培养高等专科学历工程人才，促进科技发展。 机械学科、电气工程及自动化、电子信息工程、通信工程、计算机科学与技术、电子科学与技术、经济学、国际经济与贸易、工商管理、市场营销、会计学、财务管理、农业机械化及其自动化、环境工程学科高等专科学历教育 相关学术交流、科学研究、继续教育与专业培训
Analysis of main components and quantitative analysis of antibacterial composition of basil essential oil are conducted by using gas chromatography-mass spectrometry (GC-MS).Stability analysis of supermarket fresh light beam and pH value on antibacterial components is studied by ultraviolet spectrophotometry.Antibacterial effect of basil essential oil is determined by filter paper diffusion method.Through the observation of change of cell by using scanning electron microscope (SEM),the bacteriostatic mechanism of basil essential oil is explored.The results show that the main antibacterial composition of basil essential oil is eugenol whose absolute content is 0.9734 g/mL.Light has little influence to the stability of eugenol.It has good stability if the solution pH value is in the range of 5～8.Basil essential oil has significant inhibition on Escherichia coli and Staphylococcus aureus by breaking the integrity of cell.
For popular querying, computing resources will be wasted if the index doesn't employ any optimized query mechanism. To improve the query efficiency, we propose a modified R-tree index structure based on cache. The index tree is divided into two nodes, the upper node is for the query and the corresponding cache node solutions, and the lower node is regular R-tree node. To match the input query and the cached popular query, we propose an efficient cached popularity detection mechanism. We choose the real data of road network for verification, and the experiment shows that the proposed scheme outperforms the normal R-tree and other similar structures for popular querying.
