Blue light is visible light with wavelengths between 400 and 500 nm, which can be combined with other wavelengths of light to escape in the colorful light. Therefore, it is not the light that looks blue is called blue light. Sunlight, incandescent lights, etc. all contain blue light. There are often advertisements claiming that blue light will aggravate visual fatigue and damage eyesight. Is blue light really that dangerous?
Studies have shown that blue light in the short wavelength band is indeed harmful to the eyes, which can be called “harmful blue light”. “Harmful blue light” can penetrate the eyeball and reach the retina. The retina constantly absorbs “harmful blue light” and is prone to accumulating phototoxic lipofuscin. Lipofuscin makes it difficult for light-sensitive cells to obtain energy, which eventually leads to visual impairment.
Seeing this, you may say: blue light is so terrible, let’s go buy blue light blocking glasses. Wait a minute! Although short-wave blue light is indeed “harmful”, the blue light hazards shown in the experiment are the result of long-term, high-intensity, and uninterrupted exposure to blue light, and most people’s exposure to blue light is far less than the experimental conditions.
Moreover, a survey report released by the China Consumers Association shows that all electronic products with qualified quality on the market have filtered “harmful blue light”. As long as counterfeit products are rejected, the light emitted by electronic products has little effect on us.
In addition, studies have shown that blue light in the long wavelength band is beneficial to the human body to regulate mood, memory and biological rhythms. Therefore, even if you really want to prevent blue light, you must strike it precisely, not one size fits all. Since the most dangerous blue light in life is actually the blue light in sunlight, if you work outdoors for a long time, you can choose lenses that filter 385-445nm and retain 445-505nm light waves according to the new national standard for blue light protective films.
In recent years, with the improvement of public awareness of environmental protection, paper straws and polylactic acid straws have gradually replaced plastic straws as the types of straws provided by most milk tea shops. However, although the cost of paper straws is low, the hardness is not enough, it is difficult to break the plastic film, and it will quickly become soft and bent in hot drinks; some use polylactic acid straws made of corn starch or potato starch, which is similar to the experience in use. Plastic straws are close, but the cost is high, and the quality will decline after storage for about half a year.
Recently, scientists have used lignin as the core raw material to create a low-cost, renewable “wooden straw”, which may become the best substitute for plastic straws. Lignin is a nutrient-transporting substance contained in almost all plants, with certain hydrophobicity and mechanical strength. By mixing lignin powder with cellulose powder, shaping and drying at 150°C, the scientists successfully allowed the lignin to penetrate into the pores of the cellulose to form a dense structure. After testing, the flexural strength of this “wooden straw” is about 40% higher than that of ordinary plastic straws; after soaking in water for half an hour, its wet tensile strength is almost unchanged compared with the dry state, which is about the strength of a paper straw. 22 times; in addition, the hardness of “wooden straw” is also the highest among several straws. With it, you don’t have to worry about various problems when drinking milk tea.
At present, the odorous gases discharged from sewage plants are generally discovered by people, then captured by air bags, and finally analyzed by instruments to find the source of the problem. This process is expensive, slow, and difficult for operators to locate the direction of odor transmission. Scientists have been slow to develop automated odor gas monitoring technology because it is difficult to give machines a “cognition” of “odor”.
Not long ago, Spanish scientists used an air bag from a sewage plant to “train” the “smell” of a new type of electronic nose with artificial intelligence, and successfully improved its ability to recognize odors to the level of human smell. They put the electronic nose on the drone and let the drone “patrol” over the factory for long-term unattended monitoring.
The results showed that among the 13 measurement results obtained in this experiment, 10 of the electronic noses were consistent with the human evaluation results. In addition, the researchers used the maneuverability of the drone and artificial intelligence algorithms to map the changes in odor concentration over time and place. It can be speculated that electronic nose drones will make a big difference in places such as factories and landfills in the future.