Italian scientist Spaparat used to go for a walk on the nearby streets after dinner. He often sees that many bats fly in and out of the air, but never hit the wall. This phenomenon caused his curiosity: What special skills does the bat fly freely in the night sky?
In the summer of 1793, on a clear night, the bustling city gradually calmed down. After Passerati had finished eating, he walked out of the street and released the bats in the cage. When he saw the bats that were released and flew back and forth lightly and agilely, they could not help but scream. Because the bats, all eyes were covered by him, are "scorpions".
Why does Spallai want to blind the eyes of the bat? It turns out that whenever he sees the bat flying freely at night, he always thinks that these elves must have a pair of particularly sharp eyes, and it is impossible to dexterously move through various obstacles in the dark, and capture the fly quickly. Moth. However, the facts are completely unexpected. Spalletti is very strange: without the eyes, what does the bat use to identify objects in front and capture flexible moths?
So he blocked the bat's nose. As a result, the bat was still agile and relaxed in the air. "Is his film-like wings not only able to fly, but also to see everything at night?" Sparazie guessed. He caught a few bats and painted them all over the paint, but it still didn't affect their flight.
Finally, Spalletti blocked the ears of the bat and placed them in the night sky. This time, the bat has no previous temperament. They bumped into the air like a headless fly, and soon fell to the ground.
what! Bats fly at night, catching food, it is by hearing to identify the direction and confirm the target!
Sparazie's experiment unveiled the secret of bat flying, prompting many people to think further: How can the bat's ears "penetrate" the night and "listen" to objects without sound?
Later, people continued to study and finally figured out the mysteries. It turns out that the bat relies on the throat to make an "ultrasonic" that the human ear can't hear. This sound travels along a straight line, and when it hits the object, it reflects back like a light on the mirror. When bats receive this "ultrasound" with their ears, they can quickly make judgments, dexterously fly freely, and capture food.
Nowadays, people use ultrasound to navigate airplanes and ships and find underground treasures. Ultrasound is like a silent hero, widely used in industrial, agricultural, medical and military fields. Sparaj could not have imagined that his own experiments would bring such great benefits to mankind.
Ultrasonic welding -
Ultrasonic applications can be used to weld thermoplastic workpieces using a variety of methods such as welding, riveting, forming or spot welding. Ultrasonic welding equipment can be operated independently or in an automated production environment. Plastic parts with built-in precision electronic components, such as microswitches, are suitable for welding with ultrasonic waves. At the same time, more than one method may be used to process the finished product, such as the internal use of welding floppy disks and cassettes, while the external welding uses fusion methods.
The chemical principle of ultrasonic vacuolar refining
The strong ultrasonic waves generated inside the liquid cause high-energy-intensive air bubble groups. When the air bubbles explode, instantaneously generate pressures of up to one thousand atmospheres and high temperatures of thousands of degrees in a small space.
Under high pressure and high temperature, the CC bond breaks in the heavy oil molecules, and the hydrocarbons of the macromolecules decompose into hydrocarbons of small molecules. Under the action of ultrasonic wave and cavitation, the CS bond of the sulfur in the raw material breaks and turns into the middle. Olefins, n-alkanes, aromatics and hydrogen sulfide. The resulting olefin is converted to normal alkanes and aromatics during ultrasonic pyrolysis.
Heavy oil macromolecules with high sulfur content are converted into gasoline and diesel with low sulfur small molecules. A small amount of residue which is not converted or has a low degree of conversion is used to prepare high-quality asphalt.