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Transfer relation between subgrade frost heave and slab track deformation and vehicle dynamic response in seasonally frozen ground

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第2期25卷 130-146页

作者： Juanjuan REN Junhong DU Kaiyao zhang Bin YAN jincheng TIAN MOE Key Laboratory of High-speed Railway Engineering Southwest Jiaotong UniversityChengdu610031China School of Civil Engineering Southwest Jiaotong UniversityChengdu610031China School of Civil Engineering Central South UniversityChangsha410075China Airport Planning and Design Institute POWERCHINA Kunming Engineering Corporation LimitedKunming650051China

Subgrade frost heave in seasonally frozen ground can greatly influence the safety and smooth running of high-speed trains and the service performance of track structures.In this study,we used a static model to:(1)investigate track-subgrade frost heave and develop a dynamic model of vehicle-track-subgrade frost heave;(2)explore the transfer relation between subgrade frost heave and track structure deformation;(3)examine the characteristics of interlayer debonding;(4)study the influence of subgrade frost heave on the dynamic response of vehicles in high-speed railways in seasonally frozen regions.A Fourier series was used to fit the frost heave waveform and simulate the behavior of subgrade uneven frost heave using data collected on-site.The results show:(i)The position of frost heave significantly affects the transfer of deformation to a slab track.The largest deformation of the track slab,with the amplitude transfer ratio reaching 20%,was recorded when the frost heave occurred near the joint of the base plate.(ii)At the same frost heave amplitude,long-wave frost heave causes smaller deformation and debonding of the track structure than short-wave frost heave.In the wavelength range of 10-30 m,the main frequency of the acceleration spectral density was concentrated between 3.5 and 3.7 Hz,with larger frost heave wavelengths producing smaller superposition on the vertical acceleration of the vehicle.(ii)The maximum wheel-rail force occurs when the front bogie passes the frost heave peak,with greater frost heave amplitudes producing greater wheel-rail force.From these results,we conclude there is a clear need to control the frost heave deformation of the track to reduce the dynamic response of the vehicle and in turn improve train operatSubgrade frost heave in seasonally frozen ground can greatly influence the safety and smooth running of high-speed trains and the service performance of track structures.In this study,we used a static model to:(1)investigate track`-subgrade frost heave and develop a dynamic model of v

关键词： Slab track Subgrade frost heave Transfer relation Vehicle-track-subgrade coupling Dynamic response

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Human Visual Attention Mechanism-Inspired Point-and-Line Stereo Visual Odometry for Environments with Uneven Distributed Features

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Chinese Journal of Mechanical Engineering 2023年第3期36卷 191-204页

作者： Chang Wang Jianhua zhang Yan Zhao Youjie Zhou jincheng Jiang School of Mechanical Engineering University of Science and Technology BeijingBeijing 100083China School of Mechanical Engineering Shandong UniversityJinan 250100China School of Mechanical Engineering Hebei University of TechnologyTianjin 300401China

Visual odometry is critical in visual simultaneous localization and mapping for robot navigation.However,the pose estimation performance of most current visual odometry algorithms degrades in scenes with unevenly distributed features because dense features occupy excessive weight.Herein,a new human visual attention mechanism for point-and-line stereo visual odometry,which is called point-line-weight-mechanism visual odometry(PLWM-VO),is proposed to describe scene features in a global and balanced manner.A weight-adaptive model based on region partition and region growth is generated for the human visual attention mechanism,where sufficient attention is assigned to position-distinctive objects(sparse features in the environment).Furthermore,the sum of absolute differences algorithm is used to improve the accuracy of initialization for line features.Compared with the state-of-the-art method(ORB-VO),PLWM-VO show a 36.79%reduction in the absolute trajectory error on the Kitti and Euroc datasets.Although the time consumption of PLWM-VO is higher than that of ORB-VO,online test results indicate that PLWM-VO satisfies the real-time demand.The proposed algorithm not only significantly promotes the environmental adaptability of visual odometry,but also quantitatively demonstrates the superiority of the human visual attention mechanism.

关键词： Visual odometry Human visual attention mechanism Environmental adaptability Uneven distributed features

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Vortex 4.0 on chip

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Light(Science & Applications) 2020年第1期9卷 1025-1027页

作者： Qing zhang jincheng Ni Cheng-Wei Qiu Department of Electrical and Computer Engineering National University of SingaporeSingapore 117583Singapore

The orbital angular momentum(OAM)of light has promising applications,ranging from information multiplexing and high-speed optical communication to computation.Dynamically tunable and switchable vortex microlasers combined with direct photocurrent detection of the topological charges of OAM states have paved unexplored routes for the development and integration of fourth-generation(4.0)vortex technology,potentially on chip.

关键词： OAM tunable multiplexing

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A Golden Decade of Polar Codes:From Basic Principle to 5G Applications

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China Communications 2023年第2期20卷 94-121页

作者： Kai Niu Ping zhang jincheng Dai Zhongwei Si Chao Dong The Key Laboratory of Universal Wireless Communications Ministry of EducationBeijing University of Posts and TelecommunicationsBeijing 100876China The State Key Laboratory of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing 100876China Department of Broadband Communication Peng Cheng LaboratoryShenzhen 518055China

After the pursuit of seventy years,the invention of polar codes indicates that we have found the first capacity-achieving coding with low complexity construction and decoding,which is the great breakthrough of the coding theory in the past two decades.In this survey,we retrospect the history of polar codes and summarize the advancement in the past ten years.First,the primary principle of channel polarization is investigated such that the basic construction,coding method and the classic successive cancellation(SC)decoding are reviewed.Second,in order to improve the performance of the finite code length,we introduce the guiding principle and conclude five design criteria for the construction,design and implementation of the polar code in the practical communication system based on the exemplar schemes in the literature.Especially,we explain the design principle behind the concatenated coding and rate matching of polar codes in 5G wireless system.Furthermore,the improved SC decoding algorithms,such as SC list(SCL)decoding and SC stack(SCS)decoding etc.,are investigated and compared.Finally,the research prospects of polar codes for the future 6G communication system are explored,including the optimization of short polar codes,coding construction in fading channels,polar coded modulation and HARQ,and the polar coded transmission,namely polar processing.Predictably,as a new coding methodology,polar codes will shine a light on communication theory and unveil a revolution in transmission technology.

关键词： polar codes channel polarization successive cancellation decoding polar coded modulation polar processing

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《野草》:鲁迅的生命之维

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鲁迅研究月刊 2024年第2期 89-95,100页

作者：张金城华南师范大学文学院 510006 广东机电职业技术学院 510515

《野草》研究有待继续深入的意义有二:一是从学术出发,总结前人研究成果的共性以及各自的独创性,在既有基础上,扩大《野草》研究的共识领域;二是从思想出发,探讨鲁迅在《野草》中体现的哲学高度和精神体系,思索《野草》作为鲁迅心灵窗... 详细信息

《野草》研究有待继续深入的意义有二:一是从学术出发,总结前人研究成果的共性以及各自的独创性,在既有基础上,扩大《野草》研究的共识领域;二是从思想出发,探讨鲁迅在《野草》中体现的哲学高度和精神体系,思索《野草》作为鲁迅心灵窗户所提供的个人省思、自我拷问的思维方式,寻求其对当代知识分子和中国文化的价值和意义。

关键词：鲁迅《野草》生命维度当代

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Significant emission reductions of carbonaceous aerosols from residential coal burning by a novel stove

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Journal of Environmental Sciences 2022年第10期34卷 135-143页

作者： Xuran Li Chenglong zhang Weimin Zhuo Yuxuan Zhuo jincheng Yang Min Song Yujing Mu Research Center for Eco-Environmenta1l Sciences Chinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China Center for Excellence in Urban Atmospheric Environment Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China Xuzhou Zhongkai Mechanical&Electrical Equipment Manufacturing Co. Ltd.Xuzhou 221300China School of Environmental Science and Engineering Shandong UniversityJinan 250100China

Carbonaceous aerosols(CA) are crucial components in the atmospheric PM_(2.5) and derived from diverse sources. One of the major sources for CA is from the incomplete combustion of bituminous coal that has been prevailingly used by household stoves in rural areas for heating during winter. To efficiently eliminate the CA emission, a new household stove(NHS) was developed based on a novel combustion technology and CA emissions from the NHS and a traditional household stove(THS) were comparably investigated under the actual stove operation conditions in a farmer’s house. Compared with the THS, the emission factors of organic carbon(OC), elemental carbon(EC), and water-soluble organic carbon(WSOC) from the NHS were reduced by 96%±1%, 98%±1%, and 91%±1% under the flaming process and 95%±1%, 96%±2%, and 83%±4% under the smoldering process, respectively. Additionally,the mass absorption efficiency of WSOC from the NHS reduced by 3 folds and the radiative forcing by WSOC relative to EC shrank remarkably by a factor of 3-8. Based on the reduction of emissions and light absorption of WSOC, the promotion of the NHS offers a possible solution to achieve the clean combustion of residential solid fuel.

关键词： OC EC WSOC Emission factor Light absorption

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Highly sensitive salinity sensor based on Mach-Zehnder interferometer with double-C fiber

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Fundamental Research 2022年第2期2卷 296-302页

作者： Ya-nan zhang Like Li jincheng Zhao Yong Zhao College of Information Science and Engineering Northeastern UniversityShenyang 110819China State Key Laboratory of Synthetical Automation for Process Industries Shenyang 110819China Hebei Key Laboratory of Micro-Nano Precision Optical Sensing and Measurement Technology Qinhuangdao 066004China

This paper proposes a highly sensitive,compact,and low-cost optical fiber salinity sensor based on the Mach-Zehnder interferometer.The sensor is constructed using a single mode fiber(SMF)-no-core fiber-double-C fiber(DCF)-NCF-SMF structure,with the DCF prepared by etching the dual side-hole fiber with HF acid.The DCF’s large-size exposed microfluidic channels solve the previous microstructured optical fiber’s challenging liquid filling and replacement problems.Theoretical simulations and experiments demonstrate that the sensor is suitable for high-sensitivity salinity measurement.The sensor exhibits a high salinity sensitivity of-2.26 nm/‰ in the salinity range of 10‰-50‰,as demonstrated by the experimental results.Additionally,the sensor exhibits some fascinating characteristics,including high repeatability,hysteresis,reversibility,and stability.

关键词： Optical fiber sensor Salinity sensor Mach-Zehnder interferometer Microfluidic channel Double-C fiber

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Semantic information processing in industrial networks

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The Journal of China Universities of Posts and Telecommunications 2022年第1期29卷 41-49页

作者： Yao Shengshi Wang Sixian Dai jincheng Niu Kai Xu Wenjun zhang Ping The Key Laboratory of Universal Wireless Communications(Ministry of Education) Beijing University of Posts and TelecommunicationsBeijing 100876China The Peng Cheng Laboratory Nanshan DistrictShenzhen 518052China The State Key Laboratory of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing 100876China

The industrial Internet of things(industrial IoT, IIoT) aims at connecting everything, which poses severe challenges to existing wireless communication. To handle the demand for massive access in future industrial networks, semantic information processing is integrated into communication systems so as to improve the effectiveness and efficiency of data transmission. The semantic paradigm is particularly suitable for the purpose-oriented information exchanging scheme in industrial networks. To illustrate its applicability, typical industrial data are investigated, i.e., time series and images. Simulation results demonstrate the superiority of semantic information processing, which achieves a better rate-utility tradeoff than conventional signal processing.

关键词： semantic information semantic communication industrial Internet of things signal processing

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Advances in Sinopec's Shale Gas Drilling Technologies

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China Oil & Gas 2016年第1期23卷 16-21页

作者： Zang Yanbin ZHANG JinCheng SINOPEC Petroleum Engineering Research Institute

In order to economically and effectively develop shale gas in China, Sinopec introduced foreign technologies and integrated them with available domestic technologies and self-developed tools according to geological characteristics and complicated mountainous geomorphology in marine shale plays of southern China. A technology series composed of innovated theories concerning geological characterization during drilling, new generation of PDC bits, friction-reducing tools, low-cost oil-based drilling fluid system, high-efficient washing fluid and elastic mud systems, integrated drilling engineering design, long lateral cementing, modified well factory drilling method and etc., was developed to fulfill fast and optimized drilling for shale gas wells. The application of the technology series in about 251 wells of Fuling gas field, Chongqing City, southwestern China, showed positive results: mechanical rotating speed increased by 191%, drilling duration reduced by 53%, and quality passing percent 100%.

关键词：钻井技术中国石化页岩气钻井工程设计中国西南地区地质特征 PDC钻头钻井液体系

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Interfacial Voids Trigger Carbon-Based, All-Inorganic Cs Pb IBr2 Perovskite Solar Cells with Photovoltage Exceeding 1.33 V

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Nano-Micro Letters 2020年第7期12卷 121-134页

作者： Weidong Zhu Zeyang zhang Dandan Chen Wenming Chai Dazheng Chen jincheng zhang Chunfu zhang Yue Hao State Key Discipline Laboratory of Wide Band Gap Semiconductor Technology and Shaanxi Joint Key Laboratory of Graphene School of MicroelectronicsXidian UniversityXi’an 710071People’s Republic of China College of Science Xi’an Shiyou UniversityXi’an 710065ShaanxiPeople’s Republic of China

A novel interface design is proposed for carbon-based,all-inorganic CsPbIBr2 perovskite solar cells(PSCs)by introducing interfacial voids between TiO2 electron transport layer and CsPbIBr2 absorber.Compared with the general interfacial engineering strategies,this design exempts any extra modification layer in final PSC.More importantly,the interfacial voids produced by thermal decomposition of 2-phenylethylammonium iodide trigger three beneficial e ects.First,they promote the light scattering in CsPbIBr2 film and thereby boost absorption ability of the resulting CsPbIBr2 PSCs.Second,they suppress recombination of charge carriers and thus reduce dark saturation current density(J0)of the PSCs.Third,interfacial voids enlarge built-in potential(Vbi)of the PSCs,awarding increased driving force for dissociating photo-generated charge carriers.Consequently,the PSC yields the optimized e ciency of 10.20%coupled with an open-circuit voltage(Voc)of 1.338 V.The Voc achieved herein represents the best value among CsPbIBr2 PSCs reported earlier.Meanwhile,the non-encapsulated PSCs exhibit an excellent stability against light,thermal,and humidity stresses,since it remains^97%or^94%of its initial e ciency after being heated at 85℃for 12 h or stored in ambient atmosphere with relative humidity of 30–40%for 60 days,respectively.

关键词： All-inorganic perovskite solar cells Cs Pb IBr2 Photovoltage Interfacial engineering Stability

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