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Vector meson's spin alignments in high energy reactions

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 5-20页

作者： Jin-Hui Chen Zuo-Tang Liang Yu-gang Ma Xin-Li Sheng qun Wang Key Laboratory of Nuclear Physics and Ion-beam Application (MoE) Institute of Modern PhysicsFudan University Institute of Frontier and Interdisciplinary Science Key Laboratory of Particle Physics and Particle Irradiation (MOE)Shandong University INFN-Firenze Department of Modern Physics University of Science and Technology of China School of Mechanics and Physics Anhui University of Science and Technology

The global spin alignment of vector mesons has been observed by the STAR collaboration at the Relativistic Heavy Ion Collider （RHIC） at Brookhaven National Laboratory （BNL）.It provides a unique opportunity to probe the correlation between the polarized quark and antiquark in the strongly coupled quark-gluon plasma （sQGP） produced in relativistic heavy ion collisions,opening a new window to explore the properties of s *** addition,spin alignments of vector mesons have also been observed in other high-energy particle collisions such as e+e-annihilations at high energies where hadron production is dominated by quark fragmentation *** results obtained are quite different from those obtained in heavy ion collisions where quark coalescence/combination mechanism dominates suggesting strong dependence on hadronization *** comprehensive studies in different hadronization processes are *** this article,we present a brief review of theoretical and experimental advances in the study of vector meson’s spin alignments in a variety of high-energy particle collisions,with emphasis on hadronization mechanisms.

关键词： vector meson spin alignment global polarization relativistic heavy ion collisions fragmentation

Undersea safety mining of the large gold deposit in Xinli District of Sanshandao Gold Mine

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International Journal of Minerals,Metallurgy and Materials 2012年第7期19卷 574-583页

作者： Zhi-xiang Liu wen-gang Dang Xian-qun He School of Resources and Safety Engineering Central South University Changsha 410083 China

The exploration of undersea resources becomes popular as land resources decrease. Researches were conducted with emphasis on the safety and efficiency of undersea mining of the large gold deposit in Xinli District of Sanshandao Gold Mine. A series of tests for the physical and mechanical characteristics of rock mass were carried out, and the three-dimensional geo-stress distribution was tested in the mining area. Further, a similar experimental simulation platform, which revealed the mechanism of water inrush and ascertained the reason- able thickness of the safety isolate layer, was established for the undersea mining. Meanwhile, the feasibility of cancelling the ore pillars and the safety conditions was checked by numerical simulation. The simulation results show that it is safe to exploit the ore body below the -85 m level （presently, the exploitation level is below -160 m in Xinli District）, and the ore pillars can be cancelled below the -560 m level. Fur- thermore, a novel backfill method was designed to reduce the rock strata disturbance and settlement, and the settlement of roof strata was monitored during the mining process. Engineering practice shows that the settlement of roof strata was small and that no disaster happened. This indicates that the undersea safety mining technology of the large gold deposit is achieved in Xinli District.

关键词： undersea mining gold deposits rock mechanics mine roof control computer simulation

Unstable relationship between spring NAO and summer tropical cyclone genesis frequency over the western North Pacific

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Acta Oceanologica Sinica 2020年第5期39卷 65-76页

作者： qun Zhou wen Chen National Marine Environmental Forecasting Center Ministry of Natural ResourcesBeijing 100081China Center for Monsoon System Research Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100190China

The present study reveals the fact that the relationship between the spring(April–May)North Atlantic Oscillation(NAO)and the following summer(June–September)tropical cyclone(TC)genesis frequency over the western North Pacific(WNP)during the period of 1950–2018 was not *** is shown that the relationship between the two has experienced a pronounced interdecadal shift,being weak and insignificant before yet strong and statistically significant after the early 1980 *** we compare the spring NAO associated dynamic and thermodynamic conditions,sea surface temperature(SST)anomalies,and atmospheric circulation processes between the two subperiods of 1954–1976 and 1996–2018,so as to illucidate the possible mechanism for this interdecadal variation in the NAO-TC *** the latter epoch,when the spring NAO was positive,enhanced low-level vorticity,reduced vertical zonal wind shear,intensified vertical velocity and increased middle-level relative humidity were present over the WNP in the summer,which is conducive to the genesis of WNP *** the spring NAO is negative,the dynamic and thermodynamic factors are disadvantageous for the summertime TC formation and development over the *** results of further analysis indicate that the persistence of North Atlantic tri-pole SST anomalies from spring to the subsequent summer induced by the spring NAO plays a fundamental role in the linkage between the spring NAO and summer atmospheric *** the period of 1996–2018,a remarkable eastward propagating wave-train occurred across the northern Eurasian continent,forced by the anomalous SST tri-pole in the North *** East Asian jet flow became greatly intensified,and the deep convection in the tropics was further enhanced via the changes of the local Hadley circulation,corresponding to a positive spring *** the former epoch,the spring NAO-induced tri-pole SST anomalies in the North Atlantic were non-existent,and the related atmospheric

关键词： spring North Atlantic Oscillation summer tropical cyclone western North Pacific

In situ synthesis of Fe-based alloy clad coatings containing TiB_2–TiN –(h-BN)

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International Journal of Minerals,Metallurgy and Materials 2015年第6期22卷 613-619页

作者： Shao-qun Jiang gang Wang Qing-wen Ren Chuan-duo Yang Ze-hua Wang and Ze-hua Zhou College of Mechanics and Materials Hohai University Changzhou Hohai Institute of Science and Technology Limited Liability Company

Fe-based alloy coatings containing TiB2–TiN –（h-BN） were synthesized in situ on Q235 steel substrates by a plasma cladding process using the powders of Fe901 alloy, Ti, and h-BN as raw materials. The effects of Ti/h-BN mass ratio on interfacial bonds between the coating and substrate along with the microstructures and microhardnesses of the coatings were investigated. The results show that the Ti/h-BN mass ratio is a vital factor in the formation of the coatings. Free h-BN can be introduced into the coatings by adding an excess amount of h-BN into the precursor. Decreases in the Ti/h-BN mass ratio improve the microstructural uniformity and compactness and enhance the interfacial bonds of the coatings. At a Ti/h-BN mass ratio of 10/20, the coating is free of cracks and micropores, and mainly consists of Fe-Cr, Fe3B, TiB2, TiN, Ti2N, TiB, FeN, FeB, Fe2B, and h-BN phases. Its average microhardness in the zone between 0.1–2.8 mm from the coating surface is about Hv0.2 551.5.

关键词： iron-based materials coatings plasma cladding in situ synthesis microhardness

A LINE SEARCH AND TRUST REGION ALGORITHM WITH TRUST REGION RADIUS CONVERGING TO ZERO

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Journal of Computational Mathematics 2004年第6期22卷 865-872页

作者： Jin-yanFan wen-baoAi qun-yingZhang DepartmentofMathematics ShanghaiJiaoTongUniversityShanghai200230China SchoolofSciences BeijingUniversityofPostsandTelecommunicationsBeijing100876China DepartmentofMathematics .YangzhouUniversityYangzhou225009China

In this paper, we present a new line search and trust region algorithm for unconstrained optimization problem with the trust region radius converging to zero. The new trust region algorithm performs a backtracking line search from the failed, point instead of resolving the subproblem when the trial step results in an increase in the objective function. We show that the algorithm preserves the convergence properties of the traditional trust region algorithms. Numerical results are also given.

关键词： Unconstrained optimization Tmst region Line search

AN ADAPTIVE NONMONOTONIC TRUST REGION METHOD WITH CURVILINEAR SEARCHES

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Journal of Computational Mathematics 2006年第6期24卷 761-770页

作者： qun-yan Zhou wen-yu Sun School of Mathematics and Computer Science Nanjing Normal University Nanjing 210097 China Department of Mathematics Jiangsu Teacher University of Technology Changzhou 213001 China

In this paper, an algorithm for unconstrained optimization that employs both trust region techniques and curvilinear searches is proposed. At every iteration, we solve the trust region subproblem whose radius is generated adaptively only once. Nonmonotonic backtracking curvilinear searches are performed when the solution of the subproblem is unacceptable. The global convergence and fast local convergence rate of the proposed algorithms are established under some reasonable conditions. The results of numerical ＇experiments are reported to show the effectiveness of the proposed algorithms.

关键词： Unconstrained optimization Preconditioned gradient path Trust region method,Curvilinear search.

A NONMONOTONE SECOND-ORDER STEPLENGTH METHOD FOR UNCONSTRAINED MINIMIZATION

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Journal of Computational Mathematics 2007年第1期25卷 104-112页

作者： qun-yan Zhou wen-yu Sun Department of Basic Science Jiangsu Teachers University of Technology Changzhou 213001 China School of Mathematics and Computer Science Nanjing Normal University Nanjin9 210097 China School of Mathematics and Computer Science Nanjing Normal University Nanjing 210097 China

In this paper, a nonmonotone method based on McCormick＇s second-order Armijo＇s step-size rule [7] for unconstrained optimization problems is proposed. Every limit point of the sequence generated by using this procedure is proved to be a stationary point with the second-order optimality conditions. Numerical tests on a set of standard test problems are presented and show that the new algorithm is efficient and robust.

关键词： Nonmonotone method Armijo's line search Direction of negative curvature,Unconstrained optimization.

A theory of 2+1D bosonic topological orders

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National Science Review 2016年第1期3卷 68-106页

作者： Xiao-gang wen Perimeter Institute for Theoretical Physics Department of Physics Massachusetts Institute of Technology

In primary school, we were told that there are four phases of matter: solid, liquid, gas, and plasma. In college,we learned that there are much more than four phases of matter, such as hundreds of crystal phases, liquid crystal phases, ferromagnet, anti-ferromagnet, superfluid, etc. Those phases of matter are so rich, it is amazing that they can be understood systematically by the symmetry breaking theory of Landau. However,there are even more interesting phases of matter that are beyond Landau symmetry breaking theory. In this paper, we review new ‘topological’ phenomena, such as topological degeneracy, that reveal the existence of those new zero-temperature phase—topologically ordered phases. Microscopically, topologically orders are originated from the patterns of long-range entanglement in the ground states. As a truly new type of order and a truly new kind of phenomena, topological order and long-range entanglement require a new language and a new mathematical framework, such as unitary fusion category and modular tensor category to describe them. In this paper, we will describe a simple mathematical framework based on measurable quantities of topological orders(S, T, c) proposed around 1989. The framework allows us to systematically describe all 2+1D bosonic topological orders(i.e. topological orders in local bosonic/spin/qubit systems).

关键词： quantum matter topological order long range entanglement modular tensor category

A Lattice Non-Perturbative Definition of an SO(10) Chiral Gauge Theory and Its Induced Standard Model

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Chinese Physics Letters 2013年第11期30卷 54-58页

作者： wen Xiao-gang Perimeter Institute for Theoretical Physics WaterlooOntario N2L 2Y5Canada Department of Physics Massachusetts Institute of TechnologyCambridgeMassachusetts 02139USA

The standard model is a chiral gauge theory where the gauge fields couple to the right-hand and the left-hand fermions *** standard model is defined perturbatively and describes all elementary particles(except gravitons)very ***,for a long time,we do not know if we can have a non-perturbative definition of the standard model as a Hamiltonian quantum mechanical *** we propose a way to give a modified standard model(with 48 two-component Weyl fermions)a non-perturbative definition by embedding the modified standard model into an SO(10)chiral gauge *** show that the SO(10)chiral gauge theory can be put on a lattice(a 3D spatial lattice with a continuous time)if we allow fermions to *** a non-perturbatively defined standard model is a Hamiltonian quantum theory with a finite-dimensional Hilbert space for a finite space *** generally,using the defining connection between gauge anomalies and the symmetry-protected topological orders,one can show that any truly anomaly-free chiral gauge theory can be non-perturbatively defined by putting it on a lattice in the same dimension.

关键词： theory gauge chiral