摘要
为了探究近年湛江市PM10质量浓度的变化特征及时频特性,利用数理统计方法和时频分析技术进行了分析和研究.结果表明:湛江市PM10质量浓度逐日差异明显,分布形态属正偏(右偏)型,为尖峰分布.湛江市PM10质量浓度的近年变化呈明显减少趋势.PM10质量浓度季节变化明显,年周期性清楚.年内变化具有冬春季节值大、夏秋季节值小的特性;冬春季节振幅大,夏秋季节振幅小,变化信号频率具有从小波分解的低层至高层细节系数逐层降低的年振荡波动特性.湛江市PM10质量浓度伪Wigner-Ville分布幅值明显变化的峰和谷主要位于时间域的冬春季节、频率域的0～0.05和0.45～0.5内.伪Wigner-Ville分布的Hough变换可发现湛江市PM10浓度年内的幅值变化峰值信号.
Concentration Variation characteristics of PM10 in Zhanjiang during 2001 -2007 were analyzed by means of the numerical statement method and time-frequency analysis. The results show that the PM10 concentration in Zhanjiang varies obviously from day to day and fits the peak type, which indicates a right asymmetric distribution shape with great decline. The variance and annual spans appear to have decreased these years. The mean value and variance of PM10 are great in winter and spring, while small in the other two seasons. The frequency of variation signals shows the wave property of annual PM10 Oscillation with detail coefficient decreasing from low levels to high levels of Wavelet Decomposition. The remarkable peak and value of amplitude of pseudo Wigner-Ville distribution mainly appear in winter and spring, with the frequency between 0 - 0. 05 and 0. 45 - 0. 5. By means of Hough transform of pseudo Wigner-Ville distribution, it finds that the most 3 remarkable break signals and the highest values of amplitude in each year have similar position and different intensity.
出处
《广东工业大学学报》
CAS
2009年第1期68-74,共7页
Journal of Guangdong University of Technology
