Du Lin said: "Yes, this is indeed very abnormal, this kind of incandescent bulb is not used by many people now, it is difficult for you to buy it, but how can there be three incandescent bulbs in this room that are so out of place?"

Li Xian thought for a moment, "Could this be related to that organ?"

Durin nodded, "I think it should be like this, you reach out and feel it, how many degrees do you think the surface of this bulb must be now?"

Li Xian stepped on the ladder and raised his right hand to feel the temperature of the light bulb, and when he was still some distance away from the light bulb, he felt the heat unbearable.

"It's more than a hundred degrees. ”

"Alright, you come down, I'll tell you my guess. ”

"Come on, Detective Du, explain to me. Li Xian said with a grin.

"I guess you don't come here," said Durin, pointing to the lamp, "three light bulbs, three traces of rope, three knives, if you say that there is no connection between them, I guess no one will believe them, but it is not easy to figure out how the three are connected." Let me ask you a question first, do you have a rice cooker at home?"

"Ah, rice cooker, yes, what's wrong?" Li Xian couldn't keep up with Du Lin's big jump in thinking.

"Do you know why the rice cooker automatically trips and stops heating when the rice is ready?" asked Doolin.

Li Xian thought for a while, "When I was a child, I was quite interested in this, but I didn't study it later, and when I grew up, I didn't have the heart to think about it." ”

"Then let me tell you, the general rice cooker, I mean the most ordinary, what kind of microcomputer smart rice cooker is not among them. ”

"I know, just say it. Li Xian urged anxiously.

"The general rice cooker has two sets of temperature control facilities, one is for cooking, and the other is for heat preservation.

After picking up the inner bowl of rice in the rice cooker, we will see a heating plate, in the middle of the heating plate is a small, round metal small disc, connected to a spring, which can move up and down, this thing is the most important part of the rice cooker - the thermomagnetic switch.

Pick up the inner tank, under the action of the spring, the small disc will protrude on the heating plate, put into the inner tank, the spring is compressed, and the small disc is equal to the heating plate. This is what we see on the surface, what we can't see, and most importantly, it's the magnet. This magnet is made of special magnetic materials, with the change of temperature, its magnetism will also change, the temperature rises, the magnetism of the magnet will gradually weaken, until it disappears, this process has a professional term called 'demagnetization', the critical point of magnetization demagnetization in the thermomagnetic switch of the rice cooker is generally about 105 degrees Celsius to 107 degrees Celsius.

When we use the rice cooker to cook, we put the inner tank filled with rice and water into the pot, press the switch, and turn on the circuit. At this time, the thermomagnetic switch at room temperature is more magnetic, the magnetic force is greater than the elastic force of the spring, the magnet and the circuit contact are engaged, and the connected circuit converts the electric energy into heat energy through the heating plate, and heats the inner tank through heat conduction, so that the water in the pot boils. At this time, due to the presence of water, the heat of the heating plate is continuously carried away by the water, and the temperature is maintained at 100 degrees Celsius or slightly higher.

When the water in the pot is exhausted, there is no heat conduction of water, the temperature of the heating plate begins to rise, when the temperature reaches about 105 degrees Celsius to 107 degrees Celsius, the magnet loses magnetism, the magnetism disappears, the elastic force of the spring pushes the circuit contacts away, the circuit is interrupted, the heating plate stops heating, the residual heat on the inner tank and the heating plate will make the rice cooked thoroughly, and a pot of rice will be ready. ”

Li Xian reached out to pull Durin's hair, but was slapped away by Durin's hand,

"What?"

"I want to see how your brain grows, how do you know everything?"

Durin thought to himself, if you can live for 1,400 years, I guess you are also a "human 'flesh encyclopedia'".

"I've said so much, don't you understand what I'm trying to say?" asked Doolin.

"Roughly understood," Li Xian nodded, "What do you mean is that the murderer used the principle of the 'thermomagnetic switch' on the rice cooker to make three magnets, hung the magnets under this lamp, and then sucked the three knives on the magnets, and when the incandescent lamp heated the magnets to 105 degrees Celsius to 107 degrees Celsius, the magnetism disappeared, and the knife fell freely, killing Zhou Peihao." ”

"Yes, tie the rope to the three magnets, and when it is confirmed that Zhou Peihao is dead, use the rope to take the magnet away from the window and destroy the evidence. Doolin added.

"That's not right," Li Xian frowned, "When we found the body, the deceased Zhou Peihao was lying here on his back facing the sky, which is equivalent to watching the knife hanging over his body, even if his hands and feet are tied, he can use the strength of his body to move to the side and dodge the knife." ”

"I also thought about this problem, I guess that Zhou Peihao should have been drugged in advance, causing his body not to move, which can not be determined until his blood pharmacology test results come out, but I think this is the case nine times out of ten, otherwise there is no way to explain why he can clearly see the knife on it and don't know how to hide. Durin muttered.

"Anyway, that's how it happened. Li Xian clapped his hands and turned his head to shout to the police present. "Everyone has worked hard, take away everything that should be taken away, block the scene, and close the team! The cafeteria has left lunch for everyone, let's go back to eat!"

"No!" said Durin suddenly.

"What's wrong?" Li Xian said in surprise.

"I just remembered, you chicken thief, you said that you invited me to Fu'an Restaurant for dinner next Saturday, isn't that the day when Mo Lilun and Qu Mingming got married?

Li Xian hurriedly ran away, and said with a smile as he ran, "You are a rich man now, I am a poor policeman, don't be picky!"

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In the evening of the next day, in the large office of the criminal police team of the Zhonghu City Bureau, a case analysis meeting was held for the "closed room murder case", and Du Lin and Zhuang Poshi were invited to participate.

"Obviously, this case directly affects whether you can take this marriage leave or not, so you have to stand on the last shift before this vacation!" Before the meeting began, Li Xian teased Qu Mingming and adjusted the atmosphere.

"Do you think I'm willing to marry that and take that divorce? If it weren't for Mo Lilun's kid crying and shouting to marry me, my aunt and grandmother wouldn't be willing to marry. Qu Mingming said disdainfully, but everyone could see the happy smile on her face.