low-frequency spectrum 中文意思是什麼

low-frequency spectrum 解釋
低頻光譜
  • 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。
  • spectrum : n. (pl. -tra )1. 【物理學】譜,光譜;波譜;能譜,質譜。2. 【無線電】射頻頻譜;無線電(信號)頻譜。3. 【心理學】(眼睛的)余像;殘像。4. 〈轉義〉范圍,幅度;(連續的)系列。
  1. 2. the spectrum correcting technique is applied in one dimension distance sidelobe restraining successly and deal with well with this understanding of zero or low doppler frequency and without noise, mussy weaves

    2 、在一維距離旁瓣抑制中成功地應用了譜修正技術,在無噪聲、雜波干擾,零或低多普勒頻率情況下,處理效果良好。
  2. However, the efficiency of pwm at light load is low and the filter design of pfm is rather difficult due to the random characteristic of the frequency spectrum distribution

    採用相應調制方式的ic品種繁多,各有千秋。但pwm在輕載時效率較低,而pfm由於頻譜分佈隨機,不利於后續濾波器的設計。
  3. Because blue and red are respectively near the frequency of high and low ends of the visible spectrum

    由於藍及紅為可見光譜中頻率最高及最低的兩端,所以在天文學中,我們稱恆星光的
  4. Frequency - hopping ( fh ) is a novel spread spectrum communication technique, which develops very fast in military field due to its lpi / lpd ( low probability of intercept / detection ) properties and immunity against interferences, the extensive application of hf ( high frequency ) frequency - hopping radios in military has greatly enhanced the ability of military equipments against jamming and interception and brought up a new austere challenge for communication countermeasures

    跳頻通信具有良好的抗干擾性,低截獲概率及組網能力,因此跳頻技術的一出現,便在軍事領域得到了極大的發展,採用跳頻技術的短波電臺在軍事通信中得到了廣泛應用,極大地提高了軍事裝備的抗截獲和抗干擾能力,向通信對抗提出了嚴峻的挑戰。
  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 main purpose of this study is to simulation a random fluctuation of wind velocity fitted to specified power spectrum in low frequency range in our wind tunnel

    本文研究的目的是在風洞中模擬風速隨機波動的陣風,這個基礎性工作對于開展風洞中的其它研究有著重要意義。
  7. After filtering out the part of low frequency from the data coming from condition monitor and calculating the comprehensive magnitude of spectrum around the clap - frequency, the alarm limit of clap - frequency vibration mal - functions are determined by using statistical method

    從信號中濾除高頻成分,求得樣本拍頻附近譜線的綜合幅值,用數理統計的方法確定了拍振故障報警限。
  8. Doing the further research on the division frequency stack on the foundation of study of predecessor, at first the residual moveout correction is done to the seismic record, make the phase axle regularity, doing foundation for the same phase stack ; then carried on division scale processing by wavelet transform ; spectrum whitening is done to each scale, the high and low frequency band need to do prolongs, the middle frequency bands only increase the value of the frequency spectrum ; several kinds of methods that estimate the value of signal - noise ratio has been studied further, and summarize their advantage and disadvantage as well as the scope of application ; the seismic record after spectrum whitening is stacked by weighting with the value of the signal - noise ratio ; then estimate the value of signal - noise ratio which is each scale section after stacking, the scale that the signal - noise ratio is big is assigned big weighting, otherwise, the scale that signal - noise ratio value is small is assigned small weight ing, and carried on weighted reconstruct to each scale section

    本文在前人研究的基礎上,在分頻疊加方面做了進一步的研究。首先對地震記錄進行剩餘時差校正,校齊同相軸,為同相疊加做好基礎工作;然後對地震記錄用小波變換的方法進行分尺度處理;對各個尺度分別做譜白化,對于高、低頻段需要做頻帶延拓,中間頻段僅提升頻譜值;對于幾種信噪比定量估計的方法進行了深入的研究,並且總結了它們的優缺點以及適用范圍;對譜白化后的地震記錄用信噪比估計值作為加權系數進行加權疊加;對于各尺度的疊加剖面也進行信噪比估計,對于信噪比大的尺度給予大的加權系數,反之,信噪比值小的尺度給予小的加權系數,對各尺度疊加剖面進行加權重構。
  9. Results show that all the parts of the artillery produce vibration acceleration in the traveling course. the power spectrum is mainly in the low frequency segment. worse road surface and higher speed will cause higher power spectrum value of the acceleration response

    結果表明火炮牽引行駛過程中各部件均產生振動加速度,其功率譜主要分佈在在低頻段,路況差、速度高則加速度響應的功率譜值高。
  10. In the end of this chapter, the power spectrum density ( psd ) analysis of hrg is given, which shows that the main noise of hrg is low frequency noise

    論文還對陀螺信號進行了功率譜密度分析,分析結果表明陀螺的主要誤差都集中在低頻段。
  11. Frequency sweep flight technique is used to collect the flight data of a model helicopter near its hover and low speed working condition, window frequency spectrum is combined to obtain the frequency response of both lateral and longitudinal channels, then weighted fitting method is utilized to obtain the transfer functions of the two channel

    摘要利用掃頻試飛技術獲取了某無人直升機在懸停工作點附近的舵機輸入和直升機動態輸出數據,利用組合窗頻譜分析的方法獲取了直升機橫滾通道與俯仰通道動態的頻率響應特性,利用加權擬合的方法獲取了各自的傳遞函數。
  12. Abstract : the recent theory and design method of the magnetoelectric induction sensor in bearing field is introduced. the author provides two sensors ' main technical performances and a new measurement method of the bearing and other wide frequency spectrum and low amplitude vibration objects

    文摘:主要介紹了國內外近些年在軸承行業開發的軸承振動測量中應用的磁電感應式傳感器的原理與設計方法,並介紹了二套傳感器的主要技術指標,對軸承及其它寬頻譜低振幅振動量的測試提供了一套新的測試手段。
  13. From theoretical analysis, we know the existing demodulation methods have limitations as following : one is that the subtraction of the two signals frequencies will display as the result of demodulation when we demodulate two time - domain adding signals without modulating information ( fault information ) ; the other one is that aliasing phenomenon will occur as a result of getting absolute value, detection or square in the process of generalized demodulation analysis, such phenomenon will result in some superfluous frequency composition on the frequency spectrum, which will puzzle the detec tion of mechanical vibration. if the sampling frequency is selected from a suitable range, the aliasing phenomenon will be avoided ; the last one is that aliasing frequencies will be produced in zoom demodulation analysis because this algorithm cannot employ digital low - pass filtering to avert the folding frequencies of higher harmonics in the process of zoom sub - sampling

    現有的解調分析方法存在以下三種局限性:將不包括調制信息(故障信息)的兩時域相加信號,也以其頻率之差作為解調信號而解出;廣義檢波濾波解調分析中,由於取絕對值、檢波或平方過程可能產生混頻效應,在解調譜中表現為無法分析的頻率成分,並由此推導出避免這種混頻現象的采樣頻率的選取范圍,從根本上避免此類誤診斷的產生;幾種細化解調分析新演算法中,因為無法在細化分析的選抽時進行數字低通濾波,有可能會出現調制頻率的高次諧波成分發生頻率混疊而反折到低頻部分的現象。
  14. During this process electrons will not only lose energy for self - radiation, but also gain energy from induced absorption. on the basis of analyses, the radiation with low frequency by relativistic electrons will form rayleigh - jeans spectrum in optically thick medium

    由等離子體中輻射譜計算公式得到,在光學厚的介質中麥克斯韋分佈的極端相對論性電子產生的同步加速輻射譜為瑞利?金斯譜。
  15. As a result, the low - frequency contents increase as the centroid of signal spectrum experiences a downshift, in case that frequency is independent on quality factor, the offset of the centroid frequency is proportional to the integral of attenuation factor along wavepath, thus can he used to reconstruct the attenuation distribution

    假設介質的品質因子與頻率無關,地震波主頻的偏移量與吸收系數對傳播路徑的積分成比例,則通過它們之間的關系可以估測介質的吸收系數。
  16. The mechanism for the fault of the working state of anode is studied in this paper. the spectrum of the sampled signals is got using the technique of amplitude - frequency analysis, then the corresponding iir butterworth digital filter is designed to separate the low - frequency part and the high - frequency part using digital filter design technique

    利用頻譜分析技術對采樣信號進行頻譜分析,並採用數字濾波器設計技術設計了相應的r型butterworth數字濾波器,將信號中的低頻信號和高頻組分進行分離,從中提取出與陽極工作故障有關的特徵量。
  17. This paper has discussed preparing diamond - like carbon films by means of micro - wave ecr plasma source ion implantation and plasma enhanced chemical vapour deposition. we use the raman spectrum, ft - ir, afm and so on to study the dlc film. the result indicates : different bias voltage, frequency and gas flow rate of psii will have impact on sp3 proportion of dlc films, we find high bias voltage, low frequency and moderate gas flow rate can prepare high sp3 proportion dlc films ; we simply illustrate the influence of bias voltage on sp3 proportion of dlc films in pecvd

    研究結果表明:在全方位離子注入技術中,不同的偏壓、頻率、氣體流量都對薄膜中sp ~ 3鍵比例有所影響,文中對具體的影響進行了分析,發現偏壓的增加、頻率的降低和適中的氣體流量可以制備出sp ~ 3鍵比例高的類金剛石膜;在等離子增強化學氣相沉積技術中,對偏壓對sp ~ 3鍵比例的影響也進行了簡單分析。
  18. The multiresolution method is extended and applied to random vibration control system, thus a multiresolution random vibration control algorithm is created, which provides a satisfied solution to the poor control precision problem at low frequency that was pointed out and remained unsettled for many years. the control algorithm has been successfully implemented on dactron ' s shaker control system, showing great improvement in low frequency control precision, with a little more computation resource consumed. high resolution octave analysis is another successful application of multiresolution spectrum estimation theory

    在多抽樣率信號處理理論和多分辨譜估計理論的基礎上,本文進而將多解析度思想推廣到隨機振動控制理論中,提出了多分辨隨機振動控制演算法,解決了振動控制界多年來懸而未決的低頻控制精度問題,並在dactron公司laser ~ ( tm )和comet ~ ( tm )等多種振動控制產品中得到了成功的應用,在計算量增加不大的前提下取得了令人滿意的控制效果。
  19. The super - low frequency and distortion power amplifier is developed with opa512 operation amplifier produced by bb co. in america. and the analyses software of frequency spectrum based on fft is designed

    研製了超低頻、低失真功率放大器;開發了基於fft超低頻頻譜分析軟體,並對它們進行測試與分析。
  20. Actual measurement indicates that the displacement and acceleration of rail vibration both have random property, the displacement spectrum mostly has obvious low frequency contets which occupy dominant peak value range

    實測表明,軌道振動的位移和加速度都具有隨機特性,位移頻譜組成以低階頻率為主,且有明顯占優勢的峰值區域。
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