Ancient Greeks and Chinese found in nature a kind of natural magnetized stone, called "magnetite." This kind of stone can be trickily sucked small pieces of iron, and after swinging always point to the same bias. Early voyagers used the magnet as their earliest compass at sea to discern bias.
After thousands of years of growth, the magnet has become a strong material in our life today. After the decomposition of different quality alloy can reach the same effect with the magnet, and can also improve the magnetic force. Artificial magnets were presented in the 18th century, but the process of making the more magnetic materials was rather slow until the Alnico was made in the 1920s. Ferrite was subsequently produced in the 1950s and rare earth magnets [Rare Earth magnet including NdFeB and SmCo] were made in the 1970s. At this point, magnetic technology has been rapid growth, strong magnetic material also makes the components more miniaturized.
Magnetization (orientation) is biased
Most magnetic materials can be magnetized along the same bias to saturation, the bias is called "magnetization bias" (orientation bias). Magnets without orientation bias (also called isotropic magnets) are much weaker than those of oriented magnets (also called anisotropic magnets).
What is the standard "North and South Pole" industry said?
The term "North Pole" refers to the North Pole of a magnet whose North Pole points to the Earth after its random rotation. Similarly, the south pole of the magnet is also pointing to the south pole of the earth.
How to identify the magnet's north pole in an unmarked environment?
Obviously, eyes alone can not tell. You can use a compass close to the magnet, the pointer pointing to the north pole of the earth points to the south pole of the magnet.
How to deal with and deposit magnet quietly?
Always be very careful because the magnets will stick to themselves and will probably pinch your fingers. When the magnets are adsorbed to each other, the magnets themselves may also be damaged due to collisions (missing corners or bumps into cracks).
Keep magnets away from easily magnetized items such as floppy disks, credit cards, computer monitors, watches, cell phones, medical stuff and more.
Keep the magnet away from pacemakers.
Larger size magnets, each between the sheet should be plastic or cardboard to ensure that the magnet can easily be left.
Magnets should be stored in a dry, constant temperature environment.
How to do magnetic separation?
As long as the material can be adsorbed on the magnet can play a role in isolating the magnetic field, and the thicker the material, the better the effect of magnetic isolation.
Now the highest function of the magnet is a rare earth magnet, NdFeB magnets in the rare earth magnets is the most powerful. However, in the environment of 200 degrees Celsius or above, samarium-cobalt is the most powerful magnet.