真善美,假恶丑,一旦混淆了,名实将不符,泾渭将难分,黑白将莫辨,孔子就要呼吁了:“必也正名乎！”孟子就要感叹了:“世衰！道微！邪说暴行有作！”倒霉的老百姓无力回天,却又欠缺涵养,只好去茶厅中酒馆里说一说风凉话。 现代世界,千奇百...真善美,假恶丑,一旦混淆了,名实将不符,泾渭将难分,黑白将莫辨,孔子就要呼吁了:“必也正名乎！”孟子就要感叹了:“世衰！道微！邪说暴行有作！”倒霉的老百姓无力回天,却又欠缺涵养,只好去茶厅中酒馆里说一说风凉话。 现代世界,千奇百怪,是战国的再版。在西方,新批评家(The New Critic),这是一个文学流派的名称,把那些风凉话叫作反讽。反讽一词,原文是irony。irony的字根是iron,其第一义是铁,其第二义是烙铁或熨斗(此二物冷不防烫伤手指)。引申为irony,我们译成冷嘲或反话,海外译成反讽。在台湾。展开更多
The electronic structures and elastic properties of Al-doped MoSi2 were calculated using the plane wave pseudo-potential method based on the density functional theory,in which the generalized-gradient approximation(GG...The electronic structures and elastic properties of Al-doped MoSi2 were calculated using the plane wave pseudo-potential method based on the density functional theory,in which the generalized-gradient approximation(GGA) was used to describe the exchange-correlation potential.Starting from the elastic constants,bulk modulus,shear modulus,elastic modulus and Poisson ratio of Al-doped MoSi2 were obtained by using the Hill method.The results indicate that conductivity of Al-doped MoSi2 is improved to some extent in comparison with that of pure MoSi2 due to the orbit hybridization of Mo 4d,Al 3p and Si 3p electrons.In addition,calculations show that the elastic modulus and the brittleness of Al-doped MoSi2 are smaller than those of pure MoSi2,which implies that it is feasible to toughen MoSi2 by doping Al.The agreement of the conclusion with experiment shows that the present theory is reasonable.展开更多
The electronic structure and optical properties of the tetragonal phase quaternary arsenide oxides YZnAsO and LaZnAsO were studied using density-functional theory(DFT) within generalized gradient approximation(GGA).Th...The electronic structure and optical properties of the tetragonal phase quaternary arsenide oxides YZnAsO and LaZnAsO were studied using density-functional theory(DFT) within generalized gradient approximation(GGA).The band structure along the higher symmetry axes in the Brillouin zone,the density of states(DOS) and the partial density of states(PDOS) were presented.The calculated energy band structures show that both YZnAsO and LaZnAsO are indirect gap semiconductors with band gap of 1.173 1 eV and 1.166 5 eV,respectively.The DOS and PDOS show the hybridization of Y-O/La-O atom orbits and Zn-As atom orbits.The dielectric function,reflectivity,absorption coefficient,refractive index,electron energy-loss function and optical conductivity were presented in an energy range from 0 to 25 eV for discussing the optical properties of YZnAsO and LaZnAsO.展开更多
文摘真善美,假恶丑,一旦混淆了,名实将不符,泾渭将难分,黑白将莫辨,孔子就要呼吁了:“必也正名乎！”孟子就要感叹了:“世衰！道微！邪说暴行有作！”倒霉的老百姓无力回天,却又欠缺涵养,只好去茶厅中酒馆里说一说风凉话。 现代世界,千奇百怪,是战国的再版。在西方,新批评家(The New Critic),这是一个文学流派的名称,把那些风凉话叫作反讽。反讽一词,原文是irony。irony的字根是iron,其第一义是铁,其第二义是烙铁或熨斗(此二物冷不防烫伤手指)。引申为irony,我们译成冷嘲或反话,海外译成反讽。在台湾。
基金Project(20080431025) supported by Chinese Postdoctoral Science FoundationProject(08JJ3005) supported by Hunan Provincial Natural Science Foundation of ChinaProject(2007) supported by Postdoctoral Science Foundation of Central South University,China
文摘The electronic structures and elastic properties of Al-doped MoSi2 were calculated using the plane wave pseudo-potential method based on the density functional theory,in which the generalized-gradient approximation(GGA) was used to describe the exchange-correlation potential.Starting from the elastic constants,bulk modulus,shear modulus,elastic modulus and Poisson ratio of Al-doped MoSi2 were obtained by using the Hill method.The results indicate that conductivity of Al-doped MoSi2 is improved to some extent in comparison with that of pure MoSi2 due to the orbit hybridization of Mo 4d,Al 3p and Si 3p electrons.In addition,calculations show that the elastic modulus and the brittleness of Al-doped MoSi2 are smaller than those of pure MoSi2,which implies that it is feasible to toughen MoSi2 by doping Al.The agreement of the conclusion with experiment shows that the present theory is reasonable.
基金Project(50474051) supported by the National Natural Science Foundation of China
文摘The electronic structure and optical properties of the tetragonal phase quaternary arsenide oxides YZnAsO and LaZnAsO were studied using density-functional theory(DFT) within generalized gradient approximation(GGA).The band structure along the higher symmetry axes in the Brillouin zone,the density of states(DOS) and the partial density of states(PDOS) were presented.The calculated energy band structures show that both YZnAsO and LaZnAsO are indirect gap semiconductors with band gap of 1.173 1 eV and 1.166 5 eV,respectively.The DOS and PDOS show the hybridization of Y-O/La-O atom orbits and Zn-As atom orbits.The dielectric function,reflectivity,absorption coefficient,refractive index,electron energy-loss function and optical conductivity were presented in an energy range from 0 to 25 eV for discussing the optical properties of YZnAsO and LaZnAsO.
