Narrow Results

Physical mechanisms of laser cleaning of solid surface from soiling particles and films are discussed. Dry laser cleaning of surface from particles is considered to be a result of inertial force, appearing due to thermal expansion of absorbing particles and/or substrate (shaking-off mechanism). Steam laser cleaning is considered for the cases of absorbing particles and absorbing substrate. In the latter case, peculiarities of bubble formation in the liquid layer under the conditions of ns laser action are analyzed. Laser cleaning of surfaces from films by shaking-off and buckling mechanisms (due to thermal tension) is considered. Conditions of the action of each of them are defined. Other physical mechanisms, blasting and evaporation, are briefly discussed.

Novel processes for fabricating micro/nano sized oxide devices employing self-assembled monolayers (SAM) were developed. SAM of PTCS (phenyltrichlorosilane) was modified to have a phenyl / hydroxyl-group pattern by UV irradiation using a photomask and was used as a template to arrange inorganic fine particles. Surface modification of micro/nano sized inorganic particles and chemical reactions between those particles and SAM were studied. Two-dimensional arrangement of functional particles on a SAM in a controlled manner through the formation of strong chemical bonds, such as amide or ester bonds, can be applied to the future microelectronics and photonics.

About 30 years ago, I was among several students mentored by Professor Yang at Stony Brook to enter the field of particle accelerator physics. Since then, I have been fortunate to work on several major accelerator projects in USA and in China, guided and at times directly supported by Professor Yang. The field of accelerator physics is flourishing worldwide both providing indispensable tools for fundamental physics research and covering an increasingly wide spectrum of applications beneficial to our society.

We investigate on dynamic properties of particles in fluidized bed for separation with considering on gravity force, flotation, drag force and additional mass force for particles. The kinetic equations of particles in fluidized beds are built in detail based on the dynamic equations. It is found that the velocity of falling in fluidized bed can be described by hyperbolic tangent function and the distance of falling is described by the natural logarithm function. The results show that the particle size and the rate of density between the particle and the fluidized bed are the best of all basic factors in the course of efficiency particle separations. The theoretical study is pertinent to the application of mineral processing and efficient separations for fluidized bed.