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Modal analysis of subway tunnel in soft soil during operation

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Underground Space 2023年第1期8卷 181-195页

作者： Ling wan Xiongyao Xie Lujun wang Pan Li qiang Huang College of Civil Engineering and Architecture Nanchang Hangkong UniversityNanchang 330063China Jiangxi Transportation Institute Co LtdNanchang 330200China Key Laboratory of Geotechnical and Underground Engineering Ministry of EducationTongji UniversityShanghai 20092China Center for Hypergravity Experimental and Interdisciplinary Research MOE Key Laboratory of Soft Soils and Geoenvironmental EngineeringCollege of Civil Engineering and ArchitectureZhejiang UniversityHangzhou 310058China Institute of Geotechnical Engineering Ningbo UniversityNingbo 315211China

Modal parameters are of great significance in civil engineering because they can characterize the properties of structures and be used for vibration control and structural health *** tunnels are long linear truss structures combined with the mutual cou-pling of the surrounding ***,the operational modal analysis of a mutual coupling tunnel is complicate,as is the modal iden-tification of shield tunnels in a time–frequency domain,and these are hot civil engineering *** the shield tunnel of Shanghai metro line No.12 project as a case study,we carried out the vibration response monitoring of a subway tunnel during operation and presented methods to identify structural modal *** modal parameters of lower vibration modes were estimated using response *** frequencies and shapes were identified with high precision and accuracy using the orthogonal polynomial clustering algorithm under hammer excitation conditions and the autoregressive-moving-average model under ambient excitation *** dynamic behavior of a mutual coupling tunnel presented obvious low frequency characteristics,and the first 9th order mode frequencies were less than 100 *** diagonal values of the modal assurance criteria were all greater than *** modal parameters can be used for the health monitoring of operational subway tunnels.

关键词： Monitoring method Modal identification Vibration response Operational subway tunnel

Prediction of Eight Earings in Deep Drawing of 5754O Aluminum Alloy Sheet

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Chinese Journal of Mechanical Engineering 2019年第5期32卷 136-144页

作者： Haibo wang Mingliang Men Yu Yan Min wan qiang Li School of Mechanical and Materials Engineering North China University of TechnologyBeijing 100144China School of Mechanical Engineering and Automation Beihang UniversityBeijing 100083China

Earings appear easily during deep drawing of cylindrical parts owing to the anisotropic properties of ***,current methods cannot fully utilize the mechanical properties of material,and the number of earings obtained differ with the simulation *** order to predict the eight-earing problem in the cylindrical deep drawing of 5754O aluminum alloy sheet,a new method of combining the yield stress and anisotropy index(r-value)to solve the parameters of the Hil 148 yield function is *** general formula for the yield stress and r-value in any direction is *** a 5754O aluminum alloy sheet as an example in this study,the deformation area in deep drawing is divided into several equal sectorial regions based on the *** parameters of the Hill48 yield function are solved based on the yield stress and r-value simultaneously for the corresponding deformation *** element simulations of deep drawing based on new and existing methods are carried out for comparison with experimental *** study provides a convenient and reliable way to predict the formation of eight earings in the deep drawing process,which is expected to be useful in industrial *** results of this study lay the foundation for the optimization of the cylindrical deep drawing process,including the optimization of the blank shape to eliminate earing defects on the final product,which is of great importance in the actual production process.

关键词： Anisotropy Deep drawing Yield function Finite element simulation

前路腰方肌-阴部神经阻滞对PCNL患者痛敏反应、血流动力学的影响

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临床和实验医学杂志 2024年第16期23卷 1768-1772页

作者：万勤李晓强四川大学华西医院麻醉手术中心四川成都610000 四川大学华西护理学院四川成都610200

目的观察前路腰方肌-阴部神经阻滞对经皮肾镜碎石术(PCNL)患者痛敏反应、血流动力学的影响。方法前瞻性选取2022年5月至2023年2月在四川大学华西医院行全身麻醉下PCNL手术治疗的80例患者,按照简单随机法将其分为两组,每组各40例。全麻... 详细信息

目的观察前路腰方肌-阴部神经阻滞对经皮肾镜碎石术(PCNL)患者痛敏反应、血流动力学的影响。方法前瞻性选取2022年5月至2023年2月在四川大学华西医院行全身麻醉下PCNL手术治疗的80例患者,按照简单随机法将其分为两组,每组各40例。全麻组单纯行全身麻醉,神经阻滞组全麻诱导后在超声引导下行前路腰方肌-阴部神经阻滞。比较两组手术一般情况(两组麻醉时间、术中出血量、苏醒时间、丙泊酚用量、术中瑞芬太尼用量、术后补救镇痛率、术后艾司洛尔和阿托品使用率、住院时间),麻醉诱导前(T_(0))、建立工作通道(T_(1))、取石即刻(T_(2))、手术结束(T_(3))的血流动力学指标[心率、平均动脉压(MAP)],术后3、6、12、24、48 h的咳嗽和静息视觉模拟评分法(VAS)评分,检测两组术前、术后1 d应激指标[皮质醇、促肾上腺皮质激素(ACTH)、去甲肾上腺素(NE)、肾素]的差异,记录并比较两组术后24、48 h术后恢复质量(QoR40)评分。结果两组的麻醉时间、术中出血量、苏醒时间、术后艾司洛尔和阿托品使用率、住院时间比较,差异均无统计学意义(P>0.05);神经阻滞组的丙泊酚用量、术中瑞芬太尼用量均少于全麻组,术后补救镇痛率低于全麻组,差异均有统计学意义(P2)、T_(3)时的心率及T_(0)、T_(1)、T_(2)、T_(3)时的MAP与同时间点全麻组比较,差异均无统计学意义(P>0.05)。神经阻滞组术后3、6、12、24、48 h的咳嗽和静息VAS评分均低于全麻组,差异均有统计学意义(P24 h的QoR40评分高于全麻组,差异有统计学意义(P0.05)。结论前路腰方肌-阴部神经阻滞可降低PCNL患者痛敏反应,稳定血流动力学,术后应激反应较小。

关键词：前路腰方肌-阴部神经阻滞经皮肾镜碎石术痛敏反应血流动力学

Study of ultra-wideband radar signals-generated technology using two-channel signal generator

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Journal of Systems Engineering and Electronics 2007年第4期18卷 710-715页

作者： wan Yonglun Lu Youxin Si qiang wang Xuegang Cao Guangping Southwest China Inst. of Electronic Technology Chengdu 610036 P. R. China Coll. of Electronic Engineering Univ. of Electronic Science and Technology of China Chengdu 610054 P.R. China

Synthesis of ultra-wideband （UWB） linear frequency modulation radar signals is a very important technology for microwave imaging, target identification and detection of low radar-cross-section （RCS） targets. A new method of UWB radar signals generation with two-channel signal generator is presented. The realization structure is given; the principle and errors of signal synthesis are analyzed. At the same time, an automatic .adjustment measure of signal phase is proposed because of phase discontinuity of waveform in this method. The simulation experiment and analysis results indicate that radar signals with large instantaneous bandwidth can be generated by means of this method on the condition that the high-speed digital devices are limited.

关键词： UWB DDS LFM two-channel signal generator pulse compression

A Nano-Cantilever Method for Crack Initiation at the Free Edge of the Cu/Si Interface in Nanoscale Components

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Acta Mechanica Solida Sinica 2016年第4期29卷 416-428页

作者： Xiaoyuan wang Yabin Yan qiang wan Takashi Sumigawa Takayuki Kitamura Institute of Systems Engineering China Academy of Engineering Physics Department of Mechanical Engineering and Science Kyoto University

Straight and Bent nano-cantilever specimens are respectively proposed to investigate the single-mode and mixed-mode crack initiation at the Cu/Si interface edge in nanoscale components. With a minute loading apparatus, all nanoscale samples are in situ loaded and observed. Numerical analysis is employed to acquire the critical interfacial stress distributions during crack initiation. The stress concentration regions near the edge of Cu/Si interface in all specimens are within the scale of 100 nm, and the critical normal and shear stresses have a circular relation in nanoscale components, which represents the fracture criterion of the interface in nanoscale components.

关键词： nanoscale cantilever interface crack initiation mixed mode thin film

Multi-Sensor Estimation for Unreliable Wireless Networks with Contention-Based Protocols

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Journal of Computer Science & Technology 2018年第5期33卷 1072-1085页

作者： Shou-wan Gao Peng-Peng Chen Xu Yang qiang Niu Key Laboratory of Gas and Fire Control for Coal Mines China University of Mining and Technology Xuzhou 221116 China School of Computer Science and Technology China University of Mining and Technology Xuzhou 221116 China

The state estimation plays an irreplaceable role in many real applications since it lays the foundation for decision-making and control. This paper studies the multi-sensor estimation problem for a contention-based unreliable wireless network. At each time step, no more than one sensor can communicate with the base station due to the potential contention and collision. In addition, data packets may be lost during transmission since wireless channels are unreliable. A novel packet arrival model is proposed which simultaneously takes into account the above two issues. Two scenarios of wireless sensor networks （WSNs） are considered： the sensors transmit the raw measurements directly and the sensors send the local estimation instead. Based on the obtained packet arrival model, necessary and sufficient stability conditions of the estimation at the base station side are provided for both network scenarios. In particular, all offered stability conditions are expressed by simple inequalities in terms of the packet arrival rates and the spectral radius of the system matrix. Their relationships with existing related results are also discussed. Finally, the proposed results are demonstrated by simulation examples and an environment monitoring prototype system.

关键词： wireless sensor network packet loss state estimation contention-based protocol

不同抗感水稻品种对褐飞虱胁迫的高光谱响应特征

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中国水稻科学 2024年第1期38卷 81-90页

作者：杨奇欣赖凤香何佳春魏琪王渭霞万品俊傅强中国水稻研究所水稻生物育种全国重点实验室杭州310006

【目的】探究不同抗感水稻受褐飞虱胁迫的高光谱反射率曲线变化及敏感光谱差异,研究水稻植株不同部位的高光谱变化。在此基础上,采用机器学习技术建立水稻褐飞虱抗性鉴定模型,为下一步开发智能化褐飞虱抗性鉴定技术提供重要基础资料。... 详细信息

【目的】探究不同抗感水稻受褐飞虱胁迫的高光谱反射率曲线变化及敏感光谱差异,研究水稻植株不同部位的高光谱变化。在此基础上,采用机器学习技术建立水稻褐飞虱抗性鉴定模型,为下一步开发智能化褐飞虱抗性鉴定技术提供重要基础资料。【方法】以三个具不同褐飞虱抗感特征的水稻品种(TN1、Mudgo、RHT)为对象,分析其光谱、植被指数差异并建立抗性级别预测的随机森林模型。【结果】研究发现,褐飞虱胁迫天数与光谱反射率显著相关的波段数及差异显著的波段数随着水稻的抗性水平的上升而减少。同时,在680 nm左右,三个品种的光谱反射率与褐飞虫胁迫时间的相关性最好。植被指数分析表明,SIPI、SR605/760和PSNDb与抗性级别的相关系数绝对值要高于680 nm的结果。感虫品种TN1差异最早体现,中抗品种Mudgo其次,高抗品种RHT最后。不同部位的差异首先出现在第1叶叶片和第1叶叶鞘,然后依次为第2叶叶片和第2叶叶鞘以及第3叶叶片和第3叶叶鞘。预测模型的结果表明,全波段作为输入的模型效果比以单一植被指数SIPI构建的随机森林模型更好,模型准确率达到85.9%。【结论】本研究反映了不同抗感水稻品种受褐飞虱危害后的高光谱变化规律与不同抗感品种和不同部位的差异,并证实了机器学习技术对水稻抗性级别的分类能力。

关键词：褐飞虱水稻抗性高光谱植被指数机器学习

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Strain Softening of Styrene-Isoprene-Styrene Copolymers under Large Amplitude Oscillatory Shear for Clarifying Payne Effect in Rubbers and Their Nanocomposites

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Chinese Journal of Polymer Science 2023年第1期41卷 153-165页

作者： Xin-Peng Fan Yi-Hu Song qiang Zheng wan-Jie wang MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and EngineeringZhejiang UniversityHangzhou310027China Shanxi-Zheda Institute of New Materials and Chemical Engineering Taiyuan030000China College of Materials Science and Engineering Henan Key Laboratory of Advanced Nylon Materials and ApplicationZhengzhou UniversityZhengzhou450001China

To illustrate mechanisms of Payne effect in rubbers and their nanocomposites experiencing large amplitude oscillatory shear(LAOS),comparison studies were performed in styrene-isoprene-styrene(SIS)copolymers and their selectively crosslinked materials at temperatures below and above glass transition temperature of the polystyrene(PS)*** was found that under periodic dynamic shear,the strain softening is reversible when the polyisoprene(PI)phase,either crosslinked or not,is restricted by hard PS domains but it shows hysteresis once the PS domains *** strain softening can happen at the time scale of intrinsic Rouse relaxation of elastically active network *** stress of strain softening scales with number density of elastically active network strands,a simple relation being verified not only in the selectively crosslinked SIS copolymers but also in PI gum vulcanizates and carbon black filled PI *** effect is traditionally used to term strain softening of highly filled rubber vulcanizates under LAOS deformation while evidenced herein is that the Payne effect of highly filled rubber vulcanizates shares the mechanism being common to the strain softening of SIS copolymers.

关键词： Large amplitude oscillatory shear SIS Rubber nanocomposites Strain softening

血清PIVKA-Ⅱ、AFP与HBV-DNA联合检测对HBV所致肝癌的诊断及预后预测价值

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标记免疫分析与临床 2024年第4期31卷 685-691页

作者：万强赵波王瑶瑶青岛市城阳区人民医院感染性疾病科山东青岛266109

目的探究血清异常凝血酶原Ⅱ(PIVKA-Ⅱ)、甲胎蛋白(AFP)与乙肝病毒脱氧核糖核酸(HBV-DNA)联合检测对HBV所致肝癌(HCC)的诊断及预后预测价值。方法选取2018年8月至2020年7月在本院接受治疗的98例HCC患者作为研究对象(肝癌组),另取同期95... 详细信息

目的探究血清异常凝血酶原Ⅱ(PIVKA-Ⅱ)、甲胎蛋白(AFP)与乙肝病毒脱氧核糖核酸(HBV-DNA)联合检测对HBV所致肝癌(HCC)的诊断及预后预测价值。方法选取2018年8月至2020年7月在本院接受治疗的98例HCC患者作为研究对象(肝癌组),另取同期95例体检健康人群作为健康组,95例肝硬化患者作为肝硬化组,观察3组受试者血清PIVKA-Ⅱ、AFP与HBV-DNA表达水平和一般资料差异。根据肝癌组3年内预后情况将患者分为生存组(57例)和死亡组(41例)。比较肝癌组一般资料和血清PIVKA-Ⅱ、AFP与HBV-DNA水平关系;多因素Logistic和COX回归分析分别分析影响受试者患肝癌和患者预后不良的影响因素;四格表法计算血清PIVKA-Ⅱ、AFP与HBV-DNA水平对HCC的预测价值;ROC曲线分析评估血清PIVKA-Ⅱ、AFP与HBV-DNA水平对HCC患者预后的预测价值。结果肝癌组患者血清PIVKA-Ⅱ、AFP与HBV-DNA水平显著高于健康组和肝硬化组(P2.57%、77.43%和84.72%。血清PIVKA-Ⅱ、AFP与HBV-DNA水平以及3项联合诊断HCC预后不良的AUC分别为0.823、0.841、0.824和0.958,3项联合诊断效能优于单一诊断(P<0.05)。结论血清PIVKA-Ⅱ、AFP与HBV-DNA水平在HCC患者和预后不良患者中呈高表达,且3项联合可有效预测HCC发病和HCC患者预后情况。

关键词：肝癌异常凝血酶原Ⅱ 甲胎蛋白乙肝病毒脱氧核糖核酸诊断预后