第三次聲波 的英文怎麼說

中文拼音 [sānshēng]
第三次聲波 英文
third sound
  • : Ⅰ助詞(用在整數的數詞前 表示次序) auxiliary word for ordinal numbers Ⅱ名詞1 [書面語] (科第) gr...
  • : Ⅰ數詞1. (二加一后所得) three 2. (表示多數或多次) more than two; several; many Ⅱ名詞(姓氏) a surname
  • : Ⅰ名詞1 (次序; 等第) order; sequence 2 [書面語] (出外遠行時停留的處所) stopping place on a jou...
  • : Ⅰ名詞1 (波浪) wave 2 [物理學] (振動傳播的過程) wave 3 (意外變化) an unexpected turn of even...
  • 第三 : third第三帝國 [德國] the third reich (1934 1945); 第三 (層)樓 [美國] third story; [英國] seco...
  1. In this dissertation, the numerical computation for the acoustic radiation problem ( arp ) is studied deeply and systematically in the theory, method and the application technique, based on analyzing the situation of the home and abroad on the numerical computation for the acoustic radiation problem. the calculation formulas of the boundary element method ( bem ) for the exterior acoustic radiation problem in the full - space and half - space are deduced, based on the wave propagation theorem ; the arising of the non - unique solutions, which is associated with the application of the boundary integral equation ( bie ) in acoustic radiation problem, is analyzed and proofed ; the improved combined helmholtz integral equation formulation ( ichief ) is presented to overcome the non - uniqueness problem more effectively and reliably ; the determination of the singular integral coefficients on various occasions is analyzed ; the properties and treatments of the singular integrals with different orders axe studied ; the computation program of the cubic spline ichief is developed and its ability to overcome the non - uniqueness problem and feasibility to discrete the surface coarsely with the sufficient calculation precision are examined through examples

    二章在動理論基礎上,詳細地推導出對應于無限域和半無限域的外部振動輻射問題的邊界積分方程計算公式;根據fredholm積分理論,對利用邊界積分方程計算振動輻射問題過程中解的非唯一性的產生進行了分析和證明;改進了chief法以提高其克服解的非唯一性的有效性和可靠性;對不同條件下奇性系數的計算、強奇性積分的收斂性及其在變量替換時與普通積分的差異性、不同階奇性積分的計算、數值求積分等進行了研究;開發了樣條改進chief法計算軟體,並通過算例考核了該方法在特徵數處克服解的非唯一性的有效性和在保證計算精度的前提下實現剖分粗化以提高計算效率的可行性。
  2. Based on the study of the test pressure data, the acoustic time and the reconstrction of paleoformation pressure, through the study of abnormal pressure in the middle and western sichuan basin, it ' s shown that the distribution of stratum pressure differs greatly in different zones ; the evolution history of paleo - formation pressure has been restored according to the models of the evolution history of pressure, and it shows that there were two high pressure arouse, the first arouse in later jurassic and the second in erlier triassic, analyzing the relations between the excessive pressure distribution and the petroleum migration

    摘要通過實測壓力數據、泥巖壓實研究、古壓力恢復研究,對川西、川中地區異常壓力在縱向、橫向上的分佈特點的分析,認?該區異常壓力分佈有明顯的分區性;同時,依據異常壓力的孕育史模型,恢復本地區的上疊統古壓力的形成與演化歷史,認?上疊統過剩壓力高峰出現過兩,分別在晚侏羅世末和早紀末;最後分析了該區異常壓力與油氣運聚的關系。
  3. Secondly, the dissertation proposes a novel blind symbol - timing scheme for ofdm systems based on cyclostationarity feature of received symbols. the proposed schemes also exploits the periodicity of ofdm symbol introduced by cyclic prefix, by applying 2 - dimentional fourier transformation and choosing the appropriate correlation peak value as the symbol start location, the precision of this scheme is higher than previous conventional method. thirdly, the dissertation presents analysis with regard to channel estimation of ofdm systems. several interpolation algorithm in ofdm systems which based on pilot sequence have been analyzed in the first instance, and the influence of the channel noise on interpolation precision has discussed. the theoretic analysis and simulation results show that : the interpolation error induced by the precision of interpolation procedure itself has out weight

    ,論文在ofdm系統的通道估計方面,先對基於導頻的ofdm通道估計中的多種插值方法進行了分析,討論了噪對插值精度的影響,指出插值本身的精度所造成的插值誤差遠大於噪所帶來的插值誤差,從而階更高的插值演算法在實用中並非最優的;並指出插值濾法比變采樣率演算法對噪的影響更為敏感,在信噪比較高時插值濾演算法比變采樣率演算法更優。
  4. Second, introduce the dyadic wavelet analysis, and use it realized the signal monitor and analysis to the turbine compressor, obtained the detail signal and approach signal at different frequency parts of the compressor s original signal. one type of electromotor that made in china is choose, and it s noise is tested. the noise signal is analyzed by wavelet analysis and spectrum analysis. several high spectral peaks that make people hearing disameniry are found. by contrast with theory calculating results and farther analysis. the cause that producing these spectral peaks is located

    ,介紹了二進小分析,並應用二進小分析實現了對透平壓縮機信號的監測分析,得到了壓縮機原始信號在不同頻率段分解的細節信號和逼近信號。用小分析和譜分析相結合的方法對某國產電機的噪進行了分析,找出了人的聽閾不閱的幾個高譜峰位置,進行了空氣動力噪計算,通過與理論計算結果進行對比分析,進一步找出了產生該頻閩譜峰的幾個原因,,介紹了諧和分形的基本原理。
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