论文标题
使用udeft（均匀驱动的平衡傅立叶变换）对$ {}^{29} $ si NMR实验的提高灵敏度和量化
Improved sensitivity and quantification for ${}^{29}$Si NMR experiments on solids using UDEFT (Uniform Driven Equilibrium Fourier Transform)
论文作者
论文摘要
我们证明了使用Udeft（均匀驱动平衡傅立叶变换）技术的可能性，以提高一维$ {}^{29} $ si NMR实验的灵敏度和量化魔法旋转（MAS）。我们得出UDEFT和单脉冲（SP）实验的信噪比的分析表达，从而累积了瞬态和稳态状态的贡献。 Using numerical spin dynamics simulations and experiments on ${}^{29}$Si-enriched amorphous silica and borosilicate glass, we show that 59${}_{180}$298${}_{0}$59${}_{180}$ refocusing composite $π$-pulse and the adiabatic使用TANH/TAN调制的反演提高了UDEFT技术的鲁棒性，对RF感染，偏移和化学移动各向异性。这些脉冲与两步相循环结合限制了脉冲缺陷和刺激回声产生的伪影。 SP，UDEFT和CPMG（Carr-Purcell Meiboom-Gill）技术的灵敏度在实验化和非官能化介孔二氧化硅上进行了比较。此外，对火焰材料的实验证明，Udeft技术可以更好地量化$ {}^{29} $ SI位点，其灵敏度比SP方法更高。
We demonstrate the possibility to use UDEFT (Uniform Driven Equilibrium Fourier Transform) technique in order to improve the sensitivity and the quantification of one-dimensional ${}^{29}$Si NMR experiments under Magic-Angle Spinning (MAS). We derive an analytical expression of the signal-to-noise ratios of UDEFT and single-pulse (SP) experiments subsuming the contributions of transient and steady-state regimes. Using numerical spin dynamics simulations and experiments on ${}^{29}$Si-enriched amorphous silica and borosilicate glass, we show that 59${}_{180}$298${}_{0}$59${}_{180}$ refocusing composite $π$-pulse and the adiabatic inversion using tanh/tan modulation improve the robustness of UDEFT technique to rf-inhomogeneity, offset, and chemical shift anisotropy. These pulses combined with a two-step phase cycling limit the pulse imperfections and the artifacts produced by stimulated echoes. The sensitivity of SP, UDEFT and CPMG (Carr-Purcell Meiboom-Gill) techniques are compared experimentally on functionalized and non-functionalized mesoporous silica. Furthermore, experiments on a flame retardant material prove that UDEFT technique provides a better quantification of ${}^{29}$Si sites with higher sensitivity than SP method.
