A nucleus-encoded MinE gene, designated PpMinE, from Physcomitrella patens was identified using RT-PCR. The presence of both N- and C-terminal extensions in PpMinE protein suggested its cyanobacterial origin. The tran...A nucleus-encoded MinE gene, designated PpMinE, from Physcomitrella patens was identified using RT-PCR. The presence of both N- and C-terminal extensions in PpMinE protein suggested its cyanobacterial origin. The transient expression of PpMinE using green fluorescent protein fusion in tobacco （Nicotiana tabacum L.） indicated that the PpMinE was a chloroplast-targeted protein. Overexpression of PpMinE in Escherichia coli caused division site misplacement and minicell formation, suggesting evolutionary functional conservation of MinE during plant phylogenesis. According to the phylogenetic tree, PpMinE protein has a close relationship with the highland plants, which suggests that the transfer events of MinE gene from plastid to nucleus might have occurred before the origin of the land plants.展开更多
The theory of conceptual transfer investigates the extent to which the perception of a previously learned language influences the conceptualization of a language learned subsequently.To provide further evidence suppor...The theory of conceptual transfer investigates the extent to which the perception of a previously learned language influences the conceptualization of a language learned subsequently.To provide further evidence supporting such hypotheses,the present study invites three groups of native Chinese-speaking college students to finish selected language tasks with an aim to explore whether the perception of L3 French motion verbs presents itself in the acquisition of L2 English path particles.All three participating groups have learned English as L2 and reached intermediate level,with one group being Chinese majors and the other two specializing in French with different proficiency levels.The findings suggest L3 would exhibit negative transfer in the acquisition of motion events in L2 English.Based on the analysis of participants’retrospective data and the comparison between Chinese group and French groups,the nature of such transfer is claimed to be conceptual.Results also reveal L3 proficiency exerts no influence on conceptual transfer.展开更多
Rollover of commercial heavy vehicles can cause enormous economic losses and fatalities.It is easier for such vehicles to rollover if the driver’s steering frequency is close to the critical frequency of the vehicle...Rollover of commercial heavy vehicles can cause enormous economic losses and fatalities.It is easier for such vehicles to rollover if the driver’s steering frequency is close to the critical frequency of the vehicle’s roll motion;however,the critical roll frequency has rarely been investigated.In this study,the second-order transfer function between the steering input and roll angle was developed to calculate the critical frequency of the vehicle’s roll motion.The simulated spectrum and transfer function were then used to dynamically predict the peak lateral load transfer ratio.Laboratory experiments were conducted using a scaled vehicle to verify the critical roll frequency.The results suggest that the peak value of the lateral load transfer ratio during steering can be accurately determined from the driver’s input,and the critical roll frequency has a dominant effect on the dynamic rollover of heavy vehicles.展开更多
基金This work was supported by the National Natural Science Foundation of China (No. 30470879).
文摘A nucleus-encoded MinE gene, designated PpMinE, from Physcomitrella patens was identified using RT-PCR. The presence of both N- and C-terminal extensions in PpMinE protein suggested its cyanobacterial origin. The transient expression of PpMinE using green fluorescent protein fusion in tobacco （Nicotiana tabacum L.） indicated that the PpMinE was a chloroplast-targeted protein. Overexpression of PpMinE in Escherichia coli caused division site misplacement and minicell formation, suggesting evolutionary functional conservation of MinE during plant phylogenesis. According to the phylogenetic tree, PpMinE protein has a close relationship with the highland plants, which suggests that the transfer events of MinE gene from plastid to nucleus might have occurred before the origin of the land plants.
文摘The theory of conceptual transfer investigates the extent to which the perception of a previously learned language influences the conceptualization of a language learned subsequently.To provide further evidence supporting such hypotheses,the present study invites three groups of native Chinese-speaking college students to finish selected language tasks with an aim to explore whether the perception of L3 French motion verbs presents itself in the acquisition of L2 English path particles.All three participating groups have learned English as L2 and reached intermediate level,with one group being Chinese majors and the other two specializing in French with different proficiency levels.The findings suggest L3 would exhibit negative transfer in the acquisition of motion events in L2 English.Based on the analysis of participants’retrospective data and the comparison between Chinese group and French groups,the nature of such transfer is claimed to be conceptual.Results also reveal L3 proficiency exerts no influence on conceptual transfer.
基金supported by the National Natural Science Foundation of China(NSFC)under Grant 51905483.
文摘Rollover of commercial heavy vehicles can cause enormous economic losses and fatalities.It is easier for such vehicles to rollover if the driver’s steering frequency is close to the critical frequency of the vehicle’s roll motion;however,the critical roll frequency has rarely been investigated.In this study,the second-order transfer function between the steering input and roll angle was developed to calculate the critical frequency of the vehicle’s roll motion.The simulated spectrum and transfer function were then used to dynamically predict the peak lateral load transfer ratio.Laboratory experiments were conducted using a scaled vehicle to verify the critical roll frequency.The results suggest that the peak value of the lateral load transfer ratio during steering can be accurately determined from the driver’s input,and the critical roll frequency has a dominant effect on the dynamic rollover of heavy vehicles.
