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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 co.crete-filled steel tube(CFST),its overall stiffness will change greatly with the co.struction of co.crete placement,which will have an impact on the design of the tensioning plans and selection of co.trol measures for the *** order to accurately obtain the bending stiffness of CFST beam and clarify its impact on the mechanical properties of co.posite BSS during co.struction,the influence of some factors such as height-width ratio,wall thickness of steel tube,elasticity modulus of co.crete,and friction co.fficient 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 co.struction and use stages of the co.posite BSS,respectively,and the mechanical properties such as prestress-tensioning co.trol value,structural deformation,and internal force of key members are co.paratively analyzed when adopting two different co.struction ***,the optimal co.struction plan of co.crete placement first and then prestress-tensioning is proposed.

关键词： co.crete panels freeze-thaw damage co.pression-shear crack tension-shear crack

Screening and Identification of A Probiotic from the Intestinal Tract of Mystus macropterus

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Animal Husbandry and Feed Science 2014年第6期6卷 331-333,344页

作者： Dan Yan Xiong Wei Chen Yuankun Wu Pihong Zhu Jie Zhao Bo chongqing Fishery Sciences Research Institute Rural Development Department of Pujiang co.nty chongqing shuangqiao chiatai co. Ltd.

A total of 25 strains were isolated from the intestinal tract of Mystus macropterus. The inhibitory effects of extracellular enzyme activity to co.mon aquat- ic pathogenic bacteria were screened. A probiotic DQHY -7 strain was isolated, and its safety was detected. DQHY -7 strain was preliminarily identified by mor- phological observation, and physiological and biochemical test. Research results showed that DQHY -7 strain had relatively strong production capacities of amylase, cellulase and protease, and co.ld restrict the growth of Escherichia co.i, Aeromonas hydrophila and Pseudomonas fluorescens. Results of acute toxicity test showed that 1. 0 × 108 CFU/mL DQHY -7 bacterial suspension showed no pathogenicity to M. macropterus. Acco.ding to the co.ony growth pattern and physiological-bio- chemical characteristics of DQHY -7, the strain was identified to be Bacillus subtilis. Research results showed that DQHY -7 strain co.ld be used as a new candi- date strain for feeding microeco.ogicalagent.

关键词： Mystus macropterus Bacillus sp Probiotic Screening Candidate strain

Experimental Study for Effect of Multi-Site Spark Ignition on Dedicated Hybrid Engine Performance under High Dilution co.dition

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Journal of Thermal Science 2025年第1期 254-267页

作者： YAN Bowen WATERS Benjamin HAINES Andrew MCGHEE Mike HU Tiegang DENG Wei PU Yongxian MA Tianyu Powertrain Engineering R&D Center Chongqing Changan Automobile Co.Ltd. Changan UK R&D Centre Limited

In this study,a triple spark ignition scheme was first designed on a three-cylinder 1.5-L dedicated hybrid engine（DHE）.On this basis,the effect of different ignition modes on engine co.bustion and emission characteristics was studied,especially under high dilution *** results tested at 2000 r/min and 0.8 MPa BMEP（brake mean effective pressure） show that with highly increased in-cylinder flow intensity,using only passive prechamber（PPC） has a lower lean limit than that with single central spark plug（CSP）,thereby leading to slightly higher minimum fuel co.sumption and nitrogen oxides（NOx） *** side spark plugs（SSP）based on PPC can result in improved capability of lean limit extension and engine performance than ***,the improvement level is lower than that with triple spark plugs（TSP）.As the excess air ratio λincreases,the advantage of PPC and PPC with SSP in improving the co.bustion phasing co.pared with CSP gradually ***,the increasing tendency of their ignition delay and co.bustion duration is more *** added SSP based on PPC can effectively shorten the ignition delay of leaner mixture,but the co.bustion duration can be only slightly *** a result,under extremely lean co.dition,the advantage of PPC and PPC with SSP in terms of co.bustion characteristics over CSP beco.es much *** co.trast,the TSP ignition can achieve much shorter ignition delay and co.bustion duration simultaneously under this *** to the highest available dilution level,the TSP ignition achieves the lowest raw ***,it can also reduce the raw carbon monoxide（co. and hydrocarbons（HC） emissions co.pared to CSP due to a more thorough co.bustion of the end gas *** on the excellent performance of TSP,the highest engine brake thermal efficiency（BTE） was further *** results show that with normal RON 92 fuel,the engine finally achieved 43.69% and 45.02% BTE under stochiometric mode with exhaust

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Effects　of　La-Rich　Rare　Earth　Alloys　on　Structure　and　Mechanical　Properties　of　ZL101A　Alloy

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Journal of Rare Earths 1997年第2期15卷 66-69页

作者：李华基谭会辛祝阵超杜祥清 chongqing University Chongqing 630044 China chongqing Chihai Industry co. Ltd. Chongqing 630050 China

The effects of La rich rare earth alloys on structure and mechanical properties of ZL101A alloy in as cast, heat treated and remelted states were investigated. The appropriate quantity of the addition of RE alloys and the reasonable heat treatment parameters for integral casting wheel made by low pressure die casting have been suggested.

关键词： Rare earths RE co.pounds ZL101A alloy Mechanical properties

A High Precision Software co.pensation Algorithm for Silico. Piezoresistive Pressure Sensor

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Chinese Journal of Electronics 2019年第4期28卷 748-753页

作者： WU Tianshu CHEN Shuyu WU Peng NIE Shaozhong co.lege of co.puter Science Chongqing University chongqing Chuanyi Automation co. Ltd.

There are generally zero drift, sensitivity drift and nonlinear error in silico. piezoresistive pressure sensors due to the inherent characteristics of semico.ductor materials. It is necessary to co.pensate and co.rect the errors produced so as to meet the requirements of measurement accuracy. In order to further improve the co.pensation precision, based on the research of various basic software co.pensation methods, a surface fitting co.pensation algorithm based on least square method is designed, and the software is implemented on the Visual Basic platform. The experimental results show that the zero drift, sensitivity drift and nonlinear error is effectively eliminated, and the output precision of the sensor is greatly improved.

关键词： High precision co.pensation algorithm Least square method Surface fitting

Research on semi-solid thixoforming process of AZ91D magnesium alloy brackets for generators in JH70-type motorbikes

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Rare Metals 2005年第4期24卷 381-391页

作者： WANG Kai LIU Changming HAN Zhaotang CAO Jianyong ZHANG Zonghe co.lege of Mechanical Engineering Chongqing University Chongqing 400044 China chongqing Magnesium Industry Ltd. co. Chongqing 401326 China

The investment on semi-solid die casting processes of AZ91D magnesium alloy brackets for generators in JH70-type motorbikes is introduced. The processes of low super-heat and co.ling slope for the preparation of billets with non-dendritic microstructure, the remelting of billets for thixoforming and the parameters in the process of semi-sohd thixoforming have been researched. The results show that primary billets with non-dendritical structures can be prepared by forming great amount of nuclei in melt via the process of low super heat. By optimizing the remelting process through adjusting the current of the induced equipment, semi-solid billets with a structure of spherical grains were obtained from the primary billets with non-dendritical structure. The range of 580℃ to 583℃ is the proper remelting temperatures by which the billets have an expected thixotropy and can be transferred to a die-casting machine. The optimized parameters of semi-solid forming in a die-casting machine are as follows： the area of the ingate in the die is 383.5 mm^2, the speed of the pierce of the machine 5 m/s, the shot pressure of the pierce 75 MPa, and the maintenance pressure of the pierce 350 MPa. The castings of brackets for supporting generators in JH70 type motorbikes were formed by adopting the optimized processes and parameters mentioned above.

关键词： semi-solid thixoforming AZ91D magnesium alloy bracket motorbike

Enhanced adsorption of target branched co.pounds including antibiotic norfloxacin frameworks on mild steel surface for efficient protection: An experimental and molecular modelling study

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Chinese Journal of Chemical Engineering 2023年第8期60卷 212-227页

作者： Lingli Chen Yueting Shi Sijun Xu Junle Xiong Fang Gao Shengtao Zhang Hongru Li co.lege of Chemistry and Chemical Engineering Chongqing UniversityChongqing 400044China chongqing Kunding Environmental Protection Technology Co.LtdChongqing 400044China

In this study, an approach was proposed to employ new target branched co.pounds(TBCs) including multiple antibiotic norfloxacin frameworks for intensified adsorption films to achieve super protection of mild steel in HCl medium. Thus, the TBCs co.taining bis/tri norfloxacin skeletons were synthesized by multi-step preparation route. In addition, the reference linear co.pound(RLC) including a single norfloxacin part was also synthesized. The chemical structures of these co.pounds were co.firmed by various means. It was demonstrated that the TBCs co.ld form the tough adsorption films on the surface of mild steel, which co.ld be processed mainly through chemisorption effect. The electrochemical analysis suggested that the TBCs displayed superior co.rosion inhibition performance for low carbon steel in1.0 mol·L^(-1) HCl solution over the RLC(RLC, 87.80%;TBC1, 97.63%;TBC2, 98.35%), which was further understood by the molecular modelling. The isotherm adsorption plots were employed to analyze the spontaneous adsorption process of the TBCs on low carbon steel surface, and a prominent chemisorption co.ld be inferred by the standard Gibbs free energy changes of the adsorption.

关键词： Branched co.pounds Norfloxacin part Adsorption Antico.rosion Mild steel

Improved Relief Grinding Method of Gear Hob with Equal Relief Angle

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Chinese Journal of Mechanical Engineering 2011年第5期24卷 842-850页

作者： LI Guolong SUN Menghui LI Xianguang LIU Fei HUANG Chao State Key Laboratory of Mechanical Transmission Chongqing University Chongqing 400030 China chongqing Machine Tool （Group） co. Ltd. Chongqing 400055 China

The regrinding error is the main factor affecting the eligible length of hob tooth,how to decrease the regrinding error is a hot issue in the research area of hob *** present,researches focus on changing the trajectory of relief moving,because of no unified relief grinding path planning method,the research result is restricted in the practical *** solving the problem,the calculation model of the hob relief angle is established with the Archimedes relieving motion to analyze the interaction between the increasing relief angle of the hob and the accelerating tooth profile *** on it,the improved relief grinding method of gear hob is proposed with equal relief angle（ERA）.Furthermore,the relief grinding method with ERA is developed with the following two ***,the co.vergence numerical solution algorithm of the tooth top curve is designed to form the wheel motion path which is co.pared with that of traditional *** seco.d step is to establish the solution model of ERA grinding *** order to verify the effect of the method,hob grinding simulation system of 3D solid was built under the AutoCAD *** regrinding errors is analyzed by intercepting the hob axial profiles of the various regrinding angles with Boolean operations and further co.verting it to basic rack tooth,then the simulation example of zero rake straight flute hob is used to co.pare the regrinding errors between ERA grinding and traditional ***,the experiments were implemented on the five-axis CNC relief grinder with the relief motion of ERA grinding driven by *** results of experiments show that the method can effectively reduce the regrinding errors of hob and grind expediently gear hob of AA rank and *** research provide an effective model of relief moving path plan reducing regrinding error,and have practicable value in CNC relief grinder.

关键词： gear hob relief grinding grinding wheel regrinding error simulation

Numerical study on butterfly wings around inclusion based on damage evolution and semi-analytical method

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Friction 2022年第9期10卷 1335-1352页

作者： Ye ZHOU Caichao ZHU Xiaojin CHEN Wei YE State Key Laboratory of Mechanical Transmissions Chongqing UniversityChongqing 400030China co.lege of Aerospace Engineering Chongqing UniversityChongqing 400044China chongqing Wangjiang Industrial co. Chongqing 400071China

Butterfly wings are closely related to the premature failure of rolling element *** this study,butterfly formation is investigated using the developed semi-analytical three-dimensional(3D)co.tact model inco.porating inclusion and material property *** 3D elastic field introduced by inhomogeneous inclusion is solved by using numerical approaches,which include the equivalent inclusion method(EIM)and the co.jugate gradient method(CGM).The accumulation of fatigue damage surrounding inclusions is described using co.tinuum damage *** co.pling between the development of the damaged zone and the stress field is *** effects of the inclusion properties on the co.tact status and butterfly formation are discussed in *** model provides a potential method for quantifying material defects and fatigue behavior in terms of the deterioration of material properties.

关键词： co.tact fatigue butterfly wings semi-analytical method damage evolution

Experimental Study on Fatigue Performance of Gussasphalt Mixture

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Journal of Wuhan University of Technology(Materials Science) 2014年第4期29卷 745-750页

作者：吴文军 HE Zhaoyi HAO Zengheng ZHANG Hua School of Civil and Architectural Engineering Chongqing Jiaotong University chongqing Zhixiang Paving Technology Engineering co. Ltd China Merchants chongqing co.munications Research & Design Institute co. Ltd

Four-point flexural fatigue test for Gussasphalt mixture specimen was carried out at a strainco.trolled mode system. The results showed that the development of the tested stiffness modulus and phase angle of the mixtures with increasing load cycles exhibited three periods, initial generation, slow development and failure period. The fatigue crack generation zone formed in the third period, in which the macro mechanical properties were signifi cantly decreased. Moreover, we also analyzed the effects of asphalt co.tent and mixing temperature on the fatigue life of the mixture. The results showed that the fi rst period when the specimen＇s initial stiffness modulus was reduced to 80% acco.nted for 5%-10% of the total fatigue life; the seco.d period in which the reduction became slow and demonstrated a liner relationship with load cycles occupied 70%-85% of the fatigue life; and the third period was about 5%-10%. The results indicated that the lower the mixing temperature, the longer the fatigue life of Gussasphalt mixture. Besides, the increasing of asphalt co.tent has a minor effect on the fatigue life of Gussasphalt mixture

关键词： gussasphalt mixture stiffness modulus fatigue performance mix temperature asphalt co.tent