Electronic States of F-Type Centers in Oxide Crystals-A New Picture
材料科学(10)12章-Electrical-Properties
Conduction & Electron Transport
• Metals (Conductors):
-- for metals, empty energy states are adjacent to filled states.
• thermal energy excites electrons into empty higher energy states.
Resistance (电阻), Resistivity (电阻率)
Resistance, R, depends on the intrinsic resistivity r of the material [W-m] and on the geometry (length L and area A through which the current passes): R = r L/A
filled band
The outmost band largely determines the electron band structures in solids (group of atoms bonding to each other)
Cu
filled band
Mg
In a metal, n is large. In an insulator, n is very, very small.
Classification of Materials
based on their electrical conductivity
Electrical conductivity varies between different materials by over 27 orders of magnitude, the greatest variation of any physical property.
材料专业英语常见词汇
材料专业英语常见词汇The saying "the more diligent, the more luckier you are" really should be my charm in2006.材料专业英语常见词汇一Structure 组织Ceramic 陶瓷Ductility 塑性Stiffness 刚度Grain 晶粒Phase 相Unit cell 单胞Bravais lattice 布拉菲点阵Stack 堆垛Crystal 晶体Metallic crystal structure 金属性晶体点阵 Non-directional 无方向性Face-centered cubic 面心立方Body-centered cubic体心立方 Hexagonal close-packed 密排六方 Copper 铜Aluminum 铝Chromium 铬 Tungsten 钨Crystallographic Plane晶面 Crystallographic direction 晶向 Property性质 Miller indices米勒指数 Lattice parameters 点阵参数Tetragonal 四方的Hexagonal 六方的Orthorhombic 正交的Rhombohedra 菱方的Monoclinic 单斜的Prism 棱镜 Cadmium 镉 Coordinate system 坐 Point defec点缺陷Lattice 点阵 Vacancy 空位Solidification 结晶Interstitial 间隙Substitution 置换Solid solution strengthening 固溶强化Diffusion 扩散Homogeneous 均匀的Diffusion Mechanisms 扩散机制Lattice distortion 点阵畸变Self-diffusion 自扩散Fick’s First Law 菲克第一定律 Unit time 单位时间Coefficient 系数Concentration gradient 浓度梯度Dislocations 位错Linear defect 线缺陷Screw dislocation 螺型位错Edge dislocation 刃型位错Vector 矢量Loop 环路Burgers’vector 柏氏矢量Perpendicular 垂直于Surface defect 面缺陷Grain boundary 晶界Twin boundary 晶界 Shear force 剪应力Deformation 变形Small or low angel grain boundary 小角度晶界Tilt boundary 倾斜晶界Supercooled 过冷的Solidification 凝固Ordering process 有序化过程Crystallinity 结晶度Microstructure 纤维组织Term 术语Phase Diagram 相图Equilibrium 平衡Melt 熔化Cast 浇注Crystallization 结晶Binary Isomorphous Systems 二元匀晶相图Soluble 溶解Phase Present 存在相Locate 确定Tie line 连接线Isotherm 等温线Concentration 浓度Intersection 交点The Lever Law 杠杆定律Binary Eutectic System 二元共晶相图Solvus Line 溶解线Invariant 恒定Isotherm 恒温线Cast Iron 铸铁Ferrite 珠光体Polymorphic transformation 多晶体转变Austenite 奥氏体Revert 回复Intermediate compound 中间化合物Cementite 渗碳体Vertical 垂线Nonmagnetic 无磁性的Solubility 溶解度Brittle 易脆的Eutectic 共晶Eutectoid invariant point 共析点Phase transformation 相变Allotropic 同素异形体Recrystallization 再结晶Metastable 亚稳的Martensitic transformation 马氏体转变Lamellae 薄片Simultaneously 同时存在Pearlite 珠光体Ductile 可塑的Mechanically 机械性能Hypo eutectoid 过共析的Particle 颗粒Matrix基体Proeutectoid 先共析Hypereutectoid 亚共析的Bainite 贝氏体Martensite 马氏体Linearity 线性的Stress-strain curve 应力-应变曲线Proportional limit 比例极限Tensile strength 抗拉强度Ductility 延展性Percent reduction in area 断面收缩率Hardness 硬度Modulus of Elasticity 弹性模量Tolerance 公差Rub 摩擦Wear 磨损Corrosion resistance 抗腐蚀性Aluminum 铝Zinc 锌Iron ore 铁矿Blast furnace 高炉Coke 焦炭Limestone 石灰石Slag 熔渣Pig iron 生铁Ladle 钢水包Silicon 硅Sulphur 硫Wrought 可锻的Graphite 石墨Flaky 片状Low-carbon steels 低碳钢Case hardening 表面硬化Medium-carbon steels 中碳钢Electrode 电极As a rule 通常Preheating 预热Quench 淬火Body-centered lattice 体心晶格Carbide 碳化物Hypereutectoid过共晶Chromium 铬Manganese 锰Molybdenum 钼Titanium 钛Cobalt 钴Tungsten 钨Vanadium 钒Pearlitic microstructure 珠光体组织Martensitic microstructure 马氏体组织Viscosity 粘性Wrought 锻造的Magnesium 镁Flake 片状Malleable 可锻的Nodular 球状Spheroidal 球状Superior property 优越性Galvanization 镀锌Versatile 通用的Battery grid 电极板Calcium 钙Tin 锡Toxicity 毒性Refractory 耐火的Platinum铂Polymer 聚合物Composite 混合物Erosive 腐蚀性Inert 惰性Thermo chemically 热化学Generator 发电机Flaw 缺陷Variability 易变的Annealing 退火Tempering回火Texture 织构Kinetic 动力学Peculiarity 特性Critical point 临界点Dispersity 弥散程度Spontaneous 自发的Inherent grain 本质晶粒Toughness 韧性Rupture 断裂Kinetic curve of transformation 转变动力学曲线Incubation period 孕育期Sorbite 索氏体Troostite 屈氏体Disperse 弥散的Granular 颗粒状Metallurgical 冶金学的Precipitation 析出Depletion 减少Quasi-eutectoid 伪共析Superposition 重叠Supersede 代替Dilatometric 膨胀Unstable 不稳定Supersaturate 使过饱和Tetragonality 正方度Shear 切变Displacement 位移Irreversible 不可逆的金属材料工程专业英语acid-base equilibrium酸碱平衡 acid-base indicator酸碱指示剂 acid bath酸槽 acidBessemerconverter 酸性转炉 acid brick酸性耐火砖 acid brittleness酸洗脆性、氢脆性 acid burden酸性炉料acid clay酸性粘土 acid cleaning同pickling酸洗 acid concentration酸浓度 acid converter酸性转炉 acid converter steel酸性转炉钢 acid content酸含量 acid corrosion酸腐蚀 acid deficient弱酸的、酸不足的 acid dip酸浸acid dip pickler沉浸式酸洗装置 aciddiptank酸液浸洗槽acid drain tank排酸槽acidless descaling无酸除鳞acid medium酸性介质acid mist酸雾acid-proof paint耐酸涂料漆acid-proof steel耐酸钢acid-resistant耐酸钢acid-resisting vessel耐酸槽acid strength酸浓度acid supply pump供酸泵acid wash酸洗acid value酸值acid wash solution酸洗液acieration渗碳、增碳Acm point Acm转变点渗碳体析出温度acorn nut螺母、螺帽acoustic absorption coefficient声吸收系数acoustic susceptance声纳actifier再生器action line作用线action spot作用点activated atom激活原子activated bath活化槽activated carbon活性碳activating treatment活化处理active corrosion活性腐蚀、强烈腐蚀active area有效面积active power有功功率、有效功率active product放射性产物active resistance有效电阻、纯电阻active roll gap轧辊的有效或工作开口度active state活性状态active surface有效表面activity coefficient激活系数、活度系数actual diameter钢丝绳实际直径actual efficiency实际效率actual error实际误差actual time实时actual working stress实际加工应力actuating device调节装置、传动装置、起动装置actuating lever驱动杆、起动杆actuating mechanism 动作机构、执行机构actuating motor驱动电动机、伺服电动机actuating pressure作用压力actuation shaft起动轴actuator调节器、传动装置、执行机构acute angle锐角adaptive feed back control自适应反馈控制adaptive optimization自适应最优化adaptor接头、接合器、连结装置、转接器、附件材料科学基础专业词汇:第一章晶体结构原子质量单位 Atomic mass unit amu 原子数 Atomic number 原子量 Atomic weight波尔原子模型 Bohr atomic model 键能 Bonding energy 库仑力 Coulombic force共价键 Covalent bond 分子的构型 molecular configuration电子构型electronic configuration 负电的 Electronegative 正电的 Electropositive基态 Ground state 氢键 Hydrogen bond 离子键 Ionic bond 同位素 Isotope金属键 Metallic bond 摩尔 Mole 分子 Molecule 泡利不相容原理 Pauli exclusion principle 元素周期表 Periodic table 原子 atom 分子 molecule 分子量 molecule weight极性分子 Polar molecule 量子数 quantum number 价电子 valence electron范德华键 van der waals bond 电子轨道 electron orbitals 点群 point group对称要素 symmetry elements 各向异性 anisotropy 原子堆积因数 atomic packing factorAPF 体心立方结构 body-centered cubic BCC 面心立方结构 face-centered cubic FCC布拉格定律bragg’s law 配位数 coordination number 晶体结构 crystal structure晶系 crystal system 晶体的 crystalline 衍射 diffraction 中子衍射 neutron diffraction电子衍射 electron diffraction 晶界 grain boundary 六方密堆积 hexagonal close-packed HCP 鲍林规则 Paulin g’s rules NaCl型结构 NaCl-type structureCsCl型结构Caesium Chloride structure 闪锌矿型结构 Blende-type structure纤锌矿型结构 Wurtzite structure 金红石型结构 Rutile structure萤石型结构 Fluorite structure 钙钛矿型结构 Perovskite-type structure尖晶石型结构 Spinel-type structure 硅酸盐结构 Structure of silicates岛状结构 Island structure 链状结构 Chain structure 层状结构 Layer structure架状结构 Framework structure 滑石 talc 叶蜡石 pyrophyllite 高岭石 kaolinite石英 quartz 长石 feldspar 美橄榄石 forsterite 各向同性的 isotropic各向异性的 anisotropy 晶格 lattice 晶格参数 lattice parameters 密勒指数 miller indices 非结晶的 noncrystalline多晶的 polycrystalline 多晶形 polymorphism 单晶single crystal 晶胞 unit cell电位 electron states化合价 valence 电子 electrons 共价键 covalent bonding金属键 metallic bonding 离子键Ionic bonding 极性分子 polar molecules原子面密度 atomic planar density 衍射角 diffraction angle 合金 alloy粒度,晶粒大小 grain size 显微结构 microstructure 显微照相 photomicrograph扫描电子显微镜 scanning electron microscope SEM透射电子显微镜 transmission electron microscope TEM 重量百分数 weight percent四方的 tetragonal 单斜的monoclinic 配位数 coordination number材料科学基础专业词汇:第二章晶体结构缺陷缺陷 defect, imperfection 点缺陷 point defect 线缺陷 line defect, dislocation面缺陷 interface defect 体缺陷 volume defect 位错排列 dislocation arrangement位错线 dislocation line 刃位错 edge dislocation 螺位错 screw dislocation混合位错 mixed dislocation 晶界 grain boundaries 大角度晶界 high-angle grain boundaries 小角度晶界 tilt boundary, 孪晶界 twin boundaries 位错阵列 dislocation array位错气团 dislocation atmosphere 位错轴dislocation axis 位错胞 dislocation cell位错爬移 dislocation climb 位错聚结 dislocation coalescence 位错滑移 dislocation slip位错核心能量 dislocation core energy 位错裂纹 dislocation crack位错阻尼 dislocation damping 位错密度 dislocation density原子错位 substitution of a wrong atom 间隙原子 interstitial atom晶格空位 vacant lattice sites 间隙位置 interstitial sites 杂质 impurities弗伦克尔缺陷 Frenkel disorder 肖脱基缺陷 Schottky disorder 主晶相 the host lattice错位原子 misplaced atoms 缔合中心 Associated Centers. 自由电子 Free Electrons电子空穴Electron Holes 伯格斯矢量 Burgers 克罗各-明克符号 Kroger Vink notation中性原子 neutral atom材料科学基础专业词汇:第二章晶体结构缺陷-固溶体固溶体 solid solution 固溶度 solid solubility 化合物 compound间隙固溶体 interstitial solid solution 置换固溶体 substitutional solid solution金属间化合物 intermetallics 不混溶固溶体 immiscible solid solution转熔型固溶体 peritectic solid solution 有序固溶体 ordered solid solution无序固溶体 disordered solid solution 固溶强化 solid solution strengthening取代型固溶体 Substitutional solid solutions 过饱和固溶体 supersaturated solid solution非化学计量化合物 Nonstoichiometric compound材料科学基础专业词汇:第三章熔体结构熔体结构 structure of melt过冷液体 supercooling melt 玻璃态 vitreous state软化温度 softening temperature 粘度 viscosity 表面张力 Surface tension介稳态过渡相 metastable phase 组织 constitution 淬火 quenching退火的 softened 玻璃分相 phase separation in glasses 体积收缩 volume shrinkage材料科学基础专业词汇:第四章固体的表面与界面表面 surface 界面 interface 同相界面 homophase boundary异相界面 heterophase boundary 晶界 grain boundary 表面能 surface energy小角度晶界 low angle grain boundary 大角度晶界 high angle grain boundary共格孪晶界 coherent twin boundary 晶界迁移 grain boundary migration错配度 mismatch 驰豫 relaxation 重构 reconstuction 表面吸附 surface adsorption表面能 surface energy 倾转晶界 titlt grain boundary 扭转晶界 twist grain boundary倒易密度 reciprocal density 共格界面 coherent boundary 半共格界面 semi-coherent boundary 非共格界面 noncoherent boundary 界面能 interfacial free energy应变能 strain energy 晶体学取向关系 crystallographic orientation惯习面habit plane材料科学基础专业词汇:第五章相图相图 phase diagrams 相 phase 组分 component 组元 compoonent相律 Phase rule 投影图 Projection drawing 浓度三角形 Concentration triangle冷却曲线 Cooling curve 成分 composition 自由度 freedom相平衡 phase equilibrium 化学势 chemical potential 热力学 thermodynamics相律 phase rule 吉布斯相律 Gibbs phase rule 自由能 free energy吉布斯自由能 Gibbs free energy 吉布斯混合能 Gibbs energy of mixing吉布斯熵 Gibbs entropy 吉布斯函数 Gibbs function 热力学函数 thermodynamics function 热分析 thermal analysis 过冷 supercooling 过冷度 degree of supercooling杠杆定律 lever rule 相界 phase boundary 相界线 phase boundary line相界交联 phase boundary crosslinking 共轭线 conjugate lines相界有限交联 phase boundary crosslinking 相界反应 phase boundary reaction相变 phase change 相组成 phase composition 共格相 phase-coherent金相相组织 phase constentuent 相衬 phase contrast 相衬显微镜 phase contrast microscope 相衬显微术 phase contrast microscopy 相分布 phase distribution相平衡常数 phase equilibrium constant 相平衡图 phase equilibrium diagram相变滞后 phase transition lag 相分离 phase segregation 相序 phase order相稳定性 phase stability 相态 phase state 相稳定区 phase stabile range相变温度 phase transition temperature 相变压力 phase transition pressure同质多晶转变 polymorphic transformation 同素异晶转变 allotropic transformation相平衡条件 phase equilibrium conditions 显微结构 microstructures 低共熔体 eutectoid不混溶性 immiscibility材料科学基础专业词汇:第六章扩散活化能 activation energy 扩散通量 diffusion flux 浓度梯度 concentration gradient菲克第一定律Fick’s first law 菲克第二定律Fick’s second law 相关因子 correlation factor 稳态扩散 steady state diffusion 非稳态扩散 nonsteady-state diffusion扩散系数 diffusion coefficient 跳动几率 jump frequency填隙机制 interstitalcy mechanism 晶界扩散 grain boundary diffusion短路扩散 short-circuit diffusion 上坡扩散 uphill diffusion 下坡扩散 Downhill diffusion互扩散系数 Mutual diffusion 渗碳剂 carburizing 浓度梯度 concentration gradient浓度分布曲线 concentration profile 扩散流量 diffusion flux 驱动力 driving force间隙扩散 interstitial diffusion 自扩散 self-diffusion 表面扩散 surface diffusion空位扩散 vacancy diffusion 扩散偶 diffusion couple 扩散方程 diffusion equation扩散机理 diffusion mechanism 扩散特性 diffusion property 无规行走 Random walk达肯方程 Dark equation 柯肯达尔效应 Kirkendall equation本征热缺陷 Intrinsic thermal defect 本征扩散系数 Intrinsic diffusion coefficient离子电导率 Ion-conductivity 空位机制 Vacancy concentration材料科学基础专业词汇:第七章相变过冷 supercooling 过冷度 degree of supercooling 晶核 nucleus 形核 nucleation形核功 nucleation energy 晶体长大 crystal growth 均匀形核 homogeneous nucleation非均匀形核 heterogeneous nucleation 形核率 nucleation rate 长大速率 growth rate热力学函数 thermodynamics function 临界晶核 critical nucleus临界晶核半径 critical nucleus radius 枝晶偏析 dendritic segregation局部平衡 localized equilibrium 平衡分配系数 equilibrium distributioncoefficient有效分配系数 effective distribution coefficient 成分过冷 constitutional supercooling引领领先相 leading phase 共晶组织 eutectic structure 层状共晶体 lamellar eutectic伪共晶 pseudoeutectic 离异共晶 divorsed eutectic 表面等轴晶区 chill zone柱状晶区 columnar zone 中心等轴晶区 equiaxed crystal zone定向凝固 unidirectional solidification 急冷技术 splatcooling 区域提纯 zone refining单晶提拉法 Czochralski method 晶界形核 boundary nucleation位错形核 dislocation nucleation 晶核长大 nuclei growth斯宾那多分解 spinodal decomposition 有序无序转变 disordered-order transition马氏体相变 martensite phase transformation 马氏体 martensite材料科学基础专业词汇:第八、九章固相反应和烧结固相反应 solid state reaction 烧结 sintering 烧成 fire 合金 alloy 再结晶 Recrystallization 二次再结晶 Secondary recrystallization 成核 nucleation 结晶 crystallization子晶,雏晶 matted crystal 耔晶取向 seed orientation 异质核化 heterogeneous nucleation均匀化热处理 homogenization heat treatment 铁碳合金 iron-carbon alloy渗碳体 cementite 铁素体 ferrite 奥氏体austenite 共晶反应 eutectic reaction 固溶处理 solution heat treatment。
材料科学基础英文词汇(最新整理)
材料科学基础专业词汇:第一章晶体结构原子质量单位Atomic mass unit (amu) 原子数Atomic number原子量Atomic weight 波尔原子模型Bohr atomic model键能Bonding energy 库仑力Coulombic force共价键Covalent bond 分子的构型molecular configuration 电子构型electronic configuration 负电的Electronegative正电的Electropositive 基态Ground state氢键Hydrogen bond 离子键Ionic bond同位素Isotope 金属键Metallic bond摩尔Mole泡利不相容原理 Pauli exclusion principle 元素周期表Periodic table原子atom 分子molecule分子量molecule weight 极性分子Polar molecule量子数quantum number 价电子valence electron范德华键van der waals bond 电子轨道electron orbitals点群point group 对称要素symmetry elements各向异性anisotropy 原子堆积因数Atomic packing factor(APF)体心立方结构body-centered cubic (BCC) 面心立方结构face-centered cubic (FCC) 布拉格定律bragg’s law 配位数coordination number晶体结构crystal structure 晶系crystal system晶体的crystalline 衍射diffraction中子衍射neutron diffraction 电子衍射electron diffraction晶界grain boundary 六方密堆积hexagonal close-packed(HCP)鲍林规则Pauling’s rules NaCl型结构NaCl－type structure CsCl型结构Caesium Chloride structure 闪锌矿型结构Blende-type structure纤锌矿型结构Wurtzite structure 金红石型结构Rutile structure萤石型结构Fluorite structure 钙钛矿型结构Perovskite-type structure 尖晶石型结构Spinel-type structure 硅酸盐结构Structure of silicates岛状结构Island structure 链状结构Chain structure层状结构Layer structure 架状结构Framework structure滑石talc 叶蜡石pyrophyllite高岭石kaolinite 石英quartz长石feldspar 美橄榄石forsterite各向同性的isotropic 各向异性的anisotropy晶格lattice 晶格参数lattice parameters密勒指数miller indices 非结晶的noncrystalline多晶的polycrystalline 多晶形polymorphism单晶single crystal 晶胞unit cell电位electron states (化合)价valence电子electrons 共价键covalent bonding金属键metallic bonding 离子键Ionic bonding极性分子polar molecules 原子面密度atomic planar density衍射角diffraction angle 合金alloy粒度,晶粒大小grain size 显微结构microstructure显微照相photomicrograph 扫描电子显微镜scanning electronmicroscope (SEM)重量百分数weight percent 透射电子显微镜 transmission electronmicroscope (TEM)四方的tetragonal 单斜的monoclinic配位数coordination number材料科学基础专业词汇:第二章晶体结构缺陷缺陷defect, imperfection 点缺陷point defect线缺陷line defect, dislocation 面缺陷interface defect体缺陷volume defect 位错排列dislocation arrangement位错线dislocation line 刃位错edge dislocation螺位错screw dislocation 混合位错mixed dislocation晶界grain boundaries 大角度晶界high-angle grainboundaries 小角度晶界tilt boundary, 孪晶界twin boundaries位错阵列dislocation array 位错气团dislocation atmosphere位错轴dislocation axis 位错胞dislocation cell位错爬移dislocation climb 位错聚结dislocation coalescence位错滑移dislocation slip 位错核心能量dislocation core energy位错裂纹dislocation crack 位错阻尼dislocation damping位错密度dislocation density 原子错位substitution of a wrongatom间隙原子interstitial atom 晶格空位vacant lattice sites间隙位置interstitial sites 杂质impurities弗伦克尔缺陷Frenkel disorder 肖脱基缺陷Schottky disorder主晶相the host lattice 错位原子misplaced atoms缔合中心Associated Centers. 自由电子Free Electrons电子空穴Electron Holes 伯格斯矢量Burgers克罗各-明克符号K roger Vink notation 中性原子neutral atom材料科学基础专业词汇:第二章晶体结构缺陷-固溶体固溶体solid solution 固溶度solid solubility化合物compound 间隙固溶体interstitial solid solution置换固溶体substitutional solid solution 金属间化合物intermetallics不混溶固溶体immiscible solid solution 转熔型固溶体peritectic solid solution有序固溶体ordered solid solution 无序固溶体disordered solid solution 固溶强化solid solution strengthening 取代型固溶体Substitutional solidsolutions过饱和固溶体supersaturated solid solution 非化学计量化合物Nonstoichiometric compound材料科学基础专业词汇:第三章熔体结构熔体结构structure of melt 过冷液体supercooling melt玻璃态vitreous state 软化温度softening temperature粘度viscosity 表面张力Surface tension介稳态过渡相metastable phase 组织constitution淬火quenching 退火的softened玻璃分相phase separation in glasses 体积收缩volume shrinkage材料科学基础专业词汇:第四章固体的表面与界面表面surface 界面interface同相界面homophase boundary 异相界面heterophase boundary晶界grain boundary 表面能surface energy小角度晶界low angle grain boundary 大角度晶界high angle grain boundary 共格孪晶界coherent twin boundary 晶界迁移grain boundary migration 错配度mismatch 驰豫relaxation重构reconstuction 表面吸附surface adsorption表面能surface energy 倾转晶界titlt grain boundary扭转晶界twist grain boundary 倒易密度reciprocal density共格界面coherent boundary 半共格界面semi-coherent boundary 非共格界面noncoherent boundary 界面能interfacial free energy应变能strain energy 晶体学取向关系crystallographicorientation惯习面habit plane材料科学基础专业词汇:第五章相图相图phase diagrams 相phase组分component 组元compoonent相律Phase rule 投影图Projection drawing浓度三角形Concentration triangle 冷却曲线Cooling curve成分composition 自由度freedom相平衡phase equilibrium 化学势chemical potential热力学thermodynamics 相律phase rule吉布斯相律Gibbs phase rule 自由能free energy吉布斯自由能Gibbs free energy 吉布斯混合能Gibbs energy of mixing 吉布斯熵Gibbs entropy 吉布斯函数Gibbs function热力学函数thermodynamics function 热分析thermal analysis过冷supercooling 过冷度degree of supercooling杠杆定律lever rule 相界phase boundary相界线phase boundary line 相界交联phase boundarycrosslinking共轭线conjugate lines 相界有限交联phase boundarycrosslinking相界反应phase boundary reaction 相变phase change相组成phase composition 共格相phase-coherent金相相组织phase constentuent 相衬phase contrast相衬显微镜phase contrast microscope 相衬显微术phase contrastmicroscopy相分布phase distribution 相平衡常数phase equilibriumconstant相平衡图phase equilibrium diagram 相变滞后phase transition lag相分离phase segregation 相序phase order相稳定性phase stability 相态phase state相稳定区phase stabile range 相变温度phase transitiontemperature相变压力phase transition pressure 同质多晶转变polymorphictransformation同素异晶转变allotropic transformation 相平衡条件phase equilibriumconditions显微结构microstructures 低共熔体eutectoid不混溶性immiscibility材料科学基础专业词汇:第六章扩散活化能activation energy扩散通量diffusion flux浓度梯度concentration gradient菲克第一定律Fick’s first law菲克第二定律Fick’s second law相关因子correlation factor稳态扩散steady state diffusion非稳态扩散nonsteady-state diffusion 扩散系数diffusion coefficient跳动几率jump frequency填隙机制interstitalcy mechanism晶界扩散grain boundary diffusion 短路扩散short-circuit diffusion上坡扩散uphill diffusion下坡扩散Downhill diffusion互扩散系数Mutual diffusion渗碳剂carburizing浓度梯度concentration gradient 浓度分布曲线concentration profile扩散流量diffusion flux驱动力driving force间隙扩散interstitial diffusion自扩散self-diffusion表面扩散surface diffusion空位扩散vacancy diffusion扩散偶diffusion couple扩散方程diffusion equation扩散机理diffusion mechanism扩散特性diffusion property无规行走Random walk达肯方程Dark equation柯肯达尔效应Kirkendall equation本征热缺陷Intrinsic thermal defect本征扩散系数Intrinsic diffusion coefficient离子电导率Ion-conductivity空位机制Vacancy concentration材料科学基础专业词汇:第七章相变过冷supercooling 过冷度degree of supercooling 晶核nucleus 形核nucleation形核功nucleation energy 晶体长大crystal growth均匀形核homogeneous nucleation 非均匀形核heterogeneous nucleation形核率nucleation rate 长大速率growth rate 热力学函数thermodynamics function临界晶核critical nucleus 临界晶核半径critical nucleus radius枝晶偏析dendritic segregation 局部平衡localized equilibrium平衡分配系数equilibriumdistributioncoefficient有效分配系数effective distribution coefficient成分过冷constitutional supercooling 引领（领先）相leading phase共晶组织eutectic structure 层状共晶体lamellar eutectic伪共晶pseudoeutectic 离异共晶divorsed eutectic表面等轴晶区chill zone 柱状晶区columnar zone中心等轴晶区equiaxed crystal zone 定向凝固unidirectional solidification 急冷技术splatcooling 区域提纯zone refining单晶提拉法Czochralski method 晶界形核boundary nucleation位错形核dislocation nucleation 晶核长大nuclei growth斯宾那多分解spinodal decomposition有序无序转变disordered-order transition马氏体相变martensite phase transformation 马氏体martensite材料科学基础专业词汇:第八、九章固相反应和烧结固相反应solid state reaction 烧结sintering烧成fire 合金alloy再结晶Recrystallization 二次再结晶Secondary recrystallization 成核nucleation 结晶crystallization子晶，雏晶matted crystal 耔晶取向seed orientation异质核化heterogeneous nucleation 均匀化热处理homogenization heattreatment铁碳合金iron-carbon alloy 渗碳体cementite铁素体ferrite 奥氏体austenite共晶反应eutectic reaction 固溶处理solution heat treatment。
电子商务与现代物流中英文对照外文翻译文献
电子商务与现代物流中英文对照外文翻译文献In this model。
the XXX its own logistics system。
the enterprise can control the entire process of delivery。
XXX。
this model requires a XXX.3.Third-party logistics model.XXX ns to a third-party logistics provider。
The third-party logistics provider handles the entire logistics process。
XXX。
the enterprise may lose some control over the logistics process and may have to pay higher fees for the services provided.Second。
the impact of electronic commerce on physical n1.Shortening of the n chain.XXX intermediaries in the n process。
such as XXX.2.Increased demand for logistics services.As more consumers shop online。
XXX.3.XXX.Electronic commerce has led to the XXX logistics models。
XXX connect consumers with individuals who XXX.Overall。
electronic commerce has had a significant impacton physical n。
物流专业英语
一．短语翻译(英译中）Unit 1Part 11.anchor sectors 支柱产业2.cargo container handling capacity 货物集装箱处理能力3.put in place 出台相关政策4.priority use of land resources 优先使用土地资源5.sector-by—sector 各个部门6。
tax concessions 税收优惠7。
tax-free zones 免税区8.automate much of the paperwork 文书工作自动化9.Rail freight traffic 铁路货物10。
public spending 政府开支11.terminal operators 码头营运商12。
Three Gorges Dam project 三峡工程13.Joint ventures 合资企业14.Small and medium—sized 中小型Part 21。
tendered forwarding services 提供货运代理2。
purchasing business 采购业务3。
customs-declarations 清关证明4。
explore the logistical facilities and services考察物流设施和服务5。
through the courtesy of 承蒙6。
regular freight forwarding 正规货运代理7.Shipping Agent 装船代理8.Cargo Forwarding Agent 货运代理9.Customs Clearance Agent 清关代理10。
under separate cover 在另函内11.for your information 供你参考Unit 2Part 11.work-in-process 在制品2。
identification cards 身份证3。
激发三重态（Excitedthreestates）
激发三重态（Excited three states）At most temperatures, most molecules are at the lowest vibrational level of the ground state. Molecules absorbed in the ground state absorb energy (electric energy, thermal energy, chemical energy, or light energy, etc.) and are excited to be excited. The excited state is very unstable,It will release energy quickly and re jump back to the ground state. When the molecules return to the ground state, the energy is emitted in the form of emission of electromagnetic radiation (light), known as luminescence". If the molecules of matter absorb light energy, they are stimulatedThe electromagnetic radiation emitted by the transition back to the ground state, known as fluorescence and phosphorescence. The mechanism of fluorescence and phosphorescence is discussed in terms of molecular structure theory.Each molecule has a series of strictly separated energy levels, called electron energy poles, and each electron energy level contains a series of vibrational energy levels and rotational energy levels. The state of motion of electrons in moleculesIn addition to the energy levels, the electrons contain multiple states of electrons. In M=2S+1, S is the sum of the quantum numbers of each electron spin quantum, with a value of 0 or 1. According to the principle of Pauli incompatibility, the same orbital in the moleculeThe two electrons occupied must have opposite spin directions, namely spin pairing. If all electrons in the molecule are spinpaired, then S=0, M=1, the molecule is in a singlet state (or a single line), expressed in symbolic S.The ground states of most organic compounds are in the singlet state. When the ground state molecules absorb energy, if the electron does not change in the direction of spin during the transition, it is still M=1, and the molecules are excited at a single weightIf the electron is accompanied by a change in the spin direction during the transition, then the molecule has two spin unpaired electrons, S=1, M=3, and the molecule is in the excited three state, expressed in symbolic T.Fig. 14.1 is a schematic diagram of electronic states.Fig. 14.1 sketch of excitation of three heavy states in a singlet stateThe unpaired electrons in discrete orbits are more stable than spin pairs (especially the rules), so in the same excited state, the energy levels of the three states are always slightly lower than those of the singlet state.Fig. 14.2 is a diagram of energy levels and transitions, in which S0, S1 and S2 represent the ground states of the molecules, the first and second electron excited singlet states, respectively, and T1 and T2 represent the three and second electron excited states of the molecule respectively. V=0, 1, 2, 3,... Represents the vibrational level of theground state and excited state.Fig. 14.2 energy level diagram of fluorescence and phosphorescence systemThe molecules in the excited state are very unstable, which may be activated by means of radiative transitions and nonradiative transitions (de excitation), releasing excess energy and returning to the ground state.Radiation transitions are mainly related to fluorescence, delayed fluorescence or phosphorescence emission; nonradiative transition is the release of excess energy in the form of heat, including vibrational relaxation, internal transfer, intersystem crossing and external transferCheng. Fig. 14.2 represents the energy transfer process of molecular excitation and deactivation:(1) vibrational relaxation (Vibration, relaxation, abbreviated as VR) - the transition from the lowest vibrational energy level (V=0) of the ground state to the excited singlet state may be possible when the molecules absorb the radiation of light (as shown in lambda 1, lambda 2 in Fig. 14.2)Higher vibrational levels of Sn (as shown in S1 and S2). Then，In the gas phase where the liquid phase or the pressure is high enough, the collision probability between molecules is large, and the molecules may pass excess vibrational energy to the surrounding region in the form of heatEnvironment, and its transition from the high vibrational energy level of the excited state to the lowest vibrational level of the electron energy level, this process is called vibrational relaxation. The vibrational relaxation time is 10 - 12s orders of magnitude.(2) internal transfer (Internal, conversion, abbreviated as IC) - when the low vibrational energy levels in the high electron levels overlap with the high vibrational energy levels in the lower electron levels, electrons frequently occur from the high electron energy levelsThe transition from nonradiative to low electron levels. As shown in Fig. 14. and 2, the low vibrational kinetic energy levels in S2 and T2 overlap with the high vibrational kinetic energy levels in S1 and T1, and electrons can transition from S2 to S1 through the superposition of vibrational levels, or fromT2 transition to T1. This process is called internal transfer. Time transfer for 1011s ~ 1013s magnitude. The rate of vibrational relaxation and internal transfer is much faster than the direct emission of photons by a highly excited state,Therefore, no matter which excited singlet state excited by the radiation energy, the molecules can jump to the lowest vibrational level via vibrational relaxation and internal transfer to the lowest (first) excited singlet state.(3) fluorescence emission (Fluorescence, emission, FE) - afterthe vibrational relaxation and internal transfer of electrons in the excited singlet state, reach the lowest vibrational level (V=0) of the first excited singlet (S1),The vibrational levels of the ground state (S0) transition in the form of radiation. The process is fluorescence emission with a fluorescence wavelength of. The energy loss due to vibrational relaxation and internal transfer, and hence the fluorescence emission energyThe energy is smaller than the molecular absorption, and the wavelength of fluorescence emission is longer than the wavelength of molecular absorption. The average lifetime of the lowest vibrational level in the first excited singlet state is about 10-9 - 10 - 4S, so the fluorescence lifetime is also in the rangeThis order of magnitude.(4) department (Intersystem Crossing, ISC Kuayue) - between leap refers to the non radiative transition process between different multiplets, it relates to the electronic excited spin state change.Such as the transition from the first excited singlet state S1 to the first excited three heavy state T1, so that the two spin pairs of electrons are no longer paired. This transition is prohibited (not in conformity with the spectral selection rule),But if the two energy layers have a large overlap, the minimumvibrational level of S1 in Figure 14.2 overlaps with the higher vibrational levels of T1, and it is possible to achieve this transition by spin orbit coupling.Between leap slower and experience a long time.(5) (Phosphorescence emission, PE luminescence emission) - the electronic excited state by the Department after three leap reach the excited state, after the rapid relaxation of vibrational relaxation and the transition to the first excited state threeThe lowest vibrational energy levels are then converted in the form of radiation back to the vibrational levels of the ground state, which are emitted by phosphorescence. The transition of the phosphorescence emission is still the spin forbidden, so the light speed is very slow.The life of 10-4 ~ 100s phosphor. Therefore, after the external light source is stopped, phosphorescence remains a short time. After the system vibration leap and T1 lost a part of the energy relaxation,So the phosphorescence wavelength is longer than the fluorescence wavelength, that is, the wavelength is longer than the wavelength of the phosphor.It must be pointed out that T1 may also be re excited by thermal excitation back to S1, i.e., T1S1, and then converted back to S0 by radiation from S1, S1S0, which emits fluorescence, which is called delayed fluorescence,Its lifetime is similar to that of phosphorescence, but its wavelength is shorter than phosphorescence.(6) external transfer (External, convertion, EC) - excited state molecules collide with solvent molecules or other solute molecules, and the process of energy transfer is called external transfer.External transfer can weaken or even weaken the intensity of fluorescence or phosphorescence. This phenomenon is called quenching or quenching.。
江苏省扬州市新东方中学2020年高一英语模拟试卷含解析
江苏省扬州市新东方中学2020年高一英语模拟试卷含解析一、选择题1. He is strong, brave and _____, honest.A. after allB. in allC. first of allD. above all参考答案：D2. There has been no ______ evidence to prove the ______ of life on other planets.A. convincing; existenceB. convinced; existenceC. convinced; existD. convincing; exist参考答案：23.选A。
句意：还没有令人信服的证据来证明其他行星上存在生命。
第一空表示“令人信服的证据”，第二空意思是指“生命的存在”，由此可以确定答案为A。
【解析】3. Children can get close to________nature by taking part in________series of outdoor activities.A．the；/ B．the；a C．/；the D．/；a参考答案：D略4. English has been very popular because it is the _______ language in many western countries.A. officialB. fluentC. gradualD. frequent参考答案：A5. This is the factory _____my father worked ten years ago.A. whereB. thatC. whichD. for the which参考答案：A6. Everybody in the village likes Jack because he is good at telling and __jokes.A. turning upB. putting upC. making upD. showing up参考答案：C7. This decision (决定) was due to (由于)_________ you wouldn’t get everything ready on time.A. thatB. the doubt thatC. the doubt whichD. the doubt of参考答案：B解析：doubt后接的是同位语从句，故排除C项。
Global_Supply_Chain_Promotion_Report_Is_Released
Global Supply Chain By Lily WangD uring the first CISCE,the Global Supply ChainP r o m o t i o n R e p o r t(hereinafter called report)was released. As the flagship reportof the expo, the report is the world’sfirst research report themed aroundthe supply chain promotion from the perspective of business community. Overthe past 7 months, the CCPIT research institute has conducted a survey covering526 domestic and overseas enterprisesand has also conducted interviews withmore than 100 global and domestic experts. The report is f inished withabout 150,000 letters.Show the recommendations ofthe business communityThe new type of think tank with Chinese characteristics is an important component of the country’s soft power. During his speech, Ren Hongbin stated that as the largest trade and investment promotion institution in China, the CCPIT has fully leveraged its advantages in connecting governments and enterprises, integrating internal and external resources, and facilitating supply and demand. It is rooted in enterprises in the industry and strives to build a high-level application think tank in the field of foreign trade and economic cooperation. The CCPIT has stuck to a global perspective and grasped the development trends of both international and domestic industries. The CCPIT research institute conducted in-depth research and completed the Global Supply Chain Promotion Report, making it the first to conduct research on supply chain promotion from a global perspective. It isalso the f irst report to comprehensivelyquantify the development trend of theglobal supply chain and construct aglobal supply chain promotion analysissystem, focusing on promoting globalsupply chain technology innovation,open cooperation, and interconnectionand inclusive development to offerrecommendations from the businesscommunity. It also represents the realaction used to implement the advocacyof president Xi Jinping to safeguard thestability and smoothness of the globalindustrial chain.Chen Jian’an, Vice Chairman ofthe CCPIT, released the Global SupplyChain Promotion Report. Currently, thereare increasing disruptions in the globalsupply chain, and various sectors havedifferent opinions on the developmenttrends of the global supply chain.However, the report found, throughcomprehensive quantitative analysis,that global supply chain developmentis showing trends of regionalization,diversif ication, digitization, andgreening. In terms of supply chainregionalization, Europe, East Asia,and North America have shown clearregionalization of the supply chain.Germany, China, and the United Statesare regional supply chain centers. Interms of supply chain diversification,inf luenced by geopolitical conf lictsand fluctuations in commodity prices,European multinational corporationsare accelerating their pace of supplychain diversification, especially in theareas of electronic products and textilesupply chains. In terms of supply chaindigitization, the telecommunicationsindustry has the highest degree of supplychain digitization, followed by theinformation technology and informationservices industry. The supply chain 26digitization of the financial industry differs largely among countries. In terms of supply chain greening, this has become a trend for addressing global challenges such as climate change.The report has reconstructed the global supply chain promotion system, which includes f ive dimensions: infrastructure inter-connectivity, multilateral and bilateral economic and trade rules, domestic policies of major economies, technological progress, and financial services. The multilateral and bilateral economic and trade rules establish a global supply chain institutional framework, and constitute the institutional basis of the global supply chain, which will reduce trade and investment barriers on a global scale, and will accelerate supply chain cooperation among members of regional economic agreements. The domestic policies of major economies also affect the direction of global supply chain development. When policies encourage companies to “go global”, the cost of the global supply chain layout will significantly decrease; on the contrary, implementing de-coupling policies will hinder the global supply chain layout. Technological progress further accelerates global supply chain innovation and upgrading. The rapid development of new generation information technology has changed the operation mode of traditional global supply chains, resulting in two new changes in the global supply chain: vertical extension and horizontal expansion; green and low-carbon technologies such as new materials and energy play an important role in promoting sustainable development of global supply chains. Financial services also enhance the resilience and vitality of global supply chain development.The report has also summarized Ch i na’s succe ssf u l prac t ice s i n promoting global supply chains and the opportunities it provides for promoting open cooperation in terms of global supply chains. In terms of infrastructure connectivity, China has built the world’s largest high-speed railway network, highway network, and world-class port cluster, providing strong support for promoting global infrastructure connectivity. In terms of multilateral and bilateral rules, China adheres to the correct direction of economicglobalization, maintains a multilateraltrading system centered on the WorldTrade Organization, and promotesbilateral and regional cooperation. Interms of supply chain promotion policies,China attaches strategic importance tosupply chain construction and proposesglobal supply chain cooperationinitiatives. In terms of technologicalprogress, China supports the use ofdigital technology and green low-carbontechnology by enterprises to effectivelysolve pain points such as global supplychain information asymmetry, opaquelinks, and harm to the environmentcaused during development. In terms offinancial services, China has acceleratedthe innovation and development ofsupply chain finance by establishinginternational financial institutionsand investment funds, thereby helpingextend the global supply chain todeveloping countries.Report results won recognitionof enterprisesWang Binwen, Director of theAircraft Strength Research Instituteof China, said that he had witnessedthe release of the report, as well asthe results of supply chain promotionresearch from the global perspective.“I am very excited and also educated,”he said, while stating that there arethree major trends in the developmentof the global supply chain in the eraof digital intelligence. First, digitaltechnology will play a greater roleand become the core force drivingthe development of the supply chain.Second, artificial intelligence technologywill trigger a leapfrog transformationin the supply chain. Thirdly, intelligentmanufacturing will have a greaterimpact on the development of the supplychain of the manufacturing industry.As the core enterprise of the supplychain, multinational corporations arealso commonly referred to as chainleaders and have a strong shaping andcontrolling power over the supply chain.Kenneth Stacherski, global vice presidentof Genera l Electric Hea lthcare,emphasized that the supply chainmust be a partnership. “We have beenworking with over 1,000 global partnersto create an ecosystem that provides high-end medical equipment production andimproves the quality and capacity of oursupply chain in China. In the future, wewill be committed to promoting globalinnovation and cooperation, providingproduct services and supply chains tobetter meet the demand for medicalequipment in some private sectors.”According to Qian Kun, SeniorVice President of Qualcomm, weare now in a new era full of digitaltransformation and opportunities. Newtechnologies, especially 5G and artificialintelligence, are profoundly changingour daily lives and paving the way fora new digital economy. “Over the past30 years, Qualcomm has been closelyworking with its Chinese partners tohelp them expand their domestic andinternational markets. As of now, morethan half of f lagship mobile globaldebuts on Qualcomm’s platforms belongto Chinese mobile phone producers,and many of our customers generateapproximately 50% of their revenuefrom overseas. We look forward todeepening the cooperation with ourpartners, focusing on innovation, andjointly creating a global economic systemempowered by 5G and AI technologies.”Zhao Ping, Director of t heCCPIT Research Institute, chaired aroundtable discussion. Zhang Yansheng,chief researcher of China Center forInternational Economic Exchanges,L i Jiqin, executive general manager ofCSCEC International, Jiang Zhiguo,Vice President of iFlytek TechnologyCo., L td., L i Feng, Vice President ofStandard Chartered China and GeneralManager of Personal, Private and Smalland Medium-sized Enterprise BankingDepartment, and Poul Hansen, headof Trade Facilitation at the T echnologyand L ogistics Department of theUnited Nations Conference on Tradeand Development, actively participatedin deep discussions around the themeof “global supply chain promotionexperiences and suggestions”.“We expect that with all ourefforts, the global supply chain will getbetter and better. Building safe, stableand smooth global supply chains is thecommon expectations of all enterprises,and we hope such good supply chains27。
科技英语_秦荻辉_科技英语语法习题以及答案
科技英语_秦荻辉_科技英语语法习题以及答案练习 1I、将下列句子译成汉语，注意句中有些冠词的特殊位置:1. In this case the current(电流)exists for only half the cycle(周期).2. In such a case there is no current flowing in the circuit(电路).3. Sensitivity(灵敏度)is a measure of how small a signal(信号)a receiver(接收机)canpick up and amplify(放大)to a level useful for communications.4. ε may be as small a positive constant as you please.5. Even so fundamental a dimension,量纲，as time was measured extremely crudely with sandand water clocks hundreds of years ago.6. Nonlinear distortion,非线性失真，can be caused by too large an input signal.7. The method used is quite an effective one.8. A series,级数，solution of this kind of problem allows as close a calculation of the error as needed.II、将下列句子译成汉语，注意句中“and”和“or”的确切含义:1. Air has weight and occupies space.2. In this way less collector dissipation(集电极功耗)results, and the efficiency increases.3. We can go one step farther and take into account the nonzeroslope of the actual curves.4. Try hard, and you will work the nut(螺母)loose.5. The first step in analyzing a physical situation is to select those aspects of it which are essential and disregard the others.6. This satellite was used for communications between the United States and Great Britain, France and Italy.7. Some physical quantities require only a magnitude and a unit tobe completely specified. Thus it is sufficient to say that the mass of a man is 85 kg, that the area of a farm is 160 acres, that the frequencyof a sound wave is 660 cycles/sec, and that a light bulb consumes electric energy at the rate of 100 watts.8. Geothermal energy, or energy from within the earth, can be usedto generate electricity.o9.The current in a capacitor(电容器)leads(导前)the voltage by 90, or, the voltage lagsothe current by 90.10. The message is a logical unit of user data, control data, or both.III、将下列句子译成汉语，注意句中分数和倍数的正确译法:1. By varying V only a few hundredths of a volt, the base current(基极电流)can be BEchanged significantly.2. The standard meter is accurate to about two parts in one billion.3. Cromatographic(层析的)techniques have been developed to detectair pollutants atconcentrations(浓度)of one part per million or less.4. The volume coefficient(体膨胀系数)of a solid is almost exactlythree times its linearcoefficient.5. The demand for this kind of equipment in the near future will be20 times what it is.6. The wavelength of this musical note(音符)is7.8 ft, over threetimes longer than thewavelength of the same note in air (2.5 ft).7. This causes the collector current(集电极电流)to change by afactor of approximately β.8. This factor(因子)is now equal to 9, a reduction by a factor of 11.IV、将下列句子译成英语:1、火箭是由金属制成的。
微电子专业英语翻译
费米分布函数
Fig.1.6 shows schematically（图表式的） from left to right the band diagram ,the density of states (which varies as E )，the Fermi distribution function, and the carrier concentration （浓度）for an intrinsic semiconductor .The carrier concentration can be obtained graphically from Figure 1.6 using Eq.(1.12); that is ,the product of N(E) in Fig.1.6(b) and F(E) in Fig.1.6(c) gives the n(E)-versus-E curve (upper curve ) in Fig.1.6(d).The upper shaded area in Fig.1.6(d) corresponds to the electron density.Fra bibliotek状态密度
The incremental momentum（增加的动量） dp required for a unity increase in nx is For a three-dimensional cube of side L,we have
The volume dpxdpydpz in the momentum space for a unit cube (L=1) is thus equal to h3.Each incremental change in n corresponds to a unique set of integers (nx,ny,nz) ,which in turn corresponds to an allowed energy state. Thus,the volume in momentum space for an energy state is h3 .The volume between two concentric (同中心的 同中心的)spheres (from p to p+dp is 同中心的 4πp2dp) .The number of energy states contained in this volume is then 2(4πp2dp)/ h3,where the factor 2 accounts for the electron spins .we can substitute E for p and obtain
人民邮电信管英语第三版参考答案
Unit 1【Ex1.】根据课文内容，回答以下问题。
1．In human terms and in the broadest sense, information is anything that you are capable of perceiving. 2．It includes written communications, spoken communications, photographs, art, music, and nearly anything that is perceptible.3．If we consider information in the sense of all stimuli as information, then we can’t really find organization in all cases.4．No.5．Traditionally, in libraries, information was contained in books, periodicals, newspapers, and other types of recorded media. People access it through a library’s catalog and with the assistance of indexes, in the case of periodical and newspaper articles.6．Computerized “information systems”.7．The problem for most researchers is that they have yet to discover the organizing principles that are designed to help them find the information they need.8．For library materials, the organizing principle is a detailed subject classification system available for searching in an online “catalog”.9．The one thing common to all of these access systems is organization.10．No, it isn’t.【Ex2.】根据给出的汉语词义和规定的词类写出相应的英语单词。
Lesson20FlipFlop电子技术专业英语教程
•Figure 20-1 The symbol for a SR latch
PPT文档演模板
2020/11/6
Lesson20FlipFlop电子技术专业英语 教程
•Trigger flip-flops (T flip-flops)
• A flip-flop is usually controlled by one or two control signals and/or a gate or clock signal. The output often includes the complement as well as the normal output. As flip-flops are implemented electronically, they require power and ground connections.
PPT文档演模板
2020/11/6
Lesson20FlipFlop电子技术专业英语 教程
•Backgrounds
• Terminology
– multivibrator
• n.【计】多谐振荡器
– field effect transistor
• 【计】场效应晶体管
– shift register
• 移位寄存器
Lesson20Flip-Flop电 子技术专业英语教程
PPT文档演模板
2020/11/6
Lesson20FlipFlop电子技术专业英语 教程
Lesson 20 Flip-Flop
• Backgrounds • Text tour • Language in use
互联网绿色生态英语作文
互联网绿色生态英语作文The Green Ecology of the Internet。
In recent years, the internet has become an integral part of our lives, transforming the way we communicate, work, and access information. However, the rapid growth of the internet has also led to concerns about its environmental impact. As the world becomes increasingly interconnected, it is crucial to develop a green ecologyfor the internet, ensuring its sustainability and minimizing its carbon footprint.One of the major environmental concerns associated with the internet is its energy consumption. The internet relies on data centers, which house thousands of servers that store and process information. These data centers require a significant amount of electricity to operate, leading to high levels of energy consumption and greenhouse gas emissions. According to a study by the Lawrence Berkeley National Laboratory, data centers in the United Statesalone consumed about 70 billion kilowatt-hours ofelectricity in 2014, accounting for approximately 2% of the country's total energy consumption.To address this issue, various initiatives and technologies have been developed to promote energy efficiency in data centers. One approach is the use of virtualization, which allows multiple virtual servers to run on a single physical server, reducing the overall energy consumption. Additionally, data centers can be designed with energy-efficient cooling systems and utilize renewable energy sources such as solar or wind power. Companies like Google and Facebook have already made significant strides in this area by investing in renewable energy projects and implementing energy-efficient practices in their data centers.Another aspect of the internet's environmental impactis electronic waste, commonly known as e-waste. As technology advances at a rapid pace, electronic devices become obsolete quickly, leading to a large amount of discarded electronic equipment. E-waste contains hazardoussubstances such as lead, mercury, and cadmium, which can pollute the environment and pose health risks if not properly managed.To tackle the issue of e-waste, it is essential to promote responsible electronic waste management practices. This includes recycling electronic devices, refurbishing them for reuse, or ensuring proper disposal to prevent the release of hazardous substances into the environment. Governments and organizations can play a crucial role in implementing e-waste management regulations and raising awareness among the public about the importance ofrecycling and responsible disposal of electronic devices.In addition to energy consumption and e-waste, the internet also has an impact on carbon emissions through its influence on transportation. With the rise of e-commerce and online services, more goods and services are being delivered to consumers' doorsteps. This leads to an increase in the number of delivery vehicles on the road, resulting in higher carbon emissions.To mitigate this impact, companies can adopt sustainable transportation practices, such as optimizing delivery routes, using electric or hybrid vehicles, and promoting public transportation for employees. Furthermore, individuals can contribute by consolidating their online purchases to reduce the number of deliveries and opting for eco-friendly transportation options whenever possible.Apart from these specific areas, promoting a green internet ecology also involves raising awareness and changing behaviors. Educating individuals and businesses about the environmental impact of the internet can encourage them to adopt sustainable practices. This can include simple actions like turning off devices when not in use, reducing unnecessary online activities, and choosing eco-friendly web hosting services that utilize renewable energy sources.Furthermore, the development of green technologies and innovations can contribute to a more sustainable internet. For example, the advancement of energy-efficient hardware and software, the use of artificial intelligence tooptimize energy consumption in data centers, and the implementation of blockchain technology for transparent and accountable energy management.In conclusion, the internet has revolutionized the way we live and work, but it also has a significant environmental impact. To ensure its sustainability, it is crucial to develop a green ecology for the internet. This involves promoting energy efficiency in data centers, managing electronic waste responsibly, reducing carbon emissions from transportation, and raising awareness about sustainable practices. By adopting these measures, we can minimize the environmental footprint of the internet and create a more sustainable future.。
材料英语词汇
材料英语词汇专业词汇列表晶体结构（structure of crystal）原子质量单位Atomic mass unit (amu)原子量Atomic weight键能Bonding energy共价键Covalent bond电子构型electronic configuration正电的Electropositive氢键Hydrogen bond同位素Isotope摩尔Mole泡利不相容原理Pauli exclusion principle原子atom分子量molecule weight量子数quantum number范德华键van der waals bond点群point group波尔原子模型Bohr atomic model库仑力Coulombic force分子的构型molecular configuration负电的Electronegative基态Ground state离子键Ionic bond金属键Metallic bond分子Molecule元素周期表Periodic table极性分子Polar molecule价电子valence electron电子轨道electron orbitals对称要素symmetry elements原子堆积因数atomic packing factor(APF)面心立方结构face-centered cubic (FCC)配位数coordination number晶系crystal system衍射diffraction电子衍射electron diffraction六方密堆积hexagonal close-packed (HCP)NaCl型结构NaCl－type structure闪锌矿型结构Blende-type structure金红石型结构Rutile structure钙钛矿型结构Perovskite-type structure硅酸盐结构Structure of silicates链状结构Chain structure架状结构Framework structure叶蜡石pyrophyllite石英quartz美橄榄石forsterite各向异性的anisotropy晶格参数lattice parameters非结晶的noncrystalline多晶形polymorphism单晶single crystal电位electron states电子electrons金属键metallic bonding极性分子polar molecules衍射角diffraction angle粒度,晶粒大小grain size显微照相photomicrograph透射电子显微镜transmission electron microscope (TEM)四方的tetragonal配位数coordination number 晶胞unit cell(化合)价valence共价键covalent bonding离子键Ionic bonding 原子面密度atomic planar density合金alloy显微结构microstructure扫描电子显微镜scanning electron microscope (SEM)重量百分数weight percent单斜的monoclinic 晶体结构缺陷(defect of crystal structure)缺陷defect, imperfection线缺陷line defect, dislocation体缺陷volume defect位错线dislocation line螺位错screw dislocation晶界grain boundaries小角度晶界tilt boundary,位错阵列dislocation array位错轴dislocation axis位错爬移dislocation climb位错滑移dislocation slip位错裂纹dislocation crack位错密度dislocation density间隙原子interstitial atom间隙位置interstitial sites弗伦克尔缺陷Frenkel disorder主晶相the host lattice缔合中心Associated Centers.电子空穴Electron Holes克罗各-明克符号Kroger Vink notation固溶体solid solution化合物compound置换固溶体substitutional solid solution不混溶固溶体immiscible solid solution有序固溶体ordered solid solution固溶强化solid solution strengthening点缺陷point defect面缺陷interface defect位错排列dislocation arrangement刃位错edge dislocation混合位错mixed dislocation大角度晶界high-angle grain boundaries孪晶界twin boundaries位错气团dislocation atmosphere位错胞dislocation cell位错聚结dislocation coalescence位错核心能量dislocation core energy位错阻尼dislocation damping原子错位substitution of a wrong atom晶格空位vacant lattice sites杂质impurities肖脱基缺陷Schottky disorder错位原子misplaced atoms自由电子Free Electrons伯格斯矢量Burgers中性原子neutral atom固溶度solid solubility间隙固溶体interstitial solid solution金属间化合物intermetallics转熔型固溶体peritectic solid solution无序固溶体disordered solid solution取代型固溶体Substitutional solid solutions过饱和固溶体supersaturated solid solution非化学计量化合物Nonstoichiometric compound表面结构与性质(structure and property of surface)表面surface同相界面homophase boundary晶界grain boundary小角度晶界low angle grain boundary共格孪晶界coherent twin boundary 错配度mismatch重构reconstuction表面能surface energy扭转晶界twist grain boundary共格界面coherent boundary非共格界面noncoherent boundary 应变能strain energy惯习面habit plane界面interface异相界面heterophase boundary表面能surface energy大角度晶界high angle grain boundary晶界迁移grain boundary migration驰豫relaxation表面吸附surface adsorption倾转晶界titlt grain boundary倒易密度reciprocal density半共格界面semi-coherent boundary界面能interfacial free energy晶体学取向关系crystallographic orientation非晶态结构与性质(structure and property ofuncrystalline)熔体结构structure of melt玻璃态vitreous state粘度viscosity介稳态过渡相metastable phase淬火quenching玻璃分相phase separation in glasses 过冷液体supercooling melt软化温度softening temperature表面张力Surface tension组织constitution退火的softened体积收缩volume shrinkage扩散(diffusion)活化能activation energy浓度梯度concentration gradient 菲克第二定律Fick’s second law 稳态扩散steady state diffusion扩散系数diffusion coefficient填隙机制interstitalcy mechanism 短路扩散short-circuit diffusion 下坡扩散Downhill diffusion扩散通量diffusion flux菲克第一定律Fick’s first law相关因子correlation factor非稳态扩散nonsteady-state diffusion 跳动几率jump frequency晶界扩散grain boundary diffusion 上坡扩散uphill diffusion互扩散系数Mutual diffusion渗碳剂carburizing浓度分布曲线concentration profile 驱动力driving force自扩散self-diffusion空位扩散vacancy diffusion扩散方程diffusion equation扩散特性diffusion property达肯方程Dark equation本征热缺陷Intrinsic thermal defect 离子电导率Ion-conductivity浓度梯度concentration gradient扩散流量diffusion flux间隙扩散interstitial diffusion表面扩散surface diffusion扩散偶diffusion couple扩散机理diffusion mechanism无规行走Random walk柯肯达尔效应Kirkendall equation本征扩散系数Intrinsic diffusion coefficient 空位机制Vacancy concentration腐蚀与氧化（corroding and oxidation）氧化反应Oxidation reaction还原反应Reduction reaction价电子Valence electron腐蚀介质Corroding solution电动势Electric potential推动力The driving force腐蚀系统Corroding system腐蚀速度Corrosion penetration rate 电流密度Current density电化学反应Electrochemical reaction 极化作用Polarization过电位The over voltage浓差极化Concentration polarization 电化学极化Activation polarization 极化曲线Polarization curve缓蚀剂Inhibitor原电池galvanic cell电偶腐蚀galvanic corrosion 电位序galvanic series应力腐蚀Stress corrosion冲蚀Erosion-corrosion腐蚀短裂Corrosion cracking 防腐剂Corrosion remover腐蚀电极Corrosion target隙间腐蚀Crevice corrosion 均匀腐蚀Uniform attack晶间腐蚀Intergranular corrosion焊缝破坏Weld decay选择性析出Selective leaching氢脆损坏Hydrogen embitterment阴极保护Catholic protection穿晶断裂Intergranular fracture固相反应和烧结(solid state reaction and sintering)固相反应solid state reaction烧成fire再结晶Recrystallization成核nucleation子晶，雏晶matted crystal异质核化heterogeneous nucleation铁碳合金iron-carbon alloy铁素体ferrite共晶反应eutectic reaction烧结sintering合金alloy二次再结晶Secondary recrystallization结晶crystallization耔晶取向seed orientation均匀化热处理homogenization heat treatment渗碳体cementite奥氏体austenite固溶处理solution heat treatment相变(phase transformation)过冷supercooling晶核nucleus形核功nucleation energy均匀形核homogeneous nucleation形核率nucleation rate热力学函数thermodynamics function 临界晶核critical nucleus枝晶偏析dendritic segregation平衡分配系数equilibrium distribution coefficient成分过冷constitutional supercooling共晶组织eutectic structure伪共晶pseudoeutectic表面等轴晶区chill zone中心等轴晶区equiaxed crystal zone急冷技术splatcooling单晶提拉法Czochralski method位错形核dislocation nucleation斯宾那多分解spinodal decomposition马氏体相变martensite phase transformation 成核机理nucleation mechanism过冷度degree of supercooling形核nucleation晶体长大crystal growth非均匀形核heterogeneous nucleation长大速率growth rate临界晶核半径critical nucleus radius局部平衡localized equilibrium有效分配系数effective distribution coefficient引领（领先）相leading phase层状共晶体lamellar eutectic离异共晶divorsed eutectic柱状晶区columnar zone定向凝固unidirectional solidification区域提纯zone refining晶界形核boundary nucleation晶核长大nuclei growth有序无序转变disordered-order transition 马氏体martensite成核势垒nucleation barrier相平衡与相图（Phase equilibrium and Phase diagrams）相图phase diagrams组分component相律Phase rule浓度三角形Concentration triangle成分composition相平衡phase equilibrium热力学thermodynamics吉布斯相律Gibbs phase rule吉布斯自由能Gibbs free energy吉布斯熵Gibbs entropy热力学函数thermodynamics function 过冷supercooling杠杆定律lever rule相界线phase boundary line共轭线conjugate lines相界反应phase boundary reaction相组成phase composition金相相组织phase constentuent相衬显微镜phase contrast microscope 相分布phase distribution相平衡图phase equilibrium diagram相分离phase segregation相phase组元compoonent投影图Projection drawing冷却曲线Cooling curve自由度freedom化学势chemical potential相律phase rule自由能free energy吉布斯混合能Gibbs energy of mixing 吉布斯函数Gibbs function热分析thermal analysis过冷度degree of supercooling相界phase boundary相界交联phase boundary crosslinking相界有限交联phase boundary crosslinking 相变phase change共格相phase-coherent相衬phase contrast相衬显微术phase contrast microscopy相平衡常数phase equilibrium constant相变滞后phase transition lag相序phase order相稳定性phase stability相稳定区phase stabile range相变压力phase transition pressure同素异晶转变allotropic transformation显微结构microstructures不混溶性immiscibility相态phase state相变温度phase transition temperature同质多晶转变polymorphic transformation 相平衡条件phase equilibrium conditions。
Open_Compute_Technology_Committee_established_in_B
The development and successful experience of open compute in the internet industry have greatly stimulated the innovation of hardware infrastructure and deepened the recognition of the value of open compute. It has become the main innovation impetus of data centers, which facilitates the sustainable development of data center infrastructure through innovative global collaboration.Therefore, the inaugurating ceremony and first summit of the Open Compute Technology Committee (OCTC) were held on April 24 in Beijing, which connected end users, system manufacturers, core component suppliers and scientific research institutions.The event was participated by representatives from founding members including China Electronics Standardization Association (CESA), Baidu, China Mobile, Industrial and Commercial Bank of China, State Grid Corporation of China, and Inspur Electronic Information Industry Co., Ltd. and over 40 members covering upstream and downstream industrial chain.Currently, OCTC has initiated the development of several standards for liquid cooling, rack-scale server, AI computing and relevant technologies. Its technical specifications under development are expected to fill the gap of open compute in standards for liquid plate cooler applied in data centers, which will promote the standardization and industrialization development in this field.To promote open compute, Chen Yanling, Deputy Secretary-General of OCTC, believes that the most important is to develop new standards and establish new industrial types, in order to enable better accessibility, stronger ability of technological innovation and better product support.OCTC will carry out its work in four aspects, namely innovation ability promotion, open compute standards system development, improvement of open compute industrial chain, and sound development of data centers. Developing open compute standards system is key to promote the efficient coordination, common prosperity and universal technological benefits of the open compute industry, said Duo Jing, Executive Secretary-General of CESA.Open Compute Technology Committee established in Beijing11 2023 May / June CHINA STANDARDIZATION Copyright ©博看网. All Rights Reserved.。
有关ups电源的英语
有关ups电源的英语UPS (Uninterruptible Power Supply) is a device that provides emergency power to electronic devices such as computers, servers, and other critical equipment when the main power source fails. It acts as a backup power source, allowing users to save their work and safely shut down their devices during a power outage or voltage fluctuations.UPSs are typically designed with a rechargeable battery that can store power and deliver it when needed. The battery is automatically charged when the main power is restored.There are different types of UPSs available in the market, including offline UPS, line-interactive UPS, and online UPS. Each type offers different levels of protection and efficiency.UPSs are widely used in various industries and environments to ensure uninterrupted power supply. They are commonly found in data centers, hospitals, offices, and homes where maintaining power reliability is essential.In addition to providing power backup, UPSs also offer protection against power surge, voltage spikes, and electrical noise, which can damage electronic devices. They help prevent data loss, equipment damage, and system downtime.Overall, UPSs play a crucial role in ensuring the stability and reliability of electronic devices by providing backup power and protection in the event of power outages or electrical disturbances.。
72-245-eec(无线电干扰)
1972L0245 — EN — 01.01.2007 — 008.001 — 3
►B ►M2
COUNCIL DIRECTIVE 72/245/EEC of 20 June 1972
relating to the radio interference (electromagnetic compatibility) of vehicles
欧洲共同体官方出版物办公室CONSLEG体系出版
CONSLEG: 1972L0245 — 01/05/2004
Number of pages: 78 页数：78页 `
Office for Official Publications of the European Communities
欧洲共同体官方出版物办公室
Amended by:
►M1
►M2 ►M2 ►M3 ►M4 ►M5 ►M6
Commission Directive 89/491/EEC of 17 July 1989
Commission Directive 95/54/EC of 31 October 1995 Commission Directive 2004/104/EC of 14 October 2004 Commission Directive 2005/49/EC of 25 July 2005 Commission Directive 2005/83/EC of 23 November 2005 Commission Directive 2006/28/EC of 6 March 2006 Council Directive 2006/96/EC of 20 November 2006
►A1关于捷克、爱沙尼亚共和国、塞浦路斯共和国 拉脱维亚共和国、立陶宛共和国、匈牙利共和国、马尔 他共和国、波兰共和国、斯洛文尼亚共和国和斯洛伐克 共和国的正式加入条件法案以及欧盟成立条约的调整。
能源专业外文翻译--来自太阳的能源
外文原文：ENERGY FROM THE SUNThe sun has produced energy for billions of years. Solar energy is the solar radiation that reaches the earth. Solar energy can be converted directly or indirectly into other forms of energy, such as heat and electricity. The major drawbacks (problems, or issues to overcome) of solar energy are: (1) the intermittent and variable manner in which it arrives at the earth's surface and, (2) the large area required to collect it at a useful rate. Solar energy is used for heating water for domestic use, space heating of buildings, drying agricultural products, and generating electrical energy.In the 1830s, the British astronomer John Herschel used a solar collector box to cook food during an expedition to Africa. Now, people are trying to use the sun's energy for lots of things.Electric utilities are trying photovoltaics, a process by which solar energy is converted directly to electricity. Electricity can be produced directly from solar energy using photovoltaic devices or indirectly from steam generators using solar thermal collectors to heat a working fluid. Out of the 14 known solar electric generating units operating in the US at the end of 2004, 10 of these are in California, and 4 in Arizona. No statistics are being collected on solar plants that produce less than 1 megawatt of electricity, so there may be smaller solar plants in a number of other states. PHOTOVOLTAIC ENERGYPhotovoltaic energy is the conversion of sunlight into electricity through a photovoltaic (PVs) cell, commonly called a solar cell. A photovoltaic cell is a nonmechanical device usually made from silicon alloys.Sunlight is composed of photons, or particles of solar energy. These photons contain various amounts of energy corresponding to the different wavelengths of the solar spectrum. When photons strike a photovoltaic cell, they may be reflected, pass right through, or be absorbed. Only the absorbed photons provide energy to generate electricity. When enough sunlight (energy) is absorbed by the material (a semiconductor), electrons are dislodged from the material's atoms. Special treatment of the material surface during manufacturing makes the front surface of the cell more receptive to free electrons, so the electrons naturally migrate to the surface.When the electrons leave their position, holes are formed. When many electrons, each carrying a negative charge, travel toward the front surface of the cell, the resulting imbalance of charge between the cell's front and back surfaces creates a voltage potential like the negative and positive terminals of a battery. When the two surfaces are connected through an external load, electricity flows.The photovoltaic cell is the basic building block of a PV system. Individual cells can vary in size from about 1 cm (1/2 inch) to about 10 cm (4 inches) across. However, one cell only produces 1 or 2 watts, which isn't enough power for most applications. To increase power output, cells are electrically connected into a packaged weather-tight module. Modules can be further connected to form an array. The term array refers to the entire generating plant, whether it is made up of one or several thousand modules. As many modules as needed can be connected to form the array size (power output) needed.The performance of a photovoltaic array is dependent upon sunlight. Climate conditions (e.g., clouds, fog) have a significant effect on the amount of solar energy received by a PV array and, in turn, its performance. Most current technology photovoltaic modules are about 10 percent efficient in converting sunlight with further research being conducted to raise this efficiency to 20 percent.The pv cell was discovered in 1954 by Bell Telephone researchers examining the sensitivity of a properly prepared silicon wafer to sunlight. Beginning in the late 1950s, pvs were used to power U.S. space satellites. The success of PVs in space generated commercial applications for pv technology. The simplest photovoltaic systems power many of the small calculators and wrist watches used everyday. More complicated systems provide electricity to pump water, power communications equipment, and even provide electricity to our homes.Photovoltaic conversion is useful for several reasons. Conversion from sunlight to electricity is direct, so that bulky mechanical generator systems are unnecessary. The modular characteristic of photovoltaic energy allows arrays to be installed quickly and in any size required or allowed.Also, the environmental impact of a photovoltaic system is minimal, requiring no water for system cooling and generating no by-products. Photovoltaic cells, like batteries, generate direct current (DC) which is generally used for small loads (electronic equipment). When DC from photovoltaic cells is used for commercial applications or sold to electric utilities using the electric grid, it must be converted to alternating current (AC) using inverters, solid state devices that convert DC power to AC. Historically, pvs have been used at remote sites to provide electricity. However, a market for distributed generation from PVs may be developing with the unbundling of transmission and distribution costs due to electric deregulation. The siting of numerous small-scale generators in electric distribution feeders could improve the economics and reliability of the distribution system.SOLAR THERMAL HEATThe major applications of solar thermal energy at present are heating swimming pools, heating water for domestic use, and space heating of buildings. For these purposes, the general practice is to use flat-plate solar-energy collectors with a fixed orientation (position).Where space heating is the main consideration, the highest efficiency with a fixed flat-plate collector is obtained if it faces approximately south and slopes at an angle to the horizon equal to the latitude plus about 15 degrees. Solar collectors fall into two general categories: nonconcentrating and concentrating.In the nonconcentrating type, the collector area (i.e. the area that intercepts the solar radiation) is the same as the absorber area (i.e., the area absorbing the radiation).In concentrating collectors, the area intercepting the solar radiation is greater, sometimes hundreds of times greater, than the absorber area. Where temperatures below about 200o F are sufficient, such as for space heating, flat-plate collectors of the nonconcentrating type are generally used.There are many flat-plate collector designs but generally all consist of (1) a flat-plate absorber, which intercepts and absorbs the solar energy, (2) a transparent cover(s) that allows solar energy to pass through but reduces heat loss from the absorber, (3) a heat-transport fluid (air or water) flowing through tubes to remove heat from the absorber, and (4) a heat insulating backing.Solar space heating systems can be classified as passive or active. In passive heating systems, the air is circulated past a solar heat surface(s) and through the building by convection (i.e. less dense warm air tends to rise while more dense cooler air moves downward) without the use of mechanical equipment. In active heating systems, fans and pumps are used to circulate the air or the heat absorbing fluid.SOLAR THERMAL POWER PLANTSSolar thermal power plants use the sun's rays to heat a fluid, from which heat transfer systems may be used to produce steam. The steam, in turn, is converted into mechanical energy in a turbine and into electricity from a conventional generator coupled to the turbine. Solar thermal power generation is essentially the same as conventional technologies except that in conventional technologies the energy source is from the stored energy in fossil fuels released by combustion. Solar thermal technologies use concentrator systems due to the high temperatures needed for the working fluid.PARABOLIC TROUGHThe parabolic trough is used in the largest solar power facility in the world located in the Mojave Desert at Kramer Junction, California. This facility has operated since the 1980 and accounted for the majority of solar electricity produced by the electric power sector in 2004.A parabolic trough collector has a linear parabolic-shaped reflector that focuses the sun's radiation on a linear receiver located at the focus of the parabola. The collector tracks the sun along one axis from east to west during the day to ensure that the sun is continuously focused on the receiver. Because of its parabolic shape, a trough can focus the sun at 30 to 100 times its normal intensity (concentration ratio) on a receiver pipe located along the focal line of the trough, achieving operating temperatures over 400 degrees Celcius.A collector field consists of a large field of single-axis tracking parabolic trough collectors. The solar field is modular in nature and is composed of many parallel rows of solar collectors aligned on a north-south horizontal axis. A working (heat transfer) fluid is heated as it circulates through the receivers and returns to a series of heat exchangers at a central location where the fluid is used to generate high-pressure superheated steam. The steam is then fed to a conventional steam turbine/generator to produce electricity. After the working fluid passes through the heat exchangers, the cooled fluid is recirculated through the solar field. The plant is usually designed to operate at full rated power using solar energy alone, given sufficient solar energy. However, all plants are hybrid solar/fossil plants that have a fossil-fired capability that can be used to supplement the solar output during periods of low solar energy. The Luz plant is a natural gas hybrid.SOLAR DISHA solar dish/engine system utilizes concentrating solar collectors that track the sun on two axes, concentrating the energy at the focal point of the dish because it is always pointed at the sun. The solar dish's concentration ratio is much higher that the solar trough, typically over 2,000, with a working fluid temperature over 750o C. The power-generating equipment used with a solar dish can be mounted at the focal point of the dish, making it well suited for remote operations or, as with the solar trough, the energy may be collected from a number of installations and converted to electricity at a central point. The engine in a solar dish/engine system converts heat to mechanical power by compressing the working fluid when it is cold, heating the compressed working fluid, and then expanding the fluid through a turbine or with a piston to produce work. The engine is coupled to an electric generator to convert the mechanical power to electric power.SOLAR POWER TOWERA solar power tower or central receiver generates electricity from sunlight by focusing concentrated solar energy on a tower-mounted heat exchanger (receiver). This system uses hundreds to thousands of flat sun-tracking mirrors called heliostats to reflect and concentrate the sun's energy onto a central receiver tower. The energy can be concentrated as much as 1,500times that of the energy coming in from the sun. Energy losses from thermal-energy transport are minimized as solar energy is being directly transferred by reflection from the heliostats to a single receiver, rather than being moved through a transfer medium to one central location, as with parabolic troughs. Power towers must be large to be economical. This is a promising technology for large-scale grid-connected power plants. Though power towers are in the early stages of development compared with parabolic trough technology, a number of test facilities have been constructed around the world.Last Revised: July 2008Sources: Energy Information Administration, Electric Power Annual,Form EIA-860, Annual Electric Generator Report database.中文译文：来自太阳的能源太阳产生能量已有数十亿年，太阳能是太阳辐射到地球的能量。
- 1、下载文档前请自行甄别文档内容的完整性，平台不提供额外的编辑、内容补充、找答案等附加服务。
- 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
- 3、如文档侵犯您的权益，请联系客服反馈,我们会尽快为您处理(人工客服工作时间：9:00-18:30)。
27700
A strong case is made to show that the E-'type color centers in oxide crystals are qualitatively different from the color centers of alkali halides. A semiquantitative discussion is followed by the results of an Y~,-s'elf-consistent-field calculation for the ~-A1203 crys)' tal. An oxygen-ion vacancy in 0.-Alumina is a deep electqon trap, the ground state of which lies between the two valence bands, unlike the Reenter of alkali halides whose ground state lies between the valence and conduction bands. The two electrons in the trap are stabilized by a hole.
C, (i)20& =
pulsive correlation energy between the two electrons on the 0' ion approximately 7 eV. Such a strong repulsion would make the electron pair localized in the vacancy unstable unless a hole is localized in its neighborhood. This suggests that the hole at the top of the valence band could be localized near the oxygen vacancy. In other words, an electron moves from the neighboring oxygen ions into the vacancy, leaving those oxygen ions less than doubly charged. If such stabilization occurs, then the color-center electrons are inherently coupled to the electrons on the neighboring oxygen ions, and a description of the color center should include more than the colorcenter electrons as in the case of alkali-halidePACS numbers:
71.55.Ht, 72.40.+w, 78.50.Ec
ly given by the sum of the Madelung energy and the ionization potential (negative of the atomic electron affinity) of the chlorine ion: — 8 — 0 4. 7. eV= —11.8 eV, i. e. , the site energy is lowered by 4. 0 eV as a result of the presence of the chlorine atom. Therefore, the site energy is raised by 4.0 eV if the chlorine atom is removed, leaving one electron behind and creating an I' center. Since the valence band width of the crystal is approximately 3 eV, one expects the ground state of the color-center electron to be located in the gap between the valence band and conduction band. By a similar argument, the site energy of an electron on an oxygen ion in n-A1, 03 is estimated to be —26+ 5.0 eV= — eV. If the singly charged 21 oxygen ion 0 is removed, leaving an electron behind, the site energy of the electron is losee~ed by 5. 0 eV. Since the highest valence band width is estimated to be approximately 6 eV, one might expect the vacancy-site energy to be below the valence band, forming a deep electron trap; see
"
"
Fig. 1.
Now, let us consider the ground-state electron configuration of the crystals with an anion vacancy with one "color-center electron. " In a NaC1 crystal, the valence band is full and the color-center electron occupies the localized state which lies above the valence band. In a-A1, 03 with one color-center electron the localized state must have two spin-paired electrons since it lies below the top of the valence band, and the highest energy level in the valence band must be singly occupied; i. e. , a hole exists. The difference between the first and second electron affinities of an oxygen atom suggests a strong re-
Q A 1203 is a paradigm of ce ramie oxide mate rials which play increasingly important roles in defects in +high technology. Radiation-induced alumina have received continuing interest over the past two decades. Qf the defects, E-type color centers are relatively simple, yet show various interesting optical properties. ' ' In the past, the tendency has been to try to interpret the observed color-center properties by theoretical models essentially similar to the well-established models of alkali-halide color centers, i. e. , one or two electrons in the field produced by the crystal with one oxygen-ion vacancy. The theoretical work of La, Bartram, and Cox and also of Wilson and Wood' and the assignments by Lee and Crawford' and Evans' of the optical absorption and emission spectra are typical examples. Two basic differences exist between alkalihalide crystals and oxide crystals such as eAl, O, a, nd MgO: (i) Negative halide ions are stable in vacuum while a doubly charged oxygen ion is not; (ii) multiply charged ions in the oxides lead to a relatively large electrostatic potential at the ionic sites. For example, a chlorine atom has an electron affinity of 4. 0 eV while an oxygen atom has first and second electron affinities of 2. 0 eV and — 0 e V, respectively'; the Madelung 5. potentials at the ionic sites in NaCl crystals are 7. 8 and — 8 V for chlorine and sodium ions, 7. while the values at the sites of 0' and Al" in cy36. Al, 0, are calculated to be 26. 5 and — 6 V, re-