自然響應頻率 的英文怎麼說
中文拼音 [zìránxiǎngyīngbīnlǜ]
自然響應頻率
英文
natural frequency- 自 : Ⅰ代詞(自己) self; oneself; one s own Ⅱ副詞(自然;當然) certainly; of course; naturally; willin...
- 然 : Ⅰ形容詞(對; 不錯) right; correct Ⅱ代詞(如此; 這樣; 那樣) so; like that Ⅲ連詞[書面語] (然而)...
- 應 : 應動詞1 (回答) answer; respond to; echo 2 (滿足要求) comply with; grant 3 (順應; 適應) suit...
- 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
- 自然 : 自然at ease; natural; free from affectation
- 頻率 : frequency; rate
-
And then facing the problem of the channel estimation of the adaptive modulation system, we conclude out the channel estimation algorithms on maximum likelihood ( ml ) estimation and maximum a posteriori ( map ) estimation under the condition of flat fading channel and selective fading channel in detail. to meet flat fading channel, we simulate the relationship of the ratio between the error covariance in map estimation and ml estimation and pilot symbol message length. the conclusion can be drawn from these results
接著,對自適應調制系統中的通道估計問題難點,詳細推導了平衰落通道條件下和選擇性衰落通道條件下最大似然( ml )估計和最大后驗概率( map )估計演算法,針對平衰落通道,我們模擬了map估計和ml估計的方差與導頻符號長度的關系,模擬結果表明,錯誤方差受多譜勒頻率的變化影響最大,並且對實際的自適應調制系統,導頻符號長度的取值超過20個符號長度時, map通道估計明顯優于ml通道估計。According to the guidline, two nd : yag lasers have been designed and set up, one is end - pumped by lower output power ld using a selfoc micro lens, and the other is end - pumped by high output power ld using a pair of lenses are designed, and the characteristics such as output power and power stabilization of both solid - state lasers are investigated. thirdly, when an empty liquid crystal cell is inserted in the cavity of the nd : yag laser pumped by high power ld, the laser can operates in single axial mode. finally, according to the relationship between the laser output power and the longnitudinal a ld - end - pumped nd : yag laser sensor for displacement measurement has been investigated theoretically and demonstrated experimently, the results indicate that when the mean radius of pumping inside the laser cavity is far less than that of the oscilating laser mode, the exponential of the output power is a gauss function of the longitudinal positon of focused spot of ld pumping beam, both the measurement range and the sensitivity are dependent on the incident pumping power, as the incident pumping power is increased, the measurement range is enlarged and the sensitivity is improve d
本文首先介紹了ld泵浦nd : yag激光器的發展狀況、主要特性及其應用,從四能級速率方程出發,推導了ld泵浦nd : yag激光器的閾值、輸出功率和斜效率的表達式,並簡述了激光器的工作原理、結構型式和倍頻方法;其次,以空間相關的速率方程為基礎,提出了ld端面泵浦nd : yag激光器的設計方法,給出了一定泵浦耦合方式下,振蕩光模尺寸、最佳輸出耦合率、泵浦光模尺寸、泵浦光焦斑位置等參數的選取依據,以此為依據,設計了自聚焦透鏡耦合小功率ld泵浦nd : yag激光器和透鏡組耦合高功率ld泵浦nd : yag激光器,對激光器的輸出功率和功率穩定性等特性進行了實驗研究;再次,在帶尾纖輸出的高功率ld泵浦nd : yag激光腔內插入一隻空液晶盒,觀察到了激光器以單縱模運轉;最後,根據泵浦光焦斑端面位置對激光輸出功率的影響規律,提出了ld端面泵浦nd : yag激光位移傳感新方法,並進行了理論和實驗研究,研究結果表明:當激光晶體內泵浦光平均光斑半徑遠小於振西安理工大學碩士學位論文蕩光束腰半徑時,激光輸出功率的自然指數與泵浦光焦斑的縱向位置成高斯變化規律,測量范圍和靈敏度依賴于泵浦功率,隨著泵浦功率的增加,測量范圍擴大,靈敏度提高,當端面泵浦功率為7 . 24w (最大輸出功率為1 . 926w )時,激光位移傳感器的測量范圍和靈敏度分別是13 . 045mm和0 . 148mw / pm 。To discuss the natural vulnerability of different coasts to future sea - level rise, the paper selects the coasts along the pearl river mouth as the studied area. after analyzing the impacting factors of natural vulnerability along the pearl river mouth, the paper divides the coastline of approximately 412km into 25 15 - minute gird cells. for assessment purposes, the six variables including geography, relative sea - level change, average tide range, regional slope, shoreline erosion or accretion rates and tropic cyclone impacting frequency are selected as assessed variables
為了探討不同海岸帶對未來海平面上升的自然脆弱性,本文以珠江口沿岸作為研究個案,在分析珠江口沿岸自然脆弱性的影響因子的基礎上,把珠江口沿岸412km岸線劃分為25個15 15的網格單元,選取了地質、海平面上升率、平均潮差、區域海岸坡度、海岸侵蝕/堆積率、熱帶氣旋影響頻率6個評價指標,應用cvi指數評價公式對珠江口地區進行海岸脆弱性評價,並建立海岸脆弱性評價數據庫,繪制了珠江口沿岸1 : 2 , 000 , 000的數字化cvi圖。The complex resonance frequency underlying in late - time scattering components of a conducting target is independent of waveform and polarization of the incident wave, as well as the direction of the target relative to radar. it is a unique aspect independent quantity so far used to characterize target physical structure and component
目標的后時響應中包含的自然諧振頻率成分(極點) ,不依賴于雷達發射電磁波波形、和其極化形式,與目標對雷達的取向無關,具有目標姿態不敏感性。However, by comparison with flap nozzle servo valve which has been used widely and popularly by now, the torque motor of jet pipe servo valve has a larger rotary inertia. this causes low natural frequency of servo valve, and thus the response speed of jet pipe servo valve is slow. moreover, the jet pipe of servo valve has large flexibility, and it is easy to excite oscillations and noise in the valve, which is named self - excited oscillations and noise
然而與目前普遍使用的噴嘴擋板伺服閥相比,射流管伺服閥的銜鐵組件轉動慣量大,導致力矩馬達部分固有頻率低,從而響應速度慢,此外,射流管供油管柔性大,容易產生自激現象,這些缺點都使得射流管伺服閥的動態特性差,從而影響了它的工作性能。Then, the hilbert transform is applied to each modal response to obtain the instantaneous amplitude and phase angle time histories. a linear least - square fit procedure is proposed to identify the natural frequency, damping ratios, physical mass, damping and stiffness matrices from instantaneous amplitude and phase angle for each modal response
然後對各階模態響應進行hilbert變換,得到瞬態幅值和相位角的時間歷程,再運用線性最小均方擬合來識別自然頻率、阻尼比、質量、剛度和阻尼矩陣。This is because the frequencies of a living organism inevitably influence the subject, so the sensor has to be tuned to correspond to the frequency of the living organism. it must be set at that optimal point of complete resonance with the human body
因為在分析的時候,人體振動的頻率難免會影響到分析的樣本,因此分析師必須將感應器的頻率調整到與自己一致的狀態,然後找出人體頻率和感應器頻率彼此共振的最佳點。分享友人