How We Unknowingly Eat 40,000 Bananas Every Year...

文章编号：13875 / 更新时间：2024-03-02 19:49:54 / 浏览：次

出品：科普中国

作者：科学边角料（科普创作者）

监制：中国科普博览

听到辐射这个词，很多人会下意识地感到恐惧。但实际上在生活中，辐射随处可见。即使关闭所有WIFI，关闭所有信号塔、基站，我们仍会受到环境中的本底辐射影响；我们能看各种各样的颜色，这也是依靠电磁波辐射；甚至我们食用的香蕉、瓜子、马铃薯中也含有放射性元素。因此，我们不能一概认为辐射就一定是有害。接下来我们来谈谈身边辐射的相关事宜。

电离辐射和非电离辐射在生活中根据能量的高低，大致可分为两类：电离辐射和非电离辐。电离辐射能量较高，能够从其他原子、分子中剥离出至少一个电子，而非电离辐射则不具备这种能力。让我们先看看日常生活中比较常见的非电射。

虽然名字中包含“辐射”一词，但非电离辐射在日常生活中随处可见，且极为重要。我们所看到的世界靠的是可见光，可见光上属于一种电磁波辐射，属于非电离辐射。红外线、手机信号、WIFI信号以及微波炉工作时释放的微波也属于非电离辐射。正常情况这些非电离辐射不会对人体造成不良影响。微波炉所产生的辐射是非电离辐射，用于加热食物。

相比之下，电离辐射的能量较。人们常说的核辐射即属于电离辐射，但电离辐射并非仅限于核辐射，它们在日常生活中也很常见。例如在医院拍X光片、CT扫描，车站机场行李安检所使用的安检仪发出的辐射都属于电离辐射。在存在电离辐射的场所，通常会看到下图中的标识。

遇到这些标识时，我们应尽量离，比如不要把手或头伸进地铁安检仪。在病人接受X光胸透检查时，家属也应离开检查房间。常规的医疗检查以及过机场车站安门并不需要过度担心会对健康造成危害，因为电离辐射也要考虑照射剂量。

虽然从能量上看，电离辐射的能量确实更高，但这并不意所有电离辐射都会对健康有害。对于电离辐射，剂量是至关重要的。在自然界中，很多元素存在放射性同位素，这些同位素不断释放电离辐射用于核燃料的铀-235就是一种放射性同位素。在居里夫人研究的镭元素中也具有强放射性。除了铀和镭等元素，在日常生活中我们也能接触种放射性同位素。

举例来说，我们日常食用的香蕉中含有丰富的钾，同时存在放射性同位素钾-40。尽管它会持续释放电离辐射，但于辐射剂量非常低，我们几乎没有听说过有人因为吃香蕉导致辐射中毒。人体内还存在钾-40和碳-14（碳的放射性同位素），在不断向外释电离辐射。

即使晚上与他人同床共眠，我们也会暴露于他人释放的电离辐射之下，但这些辐射的剂量同样微乎其微，不会对人体产生何影响。实际上，国际上有一个用于衡量辐射对生物体影响的单位，称为希沃特（简称Sv）。为了更形象地理解电离辐射的影响，有人提出了香蕉当量”概念，将各种行为带来的辐射剂量转化为相当于吃了多少根香蕉。

例如，一根香蕉带来的辐射剂量约为0.1微希沃特。一次机场X光安检门所受的辐射剂量小于0.2微希沃特，相当于吃了两根香蕉。接下来，我们来罗列更多日常行为中的“香蕉当量”。

了解各种活动带来的电离辐射剂量后，我们再来讨论一个可能引起人们关注的问题：住在核电站周围，核辐射对健康是否有影响？实际上，如果你住电站周围，你完全不必担心核电站释放的辐射会影响健康。例如，2019年的一项研究表明，在海阳核电站周围0—5公里范围内（这一范围经非常靠近核电站了），核电站的辐射导致的人均年有效剂量为95.8μSv，相当于每年吃了958根香蕉。相对于前述数据，我们每年从环境中接收背景辐射相当于每年摄入4万根香蕉。

写景物的英语作文

Gulangyu — A fairyland in the world

Gulangyu is a *** all island of Xiamen. It’s like a garden on the water. Cars and buses are not allowed to drive there, which makes the island so quiet that music played on the piano and violin can be heard.

Here the sky and the sea clearly meet on the horizon. When standing at the top of the Sunshine Rock, you can see much of the landscape of Xiamen, and when standing at its foot, you can gaze at the beautiful garden that surrounds it.

Gulangyu produces bananas, coconuts, sugar cane and so on. The people here, warm, simple and hardworking, are making every effort to make the island more beautiful and they hope to wele more visitors in the future.

Such is Gulangyu, a beautiful and inviting island, where a warm wele awaits.

要一篇100子的写景色的英语小短文

任何景都可以吗？那我就介绍一下田园的景了My hometown is a beautiful village which is lying in the is the best creation of our great nature. Here you can see and enjoy a very amazing scene that youve never and flowers are the main roles of the with different colours can be seen everywhere---red,yellow,white,you will get faint to count how many kinds of colours are grow together to form a huge flower-bed with a *** all but clean river flowing through are getting their colours summer and spring theyre beautiful it turns to aumtum,they put on yellow,and in winter,they change the clothe of white. 字数可能多了一点，你取舍的参考一下吧

一篇关于风景的英语作文

1. Beautiful homelandA into my village, saw the ground covered with grass, is so tender and beautiful. Scan, like a green brocade. A breeze, grass, like we nodded approvingly at to wele us. Modest willow with it that slightness green girls arm, and gently pat on the front of our house is a beautiful garden, the garden of lush trees and beautiful scenery, grass overgrown with all sorts of flowers and plants, like a big flower-bed, full of pigment beside a pool, pool of colorful fish swim to swim, clever! Our house is behind the building, neat flickering among the people, and street, car, a home is beautiful! We love our home！（。

美丽的家乡一进我的村庄，看见地上覆盖着青草，如此温柔和美丽。

扫描，像一个绿色的织锦。

一阵微风，草，就像我们频频点头来欢迎我们。

这刀适度柳绿色姑娘的胳膊，轻轻拍打岸边。

在我们的房子前面有一个漂亮的花园，花园里的绿树和美丽的风景，草长满了各种各样的花草，像个大花坛，充满了颜料在游泳池、水池的五彩缤纷的鱼游来游去，聪明！我们的房子是背后的建筑，整洁的闪烁在众民中也是如此，街道、汽车、爆破。

我们的家是美丽的！我们爱我们的家园）2. Hometown in autumnThe autumn is the hometown of neither too hot nor too cold, although the air is fresh, leaves no previous also started withered, but one thing more and more mature, it is rice. Out of the door, scan, the first saw is rice, so much rice large full yes. Rice in imperceptible in gradually grow autumn is the hometown of golden, basically everything is yellow. The autumn, the hometown of rice mature into yellow. Hometown of autumn, withered grass became yellow. Hometown of autumn, the leaves on the trees grew up, r. will wither soon. In the field, and *** all roadside, entailed, no matter what the green plant basically are withered. Especially the grass, it is waiting for the ing of spring, again to add a green is a season of harvest in autumn, peach on the big peaches and pears on the big pear, JuShu within large orange on the rice field, and mature etc can eat lots of fruits are wind was so soft, the water is so fluent, the sky is so blue, people are so active. The autumn is the hometown, and spring. The autumn of home town than in winter to much warmer than the autumn, the home more to cool in , the hometown of autumn, you how soft！（家乡的秋天是不冷不热的，虽然空气是没有以前新鲜，树叶也开始凋谢了，但是有一样东西越来越成熟了——那就是水稻。

走出家门，放眼望去，第一个看见的就是水稻了，那么多水稻一大片一大片满是的。

水稻在人们的不知不觉中渐渐地长成熟了。

家乡的秋天是金黄色的，基本上一切事物都是黄色的。

家乡的秋天，水稻成熟了变成了黄色的。

家乡的秋天，小草枯萎了变成了黄色。

家乡的秋天，树上的叶子也渐渐地黄了起来，不久后就会凋谢的。

田野里、泥路上、小路边，不管是什么绿的植物基本上都要枯萎了。

尤其是小草，它正在等待着春天的来临，再给世界添加一份绿色。

家乡的秋天是一个丰收的季节，桃树上结起了大桃子，梨树上结起了大梨子，橘树上结起硕大的橘子，田野里的水稻也成熟了等许许多多的可以吃的果实都成熟了。

风是那么的柔，水是那么的流畅，天空是那么的蓝，人们是那么的活跃。

家乡的秋天就是这样，与春天不相上下。

家乡的秋天比家乡的冬天要暖和得多，家乡的秋天更比夏天要凉爽。

啊，家乡的秋天，你是多么得柔和！）

求一篇描写景物的英语文章

A sudden, late winter, spring has quietly e to earth. Spring, are a better season, the season is full of poetry; spring, but also means that a vibrant start. Since ancient times, poets like spring, praise spring, because spring scenic are everywhere in poetry can be. Ancient hundred stroll garden, see Yong Chun colorful poetry, flourish, dizzying randomly pick几朵slowly read Goods, one of unknowingly has intoxicated. ＂Ray of light overnight drop ten thousand silk, floating瓦碧Jiguang vary. Paeoniflorin love with the spring of tears, unable to Rosa Xiao sticks lying.＂ This is the Northern Song Dynasty poet Qin Guans ＂Spring.＂ Writing this poem spring after the rain. Look, after the rain garden, the morning mist the cage thin, green glazed tile Jingying, Chunguang beautiful; Paeoniflorin rain tears, tenderness Feelings, Rosaceae supine dendrite, beautiful charming. Here there is there is close-range vision, there is action there is quiet, affectionate attitude has randomly点染， irregular scattered. Thinking绵密poem, describe vivid, since with a fresh, Wanli charm, very open to love. ＂North Korea has e to Chambers songbird tree, red and green春上Fu Yuan-lin. Suddenly there is好诗Health fundus, syntactic arrangements have been hard to find.＂ This is the Song Dynasty poet, and Chen Yis ＂spring.＂ Writing this poem Zhijing spring morning. Ear surplus birds, head Manqing sticks, green red catching different Hanfu attractive. Poet, a few pens, a desire to drop the spring will be displayed at the screen readers, then, the poet simply ended pen, no longer describe spring, turn lyrical. Spring rich, inspiration suddenly Health, but they have made use of treacherous poet ＂has a rare find,＂ subterfuge to lure readers to feel their own spring, the actual situation Aioi methods give the reader left a lot of imagination. ＂As days go far Head, Shuming the setting sun. Dogs know where the dog? Person line at the Mid-Levels.＂ This is the Southern Song Dynasty poet, Yang Wanlis ＂Spring.＂ Writing this poem of King spring evening. Xieyang Phi Cong trees, green space and access day, dogs欢叫，晚归people. This poem naturally apt often see Qiao Medium, Medium-Ping, see Qi, will bring readers a panoramic view of the Spring atmosphere, where there is wonderful landscape of Spring, there is the geous colors of Spring, there is the strong *** ell of Spring, there is春之声and Yuet , outside the meantime, open-minded people will enjoy singing. ＂Chunshui newborn milk Yanfei, Hors *** all tail to the flower head. Window with far almanac Heteropanax color, fish hook over Shannon near Rocky Stone.＂ This is the Tang Dynasty poet Li Hes ＂South Park.＂ South Parks spring, vibrant and full of charm. Chunshui newborn, before乳燕fly, honey bee child flowers stuffed fish hook over feeding, which are highly characteristic features of the spring, and the vision straight through the window into the study, people Shuxin nice, very happy. This poem vivid vivid, fresh flow of God is read to gas Yat-ching.转瞬间严冬已逝，春天已悄悄地来到人间。

春天，是美好的季节，是充满诗情的季节；春天，又意味着一个生机勃勃的开始。

自古以来，诗人喜爱春天，赞美春天，是因为春天景色宜人，处处皆可入诗。

漫步古诗百花园，只见咏春诗姹紫嫣红、争奇斗艳，令人目不暇接，随意采撷几朵，慢慢品读，不知不觉已陶醉其中。

“一夕轻雷落万丝，霁光浮瓦碧参差。

有情芍药含春泪，无力蔷薇卧晓枝。

”这是北宋诗人秦观的《春日》。

这首诗写雨后春景。

瞧，雨 *** 院，晨雾薄笼，碧瓦晶莹，春光明媚；芍药带雨含泪，脉脉含情，蔷薇静卧枝蔓，娇艳妩媚。

这里有近景有远景，有动有静，有情有姿，随意点染，参差错落。

全诗运思绵密，描摹传神，自具一种清新、婉丽的韵味，十分惹人喜爱。

“朝来庭树有鸣禽，红绿扶春上远林。

忽有好诗生眼底，安排句法已难寻。

”这是宋代诗人陈与义的《春日》。

这首诗写春天早晨之景。

耳盈鸟语，目满青枝，绿红相扶，异馥诱人。

诗人寥寥几笔，一幅春意欲滴的画面便展现在读者面前，然后，诗人索性止笔，不再描写春景，转而抒情。

春意浓郁，灵感忽生，但诡谲的诗人却用“已难寻”的遁词来诱使读者自己去感受春意，这种虚实相生的方法，给读者留下了很大的想象空间。

“远目随天去，斜阳着树明。

犬知何处吠？人在半山行。

”这是南宋诗人杨万里的《春日》。

这首诗写春天傍晚之景。

斜阳披丛树，绿地与天接，犬欢叫，人晚归。

这首诗自然贴切，常中见巧，平中见奇，将读者带进全景式的春之氛围，这里有春之境的美妙，有春之色的绚烂，有春之味的浓烈，有春之声的和悦，置身其间，人们会敞开胸襟，尽情欢歌。

“春水初生乳燕飞，黄蜂小尾扑花归。

窗含远色通书幌，鱼拥香钩近石矶。

”这是唐...

描写一个地方的景色英语作文（带翻译）

Beautiful sceneryDuring the summer vacation, my mother took me to the south of the Yangtze River touri *** good, the beautiful scenery, I still can not morning, I watch the sunrise on the Bank of the river, that river deep blue is blue eyes. Not for a moment, Water-day phase transfer line of golden light, the sky aglow. Clouds are sky, the sun seems to carry the burden of a longitudinal vertical upward, finally out of water, with a dazzling light, to open her eyes. At this time, as long as we raised his head can see the birds in the sky flowers also seems to be in the sun with the bright colors: orange, red, pink, purple·· · · · ·they were open to us *** this time, the golden Canna will water bearing on the blue river lining up, looks so sweet and charming, is really indulge in pleasures without stop. Look at it from a distance, like a blue scenery is so beautiful, so an indulge in pleasures without stop!江南美景暑假里，妈妈带我去江南旅游。

江南可美啦，那美丽的风景至今我还无法忘记。

一天早晨，我在江边观看日出，当时江水深蓝色好是蓝蓝的眸子。

不到一会，水天相接的交接线出现了金色的亮光，天空一片通红。

白云也被染红了。

天边，太阳好像负着重担似的一纵一纵往上升，最后终于跳出水面，射出一道道刺眼的光芒，使人睁不开眼睛。

此时，只要我们抬起头就可以看见雁群在天上自由的飞。

江边的鲜花似乎也被太阳染上了鲜艳的色彩：橘黄的、红的、粉红的、紫红的······它们竟相开放向我们露出灿烂的笑容。

这时，那金黄的美人蕉将的江水承托起蓝蓝的江水衬托起，显得那么甜静迷人，真令人流连忘返。

从远处看它，好似一条蓝蓝的绸带。

江南景色是那么美，那么令人流连忘返！

关于景色的英语作文

During their Duke careers, graduating seniors Gerald Oliver, Katie Mitchell and Ashley Joyce have helped improve race relations, Greek life, classroom honesty and other important aspects of campus work illustrates how many students are choosing to make a positive difference in their own munities, said Larry Moa, vice president for student affairs.＂Students are reclaiming their social life in a much broader way,＂ Moa said. ＂Its happening in key pockets around campus.＂Several student-led groups have emerged in the aftermath of the Womens Initiative, said Donna Lisker, director of the Womens Center. Active Minds encourages students to think about mental illness. Devil Dating aims to improve the campus dating scene. A womens mentoring group links students with faculty and alumni.＂These initiatives represent all different kinds of students who see some piece of the puzzle that looks familiar to them, and they decide to take this particular piece on,＂ Lisker said. ＂Thats been wonderful to see.＂Gerald OliverThe National Pan-Hellenic Council (NPHC) arrived on Dukes campus when Gerald Oliver was a sophomore. By his senior year, he was president of NPHC, the umbrella anization for the nine historically black fraternities and sororities, six of which are represented at the leader of a young anization, Oliver worked to strengthen NPHCs voice, establish its place in the Greek system and *** ooth out munication beeen Duke administrators and black Greeks. That entailed going to lots of meetings and speaking up, he said.＂I havent been involved with big stuff that makes the paper,＂ Oliver said. ＂I didnt anize a super program; it was more day-to-day things.＂Oliver, who is also a member of Campus Council, made time for weekly meetings of the Community Executive Council, where the presidents of the four Greek councils -- NPHC, the Interfraternity Council, the Inter-Greek Council and the Pan-Hellenic Association -- discussed such issues as housing, recruitment, hazing policies and munity service.＂The things that IFC and Pan-Hell do affect us, and the things we do affect them,＂ Oliver said. ＂We made a lot of effort in that group to make sure we were working together since our fates are tied.＂Fraternities and sororities have been viewed as self-segregating anizations, but Oliver said that black fraternities and sororities have helped lift up the black munity that historically has had a disadvantage in higher education.＂It would be inaccurate to say there is no color division,＂ said Oliver, a psychology major who is applying to business schools for the fall. ＂But just because the anizations serve different purposes doesnt mean they cant interact and understand each other.＂The student-run Center for Race Relations has helped open lines of munication by bringing together Olivers fraternity, Alpha Phi Alpha, and the almost all-white Kappa Alpha fraternity to discuss issues they previously hadnt had a venue to address.＂We had a lot of good conversations,＂ Oliver said, ＂but it doesnt mean much if nobody beyond the leaders buys into that.＂The diversity of Duke provides an opportunity for ethnic and cultural exchange that many students might not have had up to that point. When he returns to Duke over the years for homeing, he would like to see race relations remain a priority and more members involved in the discussions.＂As long as conversations like that continue to happen,＂ he said, ＂race relations on campus will get better.＂Katie MitchellThe Greek system still needs work, said Katie Mitchell, president of the Duke chapter of Delta Delta Delta sorority. But changes wont be easy to make because the Greek system is a microco *** of the larger world.＂The world is petitive; the world is exclusive; the world has standards that have little to do with who you are,＂ Mitchell , and the Tri-Delts, fed ahead alcohol-free casino night the Tri-Delts sponsored in November was open to everyone on campus. The party attracted a cross-section of the student body, raised money for charity and may bee a Tri-Delt tradition to help shrug off a reputation of the Womens Initiative report added ＂effortless perfection＂ to the campus lexicon, Mitchell gathered the 170 women in her chapter for a discussion about eating disorders.＂Talking about it is the first step,＂ she said. ＂We need to talk about our experiences and move past them.＂Mitchell believes that change can evolve through ＂ *** all things done with a good heart and good intentions.＂＂I ...

一段描写优美景物的英语小短文

SNOW At dusk,the weather became colder while the sky was gray,and the cold wind was blowing seemed that it was going to snow soon. A moment later,the snowflakes began to fall the land before my eyes was all white,like a beautiful it snowed more and more trees were all covered with white whole city became a silver world. The next morning,it stopped snowing and cleared up.I went into the far away,I saw a beautiful silver white world.A group of children were playing were throwing snowballs to each other,others were making a seemed to bring us warm and as it was,nobaby felt cold in the white world. I love snow,because it is pure brings us hope and vigour.

求写旅游景点的英语作文,80到100个单词就行了。
急要！

描写游玩西湖景点的作文 I have been to many interesting places in Yiwu,but I have not been to many other parts of China month I went to the West Lake with my family by three hours we got to we took a taxi to the West Lake. The scenery around the lake was very were many tall trees and beautiful people were walking around the lake and some people were boating on the lake. We played near the lake and enjoyed the beautiful of us lost ourselves in the beautiful it ran in the rain and we were all we were very a while the rain sky became very colourful. “How beautiful it is!”I said to the afternoon we went back home by train trip seemed very short,but my memory of the pleasant trip will last long....

我的家乡是一个很吸引人的地方，不信，便来我的家乡看一看吧！我们家乡的美丽，全是我们热爱家乡的结果。

所以我们要热爱自己的家乡的风土人情，还要保护大自然的景观，我的家乡在乾州火车站兔岩组，家乡的风景可好了，景色十分吸引人的注意，我都想请大家来我的家乡观光。

我的家乡有高大的树木，肥沃的土地，高耸入云的山峰，天上的白云飘来飘去，还有奔腾的大河流向天边。

人们在河边钓鱼，嬉戏。

我每天上学回家都在想：如果我也有一根钓鱼竿该多好啊！这样我就可以天天享受钓鱼的乐趣了。

不光如此，每天河边的景色都不同，每天的景色都充满生趣。

我爱我家乡的山水！我的家乡一年四季的景色都不同。

一到春天，春姑娘就给我的家乡带来了生趣，给人们带来了生的希望。

她穿过奔腾的河流，穿过肥沃的田地。

祛除了冬日的严寒，使草儿从土里钻了出来，给大地披上了一件绿色的花衣。

使树梢长出了嫩芽，给大树披上了绿衬衫。

一年四季中，我唯爱春天。