g-factors in the ground state and in the γ-bands in 160,162,164Dy

The g-factors of some members of the ground state band and of the 2⁺ state in the %-vibrational band have been measured in ^160,162,164Dy using the Coulomb Excitation Transient Field technique, induced by ⁵⁸Ni projectiles at 230, 210 and 217 MeV, respectively. The g-factors in the ground state band are consistent with a constant value, while that of the 2⁺_% states is about 20% larger in average than those in the ground state band. Results are discussed in the frame of the systematics in this nuclear region.     

Focusing in solids and application in acoustic imaging

Focusing in solids by surface transducer arrays(STA)and the acousticfield distribution on the focal axis are studied in this paper.The relation betweenthe source element width and the field strength at different order focuses is alsodiscussed.Numerical calculation is used to get the focal field distribution as theelement width is changed.Some practical problems such as the minimumdistinguishable frequency,the transversal and longitudinal resolution are investi-gated when this kind of focusing is used for NDT and acoustic imaging.Someexplorative experiments have been done to demonstrate the theory.     

Superconductivity in Supersymmetric Theory in Restricted Chromodynamics

The study of superconductivity, dual superconductivity and color superconductivity has been undertaken through the breaking of super symmetric gauge theory in restricted chromo dynamics (RCD) which automatically incorporates the condensation of monopoles and dyons leading to confining and superconducting phases. Dyonic supermultiplets in N=1 super symmetry have been obtained quantum mechanically in RCD and it has been shown that dyon appears in RCD theory only through restricted part of the generalized potential and it is only this part of this potential which is responsible for quark confinement and the resulting superconductivity through the mechanism of dyonic condensation.     

Peng in Dublin

In February 1946, I arrived at the Institute for Advanced Studies, 64 Merrion Square, Dublin. I was greeted by Peng H W and Hu Ning (known as Ning Hu). Arriving from war- torn France, I was bewildered by Ireland, and assumed that Peng and Ning Hu were Irish !     

Degenerate Four-Wave Mixing in SO2 in Free Jets

A rotational excitation spectrum of SO2 [^-A^1A2(511)←^-X^1A1(000)] at about 33331cm^-1 in free jets was observed by using the forward degenerate four-wave mixing (DFWM).Twelve lines of the G band and 11 ones of the E band were marked based on the rotational constants according to Hamada‘s result [Can.J.Phys.53(1975)2555].The relation between the DFWM signal intensity and the pressure of the buffer gas in free-jets was experimentally investigated.     

Radiation ordering in quenched alloy sobserved “in situ” in the high voltage microscope

Different alloys with a face centered cubic disordered structure have been electron irradiated in the quenched or short range order state under direct observation in a high voltage electron microscope. Ordering due to 1 MeV irradiation has been observed in Au₄Mn, Ni₄Mo and Cu₃Pd. Care has been taken to avoid ordering due to the thermal effect of the electron beam. It has been demonstated that although similar states of order can be achieved by thermal and irradiation ordering, the path followed can be different however.     

Tachyon Pole in σ Meson Propagator in Nuclear Matter in the Relativistic σ—ω Model

The conditions that the tachyon pole of the σ meson propagator in nuclear matter appears are studied in the one-loop approximation in the relativistic σ-ω model.Different from the results of the previous paper,we find that the effect of the constant a in the self-interaction,U(σ)=aσ 1/2! bσ^2 1/3!cσ^3 1/4!dσ^4,of the σ meson cannot be neglected.It determines the critical density where techyon appears.The smaller the a,the larger the critical density.The binding energy,pressure,incompressibility coefficient,nucleon effective mass are calculated and the relation between parameters to the tachyon pole is also studied.     

The singular integration in sound-radiation from structures submerged in water

I.IntroductionTheboundaryelementmethod(BEM),basedontheHelmholtzintegralequation(HIE),hasbeenappliedtothesolutionofexternalandinternalacousticradiationandscatteringproblemssincetheearly196Os.Inrecentyears,extensiveworkhasbeenperformedtoaddressthetwomajordrawbacksoftheuseofboundaryelementmethodinacousticprobIems'singularintegralkerneIsanduniquenessofsolution.ThisarticlepresentsanewmethodoftheBEMforexternalsoundradiationthateliminatesthesingularintegrationinasimpleway.TheBEMinsoundradiatio…     

The anisotropic phenomenon in the β decay of radioactive elements and in other processes in nature

Results from experimental studies of a new hypothetical interaction in nature based on analyzing fluctuations in the intensity of the ?? decay of radioactive elements are presented. One possible explanation of the results, based on a hypothesis as to the global anisotropy of physical space caused by the existence of cosmological vector potential $\vec A_g $ , is given. It is shown that vector $\vec A_g $ has the following coordinates in the second equatorial coordinate system: right ascension ?? = 293° ± 10°; declination ?? = 36° ± 10°.     

Photoinduced effects in γ-glycine nanocrystallites embedded in polymer matrices

We have established a principal role of the polarity of polymer matrices on the piezooptical dispersion of the γ-glycine nanocrystallites embedded into the polymethymethacrylate (PMMA) and polycarbonate (PC) matrices. We found that the optical treatment by bicolor two laser beams at 1064 nm and 532 nm which are originating from the same 10 ns Nd:YAG laser, causes occurrence of the piezooptical effects. The optimal content of the γ-glycine nanocrystallites with respect to the magnitude of piezooptical coefficients was within the range of size 50-80 nm, corresponding to the 6.5 wt.%. We studied relaxation and spectral dependence of the corresponding coefficients of the piezooptic tensor.     

Spin transition in magnesiowüstite in earth's lower mantle

Iron in the major lower mantle (LM) minerals undergoes a high spin (HS) to low spin (LS) transition at relevant pressures (23-135 GPa). Previous failures of standard first principles approaches to describe this phenomenon have hindered its investigation and the clarification of important consequences. Using a rotationally invariant formulation of LDA + U we report a successful study of this transition in low solute concentration magnesiowüstite, (Mg(1-x)Fe(x)(O), (x < 0.2) the second most abundant LM phase. We show that the HS-LS transition goes through an insulating (semiconducting) intermediate mixed spins (MS) state without discontinuous changes in properties, as seen experimentally. We show that the HS state crosses over smoothly to the LS state passing through an insulating MS state where properties change continuously, as seen experimentally.     

Coulomb Potential Recapture Effect in Above-Barrier Ionization in Laser Pulses

The Coulomb potential recapture effect in above-barrier ionization with ultrashort long-wavelength laser pulses is investigated theoretically by solving the one-dimensional time-dependent Schrodinger equation. We find that electrons can be recaptured with considerable possibility by the Coulomb potential near the end of the pulse though atoms are ionized almost completely within the first few half optical cycles. Therefore there is a high probability of the atom surviving after the pulse. We also check this process in the three-dimensional case and find that this kind of stabilization can still exist in three-dimensional atoms.     

Solution of Electromagnetic Wave in Time-Varying Media in Two-Dimensional Space

The analytical solution of gradual change media in two-dimensional free space is studied. Using separation of variables, the solution of electromagnetic wave in time-varying media, which is an exponential function of time, is derived in two-dimensional space. The rationality of the solution is verified indirectly. According to the solution, the figures of the wave are depicted. Based on these figures, the character of the wave in time-varying media is obtained, which shows frequency shift and changes of phase velocity and amplitude.     

Many-Body Effect in Spin Dephasing in n-Type GaAs Quantum Wells

By constructing and numerically solving the kinetic Bloch equations we perform a many-body study of the spin dephasing due to the D‘yakonov-Perel‘ effect in n-type GaAs (100) quantum wells for high temperatures. In our study, we include the spin-conserving scattering such as the electron-phonon, the electron-nonmagnetic impurity as well as the electron-electron Coulomb scattering into consideration. The dephasing obtained from our theory contains both the single-particle and the many-body contributions with the latter originating from the inhomogeneous broadening introduced by the DP term [J. Supercond.: Incorp. Novel Magn. 14 (2001) 245; Eur. Phys. J. B 18 (2000) 373]. Our result agrees very well with the experimental data [Phys. Rev. B 62 (2000) 13034] of Malinowski et al. We further show that in the case we study, the spin dephasing is dominated by the many-body effect.     

Electron-Helium Scattering in Free-Free Transitions in a Bichromatic Laser Field

Theoretical calculation of the differential cross section （DCS） for elastic electron-helium scattering in the presence of a bichromatic CO2 laser field is carried out in the first Born approximation with a simple screening electric potential. The two components of the laser field have the frequencies w and 2w, which are out of phase by an arbitrary scale φ. The variations of the differential cross section as a function of the phase angle φ in the domain 0°≤ φ ≤360° are presented. We discuss the influence of the number of photons exchanged on the phase-dependee effect. Moreover, for different scattering angles and incident electron energies, the DCS has outstanding ditferences. These illustrate that the two parameters have important effects on the differential cross section and the screening electric potential is effective.     

Charmonium dissociation in collisions with φ mesons in hadronic matter

The φ-charmonium dissociation reactions in hadronic matter are studied.Unpolarised cross sections forφJ/ψ→D_s~-D_s~+,φJ/ψ→D_s~(*-)D_s~+ or D_s~-D_s~(*+),φJ/ψ→D_s~(*-)D_s~(*+),φψ'→D_s~-D_s~+,φψ'→D_s~(*-)D_s~+ or D_s~-D_s~(*+),φψ'→D_s~(*-)D_s~(*+),φχ_c→D_s~-D_s~+,φχ_c→D_s~(*-)D_s~+ or D_s~-D_s~(*+) and φχ_c→D_s~(*-)D_s~(*+) are calculated in the Born approximation,in the quark-interchange mechanism and with a temperature-dependent quark potential.The potential leads to remarkable temperature dependence of the cross sections.With the cross sections and the φ distribution function we calculate the dissociation rates of the charmonia in interactions with the φ meson in hadronic matter.The dependence of the rates on temperature and charmonium momentum is relevant to the influence of φ mesons on charmonium suppression.