在高极化自旋体系中由于强辐射阻尼效应的影响,常规的纵向弛豫时间(T1)测量方法不再适用或需修改.本文提出了高极化自旋体系T1的分子间多量子相干测量方法.通过相干脉冲梯度场抑制演化期的辐射阻尼效应,利用分子间多量子相干信号的性质消除检测期的辐射阻尼效应,在绝对值谱模式下对谱峰峰高拟合,准确计算出T1.在此基础上,分析和比较了分子间多量子相干法与饱和恢复法对辐射阻尼效应的抑制作用.实验结果表明,分子间多量子相干方法能有效地抑制辐射阻尼效应,准确测量高极化自旋体系纵向弛豫时间.Strong radiation damping effects in highly polarized system often make the common methods of longitudinal relaxation time determination invalid.A method utilizing intermolecular multiple-quantum coherences is proposed and discussed.For comparison,the saturation recovery method is also revisited.It is shown that intermolecular multiple-quantum coherences method can effectively suppress the effects of radiation damping in evolving and detecting periods and exactly calculate the longitudinal relaxation time of highly polarized system.国家自然科学基金(20573084,10575085);; 中国博士后科学基金资
