提出了一种离散奇异卷积(DSC:D iscrete S ingu lar Convolution)方法来对基于M ind lin剪切变形理论的矩形厚板进行自由振动分析。此方法采用了Gauss delta序列核作为基函数并结合pb-2 Rayle igh-R itz方法(pb-2指的是a two-d im ensio...提出了一种离散奇异卷积(DSC:D iscrete S ingu lar Convolution)方法来对基于M ind lin剪切变形理论的矩形厚板进行自由振动分析。此方法采用了Gauss delta序列核作为基函数并结合pb-2 Rayle igh-R itz方法(pb-2指的是a two-d im ensional polynom ial function(p-2)and a boundary function(b))的边界函数得到了一种新型的R itz方法。数值结果表明此方法相当精确有效。展开更多
The mechanical stability,elastic,and thermodynamic properties of the anti-perovskite superconductors MNNi 3（M=Zn,Mg,Al） are investigated by means of the first-principles calculations.The calculated structural parame...The mechanical stability,elastic,and thermodynamic properties of the anti-perovskite superconductors MNNi 3（M=Zn,Mg,Al） are investigated by means of the first-principles calculations.The calculated structural parameters and elastic properties of MNNi 3 are in good agreement with the experimental and the other theoretical results.From the elastic constants under high pressure,we predict that ZnNNi 3,MgNNi 3,and AlNNi 3 are not stable at the pressures above 61.2 GPa,113.3 GPa,and 122.4 GPa,respectively.By employing the Debye model,the thermodynamic properties,such as the heat capacity and the thermal expansion coefficient,under pressures and at finite temperatures are also obtained successfully.展开更多
A first-principles study on the mechanical stability, elastic and thermodynamic properties of WN2 with P63/mmc and P-6m2 phases are reported using the pseudo potential plane wave method within the generalized gradient...A first-principles study on the mechanical stability, elastic and thermodynamic properties of WN2 with P63/mmc and P-6m2 phases are reported using the pseudo potential plane wave method within the generalized gradient approx- imation. The calculated equilibrium parameters are in good agreement with the available theoretical data. A complete elastic tensor and crystal anisotropies of the ultra-incompressible WN2 are determined in the wide pressure range. By the elastic stability criteria, it is predicted that P63/mmc and P-6m2 phases in WN2 are not stable above 175.1 GPa and 170.1 GPa, respectively. Finally, by using the quasiharmonic Debye model, the isothermal and adiabatic bulk modulus, and the heat capacity of WN2 are also successfully obtained.展开更多
文摘提出了一种离散奇异卷积(DSC:D iscrete S ingu lar Convolution)方法来对基于M ind lin剪切变形理论的矩形厚板进行自由振动分析。此方法采用了Gauss delta序列核作为基函数并结合pb-2 Rayle igh-R itz方法(pb-2指的是a two-d im ensional polynom ial function(p-2)and a boundary function(b))的边界函数得到了一种新型的R itz方法。数值结果表明此方法相当精确有效。
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11147101 and 11071107)the Henan Research Program of Basic and Frontier Technology,China(Grant Nos.112300410024 and 102102210452)+1 种基金the Henan Natural Science Basic Research,China(Grant Nos.2011B140013 and 2010A140011)the Scientific Research Foundation of Luoyang Normal University, China(Grant No.2010-QNJJ-003)
文摘The mechanical stability,elastic,and thermodynamic properties of the anti-perovskite superconductors MNNi 3（M=Zn,Mg,Al） are investigated by means of the first-principles calculations.The calculated structural parameters and elastic properties of MNNi 3 are in good agreement with the experimental and the other theoretical results.From the elastic constants under high pressure,we predict that ZnNNi 3,MgNNi 3,and AlNNi 3 are not stable at the pressures above 61.2 GPa,113.3 GPa,and 122.4 GPa,respectively.By employing the Debye model,the thermodynamic properties,such as the heat capacity and the thermal expansion coefficient,under pressures and at finite temperatures are also obtained successfully.
基金Project supported by the National Natural Science Foundation of China (Grant No.11047151)the Henan Research Program of Basic and Frontier Technology,China (Grant Nos.102300410213 and 112300410024)+2 种基金the Natural Science Basic Research Fund of Henan Province,China (Grant No.2011B140013)the Scientific Research Foundation of Luoyang Normal University,China (Grant No.2010-QNJJ-003)the Open Research Fund of State Key Laboratory of Breeding Base of Green Chemistry Synthesis Technology,China (Grant No.GCTKF 2010017)
文摘A first-principles study on the mechanical stability, elastic and thermodynamic properties of WN2 with P63/mmc and P-6m2 phases are reported using the pseudo potential plane wave method within the generalized gradient approx- imation. The calculated equilibrium parameters are in good agreement with the available theoretical data. A complete elastic tensor and crystal anisotropies of the ultra-incompressible WN2 are determined in the wide pressure range. By the elastic stability criteria, it is predicted that P63/mmc and P-6m2 phases in WN2 are not stable above 175.1 GPa and 170.1 GPa, respectively. Finally, by using the quasiharmonic Debye model, the isothermal and adiabatic bulk modulus, and the heat capacity of WN2 are also successfully obtained.
