散射頻率 的英文怎麼說
中文拼音 [sǎnshèbīnlǜ]
散射頻率
英文
scattering frequency- 散 : 散動詞1. (由聚集而分離) break up; disperse 2. (散布) distribute; disseminate; give out 3. (排除) dispel; let out
- 射 : Ⅰ動詞1 (用推力或彈力送出) shoot; fire 2 (液體受到壓力迅速擠出) discharge in a jet 3 (放出) ...
- 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
- 散射 : [物理學] [電學] scattering; radio scattering; scatter; dispersion
- 頻率 : frequency; rate
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2. a frequency extrapolation scheme is developed to effectively predict radar cross section using floating genetic algorithm based on the geometrical theory of diffraction ( gtd ) model. the threshold discrete fourier transform ( tdft ) is introduced for the data compression in angle domain
在目標散射中心建模方面,我們將浮點型遺傳演算法( fga )應用於實際人工目標的gtd模型參數的抽取,利用所抽取的模型參數完成了雷達散射截面rcs的頻率擴展以及數據壓縮,並利用擴展的數據提高了距離解析度。The master dissertation introduces passive correlative orientation system and base theory in signal dispose briefly in the first place. the system takes tv sound fm signal from tv satation signal. the power rate of tv station signal to sound signal is ten to one. in the case of submerged by mussy weave and machine ' s hot noise, dispersed target signal is feeble
系統採用電臺的電視伴音調頻信號,其中電臺信號與伴音信號功率之比基本為10 : 1 ,並且目標散射信號較弱,一般情況下淹沒在雜波和機器熱噪聲之下,採用常規的脈沖檢測方法很難對遠距離的目標進行檢測,而以電臺直達信號作為參考與目標回波信號進行相關檢測;系統中信號的相關處理會產生旁瓣,而強目標的旁瓣會影響附近的弱目標檢測。The key components in laser gyro is he - ne ring laser, and the reciprocal action theory between light and medium is the base in studying the ring laser, use the lamb half classical theory, and on the base of density matrix theory, the optical brounch equation was established, which described the movement of amplifying medium atom in the ring syntonic cavity, and according to the medium polarize theory the self consistent equations was deduced, which describe the light intensity and phasic of the counter - propagating wave. on the basis of this equations, adopted the simulation software matlab and virtual instrument programming language labwindows / cvi, we can do some simulated experiments in study the phenomenas such as amplify and dispersive characteristic of medium, mode pushing effection, burned hole effection and pattern competition, lock - in of frequency and the characteristic of light intensity and phasic of the counter - propagating wave in laser gyro
激光陀螺的核心部件為he - ne環形激光器,而掌握光與介質的相互作用理論是研究激光器的關鍵,採用拉姆半經典理論為主,在密度矩陣理論的基礎上,推導環形諧振腔中描述he - ne氣體增益介質原子運動的光學布洛赫方程,運用介質極化理論得出描述激光陀螺反向行波的光強、位相所滿足的自洽場方程組,在此基礎上,運用matlab模擬軟體和虛擬儀器編程語言labwindows / cvi ,對激光陀螺中的介質增益色散特性、頻率牽引效應、燒孔效應及模競爭、閉鎖效應及環激光的光強和相位特性進行模擬試驗研究,並且運用全量子理論,對激光工作原理進行分析,得出二能級系統單模輻射場的光子數密度分佈,得出激光場的光子統計分佈,模擬激光場的動態建立過程。The efficient sppc had been performed with 1 - hz - repetition - rate 532nm nanosecond pulses, in which phase conjugate reflectivity as high as 21. 5 % was obtained. when sppc were operated in ce : batio3 with 532nm, 632. 8nm and 790nm cw lasers, the maximum sppc reflectivity of 54. 1 %, 88. 2 % and 80. 5 % were obtained, respectively. unlike the results reported before that four - wave mixing by stimulated photorefractive backscattering ( spb - fwm ) only exists at short wavelengths while four - wave mixing by total internal reflection ( tir - fwm ) only exists at long wavelengths, both of these two mechanisms coexist at all wavelengths from 532nm to 790nm in our experiments
通過大量的實驗全面研究了ce : batio _ 3自泵浦位相共軛特性:在低重復頻率( 1hz ) 、 532nm調q激光泵浦時最高獲得了21 . 5的位相共軛反射率,而此前報道過的建立位相共軛脈沖光最低重復頻率是10hz ;實驗中發現在532nm 790nm波長范圍內,在不同的波長激光泵浦時,同時存在兩種自泵浦位相共軛機制:全內反射?四波混頻( tir - fwm )和受激背向散射?四波混頻( spb - fwm ) ;在連續激光泵浦時,對532nm 、 632 . 8nm和790nm三種波長,最高分別獲得了54 . 1 、 88 . 2和80 . 5的位相共軛反射率;同時還研究了自泵浦位相共軛光的時間穩定性。The doppler frequency is a function of the two scattering directions.
多普勒頻率是兩個散射方向的函數。Analysis of finite array structure plays an important role in the design of array antenna and frequency selective surface
有限陣列散射場的分析對于陣列天線的隱身設計和頻率選擇表面的設計具有重要作用。Among those nonlinear effects, stimulated brillouin scattering has the worst effects on the fiber hydrophone system due to its low threshold and it produces a new light wave which is different from the incident light in frequency. this dissertation discusses the physical mechanism and quantum explanation of sbs in fiber
在眾多非線性效應中,由於受激布里淵散射( stimulatedbrillouinscattering )效應的閾值最低,且產生了與入射光場不同頻率的新的光場,故對光纖水聽器系統而言,影響最大的即是受激布里淵散射效應。The relations between the parameters of gas charging and exhausting, heat quantity through the shell of tube ( q ), the length of the tube ( l ), the ratio of gas charging time to gas exhausting time ( ), the frequency of the jet flow ( f ), the ratio of the expansion ( ), the nature of thermal separator and the unsteady flow in the tube were established
建立了進、排氣參數、管壁散熱量( q ) 、管長( l ) 、充、排氣時間比( ) 、射流頻率( f ) 、膨脹比( )等參數與熱分離機性能及管內非定常流動的關系,並分析了有關因素對熱分離機性能的影響。Moreover, the signal processing method of high range resolution based on inverse discrete fourier transform is analyzed. the synthetic high range resolution of the several scatters is simulated
此外,本文還闡述了頻率步進信號的逆傅立葉變換合成距離高分辨的處理方法,並對多散射點目標的合成距離高分辨效果進行了計算機模擬。The model includes the obscuration ’ s character of position, shape, scale, number, area percent, greyhound, and it also includes the sampling frequency of analyzing the obscuration and the area of optical component
該模型包括散射點位置,形狀,尺度,數目,散射面積比,灰度,還包括分析散射點的采樣頻率,散射點所在的光學元件面積等特徵。Test method for small - signal scattering parameters of low - power transistors in the 0. 2 to 2. 0 - ghz frequency range
在0 . 2至2 . 0千兆赫頻率范圍內小功率晶體管的小信號散射參數的試驗方法Spurious response frequency
散射響應頻率The principle advantages of vcsels over conventional edge - emitting lasers lie in ultralow threshold current, small far - field divergent angle, high modulation frequency, potential for wafer level testing and the ease for single longitudinal mode operation and two - dimension integration. as a result they show considerable promise for applications such as optical fiber communication, parallel optical interconnects, optical information processing and neural networks, etc. a direct coupling theoretical model in quasi - three - dimension for the gain - wave guide vertical - cavity surface - emitting lasers has been created in this paper
它與傳統的邊發射激光器相比具有更優越的特性,例如,具有極低的閾值、較小的遠場發散角、調制頻率高、易實現單縱模工作和二維集成,無須解理封裝即可進行在片測試等,所以,它被廣泛應用於光纖通訊、并行光互聯、光信息處理、光神經網路等領域。According to the raman selection rule and the pl measurement, it is reasonable to evaluate the quality of galnp / algalnp mqw by analyzing the relative intensity ratio of a1p - lo / to. ( 4 ) a new modified random element isodisplacement ( mrei ) model is set up to calculate the dependence between the long - wavelength optical phonon frequencies and the composition of iii - v - type ab1 - xcx mixed crystals. the second neighbor force constants are still assumed to be a linear variation with the composition, but the two first neighbor force constants can be evaluated to be a negative exponent variation with the composition, using the overlapped repulsive potential of the ion crystal combination
通過實驗我們找到了在這些結構參數上生產gainp algainpmqw的較理想的結果; ( 3 )首次用喇曼( raman )散射方法研究了常溫下的gainp algainp多量子阱結構,除了指認出喇曼光譜中各光學聲子模外,還結合樣品光致發光譜的測量結果,分析發現喇曼光譜中alp - lo to的相對強度比可以在一定程度上評定晶體gainp algainpmqw的生長質量; ( 4 )在修正的隨機元素等位移? mrei模型的基礎上建立了一個新模型,計算了ab _ ( 1 - x ) c _ x型?族半導體混晶的長波長光學聲子模頻率的組分變化關系。We, then, parameterized a semi - empirical model for the different land surface cover types. this semi - empirical model was applied to minimize the effects of the vegetation volume scattering and extinction in radar measurements
此外,目前星載合成孔徑雷達如ers - 1 2 、 radarsat等均為單一頻率、單一極化的雷達,無法從得到的單參數雷達後向散射系數中直接提取地表土壤水分信息。This technique is mainly involved two steps : 1 ) vegetation effects correction : we used ndvi ( normalized difference vegetation index ) derived from tm and avhrr measurements for spatial and temporal variations of vegetation covers at different scales
但由於電磁波與地表相互作用的復雜性,雷達後向散射系數除受地表介電常數(土壤水分)影響外,還受到地表粗糙度、土壤類型、植被覆蓋以及雷達入射角、頻率、極化等多種因素的影響。2 ) radar incidence angle and surface roughness correction : to make radar incidence correction and eliminate the surface roughness effects, a wide range of surface parameters ( soil moisture, surface rms height, correlation length, incidence angle ) was input to the ibm model to simulate the effect of surface roughness and radar incidence angle on the sensitivity of soil moisture to the radar backscattering coefficient. a simple model was established to simulate the effects of incidence angle and surface roughness. 3 ) establishment of soil moisture change inversion model : according to a modified ibm model simulation results, the bare surface backscattering coefficients can be expressed as a funtion of the dielectric component for a given surface roughness when the surface slope greater than 2. 0, which is valid for most nature surface : in above equation, r0 is the surface reflectivity at normal incidence
本研究中,首先利用基於微波輻射傳輸方程的微波植被模型和積分方程( iem )模型模擬了各種地表土壤水分含量情況下,植被覆蓋、地表粗糙度(包括地表均方根高度和相關長度) 、雷達入射角對c波段(頻率4 . 7ghz )水平極化( hh )雷達後向散射系數的影響,在此基礎上,建立模型消除了植被覆蓋、地表粗糙度、及雷達入射角對雷達後向散射的影響,利用多時相50m解析度radarsatscansar雷達後向散射系數圖像反演得到了地表土壤水分變化模式信息。When the frequency of elastic scattering becomes large, the resonant peaks may be cancelled
隨著彈性散射頻率的增大,共振峰會逐漸消失。The backward scattering field of extended target is approximated as the synthesis of many strong scatter centers on target, and geometric optical method is used in establishing deterministic model of a aircraft in the paper, the model is used to evaluate the performance of frequency diversity in suppressing glint at last
本文將復雜目標後向散射回波近似為目標上若干強散射中心回波的合成,結合幾何光學法得到了某種飛機目標的確定性模型,並用該模型評定頻率分集對角閃爍抑制的改善性能。We give ptr ' s amplitude and phase signal of one dimension based on the theory of ptr, discuss the ptr ' s signal ' s frequency characteristic, and a method for measuring thermal diffusivity of opaque materials is introduced. then, we study on anisotropic materials " thermal conductivity, the temperature field and thermal conductivity tensor of anisotropic materials is theoretically deduced from the theory of ptr, and is proved by the experiment
從光熱輻射理論出發,推導出一維情況下ptr信號的振幅和位相表達式,討論了光熱信號的頻率特性,介紹了一種用ptr技術測量不透明材料熱擴散系數的優化方法;接著研究分析了各向異性介質受調制激光束輻照下產生的光熱信號,在理論上推導出各向異性介質的溫度場以及熱導率張量並給予一定的實驗驗證。分享友人