用电子秤测液体的表面张力系数

介绍了用电子秤测液体表面张力系数的原理和方法。     

电子秤的制作与校准实验

介绍了压力传感器的工作原理,以及用压力传感器制作电子秤并校准的实验过程。     

电子秤的结构和工作原理

日常生活中常用电子秤来秤量物体的质量，它以较高的精确度得到大家的信赖．下面就电子秤的结构和原理作些介绍．电子秤主要是由电桥电路及电阻应变式传感器组成，在现代测量技术中常常需要将非电量利用传感器转变成电量后再进行测量．电阻应变式传感器是一种利用金属电阻应变片将应变转换为电阻变化的传感器．它一般分为金属丝式和箔式两类，这里分别介绍其结构和工作原理，其结构如图1、2所示．     

巧用电子秤测量静电力及真空电容率

介绍了用电子秤测量平行板电容器两极板间的静电力和真空电容率的原理和方法。     

简易电子天平的制作

在人教版教材《选修3—2》第六章第二节中介绍了一些常见传感器,其中就有电子秤．但是这里提到的主要原理是压力使得应变片发生形变,从而引起一个电压差,由于应变片的形变量与压力是一个比较复杂的对应关系,学生只能定性地分析其传感原理．笔者一直在思考能不能制作一个传感器,能够定量地研究其传感原理,从而凸显知识的应用性．于是想到了传统的电磁力平衡原理的电子天平,它用到的大多数原理都属于中学物理的内容．     

巧用电子秤测量浮力

根据力的相互性作用原理,经理论推理得到直接称出物体的重力大小、称物体受到液体的浮力大小的方法.运用电子秤的功能键,对阿基米德原理和影响浮力的因素等实验进行了探究,与使用弹簧测力计类探究浮力实验相比较,实验现象更明显,状态更稳定,步骤更简洁,数据读取更直接.     

基于样条函数的高精度电子秤设计

通过对已有的各种电子秤的分析,从硬件和软件两个方面,提出提高电子秤测量精度的方法。硬件上采用专门为高精度设计的24位A/D转换芯片HX711,该芯片具有分辨率高、线性度好、功耗低等优点,特别适合低频高精度的应用场合。软件上引入样条函数,用光滑的参数曲线段逼近折线多边形,实现对非线性称重关系特性曲线的拟合和自校准,达到减小误差的目的。最后通过实验证明了该方法的有效性。     

光学码盘简易制造法

<正> 近几年来,光学码盘在各种大型电子秤中的应用是比较广泛的。目前国内除长春光机所等极少几个单位采用光电投影法能制造光学码盘外,绝大部分光学仪器厂尚无制备手段。     

传感器系列实验的设计

从实验内容和实验仪器两方面对SET-998型综合传感器实验仪进行改革.设计了应变片电子秤、热敏温度计、气敏传感器、热释电传感器和气压传感器实验.在实验内容方面,学生通过系列实验除了能掌握传感器的基本原理、验证物理效应外,还能了解传感器功能的应用演示实验;在实验仪器方面,将集成化的仪器设备转化为开放式的实验平台,便于学生直接观察实验现象和掌握实验原理.将传感器理论教学和实践应用相结合,更让学生直观深刻地了解传感器的原理、功能与特性,也加强了学生创新和实践能力的培养.通过对传感器实验的有益改革,使其更有效地为实验教学服务.     

自制"磁感应强度的测量"原理演示装置

介绍了自制“磁感应强度的测量”原理的演示装置,演示了安培力的存在和测量的原理.     

空间光学遥感器大功率控制电箱的热设计

根据空间应用电子设备的热控要求,对空间光学遥感器的控制电箱进行了热控设计。首先,总结了空间电子设备的热设计原则。针对空间光学遥感器控制电箱介绍了相应的热设计流程,对典型的大功率器件进行了温差推算,并说明了电箱的各电路板和大功率元器件的热设计方案。最后,通过热分析和热试验手段对热控电箱的热控方案进行了验证。试验结果表明：控制电箱的整机稳态工况热平衡温度小于30℃,各元器件的最高壳温在54.2℃以内。结果验证了该设计方案完全满足设计指标要求。     

富勒稀C36的电子结构与电子传导

本文采用基于第一性原理的密度泛函理论和非平衡格林函数方法研究了C36分子的电子结构和电子传导特性．本文以Au(1,1,1)为电极分别建立了4个电子输运模型,分别计算了他们的电子传输概率、伏安曲线,同时分析了产生这些分子器件电子输运性质的原因．研究计算结果发现, C36的电子输运主要发生在分子壳上,当左、右电极分别连接在第6号和第35号碳原子两端时,C36的电子输运性能最好,伏安曲线显示该分子具有半导体特性．     

Quantum Homodyne Detection Based on Polarization Diversity Technique

A polarization diversity receiver scheme is presented for improving efficiency of balance homodyne detection. The proposed scheme may mitigate polarization fluctuation between signal and local oscillator field. With simple linear optical component and electronic processing circuit, the noise caused by differential phase and polarization mode between signed and local oscillators may be significantly decreased. To track the polarization fluctuation, a novel algorithm based on polarization diversity receiver which can achieve better performance in terms of linear quantum optics principle is proposed.     

Growth,spectral properties,and laser demonstration of Nd:GYSO crystal

A generic nonlocal nonlinear optical system with a diffusive type of nonlinearity is investigated analytically, using the homogeneous balance principle and the F-expansion technique. Exact traveling wave and soliton solutions are discovered. Numerical simulation of their propagation and interaction properties is carried out. Our results demonstrate that the nonlocal solitary waves can be manipulated and controlled by changing the nonlocality parameter.     

Exciton optoelectronic transistor

We demonstrate experimental proof of principle for an optoelectronic transistor based on the modulation of exciton flux via gate voltage. The exciton optoelectronic transistor (EXOT) implements electronic operation on photons by using excitons as intermediate media; the intensity of light emitted at the optical output is proportional to the intensity of light at the optical input and is controlled electronically by the gate. We demonstrate a contrast ratio of 30 between an on state and an off state of the EXOT and its operation at speeds greater than 1 GHz. Our studies also demonstrate high-speed control of both the flux and the potential energy of excitons on a time scale much shorter than the exciton lifetime.     

Role of electronic versus atomic relaxations in Stokes shifts at defects in solids

Redshifts of luminescence relative to optical absorption bands (Stokes shifts) of molecules and of defects in solids are universally attributed to slow atomic relaxations on the grounds that electronic transitions are fast (Franck-Condon principle). Here we report a novel phenomenon that can occur only in the solid state: Stokes shifts caused by slow electronic relaxations. We demonstrate that the phenomenon occurs in the nonbridging oxygen defect in amorphous SiO2. We predict that another defect (OH group), which can exist in either crystalline or amorphous SiO2, has a similar Stokes shift, but it arises from a mix of lattice and electronic relaxations with manifest differences in the two phases.     

彩色计算全息颜色匹配的研究

基于色度学原理,研究了彩色计算全息颜色的匹配问题,给出了电子显示色系下颜色量与计算全息物光波振幅之间的等色传递关系.首先,讨论了电子显示色系和彩色计算全息色系之间的颜色传递问题,并且给出了这两个色系下颜色量的转换方法.其次,以彩色全息再现像与原始计算目标颜色一致为目的,分析了彩色计算全息色系下的颜色量和与其对应物光波振幅的关系,并得出了颜色量和物光波振幅间应满足的一般方程.最后,本文选取PAL制式彩色显示色系下的彩色目标为全息图计算物体进行了彩色全息显示实验,结果表明本文所述彩色计算全息颜色匹配方法是有效的.本文的研究工作将为彩色计算全息显示的实用化奠定一定的理论基础和技术依据.     

动态图像序列运动矢量估计算法的研究

运动估计在电子稳像系统中起重要的作用。介绍和比较了几种运动矢量估计算法。为了提高电子稳像系统的性能,提出了在设计电子稳像系统时选取运动矢量估计算法的原则。通过比较应用在航摄图像序列中的投影算法和匹配算法的性能,说明了如何应用运动矢量估计算法的原则。仿真结果表明,根据此原则选取的运动矢量估计算法应用于电子稳像系统是可行的。     

标志位频谱感知方法研究

文章提出了一种新的标志位频谱感知方法,主要由数据采集和频谱感知两部分组成.前者主要基于标准的压缩感知技术,研究了一种标志位数据采集方法,仅保留测量数据的标志位信息,从而减少了测量数据的存储量.后者基于一致恢复原理和共轭梯度算法来构造频谱感知算法.仿真结果表明,标志位频谱感知方法可以在降低数据采集量及存储量的同时完美获取原始信号的频谱信息.该方法可以应用于无线通信、电子对抗、智能吸波结构以及感知无线电的前端频谱测量设计阶段中. 关键词： 频谱感知 标志位压缩感知 智能吸波结构     

Calculation of radiative properties of nonequilibrium hydrogen plasma

A computer program called NEQRAP is described that calculates the radiative properties of nonequilibrium ionized hydrogen. From the given electron temperature, electron density, and atom density values (which do not necessarily satisfy the equilibrium relationship) and intensities of incident radiation, the non-Boltzmann populations of electronic states are computed by solving the equation of quasi-steady- state population distribution. Emission and absorption coefficients are determined as functions of wavelength by invoking the principle of detailed balance between the upper and lower states of each radiative transition. Radiative transport through the medium is computed assuming a one-dimensional uniform slab. The rate of ionic reaction is also computed. When used on a sample case, the program shows that there is a large difference between the calculated intensities of radiation emitted by a bulk of equilibrium and nonequilibrium hydrogen. Accuracy of the program is estimated to be better than 10%.