On November 12, “I’m a Scientist” held the 42nd speech event “Annual Grand Ceremony·Future Progress”. Five experts from various fields gave wonderful speeches on the field of future technological development. We selected three interesting questions from the Q&A session to share, hoping to answer your doubts.
audience ask
Why do superconductors require such a low temperature?
Luo Huiqian answered
In order for a superconductor to reach a superconducting state, we need to soak it in a very low temperature liquid nitrogen, or even lower temperature liquid helium. Why use a very low temperature to achieve superconductivity? Because it needs to resist heat, heat is actually the vibration of atoms.
Heat, in fact, is the vibration of atoms | Pixabay
You can imagine that electrons are very small, only one-thousandth of an atom. If the atom stays still, then when the electrons run inside, they can easily bypass the atom. However, if the temperature is high and the atoms are running around, the electrons will easily touch the atoms when they move. Even if the electrons form a stable electron pair, they will be dismantled and cannot form an unimpeded electron pair movement, so they cannot form superconductivity.
Therefore, we need to resist the phenomenon of heat. Most superconductors need to be lowered to a very low temperature, and the thermal effect is weak to achieve superconductivity.
audience ask
Compared with Brazil, China does not have particularly large-scale production of biodiesel. I would like to ask what is the resistance to the development of biodiesel in our country?
Andy Lau’s answer
This question is so professionally asked and it is a question that has been bugging me all these years. what reason? Not because of technology, we have the world’s leading biodiesel technology, and there is no limit to biodiesel technology, even if it is the earliest technology introduced from overseas. Why? It is related to China’s resource endowment.
The per capita consumption of cooking oil in China is almost the highest in the world, but we don’t have enough plants that can be used to make cooking oil. Now we are working hard to produce more than 10 million tons of soybeans a year, but we have to import 100 million tons of soybeans, so our government has always discouraged the use of directly edible oils for biodiesel, because we don’t even have enough food, we have to first Protect people’s livelihood.
We have always discouraged the use of directly edible fats and oils as biodiesel, because we must first protect people’s livelihood | www.pxhere.com
But some countries are rich in biomass resources, such as Argentina, which has 43 million people and produces 48 million tons of soybeans a year, more than one ton of soybeans per capita. I was in a meeting at the United Nations, and the Argentine professor said thank you, China, otherwise the soybeans would not be sold anywhere. Therefore, uneven distribution of resources is the biggest problem. The Chinese government does not dare to force diesel to add biodiesel like Europe and the United States. Because our country does not have such a large amount, we finally have a little biodiesel made from waste oil. , not used in China, but exported to Europe, because in their side, biodiesel made from waste oil can be sold for 10,000 yuan per ton, and they finally collected some waste oil and sold it directly to Europe.
In 2012, the General Secretary visited our laboratory, and I reported to him: the next step is to cooperate with powerful and far-sighted Chinese companies. The technology of biorefining diesel in our laboratory has already started to be transformed in Brazil. However, the transfer and transformation of this technology cannot be done well by a professor and two students. Enterprises are required to participate, especially the biodiesel industry is limited. Restricted technology, if the technology is transferred to Europe and the United States, we drive enterprises to build factories or renovate, and we can get foreign exchange back.
However, what China lacks is not foreign exchange, but resource products, so we can import biodiesel. Last year, our country imported 280 million tons of oil. If we can import more and more environmentally friendly biodiesel, it will promote employment and improve the environment for the local area. For us, it will make up for the shortage of energy and bring The most important thing is clean energy, and the resulting reduction in carbon dioxide emissions counts as China’s share.
I have always said that since human beings can share the sunlight and oil hundreds of millions of years ago, why can’t they share the biomass of today? Petroleum is unevenly distributed, and biomass is also unevenly distributed. There are more near the equator, and humans can cooperate and share.
audience ask
You said that in the future, we will use unused petroleum to produce plastics and fibers. Have you considered the issue of plastic reduction? It seems that the production of plastics by coal chemical industry is not particularly respected and environmentally friendly?
Jin Yong A
You have misunderstood the product of plastic. Polymer materials synthesized from petroleum, such as plastics, rubber, fibers, and human life are closely related and inseparable. When I wake up in the morning, the toothbrush I use to brush my teeth is made of plastic, the stool I sit on is made of plastic, and the clothes I wear are made of synthetic fibers.
A toothbrush for brushing your teeth is plastic | Pixabay
The output of plastics is already close to that of steel and, by volume, has surpassed that of steel. Their performance is very superior, and they are very easy to process. Plastics can now withstand temperatures up to 300 degrees. Human beings cannot do without plastics, as well as synthetic rubber and synthetic fibers. China’s synthetic fiber production accounts for 60% of the world’s total. We can make four sets of clothes for everyone in the world and export a large amount of textiles. We don’t have natural rubber, but our synthetic rubber is an irreplaceable resource.
Of course, there is a problem with plastic now, not the plastic itself, but the problem of our use of plastic and our irresponsible disposal. If circular economy is adopted, waste plastics can be turned into new plastics, or degradable plastics, and waste plastics can be refined into oil. The method of recycling plastics has been successful now, so the problem of plastics is that human beings use them improperly and throw them away at will. It is our human problem, and we have to solve it.
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