First-principles computation on the basis of density functional theory(DFT) is executed with the CASTEP code to explore the structural, elastic, and electronic properties along with Debye temperature and theoretical V...First-principles computation on the basis of density functional theory(DFT) is executed with the CASTEP code to explore the structural, elastic, and electronic properties along with Debye temperature and theoretical Vickers’ hardness of newly discovered ordered MAX phase carbide Mo2TiAlC2. The computed structural parameters are very reasonable compared with the experimental results. The mechanical stability is verified by using the computed elastic constants. The brittleness of the compound is indicated by both the Poisson’s and Pugh’s ratios. The new MAX phase is capable of resisting the pressure and tension and also has the clear directional bonding between atoms. The compound shows significant elastic anisotropy. The Debye temperature estimated from elastic moduli(B, G) is found to be 413.6 K. The electronic structure indicates that the bonding nature of Mo2TiAlC2is a mixture of covalent and metallic with few ionic characters. The electron charge density map shows a strong directional Mo–C–Mo covalent bonding associated with a relatively weak Ti–C bond.The calculated Fermi surface is due to the low-dispersive Mo 4d-like bands, which makes the compound a conductive one.The hardness of the compound is also evaluated and a high value of 9.01 GPa is an indication of its strong covalent bonding.展开更多
Cancellidium is a remarkable fungal genus which has been collected from wood submerged in freshwater and has unique conidia that are important in dispersal in running streams.With such a remarkable morphology,one woul...Cancellidium is a remarkable fungal genus which has been collected from wood submerged in freshwater and has unique conidia that are important in dispersal in running streams.With such a remarkable morphology,one would have expected it to be a distinct family or order.However,due to the dearth of molecular evidence in related taxa,this genus has previ-ously been placed in the order Hypocreales,subclass Hypocreomycetidae of Sordariomycetes.In this study,we made three new collections of this remarkable aquatic genus from streams in China and Thailand,isolated them into culture,extracted DNA and carried out multigene phylogenetic analysis and divergence time estimation which placed the genus in Diaporthomycetidae.This is one of the seven subclasses of Sordariomycetes and contains 30 lineages that are only known from freshwater.The subclass is therefore of interest when considering the evolution of freshwater fungi.Several lineages of Diaporthomycetidae are morphologically unique and taxa cluster with strong support,but have weak support at the base of the trees.The phylogenetic and MCC trees generated in this study indicate that Aquapteridospora,Barbatosphaeriaceae,Bullimyces,Cancellidium,Ceratolenta,Conlarium,Phialemoniopsis,Pseudostanjehughesia and Rhamphoriaceae are distinct genera/families that evolved in the family/order time frame.The new orders Barbatosphaeriales(177 MYA),Cancellidiales(137 MYA),Ceratolentales(147 MYA),Conlariales(138 MYA)and Rhamphoriales(133 MYA)and six new families,Aquapteridosporaceae(110 MYA),Cancellidiaceae(137 MYA),Ceratolentaceae(81 MYA),Bullimycetaceae(81 MYA),Phialemoniopsaceae(59 MYA),and Pseudostanjehughesiaceae(111 MYA)are introduced with evidence from phylogenies,divergence estimates and distinct morphologies.Of these families,Aquapteridosporaceae,Cancellidiaceae,Bullimycetaceae,and Pseudostanjehughesiaceae are only known from freshwater.展开更多
AGE-hardened Cu-Ti has been an important alloy of investigation in the field of continuousphase transformation due to its complicated transformation processes which involve short rangeordering (SRO), spinodal decompos...AGE-hardened Cu-Ti has been an important alloy of investigation in the field of continuousphase transformation due to its complicated transformation processes which involve short rangeordering (SRO), spinodal decomposition (SD), long range ordering (LRO), etc. So far, ithas been a controversial topic whether each process exists, and in what sequence they pro-ceed.展开更多
Variational principle for non-vortex, non-linear wave theories is established in this paper. By using this variational principle and related functional minimum condition, the fifth and sixth order Stokes Vaves are giv...Variational principle for non-vortex, non-linear wave theories is established in this paper. By using this variational principle and related functional minimum condition, the fifth and sixth order Stokes Vaves are given as an example and the results are compared with those in Reference (Skjel-breia, 1961).展开更多
The 20th century is a century when both intra-national order and internationalorder were frequently changing. The struggles have never stopped focusingon setting order. Today with the East-west cold war over for 10 ye...The 20th century is a century when both intra-national order and internationalorder were frequently changing. The struggles have never stopped focusingon setting order. Today with the East-west cold war over for 10 years, there arestill strong appeals for peace and stability, and demands for establishing a newinternational order. The War on Kosovo in the end of the 20th century is a sig-nificant attempt from the U. S. and other major Western powers to set up a newworld order without caring whether by means of force or even of war. This展开更多
We propose a new two-fold integration transformation in p-q phase space∫∫_(-∞)~∞ (dqdq/π) e^(2i(p-x)(q-y))f(p,q)2≡G(x,y),which possesses some well-behaved transformation properties.We apply this transformation t...We propose a new two-fold integration transformation in p-q phase space∫∫_(-∞)~∞ (dqdq/π) e^(2i(p-x)(q-y))f(p,q)2≡G(x,y),which possesses some well-behaved transformation properties.We apply this transformation to the Weyl ordering ofoperators,especially those Q-P ordered and P-Q ordered operators.展开更多
CURRENTLY, the world is undergoing significant change as emerging powers become more important and active participants in the international system. Significant changes in the relative economic and political power of s...CURRENTLY, the world is undergoing significant change as emerging powers become more important and active participants in the international system. Significant changes in the relative economic and political power of states pose new challenges and opportunities for international peace and development,展开更多
In this paper,the Mei symmetry of Tzénoff equations for the higher-order nonholonomic system and the new conserved quantities derived from that are researched,and the function expression of new conserved quantiti...In this paper,the Mei symmetry of Tzénoff equations for the higher-order nonholonomic system and the new conserved quantities derived from that are researched,and the function expression of new conserved quantities and criterion equation which deduces these conserved quantities are presented.This result establishes the theory basis for further researches on conservation laws of Tzénoff equations of the higher-order nonholonomic constraint system.展开更多
A new stability theory of nonlinear dynamic systems is proposed, and a novel adaptive synchronisation method is presented for fractional-order chaotic and hyperchaotic systems based on the theory described in this pap...A new stability theory of nonlinear dynamic systems is proposed, and a novel adaptive synchronisation method is presented for fractional-order chaotic and hyperchaotic systems based on the theory described in this paper. In comparison with previous methods, not only is the present control scheme simple but also it employs only one control strength, converges very fast, and it is also suitable for a large class of fractional-order chaotic and hyperchaotic systems. Moreover, this scheme is analytical and simple to implement in practice. Numerical and circuit simulations are used to validate and demonstrate the effectiveness of the method.展开更多
文摘First-principles computation on the basis of density functional theory(DFT) is executed with the CASTEP code to explore the structural, elastic, and electronic properties along with Debye temperature and theoretical Vickers’ hardness of newly discovered ordered MAX phase carbide Mo2TiAlC2. The computed structural parameters are very reasonable compared with the experimental results. The mechanical stability is verified by using the computed elastic constants. The brittleness of the compound is indicated by both the Poisson’s and Pugh’s ratios. The new MAX phase is capable of resisting the pressure and tension and also has the clear directional bonding between atoms. The compound shows significant elastic anisotropy. The Debye temperature estimated from elastic moduli(B, G) is found to be 413.6 K. The electronic structure indicates that the bonding nature of Mo2TiAlC2is a mixture of covalent and metallic with few ionic characters. The electron charge density map shows a strong directional Mo–C–Mo covalent bonding associated with a relatively weak Ti–C bond.The calculated Fermi surface is due to the low-dispersive Mo 4d-like bands, which makes the compound a conductive one.The hardness of the compound is also evaluated and a high value of 9.01 GPa is an indication of its strong covalent bonding.
基金the Thailand Research Fund for the grant RDG6130001MSImpact of climate change on fungal diversity and biogeography in the Greater Mekong Subregion.S.Honsanan would like to thank National Natural Science Foundation of China(Project ID:31950410548)+1 种基金J.Yang would like to thank Prof.Zuoyi Liu for the financial support of the lab work in China.D.F.Bao would like to thank the National Natural Science Foundation of China(Project ID:31660008 and 31860006)Fungal diversity conservation and utilization innovation team of Dali University(ZKLX2019213).
文摘Cancellidium is a remarkable fungal genus which has been collected from wood submerged in freshwater and has unique conidia that are important in dispersal in running streams.With such a remarkable morphology,one would have expected it to be a distinct family or order.However,due to the dearth of molecular evidence in related taxa,this genus has previ-ously been placed in the order Hypocreales,subclass Hypocreomycetidae of Sordariomycetes.In this study,we made three new collections of this remarkable aquatic genus from streams in China and Thailand,isolated them into culture,extracted DNA and carried out multigene phylogenetic analysis and divergence time estimation which placed the genus in Diaporthomycetidae.This is one of the seven subclasses of Sordariomycetes and contains 30 lineages that are only known from freshwater.The subclass is therefore of interest when considering the evolution of freshwater fungi.Several lineages of Diaporthomycetidae are morphologically unique and taxa cluster with strong support,but have weak support at the base of the trees.The phylogenetic and MCC trees generated in this study indicate that Aquapteridospora,Barbatosphaeriaceae,Bullimyces,Cancellidium,Ceratolenta,Conlarium,Phialemoniopsis,Pseudostanjehughesia and Rhamphoriaceae are distinct genera/families that evolved in the family/order time frame.The new orders Barbatosphaeriales(177 MYA),Cancellidiales(137 MYA),Ceratolentales(147 MYA),Conlariales(138 MYA)and Rhamphoriales(133 MYA)and six new families,Aquapteridosporaceae(110 MYA),Cancellidiaceae(137 MYA),Ceratolentaceae(81 MYA),Bullimycetaceae(81 MYA),Phialemoniopsaceae(59 MYA),and Pseudostanjehughesiaceae(111 MYA)are introduced with evidence from phylogenies,divergence estimates and distinct morphologies.Of these families,Aquapteridosporaceae,Cancellidiaceae,Bullimycetaceae,and Pseudostanjehughesiaceae are only known from freshwater.
文摘AGE-hardened Cu-Ti has been an important alloy of investigation in the field of continuousphase transformation due to its complicated transformation processes which involve short rangeordering (SRO), spinodal decomposition (SD), long range ordering (LRO), etc. So far, ithas been a controversial topic whether each process exists, and in what sequence they pro-ceed.
文摘Variational principle for non-vortex, non-linear wave theories is established in this paper. By using this variational principle and related functional minimum condition, the fifth and sixth order Stokes Vaves are given as an example and the results are compared with those in Reference (Skjel-breia, 1961).
文摘The 20th century is a century when both intra-national order and internationalorder were frequently changing. The struggles have never stopped focusingon setting order. Today with the East-west cold war over for 10 years, there arestill strong appeals for peace and stability, and demands for establishing a newinternational order. The War on Kosovo in the end of the 20th century is a sig-nificant attempt from the U. S. and other major Western powers to set up a newworld order without caring whether by means of force or even of war. This
基金National Natural Science Foundation of China under Grant Nos.10775097 and 10874174
文摘We propose a new two-fold integration transformation in p-q phase space∫∫_(-∞)~∞ (dqdq/π) e^(2i(p-x)(q-y))f(p,q)2≡G(x,y),which possesses some well-behaved transformation properties.We apply this transformation to the Weyl ordering ofoperators,especially those Q-P ordered and P-Q ordered operators.
文摘CURRENTLY, the world is undergoing significant change as emerging powers become more important and active participants in the international system. Significant changes in the relative economic and political power of states pose new challenges and opportunities for international peace and development,
基金Project supported by the National Natural Science Foundation of China(Grant No.10972127)
文摘In this paper,the Mei symmetry of Tzénoff equations for the higher-order nonholonomic system and the new conserved quantities derived from that are researched,and the function expression of new conserved quantities and criterion equation which deduces these conserved quantities are presented.This result establishes the theory basis for further researches on conservation laws of Tzénoff equations of the higher-order nonholonomic constraint system.
基金supported by the Natural Science Foundation of Hebei Province of China (Grant No. A2008000136)
文摘A new stability theory of nonlinear dynamic systems is proposed, and a novel adaptive synchronisation method is presented for fractional-order chaotic and hyperchaotic systems based on the theory described in this paper. In comparison with previous methods, not only is the present control scheme simple but also it employs only one control strength, converges very fast, and it is also suitable for a large class of fractional-order chaotic and hyperchaotic systems. Moreover, this scheme is analytical and simple to implement in practice. Numerical and circuit simulations are used to validate and demonstrate the effectiveness of the method.
