Based on the in-vitro study, 3 patients with hemorrhagic cholecystitis were diagnosed preoperatively and hemorrhagic cholecystitis can be subdivided into mixed and non-mixed types. In-vitro experiments show that 0.2mL of blood in 10mL of bile could be detected as a hyperintense area on T₁-weighted image, 0.4mL of blood on proton density weighted image as a slightly hyperintense area if the blood was hot mixed with bile. T₂ weighted image was found insensitive in detecting blood in the bile. If the blood mixed with bile completely it increased the sighal intensity of the bile uniformly on all the MR images.
The MRI appearance of non-mixed hemorrhagic cholecystitis is pathognomonic, on T₁-and proton density-weighted images in the gallbladder there is (are) hyperintense area(areas), on T₂-weighted image the area(areas) is (are) isointinse or hypointense in its center and hyperintense in its periphery relative to the surrounding bile. The MRI appearance of mixed hemorrhagic cholecystitis is that relative to the liver, the signal intensity of gallbladder contents is uniformly high on all the MR images. This type of hemorrhagic cholecystitis can be diagnosed with reference of clinical finding and gallbladder wail and pericholecystic effusion.

We reported both the open-chain and closed-ring ethene cation radicals derivatives formation on pretreated H-ZSM-5 studied by ESR techniques and the use of colnputer simulations at various stages to understand the details of chemical reactions inside the three-dimensional channels of the zeolite. The comparison of these four related open chain cation radicals with two related closed ring cyclopentene and cyclohexene canon radicals shows that the unequivalent β-proton hyperfine splittings in the 2,3-dimethyl-2-hexene cation radicals can be understood by the contact of these canon molecules within the three-dimensional pore structure. Thus, we use the computer simulations to help us correct assignment of the isotropic proton hyperfine splittings on the surface as well as to study both the intramolecular hindered torsional motions of the solid-gas interactions and ion-molecule reactions.
A new equation relating the observed proton hyperfine splitting to the non-planar structure of the cation radicals is proposed. The equation is supported by the basic symmetry principle as well as our experimental results.

In this paper, the time-resolved ESR technique has been used to study the photochemical process of phenothiazine and p-benzoquinone in ethylene glycol. From the CIDEP spectra and the thermodynamic calculations, we come to the conclusion that the electron transfer and the hydrogen abstraction proceeded simultaneously and competed with each other during the photolysis.

ESR spectra of the catalyst for propylene polymerization MgCl₂/TiCl₄/di-n-butyl phthalate (DNBP)-AlEt₃/diophenyl dimethoxyl silane (DPDMS) with better resolution was obtained. The situations of Ti ions supported on MgCl₂ and the assignments of observed signals were correlated. The influence of electron donors on the ESR spectra of catalyst was also investigated.

A new diterpene ester (5, 20-O-diacetylingenol-3-O-(2'E, 4'Z)-teteradecadienoate) and a known sesquiterpene glucoside(Roseoside) were isolated from the whole part of Euphorbia petiolata and E.macroclada, respectively. The position of the three esters of compound (1) and one glucose moiety of compound (2) were umbiguously assigned on the basis of HMBC experiment, and all the ¹H and ¹³C NMR chemical shifts of the two compounds were also assigned by 2D NMR techniques, such as H-¹H COSY, ¹³C-¹H COSY, HMQC and HMBC.

In this paper, problems associated to recognition of known signal submerged in noise is studied with computer simulations by Fuzzy Neural Networks. The research results show that, under very low signal-to-noise ratio, a very high recognition rate was still kept by the networkss with combination of fuzzy membership function and BP algorithm. In addition, the practicability of this recognition method was investigated.The approach opens a new way to recognition of signal embeded in strong noise in NMR.

The NMR data of the newly synthesized complexes of neodymium and terbium nitrate with N,N-disallcyclideneethylenediamine and dimethyl sulfoxide were and collected in this report. Proton and carbon chemical shifts were unambiguously assigned with two dimensional proton NOE spectroscopy (NOESY) and ¹H-¹³C heteronuclear multiquantum coherence spectroscopy (HMQC).

Methyl methacrylate-naphthyl ethylene copolymer was studied by two dimensional NMR spectroscopy (2D H, X-COSY, NOESY). ¹³C and ¹H chemical shifts of the copolymer were assigned (Tab.2). Results show that the structure of the copolymer is mainly random with respect to the stereochemical configuration, there are some head-head (or tail-tail) copolymers linked by methyl methacrylate and naphthyl ethylene. The content of copolymers was measured by inverse gated heteronuclear decoupling.

The ²⁷Al、²⁹Si chemical shifts in the artificially-cemented specimens of kaolinite with goethite are, according to the NMR experiments, greater than those in pure kaolinite respectively by 2.7ppm and 2.33ppm. The atomic charges in the same artificially-cemented specimens are, on the basis of the computation results of CNDO/2 method, less than those in pure kaolinite respectively by 0.0787 and 0.0286. The changes of the atomic charges agree with those of ²⁷Al、²⁹Si chemical shifts. It has been considered that there are hydrogen bonds between kaolinite and geothite and they are in cemented state.

Systematic studies were made on ¹³C NMR and its regularity of chemical shift sum (CSS). In this paper, a set of novel molecular graph-theoretical parameters, called the distance-edge vector (lambt,λ) was developed and found to be excellent correlated with ¹³C NMR CSS of alkanes as
CSS=-24.2937+32.1835λ₁+24.8344λ₂+24.4614λ₃+25.9988λ₄+15.2348λ₅+0.4016λ₆+23.8872-λ₇+38.9112λ₈+78.3879λ₉+146.0000λ₁₀
which gave good results.

Intermediates of pyrethroid pesticides-ethyl (or methyl). 3,3-dimethyl-4-pentenoate. ethyl (or methyl). 4, 6, 6, 6-tetrachloro-3, 3-dimethyl hexanoate and ethyl. (or methyl) 2,2-dimethyl-3-(2,2-dichloroethenyl) cyclopanecarboxylate were synthesized in succession through prenol-orthoacetate method. Their elemental analysis. IR spectrum and ¹H NMR were consistent with those reported. In order'to make clear the structures of these compounds further, the ¹³C and ¹H NMR chemical shifts were assigned completely by H-H COSY and ¹³C-¹H COSY spectra.

The basic values and parameters in the formulas for calculating chemical shifts and their relationship to molecular structure were discussed. The results reveal that the main factor to influence chemical shifts of a spill nuclei was the electron cloud density around the nuclei (including the electron cloud distribution).

NMR spectra of 5 new kinds of α,α'-dioxoketene cyclic N, N-acetals are reported in this paper. The structures. were determined by ¹H、¹³C NMR spectra etc., and the chemical shifts of all NMR peaks kaye been assigned. The effects of structure on the chemical shifts are discussed.

In the present paper ¹H chemical shifts of hundreds of tetra-coordinated organogermanium compounds, which were published in the past thirty years, are reviewed.