Boundary controllability problems for the wave equation in a parallelepiped

AbstractThe wave equation in an N-dimensional parallelepiped with boundary control equal zero everywhere except of an edge of dimension N − 2 is considered. The other case which is investigated is the boundary control acting on a face of dimension N − 1 and depending on N − 1 independent variables (including t). It is proved that, in both cases, the system is not approximately controllable for any T > 0

An Alanic marginal note and the exact date of John II's battle with the Pechenegs

Descriptive and Comparative Linguistic

Structural and magnetic properties of Mn3-xCdxTeO6 (x = 0, 1, 1.5 and 2)

Mn3TeO6 exhibits a corundum-related A3TeO6 structure and a complex magnetic structure involving two magnetic orbits for the Mn atoms [*]. Mn3-xCdxTeO6 (x=0, 1, 1.5 and 2) ceramics were synthesized by solid state reaction and investigated using X-ray powder diffraction, electron microscopy, calorimetric and magnetic measurements. Cd2+ replaces Mn2+ cations without greatly affecting the structure of the compound. The Mn and Cd cations were found to be randomly distributed over the A-site. Magnetization measurements indicated that the samples order antiferromagnetically at low temperature with a transition temperature that decreases with increasing Cd doping. The nuclear and magnetic structure of one specially prepared 114Cd containing sample: Mn1.5(114Cd)1.5TeO6, was studied using neutron powder diffraction over the temperature range 2 to 295 K. Mn1.5(114Cd)1.5TeO6 was found to order in an incommensurate helical magnetic structure, very similar to that of Mn3TeO6 [*]. However, with a lower transition temperature and the extension of the ordered structure confined to order 240(10) {\AA}. [*] S. A. Ivanov et al. Mater. Res. Bull. 46 (2011) 1870.Comment: 20 pages, 8 figure

Искаженная картография как отражение конфликтов и политических противоречий в современном мире

Some features of modern political cartography are analyzed. The authors note that sometimes for the sake of political interests of some international actors, geographic maps, distorted and not responding to modern political realities, are produced. Such false maps mislead the mass audience. The authors emphasize the particular danger of a “war of maps” in regions of heightened conflict, to which, above all, the Middle East and North Africa belong. They conclude that the forged geographic maps, along with the distortion of historical truth and the essence of historical and modern events and processes, become an integral element of a new destructive type of weapons of the 21st century - information confrontation.В статье анализируются некоторые особенности современной политической картографии, связанные с тем, что нередко в угоду политическим интересам конкретных международных акторов производятся на свет искаженные, не соответствующие современным политическим реалиям карты. Такие фальшивые карты вводят массовую аудиторию в заблуждение. Подчеркивается особая опасность «войны карт» в регионах повышенной конфликтности, к которым относится, прежде всего, Ближний Восток и Северная Африка. Делается вывод, что подложные географические карты, наряду с искажением исторической правды и сущности исторических и современных событий и процессов, становятся составным элементом нового разрушительного вида оружия ХХI века - информационного противоборства

Power system for schoolchildren based on their genotypes

The article discusses a decision support system based on the clustering of genotypes and used in managing personalized nutrition for schoolchildren. The results of solving the problem for specific objects that have passed laboratory studies of gene states are presented. Modern scientific research in the field of nutrigenomics has shown that the selection of the optimal nutrition plan, taking into account genetic characteristics, increases the effectiveness of such programs by 200-300% compared with traditional approaches. This report discusses the use of soft computing (the method of clustering multidimensional objects) to determine typical clusters for managing personalized customer nutrition based on their genotypes

Molecular structures of thymidine isomers isolated in low-temperature inert matrices

The Fourier transform infrared spectra of 2`-deoxyribonucleoside — thymidine (dT) in low-temperature Ar matrices are obtained in the range 4000–1300 cm–¹. It is determined that anti-conformers of thymidine are dominant. The ribose rings of the main anti-conformers dT_a0, dT_a1 are in the C2`-endo conformation, but the ribose rings of minor anti-conformers dT_a2, dT_a3 have the C3`-endo conformation, stabilized by intramolecular hydrogen bonds O3`H…O5` and O5`H…O3`, respectively. The main syn-conformer dT_s2 is stabilized by the intramolecular hydrogen bond O5`H…O2 and has C2`-endo conformation of the ribose ring

Первая краевая задача для уравнения теплопроводности с нагрузкой дробного порядка. II

В статье рассмотрена первая краевая задача для нагруженного уравнения теплопроводности в четверти плоскости. Нагруженное слагаемое - след производной дробного порядка на многообразии x=t. Решение задачи сводится к исследованию особого интегрального уравнения Вольтерра второго рода с несжимаемым ядром. Решение характеристического уравнения методом регуляризации показало, что особое интегральное уравнение Вольтерра имеет непустой спектр при 1/2≤β<1. Доказана теорема осуществовании нетривиального решения однородной краевой задачи в неограниченной области

The alpha-particle in nuclear matter

Among the light nuclear clusters the alpha-particle is by far the strongest bound system and therefore expected to play a significant role in the dynamics of nuclei and the phases of nuclear matter. To systematically study the properties of the alpha-particle we have derived an effective four-body equation of the Alt-Grassberger-Sandhas (AGS) type that includes the dominant medium effects, i.e. self energy corrections and Pauli-blocking in a consistent way. The equation is solved utilizing the energy dependent pole expansion for the sub system amplitudes. We find that the Mott transition of an alpha-particle at rest differs from that expected from perturbation theory and occurs at approximately 1/10 of nuclear matter densities.Comment: 9 pages RevTex file, 1 figure, submitted to Phys. Lett.

Overcoming the limits of vortex formation in magnetic nanodots by coupling to antidot matrix

Static magnetic configurations of thin circular soft (permalloy) magnetic nanodots, coupled to a hard antidot matrix with perpendicular magnetization, are studied by micromagnetic simulations. It is demonstrated, that dipolar fields of the antidot matrix promotes the formation of a magnetic vortex state in nanodots. The vortex is the dot ground state at zero external field in ultrathin nanodots with diameters as low as 60 nm, that is far beyond the vortex stability range in an isolated permalloy nanodot. Depending on the geometry and antidot matrix material it is possible to stabilize either radial vortex state or unconventional vortices with the angle between in-plane magnetization and radial direction ψ ≠ 0 , π / 2

Использование устройств аспирации тромба при острых окклюзиях коронарных артерий

There were analyzed 38 patients with acute coronary syndrome with ST segment elevation. Every patient was revealed by coronary angiography to have an occlusion in one of the main coronary arteries. The patients were divided in two groups by the technique of percutaneous coronary intervention. In the first group (n = 18) after mechanical recanalisation with wire we used a catheter for thrombus aspiration. Furthermore according to results after coronary angiography these patients underwent either direct stenting or predilatation with further stenting. After mechanical recanalisation in the second group (n = 20) routine stenting with predilatation were performed. The reperfusion quality was evaluated by TIMI scale by the angiography and ST segment decrease during 30 minutes after the intervention. It was statistically proved that adequate reperfusion was achieved in the group with thrombus aspiration catheter.Проанализированы результаты обследования и лечения 38 пациентов с инфарктом миокарда с подъемом сегмента ST. По результатам коронарной ангиографии во всех наблюдениях определялась окклюзия одной из магистральных коронарных артерий. Пациенты были разделены на две группы в зависимости от тактики выполнения чрескожного коронарного вмешательства. В первой группе (n = 18) после механической реканализации проводником в зону окклюзии вводили катетер для аспирации тромба. Далее в зависимости от ангиографического результата выполнялось прямое стентирование поражения или предварительная баллонная ангиопластика с последующим стентированием. Во второй группе (n = 20) после механической реканализации выполнялась баллонная ангиопластика с последующим стентированием. Адекватность реперфузии оценивалась по степени восстановления кровотока по шкале TIMI по результатам коронарной ангиографии и по снижению сегмента ST по данным ЭКГ через 30 минут после окончания вмешательства. При сравнении результатов первой и второй групп установлено, что достоверно чаще в первой группе пациентов удавалось достигнуть адекватной реперфузии