The freezing-thawing circulation was the most common security problems of buried pipeline in permafrost regions, and it could make pipeline generate additional stress. For the regional with the special structure of topographic, the freezing-thawing circulation would change the original geological characteristics, and caused geological disasters under certain conditions. The stress impact of the pipeline was studied generated by the freezing-thawing landslide because of the melting permafrost. The degree of influence of axial landslide with different displacement on the pipeline was analyzed. The simulation analysis showed that different forms of landslide generated a great impact on the pipelines; furthermore, the effects of stress on the pipeline had a greater impact by changing the location of the landslide. The influence on the pipelines generated by the freezing-thawing landslide were simulated and analyzed ,which could well reflect the changes in stress and provide a theoretical basis for building construction of buried pipelines in the permafrost regions.

To solve the overlap of part of fault classes in the analog circuit fault diagnostics, a novel analog circuit fault diagnostics approach based on quantum neural networks algorithm was presented. Kurtosis and entropy were calculated as features after the time domain response signals of the circuit under test were measured, and then the different fault classes were identified by quantum neural networks algorithm. The simulation demonstrated that constructed neural network had simple network structure and the fault diagnosis accuracy was higher, which reached 99.62%.

Natural ()huperzine A has been found to be an effective inhibitor of acetylcholinesterase (AChE) and can be applied in the treatment of Alzheimer`s disease (AD). The pharmaceutical prospects and lack in natural resource have made the total synthesis of huperzine A an extremely attractive topic in the past decades. In this paper, the progress in the synthesis of the core carbonlectone of huperzine A is reviewed and various types of reactions are summarized in this area.