尾向加速度 的英文怎麼說

In this paper, some characteristics of flow movement and sediment transport are analyzed by using the flume experiment data. the cross section of compound channel can be divided into four regions : the undisturbed region in main channel, the interactive region between channel and plain, the undisturbed region in flood plain and the boundary region. in the undisturbed regions, the distribution of longitudinal velocity along the depth has the feature of lograithmic. whereas, in the interactive region, the longitudinal velocity does not obey the logarithmic distribution law, but it can expressed as a revised logarithmic function by using a wake function. on the basis of the kinematic equation the velocity distribution of transverse velocity is obtained. in the boundary region, the longitudinal velocity obeys the law of parabolic distribution. furthermore, according to the simplified diffusion equation, the transverse distribution of sediment concentration in the interactive region is deduced. the analysis is in good agreement with the measured data

本文根據漫灘水流的運動特點，將漫灘水流的復式斷面分為主槽平衡區、灘槽交互區、灘地平衡區及邊壁區等4個區，並給出了各區寬度的經驗公式.根據灘槽交互區垂線流速分佈的變化特點，提出了附加尾流函數的對數流速分佈公式.在簡化水流運動方程和泥沙擴散方程的基礎上，對灘槽交互區內垂線平均流速及含沙量沿橫向分佈進行了理論分析，提出了反映灘槽水流動量交換強度的橫向渦量粘性系數及橫向擴散系數的表達式，得到了漫灘水流垂線平均流速及含沙量沿橫向分佈的解析解，並與實測資料吻合較好

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 。

On the rotor blade pressure surface, the dominant frequencies of unsteady surface pressure are the up - stream blade wake passing frequency and its harmonics, and the amplitudes of pressure fluctuations decrease from leading edge to trailing edge

轉子葉片吸力面非定常壓力受葉片附面層和上游葉片尾跡共同影響，其主導頻率為上游葉片尾跡頻率及其倍頻，但是在吸力面前部氣流加速區壓力波動幅度沿流向增大，而在吸力面後部氣流減速區壓力波動幅度沿流向減小。