直達體波 的英文怎麼說
中文拼音 [zhídátǐbō]
直達體波
英文
direct body wave-
The various colours significant of various degrees of vitality white, yellow, crimson, vermilion, cinnabar : their degrees of brilliancy : their magnitudes revealed up to and including the 7th : their positions : the waggoner s star : walsingham way : the chariot of david : the annular cinctures of saturn : the condensation of spiral nebulae into suns : the interdependent gyrations of double suns : the independent synchronous discoveries of galileo, simon marius, piazzi, le verrier, herschel, galle : the systematisations attempted by bode and kepler of cubes of distances and squares of times of revolution : the almost infinite compressibility of hirsute comets and their vast elliptical egressive and reentrant orbits from perihelion to aphelion : the sidereal origin of meteoric stones : the libyan floods on mars about the period of the birth of the younger astroscopist : the annual recurrence of meteoric showers about the period of the feast of s. lawrence martyr, 10 august : the monthly recurrence known as the new moon with the old moon in her arms : the posited influence of celestial on human bodies : the appearance of a star 1st magnitude of exceeding brilliancy dominating by night and day a new luminous sun generated by the collision and amalgamation in incandescence of two nonluminous exsuns about the period of the birth of william shakespeare over delta in the recumbent neversetting constellation of cassiopeia and of a star 2nd magnitude of similar origin but lesser brilliancy which had appeared in and disappeared from the constellation of the corona septentrionalis about the period of the birth of leopold bloom and of other stars of presumably similar origin which had effectively or presumably appeared in and disappeared from the constellation of andromeda about the period of the birth of stephen dedalus, and in and from the constellation of auriga some years after the birth and death of rudolph bloom, junior, and in and from other constellations some years before or after the birth or death of other persons : the attendant phenomena of eclipses, solar and lunar, from immersion to emersion, abatement of wind, transit of shadow, taciturnity of winged creatures, emergence of nocturnal or crepuscular animals, persistence of infernal light, obscurity of terrestrial waters, pallor of human beings
顯示出不同程度之生命力的繽紛色彩白淺黃深紅朱紅銀朱諸星之亮度一直包括到七等星以等級標志的諸星之大小諸星的位置御夫座沃爾辛厄姆路172大衛的戰車173土星光環螺旋星雲凝固后形成有衛星的恆星群兩重大陽相互依存的旋轉運動伽利略西蒙馬里烏斯174皮亞175勒威耶赫歇耳加勒176等人各自獨立地同時所做的發現波得和開普勒所嘗試的距離的立方與回轉次數的平方的體系化177多毛的眾彗星178那幾殆無限的被壓縮性，以及自近日點至遠日點那廣漠的遠心的重返大氣層的橢圓軌道隕石的恆星之起源年紀較輕的天體觀測者誕生的那個時期火星上所出現的「暗波」現象179每年在聖勞倫斯節殉教者，八月十日前後降落的隕石雨每月都發生的所謂「新月抱舊月」現象180關于天體對人體的影響的假定威廉莎士比亞出生的時期，在斜倚卻永不沒落的仙后座那三角形上端，一顆不分晝夜散發著極亮光彩的星辰一等星出現了181這是兩個無光死滅了的太陽因相撞並汞合為白熱體而形成的燦爛的新太陽大約在利奧波德布盧姆出生時，出現在七星花冠星座里而後又消失了的一顆同一起源亮度卻稍遜的星宿二等星182還有約於斯蒂芬迪達勒斯出生時，出現在仙女座中之後又消失，小魯道爾夫布盧姆出生與夭折數年後出現于御夫座后又消失，以及另外一些人出生或去世前前後後出現在許許多多其他星座中而又消失了的假定是同一起源的實際存在或假定存在的星斗183 。Third, this dissertation analyzes the complicacy of result size estimation problem for xml structure based query optimization compared to its counterpart in traditionally relational database, and proposes a full - featured result size estimation algorithm for xml query, sxm. for simple path expression query, this dissertation proposes a dynamic synopsis model for xml data based on the concept of f - stable and b - stable, xmap. for complicated path expression query, this dissertation adopts an improved bifocal sampling method for result size estimation
第三，分析了xml結構化查詢優化中的查詢代價估計問題與傳統關系型數據庫中的查詢代價估計問題的區別，提出了一套完整的xml結構化查詢代價估計體系sxm ，包括對簡單路徑表達進行查詢代價估計的動態xml數據統計模型xmap ，對復雜路徑表達進行查詢代價估計的雙焦點例舉法，以及對值匹配條件進行查詢代價估計的基於小波的多維直方圖方法，並能將多種查詢表達的查詢代價估計結果結合在一起，以給出一個完整的xpath查詢的代價估計。Main conclusions drawn from the analyses of calculating results are as follows : ( 1 ) the microwave absorption of atmosphere gas have obvious attenuation at the wavelengths for cloud detection, thereinto, the water attenuation effect changes greatly, so the 94ghz cloud detecting radar should have water vapor attenuation correction scheme. ( 2 ) when 37ghz and 94ghz radars detect clouds, the difference between the atmosphere and cloud attenuation and the large variety of radar reflectivity conduce the intension of the radar backscatter signals change. ( 3 ) for the thin cloud layer and low water content of cloud, 37 - ghz radar backscatter signals are not as good as 94 - ghz radar, that is to say that the 94ghz radar has better capability in thin clouds detection
本工作得出如下結論： （ 1 ）大氣氣體的微波吸收在測雲波段產生明顯的衰減，其中水汽衰減效應變化很大；即將上天的空間94ghz測雲雷達必須有水汽衰減訂正方案； （ 2 ） 37ghz和94ghz雷達測雲，由於大氣和雲衰減不同和雷達反射率的很大差異，導致雷達回波信號強弱不同； （ 3 ）對雲層較薄、含水量較少的雲，在不計雷達參數的情況下， 37ghz雷達回波信號不如94ghz測雲雷達，也就是說94ghz對薄雲有更強的探測能力；對雲層較厚、含水量大的雲，由於強衰減的作用， 94ghz雷達回波信號小於37ghz雷達； （ 4 ）從大氣衰減的不利因素方面考慮，空間94ghz雷達測高層薄雲的效果最好；測低層薄雲時需要考慮氣體衰減訂正；因濃厚雲的強衰減作用，探測其中下部的能力大大減弱，不僅要進行衰減訂正，而且要藉助其他信息來反演整個雲層的含水量垂直分佈； （ 5 ）為了獲得從極薄到極濃厚雲的垂直分佈探測能力，未來測雲雷達系統最好採用雙波長甚至三波長（如94 、 37和13ghz ） 。From the result we get the following conclusion : for narrow - band signal, the effect of the method based on fft is best. for wide - band signal, when snr is up to certain degree ( higher than - 7db or so ), the curves of square error of modified methods are more obvious and closer to crb. for an echo composed of more than one frequency or direction, space - frequency distribution could show more direct information of frequency and direction, which is more advantaged to make precise judge and estimation for doa of echo
從估計結果發現，對于窄帶回波信號，基於fft的方法估計性能大大優于其他方法；對于寬帶回波信號，在信噪比達到一定程度（高於約- 7db ）時，補償后的幾種估計法的性能改善均比較明顯，誤差曲線越來越接近crb曲線；對于回波中存在多頻率多方位的情況，空間?頻率分布圖能提供較為直觀的頻率及方位信息，因此應用空間?頻率估計法來進行方位估計，更有利於進一步對回波的具體方位進行準確判斷和估計。For parameter a, there is a close relationship exist between a ( 9, sr ) in two different radar incident angle that can be expressed as : with considering the effects of soil texture, we get the final expression of the inversion model : where mv ( t1 ), mv ( t2 ) is volumetric soil moisture content in two different temp, c, d is soil type related parameters, and v ( t1 ), s ( t2 ) is coresponding bare soil radar backscattering coefficients. inversion results show that for the c band hh polarized radarsat scansar data with a range of incidence angle from 20 to 40, the soil moisture change value can be derived with an acceptable accuracy using the above model. the temporal and spatial soil moisture change patterns are associated with rainfall and vegetation cover, as well as the soil hydraulic characteristics
利用最新發展的電磁波散射模型研究了不同植被覆蓋地表雷達波對地表土壤水分的敏感性，建立了半經驗植被雷達後向散射模型; 2 ） .研究發現在農作物等矮小植被覆蓋地表，植被層直接後向散射與植被類型相關，且在植被生長期，雷達後向散射系數對植被含水量的敏感性要高於對植被高度變化的敏感性; 3 ） .解決了單參數雷達地表土壤水分反演問題中，雷達入射角和地表粗糙度的影響這一難點問題; 4 ） .利用土壤介電模型校正了不同土壤類型對反演地表土壤體積含水量的影響; 5 ） .在以上成果基礎上，建立了完整的單參數雷達地表土壤水分變化探測反演演算法，經地表驗證，模型反演地表土壤水分變化值的精度為rmse = 0In the simulation work, one 1. 5kw and one 18kw induction motors ? control system were simulated and two simplified control scheme were proposed. when developing the program in tms320f240 dsp, this paper solved two practical problems : the finite - length effect and dc bias effect. finally, sensorless control system based on adaptive filter theory are tested on the platform of 1. 5kw induction motor, the results show that the scheme ? performance is good
在模擬過程中，針對1 . 5kw和18kw異步電機進行了模擬，並在此基礎上提出兩種簡化控制方式；在tms320f240的具體編程過程中，分別對自適應濾波器的有限字長效應、直流偏置效應等非理想因素進行了修正和補償；最後，在1 . 5kw微型異步電機上進行了轉矩閉環無速度傳感器實驗，實驗結果表明了演算法完全可以達到預期的目標。The system uses the permanent magnet synchronous machine as the driver motor based on the idea of polygonal flux linkage locus and the permanent magnet brush - less motor is as the momentum balance motor by means of speed and current loop in order to track driver motor precisely and rapidly. the harmonious control of driver motor and balance motor is realized by making full use of the dsp hardware resource and complicated programmable logic device. the software design is composed of c and assembly language to realize motor control arithmetic of polygonal flux linkage locus
衛星天線伺服控制系統以正弦波永磁同步電機作為驅動電機，採用多邊形磁鏈軌跡法（電壓空間矢量法）的控制策略；動量平衡電機採用永磁無刷直流電機，通過電流環、速度環達到快速、精確跟蹤驅動電機的目的，確保了衛星姿態恆定；設計方案中充分利用了dsp硬體資源和復雜邏輯陣列實現了驅動電機和平衡電機的協調控制，並通過c語言和匯編語言的混合編程實現了電機的多邊形磁鏈軌跡控制演算法。At last, pointing to the temporal characteristics and the spectral characteristics, this paper discussed the methods for estimating the maximal line velocity ( vmax ) and the glint periods ( tp ) of the hovering helicopter, and then fulfilled the recognition of hovering helicopter using these two message. in chapter 5, the summary of all the works in the paper and related conlusions are presented, and the defects are analized at last, at last this paper demonstrated the d
最後，本文針對懸停直升機旋翼回波的時頻域特點，探討了從回波信號中提取旋翼回波最大線速度v和旋翼回波閃爍周期tp的方法，在綜合利用這兩種信息的基礎上完成了彈載高重頻脈沖多普勒體制雷達對懸停直升機回波信號的識別。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。Combined with the key project of the preliminary research of national defence science and technology, the target recognition system for millimeter wave initiative homing guidance, a systematic study on the signal processing method based on the background of millimeter mave ( mmw ) missle - borne pulsed doppler radar is performed. it include specifically the detction and the recognition of the moving target and hovering helicopter under strong clutter background
本文結合國防科技重點預研項目「毫米波主動尋的制導目標識別」 ，針對脈沖多普勒體制雷達導引頭的應用背景，對基於彈載高重頻脈沖多普勒體制雷達的信號處理方法進行了較深入的研究。主要研究內容包括對雜波背景中的機動目標以及對懸停直升機的檢測和識別方法。In recent years, the metrological scholars of some developed countries have been taking great efforts on capacitance metrology in the frequency range from acoustic frequency to microwave, and several countries have set up their capacitance standard in the extended frequency range
十幾年來，發達國家的計量學者一直進行音頻到微波段電容計量的研究，少數國家已經建立了擴展頻段電容標準及溯源體系。By the use of “ radar target backscattering simulation software ” and through many flight mode and research mode experiments with the u. s. - made helicopter ah - 64 as an example, a detailed analysis of helicopter echoes ’ time, frequency domain and time - frequency distribution characteristics is made. finally, according to these features, a tentative plan to detect hovering helicopters is proposed
本文利用專門的電磁模擬軟體，以美製「阿帕奇」直升機為例，詳細分析了直升機雷達回波的時域、頻域和時頻分佈的特性，並根據這些特點提出了雷達探測武裝懸停直升機的初步方案。The method has distinct advantages as fllows : ( 1 ) microwave radiometer itself do not radiate electromagnetic wave, so it have the attribute of concealment. ( 2 ) microwave radiometer is not directly disturbed by other eleclro - magnetic signal, and it can work in all weather condition. ( 3 ) power loss and equipment volume are greatly decreased than usual radar
此方法具有： （ 1 ）本身不發射電磁波信號，具有隱蔽性； （ 2 ）不受到其他電磁信號直接干擾，並可以全天侯工作； （ 3 ）功率損耗和整機體積比一般雷達大大減小。The video simulator is of significant flexibility and commonality. so long as the simulation software is changed, simulation of different radar signals can be implemented. the video simulator can dominate radio frequency ( rf ) equipment to export rf pulse to implement the function of radar signal environment integrated simulation system
模擬器控制射頻設備輸出的射頻脈沖，既可作為注入信號直接輸入雷達偵察接收機，也可以放大到足夠的功率后通過天線輻射，作為微波暗室的輻射源，實現雷達信號環境一體化模擬系統的功能。分享友人