In this paper, a series of α, ω-diaminopropyl terminated polydimethylsiioxane-polyurea and α, ω-diaminopropyl terminated polycyanopropyl methylsiloxane-polyurea were characterized by high resolution NMR.
The phase separation of these polymers was studied with breadline solid state NMR. The length of the hard segment and that of the soft segment have strong effect on the extent of phase separation.
The interactions between the soft segments and the hard segments (for example, hydrogen bonding) also affect the extent of phase separation.The hydrogen bonding in these polymers was studied by high resolution ¹H NMR. In concentrated solution the relative amounts of NH peaks have little dependence on concentration. The hydrogen bondings have significant effect on mechanical properties. The more the hydrogen bondings, the better the mechanical properties are.

Vanadium mercaptophenolate complexes (Ph₄P)[V₃(mp)₆] (I) and (Ph₄P)₂[NaV (mp)₃ (MeCN) (MeOH)]₂ (Ⅱ) are paramagnetic. Their EPR spectra were measured in solution or/and in polycrystalline form at both ambient and liquid nitrogen temperatures. The simulated spectra were computed with try-or-error values of g, A, and δ_w (half-line width) based on the computer program. The unpaired electrons are essentially localized around the vanadium atoms.

The ¹H and ¹³C NMR spectra of guan-fu base G (1) were studied by selec-we long-range ¹³C DEPT, 1 D COSY and 1 D relay COSY new techniques, otal assignment of ¹H and ¹³C NMR spectra of the compound can be obtained. The results obtained showed that the techniques described in this paper are very ffective and convenient for the structure determination and oectral assignment of this class of compounds.

The chemical structure of a new phytoecdysteroid obtained from Rhaponticum uniflorum (L.)DC. has been first reported in this paper. It has been identified as 2β, 3β, llα, 14α, 20,22,24-heptahydroxy-5β (20R, 22R, 24S)-choiest-7-en-6-one by using several NMR techniques and other spectraldata.

This paper reports on the study of thermostability of radiated trapped electrons in tooth fossil. The samples of tooth fossil were collected from the Peking-Man site at zhoukoudian. We made a comparison of thermostability between enamel and dentin and got that the mean-live of the ESR signal (g=2.0016) is 7.1×10⁶ years (20℃). The result shows that it is reliable to date by this signal (g=2.0016). Choosing enamel sample for dating is more appropriate.

A better resolution of ESR spectra of labelled ⁶³Cu-¹⁴N-HAP,⁶⁵Cu-¹⁴N-HAP, ⁶³Cu-¹⁵N-HAP, ⁶⁵Cu-¹⁵N-HAP and Cu-¹⁵N-HAP complexes in tetrahydrofuran (THF) solution, measured at 77K, was analyzed. From the spectra, we have got not only hyperfine splitting of the ⁶³Cu and ⁶⁵Cu; but also very nice superhyperfine splitting arising from ¹⁴N and ¹⁵N nuclei. The g_x,g_y,g_z;A_x⁶⁵,A_y⁶⁵,A_z⁶⁵; A_⊥¹⁵,A_⊥¹⁵,A_⊥¹⁴,A_⊥¹⁴ etc. tensor parameters were determined rather reasonably. The bonding parameters were calculated by using measured spectral parameters, and its electronic structure and the bonding character of these complexes are discussed, and better satisfactory results were obtained.

Under phase transfer condition enantiomerically pure tetrahydro-β-carboline underwent Aldol condensation and dehydration gave rise to corresponding indoloquinolizine. The Michael addition of indoloquinolizine and methyl malonate showed high stereospecificity which depends on the stereochemistry of the title compounds. In this paper COSY and NOESY of 2D-NMR spectroscopy for 6 indoloquinolizine derivatives were studied. In la and 2a there are NOE relationship between 12b-H and COCH₃ for Ib and 2bhowever there is not any NOE effect at all. In 3a there is NOE relationship between 12b-H and COCH₃; in 3b there is NOE relationship between 6-CO₂CH₃ and COCH₂. Based on these results and Dreiding Stereomodels their configurations, conformations and reactivities of Michael additions with methyl malonate are discussed.

The COLOC-S pulse sequence (modification of COLOC) for obtaining long-range ¹³C-¹H chemical shift correlated spectra was applied to study the structures of oridonin and amethystonal. The results show that the COLOC-S pulse sequence is very useful for structure elucidation and NMR spectra assignments of natural organic compounds.

The ¹³C CP MAS NMR spectra of three cocoon shells (inside, middle and outside layer of the shell) of Dong Bei Antheraea yamamai (A. yamamai) and Rhodinia fugax were recorded and spectral lines were assigned. The ratioes of main Ine in the spectral area and amorphous region percentage were calculated. The spectra show that the structure of silk protein of Dong Bei Antheraea yamamai cocoon shell is different from that of Rhodinia fugax.

High resolution solid state NMR techniques (such as MAS, CP/MAS and CRAMPS) were employed to study the nature of organic molecules adsorbed on porous solids.
A magic angle spinning system was achieved for sealed samples with a spinning speed from 2KHz to 4.2KHz. Using this technique, high resolution ¹H MAS spectra of organic molecules and H₂S adsorbed on charcoal were obtained. Experimental results suggest that for high coverage of adsorbed organic molecules, the spectral lines were resolved very well. But for low coverage, the spectral lines could not be separated completely. As the organic molecules condensed in pores (liquid-like phase) dominate for high coverage, the spectra could be easily resolved under lower spinning speed rate. While for low coverage, the portion of molecules adsorbed on solid surface (solid-like phase) is relatively larger and the resonance lines could not be narrowed even under higher spinning speed rate due to the increase in various kinds of interactions of adsorbed molecules. We could not obtain further narrowed spectrum by CRAMPS technique. The contribution to the residual spectral width was discussed.
A modified Goldman-shen pulse sequence was provided to measure the ¹H spin diffusion times of toluene (MB) and tetrahydrofuran (THF) adsorbed on a series of porous solids (charcoal, SiO₂ and Al₂O₃). In the experiment, the two peaks of THF and MB were selectively reversed to produce effective spin diffusion. The spin diffusion times of MB and THF adsorbed on different types of solids vary in a wide range (from several milliseconds to several hundreds of milliseconds). This implies that the motions of molecules adsorbed on different solids experience different degrees of hindrance owing to their molecular structures and adsorbed states. For THF and MB adsorbed on Al₂O₃,biexponential behavior was observed in the recovery processes of the negative peaks. This was attributed to the existence of two different kinds of spin diffusion processes. One was the intramolecular spin diffusion of adsorbed molecules, the other was the intermolecular one between molecules adsorbed on solid surface and acidic groups of Al₂O₃. It is owing to the adsorbed state the bi-exponential character was obvious in the cases of THF and MB adsorbed on Al₂O₃.It is possible that the oxygen atom of THF and aromatic ring of MB are closely connected to Lewis acid sites, the neighbour acidic groups of Bronsted sites (or a small tiny amount of coadsorbed water molecules) will affect the protons of those molecules adsorbed on surface and enhance their spin diffusion. In addition, the intermolecular ¹H spin diffusion between charcoal and adsorbed THF molecules was confirmed by the indirect measurement proposed by Tekely et al.
The ¹³C-¹³C spin diffusion between enriched methanol (30%) and charcoal was investigated by ¹³C CP/MAS combining with selective excitation methods. The experimental results and ¹³C T₁ measurement show that there is no obvious ¹³C-¹³C spin diffusion and the relaxation of methanol carbon appears to be bi-exponential recovery which was assigned to two different kinds of adsorbedstates.
DNP (Dynamic Nuclear Polarization) was used to study CO (natural abundance) adsorbed on Co-Mo/Al₂O₃ catalysts. After only several hundreds of accumulation, the enhanced ¹³C signal was obtained. But the experiment could not be reproduced. The experimental details were discussed and some suggestion for further investigation was provided.

The oil of Brucea javanica (L.) Merr. has a better therapeutic effects for intrauterine, stomach and lungs cancer. ¹H NMR determination of this oil was carried out. Using an equation of author's thumb we estimated partial peak integrations in order to correct the interference of the CCH₂C strong peak to the neighbouring weak ones.
After the manner of reference[3] the amount of each functional group, ratio of quantities among various functional groups, esterification degree, unsaturation degree, average length of the saturated carbon chain, average carbon numbers in the combined fatty acids and average molecular weight per mole of oil were calculated. The analytical result showed that the amount of oleic acid in Brucea javanica (L.) Merr oil agrees with analytical result of gas chromatography.

In this paper, the two derivatives of cyclobutanone were determined by ¹H-NMR, ¹³C-NMR, H-H COSY and C-H COSY. Their predominant configuration were obtained and all ¹H、¹³C chemical shifts were assigned.

Two equivalent theorems are presented which judge whether phase cycles of different arrangements are equivalent. A new method of pulse unit for the design of phase cycles is also presented which overcomes the difficulty of multiple-yalue arising from donble coherce-transfer pathways.

Seven alkaloids have been isolated from Sophora flavescens Ait, which has its origin in Northeast China. Six of these alkaloids have been positively identified by MS, IR and 2D-NMR. These are (+)-matrine (1), (+)-oxymatrine (2), (+)-5α-hydroxymatrine (3), (-)-N-methylcytisine (4), (+)-9α-hydroxymatrine (5), and (+)-oxysophocarpine (7). The structure of the other alkaloid (6) is currently being determined. Two types of 2D-NMR H-H COSY (500MHz, 400MHz or 300MHz)and C-H COSY (C:75MHz, H:300MHz) techniques have been used.

The ¹H-NMR spectrum of clavudiol A (1) has been studied in the existence of chiral reagent Eu (tfc)₃. In addition, the chemical shifts of 19-methyl and 20-methyl of 1 was determined by ¹H-NMR spectrum.

Three ethylene-propylene copolymers were investigated by ¹³C-NMR in an ordinary solvent (CCl₄) and at room temperature (22℃). For the present measurements, the resolution was higher and peaks were assigned comonomcr compositions and sequence distributions of these copolymers were quantitatively determined. The results show that samples A, B have sequence structures of block propylene and block ethylene mostly while Sample C has a tendency toward alternating propylene-ethylene-propylene sequences.
Two statistical models were used to deduce the mechanism of polymerization process.

The ¹³C, ¹¹⁹Sn NMR spectra of several organotinferrocence derivatives recently prepared were recorded and ¹³CNMR spectal peaks assigned, so the structures of this kind of compounds are confirmed further. The influence of variation of X incompounds with structure ofon chemical shift of ¹¹⁹Sn is discussed em-phatically It is found that change of X has little effect on ¹¹⁹Sn N-Sn transdirect coordination in the compoundwas also investigated.