Brønsted acid in Y zeolite plays a key role in the processes of catalyst,and the structure reflects the strength of B acid.The stable structures of Brønsted acid sites of HY,[AlO]+/HY,and [Al(OH)]2+/HY were simulated by periotic models.The relationship between the structures of Brønsted acid sites and its environments was identified by combination of dynamic simulation with DFT calculation.By analyzing the structure and electronic permanent,together with the statistical results of molecular dynamics,it can be found that the strength of Brønsted acid can connected with the number of H atoms in the 12 membered ring that the small number.The weaker the binding ability of H atoms to O atoms in B acid center is,and the more electrons H atoms lose,the stronger the B acid acidity is.The addition of extra⁃framework aluminum can enhance the acidity of B acid,and [Al(OH)]2+ has more obvious effect on B acid properties.These results can lead the synthetic and modification of B acid site in a theoretical support.

The prediction and analysis of natural gas demand can provide help for reasonable production scheduling and resource allocation, and then bring economic benefits to the network companies. This paper discusses the current research progress of natural gas demand prediction and other energy demand prediction, analyzes the research status and development direction in this field at home and abroad, and introduces the characteristics and development trend of the models used specially. The problems in current study and future research direction are pointed out, and the research results and the research results that can be used for reference are summarized, which can provide reference for future research on the further development of natural gas demand.

A series of MP-like catalysts LaAAl ₁₁O ₁₉ and LaAMnAl ₁₀O ₁₉ (A stands of Cd,Zn,Zr) were prepared by co-precipitation method. The structure and the properties of these catalysts were investigated by using BET,XRD techniques and activities of methane catalytic combustion. The influence of different transition metal on the morphological and catalytic activity of the catalysts was studied. The results show that the catalyst with good crystal is obtained after calcination at 1 200 ℃. And all catalysts have the high catalytic activity and stability. The introduction of different transition metal has much effect on the properties of catalysts. The synergism is observed between the different metal ion. Catalytic activity is enhanced by synergism. LaZnMnAl ₁₀O ₁₉  has the higher catalytic activity in methane combustion and its light-off T 10% is 472 ℃, total conversion  T 90% is 734 ℃.