Quantum Fisher information is related to the problem of parameter estimation. Recently, a criterion has been proposed for entanglement in multipartite systems based on quantum Fisher information. This paper studies th...Quantum Fisher information is related to the problem of parameter estimation. Recently, a criterion has been proposed for entanglement in multipartite systems based on quantum Fisher information. This paper studies the behaviours of quantum Fisher information in the quantum kicked top model, whose classical correspondence can be chaotic. It finds that, first, detected by quantum Fisher information, the quantum kicked top is entangled whether the system is in chaotic or in regular case. Secondly, the quantum Fisher information is larger in chaotic case than that in regular case, which means, the system is more sensitive in the chaotic case.展开更多
A simultaneous change in the systemic property of a kicked billiard ball is observed from an entirely smooth and conservative state to a piecewise smooth and quasi-dissipative state when a single controlling parameter...A simultaneous change in the systemic property of a kicked billiard ball is observed from an entirely smooth and conservative state to a piecewise smooth and quasi-dissipative state when a single controlling parameter has been adjusted. The transition induces a sudden change of a typical conservative stochastic web into a transient web. The iterations on the transient web eventually escape to some elliptic islands. In the meantime, a fat fractal forbidden web, which appears also at the threshold, grows up and cuts away increasingly more parts from the original conservative stochastic web. We numerically show that the initial conditions that generated different attractors are mixed in a random manner and the pattern remains unchanged even when smaller and smaller scales are used for examination, indicating a riddle-like basin structure that practically rules out the possibility of predicting the attractors from a given initial condition.展开更多
On October 29th,the DHUB 2018SS Design Fair kicked off in the 79 Tank at 751D PARK.This year’s fashion fair gathered original designs from domestic and overseas designers,while also inviting well-known fashion icons,...On October 29th,the DHUB 2018SS Design Fair kicked off in the 79 Tank at 751D PARK.This year’s fashion fair gathered original designs from domestic and overseas designers,while also inviting well-known fashion icons,to provide you with a unique fashion experience!Not just a tank At the opening ceremony。展开更多
Different types of models for describing the motion of a kicked ion were suggested and studied. It is shown that certain kinds of jumping behavior of the exerting electromagnetic field can lead to a type of noninverti...Different types of models for describing the motion of a kicked ion were suggested and studied. It is shown that certain kinds of jumping behavior of the exerting electromagnetic field can lead to a type of noninvertible property, which changes this conservative system into a 'quasi-dissipative' one. The quasi-dissipative behaviors allow the particle to move along a confined chaotic 'quasi-attractor' in many regions of the parameter space. If the exerting electromagnetic field is discontinuous but the system is still invertible, it will take an unbounded chaotic diffusion with similar parameter values. We hope that this discovery could provide a helpful idea for confining the plasma.展开更多
A major basic research projectin the field of neurosciencewas launched on November26 last year at the Shanghai-basedInstitute of Neuroscience of the Chi-nese Academy of Sciences(CAS).
In this study, we propose a generalized pseudoclassical theory for the kicked rotor model in an attempt to discern the footprints of the classical dynamics in the deep quantum regime. Compared with the previous pseudo...In this study, we propose a generalized pseudoclassical theory for the kicked rotor model in an attempt to discern the footprints of the classical dynamics in the deep quantum regime. Compared with the previous pseudoclassical theory that applies only in the neighborhoods of the lowest two quantum resonances, the proposed theory is applicable in the neighborhoods of all quantum resonances in principle by considering the quantum effect of the free rotation at a quantum resonance. In particular, it is confirmed by simulations that the quantum wavepacket dynamics can be successfully forecasted based on the generalized pseudoclassical dynamics, offering an intriguing example where it is feasible to bridge the dynamics in the deep quantum regime to the classical dynamics. The application of the generalized pseudoclassical theory to the PT-symmetric kicked rotor is also discussed.展开更多
This study analyzed the difference between using a downward breaststroke kick and a horizontal breaststroke kick in a sample of world class elite swimmers.We compared average muscle activity of the gluteus maximus,qua...This study analyzed the difference between using a downward breaststroke kick and a horizontal breaststroke kick in a sample of world class elite swimmers.We compared average muscle activity of the gluteus maximus,quadriceps femoris(vastus medialis and rectus femoris),hamstring/long head of the biceps femoris,gastrocnemius medialis,rectus abdominal,and erector spinae when using the downward breaststroke kick technique.We find that when this sample of swimmers utilized the downward breaststroke kick,max speed and velocity per stroke increased,measured by 12,788 EMG samples,where the results are highly correlated to duration of the aerodynamic buoyant force in breaststroke kick technique.The increases in performance observed from measuring the world class elite swimmers is highly correlated to the duration of the kick aerodynamic buoyant force.Among this sample of elite swimmers,the longer a swimmer demonstrates a buoyant force breaststroke kick,the lower the time in a 100 breaststroke.展开更多
On March 20,2020,the central kick-off ceremony of the major projects of Jinchang in 2020 was officially held in Jinchuan Private Economy Industry Park.At the critical stage of the“second half”of the epidemic control...On March 20,2020,the central kick-off ceremony of the major projects of Jinchang in 2020 was officially held in Jinchuan Private Economy Industry Park.At the critical stage of the“second half”of the epidemic control and operation resumption,the central kick-off of the major projects of Jinchang in 2020 marked that the construction of major projects of Jinchuan and Jinchang has entered the“fast forward”mode,the construction of Jinchuan Private Economy Industry Park and Jinchang National Economic and Technological Development Zone has run on the“fast traffic lane”,and the integrated highquality development of Jinchuan and Jinchang has made a new step forward.展开更多
Life-long license plate According to a new rule from the Ministry of Public Security, owner an end-of-life car can continuously use the previous license plat with the new car, provided the vehicle has no aftermaths in...Life-long license plate According to a new rule from the Ministry of Public Security, owner an end-of-life car can continuously use the previous license plat with the new car, provided the vehicle has no aftermaths involving serious violation展开更多
On October 21,East China Ordins Co.,Ltd held a release meeting in Shanghai,and announced the formal setup of'China Ordins Titanium Industry Fund',the release meeting was co-hosted by East China Ordins and Chin...On October 21,East China Ordins Co.,Ltd held a release meeting in Shanghai,and announced the formal setup of'China Ordins Titanium Industry Fund',the release meeting was co-hosted by East China Ordins and China Nonferrous Metals News.Representatives from Yunnan Metallurgical Group,Zunyi Titanium Group,Pangang Titanium Industry and government,financial domestic organizations totaling over 100 persons attended the activity.展开更多
Floquet dynamical quantum phase transitions(DQPTs),which are nonanalytic phenomena recuring periodically in time-periodic driven quantum many-body systems,have been widely studied in recent years.In this article,the F...Floquet dynamical quantum phase transitions(DQPTs),which are nonanalytic phenomena recuring periodically in time-periodic driven quantum many-body systems,have been widely studied in recent years.In this article,the Floquet DQPTs in transverse XY spin chains under the modulation ofδ-function periodic kickings are investigated.We analytically solve the system,and by considering the eigenstate as well as the ground state as the initial state of the Floquet dynamics,we study the corresponding multiple Floquet DQPTs emerged in the micromotion with different kicking moments.The rate function of return amplitude,the Pancharatnam geometric phase and the dynamical topological order parameter are calculated,which consistently verify the emergence of Floquet DQPTs in the system.展开更多
We theoretically study the transition dynamics of a two-component Bose-Einstein condensate driven by a train of weak δ-shaped laser pulses. We find that the atomic system can experience peculiar resonant transition e...We theoretically study the transition dynamics of a two-component Bose-Einstein condensate driven by a train of weak δ-shaped laser pulses. We find that the atomic system can experience peculiar resonant transition even under weak optical excitations and derive the resonance condition by the perturbation method. Employing this mechanism, we propose a scheme to obtain an atomic ensemble with desired odd/even atom number and also a scheme to prepare a nonclassical state of the many-body system with fixed atom number.展开更多
基金Project supported by National Natural Science Foundation of China (Grant Nos. 11025527,10874151,and 10935010)
文摘Quantum Fisher information is related to the problem of parameter estimation. Recently, a criterion has been proposed for entanglement in multipartite systems based on quantum Fisher information. This paper studies the behaviours of quantum Fisher information in the quantum kicked top model, whose classical correspondence can be chaotic. It finds that, first, detected by quantum Fisher information, the quantum kicked top is entangled whether the system is in chaotic or in regular case. Secondly, the quantum Fisher information is larger in chaotic case than that in regular case, which means, the system is more sensitive in the chaotic case.
基金supported by National Natural Science Foundation of China (No. 10275053)
文摘A simultaneous change in the systemic property of a kicked billiard ball is observed from an entirely smooth and conservative state to a piecewise smooth and quasi-dissipative state when a single controlling parameter has been adjusted. The transition induces a sudden change of a typical conservative stochastic web into a transient web. The iterations on the transient web eventually escape to some elliptic islands. In the meantime, a fat fractal forbidden web, which appears also at the threshold, grows up and cuts away increasingly more parts from the original conservative stochastic web. We numerically show that the initial conditions that generated different attractors are mixed in a random manner and the pattern remains unchanged even when smaller and smaller scales are used for examination, indicating a riddle-like basin structure that practically rules out the possibility of predicting the attractors from a given initial condition.
文摘On October 29th,the DHUB 2018SS Design Fair kicked off in the 79 Tank at 751D PARK.This year’s fashion fair gathered original designs from domestic and overseas designers,while also inviting well-known fashion icons,to provide you with a unique fashion experience!Not just a tank At the opening ceremony。
基金the National Natural Foundation of China under Grant No. 19975039.
文摘Different types of models for describing the motion of a kicked ion were suggested and studied. It is shown that certain kinds of jumping behavior of the exerting electromagnetic field can lead to a type of noninvertible property, which changes this conservative system into a 'quasi-dissipative' one. The quasi-dissipative behaviors allow the particle to move along a confined chaotic 'quasi-attractor' in many regions of the parameter space. If the exerting electromagnetic field is discontinuous but the system is still invertible, it will take an unbounded chaotic diffusion with similar parameter values. We hope that this discovery could provide a helpful idea for confining the plasma.
文摘A major basic research projectin the field of neurosciencewas launched on November26 last year at the Shanghai-basedInstitute of Neuroscience of the Chi-nese Academy of Sciences(CAS).
基金supported by the National Natural Science Foundation of China (Grant Nos. 12075198, 12247106, and 12247101)。
文摘In this study, we propose a generalized pseudoclassical theory for the kicked rotor model in an attempt to discern the footprints of the classical dynamics in the deep quantum regime. Compared with the previous pseudoclassical theory that applies only in the neighborhoods of the lowest two quantum resonances, the proposed theory is applicable in the neighborhoods of all quantum resonances in principle by considering the quantum effect of the free rotation at a quantum resonance. In particular, it is confirmed by simulations that the quantum wavepacket dynamics can be successfully forecasted based on the generalized pseudoclassical dynamics, offering an intriguing example where it is feasible to bridge the dynamics in the deep quantum regime to the classical dynamics. The application of the generalized pseudoclassical theory to the PT-symmetric kicked rotor is also discussed.
文摘This study analyzed the difference between using a downward breaststroke kick and a horizontal breaststroke kick in a sample of world class elite swimmers.We compared average muscle activity of the gluteus maximus,quadriceps femoris(vastus medialis and rectus femoris),hamstring/long head of the biceps femoris,gastrocnemius medialis,rectus abdominal,and erector spinae when using the downward breaststroke kick technique.We find that when this sample of swimmers utilized the downward breaststroke kick,max speed and velocity per stroke increased,measured by 12,788 EMG samples,where the results are highly correlated to duration of the aerodynamic buoyant force in breaststroke kick technique.The increases in performance observed from measuring the world class elite swimmers is highly correlated to the duration of the kick aerodynamic buoyant force.Among this sample of elite swimmers,the longer a swimmer demonstrates a buoyant force breaststroke kick,the lower the time in a 100 breaststroke.
文摘On March 20,2020,the central kick-off ceremony of the major projects of Jinchang in 2020 was officially held in Jinchuan Private Economy Industry Park.At the critical stage of the“second half”of the epidemic control and operation resumption,the central kick-off of the major projects of Jinchang in 2020 marked that the construction of major projects of Jinchuan and Jinchang has entered the“fast forward”mode,the construction of Jinchuan Private Economy Industry Park and Jinchang National Economic and Technological Development Zone has run on the“fast traffic lane”,and the integrated highquality development of Jinchuan and Jinchang has made a new step forward.
文摘Life-long license plate According to a new rule from the Ministry of Public Security, owner an end-of-life car can continuously use the previous license plat with the new car, provided the vehicle has no aftermaths involving serious violation
文摘On October 21,East China Ordins Co.,Ltd held a release meeting in Shanghai,and announced the formal setup of'China Ordins Titanium Industry Fund',the release meeting was co-hosted by East China Ordins and China Nonferrous Metals News.Representatives from Yunnan Metallurgical Group,Zunyi Titanium Group,Pangang Titanium Industry and government,financial domestic organizations totaling over 100 persons attended the activity.
基金supported by the National Natural Science Foundation of China(Grant No.11475037)the Fundamental Research Funds for the Central Universities(Grant No.DUT19LK38)。
文摘Floquet dynamical quantum phase transitions(DQPTs),which are nonanalytic phenomena recuring periodically in time-periodic driven quantum many-body systems,have been widely studied in recent years.In this article,the Floquet DQPTs in transverse XY spin chains under the modulation ofδ-function periodic kickings are investigated.We analytically solve the system,and by considering the eigenstate as well as the ground state as the initial state of the Floquet dynamics,we study the corresponding multiple Floquet DQPTs emerged in the micromotion with different kicking moments.The rate function of return amplitude,the Pancharatnam geometric phase and the dynamical topological order parameter are calculated,which consistently verify the emergence of Floquet DQPTs in the system.
基金Project supported by the National Key Research and Development Program of China(Grant No.2016YFA0301504)the National Natural Science Foundation of China(Grant Nos.61835013 and 11774362)
文摘We theoretically study the transition dynamics of a two-component Bose-Einstein condensate driven by a train of weak δ-shaped laser pulses. We find that the atomic system can experience peculiar resonant transition even under weak optical excitations and derive the resonance condition by the perturbation method. Employing this mechanism, we propose a scheme to obtain an atomic ensemble with desired odd/even atom number and also a scheme to prepare a nonclassical state of the many-body system with fixed atom number.
