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1.
The experiment on gamma-ray spectrometry planned to be fulfilled onboard the Phobos-Grunt spacecraft is described. The principles of the experiment and the application of gamma-spectrometry to the space investigations are considered. The design and operation of the instrument are described.  相似文献   

2.
该文详细地介绍了相位校准单元的电路和数学原理以及测试结果。在电路原理部分主要介绍相位校准单元的工作原理、各个关键点的波形以及用隧道二极管产生梳状谱的典型电路。数学原理主要阐述了测量梳状谱的数学依据。最后给出了该相位校准单元的测试要求和测试结果。  相似文献   

3.
Modern ground-based gravitational-wave antennas designed to detect bursts of gravitational radiation from astrophysical catastrophes are described. Basic antenna characteristics, peculiarities of the noise background in antennas from various sources, and methods of their suppression are presented. The contribution from cosmic rays to the background is estimated. New programs of searching for low-frequency gravitational waves and potentialities for increasing the sensitivity of antennas of new types are briefly described.  相似文献   

4.
综述了脉冲星星际闪烁观测研究的进展,对脉冲星星际闪烁现象,星际介质中电子密度涨落谱,散射等离子体在银河系中的分面等方面的最新研究结果作了介绍。星际闪烁现象和昨际介质的深入理解,使脉冲星星际闪烁已成为研究诸如脉冲星辐射区结构和脉冲星速度等脉冲星本身性质的重要工具。  相似文献   

5.
G. Alecian 《Astrophysics》1995,38(4):294-299
A short review on diffusion processes in atmospheres of stars is given. The diffusion model and its application for interpretation of spectral features of Am and Ap stars are described schematically. The building of abundance stratification and the case of calcium in Am stars are described briefly.Published in Astrofizika, Vol. 38, No. 4, pp. 533–542, October–December, 1995.  相似文献   

6.
As an engineering demonstrator for SKA, the Five-hundred-meter Aperture Spherical Telescope (FAST) is proposed in China. This paper is focused on one of the most critical components of FAST, the feed support system. The engineering concept, the configuration and results from model experiments are presented. The mechanical characteristics of the structure are analyzed. The performance of the feedback control system of the model is described. The feasibility of the design is tentatively confirmed by the experiments described at the end of the report.  相似文献   

7.
The observed correlations between X-ray and type III radio emissions from solar bursts are described by means of a bivariate distribution function. Procedures for determining the form of this distribution are described using a sample of data analyzed by Kane (1981). With the help of this distribution a model is constructed to explain the correlation between the X-ray spectral index and the ratio of X-ray to radio intensities. Implications of the model are discussed.  相似文献   

8.
Pulsating structures recorded at 237 MHz that are associated to decimetric continuum enhancement during the September 9, 2001 solar radio burst are described. We analyzed the radiopolarimetric data recorded at the Trieste Solar Radio System (INAF—Trieste Astronomical Observatory—Basovizza Observing Station) with very high time resolution (1 ms) at metric frequencies. Two different types of pulsations that occur in about 4 minutes at the same frequency are described. The possible mechanisms are analyzed and some parameters of the associated magnetic structure are estimated.  相似文献   

9.
介绍了FS软件的基本特征和ES控制标准硬件的详细工作流程。还具体介绍了在FS软件下控制观测站各种特有硬件的方法、步骤。本文可供中国VLBI网观测站程序员参考。  相似文献   

10.
Instrumentation for obtaining high time resolution dynamic spectra of solar radio bursts at decimetric wavelengths is described. The spectrograph sweeps the frequency range of 565–1000 MHz at a rate of 100 times per second. All data are recorded both on film and as an analog signal on magnetic tape. The frequency and flux calibrations are discussed. A sampling system which allows the activity at three discrete frequencies to be plotted on a chart recorder is described.  相似文献   

11.
The article contains a numerical study of periodic solutions of the Planar General Three-Body Problem. Several new periodic solutions have been discovered and are described. In particular, there is a continuous family with variable masses, extending all the way from the elliptic restricted problem to the general problem with three equal masses. All our examples have special symmetry properties which are described in detail. Finally we also suggest some important applications to the natural satellites of the solar system.  相似文献   

12.
New determination of the Earth orientation parameters (EOP), based on optical astrometry observations since the beginning of the century, is now under preparation by the Working group established by Commission 19 of the IAU. The Hipparcos catalog is to define the celestial reference frame in which the new series of EOP are to be described, The novelties of the prepared solution are the higher resolution (5 days) and more parameters estimated from the solution (celestial pole offsets, rheological parameters of the Earth, certain instrumental constants). The mathematical model of the solution is described, and the results based on the observations made with 46 instruments at 29 observatories and a preliminary Hipparcos catalog are presented.  相似文献   

13.
The apparent morphologies of the major coronal mass ejection transients observed during the Skylab mission with the High Altitude Observatory's white-light coronagraph are described and illustrated. The 77 major events are grouped into classes referred to as Loop, Filled Bottle, Material Injected into Streamer, Ray, Cloud, and Streamer Separation events, with 14 being Unclassifiable because of incomplete observations. One example of each class is shown, with references to others described in the literature. A chronological listing of all the events is given.The National Center for Atmospheric Research is sponsored by the National Science Foundation.  相似文献   

14.
根据测定天文大气折射的原理,叙述了利用相应的观测值获得瞬时大气折射测定值和建立大气折射实测模型的途径,并从各种测定值与最后结果之间的关系,指出了这里对数据处理的要求;文章介绍了对测定值进行波长改正和建立折射延迟实测模型的处理方法,分析了改正模型对天文大气折射测定值的分布要求,给出了观测数据随天顶距的增大而加密的分布模型。  相似文献   

15.
A complete solution is given for a symmetric case of the problem of the planar central configurations of four bodies, when two bodies are on an axis of symmetry, and the other two bodies have equal masses and are situated symmetrically with respect to the axis of symmetry. The positions of the bodies on the axis of symmetry are described by angle coordinates with respect to the outside bodies. The solution is such, that giving the angle coordinates, the masses for which the given configuration is a central configuration, can be computed from simple analytical expressions of the angles. The central configurations can be described as one-parameter families, and these are discussed in detail in one convex and two concave cases. The derived formulae represent exact analytical solutions of the four-body problem.  相似文献   

16.
The first results of comprehensive CORONAS-F observations of solar activity are presented. The CORONAS-F instrumentation and principal scientific objectives are briefly described and examples of the first results of data reduction are given.  相似文献   

17.
The carbon decameter radio recombination line (RRL) shape is described by a Voigt profile, since explicit line broadening is observed in the wings. A Lorentz component line half width is determined by the method of a Lorentz and Gauss line profile fitting of a curve. Since the Lorentz line shape is described by the Stark effect and the interaction with the Galaxy non-thermal background radiation, then by comparing the Lorentz component experimental and theoretical values a medium component electron density can be calculated for an expanding CII region towards Cassiopeia A. So far as the decameter lines are formed due to the transitions between the levels with large principal quantum numbers n>600, the life time, and thus the line width are very large. The collision transition rate is described by the perturbation theory for a low temperature medium. The radius matrix elements for a highly excited atom are defined more exactly with determining the transition rates for radiation interaction and scattering.  相似文献   

18.
The construction costs of distributed radio telescopes are to a great extent determined by the deployment costs of the fiber optic data transport network that is needed to transport the received information to the data processor(s). As such, the baseline and data rates that are feasible for a specified amount of money are determined by the status of the technology and deployment costs of the communication network. In this paper the present day data transport status is described and, using a costing model, the most attractive data transport technologies are determined, taking the LOFAR telescope (ASTRON, 2005) as an example. In the outlook, the near-term data transport technology developments are described.  相似文献   

19.
The NASA/Marshall Space Flight Center's solar vector magnetograph system is described; this sytem allows measurements of all components of the Sun's photospheric magnetic field over a 5 × 5 or 2.0 × 2.0 arc min square field-of-view with an optimum time resolution of 100 s and an optimum signal-to-noise of 1600. The basic system components are described, including the optics, detector, digital system and associated electronics. Automatic sequencing and control functions are outlined as well as manual selections of system parameters which afford unique system flexibility. Results of system calibration and performance are presented, including linearity, dynamic range, uniformity, spatial and spectral resolutions, signal-to-noise, electro-optical retardation and polarization calibration. Scientific investigations which utilize the unique characteristics of the instrument are described and typical results are presented.  相似文献   

20.
简述了测定瞬时大气折射值以及建立电磁波折射延迟改正模型时,对视天顶距测定值的精度要求和消除系统误差的必要性;根据新的仪器误差理论,文章采取与国外高精度测量仪器的误差测量方法相对比的方式,介绍了专用测量仪器的各种主要误差的测定方法及其所能达到的精度;还介绍了在不同方位的观测时,视频CCD图像中星像的分布情况。  相似文献   

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