Refer to the Hamiltonian system, first integrals of the Birkhoffian system can be found by using of the perfect differential method. Through these first integrals, the order of the Birkhoffian system can be reduced. T...Refer to the Hamiltonian system, first integrals of the Birkhoffian system can be found by using of the perfect differential method. Through these first integrals, the order of the Birkhoffian system can be reduced. Then according to the alternate of the coordinate, a kind of new partial differential operator was defined in order to hold the Birkhoff form. The result shows that the Birkhoffian system has generalized energy integrals and cyclic integrals. Furthermore, each integral can reduce the order of equations two degrees.展开更多
The electronic structure, magnetic properties, and optical properties of Co-doped AIN are investigated based upon the Perdew-Burke-Ernzerhof form of generalized gradient approximation within the density functional the...The electronic structure, magnetic properties, and optical properties of Co-doped AIN are investigated based upon the Perdew-Burke-Ernzerhof form of generalized gradient approximation within the density functional theory. The band gaps narrowing of AI1-x Cox N are found with the increase of Co concentrations. The analyses of the band structures and density of states show that AI1-xCoxN alloys exhibit a halfometallie character. Moreover, we have succeeded in demonstrating that Co doped AIN system in x = 0.125 is always antiferromagnetie, which is in good agreement with the experimental results. Besides, it is shown that the insertion of Co atom leads to redshift of the optical absorption edge. Finally, the optical constants of pure A1N and AI1-xCoxN alloy, such as loss function, refractive index and reflectivity, are discussed.展开更多
The electronic structure and optical properties of novel Na-hP4 high pressure phase at different pressures(260,320,400 and 600 GPa)were investigated by the density functional theory(DFT)with the generalized gradient a...The electronic structure and optical properties of novel Na-hP4 high pressure phase at different pressures(260,320,400 and 600 GPa)were investigated by the density functional theory(DFT)with the generalized gradient approximation(GGA)for the exchange and correlation energy.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 band gap increases and the energy band expands to some extent with the pressure increasing.The dielectric function,reflectivity,energy-loss function,optical absorption coefficient,optical conductivity, refractive index and extinction coefficient were calculated for discussing the optical properties of Na-hP4 high pressure phase at different pressures.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 solution of nonlinear parabolic equation arising from population dynamics with boundary and initial value are established by the finite difference method,as well as it denotes the unique generalized global solution.
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
Against the backdrop of the 19^th century, the First International, guided by Marxism, emerged in the form of the early "International Socialist Federation." It viewed the seizure of power as the great mission of th...Against the backdrop of the 19^th century, the First International, guided by Marxism, emerged in the form of the early "International Socialist Federation." It viewed the seizure of power as the great mission of the proletariat, actively struggled against bourgeois regimes, strongly responded to the call of times for the theoretical self-consciousness and organized struggle of the proletariat, and exerted a profound historical influence on the stirring inauguration and nationally oriented development of the international Communist movement of the 20th century. From the socialist party political perspective, the First Intemational, once the Communist League, had raised the curtain on socialist party politics, changed the political mode of capitalist party politics' exclusive world domination through the interactive development of new organizational forms, theoretical viewpoints and political practice. It thus left an abundant historical legacy in terms of ideological creation and practical innovation for the subsequent Second International, the Communist International and the emergence and development of socialist party politics within nation-states. Although its socialist party political practice had an obvious "regional," "preliminary" and "tentative" nature, the First International had foundation-laying significance and pioneering value for the development of socialist party politics, whether in terms of organizational vehicles, value orientation and activity content, or in terms of ideological guidance, practical patterns and strategic principles.展开更多
In the process of China’s dynamic social changes over the past decades, the young-parent identity construction of an emerging middle class and the resulting changes of social-cultural values in this context have attr...In the process of China’s dynamic social changes over the past decades, the young-parent identity construction of an emerging middle class and the resulting changes of social-cultural values in this context have attracted the attention of academic research in recent years. With the focus on the discursive construction of parent identity, this study examines the utilization of first-person pronouns in three different interactional contexts, namely, parent-teacher interaction, parent-parent interaction, and parent-child interaction. The study further explores the patterns of alignment between the parents and their children, parents and teachers of their children, and peer parents during the process of identity construction, followed by a discussion of the implication that young, emerging middleclass Chinese parents fundamentally shape themselves as "concerned" and "involved" parents and the change of values between collectivity and agency. The study not only demonstrates the dynamic and pluralistic nature of parent identity but also deepens our understanding of the indexical roles of first-person pronouns in the discursive construction of emerging middle-class Chinese parent identity and its relationship with the recent social-cultural changes in the Chinese context.展开更多
The classical thermodynamics reflects the significant relationship between the heat and the temperature. On the basis of the relationships, according to the mathematical derivation, this paper structures the conceptio...The classical thermodynamics reflects the significant relationship between the heat and the temperature. On the basis of the relationships, according to the mathematical derivation, this paper structures the conceptions of generalized heat, generalized thermodynamic temperature, generalized entropy and so on. The series of conceptions in the classical thermodynamics is merely a special case of the generalized thermodynamics. Based on these conceptions of generalized thermodynamics, this paper presents the new expressions of the first law and the second law of thermodynamics. In other words, these expressions are endued with new explanations. The Eq. LZ = kTS given by this paper provides theoretical basis for these new expressions.展开更多
文摘Refer to the Hamiltonian system, first integrals of the Birkhoffian system can be found by using of the perfect differential method. Through these first integrals, the order of the Birkhoffian system can be reduced. Then according to the alternate of the coordinate, a kind of new partial differential operator was defined in order to hold the Birkhoff form. The result shows that the Birkhoffian system has generalized energy integrals and cyclic integrals. Furthermore, each integral can reduce the order of equations two degrees.
基金Supported by the Fundamental Research Funds for the Central Universities under Grant Nos.BUPT2009RC0412 and 10979065the National High Technology Research and Development Program of China under Grant No.2009AA03Z405the National Natural Science Foundation of China under Grant Nos.60644004 and 10979065
文摘The electronic structure, magnetic properties, and optical properties of Co-doped AIN are investigated based upon the Perdew-Burke-Ernzerhof form of generalized gradient approximation within the density functional theory. The band gaps narrowing of AI1-x Cox N are found with the increase of Co concentrations. The analyses of the band structures and density of states show that AI1-xCoxN alloys exhibit a halfometallie character. Moreover, we have succeeded in demonstrating that Co doped AIN system in x = 0.125 is always antiferromagnetie, which is in good agreement with the experimental results. Besides, it is shown that the insertion of Co atom leads to redshift of the optical absorption edge. Finally, the optical constants of pure A1N and AI1-xCoxN alloy, such as loss function, refractive index and reflectivity, are discussed.
基金Project(50474051) supported by the National Natural Science Foundation of China
文摘The electronic structure and optical properties of novel Na-hP4 high pressure phase at different pressures(260,320,400 and 600 GPa)were investigated by the density functional theory(DFT)with the generalized gradient approximation(GGA)for the exchange and correlation energy.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 band gap increases and the energy band expands to some extent with the pressure increasing.The dielectric function,reflectivity,energy-loss function,optical absorption coefficient,optical conductivity, refractive index and extinction coefficient were calculated for discussing the optical properties of Na-hP4 high pressure phase at different pressures.
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.
文摘The solution of nonlinear parabolic equation arising from population dynamics with boundary and initial value are established by the finite difference method,as well as it denotes the unique generalized global solution.
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.
文摘Against the backdrop of the 19^th century, the First International, guided by Marxism, emerged in the form of the early "International Socialist Federation." It viewed the seizure of power as the great mission of the proletariat, actively struggled against bourgeois regimes, strongly responded to the call of times for the theoretical self-consciousness and organized struggle of the proletariat, and exerted a profound historical influence on the stirring inauguration and nationally oriented development of the international Communist movement of the 20th century. From the socialist party political perspective, the First Intemational, once the Communist League, had raised the curtain on socialist party politics, changed the political mode of capitalist party politics' exclusive world domination through the interactive development of new organizational forms, theoretical viewpoints and political practice. It thus left an abundant historical legacy in terms of ideological creation and practical innovation for the subsequent Second International, the Communist International and the emergence and development of socialist party politics within nation-states. Although its socialist party political practice had an obvious "regional," "preliminary" and "tentative" nature, the First International had foundation-laying significance and pioneering value for the development of socialist party politics, whether in terms of organizational vehicles, value orientation and activity content, or in terms of ideological guidance, practical patterns and strategic principles.
基金a part of the Chinese MOE Key Research Project of Humanities and Social Science (Project No.: 16JJD740006) conducted by the Centre for Linguistics and Applied Linguistics, Guangdong University of Foreign Studies
文摘In the process of China’s dynamic social changes over the past decades, the young-parent identity construction of an emerging middle class and the resulting changes of social-cultural values in this context have attracted the attention of academic research in recent years. With the focus on the discursive construction of parent identity, this study examines the utilization of first-person pronouns in three different interactional contexts, namely, parent-teacher interaction, parent-parent interaction, and parent-child interaction. The study further explores the patterns of alignment between the parents and their children, parents and teachers of their children, and peer parents during the process of identity construction, followed by a discussion of the implication that young, emerging middleclass Chinese parents fundamentally shape themselves as "concerned" and "involved" parents and the change of values between collectivity and agency. The study not only demonstrates the dynamic and pluralistic nature of parent identity but also deepens our understanding of the indexical roles of first-person pronouns in the discursive construction of emerging middle-class Chinese parent identity and its relationship with the recent social-cultural changes in the Chinese context.
文摘The classical thermodynamics reflects the significant relationship between the heat and the temperature. On the basis of the relationships, according to the mathematical derivation, this paper structures the conceptions of generalized heat, generalized thermodynamic temperature, generalized entropy and so on. The series of conceptions in the classical thermodynamics is merely a special case of the generalized thermodynamics. Based on these conceptions of generalized thermodynamics, this paper presents the new expressions of the first law and the second law of thermodynamics. In other words, these expressions are endued with new explanations. The Eq. LZ = kTS given by this paper provides theoretical basis for these new expressions.