Li Kaiyue, Class Four, Dong Xiao Primary School

Once, at the end of science class, I heard several students talking in succession. I leaned down and listened carefully. It turns out that everyone is discussing a question: If an empty cup is filled with water, cover it with a piece of paper, and then turn the cup upside down, will the paper fall and the water will flow out? Will such a magical thing happen? I decided to do an experiment by myself.

So when I came home from school, I couldn't wait to find a paper cup, a piece of white paper with the right size, and then filled the cup with water and covered it with paper. At this time, I was a little nervous and worried that the experiment would not succeed. In order to know the result, I took a deep breath, picked up the cup and gently turned it upside down. Wow! If so, the paper is tightly "stuck" to the mouth of the cup, and there is no water leakage. It's amazing!

But why is this? In order to solve the mystery, I searched the internet for relevant information. The air pressure in the original cup filled with water is blocked, and the pressure is naturally small. In addition, the surface of water has expansive force, so that the water in the cup can be "fixed" stably and the paper can be sucked on it.

It suddenly dawned on me that it was air and paper that held the water in the cup!

Why do pigeons go home?

Huangdongxiao primary school siban

Scientific papers really give me a headache. I was thinking about it this morning and this afternoon. I saw the pigeon in the afternoon and thought about how he got home. My article has a theme.

I suppose pigeons go home according to some fixed scenery.

I decided to conduct an experiment in the evening. If he goes home according to some hanger rules, it happens that our family will install a new clothesline today. Division of labor and work arrangement completed.

The next day, I ran to the upper terrace with great interest, and pigeons flew by as usual. Seeing the new clothes rack, pigeons still fly as usual. Unlike ants, you can't recognize the way out with a slight change.

Looking up the information on the internet, I finally found that pigeons didn't know their way according to fixed objects, but went home according to geomagnetism.

Through this experiment, I know how pigeons go home. This also proves that my guess is wrong.

Why do earthworms regenerate?

Dong Xiao Primary School Class Four Chen Zhitao

Today, my mother and I are watching flowers by the flower bed. Suddenly I found two earthworms crawling in the soil under the flowers. I heard that earthworms can regenerate, so will it kill you to cut them into three sections?

So, I caught an earthworm as soft as jelly. I grabbed it trembling and put it on the concrete floor. I got up the courage to grab the second one and divide one of the longer earthworms into three sections in proportion. I also divided the other one into three sections. After I cut each one, I saw that the earthworm secreted yellow liquid to wrap its wound. I think it may be that the earthworm's body keeps swinging, and slowly they become quiet.

When I got home, I couldn't wait to check the information. It suddenly dawned on me that when I cut earthworms, the muscle tissue on the slice immediately contracted, and some muscles quickly dissolved themselves to form a new cell mass. At the same time, white blood cells gathered on the slice to form an embolism and quickly closed the wound. The primary cells located in the septum of body cavity quickly migrate to the slice and form nodular regeneration buds on the slice together with their dissolved muscle cells. At the same time, the cells of digestive tract, nervous system, blood vessels and other tissues in the body quickly grow into regenerated buds through a large number of mitosis. In this way, with the continuous proliferation of cells, a new head will grow on the section lacking the head; The tail will grow on the part where the tail is missing. But the tail recovers faster than the head. Some earthworms will die in three minutes, while others will not. It's amazing!

Through this observation, I know that the regeneration ability of earthworms is really strong. I must learn the spirit of earthworm not giving up life.

Science and technology essay _ _ _ Can shrimp tongs be regenerated? Have you ever eaten shrimp? Delicious! Have you ever raised shrimp? Do you know that shrimp can be regenerated? Pull out its pliers and it will grow back in a few days. Can you believe it? There is a shrimp in our fish tank. It has two big pliers. Its pliers have done many bad things, for example, it clamped the tail of the fish with pliers and clamped the beard of the angelfish. So we had a family meeting and decided to pull out the shrimp tongs. I'm afraid it will die if it drops its pliers. Dad said, "It's okay. After pulling out the pliers, the pliers will grow out after a while. " Is it really so amazing? So after a week, I went to see shrimp again. I was shocked when I saw it. The shrimp bared its teeth there, and the pliers really grew out, bigger than before. Some of them bully the little fish there! It really has the ability to regenerate! In fact, there are other animals that can regenerate, such as geckos, crabs, lobsters and earthworms. If people also have the ability to regenerate, it would be great! Then, the children injured in the Sichuan earthquake will not be disabled, but will repair themselves and become healthy people like us! Why don't you drop the paper?

Li Kaiyue in Class 3 (4) of Dong Xiao Primary School

One day, during the school holiday, I heard students talking about an empty cup filled with water, covered with a piece of paper, and then dumped the cup, so that the paper wouldn't fall off and the water wouldn't flow out. Is it really so amazing? It tickles my heart.

After coming home from school, I couldn't wait to find a cup, a piece of white paper of moderate size, then fill the cup with water and cover it with paper. I was a little nervous at this moment, so I took a deep breath in order to know the result. Pick up the cup and flip it gently, yeah! If so, it's amazing that the paper doesn't leak.

Why is this? In order to solve this mystery, I looked up relevant information on the Internet.

The answer is: "Because the air pressure in the cup filled with water is already very small, and the water surface has tension, water is not allowed to' run around' casually, so it is actually air and paper that hold the water in the cup."

Why can't waste batteries be thrown about?

Liu, Class 3 (4), Primary School.

In daily life and work, batteries are widely used. If the waste batteries are not handled properly, it will cause considerable damage to the soil and water resources on the earth.

This is because the main components of various chemicals in dry batteries and rechargeable batteries are zinc skin, mercury sulfate and copper caps. The main component of storage battery is lead, which is harmful to human body. If waste batteries are thrown into the water, the water will be polluted and the fish in the water will become toxic. Eating poisonous fish and drinking poisonous water will threaten people's health, damage the nervous system and even cause cancer.

According to the measurement, one section of 1 battery is rotten in the soil, which can make one square meter of land lose its use value; A button cell can pollute 600,000 liters of water, which is equivalent to a person's drinking water for a lifetime. For the 5 billion people in the world, if everyone loses a battery every month, it will accumulate 60 billion batteries a year, which can be said to be very destructive to the earth, and its consequences for human health are even more unimaginable.

In order to protect the environment, some communities have been equipped with garbage bins for recycling used batteries. After recycling, professionals can turn waste into treasure and recycle waste batteries reasonably. Therefore, to protect the environment, we should start from small things and things around us. The earth is our home. In order to protect the earth, we can't throw waste batteries everywhere.

Why do some animals hibernate?

Qiu Yingying is in Class 3 (4) of Dong Xiao Primary School.

I like small animals very much. I often go to the zoo to see them, and I especially like to observe their every move carefully. In winter, some animals disappear. Later I learned that some animals were going to hibernate. Why do some animals hibernate? This problem has been bothering me.

In order to solve this mystery, I consulted relevant information and got a general understanding. It turns out that in nature, many animals have the habit of dormancy. Hibernation is an adaptation of animals to harsh environmental conditions such as low temperature and less food in winter. At this time, the life activities of animals are at a very low level, which are usually manifested as stopping eating, inactivity, drowsiness, weak breathing and hypothermia. When winter comes, hibernating animals such as frogs, snakes, hedgehogs and drought victims are all lying in their caves. They take the initiative to find food early to meet the needs of dormancy and awakening.

In winter, it is very cold outside and there is little food, so some animals hide in caves and sleep late. In this way, I understood another little knowledge.

Science and technology essay _ _ _ Why is it called the Dead Sea?

Huang Jiayuan is in Class 3 (4) of Dong Xiao Primary School.

There is a kind of sea called the Dead Sea. There were no fish and shrimp in the Dead Sea, but people jumped into the Dead Sea and floated up safely. Why?

With this question, I looked up "100,000 Why" and realized:

Because there are many things like salt in the Dead Sea, fish, shrimp, seaweed and many other seafood can't live in the sea, so it is named "Dead Sea". So what's the use of the Dead Sea for people?

It is said that the Dead Sea can cure diseases. If a person with a cold lies in the dead sea with a book, he will be much better in three days, but there is a safety. Only when he jumps into the dead sea will he be safe. If he chooses another sea to jump, he will die immediately. This is one of the sciences I know.

Essays on science and technology _ _ _

Qiulin Huang, Class 3 (4), Dong Xiao Primary School.

On Sunday, my mother and I came to the gym to play table tennis. We were having fun, and suddenly my mother hit the ball, and I missed it, so I went to pick it up and accidentally stepped on it. I was so anxious that I sighed, "Mom, what should I do?"

Mother immediately put down the racket and asked, "Qiu Lin, what's the matter?"

I said, "I accidentally crushed the table tennis."

Mother said, "Don't be afraid that I have an idea."

My mother brought a thermos bottle, filled the cup with water, and then put the ping-pong ball in the cup. At this time, I found that table tennis was slowly bulging. I was particularly excited to ask my mother, "Why is this?" Mom doesn't know.

From Monday to Friday, I have been looking up information online, asking my classmates and teachers, but I still can't find a specific answer. At this time, I have to ask my learned father.

Dad said, "There are two reasons why table tennis can expand in hot water at 100℃:

First, this is due to the physical properties of table tennis when heated, and the concave surface will bulge. But when it goes up, it will be marked, and sometimes the ball will jump when it hits.

Second, because heat expands and contracts. Ping-pong is not broken, squeeze the air inside with hot water ~ let the air expand and make the ping-pong round. This is based on the principle of physical properties of table tennis when heated, in which the expansion coefficient of gas is large and the expansion coefficient of solid is small, so the gas inside is much more expanded than the table tennis itself, so the table tennis notch is pushed up. "

Oh, so much scientific knowledge is hidden in life!

Why can't we water the flowers directly with tap water?

Qiu Yingying is in Class 3 (4) of Dong Xiao Primary School.

Tap water is the water for people's daily life. This kind of water is clear and clean, with few impurities, and everyone can't live without it. I use it to water the flowers every day, but I find that my potted flowers never grow. Does it make sense? The balcony is sunny and the air is fresh, isn't it? Why is this?

With questions, I went to consult my grandfather. Grandpa told me that tap water can't be directly used to water flowers. The reason is that tap water is suitable for people's daily drinking. However, due to the addition of coagulants and disinfectants in the production process, the water has become relatively clean, but some microorganisms and nutrients needed for the growth of animals and plants are lacking. The flowers and fish we grow are living animals and plants. They need water as well as nutrients and microorganisms from water. So tap water can't be directly used to water flowers.

In order to solve this problem, some experienced people use rainwater to water flowers, or put tap water in the open air for a period of time, and then use it to water flowers when the coagulant and disinfectant in it run away and there are many impurities in the water.

I did as grandpa said, and sure enough, the flowers all smiled.

Essay on Science and Technology _ _ _ Why can't life live without water?

Lao Shuying from Class 3 (4) of Dong Xiao Primary School.

I found out why life can't be separated from water in a book "One new knowledge a day".

It turns out that water is the foundation of all things and the source of life. Life originated from the primitive ocean, so life can not be separated from water from the beginning; Life is 50%~80% water, and there is no life without water; Water is the most abundant in cells and exists in two forms: free water and bound water. Free water is a natural solvent for inorganic salts and other substances and an ideal medium for various biochemical reactions. The combined water is mainly combined with other substances (mainly protein) through hydrogen bonds. Many characteristics of water meet the needs of living things. Water is a polar molecule. Because of its strong cohesion and surface tension, it is suitable for transportation in the conduit of plants and aquatic insects walking on the water.

Therefore, we should cherish water resources, otherwise the water resources on the earth will be quietly reduced, and human beings will really be threatened by water shortage, trees will dry up, flowers and plants will wither, fish will die ... When these creatures quietly leave us, human beings will be extinct from the earth like dinosaurs.

Please cherish water resources and save water. If you save a drop of water every day, you can see an ocean.