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Multispecies coalescent and its applications to infer species phylogenies and cross-species gene flow

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National Science Review 2021年第12期8卷 86-103页

作者： x.y.n jiao Tomá■ Flouri Ziheng yang Department of Genetics Evolution and EnvironmentUniversity College London Department of Statistics and Data Science Southern University of Science and Technology

Multispecies coalescent(MSC) is the extension of the single-population coalescent model to multiple species. It integrates the phylogenetic process of species divergences and the population genetic process of coalescent, and provides a powerful framework for a number of inference problems using genomic sequence data from multiple species, including estimation of species divergence times and population sizes,estimation of species trees accommodating discordant gene trees, inference of cross-species gene flow and species delimitation. In this review, we introduce the major features of the MSC model, discuss full-likelihood and heuristic methods of species tree estimation and summarize recent methodological advances in inference of cross-species gene flow. We discuss the statistical and computational challenges in the field and research directions where breakthroughs may be likely in the next few years.

关键词： anomaly zone BPP deep coalescence gene flow Markov chain Monte Carlo multispecies coalescent species tree

Conformal minimal immersions with constant curvature from S2 to Q5

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Frontiers of Mathematics in China 2019年第2期14卷 315-348页

作者： xiaoxiang jiao Hong LI School of Mathematical Sciences University of Chinese Academy of Sciences Beijing 100049 China

We study the geometry of conformal minimal two spheres immersed in G(2, 7;R). Then we classify the linearly full irreducible conformal minimal immersions with constarit curvature from S^2 to G(2, 7;R), or equivalently, a complex hyperquadric Q5 under some conditions. We also comple tely det ermine the Gaussian curvature of all linearly full tot ally unramified irreducible and all linearly full reducible conformal minimal immersions from S^2 to G(2, 7;R) with constant curvature. For reducible case, we give some examples, up to SO(7) equivalence, in which none of the spheres are congruent, with the same Gaussian curva tute.

关键词： Conformal minimal surface isotropy order constant curvature linearly full

What is going on in magnesium alloys？

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Journal of Materials Science & Technology 2018年第2期34卷 245-247页

作者： x.J. Wang D.K. xu R.Z. Wu x.B. Chen Q.M. Peng L. Jin y.C. xin Z.Q. Zhang y. Liu x.H. Chen G. Chen K.K. Deng H.y. Wang School of Materials Science and Engineering Harbin Institute of Technology Harbin 150001 China Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China Key Laboratory of Superlight Materials & Surface Technology (Ministry of Education) Harbin Engineering University Harbin 150001 China School of Engineering RMIT University City Campus Carlton VIC 3053 Australia State Key Laboratory of Metastable Materials Science and Technology Yanshan University Qinhuangdao 066004 China National Engineering Research Center of Light Alloy Net Forming Shanghai Jiao Tong University Shanghai 200240 China College of Materials Science and Engineering Chongqing University Chongqing 400030 China Key Lab of Electromagnetic Processing of Materials Ministry of Education Northeastern UniversityShnenyang 110819China Key Laboratory of Lightweight and High Strength Structural Materials of Jiangxi Province Nanchang University Nanchang 330031 China School of Chemical Engineering and Technology Tianjin University Tianjin 300350 China Shanxi Key Laboratory of Advanced Magnesium-Based Materials Taiyuan University of Technology Taiyuan 030024 China Key Laboratory of Automobile Materials of Ministry of Education & School of Materials Science and Engineering Jilin University Changchun 130025 China

China has been developed into one of the most active regions in terms of both fundamental and applied research on magnesium （Mg） and its alloys in the world from a solid base laid by its prominent metallurgist and materials scientists over the past decades. Nowadays, a large number of young-generation researchers have been inspired by their predecessors and become the key participants in the fields of Mg alloys, which consequently led to the establishment of China youth Scholar Society for Magnesium Alloys Research in 2015. Since then, the first two China youth Scholars Symposiums on Mg Alloys Research had been held at Harbin （2015） and Chongqing （2016） China, respectively. A number of crucial research inter- ests related to fundamental and applied Mg research were discussed at the conferences and summarized in this short perspective, aiming to boost far-reaching initiatives for development of new Mg-based materials to satisfy the requirements for a broad range of industrial employments. Herein, four main aspects are included as follows： i） Plastic deformation mechanism and strengthening strategy, ii） Design and development of new Mg-based materials, iii） Key service properties, and iv） New processing technologies.

关键词： Mg alloys Plastic deformation Strengthening Alloying design High performance Corrosion Fatigue behavior Creep Processing technologies Purification

The enhanced negative thermal expansion in less-oxygen-vacancies copper pyrophosphate

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Journal of Materials Science & Technology 2023年第15期146卷 80-85页

作者： L.Lu xie T.Fei Shi J.Chao Lin x.Kai Zhang x.Kang Zhong K.Ke Liu B.Ke Dong Cheng yang x.Lian Wang T.jiao xiong W.Sheng yan J.Ping xu H.Can Chen Wen yin Ming Li Peng Tong W.Hai Song y.Ping Sun Key Laboratory of Materials Physics Institute of Solid State PhysicsHFIPSChinese Academy of SciencesHefei 230031China University of Science and Technology of China Hefei 230026China Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions High Magnetic Field LaboratoryHFIPSChinese Academy of SciencesHefei 230031China Spallation Neutron Source Science Center Dongguan 523803China Department of Chemistry University of Warsaw02093 WarsawPoland National Synchrotron Radiation Laboratory University of Science and Technology of ChinaHefei 230029China

For oxides,controlling the concentration of oxygen vacancy is a useful way to optimize their functional ***,when it comes to the field of negative thermal expansion(NTE),much less attention has been paid to the effect of oxygen vacancy on NTE,though oxide-typed NTE materials account for more than 40%of the total NTE ***,we report that the linear coefficient of thermal expansion at 250–350 K of copper pyrophosphate(i.e.,Cu_(2)P_(2)O_(7))can be significantly improved from–13.88 to–36.60 ppm/K when the synthesis temperature is raised from 1073 to 1373 *** combined study including x-ray absorption near edge structure,neutron powder diffraction,and x-ray diffraction has confirmed the selective vacancies in the O1 site for low-temperature synthesized samples,which suppress both the phase-transition and framework-structure driven NTE *** result proposes a new approach for optimizing the NTE effect of oxides.

关键词： Negative thermal expansion xANES Oxygen vacancy Oxide Lattice distortion Phase transition

Solution for integer linear bilevel programming problems using orthogonal genetic algorithm

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Journal of Systems Engineering and Electronics 2014年第3期25卷 443-451页

作者： Hong Li Li Zhang yongchang jiao School of Mathematics and Statistics Xidian University Institute of Antennas and EM Scattering Xidian University

An integer linear bilevel programming problem is firstly transformed into a binary linear bilevel programming problem, and then converted into a single-level binary implicit programming. An orthogonal genetic algorithm is developed for solving the binary linear implicit programming problem based on the orthogonal design. The orthogonal design with the factor analysis, an experimental design method is applied to the genetic algorithm to make the algorithm more robust, statistical y sound and quickly convergent. A crossover operator formed by the orthogonal array and the factor analysis is presented. First, this crossover operator can generate a smal but representative sample of points as offspring. After al of the better genes of these offspring are selected, a best combination among these offspring is then generated. The simulation results show the effectiveness of the proposed algorithm.

关键词： integer linear bilevel programming problem integer optimization genetic algorithm orthogonal experiment design

AN SEIRS EPIDEMIC MODEL WITH TWO DELAyS AND PULSE VACCINATION

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Journal of Systems Science & Complexity 2008年第2期21卷 217-225页

作者： Jianjun jiao Lansun CHEN Shaohong CAI School of Mathematics and Statistics Guizhou College of Finance & Economics Guiyang 550004 China Department of Applied Mathematics Dalian University of-Technology Dalian 116024 China Institute of Mathematics Academy of Mathematics and System Science Chinese Academy of Science Beijing100190 China Guizhou College of Finance & Economics Guiyang 550004 China

Pulse vaccination is an effective and important strategy to eradicate an infectious disease. The authors investigate an SEIRS epidemic model with two delays and pulse vaccination. By using the discrete dynamical system determined by stroboscopic map, the authors obtain that the infectious population dies out if R△ 〈 1, and the infectious population is uniformly persistent if R^△ 〉 1. The results indicate that a short period of pulse vaccination or a large pulse vaccination rate is a sufficient condition to eradicate the disease.

关键词： Delay global attractivity persistence pulse vaccination SEIRS epidemic model.

Derimorphisms over Algebras and Applications

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Algebra Colloquium 2023年第2期30卷 193-204页

作者： x.Cao S.H.Liu x.S.Lu Z.J.ye Z.R.yu y.H.Zhang School of Mathematical Sciences Shanghai Jiao Tong University 800 Dongchuan RoadShanghai 200240China MoE Key Lab of Scientific and Engineering Computing Shanghai Jiao Tong University 800 Dongchuan RoadShanghai 200240China

The new concept"derimorphism"generalizing both derivation and homomor-phism is *** a derimorphism is invertible,its inverse is a Rota-Baxter *** general theory of derimorphism is *** classification of all derimorphisms over an associative unital algebra is *** to the nonexistence of nontriv-ial positive derivations,it is shown that nontrivial positive derimorphisms do exist over any pair of opposite orderings over R[x],the lattice-ordered full matrix algebra and upper triangular matrix algebra over a totally ordered field.

关键词： derimorphism Rota-Baxter operator opposite orderings positive derimor-phism

Applicability of large-ion lithophile and high field strength element basalt discrimination diagrams

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International Journal of Digital Earth 2018年第7期11卷 752-760页

作者： x.L.Liu Q.Zhang W.C.Li F.C.yang y.Zhao Z.Li S.T.jiao J.R.Wang N.Zhang S.S.Wang W.F.Chen Z.J.Pan J.yang x.L.Du Faculty of Land and Resource Engineering Kunming University of Science and TechnologyKunmingPeople’s Republic of China Institute of Geology and Geophysics Chinese Academy of SciencesBeijingPeople’s Republic of China Chengdu Geological Survey Center of China Geological Survey ChengduPeople’s Republic of China School of Earth Science Lanzhou UniversityLanzhouPeople’s Republic of China

Basalt discriminant diagrams have been used to identify the tectonic setting of basaltic magmatism since the 1970s and have played an important role in reconstructing paleotectonic ***,the significant increase in the availability of geochemical data has led to a reassessment of these diagrams,suggesting that some of the tectonic settings indicated by these diagrams are not ***,we use a database of global ocean island basalt(OIB),mid-ocean ridge basalt(MORB),and island arc basalt(IAB)geochemistry to propose a series of new tectonic discriminant diagrams based on the ratios of large-ion lithophile elements(LILEs)to high field strength elements(HFSEs).These new diagrams indicate that the LILE can be used to differentiate OIB,MORB,and IAB samples,meaning that LILE/HFSE ratios can discriminate between these basalts that form in different tectonic *** new diagrams can correctly assign samples to OIB,MORB,and IAB categories more than 85%of the time,with the discrimination between OIB and MORB having an accuracy of slightly less than 85%.

关键词： Basalt LILE HFSE discrimination diagram geochemistry

Pressure Evolution of the Magnetism and Fermi Surface of ybPtBi Probed by a Tunnel Diode Oscillator Based Method

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Chinese Physics Letters 2022年第9期39卷 41-46页

作者： y.E.Huang F.Wu A.Wang y.Chen L.jiao M.Smidman H.Q.yuan Center for Correlated Matter and Department of Physics Zhejiang UniversityHangzhou 310058China Zhejiang Province Key Laboratory of Quantum Technology and Device Department of PhysicsZhejiang UniversityHangzhou 310058China State Key Laboratory of Silicon Materials Zhejiang UniversityHangzhou 310058China Collaborative Innovation Center of Advanced Microstructures Nanjing 210093China

A central research topic in condensed matter physics is the understanding of the evolution of various phases and phase transitions under different tuning parameters such as temperature, magnetic field and pressure. To explore the pressure-induced evolution of the magnetism and Fermi surface of the heavy fermion antiferromagnet yb Pt Bi, we performed tunnel diode oscillator based measurements under pressure at low temperatures in high magnetic fields. Our results reveal that the magnetic order strengthens and the Fermi surface shrinks as the pressure increases, which are consistent with typical observations for yb-based heavy fermion compounds. In addition, an anomalous change in the quantum oscillation amplitudes is observed above 1.5 GPa, and determining the origin requires further study.

关键词： Fermi Probe oscillation