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如何写这样的论文
《科技传播》国家级科技学术期刊 中英文目录 知网万方全文收录 部直接收稿提醒您严防学术论文抄袭 参考别人论文的时候最好用自己的语言表述一下,一般网上代写均为东拼西凑,很容易造成学术抄袭, 返回首页 登录 【FDUROP新闻】● 2008-2009学年上半学期● 2007-2008学年下半学期● 2007-2008学年上半学期● 2006-2007学年下半学期● 2006-2007学年上半学期● 2005-2006学年下半学期● 2005-2006学年上半学期【开放课题征集】【申请FDUROP资助】【成果发表情况】【〖FDUROPER〗工作日历】【《为学》报电子版】 开题报告 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课题名称:民用飞机机翼三维结冰外形的气动性能分析学者姓名: 李岱--------------------------------------------------------------------------------开题报告:民用飞机机翼三维结冰外形的气动性能分析开题报告李 岱一、课题背景和研究现状概述2008年5月“中国商用飞机有限责任公司”挂牌成立,着手研制国产大型客机,首个C919大飞机预计于2014年首飞,2016年适航取证;2008年11月,中国首架具有完全自主知识产权的商用客机ARJ 21-700在上海首飞成功,国内外订单已愈200架中国航空业的突飞猛进和良好前景对飞机设计人员提出了更高的要求,许多实际问题亟待解决。我国幅员辽阔,气象条件复杂,高寒地区广,飞机结冰现象比较常见。飞机结冰是指飞机在飞行过程中,机翼、发动机进气口等某些迎风部位聚集冰层的现象。结冰轻则使飞机飞行性能下降、飞行品质降低;重则危及飞行安全、造成坠机事故。据统计,在美国所有重大的飞行事故中,结冰作为主要失事原因占到9% 。为了研究和应对结冰现象,产生了飞行结冰动力学这一分支学科。飞机结冰动力学研究始于20世纪30年代。第二次世界大战后的30年中,研究人员主要在冰风洞中进行试验研究,探讨结冰对飞机气动性能的影响。随着计算机能力的提升和对飞机全天候飞行的要求,70年代后期以来,美国和欧洲一些国家开始领衔全面系统的结冰动力学研究,包括地面和飞行试验,结冰机理研究,防除冰技术研究等。而我国对飞机结冰动力学问题的研究起步于20世纪90年代。飞机结冰动力学的研究方法直到目前为止,主要有两个分支:冰风洞试验模拟研究和计算机数值模拟研究。前者通过流动相似性原理模拟真实飞行条件下的结冰问题,数据较为准确,但花费巨大;基于计算流体力学(Computational Fluid Dynamics)的数值模拟技术则能有效地降低研究成本,缩短研究周期。自上世纪50年代以来,国外相继开发出了一些结冰计算软件对结冰状态下飞机飞行进行模拟,例如美国的LEWICE,加拿大的FENSAP-ICE,法国的ONERA等,这些软件的开发为进一步的飞机结冰研究提供了很好的基础。但由于起步较晚,国内尚未有相应的一体化数值模拟软件。而一款适用于飞机设计过程中计算模拟研究的成熟软件,将大幅节约研发成本、提高研发效率;有效地预测冰型,也将对调整飞行控制参数、预防严重结冰、消除积冰提供帮助,从而减少因结冰发生的飞行事故概率,具有很高的实用价值。目前,国内对结冰的数值模拟分为两块:模拟积冰的形成过程和模拟积冰对飞行性能的影响。国内有西北工业大学、南京航空航天大学和北京航空航天大学等对结冰外形进行了详细研究。这些研究大多数限于二维的平面情况。二、课题意义和预期成果“民用飞机机翼三维结冰外形的气动性能分析”的预期成果,是对特定三维外形的机翼在特定的结冰外形和特定飞行条件下,进行若干迎角下流场的计算,从而比较和分析干净机翼和结冰机翼的空气动力学性能。本课题如能顺利完成,一方面将为后续的飞行控制、结冰控制提供基础参数;另一方便,也将为拓宽计算范围提供一定参考,即模拟在更复杂的机翼外形、结冰外形和飞行条件下的空气动力学特性。三、课题基本思路和主要内容,研究现状详述对机翼结冰完整的数值模拟计算包括以下5个循环流程,示意图如下:1、三维结冰机翼计算网格生成2、空气流场计算5、结冰边界重构3、水滴运动轨迹计算4、结冰量计算“民用飞机机翼三维结冰外形的气动性能分析”所涉及的内容包括上述流程中的第一步和第二步,即计算网格的生成和空气流场的计算。课题基本思路是:(1)、三维结冰机翼建模;(2)、对外形进行网格划分;(3)、基于三维流动方程求解流场;(4)、计算气动性能。具体内容和分析如下。(1)、三维结冰外型建模积冰可按复杂程度分为霜状冰、混合冰以及瘤状冰。霜状冰较为平滑,瘤状冰包含冰角,形状复杂。飞机现实飞行中,机翼积冰一般为霜状冰和瘤状冰的混合。为了模拟特定外形的流场,首先须明确原始机翼和积冰的三维空间外形。建立冰形有两种方法:1、从既有的实验数据中获取三维结冰机翼外形;2、通过软件模拟得到结冰外形。第一种方法的优点是数据由试验得到,准确程度高;外形既定,直接导入数据即可,工作量减小。缺点是可供选择的数据不多,这是由于查阅国外资料的困难和国内相关资料的欠缺。第二种方法则相反,只要给定参数,可以顺利模拟出所需要的冰型;然而冰型的精度与程序的精度密切相关。目前,通过查阅资料和求助导师,已经获得了几个简单及复杂结冰外形的数据资料,可以在此基础上对它们进行数值模拟。(2)、计算网格生成对连续的物理系统的数学描述是用偏微分方程来完成的。为了在计算机上实现对流场状态的模拟,连续的方程必须离散化,其中一个必需步骤是实现对求解区域的网格划分。结冰网格体系的好坏直接影响结冰计算结果的精度,甚至影响结冰计算的成败。以网格类型来分,可分为结构化网格和非结构化网格。结构化网格数据结构简单,生成速度快,但对于复杂的冰形,其精确程度无法满足要求;非结构化网格有以下优点:1、突破了结构网格的网格节点的限制,节点和单元的分布可任意,能较好地适应具有复杂外形的边界,具有优越的几何灵活性;2、其随机的数据结构有利于网格的自适应,可在计算过程中调整网格结构,提高计算精度。三维非结构网格由四面体构成,其节点分布、节点编号和单元编号均可任意选取,没有固定的拓扑结构,适合处理复杂边界问题,具有对复杂外形的高度贴体性。目前,比较成熟的非结构网格生成技术分为两类:1、基于Delaunay准则的网格划分方法(如Bowyer-Watson Algorithm和Watson’s Algorithm法);2、波前法(Advancing Front Triangulation)。基于Delaunay准则的网格生成方法的速度快,网格的尺寸比较容易控制,但对边界的恢复比较困难,很可能造成网格生成的失败;波前法的对区域边界拟合的较好,但是生成的区域内部网格质量较差,生成的速度较慢。结合两方面技术的非结构化生成技术是目前复杂外形生成非结构化网格的趋势。本课题将探究“与波前法相结合的Delaunay四面体网格生成技术” 。进行网格划分的具体步骤如下:1、曲面非结构网格生成:用各向异性的Delaunay三角剖分方法生成参数平面的非结构网格,再变换到空间曲面上;2、边界确认:将经典Delaunay 方法与波前法相结合,进行边界四面体剖分,解决边界还原问题;3、内点、空间网格生成:使用阵面推进法生成具有最优位置的内部节点,并用Delaunay方法将内部节点高效率地插入,生成四面体空间网格;4、网格优化:有两种方法具体可行,一种是Laplace网格光顺技术,一种是用边交换技术和面交换技术。对三维网格的优化,后者效果更加理想,但也更复杂,故选用哪种方法将在实际操作中进行选取。网格的准确生成是此课题成功与否的基础所在。查阅文献和国外网站后,已获得一些相关算法和算例。(3)、空气流场计算获得机翼的空气动力学性能主要依靠空气流场计算;同时,如前所述,获得确定的流场也是整个结冰动力学模拟过程中继而建立液滴运动形式、计算结冰量、重构结冰边界的基础。计算内容包括建立数学模型、数值求解、编程三个步骤。1、数学模型:对于可视为连续介质的空气,描述其运动的基本方程为非线性偏微分Navier-Stokes方程组(简称N-S方程)。N-S 方程参数繁多,较为复杂,求解这一方程组来模拟真实飞行器的绕流需要十分复杂和庞大的计算。为此,须根据实际问题的物理特征对 N-S方程进行简化。在本课题中,权衡结冰时的实际飞行状态和课题工作量,将N-S方程简化为Euler方程,即来流无粘情况下的流场动量方程。Euler方程仍然十分适用于复杂流场计算;也使得运算量大幅减少。2、数值求解:在已划分好的网格的基础上,使用数值计算方法求解方程。目前,基于N-S和Euler方程的流场求解方法和求解器已经十分成熟,包括有限体积法、有限差分法和有限元法。具体求解方法将在实践中比较和选择。 3、编程:在C或Fortran程序平台上对以上各个步骤进行整合:读入外形数据、网格划分、编写求解程序、调试程序和物理参数、并输出流场计算结果。这部分工作将配合画图软件完成。(4)、气动性能计算在分析飞机空气动力学特性时,其所受力和力矩以空气动力系数和空气动力导数的形式出现。空气动力系数包括升力系数、阻力系数、力矩系数等;气动导数是空气动力系数对迎角、马赫数等参数的导数和这些系数对某些参数随时间的变化率的导数。求解并比较干净机翼与结冰机翼在不同迎角下的流场、升阻力系数、力矩系数以及升力线斜率,这些系数和导数是飞机气动特性的重要表征,也是本课题预期最终获得的结果。四、课题创新点和难点(1)、课题创新点1、二维到三维:目前国内对飞机结冰气动力的研究绝大部分集中于二维情况,开展三维的研究具有一定的创新性。2、网格划分方法新:结合Delaunay和AFT两种划分方法,整合两者优点、弥补各自的缺点。3、结果可扩展性:建立起正确的流场求解方法以后,可以应用到后续的求解水滴流动状态、水滴结冰量计算、重构边界层,继而建立起一套完整的飞机结冰动力学模型,为解决真实三维情况下的防冰、除冰问题提供有力参考。(2)、课题难点1、网格生成:按照既定方法划分网格将获得良好的效果,但是需要补充大量关于网格生成方面的知识,增加时间成本;且编程过程中需要调试众多参数,工作量较大。2、选择求解方法:由于计算量比较大,必须在已有的数值求解方法中,选择效率、精度均较为理想的一种。对求解方法的调试和选择将增大课题计算量和难度。五、课题进展计划时间进程内容进展预期结果2009.4-2009.5查阅文献,了解国内外研究情况初步明确课题研究方向和方法2009.5-2009.6查阅结冰外形数据,比对并捕捉外型获得较准确的三维结冰机翼外形2009.6-2009.9参考算例完成网格生成程序,并应用于结冰机翼外形上初步获得可用的非结构网格2009.9-2009.10调试参数,对网格生成程序进行修正和优化完善网格质量2009.10中期报告2009.11-2010.1完成流场求解器调试和选择选择效率和质量相对较高的求解方法2010.1-2010.4求解流场,计算气动系数和气动导数,比对干净、结冰机翼性能获得预期流场分布图和结冰机翼气动性能2010.4结题六、课题可行性(1)、尽管课题处理的是较为复杂的三维情况,但是经过一系列的简化,如飞行状态、气动参数、流动方程,以及目前已经获得的既有成果,如冰型数据、求解器程序,课题所设计的研究方向入口已并不过宽,导师认为可在预定期限内完成。(2)、在近三年的本科学习中,申请者已完成了一些相关课程的学习,包括《空气动力学》、《实验空气动力学》、《C程序设计》、《Matlab原理及工程应用》等,具有一定的理论能力和程序编写、调试能力。(3)、导师常年从事计算流体力学研究,可对课题进行充分有力的指导;同时,多年的研究也为导师积累了大量的资料,可供学习,参考和利用。七、参考文献和书目李林,王立新,彭小东.结冰对民机飞行性能的影响研究.飞行力学,2004,22(3):12-17 Frank T. Lyncha, Abdollah Khodadoust. Effects of ice accretions on aircraft aerodynamics. Aerospace Sciences, 37 (2001) 669–767董葳,赵冬梅.飞机结冰动力学的研究发展概述.气体物理—理论与应用.2006,1(1):6-11钟长生,王立新.结冰对飞机动力学特性影响的分析方法及其进展.飞行力学,2004,22(4):22-24陈伟健,张大林. 飞机机翼结冰过程的数值模拟. 航空动力学报,2005,20(6):1010-1017常士楠,艾素霄,陈余,袁修干.一种飞机机翼表面结冰过程仿真方法.系统仿真学报,2008,20(10):2538-2541张大林,杨曦,昂海松.过冷水滴撞击结冰表面的数值模拟.航空动力学报,2003,18(1):87-91蒋胜矩,李凤蔚.基于N-S方程的翼型结冰数值模拟.西北工业大学学报,2004,22(5):559-562 A.Tam, D. Ait-Ali-Yahia, M.P. Robichaud, M. Moore, V. Kozel,W.G. Habashi. Anisotropic mesh adaptation for 3D flows on structured and unstructured grids. Computer Methods in Applied Mechanics and engineering, 189 (2000) 1205-1230A. Jahangirian, Y. Shoraka. Adaptive unstructured grid generation for engineering computation of aerodynamic flows. Mathematics and Computers in Simulation 78 (2008) 627–644R. Balasubramanian, J.C. Newman III. Adjoint-based error estimation and grid adaptation for functional outputs: Application to two-dimensional, inviscid, incompressible flows. Computers & Fluids, 38 (2009) 320–332朱培烨.三维非结构网格自动生成.计算物理,2001,18(6):573-576王德生,万水.Robust Delaunay Tetrahedronal Meshing Coupled with Advancing Front Method. Journal of Southeast University, 2002, 18(2)Lars Ferm, Per Lotstedt. Anisotropic grid adaptation for Navier -Stokes equations. Journal of Computational Physics 190 (2003) 22–41 Oh Joon Kwon, Lakshmi N. Sankar. Numerical simulation of the flow about a swept wing with leading-edge ice accretions. Computers & Fluids,1997, 26(2):183-192 陈科,曹义华,安克文,李栋. 复杂积冰翼形气动性能分析. 航空动力学报,2007,22(6):986-990 袁坤刚,曹义华. 结冰对飞机飞行动力学特性影响的仿真研究. 系统仿真学报,2007,19(9):1929-1932 张强,曹义华,潘星,蒋崇文.积冰对飞机飞行性能的影响. 北京航空航天大学学报,2006,32(6):654-658杜亮,宏冠新.结冰飞机气动系数和气动导数的估算方法.航空计算技术,2004,34(3):16-19
关于万有引力的英语介绍
Gravitation is a natural phenomenon by which all objects with mass attract each other. In everyday life, gravitation is most familiar as the agency that endows objects with weight. Gravitation is responsible for keeping the Earth and the other planets in their orbits around the Sun; for keeping the Moon in its orbit around the Earth; for the formation of tides; for convection (by which hot fluids rise); for heating the interiors of forming stars and planets to very high temperatures; and for various other phenomena that we observe. Gravitation is also the reason for the very existence of the Earth, the Sun, and most macroscopic objects in the universe; without it, matter would not have coalesced into these large masses and life, as we know it, would not exist.Modern physics describes gravitation using the general theory of relativity, but the much simpler Newton’s law of universal gravitation provides an excellent approximation in most cases.In scientific terminology gravitation and gravity are distinct. “Gravitation“ is the attractive influence that all objects exert on each other, while “gravity“ specifically refers to a force which all massive objects (objects with mass) are theorized to exert on each other to cause gravitation. Although these terms are interchangeable in everyday use, in theories other than Newton’s, gravitation is caused by factors other than gravity. For example in general relativity, gravitation is due to spacetime curvatures which causes inertially moving objects to tend to accelerate towards each other. Another (discredited) example is Le Sage’s theory of gravitation, in which massive objects are effectively pushed towards each other.
科大讯飞的英语翻译终端可以替代翻译吗
在英译汉过程中,有些句子可以逐词对译,有些句子则由于英汉两种语言的表达方式不同,就不能用“一个萝卜一个坑“的方法来逐词对译。原文中有些词在译文中需要词类转换和结构转换,才能使汉语译文通顺自然。
一、词类转换
转译成动词
1.名词转换成动词
经典例题: Interest in historical methods has arisen,less through external challenge to the validity of history as an intellectual discipline and more from internal quarrels among historians themselves.
分析:interest在原文中是名词,而在译文中为了符合中文的表达方式,在不改变意思的前提下,将它改成动词。
参考译文:人们之所以关注历史研究的方法,主要是因为史学家们内部分歧过大,其次才是因为外界并不认为历史是一门学科。(1999年真题)
经典例题: With the click of a mouse,information from the other end of the globe will be transported to your computer screen at the dizzying speed of seven_and_a_half times around the earth per second.
参考译文:只要一点鼠标,来自世界另一端的信息便会以每秒绕地球七周半的惊人速度传输到你的电脑屏幕上。
2.形容词转换成动词
经典例题: Additional social stresses may also occur because of the population explosion problems arising from mass migration movements-themselves made relatively easy nowadays by modern means of transport.
参考译文:由于人口的猛增或大量人口流动(现代交通工具使大量人口流动变得相对容易)所造成的种种问题也会增加社会压力。(2000年真题)
经典例题: Doctors have said that they are not sure they can save his life.
参考译文:医生们说他们不敢肯定能否救得了他的命。
Success is dependent on his effort.
参考译文成功与否取决于他的努力。
3.副词转换成动词
经典例题: She opened the window to let fresh air in.
参考译文:她把窗子打开,让新鲜空气进来。
4.介词转换成动词
经典例题: Many laboratories are developing medicines against AIDS.
参考译文:许多实验室正在研制治疗艾滋病的药物。
经典例题:“Coming!“Away she skimmed over the lawn,up the path,up the steps,across the veranda,and into the porch.
参考译文:“来了!“她转身蹦着跳着地跑了,越过草地,跑上小径,跨上台阶,穿过凉台,进了门廊。
转换成名词
1.动词转换成名词
经典例题: The university aims at the first rate of the world.
参考译文学校的目标是世界一流。
经典例题: The net and electronic commerce will foster a large number of free_fancers,and this will affect social structure in a big way.
参考译文:网络和电子商业将会造就一大批自由职业者,从而将对社会结构产生深远的影响。
经典例题: Numerous abstentions marked the French elections.
参考译文:这次法国选举的特点是弃权的人多。
2.形容词转换成名词
经典例题: They did their best to help the sick and the wounded.
参考译文:他们尽了最大努力帮助病号和伤号。
经典例题: The different production cost is closely associated with the sources of power.
参考译文:生产成本的差异与能源密切相关。
3.代词转换成名词
经典例题: According to a growing body of evidence,the chemicals that make up many plastics may migrate out of the material and into foods and fluids,ending up in your body.
分析: your body直译是“你的身体“,而细读原文,我们发现其实your body是泛指人体。作者为了引起与读者的共鸣,用了与读者更息息相关的your。在翻译时,应将此代词转换成名词,体现其真实含义。
参考译文越来越多的证据表明,许多塑料制品的化学成分会移动到食物或流体上去,最终进入人体内。
经典例题: Though we can\\\\’t see it,there is air all around us.参考译文虽然我们看不见空气,可我们周围到处都有空气。
4.副词转换成名词
经典例题: The new type of machine is shown schematically in Figure1.
参考译文图一所示是这种新型机器的简图。
经典例题: Internally the earth consists of two parts,a core and a mantle.参考译文地球的内部由两部分组成:地核和地幔。
转换成形容词
1.副词转换成形容词
经典例题: The engineer had prepared meticulously for his design.
参考译文:工程师为这次设计做了十分周密的准备。
经典例题: When tables and other materials are included,they should be conveniently placed,so that a student can consult them without turning over too many pages.
参考译文:当书中列有表格或其他参考资料时,应当将这些内容编排在适当的位置,以便使学生在查阅时,不必翻太多的书页。
2.名词转换成形容词
经典例题: Most teenagers feel no difficulty in learning and operating computers.
参考译文:绝大部分青少年在学习和操作电脑方面并不觉得困难。
经典例题: The instrument has been welcomed by users because of its stability in serviceability,reliability in operation and simplicity in maintenance.
参考译文:该仪器性能稳定,操作可靠,维护方便,因而受到用户的欢迎。
转换成副词
形容词转换成副词
经典例题: The wide application of electronic machines in scientific work,in designing and in economic calculations will free man from the labor of complicated computations.
参考译文:在科学研究、设计和经济计算方面广泛地应用电子计算机可以使人们从繁重的计算劳动中解放出来。
经典例题: By dialing the right number,you may be able to select a play,golf lesson or lecture in physics,from a pre-taped library in a remote city,for showing on your home screen.
参考译文只要拨对了号码,你就可以在家里电视机上选看到由远方城市一座图书馆发出的预先录制的一出戏,一堂打高尔夫球的讲课,或者一次物理学讲演。
二、结构转换
结构转换着眼于句子成分的相互转换和基本句型的改变。句子成分的相互转换主要在主语与宾语,补语与表语,主语与定语,定语与状语,状语与主语之间进行。
句子成分的转换
1.非主语译成主语
经典例题: Since the invention of the transistor at the Bell Telephone Laboratories in1984,it has found its way into varied applications in the commercial,industrial and military fields.
参考译文:自从1984年贝尔电话研究所发明晶体管以来,晶体管的种种应用已遍及商业、工业和军事各个领域。(状语译成主语)
经典例题: Television is different from radio in that it sends and receives pictures.
参考译文:电视和无线电的不同点在于电视能收发图像。(表语译成主语)
经典例题: Matter is usually electrically neutral,that is,it has as many protons,as electrons.
参考译文:物质通常是不带电的,就是说,它的质子和电子数量是相等的。(宾语译成主语)
2.非谓语译成谓语
经典例题: There is a need for improvement in your study habits.
参考译文:你的学习习惯需要改进。(主语译成谓语)
3.非宾语译成宾语
经典例题: He is admired by everybody.
参考译文:大家都很钦佩他。(主语译成宾语)
经典例题: Materials to be used for structural purpose are chosen so as to behave elastically in the environmental condition.
参考译文:用于结构上的材料必须选择得使它们在周围环境条件下具有弹性。(状语译成宾语)
4.非状语译成状语
经典例题: He drew a deep breath.
参考译文:他深深地吸了一口气。(定语译成状语)
经典例题: Pictures show him in the company of men like Churchill,Einstein and Gandhi.
参考译文:在这些照片中我们可以看到他和邱吉尔、爱因斯坦、甘地这些人的交往。(主语译成状语)
基本句型的转化
1.简单句转换成复合句
经典例题: At the slightest improvement in my work they would show warm approval.
参考译文我工作稍有进步,他们就热情肯定。
2.复合句转换成简单句
经典例题: This causes the construction of gigantic buildings where too large masses of human beings are crowded together.
参考译文:这样就盖起了许多人聚居的高楼大厦。
无论是学习还是生活,做任何事情不能生搬硬套,适当的转换一下思维或许会更好。
明天要演讲,求一篇十分钟的英语演讲,什么题目都可
什么题目都可以?我靠 我明天也有个presentation, 跟你share一下吧2.MainBody1.2 General IntroductionThe Applied Mathematics program at the University of Calgary prepares students to use mathematics to quantify and solve problems which arise in all areas of human endeavour. Applied Math students develop knowledge based upon analysis, algebra, geometry and mathematic principles associated with physics, computation and numerical analysis, allowing them a greater understanding of those areas of mathematics that have proven the most useful in solving real world problems or seem to offer promise for present problems.Applied mathematics is a broad field which historically emphasized theoretical physics and physical problems, giving deeper understanding of the physical world and enabling accurate predictions of physical phenomena. Although physics problems ranging from fluids to quantum systems remain a significant part of applied mathematics, the field has grown to include a wide variety of subjects – biomathematics, cryptography, scientific computation, mathematical modelling, economics, financial mathematics, operations research and engineering. 2.Why take this program?(Purpose)Applying yourselfDo you enjoy being challenged? Critical thinking is an extensive and integral part of every course in the Applied Mathematics program. It is a process in which applied mathematics majors learn to keep clearly in mind the precise nature of the mathematical objects defined, exactly what conclusions can be drawn, the logical progression of reaching them, and how they may relate in a consistent manner to real-world problems. This ability to identify key factors and apply appropriate methods in problem solving is a valuable asset in any work environment and can help build a successful career.3.What coures will I study? In your first year you will obtain the basic mathematical skills required in all science and engineering disciplines, including Applied Math by taking courses such as: calculus: calculating with continuous quantities linear methods: solving systems of equations via systematic techniques computer science: basic knowledge of computers and programming Your second year builds on the basic skills learned in first year, and introduces you to the calculus of several variables, vector spaces, more advanced ideas about matrices, and a calculus based first course in probability and statistics. Your first course in differential equations should also be taken in the second year.In your third and fourth years you will take courses in analysis, a study of the mathematical foundations of calculus and an investigation of advanced results, including proofs, which extend and amplify the beginning calculus material of the first and second years. For breadth and strength in your subject you will take required courses in complex variables, numerical analysis, partial differential equations, and a third course in linear algebra. Other required courses include a choice between abstract algebra and a second course in mathematical statistics plus.4.What area they can be empolyed?I:The finance industry demands recruits with strong quantitative skills and this course is intended to prepare you for careers in the area. The course provides training for those who seek a career specialising in derivative securities, investment, risk management and hedge funds. It also provides research skills for those who wish to subsequently pursue an academic career at doctoral level, particularly those wishing to pursue further and advanced studies in mathematical finance.II: The work of mathematicians falls into two broad classes -- theoretical (pure) mathematics and applied mathematics. These classes, however, are not sharply defined and often overlap. The world is full of places to do rigorous mathematics. As you begin to identify potential outlets for your talent, it may be useful to get a sense of the dimensions of the ’field’ in its entirety. Business, industry, and government use mathematical expertise, often in the context of applications. However, the job titles often do not include the word “mathematics“ or “mathematician,“ but do involve significant use of mathematics and/or quantitative reasoning. For people with advanced degrees in mathematics, careers involve development of new mathematical methods and theories and application to almost every area of science, engineering, industry and business. Those who major in mathematics in undergraduate institutions find a broad variety of opportunities. Some use their mathematical training directly and some use their training in rigorous thinking and analysis indirectly to solve problems in the business sector. Many of the contributions and uses of mathematics are closely related to the need for mathematical modeling and simulation of physical phenomena on the computer. In addition, the analysis and control of processes, and optimization and scheduling of resources use significant mathematics. For example, the finance industry uses sophisticated mathematical models for pricing of securities, while the petroleum industry models the flow of oil in underground rock formations to help in oil recovery. Image processing, whether producing clear pictures from satellite imagery or making medical images (CAT, MRI) to detect and diagnose, all use significant mathematics. Industrial design, whether structural components for airplanes or automobile parts, uses a tremendous amount of mathematical modeling; much of which is embodied in CAD/CAM computer software. Such techniques were used in the design of the Boeing 777, as well as in the design of automobiles. Computational modeling is also used in airplane and automobile design to analyze the flow of air over vehicles to determine fuel economy and efficiency. The use of mathematics is pervasive in modern industry. The result is that mathematicians are found in almost every sector of the job market, including engineering research, telecommunications, computer services and software, energy systems, computer manufacturers, aerospace and automotive, chemicals and pharmaceuticals, and government laboratories, among others.Business: Problem -- A firm wanted to decide statistically with a given confidence level what is the most it can lose over a given time interval. There are several methods to compute this value, the most precise of which tends to be very time-consuming -- requiring on the order of hours or maybe days to run on a computer, which makes it not feasible for a bank. The challenge is to come up with a quick analytical way to estimate this so-called value at risk. Process -- In order to do this, we drew upon techniques from stochastic processes, differential equations, and also Fourier analysis because we implement a Fast Fourier Transform and we used complex arithmetic in its implementation. Results -- The analysis resulted in a complete distribution of the firm’s future portfolio values. For instance, in one day or five days the full worth of the portfolio could vary by +$50 million to -$7 million or less. We assigned a probability to each of these states. Coming up with such probabilities rigorously involved some fairly interesting mathematics at that level, and it involved other people from the group and collaboration with people overseas. Part of the result of this work was a paper, and it is something that ultimately will get incorporated into our company’s product, which is software. In addition, it allowed us to do some interesting research. Industry: Problem -- The goal is to develop a methodology to reduce sonic boom in aircraft design. Process -- We use computational fluid dynamics and a computational code to study the flow over the geometry of an aircraft. once the solution is obtained, we use visualization tools to look at the physical flow field over the aircraft. We use a color monitor, called the work station, to bring the solution up visually. For example, if you want to look at the surface pressure of an aircraft we identify a blue color with the lower pressure, and a red color for the higher pressure. So by looking at the gradients of the color changes we understand the pressure on the surface of the aircraft. From this we understand a little bit more about the physics. Results -- once we have experience with this problem, we start the design phase using computational fluid dynamics codes and changing the shape of the aircraft. Bit by bit we get to what we want to achieve, a reduction in the sonic boom.Applications :The spectrum of the field is perhaps best illustrated by observing the role of mathematics as it applies to different products. Aerosol Can Chlorofluorocarbons (CFCs), like the freon used in aerosol cans and air conditioning systems, could destroy stratospheric ozone, which protects the earth from biologically damaging ultraviolet radiation. Mathematical models, simulations and the numerical solution of a special set of differential equations, called “stiff“ differential equations, are used to identify safer replacements from the members of hydrohalocarbon (HHC) family.Oil Rig Accurate models of oil reservoirs, including the simulations of oil and water moving through porous rock, sometimes covering hundreds of acres, are used by the petroleum industry to make decisions on where to drill. These problems are solved by reducing complex multidimensional differential equations to a sequence of simpler one-dimensional problems that are solved numerically Airport Operations research is used throughout the airline industry to make sure seats are sold and the airlines make money. Yield management, including mathematical models, optimization techniques, and probability calculations, is used for setting up automated reservation systems and complex systems of connecting routes. Communications Satellite Models based on computing solutions to partial differential equations are used to solve problems in signal processing and filtering of noise. Circuit The design of a circuit uses the concept of a graph, like a schematic map, with lines, called edges and intersections, called nodes. Systematic searches of the nodes are used to determine the most efficient connection from one node to another. Aircraft The design of an aircraft requires computational fluid dynamics, partial differential equations, and grid generation on complex geometries.至于Intruduction也就是开场白还用我教吧。如果需要 在补充答案里说下
physics of fluids怎么样
Physics of Fluids流体物理学 流体物理 流体物理杂志
计算流体力学的权威期刊有哪些
《空气动力学学报》,1980年创刊,1983年国内外公开发行,是中国空气动力学会主办的国家综合性一级学术刊物。多年来,刊物在学会的领导下,在中国空气动力研究与发展中心的支持下,在编委会和部的共同努力下,遵循“理论上有创新、学术上有新思想、理论与实际结合上有新特色、新方法、应用上有较大价值”的办刊宗旨,在出版工作中取得了很好的成绩,使刊物成为国内外公认的代表中国空气动力研究和发展水平的高科技学术期刊,成为航空航天类核心期刊的佼佼者。是我国比较好的计算流体力刊物。
去美国读研究生,读生物学专业算不算是敏感专业
不算敏感专业哈,现在申请此类专业的国际学生也呈逐渐上升的趋势。由于生物学是很多“生命科学”专业的基础课程,在北美大学里这个专业的录取要求非常高,而且进入专业的竞争性也非常强。很多中国学生和家长只知道这个是一个非常热门的专业,但是对这个专业以后的职业规划方向还是非常模糊。生物学专业和数学,化学,物理学科联系很紧密,同时需要的是复合型的人才。所以选择生物学方向的学生对自身的要求一向很高。
physicsoffluids不能投
physicsoffluids可以投。physicsoffluids是中科院SCI期刊分区工程技术的期刊,位于SCI的SCIE区,而且不在中科院《国际期刊预警名单(试行)》名单中,是影响因子4.980的国际期刊,能投。
physics of fluids是sci吗
是SCI,影响因子2.031 SCI三区Physics of Fluids is devoted to the publication of original theoretical, computational, and experimental contributions to the dynamics of gases, liquids, and complex or multiphase fluids. The journal is published by AIP Publishing, a not-for-profit, wholly-owned subsidiary of the American Institute of Physics. Content is published online daily, collected into monthly online and printed issues (12 issues per year).出版国家 UNITED STATES 出版周期 Monthly 出版年份 1994 年文章数 604