Our reporter Chen Xi
In the past August, the sweltering heat was unbearable, and many people were tortured by the high temperature, and they "continued their lives" by hiding in air-conditioned rooms every day.
However, the scorching sun did not affect the activity of the rumors, and they are still making waves on the Internet: the air conditioner is turned on to 26 degrees Celsius to save electricity, this year is the coolest year in the next ten years, and the cooling spray has zero harm...
With the end of this year's dog days, there is also a hint of autumn coolness all over the country. Today, the reporter of Science and Technology Daily took stock of the rumors in August one by one, and let the autumn wind give them "heat".
Is it the most power efficient to open the air conditioner to 26 degrees Celsius?
Fact: The higher the temperature, the lower the power consumption
In the past month, the high temperature weather that lasted for many days has made the air conditioner a "life-saving artifact" for many people.
However, while many people are blowing the air conditioner, they also feel distressed about the electricity bills flowing away.
There has been a saying on the Internet that "turning the air conditioner on to 26 degrees Celsius saves electricity", and this "home remedy" for saving electricity has been tried by many people.
In this regard, Zheng Zhongyuan, head of the environmental protection department of the State Grid Tianjin Electric Power Research Institute, said in an interview with a reporter from Science and Technology Daily that the statement that setting the air conditioner at 26 degrees Celsius is the most energy-efficient. The power consumption of air conditioners is affected by many factors.
First of all, the power consumption is related to the temperature set by the air conditioner.
Someone once calculated that if the cooling temperature of the air conditioner drops from 26 degrees Celsius to 25 degrees Celsius, the power consumption will increase by 47.89%; if the temperature set by the air conditioner is lowered from 27 degrees Celsius to 25 degrees Celsius, the power consumption will increase by 134.35%.
Therefore, the power consumption will decrease only if the cooling temperature of the air conditioner is increased.
"That is to say, the lower the temperature set by the air conditioner, the greater the power consumption." Zheng Zhongyuan said.
Secondly, the power consumption of air conditioners with different horsepower and energy efficiency is also different.
Air conditioners with first-level energy efficiency are more energy-efficient than those with third-level energy efficiency; air conditioners with higher horsepower can cool faster, but consume more power.
Finally, the power consumption of the air conditioner is also related to the outdoor temperature.
If the temperature difference between indoor and outdoor is too large, it will also increase the power consumption.
Usually, when the difference between the indoor temperature and the outdoor temperature is about 4 degrees Celsius, the air conditioner saves electricity.
Zheng Zhongyuan introduced two tips to save electricity for air conditioners.
"Adjust the air conditioner blades to blow upwards. Because the cold air is heavy, it will sink. Therefore, it is easier to spread the coolness into the room than blowing cold air directly to the ground. In addition, you can also use an electric fan when you turn on the air conditioner. Spread the cold air to every corner of the room." Zheng Zhongyuan said that both methods can quickly reduce the indoor temperature to the set temperature, reduce the operation of the air conditioner, and thus save electricity.
Is this the coolest year of the next decade?
Fact: The research paper does not cover future temperature predictions
This summer, the topic of high temperature has never stopped, and the highest temperature record has been broken again and again, making people "unspeakably hot".
A hot search that appeared at the end of August, "This year may be the coolest year in the next 10 years", even terrified netizens.
The self-media that released the relevant news said that the source of the conclusion was a paper published in "Nature Communications" by the Institute of Atmospheric Physics of the Chinese Academy of Sciences.
The paper said that the subtropical high pressure in the Northwest Pacific will further strengthen in the future, which will further lead to the generation of extreme weather.
Subsequently, the Institute of Atmospheric Physics of the Chinese Academy of Sciences "personally went down" to refute the rumor: the paper studies the relationship between greenhouse gases and climate change, does not involve the issue of temperature prediction in the next 10 years, and neither proposes nor supports "this year is the next 10 years". the coolest year in
"To predict the long-term climate change at the end of this century, it is necessary to use climate models. However, due to the influence of the level of scientific and technological development, the results of the current model are still uncertain." The Institute of Atmospheric Physics, Chinese Academy of Sciences said in its official Weibo post.
Although there is no such thing as "the coolest year in the next 10 years", the heat of this summer is real.
According to the monitoring and evaluation of the National Climate Center, taking into account the average intensity, impact range and duration of the high temperature heat wave event, as of August 15, the high temperature event in my country has lasted for 64 days, the longest duration since 1961; 40 degrees Celsius The coverage of the above-mentioned high temperature weather is the largest in history.
The reason for this extreme situation is that Zhang Renhe, academician of the Chinese Academy of Sciences and vice president of Fudan University, previously explained that the "amplification effect of Arctic warming" is an important reason for exacerbating extreme weather in Eurasia and North America.
In addition, Li Xichen, a researcher at the Institute of Atmospheric Physics of the Chinese Academy of Sciences, said in an interview with the media that a direct cause of the extreme high temperature in summer is the global warming caused by changes in radiative forcing caused by greenhouse gas emissions.
Greenhouse gases such as carbon dioxide and methane emitted by human activities can absorb and emit infrared rays, causing continuous warming of the surface and global warming.
Zero harm of cooling spray?
Fact: There is a risk of explosion or fire
"Going out for 5 minutes, sweating for 2 hours" - this is a true portrayal of people going out during the dog days of this year.
Baked by the scorching sun, not only people but also cars.
The car was exposed to the fiery sun for a while, and the interior of the car was like a steamer, making it unbearable for the driver and passengers.
In order to alleviate the high temperature, many motorists have purchased cooling sprays online. Some buyers said that spraying it in the car can "rapidly cool down with zero harm".
So, is it really a safe "cooling artifact"?
"The reason why the cooling spray has such a 'magical' cooling effect is that it mainly uses the principle of water mist evaporation and heat absorption." Zhang Sheng, a professor at the School of Chemical Engineering of Tianjin University, introduced in an interview with a reporter from Science and Technology Daily that the cooling spray sold online, Its main ingredient is water, with a small amount of ethanol (alcohol), menthol and other organic substances added.
Since water and alcohol "absorb" heat from the surface, the heat is taken away when it evaporates.
"It's the same reason that we feel cool after applying alcohol on the skin before the injection," Zhang Sheng said.
In addition, there are some sprays that can quickly cool down are made from liquefied petroleum gas, the main components of which are propane and butane.
"The boiling point of propane is minus 42.1 degrees Celsius, and the boiling point of butane is minus 0.5 degrees Celsius. They can instantly vaporize and absorb a lot of heat in a high temperature environment, so that the surface of the object can be rapidly cooled, and the minimum local temperature can be reduced to below 0 degrees Celsius." Zhang Sheng said.
Although the cooling effect is good, the cooling spray is not what people call zero harm, but there are huge safety hazards.
"Liquefied petroleum gas and alcohol are both flammable and explosive products. Once handled improperly, they can easily lead to dangerous accidents and become the fuse of disasters." Zhang Sheng reminded that, especially in summer, the temperature inside the car after being exposed to the sun is high, and the Flammable and explosive cooling sprays are likely to explode when placed in the car. In addition, the spray may also cause a fire if it encounters an open flame.
Zhang Sheng suggested that the public should try to avoid cooling spray products containing extremely flammable ingredients such as liquefied petroleum gas or dimethyl ether.
When using a cooling spray with water and ethanol as the main components, it is necessary to ensure that there is no open flame within the scope of use. If it is used in the car, the windows should be opened in time for ventilation after use to prevent excessive accumulation of flammable components in the car and cause safety accidents.
Is the color of bayberry faded due to the addition of dyes?
The truth: It's the anthocyanins that make the water color
The hot weather makes many people lose their appetite, and bayberry has a sour and sweet taste, which greatly increases the appetite of many people.
However, when washing bayberry, many people found that the water for washing bayberry would soon turn pink, purple or light pink, and therefore there was a saying that "wash bayberry faded because bayberry was added with dyes".
In this regard, Wang Qiang, executive deputy director of the Agricultural Products Quality Inspection Center (Hangzhou) of the Ministry of Agriculture and Rural Affairs, said that it is almost impossible to dye bayberry.
Bayberry has no outer peel and exposed pulp. If you want to dye it, you can only soak it in dye or spray it with dye.
However, it is difficult to achieve uniform coloring by spraying, and soaking will accelerate the decay and deterioration of bayberry.
In addition, adding dyeing links will also increase the cost, which is not meaningful.
If no dye is used, what is the matter with the fading of bayberry after washing?
"The pulp of bayberry is rich in anthocyanins, and anthocyanins are extremely soluble in water. The pink, purple or light pink we see is the color of anthocyanins dissolved in water." Wang Qiang introduced, bayberry The cell wall of the pulp is relatively thin. When the bayberry is washed with water or rubbed, it is easy to cause damage to the cell wall, and the anthocyanins flow out, dyeing the water.
Wang Qiang suggested that the public can soak the bayberry in water mixed with starch and salt. The salt water can stimulate the fruit fly larvae to run out automatically, and the starch can absorb the larvae and other impurities. After soaking for about 20 minutes, rinse the bayberry with clean water.
search
copy