脈動基頻 的英文怎麼說
中文拼音 [màidòngjībīn]
脈動基頻
英文
fundamental ripple frequency-
In the sub block circuit design, the contents that the author had introduced include : the principle of band gap voltage reference and the design technique in low power supply ; the analysis of spike pulse noise rejection, frequency divider and dead time in oscillator and control circuit ; the selection of the width and length ratio of four switches and 2x / 1x mode change point in driver and mode selection circuits
在子電路設計中，作者比較深入分析的內容有:基準電路的原理及低電源電壓下基準電路的設計;振蕩器和控制電路中尖峰脈沖噪聲抑制、兩分頻電路及死區時間設定;驅動及模式選擇電路中開關管的寬長比的選擇及模式轉換點的設計。Separation of artery and vena in cerebral cortex based on spectrum features
基於頻譜特徵的腦皮層動靜脈分離Backed up by the soplat theory based on particle kinematics, the second chapter of this paper presents with analysis and simulation of several single observer passive measurement models, which uses such relative movement parameters as bearings changing rates and centrifugal acceleration information on the basis of bearings measurements. in the third chapter, the observability of location respectively using bearings and its changing rates information and centrifugal acceleration information is analyzed, and its observable condition is got. the fourth chapter puts forward the modified covariance extended kalman filtering ( mvekf ) against the defect of traditional extended kalman filtering ( ekf ), whose performance is simultaneously compared in the chapter with the performance of ususal tracking algorithm such as ekf, mgekf, iekf by computer simulation
在近年來提出的基於質點運動學原理的單站無源定位理論基礎上，本文第二章提出了幾種在角度測量的基礎上增加角度變化率及相對運動的離心加速度等運動學參數的單站無源測量模型，並對它們進行了分析和模擬；第三章分別對利用角度及其變化率信息定位和利用離心加速度信息定位的可觀測性進行分析並得到了相應的可觀測條件；第四章針對傳統擴展卡爾曼（ ekf ）方法的缺點，提出了一種修正協方差的擴展卡爾曼濾波（ mvefk ）方法，並將其和ekf 、 mgekf 、 iekf等常用的單站無源定位濾波方法進行了性能模擬比較；第五章通過引入雷達機動目標跟蹤方法和模型，提出了利用角度及其變化率對機動輻射源跟蹤的多級噪聲自適應方法和imm方法；第六章主要對角度變化率和離心加速度參數的獲取技術進行了研究，提出了幾種高精度測量脈沖序列多普勒頻率變化率的方法。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。In light of the limitation of fast fourier transform ( fft ) for the method of traditional spectrum analysis to analyze the unsteady signal, wavelet and wavelet analysis are made for the typical unsteady process signal of starting up and shut down with the good characteristic of simultaneous localization in both the time and the frequency domains based on the field test on the vibration of two - row placed units in lijiaxia hydropower station, in which the signal is decomposed into different frequency band, and then the weak signal is caught and the dominant frequency is picked up for the analysis of the vibration source
摘要基於李家峽水電站雙排機組振動的現場試驗研究，並且針對傳統頻譜分析方法傅立葉變換（ fft ）對于非平穩信號已力不從心這一缺陷，利用小波分析方法在時域和頻域上同時具有良好的局部化性質，通過對開停機這一典型非平穩過程信號進行小波及小波包分析，將其分解到不同頻帶內，獲取微弱信息和提取優勢頻率，並對其作振源分析，得出開停機初始時刻因水流不穩均出現強烈的振動現象，且低頻段信號能量最大，開停機過程水流脈動壓力和尾水渦帶擺動是引起定子基礎振動的主要原因。In this thesis improved algorithms are presented as follows : ( 1 ) an algorithm based on the detection of arithmetical series is presented to deinterleave radar signals with stagger pris, especially to those with high order stagger ones. but this algorithm is limited to the model of stagger pri presented by resnick ; ( 2 ) an algorithm is presented to estimate the pris of radar signals with jittered pris based on stochastic dynamic - linear models. this algorithm fits radar signals with jittered pris well, especially when jittered amount is large
針對這種情況，本文提出了以下改進的重頻分選演算法： （ 1 ）針對參差pri脈沖列提出一種重頻分選演算法，該演算法使用等差數列的檢測進行參差鑒別，非常適于對高參差雷達脈沖列的分選，但只局限於雷斯尼克提出的參差模型； （ 2 ）針對抖動pri脈沖列提出基於動態線性模型的重頻分選演算法，非常適用於抖動量較大的情況。The actively and passive mode - locked fiber ring laser and two types of photonic switching, slalom ( semiconductor laser amplifier loop mirror ) and uni ( ultrafast nonlinear interferometer ) were developed. this thesis presented the principle and the requirements for the optical of frequency - shift sampling module under common conditions
研製了作為光取樣脈沖源的主動鎖模和被動鎖模光纖激光器；半導體光放大器環鏡及超高速非線性干涉儀的光子開關，並進行了頻差法光取樣、異步光取樣及基於時分光取樣的光子模數轉換的實驗研究。The hardware circuit design include : industrial control computer configuration, selection of industrial control board type, design of the power supply and monitoring interface circuit, design of signal processing interface circuit ( the constant current source circuit, the time base signal processing circuit, the processing circuit for the signal to be measured ), design of panel control circuit, design of the system self - checking circuit, and etc. the program flow hart include : main program flow chart, system boot - strap self - checking program flow chart, manual static testing program flow chart, semiautomatic static testing program flow chart, automatic static testing program flow chart, dynamic testing program flow chart, transient testing program flow chart, source voltage and current monitor program flow chart, investigate function testing program flow chart, and etc. the measure system offers six working power supplies, the signal of time base, the signal of constant current source, sine wave signal and step to leap signal, and measures the frequency of the output pulse signal of the wide range pulse convert circuit accurately under three kinds of different test state ( static form, dynamic form and transient form )
硬體電路設計包括：工控機配置、工控板卡選型、產品電源及監控介面電路設計、信號處理介面電路（恆流源電路、時基信號處理電路、被測信號處理電路）設計、面板控制電路設計、系統自檢電路設計等。程序流程圖包括：主程序流程圖、系統開機自檢程序流程圖、手動靜態測試程序流程圖、半自動靜態測試程序流程圖、自動靜態測試程序流程圖、動態測試程序流程圖、暫態測試程序流程圖、電源電壓和電流監控程序流程圖、研究功能測試程序流程圖等。測試系統提供六路工作電源、時基信號、恆流源信號、正弦波信號和階躍信號，並對三種不同測試狀態（靜態、動態、暫態）下大量程脈沖變換電路輸出脈沖信號的頻率進行精確測量。Combined with the key project of the preliminary research of national defence science and technology, the target recognition system for millimeter wave initiative homing guidance, a systematic study on the signal processing method based on the background of millimeter mave ( mmw ) missle - borne pulsed doppler radar is performed. it include specifically the detction and the recognition of the moving target and hovering helicopter under strong clutter background
本文結合國防科技重點預研項目「毫米波主動尋的制導目標識別」 ，針對脈沖多普勒體制雷達導引頭的應用背景，對基於彈載高重頻脈沖多普勒體制雷達的信號處理方法進行了較深入的研究。主要研究內容包括對雜波背景中的機動目標以及對懸停直升機的檢測和識別方法。The fundamental theory and equations for the pressure fluctuation are described and the wall pressure fluctuation is measured. based on the experiment data, the characteristics of pressure fluctuations are analyzed in the three - phase flow of water, air and sand. the effects of air concentration and sediment content on the amplitude and frequency of pressure fluctuations are discussed
建立了多相流壓強脈動基本方程，闡述了水流脈動壓強基本理論，分析了壓強脈動機理；根據試驗數據，探討了水、氣、沙三相流體的壓強脈動特性，初步得到了高速含沙摻氣水流脈動壓強的幅值特性與頻域特性；提出了脈動壓強強度系數、脈動壓強極差系數與含沙量、摻氣濃度的關系。Based on the dc diffusion model, we build a duplex diffusion layer model which is composed of inner pulse diffusion layer and outer stable diffusion layer. in inner pulse diffusion layer, the concentration of ions fluctuates with frequency of pulse current ; in outer stable diffusion layer, the transport speed of ions is almost stable all the time, the main purpose is to transport the ions from the mass to the pulse diffusion layer
在直流電沉積的擴散理論基礎上，建立了脈沖電沉積的雙擴散層模型，靠近電極為脈沖擴散層，擴散層內金屬離子的濃度隨脈沖電流的頻率而波動;脈沖擴散層外麵包圍著一層穩態擴散層，其中離子的擴散速度在整個過程中基本是穩定的，作用是將主體溶液中的離子不斷向脈沖擴散層中補充。Some valuable conclusions are summarized by theoretical analysis and simulation experiments : from the side of signal processing, pulse jamming can be deleted by the method of time - domain sliding window accumulation and can be restored by interpolative prediction. ; gauss white nose can be attenuated while jamming disperse point - target by the method of time - frequency analysis in time - frequency domain. ; radio frequency noise jamming can be deleted by the method of average range frequency spectrum and notching in frequency domain
通過大量的理論分析和模擬實驗，得到了一批具有一定價值的結論：從信號處理的角度出發，對于脈沖式干擾，能夠運用時域滑動窗口積累的方法去掉，並且通過預測插值得到較好的恢復；對于高斯白噪聲干擾，在時頻變換域內應用時頻分析方法可減小其對分散點目標的干擾；對于射頻噪聲，通過平均距離頻頻法和頻域陷波的方法可以去掉；從改變合成孔徑雷達系統角度出發，類似雙基地雷達能夠避免各種干擾，對發射信號進行調幅，調相以及改變調頻斜率都是較好的抗干擾方法。Secondly, based on the analysis and simulations of the doppler time - shift for chirp - subpulse stepped frequency signal, this dissertation analyses the velocity compensation method for moving targets in chirp - subpulse stepped frequency signal, and presents a method for compensation of targets ’ velocity base on the least burst error rule
其次，本文對chirp子脈沖頻率步進信號的多普勒效應進行了分析和模擬，在此基礎上，分析了對其進行運動補償的思路，提出了採用最小脈組誤差準則進行運動補償的方法。The former one is a product of the pressure pulsation resulting from the fan blade periodically cutting the air, with the blade passing frequency as its base frequency and accompanied by higher harmonics. the wide - band turbulent noise is formed when the rotating fan forces the surrounding air to produce turbulent throw - outs and results in gas thickening and thinning processes
旋轉噪聲是由於風扇的葉片周期性地切割空氣，引起空氣的壓力脈動產生的，以葉片通過頻率為基頻，並伴有高次諧波。湍流噪聲是由於風扇運動導致的周圍空氣發生湍流脫體，使空氣發生擾動，形成氣體的壓縮與稀疏過程而形成的，是一個寬頻帶噪聲。In this paper, a simplified method of calculating wind - induced response and design loads of super - high - rise buildings was proposed. coherence properties of wind load on typical tall building were analyzed and the results show that cross - wind loads at different height have strong coherence at vertex shedding frequency, and the coherence function ' s value here is near to 1
首先分析了各測點層合力的相干特性，結果顯示各測點層所受順風向風荷載之間的相干函數基本成單調衰減規律，而橫風向脈動風荷載在漩渦脫落頻率處存在和順風向不同的顯著相關性。The development of ship automation puts more requirement on the quality of electricity, whose standard can no longer be met by the traditional mechanical hydraulic pressure or analog speed regulator of marine diesel - engine generator system. as a result, speed regulator based on electronics and microcomputer appeared
船舶輪機自動化的發展，對船舶的供電質量的要求也越來越高，傳統的柴油發電機組的機械、液壓或模擬式調速器已不能滿足這種要求，因而出現了電子的基於微計算機的雙脈沖調頻調載調速器。The main contents and conclusions are as follows : 1. the dynamic pressure on the original riverbed and the scour hole are measured. the results show that the characteristics of dynamic pressure in the scour hole are the same as that on the original riverbed
表明在基巖沖刷過程中以及沖坑穩定后，射流沖擊區的脈動壓強與沖坑形成前一樣，都是以低頻大振幅為主，說明在沖刷坑形成后，射流沖擊區水流與無沖坑時一樣，都是大尺度渦不斷破碎和小尺度渦不斷生成的過程。The change of predominant period of ground micro - tremor is closely related to the formation of site soil layers, and mutually corresponds to the change of engineering geological conditions of the site
地脈動卓越周期的變化與場地土層構造密切相關，與場地工程地質條件的變化相對應。不同地基土層構造對應不同類型的頻率分佈。When analyzing in frequence domain, according to the fluctuating property of wind, based on the stochastic vibration theory, some calculation formulas of the response are obtained in frequence domain
風振響應頻域分析部分從結構風振的基本理論出發，通過對脈動風功率譜的分析，推導了結構風振響應的計算公式。Therefore, the structure and feature of different foundation soil strata can be distinguished for different kinds of frequency response of site
而這些頻率又是與由地層內的波的重復反射產生的地基固有周期相對應。地脈動的頻譜特性能夠反映出場地土的構成和特性。分享友人