<正>应用MATLAB工具箱中小波函数对刨花板受压时产生的声发射信号进行了小波降噪处理，并比较了小波分析降噪和滤波器方法降噪的异同。结果表明：选取适当的小波分解级数，进行合理的闽值门限处理，可以大大提高重构后信号的识别度，对声发射信号采用小波方法降噪可达到较理想的效果。

This p,aper studied the chemical characteristics of Pinus kesiya var. langbianensis-oleoresins from Lianghe of Yunnan using gas chromatography and mass spectrometry. The content of 3-carene is as high as 8.2%～10.0%,and average of total is 9.1% when the content of swatch is 4. The percent of 3-carene/(monoterpenes+sesquiterpenes) is 17. 5%～27.9%,average of total is 21. 7%. The content of 3-carene from one pine is as high as 21.1%,and it is higher 6% than the content of 3-carene from P. densata oleoresin. The percent of 3-carene/(monoterpenes+sesquiterpenes) is 45. 2% when the content of swatch is 12. The content of 3 carene is 27. 0% to 30. 0% of the turpentine from lab using glycerin to distil oleoresin. This is conformed to percent of 3-carene/(monoterpenes+sesquiterpenes).