共查询到20条相似文献，搜索用时 78 毫秒
1.
云南天文台天文新技术实验室工作进展 总被引：1，自引：0，他引：1
云南天文台新技术实验室成立至今已走过十几个年头，这些年来为运动天文台的发展作出了很多的贡献，从我国的第一套ＣＣＤ系统到天文遥在观测，不但在天文技术领域有所发展，而且目前拥有一支老中青相结合的相对稳定的队伍，本文主要回顾了新技术室这些年来的主要工作。 相似文献
2.
介绍云南天文台ＣＣＤ检测实验室检测天文用ＣＣＤ系统的方法,检测参数主要包括：线性、噪声、增益、量子效率以及转移效率等． 相似文献
3.
本文首先回顾了目前上ＣＣＤ控制器的最新进展。介绍了中国的第一套天文用ＣＣＤ探测器系统：云南天文台＃Ｄ１ＣＣＤ系统。 相似文献
4.
5.
6.
7.
8.
9.
10.
11.
Abdel Aziz Bakry 《Earth, Moon, and Planets》1988,42(1):77-106
In this paper of the third order Uranus-Neptune planetary theory which is the third part of this work for the third order theory, we compute the Poisson brackets in the Lie series which is used to transform canonical variables. We apply Hori-Lie technique in this work and neglect all powers higher than the second in Poincaré variables H, K, P, Q. We restrict this work to the principal part of the disturbing function. 相似文献
12.
Summary In this review we discuss recent work and progress in the modelling of photospheres of stars of spectral types F and later. Special emphasis is laid on advances as regards the consideration of atomic and molecular blanketing, non-LTE and convection and other dynamic processes. In a special chapter we discuss the possibilities of semi-empirical modelling of late-type photospheres. In the conclusions we find that much important work remains in this field, but that a considerable part of this work may in fact be carried out in a near future. 相似文献
13.
In this work, we consider the formation of electrostatic, dust-acoustic solitary structure in a unmagnetized plasma with Lorentzian electrons (kappa-distributed) and more than one species of thermal ions (Maxwellian). The work is inspired by results of different space-based observations of electrostatic solitary waves (ESW) in the near-earth and magnetospheric plasmas and recent experimental realization of existence of superthermal electron component in various space plasmas. We have, in this work, shown that existence of compressive potential structure is possible only with more than one species of thermal ions. Besides, formation of compressive double layers is also possible which depends on the amount of deviation of the electron thermal velocities from a Maxwellian distribution. We show that both dust-temperature and super-thermal electrons lead to a decrease in the soliton amplitude. 相似文献
14.
N. Andersson 《Astrophysics and Space Science》2007,308(1-4):395-402
In this brief summary I describe our recent work on superfluid neutron star dynamics. I review results on shear viscosity,
hyperon bulk viscosity, vortex mediated mutual friction and the modelling of multifluid systems in general. For each problem
I provide a set of questions that need to be addressed by future work. 相似文献
15.
Madeleine Pascal 《Celestial Mechanics and Dynamical Astronomy》1987,41(1-4):253-274
The subject of this work is the dynamics of flexible space vehicles modelled by a chain of rigid and elastic bodies with tree structure. The aim of this investigation is to obtained an impedance matrix giving in frequency domain the response of the structure to external forces. We show that it is possible to obtain an expansion of this impedance matrix in terms of an infinite set of modal frequencies termed constrained modes and an expansion of the inverse of this impedance matrix in terms of an other set of modes. The work is a generalization of the theory made by Hugues [3] and others for systems with star structure. 相似文献
16.
Stefano Campagnola Paul Skerritt Ryan P. Russell 《Celestial Mechanics and Dynamical Astronomy》2012,113(3):343-368
An analysis is presented of gravity assisted flybys in the planar, circular, restricted three-body problem (pcr3bp) that is inspired by the Keplerian map and by the Tisserand- Poincaré graph. The new Flyby map is defined and used to give insight on the flyby dynamics and on the accuracy of the linked-conics model. The first main result of this work is using the Flyby map to extend the functionality of the Tisserand graph to low energies beyond the validity of linked conics. Two families of flybys are identified: Type I (direct) flybys and Type II (retrograde) flybys. The second main result of this work shows that Type I flybys exist at all energies and are more efficient than Type II flybys, when both exist. The third main result of this work is the introduction of a new model, called ??Conics, When I Can??, which mixes numerical integration and patched conics formulas, and has applications beyond the scope of this work. The last main result is an example trajectory with multiple flybys at Ganymede, all outside the linked-conics domain of applicability. The trajectory is computed with the pcr3bp, and connects an initial orbit around Jupiter intersecting the Callisto orbit, to an approach transfer to Europa. Although the trajectory presented has similar time of flight and radiation dose of other solutions found in literature, the orbit insertion ??v is 150 m/s lower. For this reason, the transfer is included in the lander option of the Europa Habitability Mission Study. 相似文献
17.
Solar System Research - Geodetic precession is the most significant relativistic effect in the rotation of celestial bodies. In this work, for the first time, this relativistic effect is determined... 相似文献
18.
A. Gholizadeh 《Astrophysics and Space Science》1991,180(2):287-292
In this work we present the effects of temperature-dependent heat source on hydromagnetic free-convection flow (set up due to temperature as well as species concentration) of an electrically-conducting incompressible viscous fluid past a steady moving vertical porous plate through high porous medium when the free stream oscillates in magnitude. The flow is subjected to a constant suction through the porous plate. As the mean steady flow has been presented gy Gholizadeh (1990), only the solution for the transient velocity profiles, transient temperature profiles, the skin-friction (steady+unsteady), and rate of heat transfer are presented in this work. 相似文献
19.
H. Rishbeth 《Planetary and Space Science》1983,31(10):1177-1180
Previous work showed that thin ionized layers in the ionospheric E-region conduct electric current only towards the magnetic equator, if the layers are formed by wind-shears associated with “corkscrew” tidal winds. The present paper extends this work and considers also the shears produced by height-independent winds and fields near the “transition” between collision-dominated and magnetically-dominated ion motion; the layers thus produced carry current in the poleward direction. 相似文献
20.