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2020年01月19日 05:45:32

0Cohesion-tension Theory0 Cohesion-tension TheoryAtmospheric pressure can support a column of water up to meters high. But plants can move water much higher; the sequoia tree can pump water to its very top more than 0 meters above the ground. Until the end of the nineteenth century, the movement of water in trees and other tall plants was a mystery. Some botanists hypothesized that the living cells of plants acted as pumps. But many experiments demonstrated that the stems of plants in which all the cells are killed can still move water to appreciable heights. Other explanations the movement of water in plants have been based on root pressure, a push on the water from the roots at the bottom of the plant. But root pressure is not nearly great enough to push water to the tops of tall trees. Furthermore, the conifers, which are among the tallest trees, have unusually low root pressures.If water is not pumped to the top of a tall tree, and if it is not pushed to the top of a tall tree, then we may ask how does it get there? According to the currently accepted cohesion-tension theory, water is pulled there. The pull on a rising column of water in a plant results from the evaporation of water at the top of the plant. As water is lost from the surface of the leaves, a negative pressure, or tension, is created. The evaporated water is replaced by water moving from inside the plant in unbroken columns that extend from the top of a plant to its roots. The same ces that create surface tension in any sample of water are responsible the maintenance of these unbroken columns of water. When water is confined in tubes of very small bore, the ces of cohesion (the attraction between water molecules) are so great that the strength of a column of water compares with the strength of a steel wire of the same diameter. This cohesive strength permits columns of water to be pulled to great heights without being broken.内聚压力理论大气压能够持米高的水柱,但植物可将水送得更高美洲红杉就能把水泵到地面以上0多米高的树顶直到19世纪末,水在树木和其它高大植物中的输送还是一个谜一些植物学家假定植物中的活细胞充当了水泵的角色但许多实验表明细胞都已死亡的植物茎干仍能将水输送到相当可观的高度对于植物中输送水的其它解释都基于根压--植物底端的根对水的推动但根压完全不足以将水推到树顶况且,最高树木中的松柏只有很低的根压如果水不是被泵到高树的树顶,也不是被推到树顶,那么我们会问:它是怎样到达树顶的呢?根据目前为人们所接受的内聚压力的理论,水是被拉到上面去的一株植物中作用于一个正在升高的水柱之上的拉力来自该植物顶部水的蒸发由于水从叶子表面丧失,一个负压力,或张力就得以产生蒸发出去的水被植物里流动的水代替这些水形成水柱从植物顶端一直延伸到根部在任何水样中造成表面张力的力持着这些不断的水柱当水被限制在内径很小的管道中时,内聚压力(水分子之间的相互吸引力)是如此之大以致一水柱的强度相当于一根直径相同的钢丝的强度这种内聚压力使得水柱被拉到非常高的地方而不会断裂 655黄岛开发区妇女医院做彩超B超价格The man is looking itA little boy came home with a five-dollar bill and said he found it."Are you sure it was lost?” asked his mother.""Sure,I ' m sure," said the little boy."I saw the man looking it." 895青岛比较贵打胎要多少钱因而这就是生活悖论的第一个极点:不要过于忙碌而忽略了生活的奇妙,不敬畏生活要虔诚地迎接每个黎明的到来,要抓住每个小时,不浪费珍贵的每一分钟The art of living is to know when to hold fast and when to let go. life is a paradox it enjoins us to cling to its many gifts even while it ordains their eventual relinquishment. The rabbis of old put it this way “A man comes to this world with his fist clenched, but when he dies, his hand is open.”Surely we ought to hold fast to life, it is wondrous, and full of a beauty that breaks through every pore of God’s own earth. We know that this is so, but all too often we recognize this truth only in our backward glance when we remember what was and then suddenly realize that it is no more.We remember a beauty that faded, a love that waned. But we remember with far greater pain that we did not see that beauty when it flowered, that we failed to respond with love when it was tendered.A recent experience re-taught me this truth. I was hospitalized following a severe heart attack and had been in intensive care several days. It was not a pleasant place.One morning, I had to have some additional tests. The required machines were located in a building at the opposite end of the hospital, so I had to be wheeled across the courtyard on a gurney.As we emerged from our , the sunlight hit me. That’s all there was to my experience. Just the light of the sun. and yet how beautiful it was — how warming, how sparkling, how brilliant!I looked to see whether anyone else relished the sun’s golden glow, but everyone was hurrying to and fro, most with eyes fixed on the ground. Then I remembered how often I, too, had been indifferent to the grandeur of each day, too preoccupied with petty and sometimes even mean concerns to respond to the splendor of it all.The insight gleaned from that experience is really as commonplace as was the experience itself life’s gifts are precious—but we are too heedless of them.Here then is the first pole of life’s paradoxical demands on us Never too busy the wonder and the awe of life. Be reverent bee each dawning day. Embrace each hour. Seize each golden minute.Hold fast to life … but not so fast that you cannot let go. This is the second side of life’s coin, the opposite pole of its paradox we must accept our losses, and learn how to let go. 8935把所有的鸡蛋放在一个篮子里,然后小心地看好它;要量入为出;最后一点,要有耐心,就像艾默生所言:“除了你自己没人能真正阻止你成功”The Road to SuccessIt is well that young men should begin at the beginning and occupy the most subordinate positions. Many of the leading businessmen of Pittsburgh had a serious responsibility thrust upon them at the very threshold of their career. They were introduced to the broom, and spent the first hours of their business lives sweeping out the office. I notice we have janitors and janitresses now in offices, and our young men untunately miss that salutary branch of business education. But if by chance the professional sweeper is absent any morning, the boy who has the genius of the future partner in him will not hesitate to try his hand at the broom. It does not hurt the newest comer to sweep out the office if necessary. I was one of those sweepers myself.Assuming that you have all obtained employment and are fairly started, my advice to you is “aim high”. I would not give a fig the young man who does not aly see himself the partner or the head of an important firm. Do not rest content a moment in your thoughts as head clerk, or eman, or general manager in any concern, no matter how extensive. Say to yourself, “My place is at the top.” Be king in your dreams.And here is the prime condition of success, the great secret concentrate your energy, thought, and capital exclusively upon the business in which you are engaged. Having begun in one line, resolve to fight it out on that line, to lead in it, adopt every improvement, have the best machinery, and know the most about it.The concerns which fail are those which have scattered their capital, which means that they have scattered their brains also. They have investments in this, or that, or the other, here there, and everywhere. “Don’t put all your eggs in one basket.” is all wrong. I tell you to “put all your eggs in one basket, and then watch that basket.” Look round you and take notice, men who do that not often fail. It is easy to watch and carry the one basket. It is trying to carry too many baskets that breaks most eggs in this country. He who carries three baskets must put one on his head, which is apt to tumble and trip him up. One fault of the American businessman is lack of concentration.To summarize what I have said aim the highest; never enter a bar room; do not touch liquor, or if at all only at meals; never speculate; never indorse beyond your surplus cash fund; make the firm’s interest yours; break orders always to save owners; concentrate; put all your eggs in one basket, and watch that basket; expenditure always within revenue; lastly, be not impatient, as Emerson says, “no one can cheat you out of ultimate success but yourselves.” 91崂山区哪个妇科疾病医院好

黄岛开发区中医医院在线咨询青岛哪个医院的妇科好实用口语:英美人圣诞超爱用的N个习语 -01- :: 来源:   圣诞刚刚过去,你收到礼物里么?节日里好朋友之间互相祝福圣诞快乐,除了你最常听到的那句Merry Christmas,英美人过圣诞最爱用的习语有哪些呢?这些习语背后又有什么样的故事?Ho Ho Ho!快来跟小编一起来脑补一下吧!  1. White Christmas  圣诞节来了,要是能放眼望到白茫茫的一片,那是再浪漫不过了很多小伙伴都盼着圣诞节下雪,如果你也一样的话,那就可以说:  We are hoping a white Christmas.  我们盼望过一个有雪的圣诞节  . There's no place like home the holidays  圣诞节在不少西方国家都是法定假日圣诞节来了,假期也来了上班族和学生党都放假了,大家会去哪儿过节呢?传统的圣诞节,也是家人团聚的节日,亲友之间会相互拜访,互送小礼物所以,圣诞节还是回家过最温馨!  There's no place like home the holidays.  外国版常回家看看,你懂哒~  3. Christmas comes but once a year  圣诞节总是充满了美食和礼物,大家借此表达祝福和关心但节日过后,小伙伴们又开始各自忙碌起来所以,Christmas comes but once a year (圣诞节每年只有一次),这句话就是在提醒各位,平日里也要且行且珍惜啊!  . Meet me under the mistletoe  槲寄生编成的花环是圣诞节的必备装饰在英国,有个有趣的习俗——站在槲寄生下的人不能拒绝亲吻,而在槲寄生下接吻的情侣将会幸福终生  美国作家华盛顿·欧文(Washington Irving)曾在他的书中记载了英国的这一习俗,“–the young men have the privilege of kissing the girls under it, plucking each time a berry from the bush. When the berries are all plucked the privilege ceases.” 如果一对帅锅美女在槲寄生下相遇,帅锅可以吻美女,并随即摘走槲寄生的一颗浆果当所有的浆果都被摘光之后,亲吻特权就此消失如果他们是情侣,槲寄生也寓意着两人能够白头偕老  5. Ho Ho Ho!  吼~ 吼~ 吼~ 听着耳熟么?胖胖的圣诞老人会在平安夜钻进烟囱里,为乖孩纸们送上圣诞大礼圣诞老人的笑声也成了很多人模仿的对象模仿时最好做双手捧腹状,这样才会更形象!  6. Trim the tree  英文里trim有修剪的意思圣诞节里trim the tree,指的是“装点圣诞树”,在圣诞树上挂上小亮灯,还有各式各样的装饰品,这才有气氛呐!(1世纪) 口语微笑吧!谁都懂得它意味着什么;它价值连城却不花一文The thing that goes the farthest toward making life worthwhile,That costs the least and does the most, is just a pleasant smile.The smile that bubbles from the heart that loves its fellow men,Will drive away the clouds of gloom and coax the Sun again.It'sfull of worth and goodness, too, with manly kindness blent;It’s worth a million dollars, and it doesn’t cost a cent.There is no room sadness when we see a cheery smile;It always has the same good look; it’s never out of style;It nerves us on to try again when failure makes us blue;The dimples of encouragement are good me and you.It pays the highest interest — it is merely lent;It’s worth a million dollars, and it doesn’t cost a cent.A smile comes very easy — you can wrinkle up with cheer,A hundred times bee you can squeeze out a salty tear;It ripples out, moreover, to the heartstrings that will tug,And always leaves an echo that is very like a hug.So, smile away! Folks understand what by a smile is meant;It’s worth a million dollars, and it doesn’t cost a cent. 385胶南市妇女医院治疗妇科炎症好吗实用口语:如何用英语跟老外商讨保险业务 -- ::8 来源: 1. 要求对方投保全险You are requested to make arrangement to effect the insurance of AAR against the goods of our order No. 358 0,000 Yuan on our with the Shanghai Insurance Company. 要求对方将大型货品投保仓到仓险We request you cover a warehouse to warehouse insurance 500,000 Yuan on large electronic computers in transit from our warehouse to New York port3. 要求增加保费 an amount like this, it is impossible us to get both the hull and machinery insured. Theree we suggest that you increase the premium. 函询对方是否愿意接受全险As these goods are to be purchased on CIF basis, we would like to be inmed whether you can accept the insurance them against all risks5. 在限定金额内,请对方直接投保Please let us know your premium at which you can take the insurance of AAR on these goods and arrange to insure urgently our without our reply if the amount is below 1,000 Yuan6. 要求对方负责投保全险We request you arrange to insure against all risks in ten cases of color TVs amounting to 0,000 Yuan shipped by MS Pacific leaving on August .7. 告知对方已依指示投保According to your instructions to insure, we have today taken out marine insurance 50,000 Yuan on your color TV shipment8. 要求为录像机投保Please declare off our open policy No.550 London on the -recorder in wooden cases amounting to £50,000 shipped by MS Pacific from Tianjin to London9. 通知对方已完成投保We are pleased to inm you that we have closed the insurance of AAR as shown in the insurance policy enclosed 0,000 Yuan on one hundred sets of computers according to your instructions to insure on AAR as usual.保费过高,要求更换公司We have heard the rate AAR insurance premium our large computers to New York is 1.50 Yuan per 0.00 Yuan. Please let us know immediately whether we can cover marine insurance elsewhere at a more reasonable rate. 回答对方该保险率为所有保险公司所通用We have found in your letter that you have an impression that the rate of 1.50 Yuan per 0.00 Yuan AAR insurance is too expensive. However we would like to inm you it is generally adopted by all the large underwriters here. 通知对方以一般条件投保全险As instructed in your fax, we have aly arranged insurance of AAR and TPND with reliable underwriters on ordinary terms and conditions 保险 业务 英语 口语青岛大学医学院附属医院怎么走

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