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81.
贾明生 《广东海洋大学学报》1994,(2)
通过小试测定的燃料甲醇催化剂的活性数据,拟合出合成动力学方程,并对反应器模型模拟计算需要的主要基础数据来源及计算方法作了论述。 相似文献
82.
Wu Yue-fang Sun Jin Mao Xin-jie Li Shou-zhong 《Chinese Astronomy and Astrophysics》1990,14(4):381-388
Near infrared observation of the infrared source in S140 was made using the 1.26 m infrared telescope of Beijing Observatory, yielding fluxes in the J, H and K bands. Combining with data from satellite and ground-based IR and submillimetre observations, we found the spectral gradient, IR luminosity and the shell structure of the IR source.
We also combined observations of CO and NH3 in an analysis of the heating of the gas associated with the source. Besides through dust, the central source may also input energy into the gas through shock waves. External sources of heat and heating by photoelectric process and cosmic rays are also discussed. 相似文献
83.
U. Hwang R. Petre A. E. Szymkowiak S. S. Holt 《Journal of Astrophysics and Astronomy》2002,23(1-2):81-87
We present a newChandra observation of Tycho’s supernova remnant with the Advanced CCD Imaging Spectrometer. Multicolor Xray imaging reveals new
details of the outer shock and ejecta. At energies between 4 and 6 keV, the outline of the outer shock is clearly revealed
in X-rays for the first time. The distribution of the emission from lines of Si and Fe are confirmed to have a different morphology
from each other, and the Si ejecta are shown to extend to the blast shock at several locations. Characteristic spectra of
the outer shock and ejecta are also presented. 相似文献
84.
星际尘埃研究现状与进展 总被引:3,自引:0,他引:3
由于星际尘埃的广泛存在和其在恒星与行星系统的形成、星系以及整个宇宙演化中的重要作用,星际尘埃的研究成为当今天体物理领域的热点前沿课题。该文从尘埃与电磁场相互作用的观测证据出发,系统地介绍了星际消光(包括吸收和散射)、星际红外辐射、星际偏振等的研究现状,讨论了星际元素减损,以及行星际尘埃和陨石中的前太阳尘埃等问题。从相应的观测证据中,可以得到关于星际尘埃的丰度、化学组成、尺寸和形状的信息。该文还对当前比较流行的三种尘埃模型(硅酸盐-石墨-PAHs模型、硅酸盐核-碳有机耐熔质壳层模型和多孔尘埃模型)进行了讨论与比较,对该研究领域中待解决的问题也作了简要的概括。 相似文献
85.
A. V. Fisenko A. B. Verchovsky L. F. Semjonova C. T. Pillinger 《Astronomy Letters》2001,27(9):608-612
Based on the heterogeneity in the contents and isotopic compositions of carbon, nitrogen, and rare gases found in different (in grain size) interstellar diamond fractions of the meteorite Efremovka, we discuss issues associated with the nature of the diamond, the distribution of the isotopic components of impurity chemical elements in it, and the kinetics of their release. 相似文献
86.
James Cordes 《Astrophysics and Space Science》2001,278(1-2):11-16
I first review the observables and optics of interstellar seeing associated with radio wave scattering in the interstellar
medium. I then describe the Galactic distribution of electron density and its fluctuations, as inferred from a number of observables,
including angular and pulse broadening, diffractive scintillations, and dispersion measures. Propects for improving the Galactic
model are outlined.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
87.
In our work, the method that can help to predict the existence of distant objects in the Solar system is demonstrated. This
method is connected with statistical properties of a heliocentric orbital complex of meteoroids with high eccentricities.
Heliocentric meteoroid orbits with high eccentricities are escape routes for dust material from distant parental objects with
near-circular orbits to Earth-crossing orbits. Ground-based meteor observations yield trajectory information from which we
can derive their place of possible origin: comets, asteroids, and other objects (e.g. Kuiper Objects) in the Solar system
or even interstellar space. Statistical distributions of radius vectors of nodes, and other parameters of orbits of meteoroids
contain key information about position of greater bodies. We analyze meteor orbits with high eccentricities that were registered
in 1975–1976 in Kharkiv (Ukraine). The orbital data of the Kharkiv electronic catalogue are received from observations of
radiometeors with masses 10−6−10−3 g. 相似文献
88.
K. V. Krasnobaev 《Astronomy Letters》2004,30(7):451-455
We investigate the stability of a dense neutral shell that is accelerated outward by the hot-gas pressure and that loses its mass through photoionization by radiation from the central star. We assume the H I shell to be thin and use the Lagrangian coordinates to describe its motion. We show that a flow accompanied by cumulative effects emerges during the nonlinear development of the instability. We estimate the influence of the radiative cooling rate on the motion and determine parameters of the gas in the cumulative region. The results obtained are compared with the observations of the nebulae NGC 7293 and NGC 2392. 相似文献
89.
T. A. Lozinskaya A. V. Moiseev N. Yu. Podorvanyuk A. N. Burenkov 《Astronomy Letters》2008,34(4):217-230
We have investigated the structure, kinematics, and emission spectrum of the ionized gas in the synchrotron superbubble in the irregular galaxy IC 10 based on observations with the 6-m Special Astrophysical Observatory telescope with the SCORPIO focal reducer in three modes: direct imaging in the [S II] λ(6717 + 6731) Å lines, long-slit spectroscopy, and spectroscopy with a scanning Fabry-Perot interferometer. We have identified a bright (in the [S II] lines) filamentary optical shell and determined its expansion velocity, mass, and kinetic energy. The nature of the object is discussed. 相似文献
90.
V. Dikarev E. Grün J. Baggaley D. Galligan M. Landgraf R. Jehn 《Earth, Moon, and Planets》2004,95(1-4):109-122
The orbital distributions of dust particles in interplanetary space are revised in the ESA meteoroid model to incorporate
more observational data and to comply with the constraints due to the long-term particle dynamics under the planetary gravity
and Poynting–Robertson effect. Infrared observations of the zodiacal cloud by the COBE Earth-bound observatory, flux measurements
by the dust detectors on board Galileo and Ulysses spacecraft, and the crater size distributions on lunar rock samples retrieved
by the Apollo missions are fused into a single model. Within the model, the orbital distributions are expanded into a sum
of contributions due to a number of known sources, including the asteroid belt with the emphasis on the prominent families
Themis, Koronis, Eos and Veritas, as well as comets on Jupiter-encountering orbits. An attempt to incorporate the meteor orbit
database acquired by the Advanced Meteor Orbit Radar at Christchurch is also discussed.
Work was done during D. Galligan’s stay at the University of Canterbury. 相似文献