71,745 research outputs found
Geo-energetics of Ukrainian crystalline shield
Purpose. To develop an analytical method which allows investigating the energy condition of rocks within the Ukrainian Crystalline shield.
Methodology. Analytical research on the energy condition of rocks has been conducted by means of a new method of research – the entropy one. The research on processes of redistribution of potential energy in the massif of rocks was conducted by analogy with an open thermodynamic system. The accepted methodological approach allowed investigating processes of energy exchange in rocks and natural transformations of some types of energy to others.
Findings. The analysis is conducted and systematization of geodynamic conditions by underground mining of ore fields of Ukraine is executed. The ways of development of new hypotheses, theories and methods of research of the energy condition of rocks are given. The description perspective in world practice of a natural condition of rocks is enclosed. Components of redistribution of energy in the massif of rocks are defined: entropy, potential stresses and angles of their action. An inspection of the results obtained on convergence is conducted and corresponding conclusions on their application are drawn.
Originality. The thermodynamic balance in rocks of the Ukrainian Crystalline shield is formed due to equilibration of vertical and horizontal power streams which, with increasing mining depth, enhance components of a tensor of stress on sedate dependence, rejecting them from hydrostatic ones during increasing in mining depth.
Practical value. The entropy method of research which allows investigating natural state of rocks with increasing depth is developed. Classification of methods of research on the stress-strain state of rocks due to introduction of a synergetic group which includes entropy, thermodynamic and energy methods is improved. It is established that distribution of entropy in rocks of the Ukrainian Crystalline shield proceeds in mutually perpendicular directions, which correspond to vertical and horizontal energy streams
Fractional charges and quantum phase transitions in imbalanced bilayer quantum Hall systems
We extend the Composite Boson theory to study slightly im-balanced bi-layer
Quantum Hall systems. In the global symmetry breaking excitonic
superfluid side, as the imbalance increases, the system supports continuously
changing fractional charges. In the translational symmetry breaking pseudo-spin
density wave (PSDW) side, there are two quantum phase transitions from the
commensurate PSDW to an in-commensurate PSDW and then to the excitonic
superfluid state. We compare our theory with experimental data and also the
previous microscopic calculations.Comment: 4+ pages, 2 figures. 1 table, Final version to appear in Phys. Rev.
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Relative value-relevance of accounting measures based on Chinese Accounting Standards and International Financial Reporting Standards
Purpose – The purpose of this paper is to investigate the relative value relevance of accounting measures based on Chinese Accounting Standards (CAS) and International Financial Reporting Standards (IFRS) in relation to both A-share and B-share markets during three distinct phases (1994-1997, 1998-2000 and 2001-2004) over which CAS were progressively harmonized with IFRS. Design/methodology/approach – Using data for 86 Chinese listed companies which issued both A- and B-shares, the authors employ the price model to test for the association between CAS-based and IFRS-based accounting information, and A-share and B-share prices. The J-test was employed to determine the relative value relevance of the information based on the two sets of accounting standards. Findings – Overall, the authors find that for both the A-share and B-share markets, both CAS-based and IFRS-based accounting information are value relevant, but IFRS-based information is more value relevant than the CAS-based information. However, the magnitude of the differences between the explanatory powers of the CAS- and IFRS-based accounting information narrowed significantly in the 2001-2004 period in both the A-share and B-share markets. The results are robust to the deflator used and the stock exchange on which the companies are listed. Practical implications – The results have implications for China and other transitional economies attempting to integrate IFRS with a uniform accounting system. Originality/value – The paper provides the first comprehensive empirical evidence as to whether or not the progressive harmonization of CAS with IFRS improved the value relevance of CAS-based accounting in China and contributes to the debate on the (ir)relevance of IFRS in emerging and transitional economies
Local noise can enhance entanglement teleportation
Recently we have considered two-qubit teleportation via mixed states of four
qubits and defined the generalized singlet fraction. For single-qubit
teleportation, Badziag {\em et al.} [Phys. Rev. A {\bf 62}, 012311 (2000)] and
Bandyopadhyay [Phys. Rev. A {\bf 65}, 022302 (2002)] have obtained a family of
entangled two-qubit mixed states whose teleportation fidelity can be enhanced
by subjecting one of the qubits to dissipative interaction with the environment
via an amplitude damping channel. Here, we show that a dissipative interaction
with the local environment via a pair of time-correlated amplitude damping
channels can enhance fidelity of entanglement teleportation for a class of
entangled four-qubit mixed states. Interestingly, we find that this enhancement
corresponds to an enhancement in the quantum discord for some states.Comment: 10 page
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