转子作为魔角旋转(MAS)探头一个至关重要的部件,是固体样品高速旋转的载体,被广泛应用于各种固体核磁共振(NMR)实验.但国内关于MAS转子的研究极少,以至其长期被国外市场垄断.本文通过对MAS转子的深入研究,设计了常规的4 mm MAS转子;并对MAS转子进行了流固耦合仿真,分析其应力应变大小;同时进行了模态仿真,确定了MAS转子的各阶振型及临界转速;最后制作了转子,进行了转速测试和固体NMR实验.结果表明,本文设计和制作的转子能在14 kHz转速下正常运行,并在4 kHz及12.5 kHz转速下采集了金刚烷标样的1H NMR信号,结果表明该转子能满足常规固体NMR实验的需求.
王佳鑫
,
冯继文
,
陈俊飞
,
王立英
,
刘朝阳
. 魔角旋转固体核磁共振探头中转子的研制[J]. 波谱学杂志, 2019
, 36(4)
: 446
-455
.
DOI: 10.11938/cjmr20192735
Magic-angle spinning (MAS) rotor, a device for high-speed spinning of solid samples, is an essential component of the probes used in solid-state nuclear magnetic resonance (NMR) experiments. In this study, a 4 mm MAS rotor was designed and fabricated in-house. Fluid-solid coupling simulation was carried out to compute the stress and strain in the MAS rotor. Modal analysis was performed to determine the various modes and critical speeds of the MAS rotor. Actual spinning speed test and MAS NMR sampling were carried out to test the performance of the rotor. The results showed that the MAS rotor built in-house could operate normally at a spinning speed up to 14 kHz. The 1H NMR signals of adamantane collected at 4 kHz and 12.5 kHz were collected and compared. These results demonstrated that the 4 mm MAS rotor built in-house could meet the requirements of conventional solid-state NMR experiments.
[1] BLOCH F, HANSEN W W, PACKARD M. The nuclear induction experiment[J]. Phys Rev, 1946, 70(7/8):474-485.
[2] PURCELL E M. Resonance absorption by nuclear magnetic movements in a solid[J]. Phys Rev, 1946, 69(1/2):37-38.
[3] ZHANG M L, SHI Q W, GU Y C. Journal of Hebei Medical University, 2006, 27(4):314-317. 张嫚丽, 史清文, 顾玉诚. 核磁共振技术及其在天然产物结构鉴定中的应用[J]. 河北医科大学学报, 2006, 27(4):314-317.
[4] YE C H. Magic angle spinning NMR spectroscopy[J]. Chinese J Magn Reson, 1984, 1(4):415-454. 叶朝辉. 魔角旋转核磁共振波谱学[J]. 波谱学杂志, 1984, 1(4):415-454.
[5] YE C H, LI L Y, SUN B Q. High resolution mas NMR of solids by a routine spectrometer for liquids[J]. Chinese J Magn Reson, 1985, 2(3):227-236. 叶朝辉, 李丽云, 孙伯勤. 常规液体谱仪的魔角旋转固体高分辨NMR[J]. 波谱学杂志, 1985, 2(3):227-236.
[6] 邓惠文. 高分辨魔角旋转核磁共振技术在离体生物组织代谢研究中的应用[D]. 上海:华东师范大学, 2006.
[7] YANG Y, SUN X Q, GU L L, et al. Advances in the application of high-resolution magic-angle spinning NMR spectroscopy[J]. Chemical World, 2009, 50(5):308-311. 杨扬, 孙小强, 谷丽丽, 等. 高分辨率魔角旋转核磁共振技术的应用进展[J]. 化学世界, 2009, 50(5):308-311.
[8] 杨小平, 薛志元, 戴林森. 固体NMR魔角旋转转子的研制[C]//第六届全国波谱学学术会议论文摘要集. 1990.
[9] YANG B L, HU H B, ZHOU J W, et al. DNP CP/MAS probe design and discussion of DNP experimental technique[J]. Chinese J Magn Reson, 1996(2):183-190. 杨保联, 胡红兵, 周建威, 等. 固体高分辨DNPCP/MAS探头的研制及DNP实验技术的探讨[J]. 波谱学杂志, 1996(2):183-190.
[10] JIANG Y J, WOOLFENDEN W R, ALDERMAN D W, et al. Efficient stator/rotor assembly for magic-angle spinning NMR[J]. Rev Sci Instrum, 1987, 58(5):755.
[11] 冯兴令. 高速精密气浮气动主轴的设计与研究[D]. 长沙:湖南大学, 2012.
[12] CUI H L, YUE X B, LEI D J, et al. Study on radial characteristics of aerostatic bearing based on ANSYS workbench[J]. Lubrication Engineering, 2014, 39(10):100-103. 崔海龙, 岳晓斌, 雷大江, 等. 基于ANSYS Workbench的气体静压轴承径向特性分析[J]. 润滑与密封, 2014, 39(10):100-103.
[13] 吴利杰. 超高速空气静压电主轴动态性能流固耦合分析[D]. 广州:广东工业大学, 2014.
[14] LU S Y, LIU Q, YAO J H, et al. Modal analysis of aerostatic spindle based on ANSYS[J]. Machinery, 2017, 44(4):19-22, 80. 卢诗毅, 刘强, 姚建华, 等. 基于有限元气体静压主轴模态分析[J]. 机械, 2017, 44(4):19-22, 80.
[15] HU J Z, HU M Y, TOWNSEND M R, et al. High-pressure, high-temperature magic angle spinning nuclear magnetic resonance devices and processes for making and using same:US, 0044598[P]. 2014-02-13.
[16] LEE J N, ALDERMAN D W, JIN J Y, et al. Cylindrical spinner and speed controller for magic angle spinning nuclear magnetic resonance[J]. Rev Sci Instrum, 1984, 55(4):516-520.