"How do you say that you are also the world's number one swordsman, you can't get a better ship. Standing on the deck of the warship, Ye Wuji looked at the small boat dragged behind the warship, the car of Hawkeye, a little speechless.

The ship was too small, that is, the eagle eye could handle it, and if someone else dared to go to sea on such a boat, there was no need to go to sea at all, and a random wave of a larger wave would be enough to overturn the ship.

The sea is different from inland lakes and the like, even on a calm day, the sea will not be calm, the so-called windless three feet of waves, refers to the sea surface.

"Convenient. Mihawk, who was carrying the supreme fast knife and black knife night, said lightly.

As he spoke, three zigzag islands appeared in front of him, and after seeing the islands, Mihawk nodded to Ye Wuji, walked to the stern, jumped into his own boat, and headed towards the island in front of him.

The warship that Ye Wuji was riding turned in another direction and headed towards the naval headquarters.

"This guy is about the same as Gayne. Looking at the boat that Mihawk was riding far away, Ye Wuji muttered in a low voice, Hawkeye left his island this time, not because of the matter of the Seven Martial Seas.

Instead, someone wanted to challenge him for the position of the world's number one swordsman, and published the news of the challenge in the newspaper, so Hawkeye responded.

After living on Krajgana Island for a few days, he also knew something about Hawkeye, and combined with some intelligence from the Navy, he knew that Mihawk was a very religious person about swords.

This is not expected by Ye Wuji, if it is not such a person, how can he become the world's number one swordsman.

Even if he becomes the world's No. 1 swordsman, Mihawk basically does not refuse anyone who wants to challenge him, as long as you dare to challenge him, as long as you are a swordsman, even if you are a rookie swordsman who has only studied swordsmanship for a few days, Mihawk will not refuse to challenge.

However, Mihawk must be conscious, have the consciousness to give his life.

So far, none of the people who have challenged Mihawk have retreated intact from under his supreme fast knife and black knife.

Speaking of which, the only person who took the initiative to challenge Mihawk and was still alive was Sauron, who was probably still a baby.

It can be known from the newspaper that the person who challenged Mihawk this time was a swordsman who had just broken through to the Great Sword Hero, and as soon as he became a Great Sword Hero, he couldn't wait to compete for the title of the world's No. 1 Sword Hero.

Ye Wuji didn't have the slightest interest in such a challenge, so he didn't want to go to the scene to watch, and in the past few days on Krai Kana Island, although Ye Wuji didn't fight Mihawk under the pretext that his injuries had not healed.

But the two still fought a few times, without using the slightest strength, purely relying on swordsmanship, I have to say that Mihawk is worthy of being the world's number one swordsman, compared with the last time he fought with Ye Wuji, the current Mihawk swordsmanship has a trace of softness, from the rigid sword to the rigidity and softness of a big step.

"Good work. ”

"I'm ready to recuperate, and I'm going to go around the world and try not to look for me for a short time. ”

After ending the call with Sengoku, Ye Wuji asked the deputy captain to take the warship back to the naval headquarters, and he himself headed towards the East China Sea.

Because the upgrade is too fast, Ye Wuji does not have a specific position now, and he does not have his own exclusive warship, and even his current adjutant is temporarily transferred.

Originally, Ye Wuji wanted Bermel to be his adjutant, but unfortunately now Bermel is being trained by the General Staff at the headquarters.

When Ye Wuji stepped into the East China Sea, on a hidden island somewhere in the East China Sea, the naval hero Karp was looking helplessly at the figure that appeared in front of him, his son, Monchi D. Dragon.

"What do you want to do with me, uh, who is he?" Karp just wanted to teach the dragon a lesson, but was immediately stunned when he saw the baby in the dragon's arms.

"Your grandson, Monchi D Luffy. The dragon looked at the sleeping baby in his arms and said with a gentle face.

"Luffy. Looking at the fleshy little Luffy, Karp forgot about the idea that he was going to teach the dragon a lesson.

"I came to you today in the hope that you would be able to raise him, father. ”

"Yourself. ”

"Father, you should know that I can't take good care of Luffy here, Luffy will be handed over to you. "The dragon is also a decisive person, and after one last glance at Luffy, he handed Luffy to Karp, and after Karp took Luffy, the dragon immediately turned around and left.

Before Karp could speak, the dragon's figure disappeared from the island.

"You. After the dragon's figure disappeared, Karp couldn't help but shout loudly, and before Karp could finish speaking, he heard little Luffy crying loudly in his arms.

Karp, who was in a panic, didn't care about the dragon and began to slowly comfort Luffy in his arms.

"Hey. Looking at the smiling little Luffy, Karp couldn't help but sigh, with his character, he can't raise children at all, and the only people who can reassure Karp are the bandit Dadan family in Windmill Town.

Speaking of which, Ace and Luffy were both disabled by Karp, and let the bandits raise Ace and Luffy, but they thought that Ace and Luffy would become navy when they grew up, what a big heart.

Of course, if Ace and Luffy both go to be in the navy, it will not be one piece, but the king of the navy.

"That guy is hiding tightly, I really don't know what he's been doing here, Hong found that he was already one of the four emperors. Looking at the bounty order in his hand, Ye Wuji shook his head helplessly.

The unique red nose on the bounty order made Ye Wuji recognize who he was in an instant, Bucky the Clown, his Bucky Pirates, belonged to a very difficult pirate group in the East China Sea, and the navy surrounded him several times, but he didn't catch a member of the Bucky Pirates.

Ye Wuji, who came to the East China Sea, was originally going to meet Bucky, wanting to test Bucky's true strength, as well as his opinion on the redhead becoming one of the Four Emperors, but unfortunately he couldn't find the whereabouts of the Bucky Pirates.

Unable to find Bucky, Ye Wuji didn't go out of his way to search, but according to his previous plan, he continued to move towards the edge of the East China Sea, relying on the magic guide airship, Ye Wuji soon came to a country in the East China Sea, the Labor Country, which is not an island country, but a country on a bridge.

This country has a large number of bridge-building experts, and according to intelligence, it has been building bridges since the establishment of the World Government, with the goal that one day in the future, all the islands of the whole world will be connected with bridges, so that the communication between islands will be much easier.

I have to say that this is a very grand plan, more lofty than any tiling the Great Wall, but in Ye Wuji's opinion, this plan is really a bit too stupid.

How big the four seas are, even the world government, the navy, and those professionals are not clear, not to mention anything else, in the East China Sea alone, there are tens of thousands of islands.

And now the East China Sea, the bridges built by the labor countries, the islands connected to each other, but only a little more than 200 This has been built since the establishment of the world government, nearly 800 years of efforts, even if you don't count all kinds of accidents, everything is going smoothly, if you want to use the bridge to connect the entire East China Sea, I am afraid that the time will have to be doubled, at least thousands of years, or nearly 10,000 years.

This is still just the East China Sea, if you add the other three seas, there is also a great route, there is no way to calculate the time, not to mention the sea kings of the great routes, you spent nearly a hundred years to repair the bridge, the sea kings are afraid that they will be completely destroyed with one blow.

On the surface, the world government is very tolerant of those countries that do not want to join the world government, and the world government does not do anything other than that there is no navy to help these countries fight pirates.

It is a pity that all this is an illusion, since the working country is carrying out such a large project, it must need a large number of manpower, and it is the people of the countries who have not joined the world government to build bridges in the working country, as well as some criminals.

The reason why Ye Wuji knew about the Labor Country was that Long revealed it to Akunonokia.

The country of labor was also one of the frontlines of the battle between the world government and the revolutionary army, and the two sides were constantly fighting around the people of various countries who were enslaved to build bridges.

"Hey. "After looking at the country of labor for a while, looking at the civilians who were working under the strict guard of the soldiers around them,

There are many types of magnets, which are generally divided into two categories: hard (permanent) magnets (magnetic retention for a long or permanent time) and soft magnets (magnetic properties for a short period of time). Permanent magnets are further divided into two categories:

The first category is: metal alloy magnets include NdFeB magnets (Nd2Fe14B), Alnico magnets (AlNiCo), samarium cobalt magnets (SmCo), including: 1. NdFeB magnets: It is the magnet with the highest commercialization performance found at present, known as the magnet, with extremely high magnetic performance, and its maximum magnetic energy product (BHmax) is more than 10 times higher than that of ferrite (Ferrite). Its own machinability is also quite good. The operating temperature can reach up to 200 degrees Celsius. Moreover, its texture is hard, the performance is stable, and it has a good cost performance, so it is extremely widely used. However, because it is chemically active, it must be coated with a surface coating. (such as Zn, Ni plating, electrophoresis, passivation, etc.). 2. Alnico magnet: It is an alloy composed of aluminum, nickel, cobalt, iron and other trace metal elements. The casting process can be processed and produced into different sizes and shapes, and the machinability is very good. Cast Alnico permanent magnets have the lowest reversible temperature coefficient and can operate at temperatures above 600 degrees Celsius. Alnico permanent magnet products are widely used in various instrumentation and other applications. 3. Samarium cobalt (SmCo) is divided into SmCo5 and Sm2Co17 according to different components. Its development is limited due to the high price of its materials. As a rare earth permanent magnet, samarium cobalt (SmCo) not only has a high magnetic energy product (14-28MGOe), reliable coercivity and good temperature characteristics. Compared with NdFeB magnets, samarium cobalt magnets are more suitable for working in high-temperature environments.

The second category is: ferrite permanent magnet materials (Ferrite), whose main raw materials include BaFe12O19 and SrFe12O19. It is made by ceramic process, the texture is relatively hard, it is a brittle material, and it has become the most widely used permanent magnet because the ferrite magnet has good temperature resistance, low price and moderate performance.

In electromagnetism, when two magnets or magnets attract or repel each other, or when a current-carrying wire generates a magnetic field around it, causing the magnetic needle to deflect and point, or when a closed circuit moves in an inhomogeneous magnetic field, an electric current appears in a closed circuit, these are all phenomena related to magnetism. All phenomena related to magnetism are also related to magnetic fields.

Magnetism is the property of a substance in response to the action of a magnetic field. Every substance is more or less affected by the magnetic field. Ferromagnetism is the strongest and most well-known type of magnetism. Due to being ferromagnetic, a magnet or magnet creates a magnetic field. In addition, paramagnetic substances tend to move towards regions with strong magnetic fields, i.e., attracted by magnetic fields, diamagnetic substances tend to move towards regions with weak magnetic fields, i.e., repelled by magnetic fields, and some substances have more complex relationships with magnetic fields, such as spin glass properties, antiferromagnetism, and so on. The influence of the external magnetic field on some substances is very weak.

The magnetic state of a substance is related to temperature, pressure, external magnetic field, etc., and the substance will show different magnetic properties depending on the temperature or other parameters.

Development Edit

China's development history

In the pre-Qin period, our ancestors had accumulated a lot of knowledge in this area, and when exploring iron ore, they often encountered magnetite, that is, magnets (the main component is ferric tetroxide). These discoveries were documented very early. These discoveries are the earliest recorded in the chapter "Pipes and Numbers": "Those who have a good stone on it, and copper and gold under it." Other ancient books, such as the Classic of Mountains and Seas, have similar records. The iron-absorbing properties of magnets have been discovered very early, and the nine-volume mastery of "Lü's Spring and Autumn Period" has: "Cizhao Iron, or Citation." At that time, people called "magnetism" "compassion", and they saw the magnet's attraction to iron as a mother's attraction to her children. And he said: "Stone is the mother of iron, but there are two kinds of stone, benevolent and unkind, and the loving stone can attract his children, but the unkind stone cannot be attracted." Before the Han Dynasty, people wrote the magnet as "Cishi", which means loving stone.

Since magnets can attract iron, can they also attract other metals? Our ancestors made many attempts and found that magnets could not attract not only metals such as gold, silver, and copper, but also bricks and tiles. In the Western Han Dynasty, people have realized that magnets can only attract iron, but not other items.

When two magnets are placed close to each other, sometimes they attract each other and sometimes repel each other. Now people know that magnets have two poles, one is called the N pole and the other is called the S pole. Opposite-sex poles are mutually exclusive, and opposite-sex poles attract each other. At that time, people did not know this truth, but they were still aware of this phenomenon.

In the Western Han Dynasty, there was a monk named Luan Da, who used this property of the magnet to make two chess pieces, by adjusting the mutual position of the polarity of the two chess pieces, sometimes the two chess pieces attracted each other, sometimes they repel each other. Luan Da called it "fighting chess". He dedicated this novelty to Emperor Wu of Han and demonstrated it on the spot. Emperor Wu of the Han Dynasty was amazed, and the dragon's heart was so happy that he actually named Luan Da as the "General of Wuli".

The Earth is also a large magnet, and its two poles are close to the geographic south pole and the geographic north pole respectively. Therefore, when the magnets on the earth's surface can rotate freely, they will be repelled by the same sex of the magnets, and the opposite sex attracts the opposite sex. The ancients didn't understand this truth, but they knew this kind of phenomenon very well.

The first to describe the magnetic declination was Shen Kuo. He described his exploration of magnetism in "Dream Creek Writings" and described the magnetic declination. The ancestors of ancient China used magnetism to make Sinan, guide fish, and compass successively. The compass was typically used in navigation when Zheng He sailed to the Western Ocean. After the compass was introduced to Europe through the Arabs, it promoted the development of European navigation technology and provided favorable help for the opening of new shipping routes.

Development of Western theories

People have been exposed to the phenomena of electricity and magnetism for a long time and have known that magnetic rods have north and south poles. In the 18th century, it was discovered that there are two types of electric charges: positive and negative. Both the charge and the magnetic poles are repelled by the same sex, the opposite sex attracts, the direction of the force is on the connecting line between the charges or between the poles, and the magnitude of the force is inversely proportional to the square of the distance between them. On these two points and million.