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Exploring the feasibility of prestressed anchor cables as an alternative to temporary support in the excavation of super-large-span tunnel

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Railway Engineering Science 2024年第3期32卷 344-360页

作者： Shunhua Zhou Yuyin Jin Zhiyao Tian Chunhua Zou heming zhao Zengrun Miao Shanghai Key Laboratory of Rail Infrastructure Durability and System Safety Tongji UniversityShanghai 201804China Key Laboratory of Road and Traffic Engineering of the Ministry of Education Tongji UniversityShanghai 201804China China Railway Construction Corporation Limited Beijing 100855China The 2nd Engineering Co. Ltd.of China Railway Construction Bridge Engineering Bureau GroupShenzhen 518083China China Railway Construction Bridge Engineering Bureau Group Co. LtdTianjin 300300China

Excavating super-large-span tunnels in soft rock masses presents significant *** ensure safety,the sequential excavation method is commonly *** utilizes internal temporary supports to spatially partition the tunnel face and divide the excavation into multiple ***,these internal supports generally impose spatial constraints,limiting the use of large-scale excavation equipment and reducing construction *** address this constraint,this study adopts the“Shed-frame”principle to explore the feasibility of an innovative support system,which aims to replace internal supports with prestressed anchor cables and thus provide a more spacious working space with fewer internal *** evaluate its effectiveness,a field case involving the excavation of a 24-m span tunnel in soft rock is presented,and an analysis of extensive field data is conducted to study the deformation characteristics of the surrounding rock and the mechanical behavior of the support *** results revealed that prestressed anchor cables integrated the initial support with the shed,creating an effective“shed-frame”system,which successively maintained tunnel deformation and frame stress levels within safe regulatory ***,the prestressed anchor cables bolstered the surrounding rock effectively and reduced the excavation-induced disturbance zone *** summary,the proposed support system balances construction efficiency and *** field experiences may offer valuable insights into the popularization and further development of prestressed anchor cable support systems.

关键词： Super-large-span tunnel Construction safety Sequential excavation method Shed-frame principle Prestressed anchor cables

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壁厚分布对金属隔膜翻转偏心行为的影响研究

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载人航天 2024年第3期30卷 291-299页

作者：范凯施华赵和明上海空间推进研究所上海201112 上海空间发动机工程技术研究中心上海201112

为确保金属隔膜的有序翻转,实现贮箱质心规则变化和推进剂均衡排放,研究分析了壁厚分布对金属隔膜翻转偏心行为的影响。结果表明:对于等壁厚隔膜,锥壳和球冠具有一定的纠偏能力,过渡球壳不具有纠偏能力。采用过渡球壳均匀变壁厚方案,通... 详细信息

为确保金属隔膜的有序翻转,实现贮箱质心规则变化和推进剂均衡排放,研究分析了壁厚分布对金属隔膜翻转偏心行为的影响。结果表明:对于等壁厚隔膜,锥壳和球冠具有一定的纠偏能力,过渡球壳不具有纠偏能力。采用过渡球壳均匀变壁厚方案,通过增大偏向段和偏离段翻转启动压力差ΔP_(r),促使偏离段较小的轴向分力P_(y)优先达到翻转启动压力P_(r),进而提升过渡球壳纠偏能力,以更小的壁厚梯度和更低的重量代价实现隔膜翻转不偏心。

关键词：壁厚分布翻转偏心金属隔膜

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盾壳挤压上浮盾构隧道引起环缝凸榫损伤研究

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铁道建筑技术 2024年第1期 138-141,153页

作者：赵何明中铁建大桥工程局集团第二工程有限公司广东深圳518083

盾构隧道施工过程中存在上浮问题,会出现盾构机尾部局部挤压管片的现象,引起环缝凸榫破损。受损环缝凸榫成为服役盾构隧道薄弱部位,增加环缝渗漏水等盾构隧道病害的发生概率。针对该问题,建立了11环盾构隧道三维有限元模型,分析了盾尾... 详细信息

盾构隧道施工过程中存在上浮问题,会出现盾构机尾部局部挤压管片的现象,引起环缝凸榫破损。受损环缝凸榫成为服役盾构隧道薄弱部位,增加环缝渗漏水等盾构隧道病害的发生概率。针对该问题,建立了11环盾构隧道三维有限元模型,分析了盾尾挤压位置和盾构隧道上浮程度对盾构隧道环缝凸榫的破坏作用。研究结果表明:(1)盾构隧道上浮越严重,受盾尾挤压作用引起的盾构隧道结构变形越大,环缝凸榫法向接触应力最大值呈增大趋势。(2)盾尾挤压位置越靠近环缝,盾构隧道相邻环变形差异越大,环缝凸榫法向接触应力增大速率越快。(3)盾构隧道上浮较小时,环缝凸榫不存在损伤。随着盾构隧道上浮增加,环缝凸榫受拉损伤因子增加。

关键词：地铁盾构隧道上浮凸榫损伤

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限位自闭锁式引信MEMS安全与解除隔离装置

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兵器装备工程学报 2024年第8期45卷 266-273页

作者：姜学文赵河明王军付博班伟中北大学机电工程学院太原030051 淮海工业集团有限公司山西长治046000 中国船舶重工集团公司第七一〇研究所湖北宜昌443003

针对小口径榴弹引信安全与解除隔离装置(安解装置)体积缩小的同时加强冗余保险性能和结构强度的要求,提出了一种基于电铸镍材料的改进型限位自闭锁式引信MEMS安解装置。装置利用后坐环境和离心环境激励特点,加以指令控制的电动推销器实... 详细信息

针对小口径榴弹引信安全与解除隔离装置(安解装置)体积缩小的同时加强冗余保险性能和结构强度的要求,提出了一种基于电铸镍材料的改进型限位自闭锁式引信MEMS安解装置。装置利用后坐环境和离心环境激励特点,加以指令控制的电动推销器实现三道独立冗余保险和延期解除隔离功能需求,区别于传统隔爆机构需要借助额外微弹簧辅助锁紧,该装置隔爆机构借助一种反锁卡簧结构实现限位自闭锁,且能够实现环境激励下的无碰撞反弹一次闭锁到位。利用刚柔耦合动力学和有限元仿真模拟并加以样机试验的手段,探究在规定的技术指标下安解装置的解保动作和闭锁强度。仿真与样机试验结果均表明:所提装置可识别正常发射的后坐和离心环境激励,满足安全解除保险的动作要求且不会发生材料强度失效,该安解装置简单可靠。

关键词：引信微机电系统安解装置锁销结构

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Heading constraint algorithm for foot-mounted PNS using low-cost IMU

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Journal of Systems Engineering and Electronics 2022年第3期33卷 727-736页

作者： GUI Jing zhao heming XU Xiang School of Electronic and Information Engineering Soochow UniversitySuzhou 215006China

Foot-mounted pedestrian navigation system(PNS)is a common solution to pedestrian navigation using micro-electro mechanical system(MEMS)inertial *** inherent problems of inertial navigation system(INS)by the traditional algorithm,such as the accumulated errors and the lack of observation of heading and altitude information,have become obstacles to the application and development of the *** this paper,we introduce a heuristic heading constraint *** of all,according to the movement characteristics of human gait,we use the generalized likelihood ratio test(GLRT)detector and introduce a time threshold to classify the human gait,so that we can effectively identify the stationary state of the *** addition,based on zero velocity update(ZUPT)and zero angular rate update(ZARU),the cumulative error of the inertial measurement unit(IMU)is limited and corrected,and then a heuristic heading estimation is used to constrain and correct the heading of the *** simulation and experiments with low-cost IMU,the method is proved to reduce the localization error of end-point to less than 1%of the total distance,and it has great value in application.

关键词： pedestrian navigation system(PNS) zero velocity update(ZUPT) gait detection heading constraint

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Research on mold flux for hypo-peritectic steel at high casting speed

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Journal of University of Science and Technology Beijing 2007年第3期14卷 219-224页

作者： heming zhao Xinhua Wang Jiongming Zhang Metallurgical and Ecological Engineering School University of Science and Technology Beijing Beijing 100083 China

Mold fluxes having adaptable properties were developed in the laboratory to solve quality defects, such as depressions and longitudinal cracks when casting hypo-peritectic steel at high casting speed. Firstly, the effect of components on the high basicity mold flux properties was first studied using the orthogonal method. In the scope of the studied content, Li2O has the largest effect on the melting temperature, and the least effect on the viscosity; CaF2 has the largest effect on the viscosity, and the least effect on the melting temperature; Na2O and CaO/SiO2 have no obvious influence on the melting temperature and viscosity. Secondly, two powders （Z1 and Z6） have reasonable viscosity-temperature curves, higher solidification temperatures, and porous structure after solidification, but the crystal property of Z6 is worse than that of Z1, and thus Z1 is more suitable for continuous casting hypo-peritectic steel at high casting speed. Thirdly, a higher basicity of powder, a less free enthalpy of crystal compound, and a lower baffle energy are good for a higher tendentiousness of crystal.

关键词： hypo-peritectic steel mold flux crystal property heat flux

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Heterogeneous Microstructure-Induced Mechanical Responses in Various Sub-Zones of EH420 Shipbuilding Steel Welded Joint Under High Heat Input Electro-Gas Welding

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Acta Metallurgica Sinica(English Letters) 2021年第10期34卷 1427-1433页

作者： Xu Xie Tan zhao heming zhao Song Li Cong Wang School of Metallurgy Northeastern UniversityShenyang 110819China State Key Laboratory of Metal Material for Marine Equipment and Application Angang Steel Co.Ltd.Anshan 114021China Minmetals Yingkou Medium Plate Co. Ltd.Yingkou 115005China Nanjing Steel Co. Ltd.Nanjing 210035China State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819China

Heterogeneous microstructure-induced mechanical responses in EH420 shipbuilding steel welded joint by electro-gas welding processed have been systematically studied by scanning electron microscopy,electron backscatter diffraction and mechanical *** with the coarse-grained heat-affected zone(CGHAZ),the weld metal presents higher toughness(129.3 J vs.37.3 J)as it contains a large number of acicular ferrites with high-angle grain boundaries(frequency 79.2%)and special grain boundary∑3(frequency 55.3%).Moreover,coarse austenite grains in CGHAZ and slender martensite–austenite constituents between bainite laths may likely facilitate crack *** ferrites and tempered pearlites formed at the junction of the fine-grained heat-affected zone and the intercritical heat-affected zone induced a softened zone with an average hardness of 185 HV0.5,which is the main reason for the occurrence of tensile fracture.

关键词： Heterogeneous microstructure Mechanical properties Electro-gas welding High heat input Shipbuilding steel

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Effect of SEN structure on the mold level fluctuation and heat transfer for a medium thin slab caster

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Journal of University of Science and Technology Beijing 2008年第2期15卷 120-124页

作者： heming zhao Xinhua Wang Jiongming Zhang Wanjun Wang School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing 100083 China

It is important to select suitable parameters of a submerged entry nozzle （SEN） for optimizing the flow and temperature patterns in a mold. The effect of SEN design on the mould level stability, meniscus steel flow velocity, and heat transfer of the mold of a medium thin slab caster was studied by means of 1：1 water modeling and industrial testing. The advantages of a 2-port SEN compared with a 3-port SEN are the following： more optimal flow patterns with a lower mold level fluctuation and a lower meniscus steel flow velocity; proper powder consumption without slag bears due to a reasonable liquid powder thickness. The argon flow rate can be reduced and the mold average heat flux and temperature near the edges of the copper plate are reduced. At a casting speed of 2.5 m·min^-1, the mold level fluctuation lies within ＋5 mm. In addition, soft cooling of the steel shell in the mold is realized, which is suitable for casting crack susceptible steel grades.

关键词： submerged entry nozzle mold level fluctuation heat transfer water model

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基于锡合金的水下机器人密封自修复系统设计

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装备环境工程 2024年第2期21卷 89-96页

作者：赵俐蓉段捷赵河明于静中北大学长治产业技术研究院山西长治046012 中国船舶集团有限公司第七一四研究所北京100101

目的解决水下机器人推进器密封系统在驱动电机轴高速旋转和高水压情况下,密封件易磨损失效导致发生漏水故障的问题。方法利用余度设计思想,在原有密封结构的基础上,设计一种基于锡合金的水下机器人密封自修复系统,当原有密封结构失效... 详细信息

目的解决水下机器人推进器密封系统在驱动电机轴高速旋转和高水压情况下,密封件易磨损失效导致发生漏水故障的问题。方法利用余度设计思想,在原有密封结构的基础上,设计一种基于锡合金的水下机器人密封自修复系统,当原有密封结构失效漏水,密封自修复系统便控制限位锡合金块加热至融化,使锡合金块的限位作用消失,进而释放冗余密封圈,并通过拉簧的作用将冗余密封圈推至密封槽内,从而恢复推进器的密封功能。为验证设计的可靠性,又通过有限元软件ANSYS对密封自修复结构中影响密封性能的关键部件进行静力学分析。结果关键部件的强度仿真结果均满足设计要求,在密封自修复实验装置箱体内注适量水,并施加2MPa的水压保持一段时间,密封自修复系统成功启动,且其密封性能传感器未检测到其漏水。结论密封自修复系统可在漏水的情况下顺利启动,并起到密封的作用,验证了设计的可行性。

关键词：水下机器人漏水故障余度设计密封自修复锡合金静力学分析

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Sparse Decomposition Algorithm Using Immune Matching Pursuit 11th

Sparse Decomposition Algorithm Using Immune Matching Pursuit

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2012 IEEE 11th International Conference on Signal Processing(ICSP 2012)

作者： Yan Zhou heming zhao Tao Liu School of Electronics and Information Engineering Soochow University Department of Electronics and Information Engineering Soochow Vocational University

ISBN: (纸本)9781467321969

The optimal sparse expression for a signal is critical to the application of compressed sensing theory. Since the standard matching pursuit uses greedy strategy to approximate the objective function, which is aim to search for the linear combination of the optimal atoms in a redundant dictionary. It is inevitable to cause enormous calculation quantity, to overcome this defect, a scheme based on immune matching pursuit algorithm is proposed in this paper which is suitable for speech signal sparse decomposition. In this matching pursuit algorithm, each matching process has been optimized by the immune algorithm with the characteristics of local fast convergence and global optimal. As a result, according to this algorithm, the speed of sparse decomposition and the quality of reconstructed signal all have been effectively improved, and the storage space requirement for redundant dictionary also has been degraded. Simulation results show that, the matching pursuit computational cost can be obviously reduced by using this algorithm, Moreover, the performance of this algorithm is stable, and it also has high signal decomposition accuracy. In a word, the efficiency of sparse decomposition can be significantly improved by combining the immune evolution mechanism and matching pursuit algorithm.

关键词： Matching Pursuit Immune Algorithm Sparse decomposition Redundant dictionary Reconstructed signal

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