We study the kick dynamics of periodically driven quantum systems,and provide a time-independent effective Hamiltonian with the analytical form to reasonably describe the effective dynamics in a long timescale.It is s...We study the kick dynamics of periodically driven quantum systems,and provide a time-independent effective Hamiltonian with the analytical form to reasonably describe the effective dynamics in a long timescale.It is shown that the effective coupling strength can be much larger than the coupling strength of the original system in some parameter regions,which stems from the zero time duration of kicks.Furthermore,different regimes can be transformed from and to each other in the same three-level system by only modulating the period of periodic kicks.In particular,the population of excited states can be selectively suppressed in periodic kicks,benefiting from the large detuning regime of the original system.Finally,some applications and physical implementation of periodic kicks are demonstrated in quantum systems.These unique features would make periodic kicks become a powerful tool for quantum state engineering.展开更多
We establish a model for a four-terminal thermoelectric system,based on three coupled quantum dots,which consists of a left/right electron reservoir(the source and the drain),two thermal reservoirs and three coupled q...We establish a model for a four-terminal thermoelectric system,based on three coupled quantum dots,which consists of a left/right electron reservoir(the source and the drain),two thermal reservoirs and three coupled quantum dots.Based on the master equation theory,we derive the expressions of the electron current and heat flow among the three quantum dots and the corresponding reservoir.We show that the source can be cooled by passing a thermal current between the two thermal reservoirs,with no net heat exchange between the thermal reservoirs and the electron reservoirs.This effect is called the Coulomb heat drag effect.Then,we define the coefficient of performance(COP) and the cooling power.The influence of the main system parameters,such as charging energy,energy level,and temperature,on the performance of the four-terminal thermoelectric system is analyzed in detail.By choosing appropriate parameters one can obtain the maximum cooling power and the corresponding COP.Finally,we also show that the Maxwell demon effect can be realized by using nonequilibrium thermal reservoirs in our four-terminal thermoelectric system.展开更多
基因表达量测定对基因功能解析和探索生命机理具有重大意义,目前实时荧光PCR和微滴式数字PCR技术是进行基因表达量测定的有效方法。本文以低温处理的霍乱弧菌sfs、vcc、Rec A、hly及16S r RNA基因为研究对象,分别用实时荧光PCR和微滴式...基因表达量测定对基因功能解析和探索生命机理具有重大意义,目前实时荧光PCR和微滴式数字PCR技术是进行基因表达量测定的有效方法。本文以低温处理的霍乱弧菌sfs、vcc、Rec A、hly及16S r RNA基因为研究对象,分别用实时荧光PCR和微滴式数字PCR技术对低温处理前后霍乱弧菌的上述基因表达量进行测定,实时荧光PCR实验数据分别采用??CT和ge Norm法进行分析,微滴式数字PCR实验数据分别采用相对定量和绝对定量法进行分析,获得处理组基因表达量相对于对照组的变化倍数;使用多维尺度法来分析四种基因定量方法的数据。结果表明,在本实验条件下,四种基因定量方法的分析结果存在差异;16S r RNA基因表达量发生了变化,不适合作为内参基因;微滴式数字PCR能更直观的给出基因表达量变化的结果,并且基因表达差异相对定量分析的准确度更高。展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11805036,12175033,12147206)the Natural Science Foundation of Fujian Province,China(Grant No.2021J01575)+1 种基金the Natural Science Funds for Distinguished Young Scholar of Fujian Province,China(Grant No.2020J06011)the Project from Fuzhou University(Grant No.JG202001-2)。
文摘We study the kick dynamics of periodically driven quantum systems,and provide a time-independent effective Hamiltonian with the analytical form to reasonably describe the effective dynamics in a long timescale.It is shown that the effective coupling strength can be much larger than the coupling strength of the original system in some parameter regions,which stems from the zero time duration of kicks.Furthermore,different regimes can be transformed from and to each other in the same three-level system by only modulating the period of periodic kicks.In particular,the population of excited states can be selectively suppressed in periodic kicks,benefiting from the large detuning regime of the original system.Finally,some applications and physical implementation of periodic kicks are demonstrated in quantum systems.These unique features would make periodic kicks become a powerful tool for quantum state engineering.
基金supported by the National Natural Science Foundation of China(Grant No.11875034)。
文摘We establish a model for a four-terminal thermoelectric system,based on three coupled quantum dots,which consists of a left/right electron reservoir(the source and the drain),two thermal reservoirs and three coupled quantum dots.Based on the master equation theory,we derive the expressions of the electron current and heat flow among the three quantum dots and the corresponding reservoir.We show that the source can be cooled by passing a thermal current between the two thermal reservoirs,with no net heat exchange between the thermal reservoirs and the electron reservoirs.This effect is called the Coulomb heat drag effect.Then,we define the coefficient of performance(COP) and the cooling power.The influence of the main system parameters,such as charging energy,energy level,and temperature,on the performance of the four-terminal thermoelectric system is analyzed in detail.By choosing appropriate parameters one can obtain the maximum cooling power and the corresponding COP.Finally,we also show that the Maxwell demon effect can be realized by using nonequilibrium thermal reservoirs in our four-terminal thermoelectric system.
文摘基因表达量测定对基因功能解析和探索生命机理具有重大意义,目前实时荧光PCR和微滴式数字PCR技术是进行基因表达量测定的有效方法。本文以低温处理的霍乱弧菌sfs、vcc、Rec A、hly及16S r RNA基因为研究对象,分别用实时荧光PCR和微滴式数字PCR技术对低温处理前后霍乱弧菌的上述基因表达量进行测定,实时荧光PCR实验数据分别采用??CT和ge Norm法进行分析,微滴式数字PCR实验数据分别采用相对定量和绝对定量法进行分析,获得处理组基因表达量相对于对照组的变化倍数;使用多维尺度法来分析四种基因定量方法的数据。结果表明,在本实验条件下,四种基因定量方法的分析结果存在差异;16S r RNA基因表达量发生了变化,不适合作为内参基因;微滴式数字PCR能更直观的给出基因表达量变化的结果,并且基因表达差异相对定量分析的准确度更高。
