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Microstructure and properties of 1100 MPa grade low-carbon hot-rolled steel by laser welding

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Journal of Iron and Steel Research International 2018年第2期25卷 228-234页

作者： Chen Dong Ai-min Zhao Xi-tao Wang qi-hang Pang Hui-bin Wu Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing 100083 China Engineering Research Institute University of Scienceand Technology Beijing Beijing 100083 China

The microstructure and mechanical properties of the butt joint of 1100 MPa grade hot-rolled low-carbon steel by laser welding were investigated by scanning electron microscopy, micro-hardness and tensile tests. The yield strength and tensile strength of the laser welded joint reached 100.2 and 99.5% of the base material （BM）, respectively. However, the elongation of the welded joint only reached about 60% of BM. The lowest and highest hardness areas both existed in the incomplete recrystallization zone. The width of the softened area of the welded joint is about 240-260 pro. The element distribution has no obvious change for C, Cr, Si, Mn, Ti, etc.

关键词： Hot-rolled steel Laser welding Microstructure Mechanical property Element distribution

Effect of Cr content and cooling rate on the primary phase of Al-2.5Mn alloy

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International Journal of Minerals,Metallurgy and Materials 2019年第12期26卷 1551-1558页

作者： hang-qi Feng Zhi-bo Yang Ye-tong Bai Li Zhang Yu-lin Liu School of Materials Science and Engineering Shenyang Aerospace University

The effect of Cr content and cooling rate on the microstructure of Al-Mn alloy was studied using well resistance furnace melting,and the alloy was analyzed using scanning electron microscopy(SEM)and X-ray diffraction(XRD).The experimental results showed that adding Cr could significantly improve the morphology of the primary phase in the Al-2.5Mn *** Cr,the primary phase in the alloy was thick,needle-like,and strip-like *** adding 0.2wt%-0.5wt%Cr,the primary phase in the upper part of the alloy was gradually fined and reached the best effect at 0.35wt%*** the content of Cr was 0.5wt%,the microstructure of the primary phase in the upper part began to *** bottom of the alloy was a large bulk phase,but still much finer than that without adding *** and SEM analysis showed that the precipitation phase at the bottom was mainly Al85Mn7Cr8,while the fine microstructure at the top was Al6Mn and *** results of the cooling rate experiments showed that the primary phase of Al-2.5Mn-0.35Cr was further refined,and the eutectic microstructure was partly achieved,under air-cooling *** when the cooling method was iron die-cooling,the microstructure of the Al-2.5Mn-0.35Cr alloy was changed into a eutectic microstructure.

关键词： Al-2.5Mn alloy Cr content primary phase cooling rate

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EPC项目中暖通专业的优化设计要点研究

建筑技术 2024年第17期55卷 2154-2158页

作者：朱建邦王振军聂其林邓瑶麒王启航中建二局第三建筑工程有限公司北京100070

EPC总承包商关注的重点是高效、规范、专业地开展EPC项目的优化设计创效工作,节约工程建设成本,提高项目经济效益。暖通工程是EPC项目实施中的重要组成之一,也是整个EPC项目利润提升空间较大的一部分,因此开展EPC项目暖通工程的优化创... 详细信息

EPC总承包商关注的重点是高效、规范、专业地开展EPC项目的优化设计创效工作,节约工程建设成本,提高项目经济效益。暖通工程是EPC项目实施中的重要组成之一,也是整个EPC项目利润提升空间较大的一部分,因此开展EPC项目暖通工程的优化创效要点研究则显得尤为重要。研究结合具体项目案例,制订了高效技术路线,充分考虑EPC项目设计流程的特点,从方案设计、初步设计、施工图设计3个阶段着手对暖通专业涉及的系统、材料、设备、路由、参数等方面进行了全面系统地分析,完成暖通专业设计环节的优化创效要点研究。

关键词： EPC项目暖通专业设计创效

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某核电用上充泵转子动力学特性分析

化工机械 2024年第1期51卷 106-113页

作者：刘政马宇航肖志慧吴骞任映霖李启行辽宁红沿河核电有限公司北京化工大学高端机械装备健康监控与自愈化北京市重点实验室

以一台RCV上充泵为研究对象,构建了考虑流体激励的泵转子动力学方程,通过流体动力学仿真方法获得导轴承和密封构件支承点的动力学参数,并进行多级充液态(即湿态)离心泵的转子进行了动力学分析。仿真结果表明:在该型转子中,充液使得支承... 详细信息

以一台RCV上充泵为研究对象,构建了考虑流体激励的泵转子动力学方程,通过流体动力学仿真方法获得导轴承和密封构件支承点的动力学参数,并进行多级充液态(即湿态)离心泵的转子进行了动力学分析。仿真结果表明:在该型转子中,充液使得支承点等效刚度增加,进而整体固有频率增加,由干态的柔性转子转变为湿态下的刚性转子。最后,结合现场振动数据的功率谱函数曲线峰值,确定了转子在刚性状态工作时的系统的固有频率,验证了建模的有效性。研究结果为整级上充泵的动力学建模仿真及模型验证提供了清晰的分析路径,对于后续的状态监测与故障诊断也有着重要意义。

关键词：离心式上充泵转子动力学轴承密封

双重退火工艺对TC21钛合金板材组织和性能的影响

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金属世界 2024年第1期 66-69页

作者：巨朝飞苗阳齐航雷挺吴家兴宝鸡钛业股份有限公司陕西宝鸡721014

通过热轧的方式制备出TC21板材,并对TC21板材在经不同热处理制度处理后的抗拉强度、显微组织、延伸率和断面收缩率进行了检测,得出了双重退火制度对板材性能和组织的影响规律。TC21板材经900°C/1 h固溶处理,600°C/4 h时效处理后显微... 详细信息

通过热轧的方式制备出TC21板材,并对TC21板材在经不同热处理制度处理后的抗拉强度、显微组织、延伸率和断面收缩率进行了检测,得出了双重退火制度对板材性能和组织的影响规律。TC21板材经900°C/1 h固溶处理,600°C/4 h时效处理后显微组织均匀,晶粒细小,均为α+β转变组织,此制度下的板材性能最优,抗拉强度达到1350 MPa,屈服强度达到1275 MPa,板材的延伸率变化不大,断面收缩率达到最大值32.6%。

关键词：断面收缩率双重退火固溶处理时效处理延伸率 TC21钛合金显微组织热处理制度

High-temperature properties and microstructure of Mo microalloyed ultra-high-strength steel

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International Journal of Minerals,Metallurgy and Materials 2011年第4期18卷 407-412页

作者： qi-hang Han Yong-lin Kang Xian-meng Zhao Lu-feng Gao Xue-song qiu School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Beijing 100083 China

The high-temperature mechanical properties and microstructure of forging billets of C-Si-Mn-Cr and C-Si-Mn-Cr-Mo ultra-high-strength cold-rolled steels（tensile strength≥1000 MPa,elongation≥10%） were *** the comparison of reduction in area and hot deformation resistance at 600-1300°C,the Mo-containing steel was found to possess a higher strength and a better plasticity than the Mo-free *** equilibrium phase diagram and atom fraction of Mo in different phases at different temperatures were calculated by Thermo-Calc software（TCW）.The results analyzed by using transmission electron microscopy and TCW show that precipitates in the Mo-containing steel are primarily M23C6,which promote pearlite *** experimental data also show that a lower ductility point existing in the Mo-free steel at 850°C is eliminated in the Mo-containing *** is mainly due to the segregation of Mo at grain boundaries investigated by electron probe microanalysis（EPMA）,which improves the strength of grain boundaries.

关键词： high strength steels high temperature properties microstructure molybdenum thermodynamics

Enhanced persulfate activation process by magnetically separable catalysts for water purification:A review

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Chinese Journal of Structural Chemistry 2023年第6期42卷 55-67页

作者： Chuan Pu Gang Lu hang qi Abdulgalim B.Isaev Mingshan Zhu School of Environment Jinan UniversityGuangzhou510632China School of Environment and Energy Engineering Anhui Jianzhu University230601China Department of Inorganic Chemistry and Chemical Ecology Dagestan State UniversityM.Gadjieva 43a367001MakhachkalaRussian Federation

In recent years,persulfate(PS)-based advanced oxidation processes(AOPs)have become a hot research topic for degrading environmental pollutants due to their excellent oxidation capacity,selectivity,and ***-AOPs can generate sulfate radicals(SO^(·-)_(4))with strong oxidation ability,but single PS produces limited or no ***,activation of PS by energy input or catalyst dosing is used to improve its oxidation ***,the addition of disposable catalyst not only causes a waste of resources,but also may lead to secondary ***,magnetically separable catalysts for activating PS have received widespread attention due to their *** there are few literature reviews on the activation of PS by carbon-or iron-based magnetic materials,the mechanism analysis of the activation of PS by magnetic materials to degrade pollut-ants is not deep enough,and the discussion of material types is not comprehensive and ***,the discussion of magnetic materials in terms of recycling properties is ***,this review firstly sum-marizes and analyzes the mechanism of magnetically separable catalysts activating PS to degrade ***,the research progress of zero-valent iron(ZVI,Fe^(0))-based,iron oxide-based,bimetallic oxide-based,and other magnetically separable catalyst is introduced,and the tailoring engineering approaches and reusability of magnetically separable catalysts are ***,some possible material optimization suggestions are proposed in this *** conclusion,this review is expected to provide useful insights for improving the per-formance and reusability of magnetically separable materials activated PS in the future.

关键词： Magnetically separable catalysts AOPs Sulfate radicals Mechanism Reusability

A mixed behaviour equilibrium model with mode choice and its application to the endogenous demand of automated vehicles

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Journal of Management Science and Engineering 2020年第4期5卷 227-248页

作者： Guangchao Wang hang qi Huiling Xu Seungkyu Ryu School of Information Management Central China Normal UniversityWuhan430079China Institute for Advanced Studies in Finance and Economics Hubei University of EconomicsWuhan430205China Korea Institute Science Technology Information Dajeon02792South Korea

This study develops a mixed behavioural equilibrium model with explicit consideration of mode choice(MBE-MC)in a transportation system where fully automated vehicles(AV)coexist with conventional human-driven vehicles(HV).For the mode choice,travellers select among three options,following a logit modal split:driving their private HV,or taking an AV mobility service provided by either a firm or the *** the route choice,the HV drivers follow the random utility maximisation principle while central agents route the AV passengers following the Cournot Nash(firm agent)or Social Optimal(government agent)*** consider two types of travel costs(*** time and monetary travel cost)to characterise the new features(*** link capacity and reduced value of time)of the mixed AVeHV transportation *** model the MBE-MC problem in a combined modeeroute choice framework and formulate it as a route-based variational inequality(VI)*** show the equivalence between the VI formulation and the MBE-MC problem,and the existence of a solution to the MBE-MC ***,we modify a partial linearisation algorithm for solving the proposed *** results validate the equilibrium conditions and show the efficacy of the new model in capturing the features of the mixed AVeHV transportation *** impact patterns of different parameters on(1)the network performance in terms of AV share and system cost and(2)on the solution efficiency are analysed.

关键词： Mixed behaviour equilibrium Automated vehicle SUE-CN-SO Combined travel choices Variational inequality

建筑工程高大模板施工技术运用的相关研究与分析

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工程建设与设计 2024年第19期 217-219页

作者：孙明海李治山杨启航西安建工交建集团有限公司西安710061

在详细分析高大模板支架的设计刚度、平稳性、误差控制等构造标准的基础上,研究了高支模模板体系施工的关键要点,并对混凝土浇捣、梁模板安装、楼面模板安装、模板拆除等关键环节的实施流程、注意事项进行分析,同时,针对高大模板施工技... 详细信息

在详细分析高大模板支架的设计刚度、平稳性、误差控制等构造标准的基础上,研究了高支模模板体系施工的关键要点,并对混凝土浇捣、梁模板安装、楼面模板安装、模板拆除等关键环节的实施流程、注意事项进行分析,同时,针对高大模板施工技术运用质效,论述了方案专家论证、动态垂直监测与沉降监测、材料合理选型与质量控制、钢筋保护层控制等要点,进一步完善建筑工程高大模板施工工艺体系。

关键词：建筑工程高大模板施工技术

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