Several mathematical models describing particle separation and predict the separations in TBS are available. Because of the complexity of these models, Galvin’s model and Das’s model are of most interest. Equations of Galvin’s model, Das’s model and Alien’s law are used to predict the values of the terminal velocities. Free settling tests of 25 samples were undertaken. The average deviation of Galvin’s model is 0.019043, the values predicted by equations of Galvin’s model are most closes to the experimental data. Therefore, correlation equations of Galvin’s model should be chosen to calculate the terminal velocity of particles in the TBS.

With the development of powder metallurgy industry, the fine-metal-powder classification becomes one of the vital techniques in powder technology. A pneumatic classifier without screen and mechanical moving parts is designed and developed. Theoretical analysis and experiments of Pneumatic-Classification was conducted. The oversize ratio in fine powder can be reduced to less than 5% and the undersize ratio in coarse powder less than 15% when the air flow is suitable. The classification effect is satisfactory for the customers.

We summarize our model that high frequency quasi-periodic oscillations (QPOs) both in the neutron star low mass X-ray binaries (NS-LMXBs) and black hole LMXBs may originate from magnetohydrodynamic (MHD) waves. Based on the MHD model in NS-LMXBs, the explanation of the parallel tracks is presented. The slowly varying effective surface magnetic field of a NS leads to the shift of parallel tracks of QPOs in NS-LMXBs. In the study of kilohertz (kHz) QPOs in NS-LMXBs, we obtain a simple power-law relation between the kHz QPO frequencies and the combined parameter of accretion rate and the effective surface magnetic field. Based on the MHD model in BH-LMXBs, we suggest that two stable modes of the Alfv́en waves in the accretion disks with a toroidal magnetic field may lead to the double high frequency QPOs. This model, in which the effect of the general relativity in BH-LMXBs is considered, naturally accounts for the 3:2 relation for the upper and lower frequencies of the QPOs and the relation between the BH mass and QPO frequency.

With the development of powder metallurgy industry, the fine-metal-powder classification becomes one of the vital techniques in powder technology. A pneumatic classifier without screen and mechanical moving parts is designed and developed. Three samples are used in the pneumatic classification experiments and the separation sizes are 45μm， 45μm and 30μm, respectively. The oversize ratio in fine powder can be reduced to less than 5% and the undersize ratio in coarse powder less than 15% when the air flow is suitable, simultaneously. The classification effect is satisfactory.

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