专业英语第二讲.ppt

Physics of Semiconductor Devices (双语) 李聪 Email:cong.li@mail.xidian.edu.cn Tel:801 Add: 老校区新科技楼503室 3、结合专业内容 The associated delay times are found by dividing the charge that must be moved by the current that moves it. 提示：根据物理含义分析，“by the current”应该是修饰动名词dividing（表示数学运算中的“除”），表示用……来除“the charge”。如果从语法角度分析，可以认为“by the current”修饰直接位于其前面的moved，但是如果这样翻译成汉语，尽管不应该说语法错误，但是物理含义不对；句子两个that均是引导定语从句，分别修饰各自前面的名词charge和current。 全句可翻译为：用必须被移开的电荷除以用于移动电荷的电流，就得到相应的延迟时间。 3、结合专业内容 When passing current all devices have been found to have low-frequency noise power in excess of the value predicted by 4kTRdf. 提示：“by 4kTRdf”修饰“predicted”表示预计值为4kTRdf，而不是修饰“in excess of”表示超过的大小为4kTRdf。如果仅仅从英语语法考虑，上述两种修饰关系均有可能。但是结合物理含义分析，只能理解为修饰“predicted”，否则翻译出的语句出现物理含义错误。 全句可翻译为：业已发现，在有电流通过时，所有器件都具有比预计值4kTRdf大的低频噪声功率。 课堂作业 (P130，中文P94) We can determine the relative number of electrons in the donor state compared with the total number of electrons; therefore we can consider the ratio of electrons in the donor state to the total number of electrons in the conduction band plus (electrons in the) donor state. Using the expressions of Equations (4.53) and (4.11), we write ………………………………………….. (4.54) The Fermi energy cancels out of this expression. Dividing by the numerator term, we obtain …………………………………………….(4.55) (P134，中文P97) ………………………………………….. (4.60) The positive sign in the quadratic formula must be used, since, in the limit of an intrinsic semiconductor when Na = Nd = 0, the electron concentration must he a positive quantity, or n0 = n i . (P139，中文P100) However, we would be subtracting two numbers on the order of 1016 cm-3, for example, to obtain a number on the order of 104 cm-3, which from a practical point of view is not possible. 专业词汇 Doner state：施主态，施主能级（不是“失主”） Fermi energy：费米能级； Numerator term：分子项； Positive sign：正号 Quadratic formula：二次方程； Concentration：浓度； Positive quantity：正值； 分句解释 We can determine the