1 Science and Technology Museum This week is a "large-scale scientific exhibition of human mysteries". This morning, the three of us went to visit the Science and Technology Museum together.
As soon as we entered the exhibition hall, we were greeted by paintings and various specimens. We moved slowly along with the crowd. Rilla took my hand and said she was scared. Her father and I encouraged her, but it was really mysterious to see various organs of the human body, especially normal lungs and smokers' lungs. This sharp contrast is really terrible. Rui is most interested in the formation of fetus, from embryo to 7-month-old fetus. We let Rui know the structure and function of various organs of the human body. Although some places are incomprehensible, at least we have learned some common sense of self-protection, and we also know that we should develop healthy living habits from an early age.
Today, I am concentrating on my homework. Suddenly, there was a buzz. I looked up and saw a bee humming leisurely across from me! I have always been afraid of bees, so I quickly called my father to "kill pests" for me.
When my father heard me calling him, he rushed over and asked me, "What is it?" I pointed to the bee and said, "Get it away, it's terrible." Dad said, "Look at you. If you leave it alone, it won't attack you easily. " I was surprised and said, "Why?" Dad said, "Because if a bee stings you, the sting on the back of its ass will be pulled out with its internal organs, and it won't live." As soon as I heard it, I became interested and said, "Let me see what the thorn on the back of its ass looks like." "Very good."
Dad pulled out a small napkin and gave the bee a yank. Before the bees could react, they became his prey and struggled feebly in his hands. Dad took it and hung it upside down, pointing to the thorn that stretched and shrank on its ass and saying, "This is its thorn. As long as it is unplugged, the bee will soon die. " As he spoke, dad took advantage of the bee to stab the thorn again. When he pulled it, a yellow thing came out. I asked, "Is that its internal organs?" Dad said, "yes, now it has no resistance." Let go! " "I nodded. As soon as dad let go, it struggled to fly out.
I learned a lot through this. It turns out that science is really everywhere!
The earth we live in, like the mother of human beings, is amiable most of the time. Spring, birds and flowers; In summer, the sun shines high; In autumn, a cool breeze blows gently; In winter, it is covered with snow. However, once Mother Earth gets angry, it will cause devastating damage. In order to let us calmly and tactfully deal with disasters, the school organized interesting popular science activities.
First, we watched a popular science movie. I will never forget some scenes in the movie: when the tsunami broke out, the surging tide rushed to the buildings on the shore like a fierce lion; When the earthquake came, the house first shook violently, and then the wall collapsed instantly, which was a mess; When the fire comes, the raging fire devours everything around it like a wild animal.
Next, we lined up neatly and went to the playground to participate in the "crossing the line of fire" activity. The staff said: As long as the steel goes around the steel pole to the finish line and does not touch each other, it is victory. If the steel ring touches the steel pole, it will call the police. When the alarm sounds, it means that the game has failed. A seemingly simple game is actually a psychological quality. When I walked slowly around the steel pole with a steel ring in my hand, the steel ring was attracted by the steel pole with a slight shake of my hand, and the alarm sounded, and I failed. Then, one after another failed. In the end, Liu Wang in our class lived up to expectations and won success with his composure.
Today's popular science activities, I not only learned some principles and common sense of tsunami, earthquake and fire, but also learned how to deal with these disasters correctly and how to escape in the face of disasters. What a big receipt!
During the summer vacation, the teacher took us to the gym and watched an interesting popular science exhibition.
Walking into the gymnasium, I saw many strange sights. Hey, what's that? A faucet has been running out of water, but there is no water pipe connector. Only when I saw the introduction did I know that there was a transparent water pipe hidden in the water. Ah! It turns out that the water pipe is the water in the water supply faucet. This is the so-called "passive water". My favorite is a mirage. I stood a meter away and looked ahead. There is a spring hanging in the air. I reached out to touch curiously, but I couldn't touch anything. That's a mirage!
I saw another big screen. There are many strange patterns on it. The most striking thing is that there are two people on a big head. It says below that this painting has nine faces. It is said that all they found were IQ 180. Seeing that many teachers are coming, I am curious. Alas, I only found three faces. Our Chinese teacher Ma pointed to the back and soon found nine long faces. What a good teacher!
There are many interesting things. I stopped, talking and laughing all the way, watching my classmates touch the big microphone with their hands. Listen to the students playing Doraemon on the electronic piano; Feeling the laughter of my classmates, I really gained a lot.
Reluctantly left, I think the progress of science is really fast, and it fascinates me more and more. Also let us know that some things should not be too superstitious. We should believe in science, which can lead us to explore many unknown secrets.
I think this popular science exhibition is very meaningful.
On Friday, our school held a popular science performance. Come, let's explore the mysteries of science together!
"Good afternoon, children and friends." A dragonfly flew out and said that after some self-introduction, we finally knew her purpose. She wanted to give us a present, so she gave us a little magic trick. We stood up with our eyes wide open and held our breath. Wow, this dragonfly turned a rope without any difference into three ropes. She changed it into a long rope from beginning to end, and she changed it from beginning to end.
"Dragonfly, dragonfly." When the doctor shouted, the dragonfly thought that the doctor was going to criticize the dragonfly, so the dragonfly hid among us, but it was still discovered by the doctor who knew astronomy and geography. Dragonfly is thirsty. Dragonfly asks the doctor for water to drink. The doctor prepared light salt water for the dragonfly, but the dragonfly didn't like it. After that, the doctor asked the dragonfly to pour the light salt water into another empty cup, and suddenly it turned into bright red watermelon juice. The doctor said, "Are you satisfied now?" Dragonfly and others still didn't wake up in surprise. Dragonfly man seems to deliberately say to the doctor, "I don't like drinking watermelon juice." The doctor said, "Then pour the watermelon juice into another empty cup." After pouring it in, the watermelon juice really turned into milky white milk. God, it's amazing! But the dragonfly said, "I don't like drinking milk either." Dragonfly thought the doctor was helpless, but the doctor didn't change his face. Instead, he smiled and said, "You put the milk in another cup again. As soon as the dragonfly was released, the milk immediately turned into light yellow cantaloupe juice. Now dragonfly has been persuaded. She picked up the cantaloupe juice and drank it, but the doctor stopped her. The doctor said, "Actually, I put scientific items in it in advance and turned it into juice just now. "
Dragonfly invited six children to dance molecular dance, and everyone ended the popular science activity with beautiful music and happy laughter. I also learned a lot of popular science knowledge through this popular science activity.
Hedgehogs are most afraid of weasels
In the weasel's view, the hedgehog is fat, big and delicious, and it is a good meal.
However, hedgehogs can't be dealt with by ordinary animals. When they meet wild animals, they always shrink back immediately, roll the whole body to the belly, and form a fully armed embroidery, which disappoints the wild animals. Cats and dogs can't do anything about them. How does the weasel deal with the hedgehog?
It turns out that there is a smelly gland in the anus of the weasel, which can secrete a lot of smelly liquid at any time when necessary, which is extremely powerful and can smoke down the enemy or medical special prey. When the hedgehog shrinks into a ball, the weasel will find a gap where the hedgehog curls up, that is, by injection, put the fart in the gap. In a short time, the hedgehog was used for medical purposes by the Smelly Liquid Research Institute, and its body slowly stretched out. At this time, the weasel immediately put out its sharp teeth and killed the hedgehog, enjoying its delicious food calmly.
Weasels, carnivores, come out to look for food at night. They walk across the grass quickly and can swim. Besides catching common mice and birds, you can also taste delicious hedgehogs, which are really delicious.
If you take a boat, you will find an interesting phenomenon: whenever the boat is going to dock, it is always necessary to slowly tilt the bow against the current to the dock and then dock smoothly. The more urgent the river is, the more obvious this phenomenon is. Ships sailing along the Yangtze River and other rivers do not dock immediately after arriving at the shore, but sail around a big circle against the current before slowly landing.
This is because when the ship stops against the current, it can use the resistance of the current to the hull to play a part of the "braking" role. Children, you must pay attention to this interesting phenomenon when you take a spaceship in the future!
When we look at the water quietly by the water, we will find that when there is no wind, the water surface is almost as smooth as a mirror; But when there is wind and rain, there will be waves on the water.
Obviously, the cause of the waves is the wind. Waves are actually formed by the movement of energy from one place to another. Wind is such energy. When the wind exerts energy on water, it will fluctuate.
When people see the waves rolling, they will think that the water is rolling forward. However, if you throw a piece of wood on the wave, you will find that the wood does not roll forward with the wave, but rises for a while on the wave and then falls into the valley. If the stone moves forward, it is also wind or water flowing.
It seems strange for an airplane to take off against the wind, because it will reduce the relative speed between the airplane and the ground.
You may not know one thing. In fact, when an airplane takes off from the ground, what matters is not the relative speed between the airplane and the ground, but the relative speed with the air. Assuming that the aircraft speed reaches 150km/h and the head wind speed is 30km/h, the relative speed between the aircraft and the air is 150+30 = 180km/h ... If the aircraft flies downwind, the relative speed between the aircraft and the ground will be faster, assuming that it is165.
You know, planes usually take off against the wind.
China Science and Technology Museum is located in Beijing North Third Ring Road. It is made of red bricks and has three floors. There is also a silver circular building next to the China Science and Technology Museum, which is the famous variable screen cinema.
My mother and I first came to the experimental site on the second floor. At this time, the experiment has just begun, only to see the instructor aunt take out an alloy bud and take out a hair dryer to heat the bud, only to see the bud slowly blooming. Turn off the hair dryer. When the temperature drops, the blooming buds gradually close again. The commentator's aunt said that this phenomenon is called two-way memory.
The commentator's aunt picked up a spring made of another alloy material. A fluffy duckling is tied to one end of the spring. She asked a child to hold a fluffy duck, and then heated the spring, which gradually straightened and became a straight wire. When the temperature drops, the spring is still straight and cannot return to its original position. Only by heating again can the spring shrink back to its original position bit by bit. This phenomenon is called one-way memory.
After explanation, I understand that this material is very useful, for example, it is often used in hotel fireworks alarm devices. The third experiment is faraday cage. There is a big iron cage with insulation board inside, and people standing on it can be isolated from the ground. Aunt commentator invited two uncles into the cage and closed the door. At this time, she pressed the power switch and the cage was charged. She told everyone that the voltage of the cage was 50,000 volts at this time. Wow! People are worried about people in cages, but people in cages are not in danger. They even dare to touch the cage with their hands Dare outsiders touch the cage? The narrator's aunt said she didn't dare to take the risk. She brought a long pole with a piece of wire at the top. She touched the cage with the top of the pole and only saw a blue electric spark and a click. It's really scary Why? The commentator's aunt told us: This is because the people in the cage are standing on the insulation board, and the voltage at any part of them is 50,000 volts. The voltage in the cage is 50,000 volts, and the voltage is zero. People outside are standing on the ground, and the ground voltage is zero. The voltage of the cage is 50 thousand volts, so people outside must never touch the cage. This experiment also told me a truth-children are not easy to move electricity, because their eyes are invisible without electricity.
After watching the experimental performance, I saw wonderful water drops, submarines, soap film walls, you or me, etc. This has taught me a lot of scientific knowledge.
China Science and Technology Museum, you are like a book, let people learn scientific knowledge; You are like a huge picture, showing people the science of this day. I praise you China Science and Technology Museum!
On a Sunday in mid-August, after the continuous drizzle moistened everything, the sun smiled again, birds sang happily, and plants dripped dew, as if praising the drizzle. Chinese rose flowers on both sides of the road, red flowers stand on the green branches and leaves, and the sun is floating on the colorful flowers. On such a beautiful day, my mother and I visited the China Science and Technology Museum.
At the moment, the earth is basically yellow, and there are too many greens to be reduced. Why? At first, people cut down forests excessively, making not only birds homeless, but also other animals homeless. It also caused disasters such as collapse, flood and debris flow. Without forests, our earth seems to have no pillars.
At present, every store is following our hobby, producing too many sodas and drinks, and the coats of sodas and drinks are canned. After drinking soda, the children threw the cans on the roadside and in the park. Roads, parks and even more places have become their homes. The jar is made of aluminum, and aluminum is also harmful to human body.
Understand? Waste batteries contain too many pollutants. The pollution caused by waste batteries is very harmful. When they are mixed with ordinary garbage, they will release a lot of toxic substances, which will pollute the air once burned; It will also pollute rivers, lakes and seas; Once it enters the soil sac and water source, it will enter the human body through various foods, damaging all parts of the human body. Therefore, it belongs to hazardous waste.
In the past, lovely little fish lived in small rivers and streams, but now the factory is built by the river and discharges sewage to improve efficiency. Since then, this river has become a good place for factories to discharge sewage. The river was polluted by sewage, and the bodies of small fish floated on the water. Passers-by smelled the smell and left quickly.
Saving water means protecting our environment, that is, saving resources. We should show it with practical actions and pay attention to saving water: for example, turn off the faucet at any time after use; The water used for washing vegetables is used for watering flowers and washing mops.
Fortunately, at this moment, people have realized that the earth is polluted, and everyone is taking action. I hope those who haven't acted will bend down and pick up the paper on the ground, so that our tomorrow will be more beautiful and tidy!
Is there a difference between astronauts bathing in space and bathing on earth? Very different! In the space environment, all objects have no weight, and water will not automatically spray out from the nozzle like on the earth, but will float everywhere after spraying out.
So how do scientists solve this problem? They put enough pressure on water to force it to spray outward, just like using a high-pressure sprayer, and designed a special space shower device according to this principle. This is a strange and interesting device: it is a cylinder in itself. Astronauts can get into the bucket, pull up the sealed zipper and put their feet into a pair of special slippers fixed at the bottom of the bucket, so that they can stand firm and not float. Astronauts turn on the shower nozzle at the top of the bucket, and pressurized hot water will gush out. Because water drops fly around in the tube, it is easy to enter the nostrils of astronauts and affect their breathing. Therefore, astronauts should wear a respirator on their nose and mouth before turning on the shower nozzle to prevent water droplets from entering the trachea. With the new bathing equipment, astronauts can take a bath comfortably.
Taking a bath in space is so interesting. If one day we become astronauts, we must have a good experience of bathing in space!
If you want to know the weather changes, you don't need to look at the "weather forecast". There are many things in nature that will tell us the answer. For example, "If you want to know that it won't rain, let's see if the banana is crying". The banana is a good helper to forecast the weather.
In Dominica, USA, people will plant several rain bananas in front of their homes and have a look before going out to judge the weather.
This kind of tree is really common in the local area.
How does the banana tree predict the weather?
It turns out that the skin of banana leaves and stems is very thin, and the whole body seems to be covered with a layer of poncho. Before the rain, the temperature was very high, so it was difficult for the water of banana trees to be emitted by the usual transpiration, so it overflowed from the leaves and formed water droplets, which kept flowing downwards. This is what people call the banana tree "crying" after seeing it. Because it rains every day after seeing the banana tree cry, people take the banana tree "crying" as a sign of rain.
The laws of nature are always so magical that people who care can always learn from them.
If you take a boat, you will find an interesting phenomenon: whenever the boat is going to dock, it is always necessary to slowly tilt the bow against the current to the dock and then dock smoothly. The more urgent the river is, the more obvious this phenomenon is. Ships sailing along the Yangtze River and other rivers do not dock immediately after arriving at the shore, but sail around a big circle against the current before slowly landing.
This is because when the ship stops against the current, it can use the resistance of the current to the hull to play a part of the "braking" role. Children, you must pay attention to this interesting phenomenon when you take a spaceship in the future!
Many children are surprised by popcorn, but it's actually very simple. Corn kernels are small and hard. When heated, the water in the hard shell of corn turns into steam and bursts, making popcorn that everyone likes.
Corn is a very strange plant, and its products have many uses. Corn starch is used on stamps and envelopes; Corn oil is used in food, painting, rubber substitutes and soap; Alcohol is also made from corn; Paper, smokeless gunpowder and collodion are all made of corn stalks, and even clothes can be made of corn cob.
Corn belongs to Gramineae, and there are many kinds, including hard corn, soft corn (very soft grains grown in South America) and sweet corn (which can be canned directly from corncob or eaten directly). Corn food has high nutritional value, so children might as well eat it often.
In a recent study, the University of Cambridge in England analyzed the relationship between people's eating habits and cancer in more than 10 countries. The results showed that the more starchy food they ate, the lower the incidence of small intestine, colon and rectal cancer. For example, the incidence of colon cancer in Australians who live on meat food is four times higher than that in China who live on starch food.
The so-called starchy food mainly refers to staple foods rich in carbohydrates, such as rice, corn and wheat. And root vegetables, such as potatoes, yams, potatoes, etc. In addition, it also includes various fruits with more starch, such as beans and bananas.
The researchers pointed out that starchy foods mainly inhibit intestinal cancer in two ways: First, after starch enters the intestine, a series of reactions help to increase feces, promote colon excretion, and accelerate the excretion of carcinogenic metabolites. Secondly, starch can produce a large number of butyrate through the action of intestinal fermentation enzymes. Experiments show that butyrate is an effective cancer cell growth inhibitor, which can directly inhibit the proliferation of bacteria in the large intestine and prevent the generation of cancer-causing cells on the inner wall of the large intestine.
How to choose starchy food in life? For busy office workers, roughing whole grain foods such as cereal bread in supermarkets is the first choice. Pay attention to recognition when buying cereal bread: if the first ingredient in the ingredient list is cereal, it means that its cereal content is really rich; If the cereal ingredient ranks behind other ingredients or sugar, it means that there are not many cereal ingredients in this food. Another way is to hold the bread in your hand. If you feel that bread is dense and has obvious grains, it is bread rich in grains.
Besides cereal bread, rice made of noodles, bean jelly, pancakes, steamed dumplings and buckwheat is also a good choice. Five-grain porridge rich in B vitamins and vitamin E, such as Laba porridge, Babaolian porridge and lotus leaf porridge, is more suitable for middle-aged and elderly people.
Fish live in water almost all their lives. They either swim to the left or to the right, so it is very practical to have a strong and vertical tail.
It can help fish change direction freely in the water. The lateral line of the fish can sense the subtle change of water pressure, so it will know the surrounding situation from a long distance. Generally, a large vibration will make the fish have an avoidance reaction and quickly hide in aquatic plants or gaps. I just keep quiet in the water most of the time when I sleep. Many fish sleep on or under wood at night. Corals are active during the day and rest in cracks in rocks at night. Fish look very different at rest from other times. For example, many small fishes of CYPRINIDAE are active during the day and disperse at night, so shallow water is not advised. Some fish rest during the day and move at night; But almost all fish have to sleep.
Some animals have been swimming because they have to keep spitting out water to keep breathing; But they may still sleep when they exercise. We just don't know. It's just static. Just like when people sleep, fish rest their bodies in this way!