What is the Young’s Modulus of Silicon
无机非金属专业英语词汇
unit11
1.抗氧化性，，oxidation resistant、、resistance to oxidation
2.热等静压的氮化硅，，hot isostatically pressed silion nitride
3.substitution of nitrogen with oxygen in the crystal lattice在晶格中由氧取代淡
the charge storage medium 放置在电容器两电板间的材料用作储电介质
8、tiny chip capacitors with ceramic-metal sandwich structure
微型的片状电容器有陶瓷-金属三明治结构
9、a positive temperature coefficient of resistance
18、落后于 lay behind
19、独特的性质 Unique properties
20、许多争论 a great of controversy
21、区分 distinguish
22、根据 according to
23、真溶液 true solution
24、悬浮液 suspension
16、铝硅酸盐 aluminosilicate
17、锆英石 Zircon Products
18、莫来石 porzite
19、链状排列 catenation
20、长石 feldspar
21、角连接的硅氧四体Corner connection silicon oxygen described
4、hexagonal closed-packed structure 六角形密集结构
杂说练习题
一、文学常识1. 《红楼梦》的作者是谁？2. 《三国演义》中谁被称为“卧龙”？3. 《西游记》中唐僧师徒四人分别是谁？4. 《水浒传》中梁山好汉共有多少人？5. 《骆驼祥子》的作者是谁？二、文言文阅读1. 下列句子中，哪一句是出自《论语》？a. 己所不欲，勿施于人。
b. 学而时习之，不亦说乎？c. 三人行，必有我师焉。
d. 人无远虑，必有近忧。
2. 下列词语中，哪一个是出自《庄子》？a. 鹏程万里b. 神龙见首不见尾c. 朝三暮四d. 破釜沉舟3. 下列句子中，哪一句是出自《孟子》？a. 得道多助，失道寡助。
b. 非礼勿视，非礼勿听，非礼勿言，非礼勿动。
c. 人之初，性本善。
d. 己所不欲，勿施于人。
4. 下列词语中，哪一个是出自《诗经》？a. 桃之夭夭，灼灼其华。
b. 春风得意马蹄疾，一日看尽长安花。
c. 人生得意须尽欢，莫使金樽空对月。
d. 床前明月光，疑是地上霜。
三、现代文阅读1. 下列文章中，哪一篇文章是鲁迅的作品？a. 《背影》b. 《荷塘月色》c. 《故乡》d. 《背影》2. 下列词语中，哪一个是出自朱自清的作品？a. 美不胜收b. 烟花三月下扬州c. 水天一色d. 风花雪月3. 下列句子中，哪一句是出自茅盾的作品？a. 世间万物皆有毒，唯有爱不可挡。
b. 人生如梦，岁月如歌。
c. 人生自古谁无死，留取丹心照汗青。
d. 人生得意须尽欢，莫使金樽空对月。
4. 下列词语中，哪一个是出自巴金的作品？a. 美不胜收b. 烟花三月下扬州c. 水天一色d. 风花雪月四、诗词鉴赏1. 下列诗句中，哪一句是出自唐代诗人杜甫的作品？a. 春风得意马蹄疾，一日看尽长安花。
b. 人生得意须尽欢，莫使金樽空对月。
c. 会当凌绝顶，一览众山小。
d. 床前明月光，疑是地上霜。
2. 下列诗句中，哪一句是出自宋代诗人苏轼的作品？a. 春风得意马蹄疾，一日看尽长安花。
b. 人生得意须尽欢，莫使金樽空对月。
c. 会当凌绝顶，一览众山小。
泸州2024年10版小学4年级下册第九次英语第4单元暑期作业
泸州2024年10版小学4年级下册英语第4单元暑期作业考试时间：100分钟（总分:120）B卷考试人：_________题号一二三总分得分一、选择题(共计20题，共40分)1、What is the main source of light for the planets in our Solar System?A. StarsB. The MoonC. The SunD. Galaxies2、How many letters are in the English alphabet?A. 24B. 25C. 26D. 273、What is the name of the famous ancient city in Greece?A. AthensB. CorinthC. DelphiD. All of the above4、选择题：What is the opposite of young?A. OldB. NewC. FreshD. Modern5、What do we call the tool used for measuring temperature?A. ThermometerB. BarometerC. RulerD. Stopwatch6、What is the name of the protective layer of gases surrounding Earth?A. AtmosphereB. BiosphereC. HydrosphereD. Lithosphere7、What do we call the study of human behavior?A. PsychologyB. SociologyC. AnthropologyD. Psychiatry8、选择题：What can you find in a library?A. FoodB. BooksC. ClothesD. Toys9、What do you call a young owl?A. OwletB. ChickC. CubD. Kit10、What do you call the first meal of the day?A. LunchB. DinnerC. BreakfastD. Snack11、What is the capital of Estonia?A. TallinnB. RigaC. VilniusD. Helsinki12、选择题：What is the fastest land animal?A. HorseB. CheetahC. LionD. Elephant13、What is the main source of energy for the Earth?A. WindB. SunC. WaterD. Coal14、What is the capital of Egypt?A. CairoB. AlexandriaC. LuxorD. Giza15、What is the opposite of "hard"?A. ToughB. SoftC. StrongD. Solid16、What do you call a young deer?A. CalfB. FawnC. KitD. Cub17、选择题：What do we call a person who sells goods?A. RetailerB. MerchantC. VendorD. All of the above18、What color do you get when you mix blue and yellow?A. GreenB. PurpleC. OrangeD. Brown19、选择题：What do you use to write?A. PaperB. PencilC. RulerD. Eraser20、What do you call the time when it rains?A. SunnyB. CloudyC. StormyD. Wet二、听力题(共计20题，共40分)1、听力题：A physical change does not alter the ______ of a substance.2、听力题：The ____ has a thick, warm coat for cold climates.3、听力题：I like to ___ with my friends. (hang out)4、听力题：The fish swims in the ___ (water).5、听力题：I enjoy _____ (reading/writing) stories.6、听力题：A _______ is a reaction that occurs rapidly and releases energy.7、听力题：The process of ______ involves the movement of rocks due to gravity.8、听力题：My favorite color is _____ (blue/sit).9、听力题：The chemical formula for calcium carbonate is ______.10、听力题：A __________ is a mixture of solids that can be separated by hand.11、听力题：The _____ (ball/box) is round.12、听力题：The symbol for iron is _____.13、听力题：A suspension differs from a solution because the particles can ______.I visit my ______ on weekends. (grandparents)15、听力题：We will play ______ (games) at the party.16、听力题：The capital of Brunei is __________.17、听力题：The chemical formula for sodium citrate is __________.18、听力题：My sister loves to ___ (dance/sing).19、听力题：My friend is a ______. He enjoys writing reviews.20、听力题：The ______ is a skilled sculptor.三、填空题(共计20题，共10分)1、填空题：The __________ is a major river in China. (长江)2、填空题：A goat’s milk is often used to make ______ (羊奶).3、填空题：My dog is very ____.4、填空题：A __________ (生态旅游) promotes awareness of environmental issues.5、填空题：The ______ (鸽子) coos softly in the morning.6、填空题：I saw a _______ (蟋蟀) in the grass.7、填空题：The country of India is famous for its ________ (印度以其________而闻名).This ________ (玩具) helps me learn about teamwork.9、填空题：My favorite character from a movie is _______ (名字). 他/她很 _______ (形容词).10、填空题：The _____ (花园) is full of colorful plants.11、填空题：The ancient Greeks valued ______ (运动) and physical fitness.12、填空题：The skunk sprays when it feels _________. (威胁)13、填空题：My brother loves __________ (学习新技能).14、填空题：I like to help my dad ________ (清理院子).15、填空题：The ancient Romans were known for their ________ and architecture.16、填空题：My friend is a great __________ (听众) and always supports me.17、填空题：Each toy has its own special ____. (特点)18、填空题：My sister enjoys __________ (野营).19、填空题：Dogs have a good sense of _______ (嗅觉).20、填空题：Plants need ______ (充足的) water to grow.。
evaluation of k1c
concluded that their analysis was applicable to materials with hardnesses, toughnesses and Poisson's ratios ranging from at least 1 to 30GNm -:, 0.9 to 16MNm -3/2 and 0.2 to 0.3, respectively. The present writers investigated the applicability of the Evans and Charles method to ranges of property values larger than these latter values. It was found that literature data [7] for the indentation behaviour of WC-Co composites did not agree well with Equation 1. It is the purpose of this communication to present a rationale for the observed deviation. Fig. 1 shows the data of Dawihl and Altmeyer [7] for WC-Co composites together with Equation 1 plotted as (Kxe(~/Hal/2)(H/E()) 2/s against c/a. At low values of c[a, considerable deviations appear to exist between the experimental data and Equation 1. In order to provide an explanation for this deviation it should be noted that implicit in plotting the data shown in Fig. 1 is the assumption that the cracks observed around the indentation take the form of median (half-penny) cracks, which completely surround the indentation, as shown in Fig. 2a. Another crack system, so-called Palmqvist cracks, however, have been found at low values of c/a [5, 6, 15]. Such cracks begin only at the end of the diagonals of the indentation, as illustrated in Fig. 2b. The existence of such cracks has been ascertained for a number of materials by a sectioning technique [15, 19], by fractography of a surface through an indentation [17, 23], or by direct observation of crack formation process using optical microscopy [10]. Ogilvy et al. [15] observed that for reasonably-tough materials such as WC-Co composites with more than about 6wt% Co, Palmqvist cracks were formed only even at high loads. Hagan and co-workers [17, 23]
2013年高考英语试卷(全国新课标I卷)
2013年高考英语试卷（全国新课标I卷）2013冭瘯缁撴潫鍚庯紝灏嗘湰璇曞嵎鍜岀瓟棰樺崱涓€骞朵氦鍥炪€??娉ㄦ剰浜嬮」锛?1.?2. 閫夊嚭姣忓皬棰樼瓟妗堝備笉鑳界瓟鍦ㄦ湰璇曞嵎涓婏紝鍚﹀垯鏃犳晥銆?3.叡涓よ妭锛屾弧鍒?0鍒嗭級綍闊冲唴瀹圭粨鏉熷悗锛屼綘灏嗘湁涓ゅ垎閽熺殑鏃堕棿灏嗗湪璇曞嵎涓婄殑?? 1.5鍒嗭紝婊″垎7.5鍒嗭級?A湁10?渚嬶細How much is the shirt? A. 锟?9.15. B. 锟?.18. C锟?.15. ?C銆?1. What does the man want to do? A.Take photos. B.Buy a camera. C.Help the woman.2.What are the speakers talking about> A.A noisy night B.Their life in town C.A place of living.3锛嶹here is the man now? A锛嶰n his way. B锛嶪n a restaurant. C锛嶢t home 4锛嶹hat will Celia do? A锛嶧ind a player. B锛嶹atch a game. C锛嶱lay basketball. 5锛嶹hat day is it when the conversation takes place? A锛嶴aturday. B锛嶴unday. C锛嶮onday.?5 1.5鍒嗭紝婊″垎22.5鍒嗭級?樹腑鎵€缁欑殑A5嗙粰鍑??6娈垫潗鏂欙紝鍥炵瓟6銆?棰樸€?6锛嶹hat is Sara going to do? A锛嶣uy John a gift. B锛嶨ive John a surpise C锛嶪nvite John to France. 7锛嶹hat does the man think of Sara鈥檚plan? A锛嶧unny. B锛嶦xciting. C锛嶴trange.7娈垫潗鏂欙紝鍥炵瓟绗?銆?棰樸€?8锛嶹hy does Diana say sorry to peter? A锛嶴he has to give up her travel pan. B锛嶴he wants to visit another city. C 锛嶴he needs to put off her test. 9.What does Diana want Peter to do? A. Help her with her study. B. Take a book to her friend. C. Teach a geography lesson. 8娈垫潗鏂欙紝鍥炵瓟绗?0鑷?2棰樸€?10.Why does the man call the woman? A.To tell her about her new job. B.To ask about her job program. C.To plan a meeting with her. 11.Who needs a new flat? A.Alex. B.Andrea. C.Miranda. 12.Where is the woman now? A.In Baltimore. B.In New York. C.In Avon. 9娈垫潗鏂欙紝鍥炵瓟绗?3鑷?6棰樸€?13.What does Jan consider most important when he judges a restaurant? A.Where the restaurant is. B.Whether the prices are low. C.How well the food is prepared. 14.When did Jan begin to write for a magazine? A.After he came back to Sweden. B.Before he went to the United States. C.As soon as he got his first job in 1982. 15.What may Jan do to find a good restaurant? A.Talk to people in the street. B.Speak to taxi drivers. C.Ask hotel clerks. 16.What do we know about Jan? A.He cooks for a restaurant. B.He travels a lot ofr his work. C.He prefers American food. 鍚?绗?0娈垫潗鏂欙紝鍥炵瓟绗?7鑷?0棰?17. What dowe know about the piaza Leen? A.it鈥檚new builing B.it鈥檚a small town C.it鈥檚public place 18. When do partents and children like going to the Piaza Leen? A.satyrday nightsB.Sunday afternoonsC.Fridays and Saturdays. 19. Which street is known for its food shops and markets? A.Via dei Mar Street B.Femando Street. C.Hemandes Street 20. Why does the speaker like Horation Street best ? A.It has an old stone surface. B.it is named after a writer C.It is a famous university.敤锛堝叡涓よ妭锛屾弧鍒?5鍒嗭級?鍗曢」澶╃┖锛堝叡151鍒嗭紝婊″垎15鍒嗭級秱榛戙€?渚?we____ last night, but we went to the concert instead. A.must have studied B. might study C. should have studied D. would study . 21. -Wly, this is nothing but common vegetable soup! A.Let me see Bso it is CDon 鈥榯mention it D Neither do I 22. .They might just have a place ______on the writing course涓€why don't you give it a try? A.Leave B.Left C. leaving D. to leave 23. Try not to sough more than you can since it may cause problems to your lungs. A. check B. allow C.stop D.help 24. If we now to protect the environment, we鈥檒l live to regret it. A. hadn't acted B. haven't acted C. don't act D. won't act 25. Tony can hardly boil an egg锛宻till cook dinner. A.less B.little C.much D.more 26. Police have found appears to be the lost ancient statue. A. which B. where C. how D.what 27.When I first met Bryan I didn鈥檛like him, but I my mind. A. have changed B. change C. had changed D.would change 28. The driver wanted to park his car near the roadside but was asked by}the police . A .not to do B. not to C. not do D. do not 29.The door open , no matter how hard she pushed. A. shouldn鈥檛B. couldn't C. wouldn't D. mightn't 30. At the last moment Tom-decided to a new character to make the story seem more likely. A. put up B. put in C. put on D. put off 31. India attained independence in 1947, after long struggle. A.涓嶅～;a B. the; a C. an;涓嶅～D. an; the 32.There鈥檚no way of knowing why one man makes an important discovery another man, also intelligent, fails. A. since B: if C. as D. while 33.鈥漎ou can鈥檛judge a book by its cover,鈥?. A. as the saying goes old B. goes as the old saying C. as the old saying goesD. goes as old the saying 34.It was a real race time to get the project done. Luckily, we made it. A. over B. by C. for D. against 35. The sunlight is white and blinding, hard-edged shadows on the ground. A. throwing B.being thrown C.to throw D.to be thrown ?20 1.5鍒嗭紝婊″垎30鍒嗭級夐」锛屽苟鍦ㄧ瓟棰樺崱涓婂皢璇ラ」娑傞粦I went to a group activity,鈥淪ensitivity Sunday鈥漺hich was to make us more 36 the problem faced by disabled people,We where asked asked to 鈥?37 a disability鈥漟or sever hours one Sunday,Some member 38 chose the wheel chair,Other wore sound-blocking carplug()or bilndfold(鐪肩僵). Just sitting in the wheelchair was a 39 experience,I had never considered before how 40 it would be to use one ,As soon as I sat down my 41 made the chair begin to roll ,Its wheel were not 42 Then I wondered where to put my 43 锛孖t took me quite a while to get the metal footrest into 44 ,I took my first uneasy look at what was to be my only means of 45 for serveral hours,For disabled people,鈥渁doping a wheelchair鈥漣s not a tempoarty(涓存椂鐨? 46 I tried to find a 47 position and thought it might be restful, 48 kind of nice to be 49 around for a while, Looking around,I 50 would have to handle the thing myself!My hands statred to ache as I 51 the heavy wheels,I came to know that controlling the 52 of the wheelchair as not going to be 53 task, My wheelchair experment was soon 54 It made a deep impression on me ,A few hours of 鈥渄isability鈥?gave me only a taste of the 55 ,both physical and mental,that disbled people must overcome 36.A.curious about B. interested in C. aware on D. careful with 37.A.cure B.prevent C.adopt D.analyze 38.A.inserted B.strangely C.as usualD.like me 39.A.learning B.working C.satrstying D.relaxing 40.A.convening B.awkward C.boring D.exciting 41.A.height B.force C.skill D.weight 42.A.locked B.repairedC.poweredD.grasped 43.A.hands B.feet C.keys D.handles 44.A.place B.action C.playD.effect 45.A.operation B.ecommunication C.transportation D.production46.A.exploration B.edcation C.experiment D.entertainment 47.A.flexble B. safe C. starting D. comfortable 48.A. yet B. just C. still D. even 49.A.shown B. pushed C. driven D. guided 50.A.realized B. suggested C. agreed D. admitted 51.A. lifted B. turned C. pressed D. seized 52.A. path B. position C. direction D. way 53.A. easy B. heavy C. major D. extra 54.A. forgotten B. repeated C. conducted D. finished 55.A. weaknesses B. challenges C. anxieties D. illnesses笁閮ㄥ垎В锛堝叡涓よ妭锛屾弧鍒?0鍒嗭級鍏?52鍒嗭紝婊″垎30鍒嗭級€夐」锛屽苟鍦ㄧ瓟棰樺崱涓婂皢璇ラ」娑傞粦銆?A Some people will do just about anything to save money. And I am one of them .Take my family鈥檚last vacation .It was my six-year-old son鈥檚winter break form school ,and we were heading home form Fort Lauderdale after a weeklong trip. The flight was overbooked ,and Delta , the airline ,offered us $400 per person in credits to give up our seats and leave the next day .I had meeting in New York锛孲o I had to get back . But that didn't mean my husband and my son couldn't stay. I took mynine-month-old and took off for home. The next day my husband and son were offered more credits to take an even later flight. Yes, I encouraged涓€okay, ordered-them to wait it out at the airport, to "earn" more Delta Dollars. Our total take: $1,600. Not bad, huh? Now some people may think I'm a bad mother and not such a great wife either. But as a big-time bargain hunter, I know the value of a dollar. And these days, a good deal is some-timething few of us can afford to pass up. I've made living looking for the best deals and exposing () the worst tricks .I have been the consumer reporter of NBC's Today show for over a decade. I have written a couple of books including one titled Tricks of the Trade: A Consumer Survival Guide. And I really do what I believe in.I tell you this because there is no shame in gettingyour money鈥檚worth. I鈥檓also tightfisted when it comes to shoes, clothes for my children,and expensive restaurants.But I wouldn't hesitate to spend on a good haircut. It keeps its longer, and it's the first thing people notice. And I will also spend on a classic piece of furniture. Quality lasts.56. Why did Delta give the author's family credits? A. They took a later flight. B. They had early bookings. C. Their flight had been delayed. D. Their flight had been cancelled. 57. What can we learn about the author? A. She rarely misses a good deal.B. She seldom makes a compromise.C. She is very strict with her childrenD. She is interested in cheap products. 58. What does the author do? A. She's a teacher. B. She's a housewife. C. She's a media person. D. She's a businesswoman. 59. What does the author want to tell us? A.How to expose bad tricks. B. How to reserve airline seats. C. How to spend money wisely, D. How to make a business deal. B They baby is just one day old and has not yet left hospital. She is quiet but alert ()銆俆wenty centimeters from her face researchers have placed a white card with two black spots On it.She stares at it carefully . A researcher removes the card and replaces it by another, this time with the spots differently spaced. As the cards change from one to the other,her gaze() starts to lose its focus - until a third, with three black spots, is presented. Her gaze returns锛泂he looks at it for twice as long as she did at the previous card. Can she tell that the number two is different from three, just 24 hours after coming into the world?Or do newborns simply prefer more to fewer? The same experiment,but with three spots shown before two, shows the same return of interest when the number of spots changes.Perhaps it is just the newness? When slightly older babies were shown cards with pictures of objects(a comb,a key,an orange and so on),changing the number of objects had an effect separate from changing the objects themselves.Could it be the pattern that two things make,as opposed to three? No again.Babies paid more attention to squares moving randomly on a screen whentheir number changed from two to three, or three to two. The effect even crosses between senses.Babies who were repeatedly shown two spots became more excited when they then heard three drumbeats than when they heard just two;likewist(鍚屾牱鍦? when the researchers started with drumbeats and moved to spots. 60.The experiment described in Paragraph 1 is related to the baby鈥檚__. A.sense of hearing. B.sense of sight. C.sense of touch. D.sense of smell. 61.Babies are sensitive to the change in______. A.the size of cards. B.the colour of pictures. C.the shape of patterns. D.the number of objects. 62.Why did the researchers test the babies with drumbeats? A.To reduce the difficulty of the experiment. B.To see how babies recognize sounds. C.To carry their experiment further. D.To keep the babies鈥?interest. 63.Where does this text probably come from? A.Science fiction.B.Children鈥檚literature.C.An advertisement.D.A science report. C It happened to me recently.Iwas telling someone how much Ihad enjoyed reading Barack Obama鈥檚Dreams From My Father and how it had changed my views of our President.A friend Iwas talking to agreed with me that it was ,in his words,鈥渁brilliantly锛堢簿褰╁湴锛墂ritten book鈥?however,he then went on to talk abour Mr Obama in a way which suggested he had no idea of his background at all .Isensed that Iwas talking to a book liar. And it seems that my friend is not the only one.Approximately two thirds of people have lied about reading a book which they haven鈥檛.In the World Book Day鈥檚鈥淩eport on Guilty Secrets鈥?Dreams From My Father is at number 9.The report lists ten books,and various authors,which people have lied about reading,and as I鈥檓not one to lie too often (I鈥檇hate to be caught out ),I 鈥檒ladmit here and now that I haven鈥檛read the entire top ten .But I am pleased to say that,unlike 42 percent of peoplt,I have read the book at numberone ,George Orwell鈥檚1984.I think it鈥檚really brilliant. The World Book Day report also has some other interesting information in it.It says that many people lie about having read jane Austen,Charles Dickens,Fyodor Dostoevsky(I haven鈥檛readhim,but haven鈥檛lied about it either )and Herman Melville. A sked why they lied,the most common reason was to鈥渋mpress鈥漵omeone they were speaking to.This coule be tricky if the conversation became more in 锟紺depth! But when asked which authors they actually enjoy,people named J.k.Rowling,JohnGrisham,Sophie Kinsella(ah,the big sellers,in other words).Forty-two percent of people asked admitted they turned to the back of the book to read the end before finishing the story(I鈥檒l come clean:I do this and am astonished that 58 percent said they had never dome so).64.How did the author find his friend a book liar? A.By judging his manner of speaking. B.By looking into his background. C.By mentioning a famous name. D.By discussing the book it self. 65.Which of the following is a鈥済uilty secret 鈥漚ccording to the World Book Day report? A.Charles Dickens is very low on the top-ten list. B.42% of people pretended to have read 1984. C.The author admitted having read 9 books. D.Dreams From My Father is hardly read. 66.By lying about reading ,a person hopes to . A.control the conversation B.appear knowledgeable C.learn about the book D.make more friends 67.What is the suthor鈥檚attitude to 58%of readers?A.Favorable.B.UncaringC.DoubtfulD.Friendly D The National Gallery Description: The National Gallery is the British national art museum built on the north side of European art ranging from 13th-century religious paintings to more modern ones by Renoir and Van Gogh.The older collections of the gallery are reached through the main entrance while the more modern works in the East Wing are most easily reached from Trafalgar Square by a ground floor entrance Layout: The modern Sainsbury Wing on the western side of the buileing houses 13th-to15th-century paintings,and artists include Duccio,Uccello,Van Eyck,Lippi,Mantegna,Botticelli and Memling. The main West Wing houses 16th-century paintings ,and artists include Leonardo da Vinci,Cranach,Michelangelo,Raphael,Bruegel,Bronzino,Titan and Veronest. The North Wing houses 17th-century paintings,and artists includeCaravaggio,Rubens,Poussin,Van Dyck,Velazquez,Claude and Vermeer. The East Wing houses 18th-to early 20th-century paintings,and artists includeCanaletto,Goya,Turner,Constable,Renoir and Van GoghOpening Hours: The Gallery is open every day from 10am to 6pm锛團ridays 10anm to 9pm锛塧nd is free, but charges apply to some special exhibitions. Getting There: Nearest underground stations: Charing Cross锛?-minute walk锛? Leicester Square 锛?-minute walk锛?Embankment锛?-minute walk锛?and Piccadilly Circus锛?-minute walk锛?68锛嶪n which century鈥檚collection can you see religious paintings? A锛嶵he 13th B锛嶵he 17th C锛嶵he 18th D锛嶵he 20th 69锛嶹here are Leonardo da Vinci鈥檚works shown? A锛嶪n the East Wing. B锛嶪n the main West Wing. C锛嶪n the Sainsbury Wing. D锛嶪n the North Wing. 70锛嶹hich underground station is closest to the National Gallery? A锛嶱iccadilly Circus. B锛嶭eicester Square. C锛嶦mbankment. D锛嶤haring Cross. ?鍏?:姣忓皬棰?鍒嗭紝婊″垎10鍒???Business is the organized approach to providing customers with the goods and services they want.The eord business also refers yo an organization that provides these goods and services.Most business seek to make a profit(鍒╂鼎)-that aim to achieve income that is more than the costs of operating the business. 71 Commonly called nonprofits,these organizations areprimarily nongovernmental service providers. Business management is a term used to describe the techniques of planning, direction,and control of the operations of a business. 73 One is the establishment (鍒跺畾)of broad basic policies with respect to production; sales; the purchase of equipment, materials and and supplies; and accounting. 74 The third relates to the establishment of standards of word in all departments. Direction is concerned primarily with supervision()and guidance by the management in authority. 75A. Control includes the use of records and reports to compare actual work with the set standards for work.B. In this connection there is the difference between top management and operative management.C.Examples of nonprofit business top management and operative management.D. However, some businesses only seek to enough to cover their operating costsE. The second aspect relates to the application of these policies by departments.F. In the theory of business management, organization has two main aspects. G Planning in business management has three main aspects. ?璇曞嵎涓婃棤鏁堛€?鍐欎綔锛堝叡涓ら〉锛屾弧鍒?5鍒嗭級绗?101鍒嗭紝婊″垎10鍒嗭級?0?э級锛屽苟鍦ㄥ叾涓嬮潰鍐欏嚭璇ュ姞鐨勮瘝銆?鍒犻櫎锛?敤鏂滅嚎锛圽锛夊垝鎺夈€??娉ㄦ剰锛?. 2.鏀?011澶勮捣锛変笉璁″垎銆?I hardly remember my grandmother.She used to holding me on her knees and sing old songs.I was only four when she passes away.She is just a distant memory for me now. I remember my grandfather very much.He was tall,with broad shoulder and a beard that turned from black toward gray over the years.He had a deep voice,which set himself apart from others in our small town,he was strong and powerful.In a fact,he even scared my classmates away during they came over to paly or do homeword with me.However, he was the gentlest man I have never known.。
小学上册第七次英语第1单元真题
小学上册英语第1单元真题英语试题一、综合题(本题有100小题，每小题1分，共100分.每小题不选、错误，均不给分)1. A snail leaves a ______ (黏液) trail.2.What do you call the process of plants making food?A. DigestionB. PhotosynthesisC. RespirationD. FermentationB3.My friend enjoys __________ (钓鱼).4.I like to read ______ books in my free time.5.What is the opposite of 'hot'?A. WarmB.ColdC.CoolD.Toasty答案:B6.My cousin is a talented __________ (舞者) in competitions.7.My dog has a _______ (温暖的) bed to sleep on.8.Which of these is a flying insect?A. AntB. BeetleC. ButterflyD. WormC9.Chemical reactions often require a change in ________ to occur.10.The zebra has black and _________ (白色) stripes.11.My sister has a collection of ______.12.My favorite holiday is ________ (感恩节) with family.13.Wildflowers grow __________ (自然) in the fields.14.The chemical formula for lead(II) oxide is _____.15. A butterfly's wings are very ______.16.My favorite _____ is a cute kitten.17.What do you call a young deer?A. CalfB. FawnC. KidD. Cub18.What is the largest planet in our solar system?A. EarthB. SaturnC. JupiterD. Mars19.I enjoy reading ______ at night.20.The ________ grows in the sunlight.21. A saturated solution contains the maximum amount of solute that can _____.22.What do we call a large, heavy animal that lives in the water?A. FishB. HippoC. CrocodileD. Shark23.What is the name of the famous landmark in Paris?A. Big BenB. Eiffel TowerC. Statue of LibertyD. ColosseumB24. A turtle moves very ______ (慢).25.The chemical formula for copper(II) sulfate is ______.26.The ______ of a flower can sometimes determine its fragrance. (花的结构有时会决定它的香气。
小学上册第十三次英语第4单元测验试卷
小学上册英语第4单元测验试卷英语试题一、综合题(本题有100小题，每小题1分，共100分.每小题不选、错误，均不给分)1.My mom loves to __________. (购物)2.I enjoy organizing my ________ (玩具) collection.3.What does a thermometer measure?A. DistanceB. VolumeC. TemperatureD. PressureC4.The apple tree is _______ (full) of fruit.5.I like to collect ______ (邮票) from different countries. Each one tells a ______ (故事).6.What do you call a group of sheep?A. HerdB. FlockC. PackD. TeamB7. A ____ is a tiny creature that loves to chase after insects.8.What is the name of the famous scientist who developed the theory of relativity?A. Isaac NewtonB. Albert EinsteinC. Galileo GalileiD. Nikola TeslaB9. A _______ can help to demonstrate the principles of thermodynamics.10.The chemical symbol for aluminum is ____.11.What is the opposite of young?A. OldB. NewC. FreshD. Young12.将下列表示职业的单词与相应的图片连线。
小学上册第3次英语第5单元综合卷
小学上册英语第5单元综合卷英语试题一、综合题(本题有100小题，每小题1分，共100分.每小题不选、错误，均不给分)1.The water is ________ in the pool.2. A ____ has bright feathers and can mimic sounds.3.The teacher is ______ the lesson on math. (explaining)4.I see a _____ (鱼) in the tank.5.What do we breathe?A. WaterB. AirC. FoodD. Light6.The capital of Jordan is _______.7.What is the main purpose of a refrigerator?A. To cook foodB. To freeze foodC. To keep food coldD. To wash foodC8.What do we call the protective covering of a seed?A. ShellB. HuskC. PodD. Coat9.When you drop a ball, it falls due to ______.10.The dog is ______ (playing) with a stick.11.The main component of air is ______.12.What do we call the process of breaking down food in the body?A. DigestionB. AbsorptionC. AssimilationD. IngestionA13.The __________ helps to keep the body hydrated.14.She is wearing ___ (shoes/socks).15.I feel ________ (兴奋) about going to the amusement park.16.The __________ (历史的重要性) can’t be understated.17.The ancient Greeks established the concept of ________ (市民权).18.What is 7 + 2?A. 8B. 9C. 10D. 1119.I saw a _______ (butterfly) in the garden.20.The __________ (历史的未来展望) shapes aspirations.21.The ______ is good at solving puzzles.22.What do we call a person who studies languages?A. LinguistB. PhilologistC. SociologistD. AnthropologistA23.The chemical formula for hydrochloric acid is ________.24. A zebra is a type of ______.25.What is the capital of Kazakhstan?A. AlmatyB. AstanaC. BishkekD. TashkentB26.The _____ (牛) provides milk.27.What is the capital city of the Maldives?A. MaléB. Addu CityC. FuvahmulahD. Dhidhdhoo28.How many teeth does a typical adult human have?A. 28B. 30C. 32D. 34C29.What is the name of the famous ancient city in Romania?A. SighisoaraB. BucharestC. SibiuD. ConstantaA Sighisoara30.The garden is full of lovely _______ that attract butterflies.31.What is the capital of the United Kingdom?A. LondonB. EdinburghC. CardiffD. Belfast32.What is the name of the famous scientist who developed the theory of relativity?A. Isaac NewtonB. Albert EinsteinC. Galileo GalileiD. Stephen HawkingB33.My grandpa tells jokes that are ____.34.The chemical symbol for silicon is _____.35.What is the capital of Nigeria?A. LagosB. AbujaC. KanoD. Port Harcourt36.What do we call a vehicle with two wheels?A. CarB. BusC. BicycleD. Truck37.The chemical formula for cetyl alcohol is ______.38.The puppy loves to cuddle with _______ (小狗喜欢和_______一起依偎).39.My grandma bakes ____ (bread) every week.40. A simple machine makes work ______.41.What is the main purpose of a computer?A. To play gamesB. To browse the internetC. To process informationD. To print documentsC42.My pet rabbit has a special _______ (笼子).43.The first successful spacecraft to land on the moon was ______ (阿波罗11号).44. A ____ is a small fish that can live in aquariums.45.She is helping her mom in the ___. (kitchen)46.My aunt loves to cook ____ (southern cuisine).47.The stars shine at _______ (night).48.My __________ (玩具名) is very __________ (形容词) and fun.49.sustainable energy) replaces fossil fuels. The ____50.I want to ___ (learn/know) more about science.51. A ______ (社区参与) can enhance gardening efforts.52.What is the primary color made by mixing red and blue?A. GreenB. PurpleC. OrangeD. Brown答案:B53.What is the name of the famous volcano in Italy?A. Mount EverestB. Mount VesuviusC. Mount KilimanjaroD. Mount St. HelensB54.What is the name of the famous river in China?A. AmazonB. NileC. YangtzeD. Mississippi55.I am excited to join the school ________ (合唱团) and sing with my friends.56.I like to _______ (play) the drums.57.What do you call the study of the Earth's surface?A. GeographyB. GeologyC. MeteorologyD. EcologyA58.The invention of the steam engine revolutionized _____.bustion is a reaction that produces ________ and water.60.The raccoon is known for its _________. (聪明)61.The __________ (历史的启示) guides our actions.62.What is 5 3?A. 2B. 3C. 1D. 5A63.I see a _____ (马) in the field.64.What is the name of the largest desert in the world?A. SaharaB. GobiC. ArabianD. Antarctic65. Wall of China is a famous ________ (中国的长城是著名的________). The Grea66. A small ___ (松鼠) gathers nuts for winter.67.ts need a lot of _____ (水). Some pla68.What do we call the study of chemicals and their reactions?A. ChemistryB. PhysicsC. BiologyD. GeologyA69.Which animal is known for its ability to fly?A. FishB. DogC. BirdD. Turtle70.My aunt gives me __________. (礼物)71. A _____ (自然景观) can inspire artists.72.What do we call the process of freezing a liquid to make it solid?A. MeltingB. SolidifyingC. CoolingD. Hardening73.The invention of the computer has changed modern _____.74.What is the opposite of "empty"?A. FullB. HollowC. LightD. Dense75.In a chemical equation, the substances on the left are called __________.76.I like to sing ______ (歌曲) with my friends.77.My aunt is a _____ (护士) who takes care of patients.78.The flowers are ________ and colorful.79.What color is an orange?A. BlueB. OrangeC. GreenD. Red80. A catalyst is a substance that speeds up a _____.81.I like to draw _______ (我喜欢画_______).82.What is the capital of Mongolia?A. UlaanbaatarB. ErdenetC. DarkhanD. ChoibalsanA83.My cat loves to catch ______ (小虫) in the grass.84.The chemical symbol for radium is ______.85.What is the primary color that mixes with blue to create teal?A. YellowB. RedC. GreenD. PurpleC86.What type of animal is a dolphin?A. FishB. MammalC. ReptileD. BirdB87.We take a _____ to school every day. (bus)88.My dog loves to chase after ______ (球) in the park.89.We have a ______ (愉快的) time during family outings.90.What do we call the process of water turning into vapor?A. EvaporationB. CondensationC. PrecipitationD. SublimationA91.Did you ever watch a _______ (小蜻蜓) hover?92.The symbol for osmium is _______.93.The _____ (windmill) is turning.94.My sister is my best ______ (朋友). We play games together and share our ______ (秘密).95.The _____ (营养) from the soil is vital for growth.96.In a solution, the amount of solute relative to the solvent is called the _____.97.What do you call a young horse?A. FoalB. CalfC. KidD. Pup答案:A98.What do you call a person who repairs watches?A. JewelerB. WatchmakerC. ClocksmithD. Artisan99.My teacher is very __________ (善于激励).100.In _____ (59), you can find kangaroos.。
小学下册第10次英语第五单元暑期作业(含答案)
小学下册英语第五单元暑期作业(含答案)英语试题一、综合题(本题有100小题，每小题1分，共100分.每小题不选、错误，均不给分)1.The __________ is a famous area for hiking.2.Who is the main character in a story?A. HeroB. VillainC. ProtagonistD. Antagonist3.ration of Independence was signed in _______. (1776年) The Decl4.I saw a _______ (小鸭子) swimming in the pond.5. A ____ is a small creature that loves exploring.6.My uncle is a talented __________ (写作者).7.The _______ of sound can be perceived in different ways by different people.8.What do we call the act of looking after children?A. ParentingB. BabysittingC. ChildcareD. Nurturing答案:A9.How many pairs of chromosomes do humans have?A. 23B. 46C. 22D. 4410.What is the opposite of fast?A. QuickB. SlowC. SpeedyD. Rapid答案:B11. A goat's milk is often used to make delicious ________________ (奶酪).12. A balloon filled with air is an example of a ______.13.The chemical formula for calcium cyanamide is ______.14. A __________ is a physical change that alters the appearance.15.The dog is ________ around the yard.16.What is the weather like when it rains?A. SunnyB. CloudyC. DryD. Wet答案:D17.The ________ is full of life.18._____ (pesticides) can harm beneficial insects.19. A solution with a pH of is considered ______.20.The children are ___ (laughing) and having fun.21.My favorite hobby is ______ (摄影). I love capturing beautiful ______ (瞬间).22. A ______ is a cold-blooded animal.23.What do we call a person who sells goods?A. MerchantB. FarmerC. TeacherD. Doctor24.What is the largest continent?A. AfricaB. AsiaC. EuropeD. America答案:B25.I can see the ___. (moon)26.She likes to eat ______ (cookies).27.My brother, ______ (我弟弟), studies hard for his exams.28.What color is the sky on a clear day?A. GreenB. BlueC. RedD. Yellow29.The __________ can reveal the relationships between geological layers and formations.30.What do you call a baby cat?A. PuppyB. KittenC. CubD. Foal31. A ____ is a small animal that enjoys digging.32.What is the color of a typical pepper?A. GreenB. YellowC. RedD. All of the above33.The ______ teaches us about sports.34.The puppy is _______ (调皮) and loves to chew on shoes.35.The girl enjoys ________.36. A _______ can be a solid, liquid, or gas.37.What do you call the part of the plant that absorbs water and nutrients?A. StemB. LeafC. RootD. Flower38.The ______ helps with the filtration of blood.39.The garden is ___. (beautiful)40. A snake can swallow prey much larger than its ________________ (头).41.What is the name of the famous explorer who discovered the New World?A. Christopher ColumbusB. Ferdinand MagellanC. Marco PoloD. Vasco da Gama42.I can ________ (做) math problems.43.The city of Naypyidaw is the capital of _______.44.The __________ (历史的启示) sparks creativity.45.Which fruit is red and often associated with teachers?A. BananaB. GrapeC. AppleD. Orange答案:C46.What is the name of the large mammal with tusks?A. HippoB. ElephantC. RhinoD. Giraffe47.The _______ (小紫貂) is known for its soft fur.48. A sedimentary rock that is formed from the remains of plants and animals is called ______.49.I enjoy painting with bright ______ (颜色) that bring joy to my artwork.50.What is the capital of Brazil?A. Rio de JaneiroB. BrasiliaC. Sao PauloD. Salvador51.What is a young sheep called?A. LambB. CalfC. KidD. Foal答案:A52.The Great Wall of China can be seen from ______.53.I enjoy ________ books after dinner.54.What is the main ingredient in bread?A. SugarB. FlourC. WaterD. Yeast答案:B55.The owl has excellent ______ (听力).56. (Pledge) of Allegiance was written in the 19th century. The ____57.The flamingo's social behavior includes forming large ________________ (群体).58.Which fruit is known for having seeds on the outside?A. BananaB. StrawberryC. AppleD. Peach答案:B59. A mixture that can be separated by physical means is called a ______.60.What do we call a device that takes pictures?A. CameraB. ProjectorC. TelevisionD. Computer答案:A61.What is the term for a baby cat?A. KittenB. PupC. CalfD. Cub答案:A62.Every action has an equal and opposite _______.63.I like to ________ cartoons.64.What do we call a traditional story that explains something in nature?A. MythB. FableC. LegendD. Tale65.He is playing with his ___. (toys)66.The ____ is a tiny insect that helps pollinate flowers.67. A _____ (草坪) needs regular mowing.68.The ancient Chinese created ________ to protect their empire.69.What is the opposite of loud?A. QuietB. SilentC. MuteD. All of the above答案:D70.Some _______ are used for decoration.71. A saturated fat can lead to ______ disease.72.My mom is always __________ (忙碌的).73.The stars are ___. (twinkling)74.She rides the _______ (bus) to work.75.What do you call a shape with five sides?A. PentagonB. HexagonC. OctagonD. Quadrilateral答案:A76.What do we call the study of the Earth's physical features?A. GeographyB. GeologyC. CartographyD. Meteorology答案:A Geography77.Let’s go ________ to eat ice cream.78.The __________ (历史的展现方式) affects audience engagement.79.How many colors are there in a rainbow?A. 5B. 6C. 7D. 8答案:C80.What is the name of the famous American author who wrote "The Adventures of Tom Sawyer"?A. Mark TwainB. Ernest HemingwayC. F. Scott FitzgeraldD. John Steinbeck答案:A81.What is the opposite of young?A. OldB. NewC. FreshD. Modern82.What is the largest mammal in the world?A. ElephantB. Blue WhaleC. GiraffeD. Rhino答案:B83.Mount Everest is the ________ (珠穆朗玛峰是________) mountain in the world.84.The ______ helps with the processing of information.85.The fruit is ________ (新鲜).86. A ______ (乡村) garden offers peace and quiet.87. A _______ is a type of flower that comes in many colors.88.My sister is learning to ______.89.I enjoy making ________ (贺卡) for special occasions.90.We like to play _____ (游戏) after school.91.What is the opposite of "happy"?A. SadB. AngryC. ExcitedD. Joyful答案:A92.What is the hardest natural substance on Earth?A. GoldB. IronC. DiamondD. Quartz答案:C93.My uncle is a __________. (科学家)94.My sister enjoys __________ (参与博物馆活动).95.The chemical symbol for mercury is _______.96.What is the smallest prime number?A. 0B. 1C. 2D. 3答案:C 297.What is the capital of Italy?A. VeniceB. MilanC. RomeD. Florence答案:C98.What do we call a person who studies the stars?A. BiologistB. AstronomerC. GeologistD. Chemist99.The anemone provides shelter for the ______ (小丑鱼).100.What is the process of removing trees from a forest called?A. AfforestationB. ReforestationC. DeforestationD. Urbanization答案:C。
青春和化学元素的作文
青春和化学元素的作文英文回答：Youth is like a chemical element, constantly changing and evolving. It is a period of growth, exploration, and self-discovery. Just like the elements on the periodic table, youth is a time of transformation and potential.During our teenage years, we go through various chemical reactions, both physically and emotionally. Our bodies undergo hormonal changes, leading to growth spurts and the development of secondary sexual characteristics. Similarly, our emotions are in a constant state of flux, much like the reactivity of certain elements. We may experience intense joy, sadness, anger, and love, sometimes all at once.Just as different elements have unique properties, each individual experiences youth in their own way. Some may be more reactive and outgoing, like the alkali metals, whileothers may be more stable and introverted, like the noble gases. Our personalities and temperaments, much like the atomic structure of elements, contribute to our overall experiences during this period of our lives.Youth is also a time of experimentation and exploration, much like the process of discovering new elements. We try different hobbies, activities, and relationships to findout what resonates with us. It is during this time that we may discover our passions, talents, and goals for the future. Just as scientists conduct experiments to uncover new elements, we conduct our own experiments to uncover our true selves.As we navigate through the ups and downs of youth, we may encounter challenges and obstacles, much like the chemical reactions that require energy input to proceed. These challenges can be seen as catalysts for personal growth and development. Just as chemical reactions can produce new compounds with unique properties, overcoming challenges can lead to personal growth and the developmentof resilience.中文回答：青春就像化学元素一样，不断变化和发展。
青春和化学元素的作文
青春和化学元素的作文英文回答：In the realm of chemistry, elements serve as the fundamental building blocks of matter, each possessing unique properties that shape the world around us. Similarly, in the ephemeral tapestry of youth, distinct elements coalesce to form an intricate mosaic of experiences, emotions, and aspirations.Hydrogen, the lightest and most abundant element,mirrors the unbridled energy and boundless potential that characterize youth. Its flammable nature reflects the impulsive and daring spirit that often defines this periodof life. Helium, the inert and buoyant gas, embodies the dreams and aspirations that soar high, carried aloft by the unwavering optimism of the young.Oxygen, essential for life, sustains the vibrant flameof youth. It represents the passion and enthusiasm thatignite the soul, driving individuals to pursue their dreams and aspirations. Nitrogen, an abundant but often overlooked element, symbolizes the resilience and adaptability that allow youth to navigate the complexities of life. It is the bedrock upon which young minds build their identities and forge their unique paths.Carbon, the cornerstone of organic molecules, mirrors the complex and ever-changing nature of youth. Its ability to form countless compounds reflects the myriadpossibilities and transformations that lie ahead. Calcium, vital for strong bones, represents the physical and emotional development that occurs during this period, as youth mature into young adults.Potassium, an electrolyte that regulates cellular function, symbolizes the balance and stability that youth strive to attain. It represents the search for inner harmony and the ability to navigate the tumultuous emotions that often accompany adolescence. Sodium, an essential element for nerve transmission, embodies the quick wit and sharp intellect that characterize many young minds.Just as chemical reactions transform elements into new substances, so too do the experiences of youth shape and mold individuals. The challenges and triumphs, the friendships and heartbreaks, all contribute to the unique tapestry of personal growth. Like the intricate interactions of atoms, the elements of youth combine and recombine, forging the complexities that define adulthood.中文回答：化学元素就好比青春的基石，它们各自的属性塑造着我们周围的世界。
小学下册C卷英语第一单元综合卷[有答案]
![小学下册C卷英语第一单元综合卷[有答案]](https://img.taocdn.com/s3/m/d9e5910e571252d380eb6294dd88d0d233d43c21.png)
小学下册英语第一单元综合卷[有答案]考试时间：90分钟（总分:100）A卷一、综合题(共计100题共100分)1. 填空题：The ________ loves to play.2. 选择题：What is the name of the device we use to take photos?A. CameraB. PrinterC. ScannerD. Projector3. 填空题：The _______ (Freedom Rides) challenged segregation in public transportation.4. 填空题：The ________ (花园) is filled with colorful blooms.5. 选择题：What is 10 4?A. 5B. 6C. 7D. 8答案: B6. 听力题：The teacher is very ________.7. 填空题：A ______ (鸟) can be very colorful and beautiful.8. 听力题：She is _______ (doing) her homework at the table.Substances that speed up chemical reactions are called _______.10. 听力题：The flowers bloom in _____ (spring/fall).11. 填空题：I call my grandmother __________. (奶奶/外婆)12. 选择题：What is the opposite of 'fast'?A. SlowB. QuickC. RapidD. Speedy答案: A13. 选择题：What is 20 15?A. 3B. 4C. 5D. 6答案: C14. 听力题：The chemical name for HO is _______.15. 选择题：What do we call the stories that are told at bedtime?A. FablesB. MythsC. Bedtime storiesD. Legends答案: C16. 听力题：My aunt loves to do ____ (photography).17. 填空题：My friends call me “.”18. 填空题：I enjoy _______ (参加)户外活动。
小学上册第十三次英语第四单元测验卷(有答案)
小学上册英语第四单元测验卷(有答案)考试时间：80分钟（总分:110）B卷一、综合题(共计100题共100分)1. 听力题：Many _______ are used to celebrate special occasions.2. 听力题：The _____ (火焰) is warm.3. 听力题：The festival is very _______ (exciting).4. 听力题：The movie is very ________.5. 填空题：_____ (自然灾害) can impact plant life significantly.6. 填空题：The scientist, ______ (科学家), conducts research in the lab.7. 听力题：It is _____ (晴天) today.8. 填空题：The ________ (生态友好) practices protect the earth.9. 选择题：What do we call a young female chicken?A. HenB. ChickC. RoosterD. Duck答案：B10. 填空题：I enjoy learning about different ______ (文化) around the world.11. 选择题：What is the main ingredient in pancakes?A. FlourB. SugarC. MilkD. Eggs12. 选择题：What is 30 15?A. 10B. 12C. 14D. 15答案:D13. 填空题：A __________ (草坪) can be very green and soft.14. 选择题：What is the term for the study of living organisms?A. BiologyB. ChemistryC. PhysicsD. Geology答案:A15. 听力题：Chemical bonds can be ionic or ______.16. 填空题：The _______ (骆驼) can survive in the desert.17. 选择题：What is the name of the famous mouse created by Walt Disney?A. Mickey MouseB. Jerry MouseC. Stuart LittleD. Speedy Gonzales答案: A18. 选择题：What is the opposite of "hot"?A. WarmB. ColdC. CoolD. Sunny答案: B19. 填空题：I want to _____ (harvest) my garden soon.20. 听力题：__________ are substances that can conduct heat or electricity.21. 听力题：The chemical formula for lithium hydroxide is ______.22. 填空题：The chameleon can change colors to _________ (伪装).23. 听力题：She is ___ (dancing/sitting) on the floor.24. 选择题：What do we call a person who studies the human mind?a. Psychologistb. Sociologistc. Psychiatristd. Neurologist答案:a25. 听力题：I have a _____ (favorite) toy.26. 听力填空题：I think exercising is important for staying __________.27. 听力题：In a chemical reaction, the mass of the products equals the mass of the _____.28. 选择题：What is 10 - 4?A. 5B. 6C. 7D. 829. 听力题：My favorite subject is _____ (math/science).I want to _____ (sing/dance) at the party.31. 填空题：A cricket chirps by rubbing its _______ (翅膀).32. 听力题：They are ___ a drawing. (making)33. 填空题：A lion is a majestic _______ that rules the savanna.34. 填空题：My favorite color for my toy is _____.35. 听力题：They are _____ a song together. (singing)36. 填空题：I saw a ________ perched on a fence.37. 听力题：A toy car moves when we _______ it.38. 填空题：I found a ______ (小石头) by the river. It was smooth and ______ (光滑).39. 听力题：A chemical reaction can release heat and light in an ______ reaction.40. 听力题：The capital of Chile is __________.41. 听力题：Solar flares are bursts of energy from the ______.42. 听力题：She likes to paint ___. (pictures)43. 填空题：My dog's favorite toy is a ______ (骨头).44. 填空题：The solid that forms from a chemical reaction is called a _______. (沉淀)What do you use to cut paper?A. PencilB. ScissorsC. RulerD. Glue46. 听力题：The process of making charcoal involves _______.47. 填空题：The country with the kangaroo is __________. (澳大利亚)48. 填空题：My pet hamster loves to run on its ______ (轮子).49. 听力题：The clock is ___. (ticking)50. 选择题：What is the primary color of a blueberry?A. RedB. BlueC. GreenD. Yellow答案:B51. 填空题：This ________ (玩具) inspires me to be creative.52. 听力题：A __________ is a geological feature that can impact human settlements.53. 选择题：What is the opposite of polite?A. RudeB. CourteousC. RespectfulD. Civil答案:A54. 选择题：What is the name of the action where you move your body rhythmically?A. DancingB. SingingC. ActingD. Playing答案: A55. 填空题：He is a programmer, ______ (他是一名程序员), creating apps.56. 填空题：A _______ (蜥蜴) can change color to blend in.57. 选择题：How many letters are in the English alphabet?A. 24B. 25C. 26D. 2758. 选择题：What do you call a person who studies plants?A. BotanistB. ZoologistC. GeologistD. Chemist59. city) is a large area where many people live. 填空题：The ____60. 听力填空题：I believe that everyone should have the chance to pursue their __________.61. 填空题：The _______ (The New Deal) implemented programs to aid recovery during the Great Depression.62. 听力题：The park is _______ (quiet) in the morning.63. 选择题：What is the opposite of night?A. MorningB. EveningC. DayD. Twilight答案: C64. 填空题：The capital of Eswatini is ________ (姆巴巴内).65. 选择题：What do you use to write on paper?A. BrushB. PenC. RulerD. Scissors66. 听力题：A ____ is a friendly creature that enjoys being around other animals.67. 填空题：Insects can harm some __________ (植物).68. 选择题：Which of these is a mode of transportation?A. TableB. CarC. ChairD. Bed69. 填空题：The goat climbs up the ______ (山). It is very ______ (灵活).70. 填空题：A rabbit's ______ (牙齿) keep growing.71. 选择题：What is the main ingredient in a smoothie?A. IceB. FruitC. YogurtD. Milk72. 选择题：What are the primary colors?A. Red, Blue, YellowB. Green, Orange, PurpleC. Black, White, GrayD. Pink, Brown, Teal答案:A73. 选择题：What is the fastest land animal?A. ElephantB. CheetahC. LionD. Horse74. 听力题：The phase of matter can be solid, liquid, or ______.75. 选择题：What do you call the main character in a story?A. VillainB. ProtagonistC. NarratorD. Supporting character答案:B76. 选择题：Who is the main character in "Harry Potter"?A. RonB. HermioneC. HarryD. Draco77. 听力题：Her birthday is _____ (in/on) June.78. 选择题：What is the capital city of Spain?A. BarcelonaB. MadridC. SevilleD. Valencia答案: B79. 填空题：I enjoy cooking ______ (健康的) meals with my parents.80. 选择题：What do you call the process of planting seeds?A. SowingB. HarvestingC. CultivatingD. Tilling答案:A81. 选择题：How many players are there in a soccer team?A. 7B. 9C. 11D. 1382. 填空题：I turned my room into a ________ (玩具名称) playground.83. 选择题：What is the primary reason we need to drink water?A. To feel fullB. To stay hydratedC. To wash our handsD. To eat food答案:B84. 听力题：The _____ (garden) is beautiful.85. 听力题：The first successful blood transfusion was performed in _______.86. 选择题：What do we call a young tiger?A. CubB. PuppyC. KittenD. Calf87. 填空题：My aunt is very _______ (形容词) when it comes to cooking. 她的菜很好吃，真_______ (形容词).88. 填空题：Certain plants have developed ______ to deter herbivores. (某些植物已经发展出特征来吓跑食草动物。
小学上册第11次英语第1单元期末试卷
小学上册英语第1单元期末试卷英语试题一、综合题(本题有100小题，每小题1分，共100分.每小题不选、错误，均不给分)1.The process by which plants make their own food is called _______.2.在中国，________ (philosophy) 影响了教育和社会结构。
3.The chemical symbol for rhodium is ______.4.What is the main ingredient in ketchup?A. TomatoB. PepperC. OnionD. GarlicA5.How many pairs of wings do most insects have?A. OneB. TwoC. ThreeD. Four6.Plants need _____ (水分) to survive.7.What is the name of the famous tower in Paris?A. Leaning TowerB. Big BenC. Eiffel TowerD. ColosseumC8.She has a _____ (great) idea.9.The bonding of atoms to form molecules is called _______.10.The cake is ______ (yummy)!11.What is the name of the phenomenon where the moon blocks the sun?A. Solar eclipseB. Lunar eclipseC. SupermoonD. Blood moonA12.What is the term for a baby turkey?A. ChickB. PoultC. CalfD. KitB13. (Russian) Revolution led to the establishment of the Soviet Union. The ____14.The __________ is a famous mountain located in Nepal. (珠穆朗玛峰)15.The _____ (狮子) roars loudly in the zoo. It is called the king of the jungle. 狮子在动物园里大吼。
AVisuallyServoedMEMSManipulator
A Visually Servoed MEMS ManipulatorYu Sun,Michael A.Greminger,David P.Potasek,and Bradley J.Nelson Department of Mechanical EngineeringUniversity of MinnesotaMN55455,USA*************.eduAbstract.This paper reports on a visual servoing system capable of2DOF nanoposition-ing using a novel multi-axis electrostatic MEMS(MicroElectroMechanical System)device. The high aspect ratio micromanipulator was fabricated using a high yield process with Deep Reactive Ion Etching(DRIE)on Silicon-On-Insulator(SOI)wafers,which produces larger electrostatic forces and requires lower actuation voltages compared to most existing elec-trostatic microactuators.A real-time sub-pixel parameterized feature tracking algorithm of resolution is incorporated into the visual servoing loop.The resulting system is capable of visually servoing to a precision of in two axes using the inexpensive bulk micromachined multi-axis electrostatic micromanipulator and standard microscope op-tics with a CCD camera.Potential applications of the system are in the manipulation of subcellular structures within biological cells,and microassembly of hybrid MEMS devices. 1IntroductionMany microrobotic applications require multi-degree-of-freedom positioning at mi-cro and nanoscales.Actuation technologies capable of providing motion at this scale include piezoactuators[1],microstepping motors[2],highly geared electromagnetic servomotors[3],and Lorentz force-type actuators such as voice coil motors[4]. Typically these positioning systems are expensive and require extensive calibra-tion procedures.This paper reports on a visual servoing system capable of2DOF nanopositioning using a novel multi-axis electrostatic MEMS(MicroElectroMe-chanical System)manipulator.The3-D high aspect ratio transverse comb drive micromanipulator,formed by Deep Reactive Ion Etching(DRIE)on Silicon-On-Insulator(SOI)wafers,produces two orders of magnitude larger electrostatic forces than surface micromachined lateral comb drive microactuators[5][6][7][8][9][10]while the required actuation voltages are approximately ten times smaller.By removing the substrate beneath the comb drive structure,this reported micromanipulator does not require the use of a ground plane as a typical electrostatic microactuator,and the movable structure does not suffer from the leviation effect[11],i.e.,an unbalanced electricfiled distribution forces the structure to move out of the actuation plane.When a micromanipulation system is used in micromanipulation,such as mi-crorobotic surgery or cell manipulation,precise positioning is required.To increase the positioning precision,a sub-pixel vision tracking algorithm of resolu-tion[12]was developed to provide feedback in the visual servo loop.B. Siciliano and P. Dario (Eds.): Experimental Robotics VIII, STAR 5, pp. 255--264, 2003Springer-Verlag Berlin Heidelberg 2003256Y.Sun et al.The resulting system is capable of visually servoing to a precision of us-ing a novel and inexpensive bulk micromachined multi-axis electrostatic manipulator and standard microscope optics with a CCD camera.Minimal system calibration is required.Potential applications of the device are in the manipulation of subcellular structures within biological cells[13]shown in Fig.1,microassembly of hybrid MEMS devices,and manipulation of large molecules such as DNA or proteins.Fig.1.Microrobotic pronuclei DNA injection of a mouse embryo2MEMS-based electrostatic micromanipulator2.1Manipulator designThe design of the2DOF electrostatic manipulator is based on the use of offset electrostatic interdigitated comb drives and curved springs that serve asflexure hinges to allow planar motion in and.Fig.2shows the solid model of the micromanipulator design.The constrained outer frame and the inner movable plate are connected by four curved springs.When a voltage difference is applied on comb drive1and comb drive4,the generated electrostatic force causes the movable plate to move in,resulting in the movement of the manipulator for micromanipulation.To create motion along,comb drive2 and comb drive5are configured to be orthogonal to the comb drives in.The offset comb drive model is shown in Fig.3,where is the displacement of the movablefingers from the equilibrium position.The electrostatic force acting on the movable combfingers isA Visually Servoed MEMS Manipulator257Fig.2.Solid model of the two-axis micromanipulator(1) where is the number of parallel capacitor pairs;is the dielectric constant for the material(for air);is the permittivity of free space;;;is the overlapping area of eachfinger pair;and is the applied actuation voltage.The spring dimensions determine the system stiffness.Structural analysis was performed numerically.The force-deflection model of the spring in both and is(2) where is the deflection;is the force acting on the springs;is the YoungŠs modulus of silicon;is the width of the springs;is the height of the springs;in,and in.Finite element simulations of structural and electrostatic properties were per-formed in order to ensure that a range of motion of can be achieved in both and with actuation voltages less than in and in.2.2MicrofabricationThe main fabrication steps are illustrated in Fig.4.Fig.5shows the completed device.258Y.Sun et al.Fig.3.Offset comb drive modelStep A.Start from a double polished P-type wafer with crystal orientation of <100>.Step B.LPCVD(Low Pressure Chemical Vapor Deposition)1SiO.Step C.Fusion bond the wafer with SiO with another P-type wafer.Step D.CMP(Chemical Mechanical Polishing)the top wafer down to50;this forms an SOI wafer.Step E.E-beam evaporate Al to form Ohmic contacts;Liftoff to pattern Al.Step F.DRIE(Deep Reactive Ion Etching)to form the features on the back side such as the outer frame and movable plates.The buried1SiO layer acts as an etch stop layer and also as an insulator between the capacitors.Step G.DRIE the top side to form capacitive combfingers and curved springs.Step H.RIE(Reactive Ion Etching)to remove the buried SiO layer;This releases the devices and ends the fabrication process.The released devices were then wire bonded.A yield of86.4%has been achieved without significant process optimization.3Nanometer vision tracking algorithm3.1The template matching algorithmIn traditional template matching algorithms[14],objects are typically located to one pixel resolution and no change in orientation is assumed.To overcome these limitations,the template and the image are represented as a list of edge vertices obtained by the Canny edge operator[15]rather than a2D array of pixels.The template vertices and image vertices are related by the homogeneous transformation given by(3)A Visually Servoed MEMS Manipulator259Fig.4.Fabrication sequenceFig.5.SEM micrograph of the device260Y.Sun et al.where is a template vertex coordinate with respect to the-coordinate sys-tem;is the template vertex coordinate with respect to the-coordinate system;and is a homogeneous transformation matrix.The error function is given by(4)where is the scale factor of the template about its origin;is the rotation of the template about its origin;and are the and components of the translation of the origin of the template coordinate system with respect to the image coordinate system;are the coordinates the th edge pixel of the template transformed by(3);are the coordinates of the edge pixel in the image that is nearest to the point;and is the number of edge pixels in the template.By minimizing(4),the values of,,,and that best match the image in a least squares sense can be determined.3.2Performance optimizationsThe error function(4)is minimized by afirst-order multi-variable minimization technique called the Broydon-Fletcher-Goldfarb-Shanno(BFGS)method[16].Like the steepest decent method,the BFGS method is a gradient based minimization technique.The BFGS method differs from the steepest decent method in that it uses information from previous iterations in the choice of a new search direction giving it faster convergence rates than the steepest decent method.The error function(4)is computationally expensive because for each template vertex it is necessary to locate the image vertex that is nearest to it.The data structure employed to organize the pixel data is the KD-Tree[17].A KD-Tree canfind the nearest image vertex with operations as opposed to the operations required tofind the nearest pixel without using a spacial data structure,where is the number of vertex points in the image.3.3Resolution of the template matching algorithmWhen using a50X objective lens with0.42NA,the template matching algorithm is capable of tracking position to within a1uncertainty interval of using the least squares error measure(4).By using the least squares error measure,a normal error distribution is assumed[18],which may not always be the case for a microscopy image.The following robust error measure based on the Cauchy distribution[19]is used(5)where is the distance from each template pixel to the nearest image ing the Cauchy estimator,the1uncertainty interval of the tracking algorithm wasA Visually Servoed MEMS Manipulator261 reduced to.This gain in resolution by using a robust error measure can be attributed to the existence of noise in the image with a non-normal distribution.4Visual servoingThe two-axis micromanipulator is modelled individually in and as two spring-mass-damper systems.(6) where.The system in and consists of linear equations of motionand nonlinear electrostatic forces.In this section,the variables,,,,,, and coincide with the ones defined for(1).The approach to visual servoing is a position-based one.A proportional-integral ()PI visual servoing control architecture with a feedforward component as shown in Fig.6,was implemented.The feedforward component, which significantly increases system response and reduces system overshoot,is given as(7) Table1lists the recognized system stiffness from calibration and the results fromFig.6.Visual servoing scheme for nanopositioningfinite element structural analysis.The measurement of the motion of the features,denoted in Fig.6by, must be done continuously and quickly.The nanometer visual tracking algorithm operates at a full to measure this motion.Fig.7shows the template used to track the manipulator tip.A tracking resolution of was achieved.262Y.Sun et al.Table1.System stiffness determined from calibration and simulationstiffness in()in()simulation 3.31110.75calibration 2.81104.10Fig.7.Template used to track manipulator tipThe feedforward section increases system response.The visual servoing framework allows the device to be positioned precisely despite the nonlinear characteristics exhibited by the electrostatic actuator and the fact that significant hysteresis inthe device occurs when the comb drive is overdriven and capacitor pull-in occurs. Despite a control rate of which reduces disturbance rejection capability,results demonstrate that a controllable motion range of along and can be obtained to a precision of limited by the tracking algorithm and the microscope optics,which consisted of a50X objective with0.42NA.Another factor limiting thepositioning precision is environmental vibration,though afloating table was used to reduce this.Using the visual servoing framework,desired system response can be obtained forthe micromanipulation system.For example,when the system is used in microrobotic surgery and cell manipulation,an overdamped system response is desirable.Fig.8 shows system step responses along two axes.5ConclusionsExperimental results show that the novel inexpensive MEMS micromanipulator is visually servoed to a precision of with voltages ranging from in and in as predicted by FEA.The vision tracking algorithm demon-strates precision with a variance half that of sum-of-squared-differences least-squares trackers.Potential applications of the system are in the manipulation of subcellular structures within biological cells,and microassembly of hybrid MEMS devices.A Visually Servoed MEMS Manipulator263Fig.8.Step response of the system;(a)in;(b)inReferences1.Szita N.,Sutter R.,Dual J.,and Buser R.A.(2001)A micropipettor with integratedsensors.Sensors and Actuators A89,No.1-2,112–1182.Navathe C.P.,Dashora B.L.,Roy U.N.,Singh R.,Maheswari S.,and Kukreja L.M.(1998)Control system for Langmuir-Blodgett film deposition set-up based on microstepping.Measurement Science and Technology9,No.3,540–5413.Barth O.(2000)Harmonic piezodrive miniaturized servo motor.Mechatronics10,No.4-5,545–5544.Molenaar A.,Zaaijer E.H.,and Beek H.F.(1998)A novel long stroke planar magneticbearing actuator.The4th International Conference on Motion and Vibration Control, Zurich,Switzerland,1071–10765.Harness T.and Syms R.R.A.(2000)Characteristic modes of electrostatic comb-driveX-Y microactuators.J.Micromech.Microeng.10,7–146.Indermuehle P.F.,Linder C.,Brugger J.,Jaecklin V.P.,and Rooij N.F.(1994)Designand fabrication of and overhanging xy-microactuator with integrated tip for scanning surface profiling.Sensor and Actuators A43346–3507.Indermuhle P.F.,Jaecklin V.P.,Brugger J.,Linder C.,and Rooij N.F.(1995)AFMimaging with an XY-micropostioner with integrated tip.Sensors and Actuators A46-47 562–5658.Hirano T.,Furuhata T.,Gabriel K.J.,and Fujita H.(1992)Design,fabrication,and oper-ation of submicron gap comb-drive microactuators.Journal of Microelectromechanical Systems1,No.1,52–599.Tang W.C.,Nguyen T.H.,Judy M.W.,and Howe R.T.(1990)Electrostatic-comb driveof lateral polysilicon resonators.Sensors and Actuators A21-23328–33110.Yeh J.L.A.,Jiang H.,and Tien N.C.(1999)Integrated polysilicon and DRIE bulk siliconmicromachining for an electrostatic torsional actuator.Journal of Microelectromechan-ical Systems8,No.4,456–46511.Tang W.C.,Lim M.G.,and Howe R.T.(1992)Electrostatic comb drive levitation andcontrol method.Journal of Microelectromechanical systems1,No.4,170–17812.Greminger M.A.and Nelson B.J.(2001)Vision-based force sensing at nanonewtonscales.SPIE Microrobotics and Microassembly III,78–89264Y.Sun et al.13.Sun Y.and Nelson B.J.(2001)Microrobotic cell injection.IEEE International Confer-ence on Robotics and Automation1,620–62514.Pratt W.(1991)Digital Image Processing.John Wiley and Sons,New York15.Canny J.A.(1986)A computational approach to edge detection.IEEE Transactions onPattern Analysis and Machine Intelligence,8,No.6,679–69816.Vanderplaats G.(1984)Numerical Optimization Techniques for Engineering Design.McGraw-Hill,New York17.Samet H.(1990)The Design and Analysis of Spatial Data Structures.Addison-Wesley,Reading,MA.18.Draper N.R.(1998)Applied Regression Analysis,3rd Edition.John Wiley and Sons,New York19.Stewart C.V.(1999)Robust parameter estimation in computer vision.SIAM Review,41,No.3,513–537。
Ultra light weight proppants in shale gas fracturing(超轻型陶粒在页岩气压裂中应用)
Copyrightby Abhishek Gaurav2010The Thesis Committee for Abhishek Gaurav Certifies that this is the approved version of the following thesis:Ultra Light Weight Proppants inShale Gas FracturingAPPROVED BYSUPERVISING COMMITTEE:Supervisor:Kishore K. MohantyMukul M. SharmaUltra Light Weight Proppantsin Shale Gas FracturingbyAbhishek Gaurav, B. TechThesisPresented to the Faculty of the Graduate School of The University of Texas at Austinin Partial Fulfillmentof the Requirementsfor the Degree ofMasters of Science in EngineeringThe University of Texas at AustinDecember 2010DedicationTo my family and friendsAcknowledgementsI would like to thank my advisor Dr. Kishore K. Mohanty for his help and guidance in completing my thesis. I am grateful for his patience and kindness during the course of the project. He taught me the ability to conduct research independently, which is an invaluable gift for me.I would also like to thank Dr. A. Daneshy, Dr. Qi Qu, Dr. T. J. Pisklak for their timely advice and direction in completing this project. I received valuable input from them throughout the course of this project.Finally I would like to thank Dr. Eric Dao for his constant help and support in conducting my experiments.December 3, 2010vAbstractUltra Light Weight Proppantsin Shale Gas FracturingAbhishek Gaurav, M. S. E.The University of Texas at Austin, 2010Supervisor: Kishore K. MohantyAbstract:The goal of the present work is to improve shale reservoir stimulation treatment by using ultra light weight proppants in fracturing fluids. Slickwater has become the most popular fracturing fluid for fracturing shales in recent times because it creates long and skinny fractures and it is relatively cheap. The problem with slickwater is the high rate of settling of common proppants, e.g. sand, which results in propped fractures which are much smaller than the original fractures. Use of gels can help in proppant transport but introduce large formation damage by blocking pores in nano-darcy shales. Gel trapping in the proppant pack causes reduction in permeability of the proppant pack. The light weight proppants which can easily be transported by slickwater and at the same time be able to provide enough fracture conductivity may solve this problem. Three ultra light weight proppants (ULW1, ULW2, and ULW3) have been studied. Thevimechanical properties of the proppant packs as well as single proppants have been measured. Conductivity of proppant packs has been determined as a function of proppant concentration and confining stress at an average Barnett shale temperature of 95o C. The crush strengths of all the three proppant packs are higher than typical stresses encountered (e.g., Barnett).ULW1 and ULW2 are highly deformable and do not produce many fines. ULW3 ha s a higher Young‟s modulus and produces fines. Conventionally, the proppant conductivity decreases with decreasing proppant concentration and increasing confining stress. But in cases of ULWs, for a partial monolayer, conductivity can be as large as that of a thick proppant pack. The settling velocity is the lowest for ULW1, intermediate for ULW2 and the highest for ULW3. This work contributes new mechanical, conductivity, and settling data on three ultra light weight proppants. Application of light weight proppants in stimulation treatments in shale reservoirs can lead to large propped fractures, which can improve the productivity of fractured shale reservoirs.viiTable of ContentsList of Tables (x)List of Figures (xi)1.Introduction (1)1.1.Ultra Light weight Proppants (2)1.2.Objective (2)2.Literature Review (3)2.1.Fracturing Aspects (3)2.2.Proppants and Fracturing (7)2.2.1.Slickwater Fracturing (7)2.2.2.Partial Monolayers (12)2.2.3.Ultra light weight proppants (18)2.2.4.Conclusions (20)3.Approach and Methodology (22)3.1.Estimation of physical properties (22)3.1.1.Bulk Density (22)3.1.2.Absolute Density (22)3.1.3.Sphericity (22)3.1.4.Sieve-size distribution (23)3.2.Estimation of mechanical properties (24)3.2.1.Strength (24)3.2.2.Crush Test (24)3.2.3.Conductivity Test (24)4.Description and Application of Equipment and Processes (25)4.1.Estimation of physical properties (25)4.1.1.Bulk Density (25)4.1.2.Absolute Density (27)4.1.3.Strength and Crush Test (29)viii4.1.4.Conductivity Test (30)5.Results (33)5.1.Absolute Density, Bulk Density, Porosity and Sphericity (33)5.2.Size Distribution (37)5.3.Crush Test (37)5.4.Strength Test of Single Proppant Particle (45)5.4.1.ULW 1 (45)5.4.2.ULW 2 (47)5.4.3.ULW 3 (48)5.5.Deformability (50)5.6.Conductivity Tests (52)6.Conclusions and Recommendations for Future Work (57)6.1.Conclusions (57)6.2.Recommendations for future work (58)References (59)Vita (62)ixList of TablesTable 5.1 Tabular representation of bulk density, nominal density, porosity and sphericity for the three proppants being studied (33)Table 5.2 Tabular representation of fines formation and Young‟s mod ulus value for proppant packs for various cases (41)xList of FiguresFigure 2.1 McGuire and Sikiora‟s producing-rate folds-of-increase curves (1960) (3)Figure 2.2 Productivity-index-ratio increase from fracturing steady-state flow, vertical propped fractures (Tinsley et al., 1969) (4)Figure 2.3 Producing-rate type curves with propped vertical fractures-transient flow, constant wellbore pressure (Agarwal et al., 1979) (5)Figure 2.4 Producing-rate type curves with propped vertical fractures-transient flow, constant flow-rate (Cinco et al., 1978) (6)Figure 2.5 Fracture width comparison for various fracturing treatments (Palisch and Vincent, 2008) (8)Figure 2.6 Proppant settling in freshwater for various proppants (Aboud and Melo, 2007) (9)Figure 2.7 Terminal velocity of different sized particles predicted by Stoke‟s equation and corrected for inertial effects in 1 cp fluid (10)Figure 2.8 Terminal velocity of different sized particles predicted by Stoke‟s equation and corrected for inertial effects in 10 cp fluid (11)Figure 2.9 Correlations for effect of solids concentration on settling velocity (11)Figure 2.10 Wall effects using the average velocity (12)Figure 2.11 Proppant particles in contact with each other in a full mono-Layer and sparsely distributed particles in a partial mono-layer (Brannon and Malone, 2004) (13)Figure 2.12 Darin and Huitt‟s work on monolayers and thick packs of 20/40 Sand (13)Figure 2.13 Weight percent crushed for various concentrations at 6000 psi stress (Howard and Fast, 1970) (14)Figure 2.14 Full monolayers of various proppant being tested for conductivity at 1000 psi stress (Wang and Fredd, 2008) (15)Figure 2.15 Base line conductivity vs. stress for a thick multi layered pack and a partial monolayer for 16/25 ULW 1.25 at 150o F (16)Figure 2.16 Conductivity vs. proppant concentration for various sizes of Brady sand at 1,000 psi closure stress and 100o F (16)Figure 2.17 Conductivity vs. proppant concentration for 8/12 Brady sand at various closure stress (17)Figure 2.18 Conductivity vs. proppant concentration at 1000 psi closure stress comparing Brady sand and ULW 1.25 (17)Figure 2.19 Conductivity vs. proppant concentration for 8/12 ULW 1.25 at different temperatures (18)Figure 2.20 Simulation of Ottawa sand proppant placement at pumping rate of 80 bpm using Mfrac simulator (19)Figure 2.21 Simulation of light weight proppant placement at pumping rate of 80 bpm using Mfrac simulator (20)Figure 3.1 Chart for visual estimation of sphericity and roundness, X axis-roundness and Y axis-sphericity (23)Figure 3.2 Riley Sphericity: ΨR= (Di/Dc) 0.5 (23)xiFigure 4.1 Bulk density measurement for ULW 1 in a graduated glass cylinder (25)Figure 4.2 Bulk density measurement for ULW 2 in a graduated glass cylinder (26)Figure 4.3 Bulk density measurement for ULW 3 in a graduated glass cylinder (26)Figure 4.4 Absolute density measurement for ULW 1 in a graduated glass cylinder using propyl alcohol (27)Figure 4.5 Absolute density measurement for ULW 2 in a graduated glass cylinder using propyl alcohol (28)Figure 4.6 Absolute density measurement for ULW 3 in a graduated glass cylinder using propyl alcohol (28)Figure 4.7 Tool used for testing strength or proppant in a HUMBOLDT strength test machine (29)Figure 4.8 API conductivity Cell under stress inside an oven maintained at 95o C (31)Figure 5.1 Two-dimensional close up image of ULW 1 (34)Figure 5.2 Two-dimensional close up image of ULW 2 (35)Figure 5.3 Two-dimensional close up image of ULW 3 (35)Figure 5.4 Sphericity and Roundness distribution for three types of proppants ULW 1, ULW 2 and ULW 3 (36)Figure 5.5 Size Distribution of the three types of proppants (37)Figure 5.6 Maximum possible values for horizontal stresses in Barnett shale, Haynesville shale and Woodford shale (40)Figure 5.7 Stress vs. Strain curve for ULW 1 at ~95o C (42)Figure 5.8 Stress vs. Strain curve for ULW 1 at ~25o C (42)Figure 5.9 Stress vs. Strain curve for ULW 2 at ~95o C (43)Figure 5.10 Stress vs. Strain curve for ULW 2 at ~25o C (43)Figure 5.11 Stress vs. Strain curve for ULW 3 at ~95o C (44)Figure 5.12 Stress vs. Strain curve for ULW 3 at ~25o C (44)Figure 5.13 Strength test for single particles of ULW 1 at ~95o C (46)Figure 5.14 Strength test for single particles of ULW 1 at ~25o C (46)Figure 5.15 Strength test for single particles of ULW 2 at ~95o C (47)Figure 5.16 Strength test for single particles of ULW 2 at ~25o C (48)Figure 5.17 Strength test for single particles of ULW 3 at ~95o C (49)Figure 5.18 Strength test for single particles of ULW 3 at ~25o C (49)Figure 5.19 Elastic modulus of ULW 1 at ~25o C (51)Figure 5.20 Elastic modulus of ULW 2 at ~25o C (51)Figure 5.21 Elastic modulus of ULW 3 at ~25o C (52)Figure 5.22 Fracture conductivity for ULW 1 (54)Figure 5.23 Fracture conductivity for ULW 2 (55)Figure 5.24 Fracture conductivity for ULW 3 (56)xii1.IntroductionThe Barnett shale, since its discovery, is being produced from more than 8,000 wells today (Wang et al., 2008). The success of gas production from Barnett can be attributed to horizontal drilling and hydraulic fracture stimulation. But there were many lessons learned while exploiting Barnett shale gas reserves. Fracture stimulation in shale gas reserves is not the same as fracturing typical gas reservoirs. These shale gas formations have permeability of the order of 10-9 Darcies. Therefore, hydraulic fractures need to be long and extensive to maximize reservoir contact.Silica sand has been the most commonly used proppant. The ready availability and lower cost makes it attractive for stimulation treatments. If conventional proppants, like Ottawa sand (specific gravity = 2.65), are used in typical fracturing fluid like slick water, proppants settle during the fracturing process before reaching the end of the long fractures, due to which a lot of producible surface area is lost after stimulation. Re-stimulation is an option, but it makes the process more expensive. Sintered bauxite, another commonly used proppant material, is significantly stronger than sand and is used in deeper formations where high fracture closure stresses severely crush sand. The fracturing fluids can carry the conventionally used heavy proppants if they are made more viscous by using polymers in them. This viscosity can be further increased by cross-linking these polymers. However, when the fracturing fluid is very viscous, the resulting fractures are short and wide, and do not reach a major part of the producible area. Also, the large polymer molecules can plug the fracture faces of these extremely low permeability shales.11.1.U LTRA L IGHT WEIGHT P ROPPANTSOne way to overcome these problems is to use light weight proppants which can be transported by a less complex fracturing fluid and at the same time, be strong enough to withstand reservoir stresses. The result of multi-disciplined research and development efforts created a new class of ultra-light weight proppants, having both low specific gravity and requisite mechanical strength (Brannon and Malone). These light weight proppants could effectively be used with simpler fracturing fluids, like slick water. The first generation of ULWPs were resin-impregnated and coated, sized, chemically modified walnut hulls, having a specific gravity of 1.25; less than half that of sand (2.65). These proppant particles could achieve neutral buoyancy in fracturing water. Settling rates for these first generation ULWPs were 24% that of similarly sized sand. Another type of ULWPs developed around the same period were resin coated ceramic proppants, which had a specific gravity of 1.75; much lighter than sand particles. In terms of transportability, these proppants showed more promise with slickwater than conventional sand or sintered bauxite (sp. gr. ~ 3.6). Typical fracturing processes are extremely water intensive. Once the fracturing job is over, there are other issues with the disposal of the fracturing fluids. The proppants being light also gives us an option of using fracturing foams (mixture of gas and liquid phase), thereby reducing the usage of water.1.2.O BJECTIVEThis work focuses on three ultra light weight proppants, ULW-1 (polymeric), ULW-2 (resin coated and impregnated ground walnut hull) and ULW-3 (resin coated ceramic), supplied by BJ services. The physical properties of these proppants have been evaluated along with their mechanical properties. These tests are followed up with conductivity measurements of various concentrations of proppants at different stress levels.22.Literature Review2.1.F RACTURING A SPECTSVarious graphical/computerized methods have been developed to estimate the effects of fracture length and fracture conductivity on well productivity increase for both low permeability and high permeability reservoirs. For high permeability reservoirs, where steady-state (or pseudo steady state) flow develops relatively quickly, methods provided by McGuire and Sikora (1960), can be used to estimate the productivity increase from a fracturing treatment. Figure 2.1 and Figure 2.2 indicate productivity increase as a function of various fracturing parameters. If the fracturing parameters can be controlled using a systematic fracture design, productivity can be increased up to a certain extent.Figure 2.1 McGuir e and Sikiora‟s producing-rate folds-of-increase curves (1960)3In Figure 2.1, it is shown that increasing the value of fracture conductivity can increase the productivity of the well significantly only if the fracture penetration (L/R e = Fracture half-length/Reservoir Radius > 0.2) is high enough. As fracture length increases, productivity enhancement increases. For lower fracture penetration (around 0.1 or less), even a significant increase in fracture conductivity, helps in enhancing the productivity only by a factor of 3. This graph also shows that the productivity enhancement does not increase with the increase in conductivity beyond a certain value of fracture conductivity (or relative conductivity) for a given fracture length.Figure 2.2 Productivity-index-ratio increase from fracturing, steady-state flow, vertical propped fractures (Tinsley et al., 1969)4Figure 2.2 indicates for a high L/Re, a good stimulation treatment (high fracture conductivity) value can stimulate the productivity up to 8 times the original productivity.These methods do not apply to low permeability reservoirs because, for low permeability reservoirs, flow remains in transient state throughout the major portion of well‟s life. Agarwal et al. (1979) and Cinco et al. (1978) developed methods for evaluation of increase in productivity through fracturing treatments for low permeability reservoirs. Figure 2.3 indicates the plot developed for the case of constant wellbore pressure system. Figure 2.4 indicates the same plot developed for constant flow rate system.Figure 2.3 Producing-rate type curves with propped vertical fractures-transient flow, constant wellbore pressure (Agarwal et al., 1979)5Figure 2.4 Producing-rate type curves with propped vertical fractures-transient flow, constant flow-rate (Cinco et al., 1978)The ratio of (fracture conductivity)/ (reservoir permeability x fracture half length) i.e., dimensionless fracture conductivity, is a key parameter in these plots. It should be noticed, value for this dimensionless parameter can be high for a low permeability reservoir even when the fracture conductivity is small (of the order of 1 mD-ft). From figures 2.3 and 2.4, for any stimulation treatment, higher dimensionless fracture conductivity gives a higher cumulative production over time (or a lower flowing wellbore pressure), but production does not increase much beyond a dimensionless fracture conductivity of 10. Along with fracture penetration, fracture conductivity plays a pivotal role in enhancing production from any fracturing treatment.62.2.P ROPPANTS AND F RACTURINGConventional wisdom suggests, stronger the proppant, higher is its density (Rickards et al., 2003). It is difficult to place heavier proppants efficiently in between the fracture faces in long fractures. Rickards and Brannon (2003) conducted a series of experiments testing the utility of lower density proppants under various stress conditions. Efforts in the past in this direction led to the conclusion, that, light weight proppants cannot even maintain sufficient conductivity at a stress level as low as 1000 psi. But with increased usage of slickwater or foam fracturing, the necessity of using …easy to transport‟ proppants in particular stimulation treatments has risen.2.2.1.Slickwater FracturingPalisch and Vincent (2008) in their works have highlighted the importance of slickwater fracturing treatments. More than 30% of stimulation treatments in 2004 have been slickwater fracturing (Schein, 2005). Slickwater fracturing, as defined by Schein, is a fracture treatment that utilizes a large volume of water to create an adequate fracture geometry and conductivity to obtain commercial production from low perm, large net pay reservoirs. These reservoirs come broadly in the area of Coal Bed Methane, Tight Gas Sands and Shale Gas Plays. The most desirable fracture system in these reservoirs is long and narrow extending to a wider area. The most important slickwater fracturing benefits lie in, reduced gel damage, cost containment, higher stimulated reservoir volume and better fracture containment. But concerns come along with the benefits of using slickwater treatments. The foremost would be poor proppant transport, followed by excessive usage of water and narrower fracture widths.7Figure 2.5 Fracture width comparison for various fracturing treatments (Palisch and Vincent, 2008)Figure 2.5 clearly indicates the decrease in fracture width, once we switch from cross-linked gels to slickwater. But this might be a blessing in disguise for low perm reservoirs. In a nano-darcy permeability reservoir, a long-extensive-wide network of fracture system is desired. With such a fracture system our SRV (stimulated reservoir volume) would be greater than usual. Bigger the SRV, higher is the production from shale wells. To create such a fracture system, a less viscous fracturing fluid like slickwater (unlike cross linked gels) is needed, which can effectively create thin fractures distributed over a wider area. But, proppants should be properly placed throughout the fracture network system before the fracturing fluid is withdrawn. If there are proppants available, which are easy to transport throughout the fracture network with slickwater, possibility of their usage should be looked into.8Figure 2.6 Proppant settling in freshwater for various proppants (Aboud and Melo, 2007)Aboud and Melo (2007) compared the static settling rates of various proppants in freshwater based on Stoke‟s law (Figure 2.6),V s = () (2.1)where, V s is the Stoke‟s settling velocity of a single particle, and are the density of the particle and the suspending fluid, respectively, d p is the diameter of the particle, g is acceleration due to gravity and µ is the viscosity of the fluid.Stokes law has many simplifying assumptions. For Example,-Fluid must be stagnant-Absence of “wall effects”-Proppant particles are perfectly spherical-Particles fall gradually (laminar flow)-Absence of inter-particle contact9In spite of these assumptions, Stoke‟s law helps us to compare the relative settling rate of various proppants based on their density/size and density/viscosity of the fluid (Palisch and Vincent, 2008). This settling velocity is applicable only for small particles Reynolds numbers (Re p<2) settling in static fluid when wall effects are not important (Asmolov, 2002). For larger Reynolds numbers, settling velocity is affected by the turbulent wakes generated behind the particle. To account for this, Stokes law has been corrected as,V Re = V s f(Re p) (2.2)As indicated in Figure 2.7 and Figure 2.8, the creation of wakes due to higher Reynolds number resulted in decrease in settling velocity.Figure 2.7 Terminal velocity of different sized particles predicted by Stoke‟s equation and corrected for inertial effects in 1 cp fluid10Figure 2.8 Terminal velocity of different sized particles predicted by Stoke‟s equation and corrected for inertial effects in 10 cp fluidThese results are applicable to single particles and cannot be applied to proppant slurries which are pumped during any fracturing treatment. Gadde et al. (2004) included the effect of proppant concentration on settling which is shown in Figure 2.9. The overall effect of higher proppant concentration resulted in reduction of settling.Figure 2.9 Correlations for effect of solids concentration on settling velocity11Gadde et al. (2004) studied the effect of fracture width on settling velocities and found out the modified stokes settling velocity also depends on ratio of the radius of the particle to the width of the slot, guided by equation 2.3,(2.3)where, a is the radius of the sphere, l is the distance of the centre of sphere to either wall, V s is the stokes settling velocity and V w is the modified settling velocity which includes the wall effects. Figure 2.10 shows the wall effects tend to reduce settling of proppant particles.Figure 2.10 Wall effects using the average velocity2.2.2.Partial MonolayersDarin and Huitt (1959) introduced the concept of partial monolayers which is shown in the Figure 2.11.12Figure 2.11 Proppant particles in contact with each other in a full mono-Layer and sparsely distributed particles in a partial mono-layer (Brannon and Malone, 2004)Their reasoning for the success of a partial monolayer was attributed to possibility of flow through open spaces around the sparsely distributed proppant particles.Figure 2.12 Darin and Huitt‟s work on monolayers and thick packs of 20/40 SandBut, doubts on uniform distribution of these proppants, their crush strength and embedment into the fracture faces, made this concept unpopular. Howard and Fast (1970) tried to determine the percent of proppants crushed when used as a full-monolayer. They13tested various concentrations of three different 20/40 proppants (resin coated sand, light weight ceramic and white sand) and tried to determine the amount of fines formed for each of them at 6000 psi stress, the results of which are shown in the Figure 2.13.Figure 2.13 Weight percent crushed for various concentrations at 6000 psi stress (Howard and Fast, 1970)If the success of proppant pack is attributed to less crushing of the pack, then, it is clear that at around a concentration of 0.2 lbm/ft2 (a monolayer) this proppant is a complete failure at 6000 psi stress. Light weight proppants are needed that do not form much fines at a high confining stress.14Figure 2.14 Full monolayers of various proppant being tested for conductivity at 1000 psi stress (Wang and Fredd, 2008)Fredd et al. (2008) showed (Figure 2.14), how there can be a two-order magnitude difference in conductivity when using different materials for full monolayers. High strength material like sintered bauxite full monolayer gives 100 times more conductivity than monolayer of white sand at a stress level of 4000 psi. Sintered bauxite is heavier than even conventional proppant (sand), which means, its monolayer placement with slickwater is doubtful.Brannon and Malone (2004) measured the conductivity of differently sized sand proppant particles and ULW 1.25 (resin coated and impregnated light weight proppant) proppant particles at different temperatures. They used sandstone cores enclosing proppant pack. In Figure 2.15, conductivity results for 16/25 ULW 1.25 is plotted. The conductivity plot for a partial monolayer runs almost parallel to the conductivity plot for a thick pack of the same proppant with an offset of around 1000 mD-ft.15Figure 2.15 Base line conductivity vs. stress for a thick multi layered pack and a partial monolayer for 16/25 ULW 1.25 at 150o FFigure 2.16 Conductivity vs. proppant concentration for various sizes of Brady sand at 1,000 psi closure stress and 100o F16Figure 2.17 Conductivity vs. proppant concentration for 8/12 Brady sand at various closure stressFigure 2.18 Conductivity vs. proppant concentration at 1000 psi closure stress comparing Brady sand and ULW 1.2517Figure 2.19 Conductivity for 8/12 ULW 1.25 at different confining stress and temperaturesIt can be inferred from this study that, increasing the size of proppant enhances the proppant conductivity. Monolayers of both Brady sand and ULW 1.25 were as good as thick packs. Conductivity value of as high as 100000 mD-ft could be achieved using partial monolayers at a closure stress of 1000 psi for these proppants. It should be noted though; sp. gr. of ULW 1.25 is less than half of Brady sand. So, a significantly smaller amount of ULW 1.25 is required to fill the same space as compared to sand particles. As shown in Figure 2.19, increasing temperature decreased the overall conductivity of the ULW 1.25. This decrease was more significant at higher stress levels.2.2.3.Ultra light weight proppantsAs Palisch and Vincent (2008) rightly pointed out, the ideal properties of a proppant for its application in slick water fracturing treatments for low permeability reservoirs would be light as water, high strength, and cheap. But, it is impossible to get all these ideal18properties in one product. Unless, the concept of monolayer can be rightly applied in the field and these individual proppant particles can sustain high stresses for longer periods of time at reservoir conditions. Rickards and Brannon (2004) tested resin coated/impregnated walnut hull proppants and resin coated porous ceramic proppants in their work, where, physical and mechanical properties of these proppants were tested at room temperature. Using Mfrac (Figure 2.20 and Figure 2.21) they tried to highlight better placement properties of light weight proppants with slickwater as compared to sand with slickwater.Figure 2.20 Simulation of Ottawa sand proppant placement at pumping rate of 80 bpm using Mfrac simulator19Figure 2.21 Simulation of light weight proppant placement at pumping rate of 80 bpm using Mfrac simulatorTerracina et al. (2010) in their recent publication stressed on the problem of proppant embedment, which is usually overlooked before evaluating proppant performance. While using proppants in soft rocks (soft shales), significant embedment might decrease the conductivity of a monolayer significantly. Though, monolayer of the same proppant might perform very well when used in harder formations (hard shales).2.2.4.Conclusions-Slick water fracturing is the stimulation treatment of choice for low permeability reservoirs.-Settling of conventional proppants is a huge concern in slick water stimulation treatments.-Partial monolayers of light weight proppants which are easy to transport with slick water might be a solution.-Crush test might not apply as much to deformable proppants as it does to ceramic proppants and sand grains.20。
2024年01版小学6年级下册第十一次英语第六单元真题
2024年01版小学6年级下册英语第六单元真题考试时间：80分钟（总分:110）B卷考试人：_________题号一二三总分得分一、选择题(共计20题，共40分)1、What is the capital of El Salvador?A. San SalvadorB. Santa AnaC. San MiguelD. La Libertad2、What is the capital of Denmark?A. CopenhagenB. AarhusC. OdenseD. Aalborg3、选择题：What do we call a person who studies meteorology?A. MeteorologistB. ClimatologistC. GeographerD. Environmental Scientist4、What is the name of the fairy tale character who had a magic mirror?A. CinderellaB. Snow WhiteC. RapunzelD. Belle5、Which planet is known as the Red Planet?A. EarthB. MarsC. JupiterD. Saturn6、What is the name of the boundary beyond which no light can escape a black hole?A. Event HorizonB. SingularityC. Photon SphereD. Accretion Disk7、选择题：What is the name of the toy that can fly?A. CarB. KiteC. TrainD. Boat8、Which animal is known for its stripes?A. LionB. ElephantC. ZebraD. Giraffe9、选择题：What do we call the time of day when the sun sets?A. SunriseB. NoonC. SunsetD. Midnight10、选择题：What is the primary color of the sun?A. BlueB. YellowC. PurpleD. Green11、选择题：What do we call the area where a river meets the ocean?A. DeltaB. EstuaryC. BayD. Coast12、选择题：What is the name of the famous detective created by Arthur Conan Doyle?A. Hercule PoirotB. Sherlock HolmesC. Philip MarloweD. Sam Spade13、Which of these is a type of measurement?A. LengthB. ColorC. ShapeD. Size14、What is the largest mammal?A. ElephantB. Blue WhaleC. GiraffeD. Hippo15、What is the currency used in the USA?A. EuroB. DollarC. PoundD. Yen16、选择题：What is the name of the famous scientist who formulated the laws of motion?A. Isaac NewtonB. Albert EinsteinC. Galileo GalileiD. Nikola Tesla17、What is the opposite of ‘young’?A. NewB. OldC. FreshD. Recent18、What is the main ingredient in chocolate?A. CocoaB. WheatC. SugarD. Milk19、How many bones are there in the human body?A. 206B. 215C. 195D. 25020、Which of these is a common pet?A. CowB. DogC. HorseD. Sheep二、听力题(共计20题，共40分)1、听力题：The dog is _______ (barking).2、听力题：The rabbit is ___ (hiding) in the bushes.3、听力题：The main product of cellular respiration is _______.4、听力题：The _____ (whistle) is loud.5、听力题：The chemical formula for bismuth oxide is _______.6、听力题：The ______ loves to teach children.7、听力题：My brother is very ________.8、听力题：Astronomical events can be predicted using _______.9、听力题：A _______ is a measure of the amount of solute in a solution.10、听力题：A solution that does not conduct electricity is called a ______ solution.11、听力题：Many plants grow well in _______ soil.12、听力题：The Earth's surface is constantly reshaped by natural ______.13、听力题：Oxygen is necessary for ______.They are _____ (playing) in the park.15、听力题：We play ______ at recess. (tag)16、听力题：An alkaline solution has a pH greater than _____.17、听力题：The periodic table is organized by increasing ______ number.18、听力题：A chemical reaction that produces light and heat is called a _____ reaction.19、听力题：The ______ is known for her artistic flair.20、听力题：We will _____ (visit/stay) our friends this weekend.三、填空题(共计20题，共10分)1、corporate responsibility) promotes ethical business practices. 填空题：The ____2、填空题：Many flowers can attract __________ (蝴蝶).3、填空题：My sister loves to play with ______ (小猫).4、填空题：My _______ (猫) loves to chase after strings.5、填空题：The cake is _______ (在桌子上).6、填空题：I have a toy ______ (飞机) that can fly high in the sky. It is very ______ (酷).7、填空题：The first electric car was invented in the _______ century. (19)My _____ (小猫) likes to climb.9、填空题：My sister’s birthday is in _______ (月份). 她会 _______ (动词)庆祝.10、填空题：We have a ______ (丰富的) range of activities at school.11、填空题：My sister is known for her __________ (创造性).12、填空题：My _____ (爷爷) tells great stories.13、填空题：The _______ (老虎) hunts for food.14、填空题：I enjoy ______ (参与) in discussion forums.15、填空题：The tree has green ______.16、填空题：I want to learn how to _______ (骑自行车).17、填空题：The caterpillar will become a _______ (毛毛虫会变成_______).18、填空题：The bird is perched high in the ______.19、填空题：My _____ (外婆) tells me stories about her life when she was young. 我外婆告诉我她年轻时的生活故事。
2024年小学三年级下册I卷英语第一单元测验试卷
2024年小学三年级下册英语第一单元测验试卷考试时间：100分钟（总分:140）A卷考试人：_________题号一二三四五总分得分一、综合题(共计100题)1、选择题：What is the name of the famous mountain range in Europe?A. RockiesB. HimalayasC. AlpsD. Andes2、听力题：I want to ________ (encourage) others.3、填空题：The lion is known as the ______ of the jungle.4、What do you call a young pelican?A. ChickB. CalfC. KitD. Pup5、听力题：The cassowary is a large ____.6、听力题：A _____ (solution) is a homogeneous mixture of two or more substances.7、What do we call the spiral-shaped galaxies?A. Elliptical GalaxiesB. Irregular GalaxiesC. Spiral GalaxiesD. Lenticular Galaxies8、听力题：The Big Bang theory explains how the _______ began.9、Listen and color.(听录音，涂颜色)10、Which is the smallest planet in our solar system?A. MercuryB. VenusC. MarsD. Pluto11、填空题：A small ___ (小鹦鹉) sits on my shoulder.12、选择题：How many rings are on the Olympic flag?A. 3B. 4C. 5D. 613、What do we call the act of protecting an area of wildlife?A. ConservationB. PollutionC. PreservationD. Restoration答案:A14、听力题：She loves to ________ (write) stories.15、What do you call a musical performance by a group of singers?A. SoloB. ChoirC. BandD. Orchestra答案: B16、What do we call a young female cat?A. KittenB. PuppyC. CubD. Chick答案：A17、填空题：We can _______ a fun game night.18、听力题：A reaction that releases gas and energy is often an indicator of a ______ change.19、听力题：A reaction that produces a color change is often indicative of a ______ change.20、填空题：The __________ (古代波斯) was known for its great emperors.21、permaculture) design mimics natural ecosystems. 填空题：The ____22、填空题：The sunflower grows tall in the ______.23、填空题：My dog loves to chase _______ (球).24、What is the capital of Jamaica?A. KingstonB. Montego BayC. Ocho RiosD. Negril答案: A25、How do you say "forest" in Spanish?A. BosqueB. ForêtC. WaldD. ForestaBirds can _______ in the sky.27、听力题：The snow is ___. (falling)28、听力题：My grandma enjoys baking ____ (cakes) for birthdays.29、What shape has three sides?A. SquareB. TriangleC. CircleD. Rectangle答案:B30、What is the only mammal that can fly?A. BatB. EagleC. SparrowD. Pigeon答案:A31、听力题：The process of burning is called ______.32、What do we call the frozen form of water?A. SteamB. LiquidC. IceD. Snow答案:C33、填空题：The signing of the Magna Carta took place in ________ (1215).34、tropical) region has a warm climate year-round. 填空题：The ____35、How many colors are in a traffic light?A. OneB. TwoC. ThreeD. Four答案: CMy ________ (玩具) is a celebration of creativity.37、听力题：The stars _____ (shine/shining) at night.38、What is the name of the famous American actress known for "Pride and Prejudice"?A. Keira KnightleyB. Natalie PortmanC. Emma WatsonD. Anne Hathaway答案：A39、填空题：I love watching _______ (企鹅) slide on ice.40、What do we call the small pieces of paper we use to write notes?A. NotebookB. Sticky NotesC. Index CardsD. Post-it Notes41、听力题：She is a great ___. (friend)42、听力题：A wave can be described using its frequency and ______.43、填空题：Julius Caesar was a famous leader in __________ (罗马).44、How many players are on a netball team?A. 6B. 7C. 8D. 945、What do we call the process of water turning into vapor?A. EvaporationB. CondensationC. PrecipitationD. Freezing答案:A46、What is the term for a group of wolves?A. PackB. PodC. FlockD. Pride47、听力题：The capital city of Nicaragua is __________.48、填空题：My _____ (朋友) is coming over today.49、community engagement strategy) fosters participation. 填空题：The ____50、填空题：My aunt loves __________ (画画).51、听力题：Organic compounds always contain _____.52、填空题：The __________ (历史的协作) encourages partnership.53、听力题：A _______ is an important part of the ecosystem.54、What is the name of the famous ancient city in Greece?A. AthensB. CorinthC. DelphiD. All of the above55、填空题：_____ (earthworms) help aerate the soil.56、Which planet is known as the Red Planet?A. EarthB. MarsC. JupiterD. Venus57、填空题：We have a ______ (丰富的) variety of activities.I can _____ my bicycle very fast. (ride)59、选择题：What is the name of the famous musician known for his "Moonwalk" dance move?A. Elvis PresleyB. Michael JacksonC. PrinceD. Freddie Mercury60、How many hours are there in a day?A. 24B. 12C. 36D. 2061、Which bird is known for its colorful feathers?A. SparrowB. PeacockC. EagleD. Penguin答案:B62、What do we call a scientist who studies fossils?a. Paleontologistb. Archaeologistc. Geologistd. Biologist答案:a63、填空题：My _____ (小猫) purrs when happy.64、填空题：The ________ (交通工具) in our city includes buses and trains.65、听力题：A __________ is a famous archaeological site.66、填空题：The country known for its traditional dances is ________ (印度).67、听力题：The teacher is ___ (kind/mean).The __________ is famous for its geothermal activity.69、填空题：I like to _____ (decorate) my home with plants.70、填空题：My dad encourages me to be __________ (自信).71、听力题：The __________ is a region known for its natural beauty.72、What color do you get when you mix red and white?A. PinkB. PurpleC. OrangeD. Brown答案:A73、What do you call a scientist who studies rocks?A. BiologistB. ChemistC. GeologistD. Physicist答案: C74、听力题：A __________ is a mixture where one substance is uniformly distributed in another.75、听力题：My uncle is a talented ____ (actor).76、填空题：Learning about _____ (传统) plants is interesting.77、What do we call a scientist who studies plants?A. BotanistB. ZoologistC. ChemistD. Ecologist答案: A78、听力题：The _____ (music/dance) is fun.The elephant is the largest _______ (大象是最大的_______).80、Which planet is closest to the sun?A. VenusB. EarthC. MercuryD. Mars81、What do we call the process of plants making food?A. PhotosynthesisB. RespirationC. DigestionD. Evaporation答案: A82、What is the capital of Iceland?A. ReykjavikB. OsloC. HelsinkiD. Copenhagen答案:A83、选择题：What is the name of the famous castle in Scotland?A. Edinburgh CastleB. Windsor CastleC. Neuschwanstein CastleD. Château de Chambord84、填空题：My aunt gives me good ____.85、听力题：The city of Kuala Lumpur is the capital of _______.86、小猫) curls up in my lap. 填空题：The ___87、填空题：The _______ (小金丝雀) chirps happily in its cage.88、听力题：A catalyst is not consumed in a ______ reaction.The cat purrs when it is _____ happy.90、What is the capital of the United States?A. New YorkB. Washington, D.C.C. ChicagoD. Los Angeles答案:B91、How many continents are there?A. FiveB. SixC. SevenD. Eight92、填空题：He is very _____ (安静) but has great ideas.93、填空题：The coyote is known for its ________________ (嚎叫).94、填空题：The _____ (果实) contains seeds for reproduction.95、填空题：The first successful blood transfusion was performed in ______ (17世纪).96、填空题：The squirrel climbs up the ______ (树) quickly.97、填空题：My pet ______ (猫) likes to play with string.98、What do you call a place where animals are kept?A. ZooB. FarmC. BarnD. Forest答案:A99、听力题：The ____ is a small creature that loves to eat carrots.100、What is the term for a young seagull?a. Chickb. Hatchlingc. Calfd. Kit答案:a。
氮化硅薄膜力学性能的纳米压痕测试与分析
氮化硅薄膜力学性能的纳米压痕测试与分析张良昌, 许向东, 吴志明, 蒋亚东, 张辉乐电子科技大学，成都（610054）E-mail：zcclhl@摘要：纳米压入法在薄膜材料力学性能测试领域中有着广泛的应用。
本文利用纳米压入技术对PECVD氮化硅（SiNx）薄膜的力学性能进行了测量与分析，通过对加载卸载曲线的分析，得到了SiNx薄膜的杨氏模量为226GPa。
此外，本次试验对氧化硅（SiOx）薄膜、SiNx 与SiOx薄膜的复合膜也进行了测试。
结果表明，薄膜的应力变化导致其杨氏模量随之发生改变。
关键词：氮化硅纳米压入机械性能薄膜中图分类号：TB1．引言随着微电子机械系统（MEMS）的快速发展与不断深入，薄膜材料的性能越来越为人们所重视。
薄膜材料的力学性能对产品的设计、制造及可靠性分析具有重要意义。
其中，材料的杨氏模量（E）倍受关注。
人们对薄膜力学性能的研究早在19世纪末已经开始。
从那时起，各种测量方法和测量理论便不断涌现出来，这些方法大致可以分为两类：一类是直接测量方法，它是根据力学量的定义来测量的方法，如单轴拉伸法[1]；另一类是间接测量方法，它是通过测量由于力学量而引起的某些物理性能的改变来计算力学量的方法，如共振频率法[2]、声表面波法[3]等。
除此之外国内外还报道了还有其它测试方法：衬底弯曲法[4]、微桥法[5]、鼓泡法等[6]。
近10多年来，纳米压痕技术发展较快。
由于试样安装简单、仪器分辨率高、作用区域小、可以直接在器件上测量，纳米压入法成为现阶段广泛使用的薄膜材料力学性能测量方法[7,8]。
另一方面，氮化硅因其特殊的光学、电学、机械、化学惰性等性能，广泛被应用做减反射膜、钝化层、支撑层及介电薄膜。
而氮化硅薄膜的力学性能将密切影响材料质量与器件性能，是一个关键性指标。
目前为止，许多文献一般只报道SiNx薄膜应力、或杨氏模量的单独测量结果，这种现象影响到人们对相关材料的全面、准确评价。
本文通过膜层结构的改变促使薄膜的力学性能发生变化，同时，还对相关薄膜的应力和杨氏模量进行了综合评估。