showed that the detected cloud system was the precipitation stratiform cloud in the later stage of development. The cloud layer developed stably, and the vertical structure was unevenly distributed. The concentration of small cloud particles in high-level clouds was low, and it fluctuated greatly in space, and presented a discontinuous distribution state. The concentration of large cloud particles and precipitation particles was high, which was conducive to the growth of cloud droplets and the aggregation of ice crystals. The concentration of small cloud particles and the content of supercooled water were high in the middle and low-level clouds. The precipitation cloud system had a significant hierarchical structure, which conformed to the "catalysis-supply" mechanism. From the upper layer to the lower layer, the cloud particle spectrum was mainly in the form of single peak or double peak distribution, which showed a monotonic decreasing trend in general. The spectral distribution of small cloud particles in the cloud was discontinuous, and the high-value areas of spectral concentration of large cloud particles and precipitation particles were concentrated in the upper part of the cloud layer, and the particle spectrum was significantly widened. There was inversion zone at the bottom of the cloud layer, which was conducive to the continuous increase of particle concentration and the formation of large supercooled water droplets.
基金Supported by National Natural Science Foundation of China(11175254,11375264)
文摘A new frequency domain method for charged particle identification, called Frequency Ratio Analysis（FRA）, is proposed by analyzing the frequency spectra of proton pulses and alpha pulses acquired from a totally depleted Si detector. Identification performance of the FRA method is evaluated and compared with two time domain methods, the current pulse amplitude method and the second moment method. The results show that the FRA method is not only feasible and effective but also superior to the two time domain methods, as it achieves an obvious increase in value of the figure-of-merit（FOM）.
文摘A 2-D slab-symmetric model of mixed convective-stratiform cloud is developed by superimposing convective cloud-size field on the convergence field,in order to simulate and study the mixed clouds consisting of stratiform cloud and convective cloud.A deep convective,anelastic and conservative system of equations with basic variables(V,θ,π')is solved by a new method to calculate dynamic field.The water substance in the cloud is divided into 6 categories and the microphysical processes are described in spectrum with two variable parameters and more reasonable particle number/size distributions.To compare with measured radar echo intensity and structure,the model may calculate echo intensity of the model cloud observed by radar.
文摘Extensive Air Showers(EAS)induced by cosmic ray particles of very low energies,owing to the significantly steep cosmic ray energy spectrum,dominate the secondary particle flux measured by single detectors and small shower arrays.Such arrays connected in extended networks can be used to determine potentially interesting spatial correlations between showers,which may shed new light on the nature of ultra high-energy cosmic rays.The quantitative interpretation of showers recorded by small local arrays requires a methodology that differs from that used by ordinary large EAS arrays operating in the"knee"region and above.We present"small EAS generator,"a semi-analytical method for integrating cosmic ray spectra over energies of interest and summing over the mass spectra of primary nuclei in arbitrary detector configurations.Furthermore,we provide results on the EAS electron and muon fluxes and particle density spectra.
