This paper presents a novel capacitance probe, i.e., paraUel-wire capacitance probe （PWCP）, for two-phase flow measurement. Using finite element method （FEM）, the sensitivity field of the PWCP is investigated and ...This paper presents a novel capacitance probe, i.e., paraUel-wire capacitance probe （PWCP）, for two-phase flow measurement. Using finite element method （FEM）, the sensitivity field of the PWCP is investigated and the optimum sensor geometry is determiend in term of the characterisitc parameters. Then, the response of PWCP for the oil-water stratified flow is calculated, and it is found the PWCP has better linearity and sensitivity to the variation of water-layer thickness, and is almost independant of the angle between the oil-water interface and the sensor electrode. Finally, the static experiment for oil-water stratified flow is carried out and the calibration method of liquid holdup is presented.展开更多
Employing the accurate frozen-core full-potential projector augmented-wave method,the self-consistentelectronic structure calculations were carried out on pure Ni,Pd,Pt and mixed Ni-Pd and Ni-Pt free-standing linear a...Employing the accurate frozen-core full-potential projector augmented-wave method,the self-consistentelectronic structure calculations were carried out on pure Ni,Pd,Pt and mixed Ni-Pd and Ni-Pt free-standing linear andzigzag nanowires.The bond lengths for all these systems are generally increased as their structures change from the linearto the zigzag chain.The bond lengths for Ni-Pd and Ni-Pt wires are in between the values of corresponding pure systemand the bond angles around 60° suggesting the possible formation of Ni-Pd and Ni-Pt bimetallic materials.In mixedNi-Pd and Ni-Pt chains,the Ni,Pd,and Pt atoms have quite high local magnetic moments.The calculations suggestthat the magnetic moments in linear nanowires are generally larger than the ones of corresponding zigzag nanowires.Itis found that there is hybridization between Ni 3d and Pd 4d,Ni 3d and Pt 5d states,which may significantly affectstructural stability and magnetism of Ni-Pd and Ni-Pt nanowires.展开更多
Excess electrons are not only an important source of radiation damage,but also participate in the repair process of radiation damage such as cyclobutane pyrimidine dimer(CPD).Using ab initio molecular dynamics(AIMD)si...Excess electrons are not only an important source of radiation damage,but also participate in the repair process of radiation damage such as cyclobutane pyrimidine dimer(CPD).Using ab initio molecular dynamics(AIMD)simulations,we reproduce the single excess electron stepwise catalytic CPD dissociation process in detail with an emphasis on the energy levels and molecular structure details associated with excess electrons.On the basis of the AIMD simulations on the CPD aqueous solution with two vertically added excess electrons,we exclude the early-proposed[2+2]-like concerted synchronous dissociation mechanism,and analyze the difference between the symmetry of the actual reaction and the symmetry of the frontier molecular orbitals which deeply impact the mechanism.Importantly,we propose a new model of the stepwise electron-catalyzed dissociation mechanism that conforms to the reality.This work not only provides dynamics insights into the excess electron catalyzed dissociation mechanism,but also reveals different roles of two excess electrons in two bond-cleavage steps(promoting versus inhibiting).展开更多
Migration of wires or pins around the shoulder is a known complication, though their migration within the chest is uncommon. We report an unusual case of hydropneumothorax due to migration of a bent Kirschner wire fro...Migration of wires or pins around the shoulder is a known complication, though their migration within the chest is uncommon. We report an unusual case of hydropneumothorax due to migration of a bent Kirschner wire from the right proximal humerus in a 63 year-old man. We reviewed his clinical history, physical examination, imaging findings, surgical method and outcome. We also reviewed the literature on orthopaedic wire migration and latest technique in removal of the wires. Chest radiographs and chest computerized tomography are useful in detection and diagnosis of this disorder. Regular radiographic follow-up is needed for patients with internal fixation devices; any fractured or migrated pins or wires must be removed immediately to prevent dangerous complications. It is always important to remove the wires at the end of the treatment. Early removal of fixation wires and regular follow-up if wires are retained are essential to prevent serious complications.展开更多
基金Supported by the National Natural Science Foundation of China （50974095, 41174109, 61104148）, and the National Science and Technology Mai or Projects （2011ZX05020-006）.
文摘This paper presents a novel capacitance probe, i.e., paraUel-wire capacitance probe （PWCP）, for two-phase flow measurement. Using finite element method （FEM）, the sensitivity field of the PWCP is investigated and the optimum sensor geometry is determiend in term of the characterisitc parameters. Then, the response of PWCP for the oil-water stratified flow is calculated, and it is found the PWCP has better linearity and sensitivity to the variation of water-layer thickness, and is almost independant of the angle between the oil-water interface and the sensor electrode. Finally, the static experiment for oil-water stratified flow is carried out and the calibration method of liquid holdup is presented.
基金Supported by the National Natural Science Foundation of China under Grant Nos.50531040 and 50871058the Ministry of Science and Technology of China under Grant No.2006CB605201
文摘Employing the accurate frozen-core full-potential projector augmented-wave method,the self-consistentelectronic structure calculations were carried out on pure Ni,Pd,Pt and mixed Ni-Pd and Ni-Pt free-standing linear andzigzag nanowires.The bond lengths for all these systems are generally increased as their structures change from the linearto the zigzag chain.The bond lengths for Ni-Pd and Ni-Pt wires are in between the values of corresponding pure systemand the bond angles around 60° suggesting the possible formation of Ni-Pd and Ni-Pt bimetallic materials.In mixedNi-Pd and Ni-Pt chains,the Ni,Pd,and Pt atoms have quite high local magnetic moments.The calculations suggestthat the magnetic moments in linear nanowires are generally larger than the ones of corresponding zigzag nanowires.Itis found that there is hybridization between Ni 3d and Pd 4d,Ni 3d and Pt 5d states,which may significantly affectstructural stability and magnetism of Ni-Pd and Ni-Pt nanowires.
基金supported by the National Natural Science Foundation of China(No.21873056,No.21773137,and No.21573128)。
文摘Excess electrons are not only an important source of radiation damage,but also participate in the repair process of radiation damage such as cyclobutane pyrimidine dimer(CPD).Using ab initio molecular dynamics(AIMD)simulations,we reproduce the single excess electron stepwise catalytic CPD dissociation process in detail with an emphasis on the energy levels and molecular structure details associated with excess electrons.On the basis of the AIMD simulations on the CPD aqueous solution with two vertically added excess electrons,we exclude the early-proposed[2+2]-like concerted synchronous dissociation mechanism,and analyze the difference between the symmetry of the actual reaction and the symmetry of the frontier molecular orbitals which deeply impact the mechanism.Importantly,we propose a new model of the stepwise electron-catalyzed dissociation mechanism that conforms to the reality.This work not only provides dynamics insights into the excess electron catalyzed dissociation mechanism,but also reveals different roles of two excess electrons in two bond-cleavage steps(promoting versus inhibiting).
文摘Migration of wires or pins around the shoulder is a known complication, though their migration within the chest is uncommon. We report an unusual case of hydropneumothorax due to migration of a bent Kirschner wire from the right proximal humerus in a 63 year-old man. We reviewed his clinical history, physical examination, imaging findings, surgical method and outcome. We also reviewed the literature on orthopaedic wire migration and latest technique in removal of the wires. Chest radiographs and chest computerized tomography are useful in detection and diagnosis of this disorder. Regular radiographic follow-up is needed for patients with internal fixation devices; any fractured or migrated pins or wires must be removed immediately to prevent dangerous complications. It is always important to remove the wires at the end of the treatment. Early removal of fixation wires and regular follow-up if wires are retained are essential to prevent serious complications.
