The reporter learned from Xi'an Jiaotong University that the team of Li Fei and Professor Xu Zhuo of the school's Department of Telecommunications and their collaborators have developed a samarium-doped lead niobate-lead titanate piezoelectric single crystal, which has significantly improved the use of medical ultrasonic transduction The piezoelectric material performance of the device has laid a new piezoelectric single crystal material foundation for high frequency medical ultrasound probes and high precision and large displacement piezoelectric actuators. His research results will be published in Science.
Since the discovery of the relaxation ferroelectric single crystal in 1997, the performance of piezoelectric materials and the imaging resolution of medical ultrasound have been greatly improved. However, as people continue to increase the accuracy requirements of medical ultrasound systems, how to further improve the piezoelectric and dielectric properties of relaxation ferroelectric single crystals has become an important scientific issue that has been widely concerned by scientists at home and abroad for more than 20 years. In recent years, the team of Professor Xu Zhuo and Professor Li Fei from the Key Laboratory of Electronic Ceramics and Devices of the Ministry of Education and the International Dielectric Research Center of Xi’an Jiaotong University have conducted a lot of research on the origin and performance optimization of high-voltage electrical properties of relaxation ferroelectric single crystals jobs. In 2016, the research team revealed the mechanism of the high-voltage electrical effect of relaxed ferroelectric single crystals on a mesoscopic scale. In 2018, a theoretical method was proposed to further enhance the piezoelectric performance of ferroelectric materials by enhancing the disorder of the local structure, and it was experimentally verified in the rare earth element samarium doped lead niobate-lead titanate ceramic material.
On this basis, the research team of Xi'an Jiaotong University cooperated with Pennsylvania State University in the United States, Wollongong University in Australia, and North Carolina State University in the United States to design and grow a samarium-doped lead niobate-lead titanate piezoelectric single crystal, which was successful Organically combining the causes of the three types of high-voltage electrical effects, "enhanced local structural disorder", "quasi-homogeneous phase boundary" and "engineered domain structure", greatly improves the piezoelectricity and dielectric of the relaxed ferroelectric single crystal Performance, the piezoelectric coefficient is up to 4000 pC / N (picoulon per Newton) or more, and the dielectric constant is more than 12000, which is compared with the performance of the same component lead niobate-lead titanate piezoelectric single crystal without samarium Increased by about one time; at the same time, the use of samarium element in the crystal growth process of the segregation characteristics, optimized the uniformity of the performance of single crystal rods, laid a new piezoelectric for high-frequency medical ultrasound probes and high-precision and large displacement piezoelectric actuators Material foundation. (Reporter Shi Junbin)
PP plastic, polypropylene, commonly known as "baijiao",Scientific name: polypropylene.
Description:
PP Plastic is a kind of semi crystalline material. It is more hard than PE and has a higher melting point. Due to the high crystallinity, the surface of the material stiffness and resistance to scratch characteristics very well. PP Plastic don't have the problem of environmental stress cracking.Polypropylene (PP Plastic) is a semi-crystalline thermoplastic.PP Plastichas high impact resistance, strong mechanical properties, resistance to many organic solvents and acid and alkali corrosion.
PP Plastic is widely used in industry and is one of the most common polymer materials.
Australian COINS are also made of polypropylene.
Polypropylene bonding:
K-720 is suitable for polypropylene PP plastic adhesion, suitable for large area plate lamination, high transparency, suitable for PP adhesion PP, PP adhesive PC, PP adhesive ABS,PP adhesive PVC, PP adhesive acrylic, PP sticky metal, PP stick wood.
K-7007 adhesion performance is roughly the same as k-720, light yellow and more economical.
K-620 is adhesive small area polypropylene PP glue, must be used with the k-650 treatment agent, the instant positioning, the strength is high.
Advantages:
1. Low density;
2. Heat resistance ;
3. Non deformation;
4. High stiffness;
5. High surface strength;
6. Good chemical stability;
7. Nontoxic and safe.
Disadvantage:
The main disadvantage of the fault polypropylene is that the high temperature rigidity is not enough, and the low temperature is brittle.
Poor environmental tolerance, outdoor use, easy to turn yellow and brittle.
Tensile strength of anisotropy, the products are easy to deform, continuous use of low temperature, high creep performance, and long - term load.
Poor printing performance.
Application:
1,Valve part, drinking water and sewage water pipe,
2,Sealing element, spraying carrier,
3,Corrosion-resistant trough and barrel, industrial applications that have acid and alkali-resistant requirement; wastewater and gas discharge equipment for industrial purpose,
4,Scrubbing tower, clean room, semiconductor plant and other related industrial equipment and machinery, food machinery and chopping board,
5,Electroplating process, toy part
Combustion characteristics: PP Plastic easy to burn, polypropylene from continue to burn after the fire, with the top of the flame is yellow, the bottom made in blue, with a small amount of smoke generated, burning melt dripping, and oil.
Specification: the thickness of PP sheet material can be produced from 0.3mm to 2mm, and the PP sheet material is of rolling material and width of 500-1000mm.
The thickness of the plate can be produced from 2mm to 200mm. The specification is 600*1200mm 1000*1000mm 1000* 2000mm. Other specifications can be customized as needed,and The diameter of the PP rod can be produced from 2mm to 250mm, the length is 1 meter, PP rod can be ordered to be more than 3 meters in length.
Color: white and black, other colors can be customized
Modified varieties: PP sheet have various enhancers and other auxiliaries can be added to make modified varieties, depending on the requirements
Storage methods:
Keep in tight, cool and dry place to ensure good ventilation
Product certification: most environmental certification reports and safety reports for raw materials, such as SGS report, CTI report, UL report, MSDS safety information, etc.
Pp Plastic Rod,Polypropylene Plastic Rod,Extruded Polypropylene Plastic Rod,Pp Plastic Welding Rods
Dongguan Noegem Plastic Products Co.,Ltd , https://www.noegempLastic.com