The internal microbial diversity and small molecular metabolites of Nuodeng ham in different processing years(the first,second and third year sample)were analyzed by high-throughput sequencing technology and gas chrom...The internal microbial diversity and small molecular metabolites of Nuodeng ham in different processing years(the first,second and third year sample)were analyzed by high-throughput sequencing technology and gas chromatography-time of flight mass spectrography(GC-TOF-MS)to study the effects of microorganisms and small molecular metabolites on the quality of ham in different processing years.The results showed that the dominant bacteria phyla of Nuodeng ham in different processing years were Proteobacteria and Firmicutes,the dominant fungi phyla were Ascomycota and Basidiomycota,while Staphylococcus and Aspergillus were the dominant bacteria and fungi of Nuodeng ham,respectively.Totally,252 kinds of small molecular metabolites were identified from Nuodeng ham in different processing years,and 12 different metabolites were screened through multivariate statistical analysis.Further metabolic pathway analysis showed that 23 metabolic pathways were related to ham fermentation,of which 8 metabolic pathways had significant effects on ham fermentation(Impact>0.01,P<0.05).The content of L-proline,phenyllactic acid,L-lysine,carnosine,taurine,D-proline,betaine and creatine were significantly positively correlated with the relative abundance of Staphylococcus and Serratia,but negatively correlated with the relative abundance of Halomonas,Aspergillus and Yamadazyma.展开更多
The control of flight forces and moments by flapping wings of a model bumblebee is studied using the method of computational fluid dynamics. Hovering flight is taken as the reference flight： Wing kinematic parameters...The control of flight forces and moments by flapping wings of a model bumblebee is studied using the method of computational fluid dynamics. Hovering flight is taken as the reference flight： Wing kinematic parameters are varied with respect to their values at hovering flight. Moments about （and forces along） x, y, z axes that pass the center of mass are computed. Changing stroke amplitude （or wingbeat frequency） mainly produces a vertical force. Changing mean stroke angle mainly produces a pitch moment. Changing wing angle of attack, when down- and upstrokes have equal change, mainly produces a vertical force, while when down- and upstrokes have opposite changes, mainly produces a horizontal force and a pitch moment. Changing wing rotation timing, when dorsal and ventral rotations have the same timing, mainly produces a vertical force, while when dorsal and ventral rotations have opposite timings, mainly produces a pitch moment and a horizontal force. Changing rotation duration has very small effect on forces and moments. Anti-symmetrically changing stroke amplitude （or wingbeat frequency） of the contralateral wings mainly produces a roll moment. Anti-symmetrically changing angles of attack of the contralateral wings, when down- and upstrokes have equal change, mainly produces a roll moment, while when down- and upstrokes have opposite changes, mainly produces a yaw moment. Anti-symmetrically changing wing rotation timing of the contralateral wings, when dorsal and ventral rotations have the same timing, mainly produces a roll moment and a side force, while when dorsal and ventral rotations have opposite timings, mainly produces a yaw moment. Vertical force and moments about the three axes can be separately controlled by separate kinematic variables. A very fast rotation can be achieved with moderate changes in wing kinematics.展开更多
基金supported by Major Science and Technology Projects of Yunnan Science and Technology Plan(2019ZG003)Yunnan Young and Middle-aged Academic and Technical Leader Reserve Talent Project(202105AC160068)。
文摘The internal microbial diversity and small molecular metabolites of Nuodeng ham in different processing years(the first,second and third year sample)were analyzed by high-throughput sequencing technology and gas chromatography-time of flight mass spectrography(GC-TOF-MS)to study the effects of microorganisms and small molecular metabolites on the quality of ham in different processing years.The results showed that the dominant bacteria phyla of Nuodeng ham in different processing years were Proteobacteria and Firmicutes,the dominant fungi phyla were Ascomycota and Basidiomycota,while Staphylococcus and Aspergillus were the dominant bacteria and fungi of Nuodeng ham,respectively.Totally,252 kinds of small molecular metabolites were identified from Nuodeng ham in different processing years,and 12 different metabolites were screened through multivariate statistical analysis.Further metabolic pathway analysis showed that 23 metabolic pathways were related to ham fermentation,of which 8 metabolic pathways had significant effects on ham fermentation(Impact>0.01,P<0.05).The content of L-proline,phenyllactic acid,L-lysine,carnosine,taurine,D-proline,betaine and creatine were significantly positively correlated with the relative abundance of Staphylococcus and Serratia,but negatively correlated with the relative abundance of Halomonas,Aspergillus and Yamadazyma.
基金the National Natural Science Foundation of China(No.10732030)the"Fan Zhou"Youth Science Fund of Beijing University of Aeronautics and Astronautics(No.20070502)
文摘The control of flight forces and moments by flapping wings of a model bumblebee is studied using the method of computational fluid dynamics. Hovering flight is taken as the reference flight： Wing kinematic parameters are varied with respect to their values at hovering flight. Moments about （and forces along） x, y, z axes that pass the center of mass are computed. Changing stroke amplitude （or wingbeat frequency） mainly produces a vertical force. Changing mean stroke angle mainly produces a pitch moment. Changing wing angle of attack, when down- and upstrokes have equal change, mainly produces a vertical force, while when down- and upstrokes have opposite changes, mainly produces a horizontal force and a pitch moment. Changing wing rotation timing, when dorsal and ventral rotations have the same timing, mainly produces a vertical force, while when dorsal and ventral rotations have opposite timings, mainly produces a pitch moment and a horizontal force. Changing rotation duration has very small effect on forces and moments. Anti-symmetrically changing stroke amplitude （or wingbeat frequency） of the contralateral wings mainly produces a roll moment. Anti-symmetrically changing angles of attack of the contralateral wings, when down- and upstrokes have equal change, mainly produces a roll moment, while when down- and upstrokes have opposite changes, mainly produces a yaw moment. Anti-symmetrically changing wing rotation timing of the contralateral wings, when dorsal and ventral rotations have the same timing, mainly produces a roll moment and a side force, while when dorsal and ventral rotations have opposite timings, mainly produces a yaw moment. Vertical force and moments about the three axes can be separately controlled by separate kinematic variables. A very fast rotation can be achieved with moderate changes in wing kinematics.
