图3. 基于PSYCHE的正交相敏2D J_RES谱—RASA2DJ. (a) 脉冲序列，由1D PSYCHE和回波链J采样模块组成.在第一个非选择性π/2脉冲之前适用了一个预饱和(Presat)模块进行水峰抑制.长条形脉冲分别代表π/2和π脉冲，两个带有斜箭头的半圆形代表小翻转角(β < < π/2)的扫频方向相反的脉冲，G₁和G₂是相干选择梯度，G₃是与扫频脉冲配合使用的弱梯度，t₁是间接维演化时间，t₂是直接维采样时间，SW1是t₁对应的谱宽，T是相邻两个π脉冲之间的间隔.(b)以二维相敏谱中的单峰信号为例展示数据相敏处理流程，包括关于F₁'=0轴翻转原始谱图后，将其与原始谱图相加，并将相加后的谱图沿F₂'维进行一维相位校正可得相敏结果(摘自文献[44])

Fig.3. PSYCHE based orthogonal-pattern phase-sensitive J-resolved spectroscopy, RASA2DJ. (a) Pulse sequence diagram constituted of 1D PSYCHE and echo-train J acquisition module. A presaturation (Presat) module is adopted before the first nonselective π/2 pulse for water suppression. Vertical bars indicate nonselective π/2 and π pulses, two semicircle shaped pulses with diagonal arrows are frequency-swept chirp pulses with small flip angle β ≪ π/2, G₁ and G₂ are coherence selection gradients, G₃ is a weak gradient matching with chirp pulses, t₁ is the indirect evolution period and t₂ is the direct acquisition period, SW1 is the spectral width corresponding to t₁, and T is the time interval between two adjacent π pulses. (b) The procedure of phase-sensitive processing is illustrated using a singlet peak in a 2D phase-sensitive spectrum, including preserving an original spectrum and generating an F₁'-reversed spectrum, summing these two spectra, and performing 1D phase correction along the F₂' dimension (Excerpted from Ref. [44])