low frequency wave 中文意思是什麼

low frequency wave 解釋
低頻波
  • low : adj 1 低的;淺的,矮的。 low flight 低飛。 a low temperature 低溫。 low tide [water] 低潮。 The g...
  • frequency : n. 1. 屢次,頻仍,頻繁。2. (脈搏等的)次數,出現率;頻度;【物理學】頻率,周率。
  • wave : n 〈美海軍〉女志願軍人〈見 WAVES 條〉。n 1 波浪;碎浪; 〈the wave(s)〉 〈詩〉海。2 波動;波狀...
  1. Compared with classic wavelet technique, the proposed method can adjust not only the low frequency components of earthquake wave, but also the high frequency components

    和傳統的小波分析相比,該方法不僅對地震波低頻分量進行精確調整,還可對其高頻成分實現類似的調整。
  2. In this paper, based on the amplitude transport equation of fast varying field and the low frequency disturbance equation of electr on density, the evolutions of the density distribution of charged particles and the collapse of electric field have been calculated numerically in two dimensions with three field components under the condition of transverse wave

    所以本文採用了ftcs有限差分格式方法,利用二維三分量軸對稱,對空間飛行體與壓縮區內等離子體非穩態相互作用過程進行數值模擬,得到了電荷密度擾動與電場的變化情況。
  3. The results of the study show that, when compared with the reaction intensified with mechanical agitation, low - frequency ultrasonic wave can greatly promote the ester exchange reaction and shorten the reaction time

    研究結果表明,與機械攪拌增強反應比較,低頻超聲波可以大大強化酯交換反應過程,縮短反應時間。
  4. It was found that the dropping rate in remnant polarization, pr ( n ), of the samples would be accelerated when a high intensity or low frequency or square - wave of electric field was applied or at a lower temperature

    實驗結果表明,在高電場強度、低電場頻率和在方波電場的作用下以及較低的溫度下,鐵電陶瓷材料剩餘極化強度p _ r ( n )下降的速度變快。
  5. Traditional laser iff has poor security because of low frequency of laser beam coded pulse. this can be greatly improved when the pulses are modulated by continuous wave laser, but the power of this laser beam output is so low that it ’ s difficult to be detected and received by laser warning subsystem

    傳統的激光敵我識別器激光編碼脈沖頻率低,通信保密性差,使用連續波激光器經調制后激光編碼脈沖頻率高,保密性好,但輸出激光功率較低,難以達到激光告警分機探測接收的要求。
  6. There are five parts are as follows : in part one, the concept of switching function is introduced first to establish the nonlinear mathematical model of the induction motor variable frequency speed adjustment system which is fed by a sine pulse width modulated ( spwm ) inverter and takes the effect of the main magnetic circuit saturation into consideration, then the low frequency oscillation of the system is simulated according to the model. next, from the view point of energy conversion of the inverter - induction system, a criterion for the low frequency oscillation is proposed to determine whether the system is in low frequency oscillation which is judged by whether the interval of the negative current component of the inverter input current is more than 1 / fc ( fc is the carrier wave frequency of the inverter ) or not

    首先引入開關函數概念,建立了正弦脈寬調制( spwm )逆變器供電異步電動機,考慮主磁路飽和時的變頻調速系統整體數學模型,模擬系統的低頻振蕩;其次從逆變器-異步電動機系統能量轉換角度出發,提出通過檢測逆變器輸入電流中負電流的間隔時間是否大於1 / f _ c ( f _ c為逆變器載波頻率)來判定系統是否出現低頻振蕩;最後的實驗結果驗證了系統低頻振蕩建模和判據的實用性和正確性。
  7. The main circuit is consisted of 18 thyristors circuit and protection circuit. with the help of control subsystem, it can get the output of low frequency voltage ( current ) with the shape of sine wave ; the core of the control subsystem is the cpu of 87c196kc, and the synchronization circuit, the pulse - widen circuit, and the power - enlarged circuit form the accessorial subsystem of the control system. it possesses all the functions of digital triggering, digital tuning, analog / digital conversion ; the input transfer can isolate the input and output ; and the circumfluence reactor can reduce the circumfluence

    主迴路採用由18個晶閘管組成的三相零式電路,並輔以晶閘管的保護電路,通過控制可以得到低頻正弦波的電壓(電流)輸出;控制迴路主要以87c196kccpu為核心,其外圍電路包括同步電路,脈沖拓寬電路,功率放大驅動電路等,完成了數字觸發、數字調節、模數轉換等功能;進線電源變壓器具有變壓和隔離作用;環流電抗器則實現了有效抑制主迴路瞬時脈動環流的功能。
  8. At last, influences of the frequency, source point depth and conductivity ' s are concisely analyzed on low frequency wave ' s propagation characteristics in the earth ' s crust overburden

    最後根據模型模擬結果數據,從頻率、源點距地面深度和導電率三方面簡略地分析它們對地殼覆蓋層中低頻無線電波傳播特性的影響。
  9. Boundary condition method just amend a little for intrinsic fem program, and can obtain low frequency sound transfer function of receiver based on existed fem mesh. the big sound source is divided into some elements by lumped sound source method, in which, the biggest size of element is smaller than the smallest wavelength of sound wave

    邊界條件法僅對原有的有限元程序作較小修改,並在已有的有限摘要元網格劃分上,能夠求解出接收點處的低頻聲傳遞函數;集中聲源法將大尺度聲源劃分為若干板塊,其最大幾何尺寸小於最小聲波波長。
  10. The content of this theme is as follows : without time, without open, without stopping railway transport, and without interrupting traction current of block tested, meanwhile track circuit parameters in electrical and no electrical blocks is measured of on - line, dynamic and real - time. these parameters include voltage of fsk signal, voltage of industrial and harmonic wave interference, upper frequency, lower frequency, carrier frequency and low frequency 18 messages frequency

    本課題研究內容:在不要點,不開天窗,不中斷行車,不中斷被測區段牽引電流的情況下,在線、動態、實時測量電化區段和非電化區段的移頻信號電壓、工頻干擾電壓,移頻信號(調頻信號)的上邊頻、下邊頻、載波頻率、以及低頻18信息頻率等參數。
  11. Mechanism of the influence of low frequency modulating magnetic field on brain wave rhythm

    低頻調制磁場對腦電節律的影響機理
  12. One is to use fourier transformation to convert the source signal from time domain to frequency domain and to discard high frequency harmonious components upwards of 19 ( gb / t14953 - 93 d5. 3 demanding ), then to have static huffman coding to the quantized char array which is composed of reserved direct current component and basic wave and each high frequency " s amplitudes and angles. the other is to use discrete wavelet transformation to convert the source signal from time domain to frequency domain and to set the high frequency coefficients that its absolute value is smaller than the given threshold to zero, then to have dynamic huffman coding to the quantized char array which is composed of multiple, wavelet ' s level, datum length, low frequency coefficients and reserved high frequency coefficients. mass simulinks and analyses under the two circumstances have done to show that data compression ratio is small and the relative error is also small and within the permission of engineering and the compression problem can be solved in theory of measured datum of power system

    第一種情況的壓縮方法為:採用傳統的傅立葉變換把原始信號從時間域變換到頻率域,舍棄20次及其以上的高次諧波成分(保證了gb / t14953 ? 93d5 . 3要求) ,然後對保留的直流分量、基波和各次諧波的幅值和相角數據量化后和量化時分別乘以的倍數系數構成一個數組,以字元形式保存,採用靜態huffman編碼對變換數據進行壓縮;採用離散小波變換把原始信號從時間域變換到頻率域,然後對分解得到的高頻系數進行閾值量化處理,對乘以的倍數系數、小波變換的階數、小波變換后的低頻、各級高頻以及原始數據長度、量化后的低頻系數以及保留的高頻系數大小、位置構成一個數組,以字元形式保存,採用動態huffman編碼對這個文件進行壓縮。
  13. This can increase efficiently the signal - noise ratio of seismic record, under the general situation, the signal - noise ratio of big scale is small, because low frequency surface wave in big scale is more serious, the correlate of signal is smaller, so weighting stack can press efficiently low frequency surface wave, comparative promote the percentage of the effectual signal in constructing the signal

    這樣可以有效地提高重構后地震剖面的信噪比,一般情況下,大尺度的信噪比都較低,因為大尺度內的低頻面波比較嚴重,信號相關性較小,這樣做加權可以有效地壓制低頻面波,相對地提升有效信號在重構信號中的百分比。
  14. For few domestic and international studies of the radio propagation in the overburden of the earth ' s crust, this paper theoretically stresses the propagation problem of low frequency radio wave, including slf wave and vlf wave, in the medium and briefly introduces the theory of scale model testing method

    針對國內外有關電波在地殼覆蓋層中傳播研究工作的空白,本文主要從理論上討論低頻(包括特低頻和甚低頻)無線電波在該種介質中的傳播問題,並簡要介紹縮比模型測量理論。
  15. The low - frequency slot harmonic modulation is used to weaken the end effect or decrease the wave of the thrust, and the many projects are designed or the better project is selected

    採用齒諧波低頻調制的設計方法,來削弱直線電機固有的端部效應,使推力的波動減小,並進行了多方案計算,得出比較好的設計方案。
  16. The more poles mode, the unequal pole width mode ; the low - frequency slot harmonic modulation mode and the mode of changing end magnetic conductance are presented, and these designing method can efficiently weaken the end effect and decrease the wave of the thrust

    提出的採用多極電機方式;初級與次級極距不等的方式;齒諧波低頻調制方式和改變電機兩端部磁導的方式等電機的設計原則和方法,都可有效地削弱端部效應,減小推力的波動。
  17. An acoustic wave propagation model in low frequency multi - layered media of shallow sea

    淺海低頻多層介質中聲傳播損失的數學模型
  18. At the end of the thesis, the review on the developments of low - frequency square wave electronic ballast is given. then a novel two - stage low - frequency square wave electronic ballast for hid lamps is proposed with detailed proposed circuit analysis and control circuit description. finally simulation and experimental results are provided to verify its superiority

    論文最後對低頻方波電路的發展概況作了綜述,在此基礎上提出了一種新型的兩級式低頻方波電子鎮流器,並對其工作原理及控制電路進行了詳細的分析,最後通過模擬和實驗結果對電路進行了驗證。
  19. Ground roll wave has characteristics of strong energy, low frequency and slow attenuation

    摘要面波具有能量強、頻率低、吸收衰減緩慢等特點。
  20. At the end of the paper, a novel two - stage low frequency square wave electronic ballast for hid lamps is proposed with detail design process. simulation and experimental results are provided to verify its superiority

    最後論文提出了一種新型的兩級式低頻方波電子鎮流器,並給出了詳細的設計方法,論文同時提供了模擬及實驗結果對電路進行了驗證。
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