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The feature study on the π and proton rapidity distributions at AGS, SPS and RHIC

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Science china(physics,Mechanics & Astronomy) 2009年第2期52卷 198-206页

作者： FENG ShengQin1,2 & YUAN xianBao1,3 1 College of Science, china Three Gorges university, Yichang 443002, china 2 School of physics and Technology, Wuhan university, Wuhan 430072, china 3 Institute of Particle physics, Central china Normal university, Wuhan 430070, china College of Science China Three Gorges University Yichang China School of physics and Technology Wuhan University Wuhan China Institute of Particle physics Central China Normal University Wuhan China

The features of nuclear stopping power and multi-hadron production systematically are studied by making an analysis of rapidity distributions of pion and proton at AGS, SPS and RHIC in this work. It is found that nuclear stopping power increases linearly with project rapidity yp at AGS and SPS, but that is not liner at RHIC. It is argued that the average rapidity loss is saturated at central rapidity region at RHIC. For pion distribution, it is found that the phase space of pion distribution distributes uniformly in the longitudinal direction,and a linear relationship of L with log s is given at AGS and SPS. Non-uniform flow model may explain the features of the distribution at AGS and SPS, but may not ex- plain those of at RHIC.

关键词： non-uniform flow model average rapidity loss baryon number density nuclear stopping power

Flexible and Robust Functionalized Boron Nitride/Poly(p‑Phenylene Benzobisoxazole)Nanocomposite Paper with High Thermal Conductivity and Outstanding Electrical Insulation

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Nano-Micro Letters 2024年第2期16卷 423-437页

作者： Lin Tang Kunpeng Ruan xi Liu Yusheng Tang Yali Zhang Junwei Gu Chongqing Key Laboratory of Green Synthesis and Applications College of ChemistryChongqing Normal UniversityChongqing 401331People’s Republic of China Shaanxi Key Laboratory of Macromolecular Science and Technology School of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’an 710072People’s Republic of China

With the rapid development of 5G information technology,thermal conductivity/dissipation problems of highly integrated electronic devices and electrical equipment are becoming *** this work,“high-temperature solid-phase&diazonium salt decomposition”method is carried out to prepare benzidine-functionalized boron nitride(m-BN).Subsequently,m-BN/poly(pphenylene benzobisoxazole)nanofiber(PNF)nanocomposite paper with nacremimetic layered structures is prepared via sol–gel film transformation *** obtained m-BN/PNF nanocomposite paper with 50 wt%m-BN presents excellent thermal conductivity,incredible electrical insulation,outstanding mechanical properties and thermal stability,due to the construction of extensive hydrogen bonds andπ–πinteractions between m-BN and PNF,and stable nacre-mimetic layered ***λ∥andλ_(⊥)are 9.68 and 0.84 W m^(-1)K^(-1),and the volume resistivity and breakdown strength are as high as 2.3×10^(15)Ωcm and 324.2 kV mm^(-1),***,it also presents extremely high tensile strength of 193.6 MPa and thermal decomposition temperature of 640°C,showing a broad application prospect in high-end thermal management fields such as electronic devices and electrical equipment.

关键词： Poly(p-phenylene-2,6-benzobisoxazole)nanofiber Boron nitride Thermal conductivity Electrical insulation

Scheme for Entanglement Concentration of Unknown Multiparticle Greenberger-Horne-Zeilinger or W Class States

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Communications in Theoretical physics 2007年第12期48卷 1025-1028页

作者： SONG Wei Hefei National Laboratory for Physical Sciences at Microscale and Department of modern physics,university of Science and Technology of china,Hefei 230026,china Hefei National Laboratory for Physical Sciences at Microscale and Department of modern physics University of Science and Technology of China Hefei 230026 China

We present,two schemes for concentrating unknown nonmaximally entangled Greenberger Horme-Zeilinger(GHZ) or W class *** first scheme for concentrating the nonmaximally entangled GHZ state is based on linearoptical *** second scheme for concentrating the W class states can be applied to a wide variety of atomic *** of our schemes are not postselection ones and are within the current technologies.

关键词： entanglement concentration GHZ class states W class states

Structure analysis of ^(159)Sm and properties of odd-mass neutron-rich nuclei in mass-160 region

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Science china(physics,Mechanics & Astronomy) 2011年第S1期54卷 81-87页

作者： YANG YingChun1 & SUN Yang1,2,3 1 Department of physics, Shanghai Jiao Tong university, Shanghai 200240, china 2Institute of modern physics, Chinese Academy of Sciences, Lanzhou 730000, china 3Department of physics and Astronomy, university of Tennessee, Knoxville, Tennessee 37996, USA Department of physics Shanghai Jiao Tong University Shanghai China Institute of modern physics Chinese Academy of Sciences Lanzhou China Department of physics and Astronomy University of Tennessee Knoxville USA

Recent fission experiment data provide interesting structure information for neutron-rich nuclei in the mass A ～ 160 region. We apply the projected shell model to study the strongly-deformed, neutron-rich Sm isotopes. We perform calculations for rotational bands up to spin I = 20 (29/2) for even-even (odd-neutron) Sm isotopes, and analyze the band structure of low-lying states with quasiparticle excitations. Emphasis is given to rotational bands based on one-quasiparticle (1-qp) configurations in the odd-mass 159Sm. The 159 Sm result is discussed together with those of the even-even isotopes 158,160Sm. New bands in 159Sm based on neutron 1-qp 1/2 and 5/2+ configurations are predicted. Electromagnetic transition probabilities are discussed.

关键词： projected shell model neutron-rich nuclei low-lying excitations isomeric states

Epidemic dynamics on complex networks

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Progress in Natural Science:Materials International 2006年第5期16卷 452-457页

作者： ZHOU Tao , FU Zhongqian, and WANG Binghong (Department of Electronic Science and Technology, university of Science and Technology of china, Hefei 230026, china Department of modern physics, university of Science and Technology of china, Hefei 230026, china) Department of Electronic Science and Technology University of Science and Technology of China Hefei 230026 China Department of modern physics University of Science and Technology of China Hefei 230026 China

Recently, motivated by the pioneer work in revealing the small-world effect and scale-free property of various real-life networks, many scientists devote themselves to studying complex networks. One of the ultimate goals is to understand how the topological structures affect the dynamics upon networks. In this paper, we give a brief review on the studies of epidemic dynamics on complex networks, including the description of classical epidemic models, the epidemic spread on small-world and scale-free networks, and network immunization. Finally, perspectives and some interesting problems are proposed.

关键词： epidemic dynamics complex networks critical value immunization small-world effect scale-free property.

Impurity in Pairwise Entanglement of Heisenberg XX Open Chain

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Communications in Theoretical physics 2007年第12期 1009-1016页

作者： xi xiao-Qiang~(1,2)CHEN Wen-Xue~1 LIU Qi~3 and YUE Rui-Hong~3~1 Department of Applied Mathematics and physics,xi’an Institute of Posts and Telecommunications,xi’an 710061,china~2 Joint Laboratory of Advanced Technology in Measurements,Beijing National Laboratory for Condensed Matter physics,Institute of physics,the Chinese Academy of Sciences,Beijing 100080,china~3 Institute of modern physics,North-West university,xi’an 710069,china Department of Applied Mathematics and physics Xi'an Institute of Posts and Telecommunications Xi'an 710061 China Joint Laboratory of Advanced Technology in Measurements Beijing National Laboratory for Condensed Matter Physics Institute of Physics the Chinese Academy of Sciences Beijing 100080 China Department of Applied Mathematics and physics Xi'an Institute of Posts and Telecommunications Xi'an 710061 China Institute of modern physics North-West University Xi'an 710069 China

We calculate the concurrence of all pairwise entanglement of Heisenberg XX open chain with single systemimpurity in three-qubit and four-qubit cases,and find that the impurity parameter J_i has great effect on *** the proper parameter J_i,we can obtain the maximal pairwise entanglement of the nearestqubits and make the non-nearest qubits entangle.

关键词： system impurity pairwise entanglement Heisenberg XX chain

Recent Advances in Cobalt-Catalyzed Regio-or Stereoselective Hydrofunctionalization of Alkenes and Alkynes

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CCS Chemistry 2024年第5期6卷 1130-1156页

作者： Yan Li xi Lu Yao Fu Hefei National Research Center for Physical Sciences at the Microscale CAS Key Laboratory of Urban Pollutant ConversionAnhui Province Key Laboratory of Biomass Clean EnergyUniversity of Science and Technology of ChinaHefei 230026 Key Laboratory of Precision and Intelligent Chemistry Department of Applied ChemistrySchool of Chemistry and Materials ScienceUniversity of Science and Technology of ChinaHefei 230026

Hydrofunctionalization of alkenes and alkynes is increasingly important in preparing and modifying carbon-centered organic molecules such as pharmaceuticals,agrochemicals,andmaterial *** development of transition-metal-catalysts has revolutionized the hydrofunctionalization of unsaturated hydrocarbons,greatly improving the synthetic efficiency and selectivity of these *** recent years,notable progress has been achieved in low-cost metal-catalyzed alkene and alkyne hydrofunctionalization reactions following the utilization of traditional precious metal catalysts,including palladium,platinum,and ***-abundant cobalt catalysts,which are low in toxicity and exhibit unique reactivity and selectivity,are widely implemented in academic and industrial *** this review,we highlight recent examples of cobalt-catalyzed hydrofunctionalization of alkenes and alkynes to provide an overview of hydrofunctionalization methods,particularly hydroalkylation *** reactions greatly expand the scope and utility of cobalt-catalyzed couplings of carbon—carbon *** also highlight the mechanistic considerations and selective determinants *** hope our discussion will be informative for future developments in cobalt catalysis and hydrofunctionalization reactions.

关键词： hydrofunctionalization cobalt-catalysis alkene alkyne regioselectivity stereoselectivity

Fault Identification for Shear-Type Structures Using Low-Frequency Vibration Modes

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Computer Modeling in Engineering & Sciences 2024年第3期138卷 2769-2791页

作者： Cuihong Li Qiuwei Yang xi Peng School of Civil Engineering Shaoxing UniversityShaoxing312000China School of Civil and Transportation Engineering Ningbo University of TechnologyNingbo315211China Engineering Research Center of Industrial Construction in Civil Engineering of Zhejiang Ningbo University of TechnologyNingbo315211China

Shear-type structures are common structural forms in industrial and civil buildings,such as concrete and steel frame *** diagnosis of shear-type structures is an important topic to ensure the normal use of *** main drawback of existing damage assessment methods is that they require accurate structural finite element models for damage ***,for many shear-type structures,it is difficult to obtain accurate *** order to avoid finite elementmodeling,amodel-freemethod for diagnosing shear structure defects is developed in this *** method only needs to measure a few low-order vibration modes of the *** proposed defect diagnosis method is divided into two *** the first stage,the location of defects in the structure is determined based on the difference between the virtual displacements derived from the dynamic flexibility matrices before and after *** the second stage,damage severity is evaluated based on an improved frequency sensitivity *** innovations of this method lie in two *** first innovation is the development of a virtual displacement difference method for determining the location of damage in the shear *** second is to improve the existing frequency sensitivity equation to calculate the damage degree without constructing the finite *** has been verified on a numerical example of a 22-story shear frame structure and an experimental example of a three-story steel shear *** on numerical analysis and experimental data validation,it is shown that this method only needs to use the low-order modes of structural vibration to diagnose the defect location and damage degree,and does not require finite element *** proposed method should be a very simple and practical defect diagnosis technique in engineering practice.

关键词： Fault diagnosis shear steel structure vibration mode dynamic flexibility frequency sensitivity

Interfacial forces between silica surfaces measured by atomic force microscopy

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Journal of Environmental Sciences 2009年第1期21卷 30-34页

作者： DUAN JinmingKey Laboratory of northwest Water Resource,Environment and Ecology,MOE,xi’an university of Architecture and Technology,xi’an 710055,china Key Laboratory of northwest Water Resource Environment and Ecology MOE Xi'an University of Architecture and Technology Xi'an 710055 China

Colloidal particle stability and some other interfacial phenomena are governed by interfacial force interactions. The two well known forces are van der Waals force and electrostatic force, as documented by the classical Derjaguin, Landau, Verwey, and Overbeek （DLVO） theory. Moreover, advances in modern instrumentation and colloid science suggested that some short-ranged forces or structure forces are important for relevant colloidal systems. The interfacial and/or molecular forces can be measured as a resultant force as function of separation distance by atomic force microscopy （AFM） colloid probe. This article presents a discussion on AFM colloid probe measurement of silica particle and silica wafer surfaces in solutions with some technical notifications in measurement and data convolution mechanisms. The measured forces are then analyzed and discussed based on the ＇constant charge＇ and ＇constant potential＇ models of DLVO theory. The difference between the prediction of DLVO theory and the measured results indicates that there is a strong short-range structure force between the two hydrophilic surfaces, even at extremely low ionic concentration, such as Milli-Q water purity solution.

关键词： colloid probe DLVO theory solvation forces interfacial interactions