清华大学：《生物核磁共振波谱学》课程教学资源（PPT课件，英文版）4 NMR EXPERIMENTS

/到 生物核磁共振波谱学 NMR in Biological Science 4 NMR EXPERIMENTS THNMR AN

生物核磁共振波谱学 NMR in Biological Science 4. NMR EXPERIMENTS THNMR YAN

41 NMR HARDWARE Hardware Overview Magnet Field Lock Shim coils Sample Probe RE CoIlS Gradient coils Qadrature Detector Digital Filtering Safety THNMR AN

4.1 NMR HARDWARE Hardware Overview Magnet Field Lock Shim Coils Sample Probe RF Coils Gradient Coils Qadrature Detector * Digital Filtering * Safety THNMR YAN

脉冲傅立叶变换核磁共振谱仪 plotto A-D Convertor Pulse programmer RF Transmitter Sample and Amplifier Preamplifier ample THNMR YAN

plotter Computer Pulse Programmer A-D Convertor Audio Filter Detector Conversion to Audio Signal RF Transmitter and Amplifier Preamplifier 脉冲傅立叶变换核磁共振谱仪 To Sample From Sample Magnet Probe THNMR YAN

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v▲|Ni VARIAN :2 THNMR YAN

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脉冲傅立叶变换核磁共振谱仪 Normal rf pulses are square shaped (in the time domain), their excitation profile(in the quare Sinc frequency domain) is given by A for(0<t<T) A[sin(ot)/(ot)] ts fourier transform. the sinc function(approximation forβ180°) he excitation band width is proportional to the reciprocal of the pulse duration, pulses V(HZ must be short enough to keep the wiggles outside the range of interest. THNMR YAN

THNMR YAN 脉冲傅立叶变换核磁共振谱仪 Normal rf pulses are square shaped (in the time domain), their excitation profile (in the frequency domain) is given by its FOURIER transform, the sinc function (approximation for b«180°). The excitation band width is proportional to the reciprocal of the pulse duration, pulses must be short enough to keep the "wiggles" outside the range of interest

Magnet Most magnets are of the superconducting type N2 reservoir Vacuum He Reservoir Vacuum sUperconducting Solenoid Liquid Helium Liquid Nitrogen Container Support Superconducting Coil 2 THNMR YAN

Magnet Most magnets are of the superconducting type. THNMR YAN

Why Magnet is so Important Boltzmann statistics N/N+=e-E/kT=e-y B/kT For 300 K one gets for H a population difference n--N of B △N 1.4T 60 MHZ 9.9·10 117T500MHZ 77·10 THNMR AN

Why Magnet is so Important Boltzmann Statistics N- /N+ = e-E/kT = e-gB/kT . For 300 K one gets for 1H a population difference N- -N+ of B w DN 1.4T 60 MHz 9.9·10-6 11.7T 500 MHz 77 ·10-6 THNMR YAN

Why Magnet is so Important 费 Resolution~B 豪 Sensitivity~(B0)32 豪 Allignment~(B1)2 e Relaxation (complex)

Why Magnet is so Important  Resolution ~ B0  Sensitivity ~ (B0 ) 3/2  Allignment ~ (B0 ) 2  Relaxation ~ (complex)

400 MHz Nuclei (ppm) A 1.89 62.1 2.0 1.9 B 2.00 2.0 100 MHz Interaction J (Hz AB BC 2.1 2.0 9 2 THNMR YAN

THNMR YAN Nuclei (ppm) A 1.89 B 2.00 C 2.08 Interaction J (Hz) AB 4 BC 8