low-frequency modulation 中文意思是什麼

low-frequency modulation 解釋
低頻調制
  • 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。
  • modulation : n 調整，調節；（聲調的）抑揚，變化；【音樂】轉調，變調；【無線電】調制。 amplitude modulation 振...
  1. The calls of non - passerine are some kinds of monotonous dull vocalizations with the characteristics of low and deep frequency, single syllable, low basic frequency and with no ability of modulation in frequency and amplitude. most of the calls are monotonous and low quality mainly based on the basic song. compare the vocal of sub - oscine passerine with non - passerine, they have some similar aspects, but the former possesses of stronger capability of vocal control

    非鳴禽的叫聲低沉而單調，音節種類單一，基本音頻率低，缺乏頻率調制以及幅度調制的能力，叫聲的品質因數很低，不悅耳，大多為以基本音為主的單音調低音品叫聲，亞鳴禽的叫聲與非鳴禽近似，但在控聲能力方面又有所提高。
  2. The second, at the high frequency primary coil, when switch turn on with control signal ( the spwm pulse is modulated ), in the positive or negative semi - period of low frequency modulation signal, transformer coil with same direction voltage. the magnetic flux of transformer core will increase step by step. at the end, it leads to magnetic flux saturation

    二、在高頻變壓器原邊，當開關管接收控制信號脈沖列（經調制的spwm波列）導通時，在低頻調制信號的正半周或負半周內，施加在變壓器繞組上的是同一方向的電壓，變壓器磁芯中的磁通可能將級進地逐漸增加，導致磁芯飽和，造成磁偏或單向磁化，導致低頻電信號放大失真或由於很大的磁化電流而無法正常工作。
  3. Some people living near wind farms complain they are kept awake by a phenomenon known as aerodynamic modulation ( am ), low frequency noise made as the blades swoosh through the night air

    有些住在風力發電廠附近的人抱怨，他們因為一種稱為空氣動力調變的現象，即輪葉的颼颼聲劃過夜空，產生低頻噪音，以致無法入眠。
  4. In view of this situation this article has conducted research to the design of metallurgy auxiliary biography with the frequency conversion table electrical machinery first multianalysis to the frequency changer and the frequency conversion table electrical machinery movement characteristic is carried out, the voltage waveform harmonious which the frequency changer outputs is big, attacks in a big way, and the voltage climbing rate reaches as high as 6600v / mu s which is 20 times ordinary sine alternating voltage, the rolling mill auxiliary biography table set the extremely strict request to the electrical machinery ; its movement frequency is very low, rate frequency in 8 - 20hz ; the velocity modulation scope is wide, the lowest movement frequency lowers to 1hz, and the starting number of times is quite frequently, each hour reaches as high as 600 - 800 time, the impact shoulders in a big way, the overload capacity request is high

    針對這一情況本文對冶金輔傳用變頻輥道電機的設計進行了系統研究。首先對變頻器和變頻輥道電機的運行特性進行詳細分析，變頻器輸出的電壓波形諧波大，沖擊大，電壓上升率高達6600v / s ，是普通正弦交流電壓的20倍;軋機輔傳輥道對電機提出了十分嚴格的要求:其運行頻率很低，額定頻率在8 - 20hz ;調速范圍寬，最低運行頻率低到0 . 5hz ，起動次數相當頻繁，每小時高達600 - 800次，沖擊負荷大，過載能力要求較高。
  5. Chaotic switching modulations introduce low - frequency harmonic spectrum of output voltage as random switching modulation. in some case, low - frequency noise ripple offset the effect chaotic switching modulations reduce the level of emi. it indicates that the ccfmfd integrates the advantages of spreading harmonic power at the multiples of the switching frequency and not introducing significant noise ripple at low - frequency range. among all chaotic switching modulations, the ccfmfd is considered as the best choice in applying to dc / dc converter

    與隨機調制模式相同，混沌開關調制模式也引入輸出低頻噪聲紋波，有些情況下低頻噪聲紋波可能抵消混沌開關調制降低emi水平的效果。分析表明： ccfmfd模式具有較好的降低emi水平和引入較小低頻紋波的優點，可以作為混沌調制模式較佳的選擇。
  6. The study has completed the design of two - phase inverter and made up of the two - phase inverter - motor system for experimental use it is a variable frequency adjustable speed system with a open - loop control of rotational speed, which consists of voltage - controlled oscillator circulating assign device inverter circuit and two - phase induction motor a accurate mathematical model is set based on the whole system, and simulator program of dynamic and steady condition is established, which is used to calculate the dynamic and steady performance by kron and symmetrical coordinate converter by simulator calculation and experimental research with specific parameter of the system, a comparison is made between predicted and experimental characteristics, experimental measurements are shown to compare closely with corresponding theoretical result it is compared with some variable frequency adjus table speed system comprising inverter and single - phase induction motor from the system efficiency torque pulsation and the effect of two - phase inverter capacitance based on the conclusion, harmonic cancellation pulse width modulation control of a two - phase inverter - fed induction - motor drive system is researched, which cancelled the low harmonic and improve the system performance

    通過對電機的kron變換和對稱分量變換，建立了系統較精確的數學模型，編制了系統動態及穩態運行的模擬計算程序分別計算系統的動態和穩態性能。通過對系統的具體參數進行了模擬運算和實驗研究，實驗和模擬結果進行比較，說明實驗和理論較為一致，並從系統效率、轉矩脈動及兩相逆變器電容的影響等方面與各種逆變器和單相異步電動機組成的變頻調速系統加以比較。在此基礎上，對兩相逆變器供電-異步電動機系統使用諧波抑制pwm控制進行了研究，由於減少了低次諧波，改善了系統性能。
  7. Furthermore, the range of measurement of it was pointed out. all the analysis shows that our crsi 1il can be used to measure the spatial mid and low frequency wavefront distortion. 5. based on our crsi and algorithm, the phase modulation characteristic of an lcslm was measured

    五、利用環路徑向剪切干涉儀共光路、雙光束干涉的特點，全場準確測量了液晶空間光調制器的位相調制特性，並且利用它的位相調制特性實現了臺階位相板畸變波前的補償，由此證明了液晶空間光調制器可用於控制波前畸變。
  8. The electric power harmonic comprehensive control system with low cast and high security is applied in this article. it adopts that sourced compensation links with non - sourced compensation herewhich the former is realized by high frequency pwm control technology and the latter is carried out by crystal switch formed by non - flow and over - voltage. it can realize stepless modulation with imaginary power, mightiness compensation of harmonic and negative electricity, and circuitry consumption debasing are achieved

    提出採用有源補償與無源補償相結合的電力諧波綜合治理技術及裝置，無源部分採用無涌流和過電壓的晶閘管控制電容器技術實現，有源部分採用高頻pwm控制技術實現，成本低、可靠性高、可實現無功功率的無級調節、強力補償諧波電流和負序電流，降低線路損耗。
  9. Because frequency - shift signal is a kind of modulation signal, it ' s waveform is two ac sine signal of alternating i. e. upper frequency and lower frequency which was generated by low frequency modulating middle frequency

    由於移頻信號是一種調頻信號，其波形為低頻信號調制中心載頻信號后產生的低端載頻（下邊頻）和高端載頻（上邊頻）兩個交替變化的正弦交流信號。
  10. The three - phase high - frequency ac pulse density modulation ( pdm ) converter, which is proposed in this paper, can efficiently synthesize low - distortion variable frequency variable amplitude low frequency voltage signals from the fixed - frequency voltage of the high frequency link

    本文闡述的高頻交流脈沖密度調制（ pdm ）的控制策略能夠較容易地將高頻交流信號低失真地合成幅值和頻率變換的低頻信號。
  11. Because of the advantages of no range blind area, high range resolution, low signal power and simple structure, lfmcw ( linear frequency modulation continuous wave ) radar attracted more and more attention recently

    線性調頻連續波（ lfmcw ）雷達是一種通過對連續波進行頻率調制來獲得距離與速度信息的雷達體制系統。由於其具有無距離盲區、高距離解析度、低發射功率、結構簡單，便於集成化等優點，適合用於液位測量系統。
  12. First a diagnostic analysis is carried out to research the frequency modulation effect that the el - nino and la - nina events has on atmospheric low - frequency oscillation ( lfo ) in the mid - high latitudes

    首先用診斷的方法，研究了el - nino和la - nina事件對中高緯大氣低頻振蕩的調頻作用。
  13. 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。
  14. 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。
  15. Chaotic switching modulations generated from different chaos sequences introduce low - frequency output noise ripple : in the cpwm, cppm and ccfmvd, the output noise ripple introduced by henon map chaos sequences is smaller than chua ' s circuit chaos sequences ; in the ccfmfd, chua ' s circuit chaos sequences introduced smaller noise ripple. this clue to us that it is important to choose chaos sequences in applying chaotic modulation to dc / dc converters

    不同混沌調制信號對輸出紋波影響的分析結果表明： cppm 、 cpwm和ccfmvd模式下， henon映射混沌序列引入低頻噪聲紋波比蔡氏電路摘要混沌序列要小; ccfmfd模式下，蔡氏電路混沌序列引入的低頻紋波要小。這提示我們:在開關模式電源使用混沌調制控制時混沌序列的選擇也具有重要性。
  16. The main results and creative points in the dissertation were as follows : a ) by means of studying on the fiber - optic hydrophones ’ tdm array based on phase generated carrier ( pgc ) demodulation with laser frequency modulation, the mathematic models were set up, used for theoretical analyses of noncoherent crosstalks in the system using low coherent laser and coherent crosstalks in the system using high coherent laser. the formulas calculating crosstalks were given, and the method measuring crosstalks was shown definitely

    本論文的主要研究結果和創新在於: 1 、通過對基於光頻調制pgc （相位生成載波）解調光纖水聽器時分復用系統的研究，針對低相干光源的串擾強度迭加和高相干光源串擾的相干迭加，建立了理論分析的數學模型，得出了計算串擾的公式，明確了測試系統串擾的方法。
  17. Digital adaptive heterodyne filter adopts the heterodyne - modulation conception, which makes the filter work in low frequency and lessens the complexity of design

    數字自適應外差濾波器運用外差調制的概念，使濾波在低頻率處操作，從而降低了濾波器的復雜程度。
  18. Firstly, the low frequency vibration of benfield frame is analyzed and tested. the nature and reason of the vibration of benfield frame are analyzed. a modulation theory is suggested and displayed to explain the low frequency vibration reason of benfield frame

    文章首先分析和測試了苯菲爾框架的低頻振動，分析了苯菲爾框架大幅低頻振動的性質和原因，提出了造成框架振動的低頻調制理論。
  19. Speed sensor has the limitation of high cost, taking up more space, low reliability and high dependency of working condition. speed - - sensorless frequency modulation system avoids those defects and can meet the need of high performance of ac motor driving which is a stress field

    無速度傳感器變頻調速系統既避免了速度傳感器帶來的成本增加、體積增大、可靠性降低、易受工作環境影響等缺陷，又能夠滿足高性能交流傳動的需要，是運動控制發展的一個重要方向。
  20. A system for the weld power source was established with digital signal processor ( dsp ), and variable polarity power supply output, high - frequency pulse current, protection and process control were fulfilled with the software all, and modulate low frequency pulse current by means of amplitude modulation, through which it could also control the shape of weld seam like the low frequency pulse current welding

    在模擬控制器基礎上引入了dsp數字控制技術，用軟體編程實現了電源的變極性輸出、高頻脈沖電流的疊加及保護和電源的時序控制，使之能夠在大尺度上調制出低頻脈沖，控制焊縫成形。
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