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533.7 + 541.183 The concentration dependences of the shear-viscosity coefficient of a fluid, representing a binary mixture of components with molecules of approximately equal sizes, in narrow slot-like pores filled to a different degree (from a rarefied gas to a liquid) have been theoretically investigated with the use of a lattice-gas model accounting for the characteristic volume of atoms and interactions between them in the quasichemical approximation. This model allows one to determine the self-consistent equilibrium characteristics of a vapor-liquid system and the shear-viscosity coefficients of molecules with the use of a unique set of energy parameters. The influence of the activation energy of the surface migration of molecules on the local coefficients of viscosity has been considered. A molecular interpretation of the sliding friction of a fluid near the walls of pores has been given; this effect was explained by the surface migration of the mixture components.The transport of molecules in porous bodies determines the dynamic characteristics of gas and liquid flows in them. The sizes of the pores of disperse materials determine the catalytic, adsorption, and membrane processes occurring in them as well as the processes of their cleaning, wetting, impregnation, and drying [1-6]. The maximum width of narrow pores is equal to ,10 nm for a short-range, nonspecific, Lennard-Jones interaction potential between molecules (6-12), which corresponds to 25-30 monolayers [7][8][9]. This value was obtained from analysis of the conditions under which the surface potential influences the capillary condensation (for a long-range interaction potential, it increases with increase in the radius of the potential).In a narrow pore, the surface potential significantly influences the mobility of molecules and their distribution over the cross section of the pore. All transport characteristics of an adsorbate in such pores differ from those in the bulk of vapor and liquid phases. Among the most important dynamic characteristics of a substance is its shear viscosity. It should be noted that the Navier-Stokes equation cannot be used for narrow pores. In this case, kinetic transport equations for condensed media should be used. For organization and simulation of flows in narrow pores, it is necessary to know the transport characteristics of the system of these pores at the molecular level. In [10,11], a new molecular approach to representation of flows in narrow pores of one-component fluids with densities and temperatures varying in wide ranges has been proposed. It is based on the simplest molecular model of condensed media -the lattice-gas model that accounts for the characteristic volume of molecules and their interaction with each other [12,13]. This model can be used for fluids with concentrations changing in a wide range (from the gaseous to the liquid state) at widely varying temperatures, including the critical one, which allows one to investigate the dynamics of a fluid flow in the case of capillary condensation. Cl...