An effective component was separated from traditional Chinese medicine ampelopsis megalophylla diels et gilg and studied by 2D ¹H-¹³C heteronuclear multibond coherence spectroscopy (HMBC), ¹H-¹³C heteronuclear multiquantum coherence spectroscopy (HMQC)and proton exchange spectroscopy (EXSY).It is suggested that the compound is ampeloptin (3, 3', 4', 5, 5', 7-hexa-hydoxy dihydroflavonol), which is first obtained from ampelopsis megalophylla diels et gilg.Chemical shifts of proton and ¹³C were assigned more accurately.Protonation of solvent DMSO was also investigated and discussed in detail.

The misibility of blends of poly (styerene-co-acrylonitrile)(SAN) with poly (methyl methacrylate)(PMMA), poly (ethyl methacry late)(PEMA), poly (n-butyl methacrylate) (PnBMA), poly (i-butyl methacry late)(PiBMA) has been studied by means of NMR and DSC techniques.The results indicate that there are strong intermolecular interactions between the phenyl groups in SAN and and carbonyl groups in PMAs, the sequence distribution of SAN and dimensional conformations of PMA play critical roles in the miscibility of blends.

Some newly developed one and two dimensional ¹H NMR techniques, including totally correlated spectroscopy (TOCSY), self-diffusion coefficient measurements and maximum quantum spectroscopy (MAXY), are applied to the study of a humic acid sample suspended or dissolved in D₂O, NaOH/D₂O and DM SO-d₆.T OCSY experiments suggest that humic acids contain poly peptides that are soluble in DMSO but not in water, while the self-diffusion coefficient measurements suggest that in basic solution there are small molecules that are not included in the humic acid aggregates.From the MAXY spectra, detailed assignments for the proton resonances become possible.

Saturation transfer effect in NMR experiments on peptide and proteins in aqueous solutions has been investigated using presaturation method with varied irradiation time.The reason why most amide protons are not affected by 60s irradiation has been quantitatively analyzed.It has been shown that the labile protons in lysozyme, which is a macromolecule with stable secondary and tertiary structure, are almost not affected by saturation transfer.Very few amide protons in insulin, whose tertiary structure is less stable than lysozyme, have lost intensity due to saturation transfer.As for the peptide with six amino acid residues, because it dose not have secondary structure in solution, saturation transfer effect is severe.It is thus concluded that for the purpose of three-dimensional structure study using NMR, presaturation is still a powerful and practical technique for solvent suppression.

The motion of Li⁺ ions in anode materials of battery has been investigated by temperature varying ⁷Li solid-state NMR techniques.The results suggest that with the increase of experimental temperature, the ⁷Li NMR spectra of LiMn₂O₄ become narrowed, which indicate the increase of mobility of Li⁺, while those of LiCoO₂ remain unchanged.The changes of T₁ in LiMn₂O₄ and LiCoO₂ show opposite tendency with the increase of temperature because their T₁'s locate on different sides of the utmost point of the T₁-τ_c curve.

In order to study the absorption mechanism of liquids in oil reserviorcore, several samples were prepared using the same rock core :1)different quantities of kerosene adsorbed ;2) different quantities of water adsorbed ;3)some quantity of waker was adsorbed first and then some quantity of kerosene was adsorbed later.The NMR spin-lattice relaxation times were determined for the above three groups of samples;The conclusion is that the closer the water and oil molecules to the solid surface the shorter the relaxation time is.According to the conclusions on petroleum geology and NMR study results a NMR model of two-phase (oil/water) system in porous sandstone was proposed.

By employing spin-echo sequence, the proton spin density micro-images of a series of sandstone samples saturated with brine were obtained.The images provided detailed description of internal structure of porous core.These results show that MRI method not only can provide qualitative description of some properties such as porosity and permeability, and is also possible in the future to measure thess physical parameters quantitatively.

Immobilization of experimental animals is a basic requirement for in vivo ³¹P MRS measurements.This article studied the time-dependent effects of saanone on ³¹P MRS in murine S180 tumors.The results showed that saanone is a good anaesthetic agent with high safety index, fast action, moderate anaesthetic time period and no significant side effects on ³¹P MRS in tumors.So saanone is suitable for serial measurements of ³¹P MRS.

Spatial distribution of radiofrequency field B₁ produced by self-made ³¹P NMR surfacecoil probe was studied.The results show ed that 90° pulse width at the center of the coil was 10μs, and that radiofrequency field B₁ contributing to the signals was limited within the circumference of the coil, and that along the axis perpendicular to the surface coil the intensity of B₁ decreased sharply with the increase of the distance from the coil.Simply speaking, the spatial distribution of effective B₁ of this surface coil can be considered as a sub-hemisphere, which has a bottom radius nearly equal to the coil radius and a maximum depth of action of about the coil radius.

The crystallization processes of SAPO-34 molecular sieves were studied by MAS and CP/MAS NMR methods.It is shown that the silicon atoms were incorporated into the framework by two manners.During the process of formation of the crystal core, the silicon, phosphorus and aluminum atoms were incorporated into the framework simultaneously.At the later stage of crystallization parts of silico atoms substitute phosphorus atoms and/or phosphorus and aluminum pairs to be continually incorporated into the framework.This introduces various silicon-aluminum structures of SAPO-34 molecular sieves.

¹H, ¹³C and HMQC NMR spectra of hetero-metal Ag-Na and homo-metal Cu cryptates with cryptand N₈O₆, [Ag₂NaL] (ClO₄)₃(1) and [Cu₂L](BF₄)(ClO₄)^*DMF^*0.5EtOH(2) have been determined at room temperature in solution.All resonances of the proton and carbon of the complexes were assig ned.The solution coo rdination behavior of the complexes were studied by ¹H NMR spectra.

The ¹H NMR spectra of the three novel asymmetric Schiff bases 3, 4-dihydroxy benzal oxamidoxime, 2-hydroxy benzal oxamidoxime and benzal oxamidoxime were discussed and the assignment of the chemical shift for their reactive hydrogen was also provided.

This paper introduces the new development of Nano.nmr Probe.The unique design of this probe constrains all of a small volume sample (<40μL) to the active region of the receiver coil and use MAS to correct for any unshimmable line broadings to provide the narrow est possible linewidths. The result is a previously unattainable level of sensitivity for small-volume samples with excellent lineshapes.
The work presents excellent research in the literature demo strating the identification of homo-and heterogeneous samples, and a known application of both a Nano.nmr Probe measured 2D INADEQUATE and used FRED software to an unknown compound, the complete carbon skeleton was rigorously determined by using only 11mg (30μmol/L) of sample.

In this paper, the ¹³C NMR spectroscopy of flavonoid-O-glycosides was summarized which overlaps solvent system, number and identification of monosacchride, interglycosidic linkage, sugar sequence, identification of flavonoid agly cone, site glycosylation and appearance of acyl subtituents.In addition, more than fifty reference data of di-and oliga-saccharide moieties founded in flavonoid-O-glycosides were presented.