High level language for measurement complex control based on the computer E-100I

A high level language was designed to control the process of conducting an experiment using the computer "Elektrinika-1001". Program examples are given to control the measuring and actuating devices. The procedure of including these programs in the suggested high level language is described

Linking of the mini-computer Electronik-100I and NR-9821A

The means of transmitting digital information from the computer E-100I to the desk top calculator NR-9821A with the help of an intermediate carrier of information (perforated tape) is described. The means of removal of information from the computer E-100I in a form which is understandable for the NR-9821A are given. Instructions for the use and programming of the transcription of information onto magnetic tape from the perforated tape and from the keyboard of the calculator are included

Screened hybrid functional applied to 3d^0-->3d^8 transition-metal perovskites LaMO3 (M=Sc-Cu): influence of the exchange mixing parameter on the structural, electronic and magnetic properties

We assess the performance of the Heyd-Scuseria-Ernzerhof (HSE) screened hybrid density functional scheme applied to the perovskite family LaMO3 (M=Sc-Cu) and discuss the role of the mixing parameter alpha (which determines the fraction of exact Hartree-Fock exchange included in the density functional theory (DFT) exchange-correlation functional) on the structural, electronic, and magnetic properties. The physical complexity of this class of compounds, manifested by the largely varying electronic characters (band/Mott-Hubbard/charge-transfer insulators and metals), magnetic orderings, structural distortions (cooperative Jahn-Teller like instabilities), as well as by the strong competition between localization/delocalization effects associated with the gradual filling of the t_2g and e_g orbitals, symbolize a critical and challenging case for theory. Our results indicates that HSE is able to provide a consistent picture of the complex physical scenario encountered across the LaMO3 series and significantly improve the standard DFT description. The only exceptions are the correlated paramagnetic metals LaNiO3 and LaCuO3, which are found to be treated better within DFT. By fitting the ground state properties with respect to alpha we have constructed a set of 'optimum' values of alpha from LaScO3 to LaCuO3: it is found that the 'optimum' mixing parameter decreases with increasing filling of the d manifold (LaScO3: 0.25; LaTiO3 & LaVO3: 0.10-0.15; LaCrO3, LaMnO3, and LaFeO3: 0.15; LaCoO3: 0.05; LaNiO3 & LaCuO3: 0). This trend can be nicely correlated with the modulation of the screening and dielectric properties across the LaMO3 series, thus providing a physical justification to the empirical fitting procedure.Comment: 32 pages, 29 figure

Precision determination of band offsets in strained InGaAs/GaAs quantum wells by C-V-profiling and Schroedinger-Poisson self-consistent simulation

The results of measurements and numerical simulation of charge carrier distribution and energy states in strained quantum wells In_xGa_{1-x}As/GaAs (0.06 < x < 0.29) by C-V-profiling are presented. Precise values of conduction band offsets for these pseudomorphic QWs have been obtained by means of self-consistent solution of Schroedinger and Poisson equations and following fitting to experimental data. For the conduction band offsets in strained In_xGa_{1-x}As/GaAs - QWs the expression DE_C(x) = 0.814x - 0.21x^2 has been obtained.Comment: 9 pages, 12 figures, RevTeX

Експериментальні та теоретичні дослідження таутомерії серед 3-заміщених 2-метилхінолін-4(1H)-онів

4-Hydroxy-/4-oxo tautomerism in the series of 3-substituted 2-methyl-quinolin-4(1H)-ones has been studied by 13C NMR-spectroscopy and quantum-chemical methods in various approximations (restricted Hartree-Fock method, DFT and MP2) for the isolated molecules and for solutions using empirical correction of effects for solvents (PCM COSMO procedure). Substituents that are different in their nature have no significant influence on the value of the chemical shift of carbon in position C4 of the quinolone cycle. The only exception is the carbon shielding associated with the bromine atom in the molecule of 3-bromo-2-methyl-1,4-dihydroquinoline-4-one. Significant deshielding detected in all cases in 13C NMR-spectra of the carbon nuclei in position 4 of the ring is in favour of the existence of all derivatives studied as 4-oxo forms in DMSO-d6 solution. The experimental and calculated values for the chemical shift of carbon in position C4 of 4-oxo and 4-hydroxy isomers differ considerably and can be used as a criterion for assigning quinolin-4 (1H)-ones to a particular tautomeric form.С помощью ЯМР 13С спектроскопии и квантово-химическими методами в различных приближениях (ограниченный метод Хартри-Фока, DFT и МР2) для изолированных молекул и растворов с использованием эмпирической коррекции эффектов растворителей (процедура РСМ COSMO) исследована 4-гидрокси 4-оксо-таутомерия в ряду производных 3-замещенных 2-метилхинолин-4(1Н)-онов. Различные по своему характеру заместители не оказывают существенного влияния на значение химического сдвига углерода в положении С4 хинолонового цикла. Исключение составляет лишь экранирование углерода, связанного с атомом брома в молекуле 3-бромо-2-метил-1,4-дигидрохинолин-4-oна. Значительное дезэкранирование, обнаруженное во всех случаях в спектрах ЯМР 13С для ядер углерода в 4-ом положении кольца, говорит в пользу существования всех исследованных производных в растворе в DMSO-d6 в виде 4-оксо-форм. Экспериментальные и расчетные значения химического сдвига для углерода в положении С4 для 4-оксо- и 4-гидрокси-изомеров заметно отличаются и могут быть использованы в качестве критерия для отнесения хинолин-4(1Н)-онов к той или иной таутомерной форме.За допомогою ЯМР 13С спектроскопії і квантово-хімічними методами в різних наближеннях (обмежений метод Хартрі-Фока, DFT і МР2) для ізольованих молекул і розчинів з використанням емпіричної корекції ефектів розчинників (процедура РСМ COSMO) досліджена 4-гідрокси оксо-таутомерія в ряду похідних 3-заміщених 2-метилхінолін-4(1Н)-онів. Різні за своїм характером замісники не чинять істотного впливу на значення хімічного зсуву вуглецю в положенні С4 хінолонового циклу. Виняток становить лише екранування вуглецю, пов’язаного з атомом брому в молекулі 3-бромо-2-метил-1,4-дигідрохінолін-4-oну. Значне дезекранування виявлене у всіх випадках у спектрах ЯМР 13С для ядер вуглецю в 4-му положенні кільця вказує на користь існування всіх досліджених похідних у розчині в DMSO-d6 у вигляді 4-оксо-форм. Експериментальні та розрахункові значення хімічного зсуву для вуглецю в положенні С4 для 4-оксо- і 4-гідрокси-ізомерів помітно відрізняються і можуть бути використані в якості критерію для віднесення хінолін-4 (1Н)-онів до тієї чи іншої таутомерної форми

Magnetic neutron scattering study of YVO3: Evidence for an orbital Peierls state

Neutron spectroscopy has revealed a highly unusual magnetic structure and dynamics in YVO$_3$, an insulating pseudocubic perovskite that undergoes a series of temperature induced phase transitions between states with different spin and orbital ordering patterns. A good description of the neutron data is obtained by a theoretical analysis of the spin and orbital correlations of a realistic one-dimensional model. This leads to the tentative identification of one of the phases of YVO$_3$ with the ``orbital Peierls state'', a theoretically proposed many-body state comprised of orbital singlet bonds.Comment: final version, to appear in PR

Neutron diffraction study of YVO3, NdVO3, and TbVO3

The structural and magnetic properties of YVO3, NdVO3 and TbVO3 were investigated by single-crystal and powder neutron diffraction. YVO3 shows a structural phase transition at 200 K from an orthorhombic structure with the space group Pbnm to a monoclinic one with the space group P21/b. But supplementary high-resolution synchrotron diffraction experiments showed that the monoclinic distortion is extremely small. A group theoretical analysis shows that this magnetic state in the monoclinic phase is incompatible with the lattice structure, unless terms of higher than bilinear order in the spin operators are incorporated in the spin Hamiltonian. This observation is discussed in the light of recent theories invoking unusual many-body correlations between the vanadium t2g orbitals. A structural phase transition back to the orthorhombic space group Pbnm is observed upon cooling below 77 K. This transition is accompanied by a rearrangement of the magnetic structure into a mode compatible with the lattice structure. The crystal structures of NdVO3 and TbVO3 are closely similar to that of YVO3. However, only a single magnetic phase transition was found in the vanadium sublattice down to 9.5 K. Below 60 K the magnetic moments of the Nd- and Tb-ions are gradually polarized by the ordered vanadium moments. Below 11 K, we found a noncollinear order of the terbium moments

Bacterioplankton reveal years-long retention of Atlantic deep-ocean water by the Tropic Seamount.

Seamounts, often rising hundreds of metres above surrounding seafloor, obstruct the flow of deep-ocean water. While the retention of deep-water by seamounts is predicted from ocean circulation models, its empirical validation has been hampered by large scale and slow rate of the interaction. To overcome these limitations we use the growth of planktonic bacteria to assess the retention time of deep-ocean water by a seamount. The selected Tropic Seamount in the North-Eastern Atlantic is representative for the majority of isolated seamounts, which do not affect the surface ocean waters. We prove deep-water is retained by the seamount by measuring 2.4* higher bacterial concentrations in the seamount-associated or 'sheath'-water than in deep-ocean water unaffected by seamounts. Genomic analyses of flow-sorted, dominant sheath-water bacteria confirm their planktonic origin, whilst proteomic analyses of the sheath-water bacteria, isotopically labelled in situ, indicate their slow growth. According to our radiotracer experiments, it takes the sheath-water bacterioplankton 1.5 years to double their concentration. Therefore, the seamount should retain the deep-ocean water for 1.8 years for the deep-ocean bacterioplankton to grow to the 2.4* higher concentration in the sheath-water. We propose that turbulent mixing of the seamount sheath-water stimulates bacterioplankton growth by increasing cell encounter rate with ambient dissolved organic molecules