Eating bamboo charcoal food detoxification and beauty, the super loop is coming... Are these rumors reliable?

◎ Chen Xi, reporter of this newspaper

Entering May, the new crown virus brushed another wave of presence. While we are fighting the new crown virus, we must also be wary of those low-cost and fast-spreading "rumor viruses". Eating bamboo charcoal food detoxification and beauty, mobile phone batteries can only be charged 5 times, marine carbon dioxide sequestration destroys the environment, "super high-loop" is coming... These rumors cause great anxiety among people.

Today, the reporter of Science and Technology Daily will take stock of the rumors in May one by one, helping you clear the fog and find the truth.

Eat bamboo charcoal food to detoxify and rejuvenate?

Truth: Instead, it can cause problems such as indigestion

In previous years, bamboo charcoal peanuts were popular "out of the circle", and this year, a bamboo charcoal drink featuring super cool "industrial style" has appeared. In addition, there are bamboo charcoal foods such as bamboo charcoal cake, bamboo charcoal bread, and bamboo charcoal mille-feuille in the market. There is such a saying on the Internet: bamboo charcoal can absorb harmful substances in the human body, and also help clean the intestines, and has the effect of detoxifying and rejuvenating.

In this regard, Wang Hao, a professor at the School of Food Science and Engineering of Tianjin University of Science and Technology, said in an interview with a reporter from Science and Technology Daily that the detoxification effect of bamboo charcoal food lacks a strong scientific basis.

In daily life, bamboo charcoal itself has an adsorption effect and can be placed indoors or in the refrigerator as a moisture absorbent, deodorant, etc.

"The molecular diameter of bamboo charcoal is very large, and such large particles cannot be absorbed by the human body. When the substance enters the human body, it is likely to be discharged as it is, so it not only has no effects such as cleansing the intestines, detoxifying and rejuvenating, but also affects the absorption of nutrients, causing problems such as indigestion and constipation. Wang Hao said that the human body has its own metabolic system, and harmful substances entering the human body can be discharged through the normal metabolic system, and there is no need to "detoxify" with the help of bamboo charcoal food.

Wang Hao stressed that bamboo charcoal has not yet been listed in the National Standard for Food Safety, Standard for the Use of Food Additives (GB 2760-2014). Therefore, at present, in China, bamboo charcoal is added to food as an additive, which is illegal. "For bamboo charcoal food, consumers should be cautious." He reminded.

Can the phone battery only be charged 500 times?

Truth: The better the habit, the more times it is charged

Nowadays, many people do not leave their mobile phones and have to charge their mobile phones every day. It is said on the Internet that "the mobile phone battery can only be charged 500 times, and then it will 'die'", so many people feel that it is necessary to minimize the number of times they charge their mobile phones.

Ji Kemeng, associate professor of the School of Chemical Engineering of Tianjin University, said in an interview with a reporter from Science and Technology Daily that the batteries currently used in smartphones are basically lithium-ion batteries, which use lithium-containing compounds as cathode materials and artificial graphite as anode materials. The charging and discharging process of lithium-ion batteries is the process of repeated intercalation and deintercalation of lithium ions in positive and negative electrode materials.

"Theoretically, as long as the structure of the positive and negative materials of lithium-ion batteries and the electrolyte used are stable enough within their operating voltage range, then mobile phone batteries can achieve unlimited charge-discharge cycles." Jike Meng introduced that in the laboratory constant temperature test, the battery can achieve more than two or three thousand times, stable charge and discharge cycles. In real use, mobile phone batteries can usually only achieve 500 to 1000 charge and discharge cycles (about 3 to 5 years).

Jikomeng explained that the reason why the number of rechargeable times of the battery in daily use is low is because people will inevitably have some wrong mobile phone habits, such as full charge or even overcharge (at this time, lithium ions will be completely pulled out of the cathode material, which will destroy the structure of the cathode material), fast charging (easy to cause the mobile phone to heat, will accelerate the decomposition and loss of electrolyte), etc., these behaviors will theoretically cause irreversible damage to the microstructure of key battery materials, which in turn leads to the continuous reduction of battery capacity.

Jikemeng reminds that in real use, usually after the mobile phone battery is fully charged and discharged 400 to 500 times, the battery performance may begin to decay, such as the battery capacity is lower than 80% of the original. In order to extend the battery life of the mobile phone as much as possible, we must maintain good mobile phone habits, such as do not charge overnight, do not use the mobile phone until it is turned off and then charged, and avoid overheating of the mobile phone.

Offshore CO2 sequestration damaging the environment?

Truth: There is no direct evidence to support this view

Deep in the underground rock formation, there are not only precious oil and gas resources, but also greenhouse gases such as carbon dioxide. In the process of offshore oil and gas drilling, how can the associated carbon dioxide be captured by technical means and stored on the seabed?

China's first megaton carbon dioxide storage project was officially put into use in the eastern waters of the South China Sea on June 6, and began to inject carbon dioxide produced by offshore oil exploitation into the seabed formation on a large scale to achieve long-term stable storage.

Before its official use, the concept gradually entered the public eye as the media increased its publicity about "offshore carbon dioxide storage". For related projects, some netizens said that sequestering carbon dioxide on the seabed will damage the ecological environment of the ocean.

In this regard, Hu Xiangang, a professor at the School of Environmental Science and Engineering of Nankai University, said in an interview with Science and Technology Daily that marine carbon sequestration is a complex engineering technology, which also involves many physical, chemical and biological processes. There is no direct evidence that offshore CO2 sequestration will have an impact on the ecological environment.

CO3000 injection is a common form of offshore carbon sequestration. At present, most scholars believe that the deeper the carbon dioxide is injected into the ocean, the better the sequestration effect. Injected into the ocean at depths of more than 70,500 meters, more than <>% of carbon dioxide is preserved for more than <> years, even thousands of years.

Hu Xiangang said that the implementation of seabed carbon sequestration has been proven safe and effective abroad. Among them, the more successful cases of seabed carbon sequestration are in Norway.

In 1996, Norway separated the carbon dioxide produced during oil and gas extraction and injected it back into the saline aquifer through an inclined well, using the airtightness of the geological structure of the saline aquifer to sequester carbon dioxide, which was also the world's first commercial-scale saline aquifer carbon sequestration project. In the more than 20 years of operation of the project, there has never been a carbon dioxide leakage, and 100 million tons of carbon dioxide are stored every year, and there has been no abnormal activity in the stored carbon dioxide.

At present, in addition to China, Brazil, Australia, Denmark and other countries have also launched seabed carbon sequestration projects.

The "hyperloop" is coming?

Truth: Technology is hard to land in the short term

"It only takes 15 minutes from Hangzhou to Shanghai" "1000 kilometers per hour!" The first 'hyperloop' is coming"... The recent news about the "hyperloop" circulating on the Internet has made many netizens' hearts "take off", and they can't wait to experience it.

In this regard, industry experts said that each technology takes a long time to land, and it is difficult to appear a "hyperloop" with a speed of 1000,<> kilometers per hour in the short term.

The news of the "hyperloop" came "from" a themed popular science exhibition called "high-speed speeding". At the exhibition, exhibitors revealed that the "high-speed speeding car" under development has made new progress, and recently completed the first full-scale super-navigation test in China. Next, the team will conduct more tests on the test line, with the goal of enabling the "high-speed speeder" to reach speeds of up to 1000,<> kilometers per hour.

In fact, as early as 2017, Chinese researchers decided to start developing the "hyperloop", combining supersonic flight technology and rail transit technology, and realizing supersonic near-earth "flight" of trains through the application of superconducting magnetic levitation technology and vacuum pipeline technology.

At present, China has formed three high-speed maglev technology routes, namely the standing technology represented by CRRC Sifang Joint Stock Company and Tongji University, the high-temperature superconducting technology represented by Southwest Jiaotong University, and the high-temperature superconducting electric technology represented by CRRC Changchun Rail Bus Co., Ltd. and China Aerospace Science and Industry Group Co., Ltd.

However, the existing test lines are relatively short and cannot be tested over long distances. In addition, industry experts said that if the new technology wants to really land, it is also necessary to consider many issues such as the safety and economy of operations. So it's too early to say that Hyperloop is coming.

Although the "hyperloop" cannot appear in the short term, China has never stopped exploring the pace of related technologies, and I believe that in the near future, it will become our good travel "helper".