粮仓温度实时监测系统研究

粮食在仓储过程中,容易霉烂、变质,粮仓温度实时监测系统是针对大型粮库中粮食贮存的需要而设计的。文章的粮仓温度测控系统是由89C51单片机构成的对传感器进行采样的控制系统,实时显示温度系统对温度的控制合理、有效,在任何时候把粮仓的现场信息实时地传达到控制室,实现自动化、智能化。     

染整工艺温度的在线测控

染整工艺过程温度测控贯穿工艺的全过程,文章论述了温度测控必须解决采样点的合理性及检测方法的科学性;指出烘房因热源不一样而致使织物布身温度与烘房的气氛温度的相异;阐明了热辊、烘筒非接触测温的方案及传感器的应用机理;介绍了采用现场总线的智能温度变送器的应用。     

PLC在肉类行业腊肠生产工艺中的应用

介绍在腊肠生产中,依靠热风机通过风道使烘房内温度升高,并且形成烘房内均匀送风,通过可编程控制器的控制,接收温度传感器、湿度传感器、压力传感器检测的信号,调节热媒电磁阀、送风调节阀、回风调节阀、排风调节阀及排风机,使烘房内的温度、湿度、风压满足腊肠生产过程各个阶段的要求,实现了腊肠烘制自动化、标准化。     

基于Kriging插值算法的粮堆内部温度可视化研究

为了更直观地获得粮堆内部三维温度分布信息以及变化情况,本文对Kriging插值算法进行研究。建立了粮仓内部温度可视化插值模型,并将其运用到实验过程。经过采样点的数据插值,分别对1 000个数据点和27 000个数据点进行仿真可视化,并对27 000个数据点进行单切片专题图分析比较。在可视化程度相比较分析中,原始216个数据远远不能实现粮堆内部的温度可视化,在将温度插值分为27 000个点后再次进行可视化,便能直观清楚的反映粮仓粮堆内部温度信息。从而验证了Kriging插值算法在粮堆内部温度可视化中的有效性,通过采用Kriging插值算法对粮堆内部温度进行可视化研究有前瞻应用意义。     

温室环境微机监控管理系统设计

为满足作物生长需要,需调节温室内的温度、湿度光照及通风等条件。本文简单介绍了温室环境管理系统软、硬件的设计。     

速热新品

<正>格林姆斯即热新品GL5◎德国霍尔水流量传感器,精确恒温;◎"双核"可控硅控制电路,无极调温;◎滑动触摸感应技术,精准调节温度;     

太阳能智能调温变色百叶窗的设计

文章设计了一套基于太阳能发电的单片机智能调节室内温度湿度的变色百叶窗。利用太阳能电池板,结合ADS1115转换芯片以及STC89C52RC单片机、风速传感器以及温湿度传感器检测并发送数据信息,实现了具有能够主动调节室内温湿度以及控制室内进光量的智能百叶窗,解决了当前窗户被动式、灵活性差、功能单一的问题。     

基于多传感器数据融合的纸浆浓度自适应调节方法

纸浆浓度控制过程中,需要对即时温度、浆液状态、料口状态等数据进行实时综合分析,受到不同传感器模量之间的差量的影响,实际控制调节效果与预期调节指令之间误差较大。通过对问题的分析发现,减小误差的关键在于提升多传感器之间的适应度,因此基于多传感器数据融合算法与思路,通过对常规纸浆浓度控制参数优化、多传感器控制量的浓度指标深度优化、多传感器优化量自适应优化、数据融合输出,实现提升调节精度,改善多传感器数据融合适应度的效果。实验通过3种不同函数环境的测试,证明了提出方法能够应对不同函数变量,精度调节纸浆浓度,并且在多传感器数据融合过程中,实现函数级别的自适应阈值优化,保证实际应用过程中的效果稳定。     

采样时间点和温度对气袋法检测家具部件中挥发性有机物的影响

将家具部件样品放入气体采样袋中,间隔固定的时间（30 min）对袋内的挥发性有机物（VOCs）进行采样分析,并采用最小二乘法对各浓度值进行数学拟合形成斜率曲线,通过修正初始浓度值,改变采样时间点数量和背景温度,探究了其对样品VOCs释放速率和回归方程相关系数R2的影响。结果表明：对于VOCs释放较低的样品,修正初始浓度能取得更好的曲线拟合效果;在采样间隔时间不变的前体下,增加采样时间点的数量可以有效提升相关系数R2,从而更加真实地反应样品VOCs的释放状态;温度波动5℃会显著影响样品VOCs的释放速率,其中苯系物释放速率对温度上升的响应更加明显。在确定标准的试验方法时,应设置不少于5个采样时间点并将背景温度偏差范围控制在2℃以内,以确保最终测试结果的偏差满足相关国家标准的要求。     

捣固焦炉炉头温度的控制与调节

炉头温度是焦炉加热调节的温度指标之一,结合酒钢焦化厂5.5m捣固焦炉炉头温度的控制与调节,探索捣固焦炉炉头温度的控制与调节。     

基于无线传感器网络的人体体温监测系统

设计了一种基于无线传感器网络人体体温监测系统,系统由10-20个监测点和中心计算机组成无线监测网．各监测点红外温度传感器测量被检测人群的人体体温,通过无线模块将监测数据传送到中心计算机,中心计算机对被监测人群的人体体温数据进行分析、存储．运行试验结果表明,系统工作稳定、可靠．     

食品安全无菌抽样现状及操作规范研究

目的了解食品安全无菌抽样过程存在的问题,为规范无菌抽样工作流程提供参考依据。方法通过问卷调查、专家访谈、现场调研等方法对24家承担上海市食品药品监督管理局食品安全抽检任务的检验机构开展调查和分析,并通过模拟样品运送时间温度和开展实验室验证,确定合适的运输存储条件。结果部分检验机构存在抽样人员管理不到位、取样工具差异性较大、抽样记录不完整、样品运输时间和温度不符合要求等问题。结论建议加强抽样人员管理,提升抽样人员专业水平;无菌抽样关键过程进行视频信息采集,实现抽样过程的电子化记录和信息追溯;提倡样品在储存运输时进行连续温度监控。     

造纸机密闭气罩内温度、湿度测量传感器的设计与开发

针对目前造纸机密闭气罩内温、湿度控制及测量不准确的情况,基于STC89C52单片机为核心的控制器,利用温、湿度传感单元DS18B20/HS1101构成环境温、湿度测量探头,通过单总线实现数据采集,设计一款用于密闭气罩内温、湿度测量的传感器。通过实验测试,对数据进行计算得出系统温度测量误差不大于±1℃,湿度测量误差不大于2%,使用该系统可实现密闭气罩内的环境智能化控制。     

粮库粮情监测系统研制

研制了一套粮库粮情监测系统,可以监测粮库粮堆内的温度,同时,系统自带无线射频模块和预留RS485接口,可以接入其它有线或无线的传感器,监测粮库内环境温湿度、粮食水分、气体(O2、CO2、PH3)等物理量。系统包括测温电缆、无线数据集中器及无线测温杆。测温电缆和无线测温杆内嵌入的所有DS18b20传感器通过单总线与无线数据集中器连接。无线数据集中器既是数据转发装置亦是数据采集装置,它将粮情监测设备测取的数据通过GPRS或以太网传输至远程监控主机。     

The influence of ripening temperature and sampling site on the proteolysis in Reggianito Argentino cheese

The effects of elevated ripening temperature and sampling site on proteolysis in Reggianito Argentino cheese were evaluated. Cheeses ripened at 12 or 18 °C and 85% relative humidity were analysed at 2, 4 and 6 months in 2 sampling zones (central and external). Samples were analysed to determine the physicochemical and proteolysis parameters through the urea-PAGE of the urea-soluble fraction, RP-HPLC analysis of the water-soluble fraction at pH 4.6, and the free amino acid analysis. Proteolysis was significantly affected by ripening temperature and sampling site. Urea-PAGE analysis showed that elevated temperature increased the degradation of α_s1- and β-casein. The degradation of α_s1-casein was larger in the central zone than in the external one, while β-casein degradation was similar in both zones. The majority peaks detected by RP-HPLC of the water-soluble fraction at pH 4.6 and free amino acids were significantly affected by ripening temperature and sampling site. Glu, His, Val, Leu, and Lys had the higher concentrations. Principal component analysis showed useful groupings when results from chromatograms were studied. In conclusion, the results obtained not only are useful to characterise the ripening of an Argentinean hard cheese, but also to evaluate the effect of an increase of ripening temperature on Reggianito Argentino cheese proteolysis.     

The influence of ripening temperature and sampling site on the lipolysis in Reggianito Argentino cheese

The effect of ripening temperature elevation and sampling site on lipolysis in Reggianito Argentino cheese was evaluated. Cheeses ripened at 12 or 18 °C and 85% relative humidity were assayed at 2, 4 and 6 months at two sampling zones (central and external). Samples were analysed to determine physicochemical parameters and the concentration of nine free fatty acids (FFAs) (C_6:0–C_18:2). Myristic, palmitic, stearic and oleic acids were found in higher concentration. While ripening time and temperature significantly affected the concentrations of the nine FFAs analysed, sampling zone significantly affected only two FFAs. Ripening temperature increased the lipolytic process, but it seems to have no effect on the pathways of lipolysis in Reggianito Argentino cheese.     

木工高速电主轴表面温度检测系统标定模块设计

实现木工高速电主轴表面温度测量,需对温度传感器进行精确标定。本文介绍了基于LabVIEW的表面温度检测系统标定模块。标定对象为Pt100型热电偶传感器。分别采用线性、二次、三次、四次最小二乘法对实验结果拟合且得出误差结果。实验证明利用二次最小二乘法拟合标定获得较好效果。本标定模块预留与其他模块连接接口。实验证明本标定模块具有精度较高、可靠、稳定、操作简单、实用、可移植性强等优点。     

干燥器法测定木家具中甲醛释放量影响因子的研究

通过改变取样比例、吸收温度、制样时间、吸收水表面积及吸收水体积等试验条件测定床头柜甲醛释放量,探讨影响木家具甲醛释放量的因子。结果表明:1)不同的取样比例将导致不同测试结果;2)随着温度升高甲醛释放量呈增长趋势;3)在2h内完成制样对甲醛释放量测定值影响不大,而在4 h完成制样则测定值呈降低趋势;4)甲醛测定值随吸收水表面积增大呈逐渐增大趋势,而随着吸收水体积增大呈逐渐减少趋势。     

Assessing the influence of meteorological parameters on the performance of polyurethane foam-based passive air samplers

Polyurethane foam (PUF) disk passive air samplers were evaluated under field conditionsto assessthe effect of temperature and wind speed on the sampling rate for polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs). Passive samples integrated over 28-day periods were compared to high-volume air samples collected for 24 h, every 7 days. This provided a large data set of 42 passive sampling events and 168 high-volume samples over a 3-year period, starting in October 2003. Average PUF disk sampling rates for gas-phase chemicals was approximately 7 m3 d(-1) and comparable to previous reports. The high molecular weight PAHs, which are mainly particle-bound, experienced much lower sampling rates of approximately 0.7 m3 d(-1). This small rate was attributed to the ability of the sampling chamber to filter out coarse particles with only the fine/ultrafine fraction capable of penetration and collection on the PUF disk. Passive sampler-derived data were converted to equivalent air volumes (V(EQ), m3) using the high-volume air measurement results. Correlations of V(EQ) against meteorological data collected on-site yielded different behavior for gas- and particle-associated compounds. For gas-phase chemicals, sampling rates varied by about a factor of 2 with temperature and wind speed. The higher sampling rates at colder temperatures were explained bythe wind effecton sampling rates. Temperature and wind were strongly correlated with the greatest winds at coldertemperatures. Mainly particle-phase compounds (namely, the high molecular weight PAHs) had more variable sampling rates. Sampling rates increased greatly atwarmertemperatures as the high molecular weight PAH burden was shifted toward the gas phase and subject to higher gas-phase sampling rates. At colder temperatures, sampling rates were reduced as the partitioning of the high molecular weight PAHs was shifted toward the particle phase. The observed wind effect on sampling for the particle-phase compounds is believed to be tied to this strong temperature dependence on phase partitioning and hence sampling rate. For purposes of comparing passive sampler derived data for persistent organic pollutants, the factor of 2 variability observed for mainly gas-phase compounds is deemed to be acceptable in many instances for semiquantitative analysis. Depuration compounds may be used to improve accuracy and provide site-specific sampling rates, although this adds a level of complexity to the analysis. More research is needed to develop and test passive air samplers for particle-associated chemicals.     

Development of a passive sampler to measure personal exposure to gaseous PAHs in community settings

A sensitive, simple, and cost-effective passive sampling methodology was developed to quantify personal exposure to gaseous polycyclic aromatic hydrocarbons (PAHs). A Fan-Lioy passive PAH sampler (FL-PPS) is constructed from 320 sections of 1-cm long SPB-5 GC columns (0.75-mm i.d. and 7-microm film thickness), similar to a mini-honeycomb denuder. Given the unique feature of the GC column stationary phase, gaseous PAHs are collected on the inner surfaces of the columns by molecular diffusion and thermally desorbed to GC/MS for analysis. The sampling rates of FL-PPS were determined in the laboratory using a controlled test atmosphere containing eight PAHs for a range of face velocity, temperature, relative humidity, PAH concentration, and sampling duration. The sampling rate (mean, %RSD, cm3/min) was 26.7 (21%) for acenaphthylene, 37.6 (25%) for acenaphthene, 56.2 (13%) for fluorene, 49.1 (25%) for phenanthrene, 62.7 (22%) for anthracene, 65.4 (24%) for fluoranthene, and 64.4 (18%) for pyrene over a sampling duration of 8-48 h. The sampling rate for naphthalene was approximately 14.1 (12%) cm3/min over a sampling period of 8 h but decreased along with an increase of sampling time. The effects of temperature, humidity, face velocity, and PAH concentration on the sampling rate were not significant for all the compounds tested. A reasonable agreement (<30%) was obtained for most compounds measured by FL-PPS and a conventional active PAH sampling method colocated side-by-side in the field, but a sampling time of 24 h or longer was required for detection of less abundant PAHs in community settings.