Rumors heat up with hot spots, it’s time to let them "cool"
Our reporter Chen Xi
Refute rumors
Since July, many places across the country have entered the "steaming and grilling mode."
Just like the temperature in the dog days, "hot" events and various rumors also followed: "The temperature in Kuwait reached 73 degrees Celsius, and the car was roasted." "'Weird clouds' heralded the end of the world." Nucleic acid testing can not detect ""The Yellow River has affected Zhengzhou's drainage"...
Today, a reporter from the Science and Technology Daily will take stock of the July "hotspot" rumors one by one to help you clear the fog and find the truth.
Kuwaiti cars are roasted?
The truth: the sun's high temperature is not enough to melt the car body
On July 13, a video circulated on the Internet quickly made the topic "Kuwait's cars exposed to high temperatures" quickly appeared on the Internet.
The car bumpers, lights and even tires in the video melt into liquid like ice cream.
The temperature on site was as high as 73 degrees Celsius.
The accompanying article claims that Kuwait has recently experienced extreme high temperature weather, which has caused the vehicle to be "baked".
"Cars cannot be easily'baked'. The video is suspected of being faked." Zhang Sheng, a professor at the School of Chemical Engineering of Tianjin University, told a reporter from Science and Technology Daily. Although the materials of car shells for different purposes may be slightly different, most of the materials are different. The car shell is made of metal materials, such as steel, aluminum, aluminum alloy, or non-metallic materials such as engineering plastics, high-strength fiber composite materials, and ceramic materials.
The bumper part of a car is usually made of polypropylene.
"These materials are generally resistant to high temperatures. The melting point of aluminum alloy is 600 degrees Celsius, the melting point of aluminum is 660 degrees Celsius, the melting point of steel is between 1100 degrees Celsius and 1600 degrees Celsius, the melting point of ceramics is above 2000 degrees Celsius, and the melting point of engineering plastics is above 230 degrees Celsius. The melting point of fiber composite materials is also hundreds of degrees Celsius."
According to Zhang Sheng, the most likely to be "baked" is the car bumper made of polypropylene, but its melting point is also between 158 degrees Celsius and 168 degrees Celsius, which is much higher than 73 degrees Celsius.
Zhang Sheng said that even if it is exposed to the sun on a hot day, the temperature that can be reached is too "pediatric" for the car, so there is no need to worry about the car being "baked".
Weird clouds herald the end of the world?
Truth: Rough clouds are ordinary natural phenomena
On July 5th, Tianjin citizens were frightened by the "menacing" cloud group.
In the video posted by netizens, the clouds over the city are rapidly tumbling and rolling, looking like hideous faces, very strange.
Many citizens said that they had never seen such a cloud, and began to worry about whether it was a harbinger of severe weather.
In fact, the cloud that aroused public attention this time is called the rough cloud.
As the name suggests, it is a cloud with a rough surface.
Rough cloud is a fold phenomenon that occurs when the wave-shaped stratocumulus cloud accumulates to the limit under the action of the front (the interface of two cold and warm masses with different physical properties such as temperature and humidity) or strong convective weather.
The reason why the rough cloud looks so scary is because the cloud bottom of the rough cloud has granular clumps, extreme roughness, and a strongly distorted wave-like structure, and these folds are irregular, strange in shape, and thick, dark and dark. , So the appearance is easy to give people a sense of horror and discomfort.
Rough clouds, like other clouds, are objects suspended in the air formed by the aggregation of water droplets and ice crystals. Like rainbows, aurora, etc., they are natural phenomena that can appear under appropriate meteorological conditions and do not "foretell." Disaster".
Although the posture of the cloud has nothing to do with the disaster, it can be used to predict the weather.
For example, there are many meteorological proverbs circulating among the people about seeing the clouds and knowing the weather, such as "Do not go out in the morning, and go for thousands of miles in the sunset", "The sky is hooked on the clouds, and the ground is raining", "The scales of the sky, the rain and the wind", "There are cotton clouds in the morning," Thunderstorms in the afternoon, etc., provide an important reference for the production and life of the people.
The appearance of rough clouds often means that severe weather is coming to an end.
This is because frontal transit or severe convective weather is often accompanied by severe weather such as thunder and lightning, heavy rain, strong wind, hail, etc., resulting in rapid and violent cloud changes.
Therefore, rough clouds generally appear in the last moments of this kind of weather, especially after heavy rains.
Nucleic acid test can't detect Delta virus?
Truth: Mutant viruses can't escape the "legal eye" of nucleic acid detection
A few days ago, in Nanjing this round of new crown pneumonia outbreak, the culprit targeted India's new crown pneumonia variant virus-Delta strain.
This reminds many people of the three Chinese working in India who went viral on the Internet not long ago. When they returned to Chongqing and arrived in Chongqing, their initial nucleic acid tests were all negative. Finally, they were diagnosed with a CT scan and found lung lesions. It is a variant of the new crown pneumonia virus in India.
Many people worry that the reason why the Nanjing epidemic has spread so widely is also because the new coronary pneumonia variant virus can evade existing nucleic acid tests.
In this regard, Hubei University’s provincial and ministerial co-construction of the State Key Laboratory of Biocatalysis and Enzyme Engineering, and Professor Chen Chunqi of the School of Life Sciences of the school, introduced that the new coronavirus pneumonia virus is an RNA virus, that is, the viral nucleic acid wrapped in the virus particle is RNA (ribonucleic acid). ), and using the sequence of viral RNA and human chromosomes to be different, the presence of the virus can be detected by the method of specific nucleic acid detection.
“At present, the method of nucleic acid detection for the new coronavirus pneumonia virus is mainly to first extract the viral RNA from the nasal swab or throat swab sample. If the sample contains the virus, the polymerase chain reaction (PCR) is used to remove the virus. When the gene sequence of the virus is amplified, the fluorescence can be seen through the instrument; if there is no virus in the sample, the fluorescence cannot be seen. This method is used to estimate the virus content in the original sample.” Chen Chunqi explained, because the delta strain is still mainly It is a mutation from the original new coronavirus pneumonia virus strain. The mutation is mainly the spike protein on the surface of the virus particle that binds to the receptor. Such mutation will not affect the results of the nucleic acid test. Therefore, the nucleic acid test is still the current test. The most effective method for the new crown pneumonia virus.
According to the weekly report of the China Centers for Disease Control and Prevention, the three imported cases in the online information showed positive nucleic acid test results at Chongqing Customs, which was inconsistent with the rumor that "the initial test in Chongqing was negative."
Ke Changwen, chief scientist of the Guangdong Provincial Center for Disease Control and Prevention, also said that nucleic acid testing is the current "gold standard" for the diagnosis of new coronary pneumonia cases. Detected positive for nucleic acid.
As a more mature diagnostic method, its test results are more reliable.
It can be seen that India's new crown pneumonia variant virus has not circumvented the current detection methods.
The Yellow River affected Zhengzhou's drainage?
The truth: the occurrence of waterlogging in Zhengzhou has nothing to do with the Yellow River
From 18:00 on July 18th to 0:00 on 21st, Zhengzhou, Henan Province experienced a rare and continuous heavy precipitation weather process. There were heavy rainstorms and extremely heavy rainstorms throughout the city, which caused waterlogging in Zhengzhou in a short period of time.
Some people say that the Yellow River is a "hanging river", causing poor drainage in Zhengzhou.
"The Yellow River is a hanging river refers to the Kaifeng section of Henan, and it is not considered a hanging river in Zhengzhou." Zheng Yongliang, deputy chief engineer and senior engineer of China Water Northern Survey, Design and Research Co., Ltd., based on preliminary analysis of relevant information. The occurrence of waterlogging should have nothing to do with the Yellow River.
First of all, the Yellow River does not undertake the flood control and drainage functions of Zhengzhou.
The Xiong'er River, Wei River, and Dongfeng Canal in Zhengzhou are the backbone rivers for flood discharge and drainage in Zhengzhou City. All the rivers eventually drain water to the Jialu River. The Jialu River undertakes the important function of urban flood control and drainage. It belongs to the Huaihe River II. tributary.
Secondly, generally speaking, July and August are the two months with the highest average rainfall in Zhengzhou. The average rainfall in the two months is 155.5 mm and 112.5 mm, which is only 228 mm in total.
When planning and constructing the urban drainage system, it is necessary to refer to the meteorological data of previous years. The extreme heavy rain caused Zhengzhou's maximum total rainfall in 24 hours to exceed 622 mm, which was not available in previous years and has exceeded the drainage capacity of the Zhengzhou drainage system.
In addition, 1 hour before the extreme rainstorm occurred in Zhengzhou (from 16:00 to 17:00 on July 20), that is, from 20:00 on July 18 to 15:00 on the 20th, Songshan Station, Gongyi Station and Xinmi Station located in the upper reaches of the main city of Zhengzhou Heavy rainfall has already occurred.
On July 20, the rainstorm center gradually developed from the mountainous area in the southwest to the urban area of Zhengzhou in the northeast, causing the urban rivers to rise rapidly due to the mountainous rainstorm runoff and the safe discharge of the reservoirs. When a heavy rainstorm occurs in the urban areas, the drainage conditions of the urban rivers are unfavorable.
Zheng Yongliang said that when Zhengzhou experienced waterlogging, there was no major flooding on the main stream of the Yellow River, so there is no possibility of affecting Zhengzhou.