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盾壳挤压上浮盾构隧道引起环缝凸榫损伤研究

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

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

Application of improved U-Net network with attention mechanism in end-to-end speech enhancement

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Chinese Journal of Acoustics 2022年第4期41卷 390-403页

作者： WU Ruiqin CHEN Xueqin YU Jie WANG Lirong zhao heming School of Electronic and Information Engineering Soochow UniversitySuzhou 215006

An improved U-Net(Attention Dilated Convolution U-Net,ADC-U-Net)network model for end-to-end speech enhancement is designed based on the U-Net *** with the baseline U-Net network,the dilated convolution is added to reduce the loss of information caused by ***,the attention mechanism structure is introduced,which combines more contextual information of noisy speech to extract deeper and richer feature *** proposed model avoids the extraction of features with distinct step,so it does not need three steps of traditional methods,including feature extraction,feature denoising and waveform *** proposed network model obtains complex structural features to represent speech through multi-level and multi-scale *** quality and intelligibility of enhanced speech are evaluated by several subjective and objective *** data show that the proposed algorithm performs well in noise suppression and adaptability,and has advantage over baseline U-Net network and other models in speech quality and intelligibility.

关键词： network speech mechanism

40mm厚度Q500MC钢板大热输入焊接试验

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机械制造文摘（焊接分册） 2024年第3期 16-22页

作者：曲之国王东明王立志赵和明杨海峰日钢营口中板有限公司辽宁营口115005 辽宁省中厚板专业技术创新中心辽宁营口115005

采用Mg-Ti复合氧化物冶金处理方式试制了40 mm Q500MC钢板,并进行了热输入为276 KJ/cm的大热输入焊接实验。结果表明,钢板各项力学性能满足GB/T 1591要求,且韧脆转变温度T VE低于-60℃。焊接接头各项力学性能满足标准要求,热影响区各位... 详细信息

采用Mg-Ti复合氧化物冶金处理方式试制了40 mm Q500MC钢板,并进行了热输入为276 KJ/cm的大热输入焊接实验。结果表明,钢板各项力学性能满足GB/T 1591要求,且韧脆转变温度T VE低于-60℃。焊接接头各项力学性能满足标准要求,热影响区各位置0℃、-20℃冲击韧性满足标准要求且有一定余量。对比母材,焊接热影响区0℃冲击吸收能量降低约56%,-20℃冲击吸收能量降低约77%,热影响区韧脆转变温度T VE约为-18.4℃。经过大热输入焊接后,粗晶热影响区获得以晶内针状铁素体为主的组织,韧性水平较理想,热影响区正火区域宽度可达5~6 mm,组织以铁素体+珠光体为主,对应区域硬度较低,软化严重。

关键词： Q500MC 大热输入焊接气电立焊冲击吸收能量软化

Research advances in peptide-drug conjugates

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药学学报:英文版 2023年第9期13卷 3659-3677页

作者： Liming Gong heming zhao Yanhong Liu Hao Wu Chao Liu Shuangyan Chang Liqing Chen Mingji Jin Qiming Wang Zhonggao Gao Wei Huang State Key Laboratory of Bioactive Substance and Function of Natural Medicines Institute of Materia MedicaChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100050China Beijing Key Laboratory of Drug Delivery Technology and Novel Formulations Department of PharmaceuticsInstitute of Materia MedicaChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100050China Department of Pharmacy Yanbian UniversityYanji 133000China

Peptide-drug conjugates(PDCs)are drug delivery systems consisting of a drug covalently coupled to a multifunctional peptide via a cleavable *** an emerging prodrug strategy,PDCs not only preserve the function and bioactivity of the peptides but also release the drugs responsively with the cleavable property of the *** the ability to significantly improve the circulation stability and targeting of drugs in vivo and reduce the toxic side effects of drugs,PDCs have already been extensively applied in drug ***,we review the types and mechanisms of peptides,linkers and drugs used to construct PDCs,and summarize the clinical applications and challenges of PDC drugs.

关键词： Peptide-drug conjugates Peptides Linkers Drug delivery systems Prodrug strategy

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

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

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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基于感应回火的梯度性能刀圈的制备工艺

金属热处理 2023年第7期48卷 124-130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

采用感应加热方法对刀圈进行局部高温回火处理,研究了回火温度以及感应回火时间对H13E钢刀圈微观组织、硬度、冲击吸收能量以及抗拉强度和塑性的影响。结果表明,在580~680℃范围内回火,刀圈的组织为回火索氏体,且随着回火温度的升高,析... 详细信息

采用感应加热方法对刀圈进行局部高温回火处理,研究了回火温度以及感应回火时间对H13E钢刀圈微观组织、硬度、冲击吸收能量以及抗拉强度和塑性的影响。结果表明,在580~680℃范围内回火,刀圈的组织为回火索氏体,且随着回火温度的升高,析出的粒状碳化物数量增加,刀圈硬度逐渐降低,冲击吸收能量则逐渐升高。随着感应回火时间的增加,刀圈微观组织、硬度和冲击吸收能量初始阶段变化显著,在回火时间大于30 min后,组织和性能趋于稳定。采用640℃保温30 min的工艺对刀圈进行了感应回火处理,测试了刀圈截面硬度分布和不同位置的组织状态,证明了感应回火制备梯度性能刀圈方法和工艺的可行性。

关键词： H13E钢刀圈感应回火热处理梯度性能