SCATTERING OF u TO ū ON THE SU(5) COLORLESS MAGNETIC MONOPOLE

The scattering of quark u to antiquark u^C on the SU(5) colorless magnetic monopole is discussed in some detail.The baryon number non-conserved processes occur to the state j=1/2 and j=3/2 of the third type solutions. Solving the radial equation with j=1/2 and j=3/2 numerically,we show that the plane wave of quark u with helicity-1 can be scattered by the colorless monopole into antiquark u^C with the cross section σ=2π/p2.     

ON THE IRREDUCIBLE REPRESENTATIONS OF THE SIMPLE LIE GROUPS I——THE TENSOR BASIS FOR THE INFINITESIMAL GENERATORS OF THE CLASSICAL SIMPLE LIE GROUPS

In this paper, we analyse the commutation relations of the infinitesimal generatorsof all simple classical Lie groups and establish a new basis for these generators, calledthe tensor basis. In tensor basis, the infinitesimal, generators can be written as somescalar operators, some sets of angular momentum operators and some sets of irreducibletensor operators. The commutation relations, of these operators are very simple andhave many regularities. By means of the method that has been used in the earlier papers, "On the irre-ducible representations of the compact simple Lie groups of rank 2, I,II,III" and thetensor basis, all the irreducible representations of the classical simple Lie groups canbe calculated systematically.     

ON THE SUPERHEAVY FERMION——SO(10) MONOPOLE ZERO-ENERGY BOUND STATES

It is found that the zero-energy bound state of the superheavy fermion and SO(10) Monopole is possible. As a result we conclude that the Rubakov effect may exist in the presence of superheavy fermions.     

ON THE ELECTRIC DIPOLE TRANSITIONS OF ψ(3770)

Various E1 transition rates for cc states are calculated in a QCD-motivated potential model.Relativistic corrections are found to be substantial.While a good agreement between theory and experiment is achieved for the rates of ψ(2s)→γχ_cJ and χ_cJ→γψ(1S)(J=0,1,2),the calculated rates for ψ(3770)→γχ_cJ are smaller by a factor of～2 than their experimental values obtained by the MarkⅢ collaboration.The effect of the 2³S₁—1³D1 mixing is possibly important and needed to be considered.     

CORRELATION EFFECTS ON THE GROUNDSTATES OF THREE-ELECTRON QUANTUM DOTS IN A STRONG MAGNETIC FIELD

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ON THE MAGNETIC MOMENT OF W± BOSONS IN WEINBERG-SALAM MODEL

We discuss the magnetic moment of W^± bosons in W-S model. First we assume that there is no spontaneous symmetry broking. starting from the formalism of path integrals and using the gauge invariance requirement, we obtain the Ward-Takahashi identities for the 3-line VIB proper vertex functions and prove that its tensor structure is the same form as that of bare vertex couplings, which indicated the W^± bosons have neither anomalous magnetic moment nor electric quadrupole moment. For the realistic case of spontaneous symmetry breaking, we introduce in the Lagrangian an explicit symmetry breaking term. After discussing the problem of analytic continuation for mass of W^± bosons, we prove that prove that the above mentioned conclusion is still valid here.     

ON NUCLEAR SINGLE-PARTICLE POTENTIALS (Ⅱ) THE NONHERMITIAN CHOICE

The cancellation properties of the nonhermitian single-particle （SP） potential u_αβ=M_αβ （ε_β） [or M_αβ（ε_α）] according to the principle of maximal cancellation of perturbation diagrams are investigated in detail. The mass operator M_αβ（ω） is separated into two parts M_αβ^on （ω） and M_αβ^off （ω） as usual, however, a new criterion for their definition will be proposed. It is shown that the exact mass operator insertion is equal to the sum of the following three types of terms:（1） terms contributed by the poles of M_αβ^off（ω）. They are truly non-factorizable and must be considered separately,（2） terms which can be cancelled to all orders by the nonhermitian choice u_αβ=M_αβ （ε_β） [or M_αβ（ε_α）]. Hence, they serve to define u_αβ,（3） the remaining terms, which can be summed to all orders in a simple way and may be interpreted as amplitude renormalization of the SP Green function.In order to illustrate the usefulness of the above results, we have considered the renormalized random phase approximation （RRPA） for the particle-hole Green function as an example. Related formulae are derived. In RRPA, not only the SP propagator renormalization which includes all the effects except those contributed by the poles of M_αβ^off （ω）, but also the off energy shell property of the G matrix elements have been taken into account.     

ATOMIC CHARGE SUPERPOSITION CALCULATIONS OF STM IMAGES OF 2D-ORDERED AMINO ACID ADSORBATES(Ⅱ)

In the preceding paper, we have successfully used the atomic charge superposition (ACS) method to calculate STM images of 2D-ordered structures of glycine molecules adsorbed on graphite (HOPG). In this work we focus on alanine/HOPG system. Firstly, we make a thorough searching for all of the possible 2D-ordered aggregation structures that can form linear chains or 2D nets of hydrogen bonds between the molecules and simultaneously satisfy the Van der Waal's radii of the condtituent atoms, just like in the case of 3D crystal of the molecules. Secondly, in order to interpret the experimental images, we use the ACS method to calculate STM images of the possible structures. It turns out that many of the experimental images can be interpreted satisfactorily with their calculated counterparts. This result further exhibits the great potential of using STM to study organic and biological molecules.     

STUDY ON BINDING PROBLEM OF Δ(1232) IN NUCLEI WITH HARTREE-FOCK METHOD

The binding problem of isobar Δ(1232) in ⁴He ¹²C and ¹⁶O systems is studied in detail by Hartree-Fock method. The OBEP is used for the nucleon-nucleon potential and the nucleon-Δ(1232) interaction. The calculated results show that Δ(1232) can be bound only in ⁴He and not in ¹²C and ¹⁶O systems.     

ON THE DYNAMIC SPECTRA OF SPEECH

Using a testing sentence(Ta qu Wuxishi,wo dao Heilongjiang.)well designed for measure-ments of telephone transmission qualality,we studied some dynamic characteristics of speech.Twelvetalkers individually uttered the testing sentence in an anechoic chamber.Testing conditions included:1. different talker's efforts(SPL of speech at 1 m from talker's lips is 55,60,65,70 and 75 dB),2.different utterance rates(normal and speed up).It is shown that:(1) The long-term averagespectrum of speech is varied with the talker's effort,and variation especially appeared in low andmid band of speech.(2) The fundamental frequency F_0 and formant frequencies F_1,F_2,F_3 areincrased with the increasing of the SPL of speech.(3) If utterance picks up speed,the vowel triangletends to be smaller than normal i.e.the vowels tend to be centralized.(4) As a consequence ofincreasing SPL of speech,vowel-to-consonant ratio is increased,but it is closely related to the mannerof articulation of consonants.     

ON THE INVESTIGATION OF THE SOUND ABSORPTION OF LINEAR TRANSITION WEDGES

In this article the reflection coefficient of linear transition wedges is discussed,and an analyticalexpression and a simple real expression of the reflection coefficient under W.K.B.approximationare derived.The approximate expression of the reflection coefficient proves to be simple and con-venient for the design of absorbers. The sound absorbent structure of rib is also computed and analyzed,with emphasis on the rela-tionship between the size of the structure and the parameters of the material. In design of two types of wedges mentioned above,for the required frequency range,the materialperameters can be chosen properly and the dependence of the Wedge length on the lower limit fre-quency can be determined easily based on the derived expression.The theoretical computationsagree well with the experimental results.     

EFFECT OF THE INERTIAL TERM ON THE CDW TRANSPORT PROPERTIES Ⅱ. NUMERICAL SOLUTIONS

Using the classical particle model with an inertial term, we have numerically analyzed the effect on the nonlinear transport properties of the CDW system,e.g., the hysteresis effect, the interference phenomena between the dc and ac applied fields. Our calculations demonstrate the importance of the inertial effect on the sliding CDW states. Some results are probably new, and important to experimental observations; for example, the zero step width region exists for the 1/2 subharmonic step in its variation with amplitude of the ac driving field.     

LEPAGE EQUIVALENTS OF SECOND-ORDER EULER–LAGRANGE FORMS AND THE INVERSE PROBLEM OF THE CALCULUS OF VARIATIONS

In the calculus of variations, Lepage (n + 1)-forms are closed differential forms, representing Euler–Lagrange equations. They are fundamental for investigation of variational equations by means of exterior differential systems methods, with important applications in Hamilton and Hamilton–Jacobi theory and theory of integration of variational equations. In this paper, Lepage equivalents of second-order Euler–Lagrange quasi-linear PDE's are characterised explicitly. A closed (n + 1)-form uniquely determined by the Euler–Lagrange form is constructed, and used to find a geometric solution of the inverse problem of the calculus of variations.     

CALCULATION ON A CLUSTER MODEL FOR THE ELECTRONIC CHARGE DENSITY AT NUCLEAR SITE AND THE ELECTRONIC STRUCTURE PARAMETERS OF α IRON

In order to investigate the M6ssbauer isomer shifts and its related electronic charge densities for some substances, the electronic charge density at nuclear site of a iron have been computed for an octahedral cluster Fe₆ with SCF MS-X_α method. Some other electronic structure parameters of the cluster have also been obtained, such as the orbital energy distri- bution, the electron density of states, the Fermi level and various kinds of electron energies, etc. The cohesive energy of α iron have also been calculated and discussed.     

A STUDY ON THE ULTRASONIC VELOCITY AND ATTENU-ATION IN NdFeB MAGNET WITHIN THE TEMPERATURE RANGE OF 80 - 300K (Ⅱ)

Based on the ultrasonic measurements of an isotropic NdFeB magnet in the temperature range of 77 -300 K, it was found that the elastic parameters, such as Young's modulus E, and Poisson ratio v, change abruptly near the spin reorientation temperature T_sr. This indicates that soft mode emerges in the process of spin reorientation. Thermal hysteresis was observed during heating-up and cooling-down processes. Both Debye temperature and heat capacity were calculated, which suggests that the magnetic entropy of the Nd-sublattice is larger in easy-cone state than in easy-axis state.     

A STUDY ON THE ULTRASONIC VELOCITY AND ATTENU-ATION IN NdFeB MAGNET WITHIN THE TEMPERATURE RANGE OF 80 - 300K (Ⅱ)

Based on the ultrasonic measurements of an isotropic NdFeB magnet in the temperature range of 77 - 300 K, it was found that the elastic parameters, such as Young's modulus E, and Poisson ratio v, change abruptly near the spin reorientation temperature Tsr. This indicates that soft mode emerges in the process of spin reorientation. Thermal hysteresis was observed during heating-up and cooling-down processes. Both Debye temperature and heat capacity were calculated, which suggests that the magnetic entropy of the Nd-sublattice is larger in easy-cone state than in easy-axis state.     

SOLUTION OF MALYUZHINETS FUNCTIONAL EQUATIONS ON IMPEDANCE WEDGE DIFFRACTION PROBLEM

A solution of the impedance wedge diffraction problem has been given by Malyuzhinets in Ref.[1].The key to the problem is to seek the solution of Malyuzhinets functional equations.However,how to go about getting the solution of the functional equations is not given in Ref.[1].A detailedprocess to get the solution of the functional equations is provided by using the infinite product theoryin Ref.[2],in which,however,there exist some errors and indistinct places. In this paper,these errors in Ref.[2] are corrected and another simpler method to obtain thesolution of the functional equations is also provided for the purpose of comparison.     

SEEKING FOR THE U(5) LIMITING CASE OF IBA-Ⅱ

In the region of even-even nuclei from A=96 to A=120, only the energy spectrum of ¹¹⁰₄₈Cd₆₂ may be described by IBA-Ⅱ involving the states {N_π +N _L -1,1}. But it can be described by IBA-Ⅰ too. To distinguish these two schemes, more angular momentum measurement is needed.