频率

The module has stabled the center frequency of laser diode by controlling it'...

该控温模块通过控制 2 。5Gbit/s光发射模块中激光器管芯温度来稳定其中心频率，为波分复用系统的应用提供了具备稳定中心频率特性的光源。

Results indicated there were significant seasonal and spatial distribution characteristics. Drought occurred in high frequency at the stage of tasselling to silking and thereafter. Drought frequency obviously increased with backwards shift of growth stage. Light drought happened in higher frequency than medium and severe drought.

结果表明，湖南春玉米生长季节内干旱呈现明显的季节性和空间区域分布特征：干旱频率较高的时段主要在玉米抽雄－吐丝阶段及其后的生育阶段，且随生育期后移干旱频率明显增加，以轻旱程度为主。

The results show that, under each drip irrigation treatment before the tasselling stage of spring maize, the fluctuation of average soil water content and soil matric potential at different soil depthes are comparative low under high frequency drip irrigation treatment, and the HDI can hold stable soil water content. The drip irrigation can obviously delay the effect of air temperature on the soil temperature, which was influenced by irrigation process, soil water content and crop growth stages. In addition, the irrigation frequency affects the spring maize root distribution in the soil, and the HDI improves the probability of root distribution in upper soil(0~40 cm). The yield difference of spring maize for irrigation frequency treatments is not significant under the typical field irrigation model combined irrigation with precipitation.

试验结果表明：在春玉米抽雄期以前阶段实施的滴灌各处理中，高频滴灌下土壤平均含水率和不同深度处的土壤基质势波动幅度较小，高频滴灌下土壤水分能保持在一个比较稳定的范围；土壤温度受灌水过程、土壤含水率及作物生育阶段的影响较明显，滴灌能显著延迟气温对土壤温度的影响；灌水频率对春玉米根系分布存在一定影响，高频灌溉能显著促进春玉米根系在上层土壤(0～40 cm)中的分布；此外，在这种典型的灌溉和降雨相结合灌溉模式下，不同灌水频率下玉米产量差异不显著。

A two-times locating method based on the gray contrast of surroundings is presented in locating central reference point. This method has better adaptability and robustness, and can basically meet for the accuracy of automatic locating center. Fourier spectral analysis is improved to obtain a more accurate ridge frequency in computing ridge frequency. The average ridge width is used in designing Gabor filters, so the filters have certain adjustability. The rotating invariance of fingerprint images is solved by the rotating of feature models in feature matching.

在中心参考点定位部分，提出了基于局部邻域灰度对比度的二次定位方法，该方法具有较强的适应性和鲁棒性，基本满足自动中心定位的准确度要求；在频率域估计中，改进了傅立叶谱分析法，提高了纹线频率计算的准确度；引入平均纹线宽度作为Gabor滤波器的设计参数，使滤波器具有一定的自适应性；在特征匹配阶段，通过对特征模板的旋转解决指纹图像的旋转不变性问题。

By locking laser frequency to atomic absorption spectrum through current negative feedback and locking microwave frequency to electromagnetic induced transparency resonance peak through voltage negative feedback, it is realized to lock the clock frequency of this laboratorial desktop experimental CPT frequency standard.

通过采用电流负反馈将激光频率锁定在原子对激光的吸收峰上，电压负反馈将微波频率锁定在电磁感应透明共振峰上，用该物理系统实现了闭环锁定的实验室桌面CPT频标实验系统。

By locking laser frequency to atomic absorption spectrum through current negative feedback and locking microwave frequency to electromagnetic induced transparency resonance peak through voltage negative feedback respectively, the locking of the clock frequency of this laboratorial desktop experimental CPT frequency standard is realized.

介绍了相干布居囚禁原子频标的小型、低功耗物理系统，并应用它开展实现了CPT原子频标的激光锁定、微波锁定方案的实验室研究。通过采用电流负反馈将激光频率锁定在原子对激光的吸收峰上，电压负反馈将微波频率锁定在电磁感应透明共振峰上，用该物理系统实现了闭环锁定的实验室桌面CPT频标实验系统。

On the other hand, temperature compensation of the resonance frequency might become a problem if the bandwidth of the antenna circuit is low compared to the temperature variation of the resonance frequency.

另一方面，温度补偿的共振频率可能会成为一个问题，如果天线的电路带宽比较低的共振频率的温度变化。

In the fourth paragraph, how the theory of the damping to forging hammer foundation advances at home and abroad, the research and application of the implement for damping to forging hammer, the structure of damping to forging hammer and the calculation methods for forging hammer foundation vibration system, which are used at home nowadays, are particularly introduced.In the fifth paragraph, aiming at direct damping under anvil block of forging hammer, the author bases a mechanics model of two-degree with damping, and optimizes the vibration parameters both in frequency field and in time field, then finds out the new simple method of optimizing the vibration parameters of the damping device under anvil block of forging hammer.

第五章针对锻锤砧下直接支承式减振基础，建立了锻锤减振系统的二自由度有阻尼振动力学模型，然后用傅立叶变换法求出振动传递率的频率关系，用直接积分法求出砧座和基础位移的时域响应，并分别对频域函数和时域函数进行参数优化，最终建立起频率函数—时域函数—优化参数间的相互关系，从而找到了锻锤砧下隔振器参数优化的简便新方法。

The experimental results of the two models of the brick house with arch floor whose rise to span ratio is 1/10 and 1/6 respectively are given in this paper, and then a mechanical model with clastic support for the whole model house is established, its displacement response is analyzed by using frequency response function method, a corresponding frequency response function is derived, and model stiffness parameter for different stages is discussed.

本文给出了矢跨比分别为1/10和1/6的两幢二层砖拱楼盖房屋模型的振动台试验结果。对整个模型房屋建立了弹性支承杆系力学模型，用频率响应法分析了模型的位移反应，导出了相应的频率响应函数，并对各阶段的模型刚度参数进行了讨论。

Due to FC nature of the repeater, FC repeater uses twice as much frequency as the conventional CS, PS, or amplifiers. Thus, one must pay special attention not to let the signal leaks out to the un-intended coverage area, especially areas under noticeable frequency blockage. When used for outdoor application, it should only be used for low traffic areas.

由于变频直放机的工作需要占用比一般设备（基站、手机、基站放大器等）多一倍的频率资源，所以在应用中要注意：用于室内覆盖时避免直放机与手机通信时的信号泄漏到话务量很高的室外引起频率阻塞；用于室外覆盖时，应该使用在基站稀疏，话务量低的区域。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。