3D打印机英文论文

第一篇：3D打印机英文论文

TSINGHUA SCIENCE AND TECHNOLOGY

ISSN

1007-0214 04/38 pp24-28 Volume 14, Number S1, June 2009

Abstract: Rapid prototyping(RP)is a computerized fabrication technology that additively builds highly com-plex three-dimensional physical objects layer by layer using data generated by computer, for example CAD or digital graphic.Three-dimensional printing(3DP)is one of such technologies that employ ink-jet printing technology for processing powder materials.During fabrication, a printer head is used to print a liquid on to thin layers of powder following the object's profile as generated by the system computer.This work looks at redesigning 3DP machine, using piezoelectric demand-mode technology head in order to improve accuracy, surface finishing and color quality of constructed models.The layers created with aforesaid system are be-tween 25 to 150 µm(steps of 25 µm).Key words: prototyping;three-dimensional printing(3DP);piezoelectric head Perusing Piezoelectric Head Performance in a New

3-D Printing Design

RAHMATI Sadegh，†,**†

SHIRAZI Farid, BAGHAYERI Hesam

Mechanical Engineering Group, Faculty of Engineering, Azad Islamic University, Majlesi Branch, Iran;

† Mechanical Engineering Department, Khaje Nasir Toosi University, Tehran, Iran

Introduction

Solid freeform fabrication(SFF)technologies are manufacturing/prototyping technologies that are char-acterized by layer-by-layer addition of material to fab-ricate components.These techniques are also known as layered manufacturing and rapid prototyping.The layer-by-layer building approach allows significantly more complex parts to be built in one fabrication step than was previously possible thus simplifying process planning.SFF technology therefore can automate the process planning and fabrication of a part under computer con-

trol so that the only input needed is a solid model of [1,2]the part.Over the last decade, many different technologies for SFF have evolved.Broadly, the SFF techniques available currently can be classified as stereo lithogra-phy, solid fusion and solidification, laminated object

manufacturing, and powder-based techniques.The ste-reo lithography technique selectively solidifies a liquid photopolymer while solid fusion and solidification fuse/melt the material and deposit it layer-by-layer.The laminated object manufacturing technology cuts out laminates from sheets of part material and glues or fuses them together.In most methods of SFF, special

support structures are needed to support overhanging

[1,3]

features of the part.Received: 2008-11-09;revised: 2009-03-30 To whom correspondence should be addressed.E-** mail: s_farid_sh@yahoo.com;Tel: 98-912-1350938

The two main powder-based techniques that have

been commercialized are selective laser sintering and three-dimensional printing(3DP)printing.For powder-based methods, no support structures are typically re-quired to create complex shapes.Powder is selectively consolidated into a part and the remaining powder can be removed.In the SLS process, a thin layer of powder is deposited in a workspace container and the powder is then fused together using a laser beam that traces the shape of the desired cross-section.The process is re-peated by depositing layers of powder thus building the part layer-by-layer.In the 3DP process, a binder material selectively binds powder deposited in layers.RAHMATI Sadegh et al：Perusing Piezoelectric Head Performance in a New …

Ink-jet printing head(IJH)technology is used to print

the binder in the shape of the cross-section of the part on each layer of powder(Fig.1)[4,5]

.Fig.1 3-D Printing process

Two kinds of drop-on-demand heads can be used in IJH systems, piezoelectric and thermal heads

[6], and the thermal heads are used in current 3DP systems.Since thermal heads have some drawbacks, hence piezoelec-tric head has been employed for new generation of 3DP machines.In addition, piezoelectric technology can help to inject the live cells in to vital textures in order to create bones, members and dentures without any chemical or physical changes in cells.1 Ink-jet Head Technologies

1.1 Thermal heads In thermal systems there is a heating element as a thin-film resistor.When an electrical pulse is applied to the head, a high current passes through this resistor and the fluid in contact with it is vaporized, forming a vapor bubble over the resistor.This vapor bubble expands in

fluid reservoir and is ejected as a droplet through the nozzle(Fig.2)[6,7].Fig.2 Schematic of a thermal head

1.2 Piezoelectric heads In this type of system a volumetric change in the fluid reservoir is induced by the application of a voltage pulse to a piezoelectric material element that is cou-pled, directly or indirectly, to the fluid.This volumetric

change causes pressure/velocity transients to occur in

the fluid and these are directed so as to produce a drop

that issues from a nozzle(Fig.3)

[6,8]

.A result of simu-lated droplet ejection is shown in Fig.4.Fig.3 Schematic of a piezoelectric head

Fig.4 A result of simulated droplet ejection in piezo-

electric heads

[9]

When a voltage pulse is applied in the direction or-thogonal to the polarization direction of the piezoelec-tric element, it is deformed and the fluid in the channel reservoir is pressurized.When the pressure wave gen-erated in the channel is reflected between nozzle and common fluid chamber and resonated, the pressure ap-

plied to the nozzle change in time, and as a result drop-let is ejected

[9]

.1.3 Comparison between thermal and

piezoelectric technology

Thermal demand-mode ink-jet systems can achieve ex-tremely high fluid-dispensing performance at a very low cost.However, this performance/cost has been achieved by highly tailoring the fluid: thermal ink-jet systems are restricted to fluids that can be vaporized by the heater element(without igniting the fluid)and their performance/life can be degraded drastically if other fluids are used.In practice, thermal ink-jet systems are limited to use for aqueous fluids while the work of piezoelectric demand-mode ink-jet technology does not depend on thermal process and because of this reason, does not 26

create thermal stress on the fluids which is being jetted from the nozzles of head.Meantime, the diversity of fluids that can [6]be jetted by the piezoelectric heads grows vastly.In addition, some thermal ink-jet sys-tems in comparison with piezoelectric type produce more inconsistent droplets with satellite and misting, which causes dimensional error, rough surface [9]

finish-ing, and low color quality in constructed models.Control of the Ejection and Impact Phenomena As the ink-jet printed models structures strongly de-pend on the velocity, the initial size and the path of the droplet just before spreading, it is essential to control

these different characteristics as a function of the driv-ing parameters of the printing head

[10]

.To obtain this data, the mathematical equation was used based on two different voltages(5 and 12 V).This reveals that the increase of the amplitude(up to 12 V)leads to the formation of a satellite droplet, which catches up with the main one later.Moreover, this shows that the final volume increases with the amplitude of the pulse(Fig.5).Fig.5 Resonance frequency vs.droplet volume

The equation is given as[10]

V  πr 2V /(2 f)d

(1)

where Vd is the volume of droplet, r is the radius of the nozzle, V is the velocity of droplet, and f is the reso-nance frequency.As can be inferred from Eq.(1), when Vd is increased, the necessary velocity of droplet in-creases rapidly.Also, the frequency of head movement to print the layers decreases contemporary.Consider-ing these conditions, accurate dimensional layers of model are possible to be made.The only downside to these attitudes is the rate of building layers because the

Tsinghua Science and Technology, June 2009, 14(S1): 24-28

frequency of working head has direct effect on the ve-locity of printing layers.Nozzles

Another important parameter to build accurate layers is the inner nozzle diameter.When a nozzle diameter is decreased, the droplet volume decreases, however, the viscous resistance in the nozzle is greatly increased, and the energy loss grows rapidly.Figure 6 shows the relationship between the nozzle diameter and the drop-let velocity.Fig.6 Nozzle diameter vs.droplet velocity at differ-ent

viscosity

In a situation where the binder viscosity is increas-ing, if nozzle throat area gets smaller, velocity drop is significant.In other words, increasing binder viscosity has predominant effect on velocity drop compared with increasing velocity by changing nozzle cross sectional area.The relation between inner nozzle diameters，droplet size, and droplet volume is shown in Table 1.Table 1 Relation between inner nozzle diameter, drop-

let size, and droplet volume[11]

Inner nozzle diameter

Droplet size Droplet volume

(µm)

(µm)(pL)35 20 50 55 90 70

180 Binder Properties

To adjust the fluid properties of the organic suspen-sions to be compatible with the type of printing head, viscosity and surface tension must be 5-20 mPa s and 35-40 mJ/N, respectively.This will provide the ratio of Re / we

1/ 2

to be in the adequate range(1-10)for

ejection of a consistent droplet.RAHMATI Sadegh et al：Perusing Piezoelectric Head Performance in a New … 27

Fig.7 Nozzle configuration of piezoelectric head

In fact successful drop ejection occurs when the ra-1/2R/Weetio has a value ranged between 1 and 10 with e,where Re is the Reynolds number(vrρ/η);We, the Weber number(V2rρ/σ);ρ, η, and σ are the ink density, viscosity, and surface tension, respec-tively;r, the radius of the R/Wer/nozzle;and v the fluid veloc-ity.When this ratio is too small, viscous forces are

dominant which implies large pressure for ejection;in-versely, if this ratio is too large, a continuous column is ejected that can lead to the formation of satellite drops behind the main drop.As demonstrated previously, piezoelectric head tech-nology is capable of jetting the binder from the nozzle continuously and more efficiently.Moreover, this tech-nology assures that the binder drops after leaving the nozzle, would rest accurately at the interested position.Therefore, in general, piezoelectric technology is the most adapted of the ink-jet printing technologies to flu-id jetting or micro dispensing and in particular to rapid prototyping applications.Hence, a piezoelectric head with these specifications has characteristics as given in Table 2.[6][12] Table 2 Piezoelectric head characteristics Print method: Nozzle configuration:

Drop-on-demand ink-jet Monochrome: 48 nozzle(120dpi)Cyan, Magenta, yellow, light cyan, light magnet Bi-direction with logic seeking 238 CPS

3000 million dots/nozzle 110 mm/s(720×2880)dpi Color(48 nozzle×5)Print direction: Print speed: Print head life: Feed speed: Max resolution:

Figure 7 shows the nozzle configuration viewed from the back of the print head.The required energy to eject the binder droplet includes the energy to form the

droplet surface and the kinetic energy of the droplet.In addition, a considerable amount of energy is consumed for the flow of the binder in the nozzle.Fur-ther, even after droplet ejection, more energy is con-sumed until the residual oscillation of the binder is terminated.Conclusions

The advantages and disadvantages of piezoelectric and thermal heads were investigated.Based on the results, parameters such as accuracy, life time and diversity of materials, and piezoelectric heads were recognized as the most adapted to rapid prototyping applications.Based on the new design, piezoelectric demand-mode technology was employed to jet the binder from noz-zles.The printed layer samples with piezoelectric head are shown in Fig.8.Fig.8 A single layer printed by new 3-D printer

Parameters such as dimensional accuracy, surface finishing, and color quality of fabricated models of the new 3DP system demonstrate a significant improve-ment over the common 3DP models.Moreover, the ca-pability of layer dispending mechanism is improved by up to 3 times(minimum layer thickness is 25 μm), and the surface finishing of fabricated models is also im-proved.The fabricated models are colorful, with excellent accuracy and improved surface quality, compared with the fabricated models using current commercial 3-D printers.As a matter of fact, thin layer thickness has significant effect on surface texture quality of the model.Applying piezoelectric technology enables the binder to penetrate the required depth, resulting in layer thickness as thin as 25 μm and improving surface texture quality.This work is currently in progress and initial results have been promising.References

[1] Kumar A V, Dutta A, Fay J E.Electrophotographic printing of part and binder powder.Rapid Prototyping Journal, 2004, 10: 7-13.[2] Noorani R.Rapid Prototyping Principles and Application.New Jersey: John Wiley & Sons Inc., 2006.[3] Waterman P J.Rapid Prototyping.DE March, 1997.[4] Bak D.Rapid prototyping or rapid production? 3-D print-ing processes move industry towards the latter.Assembly Automation, 2007, 23(4): 340-345

[5] Jee H J, Sachs E.A visual simulation technique for 3-D printing.Advances in Engineering Software, 2000, 31(2): 97-106.[6] Piqué A, Chrisey D B.Direct-Write Technologies for Rapid Prototyping Applications.A Division of Harcourt, Inc., 2002.Tsinghua Science and Technology, June 2009, 14(S1): 24-28

[7] Sachs E, Vezzetti E.Numerical simulation of deposition

process for a new 3DP printhead design.Journal of Mate-rials Processing Technology, 2005, 161(2): 509-515.[8] Carrión A.Technology forecast on ink-jet head technology

application.Rapid Prototyping Journal, 1997, 3(3): 99-115.[9] Takeuchi Y, Takeuchi H, Komatsu K, Nishi S.Improve-ment of drive energy efficiency in a shear mode piezo-ink-

jet head.Hp Company Report, 2005.[10] Kar S, McWhorter S, Ford S M, et al.Piezoelectric me-chanical pump with nanoliter per minute pulse-free flow delivery for pressure pumping in Micro-channels.Analyst，1997, 123: 1435-1441.[11] Microdrop Technology Co., 2006, Brouchour.[12] Noguera R, Lejeune M, Chartier T.3-D fine scale ceramic

components formed by ink-jet prototyping process.Jour-nal of the European Ceramic Society, 2005, 25(12): 2055-2059.

第二篇：如何写英文论文

如何写英文论文

一、开头段常用思路

1.介绍当前背景、现象、形势+说出自己的观点

2.介绍双方观点+说出自己的观点

3.提个问题+介绍双方观点+说出自己的观点

4.介绍当前背景、现象、形势+介绍双方观点+说出自己的观点

5.说个与题目相关的故事+说出自己的观点

6.介绍当前背景+介绍对方观点+说出自己的观点

7.连续发问式

8.说出名人名言或谚语+介绍当前背景、现象、形势+说出自己的观点

9.以调查数据为佐证

10.以典型事实为佐证

二、理由常用思路

1.说出自己观点的好处或赞成这种观点的原因

2.批驳对方观点的弱点

3.为自己观点的不足做辩解

4.结合当前的背景和现象

5.围绕涉及不同对象

三、段落展开方法

1.列举事实法

2.举例子论证法

3.对比论证法

4.类比论证法

5.假设论证法

6.结合统计数据，名人名言和谚语，专家和权威的观点

四．结尾段常用思路

1.重申观点

2.重申观点+改写各理由段理由

3.灵活的结尾

4.重申观点+灵活结尾

5.让步+重申观点

文章写得连贯 关联词

并列和递进

And moreover further furthermore also likewise similarly tooin like manneragainin the same waybesidesin addition

转折和让步

But nevertheless otherwiseon the other handconverselyon the contraryhowever yet stillin spite ofall the sameeven soafter allalthougheven if

原因和结果

Because since as forbecause ofhenceconsequentlythussofor this reasonaccordinglythereforeas a resultit follows that

比较与对照

Similarlylikewiseequally importantin factat the same timeaccordinglyin the same waylikeon the contrary

different fromin contrastin comparisondespiteyetbuthoweverunlikenot only but alsoyears ago…today

the former…the latterthe first…whereas the secondwhereasneverthelessinsteadhere…therethis…thatthen…now

some…othersonce…now

提示陈述顺序

Firstto begin withto start within the first placenextsecondthirdin the second placebesidesin additionwhat’s morefurthermoremoreoverto make matters worsefinally

Last but not least

举例

For instancefor exampleto illustrateas an illustration

结论

In a wordin shortin briefto sum upin summary

in conclusionto conclude

表明时间顺序

Thennowcurrentlyat presentsomewhat laterpresentlyThereuponthereaftereventuallyat the same timemeanwhile First secondin the mean timesoonnextfinallyat last 复述

Brieflythat is to sayin factindeedin other words 表明方位

To the rightin the distancestraight aheadon the left belowbetweenadjacent tounderbeyondaround close toopposite toon top ofoveracross from

above next to

第三篇：英文论文

浅谈高中英语写作中语域知识的习得

总论：新课程标准中＂语域＂的概念在中学阶段英语教学中是个新鲜词汇，第一次提到，并且明确列入评分标准之中。语域知识的习得是学生写作能力发展过程中的一大难点，因此，了解其含义及要求，对于我们教师当前如何有效指导学生的写作就显得尤为重要和迫切。比方说：photograph与photo均可指照片、图片，但photograph是newspaper language，属于正式体，一般常见于报刊杂志，而photo则是随便体，使用较为自由，这主要是语域功能的差异造成的。

关键字：高中英语课程标准、语域、中学写作、新要求

一、语域知识的习得是《英语课程标准》的新要求

普通高中《英语课程标准》（人民教育出版社2003年4月第一版，第55页）所附的写作评价标准中明确提到：对学生的作文主要从内容要点、语言使用效果、结构和连贯性、格式和语域以及与目标读者的交流五个方面进行评价。可以采用综合性评价，也可以采用分析性评价。通常采用分档次按等级评分制。其中第五档分类高分标准如下：

第五档（新课程标准）

——很好地完成了试题规定的任务；

——按要求写出了内容要点；

——语言结构和词汇选用恰当、丰富；语言错误极少；

——有效采用不同的连接手段，层次清楚；

——格式和语域恰当；——完全达到与目标读者交流的目的。

附：（原标准对比）第五档（很好）：

——完全完成了试题规定的任务。

——覆盖所有内容要点。

——应用了较多的语法结构和词汇。

——语法结构或词汇方面有些许错误，但为尽力使用较复杂结构或较高级词汇所致；具备较强的语言运用能力。

——有效地使用了语句间的连接成分，使全文结构紧凑。

——完全达到了预期的写作目的。

其中最后两项和原来的高考评分标准有着很大的区别，其要求进一步明确：①强调格式和语域恰当；②强调达到与目标读者交流的目的。而这其中＂语域＂的概念在中学阶段英语教学中是个新鲜词汇，第一次提到，并且明确列入评分标准之中。因此，了解其含义及要求，对于我们教师当前如何有效指导学生的写作就显得尤为重要和迫切。那么，什么是语域呢？

二、语域的涵义

语域（register）：［(linguistics)range of vocabulary, grammar etc used by writers

in professional contexts.］是指根据语言使用的社会情景定义的一种具有某种具

体用途的语言变体，如科技语体、艺术语体、政论语体、公文语体等等。简言之，指在专业领域中作者所使用的词汇，可以理解为与题目相关领域的vocabulary。＂

各语域的词汇具有明确的语域功能＂（王珏,1999）。比方说：photograph与photo

均可指照片、图片，但photograph是newspaperlanguage，属于正式体，一般

常见于报刊杂志，而photo则是随便体，使用较为自由，这主要是语域功能的差

异造成的。一般情况，法律、科技、报道，讲演词，政论文等都比较正式，而小

说中文体、语域最复杂，要视情况而定，不可一概而论。

三、语域的区别

语法正确的句子并不一定是好的句子，这其中牵涉到语域的因素。口头交际

时，当然不要使用正式语体；同样，书面交流时，千万避免随意语体。国内（20

世纪80年代中后期交际教学法）教学改革前指摘学生的英语口语过于书面化；

教学改革后的情况又如何呢？批改学生的作文时，教师都有一种感觉：学生的作

文大多用词简单、结构松散，从语体角度分析，正式程度都较低，呈口语化的倾

向（蔡基刚2001：302）。

但是，目前中学英语写作教学的写作培训时间很少，有限的时间又多放在应

试讲评上，缺乏对语域等全局层次的特征传授。学术英语（English for Academic

Purposes,EAP）研究专家Hyland博士曾指出，学生的绝大多数语篇语域知识是

通过在写作中表达自己的思想获得的(1998: 243)。什么是冷漠体，正式体，商量

体，随便体，亲密体，正式体，半正式体，公共体，半非正式体，非正式体等只

有在语篇环境或讲话者的口吻中才能体会出来。不同的语域语言变体彼此是有区

别的，如果用几个简单的例子来说明一下就会看得很清楚。如＂汤姆病了，今天

没去上学＂，如果说Tom didn't go to school, because he was ill.这就是一句公共语，而如果说Tom was ill,so he didn't go to school.这就是口语体，即非正式语体，如

果说：Being ill ,Tom didn't go to school或Tom didn't go to school because of illness.都是正式语体(当然这句话的内容用这种句式表达并不合适)。从中我们可以看到

用原因从句的表达方式是比较正常的，用so连接的句子显得不怎么正式，用抽

象名词和分词短语的形式都显得十分正式。

另外有些表示相同意思的不同表示形式也有语域方面的区别。如according to

和in accordance with,前者为公共语，而后者为正式用语，It is important 和It is of

importance相比，也是前者为公共语，而后者为正式体。甚至连冠词的用法都可

以表示这种区别，The horse is a useful animal;A horse is a useful animal;Horses are

useful animals。第一种用定冠词加单数名词表示类属的是正式用法，而用不定冠

词加单数名词表示类属的则为公共语，最后一种，复数泛指的类属表示法则为非

正式语体。

所以，我们在学生英语写作之初时，引导他们弄清所写文章的语域情况是十

分重要的，因为这将决定我们在写作时如何选词组句，可谓＂看菜吃饭，量体裁

衣＂。例如：我们在写一篇游记时要用到下面一个句子：＂一小时后，我们终于

登上高达海拔1296公尺的衡山之巅祝融峰。＂可译为：After an hour of climbing,we finally found ourselves at zhurong Peak, the very apex of Mt, Hengshan, towering

1,296m above the sea level.我们可以从after……climbing这种动名词用法看出比

较正式，它不是用短句表示(After we had climbed for an hour)，如用短句则显得更

为常见的公共语体，另外，apex，顶峰，巅峰，与之同义的词还有summit, top

等词，但apex更为典雅，正式程度高于summit，更高于top.再有towering这一分词的使用，也说明其正式性，不是用短句(it towers

1,296m above sea level)。那么，我们在翻译这句时则用了比较正式的语言。但如

果我们是在记录人们交谈中听到下面这样一些简短而连续句子：＂我们爬了一个

钟头，终于到了祝融峰的山顶，它是衡山的最高峰，有1296公尺＂则译为这样

较合适：After we had climbed for an hour，we finally found ourselves at zhurongPeak.This is the very top of Mt, Hengshan and it towers 1,296 meters above sea level.这就是语域决定作用的初步体验。

四、语域使用应遵循的要求

在语言是否达到与目标读者交流的目的的制约下，写作中语域的使用应遵循

以下要求：

（一）合乎规范

事物、现象之间的相似性、相关性和相通性是词语跨域使用产生的基础，事

物和现象之间的这些关系使人们可以通过比喻、借代、引申的手法进行表达。

如：＂bug＂一词译成汉语＂臭虫＂。其电脑术语义指＂系统、设备或程序中的一种错误或故障＂。＂臭虫＂获其殊荣完全是因为搔扰电脑科研人员晚上工作，遭人痛恨而得。这就要求人们在选择词语时，注意使用词语中最具普遍性的意义。

要多模仿原汁原味的精美句型、短文，使用比喻、借代、典故等不能生搬硬套，必须理解其文化背景，适应交际的需要，符合词语规范化的原则，才能避免

chinglish的。

即coherence（being(of ideas, thoughts, speech, reasoning, etc)connected

logically or consistently;easy to understand;clear.）连贯性，一致性。可以理解为

观念、思想、言论、推理等表达准确、合乎逻辑；前后一致；让人易懂。这就要

求写作时明确试题规定的任务，准确贴切地选择词语有效地表达事物的概念和人的思想情感。如不能准确地理解词语的词义就去跨域使用，必将会出现词不达义、张冠李戴的现象，达不到指称事物和目标读者交际的目的。如要表达的是演讲稿、发言稿，则语言必须符合口语习惯，随意体较为受欢迎，如果过多地采用正式体则显得教条、呆板，缺乏应有的生机活力，语言也就没有感染力。如：为了帮助学生认识到因果关系表达的丰富性及其文体差别，减少过分依赖死记硬背常用范式的熟悉度，我们从原因表达用词because等其它因果标记（诸如as，since与for，以及复合介词类（because of/as a result of等）、名词类（cause/reason等）、介词（with/through/by等）、动词类（cause/result in/contribute to等）的语料的掌握上，应该提供给学生足够的语境练习以强化域语知识的掌握。

例如：I am not able to watch TV, because I live in school.（逗号显示非正式的特征）→I cannot watch TV because my dorm has no TV set.用since, for表共享原因可能更好，因为本句重点说明我无法看到电视，进而为以后阐释自己对外界知识了解不多提供立论基础；但作者提供的原因并不直接，他所认为的共享知识-＂学校宿舍没有电视＂并非一定共享。另外，be able to 指'能力'，实际上作者想表达'不可能'-cannot。

（三）避免滥用

即cohesion（tendency to stick together.）凝聚力。凝聚力，可以理解为围绕一个中心展开讨论，思路清晰，支持有力，不写与题目无关的东西。为追求新奇、标新立异或故作高深，有人不顾是否达到与目标读者交流的目的，把词语跨域使用作为一种新颖、超常的言语方式大加运用，必将适得其反。中国学生易受发展性因素和汉语负迁移的影响，过分依赖于汉语运用的感觉且表现出明显的口语化现象，偏离了原汁原味英语语篇运用的常规。因此，作为学生在英语学习过程中，要多分析语言现象，注意词汇句型的语域功能，多积累，多感知，多体会，方能为写出好文章打下坚实的基础。

总之，只有充分理解语域的内涵及其功能特点，才能把握好高中英语课程标准对中学写作的新要求，才能写出内容充实、要点全面、语言丰富、文字优美、行文连贯、过渡自然、表达地道、语域恰当的好文章，才能完全达到与目标读者交流的目的，也才能很好地完成试题规定的任务，取得理想的高分。

参考书目：

1.普通高中《英语课程标准》（人民教育出版社2003年4月第一版）

2.2003年高考英语试卷及答案(天津卷)扫描版评分标准（人民网）

3.《英语翻译课程学习方法》凡夫著

4.《对于雅思考试写作评分标准的解析》赖劲松著

第四篇：机三信息员论文

人人都是通风员

将理念引深到班子建设，从决策中堵塞安全隐患漏洞。实现安全管理科学化，领导班子建设是核心。只有领导班子树立以人为本，安全发展的科学发展观，落实正确的政绩观和业绩观，进一步加强对安全工作的领导，强化安全责任意识和安全工作敏感性，才能促进企业安全发展。将“人人都是通风员”理念引深到班子建设，就是要高度重视并能以这一理念统领安全工作。采取会议、座谈、讨论、沟通等多种形式来统一班子成员的思想，形成“安全是企业安全发展的前提与保障”的共识。从而在全矿的安全工作上做到了思想统一、步调一致，能够不折不扣地把各个时期上级对安全工作的指示精神和要求落实到日常的安全工作当中。就是要进一步明确各级领导干部“人人都是通风管理员”责任，站在更高的角度落实“人人都是通风员”安全理念，做好安全管理工作。特别是安全管理的决策中，决不能拍脑门、拍胸脯，必须冷静思考，多听取周围同志的意见，明确工作思路，做出英明的决策。各级领导班子要进一步转变作风，狠抓落实，从根本上提高控制效能，加强和完善安全管理体系建设，严格落实安全生产责任制和各项安全生产管理制度。要经常分析研究安全生产状况，深入把握安全生产的规律和特点，抓紧解决安全生产中的矛盾和问题，针对性地制定和强化安全

生产的制度、措施，使生产过程中各种事故风险和伤害因素始终处于有效控制状态。

将理念引深到安全培训，不断提高员工安全素质。实现安全管理科学化做好员工培训是基础。安全生产作业过程中，人的不安全行为是诱发事故的主要原因，员工的安全意识和业务素质成为避免事故的重要因素。将“人人都是通风员”理念引深到安全培训，就是要通过多种形式，多种渠道搞好员工日常安全培训工作。采取实地走避灾路线、现场说法等各种便于职工接受的方法，深入推进“人人都是通风员”安全理念和安全应知应会知识的贯彻落实，把学习“一通三防”知识同员工的岗位特点相结合，把学习“一通三防”知识与“三违”人员的教育相结合，把学习“一通三防”知识与案例分析相结合，把学习“一通三防”知识与演示实验和井下学习相结合，确保培训效果，提高员工的实际操作能力和自保能力。随着“人人都是通风”安全理念的不断深化，这一理念的内涵将牢牢地扎根在每一位员工的心上，使员工现场的应急思维实现本质安全化，有效提高煤矿的安全管理层次，为企业稳步、高效、健康、持久地向前发展，提供可靠的安全保证。

将理念引深到现场管理，从源头控制事故的发生。实现安全管理科学化，现场是重点。安全工作的源头在现场，安全工作的重点在现场。“人人都是通风员”的引深也必须在

现场、在岗位。要以“想、看、干、管”为要决，真正做到干部指挥到位、隐患排查到位、环境监控到位，实现从源头控制事故、杜绝事故发生。安全工作有指标不是高水平，安全目标为零才是真水平。实现安全事故为零的目标，就是要求各级领导干部要深入井下，盯住现场，盯班上岗，盯住不安全隐患，盯住不放心的人和事，消除人的不安全行为和物的不安全状态，从现场这个生产源头上保障安全生产。同时要狠抓质量标准化管理，从基层、基础抓起，从现场抓起，从岗位抓起，大力开展标准岗、精品岗创建活动，将“人人都是通风员”的“三懂三会三做到”岗位标准融入标准岗、精品岗建设中，在生产过程中每个环节、每道工序、每个岗位的现场管理上落实“人人都是通风员”岗位标准，规范工作流程、作业流程和操作流程，规范岗位人员的现场操作行为。

引深“人人都是通风员”理念保证一流矿井建设顺利进行的有效途径，是建设企业文化的有效手段，是优秀领导班子的具体体现，是本质安全矿井建设的基础，为创新管理模式提供了新思路，是争创成功企业的先决条件。我们一定要遵循事物发展的规律，牢固树立“安全责任重于泰山”思想，深刻把握和积极实践理念，始终把安全管理摆在企业管理和生产全过程的首位。确保企业稳步、健康、有序地向前发展，确保安全生产长治久安。

人人都是通风员

一条理念管百年

第五篇：英文论文演讲稿

篇一：英语论文展示演讲稿

1、hello everyone！today i will introduce you a paper, which is called “effects of corporate governance on capital structure: empirical evidence from pakistan “

2、i will use the following four parts to introduce

3、i got this paper from the emerald reprints the world’s leading publisher of management research and the type of the paper is research paper 纳迪姆阿麦的sheke

4、then we can have a simple knowledge of the two authors:nadeem ahmed sheikh and 王宗军 one is a doctoral degree candidate in the school of management, hua zhong university of science and technology, wuhan.the other is a professor in this college 5.about the paper’s outline firstly the aim of this empirical study is to investigate whether corporate governance attributes affect capital structure choices of pakistani firms then the design of the paper is multiple regression analysis

6、in order to have a good knowledge of the paper we can from the following three aspects to the attributes of the corporate governance are background also includes ：measures of corporate governance and their relation to capital structure

8、research design firstly 1.research methodology：it includes three aspects: data variables and methodology date: this study investigates the significant corporate governance attributes that may affect the capital structure of non-financial firms listed on the karachi stock exchange pakistan during 2004-2008.and the final sample set consists of 775 observations for 155 firms over a period of five years.this study employed panel data methodology(面板数据方式)because sample contained data across firms and over time

9、this table is the definition of variables.it includes three parts: 10.dependent variables consist of total debt ratio and long-term debt ratio.this is a basic formula.12、this table is the yearly mean value of shareholding pattern

13、here are some of regression analysis tables, through the multiple regression analysis the paper gives the conclusions

14、the results is as follows: capital structure is positively related to board size、outside directors and ownership concentration.that is to say: a large board serve as a means to obtain support from external environment;boards with more independent directors can take on more debt on favorable terms due to effective monitoring;block holders have more ability than dispersed shareholders to force management to take those actions that maximize the shareholder wealth.15、on the other hand, capital structure is negative related to managerial ownership、director remuneration、profitability and liquidity.16、in the end, i have a summary: the results of the paper indicate that corporate governance attributes, in part, explicate the financing behavior of pakistani firms and, the empirical results of this study provide support to corporate managers in establishing an optimal capital structure, and to regulatory authorities for enacting laws and developing institutional support to make corporate governance mechanisms work more effectively in the country.17、thats all, thank you for listen to me, if you are interested in this paper you can have a study after class thank you!篇二：英语论文演讲稿

my paper is revenge tragedy in english renaissance——about 《hamlet》 ppt1:....ppt2:....ppt3:....ppt4:next, let`s analyse the relationship between the characters in the drama.this is a relationship diagram.hamlet ,the prince of denmark and also the protagonist(主角、主要人物、领导者）was about thirty years old at the start of the play.hamlet is the son of queen gertrude and the late king hamlet, and the nephew of the present king, claudius.hamlet is melancholy, bitter, and cynical, full of hatred for his uncle’s scheming and disgust for his mother’s sexuality.a reflective and thoughtful young man who has studied at the university of wittenberg, hamlet is often indecisive and hesitant, but at other times prone to rash and impulsive acts.哈姆雷特 prince hamlet —— 丹麦王子。为父王的鬼魂所困扰，要对杀父凶手复仇。经历了痛苦的挣扎之后他达成了目的，整个王宫也陷入了死亡的恐怖之中。他最后也中了致命的毒剑死去。

claudius, as the king of denmark, hamlet’s uncle and the villain（反派角色）of the play, was a calculating, ambitious politician,and was driven by his sexual appetites and his lust for power, but he occasionally showed signs of guilt and human feeling—his love for gertrude, for instance, seems sincere.克劳迪斯 claudius —— 丹麦现任国王。他是哈姆雷特的叔父，在哥哥死后继任了王位。老国王的鬼魂告诉哈姆雷特，他正是谋杀自己的凶手。他罪有应得，最后死在侄子复仇的毒剑下。

鬼魂 king hamlet(ghost)—— 哈姆雷特的父亲死后化成的鬼魂。他被弟弟毒死时，哈姆雷特正在国外。

ophelia-polonius’s daughter, a beautiful young woman with whom hamlet has been in love.ophelia is a sweet and innocent young girl, who obeys her father and her brother, laertes.dependent on men to tell her how to behave, she gives in to polonius’s schemes（诡计）to spy（侦察）on hamlet.even in her lapse into（陷入）madness and death, she remains maiden, singing songs about flowers and finally drowning in the river。

欧菲莉 ophelia—— 波洛涅斯的女儿。她与哈姆雷特双双陷入爱河，但种种阻力警告王子，政治地位使他们无望结合。作为哈姆雷特疯狂复仇计划的一部分，她被他无情抛弃，加上父亲的死让她陷入精神错乱，最终失足落水溺毙。

ppt6: then let`s look at the character analysis of hamlet.hamlet pretended to be mad in order to revenge.he also use his intelligence to approve his uncle`s guilt.when hamlet confirmed that claudius was guilt, he decided to revenge without fear.then he also use stratagem to make himself avoid being killed.all of these approved that he was brave and smart.ppt7: he pursued ophelia and finally gave up because of the revenge.before he was fight with laertes, he said sorry to him.this indicates he was guilt and sorry for laertes because it was he that made laertes lose his father.these approved that he was a kind and sincere man.ppt8:.....ppt9: when we read the play, we can also easily feel the dilemma.just like the words “to be or not to be-that is the question” ppt10:.....ppt11:......篇三：如何写好英文演讲稿

淘宝专业编制 id:文章团购网

如何写好英文演讲稿

从很多方面来说，写演讲稿就像写论文，但演讲稿却没有像论文那般特别注重单词的拼写与标点的错误。写演讲稿的时候，不要用一些发音不顺畅或是你不明白意思的单词，因为会导致你的演讲不够流畅。instructions 说明

1.assess how much time your speech should take.if you dont have a time limit, try to keep your speech brief yet informative.估算自己演讲所需的时间。如果没有演讲上的时间限制，就尽量让你的演讲篇幅简短且内容丰富。

2.think about your audience and let your perception of the audience shape the tone of your speech as you write it.站在听众的角度多想想，当你撰写演讲稿时，你要让观众也能在演讲稿中切身体会你的演讲魅力。

3.begin with an introduction that establishes who you are, what your purpose is, what youll be talking about and how long youre going to take.you may want to include a joke, anecdote or interesting fact to grab the audiences attention.先介绍自己，以表述演讲目的、演讲主题和演讲时长作为开端。在这段话中，你要说一个笑话、奇闻奇事或趣事来直接引起听众的注意。

4.organize your information into three to seven main points and prioritize them according to importance and effectiveness.用3-7条大纲组织演讲内容信息，并根据重要性和有效性分清要点主次。

5.delete points that arent crucial to your speech if you have too many for your time frame.假如时间不允许，你可以删减一些演讲中不重要的点。

6.start with your most important point, then go to your least important point and move slowly back toward the most important.for example, if you have five points with no.5 being the most important and no.1 being the least important, your presentation order would be 淘宝专业编制 id:文章团购网

5-1-2-3-4.从最重要的一点开始你的演讲，之后到次重要点，然后再慢慢回到最重要点上。例如，你的演讲稿中有5点要讲，第5点是其中的重中之重，而第1点是次重要点，你的演讲顺序应为：51234。7.add support to each point using statistics, facts, examples, anecdotes, quotations or other supporting material.借助图表、事实、例子、奇闻轶事、引文与其它材料作为演讲点的支撑部分。

8.link your introduction, points and conclusions together with smooth transitions.引言、演讲要点和结论连贯顺承地串在一起。

9.write a conclusion that summarizes each of your points, restates your main purpose and leaves the audience with a lasting impression.用结论总结所有演讲点，重申主题，让观众留下最后的深刻印象。