功能材料雙語-電功能材料(編輯修改稿)
2025-02-08 15:39 本頁面
【文章內(nèi)容簡介】 power transmission（ 電力輸送 ） , transformers（ 變壓器 ） , power storage devices, electric motors（ 電動機 ） (. for vehicle propulsion（ 汽車驅(qū)動 ） , as in maglev trains（ 磁懸浮列車 ） ), magic levitation devices（ 磁懸浮裝置 ） , fault current limiters, （ 故 障 電 流 限 流 器 ） and superconducting magic refrigeration（ 超導(dǎo)磁制冷 ） . ?They can also be used for magic separation(磁選 ), where weakly magic particles are extracted from a background of less or nonmagic particles, as in the pigment industries. 核聚變堆用超導(dǎo)線圈 Superconducting submarine（超導(dǎo)潛水艇） 超導(dǎo)磁流體推進船 1992年 1月27日，由日本船舶和海洋基金會建造的，第一艘采用超導(dǎo)磁流體推進器的輪船 ——“ 大和” 1號在日本神戶下水試航。 maglev trains（磁懸浮列車） 近日，國家“十三五”重點研發(fā)計劃 《 現(xiàn)代軌道交通專項 》 啟動時速 600公里高速磁懸浮交通和時速 200公里中速磁浮交通研發(fā)項目 superconducting electric power transmission 未來超導(dǎo)體汽車 尋找現(xiàn)實中的哈利路亞山 ——室溫超導(dǎo)體 semiconductor ?has electrical conductivity between that of a conductor such as copper and that of an insulator such as glass（ σ＝ 107～ 104） ?Negative temperature coefficient （ 負 的 電 阻 溫 度 系數(shù) ） : thermal conductivity or electrical resistivity of a semiconductor lowers with increasing temperature, which is opposite to that of a metal. semiconductor useful properties: ?passing current more easily in one direction than the other。 ? showing variable resistance(可變電阻 )。 ? sensitivity to light or heat（ 對光 /熱敏感 ） So, electrical properties of a semiconductor material can be modified（ 修飾 ） by controlled addition of impurities（ 雜質(zhì) ） , or by the application of electrical fields or light. basic concepts: In solidstate physics, the electronic band structure (or simply band structure) of a solid describes those ranges of energy that an electron within the solid may have and ranges of energy that it may not have (called band gaps or forbidden bands)帶隙或禁帶 . （ 1） Electronic band structure(band structure)電子能帶結(jié)構(gòu) Physics of semiconductors（半導(dǎo)體物理學(xué)） band gap, also called an energy gap （ 能隙 ） or bandgap（ 帶隙 ） , is an energy range in a solid where no electron states can exist. generally refers to the energy difference (in electron volts) between the top of the valence band and the bottom of the conduction band in insulators and semiconductors. (2) Band Gap（帶隙） (3) Forbidden Band（ 禁帶 ） energy gap should be the energy difference between two different energy band. for example conducting band and valence band. However, energy in between the two band is allowed. Forbidden band do not allow any energy resident in it (4) Valence Band（ 價帶 ） In solids, the valence band is the highest range of electron energies in which electrons are normally present at absolute zero temperature. On a graph of the electronic band structure of a material,
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