focaladj.焦点的；[医]病灶focal symptom局灶性症状,病灶症状focal myelitis[医] 局灶性脊髓炎focal interval焦间节focal parabola焦抛物线focal distancen.〈摄〉焦距focalisolation焦聚分光Focal fibrosis局灶性纤维化focal epilepsy病灶性癫痫发作,局部性癫痫,局灶性癫痫,焦点性癫痫focal necrosis局灶性坏死focal ischemia局部缺血

1. On the assumption that there was a small solid sphere in the focusing area, the scattering field of concave sphere ultrasonic transducer was analyzed.
   以凹球面超声换能器为研究对象，假设聚焦区存在一刚性球形微粒，对此时的散射场进行分析。