Bounds on the Growth of the Velocity Support for the Solutions of the Vlasov–Poisson Equation in a Torus

A bound on the growth of the velocity for the Vlasov–Poisson equation in a torus is given in one and two dimensions. The main tool used in the proof is a partition into fast and slow particles and the ergodic property of the free motion in a torus.     

Effect of the Initial Laser Phase on the Interaction Between Relativistic Electron and Ultra－Intense Laser Field in a Strong Uniform Magnetic Field

We investigate the influence of the initial laser phase on the interaction between relativistic electron and ultraintense linear polarized laser field in a strong uniform magnetic field. It is found that the dynamic behaviour of the relativistic electron and the emission spectrum varies dramatically with different initial laser field phases.The effect of changing initial phase is contrary in the two parameter regions divided by the resonance condition.The phase dependence of the electron energy and velocity components are also studied. Some beat structure is found when the initial laser phase is zero and this structure is absent when the initial laser phase is a quarter of a period.     

Whether the Sun’s supergranulation possesses a scaling?

The Sun’s supergranulation is considered as a collective effect provided by a statistical ensemble of narrow upflow jets. The responsibility for their occurrence rests with the Rayleigh-Taylor blow-up instability. It is this mechanism that is a trigger for the collapse of thermal irregularities and leads to the formation of such jets. The scaling laws of turbulence generated by these jets are discussed.     

Effects of Impurity on the Ground—State Transitions of a Quantum Dot in Strong Magnetic Field

The low-lying spectra of parabolic quantum dots with or without an impurity at the center are investigated.While it has been known that the electron-electron interaction leads to ground-state transitions on magic values of angular momentum in a magnetic field.We show,in this paper,that the implantation of an impurity ion at the center can either enhance or suppress such transitions,depending on whether it is an acceptor or a donor ion.     

FEM Modal Analysis on the Gravity Support System of ITER

The three-dimensional finite element method model with 20 degree sector of the ITER overall gravity support system was built by the ANSYS software. The modal analysis of the gravity support system was made and first ten natural frequencies and vibration modes of the gravity support system were calculated by using Block Lanczos method. The results of modal analysis on ITER represent that the stiffness of flexible plates has influenced greatly for the natural frequency of the system.     

Further Study on the Conservation Laws of?Energy-Momentum Tensor Density for a Gravitational System

The various methods to derive Einstein conservation laws and the relevant definitions of energy-momentum tensor density for gravitational fields are studied in greater detail. It is shown that these methods are all equivalent. The study on the identical and different characteristics between Lorentz and Levi-Civita conservation laws and Einstein conservation laws is thoroughly explored. Whether gravitational waves carry the energy-momentum is discussed and some new interpretations for the energy exchanges in the gravitational systems are given.     

Neutral-Pion Photoproduction on a 7Li Nucleus in the Excitation Region of the First Pion—Nucleon Resonance

Physics of Atomic Nuclei - In order to explain elastic neutral-pion photoproduction on a 7Li nucleus in the excitation-energy region of the Δ(1232)3/2+ resonance, a new interpretation of...     

Polymer Quantization in the Bogoliubov’s Regime for a Homogeneous One-Dimensional Bose-Einstein Condensate

In the present report we analyze the modifications caused by the polymer quantization upon the ground state of a homogeneous one–dimensional Bose–Einstein condensate. We obtain the ground state energy of the corresponding N–body system and consequently, the corresponding speed of sound, allowing us to explore the sensitivity of the system to corrections caused by the polymer length scale. Such corrections can be enhanced for dense systems together with small values of the corresponding one–dimensional scattering length. However, these corrections remain constrained due to finite size effects of the system. The contributions of the polymer length scale to the properties of the ground state energy of the system allow us to explore, as a first approximation and when the Bogoliubov’s formalism is valid, the sensitivity of this many–body system to traces caused by the discreteness of space suggested by the polymer quantization.     

Is there a fundamental limitation on the measurement of spatial coherence for highly incoherent fields?

We investigate a fundamental limitation on the measurement of spatial coherence for highly incoherent fields. We model the near-field detection scheme, required for such a measurement, with pointlike induced dipoles. We find that this fully vector model sets a characteristic length scale beyond which the spatial coherence of an optical field cannot be accurately measured. This length scale forms an uncertainty relationship with the photodetector integration time.     

Effects of the Scattering Length on the Yrast Spectrum for a Two-Component Bose-Einstein Condensates

We study the energy eigenvalue and the yrast states for a harmonically two-component weak-interacting Bose-Einstein condensate (BEC) when the intra-species and interspecies scattering length are different. The energy shift for different energy eigenvalues related to intra-and interspecies scattering lengths is calculated with the perturbation method. The actual yrast spectrum is more complicated than that when intra-species and interspecies scattering length are equal. The degenerated features disappear and so do the perfect symmetric features.     

On Quasi-Exact Solvability of the Schrödinger Equation for a Free Particle on the Surface of a Spindle Torus

We show that the Schrödinger equation for a free particle on the surface of a spindle torus is quasi-exactly solvable. Our result complements former ones in an interesting way: it is known that the Schrödinger equation for a free particle on a ring torus is non-solvable, whereas it is exactly solvable for a particle on a horn torus.     

Investigation of a Compressible Laminar Boundary Layer on a Permeable Plate with Uniform Injection for Gas Prandtl Numbers Pr = 0.1…1.0

Doklady Physics - A compressible laminar boundary layer on a permeable plate with uniform injection is studied numerically for the gas Prandtl numbers Pr = 0.1…1.0. Regimes in which the...     

Quantum–Chemical Studies on the Superposition of Absorption Bands in the Carbonyl Region of the IR Spectra of Acetylacetone

Using the MO LCAO SCF method in the PM3 approximation, we have investigated the influence of various internal motions of the enol molecule of acetylacetone on the harmonic vibrational frequencies of the C=O and C=C groups. The results of the investigation are discussed with reference to the available literature data on vibrational spectra of acetylacetone and its substituted derivatives. They suggest that the nature of the wide intense IR band 1620 cm^–1 in the spectra of acetylacetone vapors responsible for the absorption of its enol double bonds and its temperature dependence are determined by the tunnel mechanism of enol proton motion in the H–bond channel, the probability of whose realization is controlled by the internal rotation of methyl substituents.     

Structure of the Partition Function and Transfer Matrices for the Potts Model in a Magnetic Field on?Lattice Strips

We determine the general structure of the partition function of the q-state Potts model in an external magnetic field, Z(G,q,v,w) for arbitrary q, temperature variable v, and magnetic field variable w, on cyclic, M?bius, and free strip graphs G of the square (sq), triangular (tri), and honeycomb (hc) lattices with width L _y and arbitrarily great length L _x . For the cyclic case we prove that the partition function has the form Z(L,L_y×L_x,q,v,w)=?_d=0^L_y[(c)tilde]^(d)Tr[(T_Z,L,Ly,d)^m]Z(Lambda,L_{y}times L_{x},q,v,w)=sum_{d=0}^{L_{y}}tilde{c}^{(d)}mathrm{Tr}[(T_{Z,Lambda,L_{y},d})^{m}] , where Λ denotes the lattice type, [(c)tilde]^(d)tilde{c}^{(d)} are specified polynomials of degree d in q, T_Z,L,Ly,dT_{Z,Lambda,L_{y},d} is the corresponding transfer matrix, and m=L _x (L _x /2) for Λ=sq,tri (hc), respectively. An analogous formula is given for M?bius strips, while only T_Z,L,Ly,d=0T_{Z,Lambda,L_{y},d=0} appears for free strips. We exhibit a method for calculating T_Z,L,Ly,dT_{Z,Lambda,L_{y},d} for arbitrary L _y and give illustrative examples. Explicit results for arbitrary L _y are presented for T_Z,L,Ly,dT_{Z,Lambda,L_{y},d} with d=L _y and d=L _y −1. We find very simple formulas for the determinant det(T_Z,L,Ly,d)mathrm{det}(T_{Z,Lambda,L_{y},d}) . We also give results for self-dual cyclic strips of the square lattice.