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31.
K.?V.?Zubowa A.?V.?Zubow V.?A.?ZubowEmail author 《Journal of Applied Spectroscopy》2005,72(6):840-847
Using the flicker-noise method (FNM), we investigated the oscillations of clusters in aqueous solutions of NaCl in the range
of concentrations from 0.1 to 26.0 mass %. It has been established that in the solutions oscillators whose masses are similar
to the masses of the models of aggregates of solvate clusters of ion pairs (SCIP) of salt with a different water content are
present. In diluted solutions (<10%), the elementary SCIP has the form NaCl· 40H2O. For the entire range of concentrations the SCIPs are given by structures based on the cubic system of the sodium chloride
system. The base structure for them is a cube formed from 12 SCIPs of salt. The largest cluster revealed by the FNM method
for all investigated concentrations of salt had a mass of ≈1.5 million D. The presence of NaCl in water leads to a collapse
of its cluster structure, except for the smallest clusters (H2O)10…11, whose concentration increases with temperature or solution concentration. The distribution of SCIPs changes dramatically
at a temperature above 300 K. The possible structures of SCIPs are given and the mechanism of their formation is discussed.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 6, pp. 766–772, November–December, 2005. 相似文献
32.
Marek Biesiada 《General Relativity and Gravitation》2003,35(8):1503-1510
In a recent paper Abramowicz and Kluniak [1] have discussed the problem of epicyclic oscillations in Newton's and Einstein's dynamics and have shown that Newton's dynamics in a properly curved three-dimensional space is identical to test-body dynamics in the three-dimensional optical geometry of Schwarzschild space-time. One of the main results of this paper was the proof that different behaviour of radial epicyclic frequency and Keplerian frequency in Newtonian and General Relativistic regimes had purely geometric origin contrary to claims that nonlinearity of Einstein's theory was responsible for this effect. In this paper we obtain the same result from another perspective: by representing these two distinct problems (Newtonian and Einstein's test body motion in central gravitational field) in a uniform way — as a geodesic motion. The solution of geodesic deviation equation reproduces the well known results concerning epicyclic frequencies and clearly demonstrates geometric origin of the difference between Newtonian and Einstein's problems. 相似文献
33.
A. L. Tukmakov 《Journal of Applied Mechanics and Technical Physics》2003,44(1):64-68
Synchronization of oscillations of thin elastic plates that are walls of a gasfilled channel is considered. The gas motion is described by a system of Navier–Stokes equations, which is solved using the secondorder MacCormack method with time splitting. The motion of the channel walls is described by a system of geometrically nonlinear dynamic equations of the theory of this plates, which is solved by the finitedifference method. Kinematic and dynamic contact conditions are imposed at the interface between the media. A numerical experiment is performed to determine typical dynamic regimes and study the transition of the aeroelastic system to inphase oscillations. 相似文献
34.
Dynamic properties of simple mechanical 1 DOF system containing soft stop is described and analyzed. The proposed general dynamical impact model respects the nonlinearity of the restoring contact force between solid bodies as function of deformation and velocity. It describes the real behavior of impacting system more exact than the piecewise linear model or the Kelvin–Voigt model and even model based on application of constant coefficient of restitution. Free and forced vibrations of system with Hertz's contact are investigated and domains of various types of impact motion, response curves and phase-plane trajectories are presented. 相似文献
35.
The asymptotic behavior of difference equations of type 0, \end{equation*}">is studied, where and each are continuous real functions with decreasing and increasing. Results include sufficient conditions for permanence, oscillations and global attractivity.
36.
Margarita A. Deneva Pepa I. Uzunova Marin N. Nenchev 《Optical and Quantum Electronics》2007,39(3):193-212
We report (theory, experimental check) an improved approach for generation of a tunable, subnanosecond pulse (0.1–0.4 ns),
based on a single pulsation (“spike”) separation from the transient oscillations in a dye laser with active mirror (AMIR).
A pumping by 20–50 ns pulses from Q-switched Nd:YAG laser is considered. The separation is in original, two-spectral selective
channels cavity, where the forced by AMIR quenched generation at one of the wavelength stops initially started spiking generation
at the other wavelength after the first spike development. The AMIR quickly starts the quenching generation at a precisely
controlled moment and with necessary intensity thus assuring the desired separation. An advantage is a high reproducibility
of the separation for high (~250%) pump power fluctuations combined with tuning in large range (~20 nm). To obtain such an
operation we form ~1 ns leading front pump pulse by electrooptical temporal cutting of the input pump pulse and use an optical
delay line. This increases also a few times the power in the separated spike (to be ~100 kW). Our approach widens the combinations
of lasers for effective applications of spike separation technique (dye lasers excited by Q-switched solid-state or Cu-vapor
lasers). 相似文献
37.
Alexander M. Kuznetsov Jens Ulstrup 《Journal of inclusion phenomena and macrocyclic chemistry》1999,35(1-2):45-54
Expressions are derived for the tunnel electric current between two metals produced by the adiabatic transitions of the electrons through a bridge electron level. A new possible physical phenomenon is discussed, viz. electronically driven oscillations of the electron bridge level between two molecular wires. 相似文献
38.
39.
In the Shubnikov–de Haas oscillation spectrum of doped InAs/AlSb structures, high-amplitude peaks are established at combination
frequencies. It is demonstrated that they are caused by a significant contribution of intersubband scattering to the processes
of electron-electron interaction.
Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 32–38, December, 2008. 相似文献
40.
自然循环过冷沸腾流动不稳定性的实验研究 总被引:2,自引:0,他引:2
本文以氟里昂作工质,对自然循环过冷沸腾流动不稳定性进行了实验研究.实验过程中发现自然循环系统内可能发生高频脉动和低频脉动二种类型的过冷沸腾流动不稳定性.通过实验研究揭示了这二种类型流动不稳定性的发生机理,证实高频脉动属于声波型脉动,低频脉动属于密度波型脉动.通过实验得出了判断系统稳定性的界限,并使用积分方程无因次分析方法得出了预测密度波型流动不稳定性的经验公式. 相似文献