Scientific Composition of Junior Two (for Competition)

Water sprite in the sky (water sprite is something like jelly, I wonder if you have it there).

Introduction:

Recently, a toy called "water sprite" appeared in the street, especially in the toy stalls around the school. Because of the bright colors, it really attracted the attention of many students. Many people can't resist the boasting of vendors and often buy a few to take home. At the beginning of school, many students in our class also joined the ranks of buying water sprite. What is water sprite? What is it made of? Harmless to human body. With these questions, I launched a survey of water sprite.

I. water sprite's Analysis

At the end of September, I interviewed the businesses around the school for the first time, and wanted to know where these water sprite came from, whether there were any manufacturers, and whether they met the national health standards, but the businesses around the school avoided answering, and some even threatened us. I had to change my strategy and conduct a secret investigation. I bought a pack first, and immediately dissected water sprite with a knife. Immediately stopped by a vendor: "These are all living things. If you keep touching them, you will kill them. " According to it, this is a kind of artificially cultivated mushroom-like submarine fungus, which is soft, non-toxic and pollution-free. Touching with your hands feels like jelly. Cut it from the middle with a knife, and a transparent liquid flows out. By feeling, I think it is a substance similar to gelatin, which is the main material for making jelly. These water sprite are red, yellow, green, blue, transparent and colorful. They are very beautiful. Round, about the size of soybeans, about 0.5 cm in diameter, soft to pinch, elastic and sticky. A pungent smell makes people dizzy.

After preliminary observation, we think this is a kind of children's toy that is rarely seen. But why does it have so many colors, why does it smell so pungent, and what is its composition? I started the second step; Start recording;

Day 1 day: began to swell. I dropped a drop of ink into the water, and soon the water became clear again. I wonder, is water sprite a sewage cleaner?

On the 2nd-3rd day, water sprite grew a tail. At the same time, it began to decolorize, and its tail was very short, like that of a tadpole.

Day 4-5: Grow wings. (It hasn't grown)

Day 6: Laying eggs. Water sprite's ball is particularly round, can be crushed and has a smooth surface. It doesn't seem to move. After crushing, the inside looks like broken glass, and the inside and outside are transparent. We doubt whether it is still alive, but we will lay eggs again. And very elastic. That's weird.

Second, the composition of water sprite

The whole growth process of water sprite is like a process of cell division. Later, I learned that water sprite is a kind of water-absorbent resin (chemical substance), which is usually made of starch mixed with acrylonitrile or acrylate. They are transparent balls the size of rubber balls, with three colors of red, yellow and blue, which are very eye-catching. They are packed in small plastic bags or small glass bottles. About 60 balls per bottle, the price is 0.5 yuan. Because they change magically when put into water, there is also a mysterious name-"water sprite". These beads are soft, slippery and wet. After swelling in water, some will bulge out a bag and slowly separate it, so that more and more beads will be produced.

Third, water sprite's harm to human body.

Acrylonitrile and acrylate have certain toxicity, so it is impossible for merchants to use expensive food pigments in their production, and some industrial pigments may be added. Therefore, it is suggested that primary school students should not play with this kind of thing, and wash it quickly if the skin comes into contact with it. Of course, parents should also be very careful not to let children play, so as not to eat by mistake.

Fourth, the damage caused by the water demon.

1, the harm to human body. Acrylonitrile and acrylate have certain toxicity, so it is impossible for merchants to use expensive food pigments in their production, and some industrial pigments may be added. Therefore, primary school students are advised not to play with such things. If it comes into contact with skin, it should be cleaned quickly. Of course, parents should also pay great attention to avoid letting younger children play to avoid eating by mistake.

2. Let students develop the bad habit of abusing pocket money. Some even steal money from their parents and blindly follow suit.

3. If water sprite is brought to school, some students will play with water elves under their desks, and they will not listen carefully and distract their attention, thus affecting our study.

Tips for saving electricity

Abstract: With the decrease of energy, people pay more attention to energy conservation. When I was still in primary school, I taught us the concept of energy conservation, just for us humans to live on the earth forever. In real life, people still don't know how to save energy, so that saving energy is just talk and can't be done completely. Often due to the lack of scientific common sense and "tips", resulting in unnecessary waste. Now I want to introduce home power saving.

Key words: 1, rice cooker energy saving 2, TV power saving tips 3, air conditioning power saving tips 4, refrigerator power saving tips.

Introduction: With the decrease of energy, people pay more attention to energy conservation. When I was still in primary school, I taught us the concept of energy conservation, just for us humans to live on the earth forever. In real life, people still don't know how to save energy, so that saving energy is just talk and can't be done completely. Often due to the lack of scientific common sense and "tips", resulting in unnecessary waste. Now I want to introduce home power saving.

Tips for saving electricity in rice cookers

First, the energy saving of rice cookers

There are two kinds of rice cookers on the market now: one is mechanical rice cookers, and the other is computer rice cookers. When using the mechanical rice cooker, cover the rice cooker with a towel, and be careful not to cover the air outlet, which can reduce the heat loss. When the rice soup is boiling, raise the button to dry the rice soup with the waste heat of the electric heating plate, then press the button and stew for 15 minutes. Be sure to unplug the power plug after using the rice cooker, otherwise the temperature in the rice cooker will automatically turn on when it drops below 70 degrees, which will not only consume electricity but also shorten the service life. Try to choose a high-power rice cooker, because cooking the same amount of rice, a 700-watt rice cooker is more time-saving than a 500-watt rice cooker. Generally, the power of computer rice cookers is about 800 watts, which is more energy-saving, but the price is a bit expensive, generally between 500 yuan and 800 yuan.

Second, TV power saving tips

Television can save energy in the following ways: First, control the contrast and brightness. Generally, the power consumption of the brightest and darkest color TVs can range from 30W to 50W. It is suggested to turn on the low wattage fluorescent lamp indoors and adjust the contrast and brightness of the TV set to the middle. The second is to control the volume, which is loud and consumes high power. The third way to save electricity is to watch DVD, preferably av status. Because in the av state, the signal is directly connected, which reduces the work of the TV tuner and naturally reduces the power consumption. Fourth, after watching TV, don't turn it off with the remote control, but turn off the power on the TV. Because after the remote control is turned off, the TV is still in standby state and still using electricity. Under normal circumstances, the standby time is 10 hour, which is equivalent to consuming half a kilowatt hour. Finally, add a dust cover to the TV set. This can prevent the TV from inhaling dust and increase power consumption.

Third, air conditioning power saving tips

1. Don't adjust the temperature of the air conditioner too low during use. Because the lower the temperature controlled by the air conditioner, the more power is consumed, so it is generally enough to reduce the indoor temperature by 6 to 7 degrees.

2. When the cooling at room temperature is set to 1 degree and the heating is set to 2 degrees, it can save more than 10%, but the human body can hardly notice this subtle difference.

3. Set high cold/high heat when starting to achieve the control purpose at the fastest speed; When the temperature is suitable, change it to medium-low wind to reduce energy consumption and noise.

4. The "ventilation" switch cannot be in the normally open state, otherwise it will increase the power consumption.

5. Less doors and windows can reduce the heat entering the outdoor, which is conducive to saving electricity.

6. For air-conditioned rooms, it is best to use thick curtains to reduce the loss of cold air.

7. The connecting pipe between indoor unit and outdoor unit should not exceed the recommended length, which can enhance the cooling effect.

8. When installing air conditioning, try to choose the dark side of the room to avoid direct sunlight. If there is no such condition, cover the air conditioner with a sunshade.

9, regularly remove the dust on the outdoor heat sink, keep clean. Too much dust on the radiator will greatly increase power consumption.

Fourth, the refrigerator power saving tips

At present, the a++ class energy-saving refrigerators on the market are more energy-saving than ordinary refrigerators. Household energy-saving refrigerators generally consume 0.5 ~ 0.8 kWh/day, while ordinary refrigerators generally consume 1 ~ 1.5 kWh/day, which can save about half of electricity. In addition, in the process of using the refrigerator, we should pay attention to the following issues:

1. Don't put the refrigerated goods too close, leaving a gap to facilitate the circulation of cold air, make food cool faster, reduce the number of compressor operations and save electricity.

When you put fresh fruits and vegetables in the refrigerator, you must spread them out. If fruits and vegetables are piled together, it will cause external cooling and internal heating, which will consume more electricity.

3. For those big foods, you can pack them separately according to the amount that a family eats at one time, and only take out the amount that they eat at one time, instead of taking out a large piece of food from the refrigerator and putting it back after use. Repeated freezing not only wastes electricity, but also damages food.

There are several methods of thawing, such as water flushing and natural thawing. A few hours before eating, you can take the food from the cold room (about 4 degrees) to the micro-freezing room (about/kloc-0 degrees), because the cold air of frozen food can help keep the temperature and reduce the operation of the compressor, thus achieving the purpose of saving electricity.

The layout of the refrigerator is also exquisite. Generally, we should pay attention to the following two issues:

1. When the refrigerator is placed, generally 5 ~ 10 cm should be reserved on both sides, with 10 cm above and 10 cm behind, which can help the refrigerator to dissipate heat.

2. Don't put it with audio, TV, microwave oven and other electrical appliances. The heat generated by these appliances will increase the power consumption of the refrigerator.

Energy saving is very important. Everyone should use these skills and should not stop doing these things because it is too much trouble. These things are of great benefit to everyone, it's just a little effort. Relevant departments should also increase capacity and publicize more. Let all mankind save energy, which is not always available! Work hard for our future generations!