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Structural Durability & Health Monitoring 2025年第1期19卷 55-75页

作者： Zhenyu Zhang Quan Jin Haitao Zhang zhao liu Yuyang Wu Longfei Zhang Renzhang Yan CCCC Third Highway Engineering Co. Ltd.Beijing101300China School of Civil Engineering Chongqing Jiaotong UniversityChongqing400074China

When the upper chord beam of the beam-string structure(BSS)is made of concrete-filled steel tube(CFST),its overall stiffness will change greatly with the construction of concrete placement,which will have an impact on the design of the tensioning plans and selection of control measures for the *** order to accurately obtain the bending stiffness of CFST beam and clarify its impact on the mechanical properties of composite BSS during construction,the influence of some factors such as height-width ratio,wall thickness of steel tube,elasticity modulus of concrete,and friction coefficient on the bending stiffness are analyzed parametrically by the numerical simulation technology based on an actual *** calculation formula of the equivalent bending stiffness of CFST is also established through mathematical statistical ***,the equivalent bending stiffness is introduced into the construction and use stages of the composite BSS,respectively,and the mechanical properties such as prestress-tensioning control value,structural deformation,and internal force of key members are comparatively analyzed when adopting two different construction ***,the optimal construction plan of concrete placement first and then prestress-tensioning is proposed.

关键词： Concrete panels freeze-thaw damage compression-shear crack tension-shear crack

地区新质生产力对企业全要素生产率的影响与机制

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中国流通经济 2025年第1期39卷 100-114页

作者：张树山刘赵宁东北师范大学经济与管理学院吉林长春130117

发展新质生产力是推动经济高质量发展的内在要求和重要着力点。从微观视角出发,考察具有显著差异化特征的地区新质生产力对企业全要素生产率的影响效应及其内在机制,不仅能够为加速形成新质生产力提供精准的政策指引,还能够为经济运行... 详细信息

发展新质生产力是推动经济高质量发展的内在要求和重要着力点。从微观视角出发,考察具有显著差异化特征的地区新质生产力对企业全要素生产率的影响效应及其内在机制,不仅能够为加速形成新质生产力提供精准的政策指引,还能够为经济运行的关键微观基础提供有效改善生产效率的战略指导。基于2012—2022年我国30个省份(未含港澳台藏)和沪深A股上市公司数据,在通过熵值法测算地区新质生产力发展水平的基础上,利用文本分析法、固定效应模型,深入探究地区新质生产力对企业全要素生产率的影响及其机制。研究发现,地区新质生产力能显著提升企业全要素生产率。从机制检验结果来看,地区新质生产力能够通过赋能企业数字技术创新突破、数字技术应用成效以及内外部交易成本降低,进而提高企业全要素生产率,且公司内部治理与市场公平竞争环境的强化均能增强地区新质生产力对企业生产率的提升效应。异质性检验结果表明,在非国有企业、制造业以及胡焕庸线以东地区,地区新质生产力对企业全要素生产率提升作用更加明显。为此,应在因地制宜的原则下培育和发展新质生产力,统筹推进新型基础设施建设,重视并激发数据要素潜能,促进传统产业和新兴产业协调发展;重视企业治理效能提升,优化信息披露机制,强化披露质量,同时鼓励金融机构将公司治理水平纳入信用评估体系,切实提升公司治理能力;努力营造公平竞争的市场环境,严格落实公平竞争审查,维护良好市场秩序与健康竞争生态,以期助力新质生产力的重大战略意义实现。

关键词：新质生产力全要素生产率市场公平竞争公司治理

Evolution of grain size and grain shape during thermomechanical processing in a powder metallurgical nickel-based superalloy

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Journal of Iron and Steel Research International 2022年第2期29卷 350-358页

作者： Yan-hui liu zhao-zhao liu Miao Wang College of Mechanical and Electrical Engineering Shaanxi University of Science and TechnologyXi’an710021ShaanxiChina School of Materials Science and Engineering Northwestern Polytechnical UniversityXi’an710072ShaanxiChina Zhejiang Wenzhou Research Institute of Light Inousty Wenzhou325002ZhejiangChina

With a strain rate range of 0.01–10 s^(−1) and a deformation temperature range of 1110–1200℃,the isothermal compression test was performed on one powder metallurgy superalloy which is macroscopic segregation *** electron backscatter diffraction,the effect of strain rate and deformation temperature on grain shape and grain size of superalloys during thermal deformation was *** results established that exquisite and equiaxed dynamic recrystallization(DRX)grains are procured at supernal deformation temperature and high strain rate because of the high dislocation *** the same time,the interaction between high DRX nucleation rate and low grain growth rate at high strain rate is favorable in making finer DRX *** equivalent medial grain size expanded with lowering strain rate and elevating proof ***,the grain shape was researched by the effective method of aspect *** aspect ratio of original grains is 0.61,and the aspect ratio has important implications for DRX and grain growth *** average aspect ratio increases slightly when deformation temperature rises from 1110 to 1140℃,while the average aspect ratio increases memorably as the deformation temperature is higher than 1140℃.

关键词： Powder metallurgy nickel-based superalloy Isothermal compression Grain size Grain shape calculation method Electron backscatter diffraction Grain shape aspect ratio

Velocity distribution and scaling properties of wall bounded flow

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第7期11卷 505-510页

作者： zhao-cun liu Key Laboratory o finland Waterway Regulation of Communications Industry Chongqing Jiaotong University Chongqing 400074 China Key Laboratory of Waterway Engineering of Communication Ministry and Chongqing City Chongqing Jiaotong UniversityChongqing 400074 China

The scaling and similarity of wall bounded turbulent flow were studied. The properties of such flows and the relationship between a power law and a logarithmic type of velocity distribution were investigated. Based on the physical mechanism involved, our results show that the power law and the logarithmic distribution are only different forms with the same hypothesis and hold only in the outer flow zone. Thus, a universal explanation for various empirical formulae of velocity distribution was obtained. Manning’s formula was studied to explain theoretically the experiential result that the roughness coefficient is only a comprehensive parameter of the whole system without a corresponding physical factor. The physical mechanism of the velocity distribution of parallel to wall bounded flow was explored, the results show that the parameters in the formula of velocity distribution are indices of the system responding to flowing environmental factors to represent general case of boundary roughness and the flowing state, corresponding physical mechanism is vortex motion.

关键词： Velocity distribution Scaling Turbulence

Scaling properties of Navier-Stokes turbulence

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第3期10卷 392-397页

作者： zhao-cun liu School of Environment and Planning Henan University Kaifeng 475001 China

The property of the velocity field and the cascade process of the fluid flow are key problems in turbulence research. This study presents the scaling property of the turbulent velocity field and a mathematical description of the cascade process, using the following methods: (1) a discussion of the general self-similarity and scaling invariance of fluid flow from the viewpoint of the physical mechanism of turbulent flow; (2) the development of the relationship between the scaling indices and the key parameters of the She and Leveque (SL) model in the inertial range; (3) an investigation of the basis of the fractal model and the multi-fractal model of turbulence; (4) a demonstration of the physical meaning of the flowing field scaling that is related to the real flowing vortex. The results illustrate that the SL model could be regarded as an approximate mathematical solution of Navier-Stokes (N-S) equations, and that the phenomena of normal scaling and anomalous scaling is the result of the mutual interactions among the physical factors of nonlinearity, dissipation, and dispersion. Finally, a simple turbulent movement conceptional description model is developed to show the local properties and the instantaneous properties of turbulence.

关键词： Transformation equations Scaling Spiral structure Cascade Turbulence

Existence of Solutions for the Critical Elliptic System with Inverse Square Potentials

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Acta Mathematicae Applicatae Sinica 2013年第2期29卷 315-328页

作者： zhao-xia liu zhao-hui liu Department of Information and Computational Science School of Sciences Minzu University of China Suncun Middle School Gaoxin District of Jinan

Let Ω∈← 0 be an open bounded domain in RN （N 〉 3） and 2＊（s） = 2（N-8） =2（N-s）N-22. We consider the following elliptic system of two equations in where A, μ 〉 0 and α, β 〉 1 satisfy α ＋ β = 2＊（s... 详细信息

Let Ω∈← 0 be an open bounded domain in RN （N 〉 3） and 2＊（s） = 2（N-8） =2（N-s）N-22. We consider the following elliptic system of two equations in where A, μ 〉 0 and α, β 〉 1 satisfy α ＋ β = 2＊（s）. Using the Moser iteration, we prove the asymptotic behavior of solutions at the origin. In addition, by exploiting the Mountain-Pass theorem, we establish the existence of solutions.

关键词： elliptic system variational functional Palais-Smale condition critical point

Thermodynamics for higher dimensional rotating black holes with variable Newton constant

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Chinese Physics C 2022年第5期46卷 198-205页

作者： liu zhao School of Physics Nankai UniversityTianjin 300071China

The extensivity for the thermodynamics of general D-dimensional rotating black holes with or without a cosmological constant can be proved analytically,provided that the effective number of microscopic degrees of freedom and the chemical potential are given respectively as N=L^(D−2)/G,μ=GTI_(D)/L^(D−2),where G is the variable Newton constant,I_(D) is the Euclidean action,and L is a constant length *** the cases without a cosmological constant,i.e.,the Myers-Perry black holes,the physical mass and the intensive variables can be expressed as explicit macro state functions in the extensive variables in a simple and compact form,which allows for an analytical calculation of the heat *** results indicate that the Myers-Perry black holes with zero,one,and k equal rotation parameters are all thermodynamically unstable.

关键词： black hole thermodynamics higher dimensional spacetime Euler relation thermodynamic instability extensive thermodynamics

Degradation algorithm of compressive sensing

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Journal of Systems Engineering and Electronics 2011年第5期22卷 832-839页

作者： Chunhui zhao Wei liu College of Information and Communication Engineering Harbin Engineering University Harbin 150001 P. R. China

The compressive sensing （CS） theory allows people to obtain signal in the frequency much lower than the requested one of sampling theorem. Because the theory is based on the assumption of that the location of sparse values is unknown, it has many constraints in practical applications. In fact, in many cases such as image processing, the location of sparse values is knowable, and CS can degrade to a linear process. In order to take full advantage of the visual information of images, this paper proposes the concept of dimensionality reduction transform matrix and then se- lects sparse values by constructing an accuracy control matrix, so on this basis, a degradation algorithm is designed that the signal can be obtained by the measurements as many as sparse values and reconstructed through a linear process. In comparison with similar methods, the degradation algorithm is effective in reducing the number of sensors and improving operational efficiency. The algorithm is also used to achieve the CS process with the same amount of data as joint photographic exports group （JPEG） compression and acquires the same display effect.

关键词： compressive sensing (CS) dimensionality reduction transform matrix accuracy control matrix degradation algorithm joint photographic exports group (JPEG) compression.

Generalized Quantum Current Algebras

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Communications in Theoretical Physics 2001年第3期35卷 301-303页

作者： zhao liu The Abdus Salam International Centre for Theoretical Physics P.O. Box 586 34100 Trieste Italy Institute of Modern Physics Northwest University Xi'an 710069 China

Two general families of new quantum-deformed current algebras are proposed and identified both as infinite Hopf family of algebras, a structure which enables one to define "tensor products" of these algebras. The standard quantum affine algebras turn out to be a very special case of the two algebra families, in which case the infinite Hopf family structure degenerates into a standard Hopf algebra. The relationship between the two algebraic families as well as thefr various special examples are discussed, and the free boson representation is also considered.

关键词：理论物理量子流代数量子群

Study on Duality of Wave and Particle of Turbulence Using CML Models

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Communications in Theoretical Physics 2009年第5期51卷 857-864页

作者： liu zhao-Cun School of Environment and Planning Henan University Kaifeng 475001 China Southwest Engineering Research Institute for Waterway Chongqing Jiaotong University Key Waterway Laboratory of Chongqing City and Ministry of Communications Chongqing 400016 China

A family of coupled map lattice （CML） models has been developed to simulate the evolutional mechanism of interactions of convection, diffusion, and dispersion in both weakly and strongly coupled cases. Not only coherent and turbulent properties as well as their relations, but also the transitional states between convection dominating, diffusion dominating and dispersion dominating are analyzed to demonstrate the essential characteristics of any state. Numerical results show that the models are capable of simulating both layered coupling and stochastic mechanism, and lead us to understand whether or not turbulence coherent structure is formed by modulation of wave packet. The duality of wave and particle characters of turbulence is illustrated in the numerical simulation; a sketch picture is given to explain the questions associated with the turbulent inverse cascade, which is the result of the mutual interactions among the physical factors of nonlinearity, dissipation and dispersion.

关键词： CML model non-linearity dissipation dispersion duality of wave and particle