The study of the micro high viscosity mechanism of heavy oil is of great significance for the efficient development of Bohai heavy oil. Therefore, aiming at the typical heavy oil reservoirs in Bohai Sea, the microscopic mechanism of high viscosity of heavy oil is analyzed and studied from the aspects of viscosity?temperature relationship, crude oil composition and component polarity, heteroatom distribution and asphaltene aggregate structure. The results show that compared with N oilfield in Bohai Sea, the content of alkanes and aromatics in L oilfield in Bohai Sea is lower, and the quality score of resins and asphaltenes is higher, reaching 29.95% and 9.76% (23.25% and 6.59% in N oilfield). The quality score of heteroatoms such as O,N and S are high, and the relative molecular mass of resins and asphaltenes are also high. The polarity of each component is strong, and the dipole moments of resins and asphaltenes reach 14.01 D and 17.94 D, respectively (9.12 D and 12.25 D in N oilfield ). These will lead to stronger intermolecular forces and stronger intermolecular association between resins and asphaltenes. The smaller asphaltene molecular spacing and the denser aggregate structure,which will eventually lead to higher viscosity of crude oil.

Polyoxometalates (POMs) are molecular metal oxides composed of transition metals in their highes oxidation states (Mo,W,V,Nb,Ta). The high solubility and low specific surface area of pure inorganic POMs limi its practical applications in polar solvents. Due to the widespread applications of organic?inorganic hybrid POMs and immobilized POMs in the field of catalysis, energy conversion, storage and magnetism have attracted considerable attention.The design and synthesis of transition metal/Lanthanide modified organic?inorganic polyoxometalates and immobilized polyoxometalates composites are reviewed,and the practical applications of POMs with novel structures are summarized and outlooked.

In this work, the HTO (H_4x/3Ti_2-x/3□ _x/3O₄·nH₂O) was used as the precursor raw material, and the nanoscale titanium oxide particles (ST01) were loaded on the surface of the HTO by water bath impregnation, and the TiO₂ homogeneous structure composite was topologically synthesized by calcination method. Using X?ray diffraction （XRD）, Raman spectroscopy (Raman) and other testing methods, the effect of calcination temperature on the phase transition process with titanium dioxide was studied in detail. The results indicate that the HTO can transfer to TiO₂（B）, anatase TiO₂ and rutile TiO₂ with increased temperatures, and the TiO₂ homophase composites are obtained with various structure and content of TiO₂. The degradation experiment was carried out with Rhodamine B （RhB） as the pollutant model. The photocatalytic activity of the sample at 600 ℃ is significantly higher than that of other samples, mainly because the separation efficiency of electrons and holes of the sample is the highest at this time, indicating that the structure and composition of homogeneous composite TiO₂ affect its photocatalytic activity. In addition, dye?sensitized solar cell （DSSCs） experiments show that the reason for the higher optoelectronic performance of the samples at 600 ℃ is that the two?dimensional sheet?like morphology facilitates the rapid migration of photogenerated carriers.