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Face stability analysis of large shield-driven tunnel in rock-soil interface composite formations

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Underground Space 2022年第6期7卷 1021-1035页

作者： Xiaobin Ding Kang Li yuxuan xie Shuzhuo Liu School of Civil Engineering and Transportation South China University of TechnologyGuangzhou 510641China Guangdong Provincial Key Laboratory of Modern Civil Engineering Technology South China Institute of Geotechnical EngineeringGuangzhou 510650China

A new 3D log-spiral model(LS-M model)is proposed to determine the minimal support pressure on the tunnel face of a large shielddriven tunnel in rock-soil interface(RSI)composite *** the proposed LS-M model,we define the RSI angle ω and use a new approach to calculate the equivalent tunnel face area,which provides a collapse zone with more realistic geometry than the traditional wedge *** it has acceptable accuracy with simpler implementation than limit equilibrium *** with previous studies and 3D numerical analysis,it indicates that:(i)the LS-M results agree well with others in full-soil formations on the variation patterns of minimum support pressure and stability coefficients N_(c) and N_(γ);(ii)the critical RSI angle ω_(cr),which is predominantly influenced by soil cohesion,increases with the soil property values;(iii)the limit support pressure starts to increase with ω only when ω>ω_(cr);(iv)the peak support pressure occurs at lower C/D with a lower ω;(v)ω can only affect stability coefficients N_(c) and N_(γ) when ω and the friction angle are relatively small,while N_(s) is substantially influenced by RSI angle ω.

关键词： Tunnel Stability Limit support pressure RSI composite formations 3D failure mechanism

Chinese Spirits Identification Model Based on Mid-Infrared Spectrum

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Computers, Materials & Continua 2020年第9期64卷 1869-1883页

作者： Wu Zeng Zhanxiong Huo yuxuan xie Yingxiang Jiang Kun Hu School of Electrical and Electronic Engineering Wuhan Polytechnic UniversityWuhan430000China Gina Cody School of Engineering and Computer Science Concordia UniversityMontrealH3G 1M8Canada

Applying computer technology to the field of food safety,and how to identify liquor quickly and accurately,is of vital importance and has become a research *** this paper,sparse principal component analysis(SPCA)was applied to seek sparse factors of the mid-infrared(MIR)spectra of five famous vintage year Chinese *** results showed while meeting the maximum explained variance,23 sparse principal components(PCs)were selected as features in a support vector machine(SVM)model,which obtained a 97%classification *** comparison principal component analysis(PCA)selected 10 PCs as features but only achieved an 83%classification *** both approaches were better than a direct SVM approach based on the classification results(64%classification accuracy),they also demonstrated the importance of extracting sparse PCs,which captured most important *** combination of computer technology SPCA and MIR provides a new and convenient method for liquor identification in food safety.

关键词： Mid-infrared spectra Chinese spirits SPCA SVM liquor identification

Microwave Absorption and Mechanical Properties of Short-cutted Carbon Fiber/glass Fiber Hybrid Veil Reinforced Epoxy Composites

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Journal of Wuhan University of Technology(Materials Science) 2023年第1期38卷 248-254页

作者：陈威 ZHEN Bowen xie yuxuan 贺行洋 SU Ying WANG Jun WU Yan School of Civil Engineering Architecture and EnvironmentHubei University of TechnologyWuhan 430068China Building Waterproof Engineering and Technology Research Center of Hubei Province Hubei University of TechnologyWuhan 430068China School of Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China Institute of Advanced Material Manufacturing Equipment and Technology Wuhan University of TechnologyWuhan 430070China Hubei Standardization and Quality Institute Wuhan 430061China

This work aims at investigating the microwave absorption and mechanical properties of short-cutted carbon fiber/glass fiber hybrid veil reinforced epoxy *** short-cutted carbon fibers(CFs)/glass fibers(GFs)hybrid veil were prepared by papermaking technology,and composites liquid molding was employed to manufacture CFs/GFs hybrid epoxy *** microstructure,microwave absorbing properties and mechanical properties of the hybrid epoxy composites were studied by using SEM,vector network analyzer and universal material testing,*** reflection coefficient of the composites were calculated by the measured complex permittivity and permeability in the X-band(8.2-12.4 GHz)*** optimum microwave absorption properties can be obtained when the content of CFs in the hybrid veil is 6 wt%and the thickness of the composites is 2 mm,the minimum reflection coefficient of-31.8 dB and the effective absorption bandwidth is 2.1 GHz,which is ascribed to benefitting impedance matching characteristic and dielectric loss of the carbon *** the tensile strength and modulus can achieve 104.0 and 2.98GPa,demonstrating that the CFs/GFs hybrid epoxy composites can be a promising candidate of microwave absorbing materials with high mechanical properties.

关键词： microwave absorption fiber reinforced composites papermaking carbon fiber

An Improved Approach to the Performance of Remote Photoplethysmography

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Computers, Materials & Continua 2022年第11期73卷 2773-2783页

作者： Yi Sheng Wu Zeng Qiuyu Hu Weihua Ou yuxuan xie Jie Li School of Electrical and Electronic Engineering Wuhan Polytechnic UniversityWuhan430000China School of Electronic and Information Engineering Guizhou Normal UniversityGuizhou550000China Gina Cody School of Engineering and Computer Science Concordia UniversityW.MontrealQuebecH3G1M8Canada

Heart rate is an important metric for determining physical and mental *** recent years,remote photoplethysmography(rPPG)has been widely used in characterizing physiological signals in human ***,research on non-contact detection of heart rate mainly focuses on the capture and separation of spectral signals from video ***,this method is very sensitive to the movement of the test subject and light intensity variation,and this results in motion artifacts which presents challenges in extracting accurate physiological signals such as heart *** this paper,an improved method for rPPG signal preprocessing is *** on the well known red green blue(RGB)color space,we segmented skin tone in different color spaces and extracted rPPG signals,after which we use a skin segmentation training model based on the luminance component,the blue-difference chroma components,and red-difference chroma components(YCbCr),as well as hue saturation intensity(HSI)color *** the experimental verification section,we compare the robustness of the signal on different color *** summary,we are experimentally verifying a better image pre-processing method based on real-time rPPG,which results in more precise measurements through the comparative analysis of skin segmentation and signal quality.

关键词： Remote photoplethysmography skin segmentation heart rate

A prognostic model of patients with pancreatic cancer based on four N^(6)-methyladenosine-related IncRNAs and analysis of related immune infiltration

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Genes & Diseases 2024年第4期11卷 109-112页

作者： Kaili Liao Yuhan Xu Bingying Lin yuxuan xie Qijun Yang Wenyige Zhang Beining Zhang Jiarong Wen Jingyi Wang Zimeng Li Yunqi Cheng Xiaozhong Wang Jiangxi Province Key Laboratory of Laboratory Medicine Jiangxi Provincial Clinical Research Center for Laboratory MedicineDepartment of Clinical LaboratoryThe Second Affiliated Hospital of Nanchang UniversityNanchangJiangxi 330006China Queen Mary College of Nanchang University NanchangJiangxi 330001China School of Public Health Nanchang UniversityNanchangJiangxi 330006China The Second Clinical Medical College Nanchang UniversityNanchangJiangxi 330006China The First Clinical Medical College of Nanchang University NanchangJiangxi 330006China

Pancreatic cancer is one of the most lethal malignant tumors in the *** advances in diagnosis and treatment,the five-year survival rate for pancreatic cancer patients remains only 9%.1 Pancreatic adenocarcinoma(PAAD)belongs to pancreatic cancer,which occupies 85%of the whole pancreatic cancer.2 Reversible modification of Ne-methyladenosine(m^(6)A)has been shown to be involved in cancer progression,resulting in up-regulation of oncogene expression or down-regulation of tumor-suppressing genes and may affect the prognosis of patients with pancreatic cancer.

关键词： patients cancer diagnosis

Spatial Layout Analysis of Monumental Landscape of Zhongshan Park in Beijing

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Journal of Landscape Research 2022年第6期14卷 25-28,32页

作者： xie yuxuan XU Zhendong CHEN Zhongyi College of Horticulture and Gardening Yangtze UniversityJingzhouHubei 434025China Jingzhou Park Administrative Office JingzhouHubei 434000China

The creation of monumental landscapes in urban parks is a materialized expression of human spiritual emotions, carrying the functions of triggering people's thinking, arousing inner emotions and spreading spiritual connotations such as regional culture. Scientific spatial layout and functional analysis of commemorative landscape is conducive to giving full play to the effect of commemorative *** field investigation and literature reading, the spatial layout, landscape elements and locality of the monumental theme landscape in Zhongshan Park in Beijing were comprehensively analyzed, showing that there is a close correspondence between spatial change and commemorative emotional ups and downs.

关键词： Monumental landscapes Landscape space layout Zhongshan Park Beijing

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基于改进接触模型的类岩石材料裂纹扩展分析

华南理工大学学报（自然科学版） 2024年第8期52卷 146-158页

作者：丁小彬谢宇轩施钰华南理工大学土木与交通学院广东广州510640 韦仕敦大学土木与环境工程学院加拿大安大略伦敦N6A 3K7

为了探究复杂应力状态下岩体内缺陷(裂隙)的扩展与贯通机理,基于三维离散元软件(PFC3D)和改进的平行黏结模型(IPBM),模拟了双轴压缩试验中含双预制裂纹类岩石材料的裂纹扩展过程。通过逼近实验试件抗压强度、抗拉强度和弹性模量的宏观... 详细信息

为了探究复杂应力状态下岩体内缺陷(裂隙)的扩展与贯通机理,基于三维离散元软件(PFC3D)和改进的平行黏结模型(IPBM),模拟了双轴压缩试验中含双预制裂纹类岩石材料的裂纹扩展过程。通过逼近实验试件抗压强度、抗拉强度和弹性模量的宏观力学参数和裂纹扩展模式,调整数值模型微观参数。针对离散元模拟中的关键预制裂隙参数与围压对裂纹萌生、扩展及贯通过程的影响进行详尽的分析,结果表明:初始裂纹通常为拉伸裂纹,而次生裂纹通常为剪切裂纹,裂隙倾角主要影响初始裂纹位置;围压抑制初始裂纹,但促进次生裂纹发展;预制裂隙间的贯通裂纹与裂隙的参数和围压密切相关;围压σc>0 MPa时,观察到两种新的剪切贯通类型(New1和New2);数值试样中微裂纹的数量主要受围压影响,与裂隙参数无明显关联;试样的裂纹起始应力、峰值应力与围压和裂隙倾角相关,与岩桥长度和岩桥倾角无关;裂纹的扩展与试样内应力分布密切相关,裂纹最先在裂隙周围的应力集中区产生。结果为后续岩石与类岩石材料的离散元模型参数校准,以及基于离散元的裂纹扩展机理研究提供了可靠参考。

关键词：类岩石材料裂纹扩展三维离散元数值模拟双轴压缩

PPP模式与地方财政压力:来自中国地级市的经验证据

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财贸研究 2023年第9期34卷 58-68页

作者：唐祥来谢雨轩南京财经大学江苏南京210046

以中国262个地级市的面板数据为样本,利用双向固定效应模型,实证检验PPP模式对财政压力的作用机制及效果。研究发现:实施PPP模式显著缓解了地方政府的财政压力;PPP模式主要通过提升政府公共服务供给能力和提高地区基础设施水平两个路径... 详细信息

以中国262个地级市的面板数据为样本,利用双向固定效应模型,实证检验PPP模式对财政压力的作用机制及效果。研究发现:实施PPP模式显著缓解了地方政府的财政压力;PPP模式主要通过提升政府公共服务供给能力和提高地区基础设施水平两个路径降低了地方政府财政压力;PPP模式缓解财政压力的效果存在异质性,东部地区效果最明显,中部地区次之,西部地区不显著。建议通过完善PPP法规体系,合理配置PPP资源,分层设立风险预警机制,有效防控PPP模式财政风险等措施,提高PPP模式的经济和财政治理效能。

关键词： PPP模式地方财政压力公共服务供给

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中低速磁浮列车电弧对机场塔台甚高频电磁干扰研究

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铁道科学与工程学报 2020年第3期17卷 750-755页

作者：朱峰谢雨轩翁文雯李鑫周超西南交通大学电气工程学院四川成都610031 中国民用航空飞行学院民航飞行技术与飞行安全重点实验室四川广汉618307

为了从实测与标准的比较上研究磁浮列车电弧对机场VHF(甚高频)的影响,在国内某磁浮线路选取一些典型位置,采用点频测试和峰值、准峰值、平均值的检波方式在VHF的工作频段内开展磁浮列车电弧的电磁辐射测试;在获取标准10 m法处的电磁辐... 详细信息

为了从实测与标准的比较上研究磁浮列车电弧对机场VHF(甚高频)的影响,在国内某磁浮线路选取一些典型位置,采用点频测试和峰值、准峰值、平均值的检波方式在VHF的工作频段内开展磁浮列车电弧的电磁辐射测试;在获取标准10 m法处的电磁辐射特性后,结合GB/T 6364《航空无线电导航台(站)电磁环境要求》和MH 4001.1中关于保护率的相关要求对其进行电磁兼容分析,得出保护距离与磁浮列车电弧辐射特性的关系。研究结果表明:当磁浮列车线路与机场跑道延长线的距离大于183 m时,该磁浮列车电弧辐射不会对VHF的正常工作造成干扰。本文的研究结果可为机场区域轨道交通化和磁浮列车的选址提供依据。

关键词：铁路运输磁浮列车电弧电磁辐射测试 VHF 电磁兼容