Popular science essay
Three Essays on Popular Science
Science is magical, so here are three essays on popular science that I have collected for you, hoping to help you.
popular science essay 1
dust is something that everyone hates. The harm of dust and bacteria is one of the phenomena that human beings can't tolerate. Dust is concrete, and sometimes it is abstract. It is ubiquitous and hard to prevent, but it breeds harmful particles. Dust flies everywhere with many bacteria, viruses and eggs, spreading diseases. Industrial dust and fiber dust can make workers suffer from all kinds of incurable occupational diseases. Excessive dust can also cause environmental pollution, affect people's normal life and work, and induce human respiratory diseases.
From the physical characteristics of dust, dust is a solid impurity with irregular shapes, mostly angular, gray, brown, black and other colors, and has water absorption. When there is too much dust in the air and the relative humidity reaches a necessary level, water vapor constitutes water droplets, so the dust is easily wetted by water and absorbed by water.
Looking at its chemical characteristics, the composition of dust is complicated, which sometimes brings acid radicals and metal ions that lead to degradation. Some dust itself is acidic or alkaline, such as sulfuric acid smog and photochemical smog, and metal oxides and other particles are alkaline. In addition, the floating dust in the dust has strong adsorption potential because of its small particle size and small surface area, and can adsorb harmful substances in the air on their surfaces, which is acidic or alkaline. Dust often contains clay and other substances, which will absorb the moisture in the air or the materials made of archives, make it undergo hydrolysis reaction, and decompose the sticky aluminum hydroxide.
its biological characteristics: because the spores of mold are small in size and heavy, they are inevitably attached to dust as they drift around with the air, so dust is an ideal culture medium, breeding ground and disseminator for microorganisms. Microorganisms will secrete mildew spots containing enzymes and organic acids during their growth. Dust is an abomination to everyone, and it is harmful to the environment? Health, endangering human health. Therefore, throughout the ages, people always "frequently wipe away, so as not to get dust." However, have you ever thought that human beings can't live without dust? If there is really no dust in nature, what kind of situation will we face?
the diameter of dust particles is generally between one ten thousandth and one millionth of a millimeter. The dust that the human eye can see is a monster in the dust, and the tiny dust can only be seen under a high-power microscope. The main sources of dust are soil and rocks. After weathering, they split into fine particles. These particles float in the air with other organic particles. They absorb part of the sun's light and reflect it around, just like countless point light sources. Sunlight is greatly weakened by the reflection of dust, so it becomes soft. If there is no dust in the atmosphere, strong sunlight will make people unable to open their eyes.
Funny. Dust particles also have a "strange temper", which tends to reflect violet, blue and cyan light with short wavelength, but "likes" to absorb other light with long wavelength. Because of the high dust content in the lower atmosphere, the sky we see on the ground is blue. If there is no dust in the atmosphere, the sky will become a vast expanse of whiteness.
most dust has hygroscopicity. The water vapor in the air must be attached to the dust to condense into small water droplets. In this way, when the water vapor in the air reaches saturation, the dispersed water vapor will attach? Dust forms stable water droplets, which can float in the air for a long time. If there were no dust in the air, everything on the ground would be wet. What's more, there can't be clouds in the sky, and it can't be rain or snow to adjust the climate. The water evaporated from the ground to the sky can't come back to the ground. If there is less and less water on the earth and it dries up completely, living things can't survive. In addition, due to the refraction of sunlight by these small water droplets, there will be colorful natural scenery such as sunset glow from zhaohui, idle clouds and fog, rainbow halo and so on. If there were no dust in the air, how monotonous nature would be!
The role of dust tells us that everything has its two sides, and even some things that people regard as "waste" often have its existence value that cannot be ignored. Only by correctly understanding them can we seek advantages and avoid disadvantages and benefit mankind. A few days ago, my mother took me to the supermarket for shopping. We bought drinks, snacks and a bag of eggs. On the way home, my mother asked me to carry the eggs. Because the eggs were too heavy, I lifted them with one hand and held them from below with the other. When I got home soon, my mother asked me if the eggs were broken. I looked at the eggs and said, "There are a lot of broken eggs in the middle." I didn't wrestle on the road either. How could my eggs be broken? So I went to ask my mother. My mother asked me, "What shape is the egg?" "It's oval." I replied. I asked my mother, "What does this have to do with broken eggs?" My mother asked me to take two eggs and put them together. I tried for a long time, but I couldn't get them together. At most, I could only get the eggshells of the two eggs together. I asked my mother what this meant. My mother pointed to the contact point of the two eggs and said, "The key to egg breakage is this contact point." When my mother saw me, she said, "There are many contact points of eggs, but the contact area between eggs is very small. Although the contact area is very small, it bears great force, so the eggs are broken." Then my mother asked me to put an egg on the table and let me stick it with a pen tip. It didn't take much effort to get stuck.
There are many scientific truths in our life, waiting for us to explore and learn! Popular Science Essay III
Ink is used for writing. However, ordinary ink is difficult to eliminate after writing, which hinders the recycling of paper. On this day, I saw a magical ink in the column "I love inventions".
According to Professor Dong Chuan, the inventor of this ink, the magic of this ink is that it will disappear under the action of light and water after writing. Therefore, we named this ink' Fadable Ink'. The reporter is a little incredulous and is going to do an experiment to verify Professor Dong's ink.
The reporter has prepared three kinds of paper: printing paper, stationery and newspaper. First of all, the reporter wrote and drew on the printing paper with fadeable ink, ordinary watercolor pen and watercolor pigment respectively, and then sprayed water on the top with a sprinkler for watering the flowers. In less than a minute, it can be clearly seen that the words written in fading ink have changed obviously, and the color has faded a lot, but it will take some time to disappear. After that, the reporter wrote on stationery and newspapers. However, what is written on the stationery has not been erased. Professor Dong explained: Because the fibers used to make all kinds of paper are different, and the penetration degree of this kind of ink is different from that of all kinds of paper, the penetration of the fibers and ink of this kind of stationery is very strong, so it takes a long time. Next, I read the newspaper, and the result was greatly unexpected. The words in the newspaper disappeared as soon as they touched the water. Looking at the three pieces of paper together, the words written in Professor Dong's ink are almost invisible, but there are still some traces.
To this end, Professor Dong invented another kind of paper. In fact, this kind of paper has no personality, just covering ordinary paper with a plastic film. Write on the top with fading ink. After wiping with a wet cloth, there is no trace at all, and the trace on the cloth is gone after gently rubbing.
Although this kind of ink can improve the utilization rate of waste paper, it will disappear if it is dipped in water, so it is not good if it is a roll paper for the exam. In order to perfect this kind of ink, Professor Dong invented another kind of ink, which can dissolve in boiling water. Later, the reporter started the experiment again.
On a table, there are two pots that are being heated. After the water boils, the reporter puts ordinary printed printing paper in one pot and paper with ink invented by Professor Dong in the other pot. The water temperature rises slowly. When the water temperature reaches 5℃, you can see that the ink characters have disappeared and the water has not changed, but the ordinary printing paper has not changed.
it's amazing! It is expected that this kind of ink can be used in our daily life in the future, greatly reducing the waste of paper. ;