# 编者信息 熊荣川 明湖实验室 xiongrongchuan@126.com http://blog.sciencenet.cn/u/Bearjazz These theoretical expectations are only partially consistent with the limited data that we have on gene duplication. First, comparative studies of nucleotide sequences suggest that although both copies of a gene may often accumulate degenerative mutations at an accelerated rate following a duplication event, selection may not be relaxed completely (14– 16). Second, the frequency of duplicate-gene preservation following ancient polyploidization events, often suggested to be in the neighborhood of 30 to 50% over periods of tens to hundreds of millions of years (17–20), is unexpectedly high. 这些理论假设只是部分地与我们在基因复制方面的有限数据相一致。首先，对核苷酸序列的比较研究表明，尽管一个基因的两个拷贝在重复事件发生后往往会加速积累退行性突变，但选择压力可能不会完全放松（ 14-16 ）。第二，在古代多倍体化事件之后，在几千万到数亿年（ 17-20 年）的时间里，重复基因的保存频率出人意料地高，通常被认为大约在 30% 到 50% 。 Lynch, M. The Evolutionary Fate and Consequences of Duplicate Genes . Science, 2000, 290(5494):1151-1155.
1.角频率（rad/s）和频率(Hz) 维基百科： https://en.wikipedia.org/wiki/Radian_per_second Angular frequency ω (Ordinary) frequency {\\displaystyle \\nu =\\omega /{2\\pi }} 2π radians per second exactly 1 hertz (Hz) 1 radian per second approximately 0.159155Hz 1 radian per second approximately 57.29578 degrees per second 1 radian per second approximately 9.5493 revolutions per minute (rpm) 0.1047 radians per second approximately 1rpm An angular frequency, ω = 1rad/s , corresponds to an ordinary frequency, ν = 1/(2π)Hz ≈ 0.159Hz 1 rad = 1/(2 π ) 2. 波数定义 维基百科： https://en.wikipedia.org/wiki/Wavenumber Wavenumber, as used in spectroscopy and most chemistry fields, is defined as the number of wavelengths per unit distance, typically centimeters (cm −1 ): {\\displaystyle {\\tilde {\\nu }}\\;=\\;{\\frac {1}{\\lambda }}} , where λ is the wavelength. It is sometimes called the spectroscopic wavenumber. In theoretical physics, a wave number defined as the number of radians per unit distance, sometimes called the angular wavenumber, is more often used: {\\displaystyle k\\;=\\;{\\frac {2\\pi }{\\lambda }}} When wavenumber is represented by the symbol ν , a frequency is still being represented, albeit indirectly. As described in the spectroscopy section, this is done through the relationship {\\displaystyle {\\frac {\\nu _{s}}{c}}\\;=\\;{\\frac {1}{\\lambda }}\\;\\equiv \\;{\\tilde {\\nu }}} , where ν s is a frequency in hertz . This is done for convenience as frequencies tend to be very large. It has dimensions of reciprocal length , so its SI unit is the reciprocal of meters (m −1 ). In spectroscopy it is usual to give wavenumbers in cgs unit (i.e., reciprocal centimeters; cm −1 ); in this context, the wavenumber was formerly called the Kayser , after Heinrich Kayser (some older scientific papers used this unit, abbreviated as K , where 1 K = 1 cm −1 ). The angular wavenumber may be expressed in radians per meter (rad·m −1 ), or as above, since the radian is dimensionless . For electromagnetic radiation in vacuum, wavenumber is proportional to frequency and to photon energy. Because of this, wavenumbers are used as a unit of energy in spectroscopy.
之前一直疑惑我计算的声子谱纵坐标是什么，别人的是频率单位，我的数值和别人不一样，看文献还有人用波矢的单位（cm-1），现在终于搞懂了，分享给大家！ 转载自新浪博客： 点击可以查看更多信息。 http://blog.sina.com.cn/s/blog_5f15ead20100cwwo.html Magnitude Unit name MKS value mass Kg 1.E0 mass g 1.E-3 mass amu 1.66054E-27 length m 1.E0 length cm 1.E-2 length nm 1.E-9 length Ang 1.E-10 length Bohr 0.529177E-10 time s 1.E0 time fs 1.E-15 time ps 1.E-12 time ns 1.E-9 energy J 1.E0 energy erg 1.E-7 energy eV 1.60219E-19 energy meV 1.60219E-22 energy Ry 2.17991E-18 energy mRy 2.17991E-21 energy Hartree 4.35982E-18 energy K 1.38066E-23 energy kcal/mol 6.94780E-21 energy mHartree 4.35982E-21 energy kJ/mol 1.6606E-21 energy Hz 6.6262E-34 energy THz 6.6262E-22 energy cm-1 1.986E-23 energy cm**-1 1.986E-23 energy cm-1 1.986E-23 force N 1.E0 force eV/Ang 1.60219E-9 force Ry/Bohr 4.11943E-8 Magnitude Unit name MKS value pressure Pa 1.E0 pressure MPa 1.E6 pressure GPa 1.E9 pressure atm 1.01325E5 pressure bar 1.E5 pressure Kbar 1.E8 pressure Mbar 1.E11 pressure Ry/Bohr**3 1.47108E13 pressure eV/Ang**3 1.60219E11 charge C 1.E0 charge e 1.602177E-19 dipole C*m 1.E0 dipole D 3.33564E-30 dipole debye 3.33564E-30 dipole e*Bohr 8.47835E-30 dipole e*Ang 1.602177E-29 MomInert Kg*m**2 1.E0 MomInert Ry*fs**2 2.17991E-48 Efield V/m 1.E0 Efield V/nm 1.E9 Efield V/Ang 1.E10 Efield V/Bohr 1.8897268E10 Efield Ry/Bohr/e 2.5711273E11 Efield Har/Bohr/e 5.1422546E11 angle deg 1.d0 angle rad 5.72957795E1 torque eV/deg 1.E0 torque eV/rad 1.745533E-2 torque Ry/deg 13.6058E0 torque Ry/rad 0.237466E0 torque meV/deg 1.E-3 torque meV/rad 1.745533E-5 torque mRy/deg 13.6058E-3 torque mRy/rad 0.237466E-3
之前一直疑惑我计算的声子谱纵坐标是什么，别人的是频率单位，我的数值和别人不一样，看文献还有人用波矢的单位（cm-1），现在终于搞懂了，分享给大家！ 转载自新浪博客： http://blog.sina.com.cn/s/blog_5f15ead20100cwwo.html，点击可以查看更多信息。 Magnitude Unit name MKS value mass Kg 1.E0 mass g 1.E-3 mass amu 1.66054E-27 length m 1.E0 length cm 1.E-2 length nm 1.E-9 length Ang 1.E-10 length Bohr 0.529177E-10 time s 1.E0 time fs 1.E-15 time ps 1.E-12 time ns 1.E-9 energy J 1.E0 energy erg 1.E-7 energy eV 1.60219E-19 energy meV 1.60219E-22 energy Ry 2.17991E-18 energy mRy 2.17991E-21 energy Hartree 4.35982E-18 energy K 1.38066E-23 energy kcal/mol 6.94780E-21 energy mHartree 4.35982E-21 energy kJ/mol 1.6606E-21 energy Hz 6.6262E-34 energy THz 6.6262E-22 energy cm-1 1.986E-23 energy cm**-1 1.986E-23 energy cm-1 1.986E-23 force N 1.E0 force eV/Ang 1.60219E-9 force Ry/Bohr 4.11943E-8 Magnitude Unit name MKS value pressure Pa 1.E0 pressure MPa 1.E6 pressure GPa 1.E9 pressure atm 1.01325E5 pressure bar 1.E5 pressure Kbar 1.E8 pressure Mbar 1.E11 pressure Ry/Bohr**3 1.47108E13 pressure eV/Ang**3 1.60219E11 charge C 1.E0 charge e 1.602177E-19 dipole C*m 1.E0 dipole D 3.33564E-30 dipole debye 3.33564E-30 dipole e*Bohr 8.47835E-30 dipole e*Ang 1.602177E-29 MomInert Kg*m**2 1.E0 MomInert Ry*fs**2 2.17991E-48 Efield V/m 1.E0 Efield V/nm 1.E9 Efield V/Ang 1.E10 Efield V/Bohr 1.8897268E10 Efield Ry/Bohr/e 2.5711273E11 Efield Har/Bohr/e 5.1422546E11 angle deg 1.d0 angle rad 5.72957795E1 torque eV/deg 1.E0 torque eV/rad 1.745533E-2 torque Ry/deg 13.6058E0 torque Ry/rad 0.237466E0 torque meV/deg 1.E-3 torque meV/rad 1.745533E-5 torque mRy/deg 13.6058E-3 torque mRy/rad 0.237466E-3
标签: 频率
