传感器技术应用于物理实验的优势

随着信息技术的发展，传感器技术在生产和生活中扮演着越来越重要的角色．早在几年前，我国就把传感器技术列入“八五”、“九五”的重点研究项目之中．2003年3月国家教育部颁布的《全日制高级中学物理课程标准》紧扣时代脉搏，将传感器的知识也纳入高中物理教学之中，并首次阐述了“数据采集器应用于物理实验”的思想，这些都充分体现了时代的要求．基于这种背景，本文将就中学物理实验中应用传感器技术的好处作一下简单分析，期待着这一新的知识、技术能早日并广泛地应用于物理教学，尤其是物理实验教学之中，给传统的物理实验教学注入新的活力。     

在物理实验中引入通用数据采集器搭建自组实验平台的研究

文章以集成霍尔传感器特性研究实验为例,介绍在物理实验教学中引入通用数据采集器搭建自组实验平台的具体应用．实验中所用设备都为传统通用设备,实验现象直接由计算机显示,实验数据导出为Excel文档,利于数据处理、分析．既保留了传统仪器的所有功能,又增加了现代测量手段的自动采集、显示、分析功能．培养学生把多种物理知识交叉使用来解决实际问题．     

用废旧钠光灯管观察钠的吸收光谱

用废旧钠光灯管观察钠的吸收光谱金昌祚，周延怀（南京师范大学物理系）钠的吸收光谱实验是高中物理光谱教学中的一个基本实验．用“钠的吸收光谱实验器”（’）来演示，实验现象稳定可靠，且不污染环境，颇受广大教师的欢迎．然而“钠的吸收光谱实验器”中的“钠泡”是消...     

8098单片机在物理实验仪器中的应用介绍

介绍采用8098单片机设计智能化物理实验仪器的方法，对被测物理量进行数据采集和处理，结果由显示器数字显示和打印机打印输出．     

利用激光器测量三棱镜折射率

在物理实验中，激光器的应用是很多的，利用激光器测量三棱镜玻璃折射率的方法与用分光计测量三棱镜折射率方法相比，操作变得简单．在我们的实验操作考试中也曾出了此题．具体方法如下．如图1，调整激光器，使激光垂直照射在接收屏M上，记下O点位置，将三棱镜放置在平台上，让     

加速器驱动次临界系统注入器Ⅱ数据归档系统

针对加速器驱动次临界系统(ADS)中强流质子直线加速器，即ADS注入器Ⅱ，设计了数据归档系统。该系统能实时采集加速器运行时各设备的状态信息和通过中央控制室远程发出的指令信息，为加速器调束人员和系统维护人员提供最真实的参考信息，方便故障排查和后期数据分析。系统基于以太网，运行于实验物理与工业控制系统EPICS(Experimental Physics and Industrial Control System)架构上，和设备的数据交换采用CA协议(Channel Access Protocol)。采用Keepalived和MySQL实现高可用数据库服务，采用ArchiveEngine作为数据采集工具，采用DataBrower进行数据查询和曲线绘制。对归档数据库进行了查询优化，并自行开发了数据库服务器和归档引擎的运行状态监控程序，从而保证了整个数据归档系统的稳定运行。通过现场运行，系统可满足ADS注入器Ⅱ运行要求，维护方便，只需将相应PV(Process Variable)信息添加到数据库channel表格中即可实现数据采集。     

多功能波动演示器的研制及应用

1前言演示仪器是物理形象化教学不可缺少的物质基础．我们在物理教学形象化的研究与实践中研制了“多功能波动演示器”，本文仅对该演示仪器的研制及其应用作以介绍．2仪器的构造及特征多功能波动演示器的构造如图a所示．该仪器采用以弹簧联接起来的数根等间隔分布的平衡式金属杆作为波媒质体系，每根金属杆可绕自身的中心对称轴转动，中心对称轴由上下两横梁固定，下横梁固定在仪器支架上，每根金瞩杆的中心对称轴可随上横梁在校、竖二维方向上同步转动。当把上横梁拉起时，全同杆的中心对称轴竖起来，金属杆可在水平面上转动（振动）。可…     

利用传感器研究电容器的充电和放电

DISLab新型数字化实验系统是由“传感器＋数据采集器＋实验软件包＋计算机”构成的．数字化实验系统是信息技术与传统实验课程整合的重要载体．基于传感器的计算机实时数据采集和基于计算机数据处理软件的计算机建模和图像分析等技术是开展现代化中学物理探究教学的两大技术支撑,     

数据采集器在大学物理设计性实验中应用的探讨

为了更好地开展大学物理设计性实验教学,可以将数据采集器作为现代科技中的微机实时测量技术引入到实验教学中. 本文阐述了数据采集器的优势,并根据设计性实验分类,进一步探讨数据采集器的应用,并通过具体示例详细说明.     

自感现象的定量研究

采用美国PASCO公司生产的“科学工作室”数据采集器系统设计自感现象实验,既能定量验证理论结论,又能大大提高实验的质量．     

两个探究性实验活动的设计

基于科学探究性学习的理念，为高中生设计了“静电现象”和“光电效应”两个科学探究性的实验活动，对中学物理课堂教学如何实施探究性学习做了简要论述。     

激光敌我识别

本文论述了协同式激光敌我识别的工作原理和回波信号调制方法。在这一系统中,激光发射和接收机安装在稳象转台上;激光探测和反射棱镜组是复眼式全方位探测系统,当它接收到询问方(友方)发来的询问码时,控制反射棱镜前方的调制器,由反射棱镜返回调制的识别码,再由询问方(友方)接收加以判别。本系统适用于空对空、空对地、地对地及海上运动目标间的敌我识别。     

自适应模糊控制器在光学透镜抛光中的应用

根据抛光机压力、摆幅和摆角对光学透镜磨抛加工质量的影响程度不同，应用模糊逻辑系统表格查询学习算法，构建了一种二维自适应模糊控制器，为抛光工艺的深入探讨奠定了基础。     

含油废水紫外荧光信息管理系统的开发

针对含油废水的荧光信息管理,基于管理信息系统(MIS)系统,根据面向对象的程序设计要求,分析了含油废水紫外荧光信息管理系统的建设目标、体系结构、数据组织、模块功能等,使用Visual FoxPro开发了用于典型行业的含油废水紫外荧光信息管理系统,实现了对样本进行处理时信息的输入、查询、删除、对比以及数据输出等功能.使得...     

白光干涉双环传感网络理论与实验研究

构造了一种基于双环形拓扑结构的白光干涉光纤传感网络．可用于智能结构中准分布应变或温度的测量。光纤传感网络基于空分多路复用技术(SDM)．目的是增强带载能力．降低单点传感器的测量成本,并借助丁双端口问询技术．增强传感网络的抗毁坏能力。分析了环形网络结构的低相干多路复用原理．根据空分复用的光程匹配条件．推导了传感器干涉信号的强度特性。实验中对连接9个传感器的双环传感网络特征及其抗损坏特性进行了验证．并对实验结果进行了分析和讨论。     

The unbearable heaviness of colloids: facts, surprises, and puzzles in sedimentation

Sedimentation has played a key role in the development of colloid science. In fact, it is because of the celebrated experiments by Perrin, yielding a concrete demonstration of molecular reality and giving strong support to Einstein's theory of Brownian motion, that colloids enter the realm of basic physics. Subsequent investigations have shown that a lot more can be learnt both from sedimentation equilibrium and from particle settling dynamics. These advances, together with new experimental approaches, will be reviewed in this paper. Yet, we shall also show that inquiring about gravity settling is far from being a closed matter: for instance, the concept of buoyancy for a settling colloidal mixture is far from being obvious. Moreover, sedimentation holds novel surprises, such as colloidal inflations and settling disasters, showing that a simple external field like gravity may induce mind-boggling, and theoretically challenging effects.     

Full-field wrist pulse signal acquisition and analysis by 3D Digital Image Correlation

Pulse diagnosis is an essential part in four basic diagnostic methods (inspection, listening, inquiring and palpation) in traditional Chinese medicine, which depends on longtime training and rich experience, so computerized pulse acquisition has been proposed and studied to ensure the objectivity. To imitate the process that doctors using three fingertips with different pressures to feel fluctuations in certain areas containing three acupoints, we established a five dimensional pulse signal acquisition system adopting a non-contacting optical metrology method, 3D digital image correlation, to record the full-field displacements of skin fluctuations under different pressures. The system realizes real-time full-field vibration mode observation with 10 FPS. The maximum sample frequency is 472 Hz for detailed post-processing. After acquisition, the signals are analyzed according to the amplitude, pressure, and pulse wave velocity. The proposed system provides a novel optical approach for digitalizing pulse diagnosis and massive pulse signal data acquisition for various types of patients.     

New method of applying conformal group to quantum fields

Most of previous work on applying the conformal group to quantum fields has emphasized its invariant aspects, whereas in this paper we find that the conformal group can give us running quantum fields, with some constants, vertex and Green functions running, compatible with the scaling properties of renormalization group method(RGM). We start with the renormalization group equation(RGE), in which the differential operator happens to be a generator of the conformal group, named dilatation operator. In addition we link the operator/spatial representation and unitary/spinor representation of the conformal group by inquiring a conformal-invariant interaction vertex mimicking the similar process of Lorentz transformation applied to Dirac equation. By this kind of application,we find out that quite a few interaction vertices are separately invariant under certain transformations(generators) of the conformal group. The significance of these transformations and vertices is explained. Using a particular generator of the conformal group, we suggest a new equation analogous to RGE which may lead a system to evolve from asymptotic regime to nonperturbative regime, in contrast to the effect of the conventional RGE from nonperturbative regime to asymptotic regime.     

The Impact of Voice Disorders Among Teachers: Vocal Complaints, Treatment-Seeking Behavior, Knowledge of Vocal Care, and Voice-Related Absenteeism

Objectives

Teachers are at increased risk for developing voice disorders. Occupational risk factors have been extensively examined; however, little attention has been paid to the consequences of the vocal complaints. The objective of this study was to investigate the knowledge that teachers have about vocal care, treatment-seeking behavior, and voice-related absenteeism.

Methods

The study group comprised 994 teachers and 290 controls whose jobs did not involve vocal effort. All participants completed a questionnaire inquiring about vocal complaints, treatment-seeking behavior, voice-related absenteeism, and knowledge about vocal care. Comparisons were made between teachers with and without vocal complaints and with the control group.

Results

Teachers reported significantly more voice problems than the control population (51.2% vs 27.4%) (χ² = 50.45, df = 1, P < 0.001). Female teachers reported significantly higher levels of voice disorders than their male colleagues (38% vs 13.2%, χ² = 22.34, df = 1, P < 0.001). Teachers (25.4%) sought medical care and eventually 20.6% had missed at least 1 day of work because of voice problems. Female teachers were significantly more likely to seek medical help (χ² = 7.24, df = 1, P = 0.007) and to stay at home (χ² = 7.10, df = 1, P = 0.008) in comparison with their male colleagues. Only 13.5% of all teachers received information during their education.

Conclusions

Voice disorders have an impact on teachers' personal and professional life and imply a major financial burden for society. A substantial number of teachers needed medical help and was obligated to stay at home because of voice problems. This study strongly recommends the implementation of vocal education during the training of teacher students to prepare the vocal professional user.     

Brain-derived neurotrophic factor modulation of Kv1.3 channel is disregulated by adaptor proteins Grb10 and nShc

Background

Developmental dyslexia is a specific cognitive disorder in reading acquisition that has genetic and neurological origins. Despite histological evidence for brain differences in dyslexia, we recently demonstrated that in large cohort of subjects, no differences between control and dyslexic readers can be found at the macroscopic level (MRI voxel), because of large variances in brain local volumes. In the present study, we aimed at finding brain areas that most discriminate dyslexic from control normal readers despite the large variance across subjects. After segmenting brain grey matter, normalizing brain size and shape and modulating the voxels' content, normal readers' brains were used to build a 'typical' brain via bootstrapped confidence intervals. Each dyslexic reader's brain was then classified independently at each voxel as being within or outside the normal range. We used this simple strategy to build a brain map showing regional percentages of differences between groups. The significance of this map was then assessed using a randomization technique.

Results

The right cerebellar declive and the right lentiform nucleus were the two areas that significantly differed the most between groups with 100% of the dyslexic subjects (N = 38) falling outside of the control group (N = 39) 95% confidence interval boundaries. The clinical relevance of this result was assessed by inquiring cognitive brain-based differences among dyslexic brain subgroups in comparison to normal readers' performances. The strongest difference between dyslexic subgroups was observed between subjects with lower cerebellar declive (LCD) grey matter volumes than controls and subjects with higher cerebellar declive (HCD) grey matter volumes than controls. Dyslexic subjects with LCD volumes performed worse than subjects with HCD volumes in phonologically and lexicon related tasks. Furthermore, cerebellar and lentiform grey matter volumes interacted in dyslexic subjects, so that lower and higher lentiform grey matter volumes compared to controls differently modulated the phonological and lexical performances. Best performances (observed in controls) corresponded to an optimal value of grey matter and they dropped for higher or lower volumes.

Conclusion

These results provide evidence for the existence of various subtypes of dyslexia characterized by different brain phenotypes. In addition, behavioural analyses suggest that these brain phenotypes relate to different deficits of automatization of language-based processes such as grapheme/phoneme correspondence and/or rapid access to lexicon entries.