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Weyl and Nodal Ring Magnons in Three-Dimensional Honeycomb Lattices
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作者 厉康康 胡江平 《Chinese Physics Letters》 SCIE CAS CSCD 2017年第7期246-248,共3页
We study the topological properties of magnon excitations in a wide class of three-dimensional (3D) honeycomb lattices with ferromagnetic ground states. It is found that they host nodal ring magnon excitations. Thes... We study the topological properties of magnon excitations in a wide class of three-dimensional (3D) honeycomb lattices with ferromagnetic ground states. It is found that they host nodal ring magnon excitations. These rings locate on the same plane in the momentum space. The nodal ring degeneracy can be lifted by the Dzyaloshinskii- Moriya interactions to form two Weyl points with opposite charges. We explicitly discuss these physics in the simplest 3D honeycomb lattice and the hyperhoneycomb lattice, and show drumhead and are surface states in the nodal ring and Weyl phases, respectively, due to the bulk-boundary correspondence. 展开更多
关键词 Weyl and Nodal Ring Magnons in three-dimensional Honeycomb lattices
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LI-ideal Spaces of Lattice Implication Algebra 被引量:3
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作者 CHEN Shu-wei JIANG Bao-qing YANG Xiao-wei 《Chinese Quarterly Journal of Mathematics》 CSCD 北大核心 2007年第4期504-511,共8页
In this paper, a topological space based on LI-ideals of a lattice implication algebra is constructed, and its topological properties, such as separability, compactness and connectedness are discussed.
关键词 lattice implication algebra LI-ideal topological space topological properties
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Risk Assessment of Coal Mine Water Hazard Based on Three-Dimensional Model of Geology and Underground Space 被引量:1
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作者 Kai Zhang~1,Ming Huang~1,Bin Tang~2,Fan Cui~1 1.Laboratory of Coal Resources and Mine Safety,China University of Mining and Technology,Beijing 100083,China. 2.China Water Investment Co.Ltd,Beijing 100053,China 《地学前缘》 EI CAS CSCD 北大核心 2009年第S1期279-279,共1页
Mine safety have top-five disasters,which including the water,gas,fire,dust and geological dynamic disaster.The coal mine water disaster is one of the important factors which restricted the development of China’s coa... Mine safety have top-five disasters,which including the water,gas,fire,dust and geological dynamic disaster.The coal mine water disaster is one of the important factors which restricted the development of China’s coal production.It is showed by statistics that 60%of mine accidents are affected by groundwater,which not only result in the production losses,casualties and a variety of 展开更多
关键词 DISASTER risk assessment three-dimensional model of GEOLOGY and UNDERGROUND space emergency RESCUE
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Three-dimensionally ordered macroporous cross-linked polystyrene incorporating functional group via hydrophilic spacer arm 被引量:1
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作者 Li Xia Yuan Xiao Mei Wang Xu Zhang Pan Ge Liu Wei Dong Yan 《Chinese Chemical Letters》 SCIE CAS CSCD 2010年第12期1493-1496,共4页
A versatile and effective method for incorporating functional groups on the pore wall of three-dimensionally ordered macroporous cross-linked polystyrene(3DOM CLPS) by hydrophilic spacer arm has been investigated.Th... A versatile and effective method for incorporating functional groups on the pore wall of three-dimensionally ordered macroporous cross-linked polystyrene(3DOM CLPS) by hydrophilic spacer arm has been investigated.The 3DOM CLPS with pore size 865 nm was prepared by sacrifice template method.The hydrophilic spacer arm(polyethylene glycol,molecular weight is 600) was grafted to the 3DOM CLPS via nucleophilic substitution reaction.The other side of active hydroxyl can be further converted into a lot of other functional groups.In this report,the chelating ligand 2-mercaptobenzothiazole(MBZ) group was introduced on the end of the PGE chain to evidence the versatile functionalization approach.The functionalized ordered macroporous materials were characterized by FT-IR,element analyzer,SEM.The results reveal that the pores were successfully bonded with 2-mercaptobenzothiazole groups via hydrophilic spacer arms and the original morphology of ordered macroporous materials were remained after functionalization.The MBZ group density is 0.052 mmol/m^2.The functionalized 3DOM CLPS are expected to application as heavy metal ions adsorbent. 展开更多
关键词 three-dimensionally ordered macroporous polymer FUNCTIONALIZATION Hydrophilic space arm Heterocyclic functional group
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Continuous imaging space in three-dimensional integral imaging 被引量:1
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作者 张雷 杨勇 +3 位作者 王金刚 赵星 方志良 袁小聪 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第5期303-305,共3页
We report an integral imaging method with continuous imaging space. This method simultaneously reconstructs real and virtual images in the virtual mode, with a minimum gap that separates the entire imaging space into ... We report an integral imaging method with continuous imaging space. This method simultaneously reconstructs real and virtual images in the virtual mode, with a minimum gap that separates the entire imaging space into real and virtual space. Experimental results show that the gap is reduced to 45% of that in a conventional integral imaging system with the same parameters. 展开更多
关键词 three-dimensional integral imaging imaging space
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Lattice Im plication Homom orphism inIm plication Filter Spaces 被引量:1
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作者 宋振明 王建平 《Chinese Quarterly Journal of Mathematics》 CSCD 1998年第4期17-23, ,共7页
In this paper,we investigate some special properties of lattice implication homomorphism in implication filter spaces. We show that lattice implication homomorphism is a continuous function with respect to implication... In this paper,we investigate some special properties of lattice implication homomorphism in implication filter spaces. We show that lattice implication homomorphism is a continuous function with respect to implication filter topology. Moreover,we give a structural characterstic of left translation topology and right translation topology,which finally leads to the structural characteristics of product topology. 展开更多
关键词 lattice implication homomorphism implication filter spaces implication filter topology
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Using"Three-dimensional Space Resources"for Fenlong Technology to Improve Grain Econoloy and Expand Human Living Spaces 被引量:1
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作者 Benhui WEI 《Asian Agricultural Research》 2020年第12期32-38,共7页
Fenlong Technology has been applied to increase yield by 20%-50%,improve quality by 5%,and retain water by 100%in 40 kinds of crop cultivated land and saline-alkali land in 26 provinces of China.This paper clarified f... Fenlong Technology has been applied to increase yield by 20%-50%,improve quality by 5%,and retain water by 100%in 40 kinds of crop cultivated land and saline-alkali land in 26 provinces of China.This paper clarified for the first time the scientific theory system of Fenlong Technology using three-dimensional space resources"Fenlong Agricultural Nature Theory"and the development of the relative"limits"of agricultural growth,which provides a huge power support and natural force for expanding human living spaces.Through inventing and creating a scientific and technological system of farming tools,farming machinery,farming modes,and magic weapons for cultivation,Fenlong Technology can increase grain,promote ecological development,and greatly expand the living spaces of the Chinese nation and achieve sustainable development.Using Fenlong Technology,China has expanded from the current single"cultivated land agriculture"to the"big pattern agriculture"of Fenlong"cultivated land+saline land+degraded grassland+marginal land+desertified land+river water",flexibly used 147 million ha of"three-dimensional space resources"of land,and the newly increased food,meat,and fish can feed 300 million to 400 million people,increased the water storage by 100 billion m^(3),and reduced the collection of groundwater by 20 million to 60 billion m^(3). 展开更多
关键词 three-dimensional space resources Fenlong Agricultural Nature Theory Relative"limits" Expanding the living spaces Improving the grain ecology Fenlong farming
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Lattices Associated with a Finite Vector Space
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作者 Mengtian Yue 《Applied Mathematics》 2014年第4期672-676,共5页
Let be a n-dimensional row vector space over a finite field For , let be a d-?dimensional subspace of . denotes the set of all the spaces which are the subspaces of and not the subspaces of except . We define the part... Let be a n-dimensional row vector space over a finite field For , let be a d-?dimensional subspace of . denotes the set of all the spaces which are the subspaces of and not the subspaces of except . We define the partial order on by ordinary inclusion (resp. reverse inclusion), and then is a poset, denoted by (resp. ). In this paper we show that both and are finite atomic lattices. Further, we discuss the geometricity of and , and obtain their characteristic polynomials. 展开更多
关键词 VECTOR space GEOMETRIC lattice Characteristic POLYNOMIAL
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A Euclidean-Like Discrete Spacetime from the Unification of a Multitude of Hypercubic Lattices
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作者 Christiaan Theodorus de Groot 《Journal of Modern Physics》 2017年第8期1175-1189,共15页
An autonomous discrete space is proposed consisting of a huge number of four dimensional hypercubic lattices, unified along one of the four axes. The unification is such that the properties of the individual lattice a... An autonomous discrete space is proposed consisting of a huge number of four dimensional hypercubic lattices, unified along one of the four axes. The unification is such that the properties of the individual lattice are preserved. All the unifying axes are parallel, and the other axes have indeterminate mutual relations. The two kinds of axes are non-interchangeable resembling time and space of reality. The unification constitutes a framework without spatial properties. In case the axes with indeterminate relations are present at regular intervals in the time and the space, a Euclidean-like metric and goniometry can be obtained. In thus defined space-like structure, differences in speed and relativistic relations are only possible within regions of space enclosed by aberrations of the structure. 展开更多
关键词 DISCRETE space Hypercubic lattice spaceTIME ANISOTROPY Euclidean Metric RELATIVITY
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Prime Space of Lattice Implication Algebras
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作者 宋振明 郭天榜 《Chinese Quarterly Journal of Mathematics》 CSCD 1997年第4期46-50, ,共5页
In this paper,after discussing the prime implication filter of lattice implication algebra,we introduced the concept of prime space of lattice implication algebra,in which we analysised its topological property and di... In this paper,after discussing the prime implication filter of lattice implication algebra,we introduced the concept of prime space of lattice implication algebra,in which we analysised its topological property and discussed the relation between the category of topological space and the category of lattice implication algebras. 展开更多
关键词 lattice implication algebra prime implication filter topological space prime space CATEGORY
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<i>L</i>-Topological Spaces Based on Residuated Lattices
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作者 Zhudeng Wang Xuejun Liu 《Advances in Pure Mathematics》 2012年第1期41-44,共4页
In this paper, we introduce the notion of L-topological spaces based on a complete bounded integral residuated lattice and discuss some properties of interior and left (right) closure operators.
关键词 Residuated lattice L-Topological space Interior OPERATOR LEFT (Right) CLOSURE OPERATOR
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Three-Dimensional Space Interpolation of Grey / Depth Image Sequence-A New Technique of Computer Graphics Synthesis
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作者 Wang Xincheng, Zhu Weile, Zhu Xiaokun and Gu DerenChengdu University of Electronic Science and Technology, Chengdu 610054 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 1993年第3期70-77,共8页
This paper advances a three-dimensional space interpolation method of grey / depth image sequence, which breaks free from the limit of original practical photographing route. Pictures can cruise at will in space. By u... This paper advances a three-dimensional space interpolation method of grey / depth image sequence, which breaks free from the limit of original practical photographing route. Pictures can cruise at will in space. By using space sparse sampling, great memorial capacity can be saved and reproduced scenes can be controlled. To solve time consuming and complex computations in three-dimensional interpolation algorithm, we have studied a fast and practical algorithm of scattered space lattice and that of 'Warp' algorithm with proper depth. By several simple aspects of three dimensional space interpolation, we succeed in developing some simple and practical algorithms. Some results of simulated experiments with computers have shown that the new method is absolutely feasible. 展开更多
关键词 Grey / depth image three-dimensional space interpolation Computer graphics synthesis Algorithms.
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The Level Structures of the Kernel and Hull on Lattice—Valued Funcetions and Induced Spaces
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作者 李永明 《Chinese Quarterly Journal of Mathematics》 CSCD 1993年第3期82-87,共6页
It is studied systematically for the level strcture of the kernel and hull on continuous-lattice- calued function.In terms of these results,the level characterixations of induced space are odtained.
关键词 HULL KERNEL lattice—valude lower (upper) semicontinuous function induced space
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Physical Constants as Result of the Many Hypercubic Lattices of a Multidirectional Discrete Space
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作者 Christiaan T. de Groot 《Journal of Modern Physics》 2020年第3期432-447,共16页
A multidirectional discrete space consists of numerous hypercubic lattices each of which contains one of the spatial directions. In such a space, several groups of lattices can be distinguished with a certain property... A multidirectional discrete space consists of numerous hypercubic lattices each of which contains one of the spatial directions. In such a space, several groups of lattices can be distinguished with a certain property. Each group is determined by the number of lattices it comprises, forming the characterizing numbers of the space. Using the specific properties of a multidirectional discrete space, it is shown that some of the characterizing numbers can be associated with a physical constant. The fine structure constant appears to be equal to the ratio of two of these numbers, which offers the possibility of calculating the series of smallest numerical values of these numbers. With these values, a reasoned estimate can be made of the upper limit of the smallest distance of the discrete space of approximately the Planck length. 展开更多
关键词 Hypercubic lattice Multidirectional DISCRETE space Characterizing NUMBERS Fine Structure Constant Physical CONSTANTS PLANCK Length
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并列双方柱绕流的Lattice Boltzmann模拟分析 被引量:10
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作者 饶勇 倪玉山 刘超峰 《应用力学学报》 EI CAS CSCD 北大核心 2008年第2期192-197,共6页
采用Lattice Boltzmann方法对并列双方柱绕流问题进行数值模拟。对方柱间距比s/D=0.2、0.3、0.4、0.5、1.0、1.4、1.5、1.6、1.8、2.0、2.5共11种情况下的流场分别进行计算,给出了对应的流线图、方柱的升力图及阻力图,同时计算了方柱各... 采用Lattice Boltzmann方法对并列双方柱绕流问题进行数值模拟。对方柱间距比s/D=0.2、0.3、0.4、0.5、1.0、1.4、1.5、1.6、1.8、2.0、2.5共11种情况下的流场分别进行计算,给出了对应的流线图、方柱的升力图及阻力图,同时计算了方柱各边中点的压力,给出了压力与间距比的变化曲线,并对各个流线图、升力图、阻力图及压力图进行了分析讨论。结果表明:当s/D≤1.5时,流动呈偏流型,形成周期漩涡;当s/D>1.5时,流动呈对称型,形成对称漩涡;s/D=1.5为流动从偏流型向对称型转换的临界间距比。该结果对工程中建筑物位置的安排及其安全系数的提高有一定的参考价值。 展开更多
关键词 lattice Bo[tzmann 方柱绕流 流场模拟 间距比
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GENERALIZATIONS AND CARTESIAN CLOSED SUBCATEGORIES OF SEMICONTINUOUS LATTICES 被引量:4
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作者 李庆国 伍秀华 《Acta Mathematica Scientia》 SCIE CSCD 2009年第5期1366-1374,共9页
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
关键词 semicontinuous lattices strongly semicontinuous lattices semicontinuous mapping HEREDITARY function space Cartesian closed category
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Urban Three-dimensional Expansion and Its Driving Forces——A Case Study of Shanghai,China 被引量:20
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作者 SHI Longyu SHAO Guofan +4 位作者 CUI Shenghui LI Xuanqi LIN Tao YIN Kai ZHAO Jingzhu 《Chinese Geographical Science》 SCIE CSCD 2009年第4期291-298,共8页
Urban expansion is a phenomenon of urban space increase,and an important measuring index of the process of urbanization.Taking Shanghai as an example,the changes of urban average height and built-up area were studied ... Urban expansion is a phenomenon of urban space increase,and an important measuring index of the process of urbanization.Taking Shanghai as an example,the changes of urban average height and built-up area were studied to represent city's vertical and horizontal increases respectively,and statistical methods were used to analyze the driving forces of urban expansion.The research drew following conclusions:1) The urban expansion process of Shanghai from 1985 to 2006 had a clear periodic feature,and could be divided into three stages:vertical expansion in dominance,coordinated vertical and horizontal expansion,and horizontal expansion in dominance.2) The average height and quantity of buildings in core city were significantly bigger than those in suburbs,but the changing speed of the latter was faster.And 3) urbanization process was the major driving force for the city's horizontal expansion,while industrial structure improvement was the key driving factor for the vertical expansion.Those two driving forces were simultaneously affected by city's political factors. 展开更多
关键词 urban expansion three-dimensional space URBANIZATION urban vertical expansion urban horizontal ex-pansion SHANGHAI China
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Multiconstraint adaptive three-dimensional guidance law using convex optimization 被引量:6
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作者 FU Shengnan LIU Xiaodong +1 位作者 ZHANG Wenjie XIA Qunli 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2020年第4期791-803,共13页
The traditional guidance law only guarantees the accuracy of attacking a target. However, the look angle and acceleration constraints are indispensable in applications. A new adaptive three-dimensional proportional na... The traditional guidance law only guarantees the accuracy of attacking a target. However, the look angle and acceleration constraints are indispensable in applications. A new adaptive three-dimensional proportional navigation(PN) guidance law is proposed based on convex optimization. Decomposition of the three-dimensional space is carried out to establish threedimensional kinematic engagements. The constraints and the performance index are disposed by using the convex optimization method. PN guidance gains can be obtained by solving the optimization problem. This solution is more rapid and programmatic than the traditional method and provides a foundation for future online guidance methods, which is of great value for engineering applications. 展开更多
关键词 proportional navigation(PN) adaptive guidance law three-dimensional space second-order cone programming(SOCP) convex optimal control
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Obstacle avoidance method of three-dimensional obstacle spherical cap 被引量:3
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作者 YANG Xiuxia ZHANG Yi ZHOU Weiwei 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2018年第5期1058-1068,共11页
Focusing on obstacle avoidance in three-dimensional space for unmanned aerial vehicle(UAV), the direct obstacle avoidance method in dynamic space based on three-dimensional velocity obstacle spherical cap is proposed,... Focusing on obstacle avoidance in three-dimensional space for unmanned aerial vehicle(UAV), the direct obstacle avoidance method in dynamic space based on three-dimensional velocity obstacle spherical cap is proposed, which quantifies the influence of threatening obstacles through velocity obstacle spherical cap parameters. In addition, the obstacle avoidance schemes of any point on the critical curve during the multi-obstacles avoidance are given. Through prediction, the insertion point for the obstacle avoidance can be obtained and the flight path can be replanned. Taking the Pythagorean Hodograph(PH) curve trajectory re-planning as an example, the three-dimensional direct obstacle avoidance method in dynamic space is tested. Simulation results show that the proposed method can realize the online obstacle avoidance trajectory re-planning, which increases the flexibility of obstacle avoidance greatly. 展开更多
关键词 three-dimensional direct space obstacle avoidance velocity obstacle cone velocity obstacle spherical cap
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Three-Dimensional Metacomposite Based on Different Ferromagnetic Microwire Spacing for Electromagnetic Shielding 被引量:4
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作者 QIAO Ye JIANG Qian +2 位作者 UDDIN Azim QIN Faxiang WU Liwei 《Journal of Donghua University(English Edition)》 CAS 2022年第3期206-210,共5页
An electromagnetic shielding metacomposite based on the absorbing mechanism was prepared by weaving ferromagnetic microwires into the three-dimensional(3D)fabric.The influence of the ferromagnetic microwire spacing on... An electromagnetic shielding metacomposite based on the absorbing mechanism was prepared by weaving ferromagnetic microwires into the three-dimensional(3D)fabric.The influence of the ferromagnetic microwire spacing on electromagnetic shielding performance and the electromagnetic shielding mechanism of 3D metacomposites were studied.The total electromagnetic shielding performance increases with the increase of electromagnetic wave frequency.3D metacomposites based on the absorbing mechanism can avoid the secondary pollution of electromagnetic waves,and have great potential in military,civil,aerospace and other fields. 展开更多
关键词 three-dimensional(3D)metacomposite ferromagnetic microwire spacing electromagnetic shielding MECHANISM
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