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求英语作文:my view on science

03月17日 编辑 39baobao.com

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This specialized raise has electronic information science and technology of the basic theory and basic knowledge, by strict scientific experimental training and scientific research training, preliminary in electronic information science and technology, computer science and technology and related fields and administrative departments engaged in scientific research, teaching, science and technology development, product design, production technology management of the electronic information science and technology senior specialized talents.本专业培养具备电子信息科学与技术的基本理论和基本知识,受到严格的科学实验训练和科学研究初步训练,能在电子信息科学与技术、计算机科学与技术及相关领域和行政部门从事科学研究、教学、科技开发、产品设计、生产技术管理工作的电子信息科学与技术高级专门人才。

求科技英语范文

Microwave and our life This article is about the electromagnetic wave. For the cooking appliance, see Microwave oven. For other uses, see Microwaves (disambiguation).A telecommunications tower with a variety of dish antennas for microwave relay links onFrazier Peak, Ventura County,California.The atmospheric attenuation of microwaves in dry air with a precipitable water vapor level of 0.001 mm. The downward spikes in the graph correspond to frequencies at which microwaves are absorbed more strongly. The right half of this graph includes the lower ranges of infrared by some standards Microwaves are a form of electromagnetic radiation with wavelengths ranging from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300 MHz (0.3 GHz) and 300 GHz.[1][2] This broad definition includes both UHF and EHF (millimeter waves), and various sources use different boundaries. In all cases, microwave includes the entire SHF band (3 to 30 GHz, or 10 to 1 cm) at minimum, with RF engineering often restricting the range between 1 and 100 GHz (300 and 3 mm).The prefix "micro-" in "microwave" is not meant to suggest a wavelength in the micrometer range. It indicates that microwaves are "small" compared to waves used in typical radio broadcasting, in that they have shorter wavelengths. The boundaries between far infrared, terahertz radiation, microwaves, and ultra-high-frequency radio waves are fairly arbitrary and are used variously between different fields of study.Beginning at about 40 GHz, the atmosphere becomes less transparent to microwaves, due at lower frequencies toabsorption from water vapor and at higher frequencies from oxygen. A spectral band structure causes absorption peaks at specific frequencies (see graph at right). Above 100 GHz, the absorption of electromagnetic radiation by Earth's atmosphere is so great that it is in effect opaque, until the atmosphere becomes transparent again in the so-called infrared and optical window frequency ranges.The term microwave also has a more technical meaning in electromagnetics and circuit theory. Apparatus and techniques may be described qualitatively as "microwave" when the frequencies used are high enough that wavelengths of signals are roughly the same as the dimensions of the equipment, so that lumped-element circuit theory is inaccurate. As a consequence, practical microwave technique tends to move away from the discrete resistors, capacitors, and inductors used with lower-frequency radio waves. Instead,distributed circuit elements and transmission-line theory are more useful methods for design and analysis. Open-wire and coaxial transmission lines used at lower frequencies are replaced bywaveguides and stripline, and lumped-element tuned circuits are replaced by cavity resonators or resonant lines. In turn, at even higher frequencies, where the wavelength of the electromagnetic waves becomes small in comparison to the size of the structures used to process them, microwave techniques become inadequate, and the methods of optics are used.

英语作文:科技

关于科技的英语作文: Science and technology have changed our life thoroughly throughout the history, especially in the last century. There is a prevailing understanding about science and technology among the general public that they are the same thing of two different names but they are acutally two things. Science is kind of series of theorrtical concepts and people can accept it or not, and it will not affect commom people's life to a large extent, but it's a different way when it comes to technology because technology has more pratical effect on people. People have to endure the results of the pactical applicance of technology whether they are good or not, such as the air pollution, and it all happens without people's acceptance, for it all depends on the local governments' or even the nations' decision. 关于科技的英语作文: 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 patients of 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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