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ideal2007

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[求助] 求助NMR高手帮翻译几个单词及短句

就是下面带红色的单词或短句，有些拿不准什么意思，把整句列出来是为了显示整个语境，请高手指点下，不会花许多时间的。

1. Each nuclide has 2I+ 1 energy levels, characterized by a quantum number m, with values I, I −1, I −2, . . . , −I. In absence of the magnetic field, these energy levels have the same energy (they are degenerate), but the degeneracy lift under a magnetic field interaction between them and the field.

2. One of the main problems in obtaining the NMR spectra of solids is that there are a number of phenomena inducing a range of magnetic field strengths at individual nuclei of the same nuclide in a sample, which causes broad peaks. These phenomena include
(a) interaction of dipole moments of individual nuclei (dipole-dipole interaction),
(b) anisotropy of the electronic shielding at individual sites (chemical shift anisotropy), and
(c) interaction of the quadrupole moment of a nuclide with I ≥ 1 with the electric field gradient at the nucleus

3.Quadrupole effects cause peak broadening, displacement of the peak from the isotropic (true) chemical shift, and distortion of the peak shape. 移动？？

4. In general, the following properties of the MAS spectra could be defined:……
(d) increasing inhomogeneous broadening （增加不均匀加宽？）reduces the sharpness of the singularity. （锐度？？）

5. Under MAS conditions, the peak is narrowed about a factor of 3, the isotropic chemical shift is at the left edge （左边缘？？）of the peak, and the center of gravity is displaced （转移？？）to the right of the isotropic chemical shift.

6. As （因为？当……时）the NMR frequencies are all in the radio frequency range, NMR spectrometers are computer operated radio （无线电？射电？还是应该翻译成电磁波？）transmitting and receiving systems controlled by a computer.

7. The attainable spinning speed depends on the gas pressure and the uniformity （均匀度？？）of the sample packing in the rotor.

8. After these pulses, the sample begins to emit a radio frequency signal at a resonance frequency as the spin system （旋转系统？？自旋系统？？）dephases (t2 relaxation time).

9. A difficulty in using NMR spectroscopy, especially for many natural samples, is that paramagnetic components or impurities (most commonly Fe or Mn) cause an extensive peak broadening. This broadening is due to a range of（一系列？？） chemical shifts caused by magnetic field non-homogeneity due to the interaction of unpaired d- or f-electrons within the applied magnetic field.

10. In the high-temperature spectra, where the solvent as well as the dissolved investigated substance are solely ionic in character, an extremely fast mutual exchange of nuclei takes place.

11. The reported 19F spectra were corrected for a broad probe-head signal due to the presence of Teflon in the probe assembly.

12. Their 27Al chemical shifts range between −13 and −1.4 ppm and are typically more shielded than the AlO6 octahedrons in oxide compounds.

13. Magnetically active samples using the NMR determinable atomic nuclei are only those, having a nonzero atomic spin.

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