In microwave communication systems,focusing and imaging have attracted widespread attention due to their application prospects in the information processing and communication fields.Most existing multi-channel focusin...In microwave communication systems,focusing and imaging have attracted widespread attention due to their application prospects in the information processing and communication fields.Most existing multi-channel focusing and imaging are implemented by interleaved metasurfaces.However,the disadvantages of their large size and low efficiency limit their practical applications in large-capacity and low-loss integrated systems.To solve these issues,here,we propose a non-interleaved polarization-frequency multiplexing metasurface for high-efficiency multi-channel focusing and imaging.The meta-atoms of the non-interleaved metasurface are composed of a metallic ground plate,two dielectric layers,a larger cross-shaped metal structure,and a smaller cross-shaped metal structure embedded by a circular metal aperture.By altering the size of two cross-shaped structures,the designed meta-atom can obtain the independent complete 2π phase coverage with high reflection efficiency at two different frequency ranges for two orthogonal linear polarization(LP)incidences,realizing polarization multiplexing and frequency multiplexing.Moreover,two types of metasurfaces based on the above meta-atoms are designed to realize multi-channel focusing and imaging with high efficiency.As a proof,the focusing metasurface is fabricated and measured,and the measured results are well consistent with simulated results.Therefore,the proposed scheme has the advantages of high efficiency,multi-channel,and compact size,which possesses broad application prospects in low-loss and multichannel communication integrated systems.展开更多
The multidimensional dynamic manipulation of spoof surface waves(SSWs)is crucial for terahertz(THz)on-chip integrated systems.However,existing metasurfaces are limited to passive,single-function wavefront shaping of S...The multidimensional dynamic manipulation of spoof surface waves(SSWs)is crucial for terahertz(THz)on-chip integrated systems.However,existing metasurfaces are limited to passive,single-function wavefront shaping of SSWs,which precludes on-chip multidimensional dynamic control and hinders their practical applications.To address these limitations,we propose a polarization multiplexing THz graphene metasurface.展开更多
A compatible left-symmetric algebra is a pair of left-symmetric algebras satisfying that any linear combination of the two left-symmetric products is a left-symmetric product.We construct a bialgebra theory of compati...A compatible left-symmetric algebra is a pair of left-symmetric algebras satisfying that any linear combination of the two left-symmetric products is a left-symmetric product.We construct a bialgebra theory of compatible left-symmetric algebras as an analogue of a Lie bialgebra.They can also be regarded as a"compatible version"of leftsymmetric bialgebras,that is,a pair of left-symmetric bialgebras satisfying that any linear combination of the two left-symmetric bialgebras is still a left-symmetric bialgebra.Many properties of compatible left-symmetric bialgebras as the"compatible version"of the corresponding properties of left-symmetric bialgebras are presented.In particular,there is a coboundary compatible left-symmetric bialgebra theory and an S-equation,which is an analogue of the classical Yang-Baxter equations in Lie algebras.展开更多
Nanomagnets are widely used to store information in non-volatile spintronic devices.Spin waves can transfer information with low-power consumption as their propagations are independent of charge transport.However,to d...Nanomagnets are widely used to store information in non-volatile spintronic devices.Spin waves can transfer information with low-power consumption as their propagations are independent of charge transport.However,to dynamically couple two distant nanomagnets via spin waves remains a major challenge for magnonics.Here we experimentally demonstrate coherent coupling of two distant Co nanowires by fast propagating spin waves in an yttrium iron garnet thin film with sub-50 nm wavelengths.Magnons in two nanomagnets are unidirectionally phase-locked with phase shifts controlled by magnon spin torque and spin-wave propagation.The coupled system is finally formulated by an analytical theory in terms of an effective non-Hermitian Hamiltonian.Our results are attractive for analog neuromorphic computing that requires unidirectional information transmission.展开更多
A compatible associative algebra is a pair of associative algebras satisfying that any linear combination of the two associative products is still an associative product.We construet a compatible associative algebra w...A compatible associative algebra is a pair of associative algebras satisfying that any linear combination of the two associative products is still an associative product.We construet a compatible associative algebra with a decomposition into the direct sum of the underlying vector space of another compatible associative algebra and its dual space such that both of them are subalgebras and the natural symmetrie bilinear form is invariant.This compatible associative algebra is equivalent to a certain bialgebra structure of compatible associative algebras,which is an analogue of a Lie bialgebra.Many properties of the bialgebra are presented.In particular,the coboundary bialgebra theory leads to the system of associative Yang-Bax ter equations in compatible associative algebras,which is an analogue of the classical Yang Baxter equation in a Lie algebra.Furthermore,the bialgebra can also be regarded as a“compatible version”of antisymmetric infinitesimal bialgebras,that is,a pair of antisymmetrie infinitesimal bialgebras satisfying any linear combination of them is still an antisymmetrie infinitesimal bialgebra.展开更多
To match nature’s prowess at using enzymes to make desired motifs in a regioselective fashion,we explore the use of visible light for the selective oxidation of the hydroxyl group to afford the corresponding ketosacc...To match nature’s prowess at using enzymes to make desired motifs in a regioselective fashion,we explore the use of visible light for the selective oxidation of the hydroxyl group to afford the corresponding ketosaccharide.This highly admirable approach offers several advantages over the enzymatic approach in terms of yields and the scope of substrates.Herein,we report the development of a simple visiblelight-promoted selective oxidation of unprotected glucosides that allows for inexpensive access to valuable keto-saccharide building blocks.The method is employed on a variety of different natural and artificial glucosides,is operationally simple and scalable,and can be used to access keto-saccharides rapidly and inexpensively.展开更多
We discuss a class of filiform Lie superalgebras Ln,m. From these Lie superalgebras, all the other filiform Lie superalgebras can be obtained by deformations. We have decompositions of Der0（Ln,m） and Dery（Ln,m）. B...We discuss a class of filiform Lie superalgebras Ln,m. From these Lie superalgebras, all the other filiform Lie superalgebras can be obtained by deformations. We have decompositions of Der0（Ln,m） and Dery（Ln,m）. By computing a maximal torus on each Ln,m, we show that Ln,m are completable nilpotent Lie superalgebras. We also view Ln,m as Lie algebras, prove that Ln,m are of maximal rank, and show that Ln,m are completable nilpotent Lie algebras. As an application of the results, we show a Heisenberg superalgebra is a completable nilpotent Lie superalgebra.展开更多
基金National Natural Science Foundation of China(62075052,6227419)National Key Research and Development Program of China(2024YFE0108300)+2 种基金Science and Technology Major Project of Guangxi,China(Gui Ke AA21077015,Gui Ke AA24263032)Science Foundation of the National Key Laboratory of Science and Technology on Advanced Composites in Special Environments(JCKYS2020603C009,6142905212711)Project of Innovative and Entrepreneurship Training Program for College Students in Heilongjiang Province(201810214105)。
文摘In microwave communication systems,focusing and imaging have attracted widespread attention due to their application prospects in the information processing and communication fields.Most existing multi-channel focusing and imaging are implemented by interleaved metasurfaces.However,the disadvantages of their large size and low efficiency limit their practical applications in large-capacity and low-loss integrated systems.To solve these issues,here,we propose a non-interleaved polarization-frequency multiplexing metasurface for high-efficiency multi-channel focusing and imaging.The meta-atoms of the non-interleaved metasurface are composed of a metallic ground plate,two dielectric layers,a larger cross-shaped metal structure,and a smaller cross-shaped metal structure embedded by a circular metal aperture.By altering the size of two cross-shaped structures,the designed meta-atom can obtain the independent complete 2π phase coverage with high reflection efficiency at two different frequency ranges for two orthogonal linear polarization(LP)incidences,realizing polarization multiplexing and frequency multiplexing.Moreover,two types of metasurfaces based on the above meta-atoms are designed to realize multi-channel focusing and imaging with high efficiency.As a proof,the focusing metasurface is fabricated and measured,and the measured results are well consistent with simulated results.Therefore,the proposed scheme has the advantages of high efficiency,multi-channel,and compact size,which possesses broad application prospects in low-loss and multichannel communication integrated systems.
基金National Key Research and Development Program of China(2024YFE0108300,2023YFB3210400)Science and Technology Major Projects of Guangxi(Gui Ke AA24263032,Gui Ke AA21077015)+3 种基金Open Fund Project of Key Laboratory of Integrated Circuits and Microsystems in Guangxi Universities(ICM-25-02)National Natural Science Foundation of China(62075052,6227419)Science Foundation of the National Key Laboratory of Science and Technology on Advanced Composites in Special Environments(JCKYS2020603C009,6142905212711)Project of Innovative and Entrepreneurship Training Program for College Students in Heilongjiang Province(201810214105)。
文摘The multidimensional dynamic manipulation of spoof surface waves(SSWs)is crucial for terahertz(THz)on-chip integrated systems.However,existing metasurfaces are limited to passive,single-function wavefront shaping of SSWs,which precludes on-chip multidimensional dynamic control and hinders their practical applications.To address these limitations,we propose a polarization multiplexing THz graphene metasurface.
基金Supported by the Meritocracy Research Funds of China West Normal University and the Fundamental Research Funds of China West Normal University(17C048,17YC392)by Scientific Research Fund of Sichuan Provincial Education Department(17AZ0378).
文摘A compatible left-symmetric algebra is a pair of left-symmetric algebras satisfying that any linear combination of the two left-symmetric products is a left-symmetric product.We construct a bialgebra theory of compatible left-symmetric algebras as an analogue of a Lie bialgebra.They can also be regarded as a"compatible version"of leftsymmetric bialgebras,that is,a pair of left-symmetric bialgebras satisfying that any linear combination of the two left-symmetric bialgebras is still a left-symmetric bialgebra.Many properties of compatible left-symmetric bialgebras as the"compatible version"of the corresponding properties of left-symmetric bialgebras are presented.In particular,there is a coboundary compatible left-symmetric bialgebra theory and an S-equation,which is an analogue of the classical Yang-Baxter equations in Lie algebras.
基金We wish to acknowledge the support by the National Key Research and Development Program of China(Nos.2016YFA0300802 and 2017YFA0206200)the National Natural Science Foundation of China(NSFC)(Nos.11674020,12074026 and U1801661)+6 种基金the 111 talent program B16001G.B.was supported by the Netherlands Organization for Scientific Research(NWO)and Japan Society for the Promotion of Science Kakenhi Grants-in-Aid for Scientific Research(No.19H006450)T.Y.was funded through the Emmy Noether Program of Deutsche Forschungsgemeinschaft(SE 2558/2-1)K.X.thanks the National Key Research and Development Program of China(Nos.2017YFA0303304 and 2018YFB0407601)the National Natural Science Foundation of China(Nos.61774017 and 11734004)K.S.was supported by the Fundamental Research Funds for the Central Universities(No.2018EYT02)M.Z.W.were supported by the US National Science Foundation(No.EFMA-1641989).
文摘Nanomagnets are widely used to store information in non-volatile spintronic devices.Spin waves can transfer information with low-power consumption as their propagations are independent of charge transport.However,to dynamically couple two distant nanomagnets via spin waves remains a major challenge for magnonics.Here we experimentally demonstrate coherent coupling of two distant Co nanowires by fast propagating spin waves in an yttrium iron garnet thin film with sub-50 nm wavelengths.Magnons in two nanomagnets are unidirectionally phase-locked with phase shifts controlled by magnon spin torque and spin-wave propagation.The coupled system is finally formulated by an analytical theory in terms of an effective non-Hermitian Hamiltonian.Our results are attractive for analog neuromorphic computing that requires unidirectional information transmission.
文摘A compatible associative algebra is a pair of associative algebras satisfying that any linear combination of the two associative products is still an associative product.We construet a compatible associative algebra with a decomposition into the direct sum of the underlying vector space of another compatible associative algebra and its dual space such that both of them are subalgebras and the natural symmetrie bilinear form is invariant.This compatible associative algebra is equivalent to a certain bialgebra structure of compatible associative algebras,which is an analogue of a Lie bialgebra.Many properties of the bialgebra are presented.In particular,the coboundary bialgebra theory leads to the system of associative Yang-Bax ter equations in compatible associative algebras,which is an analogue of the classical Yang Baxter equation in a Lie algebra.Furthermore,the bialgebra can also be regarded as a“compatible version”of antisymmetric infinitesimal bialgebras,that is,a pair of antisymmetrie infinitesimal bialgebras satisfying any linear combination of them is still an antisymmetrie infinitesimal bialgebra.
基金Financial support for this work was provided by the National Science Foundation of China(grant no.22071087)the Fundamental Research Funds for the Central Universities(grant no.lzujbky-2021-ct05)the Open Projects Funds of Shandong Key Laboratory of Carbohydrate Chemistry and Glycobiology,Shandong University(grant no.2019CCG05).X.W.also thanks the Thousand Young Talents Program and Longyuan Talents Program for financial support.
文摘To match nature’s prowess at using enzymes to make desired motifs in a regioselective fashion,we explore the use of visible light for the selective oxidation of the hydroxyl group to afford the corresponding ketosaccharide.This highly admirable approach offers several advantages over the enzymatic approach in terms of yields and the scope of substrates.Herein,we report the development of a simple visiblelight-promoted selective oxidation of unprotected glucosides that allows for inexpensive access to valuable keto-saccharide building blocks.The method is employed on a variety of different natural and artificial glucosides,is operationally simple and scalable,and can be used to access keto-saccharides rapidly and inexpensively.
文摘We discuss a class of filiform Lie superalgebras Ln,m. From these Lie superalgebras, all the other filiform Lie superalgebras can be obtained by deformations. We have decompositions of Der0（Ln,m） and Dery（Ln,m）. By computing a maximal torus on each Ln,m, we show that Ln,m are completable nilpotent Lie superalgebras. We also view Ln,m as Lie algebras, prove that Ln,m are of maximal rank, and show that Ln,m are completable nilpotent Lie algebras. As an application of the results, we show a Heisenberg superalgebra is a completable nilpotent Lie superalgebra.
