“free oscillations”的概念、定义、翻译、参考文献-科学参考

free oscillations

Electronics and Electrical Engineering

Oscillations arising in a circuit under the influence of internal forces, such as a capacitor discharging through a resistance and inductance, or of a constant external force, such as a direct voltage. Both these conditions are analogous to a mechanical vibrating system being displaced from the neutral point.
The oscillations decay gradually, depending on the amount of damping in the circuit, with a frequency, f, termed the natural frequency; this is approximately equal to (LC)^–2, where L is the inductance and C is the capacitance, when the resistance R in the circuit is small (see diagram). The amplitude of the current is given by
$i = A e^{- (\frac{R}{2 L}) t} sin ω t$
where the angular frequency ω is equal to 2πf, and A is a constant determined by the initial conditions. The maxima of successive oscillations lie on the curve
$i = A e^{- (\frac{R}{2 L}) t}$
and the amplitudes (i_m, i_m+1) of successive maxima of the same sign decrease by a constant ratio. It can be shown that
${log}_{e} (\frac{i_{m}}{i_{m + 1}}) = \frac{π}{Q}$
where Q, the Q factor of the circuit, is given by
$Q^{2} = \frac{L}{R^{2} C}$
Compare forced oscillations.
Decay of free oscillations

Geology and Earth Sciences

The harmonics at which any body, e.g. the Earth, tends to vibrate most freely, i.e. resonates. There are two fundamental types: torsional (vibration with motions perpendicular to the Earth’s radius); and spheroidal (vibrations that are both radial and tangential to the Earth’s surface). The study of such resonances, e.g. those induced by major earthquakes, provides information on the internal nature of the Earth. A major earthquake can make the entire globe vibrate or ring like a bell, and some earthquakes have been so large that sensitive seismometers have continued to record the oscillations for weeks after the event. The decay of the vibrations gives valuable information about the elastic layering of the Earth, and especially of the low-velocity zone. Moonquakes produce similar phenomena.

单词	free oscillations
释义	free oscillations Electronics and Electrical Engineering Oscillations arising in a circuit under the influence of internal forces, such as a capacitor discharging through a resistance and inductance, or of a constant external force, such as a direct voltage. Both these conditions are analogous to a mechanical vibrating system being displaced from the neutral point. The oscillations decay gradually, depending on the amount of damping in the circuit, with a frequency, f, termed the natural frequency; this is approximately equal to (LC)^–2, where L is the inductance and C is the capacitance, when the resistance R in the circuit is small (see diagram). The amplitude of the current is given by $i = A e^{- (\frac{R}{2 L}) t} sin ω t$ where the angular frequency ω is equal to 2πf, and A is a constant determined by the initial conditions. The maxima of successive oscillations lie on the curve $i = A e^{- (\frac{R}{2 L}) t}$ and the amplitudes (i_m, i_m+1) of successive maxima of the same sign decrease by a constant ratio. It can be shown that ${log}_{e} (\frac{i_{m}}{i_{m + 1}}) = \frac{π}{Q}$ where Q, the Q factor of the circuit, is given by $Q^{2} = \frac{L}{R^{2} C}$ Compare forced oscillations. Decay of free oscillations Geology and Earth Sciences The harmonics at which any body, e.g. the Earth, tends to vibrate most freely, i.e. resonates. There are two fundamental types: torsional (vibration with motions perpendicular to the Earth’s radius); and spheroidal (vibrations that are both radial and tangential to the Earth’s surface). The study of such resonances, e.g. those induced by major earthquakes, provides information on the internal nature of the Earth. A major earthquake can make the entire globe vibrate or ring like a bell, and some earthquakes have been so large that sensitive seismometers have continued to record the oscillations for weeks after the event. The decay of the vibrations gives valuable information about the elastic layering of the Earth, and especially of the low-velocity zone. Moonquakes produce similar phenomena.
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