We consider a continuous-time symmetric branching random walk on the d-dimensional lattice, d ≥?1, and assume that at the initial moment there is one particle at every lattice point. Moreover, we assume that the underlying random walk has a finite variance of jumps and the reproduction law is described by a continuous-time Markov branching process (a continuous-time analog of a Bienamye-Galton-Watson process) at every lattice point. We study the structure of the particle subpopulation generated by the initial particle situated at a lattice point x. We replay why vanishing of the majority of subpopulations does not affect the convergence to the steady state and leads to clusterization for lattice dimensions d =?1 and d =?2.
Oxide-phosphate layers 20 to 150 μm thick were obtained on titanium by plasma electrolytic deposition in individual and mixed aqueous electrolytes with polyphosphate complexes of zirconium(IV), barium(II), and copper(II). Formation features, thickness, elemental and phase compositions, and surface morphology of the films are presented. Depending on the electrolyte composition, synthesis conditions, and temperature of annealing in air, some simple and double phosphates of titanium and zirconium are formed, including ZrP2O7, NaTi2(PO4)3, BaTi2(P2O7)2, Zr0.2Ti0.8P2O7, and CuTi2(PO4)3. 相似文献
Effect of the component concentration of an orthophosphate-tetraborate aqueous electrolyte on the thickness, composition,
surface structure, and protective properties of coatings deposited from this electrolyte was studied. 相似文献
The effect of the synthesis conditions of aqueous dispersions of oxygen-containing lanthanum compounds on the size, shape, and phase composition of nanoparticles is studied. It is established that the hydrolysis of lanthanum nitrate at the boiling point of a solution affords sols with a narrower particle size distribution and a higher degree of particle crystallinity. The ranges of [OH?]/[La3+] concentration ratios are determined within which aggregatively stable aqueous dispersions of oxygen-containing lanthanum compounds can be synthesized. 相似文献
We study the groups for which the derived subgroups of all proper subgroups are Chernikov subgroups under condition that they
possess a normal system whose factors are locally graduated. 相似文献
The thermoelastic bending of a circular light-core sandwich plate on a deformable foundation is examined. To describe the
kinematics of the plate with asymmetric thickness, the hypothesis of broken normal is adopted. The reaction of the foundation
is described by Winkler’s model. The thermomechanical load is local and symmetric. The system of equilibrium equations is
derived and solved exactly. Numerical results for three-layer metal-polymer plate are presented
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Translated from Prikladnaya Mekhanika, Vol. 42, No. 2, pp. 96–103, February 2006. 相似文献
Blends of linear polyurethane and poly(methyl methacrylate) were obtained in situ in the course of simultaneously proceeding reactions of polymerization and polyaddition. The effect of filler nanoparticles on the thermodynamic properties of the systems was investigated. Introduction of filler into the monomer mixture before curing increases the compatibility of final systems, as follows from diminishing thermodynamic interaction parameters. The reverse correlation has been established between the interaction parameter and the fraction of an interfacial region between two phases, its origin being the result of incomplete phase separation. Introducing filler into the reaction system determines simultaneously the increasing compatibility and increasing fraction of an interfacial region, i.e., prevents phase separation. Both effects are due to increasing of the interaction between two polymeric components at the interface with solid and changing conditions of incomplete phase separation in the course of reaction. 相似文献
Structural and phase transformations in the course of the multistage physical aging of semi-inter-penetrating polymer networks
based on crosslinked polyurethane and linear polystyrene are studied. Dynamic mechanical and thermophysical studies make it
possible to assume that, as a result of the physical aging, a heterogeneous polymer system experiences structural rearrangements
and the fraction of the inter-facial region increases. 相似文献
Stable aqueous electrolyte emulsions with negatively charged micelles containing dispersed particles of polytetrafluoroethylene (PTFE) or graphite are obtained using siloxane-acrylate emulsion as an emulsifier. The oxide coatings formed in such electrolytes contain carbon, polytetrafluoroethylene, or graphite. The coatings with PTFE particles are similar to monolithic polytetrafluoroethylene with respect to its hydrophobic characteristics. According to X-ray photoelectron spectroscopy data, the surface of the formed coatings predominantly contains aliphatic carbon (C-C and C-H bonds) and some fraction of oxidized (or, in the case of PTFE-containing electrolytes, fluorinated) carbon. 相似文献