今天我发现网上有人问了关于SRIM那本书的问题,原来参数看起来不一样的原因是SRIM书上的单位是厘米-克-秒单位制(centimetre-gram-second system,CGS),而不是现在比较常用的国际单位制(Système International d’Unités(French),SI),那么就让我记一下有关的笔记吧。
Quantity | Quantity symbol | CGS unit name | Unit symbol | Unit definition | In coherent SI units |
---|---|---|---|---|---|
length, position | centimetre | cm | 1/100 of metre | ||
mass | gram | g | 1/1000 of kilogram | ||
time | second | s | 1 second | 1 s | |
velocity | centimetre per second | cm/s | cm/s | ||
acceleration | gal | Gal | cm/ | ||
force | dyne | dyn | g⋅cm/ | ||
energy | erg | erg | g⋅ | ||
power | erg per second | erg/s | g⋅ | ||
pressure | barye | Ba | g/(cm⋅ | ||
dynamic viscosity | poise | P | g/(cm⋅s) | ||
kinematic viscosity | stokes | St | |||
wavenumber | kayser (K) | 100 |
Quantity | Symbol | SI unit | ESU unit | Gaussian unit | EMU unit |
---|---|---|---|---|---|
electric charge | 1 C | ≘ ( | ≘ ( | ≘ ( | |
electric flux | 1 V⋅m | ≘ (4π × | ≘ (4π × | ≘ ( | |
electric current | 1 A | ≘ ( | ≘ ( | ≘ ( | |
electric potential / voltage | 1 V | ≘ ( | ≘ ( | ≘ ( | |
electric field | 1 V/m | ≘ ( | ≘ ( | ≘ ( | |
electric displacement field | 1 C/ | ≘ ( | ≘ ( | ≘ ( | |
electric dipole moment | 1 C⋅m | ≘ (10 | ≘ (10 | ≘ (10) abC⋅cm | |
magnetic dipole moment | 1 A⋅ | ≘ ( | ≘ ( | ≘ ( | |
magnetic B field | 1 T | ≘ ( | ≘ ( | ≘ ( | |
magnetic H field | 1 A/m | ≘ (4π × | ≘ (4π × | ≘ (4π × | |
magnetic flux | 1 Wb | ≘ ( | ≘ ( | ≘ ( | |
resistance | 1 Ω | ≘ ( | ≘ ( | ≘ ( | |
resistivity | 1 Ω⋅m | ≘ ( | ≘ ( | ≘ ( | |
capacitance | 1 F | ≘ ( | ≘ ( | ≘ ( | |
inductance | 1 H | ≘ ( | ≘ ( | ≘ ( |
对于公式
其中,玻尔半径
即在CGS单位制下有:
该问题下,有人给出了:
唔,看起来和国际单位制的变换还是有些不一样的,让我们一步步地看看:
由于CSG(或者说CSG中,ESU)单位制中电压单位(statV)关于SI单位制的电压单位(V)有:
由于
将上面的全部代入式子即得结果。