Mathematical Modeling of Two-Phase Convective Flows with Fine Particles

A two-phase convective flow with convection caused by a nonuniform distribution of solid particles is considered. The use of the mathematical model proposed is illustrated by an example of a two-phase flow in a shutter sedimentation reservoir.     

一类2连通（n,n＋2）图的色类

本文研究了围长为6的K_4同胚图的色性,对于其中的非色唯一图,给出了其色类。     

Analysis of Impedance Spectra of Vacuum-Annealed Undoped Polycrystalline Diamond Electrodes

Impedance spectra for a new electrode material, undoped polycrystalline diamond films vacuum-annealed at 1775 to 1915 K, taken in indifferent electrolytes are analyzed. Regular changing of parameters of the equivalent circuit (constant-phase element, ohmic and faradaic resistances) with increasing anneal temperature is demonstrated. It is concluded that both the amount of a nondiamond conducting phase in the electrode bulk increased and its properties (first and foremost, the conductivity) changed with increasing anneal temperature.     

Special feature on: Laser beam quality

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Special feature on: Laser beam quality     

Second-order Impedance in Electrode Kinetics

The kinetics of electrode reactions with a rather severe influence of the EDL structure is studied by nonlinear second-order impedance spectroscopy. Polarization impedance spectra and potential dependences of a nonlinear impedance are obtained for the reaction of electroreduction of the ferricyanide anion on the cadmium and bismuth electrodes in surface-inactive supporting NaF and Na₂SO₄ electrolytes. The results of measurements for the reaction Eu³⁺ + e Eu²⁺ on the bismuth and mercury electrodes are presented. It is shown that such important parameters of EDL as the potential of zero charge and the second derivative of potential with respect to the charge of the electrode surface can be determined directly from experimental curves even under conditions of occurrence of a faradaic process.     

Polarization Diagram of the Electrochemical Impedance of Second Order: A Theory that Accounts for the Diffusion of Reactants

With the aim of improving diagnostic possibilities of second-order impedance spectroscopy, a theory is put forward for a polarization diagram of a second-order impedance for reactions with charge transfer. The theory takes into account the diffusion of discharging particles in the absence of their specific adsorption.     

Sequencing of real-world samples using a microfabricated hybrid device having unconstrained straight separation channels

We describe a microfabricated hybrid device that consists of a microfabricated chip containing multiple twin-T injectors attached to an array of capillaries that serve as the separation channels. A new fabrication process was employed to create two differently sized round channels in a chip. Twin-T injectors were formed by the smaller round channels that match the bore of the separation capillaries and separation capillaries were incorporated to the injectors through the larger round channels that match the outer diameter of the capillaries. This allows for a minimum dead volume and provides a robust chip/capillary interface. This hybrid design takes full advantage, such as sample stacking and purification and uniform signal intensity profile, of the unique chip injection scheme for DNA sequencing while employing long straight capillaries for the separations. In essence, the separation channel length is optimized for both speed and resolution since it is unconstrained by chip size. To demonstrate the reliability and practicality of this hybrid device, we sequenced over 1000 real-world samples from Human Chromosome 5 and Ciona intestinalis, prepared at Joint Genome Institute. We achieved average Phred20 read of 675 bases in about 70 min with a success rate of 91%. For the similar type of samples on MegaBACE 1000, the average Phred20 read is about 550-600 bases in 120 min separation time with a success rate of about 80-90%.     

Kinetics of isotope exchange of dioxygen with a powdered high-temperature superconducting material Ba2YCu3O7?x

It has been found that the rate of isotope exchange in Ba₂YCu₃O_7–x–O₂ system is high. Its kinetics is exponential, first order with respect to dioxygen and the exchange is of the mixed first/third type.

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Ba₂YCu₃O_7–x–O₂ . -, -, - .

     

Mathematical modeling of sedimentation of a rarefied cloud of particles

In the present paper a mathematical model of sedimentation of a rarefied cloud of particles with account of the feedback effect of particles on the fluid is suggested. The calculations have shown that this effect changes significantly the pattern of particle motion. The results of model calculations agree fairly well with the experimental data on the sedimentation of coal dust particles in a settler. Tomsk State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 109–113, March, 1999.