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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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Transient chemical-mediated epigenetic modulation confers unrestricted lineage potential on human primed pluripotent stem cells

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Science China life Sciences 2025年

作者： Shi Chen Yuanyuan He Lejun Lv Bei liu cheng li Hongkui Deng Jun Xu Department of Cell Biology School of Basic Medical Sciences Peking University Stem Cell Research Center Peking University Health Science Center Peking University Academy of Advanced Interdisciplinary Studies Peking University BeiCell Therapeutics School of life Sciences Center for Bioinformatics Center for Statistical Science Peking University MOE Engineering Research Center of Regenerative Medicine School of Basic Medical Sciences State Key Laboratory of Natural and Biomimetic Drugs Peking University Health Science Center and the MOE Key Laboratory of Cell Proliferation and Differentiation College of Life Sciences Peking-Tsinghua Center for Life Sciences Peking University

Human primed pluripotent stem cells are capable of generating all the embryonic ***,their extraembryonic trophectoderm potentials are *** remains unclear how to expand their developmental potential to trophectoderm *** we show that transient treatment with a cocktail of small molecule epigenetic modulators imparts trophectoderm lineage potentials to human primed pluripotent stem cells while preserving their embryonic *** chemically treated cells can generate trophectoderm-like cells and downstream trophoblast stem cells,diverging into syncytiotrophoblast and extravillous trophoblast *** and CUT&Tag analyses reveal that these induced cells share transcriptional profiles with in vivo trophectoderm and cytotrophoblast,and exhibit reduced H3K27me3 modification at gene loci specific to trophoblast lineages compared with primed pluripotent *** exploration highlighted the critical roles of epigenetic modulators HDAC2,EZH1/2,and KDM5s in the activation of trophoblast lineage *** findings demonstrate that transient epigenetic resetting activates unrestricted lineage potential in human primed pluripotent stem cells,and offer new mechanistic insights into human trophoblast lineage specification and in vitro models for studying placental development and related disorders.

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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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基于蒙特卡罗法的黄土滑坡概率与可靠度分析——以榆林市朝阳路滑坡为例

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灾害学 2025年第1期40卷 74-79页

作者：黄立新李成郭伟龙陕西工程勘察研究院有限公司陕西西安710068 陕西省地质环境监测总站(陕西省地质灾害中心) 陕西西安710054

基于计算滑坡概率的蒙特卡罗法,该文以黄土高原地区的榆林市朝阳路滑坡为研究对象,通过野外调查、室内试验和综合研究,分析了黄土黏聚力和内摩擦角等多种条件下的安全系数分布、失稳概率和可靠度,探讨了参数相关性对于滑坡可靠度的影响... 详细信息

基于计算滑坡概率的蒙特卡罗法,该文以黄土高原地区的榆林市朝阳路滑坡为研究对象,通过野外调查、室内试验和综合研究,分析了黄土黏聚力和内摩擦角等多种条件下的安全系数分布、失稳概率和可靠度,探讨了参数相关性对于滑坡可靠度的影响,并进行了对黏聚力和内摩擦角的敏感性分析。研究发现,该滑坡为黄土高原区典型降雨诱发型,当同时考虑黏聚力和内摩擦角的变化时,滑坡可靠度指数为1.35,失稳概率为8.83%,安全系数介于0.794~1.305;与同单一变量情况下相比,多个变量分析计算的可靠性指数显著减小,标准偏差明显增大,滑坡失稳概率升高;不同参数相关性条件下,滑坡失稳概率、可靠度和安全系数的标准偏差不同;滑坡的稳定性系数对于不同土性参数的敏感性存在差异。该文基于研究结果提出了相应的防治措施,为黄土高原地区滑坡防治和危险性评估提供科学依据。

关键词：黄土滑坡蒙特卡罗失稳概率可靠度相关性

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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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Density Functional Theory Investigation on the Reaction Mechanisms of Ti(^3F)with CH2Cl2 and CHCl3 to CH2=TiCl2 and HC÷TiCl3

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Chinese Journal of Structural Chemistry 2016年第2期35卷 193-198页

作者： cheng Xue-li (School of Chemistry and Chemical Engineering Taishan UniversityTai'anShandong 271021China

The reaction mechanisms of Ti（~3F）＋ CH2C12→CH2=TiCl2 and Ti（~3F）＋ CHC13→HC÷TiCl3 were investigated with Gaussian 03 program package at the B3PW91/6-311＋＋G（d,p）*** computational results revealed that：1） Both reaction systems are initiated by Ti（~3F） atom attacking the C atom of CH2C12 and CHCl3 to activate a C-Cl bond;2） Both reaction systems were carried out via triplet reaction channels;3） CH2=TiCl2 has singlet and triplet isomers,and the singlet one is more stable;4） The HOMO of CH2=TiCl2（S） illustrates a π-bonding interaction between C and Ti;5） Only singlet HC÷TiCl3 was located,and the Mulliken atomic spin densities show that the two single electrons are mostly on the C atom.

关键词： B3PW91 reaction mechanism Ti(~3F) CH2=TiCl2 HOTiCl3

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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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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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