Effect of Bagasse Fiber on the Flexural Properties of Biodegradable Composites
Shinichi Shibata,Yong Cao,Isao Fukumoto
Department of Mechanical Systems Engineering,University of the Ryukyus,Nishihara Okinawa903-0213, Japan
Flexural modulus of the press-molding composites made from bagasse?ber and biodegradable resin was investigated by experiment and numerical prediction with Cox’s model that incorporates the compression ratio of the bagasse?ber in the cross section.The effect of the volume fraction of bagasse?ber and its length on the?exural modulus was examined.Up to65%volume fraction in the experiment,the?exural modulus in-creased with increase of the volume fraction of the bag-asse?ber.The numerical prediction was in good agree-ment with the experimental result.Above65%volume fraction,however,the?exural modulus decreased in the experiment,while the prediction increased.It seemed that the biodegradable resin was insuf?cient to cover all the surface of bagasse?ber in the composite.Moreover, the decrease of the?exural modulus was found below3 mm at the?ber length in the experimental and the same trend was shown in the numerical prediction.POLYM. COMPOS.,26:689–694,2005.?2005Society of Plastics Engi-neers
INTRODUCTION
Composites reinforced with natural?bers such as kenaf [1],jute[2–4],ramie,oil palm[5],hemp[6],and bagasse [7]have been the subject of intense study for cost,speci?c gravity,and ecological reasons.Especially,many studies [8–11]on the composites combined with biodegradable resins have been performed to improve the mechanical properties,which are inferior to conventional composites such as polypropylene and glass?ber.Among them,bag-asse?ber is of interest from the point of view that bagasse ?bers are the remains of squeezed sugar cane.Moreover,the worldwide production of bagasse?ber is?7times larger than that of jute,kenaf,and hemp combined[12].Thus,the bagasse?ber composites have considerable potential to become a substitute material for conventional composites.
On the other hand,as far as we know,there are few studies that predict the?exural modulus of those natural ?ber composites.Above all,bagasse?ber is expected to be compressed in a press-molding because bagasse?ber has a honeycomb structure due to the liquor extraction in a sugar mill.This compression should be incorporated in the pre-diction model.
The objective of the present study is to predict the ?exural modulus of the composites made from bagasse?ber and biodegradable resin.In order to achieve this purpose, the composites were fabricated by a press-molding and the ?exural modulus was examined in view of the volume fraction of the bagasse?ber and its?ber https://www.doczj.com/doc/3113103112.html,pared to these experimental results,the numerical prediction of the ?exural modulus was performed with Cox’s model[13], which incorporates the compression ratio of bagasse?ber.
MATERIALS AND METHODS
Fiber and Polymer
Bagasse?ber,obtained as the leftover after liquor ex-traction in a sugar mill,was dried for72h at80°C.Then the bagasse?ber was chopped and sieved by four sizes.These ?ber lengths(diameters)averaged1.6mm(0.22mm),3.2 mm(0.37mm),9.1mm(0.37mm),and16.1mm(0.41 mm).The biodegradable resin,CP-300,was a cornstarch base supplied from Miyoshi Oil Fat(Japan).The resin was originally an emulsion type,then it was dried and chopped into pellets1–2mm in diameter.The mechanical properties of the resin at26°C are shown in Table1with subscripts “m.”The bagasse-biodegradable resin composites were fab-ricated in the form of a cylindrical steel mold(30mm in diameter).The mold was heated to160°C for15min.After the temperature reached158–162°C,the materials were pressed in the cylinder and held at10MPa for10min.The fabricated composites were30mm in diameter and1.8–1.9 mm in thickness and disc-shaped.
Measurement
To determine Young’s modulus of the bagasse?ber,72?bers were tested.Span length and a crosshead speed were
Correspondence to:Shinichi Shibata;e-mail:shibata@tec.u-ryukyu.ac.jp DOI10.1002/pc.20140
Published online in Wiley InterScience(https://www.doczj.com/doc/3113103112.html,).?2005Society of Plastics Engineers
POLYMER COMPOSITES—2005
15mm and 1mm/min with a testing machine (Shimazu,type DCS-R-100,Japan).Randomly chosen bagasse ?bers were mounted on a paper tab with both ends of the bagasse ?ber glued.The diameters were measured at three different points with an optical projector (Nikon,type V16-D,Japan),assuming that the bagasse ?ber was cylindrical.Figure 1shows the result.The tensile strength and Young’s modulus were 89.9MPa and 4,526MPa.This value was used for the prediction of the ?exural modulus.
The ?exural tests were carried out according to ISO 178using a three-point bending method on ?ve specimens in each composite.The dimension of the specimen was 30?15?1.8–1.9mm.The tests were performed at room temperature (26°C)in order to avoid the in?uence of tem-perature on the ?exural properties [14].Span length and a crosshead speed were 18mm and 1mm/min.Flexural modulus and strength were determined by the inclination of the initial line and the maximum load on the load-displace-ment curve.
Prediction of Flexural Modulus
It is well known [14]that Young’s modulus of short ?ber reinforced composites is determined by:
E comp ????f V f E f ??1?V f ?E m ,
(1)
where E f ,E m ,V f ,and V m denote the Young’s modulus of the ?ber,the matrix,the volume fraction of the ?ber and the matrix,respectively.?f ,??denote ef?cient factors of ?ber length and orientation.?f is given [15,16]by:
?f ?1??tanh 12
?L ?/1
2?L ,(2)
??
?2G m E f r f 2ln ?R /r f ?
?
1/2
.(3)
Equation 2shows that the Young’s modulus of the com-posite decreases with decreasing ?ber length L ,where r f and
R denote the radius of the ?ber and the interval between ?bers.If the distribution of the ?bers is homogeneous in an ideal packing square composite,R is given by:
R ?
r f 2
?
?V f
.(4)
Shear modulus G m assuming that the composite is an isot-ropy given by:
G m ?
E m
2?1??m ?
,
(5)
where r f and ?m denote the radius of the ?ber and Poisson’s ratio of the matrix that assumed ?m is 0.3.
On the other hand,??has been analyzed in detail by Fukuda and Chou [17].According to their analysis,??is 0.27when the orientation of the ?ber in the composites is 2D and random.Figure 2shows the ?ber orientation distri-bution on the surface region of the composite.The orienta-tion angles of 200randomly chosen ?bers were
measured.
FIG.1.Young’s modulus of bagasse ?bers as a function of ?ber diam-
eter.
FIG.2.Distribution of the orientation angle of the composites.
TABLE 1.Mechanical properties of bagasse ?ber and biodegradable
resin.
Parameter Value ?f 89.9MPa ?m 24.0MPa E f 4,526MPa E m 520MPa ?f 0.341kg/cm 3?m 1.160kg/cm 3R f 0.40mm V bf 1.14mm 3f n
4,654g ?1
690POLYMER COMPOSITES—2005
The orientation angle was de?ned as the angle between the ?ber direction and the longitudinal direction of the ?exural specimen.The ?ber orientations were so randomly dis-persed that ??is assumed to be 0.27.
Finally,we bring the compression ratio of the bagasse ?ber,K ,into Eq.1.The compression ratio is de?ned as the inverse number of the ?ber volume in the specimen corre-sponding to the original ?ber volume.Hence,the compres-sion ratio,K ,is calculated by:
K ??f m V bf ?/?V ?
?
W ?W f
?m
??
,(6)
where f n ,V bf ,V ,W ,W f ,and ?m denote the number of ?bers,volume of a ?ber,volume of the composite,weight of the composite,weight of the ?bers,and density of the matrix,respectively.This compression ratio re?ects the effect of the ?ber compression on the reinforcement of the composites.Therefore,the ?nal equation that predicts ?exural modulus of the composites is:
E comp ?K ???f V f E f ??1?V f ?E m .
(7)
RESULTS AND DISCUSSION
Effect of Volume Fraction of Bagasse Fiber on the Flexural Modulus
Figure 3shows the variation of the compression ratio calculated by Eq.6with varying the volume fraction of the bagasse ?ber.The transformation of the weight fraction into the volume fraction of the ?ber is calculated by:
V f ??V ?
?
W ?W f
?m
??
/V ,(8)
where W f ,?m ,V ,and V f denote the ?ber weight,the density of the matrix,the volume of the specimen,and the volume fraction of the ?ber,respectively.
The compression ratio was ?3.4above the volume frac-tion 30%.The compression ratio,however,was 4.2at 19%volume fraction.The reason why the compression ratio at 19%was higher than any other volume fractions is not obvious.However,this higher compression may be attrib-uted to the high resin volume fraction caused by optimized movement of the bagasse ?bers in the press-molding,re-sulting in the high compression ratio.Next,the cross section of the composites was polished and observed with an optical microscope.As shown in Fig.4a,it was observed that the bagasse ?ber and the biodegradable resin were clearly sep-arated.However,in very few cases the bagasse ?ber,which had permeated the biodegradable resin,was found as shown in Fig.4b.A similar microstructure was reported in
the
FIG.3.Effect of the volume fraction of bagasse ?bers on the compres-sion
ratio.
FIG.4.Optical microphotographs of the bagasse ?ber.a:The bagasse and the biodegradable resin.b:The bagasse ?ber has permeated the biodegradable resin.
POLYMER COMPOSITES—2005691
study by Cichocki and Thomason [18].Furthermore,Fig.5a,b shows SEM micrographs of the raw bagasse ?ber and the compressed bagasse ?ber on the fracture surface.It was found that the bagasse ?ber that has originally a honeycomb structure was compressed.Also,the resin was not perme-ated in the honeycomb structure.The percentage of the area of cells on the honeycomb structure including cavities was ?25%.Hence,it is considered that the obtained compres-sion ratio,3.4,is equal to the actual compression ratio of the bagasse ?ber.
Figure 6a shows the side view of a raw bagasse ?ber in which the surface was a rough structure.On the other hand,a bagasse ?ber wetted by resin on the fracture surface is shown in Fig.6b.This photograph shows that the ?ber was completely wetted by resin and resulted in better interfacial adhesion.Similar observations were reported by Karnani et al.[10]and Hoecker et al.[20].Thus,the ?exural modulus can be predicted by Eq.7,which assumes that the ?ber and matrix is well bonded enough to transfer stress among ?bers in the composite.
Figures 7and 8show the variation of the ?exural mod-ulus and ?exural strength with varying the volume
fraction
FIG.5.SEM microphotographs of (a)a cross section of a raw bagasse,and (b)a compressed bagasse ?ber on the fracture
surface.
FIG.6.SEM microphotographs of (a)side view of a raw bagasse,(b)a bagasse ?ber wetted by resin on the fracture
surface.
FIG.7.Variation of the ?exural modulus with varying volume fraction of bagasse ?bers.
692
POLYMER COMPOSITES—2005
of the bagasse ?ber.The lines were predicted applying Eq.7with the parameters shown in Table 1.
The ?exural modulus increased gradually with increas-ing the volume fraction of the bagasse ?ber up to 65%(2,525MPa)as well as the ?exural strength.In this region,the rule of mixtures was af?rmed.However,the ?exural modulus decreased at 74%.In this case,by visual observa-tion of the surface of the specimen,it was observed that there were bagasse ?bers that had not wetted with the biodegradable resin.This is the reason why the volume fraction of 65%was seen in the maximum ?exural modulus.The prediction at K ? 5.0and 2.0is far from the experimental results while the line,K ?3.4,is close to that.Hence,it is considered that the estimation of the compres-sion ratio,K ?3.4,was correct in predicting the ?exural modulus.
Effect of Fiber Length on the Flexural Modulus
In the previous section the ?exural modulus showed its maximum 2,525MPa at 65%volume fraction.Then,at the volume fraction the effect of the ?ber length on the ?exural modulus was examined.Figures 9and 10show the variation of the ?exural modulus and strength with varying the bag-asse ?ber length.The ?exural modulus rapidly decreased at 1.6mm ?ber length.The lines on the ?gure are predicted applying Eq.7as well as the previous section.The estima-tion at K ?3.4shows good agreement with the experimen-tal results,while K ?5.0and 2.0is far from the result.In addition,below the bagasse ?ber length of 3mm a decrease of the ?exural modulus was seen.The compression ratio below 3mm in ?ber length was rather higher than that above ?ber length;this decrease is due to the shortening in the ?ber length as described in Eq.2.In other words,the ef?ciency of stress transfer between ?bers decreased with a decrease of ?ber length,and the lower ef?ciency resulted in
lower ?exural modulus.The aspect ratios of ?ber lengths 3and 1.6mm were ?12and 8.The relationship between ?exural modulus and ?ber length in a short ?ber-reinforced plastic was investigated by Hsueh [19].According to those results,the ?exural modulus sharply decreases below aspect ratio 10.In this study,the aspect ratio was 22in ?ber length 9.1mm and the decrease of ?exural modulus was not con?rmed,while the decrease was clearly found in an aspect ratio of 8in ?ber length 1.6mm.Thus,that analysis is in good accordance with the obtained results.
Figure 11shows the variation of the compression ratios with varying ?ber length.The compression ratio decreases with an increase of ?ber length.The reason for this is not obvious;however,the decrease of the ?ber length may enable the bagasse ?ber to move into an optimized
position
FIG.8.Variation of the ?exural strength with varying volume fraction of bagasse
?bers.
FIG.9.Variation of the ?exural modulus with varying the bagasse ?ber
length.
FIG.10.Variation of the ?exural strength with varying the bagasse ?ber
length.
POLYMER COMPOSITES—2005693
during press-molding and this may contribute to the shorter ?ber length and the higher compression ratio. CONCLUSION
The?exural modulus of the composites made from bag-asse?ber and the biodegradable resin increased with in-creasing the volume fraction of the bagasse?ber up to65%. However,at75vol%the?exural modulus decreased be-cause the biodegradable resin was insuf?cient to cover all the surface of the bagasse?ber.Hence,the predicted?ex-ural modulus by Cox’s model is in good agreement with the experimental result up to65volume fraction.The compres-sion ratio incorporated into Cox’s model was?3.4.Accord-ing to the optical microstructure observation,there were few bagasse?bers that permeated the resin and the?ber was actually compressed to30%of the original volume.
In65%volume fraction,the decrease of the?exural modulus was seen below?ber length3mm(aspect ratio 12).This result was in good agreement with the numerical calculation based on Cox’s model.Moreover,the compres-sion ratio decreased with an increase of the bagasse?ber length.This result may re?ect that the shorter?ber length enabled the?bers to move into an optimized position during press-molding.
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694POLYMER COMPOSITES—2005
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高中英语~词性~句子成分~语法构成 第一章节：英语句子中的词性 1.名词：n. 名词是指事物的名称，在句子中主要作主语.宾语.表语.同位语。 2.形容词;adj. 形容词是指对名词进行修饰~限定~描述~的成份，主要作定语.表语.。形容词在汉语中是（的）.其标志是: ous. Al .ful .ive。. 3.动词：vt. 动词是指主语发出的一个动作，一般用来作谓语。 4.副词：adv. 副词是指表示动作发生的地点. 时间. 条件. 方式. 原因. 目的. 结果.伴随让步. 一般用来修饰动词. 形容词。副词在汉语中是（地）.其标志是：ly。 5.代词：pron. 代词是指用来代替名词的词，名词所能担任的作用，代词也同样.代词主要用来作主语. 宾语. 表语. 同位语。 6.介词：prep.介词是指表示动词和名次关系的词，例如：in on at of about with for to。其特征：
介词后的动词要用—ing形式。介词加代词时，代词要用宾格。例如：give up her（him）这种形式是正确的，而give up she（he）这种形式是错误的。 7.冠词：冠词是指修饰名词，表名词泛指或特指。冠词有a an the 。 8.叹词：叹词表示一种语气。例如：OH. Ya 等 9.连词：连词是指连接两个并列的成分，这两个并列的成分可以是两个词也可以是两个句子。例如：and but or so 。 10.数词：数词是指表示数量关系词，一般分为基数词和序数词 第二章节：英语句子成分 主语：动作的发出者，一般放在动词前或句首。由名词. 代词. 数词. 不定时. 动名词. 或从句充当。 谓语：指主语发出来的动作，只能由动词充当，一般紧跟在主语后面。 宾语：指动作的承受着，一般由代词. 名词. 数词. 不定时. 动名词. 或从句充当. 介词后面的成分也叫介词宾语。 定语：只对名词起限定修饰的成分，一般由形容
M A: Has the case been closed yet? B: No, the magistrate still needs to decide the outcome. magistrate n.地方行政官，地方法官，治安官 A: I am unable to read the small print in the book. B: It seems you need to magnify it. magnify vt.１．放大，扩大；２．夸大，夸张 A: That was a terrible storm. B: Indeed, but it is too early to determine the magnitude of the damage. magnitude n.１．重要性，重大；２．巨大，广大 A: A young fair maiden like you shouldn’t be single. B: That is because I am a young fair independent maiden. maiden n.少女，年轻姑娘，未婚女子 a.首次的，初次的 A: You look majestic sitting on that high chair. B: Yes, I am pretending to be the king! majestic a.雄伟的，壮丽的，庄严的，高贵的 A: Please cook me dinner now. B: Yes, your majesty, I’m at your service. majesty n.１．［Ｍ－］陛下（对帝王，王后的尊称）；２．雄伟，壮丽，庄严 A: Doctor, I traveled to Africa and I think I caught malaria. B: Did you take any medicine as a precaution? malaria n.疟疾 A: I hate you! B: Why are you so full of malice? malice n.恶意，怨恨 A: I’m afraid that the test results have come back and your lump is malignant. B: That means it’s serious, doesn’t it, doctor? malignant a.１．恶性的，致命的；２．恶意的，恶毒的 A: I’m going shopping in the mall this afternoon, want to join me? B: No, thanks, I have plans already. mall n.（由许多商店组成的）购物中心 A: That child looks very unhealthy. B: Yes, he does not have enough to eat. He is suffering from malnutrition.
意见应以事实为根据. 3 来自辞典例句 192. The bombers swooped ( down ) onthe air base. 轰炸机 突袭 空军基地. 来自辞典例句 193. He mounted their engines on a rubber base. 他把他们的发动机装在一个橡胶垫座上. 14 来自辞典例句 194. The column stands on a narrow base. 柱子竖立在狭窄的地基上. 14 来自辞典例句 195. When one stretched it, it looked like grey flakes on the carvas base. 你要是把它摊直, 看上去就象好一些灰色的粉片落在帆布底子上. 18 来自辞典例句 196. Economic growth and human well - being depend on the natural resource base that supports all living systems. 经济增长和人类的福利依赖于支持所有生命系统的自然资源. 12 1 来自辞典例句 197. The base was just a smudge onthe untouched hundred - mile coast of Manila Bay. 那基地只是马尼拉湾一百英里长安然无恙的海岸线上一个硝烟滚滚的污点. 6 来自辞典例句 198. You can't base an operation on the presumption that miracles are going to happen. 你不能把行动计划建筑在可能出现奇迹的假想基础上.
英语造句大全English sentence 在句子中，更好的记忆单词！ 1、(1)、able adj. 能 句子：We are able to live under the sea in the future. (2)、ability n. 能力 句子：Most school care for children of different abilities. (3)、enable v. 使。。。能句子：This pass enables me to travel half-price on trains. 2、(1)、accurate adj. 精确的句子：We must have the accurate calculation. (2)、accurately adv. 精确地 句子：His calculation is accurately. 3、(1)、act v. 扮演 句子：He act the interesting character. （2）、actor n. 演员 句子：He was a famous actor. (3)、actress n. 女演员 句子：She was a famous actress. (4)、active adj. 积极的 句子：He is an active boy. 4、add v. 加 句子：He adds a little sugar in the milk. 5、advantage n. 优势 句子：His advantage is fight. 6、age 年龄n. 句子：His age is 15. 7、amusing 娱人的adj. 句子：This story is amusing. 8、angry 生气的adj. 句子：He is angry. 9、America 美国n.
主语+谓语 1. 理解主谓结构 1) The students arrived. The students arrived at the park. 2) They are listening. They are listening to the music. 3) The disaster happened. 2．体会状语的位置 1) Tom always works hard. 2) Sometimes I go to the park at weekends.. 3) The girl cries very often. 4) We seldom come here. The disaster happened to the poor family. 3. 多个状语的排列次序 1) He works. 2) He works hard. 3) He always works hard. 4) He always works hard in the company. 5) He always works hard in the company recently. 6) He always works hard in the company recently because he wants to get promoted. 4. 写作常用不及物动词 1. ache My head aches. I’m aching all over. 2. agree agree with sb. about sth. agree to do sth. 3. apologize to sb. for sth. 4. appear (at the meeting, on the screen) 5. arrive at / in 6. belong to 7. chat with sb. about sth. 8. come (to …) 9. cry 10. dance 11. depend on /upon 12. die 13. fall 14. go to … 15. graduate from 16. … happen 17. laugh 18. listen to... 19. live 20. rise 21. sit 22. smile 23. swim 24. stay (at home / in a hotel) 25. work 26. wait for 汉译英： 1.昨天我去了电影院。 2.我能用英语跟外国人自由交谈。 3.晚上7点我们到达了机场。 4.暑假就要到了。 5.现在很多老人独自居住。 6.老师同意了。 7.刚才发生了一场车祸。 8.课上我们应该认真听讲。9. 我们的态度很重要。 10. 能否成功取决于你的态度。 11. 能取得多大进步取决于你付出多少努力。 12. 这个木桶能盛多少水取决于最短的一块板子的长度。
【it's time to和it's time for】 ——————这其实是一个句型,只不过后面要跟不同的东西. ——————It's time to跟的是不定式（to do）.也就是说,要跟一个动词,意思是“到做某事的时候了”.如： It's time to go home. It's time to tell him the truth. ——————It's time for 跟的是名词.也就是说,不能跟动词.如： It's time for lunch.(没必要说It's time to have lunch) It's time for class.(没必要说It's time to begin the class.) They can't wait to see you Please ask liming to study tonight. Please ask liming not to play computer games tonight. Don’t make/let me to smoke I can hear/see you dance at the stage You had better go to bed early. You had better not watch tv It’s better to go to bed early It’s best to run in the morning I am enjoy running with music. With 表伴随听音乐 I already finish studying You should keep working. You should keep on studying English Keep calm and carry on 保持冷静继续前行二战开始前英国皇家政府制造的海报名字 I have to go on studying I feel like I am flying I have to stop playing computer games and stop to go home now I forget/remember to finish my homework. I forget/remember cleaning the classroom We keep/percent/stop him from eating more chips I prefer orange to apple I prefer to walk rather than run I used to sing when I was young What’s wrong with you There have nothing to do with you I am so busy studying You are too young to na?ve I am so tired that I have to go to bed early
《The Kite Runner》追风筝的人--------------------------------美句摘抄 1.I can still see Hassan up on that tree, sunlight flickering through the leaves on his almost perfectly round face, a face like a Chinese doll chiseled from hardwood: his flat, broad nose and slanting, narrow eyes like bamboo leaves, eyes that looked, depending on the light, gold, green even sapphire 翻译：我依然能记得哈桑坐在树上的样子，阳光穿过叶子，照着他那浑圆的脸庞。他的脸很像木头刻成的中国娃娃，鼻子大而扁平，双眼眯斜如同竹叶，在不同光线下会显现出金色、绿色，甚至是宝石蓝。 E.g.: A shadow of disquiet flickering over his face. 2.Never told that the mirror, like shooting walnuts at the neighbor's dog, was always my idea. 翻译：从来不提镜子、用胡桃射狗其实都是我的鬼主意。E.g.:His secret died with him, for he never told anyone. 3.We would sit across from each other on a pair of high
一、翻译 1. The idea of consciously seeking out a special title was new to me., but not without appeal. 让我自己挑选自己最喜欢的书籍这个有意思的想法真的对我具有吸引力。 2.I was plunged into the aching tragedy of the Holocaust, the extraordinary clash of good, represented by the one decent man, and evil. 我陷入到大屠杀悲剧的痛苦之中，一个体面的人所代表的善与恶的猛烈冲击之中。 3.I was astonished by the the great power a novel could contain. I lacked the vocabulary to translate my feelings into words. 我被这部小说所包含的巨大能量感到震惊。我无法用语言来表达我的感情（心情）。 4，make sth. long to short长话短说 5.I learned that summer that reading was not the innocent(简单的) pastime(消遣) I have assumed it to be., not a breezy, instantly forgettable escape in the hammock(吊床)，( though I’ ve enjoyed many of those too ). I discovered that a book, if it arrives at the right moment, in the proper season, will change the course of all that follows. 那年夏天，我懂得了读书不是我认为的简单的娱乐消遣，也不只是躺在吊床上，一阵风吹过就忘记的消遣。我发现如果在适宜的时间、合适的季节读一本书的话，他将能改变一个人以后的人生道路。 二、词组造句 1. on purpose 特意，故意 This is especially true here, and it was ~. (这一点在这里尤其准确，并且他是故意的) 2.think up 虚构，编造，想出 She has thought up a good idea. 她想出了一个好的主意。 His story was thought up. 他的故事是编出来的。 3. in the meantime 与此同时 助记：in advance 事前in the meantime 与此同时in place 适当地... In the meantime, what can you do? 在这期间您能做什么呢？ In the meantime, we may not know how it works, but we know that it works. 在此期间，我们不知道它是如何工作的，但我们知道，它的确在发挥作用。 4.as though 好像，仿佛 It sounds as though you enjoyed Great wall. 这听起来好像你喜欢长城。 5. plunge into 使陷入 He plunged the room into darkness by switching off the light. 他把灯一关，房
The effective sentences:(improve the sentences!) 1.She hopes to spend this holiday either in Shanghai or in Suzhou. 2.Showing/to show sincerity and to keep/keeping promises are the basic requirements of a real friend. 3.I want to know the space of this house and when it was built. I want to know how big this house is and when it was built. I want to know the space of this house and the building time of the house. 4.In the past ten years,Mr.Smith has been a waiter,a tour guide,and taught English. In the past ten years,Mr.Smith has been a waiter,a tour guide,and an English teacher. 5.They are sweeping the floor wearing masks. They are sweeping the floor by wearing masks. wearing masks,They are sweeping the floor. 6.the drivers are told to drive carefully on the radio. the drivers are told on the radio to drive carefully 7.I almost spent two hours on this exercises. I spent almost two hours on this exercises. 8.Checking carefully,a serious mistake was found in the design. Checking carefully,I found a serious mistake in the design.
M1 U1 一. 把下列短语填入每个句子的空白处（注意所填短语的形式变化）： add up (to) be concerned about go through set down a series of on purpose in order to according to get along with fall in love (with) join in have got to hide away face to face 1 We’ve chatted online for some time but we have never met ___________. 2 It is nearly 11 o’clock yet he is not back. His mother ____________ him. 3 The Lius ___________ hard times before liberation. 4 ____________ get a good mark I worked very hard before the exam. 5 I think the window was broken ___________ by someone. 6 You should ___________ the language points on the blackboard. They are useful. 7 They met at Tom’s party and later on ____________ with each other. 8 You can find ____________ English reading materials in the school library. 9 I am easy to be with and _____________my classmates pretty well. 10 They __________ in a small village so that they might not be found. 11 Which of the following statements is not right ____________ the above passage? 12 It’s getting dark. I ___________ be off now. 13 More than 1,000 workers ___________ the general strike last week. 14 All her earnings _____________ about 3,000 yuan per month. 二.用以下短语造句： 1.go through 2. no longer/ not… any longer 3. on purpose 4. calm… down 5. happen to 6. set down 7. wonder if 三. 翻译： 1.曾经有段时间，我对学习丧失了兴趣。（there was a time when…） 2. 这是我第一次和她交流。（It is/was the first time that …注意时态） 3.他昨天公园里遇到的是他的一个老朋友。（强调句） 4. 他是在知道真相之后才意识到错怪女儿了。（强调句） M 1 U 2 一. 把下列短语填入每个句子的空白处（注意所填短语的形式变化）： play a …role (in) because of come up such as even if play a …part (in) 1 Dujiangyan(都江堰) is still ___________in irrigation(灌溉) today. 2 That question ___________ at yesterday’s meeting. 3 Karl Marx could speak a few foreign languages, _________Russian and English. 4 You must ask for leave first __________ you have something very important. 5 The media _________ major ________ in influencing people’s opinion s. 6 _________ years of hard work she looked like a woman in her fifties. 二.用以下短语造句： 1.make (good/full) use of 2. play a(n) important role in 3. even if 4. believe it or not 5. such as 6. because of
English sentence 1、(1)、able adj. 能 句子：We are able to live under the sea in the future. (2)、ability n. 能力 句子：Most school care for children of different abilities. (3)、enable v. 使。。。能 句子：This pass enables me to travel half-price on trains. 2、(1)、accurate adj. 精确的 句子：We must have the accurate calculation. (2)、accurately adv. 精确地 句子：His calculation is accurately. 3、(1)、act v. 扮演 句子：He act the interesting character.（2）、actor n. 演员 句子：He was a famous actor. (3)、actress n. 女演员 句子：She was a famous actress. (4)、active adj. 积极的 句子：He is an active boy. 4、add v. 加 句子：He adds a little sugar in the milk. 5、advantage n. 优势 句子：His advantage is fight. 6、age 年龄n. 句子：His age is 15. 7、amusing 娱人的adj. 句子：This story is amusing. 8、angry 生气的adj. 句子：He is angry. 9、America 美国n. 句子：He is in America. 10、appear 出现v. He appears in this place. 11. artist 艺术家n. He is an artist. 12. attract 吸引 He attracts the dog. 13. Australia 澳大利亚 He is in Australia. 14.base 基地 She is in the base now. 15.basket 篮子 His basket is nice. 16.beautiful 美丽的 She is very beautiful. 17.begin 开始 He begins writing. 18.black 黑色的 He is black. 19.bright 明亮的 His eyes are bright. 20.good 好的 He is good at basketball. 21.British 英国人 He is British. 22.building 建造物 The building is highest in this city 23.busy 忙的 He is busy now. 24.calculate 计算 He calculates this test well. 25.Canada 加拿大 He borns in Canada. 26.care 照顾 He cared she yesterday. 27.certain 无疑的 They are certain to succeed. 28.change 改变 He changes the system. 29.chemical 化学药品