Let (X 1,X 2,...,X n) and (Y 1,Y 2,...,Y n) be real random vectors with the same marginal distributions,if (X 1,X 2,...,X n)≤ c(Y 1,Y 2,...,Y n), it is showed in this paper that ∑ n i=1 X i≤ c...Let (X 1,X 2,...,X n) and (Y 1,Y 2,...,Y n) be real random vectors with the same marginal distributions,if (X 1,X 2,...,X n)≤ c(Y 1,Y 2,...,Y n), it is showed in this paper that ∑ n i=1 X i≤ cx ∑ n i=1 Y i and max 1≤k≤n ∑ k i=1 X i≤ icx max 1≤k≤n ∑ k i=1 Y i hold.Based on this fact,a more general comparison theorem is obtained.展开更多
We use out-of-time order correlators(OTOCs)to investigate the quantum instability and Ehrenfest time for an inverted harmonic oscillator(IHO).For initial states located in the stable manifolds of the IHO we find that ...We use out-of-time order correlators(OTOCs)to investigate the quantum instability and Ehrenfest time for an inverted harmonic oscillator(IHO).For initial states located in the stable manifolds of the IHO we find that the corresponding OTOC exhibits identical evolutionary characteristics to the saddle point before the Ehrenfest time.For initial states located in the unstable manifolds,the OTOCs still grow exponentially but the time to maintain exponential growth is related to the center position of its wave packet in phase space.Moreover,we use the Husimi Q function to visualize the quantum wave packets during exponential growth of the OTOCs.Our results show that quantum instability exists at arbitrary orbits in the IHO system,and the Ehrenfest time in the IHO system depends not only on the photon number of the initial system but also on the central positions of the initial states in phase space.展开更多
The results of plane turbulent wake given by Chou Peiyuan are considered as the first order ap- proximation and put into the equations of turbulent fluctuation.The equations are solved numerically within the range of ...The results of plane turbulent wake given by Chou Peiyuan are considered as the first order ap- proximation and put into the equations of turbulent fluctuation.The equations are solved numerically within the range of micro-scale by means of spectrum method.The double,triple and quadruple fluctuating velocity correlations are obtained by computation.They are in good agreement with experimental results.展开更多
We investigate the quantum entanglement in a non-Hermitian kicking system.In the Hermitian case,the out-of-time ordered correlators(OTOCs)exhibit the unbounded power-law increase with time.Correspondingly,the linear e...We investigate the quantum entanglement in a non-Hermitian kicking system.In the Hermitian case,the out-of-time ordered correlators(OTOCs)exhibit the unbounded power-law increase with time.Correspondingly,the linear entropy,which is a common measurement of entanglement,rapidly increases from zero to almost unity,indicating the formation of quantum entanglement.For strong enough non-Hermitian driving,both the OTOCs and linear entropy rapidly saturate as time evolves.Interestingly,with the increase of non-Hermitian kicking strength,the long-time averaged value of both OTOCs and linear entropy has the same transition point where they exhibit the sharp decrease from a plateau,demonstrating the disentanglment.We reveal the mechanism of disentanglement with the extension of Floquet theory to non-Hermitian systems.展开更多
In order to improve the tracking performance in this paper following TBD(Track before Detection) framework multi-level crossover and matching operator is presented.In data association stage the greedy principle is ado...In order to improve the tracking performance in this paper following TBD(Track before Detection) framework multi-level crossover and matching operator is presented.In data association stage the greedy principle is adopted to handle time complexity in DPA and at the same time crossover mathing operator is given to construct candidate trajectory.In addition the corresponding strategy is introduced in preprocessing and postprocessing to remove clutter and suppress false alarm rate.By the experimental comparison and analysis it can be found that the method is more perfer to strengthen the tracking performance of targets with SNR < 2.0 dB.展开更多
The fate of the litter of dominant vegetation(willows and reeds) is one of the aspects studied in the frame of the project “Onderzoek Milieu Effecten Sigmaplan”. One of the questions to be considered is how long the...The fate of the litter of dominant vegetation(willows and reeds) is one of the aspects studied in the frame of the project “Onderzoek Milieu Effecten Sigmaplan”. One of the questions to be considered is how long the litter stays within the estuary. In this paper, the time the leaf litter(Salix triandra and Phragmites australis) stayed in the Schelde estuary was studied by using plant pigment as biomarkers with HPLC application. After analyzing the original data from the incubation experiment described by Dubuison and Geers(1999), the decomposition dynamics patterns of pigments were analyzed and described, and these decomposition dynamics patterns were used as calibration patterns. By using Spearman Rank Order Correlation, the calibration patterns of the pigments which were significant(p<0.05) were grouped. In this way, several groups of the calibration patterns of pigment decomposition were achieved. The presence or absence of these groups of pigments (whether they can be detected or not from HPLC) was shown to be useful in determining the time the litter has stayed in the water. Combining data of DW and POC, more precise timing can be obtained.展开更多
The low-lying spectra of7 Li and9Li are investigated within an ab initio Monte Carlo Shell Model（MCSM） employing a realistic potential obtained via the Unitary Correlation Operator Method（UCOM）. The MCSM calculati...The low-lying spectra of7 Li and9Li are investigated within an ab initio Monte Carlo Shell Model（MCSM） employing a realistic potential obtained via the Unitary Correlation Operator Method（UCOM）. The MCSM calculations in a 4-major-shells model space for the binding energy and mass quadrupole moment of7, 9Li show good convergence when the MCSM dimension reaches 20. The excitation energy of the Jπ= 1/2-state for7 Li and the magnetic moments for7, 9Li ground states in the MCSM with a treatment of spurious center-of-mass motion are close to the experimental data. Correct level ordering of Jπ=3/2-and 1/2-states for7, 9Li can be reproduced due to the inclusion of three-body correlations in the MCSM＋UCOM. However, the excitation energy of Jπ=1/2-state for9 Li is not reproduced in the MCSM mainly due to the lack of larger model space.展开更多
A single cesium atom is trapped in a far-off-resonance optical dipole trap （FORT） from the magneto-optical trap （MOT） and directly imaged by using a charge-coupled device （CCD） camera. The binary single-atom ste...A single cesium atom is trapped in a far-off-resonance optical dipole trap （FORT） from the magneto-optical trap （MOT） and directly imaged by using a charge-coupled device （CCD） camera. The binary single-atom steps and photon anti-bunching are observed by a photon-counting-based HBT system using fluorescence light. The average atom dwelling time in the FORT is about 9 s. To reduce the background noise in the detection procedure we employ a weak probe laser tuned to the D1 line to il- lurninate the single atom from the direction perpendicular to the large-numerical-aperture collimation system. The second or- der degree of coherence g（2）（r）=0.12_＋0.02 is obtained directly from the fluorescence light of the single atom without deducting the background. The background light has been suppressed to 10 counts per 50 ms, which is much lower compared with the reported results. The measured g（2）（r） is in good agreement with theoretical analysis. The system provides a simple and effi- cient method to manipulate and measure single neutral atoms, and opens a way to create an efficient controlled single-photon source.展开更多
基金the National Natural Science Foundation of China( 1 0 371 1 0 9)
文摘Let (X 1,X 2,...,X n) and (Y 1,Y 2,...,Y n) be real random vectors with the same marginal distributions,if (X 1,X 2,...,X n)≤ c(Y 1,Y 2,...,Y n), it is showed in this paper that ∑ n i=1 X i≤ cx ∑ n i=1 Y i and max 1≤k≤n ∑ k i=1 X i≤ icx max 1≤k≤n ∑ k i=1 Y i hold.Based on this fact,a more general comparison theorem is obtained.
基金supported by the National Natural Science Foundation of China under Grant Nos.12275078,11875026,12035005,2020YFC2201400the innovative research group of Hunan Province under Grant No.2024JJ1006。
文摘We use out-of-time order correlators(OTOCs)to investigate the quantum instability and Ehrenfest time for an inverted harmonic oscillator(IHO).For initial states located in the stable manifolds of the IHO we find that the corresponding OTOC exhibits identical evolutionary characteristics to the saddle point before the Ehrenfest time.For initial states located in the unstable manifolds,the OTOCs still grow exponentially but the time to maintain exponential growth is related to the center position of its wave packet in phase space.Moreover,we use the Husimi Q function to visualize the quantum wave packets during exponential growth of the OTOCs.Our results show that quantum instability exists at arbitrary orbits in the IHO system,and the Ehrenfest time in the IHO system depends not only on the photon number of the initial system but also on the central positions of the initial states in phase space.
文摘The results of plane turbulent wake given by Chou Peiyuan are considered as the first order ap- proximation and put into the equations of turbulent fluctuation.The equations are solved numerically within the range of micro-scale by means of spectrum method.The double,triple and quadruple fluctuating velocity correlations are obtained by computation.They are in good agreement with experimental results.
基金supported by the National Natural Science Foundation of China (Grant No. 12065009)supported by the National Natural Science Foundation of China (Grant Nos. 11704132, 11874017, and U1830111)+2 种基金Science and Technology Planning Project of Ganzhou City (Grant No. 202101095077)the Natural Science Foundation of Guangdong Province, China (Grant No. 2021A1515012350)the KPST of Guangzhou (Grant No. 201804020055)
文摘We investigate the quantum entanglement in a non-Hermitian kicking system.In the Hermitian case,the out-of-time ordered correlators(OTOCs)exhibit the unbounded power-law increase with time.Correspondingly,the linear entropy,which is a common measurement of entanglement,rapidly increases from zero to almost unity,indicating the formation of quantum entanglement.For strong enough non-Hermitian driving,both the OTOCs and linear entropy rapidly saturate as time evolves.Interestingly,with the increase of non-Hermitian kicking strength,the long-time averaged value of both OTOCs and linear entropy has the same transition point where they exhibit the sharp decrease from a plateau,demonstrating the disentanglment.We reveal the mechanism of disentanglement with the extension of Floquet theory to non-Hermitian systems.
基金Sponsored by the Young Talent Program of Fujian Province (Grant No.2007F3097)
文摘In order to improve the tracking performance in this paper following TBD(Track before Detection) framework multi-level crossover and matching operator is presented.In data association stage the greedy principle is adopted to handle time complexity in DPA and at the same time crossover mathing operator is given to construct candidate trajectory.In addition the corresponding strategy is introduced in preprocessing and postprocessing to remove clutter and suppress false alarm rate.By the experimental comparison and analysis it can be found that the method is more perfer to strengthen the tracking performance of targets with SNR < 2.0 dB.
文摘The fate of the litter of dominant vegetation(willows and reeds) is one of the aspects studied in the frame of the project “Onderzoek Milieu Effecten Sigmaplan”. One of the questions to be considered is how long the litter stays within the estuary. In this paper, the time the leaf litter(Salix triandra and Phragmites australis) stayed in the Schelde estuary was studied by using plant pigment as biomarkers with HPLC application. After analyzing the original data from the incubation experiment described by Dubuison and Geers(1999), the decomposition dynamics patterns of pigments were analyzed and described, and these decomposition dynamics patterns were used as calibration patterns. By using Spearman Rank Order Correlation, the calibration patterns of the pigments which were significant(p<0.05) were grouped. In this way, several groups of the calibration patterns of pigment decomposition were achieved. The presence or absence of these groups of pigments (whether they can be detected or not from HPLC) was shown to be useful in determining the time the litter has stayed in the water. Combining data of DW and POC, more precise timing can be obtained.
基金Supported by Fundamental Research Funds for the Central Universities(JUSRP1035)National Natural Science Foundation of China(11305077)
文摘The low-lying spectra of7 Li and9Li are investigated within an ab initio Monte Carlo Shell Model（MCSM） employing a realistic potential obtained via the Unitary Correlation Operator Method（UCOM）. The MCSM calculations in a 4-major-shells model space for the binding energy and mass quadrupole moment of7, 9Li show good convergence when the MCSM dimension reaches 20. The excitation energy of the Jπ= 1/2-state for7 Li and the magnetic moments for7, 9Li ground states in the MCSM with a treatment of spurious center-of-mass motion are close to the experimental data. Correct level ordering of Jπ=3/2-and 1/2-states for7, 9Li can be reproduced due to the inclusion of three-body correlations in the MCSM＋UCOM. However, the excitation energy of Jπ=1/2-state for9 Li is not reproduced in the MCSM mainly due to the lack of larger model space.
基金supported by the State Basic Key Research Program of China (Grant No. 2012CB921601)China National Funds for Distinguished Young Scientists (Grant No. 11125418)the National Natural Science Foundation of China (Grant Nos. 10974125,61121064 and60978017)
文摘A single cesium atom is trapped in a far-off-resonance optical dipole trap （FORT） from the magneto-optical trap （MOT） and directly imaged by using a charge-coupled device （CCD） camera. The binary single-atom steps and photon anti-bunching are observed by a photon-counting-based HBT system using fluorescence light. The average atom dwelling time in the FORT is about 9 s. To reduce the background noise in the detection procedure we employ a weak probe laser tuned to the D1 line to il- lurninate the single atom from the direction perpendicular to the large-numerical-aperture collimation system. The second or- der degree of coherence g（2）（r）=0.12_＋0.02 is obtained directly from the fluorescence light of the single atom without deducting the background. The background light has been suppressed to 10 counts per 50 ms, which is much lower compared with the reported results. The measured g（2）（r） is in good agreement with theoretical analysis. The system provides a simple and effi- cient method to manipulate and measure single neutral atoms, and opens a way to create an efficient controlled single-photon source.
