NOBOOK虚拟实验助力物理实验教学——以“电学实验”为例

初中是学生物理学习的起始阶段,实验作为教学过程的重要环节,是帮助学生建立概念、认识规律、培养物理思维的必要手段.初中物理实验教学由于一些实验室设备短缺、所授课时有限等诸多问题,导致学生无法动手实验.同时受新冠疫情影响,线下教学无法正常开展,经常只能线上教学,也使得学生实验课无法正常开展.将NOBOOK虚拟实验软件应用到初中物理教学中,课堂上教师进行仿真模拟演示实验,开展丰富的实验教学活动,学生课上课下也可以自己DIY实验,有效促进学生实验能力的提升.

Anomalous temperature dependence of photoluminescence spectra from InAs/GaAs quantum dots grown by formation–dissolution–regrowth method

Two kinds of InAs/GaAs quantum dot(QD) structures are grown by molecular beam epitaxy in formation–dissolution–regrowth method with different in-situ annealing and regrowth processes. The densities and sizes of quantum dots are different for the two samples. The variation tendencies of PL peak energy, integrated intensity, and full width at half maximum versus temperature for the two samples are analyzed, respectively. We find the anomalous temperature dependence of the InAs/GaAs quantum dots and compare it with other previous reports. We propose a new energy band model to explain the phenomenon. We obtain the activation energy of the carrier through the linear fitting of the Arrhenius curve in a high temperature range. It is found that the Ga As barrier layer is the major quenching channel if there is no defect in the material. Otherwise, the defects become the major quenching channel when some defects exist around the QDs.

光纤振动型油井防盗远程监控报警系统

近年来,油井设备被盗事件时有发生,给油井的安全生产带来了隐患。为此,采取了在抽油机井中轴处安装三鉴探测器,在采油树上安装单向流量计等防盗措施,但这些措施都存在设备自身不防盗,误报、漏报率高等问题。光纤振动型油井防盗远程监控报警系统主要由光纤传感器、前端处理器、GPRS通信模块及监控中心组成,该系统通过检测油井周围的振动信号,判断油井周围是否有异常情况发生。通过进行冬、夏季的模拟试验表明,系统具有隐蔽性好、抗干扰能力高、适应性强、可靠性高和安装简单等特点,可为视频报警联动系统的完善提供技术储备。