Coupled—Channel Investigation of Collisions of Protons and Antiprotons with Hydrogen Atoms in the 2p States

The impact parameter method is used to calculate the inelastic scattering cross sections of protons and antiprotons,which raise hydrogen atoms from the 2p states to the n=3 states.The calculation involves the n=1,2,3 states of the target and covers the energy range from 3keV to 2500keV.The study of the influence of the sign of the projectile charge is the main target of this investigation.Therefore,the exchange effects in the case of proton-induced reactions are ignored.The results of the calculations are in reasonable agreement with a previous work.     

Spectral Properties of Endohedrally Confined Hydrogen Atom and Hydrogen—Like Ions Obtained by Using B—Spline Basis Set

A B-spline method has been used to calculate the electron structure of endohedrally confined hydrogenlike atoms.The boundary conditions were conveniently satisfied with such the method.The evolution of the energy spectrum,as function of the depth of the confining well,exhibits a “mirror collapse”.Ions with higher ionicity have more “collapse lines”,the energies change more sharply at “collapse points”,and the oscillator strengths change more violently with the depth of the confining well.     

Single electron loss in and atomic the collisions of C^3＋ hydrogen

This paper studies the projectile electron loss cross sections of C^3＋ colliding with atomic hydrogen in the frame work of extended over-barrier model at intermediate velocities （25 keV/u-600 keV/u）. The electron loss is calculated in terms of the interaction between the screened target nucleus and the active projectile electron and of the interaction between projectile electron and target electron. Compared with the convergent close-coupling calculations, screening and anti-screening calculations, this model satisfactorily reproduces the experimentally obtained energy dependence of the electron-impact ionisation cross sections and the single electron loss cross sections over the energy range investigated here.     

Variation of Ionization Mechanisms with q in the Collision of He^2＋ with C^q＋

The ionization process in the collisions of He^2＋ with C^q＋ （q = 0-5） is investigated by using the continuum-distorted-wave eikonal-initial-state approximation. Double-differential cross sections for 1s and 2s sub-shells are obtained at the electron-ejected angle θ = 0° with the projectile energy ranging from 30keV/u to 10MeV/u. Variation of ionization mechanisms with q in C^q＋ is studied, and the dependences on the projectile energies and target sub-shells are also discussed. It is found that in the whole energy range, the absolute values of soft collision （SC） and binary encounter （BE） peaks decrease with increasing q. For the lower incident energies, the electron capture to the projectile continuum （ECC） peak decrease with increasing q as well as SC and BE peaks. For the higher incident energies （〉 1 MeV/u）, the absolute value of ECC peak increases with increasing q, so that the crossings of cross sections appear for C^q＋ with different q. This can be explained by the matching of velocities between the projectile and the electron initially bound to the target.     

Coherent Superposition States of Atoms and Molecules in a Bose—Einstein Condensate with Exactly Bananced Photo—Associations and Photo—Dissociations

We show that there exist a series of coherent superposition states of atoms and molecules in a dilute Bose-Einstein condensate with exactly balanced photo-associations and photo-dissociations,and their analytical expressions are explicitly given.They also correspond to the coherent superposition states of two kinds of hpotons in optical second harmonic generation processes,which shows exactly balaced down-and up-conversions.     

Calculation of Kaon Electromagnetic Form Factor in the Framework of Coupled Schwinger—Dyson and Bethe—Salpeter Formulation

The kaon electromagnetic form factor is calculated in the framework of coupled Schwinger-Dyson equation in rainbow approximation and Bethe-Salpeter equation in ladder approximation with the modified flat-bottom potential,which is the combination of the flat-bottom potential with considerations for the infrared and ultraviolet asymptotic behaviours of the effective quark-gluon coupling.All our numerical results give good fit to experimental values and other theoretical results.     

Abundant Symmetries and Exact Compacton—Like Structures in the Two—Parameter Family of the Estevez—Mansfield—Clarkson Equations

The two-parameter family of Estevez-Mansfield-Clarkson equations with fully nonlinear dispersion (called E(m,n) equations),(uz^m)zzτ γ(uz^nuτ)z uττ=0 which is a generalized model of the integrable Estevez-Mansfield-Clarkson equation uzzzτ γ(uzuzτ uzzuτ) uττ=0,is presented.Five types of symmetries of the E9m,n) equation are obtained by making use of the direct reduction method.Using these obtained reductions and some simple transformations,we obtain the solitary-like wave solutions of E(1,n) equation.In addition,we also find the compacton solutions (which are solitary waves with the property that after colliding with other compacton solutions,they reemerge with the same coherent shape) of E(3,2) equation and E(m,m-1) for its potentials,say,uz,and compacton-like solutions of E(m,m-1) equations,respectively.Whether there exist compacton-like solutions of the other E(m,n) equation with m≠n 1 is still an open problem.     

Possible 1d5／2 and 2s1／2 Level Inversion in the Proton—Rich Nucleus ^23Al

The discovered proton halo nucleus of ^23Al is investigated in the nonlinear relativistic mean-field(RMF) model with deformation using the NL075 force parameter,It is shown that there is an energy inversion between the (5/2)^ (202)and (1/2)^ (211)orbitals in the ^23Al nucleus,which may produce a large enhancement of the reaction cross section compared with the neighbouring nuclei.Meanwhile,the NL075 force parameter may be better than the other RMF parameters for the calculation of the large defromed nucleus ^23Al.     

Air broadening of the hydrogen halides—I. N2-broadening and shifting in the HCl fundamental

The widths and shifts of the fundamental band vibration-rotation lines of HCl under N₂ pressure have been calculated using the resolvent operator formalism of Kolb-Griem-Baranger. Time-development operator matrix elements are evaluated in a manner that is similar to the linked-cluster techniques, except that all anisotropic terms that are bilinear and second order are accounted for, as well as isotropic effects to all orders. The calculations include the use of a parabolic trajectory model and explicit velocity averaging. It is found that the major contributions to the linewidths arise from dipole-quadrupole, quadrupole-quadrupole and vibrationally dependent isotropic dispersion forces. Due to the reduction of the dipole-quadrupole and quadrupole-quadrupole contributions with increasing ¦m¦, the widths decrease with a leveling off at high ¦m¦, where dispersion forces dominate. A comparison between calculated and measured widths and shifts, for a range of temperatures from T=163 to 295 K, shows good overall agreement.     

Abundant New Explicit Exact Soliton—Like Solutions and Painleve Test for the Generalized Burgers Equation in （2＋1）—Dimensional Space

We obtain Backlund transformation and some new kink-like solitary wave solutions for the generalized Burgers equation in (2 1)-dimensional space,ut 1/2(uδy^-1ux)x-uxx=0,by using the extended homogeneous balance method.As is well known,the introduction of the concept of dromions (the exponentially localized solutions in (2 1)-dimensional space)has triggered renewed interest in (2 1)-dimensional soliton systems.The solutions obtained are used to show that the variable ux admits exponentially localized solutions rather than the physical field u(x,y,t) itself.In addition,it is shown that the equation passes Painleve test.     

Crystal growth of β’—Gd2（Mo4）3 and in situ observation of its domain structure by the microscope and the synchrotron X—ray topography

We report that β’-Gd2(MoO4)3 crystals have been grown by the Czochralski(CZ) method.We studied the growth conditions fo β’-Gd2(MoO4)3 crystal.A compatison between the resistance-heated method and radio frequency induction-heated method is described.Also,the in situ observation of the domain structure by the microscope and by synchrotron radiation X-ray topography under the conditions of DC polarization voltage and tempertature change were carried out.Experiments showed that multidomain structure including ferroelectric and ferroelastic domains occurred in β’-Gd2(MoO4)3 cystal.Usually ferroeletiric domains appeared in the as-grown crystal and ferroelastic domains appeared in the polished thinner piece.Both ferroelectric and ferroelastic domains disappeared when the temperature of the crystal piece was higher than the Curie tempperature Tc and they could be reproduced when the temperature of the crystal piece was lowered below TC.When a DC polarization voltage ranging from 150 to 500V was applied on a c-axis β’-Gd2(MoO4)3 piece having a thickness of 0.5mm ,the multidomain would gradually transform to a single domain.This resual means that it is possible to make a periodically poled β’-Gd2(MoO4)3 crystal.2001 Elsevier Science B.V.All rights reserved.     

Functional Correlations Between r and r –1 For Electrons of the 1S 1/.2, 2S 1/.2, and 3S 1/.2 Shells in Atoms of Elements with 10 ≤ Z ≤ 109

Russian Physics Journal -     

Interplay between the intramolecular hydrogen bonds and cation–π interactions in various complexes of salicylaldehyde,thiosalicylaldehyde and selenosalicylaldehyde with Li+, Na+, K+, Mg2+ and Ca2+ cations

For the first time, the mutual influences of the intramolecular hydrogen bond (IMHB) and cation–π interactions in various complexes of salicylaldehyde, thiosalicylaldehyde and selenosalicylaldehyde with Li⁺, Na⁺, K⁺, Mg²⁺ and Ca²⁺ cations were studied. First, the strength of IMHB and cation–π interactions of the mentioned complexes by energetic, geometrical, spectroscopic, topological and molecular orbital parameters was evaluated and compared with the corresponding results of benzene–cation complexes and salicylaldehyde analogues. The results show that the coexistence of IMHB and cation–π interactions increases the IMHB strength and decreases the cation–π interactions. Second, the significance of π–electron delocalisation (π–ED) within the resonance-assisted hydrogen bond (RAHB) unit and aromaticity of benzene ring in the studied complexes were estimated by using the harmonic oscillator model of aromaticity and compared with the respective amounts of references. The results indicated that the mentioned coupling decreases the π–ED of RAHB unit and aromaticity of the benzene ring. In addition, it was found that variations in the strength of the interactions, π–ED and aromaticity, depend on the charge-to-radius ratio of cations. Finally, the effects of replacement of O by S and Se atoms in both of the mentioned cases were explored.     

Observation of capillary discharge Ne-like Ar 46.9?nm laser with pre-pulse and main-pulse delay time in the domain of 2–130?μs

We demonstrated the lasing of Ne-like Ar 46.9?nm pumped by capillary discharge with the delay time between pre-pulse and main-pulse ranging from 2 to 130???s. Results show that the laser output reduced significantly when the delay time is much longer than 12???s. The temporal evolution of spontaneous radiation emitted from pre-ionized plasma implies that the observed reduction of the laser output is caused by the axial non-uniformity of pre-ionized plasma density and the decrease of pre-ionized plasma density.