This paper presented an investigation of particle collision and penetration using the discrete element method to understand the motion of particles and improve theoretical treatment in the sieving process. The process...This paper presented an investigation of particle collision and penetration using the discrete element method to understand the motion of particles and improve theoretical treatment in the sieving process. The process progressively was divided into looseness, stratification, collision, and penetration. Particle penetration has a direct effect on the screening performance. The penetration probability was defined, and the mathematical relationships between particle penetration and vibration parameters were established using the least squares method. To obtain the ideal penetration probability for materials the amplitude and frequency should preferably be near 3.0 mm and 25 Hz, respectively. The vibration direction angle has only a slight effect on penetration. The stage of the screening process from 0.1 to 0.7 s is the primary region for collision and penetration. This paper focused on the sieving process to more fully understand how particle collision and penetration influence the screening efficiency.展开更多
Particle Impact Noise Detection (PIND) test is a reliability screening technique for hermetic device that is prescribed by MIL-PRF-39016E. Some test conditions are specified, although MIL-PRF-39016E did not specify ho...Particle Impact Noise Detection (PIND) test is a reliability screening technique for hermetic device that is prescribed by MIL-PRF-39016E. Some test conditions are specified, although MIL-PRF-39016E did not specify how to obtain these condi- tions. This paper establishes the dynamics model of vibration process based on first order mass-spring system. The corresponding Simulink model is also established to simulate vibration process in optional input excitations. The response equations are derived in sinusoidal excitations and the required electromagnetic force waves are computed in order to obtain a given vibration and shock accelerations. Last, some simulation results are given.展开更多
In our previous theoretical study, the theoretical model of thecollision-induced electronic and rotational energy transfer of AB(~1Σ, J) + C(~sl_j) → AB(~1Σ,J′) + C(~sl_(j′)) was presented. To further study the c...In our previous theoretical study, the theoretical model of thecollision-induced electronic and rotational energy transfer of AB(~1Σ, J) + C(~sl_j) → AB(~1Σ,J′) + C(~sl_(j′)) was presented. To further study the collision-induced electronic and rotationalenergy transfer theoretically on AB( ~1Π, J) + C(~sl_j) → AB( ~1Π, J′) + C(~sl_(j′)), atheoretical model is presented, based on the time-dependent first-order Born approximation, takinginto account the anisotropic Lennard-Jones interaction potential and 'straight-line' trajectoryapproximation. The changing tendency of the transitional probabilities with the anisotropicparameter is discussed.展开更多
The multi-source pion interferometry in relativistic heavy-ion collisions is presented and two-source models for hadron gas and hadron gas plus quark-gluon plasma are proposed. The models can resolve the HBT puzzle. F...The multi-source pion interferometry in relativistic heavy-ion collisions is presented and two-source models for hadron gas and hadron gas plus quark-gluon plasma are proposed. The models can resolve the HBT puzzle. For the same q and different direction of q, the two-pion correlation functions show characteristic oscillation behaviors, which may be used to distinguish the two-source models. Our research also showes that the multi-source pion correlations can resolve the HBT puzzle.展开更多
文摘This paper presented an investigation of particle collision and penetration using the discrete element method to understand the motion of particles and improve theoretical treatment in the sieving process. The process progressively was divided into looseness, stratification, collision, and penetration. Particle penetration has a direct effect on the screening performance. The penetration probability was defined, and the mathematical relationships between particle penetration and vibration parameters were established using the least squares method. To obtain the ideal penetration probability for materials the amplitude and frequency should preferably be near 3.0 mm and 25 Hz, respectively. The vibration direction angle has only a slight effect on penetration. The stage of the screening process from 0.1 to 0.7 s is the primary region for collision and penetration. This paper focused on the sieving process to more fully understand how particle collision and penetration influence the screening efficiency.
文摘Particle Impact Noise Detection (PIND) test is a reliability screening technique for hermetic device that is prescribed by MIL-PRF-39016E. Some test conditions are specified, although MIL-PRF-39016E did not specify how to obtain these condi- tions. This paper establishes the dynamics model of vibration process based on first order mass-spring system. The corresponding Simulink model is also established to simulate vibration process in optional input excitations. The response equations are derived in sinusoidal excitations and the required electromagnetic force waves are computed in order to obtain a given vibration and shock accelerations. Last, some simulation results are given.
文摘In our previous theoretical study, the theoretical model of thecollision-induced electronic and rotational energy transfer of AB(~1Σ, J) + C(~sl_j) → AB(~1Σ,J′) + C(~sl_(j′)) was presented. To further study the collision-induced electronic and rotationalenergy transfer theoretically on AB( ~1Π, J) + C(~sl_j) → AB( ~1Π, J′) + C(~sl_(j′)), atheoretical model is presented, based on the time-dependent first-order Born approximation, takinginto account the anisotropic Lennard-Jones interaction potential and 'straight-line' trajectoryapproximation. The changing tendency of the transitional probabilities with the anisotropicparameter is discussed.
文摘The multi-source pion interferometry in relativistic heavy-ion collisions is presented and two-source models for hadron gas and hadron gas plus quark-gluon plasma are proposed. The models can resolve the HBT puzzle. For the same q and different direction of q, the two-pion correlation functions show characteristic oscillation behaviors, which may be used to distinguish the two-source models. Our research also showes that the multi-source pion correlations can resolve the HBT puzzle.
