科技英语论文范文1
科技类英语范文
科技类英语范文In today's rapidly advancing technological era, the impact of scientific innovation on our daily lives is becoming increasingly apparent. The integration of technology into every facet of our existence has transformed the way we work, learn, and communicate. As we stand on the cusp of a new industrial revolution, it is imperative to consider the potential benefits and challenges that lie ahead.The advent of new technologies such as artificial intelligence (AI) and machine learning has revolutionized the way we interact with computers. AI systems are now capable of understanding human language and responding intelligently, enabling a more natural and efficient form of communication. This technology has the potential to revolutionize education, healthcare, and customer service industries, among others.In the realm of education, AI-powered personalized learning platforms are able to tailor lesson plans to the individual needs and abilities of students, leading to more effective and engaging learning experiences. In healthcare,AI-assisted diagnostic tools can help doctors detect diseases more accurately and quickly, enabling earlier interventions and better patient outcomes. In customer service, AI chatbots are providing round-the-clock support, enhancing customer satisfaction and reducing operational costs.However, while the benefits of these technologies are numerous, we must also be mindful of the potential challenges they pose. One such challenge is the ethical implications of AI. As machines become increasingly capable of making decisions that affect human lives, it is crucial to ensure that these decisions are made ethically and fairly. This requires a concerted effort from governments, industries, and individuals to establish robust frameworks and guidelines for ethical AI development and deployment. Another challenge lies in the ever-growing divide between those who have access to cutting-edge technologies and those who do not. This digital divide has the potential to exacerbate existing social and economic inequalities, creating a two-tiered society where those with access to technology enjoy significant advantages over those without.To address this issue, it is essential to prioritize inclusive technology development and deployment, ensuring that the benefits of technological progress are accessible to all.In conclusion, the integration of technology into our daily lives presents both immense opportunities and challenges. As we embrace the benefits of scientific innovation, it is imperative that we also acknowledge and address the potential downsides. By doing so, we can ensure that technology serves as a tool for enhancing human potential and promoting societal progress, rather than a catalyst for division and inequality.**科技创新与未来生活**在当今科技飞速发展的时代，科技创新对我们日常生活的影响日益显著。
有关于科技的英语作文（精选39篇）
有关于科技的英语作文（精选39篇）有关于科技的英语作文（精选39篇）在平时的学习、工作或生活中，大家都接触过作文吧，作文是人们把记忆中所存储的有关知识、经验和思想用书面形式表达出来的记叙方式。
作文的注意事项有许多，你确定会写吗？下面是小编收集整理的有关于科技的英语作文，仅供参考，大家一起来看看吧。
科技的英语作文篇1Modern technology makes life more convenient;tools are the milestores of the technology as well as human being's progress.Men used to cut trees with hand saw.But now,by using electronic saw they can cut down a tree in only a few minutes.Another example is more vivid:You have something urgent which has to be informed to your friend whose house is two hour's ride away.You probably want to make a phone call.But no telephone is installed in your friend's home.What could you do?Nowadays,with modern technology advanting,using internet is popular with us.Some years ago,people had to get what they wanted through looking into a lot of information;at last people could become tired and spent too much time.Now,if you use Internet,all becomes a piece of cake.Only by clucking,you will gain what you expect.We all hope that modern technology will reach a higher level,because modern technology makes life more convenient indeed.翻译：现代科技使生活更加便捷；工具是科技进步和人类进步的里程碑。
科技英语论文（合集5篇）
科技英语论文（合集5篇）第一篇：科技英语论文浅谈科技英语的翻译技巧沈声松摘要本文从科技英语的特点及其内在特征出发，从四个方面(科技英语的翻译准则，正确理解原文、词义的选择和确定，以及科技英语与工程实践相结合)论述了科技英语的翻译技巧。
关键词科技英语翻译准则翻译技巧工程实践科技英语（English for Science and Technology）诞生于20世纪50年代，是第二次世界大战科学技术迅猛发展的产物，它具有客观、准确、严密的特点。
近年来，随着科技信息的大量引进，科技英语的翻译已成为翻译领域的重要组成部分之一。
以前人们存在有失偏颇的认识导向：以为科技翻译比较单纯，只要对号入座将原文译出就算完成了译事。
其实科技英语翻译并非想象的那样简单。
众所周知，翻译牵涉到两种语言，而每种语言各有其特殊的词汇组成、语法结构、及内在特征差异等，所以翻译一件作品实际上是一种再创作。
18世纪英国作家蒂特勒（Tytler）曾经说过“翻译是一门艺术，也是一门科学”。
作为科学，它必然有内在的规律；作为艺术，它需要有高超的技巧。
要真正做好简明、正确、恰当的科技英语翻译工作，就必须要掌握一定的翻译技巧。
笔者试从以下四个方面浅谈科技英语的翻译技巧。
领会科技英语的翻译准则正确理解原文词义的选择与确定科技翻译要与工程实践相结合领会科技英语的翻译准则科技英语主要是述说实理、描写现象、推导公式、论证规律，其特点是结构严谨、逻辑严密、行文规范、用词准确、技术术语正确。
针对科技英语的这些特点，在翻译科技英语时，首先考虑的就是忠实原文，著名翻译家严复一直倡导“信、达、雅”，“信”即“忠实”，也就是要完整地、准确地表达原作的思想内容，这是科技英语翻译的首要要求；其次要讲究的就是“达”，即通顺。
著名学者傅雷先生曾指出：“理想的译文仿佛是原作者的中文写作。
”海外学者钱歌川先生也指出“科技英语的翻译虽不像小说那样要求雅致优美，姿态横生，也不像翻译诗歌那样要求抑扬顿挫，押韵合辙，但要求至少文从字顺，明白流畅。
关于科技的英语作文（精选12篇）
关于科技的英语作文（精选12篇）关于科技的英语作文（精选12篇）作文是经过人的思想考虑和语言组织，通过文字来表达一个主题意义的记叙方法。
作文分为小学作文、中学作文、大学作文（论文）。
下面是小编整理的关于科技的英语作文（精选12篇），供大家参考借鉴，希望可以帮助到有需要的朋友。
科技的英语作文篇1technology is a necessary force in modern life. we use technology to develop economy， change our life and quicken the pace of development. without it，we might still stay in a poor society. we might have no tvs， no computers and even no lights. we might have to work by hands instead of by machines and read many books to gain new knowledge instead of XXX use of computer nets. it's believed that technology improves our life.but technology is not always a positive force in modern life. if it is not used in the right way， it may be harmful and even dangerous to people. for example，as a result of advanced technology， computer viruses have been made by some people with personal purposes，and obviously everyone knows what harm they do. we can see that under the influence of the negative effect of technology，our society may be faced with a great danger.so we should make use of the positive force of technology to develop our modern life and reduce its negative effects.科技的'英语作文篇2Nowadays, there is general trend that people engaging in technological revolutions. Nevertheless, a question has been raised, “how did the science change our living conditions”To begin with, the science can help us to relieve excessivestress and tension by providing a temporary escape from a day-to-day life. In a world that has increasingly focused on turning everyone into millionaire, to cope with the current social trend, people crave being actively involved in the larger world and widening circles. Work-related stress, for example, has become a major problem which plagues all of modern people. In the most cases, the TV or computer, which were invented by new technology in the 20th century, can not merely help us lessen stress accumulated from an individual's demanding work life but are also fun to indulge in, is a sound and viable plan.In addition to eliminating people’s tension, the development of telephone and internet has improved our life styles. In other words, the science can allow us to meet friends of diverse background by an interesting and effective means. Especially, the age of a student or, better yet, the stage of the personal development of a student has to be considered when they have no leisure time and opportunity to widen circles and learn how to interact socially and behave in a group of their peers.Finally, it is undeniable that continuously developing technologies have brought tremendous benefits, especially in learning area. Learning has in many ways become easier than has ever been before. Take learning English for example, In the past, few students owned tape recorders, and learning materials were scarce as well. But today, tape recorders get more and more inexpensive, and diversified learning materials are readily available. On the other hand, new devices, such as MP3 or MD players, are offered in market, and relevant learning materials (MP3 files) are easily and freely downloadable from the Internet.Admittedly, science revolution has some negative effects under certain circumstances. For instance, the new technologycan harm our environment. However, after balancing all the pros and cons, the above-mentioned disadvantage seems to be minor. 科技的英语作文篇321st century is the century of technology. Today, technology is everywhere. We often use several technologies ,such as computer and phone. These technologies make easier life for us.With the development of technology and science, people are getting richer. Computer will go into every household. Computer can help us to do many things, such as playing games, designing and making us easier to do things.With today's technology, the phone can do many things, such as taking photos and sending the e-mail on the phone. We needn’t write a letter. We just need to make a phone call, so you can know more and more from your friends or family.With better and faster development of science and technology people can live better. If we do not have science and technology, our life will become even worse, the world cannot become beautiful. Without technology, there would be no technology life科技的英语作文篇4Several reasons account for the change. Firstly， we are in the information age today. Computers are useful in editing and data processing， make it easier for people to communicate with each other and provide all sorts of information. Secondly，computer skills can be a competitive edge for job hunter， which stimulates students' interest in computers and encourages them to have a good command of them. Finally，as the price of computers drops sharply recent years， more and more students can afford them.But some problems also arise，liking wasting students’time and having negative effect on studies. Therefore， we， as students，should always keep in mind that we should use computer in an appropriate way.科技的英语作文篇5Technology is a necessary force in modern life. we use technology to develop economy， change our life and quicken the pace of development. without it，we might still stay in a poor society. we might have no tvs， no computers and even no lights. we might have to work by hands instead of by machines and read many books to gain new knowledge instead of XXX use of computer nets. it's believed that technology improves our life.But technology is not always a positive force in modern life. if it is not used in the right way， it may be harmful and even dangerous to people. for example，as a result of advanced technology， computer viruses have been made by some people with personal purposes，and obviously everyone knows what harm they do. we can see that under the influence of the negative effect of technology，our society may be faced with a great danger.So we should make use of the positive force of technology to develop our modern life and reduce its negative effects.科技的英语作文篇6May 1st Sunday Fine.It was fine today，Lily and I went to visit the Science Museum.It is about two kilometers away from our homes， so we decided to go there by bike.We set off at 8 o'clock.At the museum we saw a lot of interesting things.We could operate some equipment.There we met many classmates and friends.We thought we had learned a lot and were more interested in science.At half past eleven we left the museum for home.We enjoyedourselves in the museum today.5月1日星期日晴今天是个好天气，我和丽丽去科技馆参观。
有关科学技术英语作文（通用7篇）
科学技术英语作文有关科学技术英语作文（通用7篇）在日常的学习、工作、生活中，大家都写过作文，肯定对各类作文都很熟悉吧，借助作文可以宣泄心中的'情感，调节自己的心情。
那么你有了解过作文吗？以下是小编整理的有关科学技术英语作文，欢迎大家分享。
科学技术英语作文篇1human life can not continue without science and technology. for many years, human society has developed with the advance of science and technology while the development of science and technology has in turn brought the process to mankind. so the life we are living now is more civilized than that of our fore fathers.the development of science and technology have brought about many changes in peoples life. for eample, the invention of television and space rocket have opened a new era for mankind. through the use of tv people can hear the sound and learn the events happening thousands of miles away. owing to the invention of spaceship and rocket, the dream of mans landing on the moon has now come true.science and technology also play an important role in our socialist construction. we may say, our socialist construction is just like a skyscraper, while science and technology are its base. without the base, the skyscraper cant be built. therefore, we should try our best to contribute to the development of science and technology so as to provide a more solid base to build our country.科学技术英语作文篇2"She has this thing where she goes to a movie theater, watching a horror movie and there was a wolf howling in thebackground.” University of Cambridge zoologist Arik Kershenbaum, talking about his collaborator Holly Root-Gutteridge, a biologist at Syracuse University. She said to herself, ‘Well, thats wrong. Thats clearly a European wolf and not a North American wolf like it should be in the scene."Slight variations in the way we speak allow us to tell whether someone is from Boston or New York just by listening to them. The same turns out to be true for the animals known as canids, which includes wolves, dogs and coyotes. They all howl to communicate—but those howls vary. Canids can tell which howls belong to their known associates and which belong to strangers.So Kershenbaum and Root-Gutteridge decided to categorize the howls of different canids around the world. Together with colleagues, they compiled recordings of more than 2,000 canid howls, including European wolves, Mexican wolves, arctic wolves, dingoes, coyotes, golden jackals, domestic dogs, New Guinea singing dogs, and more. A computer program sorted the howls into different types. The study was published in the journal Behavioral Processes. [Arik Kershenbaum et al, Disentangling canid howls across multiple species and subspecies: Structure in a complex communication channel]Based on the analysis, canids use 21 different kinds of howls to communicate. If you think of the howls as words, then all canids have the same vocabulary—but each species or sub-species has its own unique dialect. Some words are more common in one dialect, while other words are more common in another dialect and so on. By matching dialect with species and geography, researchers could monitor endangered species, like red wolves, just by listening.AK: "Being able to distinguish between the howls of a coyoteand the howls of a red wolf opens the possibility for techniques of passive monitoring, passive population monitoring, using acoustics."Meanwhile, ranchers have tried to broadcast specific howls to discourage grey wolves from feasting on their livestock, but its never been successful.AK: "Because we dont really know what message were conveying to the wolves when we play back an arbitrary howl. For all we know, we could be playing back a howl that means come and eat, theres lots of interesting food over here."The research could thus finally bring peace to the conflict between ranchers and wolves, by finally speaking to the predators in their own language.科学技术英语作文篇3here is a difference between science and technology Science has to do with discovering the facts and relationships between observable phenomena in nature and with establishing theories that serve to organize these facts and relationships; technology has to do with tools,techniques, and procedures for implementing the findings of science Progress in science excludes the human factor What scientists discover may shock or anger people--as did Darwin's theory of evolution Unlike science, progress in technology must be our slave and not the reverse.We are all familiar with the abuses of technology That promise is a cleaner and healthier worldScience.科学技术英语作文篇4Knowledge is power, especially scientific and technological knowledge. Science and technology are the motive power of the social development. Without them human society could never have developed from primitive society to modern society.Therefore, to conquer and transform nature, we must master scientific knowledge.However, social knowledge is also essential. Without it we can not understand society and don＇t know the law of the social development. As a result we are unable to tovern society. Therefore, besides scientific knowledge we need to master social science, philosophy, politics, history, aesthetics, etc, so that we can know society from all perspectives and form a correct world outlook.To meet new challenges in he 21st century, we university students should lose no time to acquire as much knowledge as possible so that we will become qualified successors of the socialist cause.科学技术英语作文篇5Buckyball Traps Single Water MoleculeThe carbon molecule known as a buckyball, a member of the fullerene family, can act as a cage for a variety of other chemicals. And now researchers have used one to trap a single molecule of water. The work appears in the journal Science.[Kei Kurotobi and Yasujiro Murata, A Single Molecule of Water Encapsulated in Fullerene C60]Placing a molecule that's essential to life within a spherically symmetrical one could let researchers learn more about each.Water molecules stick together, because they carry a slight charge on each end. As the positive pole of one H2O attracts the negative pole of another, the molecules cling tightly together. You can't separate a single water molecule from its fellows with a tiny pair of tweezers, so isolating it in a carbon cage may reveal new secrets about the intrinsic nature of a lone H2O.What about the cage itself? Researchers already know thatbuckyballs refuse to dissolve in water, sometimes even floating like miniature beach balls. But what happens when the water is within? Putting polar molecules inside buckyballs may influence the chemical behavior of their outsides, and create new molecules with unique properties. Not to mention making our understanding even…fuller.科学技术英语作文篇6Many years ago, when scientists tried to make a robot to do some human work, they could never thought about how far the robot could go. T oday, some scientists even predict that the wisdom of robot will surpass human being and take place of us. In the science fiction movies, the directors have explored the consciousness of intelligent machines, who showed how these machines controlled people at last. The directors warned people that they may lose the dominant position in the future. Recently, a robot was given the citizenship and it became the first robot to be treated as human being. The public was shocked, but when they saw the robot could communicate with human beings and question about matters, they felt scared. Maybe in the future, the robot will replace us in many aspects.科学技术英语作文篇7Today, with the fast development of science and technology, the artificial intelligence has gone much further than people can imagine, such as the robot. Now the first robot is admitted to be a citizen, which scares so many people. Many scientists had predicted that someday robots would replace human being not only in physical work, but also in minds. How terrible it would be. It is said that scientists saw two robots discussing by creating a new language, then they decided to turn down the machine and made them stop working. They knew clearly the danger mayhappen in the future. Most people have thought about self-consciousness that robot may have some day, but scientists still have a lot of passion in searching the robots. They want to complete everything. But no one can make sure what they can bring for human being.。
2022年关于科技的英语作文_science and technology 5篇
关于科技的英语作文_science andtechnology 5篇导读：关于”科技“的英语作文模板5篇，作文题目：science and technology。
以下是关于科技的中考英语模板，每篇作文均为满分模板带翻译。
关于”科技“的英语作文模板5篇，作文题目：science and technology。
以下是关于科技的中考英语模板，每篇作文均为满分模板带翻译。
高分英语作文1：science and technologyAfe4be5 the operating I use is well known. Microsoft is the largest software company in the world. About PC end users use Microsoft's operating .I also use windows now XP, I use this operating for two reasons: the hardware required by the operating is low-end, which means that there is no need to improve the ability of the computer to use the operating . Second, the operation of the is humanized and intelt. I have used this operating for five years, but it never makes me feel that it is out of date.It brings me a fresh feeling, And it's easy to operate and gives me a lot of comfort.中文翻译：AFE4BE5我使用的作系统是众所周知的，微软是世界上最大的软件公司，大约有PC终端用户都使用微软公司生产的作系统，我现在也在使用Windows XP，我使用这个作系统有两个原因：，这个作系统所要求的硬件是低端的，这意味着没有必要提高计算机使用这个作系统的能力第二，系统的作是人性化和智能化的，我已经使用这个作系统xx年了，但它从来没有让我觉得它过时了，它给我带来新鲜感，而且作方便，给我很大的舒适感。
科技文化类英语作文带翻译
科技文化类英语作文带翻译1. Technology has become an integral part of our daily lives. From smartphones to smart homes, we are surrounded by gadgets and devices that make our lives easier and more convenient. It's amazing how technology has evolved and how it has seamlessly integrated into our culture. We rely on it for communication, entertainment, and even for basic tasks like grocery shopping. It's hard to imagine a world without technology now.科技已经成为我们日常生活中不可或缺的一部分。
从智能手机到智能家居，我们被各种各样的小工具和设备所包围，使我们的生活变得更加便利。
科技的发展和融入我们的文化是令人惊讶的。
我们依赖科技进行沟通、娱乐，甚至是基本的购物任务。
现在很难想象一个没有科技的世界。
2. Technology has also changed the way we interact with each other. Social media platforms have become a virtual space where people connect, share their thoughts, and express themselves. It has opened up new avenues forcommunication and has made the world a smaller place. We can now easily connect with people from different parts of the world and share our experiences with them. It has also given rise to a new form of celebrity culture, where influencers and YouTubers have millions of followers and can influence trends and opinions.科技也改变了我们彼此之间的互动方式。
科技英语范文大全
科技英语范文大全实际上科学和技术既有密切联系，又有重要区别。
下面是店铺给大家整理的科技英语范文，供大家参阅!科技英语范文：关于科技的发展With the rapid development of technology, the popularity of the network is more and more widely, more and more people like to make comments on the various events in the network. A relatively rare event or quite shocking events also can be easy to become the center of network public opinion. And the reason of network public opinion happening is that the rapid development of the network makes the rapid dissemination of information. Every small events are likely to become the center of network public opinion. And the second reason is many people have a strong sense of Equal and justice. And the network is a very good platform to make their speech attention and recognition. So that many people like to go to internet to make comments on it. In the course of time the network public opinion has become more and more frequent But the emergence of the network public opinion brings different influence.First of all is the good work public opinion can supervise the false, unfair events,officials, play a supervisory role.But on the other hand, The network of public opinion also caused a lot of bad influence.Such as Human flesh search also easy to cause the invasion of privacy.科技英语范文：Is Science DangerousThe rapid development of science and technology has brought about great changes to human life, including great harms and disasters .Then people enter into endless argument about whether science is dangerous or not.So many examples can be figured out to prove the danger of science. Advanced technology can be easily manipulated by irresponsible persons as well as terrorist. Such as the Disaster 911, airplanes fly into buildings, fire burning, huge structures collapse, a lot of victims such as intellectual and business elites were sacrificed. Besides, As technology becomes more powerful day by day , we'll be complacent and lazy. Increased dependency on modern tools like calculators has reduced on our creativity. Students can’t solve a very simple mathematical equation without using a calculator. This affects the way these students uses their brains and reduces on the level of creativity.Just like the saying goes that every coin has two sides. However, it ‘s obvious that we make the decision to choose which side. After 911, people condemn the terrorist not airplays. Student who got low marks should rethink his carelessness and laziness but not pass the buck to the calculator.Any way, There is no dangerous science, but dangerous and irresponsible people. We are working very hard to solve such problems that come along with advances in science and technology, but the efforts are not sufficient and not very successful. Actually, the key lies in the user. Moralities such as responsibility, diligence and goodness should never be lost in our heart. Otherwise , the world would be full of danger even we turn back to the stone age.科技英语范文：The impact of technology on personal communicationNowadays, with the rapid development of science and technology, people’s life takes on a brand new look, especially the communication.No one can deny that we enjoy the convenience of hi-techproducts such as mobile phones and computers. They have enormously changed the ways of communication in shortening the distance between people as well as making instant contact possible. The speeding-up mobile technology has efficiently promoted the dream of “global village”.However, each coin has two sides. Since mobile technology has progressed rapidly, there occurs some lamentable phenomenon. The high technology make our communicationmoreconvenient, but it doesn’t mean科技英语范文：高科技The development of science and technology makes our life more comfortable and convenient. However, scientists have created many problems, which are not easy to be resolved, such as air pollution, the deterioration of environment and the scarcity of natural resources, to which we must some solutions.Modern science and technology render people many advantages. Modern telecommunication shortens the distance between people and makes communication much easier. Internet is widely used now not only for collection of abundant information but also for correspondence. Email, the most effective communication device now, is becoming very popular. Besides, telephone and mobile phone make contact more convenient than before.Modern transportation, such as airplanes and high-speed trains make our journey smooth and fast. With the help of modern transportation, people can go everywhere they prefer to. The journey to outer space and other planets is not a dream any more. Rockets and space shuttles can help us realize the dream of space travel.Modern medicine prolongs peoples life and relieves patientsof sufferings from many diseases. Cancer and AIDS are fatal to peoples health. Thanks to the endeavors scientists have made, these diseases become treatable.However, the process of scientific development also arouses many sever problems to our human beings. Internet, though widely used in modern communication, is easy to be destroyed by computer virus. Outer space exploration has produced much waste in the space. A tiny metal, a screw, for example can destroy a flying man-made satellite. Industrialization is making natural resources become scarce.Confronted with these problems, scientists are seeking prompt and feasible solutions. The development of science and technology bring about both positive and negative effects to us. We must eliminate the positive effects to the least extent.。
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ON-LINE DIAGNOSIS OF MARINE DIESEL CRANKSHAFT CRACKBASED ON MAGNETIC MEMORY*LI HAN-LIN, LIN JIN-BIAO, CAI ZHEN-XIONG, LU YONG(Marine Engineering Institute, Jimei University, Xiamen, Fujian 361021) Abstract: This paper summarized recent diagnosis methods of marine diesel crankshaft crack and introduced the fundamental principle, development and application of metal magnetic memory testing (MMMT) diagnosis technology. Compared with other methods, a scheme developed from MMMT combined with torsional signal to make on-line diagnosis of crankshaft crack was proposed, and the on-line diagnosis experimental platform of diesel was designed. Finally, comments were also made on the on-line MMMT method.Keywords: marine diesel; crankshaft; crack; metal magnetic memory1IntroductionMost of the crankshaft cracks on ocean marine diesel are deeply latent and difficult to detect artificially. In general, while the crack develops to a certain extent it will rupture and cause destructive breakage1. If inchoate stress concentration and tiny crack of crankshaft are detected on-line by Non-Destructive Testing (NDT) methods, the diesel can be stopped before the full development of the crack and thus rupture can be avoided. A new NDT method, MMMT developed rapidly recent years with advantages in such areas as cheap and simple sensors, measuring without impacting diesel operation and long-term on-line detection. Therefore, there will be a great foreground to use MMMT in crankshaft crack detection.2Dynamic Diagnosis of Crankshaft Crack2.1 Static Diagnosis of Crankshaft CrackCrankshaft crack is one of the fatal faults in diesels. There are some static NDT methods to diagnose crankshaft crack2such as Ultrasonic Testing, Radiographic Testing, Magnetic Particle Testing, Penetrate Testing, Eddy Current Testing, Optical Holography,and Microwave Testing. These methods have taken an important part in crankshaft quality control and accident prevention. However, on the other hand there are several disadvantages of these methods. Firstly, all of them must find cracks already formed and can not detect unexpected ones. Secondly, they are unable to make on-line detection and fault diagnosis. Thirdly, most of them need surface pretreatment of the facilities before inspection. Finally, the accuracy of detection is affected by crankshaft configuration and personal skill.2.2 Dynamic Diagnosis of Crankshaft CrackAt present there are some methods to diagnose shaft cracks on-line: rotor engine vibration displacement method, train wheel shaft temperature testing, acoustic emission and tortional vibration signal testing. However, vibration displacement method is unfit for diesel crankshaft crack diagnosis due to the strong vibration from reciprocating movement which makes it difficult to survey displacement and acceleration. Although there is local high temperature on the cracks, it is hard to inspect the change of the crankshaft temperature due to the high temperature of the lube oil in the diesels. Acoustic emission method is still in developing as great noise from diesel operation makes it difficult to measure high frequency acoustic wave emitted by crack. Therefore at present it is feasible to diagnose crankshaft crack on-line by using torsional vibration signal.* This research is supported by Nature Science Funding Project of Fujian Province A0410022.2.3 Crankshaft Crack Diagnosis Using Torsional Vibration SignalLiterature 3 brought forward a method using torsional vibration signal detected real-time from diesel to diagnose crankshaft fault. It studied crack fault diagnosis though measuring the characteristics of the torsional vibration of the shafting flywheel system, and presented that model frequency and damp were sensitive parameters of cracks. The torsional vibration measuring system of the diesel had several advantages such as: easy measuring, no direct contact, cheap sensor and longevity. It was a long-term reliable alarm method for diesel shafting crack. Research group in Marine Engine Institute of Jimei University has done the research of internal-combustion engine score fault with intelligent torsional vibration diagnosis system4, and it was a successful case of on-line fault diagnosis based on torsional vibration signal.3Metal Magnetic Memory Testing TechniqueIn the year 1997, Russian professor A. A. Dubov brought forward correlative theory of metal magnetic memory on the World Conference on NDT, developed MMM instruments and formed MMM NDT technique5.3.1 Theory of Metal Magnetic Memory TestingUnder the condition of the existence of the outside magnetic field,usually the magnetic field of the earth, there will appear a phenomenonin the stress concentration zone of ferromagnetic components with loadthat permeability of material besides the zone reduces and surface leakmagnetic field increases, which is called magnetostriction. It will makesthe surface magnetic field of the ferromagnetic accessory increase, andthe magnetic field can remember the location of disfigurement and stressconcentration zone, thus it is named metal magnetic memory.At present, one of the most popular explanation to the magneticmemory is that, loaded by alternating stresses, unsymmetricalelasto-plastic strain will take place in the magnetic domain formed byspontaneous magnetization in ferromagnetic material, and then unequal magnetic flux density will be induced by tensile and compressive stress6. Within the magnetic field of the earth, disfigurement andstress concentration zone of ferromagnetic components will produce maximum leak magnetic field, and there will be maximum tangential component H p X of the magnetic field intensity and zero normal component H p Y.3.2 Metal Magnetic Memory Testing Instruments and Their Practical UseResearch on magnetic memory testing instruments in foreignis in pace with the technological development. Foremost ofall were TSC-1M (see Fig. 1), TSCM-2FM and TSC-IM-4stress concentration magnetic testing instrument developedby Energodiagnostika Ltd. of Russia. These instruments were associated with different types of sensor for various requirements. Software of these instruments for signal analysisand data processing was also developed in Russia. For example,MM-System data processing software produced by Energodiagnostika Ltd. was able to analyze MMM signal and display the signal in three models: 2-D, 3-D and polarcoordinates model (see Fig. 2). Fig. 1 TSC-1M Stress Concentration Magnetic Testing InstrumentFig. 2 MM-System Data Procession Software Fig. 3 EMS-2000 MMM Diagnosis InstrumentInternal MMM testing instruments were mainly developed byEddysun (Xiamen) Electronic CO., LTD. In the year 2000,EMS-2000 metal magnetic memory diagnosis instrument (see Fig.3) with different types of sensor was produced by the companyfor ferromagnetic components disfigurement diagnosis. At thesame time, M3DPS (see Fig. 4) software for signal analysis anddata processing was developed to locate early fatigue damage 7.Applications of MMM testing in China has developed rapidlyfocusing on crack testing of steel welding line, pressure vessel,aeronautical structure, thermal power plant and so on. Firstly, inthe field of steel material weld testing, it was mainly used fordissimilar steel welding, hull structure steel plate welding 8, early diagnosis of welding disfigurement, welding line quality examination, power plant EH oil pipe fillet welding joint, high pressure boiler pipe seat fillet welding joint and so on. Secondly, it was applied in pressure vessel testing for high pressure bottle, vessel welding residual stress measurement and so on. Thirdly, it was applied in aeronautical structure testing for earlier disfigurement and plane undercarriage inspection. Fourthly, it was applied in thermal power plant testing for steam turbines component, blades crack, throttle valve and reheat tube crack diagnosis.4 On-line Diagnosis of Crankshaft Crack Using Metal Magnetic Memory Testing4.1 Crankshaft Crack Metal Magnetic Memory TestingMarine diesel engine crankshafts are mainly made up fromferromagnetic material. According to MMM theory, stressconcentration zone on crankshaft will produce maximumtangential component H p X of the magnetic field intensity andzero normal component H p Y with alternation of symbol. Withscanning inspection of the surface magnetic field of crankshaftby MMM testing sensor and instrument, the stressconcentration zone will be found out according to the zeronormal component of the field intensity, and then theexistence of crack on the crankshaft can be estimatedindirectly. With this method, the location of cracks can befound out without interrupting normal operation of the diesel,and give an alarm in time to remind engineers of operationcondition of the diesel. In the design, the sensor of the instrument will be placed into the body of the diesel through the guide door of thediesel, and it can directly scan zones with the most probable existence of stress concentration, such as locations near oil bore and fillet. In case the normal component of magnetic field intensity of the location shows a change from positive to negative or from negative to positive, it means that there may be tiny crack or stress concentration taking place, and at the same time, the instrument will record in a log and give an alarm. The method is simple, effective and feasible to on-line testing on operating diesel on ships.4.2 Design for Crankshaft Crack Testing Simulation ExperimentIn order to put MMM crankshaft crack testing method into practical application to ships, simulation experiment should be done, and the model experiment platform is built from a two cylinders diesel. The platform takes shaft accessory as the research object, and uses standard ball bearings to support shaft. By means of replacing shaft and bearings, the platform is able to do simulate experiment for shafts in different sharp or length such as roll shaft and crankshaft. The shaft is connected to electromotor by adapting flange, and the motor controlled by transducer can drive the shaft with different rotate speed to simulate running of uniform velocity and accelerated velocity. The bearings are fixed on steel foundation by two bearing seats, and the shell on the steel foundation is Diesel Body Sensor Instrument Fig. 5 Diesel Crankshaft Testing Design Fig. 4 M3DPS Software 3-D Displaymade up from organic glass to make the observation and the installation of the MMM sensor easy. There is lube oil deposited in the steel foundation and heated up by electro thermal coil. Heated lube oil is pumped to the top of the shell by a small gear oil pump and injected to shaft and bearings to lubricate them and simulate high temperature in diesel. Then the oil flows into oil sump forming a cycle. The MMM sensor is installed in the sides of the platform body through a probe hole, and its installation angle, depth and horizontal location can be adjusted to scan the magnetic field intension of the whole shaft to find the stress concentration zone.At the same time, stress distribution of diesel crankshaft with crack will be analysized by finite element method software ANSYS and the magnetic field intension model varied with time and temperature will also be constructed for calculation. All of these simulations are fundamental to MMM crack testing of crankshaft9.5ConclusionMMM crankshaft crack testing method is a new technique used for on-line inspection, and there are some issues to deal with in further study. The first one is quantificational relation between leak magnetic field intension near crack and stress, surrounding magnetic field, and the depth and width of crack10. Secondly, there are several factors having certain impacts to the MMM signal such as temperature, residual magnetic field and surface roughness, therefore, data processing should be done to eliminate these impacts.At present, marine diesel crankshaft crack testing is still being done by means of static method in China. MMM testing may solve the problem of early stress concentration inspection. This method has the advantages as cheap and simple sensors, measuring without affecting diesel operation and long-term on-line detection. It may forecast stress concentration zone and avoid hidden trouble of crankshaft rupture accident. Combined with torsional signal, MMM testing on-line diagnosis of crack will be achieved.References1.Peixin Yuan and Heji Yu, Crack Fault Diagnosis in Shaft.Journal of Northeastern University (NaturalScience), 1997(1), 12-16 (in Chinese).2.Wenhu Huang, Songbo Xia and Ruiyan Liu, Theory, Technique and Application of Equipment Fault Diagnosis,Beijing, Academic Publisher, 1996 (in Chinese).3.Wanyou Li, Zhenxiong Cai, Zhiqiu Wang and Hongxing Hua, Diagnosis of Crankshaft Crack in Diesel Using TorsionalVibration. Journal of Shanghai Jiaotong University, 2004(11), 1028-1031 (in Chinese).4.Wanyou Li, Zhenxiong Cai, Yan Liu and Zhiqiu Wang, Research on Diagnosis Method for Diesel Cylinder Score UsingTorsion Vibration Signal. Ship Engineering, 2003(5), 19-23 (in Chinese).5. A. A. Dubov, Principal Features of Metal Magnetic Memory Method And Inspection. 16th WCNDT 2004 WorldConference on NDT, Montreal, Canada.6.Weichang Zhong, Theoretical Fundamentals of the Metal Magnetic Memory Diagnostics: Spontaneous Magnetization ofFerromagnetic Materials by Elastic-Plastic Strain. NDT, 2001(10), 424-426 (in Chinese).7.Junming Lin, Xingzeng Yu and Chunjing Lin, Software M3DPS for Metal Magnetic Memory Diagnostic Instrument.NDT, 2001(7), 286-288 (in Chinese).8.Qilin Qian, Hailiang Gao, Huihua Zhang and Junming Lin, Theory and Application of Hull Structure Steel PlateWelding Based on Metal Magnetic Memory Diagnosis. Ship Building Technique, 2002(1), 25-27 (in Chinese).9.Zhi Hu and Jilin Ren, Stress Analysis and Magnetic Memory Testing of Ferromagnetic Items. NDT, 2001(7), 286-288(in Chinese).10.Hui Ding, Han Zhang, Xiaohong Li and Xishan Wen. The Theoretical Model For Detecting Cracks By Metal MagneticMemory Technique. NDT, 2002(2), 78-81(in Chinese).。