UC知道英语学的好的来拿分吧！
来源：百度知道 编辑：UC知道 时间：2024/05/17 02:19:27
For the more mathematically inclined, this principle may be expressed symbolically. Suppose that A represents one waveform and B another, both at the same frequency, but shifted 120o from each other in terms of phase. Let's call the 3rd harmonic of each waveform A' and B', respectively. The phase shift between A' and B' is not 120o (that is the phase shift between A and B), but 3 times that, because the A' and B' waveforms alternate three times as fast as A and B. The shift between waveforms is only accurately expressed in terms of phase angle when the same angular velocity is assumed. When relating waveforms of different frequency, the most accurate way to represent phase shift is in terms of time; and the time-shift between A' and B' is equivalent to 120o at a frequency three times lower, or 360o at the frequency of A' and B'. A phase shift of 360o is the same as a phase shift of 0o, which is to say no phase shift at all. Thus, A' and B
为了更多的算术地倾斜, 这法则可能是急速的象征性地. 假如表现一个waveform和B另外的, 两者在一样频率, 但是移动120o从彼此在阶段的学期. 让我们喊声3rd各自的的和谐的waveform A'和B', 分别地. 阶段移动在中间A'和B'是不120o (那是阶段移动在中间和B), 但是3时期那, 广告. 因为A'和B' waveforms交替的三时期同样地紧的同样地和B. 移动在中间waveforms是唯一的精确地急速的在阶段角的学期就在那个时候一样有角的速度是假定的. 就在那个时候关联waveforms不同的频率的, 最多的精确的路到表现阶段移动是在时间的学期; 和时间-移动在中间A'和B'是相等的到120o在频率三时期较低的, 或360o在的频率A'和B'. 的阶段移动360o是与...同样的的阶段移动0o, 哪个是到说没有阶段移动根本. 因而, A'和B'必须是同相地有彼此
的这特征3rd和谐的在三-阶段系统也保存真实的为了的任何的整数多样的3rd和谐的. 因而, 不唯一的是3rd和谐的waveforms各自的基础的的waveform同相地有彼此, 但是因而是6th和声学, 9th和声学, 12th和声学, 15th和声学, 18th和声学, 21st和声学, 等等. 自从唯一的奇数的和声学出现在系统什么地方waveform扭曲是对称的关于centerline --和最多的非线性的载入创造对称的扭曲--平的-有限的的多样的3rd和谐的(6th, 12th, 18th, 等等.) 是一般不有意义的, 离开唯一的奇数的-有限的多样的(3rd, 9th, 21st, 等等.) 到意味深长地捐献中性的当前的.
哦呵呵呵呵太长了。