In the development of a L band three dimensional ESR imaging system, a software package of application programs was written with MATLAB (version 6.1),  which handles auto-processing of spectral data, and reconstruction of ESR spati al (1D, 2D, 3D) imaging and spectral-spatial imaging. The software can displa y different types of images reconstructed from the spectral data and distribution of spin density in the paramagnetic samples. In addition, this software is cap able of generating useful visible information, which can be applied in the chara
cterization of the spin density distribution of paramagnetic species, as well as in the oxygen diffusion process in chemical reactions.

The detection sensitivity and the achievable spatial resolution of a newly developed L-band three-dimensional ESR imaging system were evaluated. The detection sensitivity was measured using a group of samples of aqueous Tempo solution. A signal to noise ratio (S/N) of about 4∶1 was obtained on a cylindric al sample with diameter of 10 mm and height of 30 mm, which corresponds to the minimum detectable concentration of 1×10^-4 mol/L. To obtain projections with sufficient S/N for imaging, a higher concentration of more than 5×10^-4 mol/L and a larger sample size (diameter of φ19 mm and height of 30 mm) was needed. Measured on solid DPPH samples, the spatial resolution of imaging can reach about 1 mm. The general performance features of the ESRI system were also discussed in the paper.

Deuterium NMR spectra of strained polymers was simulated using Monte Carlo simulations with the bond fluctuation model. The excluded volume (EV) effect and the effect of mean-square end-to-end distance on the spectra were discussed. It is shown that the EV effect on the spectra of highly and lowly oriented polymers are different. The splitting of the spectrum is attributed to chains with short mean-square end-to-end distance, whereas chains with long mean-square end-to-end distance will lead to broadening and wings of the spectrum.

A PC based image reconstruction program was developed for SPIRAL magnetic resonance imaging. The functionalities of the program included 1) converting the raw data acquired with the spiral trajectory into uniform Cartesian grid; 2) fast two-dimensional Fourier transformation (2D-FFT) for all kinds of MRI, such as multiple-slice multiple echoes; 3) automatic correction of off-resonance effects caused by chemical shift and field inhomogeneity; 4) imaging analysis; 5) export processed images in the formats of TIF, GIF, JPG and BM.

¹⁴N quadrupole coupling constants and asymmetry parameters of aromatic nitro-compounds were calculated with the RHF method using the Gaussian98 program. By considering a corrective coefficient, the results calculated from RHF/3-21G agreed very well with the experimental data with a correlation coefficient of 0.91.

The B3LYP method of DFT with a 6-31G** basis set was used to calc ulate nuclear spin-spin coupling constants of C-F bonds. Forty compounds were chos en, and divided into four groups (10, 20, 30 and 40). A general equation is fitted for each group. Four compounds were chosen to test the equations. The experiment al results are basically consistent with the experimental values.

The structures of aluminum-oxide polyhedron in fly ash and their changes after a grinding process were studied by ²⁷Al MAS and 2D 3QMAS NMR. The results showed that tetrahedron and octahedron are the main forms of aluminum-oxide polyhedron in raw fly ash, and they exist in a multi-structural surrounding. Only slight changes were observed for the tetrahedron structures after grinding, indicating that they are stable, probably because they exist in a three dimensional structural net of [SiO₄]^4-. The results also showed that, after grind ing, part of the octahedron structures broken away from the net, and transformed and distributed in a symmetrical structural surrounding. The results from the 2D 3QMAS experiments showed that a small amount of hexahedron structures originally existed in the raw fly ash was damaged after grinding.

Some alkyloxyl-biphenyls show efficient biological activity. To find new compound with more effective activity, a new biphenyl compound, 4,4′-dimethoxy-5,6,5′,6′-dimethenedioxy-2-{2-[4-(4-bromobenzyl)piperazine-1-yl]}acetoxymethyl-2′-methoxycarbonyl-biphenyl was synthesized from 4,4′-dimethoxy-5,6,5′,6′-dimethenedioxyl-2-hydroxymethyl-2′-methoxycarbonyl-biphenyl. The structure of the compound was determined by means of ¹H NMR, ¹³C NMR, HMQC, HMBC, NOESY and ESI-MS

The structures of bicalutamide, rosiglitazone maleate, clopidogrel hyd rogensulfate were elucidated by 1D and 2D NMR spectroscopy. The  ¹H and ¹³C NMR chemical shifts of these compounds were assigned.

Dryocrassine was isolated from the Dryopteris crassirhizoma. 1D and 2D NMR (¹H-¹H COSY, HMQC, HMBC) methods, among which the HMBC method was the most important, were used to elucidate the structure of Dryocrassine. The ¹³C chemical\} shifts of the compound were assigned.

The effect of calcination temperature (from 773 K to 1 073 K) on the structure of HL zeolite was studied using ²⁹Si and ²⁷]Al MAS NMR. The NMR spectra of zeolite were greatly influenced by calcination. The backbone of HL zeolite suffered from severe dealumination by calcination at temperatures higher than 923 K. The results from ²⁷Al MAS NMR measurements implied that Al in the backbone of zeolite was only partially NMRvisible. The NMR-invisible Al increased with the increase of calcination temperature.

The microcrystalline structure and magnetic properties of the complex CuLL′(L=mnt^2-}，1,2-dicyano-1,2-dithiolate; L′=phen-5,6-odione,1,10-phenanthroline-5,6-dione)were studied by variable-temperature susceptibility measurements and EPR. The results showed that the complex exist in the forms of microcrystalli ne particle and high-spin tetracoordinate complex, and possesses remarkable para
magnetism. The experimental EPR observations for the complex are explained by theory.

Germacrane type sesquiterpenoids are the most abundant among all the sesquiterpenoid skeletons. Their stereostructures vary much because of the decacycle. There are four configurational isomers and every configuration has several different conformers of germacrane derivatives, which tend to exist as the most stable conformers. All these conclusions are established by NMR spectroscopic techniques, including dynamics NMR (DNMR), NOED and NOESY, etc. These four configurational isomers and their relatively stable conformers are summarized by analyzing NMR spectral data in this article.

Metabonomics has now become an important component of systems biology,  with promising applications in toxicology,  functional genomics,  disease diagnosis,  environmental analysis and nutritional assessment. In this review,  the recent developments in NMRbased metabonomics were discussed.