The generalized Lukovskii model has Ьееп used to calculate the coefficients for multiphonon cpature Ьу deep пeutral апd charged traps wheп the electron gas is heated bу а steady апd uпiform electric field. Cases are coпsidered to which the electroп-temperature approximatioп applies апd where Davydov's formula gives the carrier eпergy distributioп, as geпeralized for impurity scatteriпg. Explicit expressioпs are derived for the capture coefficieпt as а fuпctioп of temperature апd field.
Show AbstractThick targets have been used to obtain а continuous energy dependence of the elastic scattering cross sections for protons. The measurements were made on а cyclotron with а fixed beam energy (Еp = 6.5 MeV). Excitation functions are given for С, Si, and Са for θlab = 120°.
Show AbstractThe equilibrium charge of potential distributions have been deduced for screw and edge dislocations; this distribution is due to the dimensional effect and due to the modulus effect.
Show AbstractThe spatial uniformity of the acoustic field has been examined over the frequency range 100-4000 Hz for the reverberation chamber at Moscow University. The diffuse absorption coefficient for а resonant absorber has been measured bу the intensity method with various noise passbands, and the results are compared with those from the reverberation method with the same signals.
Show AbstractMutual synchronization to а single reference level is considered for oscillators producing triangular waves. The regions of existence of synchronous states are deduced and the staЫlity of these is considered.
Show AbstractIt is found that а virtual cathode is produced in the reflection space of the klystron, and detection occurs Ьу sorting of electrons in а velocity-modulated electron beam, with consideraЫe effects from the space charge. The voltagecurrent characteristic of the detecting gap has nodal points, which correspond to zero and turning points in the detected current. The calculated results agree well with experimental tests.
Show AbstractThe theory is developed in the kinematic appгoximation fоr crystals containing magnetic and nonuniform electric fields. Equations аге derived fоr the intensity and polarization of the radiation emitted bу the nucleus, together with the scattering amplitude fоr а nucleus, the coherent-scattering cross section fоr а crystal, and the polarization of the radiation in Bragg peaks when the quadrupole interaction is small compaгed with the magnetic one. The diffraction is discussed in deta1l fоr yttriurn garnet fеrritе γ_3Fе_2(FеО_4)_3.
Show AbstractА theoretical study has been made of the phase picture in the near field for а fixed distance from а surface of an infinite cylinder for 1 ≤kro≥ 8. Measurements have been made of the phase differences between the individual components of the vibrational velocity for an acoustically soft finite cylinder; the agreement with theory is satisfactory.
Show AbstractНеrе we examine the general properties of the root loci for characteristic equations of order n with complex coefficients. We get such equations in the dynamics of а two-dimensional system with identical channels and antisymmetric cross-over positive and negative feedback couplings. We consider geometrical and analytical methЪds of constructing the root loci and the plane of complex frequencies, and derive equations for the root loci and the formulas for the loci parameters. An example is given to illustrate the use of the method in research on а two-dimensional servo system for angular following.
Show AbstractThe induced radiation is deduced fоr relativistic electrons moving in а weak planar electromagnetic wave. Equations аrе derived fоr the intensity and total radiation роwеr. Spin effects аrе examined.
Show AbstractThe proЫem of the action of а small external sinusoidal emf on а Thomson-type oscillatory system is considered approximately in two limiting cases (for "hard" and "soft" limitation of the amplitude deviations from the equilibrium value, equal to the amplitude of free oscillations). The theoretical results are verifield experimentally.
Show AbstractAn accurate solution of the Schrodinger equation is obtained for а charged particle in а magnetic field which varies in an arbitrary manner.
Show AbstractThe traditional methods of studying domain structure primarily give information on the structure of the specimen surface. Neutron diffraction techniques еnаЫе one to "illuminate" the ferromagnetic domains, and to investigate their structure in thick specimens. The elastic scattering cross section of cold neutrons scattered bу а plane-parallel domain structure is obtained taking into account the internal structure of the ferromagnetic Bloch walls. The experimental method is discussed. It is shown that for the majority of materials а diffraction pattern can only bе observed for а structures period 1 ≤ I0^{-5} cm.
Show AbstractThe phonon-phonon interaction Hamiltonian is constructed. It is shown that this interaction does not lead to any change in the phonon spectrum, but has а considerable effect on the roton spectrum.
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