脈沖式發射 的英文怎麼說
中文拼音 [màichōngshìfāshè]
脈沖式發射
英文
pulsed emission-
Based on mono - pulse radar system and the analysis of terrain echoes, a geometrical model of air to ground ranging is constituted. by using the signals received from the sum and difference channels of terrain follow radar, a group of the expressions for terrain echoes are educed and characteristics of these echoes are obtained. according to the characteristics of the echoes, the theory and method of pass zero detection of difference channel and its applications are discussed in detail
針對一維單脈沖雷達體制，分析了地形目標回波特性；建立了地形跟隨雷達空地測距的幾何關系；利用雷達收發信號，導出了地形跟隨雷達和差接收通道的回波信號表達式，進行了波形模擬，得到了地形跟隨雷達的地面散射產生回波在時域中的特性；根據和差回波特性，闡述了差信號過零點檢測測距的原理和方法及工程實踐中的應用，並給出了真實雷達對外輻射試驗的結果，驗證了文中的模擬。This paper ' s study is focused on the principle of bistatic sar on the basis of giving a brief introduction of sar principle, including azimuth resolution, mapping width, focusing deepness, pulse repetition frequency limitation and radar equation etc. then the paper studies the special form of bistatic sar with stationary transmitter
在簡要介紹了合成孔徑雷達的成像原理后，本文著重從原理方面對雙站sar進行了分析，討論雙站sar的方位向解析度，測繪帶寬，聚焦深度，脈沖重復頻率限制，雷達方程等問題，然後對發射機固定的雙站sar這種特殊的雙站sar模式進行分析。In principle, ultrasonic sensors are suspended over a road, which keep emitting pulse signals periodically to nearby and feed back waves to decide existence of any obstacles, thus to detect the speed, height, length, different sizes ( heavy, medium and small ) of moving vehicles and accumulative flow as well as length of motorcade. optionally, it can be applied to multitude driving lanes simultaneously for traffic data. by integrating and analyzing these measured data, the necessary figures concerning traffic flow may be obtained, which are fundamental basis guiding road buildings
本課題設計的是一種懸掛式超聲波車流多信息檢測器，通過懸掛于路面上方的超聲波探頭向路面周期性地發射脈沖信號，利用地面回波來判斷遮擋物地存在，可用於檢測行駛中的機動車車速、車高、車長、大中小分型以及累計車流量、車隊長度等信息，並可用於多個車道車流信息的同時檢測，綜合這些測量參數可獲得車流量的必要數據，可為公路建設提供必要的基礎依據。The paper includes four sections followed here : the first section studies the modeling of signals of pulse doppler radar seeker, and establishes a radar signal simulation model, including radar emitting signal model, receiving signal model, receiving echo signal model, clutter model, noise model, sum channel directional pattern of antenna model, difference channel directional pattern of antenna model, sheltering model, rcs model, glint noise model, etc. the second section studies signal processing of pulse doppler radar seeker, and establishes radar signal processing mathematical model and data processing mathematical model for simulation, including windowing, doppler filtering, envelope demodulation, pdi, cfar, centering, velocity tracking, angle tracking, a - b filtering, etc. the third section studies the modeling of modified proportion guiding, and establishes guiding model, then dynamic simulation results is provided
論文的主要工作包括四部分：第一部分研究了脈沖多普勒雷達導引頭的信號建模問題，建立了雷達信號模型，主要包括：發射信號模型、接收信號模型、目標回波信號模型、雜波模型、噪聲模型、和差通道天線方向圖模型、遮擋因子模型、接收機噪聲模型、目標雷達截面積統計性模型、目標角閃爍模型等。第二部分研究了脈沖多普勒雷達導引頭的信號處理模式，建立了信號和數據處理模型，主要包括：加窗和多普勒濾波、包絡檢波、檢波后積累、頻域cfar處理、速度定心、速度跟蹤、角跟蹤、 ?濾波等，然後給出了信號處理流程。The condition, under which the paraxial approximation is valid, is given. 4. starting from the rayleigh diffraction integral, the propagation equation of ultrashort pulsed beams in dispersive media has been derived without making the paraxial approximation and slowly varying envelope approximation ( svea ), which allows for relatively large angles
從瑞利衍射積分公式出發，未作慢變振幅近似和近軸近似的條件下，導出了等衍射長度超短脈沖高斯光束在色散介質中非近軸傳輸方程，可用來處理色散介質較大角度的傳輸。The properties of cn thin films such as their morphology, component, crystal structure and the bonding structure and the relation between those properties and the gas - phase reaction parameters were discussed, showing that the deposition of p - c3n4 thin film is the compete result of various reaction processes in the dynamics balance conditions ; the process of cn films depo sition is diagnosed in situ through the optical emission spectra technique, the effects of experimental parameters on the concentration of the precursors and the gas - phase reactions in the plasma have been obtained ; the main reaction precursors for film deposition identified ; the relation between the characteristics of cn thin films and the reaction process in the plasma is analyzed. the cn thin films deposition under different substrate temperatures in high pressure pe - pld shows that the si atom of the substrate has participated the cn films growth process, based on this the growth mode of cn thin films on the si substrate is proposed. the further experiment of cn thin films deposition on si substrate scratched by diamond as well as covered with fe catalyzer has been attempted, which indicates that changing the dynamics conditions of the surface reaction can alter the growth characteristic of the cn thin films and can enhance obviously the films growth rate
採用pld技術進行了碳氮化合物薄膜沉積，得到了含氮量為21at的cn薄膜；研究了襯底溫度和反應氣體壓強對薄膜結構特性的影響，給出了cn薄膜中n含量較小、 sp ~ 3鍵合結構成分較少和薄膜中僅含有局域cn晶體的原因；引入脈沖輝光放電等離子體增強pld的氣相反應，給出了提高薄膜晶態sp ~ 3鍵合結構成分和薄膜的含n量可行性途徑；應用pe - cvd技術以ch _ 4 + n _ 2為反應氣體並引入輔助氣體h _ 2 ，得到了含n量為56at的晶態cn薄膜；探討了cn薄膜形貌、成分、晶體結構、價鍵狀態等特性及其與氣體壓強和放電電流的關系，證明了- c _ 3n _ 4薄膜沉積為滿足動力學平衡條件的各種反應過程的競爭結果；採用光學發射譜技術對cn薄膜生長過程進行了實時診斷，得到了實驗參量對等離子體中活性粒子相對濃度和氣相反應過程的影響規律，給出了cn薄膜沉積的主要反應前驅物，揭示了cn薄膜特性和等離子體內反應過程之間的聯系；採用高氣壓pe - pld技術研究了不同襯底溫度條件下cn化合物薄膜的結構特性，揭示了si原子對薄膜生長過程的影響，給出了si基表面碳氮薄膜的生長模式；在金剛石研磨和催化劑fe處理的si襯底上進行cn薄膜沉積，證明了通過控制材料表面動力學條件可以改變碳氮薄膜結構特性，並可顯著提高晶態碳氮材料的生長速率。Most astronomers accept the binary spin - up scenario for creating millisecond pulsars because they have observed neutron stars speeding up in x - ray binary systems, and almost all radio millisecond pulsars are observed to be in binary systems
多數天文家接受這個假想的模式，因為他們已經在x射線雙星系統中觀測到了中子星的加速現象，而且幾乎所有的毫秒脈沖星都被發現時處于雙星系統中。Then we introduce pulse position modulation ( ppm ) using pn code and analysis its multi - access performance, system capacity and power spectrum density. on the basis of those analyses, we study the pulse shape and the anti - jamming ability of the system. at last, multiple access with pseudochaotic time hopping is introduce
本文首先闡述了uwb脈沖通信系統的基本原理，重點介紹了用偽隨機碼跳時的ppm （脈沖位置調制）調制，分析了他的多址性能、系統容量和功率譜密度，在此基礎上研究了改進性能的發射信號形狀和系統抗干擾能力，最後介紹了偽混沌碼跳時的多址方式。Then a model on electromagnetic emission relying on the extent of cracks is put forward. using this model, the amplitude of electrical field and magnetic field, the largest frequency are estimated
研究表明，混凝土隨裂紋的擴展產生幅值逐漸增加的電發射脈沖；混凝土隨材料組成不同在開裂時產生不同形式的電發射脈沖。Some valuable conclusions are summarized by theoretical analysis and simulation experiments : from the side of signal processing, pulse jamming can be deleted by the method of time - domain sliding window accumulation and can be restored by interpolative prediction. ; gauss white nose can be attenuated while jamming disperse point - target by the method of time - frequency analysis in time - frequency domain. ; radio frequency noise jamming can be deleted by the method of average range frequency spectrum and notching in frequency domain
通過大量的理論分析和模擬實驗，得到了一批具有一定價值的結論：從信號處理的角度出發，對于脈沖式干擾，能夠運用時域滑動窗口積累的方法去掉，並且通過預測插值得到較好的恢復；對于高斯白噪聲干擾，在時頻變換域內應用時頻分析方法可減小其對分散點目標的干擾；對于射頻噪聲，通過平均距離頻頻法和頻域陷波的方法可以去掉；從改變合成孔徑雷達系統角度出發，類似雙基地雷達能夠避免各種干擾，對發射信號進行調幅，調相以及改變調頻斜率都是較好的抗干擾方法。In succession, the theory of chirped - pulse amplifier system is given in detail, firstly, studying from designing experimental light road and optical components to theoretical analysis, we par ' tly finished the system by ourselves. about ultr a - shoft pulse with a pulse - width of 9. 8f s and output power of 650mw and band - width of about l 20nm is output from oscillator source, secondiy, the stretching capacity of single grating four - pass stretcher is measured using abcd matrix combining collins function, and the effect of relativ e parameters to the streching ratio is also simulated. thirdly, a new type of disjunctional frequency moduiating function is provided according to the gain - narrowing and gain - saturation which are appeared in the co urse of amplification, under modulating the two effects are both controlled on some e xtent, fourthiy, the effect of ase that is often ignored by people is analyzed and the resolving methods are also given
從光路、光學元件的自行設計到理論分析計算，初步建立了一臺實驗系統；採用abcd矩陣法結合collins公式計算了四通式單光柵展寬器的展寬量，並模擬了相關參數對展寬比的影響，對實驗具有指導意義；評價了再生放大器和多通放大器的優缺點，對放大過程中通常忽略的放大自發輻射現象（ ase ）進行了分析，並提出了相應的解決方法；針對放大過程中出現的增益窄化和增益飽和現象，對輸入種子脈沖提出了一種新的分段頻率調制函數，實現了對增益窄化效應和增益飽和效應的共同抑制；提出了系統的材料（包括放大介質和光路中的普通介質）正是融合高階色散的來源。The perturbed theory given in chapter 2 and a new definition on sensitive dependence on initial values of impulse - interval functions are adopted. from the abstract to real, we discuss a real model, named integrate - and - fire circuits, simulating the dynamics of in - formation processing in neurons. by the means of marotto theorem, we prove ide g vii the existence of chaotic dynamics in this model with the parameters in some restricted regions
接著，我們探討了一般的動態神經元的數學模型與脈沖微分方程的表示關系；對一種能用來模擬動態神經元動力學行為的整合-激發電路的模型作了分析，我們構造了合理的時間映射，分析了時間映射所具有的性質，並給出了該時間映射是馬羅陀意義下混沌的相應參數選取的具體演算法與表示式。By using these mode - locking devices on novel thin - disk solid state lasers and optically pumped vertical - external - cavity surface - emitting semiconductor lasers ( opsvf. csel ) to obtain high average output power ultrashort pulses are stated, and it is emphasized that the study of high average output power ultrashort pulses laser can be accelerated greatly by using the quantum dot sesam
綜述了利用半導體可飽和吸收鏡被動鎖模薄片式固態激光器及光泵浦垂直外腔面發射半導體激光器，獲得高平均輸出功率超短脈沖的最新進展，並指出量子點半導體可飽和吸收鏡的使用將加速超短高功率脈沖的發展。This system captures the rack position signal and rotate speed signal of the fuel injection pump, and calculates the circulating fuel injection quantity by programming the computer. then the computer is programmed to control the daq board to generate a certain width pulse. finally, controlled by the pulse, the alcohol injection system injects a certain quantity alcohol into inlet manifold according to a setting diesel / alcohol proportion
該系統採用了在labview平臺上開發的pc總線?插卡式虛擬儀器系統，系統通過採集噴油泵的供油拉桿位置信號和轉速信號，利用計算機計算得出柴油的循環噴油量，再根據程序設定的柴油/酒精比例控制數據採集卡發出一定寬度的脈沖，控制低壓酒精噴射系統按比例將酒精噴入進氣歧管。This paper also introduces the following contents according to principle of field emission and human visual system ( hvs ) : the display principle of fed panel and pulse width modulation ( pwm ), the reason why pwm was used in fed system, driving method of pwm and two pwm methods used in present fed sample
此外，論文從場致發射原理和人眼視覺特性出發，介紹了fed顯示屏的顯示原理和脈沖寬度調制原理（ pwm ） ，分析了fed採用pwm工作方式的原因， pwm工作方式實現彩色fed顯示的驅動原理，還有目前本實驗室fed樣機所採用的兩種pwm方案。Then on one hand, author makes researches of anti - jamming against pulse jamming 、 gauss white noise jamming and radio frequency noise jamming from the side of signal processing. author exercises much signal processing knowledge of time - domain sliding window accumulation 、 wavelet analysis 、 time - frequency analysis and linear prediction and carries out many simulation experiments. on the other hand, author proposes the anti - jamming methods of using a sar similar to double - base radar and modulating the amplitude 、 the phase of emission signal and changing the frequency modulation slope from the side of changing sar system model
作者首先提出了合成孔徑雷達抗干擾的定義、分類以及評價抗干擾方法好壞的主客觀標準；然後，一方面從信號處理的角度出發對脈沖式干擾、高斯白噪聲干擾以及射頻噪聲干擾進行了抗干擾研究，其中運用了時域滑動窗口積累，小波分析，時頻分析以及線性預測等信號處理知識，做了大量的模擬實驗；另一方面，本文基於改變合成孔徑雷達系統模式提出了利用類似雙基地雷達來抗干擾，以及對發射信號進行調幅、調相以及改變調頻斜率來抗干擾，同樣做了相應的模擬實驗。A significant amount of power is used by the broadcast transmitter to send the sync pulse
由於大量的功率被廣播發射機用來發送同步脈沖，一般將視頻信號的極性設計為在傳送同步信號降低功耗的方式。分享友人