According to the Fresnel-Kirchhoff diffraction integral and nonlinear paraxial wave equation, we derive the functional relationship of the intensity of hot image and its location.

利用菲涅耳基尔霍夫衍射积分和非线性近轴波动方程，在远场近似及光学薄近似条件下，得出了位相调制产生“热像”出现的位置及强度满足的解析关系。

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In chapter two, wave motion equation, sound energy, sound energy flux density, sound intensity and its scaling method and the theorem of two-microphone sound intensity have been introduced.

第二章介绍波动方程、声能、声能流密度、声强及度量方法、双传声器互谱声强测量原理。

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