Rock is generally complex and heterogeneous,therefore the heterogeneity effects of effective stress and temperature on permeability should be taken into account.In this study,two-part Hooke’s model（TPHM） is introdu...Rock is generally complex and heterogeneous,therefore the heterogeneity effects of effective stress and temperature on permeability should be taken into account.In this study,two-part Hooke’s model（TPHM） is introduced to understand the influences of effective stress and temperature on permeability of soft and hard parts（two parts） of rock based on coupling thermo-hydro-mechanical tests.Under a fixed temperature level（25 ℃.35 ℃.50 ℃.65 ℃.80 ℃.90 ℃ and 95 ℃）.the tests were carried out in a conventional triaxial system whereas the confining pressure was remained at 50 MPa.and the pore pressure was increased to the specified levels step by step.i.e.8 MPa,18 MPa.28 MPa.38 MPa.41 MPa,44 MPa.46 MPa and 48 MPa.The temperature-dependent relationships for two parts permeabilities are proposed on the basis of the initial test results.We point out that temperature of 65 ℃-90 ℃ is the threshold for the development of CO2-plume geothermal（CPC） reservoir sandstone cracking under low effective stress（2-9 MPa） based on the relationship between temperature and soft part permeability.Furthermore,we discuss the effect of temperature on the two parts in the rock.The results indicate that as the temperature increases from 25 ℃ to 65 ℃.the flow channel in the hard part has a stronger response to temperature than that in the soft part at a fixed effective stress level,which is opposite to the situation of effective stress.Considering that natural rock is generally heterogeneous with non-uniform pore structure,we suggest a physical interpretation of the phenomenon that before the thermal cracking threshold the two parts have different responses to temperature.展开更多
Based on the generalizations of the Funk-Hecke formula and the Rayleigh plan-wave expansion formula,an alternative and succinct derivation of the addition theorem for general tensor field is obtained.This new derivati...Based on the generalizations of the Funk-Hecke formula and the Rayleigh plan-wave expansion formula,an alternative and succinct derivation of the addition theorem for general tensor field is obtained.This new derivation facilitates the diagonalization of the tensor addition theorem.In order to complete this derivation,we have carried out the evaluation of the generalization of the Gaunt coefficient for tensor fields.Since vector fields(special case of tensor fields)are very useful in practice,we discuss vector multipole fields and vector addition theorem in details.The work is important in multiple scattering and fast algorithms in wave physics.展开更多
Total and state-selective charge transfer,ionization and stripping cross sections due to the collision of Si^(2+)ion with atomic hydrogen are investigated using the classical-trajectory Monte-Carlo(CTMC)method in the ...Total and state-selective charge transfer,ionization and stripping cross sections due to the collision of Si^(2+)ion with atomic hydrogen are investigated using the classical-trajectory Monte-Carlo(CTMC)method in the collision energy from 1 keV/amu to 10 MeV/amu.Total electron capture rate coefficient is obtained in the temperature range from 105 Ko to 108 Ko.Comparison with the data available shows that our CTMC results are reliable.The behaviors for these cross sections varying with the projectile energy are analyzed.A classical physical picture is presented to explain the reason behind the behaviors.展开更多
基金financially supported by the International Science&Technology Cooperation Program of China(Grant No.2012DFA60760)
文摘Rock is generally complex and heterogeneous,therefore the heterogeneity effects of effective stress and temperature on permeability should be taken into account.In this study,two-part Hooke’s model（TPHM） is introduced to understand the influences of effective stress and temperature on permeability of soft and hard parts（two parts） of rock based on coupling thermo-hydro-mechanical tests.Under a fixed temperature level（25 ℃.35 ℃.50 ℃.65 ℃.80 ℃.90 ℃ and 95 ℃）.the tests were carried out in a conventional triaxial system whereas the confining pressure was remained at 50 MPa.and the pore pressure was increased to the specified levels step by step.i.e.8 MPa,18 MPa.28 MPa.38 MPa.41 MPa,44 MPa.46 MPa and 48 MPa.The temperature-dependent relationships for two parts permeabilities are proposed on the basis of the initial test results.We point out that temperature of 65 ℃-90 ℃ is the threshold for the development of CO2-plume geothermal（CPC） reservoir sandstone cracking under low effective stress（2-9 MPa） based on the relationship between temperature and soft part permeability.Furthermore,we discuss the effect of temperature on the two parts in the rock.The results indicate that as the temperature increases from 25 ℃ to 65 ℃.the flow channel in the hard part has a stronger response to temperature than that in the soft part at a fixed effective stress level,which is opposite to the situation of effective stress.Considering that natural rock is generally heterogeneous with non-uniform pore structure,we suggest a physical interpretation of the phenomenon that before the thermal cracking threshold the two parts have different responses to temperature.
文摘Based on the generalizations of the Funk-Hecke formula and the Rayleigh plan-wave expansion formula,an alternative and succinct derivation of the addition theorem for general tensor field is obtained.This new derivation facilitates the diagonalization of the tensor addition theorem.In order to complete this derivation,we have carried out the evaluation of the generalization of the Gaunt coefficient for tensor fields.Since vector fields(special case of tensor fields)are very useful in practice,we discuss vector multipole fields and vector addition theorem in details.The work is important in multiple scattering and fast algorithms in wave physics.
基金the Chinese National Foundation of Sciences(Grant#s.10344001 and 10174009)Science and Technology Foundation of Chinese Academy of Engineering Physics.J.G.W.and P.C.S.also acknowledge support from National Aeronautics and Space Administration through grant NAG5-11453.
文摘Total and state-selective charge transfer,ionization and stripping cross sections due to the collision of Si^(2+)ion with atomic hydrogen are investigated using the classical-trajectory Monte-Carlo(CTMC)method in the collision energy from 1 keV/amu to 10 MeV/amu.Total electron capture rate coefficient is obtained in the temperature range from 105 Ko to 108 Ko.Comparison with the data available shows that our CTMC results are reliable.The behaviors for these cross sections varying with the projectile energy are analyzed.A classical physical picture is presented to explain the reason behind the behaviors.
