共查询到20条相似文献，搜索用时 203 毫秒
1.
本文提出了低纬子午环 (LLMC)配备CCD后的CCD芯片跟踪运动的控制方案 ,讨论了CCD芯片的预置位置及跟踪扫描速度的计算问题 ,并介绍了实现这一控制方案的系统硬件构成及软件设计方法。 相似文献
2.
Rachad M. Shoucri 《Celestial Mechanics and Dynamical Astronomy》1996,65(4):373-388
Equations describing planar motion along a constant elliptical orbit in non-central force field are derived in a simple way and discussed. The angular moment along the elliptical orbit is not a constant of motion. The problem appears to be related to the problem of planar motion with drag force. Relations with related works are discussed. In presence of drag force, conditions for the force field to be derived from the gradient of a function are discussed, and -elation of this function with the potential function is indicated. 相似文献
3.
Igor G. Mitrofanov 《Astrophysics and Space Science》1995,231(1-2):103-110
New statistical results for cosmic gamma-ray bursts are presented, based on aligned average time profiles. General signatures are discussed of averaged flux/spectrum evolution of the full set of the Second BATSE Catalog GRBs (Fishmanet al., 1995), as well as of the bright and dim subsets. The contradictory conclusions made by Norriset al., (1994) and Mitrofanovet al., (1995a) about the presence or the absence of the time-dilation of dim GRBs are discussed. The well-established effect of hardness/brightness correlation of GRBs is presented. The consequences of these statistical studies are discussed for the cosmological and galactic paradigms of GRBs sources. 相似文献
4.
M. Ya. Marov A. V. Kolesnichenko K. K. Manuilov V. P. Osipov 《Solar System Research》2010,44(5):393-402
The methodology and the main features of the Thermophob experiment developed for the direct analysis of the thermophysical
properties of the surface of the Martian satellite Phobos from the Phobos-Grunt lander are considered. The methodical and engineering aspects of the measurements are discussed, and the design of the instrument
and the potential of the interpretation of the measurement results with accounting for the theoretical estimates and the data
of the laboratory tests are discussed. 相似文献
5.
K-line observations of enhanced network taken with the NASA/SPO Multichannel Spectrometer on 28 September 1975 in support of OSO-8 are discussed. The data show a correlation between core brightness and asymmetry for spatial scans which cross enhanced network boundaries. The implications of this result concerning mass flow in and near supergranule boundaries are discussed. 相似文献
6.
讨论了激光测距仪测距本领的限制因素,找出了诸多限制因素的内在联系,得出了影响测距能力的关键因素是目标的照明概率.在前人已有的对激光测距仪最佳发散角的选取方法基础上,对其进行了改进.新得到的方法在选取最佳发散角时具有快速、简洁和精确度高等特点,并利用多项式拟合对其进行了简化,使其可用于粗略估算.最后,利用数值模拟对新方法进行了验证分析. 相似文献
7.
Spectroscopic diagnostics for the Nev and Mgv solar ions have been investigated. The theoretical forbidden line ratios from these ions are presented for estimating the Ne/Mg variation in different solar structures. Calculations for density and temperature line diagnostics of these ions are given for the several spectral line ratios and their applications are discussed with the help of available solar observations in space. Future observations from the CDS and the SUMER experiments aboard the SOHO satellite are also discussed. 相似文献
8.
A new model for gamma-ray pulsars presented by Higgins & Henriksen is applied to the cases of the seven known gamma-ray pulsars. Those pulsars that are not presently observed in gamma-rays, but are candidates for observation by the next generation of gamma-ray telescopes, are discussed. The case of millisecond pulsars is discussed, and it is shown that these objects should radiate at detectable levels, in opposition to the predictions of other gamma-ray pulsar models. 相似文献
9.
Steven T. Manson David J. Kennedy Anthony F. Starace Dan Dill 《Planetary and Space Science》1974,22(11):1535-1543
The angular distributions of photoelectrons from atomic oxygen, nitrogen and carbon are calculated. Both Hartree-Fock and Hartree-Slater (Herman-Skillman) wave functions are used for oxygen and the agreement is excellent; thus only Hartree-Slater functions are used for carbon and nitrogen. The pitch angle distribution of photoelectrons is discussed and it is shown that previous approximations of energy independent isotropic or sin2 θ distributions are at odds with our results, which vary with energy. This variation with energy is discussed as is the reliability of these calculations. 相似文献
10.
The role of exploding objects in high-energy astrophysics is discussed. Quantitative results are obtained for the simple case of the canonical white hole which explodes from a singularity and consists of pressure-free matter in the comoving frame of reference. General relativity is used for calculating the dynamical results. Applications to X-ray background, transient X-ray sources, γ-ray bursts and high energy cosmic rays are considered. White holes of more general types are discussed in a qualitative manner. 相似文献
11.
Basant Kumar Jha 《Astrophysics and Space Science》1991,175(2):283-289
The effect of a uniform transverse magnetic field on the free-convection and mass-transform flow of an electrically-conducting fluid past an infinite vertical plate for uniformly accelerated motion of the plate through a porous medium is discussed. The magnetic lines of force are assumed to be fixed relative to the plate. Expression for the velocity field and skin-friction are obtained by the Laplace transform technique. The influence of the various parameters, entering into the problem, on the velocity field and skin-friction is extensively discussed. 相似文献
12.
A regularization method for integrating the equations of motion of small N-body systems is discussed. We select a chain of interparticle vectors in such a way that the critical interactions requiring regularization are included in the chain. The equations of motion for the chain vectors are subsequently regularized using the KS-variables and a time transformation. The method has been formulated for any number of bodies, but the most important application appears to be in the four-body problem which is therefore discussed in detail. 相似文献
13.
David Vokrouhlický 《Celestial Mechanics and Dynamical Astronomy》1989,46(1):85-104
The orbital effects of the Lorentz force on the motion of an electrically charged artificial satellite moving in the Earth's
magnetic field are determined. The geomagnetic field is considered as a multipole potential field and the satellite electrical
charge is supposed to be constant. The relativistic perturbations of the main geomagnetic field are discussed briefly. The
results are concentrated on the determination of the secular changes, and numerical values are computed for the case of the
LAGEOS satellite. The results are discussed in the context of a possible detection of the Lense-Thirring effect analyzing
the orbital perturbations of the LAGEOS and LAGEOS X satellites. 相似文献
14.
A. K. Singh 《Astrophysics and Space Science》1982,87(1-2):455-461
The effect of a uniform transverse magnetic field on the free-convection flow of an electrically-conducting fluid past an infinite, vertical, porous plate for both classes of impulsive as well as uniformly-accelerated motion of the plate is discussed. The magnetic lines of force are assumed to be fixed relative to the plate. Expressions for the velocity field and skin friction for both cases are obtained by the Laplace transform technique. The influence of the various parameters, entering into the problem, on the velocity field and skin-friction is extensively discussed with the help of graphs and tables. 相似文献
15.
For accurate electron density diagnostics in the solar transition region, the principle of electron density diagnostics are discussed by lines from Si VIII ion for kappa and Maxwellian distributions By observed line ratio of the Si VIII 1440.50 to 1445.75 Å lines in quiet sun and active region, the electron density is discussed for any observed line ratio, and results are consistent with reported values in literature. The relationships between line ratio and electron density for the kappa and Maxwellian distributions are also discussed, in the case of lower and higher electron density limits, and results indicate that different distributions have no effect on relationships between the line ratio and the electron density at lower or higher electron density limit. This discussion is significant for accurate electron density diagnostics in the solar transition region, which will be important for study on coronal heating and acceleration of solar wind. 相似文献
16.
The model first introduced by Raga & Cantó in which astrophysical jets are deflected on passing through an isothermal high‐density region is generalized by taking into account gravitational effects on the motion of the jet as it crosses the high‐density cloud. The problem is also generalized for relativistic jets in which gravitational effects induced by the cloud are neglected. Two further cases, classical and relativistic, are discussed for the cases in which the jet is deflected on passing through the interstellar gas of a galaxy in which a dark matter halo dominates the gravitational potential. The criteria for the stability of jets due to the formation of internal shocks are also discussed. 相似文献
17.
A. K. Singh 《Astrophysics and Space Science》1984,103(1):155-163
The three-dimensional flow of an electrically conducting and incompressible viscous fluid past a uniformly accelerated infinite vertical porous plate is studied in a rotating fluid. The flow is assumed to be at small magnetic Reynolds number so that the induced magnetic field is neglected. An exact solution has been obtained by defining a complex velocity with the help of the Laplace transform method for the Prandtl number equal to unity. The effects of rotation, magnetic and free-convection parameters are discussed for the whole problem. Also, the skin-friction components on the plate are discussed. 相似文献
18.
A model of similarity solution for the propagation of shock waves produced on account of an instantaneous release of energy in an inhomogeneous medium with the effect of radiation has been discussed. The disturbances of the medium are headed by a shock of variable strength. The variations of flow variables have been discussed for the different values of strength of the shock. 相似文献
19.
Basant Kumar Jha 《Astrophysics and Space Science》1991,185(1):129-135
The effects of magnetic field and mass transfer on the flow of an elasto-viscous fluid past an infinite vertical plate, when the plate is moving with uniform velocityU, are discussed. The magnetic lines of force are assumed to be fixed relative to the plate. The Laplace transform method is used to obtain the expression for velocity. The effect of various parameters, occurring into the problem, is discussed with the help of tables. 相似文献
20.
G. O. Ryabova 《Solar System Research》2013,47(3):219-238
An analytical review of the models of ejection of meteoroids from cometary nuclei is presented. Different formulas for the ejection velocity of meteoroids and the corresponding parameters are discussed and compared with the use of comet Halley and the Geminids meteoroid stream as examples. The ejection velocities obtained from observations of the dust trails of comets are discussed, and the values for comets 2P/Encke, 4P/Faye, 17P/Holmes, 22P/Kopff, and 67P/Churyumov-Gerasimenko are compared to the velocities yielded by Whipple’s model. The uncertainty intervals of the results are estimated. 相似文献