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An analytical analysis for the mechanical performance of fully-grouted rockbolts based on the exponential softening model

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International journal of Mining Science and Technology 2022年第5期32卷 981-995页

作者： zhongwen Yue Akang Li Peng Wang Peng Wang Department of Mechanics and Civil Engineering China University of Mining and Technology-BeijingBeijing 100083China Pan-China Construction Group Co. Ltd.Beijing 100070China

This paper presented a novel bond-slip model to better reveal the mechanical behavior of the bolt-grout interface for fully-grouted rockbolts under tensile loads by considering the non-linear response in the softening *** exponential decay function is adopted for describing the non-linear response in the softening *** on the improved bond-slip model,the corresponding analytical solutions for the interfacial shear stress and the axial force of the bolt under different loading stages are ***,the validity of this proposed model was verified by comparing with the experimental *** results show that compared with the linear softening model,the proposed model is more suitable for predicting the mechanical performance of fully-grouted ***,a series of parametric studies are conducted to explore the effect of model parameters on the mechanical properties of fully-grouted *** results indicate that compared with the anchor length,the bolt diameter and the bond strength of the bolt-grout interface have a significance influence on the ultimate load of bolt,especially for the elastic and softening ***,it can be found that using the linear softening model maybe overestimates the supporting performance of grouted bolt,resulting in an unsafe design for bolt.

关键词： Fully-grouted rockbolts Non-linear response Bond-slip model Anchor length Analytical solutions

Development of Hybrid ARQ Protocol for the Quantum Communication System on Stabilizer Codes

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China Communications 2021年第2期18卷 40-48页

作者： jiaxin Li zhongwen Guo Hongyang Ma College of Information Science and Engineering Ocean University of ChinaQingdao 266100China School of Science Qingdao University of TechnologyQingdao 266033China

In this paper,we develop a novel hybrid automatic-repeat-request(ARQ)protocol for the quantum communication system using quantum stabilizer *** quantum information is encoded by stabilizer codes to against the channel *** twophoton entangled state is prepared for codeword secure *** ARQ protocol rules the recognition and retransmission of error *** this protocol,the property of quantum entangled state ensures the security of information,the theory of hybrid ARQ system improves the reliability of transmission,the theory of quantum stabilizer codes corrects the flipping errors of ***,we verify the security and throughput efficiency of this protocol.

关键词： quantum communication system hybrid ARQ quantum stabilizer codes reliability security

Broadband strong optical dichroism in topological Dirac semimetals with Fermi velocity anisotropy

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Chinese Physics B 2020年第7期29卷 128-134页

作者： j Lim K j A Ooi C Zhang L K ang Yee Sin ang Science Math and TechnologySingapore University of Technology and DesignSingapore School of Energy and Chemical Engineering Xiamen University MalaysiaSelangor Darul Ehsan 43900Malaysia College of Chemistry and Chemical Engineering Xiamen UniversityXiamen 361005China School of Physics University of WollongongNorthfields AvenueNew South Wales 2522Australia

Prototypical three-dimensional(3D)topological Dirac semimetals(DSMs),such as Cd3As2 and Na3Bi,contain electrons that obey a linear momentum-energy dispersion with different Fermi velocities along the three orthogonal momentum *** being extensively studied in recent years,the inherent Fermi velocity anisotropy has often been neglected in the theoretical and numerical studies of 3D *** this omission does not qualitatively alter the physics of light-driven massless quasiparticles in 3D DSMs,it does quantitatively change the optical coefficients which can lead to nontrivial implications in terms of nanophotonics and plasmonics *** we study the linear optical response of 3D DSMs for general Fermi velocity values along each *** the signature conductivity-frequency scaling,σ(ω)∝ω,of 3D Dirac fermion is well-protected from the Fermi velocity anisotropy,the linear optical response exhibits strong linear dichroism as captured by the universal extinction ratio scaling law,Λi j=(vi/v j)^2(where i=j denotes the three spatial coordinates x,y,z,and vi is the i-direction Fermi velocity),which is independent of frequency,temperature,doping,and carrier scattering *** Cd3As2 and Na3Bi3,an exceptionally strong extinction ratio larger than 15 and covering a broad terahertz window is *** findings shed new light on the role of Fermi velocity anisotropy in the optical response of Dirac semimetals and open up novel polarization-sensitive functionalities,such as photodetection and light modulation.

关键词： topological Dirac semimetal optical anisotropy linear dichroismn linear response theory

A grand master of seismology and mentoring

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Earthquake Science 2022年第1期35卷 61-62页

作者： zhongwen Zhan Seismological Laboratory California Institute of TechnologyPasadenaCA 91125USA

I joined Don Helmberger’s group in the summer of 2008,after getting a Master’s degree in China from Sidao Ni,another graduate student of Don’s.I was very excited,because Don has a giant academic family tree and I thought I would become Don’s last student,which is quite an honor in the Chinese culture,so-called the“final apprentice”.I was wrong!Don had another seven students after me and the final apprentice honor went to Voon-Hui *** Don’s long career,he had scores of students,many of whom are now big names in academia,especially in the United States and in China,because Don mentored a number of Chinese students.

关键词： has quite excited

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数字经济、创新能力与经济高质量发展

江苏商论 2025年第1期 22-27,36页

作者：臧守芳盐城师范学院数学与统计学院盐城数字经济研究院数字金融研究所江苏盐城224002

当前,中国经济已经由高速发展转向高质量发展,数字经济作为经济发展的新动能,正成为推动经济高质量发展的重要引擎。文章基于2011—2019年省级面板数据,通过构建综合评价指标体系,利用固定效应模型,从创新视角出发,探究数字经济影响高... 详细信息

当前,中国经济已经由高速发展转向高质量发展,数字经济作为经济发展的新动能,正成为推动经济高质量发展的重要引擎。文章基于2011—2019年省级面板数据,通过构建综合评价指标体系,利用固定效应模型,从创新视角出发,探究数字经济影响高质量发展的内在机制。结果表明,数字经济有效推动了经济高质量发展;创新能力在其中发挥了正向调节作用。这种影响作用存在区域异质性,中西部地区相较于东部地区更为明显。因此,文章提出了加强科技创新,持续推进数字产业化和产业数字化建设,施行差异化数字转型策略,并加强风险防范的建议。

关键词：创新能力数字经济高质量发展

Construction of multi-factor identification model for real-time monitoring and early warning of mine water inrush

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International journal of Mining Science and Technology 2021年第5期31卷 853-866页

作者： Xin Wang Zhimin Xu Yajun Sun jieming Zheng Chenghang Zhang zhongwen Duan School of Resources and Geosciences China University of Mining and TechnologyXuzhou 221116China General Prospecting Institute China National Administration of Coal Geology Beijing 100039China Wanbei Coal Electricity Group Suzhou 234000China

As a new technical means that can detect abnormal signs of water inrush in advance and give an early warning,the automatic monitoring and early warning of water inrush in mines has been widely valued in recent *** to the many factors affecting water inrush and the complicated water inrush mechanism,many factors close to water inrush may have precursory abnormal *** present,the existing monitoring and early warning system mainly uses a few monitoring indicators such as groundwater level,water influx,and temperature,and performs water inrush early warning through the abnormal change of a single ***,there are relatively few multi-factor comprehensive early warning identification *** on the analysis of the abnormal changes of precursor factors in multiple water inrush cases,11 measurable and effective indicators including groundwater flow field,hydrochemical field and temperature field are ***,taking Hengyuan coal mine as an example,6 indicators with long-term monitoring data sequences were selected to establish a single-index hierarchical early-warning recognition model,a multi-factor linear recognition model,and a comprehensive intelligent early-warning recognition *** results show that the correct rate of early warning can reach 95.2%.

关键词： Mine water inrush Automatic monitoring Real-time warning Recognition model

Propagation and Coalescence of Blast-Induced Cracks in PMMA Material Containing an Empty Circular Hole Under Delayed Ignition Blasting Load by Using the Dynamic Caustic Method

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journal of Beijing Institute of Technology 2018年第4期27卷 547-555页

作者： zhongwen Yue Yao Song Zihang Hu Yanlong Lu School of Mechanics and Civil Engineering China University of Mining and Technology

In this paper,dynamic caustic method is applied to analyze the blast-induced crack propagation and distribution of the dynamic stress field around an empty circular hole in polymethyl methacrylate(PMMA)material under delayed ignition blasting *** following experimental results are obtained.(1)In directional-fracture-controlled blasting,the dynamic stress intensity factors(DSIFs)and the propagation paths of the blast-induced cracks are obviously influenced by the delayed ignition.(2) The circular hole situated between the two boreholes poses a strong guiding effect on the coelesence of the cracks,causing them to propagate towards each other when cracks are reaching the circular hole area.(3)Blast-induced cracks are not initiated preferentially because of the superimposed effect from the explosive stress waves on the cracking area.(4) By using the scanning electron microscopy(SEM)method,it is verified that the roughness of crack surfaces changes along the crack propagation paths.

关键词： crack propagation and coalescence dynamic caustic method delayed ignition blast-induced cracks dynamic stress intensity factor(DSIF)

Removal of cobalt(II) ion from aqueous solution by chitosan–montmorillonite

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journal of Environmental Sciences 2014年第9期26卷 1879-1884页

作者： Hailin Wang Haoqing Tang Zhaotie Liu Xin Zhang Zhengping Hao zhongwen Liu Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Key Laboratory of Applied Surface and Colloid Chemistry Shanxi Normal University School of Chemistry & Chemical Engineering Shanxi Normal University

Montmorillonite （MMT） modified with chitosan （CTS, molecular weight = S x 104） was applied to remove heavy metal cations by using Co2＋ as a model ion. An increase in MMT interlayer distance observed from X-ray diffraction indicates the intercalation of CTS into MMT. Together with the results of scanning electron microscopy and Fourier transform infrared spectroscopy, it was concluded that the composite material of CTS and MMT （CTS-- MMT） was prepared successfully. The mass ratio of CTS to MMT had a strong influence on the adsorption performance of CTS-MMT. The highest adsorption value of 150 mg/g was obtained over the composite material with CTS to MMT mass ratio of 0.25, which is much higher than those reported in other studies. The adsorption isotherms and kinetic results indicated that Co2＋ was adsorbed over CTS-MMT in a multilayer model, and the chemical sorption of Co2＋ was determined to be the rate-limiting step.

关键词： Chitosan Montmorillonite Co2+Isotherm Kinetics

Motor skills matter to physical activity——At least for children

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journal of Sport and Health Science 2013年第1期2卷 58-59页

作者： ang Chen Department of Kinesiology University of North Carolina at GreensboroGreensboroNC 27412USA

Physical activity(PA) is an effective means of curbing the prevalence of child obesity,and fundamental skills are hypothesized to be an important factor that determines physically active or inactive behavior in *** evidence suggests that adolescents and young adults with proficient motor skills in sport-related activities are more likely to have a physically active lifestyle.1 Because

关键词：学龄前儿童运动体力预测能力生活方式成年人患病率肥胖症