首页 >> 新闻 >> 正文

陕西省妇幼保健院胃肠科好不好新华面诊延安第一人民医院消化病网上预约咨询

2019年12月05日 23:33:59来源:管问答

  • Scientists studying emotions have found that basic emotions like amusement, anger, fear, and sadness are common among all cultures. And people from different cultures, whether theyrsquo;re modern Americans or pre modern aborigines, recognize sound cues like laughter to signify specific emotions. In other words, all people, everywhere around the world, laugh when theyrsquo;re amused. And cry when theyrsquo;re sad. And make scared sounds when theyrsquo;re scared. Even some non human animals, like chimps, have a type of laughter. So we may not all find the same things funny or scary or sad. But we all feel and express these emotions.研究情绪的科学家们发现在所有文化普通存在着四种基本情绪,比如:,愤怒,恐惧和悲伤。来自不同文化背景的人,无论他们是现代美国人或前现代原住民,识别诸如笑声这样的声音提示来表示特殊的情绪。换句话说,全世界各地的人,他们被逗乐时会笑。伤心时会哭。害怕时会发出令人惊恐的声音。甚至一些非人类的动物,如黑猩猩,有某种类型的笑声。因此,看待同样的事情,不是所有人都肝胆有趣,吓人或是悲桑。但我们都能感觉并表达这些情绪。166633。
  • If I told you there was a large mass of fungus infecting the roots of that lovely pine tree which shades your front lawn, would you be worried? Would you buy a strong fungicide if I said that this fungus survived by sucking valuable sugars, vitamins, and other nutrients out of your trees roots?可爱的松树在前院的草丛上投下了阴凉。如果这时我告诉你这颗松树的根部感染了大量的真菌,你会感到担心吗?如果我告诉你这种真菌是靠吸收根部的糖、维他命以及其它营养物质来生存,你会买来强力除菌剂除掉它们吗?Actually, most species of tree and plant are routinely infected by whats known as “mycorrhizal fungi,” but this is no cause for alarm. Well learn how trees can actually benefit from their fungal friends on todays moment of science.事实上,大多种类的树木和植物的根部都会感染菌根真菌,但你没有理由惊慌。在今天的科学时刻我们会一同学习树木如何与它们的真菌朋友相互依存,互惠互利。Many trees and plants not only host mycorrhizal fungi–they have actually come to depend on them. As the fungi grow, they send fine tentacles streaming into the soil. These tentacles help channel large amounts of water and nutrients back to the host tree, far more water than the tree would be able to trap with its roots alone.许多树木和植物不仅仅是菌根真菌的宿主——它们实际上是在依靠这些真菌。随着真菌不断的繁衍,大量细长的触须涌向土壤。这些触须会将大量的水分和营养物质引回宿主树木的身边,这远比树木的根部自身所捕获的水分要多。One study found that conifers with the fungus are twice as likely to survive a drought as those without. Some mycorrhizal fungi help their host tree in other ways too, secreting a tree hormone that causes the roots to grow new root tips, and a hormone that increases the longevity of these new roots.一个研究发现有真菌的针叶树比没有真菌的针叶树在干旱中幸存的几率高两倍。有些菌根真菌还能在其他方面帮助宿主树木。它们刺激树木的根部分泌激素,以长出新的根须,这种激素也能延长新树根的寿命。Other fungi release natural antibiotics into the soil, further protecting the tree. In fact, the seedlings of many tree species will die if fungus does not develop around their roots during their first year of growth.还有一些真菌会在土壤中释放天然的抗生素,进一步保护树木。实际上,如果幼树在第一年的生长期中没有真菌寄生在其根部,那么大量的幼树都会死亡。This is a striking example of the biological concept of symbiosis, in which two or more unrelated species have co-evolved and now depend on each other for survival. It shows us just how interconnected the delicate web of life is. Which covers our planting earth.生物概念下的共生现象是指两种或者多种不相关联的物种共同进化,互相依存,而树木与真菌就是一个显著的例子。它向我们展示了生命之网的内在联系。生命之网虽然脆弱,但却蕴育了繁茂的地球。原文译文属!201210/205559。
  • Why Is It So Difficult To Spot A Plane In The Air?为什么定位空中的飞机如此难?How many times have you heard a jet plane going over, looked up to see it, but not been able to find it even though you were looking toward where the sound was coming from? Well, this moment of science is going to tell you why you couldnt find it?有多少次你听到一架喷气式飞机飞过,抬起头去看它,即使你朝着声音传来的地方望去,却仍然无法找到它?那么这次科学时刻将会告诉你为什么你找不到它。Sometime during your life you might have been told that the plane wasnt with the sound because it was traveling faster than the speed of sound. It might have been, but it didnt have to be going that fast in order to appear to be separated from the sound.在你生活中的某个时候,你可能被告知看到的飞机和听到的声音是不在同时出现的,这是因为光的传播速度比声音快。它可能是这样的,但它没有必要为了同声音分离而飞的那么快。The reason the jet appeared to be apart from the noise it was making was simply that sound travels a lot more slowly than light–about a million times more slowly. For quick review, at sea level sound travels about seven-hundred-fifty miles per hour, light travels at 186,000 miles per second.喷气式飞机之所以和它产生的噪音相分离,是因为声音传播速度比光速慢一百万倍。简单回顾一下,在海平面上,声音的传播速度大约是每小时750英里,而光速则是每秒186,000英里。Commercial jets normally fly at about thirty-thousand feet. From that height it takes sound about thirty seconds to reach earth. Light gets here in only about four one-hundred-thousandths of a second, or for practical purposes,instantaneously.商用喷气式飞机一般在30,000英尺的高空飞行。从那个高度,声音传送到地面需要30秒的时间,而光到达地面仅仅需要4/100,000秒,实际上就是瞬间到达。A plane travelling at six-hundred miles an hour goes five miles in the thirty seconds it takes for the sound to reach you. By the time the sound from the plane reaches your ears, the plane is five miles from where that sound originated. So, when you look toward the sound, the plane is not there anymore.一架每小时飞行600英里的飞机在30秒中飞行了5英里,而声音传到你所在的地方需要30秒。在这30秒的时间里,声音从飞机传到你的耳朵里,而飞机离声音发出的地方已经有了5英里的距离。所以,当你朝声音发出的地方望去的时候,飞机早已不在那里了 /201207/190501。
分页 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29