pHS-3型数字式酸度计维修5例

介绍pHS-3型数字式酸度计常见的故障及故障排除方法。     

便携式pH计、电导仪、分光光度计检定PC机软件设计

提出便携式pH计、电导仪、分光光度计检定PC机软件的总体设计思路。介绍了该软件中pH计、电导仪、分光光度计3个PC机软件子系统,其中详细介绍了电导仪PC机软件子系统中的11个主要模块的功能及技术特点.     

时差法超声流量计低功耗设计方法的研究

针对时差法超声流量计系统的功耗问题,设计使用MSP430F449单片机为系统核心,硬件上采用多个独立电源为系统的不同模块供电,实现对相关模块的独立控制;软件上通过对单片机内部寄存器的合理设置,实现系统对时钟频率、时间计量以及LCD、按键等模块的精确控制.     

Rapid determination of iron oxide content in magnetically modified particulate materials

Magnetically responsive composite materials have been used in interesting applications in various areas of bioscience, biotechnology, and environmental technology. In this work, a simple method to determine the amount of magnetic iron oxide nano- and microparticles attached to magnetically-modified particulate diamagnetic materials has been developed using a commercially available magnetic permeability meter. The procedure is fast and enables dry particulate magnetically modified materials to be analysed without any modification or pretreatment. We show that the magnetic permeability can be measured for materials containing up to 20% magnetic iron oxide. The magnetic permeability measurements are highly reproducible.     

获得高精度频率差的关键技术

在利用LC振荡电路的参数变化而引起振荡频率的变化的特性进行的多种应用测量实验中,测量结果的精度都依赖于频率差Δf=f-f0.但当电路校准后进入测量状态时,电路参数会发生改变,使初始频率f0不复存在.如何在进入测量状态后保持初始频率f0以及精确提取频率差Δf,是提高测量精度的关键.为此提出一种采用锁相环自锁定技术和频率差计的方法,可以取得较好的效果.     

纳米脂质体放大血糖仪信号用于蓖麻毒素的即时检测

蓖麻毒素是已知的最致命的毒素之一,可作为一种生物武器并造成潜在的环境和食品污染.常用的蓖麻毒素检测方法存在耗时长、需要复杂且专业的实验室操作等缺点.为了克服该缺点,实现简单、快速、灵敏的蓖麻毒素非实验室检测,该文提出了一种利用负载有淀粉葡萄糖苷酶的纳米脂质体(ALN)放大血糖仪信号实现蓖麻毒素B 链(RTB)即时检测的...     

Dynamics of liposomes in the fluid phase

We review the currently available material on the morphology and dynamics of phospholipids assembled into liposomes. Key information obtained from neutron scattering, nuclear magnetic resonance (NMR), and other techniques plays a crucial role in understanding the vital role of lipids in sustaining life in living organisms. We concentrate on the dynamics in the biologically important fluid phase in the time range from picoseconds to seconds, which includes a discussion of the center of mass diffusion of liposomes, membrane fluctuations; and lateral, rotational, and flip-flop motions of the lipids. We emphasize on the sensitivity of the dynamics on interactions with a variety of biologically relevant molecules such as cholesterol. By a comparison of data from literature, we witness a good agreement of the results from different techniques and studies.     

Voltammetric applications of hydrogen bonding and proton-coupled electron transfer reactions of organic molecules

Proton-coupled electron transfer and hydrogen bonding reactions are ubiquitous requisites for the occurrence of many natural processes and man-made applications. These reactions either involve the direct transfer of charge (in the form of protons and electrons) or contain sufficient electrostatic characteristics to be affected by the application of a potential. Hence, they can be analyzed or initiated by voltammetry, which is itself highly sensitive yet tolerant to a variety of interferences and so can be used under various experimental conditions. The purpose of this review is to highlight the potential of this electrochemical technique for studying important processes such as those involved in energy storage, CO₂ reduction, and sensor applications.     

纳米铁酸锌的水热合成

利用水热合成法制备纳米铁酸锌粉体，使用XRD、TEM研究了铁酸锌晶相组成、粒度大小和形貌，并对影响合成工艺的因素如反应前驱物的pH、反应温度、反应时间与产物的关系进行系统的考察研究。结果表明：前驱物的最佳pH为11－12，反应温度为448K，反应时间为360min，可制得结晶良好、纯度高、分散性好、粒度为纳米级的ZnFe2O4粉体。     

不均匀光照和重影的仪表图像二值化方法

高压计量仪表识别过程中需要对图像进行二值化操作,然而拍摄的仪表图像多出现光照不均和数字重影现象,导致传统方法对仪表图像的二值化困难。为此,提出一种基于卷积神经网络的二值化方法,用于对复杂光照下含数字重影的仪表图像二值化。该网络使用的数据集为真实环境下的仪表图像,首先对输入的图像进行降维提取特征,然后反卷积重建图像前景,最后输出二值图。将设计的网络与传统的二值化方法进行对比,实验结果表明,经该网络训练得到的二值图数字清晰且无重影,且测得的交并比（IoU）平均值为95.12,与样本标签图像的相似度最高,能够有效解决复杂环境下有重影的仪表图像二值化问题。