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101.
    
ABSTRACT

The article deals with the study of plane wave propagation in the thermoelastic medium in the presence of voids. The problem is considered in the context of three-phase-lag model of generalized thermoelasticity. There exists three longitudinal waves, namely elastic (E-mode), thermal (T-mode) and volume fraction (V-mode) in addition to transverse waves which get decoupled from the rest of motion and not affected by thermal and volume fraction fields. The fundamental solution of the system of differential equations in case of steady oscillations in terms of the elementary functions has been constructed. The phase velocity and attenuation coefficient of these waves are computed numerically and presented graphically.  相似文献   
102.
103.
    
In this paper, we consider the three dimensional Cauchy problem of the compressible micropolar viscous flows. We prove the existence of unique global classical solution for smooth initial data with small initial energy but possibly large oscillations and the initial density may allowed to contain the interior and far field vacuum states. Furthermore, the large time behavior of the solution is obtained as well.  相似文献   
104.
    
Nonclassical effects in mesoscopic systems have attracted much attention recently. In this paper, it is shown that multiphonon bundle emission can be observed in a strong-coupling cavity optomechanical system. Theoretical analysis shows that when the driving field is adjusted to nth-order sideband excitation, the coupling between the cavity mode and the vibrational mode leads to super-Rabi oscillations, and finally results in an n-phonon bundles emission. Based on the current technology, this process can work in a wide range of parameters. Numerical simulation confirms the validity of the derivation. It is thought that this physical mechanism broadens the applications of cavity optomechanical system in realm of quantum phononics, such as in quantum metrology and phonon laser.  相似文献   
105.
    
《Comptes Rendus Physique》2018,19(5):285-305
After the discovery of graphene and of its many fascinating properties, there has been a growing interest for the study of “artificial graphenes”. These are totally different and novel systems that bear exciting similarities with graphene. Among them are lattices of ultracold atoms, microwave or photonic lattices, “molecular graphene” or new compounds like phosphorene. The advantage of these structures is that they serve as new playgrounds for measuring and testing physical phenomena that may not be reachable in graphene, in particular the possibility of controlling the existence of Dirac points (or Dirac cones) existing in the electronic spectrum of graphene, of performing interference experiments in reciprocal space, of probing geometrical properties of the wave functions, of manipulating edge states, etc. These cones, which describe the band structure in the vicinity of the two connected energy bands, are characterized by a topological “charge”. They can be moved in the reciprocal space by appropriate modification of external parameters (pressure, twist, sliding, stress, etc.). They can be manipulated, created or suppressed under the condition that the total topological charge be conserved. In this short review, I discuss several aspects of the scenarios of merging or emergence of Dirac points as well as the experimental investigations of these scenarios in condensed matter and beyond.  相似文献   
106.
A three-parameter model of neutrino oscillations based on a simple Lorentz- and CPT-violating texture is presented. The model is consistent with established data and naturally generates low-energy and neutrino–antineutrino anomalies of the MiniBooNE type. A one-parameter extension incorporates the MINOS anomaly, while a simple texture enhancement accommodates the LSND signal.  相似文献   
107.
热声波数值模拟的虚假振荡研究   总被引:6,自引:4,他引:6  
采用可压缩流动的SIMPLE算法对一维封闭空腔内由边界突然加热所引起的非稳态热声波进行了数值模拟,对流-扩散项采用了中心差分、一阶迎风差分、QUICK、及MIJSCL等不同格式。计算表明各种格式均存在不同程度的虚假振荡现象,其大小与热声波的强度及离散格式的形式等多种因素有关。这些结果对热声波的进一步研究及高效可靠的对流差分格式的开发具有重要意义。  相似文献   
108.
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   
109.
Established results on neutrino mass, mixing and flavor change (as of 2009) are briefly reviewed. Status and prospects of unknown neutrino properties (smallest mixing angle, Dirac/Majorana nature, absolute masses and their hierarchy) are also discussed.  相似文献   
110.
雷啸霖 《物理》2004,33(9):623-628
一年以前 ,人们惊奇地发现 :在相当弱的磁场中 ,并不太强的微波辐照就可以使二维半导体的磁阻产生强烈的振荡 ,振幅的最大值可超过无辐照磁阻值的十几倍 ,最小值可以一直降到零 .全世界众多的凝聚态物理学家争相聚焦到这个领域 ,进行了许多实验和理论研究 ,企图弄清这一意外发现的机理 .经过一年多的努力 ,人们已经掌握了这个现象更多的细节 ,对其物理机制也有了初步了解 .但深入的实验和理论探索可能还要继续相当一段时间 .文章将对这个物理现象及相关的理论模型 ,尤其是目前得到较多赞同的光子辅助磁输运模型 ,作一简单的介绍 .  相似文献   
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