1 the spectral power distribution of light from fluorescent uv lamps is significantly different from that produced in light and water exposure devices using other light sources 在光和水老化设备中所用的紫外荧光产生的光的光谱能量分布与别的光源有着显著差异。
2.
It is studied that small inclusions in aluminum alloy are detected by ultrasonic transmission method in this paper . frequency analysis of the ultrasonic signal is done . harmonic factor and relative valid spectral power are calculated 本文采用超声穿透法对ly12铝合金板材细小夹杂物进行了检测试验研究，并对超声信号进行了频谱分析，计算了谐波系数和相对有效谱功率。
3.
The frequency analysis results show conclusions as follows : 1 . the relative valid spectral power is declined with the volume percentage of inclusions in terms of exponent curve and the tendency of negative direction is same to that of forward direction 当ly12铝合金细小夹杂物(小于0 . 16mm )的体积百分数从0 0 . 35时，在35 50mhz的频带范围内，超声波形的有效谱功率按近似指数曲线快速下降，沿相反方向检测时其变换趋势相同。
