Ultrarelativistic electron-hole pairing in graphene bilayer

We consider ground state of electron-hole graphene bilayer composed of two independently doped graphene layers when a condensate of spatially separated electron-hole pairs is formed. In the weak coupling regime the pairing affects only conduction band of electron-doped layer and valence band of hole-doped layer, thus the ground state is similar to ordinary BCS condensate. At strong coupling, an ultrarelativistic character of electron dynamics reveals and the bands which are remote from Fermi surfaces (valence band of electron-doped layer and conduction band of hole-doped layer) are also affected by the pairing. The analysis of instability of unpaired state shows that s-wave pairing with band-diagonal condensate structure, described by two gaps, is preferable. A relative phase of the gaps is fixed, however at weak coupling this fixation diminishes allowing gapped and soliton-like excitations. The coupled self-consistent gap equations for these two gaps are solved at zero temperature in the constant-gap approximation and in the approximation of separable potential. It is shown that, if characteristic width of the pairing region is of the order of magnitude of chemical potential, then the value of the gap in the spectrum is not much different from the BCS estimation. However, if the pairing region is wider, then the gap value can be much larger and depends exponentially on its energy width.Comment: 13 pages with 8 figures; accepted to Eur. Phys. J.

Formation of a system for increasing the sustainability and productivity of the agro-industrial complex

Research into the issues of increasing the sustainability and productivity of the agro-industrial complex is becoming more and more in demand. The agro-industrial complex acts as a point of concentration of resources in the sphere of material production, a catalyst for economic development, and ensures an increase in the quality of life. This article discusses the issue of measures to increase the sustainability and productivity of the agro-industrial complex as part of strategic planning, ensuring continuous economic growth and the formation of food security, including using methods of effective human resource management. The authors analyzed the problematic aspects of the internal and external environment that affect the productivity of the agro-industrial complex, and also formulated relevant proposals to overcome pressing problems. © Published under licence by IOP Publishing Ltd

Electrochemical stability and transformations of fluorinated poly(2,6-dimethyl-1,4-phenylene oxide)

Fluorination of poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) leads to narrowing of its window of electrochemical stability in a cathodic range of potentials. It is found this is connected with appearance of both perfluorinated and incompletely fluorinated units in the polymer. The former units are liable to electrochemical reduction (at potentials <−2.0 V) followed by elimination of fluorine anions and the latter react with basic products (generated at potentials <−1.8 V) of electrochemical reduction of the background solution. In the both cases this results in appearance of conjugated multiple bonds in the fluorinated macromolecules. Quantities of these units in fluorinated PPO were determined with a help of direct and indirect electrochemical reductive degradation techniques

История политических и гражданских прав женщин в Норвегии

The formation and development of women's rights in Europe has a long history, different within each of the states. The publication is devoted to the study of the political and civil rights of women in Norway from the beginning of the 19th to the end of the 20th centuries. The authors consider the development of women's rights against the backdrop of a changing situation within the state. The key milestones in establishing the political and civil rights of women are analysed.Становление и развитие прав женщин в Европе имеет длительную историю, различную внутри каждого из государств. Публикация посвящена изучению политических и гражданских прав женщин в Норвегии в период с начала XIX до конца XX века. Авторы рассматривают развитие прав женщин на фоне меняющейся обстановки внутри государства. Анализируются ключевые вехи в установлении политических и гражданских прав женщин

Modeling of arrangement tolerances for the optical elements in a spaceborne Offner imaging hyperspectrometer

Предложен математический аппарат, проведены исследования изображения в плоскости регистратора гиперспектрометра по схеме Оффнера, определены условные допуски на положение элементов спектрометра. Результат моделирования совместного действия погрешностей показал, что вероятность удачной сборки гиперспектрометра с соблюдением требований по качеству изображения будет не меньше 0,9.Работа выполнена при частичной поддержке грантов РФФИ № 16-29-11744, № 16-29-09528 и государственного задания ИСОИ РАН (соглашение № 007-ГЗ/43363/26)

Reactions and stability of fluorinated poly(vinyl trimethylsilane) in electrochemical systems

Fluorinated poly(vinyl trimethylsilane) (FPVTMS) unlike virgin PVTMS is able to participate in electrochemical reactions and undergoes direct and indirect electrochemical reductive degradation. Specifically, its perfluorinated units are reduced irreversibly at a glass carbon electrode in a 0.05-M (C4H9)4ClO4 solution in dimethylformamide with subsequent splitting of C–F bonds and formation of conjugated double bonds in macromolecules at the polymer surface. On the other hand, the incompletely fluorinated units at the FPVTMS surface interact with the previously electrochemically reduced background solution to be dehydrofluorinated. This is accompanied by the formation of conjugated double bonds and dissolution of the dehydrofluorinated layer also. The data obtained allowed distinguishing the incompletely fluorinated units from the perfluorinated ones in the fluorinated layer of FPVTMS. Moreover, the quantity of the incompletely fluorinated units in FPVTMS can be determined. It was found that the strengthening of fluorination conditions led to an enhancement of the electrochemically induced FPVTMS transformations