Fucoidan is the primary bio-active component in Hizikia fusiforme, an algae widely distributed in China. DJL is a product of Hizikia fusiforme-originated fucoidan after desulfation and partial hydrolysis. In this study, the structure of DJL was elucidated using 2D NMR spectroscopy and methylation analysis. The result shows that DJL has a molecular weight of 11 KDa and is composed of mannose (Man) and glucouronic acid (GlcA) with a composition ratio of about 1∶1. Its possible structure was also determined to be β-D-GlcA(1→ [2)-α-D-Man(1→4)-β-D-GlcA(1→]_n1→4)-β-D-Gal(1→[4)-β-D-GlcA(1→2)-α-D-Man(1→]_n2→4)-β-D-GlcA(1→2)-α-D-Man.

A series of 1D (¹H and ¹³C NMR, DEPT experiment) and 2D NMR (including gCOSY, gHSQC and gHMBC) techniques were applied to the assignment of all proton and carbon signals of forbesoside [6′-O-(trans-feruloyl)-nodakenin] which was a new coumarins compound isolated from the underground parts of Notopterygium forbesii Boiss. and Notopterygium incisum Ting ex H. T. Chang and with anti-inflammatory bioactivity. The NMR signals changed rules from umbelliferone to 7-demethylsuberosin, nodakenetin, nodakenin and forbesoside, and of acyled hydroxymethyl moiety of glucopyranosyl group, and methods of NMR signals assignment of saccharide were discussed and summarized.

The ethanol extract of Belamcanda chinensis was separated by different kinds of chromatography methods. Eleven isoflavones were isolated and their structures were determined by ¹H NMR, ¹³C NMR, HMBC, HSQC, ¹H-¹H COSY and NOESY. A new compound named isoiridin was identified. The ¹H and ¹³C chemical shifts of these compounds were assigned and the relationship between the substitute groups and the ¹H and ¹³C chemical shifts was discussed.

Chemical screening method was used to isolate taraxerone from mangrove Excoecaria agallocha. The structure of taraxerone isolated was determined by NMR and EI-MS methods. The bio-activities of the compound were also evaluated and reported.

In this work, the NMR characteristics of several nitrogen containing compounds, including Aztreonam, Omeprazole and a Schiff base, were investigated. The results show that quadrupole moment of ¹⁴N nuclei^[1], inter-molecular hydrogen bonding and tautomic equilibria of intra-molecular proton transformation are the major factors influencing the NMR characteristics of these compounds. Based on the results, it is suggested that the aforementioned factors should be considered when designing NMR experiments for and analyzing NMR spectra of nitrogen containing compounds, since knowing the influences of these factors may help gaining more information on the structural and chemical properties of the compounds.

NMR (¹H NMR, ¹³C NMR, DEPT, HSQC, HMBC) methods were used to elucidate the structure of a new immunosuppressant FTY720 (2-amino-[2-(4-octylphenyl) ethy1]-1, 3 propanediol hydrochloride). The ¹H and ¹³C chemical shifts of the compound were assigned.

An equation: δ_cal=360.0+Δα+Δβ+Δγ for calculating ¹7O-NMR chemical shifts of carbonyls in carboxylic methyl and ethyl esters was provided. Twenty two substituent parameters for the equation were obtained with leastsquare linear regression. Experimentally measured ¹⁷O chemical shifts from 52 carboxylic esters were used as the test set to examine the accuracy of the calculated results. The confidence limit was found to be 99.5 % and the calculating errors for almost all the compounds were less than 5.0 (relative errors ≤0.5 %).

An equation: δ_cal(¹⁷O)=337.3+Δo+Δm+Δp for calculating ¹⁷O chemical shifts of carbonyl groups in substituted methyl benzoates was provided. Twenty two substituent parameters are obtained with leastsquare linear regression. Experimentally measured ¹⁷O chemical shifts from fifty two substituted methyl benzoates were used as the test set to examine the accuracy of the calculated results. The confidence limit was found to be 99.5 % and calculating errors Δδ for all compounds were less than 5.0.

Nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) technologies are widely used for physical, chemical, material and biomedical analysis and medical diagnosis. In attempting to design and build NMR/MRI systems that are significantly cheaper and with simpler configuration than the commercially available systems, we designed and built an analog receiver for NMR/MRI spectrometers based on AD607 (complete receiver on a single chip). Compared to the traditional analog receivers, the proposed design uses components with much smaller sizes and has a rather simple structure. In addition, it can work at higher frequency range than conventional digital receivers can. Detailed description of the design and experimental demonstration of the performance of the receiver are given in the paper.

A digital frequency source designed for a 300 MHz nuclear magnetic resonance spectrometer is described. Controlled by MCU or by PC, the frequency source is capable of generating a frequency- and phase-continuous tunable signal with output frequency ranging from 5 MHz to 125 MHz and 280 MHz to 301 MHz. Practical implementation of the frequency source to a 300 MHz NMR spectrometer is described, and its performance was tested with solid state NMR experiments. It is demonstrated that the frequency source results in radiofrequency output with low phase noise, high stability and high purity.

Taking slight magnetic interactions (including spin-spin interaction, spin-otherorbit interaction and orbit-orbit interaction) into account and by using complete diagonalization method and perturbation theoretical method, zero-field splitting (ZFS) of 4B₁ and ²E states for 3d³ ions was studied in tetragonal symmetry crystal field. The result show that ZFS of the ⁴B₁ state is linear to the slight magnetic interaction parameters, and ZFS of ²E state mainly depends on spin doublets.

A hexpolyamide/seryl-histidine dipeptide conjugate DNA cleavage agent was synthesized and its structure was elucidated by NMR and ESIMS/MS methods. Complete assignment of ¹H and ¹³C NMR chemical shifts of the compound was obtained using 2D NMR techniques, including ¹H-¹H COSY, HSQC and HMBC. The MS/MS fragmentation pathways of the polyamide/peptide conjugate are also discussed.

Having the potential of being used as a plant-growth regulator, 1-(4-nitro-phenylaminoacetyl)-4-phenylacetyl thiosemicarbazide was synthesized. Its ¹H and ¹³C NMR chemical shifts were assigned by 2D NMR techniques.

Entecavir sodium, an antiviral pro-drug, was a derivative of entecavir. In this study, the ¹H and ¹³C NMR chemical shifts of the compound were completely assigned using 2D NMR techniques, including HMQC, HMBC and ¹H-¹H COSY. The relative stereochemistry was established by the NOESY method.

Denoising is an important issue in image processing. However, in the classical approaches there is often a tradeoff between reducing the noise level and preserving the high-frequency edges of the image. Denoising with wavelet transform has been acknowledged as one of the most promising methods for image denoising, as the method can not only remove the noise of the image but also preserve the edges of the image. The paper reviews the literature on denoising methods with wavelet transform, with emphasis on MR images denoising with wavelet transform. The future trend of wavelet image denoising is also discussed.

In this dissertation, quantum chemical calculations and NMR experimental methods were combined to study in detail the acidities of zeolite H-MCM-22 and commercialized catalyst BF₃/γ-Al₂O₃. In addition, a new computational scheme ONIOM-GIAO was applied to calculate the NMR parameters of large systems. 
(1) We applied the new embedding NMR calculational method ONIOM-GIAO to accurately predict ¹³C NMR chemical shifts of amino acids as well as a series of organic species absorbed on zeolites. Since the effects of framework nvironments around the part interested or active center have been taken into account by the ONIOM method, the ¹³C chemical shifts predicted by the ONIOM-GIAO are in well agreement with the NMR experimental values.
(2) The distribution of Brǒnsted acidic protons and their acid strengths in zeolite H-MCM-22 have been characterized by density functional theory (DFT) calculations as well as probe molecule magic angle spinning (MAS) NMR experiments. Our theoretical and experimental results may partially explain the special selectivity of acid-catalyzed reactions occurring inside the channels of H-MCM-22 zeolite.
(3) Based on the multinuclear solid-state NMR results, DFT calculations have revealed the detailed structures of various acid sites formed on the BF₃/γ-Al₂O₃ catalyst. The detailed mechanism of interaction between the BF₃ and γAl₂O₃ surface as well as the newly formed Brǒnsted and Lewis acid structures were proposed. The DFT computational results are well consistent with the NMR observations.
(4) Our theoretical calculations have revealed a new solvent-assisted proton transfer effect in zeolite catalysis. We found that when isopropanol was coadsorbed with the naphthalene molecule in the channels of zeolite mordenite, acid strength of the Brǒnsted acidic proton of the zeolite has been considerably increased, leading to the protonation of adsorbed isopropanol molecule. The big conjugate system of naphthalene molecule is likely to stabilize the resultant isopropanol carbenium cations by dispersing the charges around them.

Dynamics of water adsorbed on MCM-41 has been investigated by ²H double quantum filtered (DQF) NMR and T₁ inversion-recovery NMR. The modified cone model is employed in this study. From temperature dependent studies with various water loadings on MCM-41, it is found that there are different sites for water adsorption on MCM-41. The signal of water molecules in the slow site dominates in the observed DQF NMR. The influence of silanol groups on the MCM-41 surface strongly affects the motion of water molecules in the slow site, resulting in a residual quadrupolar interaction. As the signal of water in fast site dominates that observed in single quantum spectra, it also appears in DQF spectra through an exchange process. It is found that the single SiOH group is the major adsorption site on MCM-41 surface and the ratio is one water molecule to on SIOH group. The wobbling motion of the water in slow site is also influenced by the translation diffusion of the second monolayer water through collision. The phase transitions of water in fast motion site are also found. The results indicate that the phase transition temperature varies with different hydration. Higher hydration sample may cause the more serious structure distortion in the pore. Therefore, the lower phase transition temperature is found in the higher hydration sample. Moreover, with the low hydration MCM-41 sample, it shows that there is only single layer of water molecules on the surface. Alternative pulse sequence for DQF NMR, which is called spinlock double quantum filtered (SLDQF) NMR, and reorientation mediated by 2D jump diffusion model have also been developed in this study.

In this dissertation, various solid-state NMR spectra and NMR relaxation measurements, together with XRD and DSC, have been used to elucidate the structures and molecular dynamics in two typical polymers.
Poly (ethylene-co-vinyl acetate) (EVA) is one of the most important ethylene copolymers. It has been found that the phase structure of EVA is very complex and there are five physically distinct components in all present EVA samples. Besides the familiar immobile orthorhombic and monoclinic crystalline phases as detected in PE, a third crystalline phase-mobile crystalline phase SOCP (possibly the rotator phase) was detected by solid-state NMR and then confirmed by DSC. Such a third crystalline phase has not only the welldefined melting point of its own, but also has different molecular mobility and different chemical shift from the orthorhombic phase (LOCP). In addition, the amorphous phase also contains two components: an anisotropic interfacial amorphous phase and a melt-like amorphous phase. Then, we investigated in more detail the chain dynamics in crystalline phase and the low-temperature freezing behavior of amorphous phase in the EVA. And we found that the motion of CH₂ chain in rigid orthorhombic phase is the 180° filp-flop motion around its chain axis, accompanied by the simultaneous hopping motion along its axis, which causes the chain diffusion between orthorhombic and amorphous phases. This chain diffusion is evidenced by NOE measurement. Furthermore, we confirmed that the chain diffusion between two phases was restricted rather than free. The low-temperature freezing behaviors of the two amorphous components are different: below-relaxation temperature, although the long-range movement of chains in the melt-like amorphous phase is frozen, the local segmental motion of several CH₂ units still occurs, while the interfacial amorphous phase is completely frozen into an orientation-ordered interphase below-relaxation temperature. 
Compared with conventional polymers, the corresponding nanocomposites typically exhibit remarkable improvement in materials properties, while the filler content is just very low. We used solid-state NMR and XRD to characterize the structure and clay-dispersion quality of the EVA/REC composites and we found that the crystalline forms of said composites depend not only on the nature of the components used but also on the type of the corresponding composites.
Poly (vinylidene fluoride-co-trifluoroethylene) (P(VDF-TrFE)) is one of the most important ferroelectric copolymers. We have investigated the effects of electron irradiation on molecular structure, conformation, dynamics and phase transition of P(VDF-TrFE) copolymers with 80 mol% VDF film by variabletemperature (VT) solid-state ¹⁹F NMR. It has been found that the electron irradiation changes not only the configuration and mobility of molecular chains but also the molecular chemical structure. Electron irradiation converts alltrans conformation into dynamically mixed trans-gauche conformation in both VDF-rich and TrFE-containing segments, accompanied by a simultaneous ferroelectric to paraelectric (or amorphous) transition. Moreover, electron irradiation enhances the molecular motion in paraelectric regions while the molecular motion in high-temperature amorphous melt (>100 ℃) is more constrained in those irradiated films.

Green tea polyphenols (GTP) are thought to be effective in preventing oxidative stressrelated diseases, including cancer, cardiovascular disease, neurodegenerative disease and aging. In this study, the protective mechanisms of GTP against pro-parkinsonian neurotoxin 6-hydroxydopamine (6-OHDA) induced apoptosis in SH-SY5Y cells were investigated. The results show that GTP treatment rescued the changes in condensed nuclear and apoptotic bodies, attenuated 6-OHDA-induced early apoptosis, prevented the decrease in mitochondrial membrane potential, and suppressed accumulation of reactive oxygen species (ROS) (measured with ESR) and of intracellular free Ca²⁺. It was found that GTP treatment also counteracted 6-OHDA-induced nitric oxide increase and overexpression of nNOS and iNOS, and decreased the level of protein-bound 3-nitrotyrosine (3-NT). In addition, GTP treatment inhibited the auto-oxidation of 6-OHDA and scavenged oxygen free radicals in a dose- and time-dependent manner. Our results show that the protective effects of GTP against 6-OHDA Induced apoptosis in SH-SY5Y cells are mediated, at least in part, by controlling the ROS-NO pathway.

In recent years aromatic polyether ketones have achieved remarkable positions among other thermoplastic polymers because of their unique combination of toughness, stiffness, thermooxidative stability, electrical performance, flame retardancy and retention of physical properties at high temperatures. So they have been successfully applied to many fields such as aviation, spaceflight, nuclear energy, communication, telecom, petroleum, machine manufacturing and traffic. But following the booming development of new science and technology revolution in world, the high performance materials have been required extensive and urgent. In order to improve the characterization of poly(aryl ether keonte)s further, and fulfill the requirement of some extreme environment like the high temperature and irradiation environment, it is made them to take place crosslinking reaction. It is thermoplastic material before process that can be molded or casted, and then becomes thermoset through crosslinking reaction after process, so it has advantage of both kinds of materials. It′s required to introduce crosslinking group. It can not be used the generally aliphatic crosslinking group over the polymer material because it can decease thermal stability of poly(aryl ether keonte)s, but only to look for the material which has aromatic crosslinking group. The aim of the dissertation is from the design of molecular structure to synthesize new monomers and then to synthesize new poly(aryl ether ketone)s containing naphthalene with different chemical environment and linking position through the nucleophilic displacement condensation reaction. Electric Spin Resonance (ESR) as the major method was used to investigate the thermal crossliniking behavior, discussed the affection of naphthalene with different chemical environment and linking position, and made up the mechanism of crosslinking reaction.

We used 1, 5-dihydroxynaphthalene(1, 5-DHN), hydroquinone(HQ) and 4, 4′-Difluorobenzophenone (DFB) to synthesize the new high molecular weight glass poly(ether ether ketone)s random copolymers containing 1, 5-naphthalene moieties. The glass transition temperature (T_g) increases and the melt temperature(T_m), crystallinity decreases with increasing the content of naphthalene moieties. The mechanical property of copolymers decreases a little but basically retains the advantage of poly(aryl ether ketone). These results can be attributed to the disturbance of the segmental movement and the destruction of the symmetry and regularity of the molecular chains due to the introduction of the naphthalene moiety. The thermal crosslinking reaction was monitored by differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD), when the poly(ether ether ketone)s random copolymers containing 1, 5-naphthalene moieties were treated above 320 ℃ under oxidative conditions. Both of speeds about the increment of T_g and decrement crystallinity increase following increasing the content of naphthalene and treated temperature. When the treated samples were measured with ESR quantificationally, typical spectra of single peaks were observed and its intension increased with increasing of treated time. When the microwave power was increased, a weak shoulder beside the single peak discovered was slowly appearing. The microwave power saturation method was used to confirm and differentiate the two kinds of free radical R₁ and R₂. Supposing from the character of spectra, whose samples treated under different air condition, R₁ is RO· free radical and links with naphthalene on molecular chains by counting method. The simulation method was used to confirm R₂ is naphthalene free radicals. As the concentration of R₁ free radicals is higher than that of R₂ free radicals, R₁ free radicals take a predominant role in crosslinking reactions. The variations of radical concentration with time for two kinds of free radical are same: the concentration increased fast at first, and then maintained, finally increased fast again. The method of isothermal degradation was used to find the degradation reaction happened when 1, 5-BFPN was treated at 340 ℃. The mechanism of crosslinking reaction about the copolymers containing 1, 5-naphthalene was made out through the above results.

We synthesized a new monomer 1, 4-bis (4-fluorobenzoyl) naphthalene(1, 4-BFN) using the acyl chloride reaction and Friedel-Crafts acylation reaction of 1, 4-Naphthalenedicarboxylic acid with fluorobenzene. Poly (aryl ether ketone) copolymers possessing various compositions of 1, 4-naphthylene and 1, 4-phenylene moieties were prepared by the reaction of hydroquinone(HQ) with 1, 4-bis(4, 4′-fluorobenzoyl) naphthalene (1, 4-BFN) and 4, 4′-difluorobenzophenone (DFB). The glass transition temperature and solubility increase, while the melting temperature decreases with increasing of 1, 4-naphthalene moieties, and the mechanical of 1, 4-PEEKNK is as well as that of PEEK. The samples of 1, 4-PEEKNK treated above 260 ℃ were detected by DSC, and the T_g increases following increasing the treated time and temperature. Based on the results of FT-IR and NMR, the crosslinking reaction takes place on the naphthalene. ESR was used to research the category of crosslinking reaction too. The variations of radical concentration with time also can be divided into three steps, which can be concluded the crosslinking reaction is free radical reaction. Meanwhile, when the samples were treated at different temperature for 8hrs, the radical concentration increased little at 260 ℃ and 300 ℃, but much at 340 ℃, which means other free radicals were generated at 340 ℃. Though the crosslinking reaction takes place at 340 ℃, it′s not beneficial to application for there are much free radicals left. The method of isothermal degradation was used to find the degradation reaction did not happen when 1, 4-PEEKNK was treated at 260 ℃. We made out the mechanism of crosslinking reaction about PEEKNK.

Concluding from above, we have synthesized two kind of new poly(aryl ether ketone)s containing naphthalene with different chemical environment and linking position through the nucleophilic displacement condensation reaction, and researched their basic characterization. We find both of them can take place crosslinking reaction via several research methods, but the mechanisms of crosslinking reaction are different. Colligated all of the property and requirement, PEEKNK containing diketo 1, 4-naphthalene has excellent applied foreground as aromatic crosslinking poly(aryl ether ketone).