If centipede poison is used to poison centipedes, will the centipede be killed by the poison? | Expo Daily

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Poison the centipede with centipede poison,

Can centipedes be killed by centipede venom?

Centipedes have neither a strong physique nor agility, but if you put a 30-gram mouse and a 2-3-gram centipede together, the centipede can quickly kill the mouse within 30 seconds.

If centipedes fight, will they be killed by the centipede venom? Interestingly, centipedes can kill prey that is 15 times heavier than themselves, but they cannot kill other centipedes.

It turns out that the centipede's receptors have evolved specifically. With this evolution, the affinity of its receptors and venom after binding will be very weak, and it will have no effect on itself.

There are many such examples in nature. For example, the venom of cobras is highly toxic and can kill prey quickly. However, cobra venom cannot kill cobras. This is because the receptors of cobras have evolved specifically, so that the venom of cobras cannot bind to their own receptors.

The content comes from the speech given by Luo Lei, an associate researcher at the Kunming Institute of Zoology, Chinese Academy of Sciences, at the Gezhi Lundao.

my country's DRO-A/B satellite launch was abnormal.

Failed to enter the planned orbit

According to Xinhua News Agency, at 20:51 on March 13, my country launched the DRO-A/B satellite at the Xichang Satellite Launch Center using the Long March 2C carrier rocket/Expedition 1S upper stage. The first and second stages of the carrier rocket flew normally, but the upper stage flew abnormally and the satellite did not accurately enter the predetermined orbit. Relevant disposal work is currently being carried out.

What does DRO mean?

DRO is expected to refer to "Distant Retrograde Orbit". The apogee of the spacecraft's lunar orbit is very far away, about 64,000 kilometers from the lunar surface, and the direction of the lunar orbit is opposite to the direction of the moon's orbit around the earth.

What does upper level mean?

The upper stage is the part above the first stage of a multi-stage rocket, usually the second or third stage. The mission nature of the upper stage is between that of a carrier and a spacecraft. It can provide thrust like a carrier rocket, and it can also have an independent electrical system like a spacecraft and work for a long time in orbit.

A small step for science, a giant leap for cultivation

On a thunderstorm day, between finding a tree to hide from the rain and running in the rain, the latter may be a more "safe" choice. This sounds outrageous, but compared to not getting wet in the rain, being wet in the rain may increase the survival rate after being struck by lightning by 70% to 90%.

Scientists used a human head model to simulate lightning strikes in dry and wet conditions. The results showed that when a wet head is struck by lightning, although the total current intensity of the head is greatly increased, the internal current rise rate is slowed down and the current distribution is changed, which reduces the current flowing through the brain and reduces the risk of brain damage.

The principle behind the research is a phenomenon called "surface flashover". It occurs when a high voltage is applied and an electric current jumps along a thin insulating layer on the surface of an object (such as skin or a wet surface), forming a discharge path with much less resistance than inside the object. This means that the current may bypass important internal organs such as the heart and brain, reducing the risk of internal damage.

Similarly, wearing metal objects may reduce the voltage required for surface flashover to occur, transferring the current to the surface of the body and thus reducing the damage caused by lightning strikes. However, don't think that you can go for a stroll in a thunderstorm without worrying about getting yourself wet and wearing a big gold chain.

Lightning strikes are still an extremely dangerous natural phenomenon that can cause high temperature burns, electrical signal disturbances, and many other injuries. Therefore, the safest approach is still to minimize outdoor activities and stay away from walls, doors, windows, and metal equipment that may introduce lightning.

The gloves you wear when eating crayfish are not to protect against oil,

But to protect you?

Every time after eating greasy delicacies such as crayfish and fried chicken, I find that the plastic gloves given by the store seem to be useless. My hands are still covered with oil. Is it because the gloves are of poor quality?

The disposable plastic gloves we use when eating crayfish are made of polyethylene PE gloves. This material is safe for the human body and is also very cheap.

The presence of branched chains in the polyethylene molecular chain creates gaps between molecules, providing an opportunity for oil to penetrate. However, gloves are watertight. Although water molecules are much smaller than oil molecules, isn't it easier for them to pass through the gaps? This is where polarity comes in.

All substances in the world are made up of molecules and have "polarity". If the charge distribution inside a molecule is uneven, it is a polar molecule; if the charge distribution is even, it is a non-polar molecule. Substances will show "same polarity is easy to dissolve, opposite polarity is difficult to dissolve" depending on whether they have the same polarity.

Water is a polar molecule, which repels non-polar polyethylene molecules, so it is not easy to penetrate. On the contrary, oil molecules, which are also non-polar molecules, are "like-minded" with polyethylene molecules, so they can easily pass through the gaps between polyethylene molecules. Therefore, in addition to the size of the molecule, the type of molecule's properties also determines whether it can break through the protection of the glove.

If they can't protect against oil, why wear them? Have you ever thought that PE gloves may not protect against grease, but against bacteria on your hands? Therefore, wearing gloves when eating crayfish is still a good habit. In order to reduce oil penetration, you can choose to change gloves frequently or wear more layers.

The monitoring device designed by Mozi more than 2,000 years ago

Mozi, who lived 2,400 years ago, can be regarded as the first master of ancient Chinese science. In the article "Mozi·Preparing for the Cave", a monitoring facility for anti-sneak attack is recorded in detail. A well is dug every five steps in the city. The well is dug 15 feet deep in high places and 3 feet deep in low places after water is found. Pottery figurines with a volume of more than 40 dou are made and buried in the well. A layer of leather is covered on the mouth of the well, and people with sensitive hearing are sent to lie on top to listen to the sound coming from underground to prevent the enemy from digging tunnels to attack the city. This is called "well listening", which can be regarded as the ancestor of monitoring equipment. This is similar to lying on the ground to listen to the sound.

The content is compiled from China Science Popularization Expo Weibo, Gezhi Lundao Forum, Science Academy, Xinhuanet, Global Science, Lithology Science, CCTV Records

This article was first published in China Science Expo (kepubolan)