大气颗粒物浓度在线监测方法研究

大气颗粒物浓度是大气污染监测中的一项重要指标.大气中的颗粒物,特别是PM10及其以下颗粒物浓度的监测一直是国内外专家关注的问题.本文提出一种采用振动原理在线测量颗粒物质量浓度的监测方法,替代了传统的离线监测技术,提高了监测工作的实时性和正确性.     

用光学原理监测烟道排放的方法

介绍了一种利用光学原理对烟道排放进行监测的方法,并详细阐述了具体的光路,以及利用光的衰减检测粉尘浓度的原理和利用红外,紫外光吸收的方法检测SO2,NH3,NO,NO2的原理。     

β射线吸收法颗粒物自动监测仪器建设及维护

按照环境空气质量新标准的要求,对颗粒物监测项目包括PM10和PM2.5。β射线吸收法是颗粒物自动监测中的一种常用方法,MetOne公司的BAM-1020颗粒物连续自动监测仪是使用该方法监测仪器的代表之一。目前对该类监测仪器的安装建设和运行维护介绍较少,这给该类仪器的安全运行以及监测数据可靠性带来了诸多问题。本文介绍了该仪器在安装建设和运行维护中出现的一些问题,给出一些维护经验和注意事项。旨在能为相关技术人员提供参考,以期为仪器的稳定运行和监测数据的可靠性提供保障。     

空气自动监测系统仪器内标源的应用

本文介绍了内标源的原理,结构及质控方法,并根据近三年来青岛市在空气自动监测中使用内标源的实际情况,结合具体事件,图例详细讨论了内标源的实际应用方法。     

DP—103数字烟道压力计在污染源监测中的应用

介绍一种新多功能数字烟道压力计的工作原理,适应范围以及替代传统斜管压力计和指针微压表的必要性。     

基于计算机视觉的烟道大颗粒在线监测系统

介绍烟道大颗粒在线监测系统,包括系统的硬件组成和软件处理方法。该系统是一个基于Windows PC平台的计算机视觉系统,其中数据处理方法以数字图像处理理论为基础。     

润滑油固体污染物监测方案研究

结合现代机器的实际情况,通过5种润滑油固体污染物检测仪器制定的监测流程,对润滑油中固体污染物的元素的性质、含量、磨损颗粒的数量及形貌等信息,进行全面分析,得出准确的报告,为监测机器的状态和润滑油的品质提供可靠依据。     

大气自动监测站常见故障原因分析及处理方法

本文对海安县环境监测站现有大气自动站主要常见故障的原因进行了分析和研究,并提出了解决办法。     

结构疲劳损伤的声发射检测可靠性研究

针对声发射技术对金属结构损伤的检测可靠性问题,以金属疲劳裂纹检测试验为基础,利用声发射特征参数的趋势分析和关联分析法,首先根据贝叶斯理论,计算了声发射对一定长度疲劳裂纹的检测概率;其次,研究了检测结构起裂时对应声发射幅度参数的阈值及其对损伤判断的影响。该研究可为减少声发射检测中的金属疲劳损伤信号误判,提高检测效率,以及确定复杂航空结构疲劳寿命提供支持。     

大规模集成电路刻蚀过程和终点的在线监测──等离子发射光谱法

文章叙述了大规模集成电路(LSI)等离子和反应离子刻蚀原理及在线监测刻蚀过程的基本方法。详述了用等离子发射光谱法进行LSI离子刻蚀过程监测的具体实施和实验结果,得到了80Å的动态监测精度和0.3cm²的最小可监测面积。最后文章还讨论了影响监测精度的因素。     

气固二相流电容式固相浓度传感器

报道一种用于测量气固两相流固相浓度的电容式浓度传感器。该传感器由沿管道轴向布置的两对相同电极板构成。两对极板的方位不同,相差二分之一极板包角。实验证明由该种“复合式极板”构成的电容式浓度传感器的检测场均匀性误差可达１３％,远远优于单对极板的该项指标。     

A Study on Incipient Damage Monitoring in Rolling Contact Fatigue Process Using Acoustic Emission

Acoustic emissions (AE) technique was applied to rolling contact fatigue tests of two radially loaded rollers running under constant load and velocity to detect the incipient damage and damage location. Signals detected from contacts were processed using signal conditioning and enhancement techniques by an AE source locator to bring out the difference between the signals from the sound and damaged rollers. It was found that AE hit count pulse observations by the AE source locator can provide an indication of the damage at its initial stage. The conventional AE parameters and the AE signal features were studied and correlated with the AE source locator counts. The results demonstrated the successful use of the combination of the AE monitoring and the AE source locator as a new technique for detecting the incipient damage and forecasting the position of the damage in the roller, and this technique could allow the user to monitor the rate of deterioration of the rolling elements.     

在Emission状态测定水中钾和钠的探讨

本方法讨论了在火焰原子吸收仪上分别于Atomic Absorption和Emission两种状态，用标准曲线法测定可过滤态钾和钠。得出在Emission状态测定钾和钠更加灵敏，加标回收率为93％-110％，相对标准偏差为〈3％，避免了因灯不稳造成的基线偏移。     

集成流体声发射传感器的设计

本文论述了一种新型流体声发射传感器的集成结构和设计原理，讨论了如何利用声能集中原理提高灵敏度和压电元件形状及边界条件对传感器频率响应的影响等理论问题，最后，对其距离传播特性进行了测试，用大量的实验验证了其实用性和可靠性。     

The application of spectral kurtosis on Acoustic Emission and vibrations from a defective bearing

The application of Acoustic Emission (AE) technology for machine health monitoring is gaining ground as power tool for health diagnostic of rolling element bearing. This paper provides an investigation that compares the applicability of AE and vibration technologies in monitoring a naturally degraded roller bearing. This research is the first known attempt investigating the comparative effectiveness of applying the Kurtogram to both vibration and AE data from a defective bearing.     

大麦种子萌发期的超微弱光子辐射图象研究

使用PIAS（光子计数图象采集系统），记录了大麦品种Igri种子萌发期的超微弱光子辐射现象，对这种混在强噪声中的光子辐射进行处理后获得了清晰的发光图象。研究表明：对生物系统的超微弱光子辐射进行二维成象，可以比时间域一维探测获得更多的生理信息。采用数字图象处理技术，选择合适的阈值亮度，可以把光子辐射和噪声有效地区分开。     

Monitoring of Ball Bearing Operation under Grease Lubrication Using a New Compound Diagnostic System Detecting Vibration and Acoustic Emission

Our new compound diagnostic system comprised of a compound sensor, a signal processor, and a personal computer installed signal processing software. The compound sensor made by an advanced sensor fusion technique was able to detect simultaneously the vibration acceleration and the acoustic emission by itself. The signal processor received a signal from the sensor and separated it into the vibration acceleration signal and the acoustic emission signal. The signal processor and the personal computer processed the acceleration signal and acoustic emission signal for diagnostic information. The rolling contact fatigue process of a ball bearing under grease lubrication was monitored using the compound system. The system outputs diagnostic information, for example, the means, the variance, the skewness, and the kurtosis of the vibration acceleration signal and the acoustic emission signal. In diagnosing the rolling contact fatigue failure, the root mean square (rms) value of the vibration acceleration was most effective, and the mean of the demodulated acoustic emission was second to the rms value of the acceleration in effectiveness. From the result of the evaluation, it became clear that the system was useful for diagnosing rolling contact bearings under grease lubrication.     

特征声发射信号的时频能量分析

由于声发射信号多频率多模式的特点，不同频率的声发射信号表现声发射源特性的能力有所不同，这在应用中给声发射信号的处理带来了很大的困难，文章将信号引入到时频域，利用时频联合分布的能量特性，在时频域中计算信号的能量，以能量为依据选取声发射信号中的特征声发射信号，得到了满意结果。