The experimental technique,spectrum analysis and results obtained in our laboratory about NO free radicals bound to hemoglobin and gencrated from ischcemia-reperfusion rat kidney, heart in vitro and in vivo and polymorphonuclear luekocytes studied with low temperature ESR and spin traping technique were summerized.

The work will confirm that ¹³C CP/MAS spectral editing at high magnetic field can be achieved by combining the standard series of editing pulse sequences with the TOSS pulse sequence which is used to suppress sidebands. The great spin-lattice relaxation time difference is used as an additional criterion to distinguish nonpronated carbons and methyl carbons in solid. The examples in this paper will show that a general ¹³C CP/MAS spectral editing can be derived from the proper combination of SCPTOSS, SCPPITOSS, LCPDTOSS and a partially relaxed LCPDTOSS spectrum.

The structure of the dry chitosan membranes crosslinked by sulfuric acid at different concentrations was investigated by ¹³C CP MAS NMR method. The results show that the crosslinking situation of the membrane can be reflected directly by the molecular conformation of the sulfate chitosan, and has a close relationship with the permeation selectivity of the membrane. We have also found that, for some types of membranes, it is not sufficient to study the membrane only in dry state.

In this paper, several swollen sulfate chitosan membranes were investigate by ¹³C CP MAS NMR method for the first time. The results indicate that the molecular conformation and motion of the swollen membrane can quite comprehensively reflect the permeation selectivity. From ¹³C CP MAS NMR spectra of the membrane with different degrees of swelling, the crosslinking strength was observed. The membrane with weak crosslinking has the poor separation ability. From T₁ values of the swollen membrane, it has found that the too fast or slow molecular motion isn't favrable to the permeation selectivity, and there is an appropriate motion rate at which the best permeation selectivity can be approached.

Very recently, Frydman et al. have shown that the combined use of MAS and two-dimensional multiple-quantum (MQ) spectroscopy can refocus the second-order anisotropic effects of half-in-teger quadrupoles. The present paper discusses theoretical aspect of this novel 2D MQ MAS method through evaluating the propagation of density matrices evolving under the effects of noncommuting time-dependent Hamiltonians. The influence of radiofrequency pulse excitation and conversion on the intensities in the spectra is analyzed and the conditions that maximize the MQ MAS signal for a spin-3/2 are obtained. Numerical simulation of the 2D experimental spectrum of ²³Na of Na₂C₂O₄ shows that the quadrupolar coupling parameters and the isotropic chemical shift can be determined.

NMR is an unique technique to study protein's three dimentional structure in solution. In this paper, the way of refinement of the three dimensional structure was discussed, in which the structure was calculated initially by metric matrix distance geometry. The refining process is divided into three steps, in which different treatments was applied. For protein with molecular weight 8000, Our approach is efficient to obtain the structure and conformation of protein with low energy and less geometry contraint violations.

¹H NMR of four new kinds of azole compounds containing sillcon were investigated, they are 1-trimethylisilicoNO_xy-1-aromatic-2-azole-ethane (Ⅰ:1, 2, 4-triazole; Ⅱ:imidazole; Ⅲ:benzotrizzole;Ⅳ:benzomidazole). The aromatic (R₁) group has no obvious influence on δ_H of Me₃SiO; the δ_H of Me₃SiO were affected by shielding effect of different azole groups (R), the order is:

The result has been proved by Molecular Mechanics Calculation.
An good linear relationship between δ_H of CH and σ_p was obtained for compound Ⅰ.

Changes of phosphates related to energetic metabolism such as PCr, Pi, ATP in C57 mouse brain in hypoxia were observed noninvasively by ³¹P in vivo NMR method. When the content of oxygen was reduced to 5%, the concentrations of PCr, ATP decreased while Pi increased, pH of brain cell decreased to 6.83~6.93. Mice were reoxygenated when the ratio of peak heights of Pi to PCr were about 1.Those that the ratio of pi after and before reoxygenation were larger than 1 and pH in reoxygenation increased immediately, could be recovered, otherwise couldn't be recovered. The results showed that Pi and pH reflect the degree of brain damage in hypoxia.

Protonation is one of the major factors for poly(aryl ether ketone)_s (PAED_s) molecules polarized in H₂SO₄. Results from UV and calculation show that degree of polarization of PAEK_s by H₂SO₄ increases with the ketone content or molecular chain regidity in polymer chains. This has been further proved by the experimental results, such as, larger λ_max (UV), more intense absorption at λ_max and greater deviatiou between experimental and practical viscosity values in concentrated H₂SO₄ than in other solvents. Based on these, we firstly suggested that the molecular rigidity is an important factor tobe considered in measuring the PAEK_s molecularweights. While, ¹⁹F NMR is adopted to quantitatively measure the molecular weight of many synthesized oligomers aud polymers, which gives a number-average molecular weights without any correction.

According to the WBR theory and using "developed matrix computation method", the authors computed the exteuded Solomon equations under RF irradiation and compared those equations with Boulat and Bodenhausen's extended Solomon equations. Finally the authors present some valuable conclutions.

The ¹H,¹³C,⁵¹V NMR spectra have been determined for four V-Cu-S cluster compounds at room temperature. The results indicate that he ¹H NMR linewidth of ligands R₂NCS₂ of cluster compounds are broadened, because electron transfarrfrom atom Cu⁺ to atom V⁵⁺ occur;and that several disproportionate reactions by ligand exchange are present in solution.

Imidazoline nitroxide radicals were synthesized and studied as "pH probes".The influence of pH on the ESR spectra of the radicals were discussed and their pKa values were measured. The substituent R on the phenyl ring has an effect on the proton exchangerate of the N3 atom which is related to the pKa value of the nitroxide radical.

A simple relation is presented to calculate group electronegativity (X_G), viz., X_G=(2.6△_α^H-n)/5+2.6. △_α^H is the group deshielding parameter in ¹H NMR, proposed by author. n is the principal quantum number of center atom in the group. The relation of X_G with chemical shift parameter in ¹³C NMR is also drawn as X_G=(△_α^C+5n)/40+2. The resulting values of electronegativities for some 46 groups/atoms are similar to those obtained in previous papers, but calculated values from deshielding parameters of aromatic ring and anisotropic groups do not stand for their inductive effect. As a result,the principal quantum number of outer layer electrons in molecular orbital, maybe the deformation of MO, is a factor to influence the chemical shift.

Complete assignments of ¹H,¹³C NMR chemical shifts for 7-Hydroxy (Methoxy, Acetoxy)-3-phenylcoumarin are presented for the first time except ¹³C NMR data of 7-Methoxy-3-phenylcoumarin.