近场长度 meaning in English

near field length
nearfieldlength

First , it was taken that a discuss about the effects of geometry parameters of each piezocrystal on direction parameters ( main lobe width , side lobe amplitude , elimination of grating lobes ) , amplitude of ultrasonic pressure , element viberation pattern , mutual radiation among elements , efficient test regions , ability to keep accurate and near - field distance and so on . based on the direction of ultrasonic field in ulpa deduced by ourselves . in addition , on the base of integrating all kinds of factors , it was put forward that the principle and method for optimized design of geometry parameters of piezocrystals in ulpa transducer , and its design programme and interface were compiled
首先在推导超声相控线阵换能器声场的指向性的基础上，就各个晶片几何参数对指向性指标(主瓣宽度、旁瓣幅度、消除栅瓣) 、声压幅值、阵元振动模式、阵元间互辐射、有效检测区域、精确控制能力、近场长度等方面的影响进行了论述，并在综合各方面影响的基础上，提出了晶片几何参数优化设计的原则和方法，编写了设计程序和界面。