Dynamic equations controlling the thermally-driven fluid convection in a single rock crack are established in the paper . The critical criteria for the onset of convection in such a configuration are found by linear d...Dynamic equations controlling the thermally-driven fluid convection in a single rock crack are established in the paper . The critical criteria for the onset of convection in such a configuration are found by linear dynamic analysis of the equations and the stability of the convection discussed by nonlinear analysis method . The research demonstrates that the critical Rayleigh number has a magnitude 103. While the Rayleigh number R of real ore-forming fluids exceeds this value , the convection happens , and as R becomes larger , the fluid convection pattern develops from nonequilibrium steady states to double-periodically produced limit cycles and eventually to chaos (turbulences ).The implication of these dynamic analyses for the ore-forming processes of late-magma tic hydrothermal deposits is also discussed in the paper .展开更多
Novel pyrimidine nucleoside-3,5-dicyanopyridine hybrids （4） or pyridine attached acylureas （5） were selectively and efficiently prepared from the reaction of 2′-deoxyuddin-5-yl-methylene malononitrile （1）, malo...Novel pyrimidine nucleoside-3,5-dicyanopyridine hybrids （4） or pyridine attached acylureas （5） were selectively and efficiently prepared from the reaction of 2′-deoxyuddin-5-yl-methylene malononitrile （1）, malononitrile （2） and thiophenol （3） or from an unexpected uracil ring-opening and pyddine ring-forming sequence via the reaction of 1 and 3. It is the first time such a sequence has ever been reported.展开更多
In this paper, we investigate the space of <em>L<sup>p</sup> p</em>-harmonic 1-forms on a complete noncompact orientable <em>δ</em>-stable hypersurface <em>M<sup>m</...In this paper, we investigate the space of <em>L<sup>p</sup> p</em>-harmonic 1-forms on a complete noncompact orientable <em>δ</em>-stable hypersurface <em>M<sup>m</sup></em> that is immersed in space form <img src="Edit_6fbc11b9-ac23-40e2-b045-0fb25419337d.png" width="35" height="23" alt="" /> with nonnegative BiRic curvature. We prove the nonexistence of <em>L<sup>p</sup> p</em>-harmonic 1-forms on <em>M<sup>m</sup></em>. Moreover, we obtain some vanishing properties for this class of harmonic 1-forms.展开更多
Using non-linear connection of Finsler manifold M, the existence of local coordinates which is normalized at a point x is proved, and the Laplace operator A on 1-form of M is defined by non-linear connection and its c...Using non-linear connection of Finsler manifold M, the existence of local coordinates which is normalized at a point x is proved, and the Laplace operator A on 1-form of M is defined by non-linear connection and its curvature tensor. After proving the maximum principle theorem of Hopf-Bochner on M, the Bochner type vanishing theorem of Killing vectors and harmonic 1-form are obtained.展开更多
In this paper,we study the(α,β)-metrics of constant flag curvature.We characterize almost regular(α,β)-metrics of constant flag curvature under the condition that β is a homothetic 1-form with respect to a.Furthe...In this paper,we study the(α,β)-metrics of constant flag curvature.We characterize almost regular(α,β)-metrics of constant flag curvature under the condition that β is a homothetic 1-form with respect to a.Furthermore,we prove that if a regular(α,β)-metric is of constant flag curvature and β is a Killing 1-form with constant length,then it must be a Riemannian metric or locally Minkowskian.展开更多
In this paper, M is a smooth manifold of finite dimension n, A is a local algebra and MA is the associated Weil bundle. We study Poisson vector fields on MA and we prove that all globally hamiltonian vector fields on ...In this paper, M is a smooth manifold of finite dimension n, A is a local algebra and MA is the associated Weil bundle. We study Poisson vector fields on MA and we prove that all globally hamiltonian vector fields on MA are Poisson vector fields.展开更多
In this paper,the(0.1)-form heat kernel of a complex projective space of dimensions n is constructed cxplicitely.As an application of the(0.1)-form heat kernel,the(0.1)type Green Form of CP~
This study aims to investigate the chemical structure and morphology of plasmapolymers produced by deposition of ethylene on the surface of polypropylene. The deposition films（sediments） of ethylene plasma on the su...This study aims to investigate the chemical structure and morphology of plasmapolymers produced by deposition of ethylene on the surface of polypropylene. The deposition films（sediments） of ethylene plasma on the surface of polypropylene are nonuniform, and the characterization results indicate the existence of hydroxyl groups and aldehyde（or ketone） groups in the sediments. The sediment of ethylene plasma on the polypropylene surface could induce the growth of β-form crystals in the surface layer of polypropylene.展开更多
Using Hodge theory and Banach fixed point theorem,Liu and Zhu developed a global method to deal with various problems in deformation theory.In this note,the authors generalize Liu-Zhu's method to treat two deforma...Using Hodge theory and Banach fixed point theorem,Liu and Zhu developed a global method to deal with various problems in deformation theory.In this note,the authors generalize Liu-Zhu's method to treat two deformation problems for non-Kahler manifolds.They apply the ■■-Hodge theory to construct a deformation formula for(p,q)-forms of compact complex manifold under deformations,which can be used to study the Hodge number of complex manifold under deformations.In the second part of this note,by using the ■■-Hodge theory,they provide a simple proof of the unobstructed deformation theorem for the non-Kahler Calabi-Yau ■■-manifolds.展开更多
Recently we have reported a number of bulk glass forming compositions in the CuHf-Ti system,with the critical thickness for complete glass formation,dc,ranging from 2 mm to 4 mm.In order to improve the glass forming a...Recently we have reported a number of bulk glass forming compositions in the CuHf-Ti system,with the critical thickness for complete glass formation,dc,ranging from 2 mm to 4 mm.In order to improve the glass forming ability （GFA） getting even larger dc,the prevailing approach is to use complex multicomponent systems.This strategy has been investigated by us for the Cu-Hf-Ti bulk glass forming alloy Cu55Hf25Ti20 using 〉1 at.pct additions of B,Y,Nb,Ta,Al,Mn,Si or V but with no significant improvement in the GFA.Clearly,it is necessary,in order to utilise the full potential of the base ternary system,to identify the best glass-forming compositions as a basis for extending the search into multi-dimensional compositional space.Thus,CuxHfyTiz alloys,where x=（40-70） at.pct,y=（5-30） at.pct,and z=（10-36） at.pct,were prepared by melt spinning andcopper mould suction-casting.The composition dependence of the GFA for the Cu-Hf-Ti alloys,as measured by dc for rod and ribbon samples,is reported over the composition range given above.展开更多
Isotactic polypropylene（i PP） samples obtained by pressure vibration injection molding（PVIM） and conventional injection molding（CIM） were studied by polarized-light microscopy（PLM）, respectively. It was found ...Isotactic polypropylene（i PP） samples obtained by pressure vibration injection molding（PVIM） and conventional injection molding（CIM） were studied by polarized-light microscopy（PLM）, respectively. It was found that the alternating bright and dark banded spherulites were generated in the transitional region of PVIM parts. It is the first time that the banded spherulites of isotactic polypropylene were observed in polymer processing. What＇s more, the banded spherulites were proved to be constituted of α-form crystal by hot stage polarized-light microscopy（HT-PLM） and wide angle X-ray diffraction（WAXD）. Morphology of the banded spherulites was also studied by scaning electronical microscopy（SEM）.展开更多
文摘Dynamic equations controlling the thermally-driven fluid convection in a single rock crack are established in the paper . The critical criteria for the onset of convection in such a configuration are found by linear dynamic analysis of the equations and the stability of the convection discussed by nonlinear analysis method . The research demonstrates that the critical Rayleigh number has a magnitude 103. While the Rayleigh number R of real ore-forming fluids exceeds this value , the convection happens , and as R becomes larger , the fluid convection pattern develops from nonequilibrium steady states to double-periodically produced limit cycles and eventually to chaos (turbulences ).The implication of these dynamic analyses for the ore-forming processes of late-magma tic hydrothermal deposits is also discussed in the paper .
基金the National Natural Science Foundation of China(No.20772025)the Program for Science & Technology Innovation Talents in Universities of Henan Province(No.2008HASTIT006)the Natural Science Foundation of Department of Education of Henan Province(No.2008A150013)
文摘Novel pyrimidine nucleoside-3,5-dicyanopyridine hybrids （4） or pyridine attached acylureas （5） were selectively and efficiently prepared from the reaction of 2′-deoxyuddin-5-yl-methylene malononitrile （1）, malononitrile （2） and thiophenol （3） or from an unexpected uracil ring-opening and pyddine ring-forming sequence via the reaction of 1 and 3. It is the first time such a sequence has ever been reported.
文摘In this paper, we investigate the space of <em>L<sup>p</sup> p</em>-harmonic 1-forms on a complete noncompact orientable <em>δ</em>-stable hypersurface <em>M<sup>m</sup></em> that is immersed in space form <img src="Edit_6fbc11b9-ac23-40e2-b045-0fb25419337d.png" width="35" height="23" alt="" /> with nonnegative BiRic curvature. We prove the nonexistence of <em>L<sup>p</sup> p</em>-harmonic 1-forms on <em>M<sup>m</sup></em>. Moreover, we obtain some vanishing properties for this class of harmonic 1-forms.
基金Project supported by the Natural Science Foundation of China(10271097)
文摘Using non-linear connection of Finsler manifold M, the existence of local coordinates which is normalized at a point x is proved, and the Laplace operator A on 1-form of M is defined by non-linear connection and its curvature tensor. After proving the maximum principle theorem of Hopf-Bochner on M, the Bochner type vanishing theorem of Killing vectors and harmonic 1-form are obtained.
基金supported by the NationalNatural Science Foundation of China(11871126)the Science Foundation of Chongqing Normal University(17XLB022)。
文摘In this paper,we study the(α,β)-metrics of constant flag curvature.We characterize almost regular(α,β)-metrics of constant flag curvature under the condition that β is a homothetic 1-form with respect to a.Furthermore,we prove that if a regular(α,β)-metric is of constant flag curvature and β is a Killing 1-form with constant length,then it must be a Riemannian metric or locally Minkowskian.
文摘In this paper, M is a smooth manifold of finite dimension n, A is a local algebra and MA is the associated Weil bundle. We study Poisson vector fields on MA and we prove that all globally hamiltonian vector fields on MA are Poisson vector fields.
基金This subject supported by NSF of ChinaThis subject supported by the Henan Fundations of Scientific Committee.
文摘In this paper,the(0.1)-form heat kernel of a complex projective space of dimensions n is constructed cxplicitely.As an application of the(0.1)-form heat kernel,the(0.1)type Green Form of CP~
基金financially supported by the National Natural Science Foundation of China(Nos.51033004 and 51473113)the Natural Science Foundation of Tianjin(No.12JCYBJC11900)
文摘This study aims to investigate the chemical structure and morphology of plasmapolymers produced by deposition of ethylene on the surface of polypropylene. The deposition films（sediments） of ethylene plasma on the surface of polypropylene are nonuniform, and the characterization results indicate the existence of hydroxyl groups and aldehyde（or ketone） groups in the sediments. The sediment of ethylene plasma on the polypropylene surface could induce the growth of β-form crystals in the surface layer of polypropylene.
基金supported by the National Natural Science Foundation of China(No.12061014).
文摘Using Hodge theory and Banach fixed point theorem,Liu and Zhu developed a global method to deal with various problems in deformation theory.In this note,the authors generalize Liu-Zhu's method to treat two deformation problems for non-Kahler manifolds.They apply the ■■-Hodge theory to construct a deformation formula for(p,q)-forms of compact complex manifold under deformations,which can be used to study the Hodge number of complex manifold under deformations.In the second part of this note,by using the ■■-Hodge theory,they provide a simple proof of the unobstructed deformation theorem for the non-Kahler Calabi-Yau ■■-manifolds.
基金support of PAPIIT-UNAM IB100712SENER-CONACYT151496 in funding the project
文摘Recently we have reported a number of bulk glass forming compositions in the CuHf-Ti system,with the critical thickness for complete glass formation,dc,ranging from 2 mm to 4 mm.In order to improve the glass forming ability （GFA） getting even larger dc,the prevailing approach is to use complex multicomponent systems.This strategy has been investigated by us for the Cu-Hf-Ti bulk glass forming alloy Cu55Hf25Ti20 using 〉1 at.pct additions of B,Y,Nb,Ta,Al,Mn,Si or V but with no significant improvement in the GFA.Clearly,it is necessary,in order to utilise the full potential of the base ternary system,to identify the best glass-forming compositions as a basis for extending the search into multi-dimensional compositional space.Thus,CuxHfyTiz alloys,where x=（40-70） at.pct,y=（5-30） at.pct,and z=（10-36） at.pct,were prepared by melt spinning andcopper mould suction-casting.The composition dependence of the GFA for the Cu-Hf-Ti alloys,as measured by dc for rod and ribbon samples,is reported over the composition range given above.
文摘Isotactic polypropylene（i PP） samples obtained by pressure vibration injection molding（PVIM） and conventional injection molding（CIM） were studied by polarized-light microscopy（PLM）, respectively. It was found that the alternating bright and dark banded spherulites were generated in the transitional region of PVIM parts. It is the first time that the banded spherulites of isotactic polypropylene were observed in polymer processing. What＇s more, the banded spherulites were proved to be constituted of α-form crystal by hot stage polarized-light microscopy（HT-PLM） and wide angle X-ray diffraction（WAXD）. Morphology of the banded spherulites was also studied by scaning electronical microscopy（SEM）.
