The combination of the parameters of temperature, humidity, and wind conditions of surface air, solar radiation fluxes, human metabolism under various modes of physical exertion and clothing properties characterize the thermal comfort. Under conditions of global warming, the climate characteristics that affect the quality of life, health, and well-being of people, in particular, the length of thermal comfort periods, are changing. Bioclimatic indices that determine the thermal comfort conditions depend not only on temperature changes, but also on humidity and wind speed trends. When comparing the results of the calculations of the thermal comfort period length with the use of air temperature observations and major bioclimatic indices, the authors have revealed a significant difference in the effect of changes in average wind speed on the length of the thermal comfort period in different regions of European Russia.

The formation of CoCu and PtCu alloys on the stepped Cu(111) substrate was simulated. Dendritic and finger-like protrusions grow near the edges of the steps. The shape and the internal structure of the protrusions depend on the type of the step edge, temperature and concentrations of impurity atoms. The internal structure and the shape of the protrusions are significantly different in PtCu and CoCu alloys. Pt atoms tend to be surrounded by Cu atoms and Co atoms tend to combine into Co backbones. The dendritic protrusions usually grow at 200 K and the finger-like protrusions usually grow at 300 K. The shape of the protrusions also depends on the type of the step edge and the concentration of impurity atoms. The main differences of PtCu and CoCu protrusions can be explained by the values of the diffusion barriers of the key processes.

The formation of Pt/Cu clusters on a stepped Cu(111) surface has been theoretically investigated using the self-learning kinetic Monte Carlo method. It has been shown that by varying Pt/Cu cluster growth conditions, one can prepare different nanostructures, such as spatially extended and branching dendrites and fingers of different geometry. It has been found that the shape of clusters depends mainly on three parameters: temperature, platinum relative concentration, and the type of step on which the cluster grows. Dendrites grow under the following conditions: the temperature in the system must be no higher than 200 K, and the system must contain platinum atoms. Depending on the type of step, either dendrites extended normally to the step or branching dendrites arise. At room temperature, fingers grow on steps, the length of fingers also being dependent on the type of step. Different shapes of clusters on different steps arise from the anisotropic diffusion of atoms near the corners of clusters, which can be explained by taking into account energy barriers for atom hops over the Cu(111) surface.

We have conducted a comparative analysis of the climatic and biometeorological characteristics of the regions with the largest Russian cities and have laid the basis for constructing maps of the heating season climatic characteristics for the territory of Russia. For the effective ambient temperature range of 17.2 to 21.7 degrees C ( comfort zone), we have calculated changes in the comfort zone for Moscow, St. Petersburg, Krasnodar, Novosibirsk, and Vladivostok according to data from 1959 to the present. Despite all climate differences between regions with selected cities, allowance for wind speed leads to a decrease in the number of days with temperature within the comfort zone.

Anthropogenic heat fluxes (AHF) have a significant impact on the weather and climate characteristics of urbanized territories. AHF plays a crucial role in the formation of an urban heat island. The structure of the urban heat island is determined not only by the AHF distribution but also by the location of the city. Moscow and St. Petersburg are the two largest Russian cities located in significantly different climatic conditions with the highest value of the AHF. In this article we compare the influence of the AHF on the temperature and wind regimes in Moscow and St. Petersburg regions.

The formation of the Cu-Pt nanocontacts has been investigated by means of classical molecular dynamics simulations. The simulations of the mechanically controlled break junction experiment have been performed in wide ranges of temperatures (0-300 K) and at relative Pt concentrations (0-20%). The structure of the breaking area has been studied 2 ns before the final breaking of the nanocontacts. The length of the breaking area increases with the increase of the temperature and decreases with the increase of the relative Pt concentration. The structure of the breaking area has been investigated by means of the radial distribution function method. The breaking area usually has one of the following structures: (i) a bulk-like structure, (ii) a structure consisting of centered icosahedrons rotated 90°, or (iii) an icosahedral structure composed of pentagonal rings. The structure of the breaking area is almost independent of the temperature and the stretching direction due to the strong Cu-Pt interaction.

In this paper we present the investigation of the diffusion-mediated processes in a Pt/Cu(001) surface alloy. We use the interatomic semiempirical TB-SMA interatomic potentials and the self-learning kinetic Monte Carlo method to investigate the following processes: order-disorder phase transition in the Pt/Cu(001) surface alloy, dissolution of small Pt clusters, and electromigration of small vacancy clusters in the topmost layer of the Pt/Cu (001) surface alloy. We have fitted the universal parameters of the interatomic TB-SMA potentials for the Pt-Cu system. The potentials reproduce bulk properties of copper and platinum as well as properties of the Pt/Cu(001) and Pt/Cu(111) surface alloys.

Growth of the Pt-Cu islands on the Cu(111) surface at different deposition fluxes, relative amounts of Pt atoms and surface temperatures is investigated on the atomic scale by performing the self-learning kinetic Monte-Carlo simulations. The shape transition of the islands from sixfold symmetry to threefold symmetry with increasing of the relative amount of Pt atoms n(Pt)/n(Cu) in clusters at room temperature was found and explained by the corner diffusion anisotropy. Nonmonotonic dependence of the fractal dimension of the dendritic islands on the ratio n(Pt)/n(Cu) is observed. It is shown that this effect can be interpreted in the framework of the generalized diffusion limited aggregation model if we assume that the dependence of the effective diffusion barrier on the ratio n(Pt)/n(Cu) has the third-degree polynomial function form. This dependence is in qualitative agreement with the analysis of the edge diffusion barriers. The dendritic cluster obtained with the simulations at room temperature looks very similar to the experimentally observed one (Soy et al. (2015) [33]).

One of the main factors of the impact of urbanization on mesoscale atmospheric and climatic processes are the anthropogenic heat fluxes (AHFs) caused by all types of heat sources in urban areas – from industry to metabolism in residents. A calculation of the influence of energy consumption in urban weather and climate made by the COSMO-CLM model with the TERRA-URB scheme shows that anthropogenic heat fluxes have a noticeable effect on urban temperature and wind regime. In Moscow’s agglomeration, the AHF contribution results in an increase of the mean annual temperature by 2°C and of the mean annual wind speed by more than 1 m/s, while the prevailing wind direction changes only slightly.

The result of investigation with the self-learning kinetic Monte Carlo method of processes, occurring during the formation of the Pt/Cu(111) surface alloy, is presented. A model is proposed that takes into account the jumps of dimers during the formation of a heterogeneous alloy on the (111) surface. The role of the diffusion of dimers at the temperature close to room temperature is investigated. The relative number of dimer jumps is calculated for the most significant stages of the Pt/Cu(111) alloy formation.

In this paper we present universal parameters of the second moment approximation to the tight-binding potentials for the Pt/Cu(111) and Pt/Cu(100) systems. The parameters are fitted and tested with both experimental and ab initio data. Potentials well reproduce values of bulk characteristics of Cu and Pt and also a lot of characteristic energies and diffusion barriers of considered systems. Calculated values of diffusion barriers predict the behavior which qualitatively agrees with the experimental results.

Presence of energy basins significantly slows down simulations with the kinetic Monte Carlo (kMC) method. Various methods of the kMC acceleration are available nowadays, but all of them require efficient energy basin finding algorithm. We present the algorithm providing significant acceleration of the kMC calculations. Use of the acceleration speeds up calculations and allows to reach experimental timescales in simulations. During the simulation of the Pt/Cu(111) surface alloy formation the acceleration is greater than 5000 times. Results of our simulation qualitatively agree with experiment.

The kinetic Monte Carlo (kMC) method is an indispensable method for studying atomic and molecular systems, which makes it possible to solve a wide range of problems associated with atomic diffusion, the formation of defects and chemical compounds of various types, as well as the growth and self-organization of nanostructures. In this paper, we consider the fundamentals of the kMC and its modern modifications, both rigid-lattice and off-lattice. Particular attention is focused on constructing self-learning algorithms based on different methods for finding the saddle points of potential energy and on the techniques for the acceleration of the Monte Carlo method. Every considered method is illustrated by relevant examples mostly associated with the physics of metal surfaces.

The difference between air temperatures in a city and the countryside - urban heat island intensity - depends primarily on the type and density of the buildings and energy consumption in municipal economy. There are many ways and methods for urban heat island intensity assessment: from empirical formulas to numerical simulation. One of the most useful numerical models for such purposes is COSMO-CLM. Various modifications of the COSMO model are now widely used in scientific research of mesoscale meteorological and climatic processes, as well as in weather forecast operational practice. The goal of this paper is to show the role of anthropogenic heat fluxes caused by urban energy consumption in Moscow’s urban heat island in wintertime nights under various weather conditions. Numerical simulations are performed using the COSMO-CLM model and a scheme called TERRA-URB with and without anthropogenic heat fluxes. Meteorological characteristics of the Moscow agglomeration are calculated using computational capacity of the A.M. Obukhov Institute of Atmospheric Physics RAS.

In this paper we present new parameters of the TB-SMA interatomic potentials for the Pt/Cu(111) surface alloy. The parameters are fitted using both the experimental and ab initio data. The potentials reproduce not only the bulk properties of copper and platinum, but also the energy characteristics of the Pt/Cu(111) surface alloy. Growth of the Pt/Cu(111) surface alloy at different Pt concentrations, deposition fluxes, and temperatures is investigated on the atomic scale by performing the self-learning kinetic Monte-Carlo simulations. The main atomic processes responsible for the surface alloy formation and the growth of the finger-like protrusions are identified. The results of our simulations are in a good qualitative agreement with the recent experimental data [J. Chem. Phys. C 118, 3015 (2014)] and can be useful for understanding details of the Pt-Cu interactions at the atomic level.

Global and regional climate change has a significant impact on the production and consumption of energy. In cities with developed infrastructure, this factor exposes the additional load or its reduction caused by heating and air conditioning systems in residential, industrial, commercial and office buildings. The impact of climate change on urban energy consumption is a latent characteristic that does not stand out directly from meteorological, statistical, or any other data. Some of Russian cities are used to discuss the possibility of its detection.