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竹纤维增强沥青混合料力学性能研究

交通科技 2024年第1期 144-149页

作者：刘一鸣夏翩翩周晓峰柳永红中建五局园林有限公司

为探究竹纤维在不同加载方式和不同温度条件下对沥青和沥青混合料力学性能的增强效果，文中采用动态剪切流变仪测试含有不同竹纤维掺量沥青的高温性能；通过Superpave旋转压实机制备含有0.3%竹纤维的沥青混合料试件，对试件进行动态模... 详细信息

为探究竹纤维在不同加载方式和不同温度条件下对沥青和沥青混合料力学性能的增强效果，文中采用动态剪切流变仪测试含有不同竹纤维掺量沥青的高温性能；通过Superpave旋转压实机制备含有0.3%竹纤维的沥青混合料试件，对试件进行动态模量和循环疲劳试验，分析在不同加载方式下其力学性能的变化。结果表明，竹纤维的加入改善了沥青的高温剪切强度；掺量为0.3%的竹纤维显著提高了沥青混合料的抗车辙性能和疲劳寿命；竹纤维的加入使得沥青混合料的动态模量值增加，相位角减小，同时也增强了常温下沥青混合料的刚度和抗裂性能，但在高温下的改善效果不明显。

关键词：道路工程沥青混合料竹纤维力学性能

Dynamic stress–strength reliability estimation of system with survivalsignature

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Statistical Theory and Related Fields 2018年第2期2卷 181-195页

作者： yiming liu Yimin Shi Xuchao Bai Bin liu Department of Applied Mathematics Northwestern Polytechnical UniversityXi’anShaanxi 710072People’s Republic of China Department of Applied Mathematics Taiyuan University of Science and TechnologyTaiyuanShanxiPeople’s Republic of China

In this paper, we proposed a dynamic stress–strength model for coherent system. It is supposedthat the system consists of n components with initial random strength and each component issubjected to random stresses. The stresses, applied repeatedly at random cycle times, will causethe degradation of strength. In addition, the number of cycles in an interval is assumed to followa Poisson distribution. In the case of the strength and stress random variables following exponential distributions, the expression for the reliability of the proposed dynamic stress–strengthmodel is derived based on survival signature. The reliability is estimated by using the best linearunbiased estimation (BLUE). Considering the Type-II censored failure times, the best linear unbiased predictors (BLUP) for the unobserved coherent system failure times are developed basedon the observed failure times. Monte Carlo simulations are performed to compare the BLUE ofparameters with different values and compute the BLUP. A real data set is also analysed for anillustration of the findings.

关键词： Dynamic stress–strength reliability best linear unbiased estimation best linear unbiased predictors survival signature coherent system

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声源音色辨识技术在钢管混凝土检测中的应用

无损检测 2024年第9期46卷 46-53,68页

作者：郭华杰贾秀丽刘一鸣铁科院(深圳)研究设计院有限公司深圳518057 华南师范大学材料与新能源学院广州510631

在人耳识别的基础上,采集同尺寸,不同工况、类型的钢管混凝土锤击声,模拟人耳识别的原理提取音色特征值,进而准确识别钢管混凝土有无空洞缺陷。通过在钢管混凝土中提前植入空洞,采集信号且引入锤击声导纳,并与密实钢管混凝土的进行对比... 详细信息

在人耳识别的基础上,采集同尺寸,不同工况、类型的钢管混凝土锤击声,模拟人耳识别的原理提取音色特征值,进而准确识别钢管混凝土有无空洞缺陷。通过在钢管混凝土中提前植入空洞,采集信号且引入锤击声导纳,并与密实钢管混凝土的进行对比。结果表明,锤击声导纳中提取的mfcc10max特征值能很好地识别钢管混凝土中的空洞缺陷;当mfcc10max特征值大于-0.4,均值大于-0.23时,即可初步判定锤击位置存在空洞或脱空缺陷;密实钢管混凝土锤击声导纳中mfcc10max特征值小于-0.5,均值为-0.72。最后将此技术和指标应用在塔楼混凝土结构空洞检测中,结果证明该方法适用性较好。利用具体指标和数值对钢管混凝土中空洞识别进行定量化,提高了识别精度,为后续现场钢管混凝土结构中的空洞缺陷识别提供了强有力的基础。

关键词： mfcc10max 密实钢管混凝土侧边空洞钢管混凝土锤击声导纳

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Early Rehabilitation After Craniosynostosis Surgery

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Computers, Materials & Continua 2022年第8期72卷 3899-3912页

作者： Dan Wang Lanzheng Bian Xiaoyan Hao yiming liu Jinyue Xia Jing Hu Department of Neurosurgery Children’s Hospital of Nanjing Medical UniversityNanjing210008China Department of Surgery Children’s Hospital of Nanjing Medical UniversityNanjing210008China Quality Management Office Children’s Hospital of Nanjing Medical UniversityNanjing210008China International Business Machines Corporation(IBM) NY10504USA Department of Rehabilitation Medicine Children’s Hospital of Nanjing Medical UniversityNanjing210008China

Craniosynostosis is a common congenital craniofacial deformity caused by premature ossification and closure of one or more cranial *** will not only affect the normal development of the skull,but also may cause a variety of complications,damage the nervous system,and cause long-term effects on the development of physical and mental ***,it is particularly important to provide new ideas for clinical treatment by studying the rehabilitation methods of craniosynostosis,and to improve the cure *** this end,this paper studies the early rehabilitation methods after craniosynostosis surgery and designs a comprehensive early rehabilitation process and corresponding comprehensive early rehabilitation measures after *** comparative data also shows that after comprehensive early rehabilitation nursing measures,the duration of the postoperative swelling of sick children was reduced and the degree was significantly reduced,which alleviated the discomfort of sick children;and the time of sick children spent in ICU treatment and monitoring was reduced,and the separation time between sick children and their parents was shorten,is of great significance to the postoperative rehabilitation of *** addition,the total cost of hospitalization was reduced accordingly,which greatly increased the satisfaction of patients.

关键词： Craniosynostosis early rehabilitation desirability function

A metal-electrode-free, fully integrated, soft triboelectric sensor array for self-powered tactile sensing

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Microsystems & Nanoengineering 2020年第1期6卷 615-623页

作者： Lingyun Wang yiming liu Qing liu Yuyan Zhu Haoyu Wang Zhaoqian Xie Xinge Yu Yunlong Zi Department of Mechanical and Automation Engineering The Chinese University of Hong KongShatinN.T.Hong Kong SARChina Department of Biomedical Engineering City University of Hong KongKowloonHong Kong SARChina Department of Applied Biology and Chemical Technology The Hong Kong Polytechnic UniversityHung HomHong Kong SARChina State Key Laboratory of Structural Analysis for Industrial Equipment International Research Center for Computational MechanicsDepartment of Engineering MechanicsDalian University of TechnologyDalian 116024China

The dramatic advances in flexible/wearable electronics have garnered great attention for touch sensors for practical applications in human health monitoring and human–machine ***-powered triboelectric tactile sensors with high sensitivity,reduced crosstalk,and simple processing routes are highly ***,we introduce a facile and low-cost fabrication approach for a metal-electrode free,fully integrated,flexible,and self-powered triboelectric tactile sensor array with 8-by-8 sensor *** the height difference between the sensor units and interconnect electrodes,the crosstalk derived from the electrodes has been successfully suppressed with no additional shielding *** tactile sensor array shows a remarkable sensitivity of 0.063VkPa^(–1) with a linear range from 5 to 50kPa,which covers a broad range of testing ***,due to the advanced mechanical design,the flexible sensor array exhibits great capability of pressure sensing even under a curved *** voltage responses from the pattern mapping by finger touching demonstrate the uniformity of the sensor ***,real-time tactile sensing associated with light-emitting diode(LED)array lighting demonstrates the potential application of the sensor array in position tracking,self-powered touch screens,human–machine interfaces and many others.

关键词： electrode sensor lighting

Statistical analysis of dependent competing risks model in constant stress accelerated life testing with progressive censoring based on copula function

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Statistical Theory and Related Fields 2018年第1期2卷 48-57页

作者： Xuchao Bai Yimin Shi yiming liu Bin liu Department of Applied Mathematics Northwestern Polytechnical UniversityXi’anChina School of Applied Science Taiyuan University of Science and TechnologyTaiyuanChina

In this paper, we consider the statistical analysis for the dependent competing risks model in theconstant stress accelerated life testing (CSALT) with Type-II progressive censoring. It is focusedon two competing risks from Lomax distribution. The maximum likelihood estimators of theunknown parameters, the acceleration coefficients and the reliability of unit are obtained by usingthe Bivariate Pareto Copula function and the measure of dependence known as Kendall’s *** addition, the 95% confidence intervals as well as the coverage percentages are obtained byusing Bootstrap-p and Bootstrap-t method. Then, a simulation study is carried out by the MonteCarlo method for different measures of Kendall’s tau and different testing schemes. Finally, a realcompeting risks data is analysed for illustrative purposes. The results indicate that using copulafunction to deal with the dependent competing risks problems is effective and feasible.

关键词： Dependent competing risks Bivariate Pareto Copula Kendall’s tau Bootstrap method constant stress accelerated life testing maximum likelihood estimators

基于多源异构数据的神经外科知识谱图构建与应用

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北京理工大学学报 2024年第8期44卷 879-886页

作者：王博冉周雪忠魏巍王睿刘一铭田昊宇戴芯瑜北京科技大学计算机与通信工程学院北京100183 首都医科大学附属北京天坛医院北京100070 北京交通大学计算机科学与技术学院北京100044 首都医科大学附属北京友谊医院北京100050

研究中收集了百万余条的病历数据,利用知识图谱算法,整合了患者临床症状、主诉、诊断、用药等多源异构数据,基于外部数据集链接了患者疾病、症状、药物和基因等信息,共计提取6 800多条实体和33万条关系数据,构建了面向神经外科领域的医... 详细信息

研究中收集了百万余条的病历数据,利用知识图谱算法,整合了患者临床症状、主诉、诊断、用药等多源异构数据,基于外部数据集链接了患者疾病、症状、药物和基因等信息,共计提取6 800多条实体和33万条关系数据,构建了面向神经外科领域的医学知识图谱.通过疾病、药物和症状之间的关系,验证了15组高频关系数据,采用富集分析方法探索各个实体之间的关联性,通过Neo4j工具对神经外科知识图谱进行可视化展示.利用知识图谱相关算法,能够补齐患者缺失的临床和微观信息,为临床医生提供准确、详细的诊断依据,提升诊断准确率和诊疗效率.此外,知识图谱还能促进知识探索,协助临床医生发现新的疾病特征、发病机制、药物靶点等,推动神经外科医学领域的知识创新和进步.

关键词：知识图谱信息抽取神经外科知识融合

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Recent progress on flexible nanogenerators toward self-powered systems

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InfoMat 2020年第2期2卷 318-340页

作者： yiming liu Lingyun Wang Ling Zhao Xinge Yu Yunlong Zi Department of Biomedical Engineering City University of Hong KongHong KongPeople's Republic of China Department of Mechanical and Automation Engineering Chinese University of Hong KongHong KongPeople's Republic of China

The advances in wearable/flexible electronics have triggered tremendous demands for flexible power sources,where flexible nanogenerators,capable of converting mechanical energy into electricity,demonstrate its great ***,recent progress on flexible nanogenerators for mechanical energy harvesting toward self-powered systems,including flexible piezoelectric and triboelectric nanogenerator,is *** emphasis is mainly on the basic working principle,the newly developed materials and structural design as well as associated typical applications for energy harvesting,sensing,and selfpowered *** addition,the progress of flexible hybrid nanogenerator in terms of its applications is also ***,the challenges and future perspectives toward flexible self-powered systems are reviewed.

关键词： flexible systems hybrid nanogenerator mechanical energy harvesting piezoelectric nanogenerator self-powered system triboelectric nanogenerator

Characteristics of bioaerosols under high-ozone periods,haze episodes,dust storms,and normal days in Xi'an,China

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Particuology 2024年第7期90卷 140-148页

作者： yiming Yang liu Yang Xiaoyan Hu Zhenxing Shen Department of Environmental Science and Engineering Xi’an Jiaotong UniversityXi’an710049China Key Lab of Aerosol Chemistry&Physics SKLLQGInstitute of Earth EnvironmentChinese Academy of SciencesXi’an710049China

The characteristics of bioaerosols and their effects on human beings'health have become a major public concern in the recent *** study compared the characteristics of bioaerosols under different types of pollution(high-ozone[HO]episodes,haze episodes,and dust storms[DSs]),with those of bioaerosols on normal days(NDs)in Xi'an,*** concentrations,diurnal variations,and size distribution of bacteria,fungi,and total airborne microbes(TAMs)were *** results showed that the bacterial and fungal concentrations were the highest during DSs and on NDs,reaching 425.2 and 956.9 colony-forming units/m^(3),*** concentration of TAMs was the highest during HO episodes,reaching 10.7×10^(6)cells/m^(3),which was significantly higher than that during the other *** maximum concentrations of bacteria and fungi during HO episodes were observed in the morning,while they appeared separately in the morning and evening during haze *** and TAMs during DSs reached peak concentrations in the morning and evening,which is opposite to the particulate matter(PM)distribution *** NDs,temperature and relative humidity had significant effects on *** size distributions of airborne bacteria exhibited bimodal patterns,whereas unimodal distributions were observed for *** mainly attached in fine particles(<2.1μm)with proportions of 67.4%and 60.5%during haze episodes and DSs,respectively,which means that fungi were easily penetrated into the human respiratory *** evaluation of influence factors revealed that PM_(2.5) and PM10 had negative effects on fungal concentration during DSs,and ozone concentration and temperature were inversely correlated with fungal concentration during HO *** results provide valuable reference data for elucidating the formation and evolution of bioaerosols under different types of pollution.

关键词： Bacteria Fungi Total airborne microbe Different air pollution types Influence factors