714 research outputs found
General Formula for Comparison of Clock Rates -- Applications to Cosmos and Solar System
In this paper we deduce a quite general formula which allows the relation of
clock rates at two different space time points to be discussed. In the case of
a perturbed Robertson-Walker metric, our analysis leads to an equation for the
comparison of clock rates at different cosmic space time points, which includes
the Hubble redshift, the Doppler effect, the gravitational redshift and the
Rees-Sciama effects. In the case of the solar system, when the 2PN metric is
substituted into the general formula, the comparison of the clock rates on both
the earth and a space station could be made. It might be useful for the
discussion on the precise measurements on future ACES and ASTROD.Comment: 17 pages. CQG submitte
Research on Industry Alliance Knowledge Transfer Network Modeling and Simulation Based on Complex Networks
The booming of the complex network research provides new avenues of research and support for various types of complex systems. And a large number of studies have shown that industrial technology innovation coalition belongs to the scope of complex system, so it is available to use the complex network theory to study it. This paper first describes the theory of complex networks. Second, the use of complex network theory in the industry alliance knowledge transfer is probed in terms of the overall network structure, network node centrality and network subgroup. Finally, the industry alliances knowledge transfer network model is constructed and the quantitative analysis of the simulation example is done with the network analysis tool, reflecting the effectiveness of analyzing knowledge transfer from a complex network perspective
Three-Layered Atmospheric Structure in Accretion Disks Around Stellar-Mass Black Holes
Modeling of the x-ray spectra of the Galactic superluminal jet sources GRS
1915+105 and GRO J1655-40 reveal a three-layered atmospheric structure in the
inner region of their accretion disks. Above the cold and optically thick disk
of a temperature 0.2-0.5 keV, there is a warm layer with a temperature of
1.0-1.5 keV and an optical depth around 10. Sometimes there is also a much
hotter, optically thin corona above the warm layer, with a temperature of 100
keV or higher and an optical depth around unity. The structural similarity
between the accretion disks and the solar atmosphere suggest that similar
physical processes may be operating in these different systems.Comment: 5 fives, 2 figures, 1 table. The online version of the paper in
Science may be accessed through http://jet.uah.edu/~zhangsn/papers.htm
Issues and challenges of reclaimed water usage: A case study of the Dragon-shaped River in the Beijing Olympic Park
Increased use of reclaimed water could be one of the solutions to Beijingâs growing water shortage, particularly for non-potable (e.g. landscaping) purposes. The âDragon-shaped Riverâ, a large artificial waterscape built on the site of the 2008 Beijing Olympic games, offers a useful case study of the issues and challenges attendant on wastewater reclamation and reuse. Of particular interest is the use of phytoremediation techniques for bioremediation of nutrient loads. This paper presents the results of ongoing monitoring which indicates that phytoremediation is succeeding in preventing eutrophication, though some challenges, notably management of aquatic biomass, remain
Enterprise Knowledge Creation Entropy Theoretical Analysis and Knowledge Entropy Model Study
Entering the 21st century, the knowledge economy as a new economic realizes the alternative of intellectual resources of material resources in the economic operational process, and it can greatly save energy and improve economic efficiency. Thus the value of existence of the enterprises in the context of knowledge economy is that the enterprises can conduct knowledge creation, transfer and use more efficient compared with the market. In essence, enterprises are the entity of knowledge production, the peculiarity of it owned to the difference between knowledge production ability and using ability. This paper used the similarity fundamental of the cross and comprehensive of natural science and social science, and imported the basic principles of entropy theory in thermodynamics to study the mechanism of knowledge creation, the key pathways and mechanisms, pointed out that the knowledge entropy can greatly save energy and improve economic efficiency. At the same time constructed a mathematical model of knowledge creation, and pointed out that any enterprises must continue to carry out knowledge creation and knowledge transfer to increase negative entropy to promote sustained and have a healthy development. Key words: Entropy theory; Knowledge creation; Mode
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