The formation and mechanical properties of amorphous copper are studied using molecular dynamics simulation. The simulations of tension and shearing show that more pronounced plasticity is found under shearing, compar...The formation and mechanical properties of amorphous copper are studied using molecular dynamics simulation. The simulations of tension and shearing show that more pronounced plasticity is found under shearing, compared to tension. Apparent strain hardening and strain rate effect are observed. Interestingly, the variations of number density of atoms during deformation indicate free volume creation, especially under higher strain rate. In particular, it is found that shear induced dilatation does appear in the amorphous metal.展开更多
The quasistatic nanoindentation process of a spherical indenter in a single crystal copper is investigated with the molecular statistical thermodynamics(MST)method based on the embedded atom method(EAM)potential.The i...The quasistatic nanoindentation process of a spherical indenter in a single crystal copper is investigated with the molecular statistical thermodynamics(MST)method based on the embedded atom method(EAM)potential.The indentation modulus obtained in the MST simulation is 129.9 GPa,which agrees well with the theoretical prediction(129GPa).In the elastic regime,the obtained maximum displacement of the indenter is two times the contact depth and the contact area is qualitatively proportional to the contact depth,which agrees well with Hertzian elastic theory of contact.The MST simulation can reproduce the nucleation of dislocation as well.Moreover,the efficiency of the MST method is about 8 times higher than that of traditional MD simulations.展开更多
Combining the merits of linear and toroidal confiprations with the fast and slow process concepts,we consider a fusion reactor concept consisting of two axisymmetric tandem mirrorlike sections and two heliac stellarat...Combining the merits of linear and toroidal confiprations with the fast and slow process concepts,we consider a fusion reactor concept consisting of two axisymmetric tandem mirrorlike sections and two heliac stellarator U-bends.The D-D reactor parameters are presented.The radio frequency(RF),energetic components and the plugs are needed only at the startup phase.These greatly cut down the coat and relax the technical requirements of engineering.展开更多
The electron cyclotron resonance heating(ECRH)processes to produce the energetic trapped electrons are proposed.Injecting the RF waves on a certain magnetic surface with proper frequency and wave vector.are suggested....The electron cyclotron resonance heating(ECRH)processes to produce the energetic trapped electrons are proposed.Injecting the RF waves on a certain magnetic surface with proper frequency and wave vector.are suggested.By the relay of different high electron cyclotron harmonic resonances a few percent of electrons are heated up to a desired energy.展开更多
The stability of m=1 internal kink mode in a tokamak plasma with an anisotropic energetic particle component has been analyzed using the generalized energy principle.It is found that employing barely trapped energetic...The stability of m=1 internal kink mode in a tokamak plasma with an anisotropic energetic particle component has been analyzed using the generalized energy principle.It is found that employing barely trapped energetic particles can significantly improve the stability properties.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos 10528205, 10772012 and 10432050)Chinese Academy of Sciences Innovation Program and KJCX2-YW-M04
文摘The formation and mechanical properties of amorphous copper are studied using molecular dynamics simulation. The simulations of tension and shearing show that more pronounced plasticity is found under shearing, compared to tension. Apparent strain hardening and strain rate effect are observed. Interestingly, the variations of number density of atoms during deformation indicate free volume creation, especially under higher strain rate. In particular, it is found that shear induced dilatation does appear in the amorphous metal.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10932011,10772181,11021262,10732090 and 10772012the National Basic Research Program of China under Grant No 2007CB814803.
文摘The quasistatic nanoindentation process of a spherical indenter in a single crystal copper is investigated with the molecular statistical thermodynamics(MST)method based on the embedded atom method(EAM)potential.The indentation modulus obtained in the MST simulation is 129.9 GPa,which agrees well with the theoretical prediction(129GPa).In the elastic regime,the obtained maximum displacement of the indenter is two times the contact depth and the contact area is qualitatively proportional to the contact depth,which agrees well with Hertzian elastic theory of contact.The MST simulation can reproduce the nucleation of dislocation as well.Moreover,the efficiency of the MST method is about 8 times higher than that of traditional MD simulations.
基金Project supported by the Science Fund of the Chinese Academy of Sciences。
文摘Combining the merits of linear and toroidal confiprations with the fast and slow process concepts,we consider a fusion reactor concept consisting of two axisymmetric tandem mirrorlike sections and two heliac stellarator U-bends.The D-D reactor parameters are presented.The radio frequency(RF),energetic components and the plugs are needed only at the startup phase.These greatly cut down the coat and relax the technical requirements of engineering.
基金This work was supported by the Science Fund of the Chinese Academy of Sciences.
文摘The electron cyclotron resonance heating(ECRH)processes to produce the energetic trapped electrons are proposed.Injecting the RF waves on a certain magnetic surface with proper frequency and wave vector.are suggested.By the relay of different high electron cyclotron harmonic resonances a few percent of electrons are heated up to a desired energy.
文摘The stability of m=1 internal kink mode in a tokamak plasma with an anisotropic energetic particle component has been analyzed using the generalized energy principle.It is found that employing barely trapped energetic particles can significantly improve the stability properties.
