Dependence of the temperature behaviour of the sputtering ratio on the channelled fraction of the ion beam

A method of calculation is presented for the yield of an electron excitation process by a channelled particle in a single encounter with an atomic row or plane in a crystal. It is shown that, if ψ is the initial angle between the ion trajectory and the row or plane, the number of inner-shell electrons excited is an increasing function of ψ whereas the number of outer electrons excited may decrease with increasing ψ.     

On the influence of viscosity on the characteristic time of the instability of a charged drop

A nonlinear integral equation describing the evolution of spheroidal deformation of a drop that is unstable with respect to its intrinsic charge is derived and solved for arbitrary values of viscosity. It was shown that, due to an essentially nonlinear character of the phenomenon, the characteristic time of instability develop-ment equals the time of tenfold increase in the amplitude of an initial, physically infinitesimal spheroidal deformation of an unstable drop. The dependence of the instability characteristic time on the drop viscosity is described by an increasing linear function.     

大气湍流对遥感系统分辨力的影响

以平面波为例,分别针对较弱和较强的湍流模型,通过计算到达角起伏讨论了高空光学遥感系统由大气湍流引起的地面图像分辨力问题。结果表明,对于给定的遥感系统口径和高度,较强湍流引起的图像分辨力的1cm左右;而较强湍流引起的图像分辨力则可达10cm量级。对于自身的地面分辨力具有m的量级的传统光学遥感系统,上述影响并不明显。对于现代高辨力光学遥感系统,这种影响便不容忽略,特别是对较强的湍流,往往需要用自适应光学等方法加以补偿。     

Influence of the conduction bandwidth of the substrate on the electronic state of an adatom

The positions of the local and quasilocal levels of an adsorption system and their contributions to the occupation number of an adatom are found within the Anderson Hamiltonian using a simple model of the density of states. The dependence of the occupancy of an adatom on the conduction bandwidth of a metallic substrate is analyzed. Zh. Tekh. Fiz. 68, 15–19 (April 1998)     

Influence of the heat loss intensity on the characteristics of the filtration combustion of solid organic fuels

The effect of lateral heat loss on the characteristics of the filtration combustion of solid organic fuels is studied experimentally and theoretically. The results show that, for an reaction trailing, an increase in the heat loss intensity leads to a marked reduction in the combustion temperature and an increase in the temperature at which fuel pyrolysis is complete, with the yield of liquid pyrolysis products remaining practically unchanged. For a reaction leading, an increase in the heat transfer coefficient causes a reduction in the combustion temperature and the yield of liquid pyrolysis products.     

Inconsistency in the application of the adiabatic theorem

The adiabatic theorem states that an initial eigenstate of a slowly varying Hamiltonian remains close to an instantaneous eigenstate of the Hamiltonian at a later time. We show that a perfunctory application of this statement is problematic if the change in eigenstate is significant, regardless of how closely the evolution satisfies the requirements of the adiabatic theorem. We also introduce an example of a two-level system with an exactly solvable evolution to demonstrate the inapplicability of the adiabatic approximation for a particular slowly varying Hamiltonian.     

On the Contribution of the Long-Range Scattering Potential in the Process of Multiphoton Above-Threshold Ionization of Atoms in the Laser Field

Journal of Experimental and Theoretical Physics - Using the quantum mechanical analysis of stimulated bremsstrahlung of an electron on an electrostatic potential in the field of a strong...     

Model of delocalized atoms in the physics of the vitreous state

A development of the model of delocalized atoms of liquids and glasses is proposed. It is shown that the basic equation of the model for the probability of delocalization (excitation) of an atom can be obtained not only from the Clausius relation but also by other methods of statistical physics. Techniques for calculating the parameters of the model are developed. The critical displacement of an atom from the equilibrium position, which corresponds to the maximum interatomic attraction force, can be considered as a delocalization (local excitation) of this atom in an elastic continuum. The energy of the critical displacement of an atom calculated as the work of the limit elastic deformation of the interatomic bond in an elastic continuum is in agreement with the results of calculation by the model of delocalized atoms. This energy can also be calculated from the data on surface tension and atomic volume. In silicate glasses, the process of delocalization of an atom represents the critical displacement of a bridging oxygen atom in the structural fragment of a silicon-oxygen (Si-O-Si) network before the switching of the valence bond, whereas, in amorphous organic polymers, the delocalization of an atom corresponds to the limit displacement of a fragment of the main chain of a macromolecule (a group of atoms in the connecting link).     

Symmetry aspects of the pion leptoproduction and the upper limit of the Levelt-Mulders asymmetry

We examined the symmetry aspect of the semi-inclusive one-pion production in the deep inelastic scattering of a lepton beam off an unpolarized nucleon target, with an emphasis on the positivity restrictions on the corresponding structure functions. In combination with the Callan-Gross-type relation between two twist-two structure functions W ₁ and W ₂, we derived an upper bound on the Levelt-Mulders asymmetry, which occurs when the lepton beam is longitudinally polarized.     

Influence of the Guinier–Preston Zones on the Concentration Dependence of the Yield Point of the Aged Two-Component Alloys in Conditions of High-Speed Deformation

Physics of the Solid State - The glide of an ensemble of edge dislocations at the high-speed deformation of an aged binary metal alloy is theoretically analyzed. The yield stress of the alloy is a...     

Areal objects and the problem of the λ term in the theory of gravitation

The following areal objects are considered: an ether thread contracting two material points and a multidimensional ether fibre in the pseudo-Euclidean world of events. An ether space-time model with an arbitrarily determined Riemannian metric is constructed and the problem of the λ term in Einstein equations is discussed in this regard.     

On the problem of measuring the degree of polarization of synchrotron radiation

The possibility for determining the degree of polarization of synchrotron radiation by measuring linear dichroism in stepwise ionization of an autoionization state of an atom with a known total momentum is considered.     

Effect of the near-lying level on the kinetics of the field of superradiance of a thin layer

The effect of the local field on the competition of transitions in the superradiance of an incompletely excited thin layer of three-level atoms (Λ-diagram of working transitions) is studied. Analysis is made for the conditions when one of the sublevels of the lower doublet is initially unpopulated. For an initially unpopulated upper sublevel of the lower doublet, a new superradiance regime is found.     

Moments of the auto-correlation function and the KMS-condition

Inequalities between successive moments of the time dependent auto-correlation function are derived. Furthermore, we prove that they provide an infinite set of characterizations of an equilibrium state.     

On the influence of the argon flow rate on the parameters of a negative corona

The pulsed-periodic regime of a negative corona in an argon flow is studied experimentally. It is found that an increase in the gas flow rate makes a negative corona current pulse longer and changes its shape.     

Effect of the spectral half-width of the driving field on the bistability

The bistability behavior of a nonlinear absorbing medium inside a Fabry–Perot resonator driven by an external quasi-monochromatic field is studied. The driving field is considered to be of a Gaussian and Lorentzian spectral line profile. The effect of the spectral half-width on the bistability is discussed. The mathematical treatment is carried out through an interferometric point of view. The dependence of the driving intensity required to initiate bistability on the standing wave established inside the resonator is represented.     

Superunification and the ultimate temperature of the universe

We suggest that the unification of all forces in the context of the supergravity theories can naturally lead to an exponential growth of the number of particles in the early universe and an ultimate maximum temperature equal to the Planck temperature.     

Analysis of the adjustment precision of the stretcher in the petawatt laser facility

Effects of stretcher adjustment aberration on the residual dispersions of the laser system is analyzed making use of the ray tracing method. It is shown that the adjustment aberrations affect the pulse contrast and we must select an appropriate adjustment precision for the stretcher in the petawatt laser system. And as an example, a proper adjustment precision of the pulse stretcher is also proposed for the SHENGUANG (SG) II laser facility.