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91.
郝红武 《西安航空技术高等专科学校学报》2005,23(3):31-32
通过对强度理论、杆件拉伸概念及公式的分析研究,引入实验元件的几何刚度和弹性稳定性系数的概念,推导出实验元件的拉伸位移变化率的公式,并以此进行实验元件的破坏预估及结构模型修正。 相似文献
92.
The Bastille-day event in 2000 produced energetic 3B/X5.6 flare with a halo CME, which had great geo-effects consequently.
This event has been studied extensively and it is considered that it follows the two-ribbon flare model. The flare/CME event
was triggered by an erupting filament and TRACE observations showed formation of giant arcade structures during the flare
process. Hard X-ray (HXR) two ribbons revealed for the first time in this flare event (Masuda et al., 2001). The reconstruction of 3-D coronal magnetic fields revealed a magnetic flux rope structure, for the first time, from
extrapolation of observed photospheric vector magnetogram data and the flux rope structure was co-spatial with portion of
the filament and a UV bright lane (Yan et al., 2001a, 2001b). Here we review some recent work related to the flux rope structure and the HXR two ribbons by comparing their
locations and the flux temporal profiles during the flare process so as to understand the energy release and particle accelerations.
It is proposed that the rope instability may have triggered the flare event, and reconnection may occur during this process.
The drifting pulsation structure in the decimetric frequency range is considered to manifest the rope ejection, or the initial
phase of the coronal mass ejection. The HXR two ribbons were distributed along the flux rope and the rope foot points coincide
with HXR sources. The energy dissipation from IPS observations occurred within about 100 R
⋅ is consistent with the estimate for the flux rope system.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
93.
A.G. Lyne 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2006,38(12):2716-2720
A recent multibeam pulsar survey of the outer Galactic plane at Parkes has discovered the first-known double-pulsar binary, a very compact double neutron star system in which both stars are observable as radio pulsars. In this review, we briefly describe the discovery and the studies which have been enabled by the unique properties of the system. These range from the most precise confirmation yet of the theory of general relativity, with the possibility of even more new tests and the measurement of second-order post-Newtonian effects, to studies of the magnetospheres and emission properties of the two pulsars. The discovery also results in a significant increase in the expected rate of occurrence of the mergers of double neutron star systems, and hence the rate of detection of such events by the new ground-based gravitational wave detectors. 相似文献
94.
Guido Chincarini 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1984,3(10-12)
In this lecture I review part of the published and unpublished observational evidence showing that cluster spiral galaxies are hydrogen deficient. Always using observational data, it is argued that the deficiency is due to the interaction between the galaxies and the intergalactic medium. Furthermore it is shown that the stellar population of deficient galaxies has also been affected and a brief discussion is given of the mechanisms at work. 相似文献
95.
M. van der Klis 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2006,38(12):2675-2679
Some aspects of the rapid X-ray variability of low magnetic-field neutron stars in low-mass X-ray binaries are briefly summarized. 相似文献
96.
Q.Z. Liu J.Z. Yan 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2006,38(12):2906-2908
We investigate the relation between the pulse and orbital periods in high-mass X-ray binaries (HMXBs), in order to find the candidates of magnetar descendants in HMXBs. We suggest that magnetar descendants can be found among the HMXBs with relatively shorter orbital periods and longer pulse periods. 相似文献
97.
The current status of the theory of a new astrophysical phenomenon, aradiation-driven diskon, is outlined.The cyclotron radiation pressure around sufficiently hot, strongly magnetized white dwarfs and neutron stars is shown to be able to drive a wind from the photosphere and support a plasma envelope in the closed part of the magnetosphere. The magnetohydrostatic configuration of an optically thin, radiatively supported plasma envelope is determined. It consists of an equatorial disk in the region where the cyclotron radiation force exceeds the local force of gravity and a closed shell near the equilibrium surface where the radiation pressure equals gravity. The effects of finite optical depth on the behaviour of the magnetospheric plasma and the influence of the envelope on the observed radiation are discussed.Classes of magnetic degenerate stars are pointed out in which radiation-driven diskons may be found. The best candidates are two individual stars, the strongly magnetized white dwarfs GD 229 and PG 1031+234. Both exhibit broad and deep depressions in the ultraviolet which are explained as a result of cyclotron scattering by an optically thick radiation-driven envelope in the inhomogeneous magnetic field of the star. We predict a temporal and spectral variability of these features due to non-stationary plasma motions in the envelope. 相似文献
98.
采用国产含氟乳液为基料,研究了辅料的种类和用量,涂料的组成及工艺参数对涂膜性能的影响,提出了能获得良好涂膜的NH-93型氟涂料的配方和成膜条件。 相似文献
99.
Observations carried out from the coronagraphs on board space missions (LASCO/SOHO, Solar Maximum and Skylab) and ground-based facilities (HAO/Mauna Loa Observatory) show that coronal mass ejections
(CMEs) can be classified into two classes based on their kinematics evolution. These two classes of CMEs are so-called fast
and slow CMEs. The fast CME starts with a high initial speed that remains more or less constant; it is also called the constant-speed CME. On the other hand, the slow CME starts with a low initial speed, but shows a gradual acceleration; it is also called
the accelerated and slow CME. Low and Zhang [Astrophys. J. 564, L53–L56, 2002] suggested that these two classes of CMEs could be a result of a difference in the initial topology of the
magnetic fields associated with the underlying quiescent prominences. A normal prominence magnetic field topology will lead
to a fast CME, while an inverse quiescent prominence results in a slow CME, because of the nature of the magnetic reconnection
processes. In a recent study given by Wu et al. [Solar Phys. 225, 157–175, 2004], it was shown that an inverse quiescent prominence magnetic topology also could produce a fast CME. In this
study, we perform a numerical MHD simulation for CMEs occurring in both normal and inverse quiescent prominence magnetic topology.
This study demonstrates three major physical processes responsible for destabilization of these two types of prominence magnetic
field topologies that can launch CMEs. These three initiation processes are identical to those used by Wu et al. [Solar Phys. 225, 157–175, 2004]. The simulations show that both fast and slow CMEs can be initiated from these two different types of magnetic
topologies. However, the normal quiescent prominence magnetic topology does show the possibility for launching a reconnection island (or secondary O-line) that might be thought of as a “CME’’. 相似文献
100.
N.M. Ashok R.K. Manchanda D.P.K. Banerjee S. Farrell R.K. Sood 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2006,38(12):2777-2778
We present near-infrared spectroscopy of the massive X-ray binary 2S 0114+650. These observations covering the spectral range 1.08–2.35 μm span the region where Paschen and Brackett series recombination lines of hydrogen are expected to be seen, namely, Paβ , Brγ and Br 10–17 lines. The absence of any of these lines in emission supports earlier inferences that the optical component in 2S 0114+650 is unlikely to be a Be star but rather a B type supergiant. Near-IR photometry gives J = 8.78, H = 8.53 and K = 7.96; these values show marginal variations from earlier reported measurements. 相似文献