Which shade is the most effective in preventing new crowns? Note: it’s better not to wear this one

Search and download Huayu app, pay attention to overseas Chinese and overseas Chinese all over the world, browse the news information of various countries without translation – Huayu is in the “hand”, the world is in control! According to the Chinese website of the United States, it is well known that masks can effectively prevent the spread of the new coronavirus, but not all masks can have the same effect. Dr. Fisher, a researcher at Duke University, came up with a simple test to measure. The experiment, published in the Journal of scientific progress on August 7, tested 14 different types of masks, inspired by Fisher’s colleague Dr. Westman, who works for Durham, an advocacy group that distributes reusable masks to people in need. Westman wants to find out if the donated masks are working. < / P > < p > to test the effect of these masks, the scientists started the experiment using a black box with a laser and a mobile phone camera, with four testers wearing 14 masks in turn. Each time the mask is put on, a tester says “stay healthy, guys” five times in the direction of the laser beam in the box. A camera records the number of droplets caused by the speech and uses an algorithm to determine how many droplets leak out of the mask. Fisher said the experiment was simple and could be easily repeated. He didn’t recommend any specific masks. He used ordinary cotton masks himself. The focus of this study is that many kinds of masks are very effective, but some masks are worse than none. < / P > < p > the next six types of cotton masks all performed the same, Fisher pointed out, indicating that variables are important. “It depends on how loud you speak and whether the beard fits your face well,” or whether it causes a mismatch. < / P > < p > the N95 mask with air change valve is designed to protect users from inhaling harmful substances, but it does not protect others in turn, which partially affects its ranking. < p > < p > celebrities like Johnny Depp and Kristen Stewart love to tie a handkerchief to their faces, which has become a fashionable cover, but a number of studies have found that it is basically useless. < / P > < p > this high elastic neck guard is worse than no mask at all. It can decompose larger particles into smaller ones, making them easier to slide out from the side. Huawei mate40 concept machine exposed, Kirin 1020 + curved surface full-scale screen, beauty hanging on iPhone 12