中文摘要：

在水一微粒混悬液中控制空化效应，对超声治疗和一些诸如药物输送和细胞标记的新应用中是非常关键的．本文通过实验研究了微粒大小、表面微结构对空化剂量的影响．首先将葡聚糖包覆的、直径分别为68nm，346nm，1234nm三种氧化铁磁性微粒悬浮在超纯水中形成混悬液，研究了在聚焦超声作用下微粒大小对惯性空化的影响；然后又研究了直径均为25μm的P（NIPAM-CO-AA）Alq3SiO2；P（NIPAM-co-20％AA）-Fe3O4-FITC-Si02和P（NIPAM-CO-20％AA）三种表面性质不同的微粒在水悬浮液中的空化剂量．实验中，所用聚焦换能器中心频率为1．37MHz，连续波模式工作．当微粒浓度为0．5mg／mL，直径从68nm增加到25μm时，对液体的空化阈值进行检测，并与声学相同条件下超纯水空化剂量进行比较．结果表明：当超纯水中加入微粒后，空化剂量增大，空化剂量与微粒性质如大小、表面微结构等有关．

英文摘要：

Abstract： Controlling the cavitation phenomenon in water-microparticles suspension is a key requirement for the improvement of the existing ultrasonic therapies and the emergence of new therapeutic application, such as drug delivery and cell labeling. In this paper,the effects of two groups of microparticles were suspended in Milli-Q wateron the degree of inertial cavitation due to focus ultrasound were investigated. The first group is three differentdiameters of iron oxide nanoparticles were prepared by means of classical co-precipitation in dextran T40 solution.Sonication of samples was performed using continuous wave generated by a 1. 37 MHz-focused transducer. Theinertial cavitation threshold was measured before and after seeding with almost spherical solid balls of diametersfrom 68 nm up to 25μm in the presence and absence of nanoparticles. Result show that the cavitation dose increasing when the presence of particles within a liquid and cavitation dose are strongly related to the particle properties such as size,the fine-scale surface structures at 0.5 mg/mL concentration.