A semiconductor optical amplifier and electroabsorption modulator monolithically integrated with a spotsize converter input and output is fabricated by means of selective area growth,quantum well intermixing,and asymm...A semiconductor optical amplifier and electroabsorption modulator monolithically integrated with a spotsize converter input and output is fabricated by means of selective area growth,quantum well intermixing,and asymmetric twin waveguide technology. A 1550-1600nm lossless operation with a high DC extinction ratio of 25dB and more than 10GHz 3dB bandwidth are successfully achieved. The output beam divergence angles of the device in the horizontal and vertical directions are as small as 7.3°× 18.0°, respectively, resulting in a 3.0dB coupling loss with a cleaved single-mode optical fiber.展开更多
The consolidation behavior of mixed in place cement and lime/cement mixed column was studied. Consolidation of the composite foundation was modeled as a three dimensional axi symmetric problem. The authors used t...The consolidation behavior of mixed in place cement and lime/cement mixed column was studied. Consolidation of the composite foundation was modeled as a three dimensional axi symmetric problem. The authors used the finite difference method to obtain the pore pressure variation with time at any location below the surface. A computer program developed by the authors was used to draw some interesting conclusions about the consolidation behaviors of cement and lime/cement mixed pile foundation. Finally, a combined model including the permeability coefficients of cement mixed piles and soil, was studied and its feasibility was evaluated.展开更多
Mixed symmetry states are studied in the framework of the neutron-proton interacting boson model. It is found that some of the mixed symmetry states with moderate high spins change very fast with respect to the Majora...Mixed symmetry states are studied in the framework of the neutron-proton interacting boson model. It is found that some of the mixed symmetry states with moderate high spins change very fast with respect to the Majorana interaction. Under certain conditions, they become the yrast state or yrare state. These states are difficult to decay and become very stable. This study suggests that a possible new mode of isomers may exist due to the special nature in their proton and neutron degrees of freedom.展开更多
The family symmetry SU(3) U(1) is proposed to solve flavor problems about fermion masses and flavor mixings. It is breaking is implemented by some flavon fields at the high-energy scale. In addition a discrete gro...The family symmetry SU(3) U(1) is proposed to solve flavor problems about fermion masses and flavor mixings. It is breaking is implemented by some flavon fields at the high-energy scale. In addition a discrete group Z2 is introduced to generate tiny neutrino masses, which is broken by a real singlet scalar field at the middle-energy scale. The low-energy effective theory is elegantly obtained after all of super-heavy fermions are integrated out and decoupling. All the fermion mass matrices are regularly characterized by four fundamental matrices and thirteen parameters. The model can perfectly fit and account for all the current experimental data about the fermion masses and flavor mixings, in particular, it finely predicts the first generation quark masses and the values of θ13and JCp in neutrino physics. All of the results are promising to be tested in the future experiments.展开更多
We consider that the Higgs triplet Yukawa coupling takes the Friedberg-Lee texture, and the Higgs doublet Yukawa coupling simply identifies with the diagonal Yutawa coupling of charged lepton in the context of left-ri...We consider that the Higgs triplet Yukawa coupling takes the Friedberg-Lee texture, and the Higgs doublet Yukawa coupling simply identifies with the diagonal Yutawa coupling of charged lepton in the context of left-right symmetric model. In this scenario, the phenomenology, including effective neutrino masses, mixings, and thermal flavor-dependent leptogenesis and lepton flavor violation decays are studied. We investigate the combined constrain of the parameters in this scenario and test its consistency with present data.展开更多
We study preconditioning techniques used in conjunction with the conjugate gradient method for solving multi-length-scale symmetric positive definite linear systems originating from the quantum Monte Carlo simulation ...We study preconditioning techniques used in conjunction with the conjugate gradient method for solving multi-length-scale symmetric positive definite linear systems originating from the quantum Monte Carlo simulation of electron interaction of correlated materials. Existing preconditioning techniques are not designed to be adaptive to varying numerical properties of the multi-length-scale systems. In this paper, we propose a hybrid incomplete Cholesky (HIC) preconditioner and demonstrate its adaptivity to the multi-length-scale systems. In addition, we propose an extension of the compressed sparse column with row access (CSCR) sparse matrix storage format to efficiently accommodate the data access pattem to compute the HIC preconditioner. We show that for moderately correlated materials, the HIC preconditioner achieves the optimal linear scaling of the simulation. The development of a linear-scaling preconditioner for strongly correlated materials remains an open topic.展开更多
The entanglement of two atomic qubits, which are coupled to a coherent state field with different couplings, is studied. The dynamical evolution of the concurrence, which measures the degree of the entanglement betwee...The entanglement of two atomic qubits, which are coupled to a coherent state field with different couplings, is studied. The dynamical evolution of the concurrence, which measures the degree of the entanglement between the two qubits, is plotted versus the scaled time gt. It is found that the two qubits can be entangled by the coherent state field even when they are initially prepared in the most mixed state, and for very weak field, the most mixed state can be; more easily entangled than some pure states. It is also found that the entanglement between the qubits sensitively depends on the relative difference of the atomic couplings and the mean photon number of the field.展开更多
According to the configuration,mixed-conducting membranes are classified as symmetric membranes and asymmetric membranes consisting of a thin dense layer and a porous support.In this study,these two kinds of SrCo0.4Fe...According to the configuration,mixed-conducting membranes are classified as symmetric membranes and asymmetric membranes consisting of a thin dense layer and a porous support.In this study,these two kinds of SrCo0.4Fe0.5Zr0.1O3-δ oxide-based membranes were systematically compared in terms of oxygen permeability and chemical stability,and their differences were elucidated by means of the theoretical calculation.For the oxygen permeability,the asymmetric membrane was greater than the symmetric membrane due to the significant decrease of bulk diffusion resistance in the thin dense layer of the asymmetric membrane.In regard to the chemical stability,the increase of oxygen partial pressure on the asymmetric membrane surface at CH4 side produced the stable time of over 1032h in partial oxidation of methane at 1123K,while the symmetric membrane was only of 528h.This study demonstrated that the asymmetric membrane was a promising geometrical configuration for the practical application.展开更多
The present investigation addresses the simultaneous effects of heat and mass transfer in the mixed convection peristaltic flow of viscous fluid in an asymmetric channel. The channel walls exhibit the convective bound...The present investigation addresses the simultaneous effects of heat and mass transfer in the mixed convection peristaltic flow of viscous fluid in an asymmetric channel. The channel walls exhibit the convective boundary conditions. In addition, the effects due to Soret and Dufour are taken into consideration. Resulting problems are solved for the series solutions. Numerical values of heat and mass transfer rates are displayed and studied. Results indicate that the concentration and temperature of the fluid increase whereas the mass transfer rate at the wall decreases with increase of the mass transfer Biot number. Furthermore, it is observed that the temperature decreases with the increase of the heat transfer Biot number.展开更多
This paper studies the control of a new chaotic system which can generate 4-scroll attractors. Based on the properties of a passive system, it derives the essential conditions under which this new chaotic system could...This paper studies the control of a new chaotic system which can generate 4-scroll attractors. Based on the properties of a passive system, it derives the essential conditions under which this new chaotic system could be equivalent to a passive system and globally asymptotically stabilize at a zero equilibrium point via smooth state feedback. Simulation results and circuit experiment show that the proposed chaos control method is effective.展开更多
In this paper, we show that there exists a twisted duality symmetry between the Maurer-Cartan equations and the equations of motion in the hybrid formalism for the type liB superstring in an AdS2 ×S2 background w...In this paper, we show that there exists a twisted duality symmetry between the Maurer-Cartan equations and the equations of motion in the hybrid formalism for the type liB superstring in an AdS2 ×S2 background with Ramond-Ramond flux. As a result, from the twisted duality transformation, we construct the Lax connection with the spectral parameter, which ensures the integrability of the system.展开更多
We first investigate the translative containment measure for convex domain K0 to contain, or to be contained in, the homothetic copy of another convex domain K1, i.e., given two convex domains K0, K1 of areas A0, A1, ...We first investigate the translative containment measure for convex domain K0 to contain, or to be contained in, the homothetic copy of another convex domain K1, i.e., given two convex domains K0, K1 of areas A0, A1, respectively, in the Euclidean plane R2, is there a translation T so that t(T K1) K0 or t(T K1) ? K0 for t > 0? Via the translative kinematic formulas of Poincar′e and Blaschke in integral geometry,we estimate the symmetric mixed isohomothetic deficit σ2(K0, K1) ≡ A201- A0A1, where A01 is the mixed area of K0 and K1. We obtain a sufficient condition for K0 to contain, or to be contained in, t(T K1). We obtain some Bonnesen-style symmetric mixed isohomothetic inequalities and reverse Bonnesen-style symmetric mixed isohomothetic inequalities. These symmetric mixed isohomothetic inequalities obtained are known as Bonnesen-style isopermetric inequalities and reverse Bonnesen-style isopermetric inequalities if one of domains is a disc. As direct consequences, we obtain some inequalities that strengthen the known Minkowski inequality for mixed areas and the Bonnesen-Blaschke-Flanders inequality.展开更多
Swirl-premixed combustion systems exhibit potential to meet future regulations on pollution emissions. However, combustion induced vortex breakdown(CIVB) flashback is frequently observed in these systems, especially f...Swirl-premixed combustion systems exhibit potential to meet future regulations on pollution emissions. However, combustion induced vortex breakdown(CIVB) flashback is frequently observed in these systems, especially for high hydrogen content fuel. In this study, a swirl-premixed burner with diverging centerbody was used to investigate CIVB flashback based on azimuthal vorticity at mixing zone exit. Through 2D axisymmetric model, it was found that there was a maximal azimuthal vorticity at mixing zone exit for each equivalence ratio. The physical meaning of these maximal azimuthal vorticity values was the minimally required azimuthal vorticity to trigger CIVB flashback. At the same time, the required azimuthal vorticity declined with the increase of equivalence ratio since turbulent burning velocity started to control flashback. Nevertheless, azimuthal vorticity offered by heat release increased with the increase of equivalence ratio, which promoted flame propagating upstream continually.展开更多
In this paper,we investigate group-invariant solutions to the hyperbolic geometric flow on Riemann surfaces,which include solutions of separation variables,traveling wave solutions,self-similar solutions and radial so...In this paper,we investigate group-invariant solutions to the hyperbolic geometric flow on Riemann surfaces,which include solutions of separation variables,traveling wave solutions,self-similar solutions and radial solutions.In the proceeding of reduction,there are elliptic,hyperbolic and mixed types of equations.For the first kind of equation,some exact solutions are found;while for the last two kinds,with implicit solutions found,we furthermore investigate whether there will be a global solution or blowing up.Referring to the work of Kong et al.(2009),the results come out perfectly.展开更多
A family of stable mixed finite elements for the linear elasticity on tetrahedral grids are constructed,where the stress is approximated by symmetric H(div)-Pk polynomial tensors and the displacement is approximated b...A family of stable mixed finite elements for the linear elasticity on tetrahedral grids are constructed,where the stress is approximated by symmetric H(div)-Pk polynomial tensors and the displacement is approximated by C-1-Pk-1polynomial vectors,for all k 4.The main ingredients for the analysis are a new basis of the space of symmetric matrices,an intrinsic H(div)bubble function space on each element,and a new technique for establishing the discrete inf-sup condition.In particular,they enable us to prove that the divergence space of the H(div)bubble function space is identical to the orthogonal complement space of the rigid motion space with respect to the vector-valued Pk-1polynomial space on each tetrahedron.The optimal error estimate is proved,verified by numerical examples.展开更多
Orthogonal arrays (OAs), mixed level or fixed level (asymmetric or symmetric), are useful in the design of various experiments. They are also a fundamental tool in the construction of various combinatorial configurati...Orthogonal arrays (OAs), mixed level or fixed level (asymmetric or symmetric), are useful in the design of various experiments. They are also a fundamental tool in the construction of various combinatorial configurations. In this paper, we establish a general "expansive replacement method" for constructing mixedlevel OAs of an arbitrary strength. As a consequence, a positive answer to the question about orthogonal arrays posed by Hedayat, Sloane and Stufken is given. Some series of mixed level OAs of strength ≥3 are produced.展开更多
Group theory(GT) provides a rigorous framework for studying symmetries in various disciplines in physics ranging from quantum field theories and the standard model to fluid mechanics and chaos theory. To date, the app...Group theory(GT) provides a rigorous framework for studying symmetries in various disciplines in physics ranging from quantum field theories and the standard model to fluid mechanics and chaos theory. To date, the application of such a powerful tool in optical physics remains limited. Over the past few years however, several quantum-inspired symmetry principles(such as parity-time invariance and supersymmetry) have been introduced in optics and photonics for the first time. Despite the intense activities in these new research directions, only few works utilized the power of group theory. Motivated by this status quo, here we present a brief overview of the application of GT in optics, deliberately choosing examples that illustrate the power of this tool in both continuous and discrete setups. We hope that this review will stimulate further research that exploits the full potential of GT for investigating various symmetry paradigms in optics, eventually leading to new photonic devices.展开更多
文摘A semiconductor optical amplifier and electroabsorption modulator monolithically integrated with a spotsize converter input and output is fabricated by means of selective area growth,quantum well intermixing,and asymmetric twin waveguide technology. A 1550-1600nm lossless operation with a high DC extinction ratio of 25dB and more than 10GHz 3dB bandwidth are successfully achieved. The output beam divergence angles of the device in the horizontal and vertical directions are as small as 7.3°× 18.0°, respectively, resulting in a 3.0dB coupling loss with a cleaved single-mode optical fiber.
文摘The consolidation behavior of mixed in place cement and lime/cement mixed column was studied. Consolidation of the composite foundation was modeled as a three dimensional axi symmetric problem. The authors used the finite difference method to obtain the pore pressure variation with time at any location below the surface. A computer program developed by the authors was used to draw some interesting conclusions about the consolidation behaviors of cement and lime/cement mixed pile foundation. Finally, a combined model including the permeability coefficients of cement mixed piles and soil, was studied and its feasibility was evaluated.
文摘Mixed symmetry states are studied in the framework of the neutron-proton interacting boson model. It is found that some of the mixed symmetry states with moderate high spins change very fast with respect to the Majorana interaction. Under certain conditions, they become the yrast state or yrare state. These states are difficult to decay and become very stable. This study suggests that a possible new mode of isomers may exist due to the special nature in their proton and neutron degrees of freedom.
基金Supported by Chinese Universities Scientific Fund
文摘The family symmetry SU(3) U(1) is proposed to solve flavor problems about fermion masses and flavor mixings. It is breaking is implemented by some flavon fields at the high-energy scale. In addition a discrete group Z2 is introduced to generate tiny neutrino masses, which is broken by a real singlet scalar field at the middle-energy scale. The low-energy effective theory is elegantly obtained after all of super-heavy fermions are integrated out and decoupling. All the fermion mass matrices are regularly characterized by four fundamental matrices and thirteen parameters. The model can perfectly fit and account for all the current experimental data about the fermion masses and flavor mixings, in particular, it finely predicts the first generation quark masses and the values of θ13and JCp in neutrino physics. All of the results are promising to be tested in the future experiments.
基金supported by National Natural Science Foundation of China under Grant No.90203002
文摘We consider that the Higgs triplet Yukawa coupling takes the Friedberg-Lee texture, and the Higgs doublet Yukawa coupling simply identifies with the diagonal Yutawa coupling of charged lepton in the context of left-right symmetric model. In this scenario, the phenomenology, including effective neutrino masses, mixings, and thermal flavor-dependent leptogenesis and lepton flavor violation decays are studied. We investigate the combined constrain of the parameters in this scenario and test its consistency with present data.
基金supported in part by the US National Science Foundation grant 0611548in part by the US Department of Energy grant DE-FC02-06ER25793
文摘We study preconditioning techniques used in conjunction with the conjugate gradient method for solving multi-length-scale symmetric positive definite linear systems originating from the quantum Monte Carlo simulation of electron interaction of correlated materials. Existing preconditioning techniques are not designed to be adaptive to varying numerical properties of the multi-length-scale systems. In this paper, we propose a hybrid incomplete Cholesky (HIC) preconditioner and demonstrate its adaptivity to the multi-length-scale systems. In addition, we propose an extension of the compressed sparse column with row access (CSCR) sparse matrix storage format to efficiently accommodate the data access pattem to compute the HIC preconditioner. We show that for moderately correlated materials, the HIC preconditioner achieves the optimal linear scaling of the simulation. The development of a linear-scaling preconditioner for strongly correlated materials remains an open topic.
基金The project supported by National Natural Science Foundation of China under Grant No. 10374007
文摘The entanglement of two atomic qubits, which are coupled to a coherent state field with different couplings, is studied. The dynamical evolution of the concurrence, which measures the degree of the entanglement between the two qubits, is plotted versus the scaled time gt. It is found that the two qubits can be entangled by the coherent state field even when they are initially prepared in the most mixed state, and for very weak field, the most mixed state can be; more easily entangled than some pure states. It is also found that the entanglement between the qubits sensitively depends on the relative difference of the atomic couplings and the mean photon number of the field.
基金Supported by the National Basic Research Program of China (2009CB623406), the National Natural Science Foundation of China (20636020), the National High Technology Research and Development Program of China (2006AA030204) and the Specialized Research Fund for the Doctoral Program of Higher Education of China (20060291003).
文摘According to the configuration,mixed-conducting membranes are classified as symmetric membranes and asymmetric membranes consisting of a thin dense layer and a porous support.In this study,these two kinds of SrCo0.4Fe0.5Zr0.1O3-δ oxide-based membranes were systematically compared in terms of oxygen permeability and chemical stability,and their differences were elucidated by means of the theoretical calculation.For the oxygen permeability,the asymmetric membrane was greater than the symmetric membrane due to the significant decrease of bulk diffusion resistance in the thin dense layer of the asymmetric membrane.In regard to the chemical stability,the increase of oxygen partial pressure on the asymmetric membrane surface at CH4 side produced the stable time of over 1032h in partial oxidation of methane at 1123K,while the symmetric membrane was only of 528h.This study demonstrated that the asymmetric membrane was a promising geometrical configuration for the practical application.
基金the Higher Education Commission of Pakistan (HEC) for the financial support through Indigenous program
文摘The present investigation addresses the simultaneous effects of heat and mass transfer in the mixed convection peristaltic flow of viscous fluid in an asymmetric channel. The channel walls exhibit the convective boundary conditions. In addition, the effects due to Soret and Dufour are taken into consideration. Resulting problems are solved for the series solutions. Numerical values of heat and mass transfer rates are displayed and studied. Results indicate that the concentration and temperature of the fluid increase whereas the mass transfer rate at the wall decreases with increase of the mass transfer Biot number. Furthermore, it is observed that the temperature decreases with the increase of the heat transfer Biot number.
文摘This paper studies the control of a new chaotic system which can generate 4-scroll attractors. Based on the properties of a passive system, it derives the essential conditions under which this new chaotic system could be equivalent to a passive system and globally asymptotically stabilize at a zero equilibrium point via smooth state feedback. Simulation results and circuit experiment show that the proposed chaos control method is effective.
基金The project supported by National Natural Science Foundation of China under Grant No. 90403019 Acknowledgments We would like to thank Prof. Kang-Jie Shi for many stimulating discussions. Xie is also grateful to Zhan-Yun Wang, Xiao-Lin Cai, Pei Song, and Jun Feng for their helpful discussions, and especially A-Ping Yang's encouragements.
文摘In this paper, we show that there exists a twisted duality symmetry between the Maurer-Cartan equations and the equations of motion in the hybrid formalism for the type liB superstring in an AdS2 ×S2 background with Ramond-Ramond flux. As a result, from the twisted duality transformation, we construct the Lax connection with the spectral parameter, which ensures the integrability of the system.
基金supported by National Natural Science Foundation of China(Grant Nos.1127130211161007 and 11401486)+1 种基金the Ph.D.Program of Higher Education Research Fund(Grant No.2012182110020)Guizhou Foundation for Science and Technology(Grant No.LKS[2011]6)
文摘We first investigate the translative containment measure for convex domain K0 to contain, or to be contained in, the homothetic copy of another convex domain K1, i.e., given two convex domains K0, K1 of areas A0, A1, respectively, in the Euclidean plane R2, is there a translation T so that t(T K1) K0 or t(T K1) ? K0 for t > 0? Via the translative kinematic formulas of Poincar′e and Blaschke in integral geometry,we estimate the symmetric mixed isohomothetic deficit σ2(K0, K1) ≡ A201- A0A1, where A01 is the mixed area of K0 and K1. We obtain a sufficient condition for K0 to contain, or to be contained in, t(T K1). We obtain some Bonnesen-style symmetric mixed isohomothetic inequalities and reverse Bonnesen-style symmetric mixed isohomothetic inequalities. These symmetric mixed isohomothetic inequalities obtained are known as Bonnesen-style isopermetric inequalities and reverse Bonnesen-style isopermetric inequalities if one of domains is a disc. As direct consequences, we obtain some inequalities that strengthen the known Minkowski inequality for mixed areas and the Bonnesen-Blaschke-Flanders inequality.
基金supported by the National Natural Science Foundation of China(Grant Nos.51306180 and 51406203)
文摘Swirl-premixed combustion systems exhibit potential to meet future regulations on pollution emissions. However, combustion induced vortex breakdown(CIVB) flashback is frequently observed in these systems, especially for high hydrogen content fuel. In this study, a swirl-premixed burner with diverging centerbody was used to investigate CIVB flashback based on azimuthal vorticity at mixing zone exit. Through 2D axisymmetric model, it was found that there was a maximal azimuthal vorticity at mixing zone exit for each equivalence ratio. The physical meaning of these maximal azimuthal vorticity values was the minimally required azimuthal vorticity to trigger CIVB flashback. At the same time, the required azimuthal vorticity declined with the increase of equivalence ratio since turbulent burning velocity started to control flashback. Nevertheless, azimuthal vorticity offered by heat release increased with the increase of equivalence ratio, which promoted flame propagating upstream continually.
文摘In this paper,we investigate group-invariant solutions to the hyperbolic geometric flow on Riemann surfaces,which include solutions of separation variables,traveling wave solutions,self-similar solutions and radial solutions.In the proceeding of reduction,there are elliptic,hyperbolic and mixed types of equations.For the first kind of equation,some exact solutions are found;while for the last two kinds,with implicit solutions found,we furthermore investigate whether there will be a global solution or blowing up.Referring to the work of Kong et al.(2009),the results come out perfectly.
基金supported by National Natural Science Foundation of China(Grant Nos.11271035,91430213 and 11421101)
文摘A family of stable mixed finite elements for the linear elasticity on tetrahedral grids are constructed,where the stress is approximated by symmetric H(div)-Pk polynomial tensors and the displacement is approximated by C-1-Pk-1polynomial vectors,for all k 4.The main ingredients for the analysis are a new basis of the space of symmetric matrices,an intrinsic H(div)bubble function space on each element,and a new technique for establishing the discrete inf-sup condition.In particular,they enable us to prove that the divergence space of the H(div)bubble function space is identical to the orthogonal complement space of the rigid motion space with respect to the vector-valued Pk-1polynomial space on each tetrahedron.The optimal error estimate is proved,verified by numerical examples.
基金supported by National Natural Science Foundation of China (Grant Nos.11271280 and 10831002)
文摘Orthogonal arrays (OAs), mixed level or fixed level (asymmetric or symmetric), are useful in the design of various experiments. They are also a fundamental tool in the construction of various combinatorial configurations. In this paper, we establish a general "expansive replacement method" for constructing mixedlevel OAs of an arbitrary strength. As a consequence, a positive answer to the question about orthogonal arrays posed by Hedayat, Sloane and Stufken is given. Some series of mixed level OAs of strength ≥3 are produced.
基金support from the Photonics and Mathematical Optics Group at Tecnologico de Monterrey and Consorcio enóptica Aplicada through CONACYT FORDECYT#290259 project grantsupport from Henes Center for Quantum Phenomena,Michigan Technological Universitysupport from Spanish MINECO projects FIS2014-57387-C3-3P and DPI2013-47100-C2-1-P
文摘Group theory(GT) provides a rigorous framework for studying symmetries in various disciplines in physics ranging from quantum field theories and the standard model to fluid mechanics and chaos theory. To date, the application of such a powerful tool in optical physics remains limited. Over the past few years however, several quantum-inspired symmetry principles(such as parity-time invariance and supersymmetry) have been introduced in optics and photonics for the first time. Despite the intense activities in these new research directions, only few works utilized the power of group theory. Motivated by this status quo, here we present a brief overview of the application of GT in optics, deliberately choosing examples that illustrate the power of this tool in both continuous and discrete setups. We hope that this review will stimulate further research that exploits the full potential of GT for investigating various symmetry paradigms in optics, eventually leading to new photonic devices.