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Reflections from geometric discontinuities can be used with ultrasonic energy to predict the temperature of an interface where classical temperature measurement techniques are impractical because of physical access limitations or harsh environmental conditions. Additionally, these same ultrasonic measurements can be used with inversion methods commonly applied to ill-posed heat transfer problems to increase the accuracy of the measurement of surface temperature or heat flux at the surface of interest. Both methods for determining surface temperature are presented, along with a comparison of results both from a verification example and using data gathered in a field test of the methods. The results obtained with these two methods are shown to be in good agreement with an empirical relationship used in the design of large caliber guns. 相似文献
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教材分析是连接教材和课程的桥梁,基于宏观辨识和微观探析核心素养,比较分析了2004年版和2019年版高中《化学1(必修)》教材的特点。通过运用“三序结合”原则,从静态视角对比教材栏目设置、内容组织形式、核心素养呈现方式、学生认知水平以及作业布置形式等5个维度要素在宏微辨析核心素养领域的建构。分析结果显示,2019年版《化学1(必修)》教材在以上要素方面均围绕宏微辨析核心素养,呈现不同水平阶梯型设置。建议在“宏微符”概念形成的过程中增设更为细致的过渡内容,以及更为详尽的与教材配套的辅助内容,便于教材的二次开发。 相似文献
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蒙皂石含量与膨胀土膨胀势指标相关关系研究 总被引:2,自引:0,他引:2
对沿南水北调中线工程邯郸—永年、南阳、平顶山等地区及襄樊、荆门钟祥地区采集的各类地表、近地表膨胀土样品5 6件 ,运用现代XRD定量方法和有机染料吸附方法测量了粘土矿物成分和蒙皂石含量 ,同时测定了它们的液限、塑限、自由膨胀率、比表面积、粘粒、胶粒含量等指标。蒙皂石含量与各种膨胀势判别指标研究表明 ,蒙皂石含量是各种膨胀势的主要控制因素。当然 ,各种测量误差 (主要是蒙皂石含量的测量误差 )也是影响膨胀势判别的因素。Seed膨胀势较本文采用的推荐方案划分结果高 1~ 2个级次。蒙皂石含量与各参量之间呈线性、对数、指数关系 ,与粘土矿物的“诊断”吸收特性一起 ,这为膨胀土遥感提供了基础. 相似文献
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In the present work, a further numerical simulation of the starting flow around a flat plate normal to the direction of motion
in a uniform fluid has been made by means of the discrete vortex method. The secondary separation occurring at rear surface
of the plate is explored, and predicted approximately using Thwait's method. The calculated results show that in the early
stages of the flow secondary separation does occur. The evolution of flow field, the vortex growing process and the characteristics
of secondary vortices have been described. The time dependent drag coefficients, the vorticity shed from the edges and rear
surface, and the separation positions are calculated as well as the distributions of velocity and pressure on the plate. In
the case of flow normal to the plate, the calculated secondary vortices are weak. Their existence will change the local velocity
distributions and affect pressure distributions. However, the effect on drag coefficient is negligible. 相似文献
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针对现场采集数据实时远程监控的要求,根据LabVIEW强大的功能模块和Arduino灵活易用的开发特点,提出以Arduino为控制器,采用Arduino软件与LabVIEW软件交互编程的设计思想。为解决LabVIEW在本地服务器Web发布的局限性,同时简化系统的硬件设计,增加使用的灵活性,使用云计算作为服务器,设计实现了一种基于LabVIEW和Arduino的无线串口采控和实时同步Web发布的系统。测试结果表明,该系统界面友好,运行可靠,可扩展性很强,可以在整个互联网上通过网页建立Web请求。 相似文献
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为实现对循环水水质的远程监测,设计并开发了一种基于嵌入式技术的热力站远程水质监测系统的监测终端。监测终端由水质传感器、GPRS模块、通信转换模块及嵌入式开发板组成。嵌入式开发板以ARM11系列的Tiny6410为硬件基础,并嵌入WinCE系统作为软件平台,同时加入SQLite数据库以实现将水质传感器采集到的氯离子、PH值、溶解氧等参数的本地存储、查询及图表显示。最后监测终端通过GPRS模块与数据中心建立无线连接,接收数据中心的配置命令,并将现场测得数据发送到远端数据中心。调试结果表明:远程监测终端实现了循环水水质远程监测的功能要求,对于实现水质自动化监测具有一定的理论意义和实用价值。 相似文献
10.
The role of remote sensing in enhancing the monitoring capabilities and the short-term prediction of the risk of flooding on a regional scale is addressed in this paper by means of the application of storm identification and cloud tracking techniques to a few case studies where cluster analysis based on infrared satellite imagery is used as the primary source of information. Polar satellite sensors, which provide passive microwave images, were also proposed in the literature for application in flood forecasting operational problems, though the accuracy of passive microwave techniques is only acceptable when rainfall estimates are integrated over quite large spatial and temporal scales. Climatological studies are well suited to make use of such data while the measure of instantaneous rainfall is still lacking of an adequate validation. A theoretical and numerical framework for the assessment of the reliability of passive microwave estimates of instantaneous rainfall within the typical resolution scales of polar satellite sensors is provided in the paper.
Sommario Il ruolo delle tecniche di monitoraggio da sensori remoti nell'incrementare le potenzialità di previsione a breve termine del rischio di inondazione a scala regionale è analizzato nel presente lavoro attraverso l'applicazione di tecniche di identificazione ed inseguimento dei corpi nuvolosi ad alcuni casi di studio in cui le immagini satellitarie nella banda dell'infrarosso termico sono utilizzate come principale strumento di monitoraggio. In letteratura viene inoltre proposta l'utilizzazione, in applicazioni operative di previsione delle inondazioni, di sensori alle microonde passive montati su satelliti ad orbita polare: l'accuratezza di tali tecniche è tuttavia accettabile solo quando le stime di precipitazione vengono integrate su ampie scale spaziali e temporali. Mentre l'uso di tali tecniche per studi climatologici è di notevole utilità, la misura della precipitazione alle piccole scale spazio-temporali necessita ancora di un adeguato processo di validazione. Nel presente lavoro viene proposto un approccio teorico per la stima dell'affidabilità di tali stime di precipitazione alle scale tipiche della risoluzione spaziale del sensore.相似文献