first critical angle 中文意思是什麼
first critical angle
解釋
第一臨界角-
This paper analyses the critical angle method that often use in focus detected. we receive two relations, the first relation between refractive index of the critical - angle prism and focus - error signal ; the second relation between numerical aperture of object lens and out - of - focus error signal
本文針對伺服系統中常用的調焦方法-臨界角方法進行了分析，理論上得到臨界角棱鏡的折射率、物鏡的數值孔徑與離焦誤差信號的關系。 -
In accordance with the occurrence behavior of roof strata and the fracture characteristics of key stratum in shallow seam longwall mining, studied post - buckling behavior of roof key stratum in the process of mining by using initial post - buckling theory, which derived a critical load and a breaking span of the main roof during the first weighting, determined the final subsidence and the maximum rotation angle for broken key stratum, and presented an application with the example of daliuta 1203 face
摘要根據淺埋煤層頂板巖層的賦存特點和長壁開采時關鍵層的變形破斷特徵，應用初始后屈曲理論探討了開采過程中頂板關鍵層的后屈曲性態，得出了老頂初次來壓時頂板的臨界載荷和破斷步距，確定了頂板破斷后的極限下沉量和回轉角，並以神東礦區大柳塔1203工作面為例給出了工程實例。 -
This article describes a way of special ultrasonic system which monitors thermal stress in seamless welded rails. this monitoring system is a non destructive testing system, which adopts avr mcu and high - precise time chip processing as the core of it, and adopts the critically refracted longitudinal wave as the object of measuring. my studying focuses on the theory of the monitoring system, which will be listed in this arctile : according to the snell theory, the theory of motivating of critically refracted longitudinal wave is described in details, and the finite element software is used to emulate the propagating course. the formulas of calculating the pts of swr are taken from the acoustoelasticity theory, and the calculating the parameters is introduced. according to assemble materials, three kinds of ways of monitoring the pts of swr using critically refracted longitudinal wave are described, which are measuring the sound - time in changeless distance, ultrasonic critical - angle refractomery and frequency spectrum, the first way of ways is used in this experiment system. the factors, which effect the monitoring system, are assaid in some degree based
本文的研究工作重點在無縫焊接鋼軌溫度應力測量系統的理論模塊，包括根據snell原理，研究極限折射縱波的激發機理，並使用有限元軟體ansys進行模擬;根據聲彈性理論以及公式推導出計算無縫焊接鋼軌中的溫度應力的公式，並對其中參數的求解方法進行介紹;根據收集的資料，介紹了三種使用極限折射縱波測量無縫焊接鋼軌溫度應力的方法，即固定距離測量聲時法、臨界角折射法和頻譜分析法，本實驗系統使用的是第一種;根據實驗經驗以及相關資料，分析了影響極限折射縱波測量溫度應力的幾個因素，並提出了相應的解決方法;根據實驗系統的需要，獨立設計並加工出相關配套的實驗設備，包括實驗鋼塊、有機玻璃楔塊、固定件、載荷外框裝置等。
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