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New Explorations of Laboratory and On-site Testing of Broadband Seismographs in China 预览
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作者 XIE Jianbo YANG Dake +6 位作者 LI Xiaojun YUAN Songyong TONG Wanglian MA Jiemei XU Weiwei DING Lisha YE Shishan 《中国地震研究:英文版》 CSCD 2019年第1期9-23,共15页
According to different testing purposes, methods and available environmental conditions, the seismograph testing can be divided into laboratory and on-site testing, respectively. The testing of the seismograph's k... According to different testing purposes, methods and available environmental conditions, the seismograph testing can be divided into laboratory and on-site testing, respectively. The testing of the seismograph's key parameters and other concerning technical specifications are well described in guide documents (China Earthquake Administration, 2017). This includes seismometer sensitivity, linearity and clip levels based on the shake table test, as well as the seismometer natural period, damping constant based on electrical calibration ( Wang Guangfu, 1986;Plesinger A., 1993 ) and instrumental self-noise collocation estimation (Holcomb L. G., 1989;Sleeman R. et al., 2006). However, with the development of seismic observation technology, many new requirements for the performance evaluation of seismographs have been put forward, and new testing items and methods have emerged. 展开更多
关键词 BROADBAND seismographs LABORATORY TESTING ON-SITE TESTING
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带垫板焊缝的超声检测回波识别 预览
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作者 邢艳亮 甘正红 丹红兵 《焊管》 2019年第1期47-50,共4页
为了准确识别带垫板焊缝进行超声波检测时出现的真假反射回波信号,对带垫板的单面焊双面成形焊缝(包括管道对接环焊缝、T形和角接焊缝)超声检测的反射回波信号的产生原因及特点进行了分析,并分别提出了识别真假回波信号的技术方法。分... 为了准确识别带垫板焊缝进行超声波检测时出现的真假反射回波信号,对带垫板的单面焊双面成形焊缝(包括管道对接环焊缝、T形和角接焊缝)超声检测的反射回波信号的产生原因及特点进行了分析,并分别提出了识别真假回波信号的技术方法。分析认为,精确校准距离轴线(时基扫描线),寻找回波源的最佳反射角,精确确定回波源的坐标,是正确判断焊缝真假缺陷的关键,同时指出超声检测人员应熟悉焊接结构和焊接工艺,有助于进行正确的判断。 展开更多
关键词 检测 焊缝 超声波检测 垫板 回波识别
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A Survey of Testing for 5G:Solutions,Opportunities,and Challenges 预览
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作者 Ping Zhang Xiaoli Yang +1 位作者 Jianqiao Chen Yuzhen Huang 《中国通信:英文版》 SCIE CSCD 2019年第1期69-85,共17页
With the development of wireless communication technology,the fifth generation mobile communications system(5G)emerges at a historic moment and devotes itself to open the curtain of the information age.Recently,in ord... With the development of wireless communication technology,the fifth generation mobile communications system(5G)emerges at a historic moment and devotes itself to open the curtain of the information age.Recently,in order to satisfy the requirement of different applications,various advanced 5G technologies have been developed in full swing.However,before applying these 5G related technologies in practical systems,effective testing methods are needed to evaluate these technologies in a real,comprehensive,rapid and flexible manner.However,the testing methods are faced with new challenges along with the continuous development of the new 5G technologies.In this paper,we present a survey of 5G testing,including solutions and opportunities.In particular,two cases are considered,i.e.,channel modelling and overthe-air(OTA)testing of antenna systems.Specifically,a non-stationary channel model is proposed to characterize and test massive multiple-input multiple-output(MIMO)channel.In addition,we propose two probe subset selection algorithms for three-dimensional(3D)OTA testing,which minimizes the number of probe antennas while ensuring the accuracy of the target channel emulation.Finally,future research directions and challenges on 5G testing are given. 展开更多
关键词 5G TESTING CHANNEL MODELLING over-the-air TESTING
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Fundamental problem in optimizing the biaxial testing specimen
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作者 IMTIAZ Haroon FANG YaoPeng +1 位作者 DU JianBin LIU Bin 《中国科学:技术科学英文版》 SCIE EI CAS CSCD 2019年第5期773-780,共8页
Most of the elements in structural design are subjected to the complex loading conditions that need to be predicted in advance for a reliable design. The failure prediction of these structural elements is based on the... Most of the elements in structural design are subjected to the complex loading conditions that need to be predicted in advance for a reliable design. The failure prediction of these structural elements is based on the failure theories that employ the experimental data of the uniaxial, the biaxial and the shear tests. Among these tests, the biaxial testing is used to model the behavior of the structure loaded in more than one direction. In this study, we discover an interesting fact for the biaxial tension specimen that the thickness reduction of the measuring region cannot increase the stress to a high level. This behavior of the biaxial testing is different from the uniaxial testing where the thickness reduction of the measuring region always increases its stress to a higher level. Therefore, we further investigate the biaxial testing specimen via related fundamental problem, i.e., an axisymmetric plate with varying thickness under axisymmetric tension. We perform the shape optimization based on our analytical solution and the FEM results. For an infinite axisymmetric disk, the optimized design should include a low slope diverging section connecting the inner to outer region. On the contrary, the larger inner measuring region for finite axisymmetric disk would result in higher corresponding stress. These conclusions can be used as a guideline for the design of a biaxial testing specimen. 展开更多
关键词 UNIAXIAL TESTING BIAXIAL TESTING AXISYMMETRIC disk PROBLEM optimization
Overburden management in open pits:options and limits in large limestone quarries 预览
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作者 Claudio Oggeri Taddeo Maria Fenoglio +1 位作者 Alberto Godio Raffaele Vinai 《矿业科学技术学报:英文版》 CSCD 2019年第2期217-228,共12页
The management of overburden is an important task in open pit exploitations.Site topography and morphology as well as geological and geotechnical properties of natural and remoulded materials are the most important fa... The management of overburden is an important task in open pit exploitations.Site topography and morphology as well as geological and geotechnical properties of natural and remoulded materials are the most important factors affecting the disposal phase.Economic and environmental requirements must be followed in order to achieve the best reclamation results,keeping into account site constraints such as slope stability,hauling and dumping issues,and interactions with groundwater.This paper deals with the above mentioned issues,illustrating a rational approach applied on the case of a large limestone quarry where the thickness of the overburden is relevant and the spoil material has to be dumped in a flooded pit.The proposed multidisciplinary approach led to the selection of most suitable methods for excavation,transportation and disposal.The selection was based on a detailed laboratory and site characterisation that defined favorable and adverse factors to be considered during the preliminary study of a large quarrying project. 展开更多
关键词 Open pit OVERBURDEN Soil TESTING LIMESTONE QUARRY Muck ON-SITE TESTING
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顶管桩施工对桩周土体扰动的现场试验研究
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作者 王祺 朱叶艇 朱雁飞 《施工技术》 CAS 2019年第15期77-80,107共5页
作为一种将钻孔灌注桩和压力平衡式顶管技术结合的新型成桩方法,顶管桩可解决存在既有建筑时围护结构打设和穿高水头承压水层成桩困难等问题。通过低净空环境下顶管桩施工现场试验,对桩周土体扰动进行研究,总结地表沉降、桩周土体水平... 作为一种将钻孔灌注桩和压力平衡式顶管技术结合的新型成桩方法,顶管桩可解决存在既有建筑时围护结构打设和穿高水头承压水层成桩困难等问题。通过低净空环境下顶管桩施工现场试验,对桩周土体扰动进行研究,总结地表沉降、桩周土体水平位移、桩周土体竖向位移和深层土体扰动分布及变化规律。 展开更多
关键词 顶管桩 围护结构 低净空 挤土效应 试验
微生物检验在感染性疾病患者预防和诊断治疗中的临床价值
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作者 蔡燕丽 《智慧健康》 2019年第16期7-8,10共3页
目的探析微生物检验在感染性疾病患者预防及诊断治疗中的应用价值。方法随机选取2017年1月至2018年12月本院接收的尿路感染患者100例,培养中段尿,并将100株大肠埃希氏菌有效分离出。随机划分两组,对照组(n=50)未实施任何处理,研究组(n=... 目的探析微生物检验在感染性疾病患者预防及诊断治疗中的应用价值。方法随机选取2017年1月至2018年12月本院接收的尿路感染患者100例,培养中段尿,并将100株大肠埃希氏菌有效分离出。随机划分两组,对照组(n=50)未实施任何处理,研究组(n=50)开展微生物检验,统计各组菌株感染控制状况。结果在重度感染、中度感染、轻度感染方面,对照组分别是26%、40%和34%,研究组分别是10%、20%和70%,研究组较对照组更优,差异均有统计学意义(P<0.05)。结论医院感染控制中,微生物检验具有重要作用,而且应用价值高,在监测病原菌及预测传播途径方面效果突出,值得进一步采纳、推广。 展开更多
关键词 预防 检验 微生物 感染性疾病
气相色谱法测定贝类中扑草净残留方法建立 预览
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作者 李如茵 王洪艳 +1 位作者 应锦玲 刘佳 《农产品加工》 2019年第1期49-51,共3页
建立了对贝类中扑草净残留的气相色谱检测方法,为扑草净残留检测和去除方法研究提供方法支持。样品用乙腈提取、正己烷脱脂后再用无水硫酸钠除水,于40℃下蒸馏至近干,2 mL正己烷溶解残渣后过滤后分析。结果表明,该方法最低检出质量浓度... 建立了对贝类中扑草净残留的气相色谱检测方法,为扑草净残留检测和去除方法研究提供方法支持。样品用乙腈提取、正己烷脱脂后再用无水硫酸钠除水,于40℃下蒸馏至近干,2 mL正己烷溶解残渣后过滤后分析。结果表明,该方法最低检出质量浓度为0.05 mg/kg,扑草净在0.05~0.50μg/mL内线性关系良好,相关系数均大于0.99。扑草净在几种贝类中回收率为80%~110%,方法标准偏差低于10%,回收率和精密度都能满足要求。 展开更多
关键词 气相色谱法 贝类 扑草净 残留 检测
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湖北省科技馆新馆长悬臂类斜拉桥结构体系复杂铸钢节点设计研究
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作者 余地华 王亚桥 +4 位作者 赵翼鸿 李友元 黄晓程 庞玉林 周钦 《施工技术》 CAS 2019年第14期49-53,共5页
湖北省科技馆新馆主体采用核心筒-钢桁架-预应力拉索结构,核心筒为整个结构的受力主体,在其内部设有36处复杂铸钢节点。针对铸钢节点相连杆件较多,节点区域内应力分布复杂,通过缩尺静力加载试验,研究铸钢节点受力性能。由于试验中测点... 湖北省科技馆新馆主体采用核心筒-钢桁架-预应力拉索结构,核心筒为整个结构的受力主体,在其内部设有36处复杂铸钢节点。针对铸钢节点相连杆件较多,节点区域内应力分布复杂,通过缩尺静力加载试验,研究铸钢节点受力性能。由于试验中测点数量有限及测点位置选取的局限性,很难仅通过试验全方位了解节点受力性能。本工程通过有限元模拟和试验结合对铸钢节点进行受力分析。结果表明,铸钢节点在设计荷载作用下安全且具有一定的安全储备。 展开更多
关键词 钢结构 核心筒 悬壁结构 节点 设计 试验 有限元分析
IOT网络中收敛算法的设计 预览
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作者 杨英 《九江职业技术学院学报》 2019年第1期15-17,共3页
近年来物联网(IOT)技术盛行于工业生产诸多领域,与其相关的感知技术也成为研究的热门问题。尤其在无法预测的现实突发网络中,如何合理地配置IOT中的感知单元,不但关系到准确挖掘异常QoS事件,同时也有助于降低整个IOT全网的开销。为此,... 近年来物联网(IOT)技术盛行于工业生产诸多领域,与其相关的感知技术也成为研究的热门问题。尤其在无法预测的现实突发网络中,如何合理地配置IOT中的感知单元,不但关系到准确挖掘异常QoS事件,同时也有助于降低整个IOT全网的开销。为此,本文构思了一种优化的收敛计算机制,可结合实际环境动态地开展深度计算,有效地突破传统收敛算法的计算偏好度。经测试,相对于传统收敛计算机制,优化收敛算法可显著改善IOT全网布局的效能度。 展开更多
关键词 物联网 感知 收敛 计算 测试
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高职院校公共英语测试中存在的问题及对策研究 预览
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作者 章素华 《芜湖职业技术学院学报》 2019年第1期4-6,10共4页
教学和测试是一种伙伴关系。教师可以通过测试的结果,改进教学方法;学生可以通过测试结果,调整学习策略。分析高职院校公共英语测试的内容、手段、标准和测试目的等现状和问题,可以使高职英语考试改革更具有目的性和针对性,更好地服务... 教学和测试是一种伙伴关系。教师可以通过测试的结果,改进教学方法;学生可以通过测试结果,调整学习策略。分析高职院校公共英语测试的内容、手段、标准和测试目的等现状和问题,可以使高职英语考试改革更具有目的性和针对性,更好地服务于英语的教和学,从而提高高职英语的教学质量。 展开更多
关键词 高职 公共英语 测试
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工业CT在电磁线圈缺陷检测中的应用
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作者 潘光勇 张敏霞 +1 位作者 鲍熠朗 张杭滨 《CT理论与应用研究》 2019年第2期205-212,共8页
通过工业CT(ICT)对电磁线圈进行内部结构分析,可以避免电磁线圈解剖的困难。ICT能有效地检测出电磁线圈中的漆包线断开、零部件安装不到位、漆包线熔断、绕组变形、包封层中气孔、多余杂线以及金属杂质等缺陷,并且能够精确地确定出缺陷... 通过工业CT(ICT)对电磁线圈进行内部结构分析,可以避免电磁线圈解剖的困难。ICT能有效地检测出电磁线圈中的漆包线断开、零部件安装不到位、漆包线熔断、绕组变形、包封层中气孔、多余杂线以及金属杂质等缺陷,并且能够精确地确定出缺陷的位置和几何形状。工业CT分析对提高电磁线圈产品的质量,改进生产工艺有指导意义。 展开更多
关键词 工业CT 电磁线圈 检测
断路器二次接线正确性检测装置设计 预览
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作者 董立锋 党丽敏 陈少军 《电气技术》 2019年第7期48-51,共4页
目前,在断路器装配完成后,为保证二次接线的正确性,需要人工用万用表对断路器储能辅助接点、分合闸辅助接点、手车工作位及试验位辅助接点的通断进行检测,效率低,准确性差。本文针对这个问题,设计二次接线正确性检测装置来提高手车的检... 目前,在断路器装配完成后,为保证二次接线的正确性,需要人工用万用表对断路器储能辅助接点、分合闸辅助接点、手车工作位及试验位辅助接点的通断进行检测,效率低,准确性差。本文针对这个问题,设计二次接线正确性检测装置来提高手车的检测效率和质量。 展开更多
关键词 断路器 二次接线 正确性 检测
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Genetic testing vs microforceps biopsy in pancreatic cysts:Systematic review and meta-analysis 预览
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作者 Sandra Faias Luisa Pereira +2 位作者 Angelo Luis Paula Chaves Marilia Cravo 《世界胃肠病学杂志:英文版》 SCIE CAS 2019年第26期3450-3467,共18页
BACKGROUND Carcinoembryonic antigen(CEA)and cytology in pancreatic cystic fluid are suboptimal for evaluation of pancreatic cystic neoplasms.Genetic testing and microforceps biopsy are promising tools for pre-operativ... BACKGROUND Carcinoembryonic antigen(CEA)and cytology in pancreatic cystic fluid are suboptimal for evaluation of pancreatic cystic neoplasms.Genetic testing and microforceps biopsy are promising tools for pre-operative diagnostic improvement but comparative performance of both methods is unknown.AIM To compare the accuracy of genetic testing and microforceps biopsy in pancreatic cysts referred for surgery.METHODS We performed a literature search in Medline,Scopus,and Web of Science for studies evaluating genetic testing of cystic fluid and microforceps biopsy of pancreatic cysts,with endoscopic ultrasound with fine-needle aspiration(EUSFNA)prior to surgery and surgical pathology as reference standard for diagnosis.We evaluated the diagnostic accuracy for:1-benign cysts;2-mucinous low-risk cysts;3-high-risk cysts,and the diagnostic yield and rate of correctly identified cysts with microforceps biopsy and molecular analysis.We also assessed publication bias,heterogeneity,and study quality.RESULTS Eight studies,including 1206 patients,of which 203(17%)referred for surgery who met the inclusion criteria were analyzed in the systematic review,and seven studies were included in the meta-analysis.Genetic testing and microforceps biopsies were identical for diagnosis of benign cysts.Molecular analysis was superior for diagnosis of both low and high-risk mucinous cysts,with sensitivities of 0.89(95%CI:0.79-0.95)and 0.57(95%CI:0.42-0.71),specificities of 0.88(95%CI:0.75-0.95)and 0.88(95%CI:0.80-0.93)and AUC of 0.9555 and 0.92,respectively.The diagnostic yield was higher in microforceps biopsies than in genetic analysis(0.73 vs 0.54,respectively)but the rates of correctly identified cysts were identical(0.73 with 95%CI:0.62-0.82 vs 0.71 with 95%CI:0.49-0.86,respectively).CONCLUSION Genetic testing and microforceps biopsies are useful second tests,with identical results in benign pancreatic cysts.Genetic analysis performs better for low-and high-risk cysts but has lower diagnostic yield. 展开更多
关键词 Pancreatic CYSTS ENDOSCOPIC ULTRASOUND ENDOSCOPIC ULTRASOUND with fineneedle ASPIRATION Genetic testing Microforceps BIOPSY Molecular analysis KRAS Carcinoembryonic antigen CYTOLOGY
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基于51单片机的电火花穿孔机穿透检测装置设计 预览
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作者 王志国 李胜多 《自动化技术与应用》 2019年第3期168-171,共4页
本文介绍的是一种电火花穿孔机的穿透检测装置,用于检测电火花穿孔机穿孔时是否穿透,在此,本文提出了基于51单片机的电火花穿孔机穿透检测控制装置的研究。利用STC89C51单片机作为控制器,通过对继电器的开关控制进而控制电极头的停止和... 本文介绍的是一种电火花穿孔机的穿透检测装置,用于检测电火花穿孔机穿孔时是否穿透,在此,本文提出了基于51单片机的电火花穿孔机穿透检测控制装置的研究。利用STC89C51单片机作为控制器,通过对继电器的开关控制进而控制电极头的停止和上升,根据穿透信号进行下一步加工条件的处理和加工完成的判定,有了此信号后,穿孔加工时铜管伸出加工工件的长度可控,大大提高加工效率和加工成功率,降低工人的劳动强度,提高加工效率,改进自动化程度。 展开更多
关键词 电火花穿孔机 检测 控制 高效
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2000m^3液化气球罐裂纹分析及修复 预览
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作者 李伯涛 许留云 胡泷艺 《化工技术与开发》 CAS 2019年第3期52-54,共3页
对连续使用3年的2000m^3的液化气球罐进行超声波检测,发现其中有一条长度为1600mm的超标缺陷,缺陷距球壳板外表面测定深度33~35mm。本文分析了该球罐裂纹缺陷形成的原因,介绍了裂纹的修复方法和修复后的处理。
关键词 球罐 裂纹 检测 修复
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渤海油田稠油精准测试技术 预览
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作者 周宝锁 谭忠健 +3 位作者 卢中原 张兴华 刘境玄 魏青涛 《油气井测试》 2019年第4期14-19,共6页
渤海油田稠油测试作业期间,稠油及天然气计量误差大,气量小时无法计量。运用保温管、地面蒸汽加热同心管,从井下到计量罐全流程加热保温,降低原油黏度;对分离器内部进行改造,采用差压式液位变送器、聚结式过滤器、精密气体计量管汇等技... 渤海油田稠油测试作业期间,稠油及天然气计量误差大,气量小时无法计量。运用保温管、地面蒸汽加热同心管,从井下到计量罐全流程加热保温,降低原油黏度;对分离器内部进行改造,采用差压式液位变送器、聚结式过滤器、精密气体计量管汇等技术,实现对稠油和天然气产量的精准计量。案例C井原油比重0.9884(20℃)、黏度2680.45mPa·s(50℃),采用稠油精准测试技术,消除了稠油中的泡沫,使油气分离更彻底,取得了准确的油气产量数据。该技术可获取油田后续开发需要的常规气样和分离器配样等,为开发方案编制提供可靠依据。 展开更多
关键词 渤海油田 稠油井 测试 计量罐 分离器 常规气样 分离器配样
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移动分组数据业务计费检测问题的研究
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作者 王若臣 刘楠楠 +1 位作者 刘一蓉 薛强 《信息通信技术与政策》 2019年第3期75-79,共5页
近年来移动分组数据业务计费方面的投诉层出不穷,引起了全社会大规模的舆论关注。移动分组数据业务计费检测能够提升电信企业的计费准确性,确保消费者的合法利益。本文以LTE移动分组数据网络为例,介绍了移动分组数据业务计费检测技术,... 近年来移动分组数据业务计费方面的投诉层出不穷,引起了全社会大规模的舆论关注。移动分组数据业务计费检测能够提升电信企业的计费准确性,确保消费者的合法利益。本文以LTE移动分组数据网络为例,介绍了移动分组数据业务计费检测技术,对移动分组数据业务计费检测中发现的问题进行研究分析。 展开更多
关键词 LTE 计费 检测
Machine Learning Approach to Enhance the Performance of MNP?Labeled Lateral Flow Immunoassay
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作者 Wenqiang Yan Kan Wang +3 位作者 Hao Xu Xuyang Huo Qinghui Jin Daxiang Cui 《纳微快报:英文版》 CAS CSCD 2019年第1期132-146,共15页
The use of magnetic nanoparticle(MNP)-labeled immunochromatography test strips(ICTSs)is very important for point-ofcare testing(POCT).However,common diagnostic methods cannot accurately analyze the weak magnetic signa... The use of magnetic nanoparticle(MNP)-labeled immunochromatography test strips(ICTSs)is very important for point-ofcare testing(POCT).However,common diagnostic methods cannot accurately analyze the weak magnetic signal from ICTSs,limiting the applications of POCT.In this study,an ultrasensitive multiplex biosensor was designed to overcome the limitations of capturing and normalization of the weak magnetic signal from MNPs on ICTSs.A machine learning model for sandwich assays was constructed and used to classify weakly positive and negative samples,which significantly enhanced the specificity and sensitivity.The potential clinical application was evaluated by detecting 50 human chorionic gonadotropin(HCG)samples and 59 myocardial infarction serum samples.The quantitative range for HCG was 1–1000 mIU mL-1 and the ideal detection limit was 0.014 mIU mL-1,which was well below the clinical threshold.Quantitative detection results of multiplex cardiac markers showed good linear correlations with standard values.The proposed multiplex assay can be readily adapted for identifying other biomolecules and also be used in other applications such as environmental monitoring,food analysis,and national security. 展开更多
关键词 POINT-OF-CARE testing IMMUNOCHROMATOGRAPHY test STRIPS Magnetic nanoparticles MACHINE learning Support vector MACHINE
Consistency check of degradation mechanism between natural storage and enhancement test for missile servo system 预览
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作者 Wang Xu Sun Quan 《系统工程与电子技术:英文版》 SCIE EI CSCD 2019年第2期415-424,共10页
Reliability enhancement testing(RET) is an accelerated testing which hastens the performance degradation process to surface its inherent defects of design and manufacture. It is an important hypothesis that the degrad... Reliability enhancement testing(RET) is an accelerated testing which hastens the performance degradation process to surface its inherent defects of design and manufacture. It is an important hypothesis that the degradation mechanism of the RET is the same as the one of the normal stress condition. In order to check the consistency of two mechanisms, we conduct two enhancement tests with a missile servo system as an object of the study, and preprocess two sets of test data to establish the accelerated degradation models regarding the temperature change rate that is assumed to be the main applied stress of the servo system during the natural storage. Based on the accelerated degradation models and natural storage profile of the servo system, we provide and demonstrate a procedure to check the consistency of two mechanisms by checking the correlation and difference of two sets of degradation data. The results indicate that the two degradation mechanisms are significantly consistent with each other. 展开更多
关键词 reliability ENHANCEMENT testing (RET) degradation model ACCELERATED equation CONSISTENCY CHECK Pearson correlation coefficient
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