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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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(K_(0.5)Na_(0.5))Nb_(1-x)Ta_(x)O_(3)铁电性的第一性原理研究

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原子与分子物理学报 2025年第4期42卷 138-146页

作者：褚新建雷博程刘晨曦刘纪博新疆科技学院信息科学与工程学院库尔勒841000 新疆大学物理科学与技术学院新疆固体物理与器件重点实验室乌鲁木齐830046 西安工业大学光电工程学院西安710032

随着铅基陶瓷的大量使用,造成了严重的环境和健康问题,为了能够找寻替代铅基陶瓷的材料,人们开始了对无铅陶瓷材料的探索.(K_(0.5)Na_(0.5))Nbo_(3)材料由于其优异的铁电压电性能,成为了无铅陶瓷材料的代表,但是碱性组分在高温下的高挥... 详细信息

随着铅基陶瓷的大量使用,造成了严重的环境和健康问题,为了能够找寻替代铅基陶瓷的材料,人们开始了对无铅陶瓷材料的探索.(K_(0.5)Na_(0.5))Nbo_(3)材料由于其优异的铁电压电性能,成为了无铅陶瓷材料的代表,但是碱性组分在高温下的高挥发性使其应用范围受到了极大的限制.基于这样的考虑,本文基于密度泛函理论的第一性原理方法,探究了(K_(0.5)Na_(0.5))Nb_(1-x)TaxO_(3)(x=0.125,0.25,0.375,0.5,0.625,0.75,0.875,1)九种体系的铁电性能,结果表明:随着Ta浓度的增加,晶格常数发生了突变,由此猜测KNN材料随着Ta浓度的增加,发生了正交-单斜的相变;Ta的掺入能够降低KNN材料的烧结难度,且随着Ta浓度的增加,形成难度逐渐降低;掺杂体系中,Ta-4f轨道与Na-3p,K-4p以及O-2s轨道电子发生了杂化,使导带底Nb-4d与Na-3p电子的态密度峰向高能区移动,禁带宽度呈现增加的趋势;在分析KNN材料铁电性作用机理时发现KNN的铁电极化类型是离子位移型极化,且在[001]方向上不具有极化能力.分析掺杂后各个体系的极化强度,发现随着Ta浓度的增加,极化强度逐渐降低,但是在低浓度掺杂时极化有向上增加的趋势,这可能是体系在低浓存在着正交与单斜的准同型相界(Morphotropic phase boundary,MPB)导致的,由此可以判断,低浓度掺杂有利于提高KNN材料的铁电性能.

关键词：第一性原理钙钛矿结果 KNN 铁电性

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The Important Roles of Water in Protein Folding:an Approach by Single Molecule Force Spectroscopy

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Chinese Journal of Polymer Science 2018年第3期36卷 379-384页

作者： bo cheng Shu-Xun Cui School of Mechanical Engineering North University of ChinaTaiyuan 030051China Key Lab of Advanced Technologies of Materials Ministry of Education of ChinaSouthwest Jiaotong UniversityChengdu 610031China

The single-chain elasticity of a completely unfolded protein （027）8, modules of human cardiac titin） is studied in different liquid environments by the atomic force microscopy （AFM）-based single molecule force spectroscopy （SMFS）. The experimental results show that there is a clear deviation between the force curves obtained in the aqueous and nonaqueous environments. Such a deviation can be attributed to the additional energy consumed by the rearrangement of the bound water molecules around the chain of the completely unfolded （I27）s chain upon stretching in aqueous solution, which is very similar to the partial dehydration process from a denatured/unfolded to a native/folded protein. Through the analysis of the free energy changes involved in protein folding, we conclude that it is due to the weak disturbance of water molecules and the special backbone structures of proteins that the self-assembly of proteins can be achieved in physiological conditions. We speculate that water is likely to be an important criterion for the selection of self-assembling macromolecules in the prebiotic chemical evolution.

关键词： SMFS Protein Folding Water

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Multiple Positive Solutions for Semi-positone m-point boundary Value Problems

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Acta Mathematicae Applicatae Sinica 2011年第3期27卷 419-426页

作者： cheng-bo Zhai cheng Yang School of Mathematical Science Shanxi University Shanxi 030006 China Business College of Shanxi University Shanxi 030031 China

In this article, we establish the existence of at least two positive solutions for the semi-positone m-point boundary value problem with a parameter u （t）＋ λf （t, u） = 0, t ∈ （0, 1）, u （0） = sum （biu （ξ i ）） from i=1 to m-2, u（1）= sum （aiu（ξ i ）） from i=1 to m-2, where λ 〉 0 is a parameter, 0 〈 ξ 1 〈 ξ 2 〈 ··· 〈 ξ m 2 〈 1 with 0 〈sum ai from i=1 to m-2 〈 1, sum bi from i=1 to m-2 =1 b i 〈 1, a i , b i ∈ [0, ∞） and f （t, u） ≥ M with M is a positive constant. The method employed is the Leggett-Williams fixed-point theorem. As an application, an example is given to demonstrate the main result.

关键词： Multiple positive solutions cone semi-positone m-point boundary value problem,concave functional parameter

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Energy Efficient Speed Scaling and Task Scheduling for Distributed Computing Systems

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Chinese Journal of Electronics 2015年第3期24卷 468-473页

作者： HUANG Jiwei LIN Chuang cheng bo State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Department of Computer Science and Technology Tsinghua University

With the rapid development of the performance of computer systems, energy consumption has been increasing dramatically as well. Energy efficiency has been paid much attention, especially in large-scale distributed computing systems. We propose an effective approach for energy reduction, by dynamic speed scaling and task scheduling simultaneously. Markov models for distributed computing systems are proposed, and detailed analyses of the models are provided. Markov decision processes(MDP) are applied for problem formulation, and MDP algorithms for obtaining the optimal solutions are introduced. The efficacy of our approach is further validated by simulation experiments.

关键词： Energy efficiency Speed scaling Task scheduling Markov decision process Distributed computing system

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A Stochastic Approach of Dependency Evaluation for IoT Devices

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Chinese Journal of Electronics 2016年第2期25卷 209-214页

作者： HUANG Jiwei CHEN Guo cheng bo State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications

Internet of things(Io T) is an emerging technique that offers advanced connectivity of devices, systems, services, and human beings. With the rapid development of hardware and network technologies, the Io T can refer to a wide variety and large number of devices, resulting in complex relationships among Io T devices. The dependencies among Io T devices, which reflect their relationships, are with reference value for the design, development and management of Io T devices. This paper proposes a stochastic model based approach for evaluating the dependencies of Io T devices. A random walk model is proposed to describe the relationships of Io T devices, and its corresponding Markov chain is obtained for dependency analysis. A framework as well as schemes and algorithms for dependency evaluation in real-world Io T are designed based on traffic measurement. Simulation experiments based on real-life data extracted from smart home environments are conducted to illustrate the efficacy of the approach.

关键词： Internet of things(IoT) Dependency Random walk Markov chain

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The Solvent Quality of Water for Poly(N-isopropylacrylamide) in the Collapsed State： Implications from Single-molecule Studies

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Chinese Journal of Polymer Science 2016年第5期34卷 578-584页

作者： Xiang-chao Pang bo cheng 崔树勋 Key Laboratory of Advanced Technologies of Materials (Ministry of Education) Southwest Jiaotong University Chengdu 610031 China Department of Materials Science and Engineering South University of Science and Technology of China Shenzhen 518055 China School of Mechanical and Power Engineering North University of China Taiyuan 030051 China

both of temperature（in water） and composition（in the water/methanol mixed solvent） can induce the coil-toglobule transition of poly（N-isopropylacrylamide）（PNIPAM）. The atomic force microscope（AFM） based single molecule force spectroscopy（SMFS） has been exploited to investigate the interactions between the polymer chain and solvent at the single-molecule level. It is found that the single-chain mechanics of PNIPAM show a remarkable dependence on the two external stimuli. A confusing experimental result is that all the force-extension（F-E） curves of unfolding an individual PNIPAM globule present a feature of elastic（monotonically increasing force） stretching but not plateau（constant force） stretching predicted by theory. In this article, we clarify that the presence of the interior solvent molecules in the single-chain globule is the origin of the discrepancy between the F-E curves obtained from theory and experiment. Although both of the external stimuli do tend to lower the solvent quality for PNIPAM, water and the water/methanol mixed solvent will never be the strongly poor solvent for PNIPAM, even at the worst condition.

关键词： PNIPAM stretching methanol hydrophilic chains remarkable hydrophobic backbone conformation interior

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Time-varying diffusion characteristics of different gases in coal particles

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International Journal of Mining Science and Technology 2017年第6期27卷 1025-1029页

作者： Long Qingming Hu Qianting cheng bo College of Resources and Environmental Science Chongqing University Chongqing 400030 China National Key Laboratory of Gas Disaster Detecting Preventing and Emergency Controlling Chongqing 400037 China Chongqing Research Institute China Coal Research Institute Chongqing 400037 China

Based on the analytical solution of gas diffusion in spherical coal particles with a constant diffusion coefficient, a calculation method of time-varying diffusion coefficient is proposed by constructing objective function. The time-varying diffusion behavior of methane, nitrogen and carbon dioxide in the coal particles was studied. The results show that with the increase of diffusion time, the diffusion coefficients of methane, nitrogen and carbon dioxide gas in the coal particles exhibit an attenuation characteristic, eventually approaching a limit value individually. The diffusion coefficient of carbon dioxide is larger than methane, and the diffusion coefficient of nitrogen is smallest. Significant phenomenon of limited diffusion was observed for coal of strong adsorption capability. Through the analysis of the diffusion coefficient of gases at different diffusion time, a mathematical model describing the time-varying diffusion characteristic of gases is obtained. The implementation of mixed gases to replace coal bed methane has a very important practical significance.

关键词： Coal Coalbed methane (CBM) Adsorption Diffusion Objective function

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Global Existence for Some 4-D Quasilinear Wave Equations with Low Regularity

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Acta Mathematica Sinica,English Series 2018年第4期34卷 629-640页

作者： Meng Yun LIU cheng bo WANG School of Mathematical Sciences Zhejiang University

In this paper, we prove the global existence for some 4-D quasilinear wave equations with small, radial data in H3 × H2. The main idea is to exploit local energy estimates with variable coefficients, together with th... 详细信息

关键词： Local energy estimates trace estimates

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Self-heating Probe Instrument and Method for Measuring High Temperature Melting Volume Change Rate of Material

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Chinese Journal of Mechanical Engineering 2013年第2期26卷 371-376页

作者： WANG Junwei WANG Zhiping LU Yang cheng bo College of Materials Science and Engineering Lanzhou University of Technology State Key Laboratory of Gansu Advanced Non-ferrous Metal Materials Lanzhou University of Technology Renewable Energy Laboratory Lanzhou University of Technology

The castings defects are affected by the melting volume change rate of material. The change rate has an important effect on running safety of the high temperature thermal storage chamber, too. But the characteristics of existing measuring installations are complex structure, troublesome operation and low precision. In order to measure the melting volume change rate of material accurately and conveniently, a self-designed measuring instrument, self-heating probe instrument, and measuring method are described. Temperature in heating cavity is controlled by PID temperature controller; melting volume change rate υ and molten density are calculated based on the melt volume which is measured by the instrument. Positive and negative υ represent expansion and shrinkage of the sample volume after melting, respectively. Taking eutectic LiF＋CaF2 for example, its melting volume change rate and melting density at 1 123 K are -20.6% and 2 651 kg/m–3 measured by this instrument, which is only 0.71% smaller than literature value. Density and melting volume change rate of industry pure aluminum at 973 K and analysis pure NaCl at 1 123 K are detected by the instrument too. The measure results are agreed with report values. Measuring error sources are analyzed and several improving measures are proposed. In theory, the measuring errors of the change rate and molten density which are measured by the self-designed instrument is nearly 1/20-1/50 of that measured by the refitted mandril thermal expansion instrument. The self-designed instrument and method have the advantages of simple structure, being easy to operate, extensive applicability for material, relatively high accuracy, and most importantly, temperature and sample vapor pressure have little effect on the measurement accuracy. The presented instrument and method solve the problems of complicated structure and procedures, and large measuring errors for the samples with high vapor pressure by existing installations.

关键词： high temperature volume expansion rate molten density measuring instrument measuring method

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