We theoretically investigate the two-center interference in high-order harmonics generated from the H2-＋ in a combination of a mid-infrared laser and a terahertz field by numerically solving the time-dependent Schr &...We theoretically investigate the two-center interference in high-order harmonics generated from the H2-＋ in a combination of a mid-infrared laser and a terahertz field by numerically solving the time-dependent Schr ¨odinger equation（TDSE）.The interference minima in high-order harmonic generation（HHG） are effectively suppressed when a THz field is added.The contribution to HHG from the two separate nuclei is used to demonstrate the locating order of the harmonic minima.Furthermore, we also investigate the emission time of harmonics. The results show that the intensity of the short path around 60^th order after adding a THz field is stronger than that in the mid-infrared laser field, which further illustrates the suppression of the interference minima in HHG.展开更多
The two-center problem,also known as Euler's three-body problem,is a classic example of integrable systems.Among its periodic solutions,planetary type solutions are periodic solutions which enclose both centers.In...The two-center problem,also known as Euler's three-body problem,is a classic example of integrable systems.Among its periodic solutions,planetary type solutions are periodic solutions which enclose both centers.Inspired by advances on n-body and n-center problems via variational techniques developed during the past two decades,a recent paper(Arch.Rat.Mech.Ana.2022)shows the minimizing property of planetary type solutions for any given masses of centers at fixed positions,as long as the period is above a mass-dependent threshold value.In this paper,we provide further discussions regarding this minimizing approach.In particular,we improve the above-mentioned mass-dependent threshold value by refining estimates for action values.展开更多
The influence of the neck parameter on the fission dynamics at low excitation energy is studied based on the three-dimensional Langevin approach,in which the nuclear shape is described with the two-center shell model(...The influence of the neck parameter on the fission dynamics at low excitation energy is studied based on the three-dimensional Langevin approach,in which the nuclear shape is described with the two-center shell model(TCSM)parametrization,and the elongation,mass asymmetry,and fragment deformation are set to be the generalized coordinates of the Langevin equation.We first study the influence of the neck parameter on the scission configuration.We find that there is almost no obvious correlation between the neck parameter and mass asymmetryηat the scission point,indicating that has no evident impact on the fragment mass distribution.The elongation Z_(0)=R_(0) and its correlation with the mass asymmetryηat the scission point are clearly influenced by the neck parameter,which has a strong effect on the total kinetic energy(TKE)distribution of the fragments.The pre-neutron emission fragment mass distributions for 14 MeV n+^(233;235;238)U and^(239)Pu are calculated,and then,based on these results,the post-neutron emission fragment mass distributions are obtained by using the experimental data of prompt neutron emission.The calculated post-neutron emission fragment mass distributions can reproduce the experimental data well.The TKE distributions for 14 MeV n+^(235)U fission are calculated for ε=0.25,0.35,and 0.45,and the results show that the TKE distribution cannot be described very well for the three cases.However,the trend of the calculated TKE distribution withεis just as expected from the scission configuration calculations.The results with ε=0.35 present a better agreement with the experiment data compared with the other two cases.展开更多
A two-center correlated orbital approach was used to calculate the electronic ground state energy for the HeH+ molecular ion. The wavefunctions were constructed from the exact solution of the Schrdinger equation for...A two-center correlated orbital approach was used to calculate the electronic ground state energy for the HeH+ molecular ion. The wavefunctions were constructed from the exact solution of the Schrdinger equation for the HeH++ problem in prolate-spheroidal coordinates taken together with a Hylleraas type correlation factor. With a simple single term wavefunction,we obtained ground state energy of -2.95308691 hartree without any variational parameters in the calculation. When a two-configuration-state wavefunction was used and effective charges were allowed to be adjusted,we found an energy of -2.97384868 hartree,which is to be compared with -2.97869074 hartree obtained by an 83 term configuration interaction wavefunction or -2.97364338 hartree by an ab initio calculation (at the MP4(SDQ)/6-311++G(3df,3dp) level) using the well-known "canned" code.展开更多
沙戈荒区域丰富的风光热资源有利于支撑高能耗数据中心集群快速发展,但会使其面临算力负载强时变性、风光出力间歇性及恶劣天气离网运行可靠性的多重挑战。为此,该文提出一种考虑任务负载需求响应及源荷不确定性的数据中心集群微网电-...沙戈荒区域丰富的风光热资源有利于支撑高能耗数据中心集群快速发展,但会使其面临算力负载强时变性、风光出力间歇性及恶劣天气离网运行可靠性的多重挑战。为此,该文提出一种考虑任务负载需求响应及源荷不确定性的数据中心集群微网电-热设备容量协同优化配置方法。首先,根据计算任务对时延的敏感性,精细化建模可推迟可中断、可推迟不可中断及不可推迟3类任务负载的时间约束,在此基础上综合源荷不确定性建立数据中心集群微网“并网-离网”2阶段分布鲁棒优化模型,采用列与约束生成(column and constraint generation,C&CG)算法求解。以青海某实际数据中心为案例的分析结果表明:所提出的方法可使微网容量配置成本下降约25.8%,弃风率下降约56%,并大幅提高数据中心集群微网离网运行可靠性。该文研究为沙戈荒区域绿色低碳数据中心建设提供了理论支撑。展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.61575077,11574117,and 11271158)the Graduate Innovation Fund of Jilin University,China(Grant No.2016153)
文摘We theoretically investigate the two-center interference in high-order harmonics generated from the H2-＋ in a combination of a mid-infrared laser and a terahertz field by numerically solving the time-dependent Schr ¨odinger equation（TDSE）.The interference minima in high-order harmonic generation（HHG） are effectively suppressed when a THz field is added.The contribution to HHG from the two separate nuclei is used to demonstrate the locating order of the harmonic minima.Furthermore, we also investigate the emission time of harmonics. The results show that the intensity of the short path around 60^th order after adding a THz field is stronger than that in the mid-infrared laser field, which further illustrates the suppression of the interference minima in HHG.
文摘The two-center problem,also known as Euler's three-body problem,is a classic example of integrable systems.Among its periodic solutions,planetary type solutions are periodic solutions which enclose both centers.Inspired by advances on n-body and n-center problems via variational techniques developed during the past two decades,a recent paper(Arch.Rat.Mech.Ana.2022)shows the minimizing property of planetary type solutions for any given masses of centers at fixed positions,as long as the period is above a mass-dependent threshold value.In this paper,we provide further discussions regarding this minimizing approach.In particular,we improve the above-mentioned mass-dependent threshold value by refining estimates for action values.
基金Supported by the National Natural Science Foundation of China(12105369,11790324,11790325,11790323,11790320)the Continuous Basic Scientific Research Project(WDJC-2019-09)。
文摘The influence of the neck parameter on the fission dynamics at low excitation energy is studied based on the three-dimensional Langevin approach,in which the nuclear shape is described with the two-center shell model(TCSM)parametrization,and the elongation,mass asymmetry,and fragment deformation are set to be the generalized coordinates of the Langevin equation.We first study the influence of the neck parameter on the scission configuration.We find that there is almost no obvious correlation between the neck parameter and mass asymmetryηat the scission point,indicating that has no evident impact on the fragment mass distribution.The elongation Z_(0)=R_(0) and its correlation with the mass asymmetryηat the scission point are clearly influenced by the neck parameter,which has a strong effect on the total kinetic energy(TKE)distribution of the fragments.The pre-neutron emission fragment mass distributions for 14 MeV n+^(233;235;238)U and^(239)Pu are calculated,and then,based on these results,the post-neutron emission fragment mass distributions are obtained by using the experimental data of prompt neutron emission.The calculated post-neutron emission fragment mass distributions can reproduce the experimental data well.The TKE distributions for 14 MeV n+^(235)U fission are calculated for ε=0.25,0.35,and 0.45,and the results show that the TKE distribution cannot be described very well for the three cases.However,the trend of the calculated TKE distribution withεis just as expected from the scission configuration calculations.The results with ε=0.35 present a better agreement with the experiment data compared with the other two cases.
基金Supported by the National Natural Science Foundation of China (Grant No. 20773618)the Research Fund of Chongqing University of Posts and Telecom-munications (Grant No. A2006-81)
文摘A two-center correlated orbital approach was used to calculate the electronic ground state energy for the HeH+ molecular ion. The wavefunctions were constructed from the exact solution of the Schrdinger equation for the HeH++ problem in prolate-spheroidal coordinates taken together with a Hylleraas type correlation factor. With a simple single term wavefunction,we obtained ground state energy of -2.95308691 hartree without any variational parameters in the calculation. When a two-configuration-state wavefunction was used and effective charges were allowed to be adjusted,we found an energy of -2.97384868 hartree,which is to be compared with -2.97869074 hartree obtained by an 83 term configuration interaction wavefunction or -2.97364338 hartree by an ab initio calculation (at the MP4(SDQ)/6-311++G(3df,3dp) level) using the well-known "canned" code.
文摘沙戈荒区域丰富的风光热资源有利于支撑高能耗数据中心集群快速发展,但会使其面临算力负载强时变性、风光出力间歇性及恶劣天气离网运行可靠性的多重挑战。为此,该文提出一种考虑任务负载需求响应及源荷不确定性的数据中心集群微网电-热设备容量协同优化配置方法。首先,根据计算任务对时延的敏感性,精细化建模可推迟可中断、可推迟不可中断及不可推迟3类任务负载的时间约束,在此基础上综合源荷不确定性建立数据中心集群微网“并网-离网”2阶段分布鲁棒优化模型,采用列与约束生成(column and constraint generation,C&CG)算法求解。以青海某实际数据中心为案例的分析结果表明:所提出的方法可使微网容量配置成本下降约25.8%,弃风率下降约56%,并大幅提高数据中心集群微网离网运行可靠性。该文研究为沙戈荒区域绿色低碳数据中心建设提供了理论支撑。
