1.英語科學小知識
1. bat an eye (show surprise, fear, or interest) 眨一下眼睛（表示驚訝、恐懼等）該成語通常用于否定句中，表示不露聲色.例：Tom told his story without batting an eye, although not a world of it was true.雖然沒有一句話是真的，湯姆編造故事卻面不改色.2. be all fingers and thumbs做事笨手笨腳例：He could not undo the string of the parcel ---- she was all fingers and thumbs.他怎么也解不開包袱上的繩子 ---- 真是笨手笨腳. 3. be born with a silver spoon in one's mouth (born with inherited privilege or wealth) 門第高貴；出生富豪[注] 銀具是富裕人家身份的象征之一，生在富貴人家的孩子多用銀匙 （silver spoon） 喂食.例：When does she know about hardship ---- she was born with a silver spoon in her mouth.她根本就不知道什么叫艱難 ---- 他出生在富貴人家.4. be in sth. up to one's neck (be very much and very seriously involved in) 深陷于.中例：She said she knew nothing about the robbery, but I'm sure she's in it up to her neck.她說她對這起搶劫案一無所知，不過我敢肯定她深深卷入其中.5. bite the hand that feeds one (be very ungrateful) 忘恩負義；以怨報德例：She felt that her protégé had bitten the hand that fed him by making unkind remarks about her in public.她覺得她的被保護人在公開場合講有損她的話是忘恩負義.6. bite off sb's nose (scold sb. severely; disagree with sb. in a bad manner) 氣勢洶洶地回答某人；聲色俱厲地訓斥某人[注] 也作snap off sb's head.該成語最早出現(xiàn)于16世紀.到了18世紀，有人用動詞 snap 替換該成語中的 bite 一詞.例：She bites off his nose on the faintest provocation.不管有事無事，她動不動就聲色俱厲地訓斥他.7. break the back of sth. (complete the heaviest or most difficult part of sth. hurt the most import part) 門第高貴；出生富豪[注] 銀具是富裕人家身份的象征之一，生在富貴人家的孩子多用銀匙 （silver spoon） 喂食.同義語有be born in （或to） the pruple; be radled in purple.例：Now that you've broken the back of the job, have a rest.你既然已經(jīng)完成了這項工作的主要部分，那就休息一下吧.8. bury one's head in the sand (deliberately ignore sth. that is obvious but unpleasant) 逃避現(xiàn)實；拒絕承認現(xiàn)實[注] 鴕鳥遇到危險時，總是把頭埋在沙里，自己看不見敵人就認為敵人也看不見自己，由此產(chǎn)生這一成語.例：He had suspected for some months that his son was taking drugs, but he had buried his head in the sand and refused to admit it, even to himself.幾個月來，他一直懷疑自己的兒子在吸毒，但他卻采取鴕鳥政策，拒絕承認現(xiàn)實. 9. carry a chip on one's shoulder (have rather an aggressive manner, as if always expecting to be insulted, ill-treated) 以挑釁的態(tài)度出現(xiàn)；像要跟人家打架似的[注] 19世紀中葉美國中西部的居民尋釁打架時，常把一塊碎木片（chip）放在肩膀上，誰要與他打架就得先擊落這塊木片.例：He is very difficult to deal with ---- he's always carried a chip on his shoulder about his lack of education.他這個人很難對付----由于沒能受到良好的教育，他整天都像要跟人家打架似的.10. chance one's arm (do sth. risky; take a risk) 冒險一試；碰碰運氣[注] 該成語原出自拳擊運動，后被裁縫吸收為行話；從1890年起，又被士兵們用來指“冒降級的險”例：The manager decided to chance his arms and try to write a book on economy.這個經(jīng)理決定碰碰運氣，試著寫一本關(guān)于經(jīng)濟的書.。
2.關(guān)于科普知識的英語作文200字
As we know, Air pllution is bad for our health.We have very
serious air pollution around, became the main environment problems in
our city.Air pollution has seriously affected our lives.
In order
to protect the air environment in the city, to protect our health,We
must do the following.First of all,We can use clean fuel When we drive
or take the bus.Of course,We can also ride a bicycle to replace
them.Second,We have to plant more trees, let us more fresh air.Of
course, there are many ways to protect environment.
I believe, as long as we all work together,We'll have a clean their homes.
3.科普英語的內(nèi)容
暗銀河系的發(fā)現(xiàn)及其科學意義 In addition to conventional galaxies, the universe contains very dim galaxies that until recently went unnoticed by astronomers. Possibly as numerous as conventional galaxies, these galaxies have the same general shape and even the same approximate number of stars as a common type of conventional galaxy, the spiral, but tend to be much larger. Because these galaxies 'mass is spread out over larger areas, they have far fewer stars per unit volume than do conventional galaxies. Apparently these low-surface-brightness galaxies, as they are called, take much longer than conventional galaxies to condense their primordial gas and convert it to stars—that is, they evolve much more slowly. These galaxies may constitute an answer to the long-standing puzzle of the missingbaryonic mass in the universe. Baryons—subatomic particles亞原子粒子 that are generally protons or neutrons—are the source of stellar, and therefore galactic, luminosity, and so their numbers can be estimated based on how luminous galaxies are. However, the amount of helium in the universe, as measured by spectroscopy光譜學， suggests that there are far more baryons in the universe than estimates based on galactic luminosity indicate. Astronomers have long speculated that the missing baryonic mass might eventuallybe discovered in intergalactic space星系際的空間 or as some large population of galaxies that are difficult to detect. -------------------------------另類海豹哺乳方式與眾不同 Until recently, zoologists believed that all species of phocids (true seals), a pinnipped family, use a different maternal strategy than do otariids (fur seals andsea lions), another pinniped family. Mother otariids use a foraging strategy. They acquire moderate energy stores in the form of blubber before arriving at breeding sites and then fast for 5 to 11 days after birth. Throughout the rest of the lactation (milk production) period, which lasts from 4 months to 3 years depending on the species, mother otariids alternately forage at sea, where they replenish their fat stores, and nurse their young at breeding sites. Zoologists had assumed that females of all phocids species, by contrast,use a fasting strategy in which mother phocids, having accumulated large energy stores before they arrive at breeding sites, fast throughout the entire lactation period, which lasts from 4 to 50 days depending on the species. However, recent studies onharbor seals, a phocids species, found that lactating females commenced foragingapproximately 6 days after giving birth and on average made 7 foraging trips during the remainder of their 24-day lactation period. The maternal strategy evolved by harbor seals may have to do with their small size and the large proportion of their fat stores depleted in lactation. Harbor seals are small compared with other phocids species such as grey seals, all of which are known to fast for the entire lactation period. Studies show that mother seals of these species use respectively 84 percent, 58 percent, and 33 percent of their fat stores during lactation. By comparison, harbor seals use 80 percent of their fat stores in just the first 19 days of lactation, even though they occasionally feed during this period. Since such a large proportion of their fat stores is exhausted despite feeding, mother harbor seals clearly cannot support all of lactation using only energy stored before giving birth. Though smallerthan many other phocids, harbor seals are similar in size to most otariids. In addition,there is already some evidence suggesting that the ringed seal, a phocids species thatis similar in size to the harbor seal, may also use a maternal foraging strategy.------------------------------pheromones是什么東東，是不是該劃為odorantThere is no consensus among researchers regarding what qualifies a substance as a pheromone. While most agree on a basic definition of pheromones as chemicals released by one individual of a species which, when detected by another individual of the same species, elicit a specific behavioral or physiological response, some researchers also specify that the response to pheromones must be unconscious. In addition, the distinctionbetween pheromones and odorants—chemicals that are consciously detected as odors---can be blurry, and some researchers classify pheromones as atype of odorant. Evidence that pheromone responses may not involve conscious odor perception comes from the finding that in many species, pheromones are processed by the vomeronasal (or accessory olfactory) system, which uses a special structure in the nose, the vomeronasal organ (VNO),。
4.英語科普小知識,急
要想學好英語不止才有這幾個方面，還要掌握一些重要的知識。
例如：英語中的“八大時態(tài)”。“八大時態(tài)”分別有：一般將來時，一般現(xiàn)在時，一般過去時，現(xiàn)在進行時，現(xiàn)在完成時，過去將來時，過去完成時和過去進行時。
當然英語的“八大時態(tài)”也很重要，它也是學好英語的最基本。以下是“八大時態(tài)”的簡介。
一、一般時態(tài) 1、一般現(xiàn)在時 （1）一般現(xiàn)在時表示沒有時限的持久存在的動作或狀態(tài)或現(xiàn)階段反復發(fā)生的動作或狀態(tài)，常和副詞 usually,often,always sometimes, regularly,near,occasionally,every year, every week 等連用。 （2）在由after,until,before,once,when,even if,in case,as long as,as soon as,the moment 以及 if,unless 等引導的時間狀語從句或條件狀語從句中，通常用一般現(xiàn)在時代替將來時。
（3）某些表示起始的動詞，可用一般現(xiàn)在時表示按規(guī)定、計劃或安排要發(fā)生的動作，這類動詞有：be,go,come,start,depart,arrive,begin,leave 等。（4）在由why,what,where,whoever,who,that,as 等引導的從句中，也常用一般現(xiàn)在時代替將來時2.一般過去時 （1）表示過去某一特定時間所發(fā)生的、可完成的動作或狀態(tài)，常與表示確切過去時間的詞、短語或從句連用。
（2）表示過去習慣性動作。（注意與be used to doing短語的區(qū)別） 3.一般將來時 1）表示將來打算進行或期待發(fā)生的動作或狀態(tài)。
2）幾種替代形式： 1)be going to +v在口語中廣泛使用，表示準備做或?qū)l(fā)生的事情2)be to +v表示計劃安排要做的事，具有“必要”的強制性意義。3)be about to +v表示即將發(fā)生的事情。
4)be due to +v表示預先確定了的事， 必定發(fā)生的事。5)be on the point/verge of +v – ing 強調(diào)即將發(fā)生的某種事態(tài)。
. 二、進行時態(tài) 1.現(xiàn)在進行時 （1）表示現(xiàn)在正在進行的動作，常與now,right now,at the mother,for the time being,for the present等連用。（2）表示現(xiàn)階段經(jīng)常發(fā)生的動作， 常與always,continually,forever,constantly等連用。
（3）表示根據(jù)計劃或安排在最近要進行的事情。具有這種語法功能的動詞僅限于過渡性動詞。
即表示從一個狀態(tài)或位置轉(zhuǎn)移到另一個狀態(tài)或位置上去的動詞。常用的有：go,come,leave,start,arrive,return等。
（4）有些動詞不能用進行時，這是一類表示“感覺，感情，存在，從屬”等的動詞。如：see,hear,smell,taste,feel, notice,look,appear，（表示感覺的詞）；hate,love,fear,like,want,wish,prefer,refuse, forgive（表示感情的動詞）；be,exist,remain,stay,obtain（表示存在狀態(tài)的動詞）；have,possess, own,contain,belong,consist of,form（表示占有與從屬的動詞）；understand,know,believe,think,doubt,forget,remember （表示思考理解的動詞）。
但是如果它們詞義改變，便也可用進行時態(tài)2. 過去進行時 過去進行時表示一個過去的動作發(fā)生時或發(fā)生后，另一個過去的動作正在進行，或表示過去反復的習慣，常與always,continually,constantly等動詞連用。3. 將來進行時 將來進行時主要表示將來某一時刻正在進行的動作，或表示要在將來某一時刻開始，并繼續(xù)下去的動作。
常用來表示禮貌的詢問、請求等4. 完成進行時 （現(xiàn)在、過去、將來）完成進行時是（現(xiàn)在、過去、將來）完成時的強調(diào)形式，將放在完成時態(tài)部分講述。 三、完成時態(tài) 完成時態(tài)通常表示已完成或從事的動作。
它可分為： 1. 現(xiàn)在完成時 （1）現(xiàn)在完成時用來表示對目前狀況仍有影響的，剛剛完成的動作（常與yet,already,just連用），或者過去某一時刻發(fā)生的，持續(xù)到現(xiàn)在的情況（常與for,since連用）。（2）常與現(xiàn)在完成時連用的時間狀語有：since, for, during, over等引導出的短語；副詞already, yet, just, ever, now, before, often, lately, recently等；狀語詞組this week (morning, month, year), so far, up to now, many times, up to the present等 （3）完成時態(tài)可用在下列結(jié)構(gòu)中：This (That, It) is (was) the first (second…) time +定語從句；This (That, It) is (was) the only (last) + n +定語從句；This (That, It) is (was) +形容詞最高級+ n +定語從句。
如果主句的謂語動詞是一般現(xiàn)在時，從句的謂語動詞通常用現(xiàn)在完成時；如果主句謂語動詞是一般過去時，從句謂語動詞通常用過去完成時。2. 過去完成時 （1）表示過去某時間前已經(jīng)發(fā)生的動作或情況，這個過去的時間可以用by,before等介詞短語或一個時間狀語從句來表示；或者表示一個動作在另一個過去動作之前已經(jīng)完成。
（2）動詞expect, hope, mean, intend, plan, suppose, wish, want, desire等用過去完成時，表示過去的希望、預期、意圖或愿望等沒有實現(xiàn)。例如： I had meant to take a good holiday this year, but I wasn't able to get away. 另外兩種表示“過去想做而未做的事”的表達方式是： 1)was / were + to have done sth, (3)過去完成時常用于以下固定句型： 1)hardly, scarcely, barely + 過去完成時+ when + 過去時。
2)no sooner +過去完成時+ than +過去時。3)by (the end of ) +過去時間，主句中謂語動詞用過去完成時。
3. 將來完成時 將來完成時表示在將來某一時刻將完成或在另一個未來的動作發(fā)生之前已經(jīng)完成的動作；也可以用來表示一種猜測。常與將來完成時連用的時間狀語有： by (the time / the end of 。
5.英語科普小知識,急
Ever since they were first put on the market in the early 1990s, gentically mondified (GM， 轉(zhuǎn)基因) foods have been increasingly developed and marketed in many countries in the word,mainly on the basis of their promise to end the worldwide food crisis. But can GM technology solve world hunger problems? Even if it would ,is it the best solutiorr? Despite what it promiises,GM technology actually has not increased the production potential of any corp. In fact Studies show that the most crown GM croo. GM soybeans, has suffered reduced productivity. For instance, a report than analysed nearly two decades of research on mojor GM food crops shows that GM engineering has failed to significantly increase US crop production. Something else, however, has been on the rise, While GM seeds are expensive, GM companics tell farmers that they will make good profits by saving money on pesticides（殺蟲劑）. On the contrary, US government data show that GM crops in the US have produced an overall increase in pesticide use compared to traditional crops. “ The promise was that you could use less chemicals and boost production. But nether is true,” said Bill Christison, President of the US National Farm Coalition. At the same time, the authors of the book World Hunger: Twelve Myths argue that there actually is more than enough food in the world and that the hunger crisis is not caused by production, but by problems in food distribution and politics. These indeed deserve our efforts and money. Meanwhile, the rise in food prices results from the increased use of crops for fuel rather than food, according to a 2008 World Bank report. As a matter of fact ,scientists see better ways to feed the world. Another World Bank report concluded that GM crops have little to offer to the challenges of worldwide poverty and hunger, because better ways out are available, among which “green” farming is supposed to be the first choice.。
6.關(guān)于科普知識的英語作文200字
As we know, Air pllution is bad for our health.We have very
serious air pollution around, became the main environment problems in
our city.Air pollution has seriously affected our lives.
In order
to protect the air environment in the city, to protect our health,We
must do the following.First of all,We can use clean fuel When we drive
or take the bus.Of course,We can also ride a bicycle to replace
them.Second,We have to plant more trees, let us more fresh air.Of
course, there are many ways to protect environment.
I believe, as long as we all work together,We'll have a clean their homes.
7.小學科普版英語總匯
一一一一。
.短語短語短語短語 go homego homego homego home回家回家回家回家 go to schoolgo to schoolgo to schoolgo to school去上學去上學去上學去上學 go swimminggo swimminggo swimminggo swimming去游泳去游泳去游泳去游泳 go fishinggo fishinggo fishinggo fishing去釣魚去釣魚去釣魚去釣魚 play basketballplay basketballplay basketballplay basketball打籃球打籃球打籃球打籃球 play footballplay footballplay footballplay football踢足球踢足球踢足球踢足球 play a gameplay a gameplay a gameplay a game做游戲做游戲做游戲做游戲 play the guitarplay the guitarplay the guitarplay the guitar彈彈彈彈吉它吉它吉它吉它 play the pianoplay the pianoplay the pianoplay the piano彈鋼琴彈鋼琴彈鋼琴彈鋼琴 read a bookread a bookread a bookread a book看書看書看書看書，，，，讀書讀書讀書讀書 read a letterread a letterread a letterread a letter看信看信看信看信，，，，讀信讀信讀信讀信 write a letterwrite a letterwrite a letterwrite a letter寫信寫信寫信寫信 listen to the teacherlisten to the teacherlisten to the teacherlisten to the teacher聽老師說聽老師說聽老師說聽老師說 listen to melisten to melisten to melisten to me聽我說聽我說聽我說聽我說 listen to the radiolisten to the radiolisten to the radiolisten to the radio聽聽聽聽收音機收音機收音機收音機 watch TVwatch TVwatch TVwatch TV看電視看電視看電視看電視 wash your facewash your facewash your facewash your face洗你的臉洗你的臉洗你的臉洗你的臉 wash your handswash your handswash your handswash your hands洗你的手洗你的手洗你的手洗你的手 sing a songsing a songsing a songsing a song唱歌唱歌唱歌唱歌 do my homeworkdo my homeworkdo my homeworkdo my homework做家庭作業(yè)做家庭作業(yè)做家庭作業(yè)做家庭作業(yè) clean the classroomclean the classroomclean the classroomclean the classroom打掃教室打掃教室打掃教室打掃教室 具體答案。
8.小學生科普知識
1.以下海洋中，屬于我國的內(nèi)海的是（ ） A.渤海 B.黃海 C.東海 D.南海 2. 我國自1999年至今，已經(jīng)進行了6次宇宙飛船飛行實驗。
2003年和2005年分別進行了兩次載真人飛行實驗。我國的這項航天計劃被命名為（） A.長征 B.神舟 C.東方紅 3.海水為什么看上去是藍色的（ ） A.藍色是海水的固有色 B.海水吸收的藍色光多 C.海水反射的藍色光多 4.我國石油資源比較短缺，有的科學家稱可以把我國豐富的煤炭資源經(jīng)過加工變成油，這就是“煤變油”計劃，你相信這是真的嗎？（ ） A.是真的 B.不是真的 5. 煮餃子的時候，餃子會浮上來，這是因為（ ） A.餃子本來就比水輕 B.翻滾的熱水把餃子沖上來的 C.餃子受熱后體內(nèi)氣體膨脹 6. 把一個生雞蛋和一個熟雞蛋放在桌子上轉(zhuǎn)，哪個轉(zhuǎn)得快？（ ） A.生雞蛋 B.熟雞蛋 7. 小狗經(jīng)常伸出舌頭直喘氣，這是因為（ ） A.小狗靠舌頭散熱 B.小狗太累需要呼吸 8. 地球上最大的淡水資源寶庫是（ ） A.南北極的冰川 B.地下水 C.陸地上的江河湖泊9. 一個完整的計算機系統(tǒng)包括（ ） A.計算機及其外部設(shè)備 B.主機、鍵盤、顯示器 C.硬件系統(tǒng)與軟件系統(tǒng) 10.計算機病毒是指（ ） A.帶細菌的磁盤 B.已損壞的磁盤 C.具有破壞性的特制程序 11.預防非典最有效的預防措施是（ ） A.露天場所戴口罩 B.生活、工作場所通風 C.使用空調(diào)保證室內(nèi)恒溫 12.發(fā)生日食是由于（ ） A.地球擋在太陽與月亮之間 B.月亮擋在地球與太陽之間 C.太陽擋在地球和月亮之間 13.哈雷彗星的回歸周期是（ ） A.70年 B.76年 C.75年 14.1969年7月12日，首次載人登上月球的宇宙飛船是（ ） A.阿波羅11號 B.阿波羅10號 C.阿波羅12號 15.恐龍生活在（ ） A.古生代 B.中生代 C.新生代 16.為什么在運送衛(wèi)星上天時，大多數(shù)火箭要向東發(fā)射？（ ） A.因為東方的陽光充足 B.因為東邊的風速較小 C.因為可以利用地球自轉(zhuǎn)的初速度 17.家用電器停止使用而不切斷電源時，處于待機狀態(tài)，這時家用電器耗電嗎 ？ （ ） A.不耗電 B.耗電 C.不一定耗電 18.地球上最熱的地方在_________附近。
（ ） A.赤道 B.南回歸線 C.北回歸線 19.地球表面（包括地表以上一定高度和地表以下一定深度的范圍），生活著150多萬種動物、30多萬種植物。所有生物相互影響，生物與環(huán)境相互作用，形成了一個稱為（ ）的大系統(tǒng)。
A.大自然 B.生物圈 C.地球圈 20.都說水火不相容，可是你知道嗎？當水結(jié)成冰后，只要我們開動腦筋，就可以用冰來取火。你認為以下哪個方法是可行的？ （ ） A. 把冰當作鏡子，利用透光聚焦的原理 B.把兩塊冰猛烈相撞，產(chǎn)生火花 C.利用鉆木取火的原理答案：1.以下海洋中，屬于我國的內(nèi)海的是（a ） A.渤海 B.黃海 C.東海 D.南海 2. 我國自1999年至今，已經(jīng)進行了6次宇宙飛船飛行實驗。
2003年和2005年分別進行了兩次載真人飛行實驗。我國的這項航天計劃被命名為（b ） A.長征 B.神舟 C.東方紅 3.海水為什么看上去是藍色的（ c） A.藍色是海水的固有色 B.海水吸收的藍色光多 C.海水反射的藍色光多 4.我國石油資源比較短缺，有的科學家稱可以把我國豐富的煤炭資源經(jīng)過加工變成油，這就是“煤變油”計劃，你相信這是真的嗎？（ a） A.是真的 B.不是真的 5. 煮餃子的時候，餃子會浮上來，這是因為（ b） A.餃子本來就比水輕 B.翻滾的熱水把餃子沖上來的 C.餃子受熱后體內(nèi)氣體膨脹 6. 把一個生雞蛋和一個熟雞蛋放在桌子上轉(zhuǎn)，哪個轉(zhuǎn)得快？（ b） A.生雞蛋 B.熟雞蛋 7. 小狗經(jīng)常伸出舌頭直喘氣，這是因為（ a） A.小狗靠舌頭散熱 B.小狗太累需要呼吸 8. 地球上最大的淡水資源寶庫是（a ） A.南北極的冰川 B.地下水 C.陸地上的江河湖泊9. 一個完整的計算機系統(tǒng)包括（c ） A.計算機及其外部設(shè)備 B.主機、鍵盤、顯示器 C.硬件系統(tǒng)與軟件系統(tǒng) 10.計算機病毒是指（c ） A.帶細菌的磁盤 B.已損壞的磁盤 C.具有破壞性的特制程序 11.預防非典最有效的預防措施是（b ） A.露天場所戴口罩 B.生活、工作場所通風 C.使用空調(diào)保證室內(nèi)恒溫 12.發(fā)生日食是由于（ b） A.地球擋在太陽與月亮之間 B.月亮擋在地球與太陽之間 C.太陽擋在地球和月亮之間 13.哈雷彗星的回歸周期是（c b ） A.70年 B.76年 C.75年 14.1969年7月12日，首次載人登上月球的宇宙飛船是（ A） A.阿波羅11號 B.阿波羅10號 C.阿波羅12號 15.恐龍生活在（B ） A.古生代 B.中生代 C.新生代 16.為什么在運送衛(wèi)星上天時，大多數(shù)火箭要向東發(fā)射？（ C） A.因為東方的陽光充足 B.因為東邊的風速較小 C.因為可以利用地球自轉(zhuǎn)的初速度 17.家用電器停止使用而不切斷電源時，處于待機狀態(tài)，這時家用電器耗電嗎 ？ （B ） A.不耗電 B.耗電 C.不一定耗電 18.地球上最熱的地方在_________附近。
（ A） A.赤道 B.南回歸線 C.北回歸線 19.地球表面（包括地表以上一定高度和地表以下一定深度的范圍），生活著150多萬種動物、30多萬種植物。所有生物相互影響，生物與環(huán)境相互作用，形成了一個稱為（ 自然界 ）的大系統(tǒng)。
A.大自然 B.生物圈 C.地球圈 20.都說水火不相容，可是你知道嗎？當水結(jié)成冰后，只要我們開動腦筋，就可以用冰來取火。你認為以下哪個方法是可行的？ （a ）。
9.有沒有科技的知識,要英文的
科技知識英文短文什么是清潔能源 Clean Energy Clean energies are forms of energy which do not pollute the air, the ground, or the sea.Clean energies include:Solar powerSolar power describes a number of methods of harnessing energy from the light of the Sun. It has been present in many traditional building methods for centuries, but has become of increasing interest in developed countries as the environmental costs and limited supply of other power sources such as fossil fuels are realized. It is already in widespread use where other supplies of power are absent such as in remote locations and in space.As the Earth orbits the Sun, it receives approximately 1,400 W / m2 of energy, as measured upon a surface kept normal (at a right angle) to the Sun (this number is referred to as the solar constant). Of the energy received, roughly 19% is absorbed by the atmosphere, while clouds on average reflect a further 35% of the total energy. The generally accepted standard is 1020 watts per square meter at sea level.After passing through the Earth's atmosphere, most of the sun's energy is in the form of visible and ultraviolet light. Plants use solar energy to create chemical energy through photosynthesis. We use this energy when we burn wood or fossil fuels or when we consume the plants as a source of food.Wind power Wind power is the kinetic energy of wind, or the extraction of this energy by wind turbines. This article deals mainly with the intricacies of large-scale deployment of wind turbines to generate electricity.Wave power Wave power refers to the capture of ocean surface wave energy to do useful work including electricity generation, desalination, and filling a reservoir with water. Wave power is a form of renewable energy. Though often co-mingled, wave power is physiologically distinct from the diurnal flux of tidal power and the steady gyre of ocean currents which are powered by the earth's rotation. Wave power generation is not a widely employed technology with only a few experimental sites in existence.Salinity gradient powerSalinity Gradient is a technology that takes advantage of the osmotic pressure differences between salt and fresh water.If we place a semipermeable membrane (like that in a reverse osmosis filter) between sealed bodies of salt water and fresh water, the fresh water will gradually travel through the filter by osmosis. By exploiting the pressure difference between these two bodies of water we can extract energy commensurate to the difference in pressure.Tidal power Tidal power is a means of electricity generation achieved by capturing the energy contained in moving water mass due to tides. Two types of tidal energy can be extracted: kinetic energy of currents due the tides and potential energy from the difference in height (or head) between high and low tides.Geothermal power Geothermal power is electricity generated by utilizing naturally occurring geological heat sources. It is a form of renewable energy.Some renewable energies are not clean energies - for example:Biofuels because they release NOX and particulates into the environment. Hydroelectric power because it destroys the river basin and has a negative effect on fish migration.。
