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Influence of Vanadium on Fracture Splitting Property of Medium Carbon Steel

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Journal of Iron and Steel Research International 2016年第5期23卷 475-483页

作者： wei-jun HUI cheng-wei SHAO Yong-jian ZHANG Si-lian CHEN Han DONG School of Mechanical Electronic and Control Engineering Beijing Jiaotong University Beijing 100044 China Central Iron and Steel Research Institute Beijing 100081 China

The fracture splitting property of medium carbon steel 37MnSiS microalloyed with V up to 0. 45% was investigated by using simulated fracture splitting test,for the development of new crackable medium carbon steel to manufacture high performance connecting rod. Conventional high carbon steel C70S6 was used for comparison. The results show that the volume fraction of both ferrite and V-rich M（ C,N） particles increases,and the pearlite interlamellar spacing decreases with increasing V content,which in turn results in gradual increase of strength and decrease of ductility and impact energy. The fracture splitting property of the tested steel could be improved significantly due to the increase of V content mainly through the precipitation hardening mechanism of fine M（ C,N） precipitates. The fraction of brittle cleavage fracture in the crack initiation area increases noticeably with increasing V content and full brittle cleavage fracture surface could be obtained when V content was increased to 0. 45%. It is concluded that medium carbon steel with V content higher than about 0. 28% possesses not only comparable or even higher mechanical properties with those of conventional steel C70S6,but also excellent fracture splitting property,and therefore,is more suitable to fabricate high performance fracture splitting connecting rod.

关键词： microalloyed medium carbon steel fracture splitting vanadium precipitation hardening microstructure

Drainage-induced ground response in a twin-tunnel system through analytical prediction over the seepage field

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Underground Space 2022年第3期7卷 408-418页

作者： cheng-wei Zhu wei Wu Hong-wei Ying Xiao-nan Gong Pan-pan Guo Research Center of Coastal and Urban Geotechnical Engineering HangzhouChina Institut fur Geotechnik Universitat fur BodenkulturFeistmantelstrasse 4A-1180 ViennaAustria Institute of Geotechinical Engineering Hohai UniversityNanjingChina

Leakage-induced hydraulic and ground responses in a twin-tunnel system are analyzed via the proposed analytical solution on the seepage *** seepage continuity conditions are rigorously satisfied at the interface between the ground and the tunnel lining,in terms of both water pressure and seepage *** analytical solution is verified by comparing the results of numerical simulations.A detailed parametric analysis is carried out to explore the effect of tunnels’spatial layouts and degraded waterproof facilities on leakageinduced hydraulic and ground response,including head decline,water inflow and ground surface *** results show that the often used single tunnel model tends to overestimate the pore pressure on the lining along with water inflow into the tunnel,and underestimate the leakage-induced ground settlement.

关键词： Twin tunnel Leakage Head decline Water inflow Ground settlement

BHONEM:Binary High-Order Network Embedding Methods for Net worked-Guarantee Loans

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Journal of Computer Science & Technology 2019年第3期34卷 657-669页

作者： Da-wei cheng Yi Tu Zhen-wei Ma Zhi-Bin Niu Li-Qing Zhang Department of Computer Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China School of Mathematical Science Shanghai Jiao Tong University.Shanghai 200240China School of Computer Software Tianjin UniversityTianjin 300354China

Networked-guarantee loans may cause systemic risk related concern for the government and banks in *** prediction of the default of enterprise loans is a typical machine learning based classification problem, and the networked guarantee makes this problem very difficult to solve. As we know, a complex network is usually stored and represented by an adjacency matrix. It is a high-dimensional and sparse matrix, whereas machine-learning methods usually need lowdimensional dense feature representations. Therefore, in this paper, we propose a binary higher-order network embedding method to learn the low-dimensional representations of a guarantee network. We first set vertices of this heterogeneous economic network by binary roles (guarantor and guarantee), and then define high-order adjacent measures based on their roles and economic domain knowledge. Afterwards, we design a penalty parameter in the objective function to balance the importance of network structure and adjacency. We optimize it by negative sampling based gradient descent algorithms,which solve the limitation of stochastic gradient descent on weighted edges without compromising efficiency. Finally, we test our proposed method on three real-world network datasets. The result shows that this method outperforms other start-of-the-art algorithms for both classification accuracy and robustness, especially in a guarantee network.

关键词： networked-guarantee loan high-order network embedding representative learning gradient descent

Thermal stability of retained austenite and mechanical properties of medium-Mn steel during tempering treatment

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Journal of Iron and Steel Research International 2017年第8期24卷 830-837页

作者： Xiao-li Zhao Yong-jian Zhang cheng-wei Shao wei-jun Hui Han Dong School of Mechanical Electronic and Control EngineeringBeijing Jiaotong UniversityBeijing 100044China Central Iron and Steel Research Institute Beijing 100081China

The thermal stability of retained austenite（RA）and the mechanical properties of the quenched and intercritical annealed 0.1C-5Mn steel with the starting ultrafine lamellar duplex structure of ferrite and retained austenite during tempering within the range from 200 to 500°C were studied by X-ray diffraction（XRD）,transmission electron microscopy（TEM）and tensile *** results showed that there was a slight decrease in the RA volume fraction with increasing tempering temperature up to 400°*** caused a slight increase in the ultimate tensile strength（UTS）and a slight decrease in the total elongation（TE）;thus,the product of UTS to TE（UTS×TE）as high as 31GPa·% was obtained and remained nearly ***,aportion of the RA began to decompose when tempered at 500°C and thus caused a^35% decrease of the RA fraction and a^16%decrease of the value of UTS×*** is concluded that the ultrafine lamellar duplex structure is rather stable and the excellent combination of strength and ductility could be retained with tempering temperature up to 400°***,thermal processes such as galvanization are feasible for the tested steel provided that their temperatures are not higher than 400°C.

关键词： Medium-manganese transformation-induced plasticity steel Tempering Microstructure Mechanical property Retained austenite

Tribological analysis of the surface layer coated by sintered serpentine-reinforced composites

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Acta Metallurgica Sinica(English Letters) 2018年第6期31卷 615-622页

作者： Xiao Wang Jun-wei Wu Lu-Hai Zhou Xi-cheng wei Wu-Rong Wang School of Materials Science and Engineering Shanghai University

In this work,the serpentine powders were sintered to make the serpentine-reinforced Al-matrix composites,and the microstructures of which were characterized by differential scanning calorimetry,thermal gravimetric analyzer,and X-ray *** electron microscopy equipped with energy dispersive *** show that the sintered serpentine powders were deeply absorbed on the worn surface and embedded in the furrows and scratches of the matrix,forming a self-repairing surface layer which reduces the friction *** surface layer coated by serpentine was compact,dense,and uniform with the friction time prolonged,compensating the worn loss and increasing the matrix mass.

关键词： Serpentine Friction Wear Surface layer

A novel method to prepare metal oxide electrode:Spin-coating with thermal decomposition

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Chinese Chemical Letters 2011年第3期22卷 354-357页

作者： Hao Xu wei Yan cheng Li Tang Department of Environmental Science and Technology Xi'an Jiaotong University Xi'an 710049 China

In this work,we propose a new spin-coating method coupling with high thermal decomposition,to prepare the tin-antimony（Sn-Sb） oxide *** character of the spin-coating electrode was compared with the dip-coating electrode through X-ray diffraction（XRD）,scanning electron microscopy（SEM）,accelerated life test,cyclic voltammetry,and electrolytic degradability. The results showed that the spin-coating electrode had a better defined crystal form,a smoother and more compact surface than that of the dip-coating *** time of the spin-coating electrode was determined to be longer than 15 h,and it was less than 2 min for the dip-coating *** characterization analysis showed that the electrolytic degradability of the spin-coating electrode is better than that of the dip-coating electrode.

关键词： Spin-coating Dip-coating Thermal decomposition Electro properties

Electromagnetic metasurfaces: from concept to applications

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Science Bulletin 2019年第12期64卷 791-792页

作者： cheng-wei Qiu weixiang Jiang Tiejun Cui Department of Electrical and Computer Engineering National University of SingaporeSingapore 117583Singapore State Key Laboratory of Millimeter Waves Department of Radio Engineering Southeast UniversityNanjing 210096China

Electromagnetic or optical metasurfaces, as a kind of quasi-twodimensional artificial interface, are patterned subwavelength structures within ultrathin thickness that interact strongly with electromagnetic waves. The history of metasurface was traced back to the two-dimensional electromagnetic bandgap structure [1], which may be regarded as the beginning of metasurface research. Such metasurface with high impedance has been widely used in reducing the size of antennas and improving their performance. Recently, generalized Snell’s laws [2] have been coined and widely applied to various designs of metasurfaces [3], which pave a clearcut physical foundation for metasurfaces. Thereby, the metasurfaces have been widely deployed in designing new devices to regulate and control the electromagnetic wavefronts. For example, 600-nm-thick TiO2 metalens have been demonstrated to focus the light [4], 105 times thinner than the optical traditional lens with similar performance. Such a metasurface lens is believed promising to replace the traditional optical lens in the future. Hence, functional structured surfaces have become the subject of several rapidly-growing research areas, and demonstrated a lot of useful properties of structure-based devices with customized electric and magnetic responses.

关键词： quasi-twodimensional artificial interface metasurface research electromagnetic wavefronts

Structural, Visual, or Iconic： Transmutations of Wooden Brackets in Modern China

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Frontiers of History in China 2015年第2期10卷 323-365页

作者： wei-cheng Lin Department of Art University of North Carolina at Chapel Hill Chapel Hill NC 27599-3405 USA

Together with pillars and roof, the bracket set is one of the most fundamental structural components of traditional timber-frame architecture in China. Not only structurally indispensable, it was also emblematic of specific building styles developed through history. Entering the modem era, however, its architectural validity was overturned by the use of modem technology and building materials, rendering brackets merely a visual and decorative motif. This paper contends that it was precisely when the bracket set lost its structural significance that it began to be discussed in ways that endowed it with layers of cultural meaning in the context of modem China. Examining its modem appropriations in materials other than wood throughout the twentieth century, the paper explores shifting meanings of brackets in their continuous transmutations from a reminder of a defunct component in the building tradition to a nostalgic sign for an irretrievable architectural past.

关键词： brackets Liang Sicheng adaptive style timber-frame architecture,enchantment

Design of structured-light vision system for tomato harvesting robot

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International Journal of Agricultural and Biological Engineering 2014年第2期7卷 19-26页

作者： Feng Qingchun cheng wei Zhou Jianjun Wang Xiu Beijing Research Center of Intelligent Equipment for Agriculture Beijing 100097China Zhejiang University of Technology Hangzhou 100085China

In order to improve the operating precision of the harvesting robot,a vision system for intelligently identifying and locating the mature tomato was *** active detection method based on structured-light stereo vision was expected to deal with the problem of variable illumination and target occlusion in the *** maximum between-cluster variances of hue(H)and saturation(S)value were adopted as the threshold for color segmentation,which weakened the impact on the image caused by the light intensity *** the limit on the pixel size and circularity of the candidate areas,the vision system recognized the fruit area and removed the noise *** fruit’s 3D position was computed on the basis of spatial relationship between the laser plane and the camera,when the linear laser was projected on the centre area of the mature *** blue view-scanning laser stripe pixels on the mature fruit were extracted according to its Cb color *** the field test results show,the measurement error on the fruit radius is less than 5 mm,the centre distance error between the fruit and camera is less than 7 mm,and the single axis coordinate error is less than 5.6 *** structured-light vision system could effectively identify and locate mature fruit.

关键词： harvesting robot tomato linear structure-light 3D measurement feature extraction