建立1∶20万(1∶5万)数字地质图空间数据库的方法(内蒙古部分)

本文总结了建立数字地质图空间数据库的工作方法与步骤 ,详细阐述了内蒙古部分建库的总体设计 ,为实用型 GIS的建库工作和实施提供参考。     

Time resolved images from the center of the Galaxy appear to counter General Relativity

Intense observations of the galactic center since 1992 have revealed the presence of a supermassive object located there, some 26 000 light years from Earth. The mass of the galactic center was determined using time resolved astrometry over a time span of 13 years, from 1992 to present. The observations clearly show that the stars in the immediate vicinity of the supermassive galactic center, denoted as Sagittarius A* (Sgr A*), move along purely Keplerian orbits around Str A*. Observation of the rapidly moving stars permitted astrophysicists to determine a mass for the galactic center of around 3.6 million solar masses. Time resolved images of the Keplerian motions of these stars has exhibited to date no evidence of distortions in the images due to gravitational light bending effects, as predicted by General Relativity. In this paper, a well known tool commonly used by astrophysicists for estimating the effect of gravitation on light rays was examined. The results reveal flaws in the understanding of fundamental principles in mathematical physics applied to gravitational effects on rays of light, as predicted by General Relativity, at the site of a point‐like gravitating masses such as the galactic center mass. Application of the Gauss Law to point‐like gravitating masses shows that a requirement for the colinear alignment of the light source, the lensing and the observer is not necessary for an observation of gravitational lensing as predicted by General Relativity. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

A massive thick disc around a massive black hole and its runaway instability

We investigate the runaway instability of configurations consisting of a massive dense but non-self-gravitating thick disc/torus surrounding a massive black hole (MBH). We limit our model parameters to values that result in a self-consistent thick disc around an MBH. We identify, analytically, the index of the angular momentum distribution that will form a thick disc as an initial equilibrium state, and obtain the mass ratio of the disc to the central black hole for which the disc is dominated by the radiation pressure. In our theoretical framework we find that a self-consistent thick disc with constant angular momentum leads to a runaway instability on a dynamical time-scale. However, even a slight increase of the specific angular momentum outwards has a strong stabilizing effect on the accretion process. Finally, we discuss our results and present possible applications to high-energy emission.     

Summary lecture

This summary lecture makes no attempt to summarize what was actually said at the meeting, since this is well covered by the other contributors. Instead I have structured my presentation in three parts: First I try to demonstrate why the Sun is unique by comparing it with laboratory plasmas. This is followed by some personal reminiscences that go back a significant fraction of the century. I conclude in the form of a poem about this memorable conference in honor of the centennial anniversary of the Kodaikanal Observatory.     

Time of explosive decay of a daemon-containing nucleus

We start from the hypothesis that the dark matter of the Galactic disc contains Planckian particles carrying a negative electric charge of up to Z =10, which we call dark electric matter objects (daemons). Daemons are capable of catalysing proton-fusion reactions, which may account for the observed solar neutrino deficiency. The inevitable poisoning of the catalytic property of daemons as they capture heavy nuclei ( A 20) in the interior of the Sun is used to estimate the decay time of a daemon-containing nucleus (nucleon) in quantum-relativistic processes, which remain largely unknown. This time is τ _ex∼10⁻⁷ s. This may mean that the lower limit on the mass of an intranucleonic particle interacting with a daemon is ∼10⁸–10¹⁰ GeV and, possibly, even ∼10¹⁴–10¹⁵ GeV. The desirability of a search for multiple events occurring with an interval ∼ τ _ex along the 'slow' daemon trajectories on operating installations dedicated to detection of the proton decay is pointed out.     

Are there three peaks in the power spectra of GX 339−4 and Cyg X-1?

Among the variability behaviours exhibited by neutron star systems are the so-called 'horizontal branch oscillations' (HBO, with frequencies ≈50 Hz), the 'lower-frequency kHz quasi-periodic oscillation' (QPO) and the 'upper-frequency kHz QPO', with the latter two features being separated in frequency by an amount comparable to, but varying slightly from, the suspected spin-frequency of the neutron star. Recently, Psaltis, Belloni & van der Klis have suggested that there exists a correlation between these three frequencies that, when certain identifications of variability features are made, even encompasses black hole sources. We consider this hypothesis by reanalysing a set of GX 339−4 observations. The power spectral density (PSD) constructed from a composite of seven separate, but very similar, observations shows evidence for three broad peaks in the PSD. If the peak frequencies of these features are identified with QPO, then their frequencies approximately fit the correlations suggested by Psaltis, Belloni, & van der Klis. We also reanalyse a Cyg X-1 observation and show that the suggested QPO correlation may also hold, but that complications arise when the QPOs (which, in reality, are fairly broad features) are considered as a function of energy band. These fits suggest the existence of at least three separate, independent physical processes in the accretion flow, a hypothesis that is also supported by consideration of the Fourier frequency-dependent time lags and coherence function between variability in different energy bands. If these variability features have a common origin in neutron star and black hole systems, then 'beat frequency models' of kHz QPO in neutron star systems are called into question.     

Black hole transients and the Eddington limit

I show that the Eddington limit implies a critical orbital period P _crit(BH)≃2 d beyond which black hole LMXBs cannot appear as persistent systems. The unusual behaviour of GRO J1655–40 may result from its location close to this critical period.     

高寒地区公路涎流冰灾害及防治

西藏浪卡子至洛扎公路是西藏山南地区环线公路的西段,全长120 km,集交通、外交、军事于一体。由于公路位于高寒、新构造运动强烈的地区,特殊的地质背景、气候因素和地理环境,为该地区地质灾害的发生孕育了良好的条件。涎流冰是指水在持续负温下随流随冻形成的积冰,水源和负温是涎流冰形成的先决条件。公路沿线有10处涎流冰灾害,影响的公路总长457 m。涎流冰灾害对公路的建设和运营构成了极大的危害,对其治理以防为主,采用涵洞或盲沟排水,同时必须防冻。     

巴东新城区紫红色泥岩工程地质性质研究

通过地质调查及大量岩土力学试验,对巴东新城区中三叠统巴东组二段T2b2紫红色泥岩工程地质性质进行了综合研究。测定了岩石的矿物成分及微观结构和岩石的物理及水理性质参数。由不同含水状态下的室内崩解试验发现,紫红色泥岩具有较强的崩解特性,且与岩石的物理状态密切相关,试验得到岩块的力学性质指标和变形特征。进行了点荷载试验,对不同风化程度和不同物理状态下的岩石的工程地质性质进行了分析,并指出其对工程的影响。