Suchergebnisse

I — Theory and Practice -- 1 Bearing Development and Bearing Theory -- 2 Current Practice in Journal Bearings -- II — Performance in Steady Running -- 3 Functioning of Journal Bearings -- 4 Conventional Hydrodynamic Theory of Laminar Flow -- 5 Similarity Rules, Flow Regimes, and Characteristic Relations -- 6 Observed Bearing Performance -- 7 Approximate Assessment of Performance -- III — Dynamic Characteristics -- 8 Journal Bearings in Vibration -- 9 Conventional Theory of Linearized Dynamic Characteristics with Laminar Flow -- 10 Effects of Inertia of Oil on Dynamic Characteristics -- 11 Experimental Investigation of Dynamic Characteristics -- 12 Influence of Bearings in Turbomachinery Vibration -- IV — Operational Experience and Prospective Development -- 13 Operation of Journal Bearings in Turbomachinery -- 14 Prospects in Development of Journal Bearings -- Appendices -- i Analytical Solution for Very Narrow Bearing -- ii Analytical Solution for Infinitely Wide Bearing -- iii Transformation of Axes -- iv Limiting Value of Characteristics at High Eccentricity Ratio -- v Definitions and Units of Viscosity -- vi Properties of Turbine Lubricating Oils -- vii The Apparent Out-of-balance Coefficients -- References.

GRS 1758–258 is the least studied of the three persistent black hole X-ray binaries in our Galaxy. It is also one of only two known black hole candidates, including all black hole transients, which shows a decrease of its 3-10 keV flux when entering the thermally dominated soft state, rather than an increase.We present the spectral evolution of GRS 1758–258 from RXTE-PCA observations spanning a time of about 11 years from 1996 to 2007. During this time, seven dim soft states are detected. We also consider INTEGRAL monitoring observations of the source and compare the long-term behavior to that of the bright persistent black hole X-ray binary Cygnus X-1. We discuss the observed state transitions in the light of physical scenarios for black hole transitions.