Self-monitoring electrically conductive asphalt-based composite containing carbon fillers

A new novel function materials, structure self-monitoring asphalt-based composite was introduced. The results show that the output resistance of electrically conductive asphalt-based composites would change under cyclic loading and vehicle loading action. The resistance change of conductive asphalt-based composites was aroused by the variation of its interior structure. When the fatigue failure was studied, the larger cracks cut the continuous electrically conductive path and the electron is difficult to overcome the potential barrier of gap. In the early period, the slight deformation and microcrack may be recovered due to the viscoelasticity character of asphalt, which leads to some cracks close again, the output resistance changes a little. But with the shear process performs continuously, the cracks become larger and larger, which would cut the conductive path and block off the transition of electrons, and if the cracks are large enough, the pitch-matrix composites containing carbon fillers will lose electrically conductive function. When the rutting failure was studied, the flowage of conductive substance results in the decrease of substance due to electrically conducting and conductive path decreasing. The decrease of electron volume contribute to electrically conducting and large stone aggregate prevent the electron from transiting. In a word, the variation of output resistance is aroused by the variation of interior structure completely.

A STUDY OF SOIL CONSERVATION MONITORING INFORMATION SYSTEM BASED ON REMOTELY SENSED DATA FOR A CATCHMENT ON THE LOESS PLATEAU

The Soil Conservation Monitorins Information System (SCMIS) presented in this paper is oriented to soil erosion control, resources exploitation, utilization, planning and management for a small watershed (about 10 sq. km.) on the Loess Plateau. It sums up Remote sensing (RS), Geographical Information System (GIS) and Expert System (ES) and consists of a integrated system. As a basic level information system of Loess Plateau, its perfection and psreading will bring about a great advance in resources exploitation and management of Loess Plateau.

Network Based Real Time Condition Monitoring of Rotating Machinery

This paper presents the development of a network based real time condition monitoring system of rotating machinery. The system is built up in a double net structure consisting of local net (including client and server) and intranet. The client serves as a field data collector and processor that samples the vibration signals and process parameters of a machine monitored in the net and processes the sampled data. The data collected by the client are transmitted to the server that processes the data further and provides the results of the diagnosis of each machine to any distant terminals through intranet or internet. Such a structure of the monitoring system is advantageous in safety, reliability and reasonably shares the existing net resources. In order to ensure real time transmission of the data, two procedures of data transmission, virtual channel and data pool, are developed and applied in the monitoring system. The experimental results show that the monitoring system works well and is suitable to monitor a large group of rotating machines.

A Web-based machining process monitoring system for E-manufacturing implementation

Recently, with the rapid growth of information technology, many studies have been performed to implement Web-based manufacturing system. Such technologies are expected to meet the need of many manufacturing industries who want to adopt E-manufacturing system for the construction of globalization, agility, and digitalization to cope with the rapid changing market requirements. In this research, a real-time Web-based machine tool and machining process monitoring system is developed as the first step for implementing E-manufacturing system. In this system, the current variations of the main spindle and feeding motors are measured using hall sensors. And the relationship between the cutting force and the spindle motor RMS (Root Mean Square) current at various spindle rotational speeds is obtained. Thermocouples are used to measure temperature variations of important heat sources of a machine tool. Also, a rule-based expert system is applied in order to decide the machining process and machine tool are in normal conditions. Finally, the effectiveness of the developed system is verified through a series of experiments.

Some Group Runs Based Multivariate Control Charts for Monitoring the Process Mean Vector

In this article, we propose two control charts namely, the “Multivariate Group Runs’ (MV-GR-M)” and the “Multivariate Modified Group Runs’ (MV-MGR-M)” control charts, based on the multivariate normal processes, for monitoring the process mean vector. Methods to obtain the design parameters and operations of these control charts are discussed. Performances of the proposed charts are compared with some existing control charts. It is verified that, the proposed charts give a significant reduction in the out-of-control “Average Time to Signal” (ATS) in the zero state, as well in the steady state compared to the Hotelling’s T2 and the synthetic T2 control charts.

An Intelligent Sensor Based System for Real Time Heart Rate Monitoring (HRM)

A method and apparatus for monitoring heart rate of the heart using a wearable system is designed and implemented in this paper. A heart rate receives from heart beat signals and stores the data to a database and after a time period this method can determine an idle heart rate of the monitoring body. This idle heart rate is compared with the stored data and can determine the normal and abnormal heart rate variability. After the certain time period this system can detect the heart rate and also can send a signal to the user in time of abnormalities. Consequent estimations of heart rate variability are contrasted with this.

Online Monitoring Volume Deformation of Cement-based Materials in Multiple Environments

Comparing and analyzing some volume deformation measuring means for cement-based materials at home and abroad, a continuous online monitor of cement-based material volume deformation in multiple environments is developed. The device is designed based on the environmental simulation technology, micro-distance measuring technology of laser and eddy current, and transmission agent online monitoring the deformation of multi-group samples. This device can be used widely, such as glass, ceramics, walling material, and so on, with high precision, low testing cost, and intellectualization.

肝癌切除手术患者目标导向性血糖监测的证据总结

目的检索并总结肝癌切除手术患者目标导向性血糖监测相关证据,为临床提供指导依据。方法应用PICO程式结构化临床问题,检索中国指南网,美国指南网,英国国家临床医学研究所指南库,国际指南图书馆,英格兰学院间指南网,UpToDate,BMJ,Cochrane Library,PubMed,Web of Science,EMbase,CINAHL,中国生物医学数据库,中国知网,万方医学数据库。采用相关评价工具对纳入的文献进行质量评价。结果共纳入文献15篇,包括指南6篇,专家共识3篇,原始研究6篇,总结出18条审查指标,包括多学科团队构建、术前评估及健康教育、监测方法、术前/术中/术后目标导向性血糖监测措施、异常血糖处理、术后交接及管理等内容。结论本研究总结了肝癌切除手术患者目标导向性血糖监测的最佳证据,为规范临床血糖监测及控制,降低血糖异常事件及并发症发生率,加速术后康复提供循证依据。

近地小行星远距离逆行轨道监测布局与效能评估

针对近地小行星地基监测系统对日不可见盲区限制、监测体系发现与编目能力不足等问题,提出了天基远距离逆行轨道4星监测系统解决方案,据此定量化分析了天基监测系统对上述问题的解决能力,建立了配套的效能评估模型,给出了对应评估软件的实现流程,按照可见光和红外谱段完成了各要素整合后得到评分。通过分析评估,印证了远距离逆行轨道监测布局对地基监测系统不可见盲区全时可见的补偿效能,以及对目标发现编目能力的提升,可为后续天基监测体系的建设提供设计参考。

Antenna and Base-Station Diversity for WSN Livestock Monitoring

Antenna and base-station diversity have been applied to a wireless sensor network for the monitoring of live-stock. A field trial has been described and the advantage to be gained in a practical environment has been assessed.

MAC技术优化日间宫腔镜手术麻醉成本的探索——基于TDABC核算模型的研究

该研究通过回顾天坛医院2021年10月-2022年9月的日间宫腔镜手术,借助估时作业成本(Timedriven Activity-based Costing,TDABC)模型计算麻醉成本,并记录围术期不良事件,评价了日间宫腔镜手术采用监测下麻醉管理(Monitored Anesthesia Care,MAC)技术消耗的麻醉成本及其安全性。717例患者完成麻醉和手术,其中466例接受了MAC麻醉,251例接受了传统的全身麻醉(General Anesthesia,GA)。MAC组平均麻醉成本为889.84元/例,明显低于GA组(1143.57元/例,P<0.0001)。MAC组围术期不良事件发生率(3.65%),与传统GA组(6.37%)相比,差异无统计学意义(P=0.0965),两组均无严重不良后果。多元回归分析显示,MAC组麻醉成本与患者年龄、手术时间和麻醉时间都有相关性(P<0.01)。MAC作为安全、有效的麻醉技术,可显著降低麻醉成本。麻醉医生可以借助TDABC模型进行成本核算,同时优化临床路径和成本控制。

数字化技术在5G基站电磁辐射监测中的应用

介绍了一个基站电磁辐射数字化检测平台,该平台利用5G+互联网技术,实现了基站电磁辐射原始监测数据、频谱图的实时上传,以及基站电磁辐射监测的全要素、全流程管理,并结合CNAS实验室认可要求介绍了数字化检测系统投入应用时的注意事项。

基于GB-SAR的矿山边坡局部变形演化与失稳预测

为了提高地基合成孔径雷达(ground-based synthetic aperture radar, GB-SAR)边坡监测效果与失稳预测能力,在广东省某石灰石矿山架设地基雷达,开展实地监测试验,结合矿山地质条件与监测数据研究不同类型的岩体变形演化特征,根据变形特征选择位移最大点的监测数据利用速度倒数法进行失稳预测。通过分析典型案例的监测数据来优化速度倒数法的算法,进而对矿山试验数据进行研究。研究结果表明:通过分析雷达三维模型变形图的局部位移差异,能够初步判断边坡岩体的变形破坏方式;适当增大移动平均滤波法的移动时间周期C,能够更早地发现灾害征兆,更好地识别岩体加速变形阶段及临滑阶段。研究结果可为基于雷达的滑坡预测提供参考。

Monitoring models for base flow effect and daily variation of dam seepage elements considering time lag effect

Affected by external environmental factors and evolution of dam performance, dam seepage behavior shows nonlinear time-varying characteristics. In this study, to predict and evaluate the long-term development trend and short-term fluctuation of the dam seepage behavior, two monitoring models were developed, one for the base flow effect and one for daily variation of dam seepage elements. In the first model, to avoid the influence of the time lag effect on the evaluation of seepage variation with the time effect component of seepage elements, the base values of the seepage element and the reservoir water level were extracted using the wavelet multi-resolution analysis method, and the time effect component was separated by the established base flow effect monitoring model. For the development of the daily variation monitoring model for dam seepage elements, all the previous factors, of which the measured time series prior to the dam seepage element monitoring time may have certain influence on the monitored results, were considered. Those factors that were positively correlated with the analyzed seepage element were initially considered to be the support vector machine(SVM) model input factors, and then the SVM kernel function-based sensitivity analysis was performed to optimize the input factor set and establish the optimized daily variation SVM model. The efficiency and rationality of the two models were verified by case studies of the water level of two piezometric tubes buried under the slope of a concrete gravity dam.Sensitivity analysis of the optimized SVM model shows that the influences of the daily variation of the upstream reservoir water level and rainfall on the daily variation of piezometric tube water level are processes subject to normal distribution.

基于OBE理念的海洋环境调查与监测实验教学改革

为提高学生的实验操作技能,在海洋环境调查与监测实验教学中引入成果导向教育理念,让学生全程参与实验准备、实验操作及实验分析过程。这种实验模式,调动了学生的学习积极性,提高了学生的学习兴趣和效率,增强了学生的实践操作能力,培养了学生的全局思维能力,达到了实验教学的目的。

基于导波监测的复合材料加筋结构冲击后剩余强度预测

对应用超声导波在线监测信息评估复合材料加筋结构冲击后剩余强度进行了研究。首先针对所监测的对象设计布置了压电传感网络并构建结构健康监测系统,通过局部信号差分系数计算出不同传感路径上的损伤指标,融合损伤概率成像方法识别损伤位置,测算形状因子以近似表征损伤尺寸。然后构建加筋结构有限元模型,由在线监测结果反馈损伤信息,采用软化夹杂法等效冲击损伤,依据复合材料损伤渐进失效分析理论,预测冲击后加筋结构的剩余极限强度。通过低速冲击、超声导波监测和压缩强度等一系列实验验证了所提出方法的有效性,为结构健康监测最高层次的应用提供基础。

纺织基应变传感器在健康监测领域的研究进展

纺织基应变传感器因高灵敏度、透气性、可穿戴舒适性和可连续监测等特点,在健康监测领域具备广阔的应用前景,如人体生理信号监测、运动与姿态监测以及远程医疗保健等。针对目前应变传感器透气性、舒适性差,无法满足人体日常穿戴等应用难题,以纺织基应变传感器为研究对象,系统综述了近几年纤维基、纱线基、织物基3种类型的应变传感器及其在健康监测领域中的研究进展,同时分析讨论了纺织基应变传感器存在标准化难,兼容性、稳定性、耐洗性差等问题,指出未来纺织基应变传感器的主要发展方向应聚焦于高集成化及多功能化,并借助人工智能等技术实现远程医疗及个性化健康管理。

城市轨道交通车辆基地防洪设计及监测方案研究

[目的]城市轨道交通车辆基地防洪关系到车辆基地及正线运营安全,为有效提高车辆基地防洪能力,需对车辆基地防洪设计要点及措施进行研究。[方法]从设计阶段对影响车辆基地防洪的场坪标高、改移河道设计等要点及注意事项进行详细分析;针对可能出现的大量积水通过车辆基地U型槽进入正线区间造成行车事故的不利情况,开展了防洪措施设计研究,分析确定了出入段线U型槽处为车辆基地防洪关键点;为提高其防洪应急处置能力,从水灾演化规律、监测原则、等级判断及预测、方案设计、智能决策及应急调度等方面进行了防洪及监测方案研究。[结果及结论]在出入段线U型槽位置,采用可移动拼接式防淹挡板设计方案;明确了防淹挡板设计及布置方案、专业接口要点、适用情况;通过设置水位监测点并结合监测融合算法系统、智能决策系统及应急调度指挥系统,构建了出入段线水灾监测、智能决策及应急调度方案,实现灾前、灾中、灾后全过程智能防洪预警及调度指挥。

基于碳基结构增敏型肥料中缩二脲检测的电化学传感器设计与评估

肥料通过调控植物生长发育而直接影响农作物产量,是推动现代集约化农业实现作物高产优质的重要因素;然而,尿素、含尿素复合肥生产过程中极易产生副产物缩二脲,目前由于肥料中缩二脲含量过高造成农田作物毒害问题不容忽视。建立高效的肥料中缩二脲检测方法对保障肥料生产安全、促进我国农业绿色高质量发展具有现实意义。本研究立足于我国现代农业发展对优质肥料的迫切需求,构建基于碳基结构材料敏感响应的电化学传感界面,实现肥料中缩二脲的在线快速评估,有效克服液相色谱法、紫外分光光度法存在的样品预处理繁琐、分析成本高、样品浊度干扰大等不足。首先,制备了兼具碳基结构表面特性和纳米金优良导电性质的石墨烯—纳米金复合物,并将其作为传感界面修饰材料固定于电极表面;其次,利用缩二脲对铜离子电化学信号的抑制作用,建立了铜离子响应电流随缩二脲浓度变化的线性回归方程,借助智能手机获取信号,进而实现缩二脲的电化学快速分析。实验结果表明,铜离子产生的响应电流与缩二脲浓度在1~80 mmol/L范围内呈良好的线性关系,检出限为0.50 mmol/L(S/N=3);利用该电化学传感体系用于肥料样品中缩二脲的分析,检测结果与高效液相色谱法分析结果相对误差不超过6.9%。该电化学分析方法应用于肥料中缩二脲的在线检测便携程度高、可靠性好、准确度高,为肥料中缩二脲快速评估提供了新方法,科技创新赋能农作物高产优质。

体外膜肺氧合患者功能锻炼的最佳证据总结

目的总结体外膜肺氧合患者功能锻炼的最佳证据,为制定科学的体外膜肺氧合患者功能锻炼方案提供参考。方法系统检索国内外相关指南网站、循证数据库、相关协会网站及学术文献数据库等关于体外膜肺氧合患者功能锻炼的相关证据。检索时限为建库至2023年6月。由2名经过循证医学方法学培训的研究人员对所纳入的文献进行质量评价。结果共纳入12篇文献,包括指南2篇,系统评价5篇,专家共识3篇,随机对照试验2篇。最终提取出了前期准备、评估、运动方法和安全监测4个方面共35条最佳证据。结论总结的最佳证据可为开展体外膜肺氧合患者功能锻炼提供依据,从而为患者提供个性化的康复训练方案。