أرسل هذا في رسالة قصيرة: Acoustic impedance and electromechanical coupling coefficient of 2-2 parallel connectivity barium titanate piezoelectric ceramic-Portland cement composites

  ____     _    _    __   _     _____     ______  
 |  _ \\  | || | || | || | ||  |  ___||  /_____// 
 | |_| || | || | || | '--' ||  | ||__    `____ `  
 | .  //  | \\_/ || | .--. ||  | ||__    /___//   
 |_|\_\\   \____//  |_|| |_||  |_____||  `__ `    
 `-` --`    `---`   `-`  `-`   `-----`   /_//     
                                         `-`