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Towards Accurate Bit Error Simulation in Wireless Sensor Networks Including Environmental Influences

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Journal of Computer Science & Technology 2020年第4期35卷 809-824页

作者： Sven Pullwitt Robert Hartung ulf Kulau Lars Wolf Institute for Operating Systems and Computer Networks Technische Universitat BraunschweigBraunschweig 38106 Germany

Simulation is a common technique for the evaluation of new approaches and protocols in networked systems and provides many ***,it is also well known that the relevance of the simulation results for real-world applications depends on the various models which are used within the simulation,e.g.,for the characteristics of the radio *** this paper,we introduce the Extended Multipath Raytracing Model,an extension to the ray-tracing radio medium available in Cooja,to improve the modelling of wireless links in simulated Wireless Sensor *** extension allows the simulation of environmental influences onto links on a per node basis,allowing the analysis of various effects observed in experiments in a virtual ***,the packet-based modelling of transmission errors is extended to provide the simulation of bit errors,allowing new usage scenarios,like the simulation of error detection and Forward Error Correction codes in Cooja.

关键词： bit error Contiki Cooja environmental influence simulation wireless sensor network

Diffusion-controlled Adsorption Kinetics at Air/Solution Surface Studied by Maximum Bubble Pressure Method

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Chinese Journal of Chemical Engineering 2004年第4期12卷 577-581页

作者：刘俊吉王创业 MESSOW ulf School of Science Tianjin University Tianjin 300072 China solution at temperature 25℃were measuredby means of Wilhelmy plate method and maximal bubble pressure method respectively. As t→0 the theoreticalanalysis is in good agreement with experimental results and the dependence of γ(t) on is linear.

In studying the diffusion-controlled adsorption kinetics of aqueous surfactant solutions at the air/solution surface by means of the maximal bubble pressure method, Fick's diffusion equation for a sphere should be used. In this paper the equation was solved by means of Laplace transformation under different initial and boundary conditions. The dynamic surface adsorption F(t) for a surfactant solution, which was used to describe the diffusion-controlled adsorption kinetics at the solution surface, was derived. Different from the planar surf aceadsorption, the dynamic surface adsorption Г(t) for the short time consists of two terms: one is the same as Ward-Tordai equation and the other reflects the geometric effect caused by the spherical bubble surface. This effect should not be neglected for the very small radius of the capillary. The equilibrium surface tension γeq and the dynamic surface tension γ(t) of aqueous C10E6 [CH3(CH2)9(OCH2CH2)6OH] solution at temperature 25℃ were measured by means of Wilhelmy plate method and maximal bubble pressure method respectively. As t→0, the theoretical analysis is in good agreement with experimental results and the dependence of γ(t) on (√t+r0/√πD)^2 is linear.

关键词：扩散控制系统吸附动力学动表面张力化学反应

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利用机器学习研究隐粲五夸克态的性质

Science Bulletin 2023年第10期68卷 981-989,M0003页

作者：张振宇刘家豪胡继峰王倩 ulf-G.Meißner Guangdong Provincial Key Laboratory of Nuclear Science Institute of Quantum MatterSouth China Normal UniversityGuangzhou 510006China Guangdong-Hong Kong Joint Laboratory of Quantum Matter Southern Nuclear Science Computing CenterSouth China Normal UniversityGuangzhou 510006China Helmholtz-Institut für Strahlen-und Kernphysik and Bethe Center for Theoretical Physics Universität BonnBonn D-53115Germany Institute for Advanced Simulation Institut für Kernphysik and Jülich Center for Hadron PhysicsForschungszentrum JülichJïlich D-52425Germany Tbilisi State University Tbilisi 0186Georgia

机器学习已经在生物、医学、生产等多个领域广泛应用并展现了其优势.最近,机器学习在物理领域也开始逐渐兴起并展现出其独特的优点.该文旨在探索机器学习在强子物理中的应用潜力.作者以隐粲五夸克态Pc(4312)、Pc(4440)和Pc(4457)为例,... 详细信息

机器学习已经在生物、医学、生产等多个领域广泛应用并展现了其优势.最近,机器学习在物理领域也开始逐渐兴起并展现出其独特的优点.该文旨在探索机器学习在强子物理中的应用潜力.作者以隐粲五夸克态Pc(4312)、Pc(4440)和Pc(4457)为例,在强子分子态图像下研究它们的性质.研究表明,神经网络方法和基于χ2的拟合方法都能够阐明基于领头阶接触势的基本物理性质.然而,χ2拟合方法无法区分Pc(4440)和Pc(4457)的量子数,神经网络方法则可以.由此,作者进一步分析了每个实验数据点对于神经网络预测的影响,以及在拟合方法中每个数据点对于关键物理参数的重要性.通过对比研究,作者发现神经网络方法可以多维度地利用实验数据信息,在强子物理中具有巨大的应用前景.

关键词： Exotic hadrons Machine learning QCD mass spectrum Hidden charm pentaquarks

Analysis of Bingham fluid radial flow in smooth fractures

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Journal of Rock Mechanics and Geotechnical Engineering 2020年第5期12卷 1112-1118页

作者： Liangchao Zou ulf Håkansson Vladimir Cvetkovic Division of Resources Energy and InfrastructureDepartment of Sustainable DevelopmentEnvironmental Science and EngineeringRoyal Institute of TechnologyStockholm10044Sweden Division of Soil and Rock Mechanics Department of Civil and Architectural EngineeringRoyal Institute of TechnologyStockholm10044Sweden Skanska Sweden AB Stockholm11274Sweden

Solutions for radial flow of a Bingham fluid are analyzed in this *** aims to eliminate confusions in the literature concerning the plug flow region in different solutions for analysis and design of grouting in rock *** analyses based on the force balance equation reveal that the plug flow region in Bingham radial flow is independent of the fracture radius,and is not a growth function adapted from the solution of one-dimensional(1D)slit flow according to‘similarity’.Based on the shear stress distribution,we analytically proposed that a non-uniform plug flow region cannot *** Bingham fluid(grout)penetration and flowrate evolution as functions of grouting time are given using the correct expression for the plug flow *** radius-independent plug flow region and the presented flowrate evolution equation are also verified *** radial flow,the relative penetration length is equal to the relative width of plug flow region,which is the same as that for 1D channel *** in analytical solutions for grout penetration and flowrate evolution were also *** clarification of the plug flow region and evaluation of discrepancies in analytical solutions presented in this work could simplify modeling and design of grouting in rock engineering applications.

关键词： Rock grouting Radial flow of Bingham fluids Plug flow region Force balance Energy dissipation Analytical solution

The proton radius:from a puzzle to precision

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Science Bulletin 2020年第4期65卷 257-258页

作者： Hans-Werner Hammer ulf-GMeiBner Institut für Kernphysik Technische Universitat Darmstadt64289 DarmstadtGermany ExtreMe Matter Institute EMMI GSI Helmholtzzentrum für Schwerionenforschung GmbH64291 DarmstadtGermany Helmholtz Institut für Strahlen-und Kernphysik and Bethe Center for Theoretical Physics Universitat BonnD-53115 BonnGermany Institute for Advanced Simulation and Institut für Kernphysik Forschungszentrum JülichD-52425 JülichGermany Tbilisi State University 0186 TbilisiGeorgia

The proton charge radius rP is a fundamental quantity in particle physics,as it challenges our understanding of the so successful Standard Model in the non-perturbative regime of the strong *** is defined by the slope of the proton charge form factor GE p etT at zero momentum transfer,with t the invariant four-momentum transfer *** proton charge radius was first indirectly measured in the Nobel prize winning electron scattering experiments by Hofstadter et al.[1,2],who fitted the form factor data with a dipole form and extracted the radius from the slope of the dipole.

关键词： DISPERSION-THEORETICAL ANALYSIS FORM-FACTORS NUCLEON SCATTERING HYDROGEN SIZE

Modeling of shear walls using finite shear connector elements based on continuum plasticity

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Frontiers of Structural and Civil Engineering 2017年第2期11卷 143-157页

作者： ulf Arne GIRHAMMAR Per Johan GUSTAFSSON Bo KALLSNER Division of Wood Science and Engineering Lulea University of Technology Skellefiea 93187 Sweden Division of Structural Mechanics Department of Building Sciences Lund University Lund 22100 Sweden Department of Building Technology Linnceus University Vaxjo 35195 Sweden

Light-frame timber buildings are often stabilized against lateral loads by using diaphragm action of roofs, floors and walls. The mechanical behavior of the sheathing-to-framing joints has a significant impact on the structural performance of shear walls. Most sheathing-to-framing joints show nonlinear load-displacement characteristics with plastic behavior. This paper is focused on the finite element modeling of shear walls. The purpose is to present a new shear connector element based on the theory of continuum plasticity. The incremental load-displacement relationship is derived based on the elastic-plastic stiffness tensor including the elastic stiffness tensor, the plastic modulus, a function representing the yield criterion and a hardening rule, and function representing the plastic potential. The plastic properties are determined from experimental results obtained from testing actual connections. Load-displacement curves for shear walls are calculated using the shear connector model and they are compared with experimental and other computational results. Also, the ultimate horizontal load-carrying capacity is compared to results obtained by an analytical plastic design method. Good agreements are found.

关键词： shear walls wall diaphragms finite element modelling plastic shear connector analytical modelling exoerimental comoarison

On the constituent counting rule for hard exclusive processes involving multi-quark states

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Chinese Physics C 2017年第5期41卷 91-96页

作者：郭奉坤 ulf-G.Mei?ner 王伟 State Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of Sciences Helmholtz-Institut fr Strahlen- und Kernphysik and Bethe Center for Theoretical Physics Universitt Bonn Institute for Advanced Simulation Institut fr Kernphysik and Jlich Center for Hadron PhysicsForschungszentrum Jlich INPAC Shanghai Key Laboratory for Particle Physics and CosmologyDepartment of Physics and AstronomyShanghai Jiao-Tong University

At high energy,the cross section at finite scattering angle of a hard exclusive process falls off as a power of the Manderstam variable *** all involved quark-gluon compositions undergo hard momentum transfers,the fall-off scaling is determined by the underlying valence structures of the initial and final hadrons,known as the constituent counting *** spite of the complication due to helicity conservation,it has been argued that when applied to exclusive process with exotic multiquark states,the counting rule is a powerful way to determine the valence degrees of freedom inside hadron *** this work,we demonstrate that for hadrons with hidden flavors,the naive application of the constituent counting rule is problematic,since it is not mandatory for all components to participate in hard scattering at the scale s1/*** illustrate the problems in the viewpoint based on effective field *** clarify the misleading results that may be obtained from the constituent counting rule in exclusive processes with exotic candidates such as Z_c~±（cd/cu）,Z_b~±（bd/bdu）,X（3872）,etc.

关键词： quark exclusive constituent hadron meson exotic problematic clarify momentum valence

Subwavelength-diameter silica wire for light in-coupling to silicon-based waveguide

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Chinese Optics Letters 2007年第10期5卷 577-579页

作者： Ziyang Zhang Min Qiu ulf Andersson 童利民 Department of Microelectronics and Applied Physics Royal Institute of Technology (KTH) Electrum 229 164 40 Kista Sweden Center for Parallel Computers Royal Institute of Technology (KTH) 100 44 Stockholm Sweden Department of Optical Engineering Zhejiang University Hangzhou 310027

Coupling between subwavelength-diameter silica wires and silicon-based waveguides is studied using the parallel three-dimensional （3D） finite-different time-domain method. Conventional butt-coupling to a silica-substrated silicon wire waveguide gives above 40% transmission at the wavelength range from 1300 to 1750 nm with good robustness against axial misalignments. Slow light can be generated by counterdirectional coupling between a silica wire and a two-dimensional （2D） silicon photonic crystal slab waveguide. Through dispersion-band engineering, 82% transmission is achieved over a coupling distance of 50 lattice constants, The group velocity is estimated as 1/35 of the light speed in vacuum.

关键词： Photonic crystals Refractive index Silica Silicon Slow light Waveguides

Neutron-antineutron oscillations in the deuteron studied with NN and ■N interactions based on chiral effective field theory

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Chinese Physics C 2020年第3期44卷 28-32页

作者： Johann Haidenbauer ulf-G.Meiβner Institute for Advanced Simulation Institut für Kernphysik and Jülich Center for Hadron PhysicsForschungszentrum JülichD-52425 JülichGermany Helmholtz-Institut für Strahlen-und Kernphysik and Bethe Center for Theoretical Physics Universität Bonn53115 BonnGermany Tbilisi State University 0186 TbilisiGeorgia

Neutron-antineutron(n−n)oscillations in the deuteron are ***,the deuteron lifetime is calculated in terms of the free-space n−n oscillation time τn−n based on NN and NN interactions derived within chiral effective field theory(EFT).This results in(2.6±0.1)×10^22τ2^n−n s,which is close to the value obtained by Dover and collaborators more than three decades ago,but disagrees with recent EFT calculations that were performed within the perturbative scheme proposed by Kaplan,Savage,and *** reasons for the difference are discussed.

关键词： neutron-antineutron oscillations chiral effective field theory NN interaction antinucleon-nucleon interaction