A fully charged phone increases battery life? September 2021
2021-09-30 |

The monthly “scientific’ rumors list, guided by Beijing Association for Science and Technology, Beijing Municipal Cyberspace Administration Office and Beijing Internet Association and jointly released by Beijing Association of Science and Technology Journalists and Editors and WWW.piano.singalong.com, is supported by the Science Communication Committee of China Science Writers Association, the Society of Science Editors and Journalists of China Evening News, Shanghai Science and Technology Communication Association and Beijing Science and Technology Information Institute.

1. Eating beef and mutton will get anthracnose

Rumor:

Anthracnose is a serious disease and mainly prevalent in cattle, sheep, deer and other herbivores, therefore, it’s better not to eat these animals.

Truth:

Animals like cattle and sheep are susceptible to Bacillus anthracis, and they often die in a short period of time after infection. Hence, dead cattle, mutton and meat from unknown source cannot be eaten, but the meat purchased through regular channels that are quarantined can be safely eaten when cooked thoroughly.

Anthrax, as a zoophytic infectious disease caused by Bacillus anthracis is rarely transmitted between humans who are often infected due to contacting with the meat, fur, discharge or articles contaminated by the discharge of diseased animals. However, contact with healthy cattle, sheep and other animals and their meat products will not lead to anthrax infection.

In addition, anthrax as a bacterial infectious disease is treatable, and penicillin is a priority choice in treatment, because in most cases, Bacillus anthracis is not resistant to penicillin. However, anthrax in its advanced stage, especially when the systemic hemorrhagic symptom occurs is really difficult to cure. It can be seen that the key to the treatment of anthrax patients is early detection, early diagnosis and early treatment, otherwise any delay may lead to serious consequences.

2. A fully charged phone increases battery life?

Rumor:

"Not less than 300 times" is the national standard requirement for the cycle life of mobile phone lithium ion battery, so it's better to fully charge it and then use it up, otherwise, the charging and discharging times will soon reach 300 times, making the battery less durable.

Truth:

Extending the battery life of mobile phone is not to charge and discharge the battery as completely as possible, which on the contrary may damage the battery and reduce its capacity. The best use mode is: shallow charging and discharging, charging when lack of electricity, and pulling out after charging.

Lithium batteries work by moving lithium ions between positive and negative electrodes, so the amount of lithium ions that can be accommodated by positive and negative poles of a battery is directly related to its capacity. When the battery is deeply charged and discharged, the structure of the positive and negative electrodes may be damaged and the space for lithium ions be reduced, resulting in reduced battery life.

Battery life is usually evaluated by "cycle life", that is, when lithium-ion battery is deeply charged and discharged, its capacity can keep more than 80% of charge-discharge cycle times. The national standard GB/T18287 requires the cycle life of lithium battery in mobile phones to be "not less than 300 times", but this does not mean that our mobile phone battery becomes less durable after 300 times of charging and discharging.

Firstly, in the measurement of cycle life, the decrease of battery capacity is a gradual process, which is not cliff-like or step-like. Secondly, the lithium ion battery is deeply charged and discharged, however, the battery management system has a protection mechanism for the battery to avoid deep charging and discharging as much as possible during daily use, which will automatically cut off the power when it is fully charged and shut down automatically when the battery is insufficient. Therefore, the actual life of mobile phone battery is more than 300 times.

However, we can't completely rely on the battery management system, and we should consciously avoid low battery or full battery. In addition, when the phone is not used for a long time, it’s an effective way to extend its service life by keeping half the battery power.

3. It's cost effective to buy dead hairy crabs

Rumor:

Live hairy crabs are expensive, while it’s more cost-effective to buy dead crabs to eat. As long as you eat them quickly after they die, you'll be fine.

Truth:

The hairy crab (crab) is a unique fresh water product in China. Its high content of free amino acids and nitrogen compounds, relatively loose meat quality and its living environment, namely the silt combined provide favorable conditions for microbial growth, which results in high total number of bacterial colony in vivo and in vitro of fresh hairy crabs.

A few hours after death, the toxic substances in the body may have reached the level of poisoning. In the dead hairy crabs, histamine increases rapidly and cannot be removed even after high temperature heating, which is also the main cause of poisoning after eating dead hairy crabs. Previous experiments showed that keeping the dead crab at room temperature for 3 hours witnessed the content of histamine in its body increasing from 3mg/100g to 6mg/100g.. . Patients who eat by mistake may have histamine poisoning for which some patients may appear symptoms such as nausea, vomiting and upper abdominal discomfort, while severe patients may have shock, premature beat and other symptoms.

Therefore, if you find that the hairy crab you bought is dead, it's best not to eat it for safety, unless it’s just dead when you find it, and then cook it immediately. When steaming crabs, you’d better ensure that the crabs are cooking continuously for 20-30 minutes at a high temperature above 100 ℃ so as to completely kill all kinds of microorganisms in their bodies. However, in real life, we often cannot accurately judge the death time of hairy crabs, so it is better not to eat.

4."Listening to a book" is just a passive reception of information

Rumor:

Reading books is active learning, while listening to books is passive receiving information.

Truth:

Both vision and hearing are encoded in the brain in the form of electrical signals and require deep processing. The brain does not distinguish between word and language for which is "active" or "passive".

The words are received by human eyes in the form of light waves, then transmit nerve signals to the brain, and finally reach the area of the cerebral cortex responsible for processing the words for analysis and understanding. The sound signals are collected by ears and encoded in the brain. Like visual signals processing, the brain needs to store, recognize, memorize and understand these two kinds of information.

The process of listening to a book is not "passive". In fact, there is one more process than reading, that is, the symbolization of sound. Chinese characters are actually both phonetic and choreographic words. When we hear a strange word, we often firstly think about which words are made up of, and then extract the relevant images from our brain. If we need to remember this word, what we try to memorize is the word, not the sound itself. Therefore, listening to the book requires more of the brain, and is more conducive to developing the habit of concentration.

5. Nuclear technology is not safe to kill mosquitoes because of radiation

Rumor:

Scientists have used nuclear technology to kill mosquitoes which is not only a little fuss, but also unsafe for possibly causing radiation.

Truth:

The spread of nuclear irradiation technology in life has proved that it is safe and residue-free, as evidence by the wide use of radiation sterilization in the field of food preservation with the words "radiation sterilization technology" printed in food packages.

One of the most vexing characteristics of mosquitoes is their powerful reproductive capacity. Nuclear irradiation is aimed at this point by performing male mosquitoes a "sterilization operation": Scientists in the laboratory use radiation to destroy the fertility of male mosquitoes then release these sterile male mosquitoes to the wild to mate with wild females, but they cannot normally breed offspring. To kill mosquitoes by this method, the pollution to the environment can be negligible, and will not damage the ecosystem balance.

In fact, the "insect irradiation sterility" derived from nuclear technology is a harmless biological control technology, which can be used not only to kill mosquitoes, but also to prevent and control pests in agriculture. This technology can not only eliminate pests, but also be more environmentally friendly and safer than using pesticides.

6.Human Y Chromosomes are degenerating, men will die

Rumor:

The Y chromosome of human beings is degenerating, and it may only exist for 4.6 million years, so there will be no man in the world in the future.

Truth:

This argument stems from some research into the evolution of the Y chromosome, bUT it is not a consensus among scientists, nor is it completely flawless.

The reason why saying "male will disappear" is that the Y chromosome, the decisive factor for male development, degrades very rapidly and continues to shrink. According to a paper published in the journal Reproduction, Fertility and Development, there are more than 1,400 genes on the Y chromosome. According to the number of existing genes on the human Y chromosome, if the rate of gene loss is linear, then the Y chromosome will lose 4.6 genes per million years. If it develops at this rate, the human Y chromosome will disappear after 4.6 million years. This is also the basis for the time of man disappearance online.

The Y chromosome did degenerated a lot in the past, but it cannot be simply assumed that the Y chromosome will degrade all the time, let alone disappear after several years. In addition, the Y chromosome also has the self-protection means to prevent mutation, for example, there are a large number of repeated sequences on the Y chromosome, which can be used to complete self-recombination. This self-recombination mechanism may help us to stabilize the Y chromosome and slow down its degeneration trend.

What’s more, the degradation of the Y chromosome can be a long process in which genes and functions on the Y chromosome are constantly transferred to other chromosomes. In other words, species will evolve new sex-determining mechanisms.

7. Space Environment Makes Astronauts Fat

Rumor:

After the three Chinese astronauts arrived at the space station, their faces obviously became round, the reasons behind this are the low pressure, delicious food and less exercise space at the space station.

Truth:

In the state of weightlessness, the astronaut's blood will flow to the brain and upper body, and the viscosity of the blood will also change, thus resulting in facial edema and even head swelling. Factors like food and sports will not quickly cause such changes.

The distribution of blood and body fluid in our body is adapted to the gravity environment on the earth, but under the weightlessness environment in space, it will change. When the astronaut takes the rocket into the air and enters into space, the whole body blood will be redistributed. At the moment of rocket ignition and launch, the astronaut will experience an extraordinary feeling of overweight. In this process, the human body's blood and body fluid will be transferred to the lower limbs. After the separation of the ship and rocket, the astronaut will experience the process from overweight to weightlessness, and the whole body's blood will suddenly flow to the head. At this moment, people will feel strong discomfort, just like the feeling of carsickness and seasickness on the ground.

In fact, too much blood in the head sometimes also cause the astronaut’s sense of smell and taste to change and even appear headache, abnormal blood pressure, etc., but as long as there are measures in advance, particularly serious situation can be avoided. Therefore, the reason for astronaut round face is not because of fat, but the result of blood redistribution in the body under the specific environment.

Source of this issue:

WeChat public accounts of "Healthy China" and “Science Facts”, WWW.qsingalong.com, Economic Daily, Center Fact Check, Beijing Science and Technology News


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