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Moment Redistribution Effect of the Continuous Glass Fiber Reinforced Polymer-Concrete Composite Slabs Based on Static Loading Experiment

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Structural Durability & Health Monitoring 2025年第1期19卷 105-123页

作者： Zhao-Jun Zhang Wen-Wei Wang Jing-Shui Zhen Bo-cheng li De-cheng Cai Yang-Yang Du Hui Huang Offshore Oil Engineering Co.Ltd. Tianjin300461China Department of Bridge Engineering School of TransportationSoutheast UniversityNanjing211189China

This study aimed to investigate the moment redistribution in continuous glass fiber reinforced polymer(GFRP)-concrete composite slabs caused by concrete cracking and steel bar yielding in the negative bending moment *** experimental bending moment redistribution test was conducted on continuous GFRP-concrete composite slabs,and a calculation method based on the conjugate beam method was *** composite slabs were formed by combining GFRP profiles with a concrete layer and supported on steel beams to create two-span continuous composite slab *** methods,epoxy resin bonding,and stud connection,were used to connect the composite slabs with the steel *** experimental findings showed that the specimen connected with epoxy resin exhibited two moments redistribution phenomena during the loading process:concrete cracking and steel bar yielding at the internal *** contrast,the composite slab connected with steel beams by studs exhibited only one-moment redistribution phenomenon throughout the loading *** the concrete at the internal support cracked,the bending moment decreased in the internal support section and increased in the midspan *** the steel bars yielded,the bending moment further decreased in the internal support section and increased in the mid-span *** GFRP profiles do not experience cracking,there was no significant decrease in the bending moment of the mid-span *** test specimens experienced compressive failure of concrete at the mid-span *** results showed good agreement between the calculated and experimental values of bending moments in the mid-span section and internal support *** proposed model can effectively predict the moment redistribution behavior of continuous GFRP-concrete composite slabs.

关键词： Moment redistribution GFRP-concrete composite slabs bending moment experimental study analysis model

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经济不确定性、资产效应与居民消费

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云南财经大学学报 2025年第1期41卷 1-18页

作者：李一帆于海东李成中国银行研究院北京100818 中国建设银行研修中心(研究院) 北京100033 西安交通大学经济与金融学院西安710061

构建包含经济不确定性的居民最优消费决策数理模型,推导出经济不确定性影响居民消费的资产效应机制,运用中国家庭追踪调查数据,设立省际经济不确定性指数,并进行实证检验。研究发现:整体上看,经济不确定性通过资产效应机制降低了居民消... 详细信息

构建包含经济不确定性的居民最优消费决策数理模型,推导出经济不确定性影响居民消费的资产效应机制,运用中国家庭追踪调查数据,设立省际经济不确定性指数,并进行实证检验。研究发现:整体上看,经济不确定性通过资产效应机制降低了居民消费支出。经济不确定性上升引发市场系统性风险上升,提高了居民资产的风险溢价,迫使资产价值缩水,降低了居民对风险资产市场的投资意愿和参与程度,导致资产性收入下降,最终抑制居民消费支出。结构上看,经济不确定性主要通过降低房产价值和资产性收入的路径抑制消费支出,其中承担房贷的居民受经济不确定性的负向影响更明显,消费缩减程度更大。由于国内居民资产配置结构不均衡,金融产品对家庭消费的资产效应相对较弱,经济不确定性难以通过股票等金融资产价值和金融市场参与度影响消费。

关键词：经济不确定性资产效应居民消费资产性收入

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Photometrically estimating the spatially-resolved stellar mass-to-light ratios for low-redshift galaxies

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Research in Astronomy and Astrophysics 2019年第12期19卷 187-198页

作者： cheng Du Niu li cheng li Department of Astronomy and Tsinghua Center for Astrophysics Tsinghua University

The stellar mass-to-light ratio(M_*/L) of galaxies in a given wave band shows tight correlations with optical colors, which have been widely applied as cheap estimators of galaxy stellar masses. These estimators are usually calibrated using either broadband spectral energy distributions(SEDs) or spectroscopy at galactic centers. However, it is unclear whether the same estimators provide unbiased M_*/L for different regions within a galaxy. In this work we employ integral field spectroscopy from the Mapping Nearby Galaxies at Apache Point Observatory(Ma NGA) survey. We also examine the correlations of spatially resolved M_*/L obtained from full spectral fitting, with different color indices, as well as galaxy morphology types, distances to the galactic center, and stellar population parameters such as stellar age and *** find that the(g-r) color is better than any other color indices, and it provides almost unbiased M_*/L for all the SDSS five bands and for all types of galaxies or regions, with only slight biases depending on stellar age and metallicity. Our analysis indicates that combining multiple colors and/or including other properties to reduce the systematics and scatters of the estimator does not work better than a single color index defined by two bands. Therefore, we have obtained a best estimator with the(g-r) color and applied it to the Ma NGA galaxies. Both the two-dimensional map and radial profile of M_*/L are reproduced well in most cases. Our estimator may be applied to obtain surface mass density maps for large samples of galaxies from imaging surveys at both low and high redshifts.

关键词： galaxies:stellar stellar content galaxies:fundamental parameters galaxies:general

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Residual stress distribution in thin diamond films and its effects on preparation of thick freestanding diamond films using DC arc plasma jet operated at gas recycling mode

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中国有色金属学会会刊：英文版 2004年第Z1期14卷 255-259页

作者： li cheng-ming Sch. of Mat. Sci. and Eng. Univ. of Sci. and Technol. Beijing Beijing 100083 China

Diamond films produced by chemical vapor deposition show excellent properties. The residual stress distribution of diamond thin films deposited by DC arc plasma jet at recycling mode was analyzed by line shifts of micro Raman spectroscopy. The results show that the compressive residual stress concentrates at the film's edge. The experimental observations show that cracks initiate at the edge of the diamond thick wafer and then propagate towards the center. The residual stress of diamond films increases with the increase of methane concentration and deposition temperature. The difference of adhesion in close area causes more shear stress and brings about the two sides of crack being not at same level. To suppress crack probability, it is favourable for increasing the film thickness and selecting a substrate with lower coefficient of thermal expansion and lower adhesion. The effects of the residual stress distribution on thick diamond films detachment were discussed.

关键词： Cracking Diamond films Residual stress

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The Commutant of Analytic Toeplitz Operators on Bergman Space

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Acta Mathematica Sinica,English Series 2008年第10期24卷 1737-1750页

作者： Yu cheng li Department of Mathematics Hebei Normal University Shijiazhuang 050016 P. R. China

In this paper, using the matrix skills and operator theory techniques we characterize the commutant of analytic Toeplitz operators on Bergman space. For f（z） = z^ng（z）（n ≥1）, g（z） = b0 ＋ b1z^p1 ＋b2z^p2 ＋.. , bk ≠ 0 （k = 0, 1, 2,...）, our main result is =A′（Mf） = A′（Mzn）∩A′（Mg） = A′（Mz^s）, where s = g.c.d.（n,p1,p2,...）. In the last section, we study the relation between strongly irreducible curve and the winding number W（f,f（α））, α ∈ D.

关键词： Bergman space analytic Toeplitz operator commutant strong irreducibility

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Remarks on homoclinic solutions for semilinear fourth-order ordinary differential equations without periodicity

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Applied Mathematics(A Journal of Chinese Universities) 2009年第1期24卷 49-55页

作者： li cheng-yue Dept. of Math. Central Univ. for Nationalities Beijing 100081 China

This paper mainly discusses the existence of nontrivial homoclinic solutions for nonperiodic semilinear fourth-order ordinary differential equation u^（4）＋pu″＋a（x）u-b（x）u^2=c（x）u^3=3arising in the study of p... 详细信息

关键词： homoclinic solution Mountain Pass Lemma Extended Fisher-Kolmogorov (EFK) equation Swift-Hohenberg (SH) equation

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Recent Advances in Base-Metal-Catalyzed Carbonylation of Unactivated Alkyl Electrophiles

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Chinese Journal of Chemistry 2023年第23期41卷 3419-3432页

作者： Wei li Donghao Jiang cheng Wang li-Jie cheng State Key Laboratory of Chemo/Biosensing and Chemometrics College of Chemistry and Chemical EngineeringHunan UniversityChangshaHunan410082 China State Key Laboratory of Elemento-Organic Chemistry Nankai UniversityTianjin300071 China

Transition metal-catalyzed carbonylation reactions represent a direct and atom-economical approach to synthesize carbonyl compounds or their derivatives by using CO as a cheap and readily available C1 *** carbonylation of C(sp^(2))-hybridized electrophiles (e.g.,aryl halides) is well developed,carbonylation of less reactive unactivated alkyl electrophiles remains ***,the use of earth-abundant base metals including Cu,Co,Mn,Fe,Ni as catalysts has enabled advances in carbonylative coupling of alkyl electrophiles for approaching diverse carbonyl compounds or their derivatives,notably,some of which are of synthetic importance but difficult to be synthesized through previous reported ***,we have summarized and discussed these recent achievements in base-metal-catalyzed carbonylative C—C,C—N,C—O,C—X coupling and other carbonylation reactions of unactivated alkyl electrophiles using CO as C1 source.

关键词： Base-metal catalyst Carbonylation Unactivated alkyl electrophiles Radical Carbon monoxide(CO)

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INTEGRAL EQUATION METHOD'S APPliCATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

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Chinese Journal of Mechanical Engineering 2008年第6期21卷 115-118页

作者： li cheng ZHENG Yanping School of Mechanical Engineering Zhengzhou University Zhengzhou 450001 China

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.

关键词： Off-axis loads Conformal mapping Aperture question Complex hole-shape Analysis Stress function of multiple complex variables

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Deformation temperature and postdeformation annealing effects on severely deformed TiNi alloy by equal channel angular extrusion

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Journal of University of Science and Technology Beijing 2007年第6期14卷 533-537页

作者： Zhenhua li Xianhua cheng School of Mechanical and Power Engineering Shanghai Jiaotong University Shanghai 200030 China

Micron TiNi alloy blocks were fabricated at high temperature by equal channel angular extrusion （ECAE） using hotforged Ti-50.3at%Ni alloy as the raw material and the effects of deformation temperature and postdeformation annealing on the severely deformed TiNi alloy by ECAE were investigated. The results show that the TiNi alloy processed by ECAE undergoes severe plastic deformation, and lowering the deformation temperature and increasing the number of extrusions contribute to grain refinement. When the annealing temperature is below 873 K, static recovery is the main restoration process; when the temperature rises to 973 K, static recrystallization occurs. It is found that fine particles are precipitated when the TiNi alloy processed by ECAE is annealed at 773 K.

关键词： TiNi shape memory alloy equal channel angular extrusion (ECAE) static recrystallization ultrafine-grained (UFG) structure

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Analysis of multi-objective optimisation method for main insulation structure configuration scheme of valve-side winding of ultra-high voltage converter transformer considering multi-field coupling

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High Voltage 2024年第2期9卷 296-308页

作者： lijun Yang Zhidong cheng li cheng Ruijin liao State Key Laboratory of Power Transmission Equipment Technology School of Electrical EngineeringChongqing UniversityChongqingChina

Because DC conductivities of oil-paper materials can be easily affected by electric field and temperature,the electrical properties under electro-thermal coupling of oil-paper materials should be considered when optimising the insulation structure of valve-side winding of the converter *** on the finite element multi-physical field coupling simulation,the multi-objective optimisation of main insulation structure of valve-side winding is carried *** view of the high time consuming of multi-physical field calculation and the actual needs of an insulation structure optimisation,the Kriging method and technique for order preference by similarity to the ideal solution(TOPSIS)method are introduced,and combines them with NSGA-II to obtain a joint algorithm that can be used for the optimisation of insulation structure of the converter *** using the joint algorithm of multi-objective optimisation,the insulation structure configuration scheme of valve-side winding is *** can be seen from the experiment result that,on the one hand,the joint algorithm adopted can obtain the insulation structure configuration scheme that meets the design *** the other hand,when facing the configuration scheme optimisation under multi-field coupling,the computational time required by this method is only 0.15%of that required by original genetic algorithm.

关键词： converter insulation coupling

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