Three-way concept analysis is an important tool for information processing,and rule acquisition is one of the research hotspots of three-way concept analysis.However,compared with three-way concept lattices,three-way ...Three-way concept analysis is an important tool for information processing,and rule acquisition is one of the research hotspots of three-way concept analysis.However,compared with three-way concept lattices,three-way semi-concept lattices have three-way operators with weaker constraints,which can generate more concepts.In this article,the problem of rule acquisition for three-way semi-concept lattices is discussed in general.The authors construct the finer relation of three-way semi-concept lattices,and propose a method of rule acquisition for three-way semi-concept lattices.The authors also discuss the set of decision rules and the relationships of decision rules among object-induced three-way semi-concept lattices,object-induced three-way concept lattices,classical concept lattices and semi-concept lattices.Finally,examples are provided to illustrate the validity of our conclusions.展开更多
Sub-wavelength nanostructure lattices provide versatile platforms for light control and the basis for various novel phenomena and applications in physics, material science, chemistry, biology,and energy. The thriving ...Sub-wavelength nanostructure lattices provide versatile platforms for light control and the basis for various novel phenomena and applications in physics, material science, chemistry, biology,and energy. The thriving study of nanostructure lattices is building on the remarkable progress of nanofabrication techniques, especially for the possibility of fabricating larger-area patterns while achieving higher-quality lattices, complex shapes, and hybrid materials units. In this review, we present a comprehensive review of techniques for large-area fabrication of optical nanostructure arrays, encompassing direct writing, self-assembly, controllable deposition, and nanoimprint/print methods. Furthermore, a particular focus is made on the recent improvement of unit accuracy and diversity, leading to integrated and multifunctional structures for devices and applications.展开更多
Moirésuperlattices,a twisted functional structure crossing the periodic and nonperiodic potentials,have recently attracted great interest in multidisciplinary fields,including optics and ultracold atoms,because o...Moirésuperlattices,a twisted functional structure crossing the periodic and nonperiodic potentials,have recently attracted great interest in multidisciplinary fields,including optics and ultracold atoms,because of their unique band structures,physical properties,and potential implications.Driven by recent experiments on quantum phenomena of bosonic gases,the atomic Bose–Einstein condensates in moiréoptical lattices,by which other quantum gases such as ultracold fermionic atoms are trapped,could be readily achieved in ultracold atom laboratories,whereas the associated nonlinear localization mechanism remains unexploited.Here,we report the nonlinear localization theory of ultracold atomic Fermi gases in two-dimensional moiréoptical lattices.The linear Bloch-wave spectrum of such a twisted structure exhibits rich nontrivial flat bands,which are separated by different finite bandgaps wherein the existence,properties,and dynamics of localized superfluid Fermi gas structures of two types,gap solitons and gap vortices(topological modes)with vortex charge S¼1,are studied numerically.Our results demonstrate the wide stability regions and robustness of these localized structures,opening up a new avenue for studying soliton physics and moiréphysics in ultracold atoms beyond bosonic gases.展开更多
Materials with kagome lattices have attracted significant research attention due to their nontrivial features in energy bands.We theoretically investigate the evolution of electronic band structures of kagome lattices...Materials with kagome lattices have attracted significant research attention due to their nontrivial features in energy bands.We theoretically investigate the evolution of electronic band structures of kagome lattices in response to uniaxial strain using both a tight-binding model and an antidot model based on a periodic muffin-tin potential.It is found that the Dirac points move with applied strain.Furthermore,the flat band of unstrained kagome lattices is found to develop into a highly anisotropic shape under a stretching strain along y direction,forming a partially flat band with a region dispersionless along ky direction while dispersive along kx direction.Our results shed light on the possibility of engineering the electronic band structures of kagome materials by mechanical strain.展开更多
Recently,many encouraging experimental advances have been achieved in ternary hydrides superconductors under high pressure.However,the extreme pressure required is indeed a challenge for practical application,which pr...Recently,many encouraging experimental advances have been achieved in ternary hydrides superconductors under high pressure.However,the extreme pressure required is indeed a challenge for practical application,which promotes a further exploration for high temperature(T_(c))superconductors at relatively low pressure.Herein,we performed a systematic theoretical investigation on a series of ternary hydrides with stoichiometry AX_(2)H_(8),which is constructed by interacting molecular XH_(4)(X=B,C,and N)into the fcc metal A lattice under low pressure of 0-150 GPa.We uncovered five compounds which are dynamically stable below 100 GPa,e.g.,AcB_(2)H_(8)(25 GPa),LaB_(2)H_(8)(40 GPa),RbC_(2)H_(8)(40 GPa),CSC_(2)H_(8)(60 GPa),and SrC_(2)H_(8)(65 GPa).Among them,AcB_(2)H_(8),which is energetically stable above 2.5 GPa,exhibits the highest Tcof 32 K at 25 GPa.The superconductivity originates mainly from the coupling between the electron of Ac atoms and the associated low-frequency phonons,distinct from the previous typical hydrides with H-derived superconductivity.Our results shed light on the future exploration of superconductivity among ternary compounds at low pressure.展开更多
We first introduce several sphere packing ways such as simple cubic packing(SC),face-centered cubic packing(FCC),body-centered cubic packing(BCC),and rectangular body-centered cuboid packing(recBCC),where the rectangu...We first introduce several sphere packing ways such as simple cubic packing(SC),face-centered cubic packing(FCC),body-centered cubic packing(BCC),and rectangular body-centered cuboid packing(recBCC),where the rectangular body-centered cuboid packing means the packing method based on a rectangular cuboid whose base is square and whose height is times the length of one side of its square base such that the congruent spheres are centered at the 8 vertices and the centroid of the cuboid.The corresponding lattices are denoted as SCL,FCCL,BCCL,and recBCCL,respectively.Then we consider properties of those lattices,and show that FCCL and recBCCL are the same.Finally we point out some possible applications of the recBCC lattices.展开更多
Traditional structural forms are difficult to meet the lightweight requirements of subsequent spacecraft for load-bearing structures.In the aerospace industry,filling structure with lattices is a popular approach to r...Traditional structural forms are difficult to meet the lightweight requirements of subsequent spacecraft for load-bearing structures.In the aerospace industry,filling structure with lattices is a popular approach to reduce the weight of a spacecraft.However,this design strategy has deficiencies in the spatial distribution of lattice cells as well as its affection on the mechanical properties.In this study,a two-step topology optimization technique is proposed to solve the spatial distribution problem of nanosatellite.Firstly,an entire nanosatellite box composed of panels which filled with uniform lattices is sent to the vibration test to obtain the frequency data.Then,a finite element(FE)model of the nanosatellite structure which contains the same uniform lattices is built and validated with the obtained frequency data above.For the subsequent calculation of topology optimization.An equivalent model of the verified FE model is established by replacing the lattice cells in the sandwich layer with equivalent fictional elements.Subsequently,a topology optimization problem under the mass constraints is formulated for maximize the nature frequency,and a new light weighted nanosatellite which filled with non-uniform lattices is established by applying the density mapping method and the previous topology configuration result.By separating the design problem of nanosatellite into two steps,the proposed optimization design method achieves the maximum frequency design under the weight constraint.Furthermore,the frequency is also guaranteed to be around the nature frequency.The results reveal that the mass of the new structure with non-uniform lattices is reduced by 50.32%and the frequency is increased by 1.19%.An important technical importance and application value of this proposed technique is that it improves the performance and design efficiency of the load-bearing structures of a nanosatellite,and this method has significant technical significance and application value.展开更多
The design of three-dimensional printing based conformal cooling channels(CCCs)in injection molding holds great significance.Compared to CCCs,conformal cooling(CC)cavity solutions show promise in delivering enhanced c...The design of three-dimensional printing based conformal cooling channels(CCCs)in injection molding holds great significance.Compared to CCCs,conformal cooling(CC)cavity solutions show promise in delivering enhanced cooling performance for plastic products,although they have been underexplored.In this research,CC cavity is designed within the mold geometry,reinforced by body-centered cubic(BCC)lattice structures to enhance mechanical strength.Three distinct BCC lattice variations have been integrated into the CC cavity:the BCC structure,BCC with cubes,and BCC with pillars.The thermal performances of the BCC lattice-added CC cavity are assessed numerically after experimental validation.To provide feasible solutions from viewpoints of thermal performances,various BCC lattice structure thicknesses are analyzed in the range of 0.8–1.2mm.Thermal simulation outcomes reveal that thicker lattice structures enhance mechanical strength but simultaneously lead to an increase in cooling time.Upon examining all the proposed CC cavity solutions supported by BCC,the cooling times range from 2.2 to 4 s,resulting in a reduction of 38.6%to 66.1%when compared to conventional straightdrilled channels.In contrast to CCCs,CC cavities have the potential to decrease the maximum temperature nonuniformity from 8.5 to 6 K.Nevertheless,the presence of lattice structures in CC cavity solutions results in an elevated pressure drop,reaching 2.8MPa,whereas the results for CCCs remain below2.1MPa.展开更多
A discrete Hopf fibration of S15 over S8 with S7 (unit octonions) as fibers leads to a 16D Polytope P16 with 4320 vertices obtained from the convex hull of the 16D Barnes-Wall lattice Λ16. It is argued (conjectured) ...A discrete Hopf fibration of S15 over S8 with S7 (unit octonions) as fibers leads to a 16D Polytope P16 with 4320 vertices obtained from the convex hull of the 16D Barnes-Wall lattice Λ16. It is argued (conjectured) how a subsequent 2-1 mapping (projection) of P16 onto a 8D-hyperplane might furnish the 2160 vertices of the uniform 241 polytope in 8-dimensions, and such that one can capture the chain sequence of polytopes 241,231,221,211in D=8,7,6,5dimensions, leading, respectively, to the sequence of Coxeter groups E8,E7,E6,SO(10)which are putative GUT group candidates. An embedding of the E8⊕E8and E8⊕E8⊕E8lattice into the Barnes-Wall Λ16 and Leech Λ24 lattices, respectively, is explicitly shown. From the 16D lattice E8⊕E8one can generate two separate families of Elser-Sloane 4D quasicrystals (QC’s) with H4 (icosahedral) symmetry via the “cut-and-project” method from 8D to 4D in each separate E8 lattice. Therefore, one obtains in this fashion the Cartesian product of two Elser-Sloane QC’s Q×Qspanning an 8D space. Similarly, from the 24D lattice E8⊕E8⊕E8one can generate the Cartesian product of three Elser-Sloane 4D quasicrystals (QC’s) Q×Q×Qwith H4 symmetry and spanning a 12D space.展开更多
In this article, the authors mainly study how to obtain new semicontinuous lattices from the given semicontinuous lattices and discuss the conditions under which the image of a semicontinuous projection operator is al...In this article, the authors mainly study how to obtain new semicontinuous lattices from the given semicontinuous lattices and discuss the conditions under which the image of a semicontinuous projection operator is also semicontinuous. Moreover, the authors investigate the relation between semicontinuous lattices and completely distributive lattices. Finally, it is proved that the strongly semicontinuous lattice category is a Cartesian closed category.展开更多
3D printing-based supercapacitors have been extensively explored,yet the rigid rheological requirement for corresponding ink preparation significantly limits the manufacturing of true 3D architecture in achieving supe...3D printing-based supercapacitors have been extensively explored,yet the rigid rheological requirement for corresponding ink preparation significantly limits the manufacturing of true 3D architecture in achieving superior energy storage.We proposed the stereolithographic technique to fabricate the metallic composite lattices with octet-truss arrangement by using electroless plating and engineering the 3D hierarchically porous graphene onto the scaffolds to build the hierarchically cellular lattices in quasi-solid supercapacitor application.The supercapacitor device that is composed of composite lattices span several pore size orders from nm to mm holds promising behavior on the areal capacitance(57.75 mF cm-2),rate capability(70% retention,2-40 mA cm-2),and long lifespan(96% after 5000 cycles),as well as superior energy density of 0.008 mWh cm-2,which are comparable to the state-of-the-art carbon-based supercapacitor.By synergistically combining this facile stereolithographic 3D printing technology with the hierarchically porous graphene architecture,we provide a novel route of manufacturing energy storage device as well as new insight into building other high-performance functional electronics.展开更多
In this paper, cascading failure is studied by coupled map lattice （CML） methods in preferential attachment community networks. It is found that external perturbation R is increasing with modularity Q growing by sim...In this paper, cascading failure is studied by coupled map lattice （CML） methods in preferential attachment community networks. It is found that external perturbation R is increasing with modularity Q growing by simulation. In particular, the large modularity Q can hold off the cascading failure dynamic process in community networks. Furthermore, different attack strategies also greatly affect the cascading failure dynamic process. It is particularly significant to control cascading failure process in real community networks.展开更多
Identity-Based Proxy Re-Encryption (IB-PRE) allows a semi-trusted proxy to convert the ciphertext encrypted under Alice’s identity into Bob’s ciphertext of the same message without leaking plaintext. Lattice-based c...Identity-Based Proxy Re-Encryption (IB-PRE) allows a semi-trusted proxy to convert the ciphertext encrypted under Alice’s identity into Bob’s ciphertext of the same message without leaking plaintext. Lattice-based cryptography enjoys potential resistance to quantum analysis and low computational complexity. A multi-hop and unidirectional IB-PRE from lattices is presented. We split the functions of decryption and ciphertext transformation separately, and design the double private keys mechanism, where two keys are generated for each user, one key is used to decrypt the ciphertext by Pre-Image Sampling technique, and the other is used to generate the re-encryption key by Bonsai Trees technique. The generation of the re-encryption key is non-interactive and collusion resistant. Moreover, its IND-sID-CPA security over the decisional Learning With Errors (LWE) assumption under the standard model is proved. Compared with some previous IBPRE schemes from Bilinear Pairings, the format of transformed ciphertext in our scheme remains unchanged, furthermore, it can also resist quantum analysis. Compared with some existing IB-PRE schemes from lattices with similar properties, the space of the message in our scheme is a vector of length l and the encryption process remains a lower encryption blowup factor. At last, a proof-of-concept implementation is provided.展开更多
The partial and complete periodic synchronization in coupled discontinuous map lattices consisting of both discon- tinuous and non-invertible maps are discussed. We classify three typical types of periodic synchroniza...The partial and complete periodic synchronization in coupled discontinuous map lattices consisting of both discon- tinuous and non-invertible maps are discussed. We classify three typical types of periodic synchronization states, which give rise to different spatiotemporal patterns including static partial periodic synchronization, dynamically periodic syn- chronization, and complete periodic synchronization patterns. A special prelude dynamics of partial and complete periodic synchronization motion, which is shown by five separated concave curves in the time series plots of the order parameters, is observed. The detailed analysis shows that the special prelude dynamics is induced by the competition between two synchronized clusters, and the analytical expression for the corresponding order parameter is obtained.展开更多
This paper stuides numerically the model equation in a one dimensional defective photonic lattice by modifying the potential function to a periodic function. It is found that defect modes （DMs） can be regarded as Bl...This paper stuides numerically the model equation in a one dimensional defective photonic lattice by modifying the potential function to a periodic function. It is found that defect modes （DMs） can be regarded as Bloch modes which are excited from the extended photonie band-gap structure at Bloch wave-numbers with kx = 0. The DMs for both positive and negative defects are considered in this method.展开更多
The chaotic ratchet effect for Bos-Einstein condensed atoms in an optical lattice is investigated. By using the direct perturbation method we obtain the chaotic solution of the condensed system. Theoretical analysis r...The chaotic ratchet effect for Bos-Einstein condensed atoms in an optical lattice is investigated. By using the direct perturbation method we obtain the chaotic solution of the condensed system. Theoretical analysis reveals that the transport of the condensed atoms in the ratchet potential is a chaotic one, and corresponding numerical results agree well with the theoretical results.展开更多
Ratchet transport of overdamped particles is investigated in superimposed driven lattices using Langevin dynamics simulations. It is found that noise can strongly affect the transport of the particles. When lattices d...Ratchet transport of overdamped particles is investigated in superimposed driven lattices using Langevin dynamics simulations. It is found that noise can strongly affect the transport of the particles. When lattices driving dominates the transport, the noise acts as a disturbance of the directed transport and slows down the average velocity of the particles.When the driving phase has less impact on particle transport, Gaussian white noise can play a positive role. By simply modulating these two parameters, we can control efficiency and the direction of the directed currents.展开更多
The impurity-induced localization of two-component Bose-Einstein condensates loaded into deep one-dimensional optical lattices is studied both analytically and numerically. It is shown that, the analytical criteria fo...The impurity-induced localization of two-component Bose-Einstein condensates loaded into deep one-dimensional optical lattices is studied both analytically and numerically. It is shown that, the analytical criteria for self-trapping and moving soliton/breather of the primary-component condensate are modified significantly by an admixture of an impurity component （the second component）. The realization of the self-trapped state and the moving soliton/breather states of the primary-component becomes more easy with the minor admixture of the impurity-component, even if the two components are partly overlapped.展开更多
Multi-objective evolutionary algorithms(MOEAs) are typically used to optimize two or three objectives in the accelerator field and perform well. However, the performance of these algorithms may severely deteriorate wh...Multi-objective evolutionary algorithms(MOEAs) are typically used to optimize two or three objectives in the accelerator field and perform well. However, the performance of these algorithms may severely deteriorate when the optimization objectives for an accelerator are equal to or greater than four. Recently, many-objective evolutionary algorithms(MaOEAs)that can solve problems with four or more optimization objectives have received extensive attention. In this study, two diffraction-limited storage ring(DLSR) lattices of the Extremely Brilliant Source(ESRF-EBS) type with different energies were designed and optimized using three MaOEAs and a widely used MOEA. The initial population was found to have a significant impact on the performance of the algorithms and was carefully studied. The performances of the four algorithms were compared, and the results demonstrated that the grid-based evolutionary algorithm(GrEA) had the best performance.Ma OEAs were applied in many-objective optimization of DLSR lattices for the first time, and lattices with natural emittances of 116 and 23 pm·rad were obtained at energies of 2 and 6 GeV, respectively, both with reasonable dynamic aperture and local momentum aperture(LMA). This work provides a valuable reference for future many-objective optimization of DLSRs.展开更多
Commercially available lattices contain various kinds of morphological imperfections which result in great degradation in lattices＇ mechanical properties, therefore, to obtain imperfection insensitive lattice structu...Commercially available lattices contain various kinds of morphological imperfections which result in great degradation in lattices＇ mechanical properties, therefore, to obtain imperfection insensitive lattice structure is obviously a practical research subject. Hierarchical structure materials were found to be a class of promising anti-defect materials, This paper builds hierarchical lattice by adding soft adhesion to lattice＇s cell edges and numerical results show that its imperfection sensitivity to missing bars is minor compared with the classic lattice. Soft adhesion with appropriate properties reinforce cell edge＇s bending stiffness and thus reduce the bending deformation in lattice caused by missing bars defect, which is confirmed by statistical analysis of normalized node displacements of imperfect lattices under hydrostatic compression and shear loads.展开更多
基金Central University Basic Research Fund of China,Grant/Award Number:FWNX04Ningxia Natural Science Foundation,Grant/Award Number:2021AAC03203National Natural Science Foundation of China,Grant/Award Number:61662001。
文摘Three-way concept analysis is an important tool for information processing,and rule acquisition is one of the research hotspots of three-way concept analysis.However,compared with three-way concept lattices,three-way semi-concept lattices have three-way operators with weaker constraints,which can generate more concepts.In this article,the problem of rule acquisition for three-way semi-concept lattices is discussed in general.The authors construct the finer relation of three-way semi-concept lattices,and propose a method of rule acquisition for three-way semi-concept lattices.The authors also discuss the set of decision rules and the relationships of decision rules among object-induced three-way semi-concept lattices,object-induced three-way concept lattices,classical concept lattices and semi-concept lattices.Finally,examples are provided to illustrate the validity of our conclusions.
基金National Natural Science Foundation of China (No. 62275257)startup funding from the Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciencesthe support of the Russian Science Foundation (No. 22-13-00126)。
文摘Sub-wavelength nanostructure lattices provide versatile platforms for light control and the basis for various novel phenomena and applications in physics, material science, chemistry, biology,and energy. The thriving study of nanostructure lattices is building on the remarkable progress of nanofabrication techniques, especially for the possibility of fabricating larger-area patterns while achieving higher-quality lattices, complex shapes, and hybrid materials units. In this review, we present a comprehensive review of techniques for large-area fabrication of optical nanostructure arrays, encompassing direct writing, self-assembly, controllable deposition, and nanoimprint/print methods. Furthermore, a particular focus is made on the recent improvement of unit accuracy and diversity, leading to integrated and multifunctional structures for devices and applications.
基金supported by the National Natural Science Foundation of China(Grant No.12074423)the Young Scholar of Chinese Academy of Sciences in Western China(Grant No.XAB2021YN18)+2 种基金the Provincial Science Fund for Distinguished Young Scholars of Shaanxi(Grant No.2024JC-JCQN-11)the China Postdoctoral Science Foundation(Grant No.2023M733722)the Postdoctoral Fellowship Program of CPSF(Grant No.GZC20232947).
文摘Moirésuperlattices,a twisted functional structure crossing the periodic and nonperiodic potentials,have recently attracted great interest in multidisciplinary fields,including optics and ultracold atoms,because of their unique band structures,physical properties,and potential implications.Driven by recent experiments on quantum phenomena of bosonic gases,the atomic Bose–Einstein condensates in moiréoptical lattices,by which other quantum gases such as ultracold fermionic atoms are trapped,could be readily achieved in ultracold atom laboratories,whereas the associated nonlinear localization mechanism remains unexploited.Here,we report the nonlinear localization theory of ultracold atomic Fermi gases in two-dimensional moiréoptical lattices.The linear Bloch-wave spectrum of such a twisted structure exhibits rich nontrivial flat bands,which are separated by different finite bandgaps wherein the existence,properties,and dynamics of localized superfluid Fermi gas structures of two types,gap solitons and gap vortices(topological modes)with vortex charge S¼1,are studied numerically.Our results demonstrate the wide stability regions and robustness of these localized structures,opening up a new avenue for studying soliton physics and moiréphysics in ultracold atoms beyond bosonic gases.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11904261 and 11904259).
文摘Materials with kagome lattices have attracted significant research attention due to their nontrivial features in energy bands.We theoretically investigate the evolution of electronic band structures of kagome lattices in response to uniaxial strain using both a tight-binding model and an antidot model based on a periodic muffin-tin potential.It is found that the Dirac points move with applied strain.Furthermore,the flat band of unstrained kagome lattices is found to develop into a highly anisotropic shape under a stretching strain along y direction,forming a partially flat band with a region dispersionless along ky direction while dispersive along kx direction.Our results shed light on the possibility of engineering the electronic band structures of kagome materials by mechanical strain.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12074154,12174160,and 11722433)the funding from the Six Talent Peaks Project+1 种基金333 High-level Talents Project of Jiangsu Provincethe Innovation and Entrepreneurship Training Programme for University Students in Jiangsu Province(Grant No.202210320140Y)。
文摘Recently,many encouraging experimental advances have been achieved in ternary hydrides superconductors under high pressure.However,the extreme pressure required is indeed a challenge for practical application,which promotes a further exploration for high temperature(T_(c))superconductors at relatively low pressure.Herein,we performed a systematic theoretical investigation on a series of ternary hydrides with stoichiometry AX_(2)H_(8),which is constructed by interacting molecular XH_(4)(X=B,C,and N)into the fcc metal A lattice under low pressure of 0-150 GPa.We uncovered five compounds which are dynamically stable below 100 GPa,e.g.,AcB_(2)H_(8)(25 GPa),LaB_(2)H_(8)(40 GPa),RbC_(2)H_(8)(40 GPa),CSC_(2)H_(8)(60 GPa),and SrC_(2)H_(8)(65 GPa).Among them,AcB_(2)H_(8),which is energetically stable above 2.5 GPa,exhibits the highest Tcof 32 K at 25 GPa.The superconductivity originates mainly from the coupling between the electron of Ac atoms and the associated low-frequency phonons,distinct from the previous typical hydrides with H-derived superconductivity.Our results shed light on the future exploration of superconductivity among ternary compounds at low pressure.
文摘We first introduce several sphere packing ways such as simple cubic packing(SC),face-centered cubic packing(FCC),body-centered cubic packing(BCC),and rectangular body-centered cuboid packing(recBCC),where the rectangular body-centered cuboid packing means the packing method based on a rectangular cuboid whose base is square and whose height is times the length of one side of its square base such that the congruent spheres are centered at the 8 vertices and the centroid of the cuboid.The corresponding lattices are denoted as SCL,FCCL,BCCL,and recBCCL,respectively.Then we consider properties of those lattices,and show that FCCL and recBCCL are the same.Finally we point out some possible applications of the recBCC lattices.
文摘Traditional structural forms are difficult to meet the lightweight requirements of subsequent spacecraft for load-bearing structures.In the aerospace industry,filling structure with lattices is a popular approach to reduce the weight of a spacecraft.However,this design strategy has deficiencies in the spatial distribution of lattice cells as well as its affection on the mechanical properties.In this study,a two-step topology optimization technique is proposed to solve the spatial distribution problem of nanosatellite.Firstly,an entire nanosatellite box composed of panels which filled with uniform lattices is sent to the vibration test to obtain the frequency data.Then,a finite element(FE)model of the nanosatellite structure which contains the same uniform lattices is built and validated with the obtained frequency data above.For the subsequent calculation of topology optimization.An equivalent model of the verified FE model is established by replacing the lattice cells in the sandwich layer with equivalent fictional elements.Subsequently,a topology optimization problem under the mass constraints is formulated for maximize the nature frequency,and a new light weighted nanosatellite which filled with non-uniform lattices is established by applying the density mapping method and the previous topology configuration result.By separating the design problem of nanosatellite into two steps,the proposed optimization design method achieves the maximum frequency design under the weight constraint.Furthermore,the frequency is also guaranteed to be around the nature frequency.The results reveal that the mass of the new structure with non-uniform lattices is reduced by 50.32%and the frequency is increased by 1.19%.An important technical importance and application value of this proposed technique is that it improves the performance and design efficiency of the load-bearing structures of a nanosatellite,and this method has significant technical significance and application value.
文摘The design of three-dimensional printing based conformal cooling channels(CCCs)in injection molding holds great significance.Compared to CCCs,conformal cooling(CC)cavity solutions show promise in delivering enhanced cooling performance for plastic products,although they have been underexplored.In this research,CC cavity is designed within the mold geometry,reinforced by body-centered cubic(BCC)lattice structures to enhance mechanical strength.Three distinct BCC lattice variations have been integrated into the CC cavity:the BCC structure,BCC with cubes,and BCC with pillars.The thermal performances of the BCC lattice-added CC cavity are assessed numerically after experimental validation.To provide feasible solutions from viewpoints of thermal performances,various BCC lattice structure thicknesses are analyzed in the range of 0.8–1.2mm.Thermal simulation outcomes reveal that thicker lattice structures enhance mechanical strength but simultaneously lead to an increase in cooling time.Upon examining all the proposed CC cavity solutions supported by BCC,the cooling times range from 2.2 to 4 s,resulting in a reduction of 38.6%to 66.1%when compared to conventional straightdrilled channels.In contrast to CCCs,CC cavities have the potential to decrease the maximum temperature nonuniformity from 8.5 to 6 K.Nevertheless,the presence of lattice structures in CC cavity solutions results in an elevated pressure drop,reaching 2.8MPa,whereas the results for CCCs remain below2.1MPa.
文摘A discrete Hopf fibration of S15 over S8 with S7 (unit octonions) as fibers leads to a 16D Polytope P16 with 4320 vertices obtained from the convex hull of the 16D Barnes-Wall lattice Λ16. It is argued (conjectured) how a subsequent 2-1 mapping (projection) of P16 onto a 8D-hyperplane might furnish the 2160 vertices of the uniform 241 polytope in 8-dimensions, and such that one can capture the chain sequence of polytopes 241,231,221,211in D=8,7,6,5dimensions, leading, respectively, to the sequence of Coxeter groups E8,E7,E6,SO(10)which are putative GUT group candidates. An embedding of the E8⊕E8and E8⊕E8⊕E8lattice into the Barnes-Wall Λ16 and Leech Λ24 lattices, respectively, is explicitly shown. From the 16D lattice E8⊕E8one can generate two separate families of Elser-Sloane 4D quasicrystals (QC’s) with H4 (icosahedral) symmetry via the “cut-and-project” method from 8D to 4D in each separate E8 lattice. Therefore, one obtains in this fashion the Cartesian product of two Elser-Sloane QC’s Q×Qspanning an 8D space. Similarly, from the 24D lattice E8⊕E8⊕E8one can generate the Cartesian product of three Elser-Sloane 4D quasicrystals (QC’s) Q×Q×Qwith H4 symmetry and spanning a 12D space.
文摘In this article, the authors mainly study how to obtain new semicontinuous lattices from the given semicontinuous lattices and discuss the conditions under which the image of a semicontinuous projection operator is also semicontinuous. Moreover, the authors investigate the relation between semicontinuous lattices and completely distributive lattices. Finally, it is proved that the strongly semicontinuous lattice category is a Cartesian closed category.
基金the Research Grants Council of the Hong Kong Special Administrative Region of China (GRF No. CityU11216515)City University of Hong Kong (Nos. 7005070 and 9667153)+1 种基金Shenzhen Science and Technology Innovation Committee under the grant JCYJ20170818103206501the Natural Science Basic Research Plan in Shaanxi Province of China (No. 2017JM5003)
文摘3D printing-based supercapacitors have been extensively explored,yet the rigid rheological requirement for corresponding ink preparation significantly limits the manufacturing of true 3D architecture in achieving superior energy storage.We proposed the stereolithographic technique to fabricate the metallic composite lattices with octet-truss arrangement by using electroless plating and engineering the 3D hierarchically porous graphene onto the scaffolds to build the hierarchically cellular lattices in quasi-solid supercapacitor application.The supercapacitor device that is composed of composite lattices span several pore size orders from nm to mm holds promising behavior on the areal capacitance(57.75 mF cm-2),rate capability(70% retention,2-40 mA cm-2),and long lifespan(96% after 5000 cycles),as well as superior energy density of 0.008 mWh cm-2,which are comparable to the state-of-the-art carbon-based supercapacitor.By synergistically combining this facile stereolithographic 3D printing technology with the hierarchically porous graphene architecture,we provide a novel route of manufacturing energy storage device as well as new insight into building other high-performance functional electronics.
基金supported by National Basic Research Program of China (Grant No 2006CB705500)Changjiang Scholars and Innovative Research Team in University (Grant No IRT0605)the National Natural Science Foundation of China (Grant No 70631001)
文摘In this paper, cascading failure is studied by coupled map lattice （CML） methods in preferential attachment community networks. It is found that external perturbation R is increasing with modularity Q growing by simulation. In particular, the large modularity Q can hold off the cascading failure dynamic process in community networks. Furthermore, different attack strategies also greatly affect the cascading failure dynamic process. It is particularly significant to control cascading failure process in real community networks.
基金supported by the National Natural Science Foundation of China under grant No.(U1636114, 61572521,61772550)Natural Science of Shaanxi Province of China under grant No.2018JM6078Innovative Research Team in Engineering University of PAP (KYTD201805)
文摘Identity-Based Proxy Re-Encryption (IB-PRE) allows a semi-trusted proxy to convert the ciphertext encrypted under Alice’s identity into Bob’s ciphertext of the same message without leaking plaintext. Lattice-based cryptography enjoys potential resistance to quantum analysis and low computational complexity. A multi-hop and unidirectional IB-PRE from lattices is presented. We split the functions of decryption and ciphertext transformation separately, and design the double private keys mechanism, where two keys are generated for each user, one key is used to decrypt the ciphertext by Pre-Image Sampling technique, and the other is used to generate the re-encryption key by Bonsai Trees technique. The generation of the re-encryption key is non-interactive and collusion resistant. Moreover, its IND-sID-CPA security over the decisional Learning With Errors (LWE) assumption under the standard model is proved. Compared with some previous IBPRE schemes from Bilinear Pairings, the format of transformed ciphertext in our scheme remains unchanged, furthermore, it can also resist quantum analysis. Compared with some existing IB-PRE schemes from lattices with similar properties, the space of the message in our scheme is a vector of length l and the encryption process remains a lower encryption blowup factor. At last, a proof-of-concept implementation is provided.
基金supported by the National Natural Science Foundation of China(Grant No.10875076)the Natural Science Foundation of Shaanxi Province,China(Grant No.SJ08A23)
文摘The partial and complete periodic synchronization in coupled discontinuous map lattices consisting of both discon- tinuous and non-invertible maps are discussed. We classify three typical types of periodic synchronization states, which give rise to different spatiotemporal patterns including static partial periodic synchronization, dynamically periodic syn- chronization, and complete periodic synchronization patterns. A special prelude dynamics of partial and complete periodic synchronization motion, which is shown by five separated concave curves in the time series plots of the order parameters, is observed. The detailed analysis shows that the special prelude dynamics is induced by the competition between two synchronized clusters, and the analytical expression for the corresponding order parameter is obtained.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 10674038 and 10604042)the National Basic Research Program of China (Grant No. 2006CB302901)
文摘This paper stuides numerically the model equation in a one dimensional defective photonic lattice by modifying the potential function to a periodic function. It is found that defect modes （DMs） can be regarded as Bloch modes which are excited from the extended photonie band-gap structure at Bloch wave-numbers with kx = 0. The DMs for both positive and negative defects are considered in this method.
基金the Key Research Foundation of the Education Bureau of Hunan Province of China under Grant No.08A015the Natural Science Foundation of Hunan Province of China under Grant No.06JJ2014 and 04JJ40006the National Natural Science Foundation of China under Grant No.10575034
文摘The chaotic ratchet effect for Bos-Einstein condensed atoms in an optical lattice is investigated. By using the direct perturbation method we obtain the chaotic solution of the condensed system. Theoretical analysis reveals that the transport of the condensed atoms in the ratchet potential is a chaotic one, and corresponding numerical results agree well with the theoretical results.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11575064 and 11175067)the PCSIRT(Grant No.IRT1243)+2 种基金the GDUPS Project(2016)the Natural Science Foundation of Guangdong Province,China(Grant Nos.2016A030313433 and 2017A030313029)the Innovation Project of Graduate School of South China Normal University
文摘Ratchet transport of overdamped particles is investigated in superimposed driven lattices using Langevin dynamics simulations. It is found that noise can strongly affect the transport of the particles. When lattices driving dominates the transport, the noise acts as a disturbance of the directed transport and slows down the average velocity of the particles.When the driving phase has less impact on particle transport, Gaussian white noise can play a positive role. By simply modulating these two parameters, we can control efficiency and the direction of the directed currents.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.10774120 and 10975114)the Natural Science Foundation of Gansu Province of China (Grant No.1010RJZA012)the Natural Science Foundation of Northwest Normal University of China (Grant No.NWNU-KJCXGC-03-48)
文摘The impurity-induced localization of two-component Bose-Einstein condensates loaded into deep one-dimensional optical lattices is studied both analytically and numerically. It is shown that, the analytical criteria for self-trapping and moving soliton/breather of the primary-component condensate are modified significantly by an admixture of an impurity component （the second component）. The realization of the self-trapped state and the moving soliton/breather states of the primary-component becomes more easy with the minor admixture of the impurity-component, even if the two components are partly overlapped.
文摘Multi-objective evolutionary algorithms(MOEAs) are typically used to optimize two or three objectives in the accelerator field and perform well. However, the performance of these algorithms may severely deteriorate when the optimization objectives for an accelerator are equal to or greater than four. Recently, many-objective evolutionary algorithms(MaOEAs)that can solve problems with four or more optimization objectives have received extensive attention. In this study, two diffraction-limited storage ring(DLSR) lattices of the Extremely Brilliant Source(ESRF-EBS) type with different energies were designed and optimized using three MaOEAs and a widely used MOEA. The initial population was found to have a significant impact on the performance of the algorithms and was carefully studied. The performances of the four algorithms were compared, and the results demonstrated that the grid-based evolutionary algorithm(GrEA) had the best performance.Ma OEAs were applied in many-objective optimization of DLSR lattices for the first time, and lattices with natural emittances of 116 and 23 pm·rad were obtained at energies of 2 and 6 GeV, respectively, both with reasonable dynamic aperture and local momentum aperture(LMA). This work provides a valuable reference for future many-objective optimization of DLSRs.
基金supported by the 973 Program(No.2014CB049000,2011CB610304)National Natural Science Foundation of China(11372062,91216201)+2 种基金LNET Program(LJQ2013005)China Postdoctoral Science Foundation(2014M551070)111Project(B14013)
文摘Commercially available lattices contain various kinds of morphological imperfections which result in great degradation in lattices＇ mechanical properties, therefore, to obtain imperfection insensitive lattice structure is obviously a practical research subject. Hierarchical structure materials were found to be a class of promising anti-defect materials, This paper builds hierarchical lattice by adding soft adhesion to lattice＇s cell edges and numerical results show that its imperfection sensitivity to missing bars is minor compared with the classic lattice. Soft adhesion with appropriate properties reinforce cell edge＇s bending stiffness and thus reduce the bending deformation in lattice caused by missing bars defect, which is confirmed by statistical analysis of normalized node displacements of imperfect lattices under hydrostatic compression and shear loads.
