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Quantum Phase Transition in Quasi-two-dimensional Heisenberg Antiferromagnet with Single-Ion Anisotropy

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Communications in Theoretical Physics 2007年第1期47卷 171-180页

作者： JI An-Chun tian Guang-shan School of Physics Peking University Beijing 100871 China

In the present paper, we investigate the quantum phase transition in a spatially anisotropic antiferrornagnetic Heisenberg model of S =1 with single-ion energy anisotropy. By using the Schwinger boson representation, we calculate the Gaussian correction to the critical value J⊥^c caused by quantum spin fluctuations. We find that, for the positive single-ion energy, a nonzero value of J⊥^c is always needed to stabilize the antiferromagnetic long-range order in this model. It resolves a difference among literature and shows clearly that the effect of quantum fluctuations may qualitatively change a result obtained by the mean-field theories on lower-dimensional systems.

关键词： spatially anisotropic Heisenberg model single-ion anisotropy functional integration Schwinger-Boson representation

Lithospheric thermal and compositional structure of South China jointly inverted from multiple geophysical observations

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Science China Earth Sciences 2021年第1期64卷 148-160页

作者： Bin shan Wanli ZHOU Yang xiao Hubei Subsurface Multi-Scale Imaging Key Laboratory.Institute of Geophysics and Geomatics China University of GeosciencesWuhan 430074China

The detailed lithospheric structure of South China is the basis for the understanding of tectonic processes of eastern ***,two essential issues in the study of lithospheric structure are the thermal and compositional structures,which are usually derived from either geophysical or geochemical ***,inversions from single geophysical or geochemical datasets have certain limitations,making it necessary to develop joint inversions of geophysical,geochemical and petrological *** this paper,through thermodynamic simulation and probabilistic inversion,we inverted multiple datasets including topography,geoid height,surface heat flow and surface wave dispersion curves for the 3D lithospheric thermal and compositional structure of South *** results reveal a thin(200 km),suggesting that the thick and cold craton lithospheric roots are *** may exist a discontinuous interface beneath the Sichuan Basin,with the saturated lower layer thicker than the refractory upper *** a result,the lithospheric mantle of the Sichuan Basin and surrounding regions is mainly composed of saturated and transitional peridotite.

关键词： South China Lithospheric thermal structure Lithospheric compositional structure Thermodynamic inversion

Flight parameter calculation method of multi-projectiles using temporal and spatial information constraint

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Defence Technology（防务技术） 2023年第1期19卷 63-75页

作者： Han-shan Li xiao-qian Zhang School of Electronic and Information Engineering Xi'an Technological UniversityXi'an710021China

The dynamic parameters of multiple projectiles that are fired using multi-barrel weapons in highfrequency continuous firing modes are important indicators to measure the performance of these *** characteristics of multiple projectiles are high randomness and large numbers launched in a short period of time,making it very difficult to obtain the real dispersion parameters of the projectiles due to the occlusion or coincidence of multiple *** six intersecting-screen testing system,in this paper,we propose an association recognition and matching algorithm of multiple projectiles using a temporal and spatial information constraint *** extract the output signal from each detection screen and then use the wavelet transform to process the output *** present a method to identify and extract the time values on which the projectiles pass through the detection screens using the wavelet transform modulus maximum *** then use the correlation of the output signals of three parallel detection screens to establish a correlation coefficient recognition constraint function for the multiple *** on the premise of linear projectile motion,we establish a temporal and spatial constraint matching model using the projectile’s position coordinates in each detection screen and the projectile’s time constraints within the multiple intersecting-screen *** then determine the time values of the multiple projectiles in each detection screen using an iterative search cycle registration,and finally obtain the flight parameters for the multiple projectiles in the presence of *** proposed method and algorithm were verified experimentally and can solve the problem of uncertainty in projectiles flight parameter under different multiple projectile firing states.

关键词： Six detection screen array Multi-projectile Recognition and matching Temporal and spatial information constraint Wavelet transform

Whole-genome resequencing of Japanese whiting(Sillago japonica) provide insights into local adaptations

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Zoological Research 2021年第5期42卷 548-561页

作者： Zhi-Qiang Han Xin-Yu Guo Qun Liu shan-shan Liu Zhi-Xin Zhang Shi-Jun xiao tian-Xiang Gao Fishery College Zhejiang Ocean UniversityZhoushanZhejiang 316002China BGI-Qingdao BGI-ShenzhennQingdaoShandong 266555China Graduate School of Marine Science and Technology Tokyo University of Marine Science and TechnologyKonanMinatoTokyo 108-8477Japan Institute of Fisheries Science Tibet Academy of Agricultural and Animal Husbandry SciencesLhasaTibet 850000China

The genetic adaptations of various organisms to heterogeneous environments in the northwestern Pacific remain poorly *** genomic divergence among populations may reflect *** understanding of the mechanisms by which organisms adapt to different temperatures in response to climate change and predicting the adaptive potential and ecological consequences of anthropogenic global warming are *** sequenced the whole genomes of Japanese whiting(Sillago japonica)specimens collected from different latitudinal locations along the coastal waters of China and Japan to detect possible thermal *** population genomics,a total of 5.48 million single nucleotide polymorphisms(SNPs)from five populations revealed a complete genetic break between the Chinese and Japanese groups,which was attributed to both geographic distance and local *** shared natural selection genes between two isolated populations(i.e.,Zhoushan and Ise Bay/Tokyo Bay)indicated possible parallel evolution at the genetic level induced by *** genes also indicated that the process of temperature selection on isolated populations is ***,we observed natural candidate genes related to membrane fluidity,possibly underlying adaptation to cold environmental *** findings advance our understanding of the genetic mechanisms underlying the rapid adaptations of fish *** distribution projection models suggested that the Chinese and Japanese groups may have different responses to future climate change,with the former expanding and the latter *** findings of this study enhance our understanding of genetic differentiation and adaptation to changing environments.

关键词： Sillago japonica Local adaptation Climate change Temperature stress Wholegenome resequencing

Three-dimensional coordinates test method with uncertain projectile proximity explosion position based on dynamic seven photoelectric detection screen

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Defence Technology（防务技术） 2022年第9期18卷 1643-1652页

作者： Han-shan Li xiao-qian Zhang School of Electronic and Information Engineering Xi'an Technological UniversityXi'an710021China

To objectively obtain the three-dimensional coordinates of the projectile fuze proximity explosion when projectile intersects the head of missile target, we propose a dynamic seven photoelectric detection screen test method, which is made up of six plane detection screens and a flash photoelectric dynamic detection screen. The three-dimensional coordinates calculation model of the projectile proximity explosion position based on seven plane detection screens with dynamic characteristics is *** to the relation of the dynamic seven photoelectric detection screen planes and the time values,the analytical function of the projectile proximity explosion position parameters under non-linear motion is derived. The projectile signal filtering method based on discrete wavelet transform is explored in this work. Additionally, the projectile signal recognition algorithm using an improved particle swarm is proposed. Based on the characteristics of the time duration and the signal peak error for the projectile passing through the detection screen, the signals attribution of the same projectile passing through six detection screens are analyzed for obtaining precise time values of the same projectile passing through the detection screens. On the basis of the projectile fuze proximity explosion test, the linear motion model and the proposed non-linear motion model are used to calculate and compare the same group of projectiles proximity explosion position parameters. The comparison of test results verifies that the proposed test method and calculation model in this work accurately obtain the actual projectile proximity explosion position parameters.

关键词： Dynamic multi-screen array plane Flash photoelectric detection target Projectile signal processing Particle swarm Proximity explosion fuze Three-dimensional coordinate

Quantum Algorithm for Boolean Equation Solving and Quantum Algebraic Attack on Cryptosystems

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Journal of Systems Science & Complexity 2022年第1期35卷 373-412页

作者： CHEN Yu-Ao GAO xiao-shan Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

This paper presents a quantum algorithm to decide whether a Boolean equation system F has a solution and to compute one if F does have solutions with any given success *** runtime complexity of the algorithm is polynomial in the size of F and the condition number of certain Macaulay matrix associated with *** a consequence,the authors give a polynomial-time quantum algorithm for solving Boolean equation systems if their condition numbers are polynomial in the size of *** authors apply the proposed quantum algorithm to the cryptanalysis of several important cryptosystems:The stream cipher Trivum,the block cipher AES,the hash function SHA-3/Keccak,the multivariate public key cryptosystems,and show that they are secure under quantum algebraic attack only if the corresponding condition numbers are *** leads to a new criterion for designing such cryptosystems which are safe against the attack of quantum computers:The corresponding condition number.

关键词： Block cipher AES Boolean equation solving condition number hash function SHA3/Keccak HHL algorithm MPKC polynomial system solving quantum algorithm stream cipher Trivum

Passive location using CDMA mobile communication system based on repeater equipment

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The Journal of China Universities of Posts and Telecommunications 2008年第2期15卷 32-38页

作者： tian Zeng-shan ZHOU Fei ZHANG tian-qi Department of Communication and Information Engineering ChongqingUniversity of Posts and Telecommunications Chongqing 400065 China

To overcome the drawback of a short operation range and low-resolution of a passive location system using a civil communication signal, the new idea that utilizes code division multiple access （CDMA） signal and repeater is disposed off. First, the CDMA passive location model and observation function are given, and the error source and error range are analyzed. Subsequently, the CDMA passive location algorithm in a repeater environment is described and simulated. The simulation result shows that the algorithm can provide the location value with high accuracy.

关键词： passive location civil communication signal,location model repeater equipment operation range

Quantitative microstructure and fatigue life of B319 casting alloys

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Rare Metals 2017年第10期36卷 780-791页

作者： Yue Shen xiao-shan Liu Guo-Qiu He Dan-Dan tian Qi-Gui Wang Shi-Quan Lv School of Materials Science and Engineering Tongji University Shanghai 201804 China shanghai Key Laboratory for R&D and Application of Metallic Functional Materials Shanghai 201804 China Mat Technol Global Powertrain Engn Gen Motors Co Pontiac MI 48340 USA

In this study, the microstructure of B319 casting alloys and effects of five different casting conditions on microstructure were studied. Multi-scale microstructure was quantified in terms of secondary dendrite arm spacing （SDAS）, and Si particle size and aspect ratio. The effects of SDAS, Si aspect ratio and size on fatigue life were analyzed. The results indicate that the size and aspect ratio of Si particles are a function of SDAS which is dependent on cooling rate during solidification. The fatigue life decreases with SDAS increasing as SDAS is smaller than 30 pm while it increases with SDAS increasing as SDAS is larger than 60 ~tm. In addition, the fatigue life decreases with Si aspect ratio and size increasing at the same SDAS. Moreover, SDAS and Si particles have also influence on fatigue fracture, such as the area of cracks propagation region and the roughness of fatigue fracture. The cracks propagation area is smaller, and the fatigue fracture is similar to tensile fracture with larger SDAS. Besides, the longitudinal section of fatigue fracture is rougher with large SDAS and elongated Si particles.

关键词： B319 aluminum alloy Microstructure SDAS Si aspect ratio Si size Fatigue life

sp^(3)-like defect structure of hetero graphene-carbon nanotubes for promoting carrier transfer and stability

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Journal of Energy Chemistry 2021年第6期30卷 189-197,I0005页

作者： shan-shan Fan Ling Shen Yuan Dong Ge tian Si-Ming Wu Gang-Gang Chang Christoph Janiak Ping Wei Jin-Song Wu xiao-Yu Yang State Key Laboratory of Advanced Technology for Materials Synthesis and Processing and School of Materials Science&EngineeringWuhan University of TechnologyWuhan 430070HubeiChina School of Chemistry Chemical Engineering and Life ScienceWuhan University of TechnologyWuhan 430070HubeiChina Institut für Anorganische Chemie und Strukturchemie Heinrich-Heine-Universität Düsseldorf40204 DüsseldorfGermany NRC(Nanostructure Research Centre) Wuhan University of TechnologyWuhan 430070HubeiChina Department of Engineering and Applied Sciences Harvard University CambridgeMA 02138United States

Three-dimensional(3 D) hybrid of nanocarbons is a very promising way to the high-performance design of electrocatalysis ***,sp^(3)-like defect structure,a combination of high strength and conduction of graphene and carbon nanotubes(CNTs) is rarely ***,3 D neural-like hybrids of graphene(from reduced graphene oxide) and carbon nanotubes(CNTs) have been integrated via sp^(3)-like defect structure by a hydrothermal *** sp^(3)-like defect structure endows 3 D nanocarbon hybrids with an enhanced carrier transfer,high structural stability,and electrocatalytic *** neural-like structure is shown to demonstrate a cascade effect of charges and significant performances regarding bio-electrocatalysis and lithium-sulfur energy *** concept and mechanism of "sp^(3)-like defect structure" are proposed at an atomic/nanoscale to clarify the generation of rational structure as well as the cascade electron transfer.

关键词： Graphene Carbon nanotubes sp^(3)-like defect structure Bio-electrocatalysis Lithium-sulfur batteries