针对存在初态误差的情形,提出多变量非线性系统的变阶采样迭代学习控制方法.相对固定阶迭代学习算法,变阶算法可有效降低跟踪误差.对变阶采样迭代学习算法进行了收敛性分析,推导出收敛充分条件.给出了变阶学习的两种实现策略-DD(Direct ...针对存在初态误差的情形,提出多变量非线性系统的变阶采样迭代学习控制方法.相对固定阶迭代学习算法,变阶算法可有效降低跟踪误差.对变阶采样迭代学习算法进行了收敛性分析,推导出收敛充分条件.给出了变阶学习的两种实现策略-DD(Direct division)和DIP(Division in phases)策略.数值仿真表明,基于DIP策略的变阶采样迭代学习算法在获得较高的控制精度的同时,具有较快的收敛速度.展开更多
Initialization and initial imbalance problem were discussed in the context of a three-dimensional variational data assimilation system of the new generation"Weather Research and Forecasting Model". Several o...Initialization and initial imbalance problem were discussed in the context of a three-dimensional variational data assimilation system of the new generation"Weather Research and Forecasting Model". Several options of digital filter initialization have been tested with a rain storm case. It is shown that digital filter initialization, especially diabatic digital filter initialization and twice digital filter initialization, have effectively removed spurious high frequency noise from initial data for numerical weather prediction and produced balanced initial conditions. For six consecutive intermittent data assimilation cycles covering a 3-day period, mean initialization increments and impact on forecast variables are studied. DFI has been demonstrated to provide better adjustment of the hydrometeors and vertical velocity, reduced spin-up time, and improved forecast variables quantity.展开更多
Algal allelopathy is an ecological/physiological phenomenon that has focused attention on the interactions among algae and the production of algal toxins. We investigated the allelopathic interactions between the dino...Algal allelopathy is an ecological/physiological phenomenon that has focused attention on the interactions among algae and the production of algal toxins. We investigated the allelopathic interactions between the dinoflagellate genus Prorocentrum micans and diatom genus Skeletonema costatum and between P. micans and dinoflagellate genus Karenia mikimotoi using bi-algal cultures. Because the effects were species-specific and size-dependent, we evaluated the effect of different initial densities. At low densities of P. mieans and high densities of S. costatum inoculated into the same medium, the growth of R rnieans was weakly restrained, whereas the growth of S. costatum was significantly suppressed. S. costatum and K. mikimotoi were strongly inhibited by P. micans, in both the bi-algal cultures and enriched filtrates. Direct cell-to-cell contact was not necessary to gain a competitive advantage, thus, our results suggest that P. micans inhibited the growth of S. costatum and K. mikimotoi by the release of allelochemical（s）. Last, a mathematical model was used to simulate growth and interactions between P. micans and S. eostatum and between P. micans and K. mikimotoi in bi-algal cultures.展开更多
Buckling of submarine pipelines under thermal stress is one of the most important problems to be considered in pipeline design. And pipeline with initial imperfections will easily undergo failure due to global bucklin...Buckling of submarine pipelines under thermal stress is one of the most important problems to be considered in pipeline design. And pipeline with initial imperfections will easily undergo failure due to global buckling under thermal stress and internal pressure. Therefore, it is vitally important to study the global buckling of the submarine pipeline with initial imperfections. On the basis of the characteristics of the initial imperfections, the global lateral buckling of submarine pipelines was analyzed. Based on the deduced analytical solutions for the global lateral buckling, effects of temperature difference and properties of foundation soil on pipeline buckling were analyzed. The results show that the snap buckling is predominantly governed by the amplitude value of initial imperfection; the triggering temperature difference of Mode I for pipelines with initial imperfections is higher than that of Mode I1; a pipeline with a larger friction coefficient is safer than that with a smaller one; pipelines with larger initial imperfections are safer than those with smaller ones.展开更多
By numerically solving the Sch6dinger equation of a three-nuclear-spin system, the effects of the non-uniform nearest-neighbor （NN） interaction on the fidelity of a quantum controlled-controlled-no （CCN） gate are...By numerically solving the Sch6dinger equation of a three-nuclear-spin system, the effects of the non-uniform nearest-neighbor （NN） interaction on the fidelity of a quantum controlled-controlled-no （CCN） gate are investigated for a digital initial state and a superposition initial state respectively. It is found from our simulation that the ratio of the deviation of the NN coupling δJ to the NN coupling J should be smaller than 0.0005 to ensure a high fidelity of the quantum CCN gate.展开更多
This paper is concerned with the generation of waves due to initial disturbances at the upper surface of a two-layer fluid, as the upper layer is covered by an inertial surface and the lower layer extends infinitely d...This paper is concerned with the generation of waves due to initial disturbances at the upper surface of a two-layer fluid, as the upper layer is covered by an inertial surface and the lower layer extends infinitely downwards. The inertial surface is composed of thin but uniform distribution of non-interacting material. In the mathematical analysis, the Fourier and Laplace transform techniques have been utilized to obtain the depressions of the inertial surface and the interface in the form of infinite integrals. For initial disturbances concentrated at a point, the inertial surface depression and the interface depression are evaluated asymptotically for large time and distance by using the method of stationary phase. They are also depicted graphically for two types of initial disturbances and appropriate conclusions are made.展开更多
Using multipohton Tavis-Cummings model,the entanglement evolution of two coupling two-level atoms in Bell states interacting with a single-mode vacuum field is investigated by using negativity.The influences of coupli...Using multipohton Tavis-Cummings model,the entanglement evolution of two coupling two-level atoms in Bell states interacting with a single-mode vacuum field is investigated by using negativity.The influences of coupling constants between atoms,the atomic initial states and the photon number of transition on the entanglement evolution of two coupling two-level atoms are discussed.The results obtained using the numerical method show that the entanglement of two atoms is related with coupling constants between atoms,the atomic initial states and the photon number of transition.The two-atom entanglement state will forever stay in the maximum entanglement state when the initial state is β11〉.When the initial state of two atoms is β01〉,the entanglement of two atoms displays periodic oscillation behavior.And its oscillation period decreases with increasing of coupling constant between atoms or the photon number of transition.On the other hand,when the initial state is β00〉 or β10〉,the entanglement of two atoms displays quasiperiodic oscillation behavior and its oscillation period decreases with increasing of coupling constant between atoms or the photon number of transition.展开更多
We investigate the dynamics of palrwise quantum discord （QD） for a mixed three-qubit W-type state in three independent non-Markovian reservoirs at zero temperature, each of which is modeled by a leaky cavity with Lo...We investigate the dynamics of palrwise quantum discord （QD） for a mixed three-qubit W-type state in three independent non-Markovian reservoirs at zero temperature, each of which is modeled by a leaky cavity with Lorentzian spectral density. The influence of the environment＇s amount of non-Markovianity, the detuning between the qubit frequency and the cavity centre frequency, and the purity of the initial state on the QD dynamics are analyzed in detail. It is found that in the non-Maxkovian regime the system-reservoir interactions induce QD revivals and oscillations no matter whether the detuning is zero or not. Moreover, QD can be preserved for a long time if the non-Markovian condition and the detuning condition are satisfied simultaneously.展开更多
We use the excited coherent states built over the initial non-de Sitter modes,to study the modification of spectra of primordial scalar fluctuation.Non-de Sitter modes are actually the asymptotic solution of the infla...We use the excited coherent states built over the initial non-de Sitter modes,to study the modification of spectra of primordial scalar fluctuation.Non-de Sitter modes are actually the asymptotic solution of the inflaton field equation[J.High Energy Phys.09（2014） 020].We build excited coherent states over the non-de Sitter modes and despite the Jack of interactions in the Lagrangian,we find a non-zero one-point function.It is shown that the primordial non-Gaussianity resulting from excited-de Sitter modes depend both of time and background space-time.It is very tiny of order（≤10^-24）,at the Planck initial fixed time that confirmed by resent observations for single field inflation but it grows in the present epoch.Moreover,our results at the leading order are similar to what obtained with general initial states and in the dS limit leads to standard results[J.Cosmol.Astropart.Phys.1202（2012） 005].We will show that the non-dS modes and its resulting spectrum are more usable for far past time limit.展开更多
文摘针对存在初态误差的情形,提出多变量非线性系统的变阶采样迭代学习控制方法.相对固定阶迭代学习算法,变阶算法可有效降低跟踪误差.对变阶采样迭代学习算法进行了收敛性分析,推导出收敛充分条件.给出了变阶学习的两种实现策略-DD(Direct division)和DIP(Division in phases)策略.数值仿真表明,基于DIP策略的变阶采样迭代学习算法在获得较高的控制精度的同时,具有较快的收敛速度.
基金National Natural Science Foundation of China (40675020)
文摘Initialization and initial imbalance problem were discussed in the context of a three-dimensional variational data assimilation system of the new generation"Weather Research and Forecasting Model". Several options of digital filter initialization have been tested with a rain storm case. It is shown that digital filter initialization, especially diabatic digital filter initialization and twice digital filter initialization, have effectively removed spurious high frequency noise from initial data for numerical weather prediction and produced balanced initial conditions. For six consecutive intermittent data assimilation cycles covering a 3-day period, mean initialization increments and impact on forecast variables are studied. DFI has been demonstrated to provide better adjustment of the hydrometeors and vertical velocity, reduced spin-up time, and improved forecast variables quantity.
基金Supported by the National Basic Research Program of China (973 Program) (Nos. 2011CB200901, 2010CB428706)the National Natural Science Foundation of China (No.40806053)
文摘Algal allelopathy is an ecological/physiological phenomenon that has focused attention on the interactions among algae and the production of algal toxins. We investigated the allelopathic interactions between the dinoflagellate genus Prorocentrum micans and diatom genus Skeletonema costatum and between P. micans and dinoflagellate genus Karenia mikimotoi using bi-algal cultures. Because the effects were species-specific and size-dependent, we evaluated the effect of different initial densities. At low densities of P. mieans and high densities of S. costatum inoculated into the same medium, the growth of R rnieans was weakly restrained, whereas the growth of S. costatum was significantly suppressed. S. costatum and K. mikimotoi were strongly inhibited by P. micans, in both the bi-algal cultures and enriched filtrates. Direct cell-to-cell contact was not necessary to gain a competitive advantage, thus, our results suggest that P. micans inhibited the growth of S. costatum and K. mikimotoi by the release of allelochemical（s）. Last, a mathematical model was used to simulate growth and interactions between P. micans and S. eostatum and between P. micans and K. mikimotoi in bi-algal cultures.
基金Project(51021004)supported by Innovative Research Groups of the National Natural Science Foundation of ChinaProject(NCET-11-0370)supported by Program for New Century Excellent Talents in Universities of China+1 种基金Project(40776055)supported by the National Natural Science Foundation of ChinaProject(1002)supported by State Key Laboratory of Ocean Engineering Foundation,China
文摘Buckling of submarine pipelines under thermal stress is one of the most important problems to be considered in pipeline design. And pipeline with initial imperfections will easily undergo failure due to global buckling under thermal stress and internal pressure. Therefore, it is vitally important to study the global buckling of the submarine pipeline with initial imperfections. On the basis of the characteristics of the initial imperfections, the global lateral buckling of submarine pipelines was analyzed. Based on the deduced analytical solutions for the global lateral buckling, effects of temperature difference and properties of foundation soil on pipeline buckling were analyzed. The results show that the snap buckling is predominantly governed by the amplitude value of initial imperfection; the triggering temperature difference of Mode I for pipelines with initial imperfections is higher than that of Mode I1; a pipeline with a larger friction coefficient is safer than that with a smaller one; pipelines with larger initial imperfections are safer than those with smaller ones.
基金Supported by National Science Foundation of China under Grant Nos. 10874021 and 10774107Science Foundation of Education Committee of Jiangsu Province under Grant No. 07KJB140002
文摘By numerically solving the Sch6dinger equation of a three-nuclear-spin system, the effects of the non-uniform nearest-neighbor （NN） interaction on the fidelity of a quantum controlled-controlled-no （CCN） gate are investigated for a digital initial state and a superposition initial state respectively. It is found from our simulation that the ratio of the deviation of the NN coupling δJ to the NN coupling J should be smaller than 0.0005 to ensure a high fidelity of the quantum CCN gate.
基金Supported by the DST Research Project No.SR/SY/MS:521/08and CSIR,New Delhi
文摘This paper is concerned with the generation of waves due to initial disturbances at the upper surface of a two-layer fluid, as the upper layer is covered by an inertial surface and the lower layer extends infinitely downwards. The inertial surface is composed of thin but uniform distribution of non-interacting material. In the mathematical analysis, the Fourier and Laplace transform techniques have been utilized to obtain the depressions of the inertial surface and the interface in the form of infinite integrals. For initial disturbances concentrated at a point, the inertial surface depression and the interface depression are evaluated asymptotically for large time and distance by using the method of stationary phase. They are also depicted graphically for two types of initial disturbances and appropriate conclusions are made.
基金Supported by the Natural Science Foundation of Fujian Province under Grant (No.2008J0217)
文摘Using multipohton Tavis-Cummings model,the entanglement evolution of two coupling two-level atoms in Bell states interacting with a single-mode vacuum field is investigated by using negativity.The influences of coupling constants between atoms,the atomic initial states and the photon number of transition on the entanglement evolution of two coupling two-level atoms are discussed.The results obtained using the numerical method show that the entanglement of two atoms is related with coupling constants between atoms,the atomic initial states and the photon number of transition.The two-atom entanglement state will forever stay in the maximum entanglement state when the initial state is β11〉.When the initial state of two atoms is β01〉,the entanglement of two atoms displays periodic oscillation behavior.And its oscillation period decreases with increasing of coupling constant between atoms or the photon number of transition.On the other hand,when the initial state is β00〉 or β10〉,the entanglement of two atoms displays quasiperiodic oscillation behavior and its oscillation period decreases with increasing of coupling constant between atoms or the photon number of transition.
基金Supported by the National Natural Science Foundation of China under Grant Nos.11174081,11034002,11134003,and 11104075Supported by the National Basic Research Program of China under Grant Nos.2011CB921602 and 2012CB821302
文摘We investigate the dynamics of palrwise quantum discord （QD） for a mixed three-qubit W-type state in three independent non-Markovian reservoirs at zero temperature, each of which is modeled by a leaky cavity with Lorentzian spectral density. The influence of the environment＇s amount of non-Markovianity, the detuning between the qubit frequency and the cavity centre frequency, and the purity of the initial state on the QD dynamics are analyzed in detail. It is found that in the non-Maxkovian regime the system-reservoir interactions induce QD revivals and oscillations no matter whether the detuning is zero or not. Moreover, QD can be preserved for a long time if the non-Markovian condition and the detuning condition are satisfied simultaneously.
基金supported by the Islamic Azad University,Ayatollah Amoli Branch, Amol,Mazandaran,Iran
文摘We use the excited coherent states built over the initial non-de Sitter modes,to study the modification of spectra of primordial scalar fluctuation.Non-de Sitter modes are actually the asymptotic solution of the inflaton field equation[J.High Energy Phys.09（2014） 020].We build excited coherent states over the non-de Sitter modes and despite the Jack of interactions in the Lagrangian,we find a non-zero one-point function.It is shown that the primordial non-Gaussianity resulting from excited-de Sitter modes depend both of time and background space-time.It is very tiny of order（≤10^-24）,at the Planck initial fixed time that confirmed by resent observations for single field inflation but it grows in the present epoch.Moreover,our results at the leading order are similar to what obtained with general initial states and in the dS limit leads to standard results[J.Cosmol.Astropart.Phys.1202（2012） 005].We will show that the non-dS modes and its resulting spectrum are more usable for far past time limit.
