The viscoelasticity of lipid shell and the hysteresis of subharmonic in liquid containing microbubbles  

作　　者：龚燕君 章东 龚秀芬 谭开彬 刘政 

机构地区：[1]Institute of Acoustics, Nanjing University, Nanjing 210093, China [2]Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China

出　　处：《Chinese Physics B》2006年第7期1526-1531,共6页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China （Grant Nos 10274032 and 320200265）, National Natural Science Foundation of Jiangsu Province, China （Grant No BK2004081）.

摘　　要：The viscoelasticity and subharmonic generation of a kind of lipid ultrasound contrast agent are investigated. Based on the measurement of the sound attenuation spectrum, the viscoelasticity of the lipid shell is estimated by use of an optimization method. Shear modulus Gs=10MPa and shear viscosity μs=1.49N.S/m^2 are obtained. The nonlinear oscillation of the encapsulated microbubble is studied with Church＇s model theoretically and experimentally. Especially, the dependence of subharmonic on the incident acoustic pressure is studied. The results reveal that the development of the subharmonic undergoes three stages, i.e. occurrence, growth and saturation, and that hysteresis appears in descending ramp insonation.The viscoelasticity and subharmonic generation of a kind of lipid ultrasound contrast agent are investigated. Based on the measurement of the sound attenuation spectrum, the viscoelasticity of the lipid shell is estimated by use of an optimization method. Shear modulus Gs=10MPa and shear viscosity μs=1.49N.S/m^2 are obtained. The nonlinear oscillation of the encapsulated microbubble is studied with Church＇s model theoretically and experimentally. Especially, the dependence of subharmonic on the incident acoustic pressure is studied. The results reveal that the development of the subharmonic undergoes three stages, i.e. occurrence, growth and saturation, and that hysteresis appears in descending ramp insonation.

关 键 词：lipid shell VISCOELASTICITY SUBHARMONIC HYSTERESIS 

分 类 号：O42[理学—声学]