The cardiac pacemaker experiment is a physical experiment with medical characteristics for freshmen of medical colleges. It won the first prize in the lecture competition in the 7th National Undergraduate Physics Experiment Contest (Innovation) Lecture Competition. Taking the experiment of t cardiac pacemaker as an example, this paper shares the process how to prepare for the competition and carry out the teaching design in the course of lectures, which reflects the guiding effect of humanistic elements in experimental teaching on students' emotional value. The medical characteristics of the cardiac pacemaker experiment are highlighted, and the highlights and innovation point of the cardiac pacemaker experimental teaching are refined, which can inspire the students' interest in physical experiments and provide references for the contestants.

基于Phyphox手机App,将圆柱形钕铁硼磁铁构成的单摆放在黄铜或铝板表面不同距离摆动,利用智能手机磁传感器研究磁阻尼摆运动.结果表明,相同距离下,黄铜和铝板阻尼系数基本与电导率成正比.对于铝板,磁阻尼摆离开板距离从50mm减小到18mm时,阻尼系数从1.139×10-2 s-1增加到1.114×10-1 s-1,随距离的变化可以用指数函数来拟合.当距离减小到2.5mm时,观察到临界阻尼现象.当磁阻尼摆离开铝板表面距离为18mm,铝板厚度从1.001mm增加到5.615mm时,磁阻尼系数从9.378×10-2 s-1增加到1.967×10-1 s-1.实验结果与基于磁偶极子的理论模型基本一致.本文所搭建的磁阻尼摆实验装置结构简单,研究内容丰富,特别是能定量地研究磁阻尼现象,可以作为居家物理实验开设.

基于Phyphox App,利用智能手机磁传感器通过测量磁感应强度的变化研究三体耦合摆运动规律.实验结果清晰地显示拍现象以及能量在三摆中的传播过程.通过改变四种不同的初始条件,发现耦合摆呈现不同的振动模式.随着耦合长度增加,中间摆拍周期单调减小.利用Maple软件得到三体耦合摆解析解,并将数值计算结果与实验数据进行对比,理论与实验结果基本一致.所搭建的三体耦合摆实验装置简单,非常适合作为居家实验来开设.

基于Phyphox手机App,利用智能手机搭建了耦合摆实验装置.通过测量磁感应强度的变化从而间接测量摆的振幅的方法,研究耦合摆同相,反相运动与耦合强度,耦合点与旋转点距离等因素的关系;还对耦合摆简正振动的拍现象进行了分析.结果表明同相位摆动时,摆动周期与耦合点位置基本无关,反相位摆动时,摆动周期倒数平方与耦合点距离平方成线性关系.在简正振动条件下,可以非常清晰地观察到能量在两摆之间的转移.另外实验测得的拍周期与理论值相对误差为7.9％.

介绍了透明介质折射率的临界位置法测定实验的设计背景、目标、设计依据及测量方法.通过对不同水深条件下测量结果显著差异比较,引导学生分析原因,改进实验,减小误差.在探索不同因素对实验结果的影响及对实验的改进过程中,培养学生发现问题,分析问题,解决问题的能力及求真务实的品格.实验完成情况分析及信息反馈表明,实验设计获得了较好的效果,为实践课程中增设自主性实验项目提供了实践依据与参考.

本文基于Phyphox手机App,利用智能手机中的磁传感器(电子罗盘)研究磁性单摆运动.结果表明,不同最大摆角测量出来的磁感应强度随时间变化规律不同.只有最大摆角小于1.时,单摆才可看作简谐振动.不同最大摆角的磁感应强度随时间变化曲线可以用磁偶极子模型结合大角度单摆公式来描述.利用磁传感器测量的当地重力加速度为9.868m/s2,由于磁性摆空气阻尼较小.测得的实验误差仅为0.8％.

目前各个高校都在积极开展"课程思政"建设,本文就上海交通大学大学物理实验教学与管理融入"课程思政"的探索略谈一二.首先分析了开展"课程思政"过程中存在的问题及解决的办法;其次以"声速测量实验"为例,展示了这种"思政元素"不突出的实验教学中如何融入"课程思政"元素;最后展示了如何在教学管理环节中融入"育人"功能.只要有"思政意识",思政教育不但可以融入实验教学,也可以融入实验教学管理中.

为了让学生居家完成空气中声速的测量,基于手机Phyphox软件设计了"共鸣管测声速"实验.本实验根据共鸣管的原理,利用手机Phyphox软件测量一端封闭,一端开口的奶茶管发出共鸣音时的基频,理论上声速大小是基频与空气柱长度乘积的4倍,但实际上有效空气柱长度是实际空气柱长度加上"管口校正量".通过公式变形,得出实际空气柱长度与基频的倒数成正比例的关系公式,采用线性拟合数据直接得出声速,从而巧妙避免了"管口校正量"的干扰,同时理论上也给出了一种得到"管口校正量"的方法,这是本实验的创新点.实验以内直径为12.0mm的奶茶管进行测量数据,通过线性拟合得到声速值,并进一步讨论了线性拟合得出的截距的物理意义和含义.

以改善大学物理实验课堂教学效果为出发点,以光学类物理实验为切入点,从课堂教学的不同环节,探讨了实验课堂存在的问题并针对性地给出了对应解决方案与措施,演示设备的研发结果有望推广至其他有教学演示需求的教学实践,所有工作为大学物理课程的全面优化提供了思路,切实促进了学校关于提升本科教学质量,提高学生实践创新能力的教学目标的实现.

在教学中适当采用探究式教学法,引导学生进行声速拓展实验的开展;对学生进行问卷调查,收集数据,分析教学效果,并提出今后教学改进的方向.

将一面贴有透明手机保护膜的光学玻璃片作为洛埃镜,激光经扩束镜形成点光源,先掠射入无膜和有膜表面,通过干涉条纹间距测量,得到激光波长和手机保护膜厚度.波长和膜厚测量结果相对误差分别为0.82％和2.7％.文章给出了测量原理、实验步骤以及数据处理结果.相对于其他透明薄膜厚度测量方法,利用洛埃镜法测量透明薄膜厚度原理简单、设备要求不高、快捷、实用性较强.文章还通过误差分析提出减少激光波长实验误差的方法是测量实虚光源间距时,光源与屏的距离应稍大于4倍透镜焦距,而测量干涉条纹间距时,光源与屏距离越大越好.在进行膜厚测量时光源与屏距离不能太大,点光源应尽量靠近膜表面.

第35届全国中学生物理竞赛决赛实验试题电学第一部分要求考生利用示波器和信号源判断黑盒子中的电路结构.标准答案只要求给出实验结论,并未指出具体测量方案.以下给出了一种详细的分析方法.

The experimental contents, test questions analysis and competition results analysis of the final test questions of the 35th Chinese Physics Olympiad Competition for middle school students were introduced.The 1st question was to measure the Young modulus and the refractive index of optical glass material, which could be divided into three parts:measuring the wavelength of semiconductor laser using Lowell method, measuring the Young modulus of optical glass strip using single slit diffraction method, and measuring the refractive index of thick optical glass sheet.The 2nd question was an electricity black box, students should judge the structure and properties of the components, and measure the vacuum permittivity and the relative permittivity of the given medium by the circuit of the black box and the permittivity measuring instrument.The design of the test questions was strong, and the grades were well differentiated.It was suggested that students should pay attention to the use of basic experimental instruments, the experimental skills, and the flexible application of basic physics principles.

介绍了周期幅值法测量地磁场的实验方法,指出了原实验设备存在的问题,同时提出了实验设备的改造方案,并详细介绍了如何软选取件模块.该工作降低了实验教学的维护成本,节约了因等待维护耗费的大量时间,保证了实验教学的顺利进行.

Exchange bias in the bilayer of half-metallic La0.7Sr0.3MnO3 and multiferroic BiFeO3 has been applied for the electric field control of magnetization, which is strongly limited by the much low blocking temperature of about 100 K (Phys. Rev. Lett. 105, 027201 (2010)). One possible solution is to strengthen the interfacial exchange coupling, thus another half-metallic oxide Sr2FeMoO6 is selected. Tetragonal-like BiFeO3 has been successfully fabricated on (0 0 1) SrTiO3 substrate using Sr2FeMoO6 as buffer layer. By replacing the exchange coupling between Fe and Mn ions in BiFeO3/La0.7Sr0.3MnO3 bilayer, stronger exchange couplings between Fe and Fe ions are established at the interface, and the blocking temperature has been significantly increased to 160 K. A second blocking temperature at 110 K due to the exchange coupling between Fe and Mo ions is also observed. Detailed magnetization measurements confirm the conventional mechanism of exchange coupling between ferromagnetic and antiferromagnetic layers and exclude the contribution from surface spin glass. Furthermore, BiFeO3 still retains excellent ferroelectric properties with Sr2FeMoO6 acting as ferromagnetic conducting electrode, which may have important applications in multiferroic spintronics devices.

通过对国外一流大学物理实验课程教学体系包括课程内容、教学方式和考核标准的调研,建立和物理理论课程讲授（授课对象以工科学生为主）相匹配的一整套可行的适应于工科创新拔尖人才培养的物理实验教学模式,包括项目设置、项目内容改革、考核方案、教学效果评价等.使得在工科同学理论课程知识点的学习中,物理实验能大大加深他们对物理概念的理解和掌握,同时物理实验将会增添他们学习物理理论的兴趣和学习效果.

3D printing is one of hotspots in scientific research and commercial area due to that any products with complex shapes can be rapidly and accurately manufactured. In medical domain,3D printing is used to fabricate medical model,bone,organ and cell. Nowadays three dimension pictures can be achieved with using Computed Tomography(CT)via professional software. However,it is difficult to simulate operation. In this paper we developed a method to prepare transparent vein models using 3D printing. The method was based on patients' CT slice graphs,and a 3D point cloud model and 3D virtual model were firstly designed by software such as MATLAB and CAD,and then two kinds of vein models in different precision degrees were successfully fabricated by 3D printer. The vein models can clearly display the detailed structure of subclavian vein,internal jugular vein and brachiocephalic vein,and would help to simulate operation and promote the method of subclavian vein catheterization. Besides,the method can be easily employed to make other vein model.

利用恒力矩转动法测量了自制的不锈钢矩形薄板状样品的转动惯量.沿长、宽,和垂直于板面3个方向的转动惯量分别是7.70×10-4kg·m2,3.23×10-3 kg· m-2和3.97×10-3 kg· m2.沿长、宽方向的转动惯量之和基本等于垂直于板面方向的转动惯量,相对偏差仅为0.84％,验证了刚体转动惯量正交轴定理.分析了由薄板厚度对长、宽方向的转动惯量贡献不超过5‰,在实验中无须考虑厚度的影响.测量结果表明:固定螺丝、定位销对测量结果影响不大.此外还分析了空气阻尼、塔轮半径和砝码质量等因素对实验结果的影响.

目的 研究磁场对锁骨下静脉穿刺置管术中导丝的作用原理,降低异位率.方法 搭建静脉置管的磁场模型.采用磁场引导法避免导丝异位,即借助钕铁硼磁铁对导丝的吸引力引导导丝走向.研究磁场作用下不同静脉角、导丝顶端不同的钩型及朝向对穿刺成功率的影响.结果 距静脉外侧46 mm处放置的磁铁,静脉角≥110°时,提高了穿刺时导丝“J”形钩朝向头臂静脉方向的成功率;对于导丝弯钩朝向胸前,静脉角＜110°时,穿刺成功率有所提高;对于导丝弯钩朝向背部,在所有静脉角情况下均无效果;对于导丝弯钩朝向颈内静脉方向,有些静脉角情况下成功率有一定提高.磁铁有效放置范围在一短边紧邻静脉汇合点,另外两长边分别位于头臂静脉两侧约40 mm的80 mm×90 mm矩形区域.结论 经锁骨下静脉进行穿刺置管时,磁场的存在能有效提高穿刺成功率.

LED's lighting was controlled by adjustable constant current source.The LED's spectra were measured by multichannel spectrometer.The peak wavelength shift of colored LED induced by the normal working current was obtained,and the corresponding variation of the chrominance was calculated.