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A Damage Mechanics Analysis on Rheological Failure of Rocks Under High Temperatures and Pressures
Zuan Chen,
Zhihe Jin,
Xiaoge Huang,
Shengwen Qi
Issue:
Volume 10, Issue 2, March 2022
Pages:
24-32
Received:
16 February 2022
Accepted:
3 March 2022
Published:
11 March 2022
DOI:
10.11648/j.ajpa.20221002.11
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Abstract: During rheological process of rocks at high temperatures and pressures, damage occurs when the visco-plastic strains accumulate to a certain level. Damage is assumed to start accumulating at the onset of tertiary creep. The evolution of damage can lead to localized deformation and eventual failure of the rock. This paper develops a damage constitutive relation and damage evolution equation for rheological failure of rocks based on the theory and method of damage mechanics. A method of determining the material constants in the constitutive relation and damage evolution equation is proposed and employed to estimate the parameters for marble based on the experiment results. One numerical example explaining deep earthquake occurrence is presented to illustrate the application of the constitutive relation and damage evolution equation. The numerical results indicate that the proposed constitutive and damage equations are capable of predicting earthquake occurrence based on the shear stress evolution. The proposed damage constitutive relation and damage evolution equation for rheological failure of rocks provide a theoretical base for numerical calculation simulating geodynamics process inside earth interior.
Abstract: During rheological process of rocks at high temperatures and pressures, damage occurs when the visco-plastic strains accumulate to a certain level. Damage is assumed to start accumulating at the onset of tertiary creep. The evolution of damage can lead to localized deformation and eventual failure of the rock. This paper develops a damage constitut...
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The Diffusion Behavior of the System Driven by Non-Gaussian Noise or Its Time Derivative
Issue:
Volume 10, Issue 2, March 2022
Pages:
33-37
Received:
16 February 2022
Accepted:
7 March 2022
Published:
14 March 2022
DOI:
10.11648/j.ajpa.20221002.12
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Abstract: The diffusion behavior of the system driven by the non-Gaussian noise and its time derivative are investigated in detail. The temperature dependence of the noise spectral profile is firstly analyzed using Monte Carlo simulations, which is shown that the spectrum of the non-Gaussian noise is a decreasing function of temperature when the frequency is sufficient small. By contrast, its derivative is Gaussian and vanishes for the low frequency. In addition, diffusion behavior of the system subjected to non Gaussian noise or its time derivative are more detailed discussed within the framework of the generalized Langevin equation. It is particularly revealed that the system driven by the internal non-Gaussian noise behaves as normal diffusion for various temperatures, while the time derivative of the non-Gaussian noise induces ballistic diffusion of a free system and the variance is sensitive to the initial condition which implies the breaking of the ergodicity.
Abstract: The diffusion behavior of the system driven by the non-Gaussian noise and its time derivative are investigated in detail. The temperature dependence of the noise spectral profile is firstly analyzed using Monte Carlo simulations, which is shown that the spectrum of the non-Gaussian noise is a decreasing function of temperature when the frequency is...
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Dependence of Orbital Feshbach Resonance in 173Yb on the Nuclear Hyperfine States
Issue:
Volume 10, Issue 2, March 2022
Pages:
38-44
Received:
9 March 2022
Accepted:
24 March 2022
Published:
31 March 2022
DOI:
10.11648/j.ajpa.20221002.13
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Abstract: A system of ultracold alkali (6Li, 40K) and alkaline-earth atoms (87Sr) will investigate the quantum simulation properties. Feshbach resonance (FR) is an essential tool for changing the interaction between particles by changing the magnetic field strength between the atoms. FR are of two kinds magnetic Feshbach resonance (MFR) and orbital Feshbach resonance (OFR), dealing with one band and two-band physics, respectively. In orbital Feshbach resonance, the energy difference between open and closed channels is in the range of Fermi energy or even smaller, reducing to zero or at no magnetic field. The atomic structural analysis of one valence electron in the outermost orbit for alkali atoms has widely explored the superfluidity and single-particle phenomena. The system of alkaline-earth atoms provides an excellent opportunity for the investigation of quantum simulation and quantum many-body matters such as the simulation of synthetic gauge field, Kondo physics, and SU(N) physics. This work studies spin-orbit coupled (SOC) physics in alkaline-earth (AE) atoms like 173Yb in two different electronic and nuclear hyperfine states. We discuss the interaction between particles in the hyperfine states by varying the interatomic distance. Here we will discuss short-range potential (in singlet and triplet channels at finite field strength) and long-range potential (open and closed channels for zero-field strength). We discuss the single-particle density-of-states (DOS) in the open and closed channel above superfluid phase transition temperature to study the normal-state properties of two particular nuclear hyperfine states.
Abstract: A system of ultracold alkali (6Li, 40K) and alkaline-earth atoms (87Sr) will investigate the quantum simulation properties. Feshbach resonance (FR) is an essential tool for changing the interaction between particles by changing the magnetic field strength between the atoms. FR are of two kinds magnetic Feshbach resonance (MFR) and orbital Feshbach ...
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Study of Thermoelectric Properties of Nickel Germano-silicides Obtained on the Basis of Bulk Solid Solutions of Silicon-germanium
Nuriddin Azadovich Matchanov,
Komiljon Abdusharipovich Bobojonov,
Dilmurad Shamuradovich Saidov,
Shokhzod Komiljonovich Abdusharipov,
Alisher Erkaboevich Rajabov
Issue:
Volume 10, Issue 2, March 2022
Pages:
45-50
Received:
15 January 2022
Accepted:
4 February 2022
Published:
9 April 2022
DOI:
10.11648/j.ajpa.20221002.14
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Abstract: The effect of thermal annealing in vacuum (in the temperature range of 200-900°C) on the electrical conductivity of the structure of a nickel film - a single-crystal layer of germanosilicide has been studied. Nickel films 15 nm thick were sputtered by adsorption sputtering in vacuum. The possibility of forming conductive layers with a surface resistance of about 4.9 mOhm * cm and on their basis bulk Si1-xGex single crystals with a thickness of 4 μm by mechanical processing and chemical etching, as well as deposition in a vacuum environment of 10-5 -10-7 Torr. The surface resistance of the film and the surface morphology (and chipping) were studied, the phase state of nickel germanium silicide films was studied by X-ray diffraction, the study of thermoelectric properties and the comparison of Ni-SiRH and Ni-Si1-x-Gex samples as thermoelectric materials. The thermopower values were obtained experimentally in the temperature range 36-107°C, and the role of the nanoscale film and substrate in the formation of the thermoelectric effect was discussed. Increasing the thermoelectric figure of merit due to nickel with decreasing surface resistance and due to phonon scattering on surfaces and heterostructures such as nickel germanosilicide, superlattices and layer/substrate systems. The best quality factor ZT = 1.98 ± 0.05 was obtained for Ni-(Si0.95Ge0.05) at T = 300K. The maximum difference with a value of ΔTmax = 326.84K.
Abstract: The effect of thermal annealing in vacuum (in the temperature range of 200-900°C) on the electrical conductivity of the structure of a nickel film - a single-crystal layer of germanosilicide has been studied. Nickel films 15 nm thick were sputtered by adsorption sputtering in vacuum. The possibility of forming conductive layers with a surface resis...
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