Уважаемые коллеги!Благодарим Вас за проявленный интерес к Четвертой российской конференции «Графен: молекула и 2D кристалл» и желание принять участие в её работе.Конференция проходит в научно-образовательном центре города Новосибирска -Академгородке.Мероприятие посвящено актуальным направлениям исследований и разработок в области углеродных и низкоразмерных материалов.Проведение конференции поможет координации усилий ученых в решении современных проблем материаловедения и привлечению молодых исследователей для решения актуальных научных задач.Оргкомитет выражает особую благодарность НГУ, Центру компетенций НТИ «Моделирование и разработка новых функциональных материалов с заданными свойствами», компаниям «Диаэм», «НТ-МДТ Спектрум Инструментс» и корпорации "Графеновая Долина" за финансовую поддержку и журналам Аналитика, Наноиндустрия и РЭНСИТ за информационную поддержку.Искренне надеемся, что пребывание в Новосибирском Академгородке и в стенах Новосибирского государственного университета оставит множество положительных эмоций и

The concept of a water thermal accumulator based on phase-change materials (PCMs) has been proposed and analyzed. In such a system, energy accumulation (release) occurs due to a phase transition in PCMs, and water is used as a working fluid. The thermal accumulator consists of identical modules, the number of which determined by the quantity of accumulated energy. Each module represents a double concentric tube, in which the inner cavity is filled with flowing water and the outer cavity is filled with PCMs. The PCM used is paraffin wax, which has a specific melting enthalpy of 216 J/g. To increase the PCM heat conductivity coefficient, an additive of thermally reduced graphene oxide is used. The passage of hot water through the inner tube results in the melting of paraffin wax, which accumulates the thermal energy corresponding to the melting enthalpy. This energy is recovered when cold water is passed through the system containing the melted paraffin wax and heated as a result of paraffin wax solidification. Some estimates of thermal accumulator regimes and the results of calculating the unsteady longitudinal and transversal temperature distributions at different time moments are given.

Phase changing materials (PCM) can accumulate and release a great quantity of energy at changing the temperature in result of the phase transition. This permits one to use PCMs as a basis of thermal accumulators storing the thermal energy at elevated temperatures and releasing it at lowering the temperature below the phase transition point. Worldwide usage of PCMs in building technology and other fields is hindered by a rather low thermal conductivity coefficient of the most PCMs which makes the response of the relevant thermal accumulators too slow and limits the possibilities of application of such devices. This drawback can be overcame through doping a PCM with particles having high thermal conduction coefficient. The present article contains results of experimental and theoretical investigations of heat propagation in PCM doped with carbon nanotubes the thermal conduction coefficient of which exceeds that of the most PCM by 4 – 5 orders of magnitude. Paraffin П-2 have been used as PCM. The experiments performed demonstrate a 2 – 3 times enhancement of thermal conductivity and 16 orders of magnitude enhancement of the electric conductivity because of doping paraffin with 10% multi-walled nanotubes. The propagation of both heat and electric current has a percolation character, so that nanotubes form conductive paths at exceeding some concentration of the dopant. The heat propagation process was modelled through the solution of the non-stationary heat conduction equation with taking into account the sorption of heat due to the phase transition. The calculations performed for composite materials with the varied thermal characteristics of a material imply that the characteristic heating time is proportional to the value of the melting enthalpy and inversely proportional to the value of the heat conduction coefficient.

for the first time (for given compositions), solid solutions of the GaAs-CdSe system have been obtained, certified on the basis of X-ray and submicroscopical studies as substitution solid solutions with sphalerite and wurtzite structure. The consistent interrelated patterns in changes with composition changes of the system, crystallochemical and structural properties have been revealed: parameters - a, c; crystal lattices interplanar distances - dhkl; theoretical calculated crystal density - ρr; the average number of the most displayed particles in the components – nav. The pH values of the system components’ surfaces isoelectric state have been determined, which fit into the faintly-acid range. On the ground of the set of obtained results, revealed patterns, correlations between them, a conclusion has been made about a possible preliminary certification of the obtained solid solutions of systems similar to the studied one and a possible facilitated way of searching for advanced, promising materials for creating measuring cells for main gases micro impurities, in particular ammonia.

The study was made of the bulk (structural, crystallochemical, optical, and electrophysical properties, i.e. the values of the bandgap were determined) and surface (acid-base) properties of new semiconductor materials, namely, solid solutions (CdS)(x)(ZnS)(1-x) with various compositions. The regularities of their changing and the relation between bulk and surface properties were detected. The state diagrams "property-composition" were constructed forming the foundation for finding solid solutions with optimal composition for gas sensors production.

Based on the direct investigation results of adsorption properties of semiconductors systems ZnTe – GaSb, ZnTe – ZnS in relation to gases of the different electronic nature (NH3, CO) the predictions of their surface activity to basic and acid gases, expressed on the basis of bulk and acid-base properties are confirmed. Practical recommendations on the use of materials (of certain composition) in the sensor equipment are proposed.