precise frequency 中文意思是什麼
precise frequency
解釋
精確頻率-
Due to existing signal processing technology ’ s shortage such aslow measurement, narrow measurement range precision and other poor performance, we introduced a high - precise signal processing technology : firstly, to get power spectrum with hanning windowed welch modified periodogram, search its peak value frequency ; secondly, to apply zooming analysis via goertzel algorithm ; at last, to get a highly precise doppler frequency with energy centrobaric rectifying algorithm 。 the simulating result indicated that this technology introduced could get accurate doppler frequency 。 depending on above discussed technology, we designed a signal processing scheme, and developed a signal processing system. the running result showed high performance, verified the feasibility and reliability of the highly precise signal processing technology introduced. in a word, the technology improved ldv ’ s performance such as measurement precision, measurement range, dynamic response time 。 and it will have a wide application foreground
針對存在的缺點，本文提出了一種應用於激光多普勒測速的高精度信號處理技術，即首先利用加hanning窗的welch修正周期圖演算法得到信號功率譜，搜索其譜峰值頻率，接著利用goertzel頻譜細化演算法對搜索的譜峰進行細化分析，再引入能量重心頻譜校正演算法對細化后的譜峰進行校正分析，從而將離散頻譜分析演算法、頻譜細化演算法和頻譜校正演算法三者有機結合起來，充分發揮各自的優點:通過加hanning窗的welch修正周期圖演算法快速得到功率譜及峰值頻率，通過goertzel演算法獲得分析頻帶的高解析度頻譜，然後通過能量重心校正演算法對細化后的頻譜進行高精度校正，這樣不僅保證了演算法的高效性，而且大大提高了分析的精度。 -
This depends on the precise radio frequency of the 21 - cm wavelength, or 1420 megacycles per second
這種通迅聯系要靠21厘料波段，即每秒1420兆周的精確無線電頻率。 -
Precise thickness - shear resonance frequency of electroded piezoelectric crystal plates and its applications in resonator design
帶電極壓電晶體板厚剪共振頻率的精確確定及其在諧振器設計中的應用 -
From the result we get the following conclusion : for narrow - band signal, the effect of the method based on fft is best. for wide - band signal, when snr is up to certain degree ( higher than - 7db or so ), the curves of square error of modified methods are more obvious and closer to crb. for an echo composed of more than one frequency or direction, space - frequency distribution could show more direct information of frequency and direction, which is more advantaged to make precise judge and estimation for doa of echo
從估計結果發現，對于窄帶回波信號，基於fft的方法估計性能大大優于其他方法；對于寬帶回波信號，在信噪比達到一定程度（高於約- 7db ）時，補償后的幾種估計法的性能改善均比較明顯，誤差曲線越來越接近crb曲線；對于回波中存在多頻率多方位的情況，空間?頻率分布圖能提供較為直觀的頻率及方位信息，因此應用空間?頻率估計法來進行方位估計，更有利於進一步對回波的具體方位進行準確判斷和估計。 -
Therefore, the three fundamentals required to obtain high precise measurements are : 1 ) frequency stability and frequency difference stability of the double - frequency laser source as well as the stable equivalent length of bore ; 2 ) the measuring beam and the reference beam are placed very co - axially ; 3 ) capability of recording the sub - division of the period of phase change and a reversible counter system
因而干涉儀系統達到高精度的基礎是：頻率及頻差穩定的雙頻激光源、穩定的等效腔長；測量光與參考光合光後有很高同軸度的光路結構；能可靠記錄相位差變化周期數的細分及可逆計數系統三部分。 -
The company owns advanced middle frequency furnace, compound centrifugal casting machine, precise and complete metal cutting equipment and advanced and modern quality measurement and control means
本公司擁有先進的中頻電爐、復合式離心澆鑄和精密齊全的金屬切削設備以及先進的現代化質量測控手段，生產的合金軋輥具有輥面度高、強度大、耐磨性能好、耐熱裂、抗剝落等特點。 -
3. according to the principle of the finite element method, the research establishes finite element models of the vibration transportation mechanisms, some model parameters such as the frequency and vibration type are confirmed and validated by the modal analysis, then which analyzes dynamic - state response of the model and confirms the swing distributing of the models, thereby make the design of models precise. 4
根據有限元法的理論，建立振動機構的有限元力學模型，對該力學模型進行模態分析，通過模態分析確定拋秧機振動形態和所需的頻率等參數；然後此基礎上再進行力學模型的穩態響應分析，研究該模態下機構的振幅分佈，以確定模型設計的準確性。 -
This article describes a way of special ultrasonic system which monitors thermal stress in seamless welded rails. this monitoring system is a non destructive testing system, which adopts avr mcu and high - precise time chip processing as the core of it, and adopts the critically refracted longitudinal wave as the object of measuring. my studying focuses on the theory of the monitoring system, which will be listed in this arctile : according to the snell theory, the theory of motivating of critically refracted longitudinal wave is described in details, and the finite element software is used to emulate the propagating course. the formulas of calculating the pts of swr are taken from the acoustoelasticity theory, and the calculating the parameters is introduced. according to assemble materials, three kinds of ways of monitoring the pts of swr using critically refracted longitudinal wave are described, which are measuring the sound - time in changeless distance, ultrasonic critical - angle refractomery and frequency spectrum, the first way of ways is used in this experiment system. the factors, which effect the monitoring system, are assaid in some degree based
本文的研究工作重點在無縫焊接鋼軌溫度應力測量系統的理論模塊，包括根據snell原理，研究極限折射縱波的激發機理，並使用有限元軟體ansys進行模擬;根據聲彈性理論以及公式推導出計算無縫焊接鋼軌中的溫度應力的公式，並對其中參數的求解方法進行介紹;根據收集的資料，介紹了三種使用極限折射縱波測量無縫焊接鋼軌溫度應力的方法，即固定距離測量聲時法、臨界角折射法和頻譜分析法，本實驗系統使用的是第一種;根據實驗經驗以及相關資料，分析了影響極限折射縱波測量溫度應力的幾個因素，並提出了相應的解決方法;根據實驗系統的需要，獨立設計並加工出相關配套的實驗設備，包括實驗鋼塊、有機玻璃楔塊、固定件、載荷外框裝置等。 -
On base of studying domestic and foreign theories and methods for evaluations of st achievements, this thesis analyze 10 methods for evaluations of st achievements, such as application frequency statistics, delphi, literature research and application relevance analysis, etc. by studying and analyzing the work of technology planning bureau, transport ministry between 1991 and 2000, and the evaluation items for the achievement identification, acceptance and check - up which were taken by transportation technology department, the author come up with some methods, which are scientific, standard and quantified, for evaluating transportation st, that is, in accordance with the transportation st achievement management and achievement precise database within eighth five and ninth five, and with the statistic analysis such as research contents, professional classification, intensity input, achievement characteristics, field distribution, characteristics of department undertaken, st talents characteristics, award inf ormation, characteristics and regularity of transportation st achievements, problems that are still existed and countermeasure are forwarded ; according to the requirement of evaluations system of the transportation st achievement, the principle and methods for the system designation are given, and the constitution of the system are provided ; in order to improving the scientific organization and management of our national transportation st achievements, many subjects are under discussion, including institution for evaluation of st achievement, valuation organization, standard for evaluation technology, database for consulting transportation experts and how to simplify the procedure of transportation st achievement, etc.
本論文在對國內外科技成果評價理論、方法廣泛調查基礎上，研究分析了諸如應用頻次統計法、德爾菲（ delphi ）法、文獻調研法、應用相關分析法等10種科技成果評價的方法，通過對1991至2000年交通部科技計劃所實施情況，由交通科技主管部門組織進行了成果鑒定、驗收和評審等成果評價的項目的分析，提出了本人對交通行業對科技成果進行科學、規范和定量地評價的方法，即：在建立「八五」 、 「九五」交通科技成果管理及成果簡要數據庫的基礎上，通過對研究內容、專業分類、投入強度、成果屬性、地域分佈、承擔單位屬性、科研人員屬性和獲獎情況等諸多方面進行統計分析，研究了交通科技成果的特點和規律，提出了存在的問題和對策；從建立交通科技成果評價指標體系的要求上，具體提出了交通科技成果評價指標體系設計原則與方法探討了交通行業科技成果評價指標體系的構成及權重確立等問題；從加強我國交通行業科技成果評價的科學化組織與管理出發，探討了如何建立科技成果評價制度、評價機構、統一的評價技術標準和交通行業專家咨詢數據庫以及如何簡化交通科技成果評審形式等問題。 -
This method offers more precise geometry for spaceborne sar system design and simulation. 3. in the analyzing on the radar doppler properties, under the ellipsoid earth model and ellipse orbit model, considering the earth rotation, the radar doppler properties with different orbit eccentricity are compared, and the fact that orbit eccentricity affects doppler frequency rate is found
在雷達多普勒特性分析中，論文採用橢球地球模型和橢圓軌道模型，結合地球的自轉，通過不同偏心率下雷達多普勒特性的比較，研究了軌道偏心率對合成孔徑雷達系統設計與模擬軟體研究雷達多普勒調頻斜率的影響。 -
It adopts 60w radio frequency laser producer and cti mirror system imported from america. the electric scissor lift table realizes precise control of focus. infrared ray - demonstrating aiming device can position the marked object more conveniently. it is a comparatively high - quality marking machine, characterized by its high efficiency and convenience, zero materials, zero pollution, and zero poison. applied fields : marking of many non - metal materials, such as cloth, leather, acrylics, wood, paper, pacage of food, electronics, and medicine, etc
該機使用美國進口60w射頻激光器和cti振鏡系統，電動升降平臺平實現焦距精確控制，用紅光指示結準器，更方便打標對象的定位，具有高效便捷無需耗材，無毒無污染等特點，是一款性價比較高的標記設備。 -
The adaptive optical transducing principle on independent variables is presented in this paper, and a new adaptive optical current transducer ( aoct ) has been developed with the new independent variables introduced to oct, in which the precise power frequency current offered by a reference model of steady state is benchmark, and the measured harmonious and transient currents from optical transducer might be adjusted adaptively applying the adaptive arithmetic, so that both the steady state and transient precision of the aoct has been improved
論文提出了獨立量自適應光學傳感原理，並應用這種原理的一種形式? ?光電獨立量自適應光學電流傳感原理，研製了一種新型的自適應光學電流互感器（ adaptiveopticalcurrenttransducer ，簡稱aoct ） ，以穩態參考模型所提供的高精度基波電流測量值為基準，應用自適應演算法對aoct中光學傳感頭輸出的穩態電流中的基波、諧波和暫態電流測量值進行自適應校正，從而能夠綜合提高oct對電力系統穩態和暫態電流的測量精度。 -
This processing line has two sszm1200c straight line double edgers and 90 transfer table. 30 spindles on each sszm12000c, high collocated, wheels. high - level of polishing ; compact and steady base, precise and smooth transfermission system ; big power frequency - conversion motor to control the speed of pedeail ; plc control system sets processing parameters via interface, to control the width and the speed, the minimum size of the glass can be 127xl27mm ; the structure of the machines is compact and stable. this line is our new designed products, and it s the ideal choice of assistant equipment for exquisite and industrial glass, besides, it can be used with other machines to form a production line set
本生產線由2臺sszml200c玻璃直線雙邊機和1個90中轉臺組成每臺sszml200c玻璃直線雙邊機配置30個磨頭，磨輪配置多，加工拋光精度好底座穩重扎實，傳動系統精確流暢大功率變頻電機調速控制傳送皮帶驅動plc控制系統通過界面設定參數控制，最小加工玻璃寬度尺寸小至127127mm機器結構緊湊性能穩定，是我公司全新設計的力作是大批量精品玻璃和工業玻璃磨邊生產的暈佳配套設備，可口與夾膠印花，鋼化等生產線配套使用 -
However, the high demand in frequency domain involves precise synchronization both in time and frequency domain. while because of the different channel characteristics in each channel, the receiver needs some mechanisms to characterize the channel effects in coherent demodulation
然而，頻域的高要求對應于同步技術的高要求；另外，各個子通道不同的通道特徵，要求接收端相關解調用一定的機制來近似每個子通道的通道特徵。 -
By means of the precise integration method with lagrangian interpolation the trajectory of the shaft center, the poincare mapping and the bifurcation graphs are numerically given. the results predicted by the floquet theory are checked and the long - term dynamic behavior of the system is predicted. it is shown that the system has rich nonlinear behaviors at some m combination of the four parameters, for examples, multi - frequency subharmonic resonance, as well as chaos phenomenon from doubling bifurcation and twice hopf bifurcation
通過lagrange插值精細積分法數值給出系統的軸心軌跡圖、 poincar映射圖、分叉圖，檢驗floquet理論預測結果並預測系統的長期性態，顯示系統在四個參數組合的某些范圍內具有豐富的非線性特性，還存在多形式次諧波解，以及由倍周期分叉、二次hopf分叉通往混沌的現象。 -
Principles for adaptive high speed precise frequency measurement
自適應高速精密測頻原理 -
Optimized to provide fast, precise frequency measurements with
它提供了與agilent 53131a和 -
A way to realize precise frequency measure by single chip microcomputer
用單片機實現精密測頻的方法 -
The precise frequency will be determined by the hkmas risk assessment of the institution
至於實際的審查次數，金融管理局會視乎其對有關機構的風險評估而決定。 -
Each satellite contains four " atomic clocks, " which vibrate at a precise frequency, according to the laws of the quantum theory
每顆衛星都裝有4個「原子鐘」 ，它們根據量子理論法則，以精確的頻率振動。
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