在我上小学三年级的时候,校长曾经给我们每人发过一本书,书名叫做《育才之路》。一天晚上,我拿着这本书做在床上,看见书的背面只写着一句话——在一张空白的纸上画出一幅美丽的画。那时我还不明白。直到最近,我整理书柜时,又发现了这本书。我才明白这句话的意思,它是多么深奥啊!我们刚来到这个世界时,脑子本是一片空白,就等于一张白纸.是知识造就了一个个杰出人才!知识就是一幅美丽的画!我家有一条已经养了三个月的小金鱼,我常常观察这条金鱼.有一天,我做在椅子上发呆。忽然,我无意中看见了这条鱼,发觉它是那么的孤单,虽然它在水里显得无忧无虑的,却很无聊。于是我又买了几条小金鱼,陪伴着它,它们自由的在水里快活的游来游去,欢唱着。于是,我把这幅美丽的画画了下来。我不仅得到了一幅美丽的画,还让小金鱼们得到了自由、快乐!生活中不缺少美,而是缺少发现美的眼睛!
这是一篇关于设备方面的英语文章吧。
成瘾"症状":身体心理俱受害 调查报告指出:电子游戏可以训练人的手脑配合能力,起到开发大脑、提升智力的作用;可以激发钻研、创造的欲望和学习的兴趣。但是,未成年人由于社会认知不足和自我防护意识缺乏,沉湎于游戏会引发违法犯罪,带来游戏者生理、心理等方面的伤害。同时,网络游戏是一种基于互联网的具有文化内涵的计算机软件,内容情节和背景信息必然反映制造国的道德观念和价值取向,具有制造国的文化特征。未成年人在玩游戏的过程中,必然在世界观、价值观和行为上受到影响。 一、网络成瘾带来心理和躯体疾病 报告指出,网络成瘾不仅影响人的心理,还影响人的身体健康,尤其是引起植物神经紊乱,体内激素水平失衡,使免疫功能降低,引发心血管疾病,胃肠神经官能病,紧张性头疼,焦虑,忧郁等,甚至可能导致死亡。同时,由于玩游戏时全神贯注,身体始终处于一种姿态,眼睛长时间注视显示屏,会导致视力下降,眼睛疼痛、怕光、暗适应能力降低,脖子酸痛,头晕眼花等。本次调查显示:玩电子游戏后感到眼睛痛的占36%;脖子酸痛的占27%;头晕的占15%。同时,沉迷于网络游戏,容易使未成年人减少人际间交流,产生自闭倾向,甚至会患上"电脑自闭症"。 二、使在校生学习成绩下降 目前,在校生因迷恋网络游戏造成学习成绩下降,甚至旷课、逃学的现象日益普遍。调查数据显示:认为容易上瘾,很难控制自己的占65%;玩起来就没完,自己控制不了的占;总想玩游戏,不想上学也不愿做作业的占5%;认为花很多时间和精力玩游戏会使学习成绩受影响的占。 三、引发社会难题 电子游戏一般以"攻击、战斗、竞争"为主要成分。未成年人长期玩飞车、砍杀、爆破、枪战等游戏,会使他们模糊道德认知,淡化游戏虚拟与现实生活的差异,误认为这种通过伤害他人而达到目的的方式是合理的。因为玩电子游戏而引发的道德失范、行为越轨甚至违法犯罪的问题正逐渐增多。本次调查的数据显示:认为因玩游戏性情变暴躁的占27%;认为玩游戏与校园暴力相关的达29%。 《中华人民共和国未成年人保护法》中规定了家庭、学校、社会等各方面对未成年人的保护条款,但可操作性不强,还缺乏必要的惩罚性条款,执法力度弱。对法律的普及、宣传也不够。 此外,缺少针对网络成瘾症的心理咨询与心理治疗的专业机构,缺乏及时救助的措施,一旦孩子出现成瘾问题,家长干着急,不知怎么办。 利大于弊。 1.必要性。这是一个知识经济的时代,信息正在以前所未有的速度膨胀和爆炸,未来的世界是网络的世界,要让我国在这个信息世界中跟上时代的步伐,作为21世纪主力军的我们,必然要能更快地适应这个高科技的社会,要具有从外界迅速、及时获取有效科学信息的能力,具有传播科学信息的能力,这就是科学素质。而因特网恰恰适应了这个要求。邓小平同志不是说:"计算机要从娃娃抓起"。 2.实用性。网络世界资源共享,它就像一个聚宝盆,一座取之不尽用之不竭的"富金山",谁勤于在这座金山上耕耘劳动,谁就会有所得。你可以从中最快地查找学习资料,可以学会更多课堂外的知识,并灵活地运用课内知识,促进思维的发展,培养中学生的创造力。上网还可以超越时空和经济的制约,在网上接受名校的教育,有什么问题,你也尽可以随时通过E-mail请求老师的指导。而且互联网上的交互式学习、丰富的三维图形展示、语言解说等多媒体内容,使得学习变得轻松、有趣,这是任何教科书都不可能具备的。 3.现实性。我省的曙光工程就是为了快速推进教育信息化,在我省每所中小学建立因特网教室,普及计算机因特网知识,推动中学生家庭上网,实现远程教育与知识共享为全省中小学生提供免费的网上课内外辅导培养中小学生学习和应用信息、技术的兴趣与意识,培养学生获取、分析、处理信息的能力。再看看我们身边,学校的网站不正搞的红红火火,林寿桦书记、陈欣老师不也建议大家去学校的网站看一看吗?年段、班级的网页不也都在紧锣密鼓的制作吗? 的确,作为一种新生事物,网络存在着一些弊端,但中学生处在学校的教育之下,学校要加强对青少年的人生观、价值观教育,培养学生对是非、美丑、善恶的判断能力,塑造学生良好的道德和行为规范。在老师的正确引导和家长的指点下,必能使我们以一个正确的心态来应用网络这种工具。 21世纪将是计算机网络时代,今日的莘莘学子将担任未来社会的栋梁。了解和掌握计算机网络知识,就是闯荡未来信息时代的最强有力的武器。让我们相信,我们今天所付出的一点一滴的努力,终将会聚沙汇塔,终将站在巨人的肩膀上。所以,上网利大于弊。 网络,给信息带来了强大而有力的传播途径,并且大大缩短了信息发布和接收的时间,避免了许多不必要的资源浪费。 类似的远程教育在许多其他教学中也有应用。像我们现在大四的学习中,因为有部分同学已经出去参加工作,不能回校参加剩余课程的学习。但是无论在校上课还是在外工作,都必须进行毕业考试。老师为了方便缺课的同学,就把笔记放在网上,让同学们易于自学。
l两篇太长了
PrefaceThe ARPANET – the Department of Defense network that is the ancestor of today’s Internet—was built in the late sixties using a proprietary protocol suite. This first protocol proved to have shortcomings for linking with other networks, which led to the development of Transfer Control Protocol/Internet Protocol (TCP/IP). TCP/IP used 32-bit address numbers. These soon proved to be unwieldy for most users, even when expressed in the less daunting formant of four 8-bit decimal numbers, delimited by periods. The obvious solution was a scheme for addressing computers by name. After all, people relate much better to names and find it much easier to remember the computer in the corner as “Frodo,” rather than “.”The First Generation: Hot TablesThe desire to refer to machines by name instead of number led to the first IP address management scheme: the host table. The host table is a file that contains all the IP address in use on a network, along with their names. The host table provides a mapping from a host’s name to its IP address, as well as reverse mapping: Given a host’s IP address, the user can look up its name. For a host table to be most user useful, it must contain the names of all the hosts with which a given host might want to communicate. For the ARPANET, that mean that the host table had to contain the names and IP address of every host on the network. Such a file was maintained by the Network Information Center (NIC), the central organization responsible for managing the ARPANET. The file was called and was similar in format to the/etc/hosts file on UNIX. Network administrators all over the network e-mailed host table changed to the NIC every time they added or deleted a host or changed a host’s IP address. The NIC made the changes to its master host table, which it made available via File Transfer Protocol (FTP). Administrators periodically downloaded the latest version of the host table to stay current.
培养学生英语科技文阅读能力:1.词汇表“八到”记忆法这是中学生使用最多的方法之一,即将生词表和人的器官相结合:眼里看到、心里想到、手里写到、嘴里拿到、耳朵听到、(结合实物还可以)鼻子嗅到、舌头尝到、手指触到。学生在记忆时不要偷懒,一定要边记边比划,把各个器官充分调动起来。这种方法使学生把目标词汇与自己的大脑神经联系,易记忆深刻,印象持久。2.分类记忆法即分析单词的形态,将所要记得单词根据其义、形、音进行分类。例如,按音标的拼读规则记忆单词,按词性变化记忆单词,按同音记忆单词,教师还可教给学生关于英语词根和词缀的知识等;通过词根加前缀或后缀可派生出新的单词,将两个或更多的词放在一起,可合成新的单词。3.联想记忆法苏联著名心理学家巴甫洛夫指出:“记忆要依靠联想,而联想则是新旧正式建立联系的产物。”美国心理学家威廉·詹姆士也说:“记忆的秘诀就是根据我们想记住的各种材料来进行各种各样的联想,而这些联想就成了各种资料的钓钩,万一资料沉没脑海,我们就可以通过联想这样的钓钩将资料钩出来。”充分运用发散思维展开自己的想象力,使所要记忆的英语单词,生动、形象和具体化,使生词与熟词之间建立一种联系,从而达到以旧带新,快速记忆的目的。
这是《科学美国人》杂志上的《PLASTICS GET WIRED》Like many technological advances, the innovations in the field ofconducting polymers began by accident. While attempting tomake an organic polymer called polyacetylene in the early1970s, Hideki Shirakawa of the Tokyo Institute of Technology mistakenlyadded 1,000 times more catalyst than the recipe called for. What he producedwas a lustrous, silvery film that resembled aluminum foil butstretched like Saran Wrap—something that sounds more like a new andimproved way to keep leftovers fresh than a potential breakthrough inmaterials substance appeared so unusual that when Alan G. MacDiarmidspied it, he wondered if it would be a candidate for his goal of making“synthetic metals”—nonmetallic substances that could transmit 1977 Shirakawa joined MacDiarmid and Alan J. Heeger in their laboratoryat the University of Pennsylvania to investigate this form of mixing in some iodine, the group found that the material’sconductivity subsequently jumped by a factor of several , cheap, manufacturable and flexible, conducting polymers inspiredvisions of a future of transparent circuits, artificial muscle and electronicdisplays that conveniently roll up under the arm. Researchers haveauditioned various demonstration devices, including components thatcould be useful for new displays, such as plastic transistors and light-emittingdiodes (LEDs). Although such a future is about as dreamy as it gets,many investigators see broad marketing opportunities possible now—inantistatic coatings, electromagnetic shielding, lights for toys and microwaveovens, among others. Perhaps mundane, such applications are nonethelesspromising enough that universities are collaborating with corporations,and scientists have initiated the pace of technological innovation has been impressivelybrisk, whether the materials will have an effect on commerce remains are unlikely to invest in new equipment if the devices performonly marginally better than existing instruments. Polymer-based batteries,for instance, have a longer shelf life than do conventional ones, but theyhave penetrated the market in only a limited way. Flat-panel displays andLEDs made of organic substances face entrenched competition from existinginorganic liquid crystals and , optimism pervades the field. Because plastic and electrical deviceshave become integral parts of the modern world, researchers are confidentthat at least some profitable uses will emerge. Conducting polymers constitutea radically novel market area, points out Ray H. Baughman of Allied-Signal in Morristown, ., who predicts confidently, “Fortunes aregoing to be made.”Polymers, the constituents of familiar plastic materials and syntheticfibers, are large organic molecules built out of smaller ones linked togetherin a long chain. Generally, they are insulators, because their moleculeshave no free electrons for carrying current. To make these substances conductive,workers exploit a technique familiar to the semiconducting industry:doping, or adding atoms with interesting electronic properties. Theadded atoms either give up some of their spare electrons to the polymerbonds or grab some electrons from the bonds (and thereby contribute positivecharges called holes). In either case, the chain becomes electrically a voltage can then send electrons scampering over thelength of the polymer.《MICROPROCESSORS IN 2020》Unlike many other technologies that fed our imaginationsand then faded away, the computer hastransformed our society. There can be little doubtthat it will continue to do so for many decades to come. Theengine driving this ongoing revolution is the microprocessor,the sliver of silicon that has led to countless inventions, suchas portable computers and fax machines, and has added intelligenceto modern automobiles and wristwatches. Astonishingly,the performance of microprocessors has improved25,000 times over since their invention only 27 years have been asked to describe the microprocessor of predictions in my opinion tend to overstate the worthof radical, new computing technologies. Hence, I boldly predictthat changes will be evolutionary in nature, and not so, if the microprocessor continues to improveat its current rate, I cannot help but suggest that 25 yearsfrom now these chips will empower revolutionary software tocompute wonderful things.《HOW THE SUPERTRANSISTORWORKS》Although it is rarely acknowledged,not one but two distinctelectronic revolutionswere set in motion by the invention ofthe transistor 50 years ago at Bell TelephoneLaboratories. The better knownof the two has as its hallmark the trendtoward miniaturization. This revolutionwas fundamentally transformed in thelate 1950s, when Robert N. Noyce andJack Kilby separately invented the integratedcircuit, in which multiple transistorsare fabricated within a single chipmade up of layers of a semiconductormaterial. Years of this miniaturizationtrend have led to fingernail-size sliversof silicon containing millions of transistors,each measuring a few microns andconsuming perhaps a millionth of a wattin operation. 如果需要更多跟我联系,我有pdf版的资料。
A Boy and His Tree A long time ago, there was a huge apple tree. A little boy loved to come and play around it every day. He climbed to the tree top, ate the apples, took a nap under the shadow… He loved the tree and the tree loved to play with him. Time went by…The little boy had grown up and he no longer played around the tree. One day, the boy came back to the tree and looked sad. “Come and play with me,” the tree asked the boy. “I am no longer a kid, I don’t play around trees anymore.” The boy replied, “I want toys. I need money to buy them.” “Sorry, but I don’t have money…but you can pick all my apples and sell them. So, you will have money.” The boy was so excited. He picked all the apples on the tree and left happily. The boy didn’t come back after he picked the apples. The tree was sad. One day, the boy returned and the tree was so excited. “Come and play with me.” The tree said. “I don’t have time to play. I have to work for my family. We need a house for shelter. Can you help me?” “Sorry, but I don’t have a house. But you can cut off my branches to build your house.” So the boy cut all the branches of the tree and left happily. The tree was glad to see him happy but the boy didn’t appear since then. The tree was again lonely and sad. One hot summer day, the boy returned and the tree was delighted. “Come and play with me!” the tree said. “I am sad and getting old. I want to go sailing to relax myself. Can you give me a boat?” “Use my trunk to build the boat. You can sail and be happy.” So the boy cut the tree trunk to make a boat. He went sailing and did not show up for a long time. Finally, the boy returned after he left for so many years. “Sorry, my boy. But I don’t have anything for you anymore. No more apples for you.” the tree said. “ I don’t have teeth to bite.” The boy replied. “ No more trunk for you to climb on.” “I am too old for that now.” the boy said. “I really want to give you something…the only thing left is my dying roots.” The tree said with tears. “I don’t need much now, just a place to rest. I am tired after all these years.” The boy replied. “Good! Old tree roots are the best place to lean on and rest. Come here, please sit down with me and have a rest.” The boy sat down and the tree was glad and smiled with tears… This is a story of everyone. The tree is our parent. When we were young, we loved to play with Mom and Dad… When we grow up, we leave them, and only come to them when we need something or when we are in trouble. No matter what, parents will always be there and give everything they could to make you happy. You may think that the boy is cruel to the tree but that's how all of us are treating our parents. 很久以前有一棵苹果树。一个小男孩每天都喜欢来到树旁玩耍。他爬到树顶,吃苹果,在树荫里打盹……他爱这棵树,树也爱和他一起玩。 随着时间的流逝,小男孩长大了。他不再到树旁玩耍了。 一天,男孩回到树旁,看起来很悲伤。“来和我玩吧!”树说。 “我不再是小孩了,我不会再到树下玩耍了。”男孩答到,“我想要玩具,我需要钱来买。” “很遗憾,我没有钱……但是你可以采摘我的所有苹果拿去卖。这样你就有钱了。”男孩很兴奋。他摘掉树上所有的苹果,然后高兴地离开了。自从那以后男孩没有回来。树很伤心。 一天,男孩回来了,树非常兴奋。“来和我玩吧。”树说。“我没有时间玩。我得为我的家庭工作。我们需要一个房子来遮风挡雨,你能帮我吗?”很遗憾,我没有房子。但是,你可以砍下我的树枝来建房。“因此,男孩砍下所有的树枝,高高兴兴地离开了。 看到他高兴,树也很高兴。但是,自从那时起男孩没再出现,树有孤独,伤心起来。 突然,在一个夏日,男孩回到树旁,树很高兴。“来和我玩吧!”树说。 “我很伤心,我开始老了。我想去航海放松自己。你能不能给我一条船?” “用我的树干去造一条船,你就能航海了,你会高兴的。”于是,男孩砍倒树干去造船。他航海去了,很长一段时间未露面。 许多年后男孩终于回来了。“很遗憾,我的孩子,我再也没有任何东西可以给你了。没有苹果给你……”树说。“我没有牙齿啃。” 男孩答到。“没有树干供你爬。”“现在我老了,爬不上去了。” 男孩说。“我真的想把一切都给你……我唯一剩下的东西是快要死去的树墩。” 树含着眼泪说。“现在,我不需要什么东西,只需要一个地方来休息。经过了这些年我太累了。”男孩答到。 “太好了!老树墩就是倚着休息的最好地方。过来,和我一起坐下休息吧。” 男孩坐下了,树很高兴,含泪而笑…… 这是一个发生在每一个人身上的故事。那棵树就像我们的父母。我们小的时候,喜欢和爸爸妈妈玩……长大后,便离开他们,只有在我们需要父母亲,或是遇到了困难的时候,才会回去找他们。尽管如此,父母却总是有求必应,为了我们的幸福,无私地奉献自己的一切。你也许觉得那个男孩很残忍,但我们何尝不是这样呢? 是演讲用的!!!!!!!!!!!
由于词意库是自学习形成,因此不需要预先设置庞大的词典库,而且最重要的是,学习是持续性的,系统对词意的理解会随着外界的变化而变化,并能不断增添新创词汇。
由于同一个词,对于不同的人,词意可能是不同的,因此可以根据每个用户的习惯形成自己的子词意库,可使用子词意库对文本进行二次分析,产生个性化结果。 系统的学习分为两种方式: 知识学习 系统自动在互联网上进行,无特定目的地吸收网上各种信息,并对收集到的信息进行分析后作为知识保留,整个过程无需人工干预,可一天 24 小时不间断地进行。
经验学习 每一次用户的具体使用,其结果也将作为经验保留下来,并对知识学习的结果进行修正。分词技术不追求 100%的准确,而讲究实用、快速,不依赖于庞大的词汇库或知识库,因此可以做到不针对特定领域,可解决人名、地名、新出现的词汇等的分词,这些问题是传统分词方法难以解决的,尤其是新词汇的分词,几乎是一个世界性的难题。
由于整个核心算法并非基于字、词典及语法,而是从模仿人类对语言文字的理解入手,比如一个儿童并不懂得查字典和语法,但能够听懂别人说的话,因此对核心只要稍作修改便能够用于英语及其它文字语言,就好象一个婴儿,你把他放到哪个国家,他就能学会当地的语言。
在欧美的大学理工科系中,在专门的课程之外,关于学术论文、调查报告的写作,也要讲20-30学时,有的大学还设置了攻读科技写作的硕士和博士学位,在社会上还出现了以科技写作为职业的科技作家和科技记者。
在我国,近几年来,有的大学将它列为选修课,有的大学开设了讲座,一些工厂、研究单位、学会、协会相继举办了各种类型的讲习班、报告会,这些都受到了广大学生、科技工作者的热烈欢迎。(《应用写作》1985年第1期第33页)科技写作语言的特点:“语言是人类最重要的交际工具”。
尤其在科学技术飞速发展的今天,运用准确、鲜明、简练、生动的语言,拟写科技作品,交流学术思想,传播科研成果是非常重要的问题。周密、准确周密、准确是科技作品语言的一大特点。
科技作品的语言是否周密、准确,关系到文章写作的成败。周密指句子之间合乎逻辑。
句子合乎逻辑了,语言也就周密了。能否使语言周密属于语言逻辑问题。
这就要求思维敏捷,言之有序,无懈可击。语言周密来自于思维的严谨。
如果思维不严谨,出现漏润,那必然使语言不周密。同时,语言周密也来自对客观事物观察的正确。
因为文章是客观事物的反映。观察不正确,反映在作品里的客观事物的语言必然不会正确。
准确是用词问题。用词准确与否,首先反映着作者对待科学本身的态度问题。
从事科学研究的人,应当老老实实地对待科学。古人说:“篇之明靡句无玷也;句之清英,字不妄也。”
介绍研究课题的重要性,“比较重要”不能写成“极其重要”。不要动辄就用“填补空白”、“国际水平”、“国内首创”、“重大创新”等字眼。
评价前人的工作、切忌轻率之言。用词准确,还表现为作者语言上的功夫。
客观事物具有不同的性质、范围、程度、关系等等,要准确地表达这些问题,确实需要“为求一字稳,耐得半宵寒”的精神。古人有推敲的佳话,鲁迅说:“写好了后不妨多改几遍”,为的是选择最准确的词来表达。
例如,“作用在一个物体上的两个刀,如果在同一直线上、大小相等,方向相反,这两个力就平衡”。这个平衡原理的表述就很准确。
如果将“同一”改成“相同”,“相等”改成“一样”就不准确了。明朗、规范明朗、规范是科技作品语言的又一特点。
语言明朗是说语言的表达要清楚明白,让人读了能够理解。语言明朗,重要的是用词和组。
例如,“我所以有这样的成就是因为我攀登在高高的山峰上。”这句话就不明朗使人发问:“攀登在高高的山峰上,怎么会有成就呢?”如果把这句话改成“如果我所看到的,我所发现的要比笛卡尔和培根远大一点的话,那是因为我站在巨人肩上的缘故②。
这就是牛顿说出的一句名言。语言明朗还必须指代明确,所谓指代是指代词指代各类实词词组或句子。
若用得好,可以节省笔墨,使文章简洁明了,若使用不当,指代不明,就会使前后文的关系不清,语意不明。例如:“物体被举得越高质量就越大,它的势能就越多。”
这个句子里的“它”指代“物体”语意明确。相反,也有指代不明的。
例如:“弹性物体的弹性形变越大,它的势能就越多。”这里的“它”是指代“弹性物体”还是指代“弹性物体的弹性形变”就不明确。
如果改成“弹性物体弹性形变越大,它的势能就越多”就指代明确了。规范是指用词和语法规则问题。
在长期的语言实践中,人们逐渐形成了习惯的用词和语法规则。它包括用词、语序和句子成分等方面的内容。
用词规范,首先,不生造词语。如“动滑轮和定滑轮组合在一起叫滑轮组”。
这个句子里的每一个词语都合乎规范。但如果改成“活滑轮和死滑轮连结在一起叫滑轮组”就不规范了。
其次,不要滥用简缩词语。例如,有些文章把“混凝土”写成“砼”,把“高层框架结构”写成“高架结构”,都是不规范的。
第三,语序要流畅。语序的安排,要反映事物的先后程序。
有些句子,用词和句法没有什么问题,但词序紊乱,意思上也不能表达清楚。如:“我关上门,走进屋里,坐在床上”就违背了事物本身的发展逻辑。
只有先走进屋里,才能关上门。又如:“互相连通的底部容器叫做连通器”就不流畅。
应该是“底部互相连通的容器叫做连通器”。第四句子成分要完整。
句子成分完整,才能明确表达意思。句子成分不完整,就不符合语法要求了。
平实、简要平实、简要是科技作品语言的另一个特点。所谓平实就是自然朴素不求粉饰。
做到“文约而旨丰”,“文简而理周③”。怎样才能简要呢?(一),应该在认识事物上下功夫。
没有对客观事物的认识就不能写出言简意深、文短旨丰的文章。(二),要在语言的概括精炼上下功夫。
要精雕细琢,选择内涵丰富的语言,表达客观事物。(三),要在删繁就简上下功夫。
总之、科技作品的语言,要周密、准确,才能正确恰当地表达客观事物,要明朗、规范,才能清楚明白地表达客观事物;要平实、简要,才能通俗易懂、直截了当地表达客观事物。一个优秀的自然科学家,同时也应当是一个语言学家。
语言是写作的工具,要把科研成果准确、鲜明、生动地表达出来,就得有熟练地使用这个工具的技能。只有经过长期修养,不断加强训练,多读多写科技。
科技论文的特点إ
ر 1、学术性إ
学术性又称理论性。科技论文是一种纯学术性的文章。它要求运用科学的原理和方法,对自然科学领域新问题进行科学分析,严密论证,抽象概括。虽然它取材于某一研究项目,某一实验,某一新产品研制等,但绝不是客观事物的外观形态和过程的描述,或者就事论事地进行叙述。而是经过提炼、加工,从理论上做出说明。可见,学术性是科技论文最基本的特征。
2、创造性إ
衡量科技论文价值的根本标准就在于它的创造性。如果没有新创造、新见解、新发现、新发明,就没有必要写论文。因为科学研究的目的就在于创造。作为科研成果的论文,它的任务即是进行学术交流,实现其科学价值。可见,广大科技人员,如果只能继承,没有创造,人类的文明和历史,就不会得到发展。إ
应用文写作的特点是什么?
应用文写作是以实用为目的的写作实践活动,从总体角度说,它是研究应用文体写作基本理论、基本知识和基本技能技巧的一门学问。在学校教育中,它是一门综合性、实践性很强的基础课程。从接受美学的角度来看,写作活动具备四个基本要素,即写作主体——作者;写作客体——所反映的客观事物(包括精神客体);写作本体(或称载体)——文本;写作受体——接受和作用对象即读者。这四个要素构成一个完整的有机的写作系统。
应用文写作具备以下几个特点:
(一)实用性
应用文的主要任务是解决实际问题的。例如:经济活动要写分析报告,要写经济合同;法律行为要写起诉状、答辩状;礼仪活动要写请柬、祝贺信、贺电,死了人要发布消息要写讣告,开追悼会要写悼词,婚丧喜庆要在门框张贴对联;开会要发通知,有重要事项请求上级答复批准要写请求。总之,为了办某件事,解决某个问题,交流某项经验,疏通某一情感,达成某种协议,都必须选择适合表达的具体文种,讲求实效。可以说,每种文体都体现出很强的实用价值。应用文不是供人审美、供人欣赏玩味,更不是供文人骚客比试高下的文体,而是供人实践运用,达成一定功利目的的文体。
(二)真实性
应用文要求作者严格按照客观事物的本来面目进行写作,决不允许虚构和凭空想象。真实性是应用文体写作的生命之所在。只有真实地向社会各方面传递各种信息,上情下达,下情上达,它的文体价值才会有效地实现,否则就会失真,给社会带来不利影响甚至造成危害。
(三)针对性
应用文写作有着明确的功利目的性,它是为处理和解决社会生活中的实际问题而进行的。因此,它有着明确的特定接受对象,有强烈的针对色彩。从文种选择、格式安排到语词的运用,都要针对写作目的与读者对象而有所选择与取舍。
(四)时效性
时效性包括应用文的时代性、及时性、作用时间的有限性三层含义。所谓时代性,是说它要与现实紧密结合,紧跟时代、适应时代的变化与需求。所谓及时性,是说它要求在一定时限内完成写作任务,延期则会影响作用的发挥,甚至贻误工作。所谓作用时间的有效性,是说它只在一定时期内产生直接作用,写作目的实现了,其直接效用就会随之消失,文本就变成了档案材料。
(五)工具性
应用文本身不是人们追求的目标,仅仅是能动地实现特定目标采取的手段。它以语言文字为中介,传递各种信息,在社会**、经济、文化、科技乃至日常生活各个方面发挥工具作用。
(六)规范性
应用文的体式是固定的,严格讲究格式准确。其文本形式和制发程序都有特定要求,讲究规范。在实际写作中,不同种类的应用文都有一套为内容服务的相应的体式,都有其惯用的格式、结构、手法及写作要求,且相对稳定,在相当长时间内不会有变化。当然,我们所说的固定,也只是一种相对意义的固定。从长远和历史的发展观点来看,应用文体还将随着时代和社会生活的发展而有所变化的。
写作过程: 1.确立主旨(文章题目);2.选择材料;3.安排结构;4.语言表达;
科技论文的写作特点 科技论文是对创造性的科研成果进行理论分析和总结的文体。
因此,科技论文有别于人文社科类论文和一般议论文,具有科学性、理论性、学术性、准确性、创新性、独创性和规范性。 首先,作者撰写科技论文时要抓住科技论文的特点。
用语准确、鲜明、贴切,多用主动句和复合句,使内容表达精准周密。而不要用过多的形容词加以修饰,忌用诸如“大概、可能、极大地,之类的模糊词语表述。
其次,忌作者用“具有重要的指导意义”、“在理论上具有重大突破”等美誉之辞自我评价,论文的意义应由读者评价,效用应让实践检验。 再次,科技论文通常用图表、照片、公式、化学式等人工语言符号作为其相关内容的表达形式。
科技论文的特点可以概括为四性:即学术性、创造性、科学性和文献性。(一)学术性 论文探讨的是某一科学领域中比较专门化的问题,带有较强的研究、论争的性质,侧重于对事物进行抽象的概括的叙述或论证,反映的不是客观事物的外部直观形态和过程,而是事物发展的内在本质和变化演进的规律。
这是学术论文存在的最基本条件。(二)创造性 论文要反映出作者对客观事物研究的独到理解和观点,它应该显示出新理论、新设想、新方法、新定理,甚至能够填补某个领域的空白。
它可以用几句话简明、清晰地表述出来。当然,论证这个基本的思想,可能需要非常丰富的材料以及种种复杂的推理。
但这种创造性是就全人类总的知识而言的,是在世界范围内来衡量的,而不能局限于某一狭窄的范围。有没有创造性,这是决定论文价值的一个根本标准。
(三)科学性 论文的内容必须是客观存在的事实,剩‹际公认的真理,它应该是成熟的理论或技术,经得起实践的检验,并且应具有当代科学技术的先进水平,在技术上行得通,不脱离实际。想要好文章何必东奔西走,我们这里应有尽有,我们为您提供涵盖面最广的代写业务,各种代写服务任您挑选,竭尽所能只为求得您的满意,尽职尽责只为争取您的信任。
二、科技论文写作技巧 论文的最后一步是精心写作。动笔写作前,应该通盘整理一下研究成果,对研究提纲进行调整和补充,进一步衍化为写作提纲,对全文的布局、观点的体系、分析的层次、材料的使用作统一的安排。
写作过程不是单纯记录研究成果的过程,而是继续深入研究的过程,是把研究成果精确化和完善化的过程。在写作过程中发现对哪些问题研究还不够深透、论证还不够充分,就要记下来继续攻关。
写论文要明确其性质和特点。科学论文专业性很强,应有自己的研究心得,以表述自己的见解为主,应对学科建设起推动作用,至少也要在综合别人成果的基础上有所加深。
更高的要求是填补学科的空白,一般要求超过前人已达到的成就,要有新的创见。写论文要力求删繁就简、突出重点,主要写自己的观点。
纳米技术就在我们身边,本文语言特点是文章语言通俗易懂,运用列数字、举例子等说明方法,使我们对纳米这一陌生而又新奇的科技有了一定的了解和认识,也让我们对科技的未来有了新的畅想。
科学语体是指科技文章中使用的冷静、客观及清晰的语言特点。它一般采用冷静、客观、严谨、简练的句式和结构,以公式、数学语言和科技术语为主。看似繁琐,实则是为了更准确、简明、规范地表达科学问题。科学语体强调客观性,要求文中不要有科技上的臆误和主观言论,也不能存在任何有偏见的观点。文中使用的术语要准确,语言合情合理、层次分明。另外,语言不能拘泥形象,需要富于想象力,以易懂的句式表达科学问题。
一般来说,科学语言的属性有以下特点:一是确定的标准语言,即业内普遍接受的术语和表述方式;二是要用客观、冷静、严谨、简洁的语言来表达科学内容;三是采用严谨、精准、清晰的公式、数学语言和科技术语。此外,句子要简洁,句子关系要清晰准确,不得出现不必要的花哨措辞和引用。科学语言的准确表达,虽然浅陋,却有一定的难度。要想运用科学语体进行完美表达,不妨先多进行研究、增强自我功力,并带着良好的习惯,不断探究科学之谜。
中国的第四次核爆炸证明人民中国不仅在原子方面,而且一般地说在尖端工业方面,取得了辉煌成就。事实上,制造和设计原子弹和导弹的要求的材料(裂变原料、特种合金、耐火器材等)、工业生产过程、电子仪器,都是只有高度工业化的国家才能实现的。法《新观察家》周刊十一月二日刊载马克希伯尔写的文章,事实上,从上星期五以来,中国在一个基本的方面,在一个对原子能的民用和军事用途都很重要的方面:即在裂变物质的生产方面,中国比其他一切国家都先进,包括美国在内。《参考消息》,
近几年来,我们看到了我们伟大的祖国的科技事业的迅猛发展,这让我为我是个中国人而感到无比的自豪。记得很久以前,手机的用途几乎只有一个,那就是打电话,可是前几年,手机有了很大的改变,不仅外观漂亮多了,而且用途也多了,可以用手机拍照、开会、上网、发短信息等等一系列的事情,这让我们的生活更为方便,也让我更加领会到了科技的力量,不过,我只是个初出茅庐的学生,对“科技”二字的内容还知之有限,我无法用一些很深奥的理论来阐述科技的玄奇,也无法对各位走上工作岗位的长辈们承诺我所能实现的科技蓝图。但我愿意用一个学生的角度来畅想科技与未来。 从基因工程“让人活到一千岁”的梦想,到纳米技术“包你穿衣不用洗”的诺言;从人工智能“送你一只可爱机器狗”的温馨,到转基因技术“让老鼠长出人耳朵”的奇观。不断有新的科技在诞生,每一个新科技的发现都会让人们欣喜若狂,因为,这些新科技正在逐步地改善我们的生活,让我们更加了解自己。就近期而言,中国首先完成了非典病毒全基因组测序,非典现在是全球公认的危害性最大的疾病,可是为什么别的国家不能首先完成,而我们国家就偏偏完成了呢?很简单,这说明了我们国家不比别人落后,不比别人差,回头看看我们祖国的过去,从曾经一个刚刚起步的改革开放的国家到现在的拥有领先的科技水平的大国,我们的祖国经历了多少的风风雨雨,多少的困难与坎坷,但是我们的祖国还是挺过来了,因为我们的祖国坚信——科技不仅改变命运,还可改变未来。 对于我们这一代人,对社会的普遍感觉是竞争意识强了,学习劲头足了。科普知识是我们关注的焦点,爱因斯坦、霍金、比尔·盖茨是我们心目中的明星,计算机科学、现代物理和化学动态更是无时不牵动着我们。我们已经明白科技的重要性,也知道了科技的普遍性。 虽然科技创造新生活的前景引人遐思,令人神往。但是归根结底是要靠我们共同的努力实现的。作为祖国未来建设的中坚,我们这一代年轻人肩上的担子的确不轻,新的机遇总是伴着风险与挑战,但是,我们不会轻易地说放弃,我们用我们的青春向前辈们发誓:决不辜负前辈们对我们的希望。 回望文明的历程,是科技之光扫荡了人类历史上蒙昧的黑暗,是科学之火点燃了人类心灵中的熊熊的希望;科技支撑了文明,科技创造着未来,而未来在我们手中。让我们成为知识的探索者,让我们在未知的道路上漫游,让我用我们的创造力将我们居住的世界变得更美好。
近几年来,我们看到了我们伟大的祖国的科技事业的迅猛发展,这让我为我是个中国人而感到无比的自豪。记得很久以前,手机的用途几乎只有一个,那就是打电话,可是前几年,手机有了很大的改变,不仅外观漂亮多了,而且用途也多了,可以用手机拍照、开会、上网、发短信息等等一系列的事情,这让我们的生活更为方便,也让我更加领会到了科技的力量,不过,我只是个初出茅庐的学生,对“科技”二字的内容还知之有限,我无法用一些很深奥的理论来阐述科技的玄奇,也无法对各位走上工作岗位的长辈们承诺我所能实现的科技蓝图。但我愿意用一个学生的角度来畅想科技与未来。从基因工程“让人活到一千岁”的梦想,到纳米技术“包你穿衣不用洗”的诺言;从人工智能“送你一只可爱机器狗”的温馨,到转基因技术“让老鼠长出人耳朵”的奇观。不断有新的科技在诞生,每一个新科技的发现都会让人们欣喜若狂,因为,这些新科技正在逐步地改善我们的生活,让我们更加了解自己。就近期而言,中国首先完成了非典病毒全基因组测序,非典现在是全球公认的危害性最大的疾病,可是为什么别的国家不能首先完成,而我们国家就偏偏完成了呢?很简单,这说明了我们国家不比别人落后,不比别人差,回头看看我们祖国的过去,从曾经一个刚刚起步的改革开放的国家到现在的拥有领先的科技水平的大国,我们的祖国经历了多少的风风雨雨,多少的困难与坎坷,但是我们的祖国还是挺过来了,因为我们的祖国坚信——科技不仅改变命运,还可改变未来。对于我们这一代人,对社会的普遍感觉是竞争意识强了,学习劲头足了。科普知识是我们关注的焦点,爱因斯坦、霍金、比尔·盖茨是我们心目中的明星,计算机科学、现代物理和化学动态更是无时不牵动着我们。我们已经明白科技的重要性,也知道了科技的普遍性。虽然科技创造新生活的前景引人遐思,令人神往。但是归根结底是要靠我们共同的努力实现的。作为祖国未来建设的中坚,我们这一代年轻人肩上的担子的确不轻,新的机遇总是伴着风险与挑战,但是,我们不会轻易地说放弃,我们用我们的青春向前辈们发誓:决不辜负前辈们对我们的希望。回望文明的历程,是科技之光扫荡了人类历史上蒙昧的黑暗,是科学之火点燃了人类心灵中的熊熊的希望;科技支撑了文明,科技创造着未来,而未来在我们手中。让我们成为知识的探索者,让我们在未知的道路上漫游,
科技,一把“双刃剑”
科技,让无数人为它趋之若鹜。无数的人,都渴望走进那神圣的科技殿堂。正是凭着科技,人们创造出了一个个不朽的奇迹,譬如汽车,正是凭着科技,人们得出了一个个真实的结论,譬如地心引力,然而,科技也是一把双刃剑,提高了我们的生活质量。
但也给我们的生存环境带来了隐患,你知道吗?现在,家家户户几乎都开着汽车,我们家也新买了一辆。汽车豪华而宽敞,就像是一座“移动的房屋”在里面可以听音乐、看视频,只要保证流通的空气,甚至可以睡觉。
坐在汽车上,开启车窗,清新的风儿扑面而来,那滋味别提多爽了,仰望着蓝天白云,背靠着软软的沙发,令人心旷神怡。而且,汽车的速度非常快,是旅游的上,上之选。可是,凡事有利必有弊,汽车也不可幸免。
其一:汽车比较耗油,偏偏汽油很贵,一升就得七、八元,还时不时涨价,简直就是只吃不吐的大黑洞,况且为了汽车的美观,汽车上掉点鸟屎、被刮了点漆、车座太脏什么的,都要去洗洗换换,又得花掉很多钱。
再有,汽车每年交的保险也不便宜。唉,自从有了汽车,俺老妈的钱包总是瘪瘪的。
其二:汽车的尾烟非常污染空气,那鸣笛声也很刺耳,若是人长期生存在这种环境里,极其危害身体健康。唉,我多么希望汽车喷出来的是清澈的水汽,汽笛声可以变成优美动听的音乐啊!
与高科技产品汽车相比,自行车“返璞归真”就有很多好处了。多骑自行车可以强身健体,而且没有尾烟,它的铃声也很清脆悦耳。可是,自行车也有弊端呀,真是“金无足赤,车无完车”。自行车的速度不快,去哪儿旅游还不得累死?
雨天要穿雨衣,否则就得淋成落汤鸡,没有空调,夏天热得汗流浃背也没办法。瞧,科技在发展,任何事物都有利有弊吧,现在,很多东西都是用木头做的,小到木筷子,大到木家具,还有造纸、建房....可与此同时,森林也在快速地消亡。
“十年树木”啊,人们栽种的意识还没有普及,植树的速度也远远跟不上。试想一下,森林资源在不断减少,它们可是地球的“绿化工程师”啊!工厂中源源不断地生产着各类高科技产品,可是,黑烟却从烟囱里冒出来,污染着空气。
那些肆意排放的污水也让小河不再清澈,鱼儿们就算没被毒死,体内也满是毒素。唉,如果继续这样下去,地球上的新鲜空气还能存在多久呢?时代在进步,科技在发展。可我,一个五年级的小学生,却要高呼,科技,一把双刃剑!用得不好,会害人害己。
Chinese Holidays and Festivals Post By:2008-12-2 19:55:05 As well known, different countries have different customs and cultures. With the development of China, it has a rich and unique culture. The holidays and festivals in China are quite different from those in other countries. We have many traditional holidays and festivals. In addition, people in different areas also have their own local Year —元旦It falls on the first day of the year. It marks the beginning of a year. People will plan what to do in the new year. Because they believe that the whole year's work depends on a good start in Festival —春节Spring Festival is the most important festival in China. It is on the first day of the first lunar month(阴历正月). On the eve of the festival, people will paste spring poems(贴春联)with lucky words. They prepare delicious food, dumpling is a must. They also clean their house, but there is no sweeping on spring festival for people think it will sweep away good luck. People often come back home to enjoy family reunion, the whole family will get together for the big dinner. They also exchange greeting with other friends and Festival 元宵节It comes on the 15th of the first lunar month and it marks the end of the Spring Festival. On this day, people often eat sweet dumplings(元宵)for good luck. They will visit the display of lanterns(灯展)or go to temple fair(庙会)Qingming 清明节Qingming —It is also called Tomb-Sweeping Day. It falls on April 4th or 5th . That is a special day for the living to show love and respect to their dead friends or relatives. People often go to sweep the tomb and put the meat, wine in front of the tomb. One interesting thing is that people burn the paper money for the dead. Dragon Boat Festival 端午节This day is on the fifth of the fifth lunar month, People often get together to watch the wonderful “Dragon Boat Race”(龙舟大赛),Rice Dumpling(粽子) is a must on Dragon Boat Festival. People eat Rice Dumpling in memory of the famous poet-屈原who died on this day many years Day —中秋It comes on the 15th of the eighth lunar month. People often gaze at the “Lady in the moon”(嫦娥) and eat moon cakes. The Mid-autumn Day also means harvest
泰哥,我给你找了几个,必须采纳啊! To Pull up the Seedlings to Help Them Grow “拔苗助长” Once upon a time, there was an old farmer who planted a plot of rice. After he planted the seedlings, every day he went to the field to watch the seedlings grow. He saw the young shoots break through the soil and grow taller each day, but still, he thought they were growing too slowly. Eventually he got impatient with the young plants and suddenly he hit upon an idea that one by one, he pulled up the young plants by half an inch. The next early morning, the young man couldn’t wait to check his “achievement”, but he was heart-broken to see all the pulled-up young plants dying. 从前,有个农夫,种了稻苗(seedlings)后,便希望能早早收成。每天他到稻田时,都发觉那些稻苗长得非常慢。他等得很不耐烦。想了又想,他终于想到一个“最佳方法”,他将稻苗全都拔高了几分。第二天,一早起身,他迫不及待地去稻田看他的“成果”。 哪知,却看到所有的稻苗都枯萎了。Plugging One’s Ears While Stealing a Bell “掩耳盗铃” Once upon a time, there was a man who wanted to steal his neighbor’s doorbell. However, he knew clearly that the bell would ring and catch the other people’s attention as long as he touched the bell. So he thought hard and suddenly hit on a clever “idea”. He plugged his ears with something, thinking that everything would go well when he stole the bell. Unfortunately to his disappointment, the bell still rang loudly and he was caught on the spot as a thief. 从前,有一个人想偷邻居门上的铃,但是他知道一碰到铃,铃就会响起来,被人发现。他想啊想,终于他想出一个“妙极”,他把自己的耳朵用东西塞起来,就听不见铃声了。但是当他去偷铃时,铃声仍旧响起来,他被别人当场抓住The Fox and the Crow “狐狸和乌鸦” One day a crow stood on a branch near his nest and felt very happy with the meat in his mouth. At that time, a fox saw the crow with the meat, so he swallowed and eagerly thought of a plan to get the meat. However, whatever the fox said to the crow, the crow just kept silent. Until the fox thought highly of the crow’s beautiful voice, the crow felt flattered and opened his mouth to sing. As soon as the meat fell down to the ground, the fox took the meat and went into his hole. 有一天,一只乌鸦站在窝旁的树枝上嘴里叼着一片肉,心里非常高兴。这时候,一只狐狸看见了乌鸦,馋得直流口水,非常想得到那片肉。但是,无论狐狸说什么,乌鸦就是不理睬狐狸。最后,狐狸赞美乌鸦的嗓音最优美,并要求乌鸦唱几句让他欣赏欣赏。乌鸦听了狐狸赞美的话,得意极了,就唱起歌来。没想到,肉一掉下来,狐狸就叼起肉,钻回了洞Draw a Snake and Add Feet to It “画蛇添足” Long long ago, several people had a jar of wine among them and all of them wanted to drink it by himself. So they set a rule that every one would draw a snake on the ground and the man who finished first would have the wine. One man finished his snake very soon and he was about to drink the wine when he saw the others were still busy drawing, so he decided to draw the feet to the snake. However, before he could finish the feet, another man finished and grabbed the jar from him, saying, "Who has ever seen a snake with feet?” The story of "Draw a snake and add feet to It.” tells us going too far is as bad as not going far enough. 古时几个人分一壶酒。他们都想独自喝完那壶酒,所以就定了一个规矩:每人在地上画一条蛇,谁画得最快,这壶酒就归谁。有一个人很快就把蛇画好了。他正打算喝这壶酒时,看见别人都还在忙着画,就决定给蛇再画上几只脚。结果,他的蛇脚还没加完,另一个人已经把蛇画好了。那人一下把酒壶夺了过去,说:“有谁见过长脚的蛇?”。这个故事告诉我们这样的道理:做得过分和做得不够都是不对的
随着科学技术的飞速发展和全球化进程的不断加快,科普 文章 在向社会大众普及科学技术知识,提高公众科学素养等方面发挥着举足轻重的作用。下面是我带来的科普类英语文章,欢迎阅读!
科普类英语文章
生物与环境平衡的危机
The history of life on earth has been a history of interaction between living things and their surroundings. To a large extent, the physical form and the habits of the earth’s vegetation and its animal life have been molded by the environment. Considering the whole span of earthly time, the opposite effect, in which life actually modifies its surroundings, has been relatively slight. Only in the present century has one species man acquired significant power to alter the nature of his world.
During the past quarter century this power has not only become increasingly great but it has changed in character. The most alarming of all man’s assaults upon the environment is the contamination of air, earth, rivers, and sea with dangerous and even lethal materials. This pollution is for the most part irrecoverable. In this now universal contamination of the environment, chemicals are the sinister partners of radiation in changing the very nature of the world the very nature of its life. Chemicals sprayed on croplands or forests or gardens lie long in soil, entering into living organisms, passing from one to another in a chain of poisoning and death. Or they pass mysteriously by underground streams until they emerge and combine into new forms that kill vegetation, sicken cattle, and work unknown harm on those who drink from once pure wells. "Man can hardly even recognize the devils of his own creation," as a scientist has said.
It took hundreds of millions of years to produce the life that now inhabits the earth. Given time not in years but in millennia life adjusts, and a balance has been reached. But in the modern world there is no time.
The rapidity of change follows the impetuous pace of man rather than the deliberate pace of nature. Radiation is now the unnatural creation of man’s tampering with the atom. The chemicals are the synthetic5 creations of man’s inventive mind, having no counterparts in nature.
To adjust to these chemicals would require not merely the years of a man’s life but the life of generations. And even this, were it by some miracle possible, would be futile, for the new chemicals come from our laboratories in an endless stream; almost five hundred annually find their way into actual use in the United States alone. Among them are many that are used in man’s war against nature. Since the mid 1940’s over 200 basic chemicals have been created for use in killing insects, weeds, and other organisms described as "pests."
It is not my contention that chemical insecticides must never be used. I do contend that we have put poisonous and biologically potent chemicals indiscriminately into the hands of persons largely or wholly ignorant of their potentials for harm. We have subjected enormous numbers of people to contact with these poisons, without their consent and often without their knowledge. I contend, furthermore, that we have allowed these chemicals to be used with little or no advance investigation of their effect on soil, water, wildlife, and man himself. Future generations are unlikely to forgive our lack of concern for the integrity of the natural world that supports all life.
地球上生命的历史一直就是一部生物与其环境相互作用的历史。在很大程度上,地球上动植物的形态以及习性都是由外部环境所塑造的。考虑到地球上生命存在的整个时间,相反作用,即生命对其周围环境的实际改变作用,却相对很小。只有在当前这个世纪(指20世纪)才有一个物种--人类,获得了强大的力量,改变了其所生存的世界的自然状态。
在过去的1/4世纪中,这种力量不仅日趋强大,而且其性质也发生了变化。在人类破坏环境的种种行为中,最令人担忧的是人类向大气、土壤、河流以及海洋中排放危险甚至致命物质,而当今这种污染在很大程度上是无法挽救的。在当今这种对环境的普遍污染中,化学制品与辐射狼狈为奸,改变着地球的自然状态,也就是改变着地球上生命的自然状态。喷洒到农田、森林或者花园里的化学物质长期滞留于土壤中,渗入有机体内,并彼此相传,形成了一个中毒与死亡的链条。化学物质还神秘地通过地下水传递,最终以新的形式出现并结合,使植物毒死,牲畜害病,并使饮用一度纯净的井水的人遭受了不明之害。正如一位科学家所言:“人类甚至对自己创造的恶魔都不认识。”
地球历经了许多亿年才创造了栖息其上的生命。经过了一定时间--不是以若干年计而是以若干千年计的时间--生命开始适应环境,并形成了一种与环境的平衡。但是在现代世界中,时间这一因素已经没有了。
环境改变的速度不再顺从大自然从容不迫的节奏,而是顺从人类急切匆匆的步伐。辐射是当今人类通过支配原子而得到的一种非自然的创造物。化学制品则是人类有发明创造力的头脑创造出来的合成物,在自然界本无相应的东西。
为了适应这些化学制品,人类需要付出的时间不会只是一个人一生的时间,而是几代人的时间。而即使这样,就算出现奇迹成为可能,这种适应也是徒劳的,因为新的化学制品从我们的实验室中源源不断地涌出。仅在美国,每年就有大约500种化学制品投入使用,其中许多是用于人类对自然的战争中。从20世纪40年代中期起,人类已经创造了200多种基本化学制品用来消灭昆虫、野草以及其他所谓的“有害生物”。
我不是说人类决不能使用化学杀虫剂。我要说的是,我们不分青红皂白地将这些有毒的、具有强大生物功能的化学制品,交给了那些对这些制品的潜在危害基本上或者完全无知的人去使用。我们使众多的人接触这些有毒物质,却没有征得他们的同意,并常常将他们蒙在鼓中。我还要说的一点是,我们允许使用这些化学制品,却事先很少或者根本没有调查它们对土壤、水、野生生物以及人类自身造成的影响。我们缺乏对万物赖以生存的自然界生态统一的关心,对此,我们的后代是不可能原谅的。
科普类英语文章
基因技术能否使人更聪明?Get Smart
Many people dream of having a smarter brain. Princeton neurobiologist Joseph Z. Tsien found the key. In September he announced that he’d built a better mouse by altering a gene that affects learning and memory. A similar process of gene manipulation might conceivably be used one day to boost intelligence in humans.
The secret lies in a feature of brain cells called the nmda receptor, which Tsien likens[1] to a cylindrical tube or window that mediates[2] the flow of information. When the window is open, chemicals called neurotransmitters flow through easily and memory is registered and stored. But as organisms mature, the window begins to close. (This may explain why children lose their facility for learning new languages when they reach sexual maturity and why some people suffer memory loss as they age.)
Tsien noticed that the receptor worked more efficiently when teamed[3] with the gene NR2B, so he introduced extra NR2B genes into a batch of fertilized mouse eggs. In a normal mouse, the memory window is open for just 150-thousandths of a second. In Tsien’s specially engineered mice, the window opens for 250-thousandths of a second, long enough to make a remarkable difference in memory retention. When he pitted[4] his mice against common mice, they won paws down. Ordinary mice could recognize a Lego block for 12 hours, but smart mice could remember the block for up to three days. "That’s a profound enhancement," Tsien says.
Can it be done with humans? Maybe, but genetic engineering will have to make some extraordinary advances first. And some thorny ethical issues will have to be resolved. Meanwhile, Tsien promises to keep his furry little geniuses locked up in a lab, far from your larder. "Otherwise," he says, "you might need a smart cat or a smart mousetrap to catch them."
许多人都希望自己能变成更聪明。普林斯顿神经生物学家Joseph Z. Tsien就找到了这把开启智慧之门的钥匙:他于九月宣布,通过改变影响学习和记忆能力的基因培养出了一只聪明的老鼠。类似的基因处理技术有望在未来日子里运用到人脑,以推动人类智慧的飞跃。
该技术的奥秘就在于名为nmda感受器的脑细胞的功能。Tsien将其比作一个传递信息流的圆柱通道或窗口。当窗口开放时,某种称为神经传递素的化学物质就能轻易流过,记忆因此登记并存储了下来。然而,当器官成熟时,这扇窗口就开始关闭。(这也能解释为何 儿童 长大后(性器官成熟之时)会失去掌握新语言的能力,以及为何某些人年老时会患失忆)。
Tsien注意到,当感受器与名为NR2B的基因协作时效率会更高。因此,他将NR2B基因植入一批老鼠的受精卵中。一只普通老鼠的记忆之窗仅开放千分之150秒。而经Tsien植入基因的老鼠,记忆之窗能开放千分之250秒,这已经能够使其 记忆力 发生惊人的改变。当他让自己的老鼠与普通老鼠互斗时,它们竟能轻而易举地取胜。普通老鼠能够保留关于Lego block的记忆12小时,而聪明的老鼠居然能将记忆保持三天。“这可是一个意义深远的进步。”Tsien这样说。
那么,人类也能接受这种基因移植吗? 或许可以,但前提是基因工程得首先做出非凡的成就,还必须解决一系列棘手的伦理问题。Tsien保证他一定会将那些披着毛皮的小天才锁入实验室,远离人们的食品柜。“否则,”他说,“为了捉住他们,人们就不得不去寻找更聪明的猫或者功能更强的捕鼠器了。”
科普类英语文章
食用转基因食品安全吗?Food Safe To Eat?
Traditional plant breeding involve s crossing varieties of the same species in ways they could cross example,disease-resistant varieties of wheat have been crossed with high-yield wheat to combine these type of natural gene exchange is safe and fairly predictable.
Genetic engineering(GE)involves exchanging genes between unrelated species that cannot naturally exchange genes with each can involve the exchange of genes between vastly different species―― scorpion toxin genes into maize or fish antifreeze genes into is possible that a scorpion toxin gene,even when it is in maize DNA,will still get the organism to produce scorpion toxin――but what other effects may it have in this alien environment?We are already seeing this problem――adding human growth hormone genes to pigs certainly makes them grow――but it also gives them arthritis and makes them cross-eyed,which was entirely unpredictable.
It will be obvious,for example,that the gene for human intelligence will not have the same effect if inserted into cabbage DNA as it had in human DNA――but what side-effect would it have?In other words,is GM food safe to eat?The answer is that nobody knows because long-term tests have not been carried out.
Companies wanting a GM product approved in the UK or USA are required to provide regulatory bodies with results of their own safety ’s soya beans were apparently fed to fish for10weeks before being was no requirement for independent testing,for long-term testing,for testing on humans or testing for specific dangers to children or allergic people.
The current position of the UK Government is that“ There is no evidence of long-term dangers from GM foods.”In the US,the American Food and Drug Administration is currently being prosecuted for covering up research that suggested possible risks from GM foods.
传统的植物培育 方法 ,是依照植物自然杂交的方式,进行相同物种的人工杂交。比如,抗病小麦同高产小麦杂交,形成了一种具有双重特性的新的小麦品种。这种自然的基因交换既安全,又具有相当的可预见性。
基因工程是在彼此毫无关系的物种之间,相互交换在自然条件下无法交换的基因。它可在有巨大差异的物种之间进行基因交换。比如,将蝎子毒素基因注入玉米,或者将鱼防冻基因注入西红柿。即使在玉米DNA中,蝎子毒素基因依然可能获得有机组织产生蝎子毒素。但是在这种异质的环境中,这种基因产品会有什么其他作用吗?我们实际上已经发现这个问题:将人类生长荷尔蒙基因植入猪的体内,一定会使猪的生长加速,但是同时也使猪患上了关节炎和内斜视,而这一切是完全无法预测的。
打个比方,人类的智力基因显而易见在人体DNA内和注入卷心菜DNA后的作用是不同的。但将它植入卷心菜中会产生什么样的副作用呢?换句话说,食用转基因食品安全吗?没有人知道答案,因为人们尚未进行长期的测试。
在英国或者美国,一个公司如果希望其转基因产品获得批准,它必须向管理机构提供本公司转基因产品安全测试的结果。Monsanto的大豆在获得批准之前,曾用了10周时间进行喂鱼试验。目前,尚无要求对转基因产品进行独立测试、长期测试、人体测试,或者就其对儿童及过敏者所造成的特定危险进行测试。
英国政府目前的态度是:“尚无证据表明食用转基因食品存在长期性的危险。”在美国,人们正在起诉美国食品药品管理局掩盖转基因食品安全性的研究结果,这些研究结果表明,食用转基因食品可能导致危险。
Scientistsdiscoveredthat"junkDNA,"thebasepairsbetweenknowngenesinthehumangeneticstructure,.:科学家发现了"垃圾DNA,"在人类的遗传基因的结构已知的基因之间的恶劣双,扮演重要角色。一些研究队已经发现DNA在基因帮助决定之间如何精力充沛地和时常基因被刺激而且为蛋白质的生产塑造那个编码。