查询词典 radio-frequency spectrum

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。

At present, the Company electromagnetic vibration feeder, air hammer, level gauge, solenoid valve and control device, screw feeder, belt conveyor, bucket elevator, dust collector, zero speed switches, proximity switches, high-frequency coil , electromagnetic vibrators, vibration hopper, vibration controllers, marking electromagnet, power conditioners, heating units, heating the first, high-frequency cable, high-frequency transformers, ignition transformers and other products have been sold all over the country, has been unanimously praised users .

目前，本公司电磁振动给料机、气锤、料位计、电磁阀及控制仪、螺旋给料机、皮带输送机、斗式提升机、除尘器、零速开关、接近开关、高频线圈、电磁振动器、振动料斗、振动控制器、打标记电磁铁、电源调节器、加热单元、加热头、高频电缆、高频变压器、点火变压器等产品已销往全国各地，得到了用户一致好评。

When the frequency is 15Hz and number of ampere turns is 20kA·turn, relative intracrytalline solubility of alloy elements (for Zn, Mg and Cu the solubility are 68.8%, 76.0% and 45.0％, respectively) is the highest; when the frequency is 15Hz and number of ampere turns is 20kA·turn, Vicker hardness is the highest of Hv160; when the frequency is 25Hz and number of ampere turns is 20kA·turn, ultimate tensile strength is the highest of 324MPa.

频率为15Hz，安匝数为20kA·turn时， Zn、 Mg和Cu元素相对溶质固溶百分数最高，分别为68.8%、 76.0%和45.0％；频率为15Hz，安匝数为20kA·turn时，锭坯维氏硬度最高为Hv160；频率为25Hz，安匝数为20kA·turn时，抗拉强度最高为324MPa。

Based on rail/wheel reaction and track/bride reaction theory and systems engineering theory, new vehicle-track and vehicle-track-bridge system dynamic models are established and discussed in details, including ballast track model and ballastless track model. The characteristics of the models are:(1) vehicle-track and vehicle-track-bridge system dynamic models are coupled in vertical and lateral;(2) track vibration on bridge is taken in account, track on bridge is considered as one or two layer continuous-point supported rail model, according to actual track structure, interaction between vehicle and bridge transfer from track structure;(3) three type of ballastless track models (tieembanked, elastic-tie-block, slab track) are presented;(4) models reflect the main feature of actual vehicle, track and bridge structure, the response computation frequency of models is relatively broad, which can be applied to analyze both low frequency and high frequency vibration.

基于轮轨相互作用和线桥相互作用特点，本文从系统工程角度出发建立了车辆、有碴轨道和无碴轨道、简支箱梁桥垂向和横向耦合系统动力分析模型，该系统模型具有以下特点：（1）车线、车线桥体系均考虑为垂向、横向耦合振动系统，车线间通过轮轨接触几何关系耦合，轨道与桥梁间通过轨道与梁体间的力与位移协调条件耦合；（2）充分考虑桥上线路在车线桥系统中参振作用，根据桥上线路轨道结构特点将桥上轨道结构模型具体化，即对桥上轨道结构视为多层支承体系，车桥间的动力作用通过轨道结构来传递；（3）建立了三种形式无碴轨道动力分析模型，即长轨枕埋入式、弹性支承块式和轨道板式无碴轨道模型；（4）系统模型详细，分析频带宽，适用范围较广。

When the digitalsignal carries on the long distance transmission, the high frequencycomponent weaken increases along with the distance increases, theelectric cable median line also advances to the betweenelectromagnetic radiation along with the frequency intensifies, thusthe clipped wave transmitting range and the transmission quality,simultaneously in the channel often also exists separates the directcurrent electric capacity and the coupling transformer, they cannottransmit the direct component and have a bigger weaken to the lowfrequency component, therefore high frequency and low frequency arepartial regarding the common channel is limited.

当数字信号进行长距离传输时，高频分量的衰减随距离的增大而增大，电缆中线对之间的电磁辐射也随着频率的增高而加剧，从而限制信号的传输距离和传输质量，同时信道中往往还存在隔直流电容和耦合变压器，他们不能传输直流分量及对低频分量有较大的衰减，因此对于一般信道高频和低频部分均是受限的。

In tested frequency range, the damping ratio keeps constant under different vibration frequency, which is verified again that the concrete is not the ideal sticky elastic material whose dissipation characteristic is correlative with frequency.

在实验的频率范围内，不同振动频率下的阻尼比近似保持常数，再次证实混凝土并非耗能特性与频率相关的粘弹性材料；砼构件的动刚度随振动频率变化不大，表明其力学参数无明显频变特征。

Finite element method is based on the actual ship models, a true reflection of the real ship distribution of the specific structure. This paper also uses empirical formula to calculate the inherent frequency of the catamaran; contrast them in the process of modeling the structural stiffness, and quality of the different treatments, as well as natural frequency calculated from the results of differences analyze the different and the reason between the finite method and the empirical formula method which used to calculate the inherent frequency of catamarans in the vibration analysis.

有限元方法是根据实际船型，较真实的反映了实船结构的具体分布特征；本文还采用经验公式对该船的固有频率进行了计算，对比它们在建模过程中对结构刚度、质量的不同处理，以及计算所得固有频率结果的差异，分析了在双体船振动特性分析中有限元法与经验公式法的结果略有差距及其原因。

Multi-conductor coupled-line Marchand baluns and broadband frequency doublers and mixers are presented in this dissertation. This research focuses on the development of miniature broadband frequency conversion circuits including frequency doublers, fundamental down-conversion mixer, and IQ-demodulator.

本论文主要是讨论多金属耦合线马逊平衡不平衡转换器及宽频的倍频器及混频器，研究方向是著重於发展包含倍频器、降频器及正交解调变器在内的微小化宽频频率转换电路。

Also included is a conversion unit that converts a receiving signal of a first frequency band received via the antenna duplexer into a second frequency band lower than the first frequency band.

还包括转换单元，该转换单元将经由所述天线双工器接收的第一频带的接收信号转换为比所述第一频带低的第二频带。

Alternatively, the con- trollers can use the synchronous rectifier itself or loss- less inductor current-sensing methods to provide overload protection with lower power dissipation.

另外，康威特罗勒斯可以使用同步整流器本身或亏损减少电感电流检测方法，以提供低功耗过载保护。

Mr. Dauber's other Schatz hangs in his home movie studio.

多伯把沙兹的另一件作品挂在家里的电影室。