In this paper, two types of the (2+1)-dimensional breaking soliton equations are investigated, whichdescribe the interactions of the Riemann waves with the long waves.With symbolic computation, the Hirota bilinearform...In this paper, two types of the (2+1)-dimensional breaking soliton equations are investigated, whichdescribe the interactions of the Riemann waves with the long waves.With symbolic computation, the Hirota bilinearforms and Bcklund transformations are derived for those two systems.Furthermore, multisoliton solutions in termsof the Wronskian determinant are constructed, which are verified through the direct substitution of the solutions intothe bilinear equations.Via the Wronskian technique, it is proved that the Bcklund transformations obtained are theones between the (N-1)-and N-soliton solutions.Propagations and interactions of the kink-/bell-shaped solitonsare presented.It is shown that the Riemann waves possess the solitonic properties, and maintain the amplitudes andvelocities in the collisions only with some phase shifts.展开更多
The Bcklund transformation and the generalized Miura transformation for the Volterra lattice equation are constructed by using point symmetry method.As an application,the explicit solution to the lattice equation is...The Bcklund transformation and the generalized Miura transformation for the Volterra lattice equation are constructed by using point symmetry method.As an application,the explicit solution to the lattice equation is obtained.展开更多
This article is concerned with the extended homogeneous balance method for studying the abundant localized solution structure of the (2+1) dimensional asymmetric Nizhnik Novikov Veselov equation. A B a¨...This article is concerned with the extended homogeneous balance method for studying the abundant localized solution structure of the (2+1) dimensional asymmetric Nizhnik Novikov Veselov equation. A B a¨ cklund transformation was first obtained, and then the richness of the localized coherent structures was found, which was caused by the entrance of two variable separated arbitrary functions, in the model. For some special choices of the arbitrary functions, it is shown that the localized structures of the model may be dromions, lumps, and ring solitons.展开更多
In this paper,the bilinear form of a generalized Kadomtsev-Petviashvili equation is obtained by applying the binary Bell polynomials.The N-soliton solution and one periodic wave solution are presented by use of the Hi...In this paper,the bilinear form of a generalized Kadomtsev-Petviashvili equation is obtained by applying the binary Bell polynomials.The N-soliton solution and one periodic wave solution are presented by use of the Hirota direct method and the Riemann theta function,respectively.And then the asymptotic analysis demonstrates one periodic wave solution can be reduced to one soliton solution.In the end,the bilinear Bcklund transformations are derived.展开更多
The prolongation structure methodologies of Wahlquist-Estabrook [H.D.Wahlquist and F.B.Estabrook,J.Math.Phys.16 (1975) 1] for nonlinear differential equations are applied to a more general set of coupled integrable di...The prolongation structure methodologies of Wahlquist-Estabrook [H.D.Wahlquist and F.B.Estabrook,J.Math.Phys.16 (1975) 1] for nonlinear differential equations are applied to a more general set of coupled integrable dispersionless system.Based on the obtained prolongation structure,a Lie-Algebra valued connection of a closed ideal of exterior differential forms related to the above system is constructed.A Lie-Algebra representation of some hidden structural symmetries of the previous system,its Bcklund transformation using the Riccati form of the linear eigenvalue problem and their general corresponding Lax-representation are derived.In the wake of the previous results,we extend the above prolongation scheme to higher-dimensional systems from which a new (2 + 1)-dimensional coupled integrable dispersionless system is unveiled along with its inverse scattering formulation,which applications are straightforward in nonlinear optics where additional propagating dimension deserves some attention.展开更多
The atmosphere is an evolutionary agent essential to the shaping of a planet,while in oceanic science and daily life,liquids are commonly seen.In this paper,we investigate a generalized variable-coefficient Korteweg-d...The atmosphere is an evolutionary agent essential to the shaping of a planet,while in oceanic science and daily life,liquids are commonly seen.In this paper,we investigate a generalized variable-coefficient Korteweg-de Vriesmodified Korteweg-de Vries equation for the atmosphere,oceanic fluids and plasmas.With symbolic computation,beginning with a presumption,we work out certain scaling transformations,bilinear forms through the binary Bell polynomials and our scaling transformations,N solitons(with N being a positive integer)via the aforementioned bilinear forms and bilinear auto-Bäcklund transformations through the Hirota method with some solitons.In addition,Painlevé-type auto-Bäcklund transformations with some solitons are symbolically computed out.Respective dependences and constraints on the variable/constant coefficients are discussed,while those coefficients correspond to the quadratic-nonlinear,cubic-nonlinear,dispersive,dissipative and line-damping effects in the atmosphere,oceanic fluids and plasmas.展开更多
Backlund transformations for the equation is an arbitrary function) is studied in this paper, using the procedure of Wahlquist and Estabrook (WEP). We conclude that the condition is sufficient for the existence of Bac...Backlund transformations for the equation is an arbitrary function) is studied in this paper, using the procedure of Wahlquist and Estabrook (WEP). We conclude that the condition is sufficient for the existence of Backlund transformations for the equation of our interest. A special case of our results leads to the conclusion of Leibbrandt[1,2]展开更多
Under investigation in this paper is a(3 + 1)-dimensional variable-coefficient Kadomtsev–Petviashvili equation, which describes the propagation of surface and internal water waves. By virtue of the binary Bell polyno...Under investigation in this paper is a(3 + 1)-dimensional variable-coefficient Kadomtsev–Petviashvili equation, which describes the propagation of surface and internal water waves. By virtue of the binary Bell polynomials,symbolic computation and auxiliary independent variable, the bilinear forms, soliton solutions, B¨acklund transformations and Lax pair are obtained. Variable coefficients of the equation can affect the solitonic structure, when they are specially chosen, while curved and linear solitons are illustrated. Elastic collisions between/among two and three solitons are discussed, through which the solitons keep their original shapes invariant except for some phase shifts.展开更多
This paper is concerned with the (2+1)-dimensional Burgers' and heat types of equations.All of the geometic vector fields of the equations are obtained,an optimal system of the equation is presented.Especially,th...This paper is concerned with the (2+1)-dimensional Burgers' and heat types of equations.All of the geometic vector fields of the equations are obtained,an optimal system of the equation is presented.Especially,the Bcklund transformations (BTs) for the Burgers' equations are constructed based on the symmetry.Then,all of the symmetry reductions are provided in terms of the optimal system method,and the exact explicit solutions are investigated by the symmetry reductions and Bcklund transformations.展开更多
We obtain the non-local residual symmetry related to truncated Painlev~ expansion of Burgers equation. In order to localize the residual symmetry, we introduce new variables to prolong the original Burgers equation in...We obtain the non-local residual symmetry related to truncated Painlev~ expansion of Burgers equation. In order to localize the residual symmetry, we introduce new variables to prolong the original Burgers equation into a new system. By using Lie's first theorem, we obtain the finite transformation for the localized residual symmetry. More importantly, we also Iocalize the linear superposition of multiple residual symmetries to find the corresponding finite transformations. It is interesting to find that the n-th B^icklund transformation for Burgers equation can be expressed by determinants in a compact way.展开更多
Burgers equation is the simplest one in soliton theory, which has been widely applied in almost all the physical branches. In this paper, we discuss the Painlev′e property of the(3+1)-dimensional Burgers equation, an...Burgers equation is the simplest one in soliton theory, which has been widely applied in almost all the physical branches. In this paper, we discuss the Painlev′e property of the(3+1)-dimensional Burgers equation, and then B¨acklund transformation is derived according to the truncated expansion of the obtained Painlev′e analysis. Using the B¨acklund transformation, we find the rouge wave solutions to the equation via the multilinear variable separation approach. And we also give an exact solution obtained by general variable separation approach, which is proved to possess abundant structures.展开更多
We modify the bilinear Backlund transformation for the discrete sine-Gordon equation and derive varietyof solutions by freely choosing parameters from the modified Backlund transformation.Dynamics of solutions andcont...We modify the bilinear Backlund transformation for the discrete sine-Gordon equation and derive varietyof solutions by freely choosing parameters from the modified Backlund transformation.Dynamics of solutions andcontinuum limits are also discussed.展开更多
The dilatometric curves of B1500HS high-strength steel at different heating rates were measured by a Gleeble-3800 thermal simulator and analyzed to investigate the effect of heating rate on austenitization.Results sho...The dilatometric curves of B1500HS high-strength steel at different heating rates were measured by a Gleeble-3800 thermal simulator and analyzed to investigate the effect of heating rate on austenitization.Results show that the value of starting temperature and ending temperature of austenite transformation increase with the rise of heating rates,whereas the temperature interval of austenite formation decreases.The kinetic equation of austenite transformation was solved using the Johnson–Mehl–Avrami model,and the related parameters of the equation were analyzed by the Kissinger method.For those calculations,the activation energy of austenite transformation is 1.01×10^6 J/mol,and the values of kinetic parameters n and ln k0 are 0.63 and 103.03,respectively.The relationship between the volume fraction of austenite and the heating time at different heating rates could be predicted using the kinetic equation.The predicted and experimental results were compared to verify the accuracy of the kinetic equation.The microstructure etched by different corrosive solutions was analyzed,and the reliability of kinetic equation was further verified from the microscopic perspective.展开更多
Agrobacterium tumefaciens-mediated transformation (ATMT) system was assessed for conducting insertional mutagenesis in Penicillium digitatum, a major fungal pathogen infecting post-harvest citrus fruits. A transformat...Agrobacterium tumefaciens-mediated transformation (ATMT) system was assessed for conducting insertional mutagenesis in Penicillium digitatum, a major fungal pathogen infecting post-harvest citrus fruits. A transformation efficiency of up to 60 transformants per 106 conidia was achieved by this system. The integration of the hph gene into the fungal genome was verified by polymerase chain reaction (PCR) amplification and sequencing. These transformants tested were also shown to be mitotically stable. Southern blot analysis of 14 randomly selected transformants showed that the hph gene was randomly integrated as single copy into the fungal genome of P. digitatum. Thus, we conclude that ATMT of P. digitatum could be used as an alter-natively practical genetic tool for conducting insertional mutagenesis in P. digitatum to study functional genomics.展开更多
Teak (Tectona grandis) provides one of the most highly sought after timber in the world and is a widely recommended species for reforestation. As such teak is widely planted in Malaysia. Though no serious outbreaks ha...Teak (Tectona grandis) provides one of the most highly sought after timber in the world and is a widely recommended species for reforestation. As such teak is widely planted in Malaysia. Though no serious outbreaks have been recorded for teak in Malaysia, but insect attack remains the most important threat to the timber industry. Thus, in efforts to overcome the problem, an integrated pest management system needs to be developed. Spraying of commercial Bt has been a common practice in addressing minor outbreaks. However, one of the main limitations of the spraying technique is poor coverage, especially on plant surfaces. Poor coverage, however, could be overcome by planting insect resistant trees. In addition, the approach of using genetic engineering in addressing the above problem proves to be possible with the advancement made in genetic transformation of trees especially in the last decade. This, together with improved knowledge on gene function following improved DNA recombinant techniques promises the major advancement in pest management of forest species. This report demonstrates the possibility of transferring foreign gene into teak cells. In this study, nodal segments of teak were subjected to particle bombardment. Nodal segments bombarded with gold particles coated with plasmid DNA carrying hygromycin phosphotransferase (hpt), β glucuronidase (gus) and cry1A(b) genes were then transferred onto medium for shoot development. The shoots were than transferred onto the same medium supplemented with 10mg/L hygromycin for selection. Selection was repeated several times with six week subculture intervals on the same Hm containing media. The presence of the transgenes in the Hmr plants was confirmed using PCR.展开更多
目的探讨程序性死亡蛋白配体-1(programmed death ligand-1,PD-L1)过表达对子宫内膜癌细胞Ishikawa上皮间质转化的影响及可能机制。方法使用实验室构建的PD-L1过表达稳转细胞株Ishikawa/PD-L1及稳转空载对照组Ishikawa/EV,qPCR及Western...目的探讨程序性死亡蛋白配体-1(programmed death ligand-1,PD-L1)过表达对子宫内膜癌细胞Ishikawa上皮间质转化的影响及可能机制。方法使用实验室构建的PD-L1过表达稳转细胞株Ishikawa/PD-L1及稳转空载对照组Ishikawa/EV,qPCR及Western blot法检测PD-L1过表达效率,Transwell和划痕实验检测细胞迁移能力和侵袭活性,Western blot法检测上皮间质转化相关蛋白表达和核转录因子-κB(nuclear factor kappa-B,NF-κB)磷酸化水平。结果与对照组相比,Ishikawa/PD-L1迁移能力与侵袭活性显著增强,Vimentin、N-cadherin、p-p65蛋白表达明显升高,E-cadherin表达明显下调。结论PD-L1可通过诱导NF-κB信号通路激活,促进上皮间质转化,进而增强子宫内膜癌细胞的迁移、侵袭能力。展开更多
A solution to the reparametrization of Bézier curves by sine transformation of Bemstein basis is presented. The new effective reparametrization method is given through the following procedures: educing Sine Bems...A solution to the reparametrization of Bézier curves by sine transformation of Bemstein basis is presented. The new effective reparametrization method is given through the following procedures: educing Sine Bemstein-Bézier Class-SBBC function, defining SBBC curve and discussing the relation between SBBC and Bézier curve.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No.60772023 the Open Fund under Grant No.BUAASKLSDE-09KF-04l+2 种基金Supported Project under Grant No.SKLSDE-2010ZX-07 of the State Key Laboratory of Software Development Environment,Beijing University of Aeronautics and Astronauticsthe National Basic Research Program of China (973 Program) under Grant No.2005CB321901 the Specialized Research Fund for the Doctoral Program of Higher Education under Grant No.200800130006,Chinese Ministry of Education
文摘In this paper, two types of the (2+1)-dimensional breaking soliton equations are investigated, whichdescribe the interactions of the Riemann waves with the long waves.With symbolic computation, the Hirota bilinearforms and Bcklund transformations are derived for those two systems.Furthermore, multisoliton solutions in termsof the Wronskian determinant are constructed, which are verified through the direct substitution of the solutions intothe bilinear equations.Via the Wronskian technique, it is proved that the Bcklund transformations obtained are theones between the (N-1)-and N-soliton solutions.Propagations and interactions of the kink-/bell-shaped solitonsare presented.It is shown that the Riemann waves possess the solitonic properties, and maintain the amplitudes andvelocities in the collisions only with some phase shifts.
基金Supported by the Science Research Foundation of Zhanjiang Normal University(L0803)
文摘The Bcklund transformation and the generalized Miura transformation for the Volterra lattice equation are constructed by using point symmetry method.As an application,the explicit solution to the lattice equation is obtained.
文摘This article is concerned with the extended homogeneous balance method for studying the abundant localized solution structure of the (2+1) dimensional asymmetric Nizhnik Novikov Veselov equation. A B a¨ cklund transformation was first obtained, and then the richness of the localized coherent structures was found, which was caused by the entrance of two variable separated arbitrary functions, in the model. For some special choices of the arbitrary functions, it is shown that the localized structures of the model may be dromions, lumps, and ring solitons.
基金Supported by the National Natural Science Foundation of China under Grant Nos. 10735030 and 11075055Innovative Research Team Program of the National Natural Science Foundation of China under Grant No. 61021004
文摘In this paper,the bilinear form of a generalized Kadomtsev-Petviashvili equation is obtained by applying the binary Bell polynomials.The N-soliton solution and one periodic wave solution are presented by use of the Hirota direct method and the Riemann theta function,respectively.And then the asymptotic analysis demonstrates one periodic wave solution can be reduced to one soliton solution.In the end,the bilinear Bcklund transformations are derived.
文摘The prolongation structure methodologies of Wahlquist-Estabrook [H.D.Wahlquist and F.B.Estabrook,J.Math.Phys.16 (1975) 1] for nonlinear differential equations are applied to a more general set of coupled integrable dispersionless system.Based on the obtained prolongation structure,a Lie-Algebra valued connection of a closed ideal of exterior differential forms related to the above system is constructed.A Lie-Algebra representation of some hidden structural symmetries of the previous system,its Bcklund transformation using the Riccati form of the linear eigenvalue problem and their general corresponding Lax-representation are derived.In the wake of the previous results,we extend the above prolongation scheme to higher-dimensional systems from which a new (2 + 1)-dimensional coupled integrable dispersionless system is unveiled along with its inverse scattering formulation,which applications are straightforward in nonlinear optics where additional propagating dimension deserves some attention.
基金the National Natural Science Foundation of China(Grant No.11871116)the Fundamental Research Funds for the Central Universities of China(Grant No.2019XD-A11)the BUPT Innovation and Entrepreneurship Support Program,Beijing University of Posts and Telecommunications,and the National Scholarship for Doctoral Students of China.
文摘The atmosphere is an evolutionary agent essential to the shaping of a planet,while in oceanic science and daily life,liquids are commonly seen.In this paper,we investigate a generalized variable-coefficient Korteweg-de Vriesmodified Korteweg-de Vries equation for the atmosphere,oceanic fluids and plasmas.With symbolic computation,beginning with a presumption,we work out certain scaling transformations,bilinear forms through the binary Bell polynomials and our scaling transformations,N solitons(with N being a positive integer)via the aforementioned bilinear forms and bilinear auto-Bäcklund transformations through the Hirota method with some solitons.In addition,Painlevé-type auto-Bäcklund transformations with some solitons are symbolically computed out.Respective dependences and constraints on the variable/constant coefficients are discussed,while those coefficients correspond to the quadratic-nonlinear,cubic-nonlinear,dispersive,dissipative and line-damping effects in the atmosphere,oceanic fluids and plasmas.
文摘Backlund transformations for the equation is an arbitrary function) is studied in this paper, using the procedure of Wahlquist and Estabrook (WEP). We conclude that the condition is sufficient for the existence of Backlund transformations for the equation of our interest. A special case of our results leads to the conclusion of Leibbrandt[1,2]
基金Supported by the National Natural Science Foundation of China under Grant No.11272023the Open Fund of State Key Laboratory of Information Photonics and Optical Communications(Beijing University of Posts and Telecommunications)under Grant No.IPOC2013B008the Fundamental Research Funds for the Central Universities of China under Grant No.2011BUPTYB02
文摘Under investigation in this paper is a(3 + 1)-dimensional variable-coefficient Kadomtsev–Petviashvili equation, which describes the propagation of surface and internal water waves. By virtue of the binary Bell polynomials,symbolic computation and auxiliary independent variable, the bilinear forms, soliton solutions, B¨acklund transformations and Lax pair are obtained. Variable coefficients of the equation can affect the solitonic structure, when they are specially chosen, while curved and linear solitons are illustrated. Elastic collisions between/among two and three solitons are discussed, through which the solitons keep their original shapes invariant except for some phase shifts.
基金Supported by the National Natural Science Foundation of China under Grant Nos.11171041 and 10971018the Natural Science Foundation of Shandong Province under Grant No.ZR2010AM029+1 种基金the Promotive Research Fund for Young and Middle-Aged Scientists of Shandong Province under Grant No.BS2010SF001the Doctoral Foundation of Binzhou University under Grant No.2009Y01
文摘This paper is concerned with the (2+1)-dimensional Burgers' and heat types of equations.All of the geometic vector fields of the equations are obtained,an optimal system of the equation is presented.Especially,the Bcklund transformations (BTs) for the Burgers' equations are constructed based on the symmetry.Then,all of the symmetry reductions are provided in terms of the optimal system method,and the exact explicit solutions are investigated by the symmetry reductions and Bcklund transformations.
基金supported by the National Natural Science Foundation of China(Grant Nos.11347183,11275129,11305106,11365017,and 11405110)the Natural Science Foundation of Zhejiang Province of China(Grant Nos.Y7080455 and LQ13A050001)
文摘We obtain the non-local residual symmetry related to truncated Painlev~ expansion of Burgers equation. In order to localize the residual symmetry, we introduce new variables to prolong the original Burgers equation into a new system. By using Lie's first theorem, we obtain the finite transformation for the localized residual symmetry. More importantly, we also Iocalize the linear superposition of multiple residual symmetries to find the corresponding finite transformations. It is interesting to find that the n-th B^icklund transformation for Burgers equation can be expressed by determinants in a compact way.
基金Supported by National Natural Science Foundation of China under Grant Nos.11175092,11275123,11205092Ningbo University Discipline Project under Grant No.xkzl1008K.C.Wong Magna Fund in Ningbo University
文摘Burgers equation is the simplest one in soliton theory, which has been widely applied in almost all the physical branches. In this paper, we discuss the Painlev′e property of the(3+1)-dimensional Burgers equation, and then B¨acklund transformation is derived according to the truncated expansion of the obtained Painlev′e analysis. Using the B¨acklund transformation, we find the rouge wave solutions to the equation via the multilinear variable separation approach. And we also give an exact solution obtained by general variable separation approach, which is proved to possess abundant structures.
基金Supported by the National Natural Science Foundation of China under Grant No.10671121Shanghai Leading Academic Discipline Project under Grant No.J50101
文摘We modify the bilinear Backlund transformation for the discrete sine-Gordon equation and derive varietyof solutions by freely choosing parameters from the modified Backlund transformation.Dynamics of solutions andcontinuum limits are also discussed.
基金This work was financially supported by the Natural Science Foundation of Hebei Province of China(No.E2018203254)the Scientific Research Program of Hebei Province Education Department,China(No.ZD2019013).
文摘The dilatometric curves of B1500HS high-strength steel at different heating rates were measured by a Gleeble-3800 thermal simulator and analyzed to investigate the effect of heating rate on austenitization.Results show that the value of starting temperature and ending temperature of austenite transformation increase with the rise of heating rates,whereas the temperature interval of austenite formation decreases.The kinetic equation of austenite transformation was solved using the Johnson–Mehl–Avrami model,and the related parameters of the equation were analyzed by the Kissinger method.For those calculations,the activation energy of austenite transformation is 1.01×10^6 J/mol,and the values of kinetic parameters n and ln k0 are 0.63 and 103.03,respectively.The relationship between the volume fraction of austenite and the heating time at different heating rates could be predicted using the kinetic equation.The predicted and experimental results were compared to verify the accuracy of the kinetic equation.The microstructure etched by different corrosive solutions was analyzed,and the reliability of kinetic equation was further verified from the microscopic perspective.
基金the National Natural Science Foundation of China (No. 30571236)the Modern Agriculture (Citrus) Technology System (MATS) of Chinathe Science and Technology Department of Zhejiang Province, China (No. 2007C22007)
文摘Agrobacterium tumefaciens-mediated transformation (ATMT) system was assessed for conducting insertional mutagenesis in Penicillium digitatum, a major fungal pathogen infecting post-harvest citrus fruits. A transformation efficiency of up to 60 transformants per 106 conidia was achieved by this system. The integration of the hph gene into the fungal genome was verified by polymerase chain reaction (PCR) amplification and sequencing. These transformants tested were also shown to be mitotically stable. Southern blot analysis of 14 randomly selected transformants showed that the hph gene was randomly integrated as single copy into the fungal genome of P. digitatum. Thus, we conclude that ATMT of P. digitatum could be used as an alter-natively practical genetic tool for conducting insertional mutagenesis in P. digitatum to study functional genomics.
文摘Teak (Tectona grandis) provides one of the most highly sought after timber in the world and is a widely recommended species for reforestation. As such teak is widely planted in Malaysia. Though no serious outbreaks have been recorded for teak in Malaysia, but insect attack remains the most important threat to the timber industry. Thus, in efforts to overcome the problem, an integrated pest management system needs to be developed. Spraying of commercial Bt has been a common practice in addressing minor outbreaks. However, one of the main limitations of the spraying technique is poor coverage, especially on plant surfaces. Poor coverage, however, could be overcome by planting insect resistant trees. In addition, the approach of using genetic engineering in addressing the above problem proves to be possible with the advancement made in genetic transformation of trees especially in the last decade. This, together with improved knowledge on gene function following improved DNA recombinant techniques promises the major advancement in pest management of forest species. This report demonstrates the possibility of transferring foreign gene into teak cells. In this study, nodal segments of teak were subjected to particle bombardment. Nodal segments bombarded with gold particles coated with plasmid DNA carrying hygromycin phosphotransferase (hpt), β glucuronidase (gus) and cry1A(b) genes were then transferred onto medium for shoot development. The shoots were than transferred onto the same medium supplemented with 10mg/L hygromycin for selection. Selection was repeated several times with six week subculture intervals on the same Hm containing media. The presence of the transgenes in the Hmr plants was confirmed using PCR.
基金Supported by the Science Research Foundation of Zhejiang Office of Education (20050718)
文摘A solution to the reparametrization of Bézier curves by sine transformation of Bemstein basis is presented. The new effective reparametrization method is given through the following procedures: educing Sine Bemstein-Bézier Class-SBBC function, defining SBBC curve and discussing the relation between SBBC and Bézier curve.