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Acta Oceanologica Sinica 2016年第12期35卷 110-118页

作者： WANG Cao LI Quanwang PANG long zou Aming ZHANG long Department of Civil Engineering Tsinghua University CCCC Highway Consultants CO. Ltd.

Natural hazards such as hurricanes may cause extensive economic losses and social disruption for civil structures and infrastructures in coastal areas, implying the importance of understanding the construction performance subjected to hurricanes and assessing the hurricane damages properly. The intensity and frequency of hurricanes have been reported to change with time due to the potential impact of climate *** this paper, a probability-based model of hurricane damage assessment for coastal constructions is proposed taking into account the non-stationarity in hurricane intensity and frequency. The nonhomogeneous Poisson process is employed to model the non-stationarity in hurricane occurrence while the non-stationarity in hurricane intensity is reflected by the time-variant statistical parameters(e.g., mean value and/or standard deviation), with which the mean value and variation of the cumulative hurricane damage are evaluated explicitly. The Miami-Dade County, Florida, USA, is chosen to illustrate the hurricane damage assessment method proposed in this paper. The role of non-stationarity in hurricane intensity and occurrence rate due to climate change in hurricane damage is investigated using some representative changing patterns of hurricane parameters.

关键词： hurricane damage assessment intensity frequency non-stationarity climate change

Detection and analysis of magnetic particle testing defects on heavy truck crankshaft manufactured by microalloyed medium-carbon forging steel

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Journal of Iron and Steel Research International 2020年第5期27卷 608-616页

作者： Jin-long Lu Guo-guang Cheng Meng Wu Guo Yang Ju-long Che State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China Research and Development Department Xining Special Steel Co.Ltd.Xining 810005QinghaiChina

An unqualifed six-cylinder heavy truck crankshaft has been studied to investigate the cause of magnetic particle testing defects on the rod ***-sized long-striped MnS inclusions are regarded as the major cause for the magnetic particle testing failure because they have been detected in situ under the magnetic particle *** the observation of macroscopic structures of the rod journals and corresponding counterweight blocks,it is found that for the 1#and 3#rod journals,the center metal of the original hot-rolled bar has been extruded to the inboard edge of the rod journals and large-sized long-striped MnS inclusions are exposed on the surface after fash removal,leading to the failure of magnetic particle *** for the 2#rod journal,the center metal of the original bar has not been extruded to the surface and MnS inclusions on the rod journal surface are small in size,few in number,resulting in passing the magnetic particle *** the quality of the hot-rolled bars fuctuates,it is more recommended to apply magnetic particle testing on samples at the center of bars before forging to evaluate the severity of defects caused by the long-striped MnS inclusions for fear of the scrap of the fnal crankshafts.

关键词： Crankshaft Magnetic particle testing MnS inclusion Microalloyed medium-carbon forging steel Defect

Rapid Ultrasonic-Assisted Soldering of AZ31B Mg Alloy/6061 Al Alloy with Low-Melting-Point Sn–xZn Solders Without Flux in Air

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Acta Metallurgica Sinica(English Letters) 2019年第3期32卷 332-342页

作者： Zhi-Wei Lai Zhe-Yuan Huang Chuan Pan Hui-Qiao Du Xiao-guang Che Lei Liu Wei-Ming long Gui-Sheng zou School of Materials Science and Engineering Tsinghua University Department of Mechanical Engineering Tsinghua University China Iron & Steel Research Institute Group College of Materials Science and Engineering Shanxi Key Laboratory of Advanced Magnesium-Based MaterialsTaiyuan University of Technology Beijing Spacecraft Manufacturing Factory The State Key Laboratory of Advanced Brazing Filler Metals and Technology Zhengzhou Research Institute of Mechanical Engineering

A novel ultrasonic-assisted low-temperature soldering was developed to join AZ31B Mg alloy and 6061 Al alloy with a series of Sn–x Zn solders. The average maximum shear strength of the joints reaches up to 87.5 MPa at soldering temperature of 300 °C under ultrasonic assistance for only 5 s using Sn–20 Zn solder. The fracture path propagates completely in the soldering seam. The results indicate that the microjet generated by ultrasonic pressure in liquid solder could strike and splinter the Mg_2Sn intermetallic compounds into small pieces, which contributes to the enhancement of the joint strength. In addition, the primary Al(Zn) solid solution phase formed during cooling stage could also strengthen the joint due to the prevention of microcracks propagation.

关键词： Ultrasonic-assisted soldering Ultrasonic effect mechanism Microjet Intermetallic compound distribution Solid solution Joint strengthening

Laser assembly nanostructured Al2O3/TiO2 coating on cast aluminum surface

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中国有色金属学会会刊:英文版 2004年第z1期14卷 264-267页

作者： ZHANG guang-jun DAI Jian-qiang WANG Hui-ping YAN Min-jie XI Wen-long zou Chang-gu GE Da-fang Laser Industrial Technology Research Institute Shanghai University of Engineering Science Shanghai 200336 China

CO2 laser quick assembly technology is adopted on the surface of cast aluminum ZL104 to form a dense ceramic coating containing a great deal of nanometer Al2O3/TiO2 particles which eliminate cracks and *** major phases of the coating are α-Al2O3 andβ-TiO2. The micro-hardness distribution of the coating is 1 813,1 504, 1 485 and 1 232 (HV0.05). The bonding strength of the coating LC1 is 11.4 N, which is 7.26 times higher than that of the conventional hot-spraying Al2O3/TiO2 coating. It has been proved by analysis that the bonding strength is achieved because of the effects of both super-quick laser consolidation and the nanometer effect of nanometer ceramic material.

关键词： laser assembly oxide ceramic coating nanometer material microhardness bonding strength

Analysis of the Load-Stress Response Characteristics of the Bogie Frame in Intercity Electric Multiple Unit

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Chinese Journal of Mechanical Engineering 2018年第2期31卷 227-237页

作者： Hua zou Shou-guang Sun Qiang Li Zun-Song Ren Engineering Research Center of Structure Reliability and Operation Measurement Technology of Rail Guided Vehicles of Ministry of Education Beijing Jiaotong University

Load spectra research for bogie frame requires establishing the load?stress relationship on working condition, which has been omitted by the researchers. With the load?stress of the bogie frame of an intercity Electric Multiple Unit(Hereinafter referred to as EMU) as the research object, an optimization model of the load?stress transfer relationship is established. The load?stress coe cient for EMU bogie frame was calibrated in the laboratory bench and online test was arranged on Dazhou?Chengdu line. Comparison of nonlinear and linear neural networks proves that the linear transitive relation between the load and stress of the bogie frame in the operating process is highly suitable. An optimization model of the load?stress transfer coe cient is obtained. The data calculated with the modified coe cient are closer to the dynamic stress results in the actual operating process than the data calculated with the calibration coe cient. The coe cient of the modified transitive relation is una ected by operating area, empty load, heavy load, or other conditions in the operating process of the intercity EMU. The real loads in actual situations are obtained. The model of online load?stress relationship that is highly suitable for line stress calculation is finally established. The research is helpful for further damage calculation and inferring the time history signal of the load in load spectra research.

关键词： Bogie frame Load Stress Transitive relation Neural network

Experimental investigation of transient characteristics of mild surge and diffuser rotating stall in a centrifugal compressor with vaned diffuser

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Science China(Technological Sciences) 2020年第7期63卷 1212-1223页

作者： ZHAO Yang XI guang zou HanSen SUN Ya Wei WANG ZhiHeng National Engineering Research Centre of Fluid Machinery&Compressors Xi’an Jiaotong UniversityXi'an 710049China

The centrifugal compressor is widely used for gas compression in various industrial fields such as aero-engine, gas turbine and turbocharger. However, the stable operating range is usually restricted by the occurrence of flow instability such as stall and surge. The paper experimentally examines the developing process of surge and stall occurring in a centrifugal compressor to advance the understanding on flow mechanism of flow instability. It is found that three types of pressure fluctuation can be observed at low flowrate region. At the critical point, the local stall firstly occurs in some specific diffuser passages and the enlarged local diffuser stall eventually induces the mild surge of compression system indicated by the sinusoidal pressure fluctuation. At lower mass flow rate, the diffuser stall cell begins to circumferentially propagate along the impeller rotating direction at 11% of rotor speed with the existence of mild surge. In comparative analysis of IGV pre-swirl angle on the occurrence of mild surge, the mild surge still occurs at the operating condition when the slope of the characteristic map of test stage is still obviously negative, in which the compression system is supposed to be stable in previous study. And a new suggested criterion for the prediction of mild surge is demonstrated that the occurrence of mild surge depends on the destabilization effect of downstream components about diffuser and volute. Combined with the experimental data, the streamwise distribution characteristic of diffuser stall can be used to develop the simplified model of lumped parameters for the analysis on the generation mechanism of the diffuser rotating stall. The quantitative investigation on the relation between the pressure-rise characteristic of subcomponents and the occurrence of mild surge and diffuser rotating stall not only advances the prediction of stability limit but also lays the theoretic foundation for controlling these unsteady behaviors to improve t

关键词： centrifugal compressor mild surge diffuser rotating stall transient measurement

Towards a New Paradigm for Brain-inspired Computer Vision

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Machine Intelligence Research 2022年第5期19卷 412-424页

作者： Xiao-long zou Tie-Jun Huang Si Wu Beijing Academy of Artificial Intelligence Beijing 100084China School of Psychology and Cognitive Sciences IDG/McGovern Institute for Brain ResearchCenter for Quantitative BiologyPKU-Tsinghua Center for Life SciencesPeking UniversityBeijing 100084China National Engineering Research Center of Visual Technology School of Computer SciencePeking UniversityBeijing 100871China Institute for Artificial Intelligence Peking UniversityBeijing 100871China

Brain-inspired computer vision aims to learn from biological systems to develop advanced image processing ***,its progress so far is not *** recognize that a main obstacle comes from that the current paradigm for brain-inspired computer vision has not captured the fundamental nature of biological vision,i.e.,the biological vision is targeted for processing spatio-temporal ***,a new paradigm for developing brain-inspired computer vision is emerging,which emphasizes on the spatio-temporal nature of visual signals and the brain-inspired models for processing this type of *** this paper,we review some recent primary works towards this new paradigm,including the development of spike cameras which acquire spiking signals directly from visual scenes,and the development of computational models learned from neural systems that are specialized to process spatio-temporal patterns,including models for object detection,tracking,and *** also discuss about the future directions to improve the paradigm.

关键词： Brain-inspired computer vision spatio-temporal patterns object detection object tracking object recognition

Influence of adjacent shield tunneling construction on existing tunnel settlement: field monitoring and intelligent prediction

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2023年第12期24卷 1106-1119页

作者： long RAN Yang DING Qizhi CHEN Baoping zou Xiaowei YE School of Civil Engineering and Architecture Zhejiang University of Science&TechnologyHangzhou 310023China Zhejiang Engineering Research Center of Intelligent Urban Infrastructure Hangzhou City UniversityHangzhou 310015China Department of Civil Engineering Zhejiang UniversityHangzhou 310058China

Urban subway tunnel construction inevitably disturbs the surrounding rock and causes the deformation of existing subway structures. Dynamic predictions of the tunnel horizontal displacement, tunnel ballast settlement, and tunnel differential settlement are important for ensuring the safety of buildings and tunnels. First, based on the Hangzhou Metro project, we analyzed the influence of construction on the deformation of existing subway structures and the difficulties and key points in monitoring. Then, a deformation prediction model, based on a back propagation(BP) neural network, was established with massive monitoring data. In particular, we analyzed the influence of four structures of the BP neural network on prediction performance, i.e., single input–single hidden layer–single output, multiple inputs–single hidden layer–single output, single input–double hidden layers–single output, and multiple inputs–double hidden layers–single output, and verified them using measured data.

关键词： Subway Horizontal displacement of tunnel Settlement of tunnel ballast Differential settlement of tunnel Deformation prediction Back propagation(BP)neural network

Physical Background of the Unified Scaling Law in Spiral Galaxies

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Chinese Physics Letters 2000年第12期17卷 935-936页

作者： zou Zhen-long HAN Jin-Lin Beijing Astronomical Observatory and Beijing Astrophysical Center National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100012

We discussed the physical background of the unified scaling law in spiral galaxies,and qualitatively obtained the power index of the empirical relation among the luminosity L,radius R and the rotation velocity *** also discussed the possible causes for the data dispersion on the plane in three-dimensional space of these parameters.

关键词： parameters galaxies rotation

Effect of MgO-Cr_(2)O_(3) and Mg0-MgAl_(2)0_(4)-based refractories on refractory-steel interface reaction and cleanliness of pipeline steel

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Journal of Iron and Steel Research International 2024年第4期31卷 849-860页

作者： guang-mei Yang Cheng Yuan Chang Liu Qiang Wang guang-qiang Li Yong-shun zou Ao Huang The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan 430081HubeiChina

The interaction of MgO-MgAl_(2)O_(4)-based and MgO-Cr_(2)O_(3)-based refractories with X70 molten steel was studied by immersion experiments at 1560℃.The effects of immersion time(30 and 60 min)on the contents of total oxygen(TO),Al,Nb,Si,Mn,and Cr as well as the composition,number density,and size distribution of inclusions in the molten steel were *** influence of the penetration and erosion degree of the molten steel to the refractory on the steel-refractory interface layer was *** results show that,at 1560℃,the MgO-MgAl_(2)O_(4)-based refractory can better control the contents of TO and the composition of molten steel compared with the MgO-Cr_(2)O_(3)-based *** TO content is only 16×10^(-4) wt.%in the molten steel after reacted with the Mg0-MgAl_(2)O_(4)-based refractory at the end point of refining,4 accounting for 11.5%of that reacted with the MgO-Cr_(2)O_(3)-based refractory(139×10^(-4) wt.%).The number density of inclusions is only 14 mm^(-2),and the average size ofinclusions is only 1.31μm,with thelargest proportion of inclusions in 1-2μm(70%).The Al_(2)O_(3)-MnS-CaO complex inclusions in the original steel changed to complex inclusions dominated by Cr-Nb-Mn-S-O and ***_(2)O_(3),corresponding to the MgO-Cr_(2)O_(3)-based and MgO-MgAl_(2)O_(4)-based refractories,*** ***_(2)O_(3) layer was formed at the reaction interface between MgO-MgAl_(2)O_(4)-based refractory and molten steel,which is helpful to restrict the erosion of refractories and the pollution of molten *** damage mechanism of the MgO-Cr_(2)O_(3)-based refractory is mainly permeation and chemical reaction,while the damage of the MgO-MgAl_(2)O_(4)-based refractory is mainlyscouring erosion.

关键词： MgO-Cr_(2)O_(3)-based refractory MgO-MgAl O_(4)-based refractory Nonmetallic inclusion Erosion interface layer Steel penetration