查询词典 frequency band

Frequency range from audio, video, radio frequency to the microwave band.

频率范围由音频、视频、射频到微波波段。

The songs of Chinese bulbul showed smaller dialect systems among the 3 different environment noise habitats. The smaller dialect systems might be resulted from fragmented habitats. For transmitting messages successfully, Chinese bulbul contending with masking of anthropogenic noise by the higher minimum frequency, the lower maximum frequency, and the narrower band in the urban area.

白头翁歌曲在台中市三个不同程度噪音干扰的栖地环境间，呈现小规模的方言系统，可能与都会破碎化的栖地类型有关；在都会环境人为的低频噪音影响下，为了抗衡噪音遮蔽干扰，白头翁歌曲的最低音频升高、最高音频降低、频宽缩窄，以有效传达声音讯息。

In the first chapter, the class of modern frequency composing techniques and the recent development situations have been introduced. Then the advantages and disadvantages of the techniques have been described. At last, based on the techniques mentioned above, a scheme to realize the X-band low phase noise frequency source has been proposed.

在第一章引言部分，主要介绍了现代频率合成技术的分类及技术发展近况，并就每一种合成技术的优缺点做了简要的陈述，最后以上述不同合成技术的优缺点为基本指导思想，提出了一种实现X波段低相噪频率源的方案。

In frequency domain analysis, we studied the dominant frequency in HF band, LF to HF ratio and the correlation coefficient between simulated and real spectra.

在频域分析上，探讨频谱上高频区主频的频率值、LF与HF的比值以及模拟与真实频谱的相关性比较。

A low in-band phase noise FM frequency synthesizer has been depicted in this paper. It bases on the fraction N PLL frequency synthesizer, and the THD of the system has been improved greatly by this closed loop modulation mode.

研制一种低带内相位噪声的立体声FM频率合成器，该合成器基于小数分频锁相环技术，利用闭环方式对载波信号进行调制，显著提高系统的THD。

Answer: Shoots the frequency wave is the wave band is the 40.67MHZ electromagnetic wave, causes through the different technique to shoot the frequency wave penetration surface layer base first floor the melanophore, depth of penetration 2mm-20mm, resonates the principle through a minute small water-kettle to cause the organization to heat up to the threshold value temperature 65 ℃-75 ℃, both affects to the collagen organization, and may affect to the fat, achieved dispels wrinkles the skin, dissolves the effect which the fat loses weight, does not have any damage to the epidermis.

答：射频波是波段为40.67MHZ的电磁波，通过不同的手法使射频波穿透表层基底层的黑色素细胞，穿透深度2mm-20mm，通过分水子共振原理使组织加热至阈值温度65℃-75℃，既作用于真皮层胶原组织，又可作用于脂肪，达到祛皱紧肤、溶脂减肥的功效，对表皮无任何损伤。

The result is that center frequency shifts to low-frequency with increase of incident angle under oblique incidence, the band width narrows correspondingly, for both square element arrangement and regular triangle arrangement.

结果发现，无论单元是按正方形布阵还是按正三角形布阵，在电磁波斜入射时中心频率都随入射角的增大而向低频漂移，带宽都相应减小。

For instance took when frequency synthesizer, emphasizes is the switching time, the frequency spectrum purity, took when modem emphasizes is the ring circuit band width and so on.

比如作为频率合成器时，强调的是转换时间，频谱纯度，作为调制解调器时强调的是环路带宽等。

The stealth warplane for the microwave radar usually have complicated structures with the coating of wave absorption. On the base of calculation and modeling of the geometrical structure of the warplane in real size, the HF RCS of the air crafts under two different polarizations in different direction have been calculated with the FDTD. The result shows that the above mentioned stealth warplane have the obvious characterstics of frequency resonance, polarization and the relatively large RCS in HF Band 10-30dBm2, which can be used as the theoretical reference for selection of working frequency for sky wave OTH Radar and it also means that the sky wave OTH radar has good capability of anti-stealth targets quantitatively.

对微波雷达具有隐身作用的飞机，其形体较为复杂且表面涂敷有强吸波材料在对一种具有隐身几何外形结构实际尺寸飞机进行计算建模的基础上，文中采用FDTD技术得到了两种极化状态下该飞机无涂敷时不同方向上的短波雷达截面RCS值其结果显示了这种隐身几何外形飞机在短波波段有明显的频率谐振特性、极化特性和较大的RCS10-30dBm2，可为天波超视距雷达在选择工作频率时提供理论参考，并定量地说明天波超视距雷达具有较优的反隐身目标能力

In order to make use of time-frequency characteristic of signal,a new method of variational estimation on signal frequency by using AR model power spectrum estimation,designing band-pass filter to gain approximatively source signals and underdetermined mixed matrix,and constructing completed observation signals by expanded subspace primer vector is proposed.

充分利用信号的时频特性，提出了AR模型功率谱估计法滑动估计信号频率，设计带通滤波器近似获取源信号和欠定混合矩阵，以及扩展子空间向量基构造完备观测信号的方法，将问题转化为完备情况下的盲分离，最后运用FastICA方法实现了信号盲分离。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。