Showing papers by "Nanjing University published in 1982"
TL;DR: In this paper, a system of equations that describe motions in the boundary layer are derived, subject to the condition that the, horizontal motions approach the ageostrophic interior flow at the top of boundary layer.
Abstract: A system of equations that describe motions in the boundary layer are derived. This system doors from the Ekman boundary layer equations by the inclusion of inertial terms through the geostrophic momentum approximation. The equations are solved, subject to the condition that the, horizontal motions approach the ageostrophic interior flow at the top of the boundary layer. The vertical velocity field at the top of the boundary layer is also determined. Interpretations of results are provided. A model of a circular vortex is to display characteristics of the velocity field in the boundary layer. In comparison with the Ekman boundary layer solution: 1) the magnitude of the horizontal and vertical velocities are relatively higher in an anticyclonic vortex and relatively lower in a cyclonic vortex, and 2) the depth of the boundary layer, which is a function of the vortex radius and the Rossby number (Ro ≤0.3), is higher in an anticyclonic vortex and lower in a cyclonic vortex than the constant Ekman la...
57 citations
21 citations
TL;DR: In this article, the solar activity during the 17th century has been examined and the question of the Maunder Minimum has been re-evaluated due to insufficient data, concluding that it is an incorrect inference due to the insufficient data.
14 citations
TL;DR: In this article, the amplitudes of the principal and fortnightly terms of nutation are derived from observations, and with the theoretical ones corresponding to the best models of a non-rigid earth.
Abstract: Summary. The z-term of latitude and the w-term of UT, as computed by the BIH, are suitable for investigating imperfections in the representation of the real nutation in space. They have been previously used for deriving only the amplitude of the principal term of nutation (Feissel & Guinot). In this study they are used more generally for deriving the amplitudes of two terms of nutation and searching for a possible nutation in space due to the nearlydiurnal wobble. Two kinds of data are used for this purpose: the values of z and w from 1962.0 to 1980.0 at 0.05yr intervals and the values of z from 1967.0 to 1980.0 at 5 day intervals. The first ones have been used previously by Feissel & Guinot (using the values up to 1974.0 and 1976.95 respectively). The second ones have not previously been used for such studies. The derived amplitudes of the principal and the fortnightly terms of nutation are in good agreement with other values deduced from observations, and with the theoretical ones corresponding to the best models of a non-rigid earth. The values obtained are not yet sufficiently precise to distinguish between these models, but could become so in the near future. The least-squares fits, performed among the z and w data in order to look for any error in the representation of nutation, show the existence of a retrograde term, of a 434 day period for z and 444 day for w and an amplitude of the order of 0.01 arcsec. It may be due to the nearly-diurnal wobble.
12 citations
01 Jan 1982
TL;DR: In this article, it was proved that a tournament T with p vertices has are-pancyclicity, if and only if T has both 3-are-cyclicity and p-arecyclicity.
Abstract: In this paper, it is proved that a tournament T with p vertices has are-pancyclicity, if andonly if T has both 3-are-cyclicity and p-are-cyclicity.
11 citations
TL;DR: In this article, the active region morphology and features of solar radio bursts and sight-line velocity distribution of a flare of Importance 3B on the solar disc (AR 2562) on 1980 July 14 are introduced.
5 citations
01 Jan 1982
TL;DR: In this article, a complex impedance theory for the interelectrode multireflection effects of surface acoustic wave is presented, where an electrode under the multire-flection may be equivalent to a transmission line with a complex wave impedance and a complex propagation phase constant.
Abstract: Starting with the postulation of impedance discontinuity, a complex impedance theory for the interelectrode multireflection effects of surface acoustic wave is presented. In this theory an electrode under the multireflection may be equivalent to a transmission line with a complex wave impedance and a complex propagation phase constant. As a result, the interelectrode multireflection effects could be expressed by simple formula. Thus, not only the frequency response of the equidistance transducers and the reflection coefficients of uniform gratings, but also the reflection coefficients of withdrawed gratings and the frequency responses of the dispersive transducers can be described by these analytical expressions inplace of the commonly used numerical computation of matrix series multiplication which can not tell the relations between the results and the parameters, and is time-consuming in computation.
2 citations
TL;DR: In this article, the phonon structures of layered ultrathin coherent structures (LUCSs) were studied for a special lattice model, including nearest-and next-nearest-neighbor harmonic interactions.
Abstract: The new artificial materials characterized as layered ultrathin coherent structures (LUCS) have attracted a great deal of research interest. They are important not only for the novel physical properties they exhibit, but also for possible additional phenomena, such as excitonic superconductivity. In previous publications, we developed a tight-binding theory for the electronic structures of these materials. The present paper studies the phonon structures of LUCSs for a special lattice model, including nearest- and next-nearest-neighbor harmonic interactions.
2 citations
TL;DR: The authors used the integral transform technique to derive a general solution of Poisson's equation (|| k || r ⪢1) for a disk galaxy when the radial profile of the perturbed density has the form of Hankel's function.
1 citations
TL;DR: In this article, a simple stabilization technique was proposed to reduce the along-track error in the numerical integration of the Lagrange's equations of motion, and the stability of the equations varies with α and in the case with the energy integral.
1 citations
TL;DR: In this paper, the authors studied the external field of a rotating and charged axisymmetric body in the frame of the vector graviton metric field theory and found that the radial force acting on a test particle is attractive or repulsive according as the particle is outside or inside the critical distance.
TL;DR: In this article, the authors considered that the cosmic γ-ray burst of 1979 March 5 may have originated in a binary system containing a neutron star and showed that if the stellar wind from the companion star is suddenly increased for some reason, a great quantity of plasma will pile up at the magnetopause of the neutron star, forming a high density accreting ring.
TL;DR: The theoretical explanation of the U-shape spectrum of Type IV solar radio bursts given in /1/ led us to expect certain correlations between this spectrum and that of the associated proton events.
TL;DR: In this article, the authors used the rigorous solution for the perturbing potential obtained in Ref. /1/, which contains a non-wavy term, and found a relation between the thickness of the galaxy (H = 2 α ) and the radius r0 at which the arms start, αr0 = 7.
01 Jan 1982
TL;DR: A scanning photoacoustic microscopy with a surface imaging resolution of about 2µm has been established in this paper, where the amplitude or the phase angle of the signal was measured.
Abstract: A scanning photoacoustic microscopy with a surface imaging resolution of about 2µm has been established. Some images of the subsurface structure of metals and layered materials have been obtained by measuring the amplitude or the phase angle of the photoacoustic signal. These preliminary results show potential applications of this instrument in nondestructive testing of materials.
TL;DR: In this article, the authors discuss Hill stability in the general three-body problem and show that the bifurcation points correspond to the five equilibrium solutions, and derive the criterion for stability in general case.
01 Jan 1982
TL;DR: In this paper, the authors introduce a set of empirical rules for the evaluation of the NFT diagrams, based on the diagrammatic perturbation theory (DPT) proposed by Mottelson in 1968.
Abstract: Mottelson in 19681 proposed the ideas of a nuclear field theory (NFT) as a theoretical scheme to treat the collective (Phonon pr particle-hole) and single-particle modes (fields) coupling. This theory was subsequently proliferated by the Copenhagen — Buenos Aires group into a diagrammatic perturbation theory (DPT)2. The central theme of the DPT is to introduce a set of “empirical” rules for the evaluation of the NFT diagrams.
TL;DR: In this article, the difficulty of near-commensurability in the motion of Hyperion (Saturn VII) was solved and a first-order solution of its motion was given.
TL;DR: In this paper, the author has constructed a speical finite element scheme and investigated the convergence of this scheme and showed that the convergence is possible with respect to a finite element finite element.
Abstract: In this short paper the author has constructed a speical finite element scheme and investigated the convergence of this scheme.