The noise data in vertical component records of 85 seismic stations in Fujian Province during 2012 is used as the research object in this paper. The noise data is divided into fiveminute segments to calculate the powe...The noise data in vertical component records of 85 seismic stations in Fujian Province during 2012 is used as the research object in this paper. The noise data is divided into fiveminute segments to calculate the power spectra. The high reference line and low reference line of station are then identified by drawing a probability density function graph( PDF)using the power spectral probability density function. Moreover, according to the anomalies of PDF graphs in 85 seismic stations,the abnormal noise is divided into four categories: dropped packet, low noise, high noise, and median noise anomalies.Afterwards,four selection methods are found by the high or low noise reference line of the stations,and the system of real-time monitoring of seismic noise is formed by combining the four selection methods. Noise records of 85 seismic stations in Fujian Province in July2013 are selected for verification,and the results show that the anomalous noise-recognition system could reach a 90% success rate at most stations and the effect of selection are very good. Therefore,it could be applied to the seismic noise real-time monitoring in stations.展开更多
计算额肯呼都格地震台测震和强震连续观测数据背景噪声,对地震观测数据PDF进行分析,发现强震观测数据存在异常干扰。对受干扰数据进行噪声功率谱(Power Spectral Density,PSD)、噪声功率谱概率密度(Probability Density Function,PDF)分...计算额肯呼都格地震台测震和强震连续观测数据背景噪声,对地震观测数据PDF进行分析,发现强震观测数据存在异常干扰。对受干扰数据进行噪声功率谱(Power Spectral Density,PSD)、噪声功率谱概率密度(Probability Density Function,PDF)分析,缩小干扰源范围,并进行现场排查,判定强震观测数据异常由电源干扰所致。将市电断开后,观测数据恢复正常。清理数据采集器和强震计接地线,并更换线缆,重新供电后观测数据噪声明显降低,再次计算数据PDF并进行傅里叶变换,结果均无异常。展开更多
采用标量联合PDF(probability density function)方法结合修正的k-ε湍流模型、EMST小尺度混合模型以及GRI3.0化学反应机理对甲烷-氢气混合燃料(体积比为1∶1)高温伴流射流J HC(jet in hot coflow)火焰进行数值模拟.比较分析了高温伴流...采用标量联合PDF(probability density function)方法结合修正的k-ε湍流模型、EMST小尺度混合模型以及GRI3.0化学反应机理对甲烷-氢气混合燃料(体积比为1∶1)高温伴流射流J HC(jet in hot coflow)火焰进行数值模拟.比较分析了高温伴流中氧气质量分数分别为3%,6%和9%时的3种不同的MILD(moderate andintense lowoxygen dilution)燃烧火焰,3种火焰的计算结果与实验值符合得较好.展开更多
基金sponsored by the National Key Technology R&D Program of China(2009BAK55B00)the Earthquake Industry Research Project(201508012)
文摘The noise data in vertical component records of 85 seismic stations in Fujian Province during 2012 is used as the research object in this paper. The noise data is divided into fiveminute segments to calculate the power spectra. The high reference line and low reference line of station are then identified by drawing a probability density function graph( PDF)using the power spectral probability density function. Moreover, according to the anomalies of PDF graphs in 85 seismic stations,the abnormal noise is divided into four categories: dropped packet, low noise, high noise, and median noise anomalies.Afterwards,four selection methods are found by the high or low noise reference line of the stations,and the system of real-time monitoring of seismic noise is formed by combining the four selection methods. Noise records of 85 seismic stations in Fujian Province in July2013 are selected for verification,and the results show that the anomalous noise-recognition system could reach a 90% success rate at most stations and the effect of selection are very good. Therefore,it could be applied to the seismic noise real-time monitoring in stations.
文摘计算额肯呼都格地震台测震和强震连续观测数据背景噪声,对地震观测数据PDF进行分析,发现强震观测数据存在异常干扰。对受干扰数据进行噪声功率谱(Power Spectral Density,PSD)、噪声功率谱概率密度(Probability Density Function,PDF)分析,缩小干扰源范围,并进行现场排查,判定强震观测数据异常由电源干扰所致。将市电断开后,观测数据恢复正常。清理数据采集器和强震计接地线,并更换线缆,重新供电后观测数据噪声明显降低,再次计算数据PDF并进行傅里叶变换,结果均无异常。
文摘采用标量联合PDF(probability density function)方法结合修正的k-ε湍流模型、EMST小尺度混合模型以及GRI3.0化学反应机理对甲烷-氢气混合燃料(体积比为1∶1)高温伴流射流J HC(jet in hot coflow)火焰进行数值模拟.比较分析了高温伴流中氧气质量分数分别为3%,6%和9%时的3种不同的MILD(moderate andintense lowoxygen dilution)燃烧火焰,3种火焰的计算结果与实验值符合得较好.
