Based on the ABCD matrix formalism,the propagation property of an Airy beam from right-handed material（RHM） to left-handed material（LHM） is investigated.The result shows that when the Airy beam propagates in the L...Based on the ABCD matrix formalism,the propagation property of an Airy beam from right-handed material（RHM） to left-handed material（LHM） is investigated.The result shows that when the Airy beam propagates in the LHM,the intensity self-bending due to its propagation in the RHM can be compensated.In particular,if the propagation distance in the RHM is equal to that in the LHM and the refractive index of the LHM is n L =-1,the transverse intensity distribution of the Airy beam can return to its original state.展开更多
The epitaxial material, device structure, and corresponding equivalent large signal circuit model of GaAs planar Schottky varactor diode are successfully developed to design and fabricate a monolithic phase shifter, w...The epitaxial material, device structure, and corresponding equivalent large signal circuit model of GaAs planar Schottky varactor diode are successfully developed to design and fabricate a monolithic phase shifter, which is based on right-handed nonlinear transmission lines and consists of a coplanar waveguide transmission line and periodically distributed GaAs planar Schottky varactor diode. The distributed-Schottky transmission-line-type phase shifter at a bias voltage greater than 1.5 V presents a continuous 0°–360° differential phase shift over a frequency range from 0 to 33 GHz. It is demonstrated that the minimum insertion loss is about 0.5 dB and that the return loss is less than-10 dB over the frequency band of 0–33 GHz at a reverse bias voltage less than 4.5 V. These excellent characteristics, such as broad differential phase shift, low insertion loss, and return loss, indicate that the proposed phase shifter can entirely be integrated into a phased array radar circuit.展开更多
Updated measurements from the LHCb and SHoES collaborations have respectively strengthened the de-viations of the ratio R_(K)in rare semi-leptonic B-meson decays and the present-day Hubble parameter H_(0)in the Uni-ve...Updated measurements from the LHCb and SHoES collaborations have respectively strengthened the de-viations of the ratio R_(K)in rare semi-leptonic B-meson decays and the present-day Hubble parameter H_(0)in the Uni-verse,implying tantalizing hints of new physics beyond the standard model.In this paper,we consider a simple fla-vor-specific two-Higgs-doublet model,where long-standing R_(K(*))anomalies can be addressed by a one-flavor right-handed neutrino.An intriguing prediction resulting from the parameter space for the R_(K(*))resolution under flavor and clliderphysics constraints points toward a shift in the efective neutrino number,ON_(eff)=N_(eff)-N_(eff)^(SM),as a-favored way to ease the H_(0)tension.Depending on whether the neutrino is of the Dirac or Majorana type,we show that the resulting shift is △N_(eff)■1.0 for the former case and △N_(eff)■0.5 for the latter case.While the Dirac case is disfavored by the CMB polarization measurements,the Majorana solution is consistent with recent studies using a combined dataset from various sources.Consequently,such a simple flavor-specific two-Higgs-doublet model provides a link between R_(K(*)) anomalies and H_(0) tension,which in turn can be readily verified or disproved by up-comingmeasurements.展开更多
Numerical methods for Differential-Algebraic systems with discontinuous right-hand sides is discussed. A class of continuous Rosenbrock methods are constructed, and numerical experiments show that the continuous Rosen...Numerical methods for Differential-Algebraic systems with discontinuous right-hand sides is discussed. A class of continuous Rosenbrock methods are constructed, and numerical experiments show that the continuous Rosenbrock methods are effective. Applying the methods, a fast and high-precision numerical algorithm is given to deal with typical discontinuous parts, which occur frequently in differential-algebraic systems(DAS).展开更多
In this paper a comprehensive framework for treating the nonlinear propagation of ultrashort pulse in metamaterial with dispersive dielectric susceptibility and magnetic permeability is presented. Under the slowly-evo...In this paper a comprehensive framework for treating the nonlinear propagation of ultrashort pulse in metamaterial with dispersive dielectric susceptibility and magnetic permeability is presented. Under the slowly-evolving-wave approximation, a generalized （3＋1）-dimensional wave equation first order in the propagation coordinate and suitable for both right-handed material （I^HM） and left-handed material （LHM） is derived. By the commonly used Drude dispersive model for LHM, a （3＋1）-dimensional nonlinear Schrodinger equation describing ultrashort pulsed beam propagation in LHM is obtained, and its difference from that for conventional RHM is discussed. Particularly, the self-steeping effect of ultrashort pulse is found to be anomalous in LHM.展开更多
A copper（Ⅱ） coordination polymer, [Cu3（HOA）2（bpp）4]n （1, HnOA = 3,3＇,4,4＇- oxidiphthalic acid, bpp = 1,3-bis（4-pyridyl） propane）, has been hydrothermally synthesized. The crystal structure is of monoclini...A copper（Ⅱ） coordination polymer, [Cu3（HOA）2（bpp）4]n （1, HnOA = 3,3＇,4,4＇- oxidiphthalic acid, bpp = 1,3-bis（4-pyridyl） propane）, has been hydrothermally synthesized. The crystal structure is of monoclinic, space group P21/c with a = 11.544（3）, b = 16.129（4）, c = 21.181 （6） A, β = 98.848（5）, V= 3897.0（2） A3, C84018N8H70Cu3, Mr = 1670.13, Z = 2, De = 1.423 g/cm^3, F（000） = 1722, μ = 0.887 mm^-1, R = 0.0878 and wR = 0.2583 for 8496 observed reflections （I 〉 2σ（I））. Single-crystal X-ray structural analysis reveals that 1 is a three-dimensional （3D） framework based on a two-dimensional （2D） mesomeric layer of alternating left- and fight-handed helical chains. The monodentate terminal and bidentate bridging bpp ligands in the same conformation are all encapsulated in the figure-of-eight-shaped channels, thus further stabilizing the whole three-dimensional framework.展开更多
Three-layer slab waveguide with left-handed materials （LHM） is discussed using the Maxwell＇s equations and their equations of dispersion relation for TM modes are obtained. By seeking the power of the slab waveguid...Three-layer slab waveguide with left-handed materials （LHM） is discussed using the Maxwell＇s equations and their equations of dispersion relation for TM modes are obtained. By seeking the power of the slab waveguide, their equations of effective thickness for TM modes are obtained. Furthermore, the interrelated equations for right-handed materials （RHM） slab waveguide are introduced and their curves plotted. To find new properties for LHM slab waveguide, the equations and their curves for the LHM and RHM slab waveguide are compared respectively.展开更多
Based on two versions of Maxwell’s Equations we investigate the Poynting vector, the energy transport and the dispersion relation both for right- and left-handed systems. Furthermore, it is shown that the latter syst...Based on two versions of Maxwell’s Equations we investigate the Poynting vector, the energy transport and the dispersion relation both for right- and left-handed systems. Furthermore, it is shown that the latter systems are necessarily dispersive in contrast to the former ones. In the end we discuss a published example where the mixing of expressions of both versions of Maxwell’s Equations leads to unphysical conclusions. The presentation demonstrates for students how flexible can be the work with different versions of electrodynamics but also how carefully one has to be thereby.展开更多
This paper examines the properties of wave propagation in transmission lines with periodic LC and CL cells, taking into account ohmic losses in resistors connected in series to lumped capacitors and inductors. First o...This paper examines the properties of wave propagation in transmission lines with periodic LC and CL cells, taking into account ohmic losses in resistors connected in series to lumped capacitors and inductors. First order time differential equations are derived for current and charge, thus allowing analysis of transient regimes of the lines being excited by a pulse of arbitrary shape. In particular we examine the propagation characteristics of periodic lines in which identical unit cells are repeated periodically and also discuss the interpretation of positive and negative phase velocities associated with the LC and CL topologies. Loss effects on the propagation bandwidths of both lines are also discussed, and it is shown that in the left-handed transmission line (CL configuration) the phase advance of the crest of the transmitted signal with respect to the source signal is due to the intrinsic dispersive nature of the CL line which, in contrast to the LC line, is highly dispersive at low propagation factors.展开更多
The symmetric linear system gives us many simplifications and a possibility to adapt the computations to the computer at hand in order to achieve better performance. The aim of this paper is to consider the block bidi...The symmetric linear system gives us many simplifications and a possibility to adapt the computations to the computer at hand in order to achieve better performance. The aim of this paper is to consider the block bidiagonalization methods derived from a symmetric augmented multiple linear systems and make a comparison with the block GMRES and block biconjugate gradient methods.展开更多
In this paper, we show that circular polarization-keeping reflection can be achieved using reflective metasurfaces. The underlying physical mechanism of the polarization-keeping reflection is analyzed using a reflecti...In this paper, we show that circular polarization-keeping reflection can be achieved using reflective metasurfaces. The underlying physical mechanism of the polarization-keeping reflection is analyzed using a reflection matrix. A wideband circular polarization-keeping reflector is demonstrated using N-shaped resonators. Both the simulation and experiment results show that the polarization-keeping reflection can be achieved with a high efficiency larger than 98% over the frequency range from 9.2 GHz to 17.7 GHz for both incident left- and right-handed circularly polarized waves. Under oblique incidence, the bandwidth increases as the incident angle varies from 0°to 80°. Moreover, the co-polarization reflection is independent of the incident azimuth angles.展开更多
In order to solve fuzzy mathematical programming with soft constraints,the initial models must first be converted into crisp models.Membership functions are employed to describe the fuzzy right-hand side parameters ne...In order to solve fuzzy mathematical programming with soft constraints,the initial models must first be converted into crisp models.Membership functions are employed to describe the fuzzy right-hand side parameters needed to achieve this conversion.In some cases,echelon form membership functions(EFMFs)are required to depict the actual fuzzy situation.However,due to their discrete properties,fuzzy programming problems with such membership functions cannot be modeled by traditional methods.Motivated by these challenges,this paper introduces a novel absolute value representation modeling approach to formulate fuzzy programming using EFMFs.This approach can translate a discrete model to a continuous one which can then be easily solved.Finally,by means of a numerical example,the effectiveness of our new approach is demonstrated.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 60977068,61178015 and 11102100)the Youth Foundation of Sanming University,China (Grant No. B201008/Q)
文摘Based on the ABCD matrix formalism,the propagation property of an Airy beam from right-handed material（RHM） to left-handed material（LHM） is investigated.The result shows that when the Airy beam propagates in the LHM,the intensity self-bending due to its propagation in the RHM can be compensated.In particular,if the propagation distance in the RHM is equal to that in the LHM and the refractive index of the LHM is n L =-1,the transverse intensity distribution of the Airy beam can return to its original state.
基金Project supported by the Fundamental Research Funds for Central Universities,China(Grant No.XDJK2013B004)the Research Fund for the Doctoral Program of Southwest University,China(Grant No.SWU111030)the State Key Laboratory for Millimeter Waves of Southeast University,China(Grant No.K201312)
文摘The epitaxial material, device structure, and corresponding equivalent large signal circuit model of GaAs planar Schottky varactor diode are successfully developed to design and fabricate a monolithic phase shifter, which is based on right-handed nonlinear transmission lines and consists of a coplanar waveguide transmission line and periodically distributed GaAs planar Schottky varactor diode. The distributed-Schottky transmission-line-type phase shifter at a bias voltage greater than 1.5 V presents a continuous 0°–360° differential phase shift over a frequency range from 0 to 33 GHz. It is demonstrated that the minimum insertion loss is about 0.5 dB and that the return loss is less than-10 dB over the frequency band of 0–33 GHz at a reverse bias voltage less than 4.5 V. These excellent characteristics, such as broad differential phase shift, low insertion loss, and return loss, indicate that the proposed phase shifter can entirely be integrated into a phased array radar circuit.
基金Supported by the National Natural Science Foundation of China(12135006,12075097,11675061,11775092)the Fundamental Research Funds for the Central Universities(CCNU20TS007,CCNU19TD012,CCNU22LJ004)。
文摘Updated measurements from the LHCb and SHoES collaborations have respectively strengthened the de-viations of the ratio R_(K)in rare semi-leptonic B-meson decays and the present-day Hubble parameter H_(0)in the Uni-verse,implying tantalizing hints of new physics beyond the standard model.In this paper,we consider a simple fla-vor-specific two-Higgs-doublet model,where long-standing R_(K(*))anomalies can be addressed by a one-flavor right-handed neutrino.An intriguing prediction resulting from the parameter space for the R_(K(*))resolution under flavor and clliderphysics constraints points toward a shift in the efective neutrino number,ON_(eff)=N_(eff)-N_(eff)^(SM),as a-favored way to ease the H_(0)tension.Depending on whether the neutrino is of the Dirac or Majorana type,we show that the resulting shift is △N_(eff)■1.0 for the former case and △N_(eff)■0.5 for the latter case.While the Dirac case is disfavored by the CMB polarization measurements,the Majorana solution is consistent with recent studies using a combined dataset from various sources.Consequently,such a simple flavor-specific two-Higgs-doublet model provides a link between R_(K(*)) anomalies and H_(0) tension,which in turn can be readily verified or disproved by up-comingmeasurements.
文摘Numerical methods for Differential-Algebraic systems with discontinuous right-hand sides is discussed. A class of continuous Rosenbrock methods are constructed, and numerical experiments show that the continuous Rosenbrock methods are effective. Applying the methods, a fast and high-precision numerical algorithm is given to deal with typical discontinuous parts, which occur frequently in differential-algebraic systems(DAS).
基金Supported by the National Natural Science Foundation of China （Grant Nos 10576012 and 60538010）, the Program for New Century Excellent Talents in University and the Specialized Research Fund for the Doctoral Program of Higher Education of China （Grant No 20040532005）.
文摘In this paper a comprehensive framework for treating the nonlinear propagation of ultrashort pulse in metamaterial with dispersive dielectric susceptibility and magnetic permeability is presented. Under the slowly-evolving-wave approximation, a generalized （3＋1）-dimensional wave equation first order in the propagation coordinate and suitable for both right-handed material （I^HM） and left-handed material （LHM） is derived. By the commonly used Drude dispersive model for LHM, a （3＋1）-dimensional nonlinear Schrodinger equation describing ultrashort pulsed beam propagation in LHM is obtained, and its difference from that for conventional RHM is discussed. Particularly, the self-steeping effect of ultrashort pulse is found to be anomalous in LHM.
基金Supported by the 973 program of China (Grants 2007CB815302, 2009CB939803)the Chinese Academy of Sciences (Grants KJCX2.YW.319 and KJCX2.YW.M10)+2 种基金Natural Science Foundation of Fujian Province (2009J05041)the Knowledge Innovation Program of the Chinese Academy of Sciences the Fund of Fujian Key Laboratory of Nanomaterials (2006L2005)
文摘A copper（Ⅱ） coordination polymer, [Cu3（HOA）2（bpp）4]n （1, HnOA = 3,3＇,4,4＇- oxidiphthalic acid, bpp = 1,3-bis（4-pyridyl） propane）, has been hydrothermally synthesized. The crystal structure is of monoclinic, space group P21/c with a = 11.544（3）, b = 16.129（4）, c = 21.181 （6） A, β = 98.848（5）, V= 3897.0（2） A3, C84018N8H70Cu3, Mr = 1670.13, Z = 2, De = 1.423 g/cm^3, F（000） = 1722, μ = 0.887 mm^-1, R = 0.0878 and wR = 0.2583 for 8496 observed reflections （I 〉 2σ（I））. Single-crystal X-ray structural analysis reveals that 1 is a three-dimensional （3D） framework based on a two-dimensional （2D） mesomeric layer of alternating left- and fight-handed helical chains. The monodentate terminal and bidentate bridging bpp ligands in the same conformation are all encapsulated in the figure-of-eight-shaped channels, thus further stabilizing the whole three-dimensional framework.
基金Project supported by the Shanghai Leading Academic Discipline Project (Grant No.T0102)
文摘Three-layer slab waveguide with left-handed materials （LHM） is discussed using the Maxwell＇s equations and their equations of dispersion relation for TM modes are obtained. By seeking the power of the slab waveguide, their equations of effective thickness for TM modes are obtained. Furthermore, the interrelated equations for right-handed materials （RHM） slab waveguide are introduced and their curves plotted. To find new properties for LHM slab waveguide, the equations and their curves for the LHM and RHM slab waveguide are compared respectively.
文摘Based on two versions of Maxwell’s Equations we investigate the Poynting vector, the energy transport and the dispersion relation both for right- and left-handed systems. Furthermore, it is shown that the latter systems are necessarily dispersive in contrast to the former ones. In the end we discuss a published example where the mixing of expressions of both versions of Maxwell’s Equations leads to unphysical conclusions. The presentation demonstrates for students how flexible can be the work with different versions of electrodynamics but also how carefully one has to be thereby.
基金the Coordination for the Improvement of Higher Level Personnel(CAPES/Brazil)for financial support.
文摘This paper examines the properties of wave propagation in transmission lines with periodic LC and CL cells, taking into account ohmic losses in resistors connected in series to lumped capacitors and inductors. First order time differential equations are derived for current and charge, thus allowing analysis of transient regimes of the lines being excited by a pulse of arbitrary shape. In particular we examine the propagation characteristics of periodic lines in which identical unit cells are repeated periodically and also discuss the interpretation of positive and negative phase velocities associated with the LC and CL topologies. Loss effects on the propagation bandwidths of both lines are also discussed, and it is shown that in the left-handed transmission line (CL configuration) the phase advance of the crest of the transmitted signal with respect to the source signal is due to the intrinsic dispersive nature of the CL line which, in contrast to the LC line, is highly dispersive at low propagation factors.
基金The research of this author was supported by the National Natural Science Foundation of China,the JiangsuProvince Natural Science Foundation,the Jiangsu Province"333Engineering" Foundation and the Jiangsu Province"Qinglan Engineering" Foundation
文摘The symmetric linear system gives us many simplifications and a possibility to adapt the computations to the computer at hand in order to achieve better performance. The aim of this paper is to consider the block bidiagonalization methods derived from a symmetric augmented multiple linear systems and make a comparison with the block GMRES and block biconjugate gradient methods.
基金Project supported by the National Natural Science Foundation of China(Grants Nos.61331005,11204378,11274389,11304393,and 61302023)the National Natural Science Foundation of Shaanxi Province,China(Grant Nos.2011JQ8031 and 2013JM6005)
文摘In this paper, we show that circular polarization-keeping reflection can be achieved using reflective metasurfaces. The underlying physical mechanism of the polarization-keeping reflection is analyzed using a reflection matrix. A wideband circular polarization-keeping reflector is demonstrated using N-shaped resonators. Both the simulation and experiment results show that the polarization-keeping reflection can be achieved with a high efficiency larger than 98% over the frequency range from 9.2 GHz to 17.7 GHz for both incident left- and right-handed circularly polarized waves. Under oblique incidence, the bandwidth increases as the incident angle varies from 0°to 80°. Moreover, the co-polarization reflection is independent of the incident azimuth angles.
文摘In order to solve fuzzy mathematical programming with soft constraints,the initial models must first be converted into crisp models.Membership functions are employed to describe the fuzzy right-hand side parameters needed to achieve this conversion.In some cases,echelon form membership functions(EFMFs)are required to depict the actual fuzzy situation.However,due to their discrete properties,fuzzy programming problems with such membership functions cannot be modeled by traditional methods.Motivated by these challenges,this paper introduces a novel absolute value representation modeling approach to formulate fuzzy programming using EFMFs.This approach can translate a discrete model to a continuous one which can then be easily solved.Finally,by means of a numerical example,the effectiveness of our new approach is demonstrated.
