[1] Barnes R B, Burton C J. Visual methods for studying ultrasonic phenomena[J]. Journal of Applied Physics, 20, 286-294(1949). http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=5119017

[2] Xu Z, Chen H, Yan X et al. 142(1): EL82[J]. the schlieren imaging method. The Journal of the Acoustical Society of America(2017).

[3] Jones H, Menon S. Liquid jet penetration and breakup in a free supersonic gas jet[J]. Experiments in Fluids, 60, 161(2019). http://link.springer.com/article/10.1007/s00348-019-2812-4

[4] Seo S W, Martinez J, Galang E et al. Optical ultrasound imaging using a line-scanned transducer[J]. Microwave and Optical Technology Letters, 59, 770-773(2017). http://onlinelibrary.wiley.com/doi/pdf/10.1002/mop.30405

[5] Xie A M, Huang J, Xu X et al. Focusing schlieren technique applied to measure the flow density in shock tunnel[J]. Journal of Experiments in Fluid Mechanics, 27, 82-86(2013).

[6] Qi S, Du Y, Zhang P L et al. Experimental study of gasoline vapor deflagration in a duct with an open end[J]. Combustion and Flame, 193, 16-24(2018). http://www.sciencedirect.com/science/article/pii/S0010218018300944

[7] Li M, Zhu Z W, Yang Y G et al. Flow visualization using double-pass schlieren technique in hypersonic flow[J]. Infrared and Laser Engineering, 46, 0211001(2017).

[8] Zhao X H, Yi S H, Ding H L et al. Influence of pressure of jet on hypersonic flow field modulation transfer function[J]. Acta Photonica Sinica, 48, 1001003(2019).

[9] Xia J P, Sun H X, Cheng Q et al. Theoretical and experimental verification of acoustic focusing in metal cylinder structure[J]. Applied Physics Express, 9, 057301(2016). http://adsabs.harvard.edu/abs/2016APExp...9e7301X

[10] Zhang Z H, Huang Z, Chen R T et al. Design of flame temperature measurement instrument based on projective background-oriented schlieren technique[J]. Laser & Optoelectronics Progress, 56, 052803(2019).

[11] Pulkkinen A, Leskinen J J, Tiihonen A et al. Ultrasound field characterization using synthetic schlieren tomography[J]. The Journal of the Acoustical Society of America, 141, 4600-4609(2017). http://www.ncbi.nlm.nih.gov/pubmed/28679248

[12] Koponen E, Leskinen J, Tarvainen T et al. Acoustic pressure field estimation methods for synthetic schlieren tomography[J]. Journal of the Acoustical Society of America, 145, 2470(2019). http://www.ncbi.nlm.nih.gov/pubmed/31046360

[13] Bucaro J A, Flax L, Carome E F et al. Quantitative schlieren visualization of unipolar acoustic transients[J]. The Journal of the Acoustical Society of America, 63, 49-54(1978). http://scitation.aip.org/content/asa/journal/jasa/63/1/10.1121/1.381693

[14] Humphrey V F, Knapp S M, Beckett C et al. Visualization of the resonances of a fluid-filled cylindrical shell using a low frequency schlieren system[M]. ∥Leroy O, Breazeale M A. Physical Acoustics. Boston, MA: Springer US, 371-376(1991).

[15] Chinnery P A, Humphrey V F, Beckett C et al. The schlieren image of two-dimensional ultrasonic fields and cavity resonances[J]. The Journal of the Acoustical Society of America, 101, 250-256(1997). http://scitation.aip.org/content/asa/journal/jasa/101/1/10.1121/1.417976

[16] Chinnery P A, Humphrey V F. Experimental visualization of acoustic resonances within a stadium-shaped cavity[J]. Physical Review E, 53, 272-276(1996). http://www.ncbi.nlm.nih.gov/pubmed/9964256

[17] Chinnery P A, Humphrey V F. On the overlapping acoustic resonances of a fluid-filled cavity: schlieren visualization of an insonified circular-cylindrical shell[J]. The Journal of the Acoustical Society of America, 102, 1383-1387(1997). http://scitation.aip.org/content/asa/journal/jasa/102/3/10.1121/1.420056

[18] Chinnery P A, Humphrey V F. Fluid column resonances of water-filled cylindrical shells of elliptical cross section[J]. Journal of the Acoustical Society of America, 103, 1296-1305(1998). http://scitation.aip.org/content/asa/journal/jasa/103/3/10.1121/1.421270

[19] Jiang X P, Cheng Q, Xu Z et al. Quantitative measurement of acoustic pressure in the focal zone of acoustic lens-line focusing using the schlieren method[J]. Applied Optics, 55, 2478-2483(2016).

[20] Wang X, Wang C J, Fan X J et al. Effects of hydrogen concentration and film thickness on the vented explosion in a small obstructed rectangular container[J]. International Journal of Hydrogen Energy, 44, 22752-22759(2019). http://www.sciencedirect.com/science/article/pii/S0360319919300023

[21] González A M, Hernández D M, Viramontes J G et al. Temperature measurement of fluid flows by using a focusing schlieren method[J]. Sensors, 19, 12(2018). http://www.ncbi.nlm.nih.gov/pubmed/30577504

[22] Garg S, Settles G S. Measurements of a supersonic turbulent boundary layer by focusing schlieren deflectometry[J]. Experiments in Fluids, 25, 254-264(1998). http://link.springer.com/article/10.1007/s003480050228

[23] Bühler M N, Förster F J, Dröske N C et al[M]. Design of a focusing schlieren setup for use in a supersonic combustion chamber, 1467-1471(2017).

[24] Ozawa R W, Cox T J, Reyes J et al. Structured light-field focusing 3D density measurements of a supersonic cone. [C]∥2018 AIAA Aerospace Sciences Meeting, January 8-12, 2018, Kissimmee, Florida. Reston, Virginia: AIAA(2018).

[25] Raman C V. Nath N S N. The diffraction of light by high frequency sound waves: part III[J]. Proceedings of the Indian Academy of Sciences - Section A, 3, 75-84(1936). http://link.springer.com/article/10.1007/BF03046238

[26] Raman V, Venkataraman K S. Determination of the adiabatic piezo-optic coefficient of liquids[J]. Proceedings of the Royal Society of London Series A Mathematical and Physical Sciences, 171, 137-147(1939). http://www.onacademic.com/detail/journal_1000036259164810_8433.html

[27] Li F Q, Song D, Zeng D P et al. Frequency dependence of the acoustic field generated from a spherical cavity transducer with open ends[J]. AIP Advances, 5, 127218(2015). http://scitation.aip.org/content/aip/journal/adva/5/12/10.1063/1.4938523

[28] Shan F, Tu J, Cheng J C et al. Acoustic field of an ultrasonic cavity resonator with two open ends: experimental measurements and lattice Boltzmann method modeling[J]. Journal of Applied Physics, 121, 124502(2017). http://adsabs.harvard.edu/abs/2017JAP...121l4502S

[29] Li F Q, Wang H, Zeng D P et al. Sub-wavelength ultrasonic therapy using a spherical cavity transducer with open ends[J]. Applied Physics Letters, 102, 204102(2013). http://scitation.aip.org/content/aip/journal/apl/102/20/10.1063/1.4807622

[30] Lu Y Y, Liu Q Q, Zhao C L et al. Reconstruction algorithm for focused ultrasonic fields based on schlieren method[J]. Journal of Applied Optics, 36, 742-747(2015).