最大可用頻率 的英文怎麼說

中文拼音 [zuìdàkěyòngbīnlǜ]
最大可用頻率 英文
maximum usable frequency, muf
  • 最 : 副詞（表示某種屬性超過所有同類的人或事物） most; best; worst; first; very; least; above all; -est
  • 用 : Ⅰ動詞1 （使用） use; employ; apply 2 （多用於否定: 需要） need 3 （敬辭: 吃; 喝） eat; drink Ⅱ名...
  • 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. The specific research methods are listed : 1. matched filter taking the max ouput snr as the best rule correlates nonstop divided signal and divided echo to detect low snr target signal. then all one dimension divided correlation outs and done fft in portrait to leach interferential signal such as static or low rate mussy meaves, many pathway echo and so on and to take target ' s time difference and doppler frequency that combine parameters that target ' s direction taken from antenna and so on to implement target ' s orientation and tracking

    具體研究方法如下： 1 、採用以輸出信噪比最大為準則的最佳匹配濾波器來對分段的參考和目標信號作相關處理來檢測低信噪比目標信號，然後對一維分段相關輸出組作縱向傅立葉變換來濾除靜態或低速的雜波、多徑回波等干擾信號，並提取目標的時差和多普勒頻率，再結合由天線獲得的目標方向等參數，就可以實現目標的定位和跟蹤。
  2. Choose two nodes on the edge of the structural to compare the results calculating by the finite element program midas, then we can draw a conclusion that these kinds of space truss systems is sensitive to the libration of the dynamic wind loads. to consider this factor is very necessary in the process of design, we will use the pulsant augmentation coefficient to realize it

    比較靜力風荷載和動力風荷載作用下的有限元軟體的計算結果，選取結構邊緣部分的兩個節點，對比它們在兩種方法計算下的最大位移的計算結果。經過比較可以看出重量輕、頻率低、阻尼小的柔性建築物對風荷載的橫向振動是很敏感的，在進行工程設計時應該考慮這種因素，並可採用乘以風振系數等相應方法來加以體現。
  3. The roots of radio - frequency identification technology stretch at least as far back as world war ii, when transponders helped distinguish between axis and allied aircraft

    無線頻率識別技術的最早運用可以追溯到第二次世界大戰，那時無線電發射機應答器幫助人們分辨軸心國和同盟國的戰機。
  4. Due to the short distance among the planes which fly in a group, the conventional low resolution radar can not distinguish them in both distance and azimuth ? if we use the technology of isar to resolve the difference among doppler frequency of the targets and obtain a fine resolution cross - cross image, we may separate them, but a long time of coherent processing is needed <, for the formation targets, it can be approximately divided to rigid body and nonrigid body, so for the formation targets, that can be regarded as rigid which has a relative position and an identical movement, can be approximately considered as a large target, and be compensated by translational phase with the rule of minimum entropy, but for the most those cannot accord with the approximation of rigid, being the doppler - frequency of the aim is linear changed, by the relax method with short data, increases the resolving performance of multiple target to the aim in the frequency domain, since cross - range resolution is based on the accumulative time, so it is greatly improve the resolution to formation targets by the instant cross - range image which produced by radon - wigner transformation

    低分辨isan成像及干涉技術應用研究一因此直接無法分辨編隊目標的架數，我們借鑒isar的技術，通過較長時間的相干積累，在多普勒頻域上對目標進行分辨。而對于編隊目標，可分為近似剛性的多目標和非剛性的多目標，所以對于可以近似為剛體的編隊目標相對位置固定，運動方式一致，可以近似看作一個大目標，採用最小墑準則對平動相位的進行補償，但是大多數並不滿足剛體近似的編隊目標，由於目標在相干積累時間的多普勒頻率近似呈線性變化，通過對較短數據利用relax的時頻分析方法，提高了頻率域上目標分辨的性能。由於橫向解析度取塊于橫向積累時間，所以利用radnwigner變換得到瞬時的一維橫向距離像大大提高了對編隊目標的分辨，對模擬和實測數據的大量分析結果表明此方法的有效性和可行。
  5. On account of qpm can take advantage of the largest element of x tensor, and any interaction with transparency range of the material can be noncritically phase matched without walk - off angle. therefore, the conversion efficiency in longer crystal may be improved

    由於準相位匹配可利用非線性光學晶體最大的二階極化張量元，在晶體的整個通光范圍內均可實現非臨界相位匹配，在較長的晶體上可望實現較高的變頻效率。
  6. At present, people usually use birefrigence and quasi - phase - matching methods to achieve higher effiency in the process of conversion. a significant advantage of quasi - phase - matching method is that the interaction is occurred through the largest element of the x ( 2 ) tensor ; the period of optical superlattice can be designed randomly, and any interaction can be matched without walk - off angle ; they are fitted to be used in frequency conversion of lower power especially. the quasi - phase - matching method has some advantages over birefrigence method, improving the efficiency of frequency conversion ; the range of frequency conversion covers its whole transperant wavelength

    由於準相位匹配技術有其獨特的優勢，可以利用非線性光學晶體的最大二階極化張量，如ppln 、 pplt 、 ppktp用的非線性極化張量都是d _ （ 33 ） ，其有效非線性系數高出普通非線性光學介質（如bbo 、 lbo 、 ktp ）一個數量級，而且可以人為靈活設計調制周期，通過周期設計其頻率變換范圍可以覆蓋準相位匹配介質的整個透明波段，選擇無走離效應，解決了常規pm難以解決的問題，拓寬了非線性晶體的應用范圍，極大地提高了頻率轉換效率，已成為非線性光學材料和固體激光器的研究熱點之一。
  7. The features of the new type of integration scheme can be described as follow : high division and easy debug are achieved in the scheme ; accumulative total is used, and the discord of integer part and decimal part are avoided in the scheme ; it can divide as well as detect direction ; it can integrate the counter into isp device and then evaluate the maxim frequency of the counter ; it also integrate square wave and some logic devices into isp device, and then improve integration, reliability, stability ; and have the character of software designation instead of hardware designation and in - system programming, and it becomes very easy to modify the circuit and to extend the function

    新型的集成化設計方案具有以下特點：細分數高而且調整方便；採用累積計數，避免大小數分別計數的不協調；細分同時完成辨向；可以在isp器件內完成計數功能，從而提高了計數器的最高工作頻率；同時將方波發生器和一些外圍的數字電路集成在一片isp器件內，提高了系統的集成度，性能可靠穩定；具有硬體設計軟體化及在系統可編程的特點，便於電路的修改和功能的擴展。
  8. In this thesis a high precision frequency ( range ) estimation technique based on the phase of the fft of the beat - note signal is presented. the phase of the fft of the beat - note signal changes with the range between the radar and the liquid surface

    差拍信號的fft幅度最大處的相位隨距離變化，因此可以利用fft相位在一個頻率（距離）分辨單元范圍內估計差拍信號的頻率（距離）的位置，從而提高頻率（距離）估計精度。
  9. It has wide frequency width and high frequency relution. the maximum output frequency can get to 80m and the highest frequency relution can get to 1 u hz, the waveform memory is 64k. it has the important reference value for three classical structures - pc bus card, stand alone, vxi module

    該任意波形發生器不僅能產生正弦波，方波，三角波等常用的標準信號，還可根據用戶的需要生成任意波形，具有寬頻帶，高的頻率解析度等特點，其波形最高輸出頻率可達80m ，頻率解析度可達1 hz ，波形最大存儲深度為64k ，對于目前三種典型的任意波形發生器的結構? pc總線插卡式，獨立儀器， vxi模塊都有重要的參考價值。
  10. Abstract : biological invasions are a continuous feature of a non - equilibrium world, ever more so as a result of accidental and deliberate introductions by mankind. while many of these introductions are apparently harmless, others have significant consequences for organisms native to the invaded range, and entire communities may be affected. here we provide a survey of common models of range expansion, and outline the consequences these models have for patterns in genetic diversity and population structure. we describe how patterns of genetic diversity at a range of markers can be used to infer invasion routes, and to reveal the roles of selection and drift in shaping population genetic patterns that accompany range expansion. we summarise a growing range of population genetic techniques that allow large changes in population size ( bottlenecks and population expansions ) to be inferred over a range of timescales. finally, we illustrate some of the approaches described using data for a suite of invasions by oak gallwasps ( hymenoptera, cynipidae, cynipini ) in europe. we show that over timescales ranging from 500 10000 years, allele frequency data for polymorphic allozymes reveal ( a ) a consistent loss of genetic diversity along invasion routes, confirming the role of glacial refugia as centres of genetic diversity over these timescales, and ( b ) that populations in the invaded range are more subdivided genetically than those in the native range of each species. this spatial variation in population structure may be the result of variation in the patchiness of resources exploited by gallwasps, particularly host oak plants

    文摘:生物入侵是不均衡世界的一個永恆話題，尤其是當人類有意或無意地引入物種后.很多引入顯然是無害的，但另外一些則有著嚴重的後果，會給入侵地的生物以至於整個生物群落造成影響.本文總結了分佈區擴張的常見模式，概述了它們對遺傳多樣性和種群結構式樣所造成的影響.描述了如何根據以一批遺傳標記所得到的遺傳多樣性式樣來推斷入侵途徑，來揭示伴隨擴張選擇和漂變在形成種群遺傳樣式中的作用.本文對日益增多的群體遺傳學方法進行了總結，這些技術可以用來在不同的時間尺度上推斷種群規模所發生的巨大變化（瓶頸效應及種群擴張） .最後，我們以歐洲櫟癭蜂（膜翅目，癭蜂科，癭蜂族）一系列入侵的數據為例對一些方法進行了說明.從500 10000年的時間尺度上，多態的等位酶位點上等位基因頻率的數據表明: 1 ）遺傳多樣性沿入侵路線呈不斷下降的趨勢，支持了冰河期避難所作為遺傳多樣性中心的作用; 2 ）入侵地區的種群與該物種原產地的種群相比，遺傳上的分化更為強烈.這種種群結構在空間上的變異可能是被櫟癭蜂開發的資源尤其是櫟樹寄主在斑塊上出現變異的反映
  11. It works at high frequency with a selectable pin outside ; the working frequency is fixed at 640k / 1. 2mhz. so far as the output signal of the single - chip ic is concerned, the maximum time proportion of its high level is 88 percent, but the minimum one is 10 percent

    該控制器為pwm脈沖寬度調制方式;電路正常工作溫度范圍為- 20oc 85oc ;工作開關頻率根據外圍電路輸出電壓需要為640k / 1 . 2mhz可選;輸出信號的最大占空比為90 % ，最小占空比為10 % ，晶元主要應用於lcd電壓電源管理設備。
  12. When the frequency approaches zero, the factor approaches zero correspondingly ; 2 ) the amplitude of interaction factors changes with the incident angle of rayleigh waves and reaches maximum when is zero. moreover, with the increase of, the wave period shortens apparently ; ( 3 ) the amplitude of interaction factors decreases as the pile spacing increases and approaches to zero when the pile spacing is 15 ; 4 ) the amplitudes of interaction factors increase clearly with the increasing stiffness ratio of pile to soil ; 5 ) the lat eral seismic response of fixed - head pile groups is much smaller than that of free - head pile groups. moreover, the pile - group effects induced by rayleigh waves can be neglected ; 6 ) the lateral seismic response of piles at different location differs from each other

    得到了以下結論： 1 ）樁的相互作用因子隨頻率呈周期性變化，在振動頻率比較低的情況下，樁的橫向相互作用因子也較低，當頻率趨近於零時，相互作用因子也趨近於零； 2 ）樁的相互作用因子的幅值隨瑞利波入射角度的變化而變化，在= 0情況下幅值最大，且隨入射角度的增加，波動的周期明顯縮短； 3 ）樁的相互作用因子的幅值隨著樁與樁間距的增加而減小，至s d = 15時，樁的相互作用因子基本趨近於0 ； 4 ）在頻率比較低時，相互作用因子幅值隨樁土相對剛度比的增加而顯著增加； 5 ）樁頂固接可以有效地降低群樁的橫向地震響應幅值，由瑞利波產生的群樁效應可以忽略不計； 6 ）群樁中不同樁位的樁的橫向地震響應是不同的，每根樁所在的樁位對其橫向地震響應有很大的影響；刀樁數的增加並不能減小樁的橫向動力響應。
  13. ( 三 ) under the dynamic load of the explosion, the numeric analysis has been done and achieve the rule as follow : ( 1 ) when the frequency of vibration is 0. 3hz, the acceleration of the slopes top gets the maximum ; so 0. 3hz is believed the natural frequency of the slope as a whole ; ( 2 ) the vibration of explosion can been magnified because of the condition of the landform, when the relative altitude is up to 45m, the acceleration of horizon gets the maximum ; when the relative altitude is up to 100m, the absolute value of acceleration and the deformation of horizon is larger than that in the bottom of the slope ; ( 3 ) in the period of forced vibration, at the top of the slope, the acceleration of horizon become larger and larger ; at the middle part of the slope, it becomes smaller ; ( 4 ) when the explosion velocity of is much little, the shallow part destruction is the primary deformation of the slope

    （三）採用模態疊加法針對爆破動力作用，進行邊坡的動力響應分析，得出了以下結論： （ 1 ）振動頻率為0 . 3hz時，坡面頂部水平向加速度峰值最大；綜合考慮，可認為該邊坡的自振頻率為0 . 3hz左右； （ 2 ）地形對爆破地振動存在放大作用，研究剖面的坡面，水平向加速度及位移在地形相對高差45米左右最大，而後隨相對高差的增高而減小，相對高差為100米時，水平向位移及加速度絕對值均大於坡腳； （ 3 ）強迫振動段，水平向加速度值隨時間變化的規律為：坡頂節點總的變化趨勢是越來越大，而坡體中部節點的變化趨勢是越來越小； （ 4 ）當爆破振速較小時，變形破壞的形式表現為坡頂表面滑塌型。
  14. 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。
  15. The thesis summarizes the basic theories of price discrimination, expatiated on the multi - class differential pricing method and dynamic differential pricing theory ; concludes the factors that have impacts on tickets - price, analyses and classfies the factors ; brings forward a canonical method of market segmentation, introduces the process of market segmentation based on the model of gray relative level, discusses the idiographic measure of ticket - price control ; improves the academic achievements of former scholars, puts forward a model of multi - class dynamic differential pricing for the air passenger transport, which is based on the maximum revenue for the airline industry, and gives a approximate arithmetic of the model, then showes the application of the model and its feasibility on increasing airline industry ’ s revenue by 25 models

    在對民航定價的國內外研究現狀進行綜述的基礎上，從經濟學角度介紹差別定價的基本理論，闡述民航客運的多等級差別定價理論和動態差別定價理論;對民航票價的影響因素進行分類說明;作為多等級定價的基礎，提出市場細分的標準和方法，用灰色關聯度模型解決航空旅客市場細分問題，並提出票價控制的具體措施;引入一種旅客到達頻率預測的統計方法，以航空公司收益最大化為目標，建立基於多等級定價基礎上的動態差別定價模型，即多等級動態差別定價模型，給出模型的遞歸演算法，通過對動態差別定價模型的運行結果進行分析，建立模型的一種近似模型，並且用25個簡單算例說明模型的用法以及在提高航空公司收益方面的可行性。
  16. The first part of the paper is designing the testing project for grounding resistance and insulation resistance in a new way. using 16bits ad converter with programmable control amplifier replaced the way which used changing resistance to change measure range. lt is not only improved testing precision and develop the system expediently, but also reduced the area of the circuit boardwith the new way. in order to make the electric implement safety testing system have upstanding expansibility, the software and hardware of the system adopted the modularization design. adopted mcu atmegal28 as a master mcu which control mmi, realtime clock and communication with slaver mcu. atemga8 as the slaver mcu to realize testing function. so it is easy to add or reduce the testing project. the testing implement system has been developed successfully, and the comments for the system is that it has high precision, high expansibility and easy maintain. but considering the electric implement system should have intelligence and humanity abi lity. so this paper bring forward a scheme of electric equipment safety testing embedded system with speech control. after introduce the basic theory of speech recognition, the paper expatiate the characters of this system. the system is a noise conditon, not special people, small glossary, insulation word system. with these characters design the speech recognition as fellow. utilizing cross zero ratio and short energy to ensure jumping - off point and end point ; adopting mfcc as the character parameters of speech recognition ; the character parameters than be recognized by dtw. in order to ensure the credibility of this project, first realized by matlab in computer

    在介紹了語音識別的基本原理后，闡述了本系統的特點：本系統是一個噪聲環境下非特定人、小詞匯量、孤立詞的語音識別系統。根據本系統的這些特點設計了如下語音識別方案：利用過零率和短時能量相結合的方式確定語音端點；採用mel頻率倒譜系數（ mfcc ）作為語音識別的特徵參數；得到的特徵參數最後通過動態時間規整（ dtw ）的模式識別方法進行識別。為了確保本系統實現方案的可靠性，首先通過計算機利用matlab軟體來模擬，在演算法模擬實現后又進一步增加環境的復雜性：加上較大的環境噪聲、突發性的噪聲等，再通過修改參數、修改參考模板、兩級識別等各種提高語音識別精度的方法來提廣東工業大學工學碩士學位論文高識別率。
  17. The system have follow characteristic : we used tlc5540 for digital converter, the maximum conversion rate of the tlc5540 is at least 40 msps ( mega samples per second ), and the typical analog input bandwidth is more than 75mhz. the design between tlc5540 and tms320vc33 interface directly

    該系統主要特點如下。我們採用的a d轉換器最高工作頻率可到40mhz 。 tms320vc33和a d之間直接介面，最大限度地發揮了a d轉換器的能力。
  18. In this paper, a three phases high - voltage power mos gate drive integrated circuit has been researched and designed successfully. it is a typical spic, which could be widely used in high power motor control and switching power supply applications. the design goal of the circuit are v0ffset ( max ) is 500v, ia ( m ~ ) is 1 a, the highest frequency of operation ( f ( ~ x ) ) is 100khz

    本文研製成功了一種可廣泛用於大功率電機控制、開關電源等應用中的spic電路?三相高壓功率mos柵驅動集成電路，其設計指標要求為：最高偏置電壓（ voffset （ max ） ）為500v 、最大輸出電流（ i _ o （ max ） ）為1a 、最高工作頻率為100khz 。
  19. Ground penetrating radar or georadar, is a new no destroying detection instrument with rapidly developing in recent years. it is applied to engineering, environment, archaeology and other aspects. data processing ' s theories and methods are one of the key aspects in gpr researching, because these are useful to picking up parameters in reflection wave including amplitude, phase, frequency and so on

    數據處理（包括濾波、反褶積、偏移等）是gpr的研究重點之一，其目的是壓制隨機的不規則的干擾波，以最大可能的解析度在探地雷達剖面上顯示反射波，提取反射波的各種有用參數（振幅、相位、頻率等）來幫助解釋。
  20. This frame can be the foundation of new development in these fields, realizing the reuse of the frame design in large granularity ; 3. by analyzing and stat icing the wis, explicitly narrate the three common components, which have been used most widely, most effectively, and most worthy in this system

    該框架可以作為領域內新系統的開發基礎，在一定程度上實現大粒度的框架設計復用； 3通過對web系統的分析統計，對系統中使用范圍最廣、使用頻率最高，使用價值最大的三類公共構件進行了詳細的說明。
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