We consider fertile hard-core (HC) models with three states on a homogeneous Cayley tree. It is known that four types of such models exist. For these models, we describe the translation-invariant and periodic HC Gibbs measures. We also construct a uncountable set of nonperiodic Gibbs measures.

We analyze the SOS (solid-on-solid) model with spins 0, 1, 2, 3 on a Cayley tree of order k ≥ 1. We consider translation-invariant and periodic splitting Gibbs measures for this model. The majority of the constructed Gibbs measures are mirror symmetric.

Agriculture in the Republic of Uzbekistan is based on irrigated agriculture, therefore, not all rivers existing in the country fully satisfy the needs of consumers, and water resources are accumulated mainly from reservoirs. From this point of view, the strength of the dams of these reservoirs has been studied in detail. However, in most cases, the external slopes of the dams of these artificial hydraulic structures are not used. This, in turn, requires new scientific solutions for the development of solar energy in Uzbekistan, where the amount of solar radiation is quite large. As an example, to study this problem, the amount of seasonal solar radiation in the southeastern region of the republic was obtained using simulation values using a geographic information system on the ArcGIS 9.3 platform and a seasonal map of solar radiation was developed. At the same time, to ensure the efficient operation of solar photovoltaic installations made of photovoltaic cells based on semiconductor silicon materials, it is proposed to use the external slope of the Talimarzhan dam located in this territory. This, in turn, makes it possible to eliminate the problem of preventing the drop in the coefficient of performance (COP) of solar photovoltaic cells, which is an important working part, with an increase in one of the most negative external factors - temperature. The results show that based on the generated direct electric current from the solar photovoltaic station, the following can be supplied: lighting system for the reservoir, uninterrupted power supply of synchronous motors installed at pump station №7, consumers of auxiliary needs of the hydroaccumulative power station, which is planned to be installed in the reservoir, potential electricity consumption, consisting of from tourism services infrastructure to the development of ecotourism.

No abstract

To obtain more photosensitive S-diodes, silicon should be compensated for by impurities, which increase the photosensitivity of the original crystals. Diffusion of vanadium in silicon was carried out in evacuated or open quartz ampoules at a temperature of 900-1250 °C for 2-20 hours. Silicon wafers 0.5-1.0 mm thick and an alloying element of vanadium were placed in the ampoule. Usually used n-Si with ρ ~ 5 ÷ 200 Ω·sm and with a thickness of 0.2-0.5 mm. The concentration of deep levels introduced during diffusion was 1014 cm-3. The resistivity of silicon after diffusion increased to 103-104 Ω·sm at 300 K, and the diffusion length Ld decreased to 10-30 μm. S-diodes were made in a vacuum by melting aluminum and Au + 0.1% Sb alloy at 700 °C for 1 min. The contact area (S) is approximately 0.2 mm2, the base thickness d = 0.2-1.0 mm. Attitude d/Ld≈10 ÷ 100. Iincline ~ 1/tinclusion in a wide range of currents is linear, where Iincline> Ibre. Determined by the slope Iincline ~ 1/tinclusion the charge is Qcr = 3.52·10-9C. In this case, the average concentration of injected current carriers in the base is n = 5.44·1013 cm-3, which is in good agreement with the concentration of electroactive atoms V in Si, determined by capacitive methods. The dependence 1 V t − 1 V ∞ for S-diodes from n-Si <V> has a complex form at each temperature and is approximated by two exponents. The obtained experimental results, their analysis and conclusions on S-diodes from Si <V> can be used as a temperature relay, photo relay, switches and photodetectors controlled by the sensitivity current.