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1.
JETP Letters - A constraint $$g_{A}^{2}\leq 4.5\times10^{-24}\big(g^{2}+1/\lambda_{A}^{2}\big)$$ on the constant gA of a new short-range (spin—orbit) interaction between nucleons, which is... 相似文献
2.
G. S. Balandina L. M. Zysina-Molozhen L. A. Fel'dberg I. G. Shapiro 《Fluid Dynamics》1969,4(3):107-112
This paper presents the results of an experimental study of a boundary layer disturbed by an incident shock for parameters which are characteristic of problems for flow about blade profiles in the final stages of high-power steam turbines. 相似文献
3.
An asymptotic model of the flow in the laminar boundary layer of a gas-evaporating droplet mixture is constructed within the framework of the two-continuum approximation. The case of evaporation of the droplets into an atmosphere of their own vapor is examined in detail with reference to the example of longitudinal flow over a hot flat plate. Numerical and asymptotic solutions of the boundary layer equations constructed are found for a number of limiting situations (low droplet concentration, no droplet deposition, significant droplet deposition). The development of the flow with respect to the longitudinal coordinate is studied and it is shown that in the absence of droplet deposition a region of pure vapor may be formed near the surface. Similarity criteria are established and the mechanism of surface heat transfer enhancement is studied for a low evaporating droplet concentration in the boundary layer. In the inertial deposition regime the results of calculating the integral heat transfer coefficient are found to correspond with the experimental data [1].Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No.3, pp. 42–50, May–June, 1992. 相似文献
4.
The uni-directional propagation of oil injected into water flowing through a water wetted porous slab of a finite length is investigated. The inlet and outlet edges of the slab are impermeable to the oil flux. Hence, the oil accumulates within the slab, thereby leading to a saturation build-up-capillary end effect. This phenomenon is studied analytically on the basis of a nonlinear equation describing oil-water transport in porous media. A dimensionless criterion is derived, which governs the appearance and relative strength of the capillary end effect. For weak oil-water interfacial tension (large capillary number) and long porous slabs the above effect is not observed and the temporal evolution of the oil saturation is described by the Buckley-Leverett solution. Short porous slabs are found to be almost entirely subjected to the capillary end effect. Intermediate situations are identified and quantitatively described, in which the downstream part of the slab may be divided into two zones: one-characterized by the capillary end effect, and the other being a Buckley-Leverett zone.It is shown, that the oil flux injected into the slab is limited by a maximum value which depends upon the location of the injection point. The partition of the inlet flux between the upstream and downstream directions is investigated. In the upstream side of the porous slab the oil moves under the action of free imbibition only. It is found that the upstream flux is limited by the value, which is independent of the slab's length and of the location of the injection point. 相似文献
5.
In the context of microbial-enhanced oil recovery (MEOR) with injection of surfactant-producing bacteria into the reservoir, different types of bacteria attachment and growth scenarios are studied using a 1D simulator. The irreversible bacteria attachment due to filtration similar to the deep bed filtration (DBF) is examined along with the commonly used reversible equilibrium adsorption (REA). The characteristics of the two models are highlighted. The options for bacteria growth are the uniform growth in both phases and growth of attached bacteria only. It is found that uniform growth scenario applied to filtration model provides formation of two oil banks during recovery. This feature is not reproduced by application of REA model or DBF with growth in attached phase. This makes it possible to select a right model based on the qualitative analysis of the experimental data. A criterion is introduced to study the process efficiency: the dimensionless time at which average recovery between pure water injection and maximum surfactant effect is reached. This characteristic recovery period (CRP) was studied as a function of the different MEOR parameters such as bacterial activity, filtration coefficients, and substrate injection concentrations. For both growth scenarios, there is a zone of optimal activity at which the CRP is minimal. Dependence of the CRP on substrate concentration for uniform growth scenario has also an optimal zone. Therefore, growth rate and the substrate concentration should be above a certain threshold value and still not be too high to obtain the minimum CRP. On the other hand, no such zone was found if the bacteria could grow only in the attached phase. Dependencies on both the injected concentration and filtration coefficient are monotonous in this case. 相似文献
6.
7.
Frederick R. Kinder Jr. Jefferson Chin Michael J. Shapiro Kenneth W. Bair 《合成通讯》2013,43(13):2541-2548
Isodehydroilludin M was synthesized from carbonyl ylid 1,3-dipolar cycloaddition product that was further elaborated with an unusual PCC-mediated double oxidation reaction. 相似文献
8.
Different dyes can produce the two-dimensional self-assembled structures called J- and H-aggregates that make them attractive material for various nano-electronics applications. This paper shows that electrokinetic deposition technique of cyanine dye J-aggregates is appropriate for the photoelectric devices production. The influence of excitation in visible on conductivity is observed in J-aggregate channel structure deposited using dielectrophoresis technique. The effect was observed in self-assembled thiamonomethinecyanine nanostructures. Samples were analyzed using AFM and micro-Raman spectroscopy methods. Analysis shows that photoelectric response must be the result of conductive channel formation in the structure of J-aggregate between the electrodes. The observed increase in conductivity manifold exceeds the structure dark conductivity: maximal increase comprised 6.3 times. 相似文献
9.
David Fuks Dina Shapiro Arnold Kiv Vyacheslav Golovanov Chung‐Chiun Liu 《International journal of quantum chemistry》2011,111(9):1902-1906
A slab approach in the framework of ab initio calculations was applied to study surface electronic states in In2O3 crystal. Density functional theory (DFT) calculations were carried out employing the WIEN 2k code and using the full potential method with Augmented Plane Waves + local orbitals (APW+lo) formalism. Total and partial DOS (Density of States) were calculated for In and O atoms in two upper (110) surface layers. Comparison of total and partial DOS allowed determining a contribution of electronic states of different In and O surface atoms into formation of surface electronic spectra and corresponding chemical bonds. A dominant ionic character of chemical bonds in In2O3 is found. Calculations were performed for three slab models with different geometry parameters. It was shown that an optimal ratio between the whole vertical size of a supercell and the vertical size of atomic cluster has to be chosen. The size of vacuum region in the slab model influences significantly on the reliability of calculated characteristics of the surface electronic structure. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011 相似文献
10.
A. D. Nekrasov B. I. Shapiro A. I. Tolmachev Yu. L. Slonimskii V. A. Kuzmin 《High Energy Chemistry》2011,45(6):525-531
H*-Aggregation of anionic meso-methyl-substituted thiacarbocyanines of different structures has been studied in dilute aqueous solutions and in the presence
of cationic organic polyelectrolytes. The thermodynamic parameters of the H*-aggregation from the trans-dimers have been determined. The thermodynamic equilibrium between two forms of the H*-aggregates in the presence of poly-N,N-dimethyl-N,N-diallylammonium chloride has been observed for the first time, and these forms have been assigned to H*
cis
and H*
trans
forms. 相似文献