The effects of induced heat loads on the propagation of Ince-Gaussian beams

Thermal effects are very much influential in high power beam generators. Their impacts on special types of beams such as Helmholtz-Gauss beams have attracted special attentions. This work reports thermal effects on the generation and propagation of Ince-Gaussian beams. The results show considerable beam spot size variations for near fields under various induced heat loads. As Ince-Gaussian beams are directly related to cavity symmetry breaking, the results can greatly help system designers for circumventing these types of symmetry breaks usually encountered in high power lasers.     

Temperature dependence of the properties of strong-coupling bipolaron in a quantum dot

Temperature dependence of the properties of strong-coupling bipolaron in a quantum dot (QD) is studied based on the Lee-Low-Pines-Huybrechts variational method and quantum statistical theory. Results of the numerical calculation show that the vibration frequency as well as the absolute value of the induced potential and the effective potential all increase with increasing coupling strength and temperature, respectively, and they also increase with decreasing relative distance of electrons. The bipolarons are closer and more stable when the temperature is higher and coupling strength is larger. The influence of radius of QD and dielectric constant ratio on the effective potential is little.     

Peristatcally induced MHD slip flow in a porous medium due to a surface acoustic wavy wall

The influences of Hall current and slip condition on the MHD flow induced by sinusoidal peristaltic wavy wall in two dimensional viscous fluid through a porous medium for moderately large Reynolds number is considered on the basis of boundary layer theory in the case where the thickness of the boundary layer is larger than the amplitude of the wavy wall. Solutions are obtained in terms of a series expansion with respect to small amplitude by a regular perturbation method. Graphs of velocity components, both for the outer and inner flows for various values of the Reynolds number, slip parameter, Hall and magnetic parameters are drawn. The inner and outer solutions are matched by the matching process. An interesting application of the present results to mechanical engineering may be the possibility of the fluid transportation without an external pressure.     

An existence theorem of Walrasian equilibrium

The purpose of this note is to establish an existence theorem for Walrasian equilibrium under weaker conditions.     

4-Ferrocenyl-1,3-oxazoline derivatives as ligands for catalytic asymmetric allylation reactions

Bis(oxazolines) and 2-(2-phosphinoaryl)oxazolines derived from highly enantiopure 2-amino-2-ferrocenylethanol have been tested as ligands in the asymmetric Pd(0)-catalysed allylic alkylation reaction. Essentially complete enantioselectivity (99.8:0.2 er) has been achieved in the nucleophilic substitution of 1,3-diphenyl-2-propenyl acetate by dimethyl malonate anion. The absolute configuration of the ligands has been unambiguously established by chiroptical methods.     

Radiation damage in Si photodiodes by high-temperature irradiation

Results are presented of a detailed study of the effects of high-temperature 4-MeV neutron irradiation on the performance degradation of Si pin photodiodes together with the radiation-induced defects, observed by deep level transient spectroscopy. The degradation of the device performance and the introduction rate of the lattice defects decrease with increasing sample temperature during irradiation. For a 250°C irradiation, the reduction of the reverse current is only 20% of the starting value. This result suggests that the creation and recovery of the radiation damage proceeds simultaneously at high temperatures. Carbon-related complex as hole capture levels is also mainly responsible for the device degradation for high-temperature neutron irradiation.     

Effects of torsion stress on the domain wall unpinning AC field in amorphous FeCoBSi wires

The unpinning or propagation field, h_p, where domain walls are unpinned and start their displacement under the AC magnetic field of as-cast amorphous wires of nominal composition (Co₉₄Fe₆)_72.5B₁₅Si_12.5, was determined for each torsion angle between –90° (counterclockwise) and +150° (clockwise) at a constant frequency of 1 kHz. A plot of h_p as a function of torsion angle showed a sharp minimum at a torsion angle of +120. The results are interpreted in terms of the counterbalance effect of the torsion against the intrinsic helical anisotropy induced during the wire fabrication.     

On p-Radical Groups

Ｏｎｐ－ＲａｄｉｃａｌＧｒｏｕｐｓ￥ＺｈｏｕＹｏｎｇｘｉｎ（周永新）（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｈｅｍａｔｉｃｓ，ＨｅｂｅｉＴｅａｃｈｅｒｓＵｎｉｖｅｒｓｉｔｙ，Ｓｈｉｊｉａｚｈｕａｎｇ，Ｈｅｂｅｉ，０５００１６）Ａｂｓｔｒａｃｔ：Ｉｎｔｈｉｓｐ...     

Electrokinetic particle translocation through a nanopore containing a floating electrode

Electrokinetic particle translocation through a nanopore containing a floating electrode is investigated by solving a continuum model, composed of the coupled Poisson-Nernst-Planck (PNP) equations for the ionic mass transport and the modified Stokes equations for the flow field. Two effects due to the presence of the floating electrode, the induced-charge electroosmosis (ICEO) and the particle-floating electrode electrostatic interaction, could significantly affect the electrokinetic mobility of DNA nanoparticles. When the electrical double layers (EDLs) of the DNA nanoparticle and the floating electrode are not overlapped, the particle-floating electrode electrostatic interaction becomes negligible. As a result, the DNA nanoparticle could be trapped near the floating electrode arising from the induced-charge electroosmosis when the applied electric field is relatively high. The presence of the floating electrode attracts more ions inside the nanopore resulting in an increase in the ionic current flowing through the nanopore; however, it has a limited effect on the deviation of the current from its base current when the particle is far from the pore.