High intensity focused ultrasound (HIFU) has developed rapidly in recent years and has become a research hotspot in the medical ultrasound engineering field. HIFU surgery is to concentrate the low-intensity ultrasound in vitro into the body through a certain focusing method (acoustic lens, concave s

The polarized PZT piezo ceramic becomes an ordered arrangement due to the polarization electric field forcing the disordered 90°domain and 180°domain steering in the unit cell, and the spontaneous polarization axis in the unit cell is longer than the non-spontaneous polarization axis. When the 90°do

The temperature of the lead oxide volatilization hydrothermally synthesized PZT piezo ceramicpowder is 944.71°C, and the reaction temperature between the particles is 811.26° C; the reaction temperature between the solid phase synthetic PZT powder particles is 1243.47 ° C, and the volatilization tem

The first is the separation of nucleation and growth process,which is promoting nucleation and controlling growth,to ensure that the nucleation rate is greater than the growth rate, that is, ensuring that the PZT materials piezo ceramic powder precursor is formed under a large degree of supercooling

PZT piezoelectric ceramics have been the focus of attention and research since the 1960s due to its high curie temperature, strong piezoelectricity, easy doping modification and good stability. In the field of piezoelectric ceramics. In terms of the preparation process of PZT piezoelectric ceramics,

The preparation has processing methods, processing difficulties,grinding and polishing of piezo ceramic transducer substrates. According to the principle of single-side grinding,double-side grinding and characteristics of grinding and polishing, the piezo ceramic substrates was efficiently thinned .

With the development of medical technology, high intensity focused ultrasound (HIFU) has been widely developed at home and abroad as a new non-invasive tumor treatment technology, and has achieved significant clinical results, especially in the treatment of uterine fibroids and good clinical results

When the piezo ceramic tile is positioned by the ceramic ring, the surface material of the alumina piezo ceramic after single-side grinding decreases with the decreasing of the hardness of the grinding disk, while the copper abrasive disk obtains the lowest surface roughness Ra.The quality of the gr

In the processing environment of double-side grinding of alumina Pzt piezo ceramic ring substrate, it is difficult to avoid the influence of iron ions, so that yellow iron oxide adsorbs and covers the surface of the substrate, and the surface of the substrate is liable to be yellow. Considering that

After the alumina piezo ceramic substrate is ground by different abrasives, the surface has different degrees of yellowing. This section uses EDS spectrum to detect the types of piezo elements before and after the surface of the alumina piezo ceramic substrate, and then explores the possible surface

The ultrasonic ranging system developed has a range of more than 32 meters, a beamwidth of less than 100, and a bandwidth of about 4 kHz (22-25. 5 kHz). If a combined ultrasonic transducer structure is used, the bandwidth can be extended to 8 kHz. A large-range ultrasonic ranging system composed of

In order to improve the anti-interference ability and measurement accuracy of the ultrasonic ranging system, an appropriately selected PN can be used.The code replaces the single pulse signal as the encoded information. The noise signal is uncorrelated with the encoded information can be filtered by

The propagation path of the ultrasonic waves is called a channel. The additive noise of the channel is mainly determined by the undulating noise, ultrasonic transducers sensor in turn can be regarded as Gaussian white noise. Since additive noise is considered to only affect the reception of the sign

In the ultrasonic ranging system, the performance of the ranging algorithm directly affects the performance of the ranging system;The operation speed of the method directly affects the performance of the ranging system. From the perspective of information theory, the ultrasonic ranging process is ac