low frequency current 中文意思是什麼
low frequency current
解釋
低頻電流-
The corrosion current and impressed against - corrosion current of a ship modulated by shaft ' s rotation will generate an extremely low frequency electric field ( elfe ) which becomes a kind of important characteristic signal in sea water
摘要艦船的腐蝕和防腐電流經螺旋槳轉動的調制后在海水中會?生極低頻電場，成?一種重要的特徵信號源。 -
Compared with weather data and earthquake activity, our result shows that thermal abnormality of low frequency part of tirls is resulted most possibly from fault activity and could offer a certain indictor for judging current tectonic activity or earthquake
結果表明，低頻成份的熱異常更接近於斷層活動所引起的熱信息，能為斷層或地震活動提供一定的指示信息。 -
On the basis of practically achieved low - frequency laser - vibration measuring - system, this thesis analyses the principle of laser - vibration measuring - system, the optical factors which have effect on contrast degree of interference fringe, the optical - electric transformation factors which have effect on measuring accuracy, the important of filter for improving the accuracy in the absolute calibration and the outward vibration which has effect on system accuracy, etc. in chapter one, the background of laser measuring vibration, and then followed by its current status, is introduced and analyzed
本論文根據實際研製的激光測振儀系統，從提高激光測振儀精度的角度出發介紹了激光測振儀的原理，並詳細地剖析了光路對測振儀干涉條紋對比度的影響、光電轉換對測量精度的影響、光電信號的濾波放大以及外界振動對測振儀系統的影響等技術問題。 -
Low frequency current therapy
低頻率電療法 -
There are five parts are as follows : in part one, the concept of switching function is introduced first to establish the nonlinear mathematical model of the induction motor variable frequency speed adjustment system which is fed by a sine pulse width modulated ( spwm ) inverter and takes the effect of the main magnetic circuit saturation into consideration, then the low frequency oscillation of the system is simulated according to the model. next, from the view point of energy conversion of the inverter - induction system, a criterion for the low frequency oscillation is proposed to determine whether the system is in low frequency oscillation which is judged by whether the interval of the negative current component of the inverter input current is more than 1 / fc ( fc is the carrier wave frequency of the inverter ) or not
首先引入開關函數概念，建立了正弦脈寬調制（ spwm ）逆變器供電異步電動機，考慮主磁路飽和時的變頻調速系統整體數學模型，模擬系統的低頻振蕩；其次從逆變器-異步電動機系統能量轉換角度出發，提出通過檢測逆變器輸入電流中負電流的間隔時間是否大於1 / f _ c （ f _ c為逆變器載波頻率）來判定系統是否出現低頻振蕩；最後的實驗結果驗證了系統低頻振蕩建模和判據的實用性和正確性。 -
The main circuit is consisted of 18 thyristors circuit and protection circuit. with the help of control subsystem, it can get the output of low frequency voltage ( current ) with the shape of sine wave ; the core of the control subsystem is the cpu of 87c196kc, and the synchronization circuit, the pulse - widen circuit, and the power - enlarged circuit form the accessorial subsystem of the control system. it possesses all the functions of digital triggering, digital tuning, analog / digital conversion ; the input transfer can isolate the input and output ; and the circumfluence reactor can reduce the circumfluence
主迴路採用由18個晶閘管組成的三相零式電路，並輔以晶閘管的保護電路，通過控制可以得到低頻正弦波的電壓（電流）輸出；控制迴路主要以87c196kccpu為核心，其外圍電路包括同步電路，脈沖拓寬電路，功率放大驅動電路等，完成了數字觸發、數字調節、模數轉換等功能；進線電源變壓器具有變壓和隔離作用；環流電抗器則實現了有效抑制主迴路瞬時脈動環流的功能。 -
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。 -
Working principle : using the low - voltage high - frequency current rtansform from high - tech molectron, conbne traditional energy - channel theory from china, it gets through the energy - channel of body in a breath stimulate bicelectricity of body for therapy, have efficacy of through but indolence it ` s able to adjust metaboilsm, eliminate subhealth, reforning bone, skin etc, fast supply energy for body, at the same time, you can got beauty, health and happiness
工作原理：採用通過尖端電子集成技術轉化的低壓高頻電流，結合中國傳統的經絡理論，瞬間打通人體經絡，激發人體生物進行治療，以達到「通而不痛」的功效，調整代謝，調動潛在的生命能量，消除亞健康，重整經，骨，皮等器官，快速補充人體生命能量，通經活洛，平衡陰陽，增強體內含氧量，調理臟腑，同時美膚修身，以達到身心健康，美好，快樂的境界！ -
The microprocessor is used to realize digital control as flip plus of the scr. the ic chip sa866ae of mitel company is utilized as the low frequency signal generator of the system. furthermore in the zero - current detection circuit, use the photocoupler gaalas ired and photo ic to detect zero - current, furthest shorten the commutating " died region ", prevent the current from distorting
設計中採用單片機控制可控硅的觸發脈沖，實現數字化控制，並利用mitel公司的三相pwm交流電機脈寬調制晶元sa866ae ，成功研製了交-交頻器中的低頻信號發生器裝置，效果良好；此外利用用光電檢測元件進行系統零電流的檢測，盡可能地縮短換相死區，防止電流發生畸變，成功地解決了原有低頻電源系統中存在的兩大難題。 -
The content of this theme is as follows : without time, without open, without stopping railway transport, and without interrupting traction current of block tested, meanwhile track circuit parameters in electrical and no electrical blocks is measured of on - line, dynamic and real - time. these parameters include voltage of fsk signal, voltage of industrial and harmonic wave interference, upper frequency, lower frequency, carrier frequency and low frequency 18 messages frequency
本課題研究內容：在不要點，不開天窗，不中斷行車，不中斷被測區段牽引電流的情況下，在線、動態、實時測量電化區段和非電化區段的移頻信號電壓、工頻干擾電壓，移頻信號（調頻信號）的上邊頻、下邊頻、載波頻率、以及低頻18信息頻率等參數。 -
One is to use fourier transformation to convert the source signal from time domain to frequency domain and to discard high frequency harmonious components upwards of 19 ( gb / t14953 - 93 d5. 3 demanding ), then to have static huffman coding to the quantized char array which is composed of reserved direct current component and basic wave and each high frequency " s amplitudes and angles. the other is to use discrete wavelet transformation to convert the source signal from time domain to frequency domain and to set the high frequency coefficients that its absolute value is smaller than the given threshold to zero, then to have dynamic huffman coding to the quantized char array which is composed of multiple, wavelet ' s level, datum length, low frequency coefficients and reserved high frequency coefficients. mass simulinks and analyses under the two circumstances have done to show that data compression ratio is small and the relative error is also small and within the permission of engineering and the compression problem can be solved in theory of measured datum of power system
第一種情況的壓縮方法為：採用傳統的傅立葉變換把原始信號從時間域變換到頻率域，舍棄20次及其以上的高次諧波成分（保證了gb / t14953 ? 93d5 . 3要求） ，然後對保留的直流分量、基波和各次諧波的幅值和相角數據量化后和量化時分別乘以的倍數系數構成一個數組，以字元形式保存，採用靜態huffman編碼對變換數據進行壓縮；採用離散小波變換把原始信號從時間域變換到頻率域，然後對分解得到的高頻系數進行閾值量化處理，對乘以的倍數系數、小波變換的階數、小波變換后的低頻、各級高頻以及原始數據長度、量化后的低頻系數以及保留的高頻系數大小、位置構成一個數組，以字元形式保存，採用動態huffman編碼對這個文件進行壓縮。 -
The strict solution of the eddy current distribution inside a conductor cylindrical boundary surface for quasi - state - state is obtained by derivation of maxwell ’ s equations ; meanwhile, the approximate solution of the eddy current and electromagnetic field in the condition of the low - frequency or the high - frequency are obtained. furthermore the penetration depth of the skin effect is achieved
五、討論了似穩條件下導體圓柱面內的渦電流分佈的規律。我們採用圓柱界面條件下獲得的趨膚效應的穿透深度與採用平面條件下獲得的趨膚效應的穿透深度相一致，我們的研究可視為對傳統教材相關論述的有益補充。 -
Study of non - self - adjoint variational problem in low - frequency eddy current electromagnetic field
低頻渦流電磁場非自伴變分問題的研究 -
In addition the h. kantz method is applied to analyze the time series of the motor current, the maximal lyapunov exponent calculation is realized, the criterion for the motor chaos is brought forward, the existence of chaotic phenomenon in the induction motor is verified by the characteristic exponents, which proves theoretically that the chaotic movement is one of the reasons that results in the low frequency oscillation of the induction motor system
應用h . kantz方法對電機電流信號的時間序列分析，實現了最大李亞普諾夫指數的具體演算法，提出了電機出現混沌運動的判定根據，通過特徵指數驗證了異步電動機現象的存在，從理論上說明混沌運動是異步電動機系統產生低頻振蕩的原因之一。第三部分深入研究了系統低頻振蕩的主要影響因素。 -
The high temperature abnormality area ( or belt ) of low frequency part of tirls is likely to attributed to the current tectonic activity and earthquake
低頻成份的高溫異常區（條帶）跟構造特徵、地震活動密切相關。 -
Modularization methods are used to establish the mathematical models and simulation program for ship ' s dp systems. it included ship ' s moving models of low frequency moving and high frequency moving, thruster ' s models and environmental mathematical models ( wind, wave and current ). the models have been proved to be correct by simulation method
利用模塊化思想研究了船舶動力定位系統的數學模型、並且建立了模擬程序，包括船舶低頻運動模型、高頻運動模型、推力器模型和環境（風、海浪和海流）數學模型，通過模擬實驗驗證了模型的正確性。 -
The driver adopted the technique of automatic power changing between high and low voltage and the driving mode of constant current cutting wave, so that the low - frequency vibration of the stepping motor was reduced and the high - frequency torque was increased
該驅動器採用高、低壓電源自動切換供電技術和恆流斬波驅動方式，降低了步進電動機的低頻振蕩，提高了步進電動機的高頻力矩。 -
Comparing to inducing - magnetic mode with 50hz alternating current, we can use lower frequency alternating current to induce the magnetic so that it can eliminate the noise at 50hz frequency and weaken the noise whose phase lags signal 90 ? greatly. comparing to inducing - magnetic mode using rectangle - wave current as the signal, using low frequency to induce magnetic can eliminate ( weaken ) the differential coefficient noise. thirdly, it eliminates or weakens all different noise by designing the circuitry effectively in the transforming signal part
相對於50hz交流勵磁，這種勵磁方法可以採用更低的頻率來對微流量的磁路進行勵磁，一方面可以完全消除工頻干擾，另一方面可以極大地減小正交干擾；相對于方波勵磁，這種勵磁方法相當于多值方波勵磁，有利於消除或減少方波法勵磁所帶來的微分干擾。 -
The operation characteristics and the limitations under high condition of hps lamps are described. according to these, a new low frequency invert circuit is designed based on current - track in this paper
針對高壓鈉燈的穩態運行特點以及工作在高頻狀態下的缺陷，本文設計了一種低頻的電子鎮流器逆變電路。 -
The algorithm takes advantage of the merits of the watermarks both in low frequency and high frequency and can embed more information with less distortion. experimental results show the algorithm is robust to many common image operations. as for the vector map data, an uniform model of embeding watermark for vector maps and raster maps is proposed after current trend of research and watermarking methods of 3 - d vector images are summarized, primary study results show the model is effective and promising to further research
目前該問題在國內外都還處于探索階段，作者在分析了國內外三維矢量水印的研究狀況、研究方法后，提出了將矢量數據中的部分信息轉化為柵格形式后再嵌入水印的方法，該方法使地圖柵格數據和矢量數據在嵌入水印時能夠使用統一模型，初步的實驗結果表明該方法為二維地圖矢量數據的水印嵌入開辟了一種新途徑。
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