查询词典 threshold frequency

In order to correct spectrum with the single frequency(multi-frequency at a distance ),this paper presents the Energy Centrobaric Correction Method,which develops the Three-point Convolution Correction Method to be a general method which can correct frequency ,amplitude and phase.

提出了对单频率成分进行频谱校正的能量重心校正法，使三点卷积幅值校正方法发展成为一种能校正频率、幅值和相位的通用方法。

Therefore, established a finite element Stable response model of a horizontal whole string and carried out t the safety varied frequency of gas well after researched the natural seriously transversal vibration and compressional vibration frequency range of tubing string with packer and packerless, so that it make the tubing string to avert the covibration frequency range of natural gas excited.

本文认为以某井高产量稳产时，天然气对油管柱的外激励为简谐激振，因此研究中建立某水平井全井段油管柱稳态响应的有限元力学模型，并获得了在无封隔器和有封隔器情况下的油管柱发生严重横振和纵振的频率范围，提出了天然气安全调节频率范围，使油管柱避开可能引起严重破坏的天然气激励频率区域。

It tells particularly the debris flow"s the encironment and the development characteristic by numbers . And according to its character , selecting the latest research results at present , the anthor calculates the debris flow"s the moving , dynamical characteristics and the scale , such as , the velocity of flow , the wallop , the peak value flux , and the total flux . And the anthor calculates density in different design frequency by the empirical formula method . In the text, the author uses the modle of evaluating a single gully to evaluate the risk of the debris flow . First , the author calculates the hazard degree in different design frequency , and forecasts the risk range of debris flow in Shenjia gully based on the maximum pile thickness and the total solid amount of a denbris flow . Then , on the basis of the risk range in different design frequency , the author carries out the damageability and risk assessment . The basic purpose of risk management is reducing risk or transferring risk , reducing the loss of life and property . The text constructs the system of risk management of debris flow in Shenjia gully , basis on the condition of Shenjia gully .

本文从地形地貌、地层岩性、地质构造、气象水文等方面系统地阐述了深家沟泥石流的发育环境及发育特征；分别从形成区、流通区、堆积区对深家沟流域特征进行描述；依据泥石流沟自身特点，选用现阶段最新的研究成果，推算了不同设计频率下的深家沟泥石流流速、峰值流量、总流量、冲击力等动力特征和规模数据；并且根据经验公式法来确定深家沟不同设计频率下的泥石流容重；本文采用单沟泥石流风险评价模型对深家沟泥石流进行风险评价，首先对不同的设计频率下的深家沟泥石流进行危险度评价，根据最大堆积厚度与一次泥石流冲出量来预测不同频率下的泥石流危险范围，然后，根据预测的评估范围，评价对应范围内的易损度，最后作出风险评价；城镇泥石流风险管理的根本目的是降低风险或转移风险，减少生命财产的损失，本论文根据泸定深家沟泥石流的具体情况，构建了深家沟泥石流风险管理体系。

In this paper,the different frequency ultrasonic and sweep frequency ultrasonic is used to degum ramie,which shows that the effect of sweep frequency ultrasonic is perfect.

文章通过采用不同频率的超声波和扫频式超声波对苎麻脱胶的对比试验，说明了扫频式超声波对苎麻脱胶的优势，并通过分析苎麻原麻的结构和超声波脱胶特性对扫频式超声波这一优势加以解释。

Except that LIF can get high precision for the laser frequency stabilization, it can make laser frequency detune from one atomic resonance frequency easy and exact.

激光感生荧光稳频技术除有很高的稳频精度以外，还可以获得相对于原子共振频率的一定失谐量。

Except that LIF can get high precision for the laser frequency stabilization, it can makelaser frequency detune from one atomic resonance frequency easy and exact.

激光感生荧光稳频技术除有很高的稳频精度以外，还可以获得相对于原子共振频率的一定失谐量。

The fre-quency equations are derived according to stress match, consid-ering gear as a thin bar and adopting exponential horn. Then the influences of vibration of transformer which consists of horn and gear are explored, which come from the length of horn and the machining frequency. It has been discovered that the reso-nance frequency of the horn is the detune one of transformer and the resonance frequency is not same as one of horn, which provide theoretical rules for transformer design.

鉴于此，根据应力耦合，将齿轮作为圆盘，采用指数型变幅杆，推导频率方程，对变幅杆的设计长度和变幅器振动频率进行数值分析，发现变幅杆的共振频率恰好是变幅器的失谐频率，变幅器的共振频率与变幅杆的固有频率也不相同，这能够为超声珩齿变幅器的设计提供理论依据。

The results showed that virulence frequency of V4a、V4b、V13、V20、V21、VXBD、V2+6、V4+8、V2+Mli、V4b+Mli、V5+6、V1+2+9 were 3.6%~29.7%, Pm4a, Pm4b, Pm13, Pm20, Pm21, PmXBD, Pm2+6, Pm4+8, Pm2+Mli, Pm4b+Mli, Pm5+6, Pm1+2+9 were effective resistant genes to Erysiphe graminis f. sp. tritici and may be applicated as resistant parents; Virulence frequency of V1、V2、V3a、V3d、V3f、V6、V17、V19、V2+Ta were 38.6%~79.4%, The validity of Pm1、Pm2、Pm3a、Pm3d、Pm3f、Pm6、Pm17、Pm19、Pm2+Ta had decreased; Virulence frequency of V3b、V3c、V3e、V5、V7、V8 were 92.5%~98.7%, Pm3b、Pm3c、Pm3e、Pm5、Pm7、Pm8 had no applicable value in breeding if they were utilized as the only resistant sources.

结果表明，毒性基因V4 a、V4 b、V13、V20、V21、VXBD、V2+6、V4+8、V2+Mli、V4 b+Mli、V5+6、V1+2+9的出现频率为3.6%29.7%，其对应抗性基因Pm4 a、Pm4 b、Pm13、Pm20、Pm21、PmXBD、Pm2+6、Pm4+8、Pm2+Mli、Pm4 b+Mli、Pm5+6、Pm1+2+9为目前山西省小麦白粉病菌的有效抗病基因，可供转育利用；毒性基因V1、V2、V3 a、V3 d、V3 f、V6、V17、V19、V2+Ta的出现频率为38.6%79.4%，其对应抗性基因Pm1、Pm2、Pm3 a、Pm3 d、Pm3 f、Pm6、Pm17、Pm19、Pm2+Ta的利用价值已下降；毒性基因V3 b、V3 c、V3 e、V5、V7、V8的出现频率为92.5%~98.7%，其对应抗性基因Pm3 b、Pm3 c、Pm3 e、Pm5、Pm7、Pm8单独使用无利用价值。

The digital frequency source this paper researched uses high integrated DDS chip AD9851 as frequency sources and signal mirac processors AT89C51 as system control center, it can output 10Hz-20MHz signal with high-precision and high stability frequency.

毕业论文字数：15850 页数：36）摘要：随着现代电子技术的发展，高精度数字频率源在通讯、雷达、宇航、电视广播、遥控遥测、电子测量等领域得到了广泛的应用。

The structure parameters of the component are further varied, to obtain multivarious frequency components. The resonance frequency of a component is reduced by filling high permittivity medium, and this makes it possible to keep the design of a component compact at low frequency even.

进一步改变结构参数，可获取不同谐振频率的器件，且可在腔体中填充高介电常数介质来减小器件的谐振频率，克服了以往使用腔体结构在低频段时体积过大等问题。

Foods high in this vitamin include oily fish such as salmon, tuna and, and fish liver oils.

维生素D含量高的食物包括诸如大麻哈鱼、金枪鱼和鲭鱼之类的油鱼以及鱼肝油。

We need you to cosign our public letter demanding that press intimidation cease immediately, and that all charges be dropped.

我们需要您cosign我们的公共信，要求记者立即停止恐吓，并要求所有收费下降。