基于GSM和LabVIEW的温室大棚远程监控系统

为了实现智慧农业,设计了基于GSM和LabVIEW的温室大棚远程监控系统,系统以MSP430F149为处理器,通过放大电路及滤波电路对土壤湿度传感器、土壤PH值等微弱信号进行放大、滤波,实现对可移动天窗、遮阳系统、保温、喷滴灌系统进行实时自动调节、检测,创造植物生长的最佳环境指标,同时将测试结果利用GSM模块传到农户手机上,并通过串口实时远程传输给LabVIEW上位机显示。系统运行稳定,可靠性好、扩展性好,人机界面良好,具有广泛的市场应用前景。     

基于GSM的远程空气质量监测系统设计

由于人们环保意识的提高,越来越多的场合期望提供实时的空气质量监测数据.对于这类应用场景,基于无线网络的远端监测站点与数据处理中心的系统架构已经十分成熟.给出了基于信号覆盖率最高的GSM中最可靠的短信服务作为数据传输媒介的远程空气质量监测系统的设计方案.方案中的硬件选型以性能、尺寸和功耗同时作为标准,力求使得系统具有更佳的工程使用价值,方便日后推广.同时监测中心除提供基本的监测软件外,还提供了开发库,便于用户利用监测站点的数据进行二次开发.通过对原型机的测试,该设计能够在无外部电源供电的情况下连续72 h对空气质量进行监测,具有实用推广价值.     

Electrospun nanofibers versus drop casting films for designing an electronic tongue: comparison of performance for monitoring geosmin and 2‐methylisoborneol in water samples

Geosmin (GSM) and 2‐Methylisoborneol (MIB) are substances commonly found in river water and arise due to eutrophication process. Such contaminants affect the organoleptic properties of water, hampering its consumption, and use in beverage industries. As the human perception threshold for these compounds is low, the devices aimed at their detection must be sensitive enough to detect concentrations as low as a few nanogram per liter in order to guarantee the water quality parameters. Due to the experimental simplicity, fast analysis, portability, and capability for on‐site analysis, the use of electronic tongues and electronic noses employing hybrid and composite materials are potential for GSM and MIB determination. In this work, two distinct electronic tongues were applied in the electrical determination of GSM and MIB in pure and river water. The difference between them consisted in the type of polymer processing used in the fabrication of sensing units. The thin films deposited onto gold IDEs were based on polyamide 6, polypirrole, and polyaniline, but fabricated by drop‐casting and electrospinning. The differences in the electronic tongue performances were correlated to the distinct morphologies of the sensitive layers. Both devices were able to discriminate pure water from solutions tainted with GSM and MIB in concentration as low as 25 ng L^?1, with high data correlation and a good reproducibility.     

Polarization changes in vector Gaussian-Schell-model beams propagating through a thin lens

Based on Wolf's general tensorial theory of coherence, in which the vector nature of electromagnetic fields is considered, the closed-form propagation equation of vector Gaussian-Schell-model (GSM) beams passing through a paraxial optical ABCD system is derived, which shows the general applicable advantage, and is used to study polarization changes of GSM beams in passage through a thin lens. It is found that polarization changes are dependent on the propagation distance, focal length of the lens, beam and coherence parameters and bandwidth of the source spectrum in general. A comparison with the previous results is also made.     

基于WiFi和GSM的无线监控系统设计与实现

针对无线监控的现实需求,设计了一种在STM32F4微处理器平台上的无线远程监控系统。该系统主要由传感器模块、主控模块、无线传输模块和监控终端模块四个部分组成,具有传感器驱动、自动报警和远程监控等功能。文中着重给出了系统的整体方案详细说明、各个模块的原理和性能参数、系统的软件设计等。经过调试与测试,系统不仅实现了预期的功能,而且具有良好的实际应用前景。     

高级氧化降解饮用水中嗅味物质土臭素和2-甲基异莰醇的研究进展

土嗅素(GSM)和2-甲基异莰醇(2-MIB)是受藻类污染的饮用水源中普遍存在的嗅味物质。常规工艺对GSM和2-MIB的去除能力十分有限,因嗅味问题引发的公众投诉时有发生,嗅味物质的有效去除已成为亟需解决的饮用水处理技术难题。本文梳理了水源中GSM和2-MIB的来源及存在形态,综述了高级氧化法降解GSM和2-MIB的研究进展,旨在为GSM和2-MIB的高效去除提供理论指导和技术支撑。     

HS-SPME–GC–MS法测定水中2-甲基异冰片及土臭素

采用顶空固相微萃取–气质联用(HS-SPME–GC–MS)的方法对地表水中2-甲基异冰片(2-MIB)和土臭素(GSM)进行分析测定。通过试验确定了HS-SPME的最佳萃取条件:萃取头为DVB/CAR/PDMS,萃取时间为30 min,萃取温度为70℃,NaCl的加入量为30%(质量分数),萃取纤维在GC上的解吸温度为250℃。用内标法进行定量,2-MIB,GSM的质量浓度在5~100 ng/L范围内与色谱峰面积呈良好的线性关系,线性相关系数(r2)分别为0.999 7,0.997 0,检出限分别为0.8,1.7 ng/L。采用该法对水样进行测定,2-MIB,GSM测定结果的相对标准偏差为2.6%~6.3%(n=6),加标回收率为92%~112%。该方法能简单、快速地测定水中痕量嗅味物质。     

Thermodynamic and structural analysis of the Pb–InSb system

Results of thermodynamic and structural analysis of the Pb–InSb system are presented in this paper. Thermodynamic investigations were performed experimentally by Oelsen’s calorimetric method and calculated by thermodynamic predicting according to Chou’s general solution model, while structural analysis of the alloys in Pb–In–Sb system was done by SEM–EDX and diffractometry.     

部分相干部分偏振电磁束通过光阑透镜的传输

基于广义斯托克斯参量,推导出了部分相干部分偏振高斯谢尔模型(GSM)电磁柬通过光阑透镜后交叉谱密度矩阵、光强、偏振度、偏振椭圆的方位角及椭偏角的解析表达式,并用以研究菲涅耳数、自相关和互相关长度以及束腰宽度对焦移和偏振特性的影响.对主要数值计算结果做了物理解释.