中文摘要：

研究基于温度梯度分布的宽频带声聚焦效应．利用两个恒温热源产生的温度梯度分布，控制声波传播路径，实现声波聚焦效应．该机理源于温度场连续变化引起声折射率连续变化，无反射能量损失，具有宽频带及高聚焦性能等优点．在此基础上，分析入射声源频率、热源温度、分界面空间分布、热源位置、介质的衰减系数、热源温度不对称分布等因素对声聚焦性能的影响，利用气凝胶材料验证单一介质中基于温度梯度分布的声聚焦系统的可行性．

英文摘要：

Acoustic focusing effect with broad bandwidth based on the temperature gradient distribution is studied. The propagation paths of the acoustic waves can be controlled by the temperature gradient distribution generated by two heat sources, which is adopted to realize the acoustic focusing effect. This focusing effect arises from the continuous change of the acoustic refractive index induced by the change of temperature, and has no reflection energy loss, Therefore, the acoustic focusing effect has the advantages of broad bandwidth and high focusing performance. In addition, we have investigated the influences of the factors （incident frequency, temperature of heat source, spatial distribution of interface, position of heat source, attenuation coefficient of the medium, and asymmetric distribution of heat source temperature） on the acoustic focusing effect in detail, and verified the feasibility of the acoustic focusing system by using aerogel based on temperature gradient distribution in single medium.