温湿度对PM2.5质量浓度监测的影响

探讨了在不同环境条件和污染状况下,带膜动态测量的微振荡天平法的自动监测方法能否准确监测空气中的PM_(2.5)质量浓度。通过自动方法与手工重量法的比对,针对2015年8月—2016年7月的监测结果进行讨论,尤其是不同温度和相对湿度对监测数据的影响,在平均相对湿度为60%~90%时夏季2种方法绝对偏差均值大于10μg/m3,并对该结果进行了原因分析,提出了自动监测的质量控制和比对溯源的建议,为PM_(2.5)的质量浓度监测工作提供了参考依据。     

HB6783、GB/T5170在温湿度试验箱性能指标验收中的应用

本文简要介绍了环境与可靠性试验领域试验设备系列检定标准HB 6783、GB/T 5170。以本单位某型温湿度试验箱验收为例,详细介绍了HB 6783、GB/T 5170系列温湿度试验设备检定/检验标准在温湿度试验箱性能指标验收中的应用,通过对比应用总结,指出综合比较不同检定标准中温湿度性能指标的检定项目、方法,结合本单位产品试验需求应用,是制定温湿度试验箱性能指标验收方法的最佳途径。     

Prediction of global solar radiation using support vector machines

This article utilizes Support Vector Machines (SVM) for predicting global solar radiation (GSR) for Sharurha, a city in the southwest of Saudi Arabia. The SVM model was trained using measured air temperature and relative humidity. Measured data of 1812 values for the period from 1998–2002 were obtained. The measurement data of 1600 were used for training the SVM, and the remaining 212 were used for comparison between the measured and predicted values of GSR. The GSR values were predicted using the following four combinations of data sets: (i) Daily mean air temperature and day of the year as inputs, and global solar radiation as output; (ii) daily maximum air temperature and day of the year as inputs, and GSR as output; (iii) daily mean air temperature and relative humidity and day of the year as inputs, and GSR as output; and (iv) daily mean air temperature, day of the year, relative humidity, and previous day’s GSR as inputs, and GSR as output. The mean square error was found to be 0.0027, 0.0023, 0.0021, and 7.65 × 10^?4 for case (i), (ii,), (iii), and (iv) respectively, while the corresponding absolute mean percentage errors were 5.64, 5.08, 4.48, and 2.8%. Obtained results show that the SVM method is capable of predicting GSR from measured values of temperature and relative humidity.     

Effects of temperature and relative humidity on the methane permeability rate of biogas storage membranes

Selecting a material for biogas storage membranes is becoming increasingly vital because of the wide applications of biogas storage membranes in biogas plants. Material selection has numerous influencing factors, including gas permeability, strength, density, and so on. Among these, gas permeability has a vital role in biogas storage membranes. In this study, three kinds of biogas storage membranes with the same thickness were selected to investigate the effects of temperature (10, 20, 30, and 40°C) and relative humidity (RH; 0%, 50%, and 100%) on the permeability rate of biogas storage membranes. Results demonstrated that when various membrane samples with the same RH values were tested, temperature exhibited a strong effect on permeability rate. Kinetic analysis showed that the relationship between permeability and temperature agrees with the Arrhenius equation. However, no remarkable variation in methane permeability was observed for membranes with the same temperature but different RH values, thus suggesting that RH nearly has no obvious direct influence on the permeability rate of membranes.     

蜂窝电话用锂离子电池的环境试验

国家标准GB/T18287-2000《蜂窝电话用锂离子电池总规范》中明确规定了锂离子电池的20℃常温,高温,恒定湿热性能,震动,碰撞,自由跌落等环境试验的具体方法及环境试验后的放电性能测试方法。     

A distributed fibre optic approach for providing early warning of Corrosion Under Insulation (CUI)

A novel fully distributed fibre optic humidity sensor technology suitable for spatially continuous monitoring of water ingress under pipeline insulation is reported. Results from controlled water ingress tests are presented, where the fibre cables were mounted on pipes insulated with air gap cell glass and aerogel insulation. The experiments revealed that the fibre optic sensor responded to water ingress equivalent to <10 ml/metre pipe, under air gap cell glass insulation. The fibre optic measurements were validated by comparison with conventional calibrated point humidity sensors. A compensation methodology using a reference optical fibre was used to effectively reduce the effect of temperature variations on the measurements. The ability of the sensor to monitor the spatial evolution of water ingress with cm scale resolution was demonstrated, as was the feasibility to make accurate water ingress measurement over 2 km fibre lengths. The technology could be used to assist targeted inspection campaigns aimed at minimizing the risk of Corrosion Under Insulation (CUI).     

Inter- and intra-specific responses to elevated ozone and chamber climate in northern birches

We studied the responses of micropropagated, northern provenances of downy, mountain and silver birches to elevated ozone (O₃) and changing climate using open-top chambers (OTCs). Contrary to our hypothesis, northern birches were sensitive to O₃, i.e. O₃ levels of 31-36 ppb reduced the leaf and root biomasses by −10%, whereas wood biomass was affected to a lesser extent. The warmer and drier OTC climate enhanced growth in general, though there were differences among the species and clones, e.g. in bud burst and biomass production. Inter- and intra-specific responses to O₃ and changing climate relate to traits such as allocation patterns between the above- and belowground parts (i.e. root/shoot ratio), which further relate to nutrient and water economy. Our experiments may have mimicked future conditions quite well, but only long-term field studies can yield the information needed to forecast responses at both tree and ecosystem levels.     

积分分离模糊PID控制器在高温湿热试验控制系统中的应用

PID算法是一个广泛应用于工业控制的算法,但它对大惯性、大延迟、多变量的湿热交变控制系统实现精确控温控湿显得较为困难。本文介绍了一种基于模糊控制规则的积分分离模糊PID控制器,当系统调节开始时由于系统误差较大,系统的控制主要由模糊PD控制来实现;当系统误差较小时加入积分控制环节,系统切换为模糊PID控制,并将其应用于高温湿热试验系统控制,结果表明这种方法比普通PID控制精度高、超调量小,特别是对大范围温湿的变化具有更好的适应性和稳定性。     

冷凝湿度控制对微振荡天平监测细颗粒物性能的改进

为提高细颗粒物(PM2.5)测量的准确性,尝试采用一种新型的气溶胶冷凝湿度控制器(简称冷凝湿度控制器)作为微振荡天平法颗粒物监测仪(TEOM)的除湿方式,在广东大气超级监测站开展了TEOM自动监测(一台采用传统的加热除湿方式,记为TEOM1405;另一台采用冷凝湿度控制器除湿,记为TEOM1405+除湿)和手工监测结果的对比。结果表明,根据PM2.5日均值相关性的拟合结果,TEOM1405监测较手工监测结果总体偏低约13%,加装冷凝湿度控制器后,TEOM1405+除湿监测较手工监测结果总体偏低在5%以内。加装冷凝湿度控制器后,显著提高了PM2.5的监测准确性;在相对湿度较高、二次颗粒物生成量较少的大气环境中,TEOM1405+除湿系统对PM2.5的监测结果是可靠的,而且在降雨过程中监测结果更为稳定;但在相对湿度较高、且二次颗粒物生成量较多的大气环境中,其对PM2.5的监测性能仍待进一步考察;在PM2.5污染比较严重的高污染时段,TEOM1405、TEOM1405+除湿监测到的PM2.5日均质量浓度分别比手工监测结果偏低26%和11%,偏低较多。但这种高污染情况在珠三角地区出现的概率很低,故采用TEOM1405+除湿系统进行PM2.5长期自动监测是可取的。     

新型G系列高低温交变湿热试验箱

本文介绍国内最新研发的新一代的环境试验设备。用于航空、航天、信息、电子、仪器仪表等行业作电工电子产品、材料、零部件、设备的高低温试验及湿热试验。