脈首波 的英文怎麼說
中文拼音 [màishǒubō]
脈首波
英文
papillary wave-
After reviewing the history and recent developments of the research on thermoacoustics, and introducing the classical thermoacoustic theory, we carry out the following investigations : 1 ) thermoacoustically driven pulse tube refrigerator ( tadptr ) experiments have been done on the self - built pulse tube refrigerator driven by standing wave thermoacoustic prime mover system
本文首先回顧了熱聲機械的歷史及現狀，詳細介紹了熱聲學理論基礎，重點研究了以下若干問題： 1駐波型熱聲驅動器驅動脈管製冷機在自行搭建的駐波型熱聲驅動脈管製冷機實驗裝置上進行了實驗研究。First, based on phased array antenna ' s mono - pulse goniometry and separate coordinate technology about phase control, the antenna beam pointing error formula, caused by phase quantization error, is derived from linear array and circular array to planar array and cylindrical array
首先以單脈沖相控陣天線測角原理為基本理論出發點，利用相位控制的坐標分離技術，基於線陣、圓形陣等簡單形式的相控陣天線，推導了平面陣、圓柱面陣等相控陣天線由相位量化誤差引起的波束指向誤差公式。The research work in nonlinear pulsatile flow and nonlinear pulse wave propagation is reviewed
本文首先回顧了前人在彎曲動脈中脈動流和脈搏波傳播方面的研究工作。This paper starts the research of the liquid floated pendulous accelerometer testing system according to the engineering. at first, this paper gives the brief introduction of the history and present status of accelerometer and its testing technology, the working principium and math model of the liquid floated pendu - lous accelerometer, and then, decides the binary width pulse force retrim loop as the design proposal of testing system, researches the transfer function of every part in the system emphasizly, analyses the stability of the whole accelerometer testing system from the angle of control theoretics by the open loop transfer function of system, and designed the correcting net, analyses the basal problems such as resolution, sampling restraint, precision and so on, designs the hardware testing circuits such as preamplification, band - pass filter, alternating amplifier, phase sensitive demodulatorn, pulse - width modulation, frequency scale circuit, moment current generator. finally, using the graphics program language labv - iew which is designed for testing field especially by ni accomplishes the solfware design of testing system, realized the testing functions
首先對加速度計及其測試技術的發展歷史和現狀，液浮擺式加速度計的工作原理和數學模型等作了簡要的介紹，然後確定了以二元調寬脈沖再平衡測試迴路為設計方案，並從控制理論的角度進行了分析，著重研究了系統中各部分的傳遞函數，利用系統開環傳遞函數分析了系統的穩定性，同時設計了系統的校正網路;分析了二元調寬脈沖再平衡測試迴路的解析度、采樣約束以及測試精度等基本問題，並按照系統分析的結果設計了包括前置放大、帶通濾波、交流放大、相敏解調、脈寬調制、頻標電路以及力矩電流發生器等測試系統各部分硬體電路，驗證了電路的正確性，最後按照測試系統的要求，採用了美國ni公司專為測試領域所開發的虛擬儀器工具? ? labview作為測試軟體開發工具，利用該圖形化編程語言完成了測試系統軟體部分的設計，實現了測試功能。This thesis was divided into eight chapters, and the main results and innovations obtained here can be summarized as follows : ( 1 ) the physics model of tsrs in frequency conversion crystals has been built up firstly. based on quantum - mechanical viewpoints and the following physical processes and parameters : the two - photo interaction of light with matter, paraxial diffraction of stokes, langevin noise sources, reflection at the faces and the edges of crystals, gain coefficient, beam aperture, pulse width and fluence of 3, the physics model of tsrs in kdp and kdp crystals acting as high - fluence frequency convector and the paraxial operator maxwell - bloch - langevin equations have been built up
全文共分八章，取得的主要成果及創新點如下： （ 1 ）首次建立了諧波轉換晶體的tsrs物理模型本文根據量子力學原理，在考慮如下物理過程和參量的基礎上：光與物質的雙光子相互作用； stokes光的傍軸衍射； langevin （郎茲萬）噪聲源；晶體表面反射和端面反射；增益系數、光束口徑、脈寬和三倍頻光能量密度，推導出高通量激光在kdp和kd ~ * p諧波轉換晶體中的tsrs物理模型和空間上的近軸算符maxwell - bloch - langevin方程組。This thesis describes the properties of millimeter wave, and development of the millimeter wave sources nowadays, and introduces the solid - state devices impatt diodes, and analyses the technology of the injection locked. then this thesis gives out how to design the pa module in detail. and practical circuit is given out with the test result and analyses
本文首先綜述了毫米波特點，毫米波源的發展現狀，介紹了w波段impatt器件的基本工作原理，分析毫米波波導電路中的注入鎖定技術，給出實現連續波或脈沖功率放大的w波段信號源的功放模塊的技術方案、測試結果和綜合分析。This dissertation mainly studies the pulse compression waveform designing and signal processing, including the following aspects : firstly, by the pulse compression basic theory, the linear frequency modulation signal ( lfm ), binary phase - coded signal ( bc ) and stepped - frequency ( sf ) signal are discussed respectively including the ambiguity function, pulse compression and spectrum characteristic
本文主要進行脈沖壓縮雷達波形設計以及信號處理方面的研究，主要體現在以下幾個方面:首先，從脈沖壓縮基本理論出發，分別給出了線性調頻、二相編碼和頻率步進信號的模糊函數、脈沖壓縮以及頻譜特性，對多普勒性能進行了簡要分析。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。Some researches about frequency doubling are made, and two methods to improve intensity of second frequency generation are given. we realized q - switched 532 nm laser, by using nd : gdvo4 as laser crystal, using cr4 + : yag as saturable absorber, using ktp as intra - cavity frequency doubling crystal. average power of 109mw, repetition of 40khz, pulse width of 30ns, pulse energy of 2. 6uj, peak power of 91w are obtained
4 .對倍頻理論進行研究和分析:討論兩種提高二次諧波功率密度的方一法;實驗匕在國內首次實現ld端面泵浦nd : gdvo4 / ktp ，用cr4 + : yag作為可飽和吸收片的綠光激光器，腔內倍頻得到了平均功率為109mw 、重復頻率為40khz 、脈寬為3ons 、單脈沖能量為2 . 6閃、峰值功率為glw的調q綠光輸出。Firstly, according to the detailed analysis on the mathematical model of pmsm, the principle of field oriented control ( foc ) is illustrated. spwm and svpwm are analyzed and contrasted in detail too, and the digital realization techniques based on dsp are given
本文首先在分析永磁同步電機數學模型的基礎上，闡述了永磁同步電機矢量控制基本原理；對正弦波調制技術（ spwm ）和空間矢量調制技術（ svpwm ）兩種脈寬調制策略進行了詳細的分析和對比研究，給出了基於dsp的數字化實現方法。In order to improve signal noise ratio ( snr ), wavelet denoising is used, and the radar in - pulse characteristics is extracted by wavelet - ridge, radar emitter signal sorting is realized by neural networks
該方法首先對接收到的雷達信號進行小波去噪，達到提高信噪比的目的，然後利用小波脊線法準確提取其脈內特徵參數，最後基於神經網路實現信號的分選。In the section 2, firstly based on the diffusion approximation theory, the temporal characteristics of the reflectance and the transmittance were theoretically analyzed in turbid tissues ; secondly, the curves were simulated that the intensity and the pulse shape of the time resolved reflectance and transmittance versus the absorption a, the scattering s and the anisotropy coefficient g in two different boundary conditions : semi - infinite turbid media and homogeneous slab ; at last, the optical properties can be derived from the curves ; in the section 3, the conditions of ultra short laser pulses of different pulse - width and shapes has been theoretical analyzed and calculated, besides, the simulated the curves of the intensity and pulse shapes of the reflectance and transmittance in a homogeneous slab are obtained for use and future studying
第二章中首先根據漫射近似理論對超短脈沖在以生物組織為典型的混濁介質中傳輸進行了理論分析，然後對兩種邊界條件下產生的漫反射、漫透射光脈沖強度和形狀隨各光學特性參數的變化情況進行了數值模擬，最後得到了混濁介質的光學特性參數與漫反射、透射脈沖強度與形狀的關系曲線。第三章對不同形狀和脈寬的脈沖光源入射到混濁介質中產生的漫反射、漫透射脈沖的強度和形狀進行了理論分析和數值模擬，並將高斯脈沖與方波脈沖情況進行了對比，得到了各種情況的漫反射、漫透射脈沖強度、形狀與各光學特性參數的關系曲線，這對從分析脈沖形狀中提取介質的光學特性參數的信息有重要的意義。Firstly, the paper, combining the characteristic of synchronous pulse bursts and inhibition with the modified pcnn model, presents a way of finding the foveation points in the images adaptively and effectively, and simulates the human vision system. secondly, pcnn is extended to pcnns, based on the properties of information couple and transmission, an algorithm that is used to fuse images of the same target got by several sensors to an image is presented to simulate the human vision system. thirdly, combining the properties of synchronous pulse bursts, capture, and transmission and competition of waves, the paper presents two ways of classification, one is an algorithm based on the properties of neuron to capture and inhibit to classify the data taking on any complex unlinear distribution robustly, the other is based on the restricted distance and modified of the former to remove the influence of inferior samples in classification ; fin ally, based on the accumulative difference pictures, and the forming and transmission of pcnn wave, selecting and controlling the direction of autowave by connecting the neighbouring neurons selectively, the paper presents a way to simulate the tracks of moving object and detect the moving direction
首先結合pcnn的同步脈沖發放和側抑制特性，提出了基於改進型pcnn的圖像凹點檢測演算法，該演算法是一種自適應而有效的圖像凹點檢測方法，並且較好地模擬了人類視覺系統；然後，結合信息傳遞和信息耦合特性，將pcnn擴展成pcnns （ pcnn網路群） ，提出了一種基於pcnns的圖像融合演算法，能夠將多個傳感器獲取的同一目標的圖像信息融合到一幅圖像中，有效模擬了人類視覺系統；另外，結合pcnn的同步脈沖發放特性、捕獲特性和波的傳播競爭特性，開拓地將pcnn用於模式分類中，提出了基於耦合神經元點火捕獲抑制特性的分類方法和改進的約束距離下的pcnn分類方法，前者可實現對樣本空間中任意復雜分佈訓練樣本的穩健非線性分類，而後者能夠消除訓練樣本中刺點對分類的影響；最後，結合累積差分圖像思想、 pcnn波的形成與傳播特性，通過各神經元之間連接取向來選擇與控制自動波的流向，將pcnn用於運動視覺分析中的運動軌跡模擬及運動方向檢測。Firstly, the characteristics of millimeter - wave and its applications are introduced. it also gives the latest development of the ka - band solid state impulse - transmitter and its correlation components
論文首先論述了毫米波的特點及其應用，並簡要介紹了毫米波固態脈沖發射機及其相關部件的發展概況以及本文的研究意義。At last, this paper put forward a recognition method using the parameter of moving target the missle - borne pulsed doppler radar can be achived and the hmm and the analized the limited performance of the method under different circumstance. in chaper 4, this paper analized the temporal chracreristic and spectral chracterisc of hovering helicopter, and then analized the possible methods for detection hovering helicopter and the message that can be achived
第四章中，本文首先分析了懸停直升機回波信號的時域特性和頻域特性，結合彈載高重頻脈沖多普勒雷達的一些具體參數分析了利用彈載高重頻脈沖多普勒雷達對懸停直升機進行檢測的可能途徑和可利用信息。After the discussion of the numerical simulation method based on the fdtd method and the pml technique, the motions of the charges and the electrical field lines were first employed to describe the radiation procedures of the pulse electromagnetic waves. then the causes of how the charges are accelerated and how the motion status of the charges are maintained were further studied from the angle of interaction of charge and field. after these analyses, it was pointed out that the pulse radiation is due to the suddenly occurred time - varying electrical field ( displacement current ) in the open space. this view was further evidenced by two examples : one is the partly resistance loaded antenna, the other is the partly curved antenna. the radiation procedures of the pulse electromagnetic waves of many different situations were simulated throughout this paper with the contours and waveforms of electric field given. these figures are very helpful to the understanding of the radiation mechanism of the pulse electromagnetic waves
在討論了基於時域有限差分法和完全匹配層技術的數值模擬方法之後，首先從運動電荷和電力線的角度直觀地描述了脈沖電磁波的輻射過程，然後進一步從場與電荷相互作用的角度分析了天線上電荷是如何被加速以及如何維持其運動狀態的，指出了開放空間中突然出現的時變電場（位移電流）是脈沖電磁波輻射的根本原因.文中還對局部電阻加載的天線和局部彎曲的天線進行了研究，以進一步說明上述觀點.對多種情況下的脈沖輻射過程進行了數值模擬，並給出了電場的等高線和空間波形圖，這些圖形對理解脈沖電磁波的輻射機理非常有益The dispersive influence, especially the influence of the second - order and third - order dispersion, is researched first. in this part, the influence of the third - order dispersion on the super - gaussian pulse is mainly discussed, and the difference between gaussian and super - gaussian pulse is also qualitatively discussed ; the effect of the initial chirps is researched
從而，本文首先對色散效應進行了研究，分析了二階和三階色散對光纖中光脈沖波形的影響，其中著重研究了三階色散對超高斯型光脈沖波形的影響，定性地分析了其與高斯型光脈沖波形演變的不同，並對初始啁啾的影響進行了闡述。In the proposed technique the bemf waveform of bldcm need to be measured in advance at first, through computer simulation and frame transformation, the optimum q - axis current command is achieved. in order to minimize the torque ripple, the d and 0 - axis current command should be zero. furthermore, through reference frame transformation from dqo - axis to abc - axis, we can get the optimum current command in static abc reference frame
在這種控制方法中首先測量出電機的實際反電動勢波形，然後通過計算機擬合和坐標變換，求得產生恆定電磁轉矩所需的q軸電流，令i _ d ~ * = i _ 0 ~ * = 0 ，通過坐標變換，得到三相靜止坐標系a - b - c下的參考電流i _ a ~ * ， i _ b ~ * ， i _ c ~ * ，利用電流滯環控制來產生pwm信號，由於這種控制方法中電流不會突變，從而可以較好的抑制轉矩脈動。In the process of building and using the mass concrete structures, because of the effect of out - side condition and themselves, some faults will form in the structure, these faults will effect the bearing capability and endurance using nondestructive testing method to test the concrete ' s quality and diagnose its healthy, which has the significant sense in assessing the safety stability and research of the administering diseases this dissertation mostly researched the testing methods in the mass concrete structure, discussed the principles, methods, features, sphere of application of the ultrasonic testing in the mass concrete structure with faults, used dynamic fem to simulate the testing process, discussed when the concrete structure with cracks is under the effect of the pulse, how the elastic waves propagate and what are their changing feature, researched the principles of the first - arriving waves " phase when the cracks " depths are not same, obtained the relation between the inversion point and the cracks " depth, which has the direction sense in the application of projects, the second part of this dissertation is ct, which used the ultrasonic wave running through the tested - substance to get arriving - time of the ultrasonic wave, then inverse the image this dissertation drawed one ct program which can well present the different little cells " ultrasonic wave velocity profiles of the substance, thereby to diagnose the quality of the part of the tested - substance, ct has the better using foreground.
在混凝土結構的施工及使用過程中，由於受其自身及外界各種因素的影響，常常會產生一些缺陷，對結構物的承載能力和耐久性造成嚴重影響，採用無損檢測技術進行質量檢測和健康診斷，這對混凝土結構開展安全、穩定性評估以及病害隱患治理研究具有重要意義。本論文主要針對大體積混凝土結構缺陷的檢測方法展開研究工作，重點討論了超聲波法檢測混凝土結構裂縫的基本原理和方法及其特點、適用范圍，運用動力有限元數值模擬其檢測過程，探討了有裂縫缺陷的混凝土結構在脈沖荷載作用下彈性波的傳播及其變化特徵，研究了不同裂縫深度下首波相位變化規律，得出了反轉臨界點與裂縫深度之間的關系，這對實際工程應用具有指導意義。聲波ct是一種新的無損檢測技術，它是利用聲波穿透被檢測體獲取聲波接收時間，來進行計算機反演成像的技術。The pulse shape of " sg - ii " laser was controlled triumphantly by avm, attaining a better uniformity of multi - beam pulse shapes, and realizing the power balance control of multi - pass main amplifiers eventually ; 6
首次實現了avm對神光n輸出脈沖波形的控制，獲得了較好的脈沖波形畸變一致性，最終實現了多程主放大器的avm功率平衡控制。分享友人