电导率是一种物质携带电力的能力。像铜，铝，银和金这样的物质非常好。它们被称为导体。其他人部分地进行电力，它们被称为半导体。电动传输的概念非常简单地理解。导通电流的导线由原子制成，其具有相同数量的质子和电子使原子电中性。如果这种平衡受到电子的增益或损失的影响，则原子将变电荷并且称为离子。电子占据能量状态。每个级别需要一定的能量。对于移动到更高水平的电子，它需要适量的能量。 Electrons can move between different levels and between different materials but to do that, they require the right amount of energy and an “empty” slot in the band they enter. The metallic conductors have a lot of these slots and this is where the free electrons will head when voltage (energy) is applied. A simpler way to look at this is to think of atoms aligned in a straight line (wire). if we add an electron to the first atom of the line, that atom would have an excess of electrons so it releases another electron which will go to the second atom and the process repeats again and again until an electron pops out from the end of the wire. We can then say that conduction of an electrical current is simply electrons moving from one empty slot to another in the atoms’ outer shells. The problem with these conductors is the fact that they do not let all the current get through. Whenever an electric current flows, it encounters some resistance, which changes the electrical energy into heat. This is what causes the wires to heat. The conductors become themselves like a resistance but an unwanted one. This explains why only 95% of the power generated by an AC generator reaches consumers. The rest is converted into useless heat along the way. The conducting wire is made of vibrating atoms called lattice. The higher the temperature, the more the lattice shakes making it harder for the electrons to travel through that wire. It becomes like a jungle full of obstacles. Some of the electrons will bump with the vibrating atoms and impurities and fly off in all directions and lose energy in form of heat. This is known as friction. This is where superconductivity comes into work. Inside a superconductor, the lattice and the impurities are still there, but their state is much different from that of an ordinary conductor.
超导性（理论/历史）
荷兰物理学家，1911年在1911年发现了超导性。它是没有电力的能力
抵抗且不损失。那时，它采用液体氦气来获得极低的温度，使物质超导，约4个开尔尔。That wasn’t very far from absolute Zero (The theoretical temperature at which the atoms and molecules of a substance lose all of their frantic heat-dependent energy and at which all resistance stops short.) Kelvin believed that electrons travelling in a conductor would come to a complete stop as the temperature got close to absolute zero. But others were not so sure. Kelvin was wrong. The colder it gets, the less the lattice shakes, making it easier for electrons to get through. There’s one theory that explains best what happens in a superconducting wire: When a conductor is cooled to super low temperatures, the electrons travelling inside it would join up in some way and move as a team. The problem with this notion was that electrons carry negative charges and like charges repel. This repulsion would prevent the electrons from forming their team. The answer to that were phonons. It is believed that packets of sound waves (phonons) that are emitted by the vibrating lattice overcome the electrons natural repulsion making it possible for them to travel in team. It’s as if they were all holding hands together. If one of them falls in a hole or bumps into something, the preceding electron would pull him and the following one would push. There was no chance of getting lost. Since the lattice was cooled, there was less vibration making it easier for the paired electrons to go through.
材料
该理论适用于常规金属，低温超导材料。但后来，发现了新材料。它在温度下在梦寐以求的温度下进行。这种材料是陶瓷的。被认为是绝缘体成为超导体。最新的陶瓷材料在125个开尔文中发现了超导体。这仍远离室温，但现在，可以使用液氮。它比罕见的昂贵的液氦便宜得多。科学家们仍然不知道新的超导是如何工作的。一些科学家建议新的陶瓷是新型的金属，携带电荷，而不是通过电子，而是通过其他带电粒子。
问题 /
解决方案
一直以来，科学家们成功地提高了过渡温度，这是一种材料超导所需要的温度。虽然超导体的温度已经远高于4k，但在工业中使用超导体仍然很困难，因为它远低于室温。另一个问题是，新的陶瓷导体太脆弱了。它们不能被弯曲、扭曲、拉伸和加工。这让它们变得毫无用处。科学家们正试图通过开发复合金属线来解决这个问题。这意味着超导材料将被一层铜覆盖。如果陶瓷失去了超导性，铜就会取而代之，直到超导体反弹回来。旧的超导体在柔韧性方面没有问题，但所需的极低温度仍然是个问题。陶瓷的一个优点是它们能产生极高的磁场。 The old superconductors use to fail under low magnetic fields but the new ones seem to do well even with extremely high magnetic field applied on them.
可能的用途
超导体的特性(低电阻和强磁场)似乎有许多用途。高效发电机;superpowerful磁铁;能在一瞬间处理数据的计算机;地球物理勘探和军事监视用超灵敏电子装置;经济储能单元;存储设备，比如一厘米长的带有超导存储环的录像带;高清晰度卫星电视;高精度医疗诊断设备;用于船舶推进的小型电动机; magnetically levitated trains; more efficient particle accelerators; fusion reactors that would generate cheap, clean power; and even electromagnetic launch vehicles and magnetic tunnels that could accelerate spacecraft to escape velocity.
磁悬浮的火车
首先，磁悬浮的火车，一个相当简单但辉煌的概念。这列车可以达到巨大的速度，因为它没有摩擦它的轨道。导轨有数千间电磁铁，用于沿途悬浮在地板上设定。用于推进的更多电磁铁被设定在U形轨道的侧面上。火车上的超导磁体具有轨道的电磁铁的相同极性，因此它们彼此推动并使火车漂浮在地上约4英寸。有趣的概念带来了推进。操作员通过侧面的电磁铁发送和交流电流，可以通过改变脉冲的频率来控制列车的速度。假设正峰值在轨道侧面到达第一电磁铁。该磁铁将推动磁铁使火车前进。当负峰值达到相同的磁体时，火车上的磁体将向前移动，因此它将通过轨道上的相同的磁体推动并通过轨道上的下面电磁铁拉动，该轨道上的下面的电磁磁体呈现，现在它现在具有正电压。 So the first would be pushing and the second would be pulling. It takes some time to clearly understand what is going on but it becomes so obvious afterwards. It’s as if the train was “surfing” on waves of voltage.
魔法
这艘船没有引擎，没有螺旋桨，也没有舵。它有一个独特的电源，这是电磁。船上的发电机产生的电流从一个电极传播到另一个电极，在船的两边的水下。这使得水带电。这只在盐水中有效，因为纯净水不会传导电流。位于船底的磁铁会产生一个磁场，将水推开，使船前进。与此相关的问题很多。磁场会吸引金属物体甚至其他船只，造成许多事故。
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