頻率變化速率 的英文怎麼說

中文拼音 [bīnlǜbiànhuàsùlǜ]
頻率變化速率 英文
frequency variation rate
  • 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
  • 速 : Ⅰ形容詞（迅速; 快） fast; rapid; quick; speedy Ⅱ名詞1 （速度） speed; velocity 2 （姓氏） a surna...
  • 頻率 : frequency; rate
  • 速率 : speed; rate; tempo
  1. Mems ( micro electromechanical system ) has become one of the most rapidly development technologies. along with the rapid development of mems techniques, capacitive sensor is used widely whose capacitance changes small, which has put forward the new request to the measurement technique. the common measure for capacitance measurement is that convert capacitance to voltage, electric current or frequency. the area of polar plate of the capacitor becomes smaller and smaller, and the total capacitance of micro capacitive sensor is usually several pico farad only. as a result, its change amount is smaller

    Mems （ microelectromechanicalsystem ）近年來發展最快的技術之一，隨著mems技術的快速發展，電容式加速度計的電容變化變化量越來越小，對檢測技術提出了新的要求。在電容式傳感器中，常用電容檢測電路是將其轉換為電壓、電流或者頻率信號。目前的微型電容傳感器的極板面積變得越來越小，電容總量只有幾個pf ，變化量就更小。
  2. In this thesis, firstly, we put forward a new algorithm of the synchronization of carrier reference phase, that is to use the curve synthesizing with the general digital carrier phase looper to have an estimation on carrier frequency within 10 ms so as to meet the need of meteor burst communication. we have done some simulations to get the performance of carrier frequency estimation using two modulation modes ( 16qam and 4 - qpsk ), and had some test on the carrier phase looper in conditions when using different baud rate transmission and when the baud tuning have windage

    我們對兩種正交調制方式（ 16qam和4 - qpsk ）進行了模擬工作並給出了模擬結果，同時討論了碼元同步定時誤差對鎖相環路工作的影響並根據流星通信中使用變速率傳輸時鎖相環路的載波同步性能進行了測試；然後在基於軟體無線電思想的數字處理平臺（該數字處理平臺實現了中頻數字化）上用dsp軟體完成了載波的相位跟蹤。
  3. 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。
  4. According to the guidline, two nd : yag lasers have been designed and set up, one is end - pumped by lower output power ld using a selfoc micro lens, and the other is end - pumped by high output power ld using a pair of lenses are designed, and the characteristics such as output power and power stabilization of both solid - state lasers are investigated. thirdly, when an empty liquid crystal cell is inserted in the cavity of the nd : yag laser pumped by high power ld, the laser can operates in single axial mode. finally, according to the relationship between the laser output power and the longnitudinal a ld - end - pumped nd : yag laser sensor for displacement measurement has been investigated theoretically and demonstrated experimently, the results indicate that when the mean radius of pumping inside the laser cavity is far less than that of the oscilating laser mode, the exponential of the output power is a gauss function of the longitudinal positon of focused spot of ld pumping beam, both the measurement range and the sensitivity are dependent on the incident pumping power, as the incident pumping power is increased, the measurement range is enlarged and the sensitivity is improve d

    本文首先介紹了ld泵浦nd ： yag激光器的發展狀況、主要特性及其應用，從四能級速率方程出發，推導了ld泵浦nd ： yag激光器的閾值、輸出功率和斜效率的表達式，並簡述了激光器的工作原理、結構型式和倍頻方法；其次，以空間相關的速率方程為基礎，提出了ld端面泵浦nd ： yag激光器的設計方法，給出了一定泵浦耦合方式下，振蕩光模尺寸、最佳輸出耦合率、泵浦光模尺寸、泵浦光焦斑位置等參數的選取依據，以此為依據，設計了自聚焦透鏡耦合小功率ld泵浦nd ： yag激光器和透鏡組耦合高功率ld泵浦nd ： yag激光器，對激光器的輸出功率和功率穩定性等特性進行了實驗研究；再次，在帶尾纖輸出的高功率ld泵浦nd ： yag激光腔內插入一隻空液晶盒，觀察到了激光器以單縱模運轉；最後，根據泵浦光焦斑端面位置對激光輸出功率的影響規律，提出了ld端面泵浦nd ： yag激光位移傳感新方法，並進行了理論和實驗研究，研究結果表明：當激光晶體內泵浦光平均光斑半徑遠小於振西安理工大學碩士學位論文蕩光束腰半徑時，激光輸出功率的自然指數與泵浦光焦斑的縱向位置成高斯變化規律，測量范圍和靈敏度依賴于泵浦功率，隨著泵浦功率的增加，測量范圍擴大，靈敏度提高，當端面泵浦功率為7 . 24w （最大輸出功率為1 . 926w ）時，激光位移傳感器的測量范圍和靈敏度分別是13 . 045mm和0 . 148mw / pm 。
  5. In this paper, several scheme of vscf is compared firstly, of which gets doubly - fed generating mode. doubly - fed vscf wind power generating system uses a doubly - fed induction generator, which rotate speed can be able to change with wind turbine, and it ensures a constant - frequency output, by controlling the frequency of current input into rotor windings. in vector trans control system, the control of stator active power and the control of stator reactive power can be essentially decoupled, and the former is via torque component and the latter is via exciting component of stator current

    本文首先比較了幾種變速恆頻方案，從中選擇了雙饋式變速恆頻方案；它運用雙饋電機的工作原理，允許發電機轉速變化，而在電機轉子側接入低頻勵磁電流，通過控制該電流的頻率，保證雙饋電機定子輸出的頻率恆定；再結合矢量控制技術，通過調節轉子電流來控制定子電流的轉矩分量和勵磁分量，相應獨立地控制發電機輸出的有功功率和無功功率。
  6. Considering the similitude law for shaking table test, we study the test results and obtain some conclusions which are a ) generally, the silty soil in test box liquefies and the liquefied time has relation with the amplitude of acceleration, b ) when the intensity is on and above eight degree, the silty soil deposit will be liquefied dramatically, c ) the relationship of the pore water pressure is relevant to the cycle loading which represents when the cycle loading ranges from little to great, the relationship is represent as a concave curve, or else as a protruding curve and tends to stability. ( 3 ) based on the triaxial compression test and the resonant column test, some studies are made such as a ) the duncan - chang parameters of constitutive model, b ) the dynamic shear modulus ratio and c ) the damping ratio of the site soil deposits. in order to deal with the test data, a computer program is compiled

    （ 2 ）利用小型振動臺進行了k _ 0固結狀態下粉土的振動液化模擬研究，通過分析正弦荷載作用下的試驗資料，驗證了粉土的孔隙水壓力增長模式的合理性；從微分方程推導了基於土體振動臺模型試驗的相似律，並從模型實體、孔壓時程曲線和相似律等方面做出了分析，得出了如下結論：在小型振動臺試驗中，模型箱中的粉土都發生了液化，液化的時刻和輸入加速度幅值有關，而對頻率的變化不太敏感；粉土在相當於8 9度地震烈度的加速度幅值作用下可能產生嚴重的液化；孔壓的增長曲線形狀與施加的荷載有關：當施加荷載為由小到大的形式時，曲線形狀為上凹的曲線；當施加荷載為等幅的正弦荷載或荷載幅值由大到小時，曲線形狀為上凸的曲線，且逐漸趨于穩定。
  7. It was found that the dropping rate in remnant polarization, pr ( n ), of the samples would be accelerated when a high intensity or low frequency or square - wave of electric field was applied or at a lower temperature

    實驗結果表明，在高電場強度、低電場頻率和在方波電場的作用下以及較低的溫度下，鐵電陶瓷材料剩餘極化強度p _ r （ n ）下降的速度變快。
  8. A new method is presented. the travel time, including the time delays associated with overland folw pathways, is obtained. it is expected that the hillslope velocity and the stream velocity are different, and different equation is used. in the method, the fact that velocity increases going downstream in river systems is taken into account. after the travel time of each cell being calculated, the frequency distribution of the times of arrival of individual water droplets at the catchment outlet - giuh, is obtained

    提出了一種匯流時間計算方法，匯流時間中包括坡地漫流時間和河道匯流時間。方法中坡地單元的匯流速度與河道單元的匯流速度採用不同的計算公式，同時考慮流速沿河道向下游的變化。流域中每一個網格單元的匯流時間得到后，將其看作隨機變量，進行統計分析后，得到匯流時間的頻率分佈? giuh 。
  9. The type, direction and frequency degree of land use change not only reflect the process of the space - time dynamic change of the earth ' s surface landscape and become the most salient landscape mark of the earth surface system, but also become the base of rebuilding the equilibration of land use - ecosystem - productivity

    土地利用變化類型、變化方向和速率以及變化的頻繁程度不僅反映了地球表面景觀的時空動態變化過程，成為地球表層系統最突出的景觀標志，而且還成為了重新建立土地利用? ?生態? ?生產均衡的基礎。
  10. Many experiments on the effects with the change of several parameters, such as initial charging current, amplitude and frequency of positive pulses, variety of the amplitude of positive pulses among each charging stages, amplitude and duration of negative pulses, duration between positive and negative pulses, have been performed. the results of analysis and comparison of experimental data verify the validity and feasibility of the fast - charging method. on this basis, a new type of control strategy is advanced

    就充電過程中的起始充電電流、正脈沖的幅值、正脈沖的頻率、各充電級之間正脈沖幅值的變化幅度、負脈沖的幅值、負脈沖的持續時間、正負脈沖之間的停歇時間等幾個參數進行了大量的實驗，對實驗數據進行分析和比較，驗證了快速充電方法的有效性和可行性，在此基礎上提出了一種新型快速充電控制策略。
  11. There is difference frequency measurement requirement for every part of pid regulating, difference between dynamic quality and static quality in response time and accuracy. according to these, it use the interrupt functions and high - speed counter of the simens s7 - 200 plc cpu226 basic unit and some peripheral circuit to measure frequency ; in software designed, the procedure frame of hydraulic - turbine governor and disperse process of parallel pid are analyzed, an improved pid algorithm is adopted to realize a pid regulation mode with variable structure and parameters ; the mechanical liquid - pressure system of the hydraulic - turbine governor is with electric - hydraulic converter unit of step motor. according to the drive character of five phase of response step motor, a variable frequency regulated voltage driver unit is designed in order to realize interface between plc and driver of step motor

    本文利用s7 - 200plc自身的特點設計了頻率測量單元，根據pid調節各個環節的特點，以及調速器動態特性、靜態特性對頻率測量的實時性和精度要求的不同，利用s7 - 200plc基本單元中內置的高速計數器以及相應的外圍放大整形、分頻電路，實現了水輪發電機組頻率的測量；在軟體上，對微機調速器的整個程序框架、並聯pid的離散化過程進行了分析，選用改進的pid演算法實現了變參數、變結構的pid調節模式；調速器的機械液壓隨動系統具有步進電機電液轉換元件，採用五相反應式步進電機，根據其驅動特性設計了變頻調壓驅動器，實現plc與步進電機驅動器之間數字介面。
  12. The variable polarity power supply circuit uses two stages full - bridge inverter, the former inverter is regarded as a constant - current source with fast dynamic response, and supplys energy for the second one, and the latter one is to produce variable polarity current excellently, and low - frequency pulse current by variable polarity power supply is used to reduce input energy and control the shape of weld bead while welding. a series of high - frequency pulse current is superposed on direct - current - electrode - negative ( dcen ) current through the high - frequency pulse power supply, which is used to compress the arc and improve process of crystallization

    其中變極性電源採用二次全橋逆變結構，一次逆變提供快速的響應速率並給二次逆變提供能量，二次逆變提供良好的變極性性能，使輸出能量最優化，並用其低頻電流特性減小電弧線能量，控制焊縫成形;高頻脈沖電源提供的高頻電流疊加在反極性電流dcen上，利用電流的高頻特性壓縮電弧，改善焊縫金屬結晶過程。
  13. The paper concentrates on seismic wave - field forward modeling and migration for the fractured reservoir. it researches the wavefield extrapolation operator for lateral variation of velocity, design four theoretical models and seven practical models with fracture and cavity. base on the progenitor, in the frequency - wavenumber domain with the pspi wavefield extrapolation operator and arithmetic of forward modeling and migration that applied lateral variation of velocity which is strong, the paper obtains the result of numerical simulation and the wavefield characteristic by the way of the forward modeling and depth migration of poststack seismic wavefield

    本文圍繞縫洞儲層地震波場正演與偏移問題，研究了適用於橫向變速波場延拓運算元，建立了四個理論的縫洞模型和七個實際的縫洞模型，在總結、分析前人的研究成果的基礎上，利用適合橫向速度劇烈變化的相移加插值的波場延拓運算元，在頻率?波數域對上述的地質模型進行正演、偏移處理，最後得到了縫洞儲層地震波場的一些特徵。
  14. The system can generate three - phase spwm pulses and has following characters : the range of modulation frequency is from 0 khz to 4 khz. and can be divided to 7 classes to control. the carrier frequency may be selected up to 24 khz, and can be divided to 8 classes to control ; rotational frequency is defined to 16 bits

    該系統能產生三相六路正弦脈寬調制（ spwm ）波形;調制頻率范圍為0 4khz ，分7級控制; 16位的速度控制解析度;載波頻率分8級控制，最高可達24khz ;系統介面兼容intel系列和motorola系列單片機;該系統控制簡單、精確，易修改，可現場編程;同時具有脈沖延時小、最小脈沖刪除、過壓和過流保護功能等特點，可應用於pwm變頻調速系統的全數字化控制。
  15. In the plate region of a vehicle image, the gray value varies frequently in cross - direction, so we define a parameter ". cross variance " to describe it. we also calculate other parameters to approximately locate the plate, they are the space length between two chars, the thickness of stroke, the peak and trough of gray value, the ratio of width and length, etc. at last, we exactly locate the plate by the theory of mathematical morphology

    該方法根據圖像車牌區域橫向灰度值變化頻率比較大這一特徵提出了橫向方差參數，並結合車牌的字元間距、筆劃粗細、灰度峰谷值、長寬比值等特徵粗定位車牌，在車牌的精確定位中利用了數學形態學的方法。我們從某高速公路收費站實地拍攝的照片中選取了1000多幅作為實驗樣本數據。
  16. Frequency variation rate

    頻率變化速率
  17. Then the pulse is modulated by pwm. after the modulated signal through a low pass filter, we can get the change of the frequency that related to the capacitor

    對頻率變化的脈沖進行寬度調制，通過低通濾波就可以輸出頻率變化量，也就可以得到相應的加速度值。
  18. Abstract : this paper proposes an self - adaptive speed - accommodating control circuit, which can get the speed - error, and can test the change of frequency of feedback signals of the single phase ac tacho generator through self comparing and automatically corrects the speed

    文摘:文章介紹了通過自比較來檢測錄音機主導軸單相永磁交流測速發電機反饋信號的頻率變化，從而獲得速度誤差，並自動校正轉速的一種自適應速度調節控制電路。
  19. Based on the torque - speed characteristic curve of induction motors, analyses were done on changes in slip with an variation in frequency when an induction motor drives different kinds of loads, including those with constant torque, constant - maximum torque, variable torque ( except fans and pumps ) and constant power, as well as fans and pumps, the formulas to calculate the slip and the speed under different frequencies and loads were presented

    摘要以異步電動機機械特性曲線為基礎，分析了變頻調速異步電動機在拖動恆轉矩負載、恆最大轉矩負載、變轉矩（非風機和泵類）負載、恆功率負載以及風機和泵類負載時，轉差率隨頻率變化的規律。
  20. To see whether it was the rapidity with which the changes were made that hastened the demise of the old mice, the researchers repeated the experiment but either delayed or advanced the light part of the cycle every four days

    為了探求老齡鼠的加速死亡是否同光周期的變化速度有關，研究人員進行了重復試驗，但是光周期提前或延遲的頻率改為4天一次。
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