| 1. | This effect is obvious at lower frequency band
这种效应在振动低频区段更为显著。 |
| 2. | Very - low frequency band
甚低频频带 |
| 3. | And waveguide has a too large structure to satisfy the requirement when working at a low frequency band
而波导天线传感器在衰减较小的低频区尺寸太大也达不到要求。 |
| 4. | Test results are analyzed in one third octave band spectrums mainly regarding vibration - sensitive instruments and emphasizing on low frequency band
测试结果的分析主要是针对振动敏感仪器的，在频域内采用1 / 3倍频程频谱，重点考虑低频段的地面响应。 |
| 5. | So a new kind of microwave cavity - mode strongly coupling double gap cavity , which has higher characteristic impedance , smaller volume and fits in with lower frequency band multi - beam klystrons , is proposed
并提出了一类新型的、具有较高特性阻抗和较小体积的低频率波段多注速调管输出腔?模强耦合双间隙微波谐振腔。 |
| 6. | But ridged waveguide antenna which is small in volume when working at a low frequency band can obtain a high resolution and is suitable in the rubber material measure . one of the features of the paper is that some improvements of fdtd are presented
脊波导天线与普通金属波导相比，在较低的频域可以有较小的工作尺寸，因而能达到较高的分辨率，且便于与同轴馈线连接，很适合用于橡胶吸收材料的测量中。 |
| 7. | Vibration of automobile in low frequency band has importment effect on automobile performance and the air spring has high performance in this frequency band , the semi - suspension with controllable spring stiffeness can be used widely to improve the vehicle ' s ride comfort
由于车辆行驶的平顺性关注的是低频振动，而空气弹簧本身在低频处具有良好的减振性能，所以利用空气弹簧组成的变刚度半主动悬架系统具有很好的应用前景。 |
| 8. | The first , the effect of the sizes of coupling slots in a coupling double gap cavity on the cavity characteristics is studied through simulation computation of three dimensions electromagnetic field and analysis of equivalent lumped element circuit . it is concluded by the research that , in lower frequency band , bigger coupling slots in a coupling double gap cavity are beneficial to raising the characteristic impedance and lowering the frequency of it mode
第一，采用三维电磁场模拟计算方法和集中元件等效电路法研究了耦合双间隙腔中耦合槽尺寸对谐振腔性能如何影响等问题，得出了重要结论：在较低频率波段，耦合双间隙腔中开大耦合槽有利于提高模的特性阻抗，降低模频率。 |
| 9. | In addition , the author puts forward that the eggs could be recognized based on the difference in the frequencies of their prompted sounds . because the eggs " prompted sounds are lied on low frequency bands , the microphone and sound amplifier that have excellent duration response should be used . the output signal from the sound amplifier is transferred to data signal by a / d card before it is put into computer
蛋品激励出的声音主要集中在低频段，因此选择在低频段有好的频率响应特性的麦克风和放大电路；放大输出信号通过a / d采集板变换成相应的电压数值信号送入计算机，对离散的信号数据进行傅立叶变换得到它的频谱图和各频段能量分布图；而后将能量分布特征数据作为神经网络的输入值，这样，好蛋和破损蛋的模型就建立起来。 |
| 10. | Doing the further research on the division frequency stack on the foundation of study of predecessor , at first the residual moveout correction is done to the seismic record , make the phase axle regularity , doing foundation for the same phase stack ; then carried on division scale processing by wavelet transform ; spectrum whitening is done to each scale , the high and low frequency band need to do prolongs , the middle frequency bands only increase the value of the frequency spectrum ; several kinds of methods that estimate the value of signal - noise ratio has been studied further , and summarize their advantage and disadvantage as well as the scope of application ; the seismic record after spectrum whitening is stacked by weighting with the value of the signal - noise ratio ; then estimate the value of signal - noise ratio which is each scale section after stacking , the scale that the signal - noise ratio is big is assigned big weighting , otherwise , the scale that signal - noise ratio value is small is assigned small weight ing , and carried on weighted reconstruct to each scale section
本文在前人研究的基础上，在分频叠加方面做了进一步的研究。首先对地震记录进行剩余时差校正，校齐同相轴，为同相叠加做好基础工作；然后对地震记录用小波变换的方法进行分尺度处理；对各个尺度分别做谱白化，对于高、低频段需要做频带延拓，中间频段仅提升频谱值；对于几种信噪比定量估计的方法进行了深入的研究，并且总结了它们的优缺点以及适用范围；对谱白化后的地震记录用信噪比估计值作为加权系数进行加权叠加；对于各尺度的叠加剖面也进行信噪比估计，对于信噪比大的尺度给予大的加权系数，反之，信噪比值小的尺度给予小的加权系数，对各尺度叠加剖面进行加权重构。 |
