無載頻率 的英文怎麼說

中文拼音 [wúzǎibīnlǜ]
無載頻率 英文
free-running frequency
  • 無 : 無Ⅰ動詞（沒有） not have; there is not; be without Ⅱ名詞1 （沒有） nothing; nil 2 （姓氏） a surn...
  • 載 : 載Ⅰ名詞（年） year : 一年半載 six to twelve months; six months to a year; 三年五載 three to five ...
  • 頻 : Ⅰ形容詞（次數多） frequent Ⅱ副詞（屢次） frequently; repeatedly Ⅲ名詞1 [物理學] （物體每秒鐘振動...
  • 率 : 率名詞（比值） rate; ratio; proportion
  • 頻率 : frequency; rate
  1. Whatever it is radar, eccm equipment, communication equipment or instrument, frequency source with high stability is needed to guarantee the quality of carrier signal

    無論是雷達、電子對抗，還是通信、儀器設備等都需要高穩定度的頻率源，以保證載波信號的質量。
  2. The programme logic controller is utilized to control the inverter ' s output frequency which accomplishes controlling the velocity of speed - controlling asynchronous moter. the velocity between main asynchronous moter and speed - controlling asynchronous moter is composed by way of the differential planetary gear train, the tranmission system is made to regulate velocity stepless in large scope which succeed in controlling starting progress of load

    使用可編程式控制制器對變頻器的輸出頻率進行控制，實現對調速電機轉速的控制。調速電機與主電機的轉速經差動行星輪系的速度合成，可使傳動系統在很大范圍內無級調速，實現對負載的可控起動。
  3. This paper describes mainly system functions, measuring methods, circuit design, software program and errors analysis of a new type of measuring instrument. this instrument can measure and monitor electric parameters in single - phase circuits, three - phase ( three - wire or four - wire ) circuits. this system can be applied to electric devices and power plants, transformer substations with harmonic pollution. it can measure current, voltage, power, energy, frequence, power factor etc. it also can detect load quality, phase sequence, alarm, display and print results, as well as detect and dispose negative power

    該儀器適用於含有諧波污染情況下的機電設備現場、發電廠、供電局、企業變電所現場，可用來測量電流、電壓、有功功率、無功功率、視在功率、有功電能、無功電能、視在電能以及頻率和功率因數等電參數，並具有負載性質（感性、容性）判別，正、逆相序判別指示功能；超限報警功能；列印記錄功能和負功檢測及處理功能。
  4. Secondly, to achieve the independent regulation of active and reactive power output from the generator side which is designed for the purpose of tracing the maximum wind - energy capturing. the paper has analyzed the mathematic model of the ac excited doubly - fed machine and the stator field orientation control strategy of the motor as vscf wind power generator. thirdly, it has put forward and designed the dual pwm converter with the capacity of energy flowing bidirectional aimed at the demand of rotor energy bidirectional flow. the author constructed reliable and integrated experimental system and did a series of experimental study including no - load, cutting - in network and power generation at, below and above the synchronous speed

    論文首先分析了風機運行特性及其最佳風能利用原理，通過模擬及實驗驗證了採用直流電機的輸出特性模擬風力機的最大輸出功率曲線的可行性，並給出了模擬系統的硬體結構；然後為了實現交流勵磁發電機有功、無功功率獨立調節機理，分析了交流勵磁雙饋發電機的數學模型和在追蹤最大風能捕獲變速恆頻風力發電時必需的定子磁鏈定向矢量控制策略；針對雙饋發電機轉子能量雙向流動的要求，提出並設計了具有能量雙向流動能力的雙pwm交流勵磁用變頻器；最後為實現從理論到實踐的全面研究，研製出了一套小功率完整的雙pwm變頻器交流勵磁的雙饋風力發電機實驗系統，進行了空載、並網、同步速及上、下的發電運行等一系列的運行實驗；所完成的模擬和實驗研究均驗證了理論、模型和控制策略的正確性、可行性。
  5. Associated with three research projects, this work is mainly concerned with array elements, array structure and calculations of array impedances versus operating frequencies. in the dissertation, the author ' s major contributions are as follows : a new types of array structure, known as circular reflection array, is proposed and studied. a detailed analysis to the new structure with two cases is presented

    本文緊密結合「十五」國防預研「軟體無線電天線」和海軍預研「智能天線在艦艇上的應用」及「機載微帶天線」等項目，著重對智能天線陣列的陣列單元、陣列結構、陣列阻抗的頻率特性計算等技術進行了分析和研究，所取得的主要成果如下： 1
  6. We, then, parameterized a semi - empirical model for the different land surface cover types. this semi - empirical model was applied to minimize the effects of the vegetation volume scattering and extinction in radar measurements

    此外，目前星載合成孔徑雷達如ers - 1 2 、 radarsat等均為單一頻率、單一極化的雷達，無法從得到的單參數雷達後向散射系數中直接提取地表土壤水分信息。
  7. A modulated signal of tria ( tt / pw ) added by a normal noise. is demonstrated for 2 - d dependence of the waveform on time and trials and 2 - d dependence of spectrum on frequency and trials to show different time domain and frequency domain properties of a random process including noise and signal

    以三角波電壓訊號加上準常態雜訊乘以無雜訊載波之調變訊號為例，圖示含有雜訊電壓訊號其波形隨時間及試驗之二維變動及頻譜隨頻率及試驗之二維變動，顯示雜訊與訊號之隨機過程在時域與頻域之不同特性。
  8. A modulated signal of eexp ( 2 * tt / pw ) added by a zero mean uniform noise. is demonstrated for 2 - d dependence of the waveform on time and trials and 2 - d dependence of spectrum on frequency and trials to show different time domain and frequency domain properties of a random process including noise and signal

    以雙邊遞減波電壓訊號加上均勻雜訊乘以無雜訊載波之調變訊號為例，圖示含有雜訊電壓訊號其波形隨時間及試驗之二維變動及頻譜隨頻率及試驗之二維變動，顯示雜訊與訊號之隨機過程在時域與頻域之不同特性。
  9. Hunting hunting is a phenomenon that can occur upon load changes in which the frequency or the voltage continues to rise above and fall below the desired value without reaching a steady - state value

    游車游車是一種在負載變化引起的頻率、電壓高於或低於期望值，無法達到穩定的現象。
  10. Based on fourth - order cumulant, a computationally efficient method for joint estimating both directions of arrival and ranges of near field sources with known carrier frequency is firstly presented. the proposed algorithm need not any spectral peak searching and the 2 - d parameters are automatically paired. lt is suitable for arbitrary additive gaussian noise environment. in the following section, a 3 - d esprit method for jointly estimating of frequencies, doa ' s and ranges of multiple near - field sources with unknown carrier frequencies is proposed. the parameters estimation are given by the eigenvalues of different matrices. furthermore, its performances are confirmed by several computer simulations

    利用四階累積量，第五章首先給出了一種載頻已知的情況下基於近場源的距離和波達方向聯合估計演算法，通過構造的陣列輸出信號四階累量矩陣使空間信號到達方向和距離估計無需譜峰搜索，且參數自動配對，適合於任意高斯噪聲環境。進一步在第三節提出了一種載頻未知的情況下的多個近場窄帶信號源doa 、距離和頻率聯合估計的3 - desprit演算法。
  11. In this paper, low power flip - flops designs by the reduction of the load of clock or the data path ; by the reduction of clock swing ; by the reduction of clock frequency and by the reduction of those idle transitions in cmos circuits with clock gating are discussed

    與此相對應的，在本論文中，分別對將少時鐘負載或數據通路的負載的觸發器設計；減小時鐘信號幅度的觸發器設計；降低時鐘頻率的雙邊沿觸發器設計以及應用門控技術來減少觸發器無效跳變設計的觸發器結構進行了討論。
  12. Radio wave is the tool of information transferring. frequency is one of the most important characteristic parameters of radio wave, which means the presentation times of a wave in a unit time

    無線電波是運載傳遞信息的工具，頻率是無線電波的一個重要參數，它是指無線電波在一個單位時間內重復出現的次數。
  13. With the downlink simulation model constructed, performance of wideband cdma under different radio propagation environment and vehicular speed is simulated. based on system model of mc ds cdma under flat fading channel with relative shifts of spreading sequences within 1 chip and frequency selective fading channel with arbitrary relative chip shifts, performance of multicarrier cdma system with go sequences under different radio environment is investigated

    基於多載波直接序列碼分多址在乎坦衰落通道中序列偏移小於1個碼片及在頻率選擇性衰落通道中偏移任意個碼片的系統模型，本文還分析了採用廣義正交序列的多載波碼分多址系統在不同無線傳播環境下的性能。
  14. On the basis of the former research works, we present the detecting method as follows : for the narrow band characteristic of the track signal we use under - sampling instead of nyquist sampling to reduce the sampling rate. as to the carrier frequency, the spectrum of the 18 - information frequency - shift track signal has two peaks, then the carrier frequency is the average of the two peak frequency, to um - 71 jointless track signal, it has only one peak, then the carrier frequency is the peak frequency

    針對移頻軌道信號的窄帶特性提出了使用欠采樣技術代替奈奎斯特采樣的方法，以降低信號的采樣頻率;國產18信息移頻軌道信號頻譜具有雙峰，雙峰頻率平均值就是信號的載頻頻率，而um - 71無絕緣軌道信號頻譜單峰，峰值頻率即為信號的載頻頻率。
  15. This paper simulates and analyses the torque pulsation because of the modulation frequency and speed variation under ambipolar pulse width modulation ; the influence of snubber circuit, dead time effects, and modulation frequency to igbt pwm inverterbridge is taken into account, too

    本文對雙極性調制的無刷直流電動機模擬，分析了轉速和調制頻率對轉矩影響；並綜合考慮緩沖電路、控制死區及載波頻率對pwm逆變電路中igbt開關損耗的影響。
  16. It ’ s significant to develop the parallel multiprocessor real time system for our space discovery cause. the single cpu ’ s frequency cannot increase endlessness, because of the space environment ’ s high radiance

    在滿足航空晶元抗輻射性能要求下，單cpu的頻率無法持續增長，研究星載嵌入式多處理器系統對於我國的航天事業具有十分深遠的意義。
  17. Realizing the impact of chirp on the effect of carrier phase, some analytical expressions of chirped few - cycle pulses are also calculated, such as frequency gravity, pulse energy, center of gravity of time, effective pulse width, etc. results show that chirp makes the pulse characteristics more sensible to carrier phase, and chirp has greatly increased the pulse width when the carrier phase takes effect

    考慮到啁啾對載波相位作用程度的影響，導出了啁啾脈沖的頻率重心、脈沖攜帶的能量、脈沖時間重心以及有效寬度等參量的解析表達式，分析表明，啁啾使得載波相位比無啁啾的情況提前起作用了，即啁啾在很大程度上增大了載波相位發揮作用所對應的脈寬范圍。
  18. However, in hf band, the band of the antennas is narrow, and the input impedance of monopole antenna with limited height undergoes rapid variation with frequency

    但是，在hf頻段，有限高無加載單極子天線帶寬相對較窄，輸入阻抗隨頻率劇烈變化，難于和50的同軸饋線匹配。
  19. Multicarrier wireless communications have been widely investigated in the past decades. recently, two - dimensional spread spectrum ( 2d - ss ) system has drawn a lot of attention because of its full utilization of spreading characteristics in the frequency domain and time domain. compared with multicarrier code division multiplex access ( mc - cdma ), 2d - ss system can effectively mitigate multiple access interference ( mai ) due to spreading in the time domain

    當前多載波無線通信技術得到了廣泛的研究，二維擴頻通信系統是近年來提出的新的擴頻通信方式，由於二維擴頻系統從時域和頻域上分別對數據信號進行頻譜擴展，因此它同時具有時域擴頻和頻率擴頻通信系統的特點，是對傳統的一維時域直接序列擴頻和多載波擴頻的推廣。
  20. Firstly, in wireless environment, receiver has no know the time delay between transmitter and itself. in ofdm system, ofdm data is transmitted as one symbol, so in order for correct demodulation, the correct start of symbol should be got from ofdm system to reduce the effect of isi. secondly, the high frequency utilization in ofdm is based on the orthogonal properties of sub carriers. if frequency offset is generated, the orthogonal properties among sub carriers will lost, that will cause inter carrier interference ( ici ) and high ber of system

    Ofdm技術也存在著一些缺陷，首先，在無線環境中傳輸的ofdm信號對定時要求高，為了減少碼間串擾（ isi ）影響，必須從接收信號中提取出正確的符號起始位;其次， ofdm系統對頻率偏移敏感， ofdm技術的高頻譜利用率和傳輸可靠性均以子載波的正交性為基礎，如果接收機和發射機之間發生頻率偏移，子載波之間就會失去正交性，導致嚴重的子載波間干擾（ ici ） ，降低系統性能。
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