Variability of quasi-stationary planetary waves

The results of the analysis of nonzonal perturbations (m = 1, 2, 3) of the geopotential field at a 30 mb level are presented. A long period modulation of the harmonics' amplitude is discovered. Calculations of eigenfunctions and eigennumbers of the Laplace tidal equation are carried out for a real latitudinal wind profile. The observed first zonal harmonic in different years is caused by the same mode. Thus, the difference in the wave amplitudes could not be accounted for by the difference in stratospheric zonal circulation in different years and should be related to tropospheric processes

A novel-type luciferin from Siberian luminous earthworm Fridericia heliota : structure elucidation by spectral studies and total synthesis

Author Posting. © The Author(s), 2014. This is the author's version of the work. It is posted here by permission of Wiley-VCH Verlag GmbH & Co for personal use, not for redistribution. The definitive version was published in Angewandte Chemie International Edition 53 (2014): 5566–5568, doi:10.1002/anie.201400529.We report structure elucidation and synthesis of the luciferin from the recently discovered luminous earthworm Fridericia heliota. This luciferin represents a key component of a novel ATP-dependent bioluminescence system. The UV, fluorescence, NMR and HRMS spectral studies were performed on 5 mkg of the isolated substance, and gave four isomeric structures, conforming with spectral data. These isomers were chemically synthesized and one of them was found to produce light in the reaction with a protein extract from Fridericia. The novel luciferin was found to have an unusual deeply modified peptidic nature, implying an unprecedented mechanism of action.We acknowledge support from the Program of the Government of the Russian Federation “Measures to attract leading scientists to Russian educational institutions” (grant no. 11. G34.31.0058), the programs MCB RAS, President of the Russian Federation “Leading science school” (grant 3951.2012.4) and the Russian Foundation for Basic Research (grant 14-03-01015). B.M.S. was supported by a stipend from the Program of the President of the Russian Federation.2015-04-1

Picosecond Fluorescence Relaxation Spectroscopy of the Calcium-Discharged Photoproteins Aequorin and Obelin

Addition of calcium ions to the Ca2+-regulated photoproteins, such as aequorin and obelin, produces a blue bioluminescence originating from a fluorescence transition of the protein-bound product, coelenteramide. The kinetics of several transient fluorescent species of the bound coelenteramide is resolved after picosecond-laser excitation and streak camera detection. The initially formed spectral distributions at picosecond-times are broad, evidently comprised of two contributions, one at higher energy (25000 cm-1) assigned as from the Ca2+-discharged photoprotein-bound coelenteramide in its neutral state. This component decays much more rapidly (t1/2 2 ps) in the case of the Ca2+-discharged obelin than aequorin (t1/2 30 ps). The second component at lower energy shows several intermediates in the 150-500 ps times, with a final species having spectral maxima 19400 cm-1, bound to Ca2+-discharged obelin, and 21300 cm-1, bound to Ca2+-discharged aequorin, and both have a fluorescence decay lifetime of 4 ns. It is proposed that the rapid kinetics of these fluorescence transients on the picosecond time scale, correspond to times for relaxation of the protein structural environment of the binding cavit

Discrete a Non-linear Hamiltonian Dynamics Models of Hyper Elastic Deformable Media

A method of mathematical modeling of the dynamics of three-dimensional nonlinear deformable hyperelastic media is developed in this paper. The method is based on the Hamiltonian description of discrete classical mechanics and on symplectic integration method for the solution at each instant of time. Comparative results of the solution of a model problem are presented. The results of solution of the topical problem of dynamic behavior of an artificial aortic artery are also presented.Разработан метод математического моделирования динамики трехмерных нелинейно деформируемых гиперупругих сред, основанный на Гамильтоновом описании дискретной классической механики и симплектическом методе интегрирования решения на временном слое. Представлены сравнительные результаты решения модельной задачи и решение актуальной задачи биомеханики о динамике аортальной артерии

On the wave dynamics in damaged shells interacting with the volume of the cavitating liquid

We study the details of shock front propagation in the system of deformable medium (shells) with damages and two-phase liquid with gas or steam bubbles. We develop the models for the nonlinear processes of media interacting taking into account the phase transformations in liquid and the damaging kinetics of deformable medium. The destruction of deformable medium is considered as the evolution of microdamages or spherical pores, taking as the gas bubbles similarly with the cavitating liquid. The aggregation of the bubbles at the viscoplastic flow cases the macrofracture forming. We formulate the nonlinear boundary value problem of the multiphase medium dynamics, that includes the equations of the phase interaction and phase transformations. The solution of the problem is based on the decomposition method (an expansion in the processes), finite difference method and finite element method. The results presented are of interest for the practical applications

Transient dynamics of 3D inelastic heterogeneous media analysis by the boundary integral equation and the discrete domains methods

For the study of transients in 3D nonlinear deformable media we develope modeling methods which based on integral representations of 3D boundary value problem of elastic dynamics, numerical high-order approximation schemes of boundaries and collocation approximation of solutions. The generalized boundary integral equation method formulations using fundamental solutions of static elasticity, equation of state of elastoplastic media with anisotropic hardening and difference methods for time integration are represented. We take into account the complex history of combined slowly changing over time and impact loading of composite piecewise-homogeneous media in the presence of local perturbation solutions areas. With the use of this method and discrete domains method the solutions of applied problems of the propagation of non-linear stress waves in inhomogeneous media are received. Comparisons with the solutions obtained by the finite element method are represented also. They confirm the computational efficiency of the developed algorithms, as well as common and useful for practical purposes of the proposed approach

Boundary Integral Equation Method in the Modeling of Nonlinear Deformation and Failure of the 3D Inhomogeneous Media

The method of boundary integral equations is applied for solving the nonlinear problems of thermo-elastic-plastic deformation and fracture of inhomogeneous 3D bodies of the complex form. Solution is constructed on the basis of the generalized identity of Somigliana involving method of sequential linearization in the form of initial plastic deformations. The increments of plastic deformation are determined on the basis of the flow theory of hardening elastoplastic media with the use of modifed Prandtl–Reus's relations. The cases of complex thermo mechanical loading of compound piecewise homogeneous media in contact are considered. For describing the processes of nonlinear deformation and fracture of the bodies with a complex geometry and local peculiarities a method of discrete domains (DDBIEM) is developed. The solutions of some practical significant 3D non-linear problems of the mechanics of deformation and fracture are presented

Viscoplastic Flows and Strain Localization in a Damageable Medium under Impact Loading

На основе экспериментальных наблюдений представлена обобщенная модель нелинейного взаимо- связанного деформирования и разрушения повреждаемых поликристаллических сред при высоко- скоростных ударных воздействиях. Учитываются геометрическая нелинейность, обусловленная конечными деформациями, и нелинейное, зависящее от скорости деформирования поведение ма- териалов с изменяемой микроструктурой, анизотропным упрочнением и эффектом Баушингера. Выполнена постановка соответствующих нелинейных краевых задач, решения которых получе- ны с использованием эффективных численных методов. Изучены нелинейные волновые процессы и локализация деформаций в объемных телах под действием взрыва и при высокоскоростном столк- новении с препятствием.On the basis of experimentally observable phenomena a generalized model of nonlinear interconnected deformation and fracture of damaged polycrystalline media at high-speed shock action was developed. The geometric nonlinearity caused by finite nonlinear deformations depending on the loading speed, the behavior of materials with a changeable microstructure, the anisotropic hardening and the Baushinger effect are considered. The corresponding nonlinear boundary value problems are stated and solved by means of efficient numerical methods. Nonlinear wave processes and localization of deformations in spatial bodies under the influence of explosion and high-speed collision with an obstacle are studied