We consider the population and decay of a qubit under the electromagnetic environment. Employing the time- convolutionless master equation, we investigate the Markovian and non-Markovian behaviour of the corresponding...We consider the population and decay of a qubit under the electromagnetic environment. Employing the time- convolutionless master equation, we investigate the Markovian and non-Markovian behaviour of the corresponding perturbation expansion. The Jaynes-Cummings model on resonance is investigated. Some figures clearly show the different evolution behaviours. The reasons are interpreted in the paper.展开更多
The approach proposed in the study is based on the revision of the concept of time as a point on the real axis. It uses the concept of fuzzy time as the set of real numbers with a finite, but not equal to one, functio...The approach proposed in the study is based on the revision of the concept of time as a point on the real axis. It uses the concept of fuzzy time as the set of real numbers with a finite, but not equal to one, function of membership to the time set, i.e. the fuzzy time concept. It is postulated that in fuzzy time t the system dynamics follows from the standard variational principle of the least action and is ordinary Hamilton-Jacobi mechanics. This validates the passage to the limit from fuzzy mechanics to ordinary variational conservative mechanics. The Liouville equation is solved by the method of successive approximations in the time domain of a much larger characteristic scale of fuzziness, using interaction as a small parameter. A standard diagram technique is used. It can be shown that the defuzzification of the Liouville equation inevitably reduces the reversible part in the description to the irreversible evolutionary equation. The latter leads to the second law of thermodynamics. Generalization to the quantum case is possible, i.e. the so-called fuzzy Pauli equation can be drawn.展开更多
The generalized master equation for the space-time coupled continuous time random walk is derived analytically, in which the space-time coupling is considered through the correlated function 9（t） ～ t^γ, 0 ≤ γ 〈...The generalized master equation for the space-time coupled continuous time random walk is derived analytically, in which the space-time coupling is considered through the correlated function 9（t） ～ t^γ, 0 ≤ γ 〈 2, and the probability density function ω（t） of a particle＇s waiting time t follows a power law form for large t： ω（t） ～t^-（1＋α）, 0 〈 α 〈 1. The results indicate that the expressions of the generalized master equation are determined by the correlation exponent 7 and the long-tailed index α of the waiting time. Moreover, the diffusion results obtained from the generalized master equation are in accordance with the previous known results and the numerical simulation results.展开更多
We study the long-time limit behavior of the solution to an atom＇s master equation. For the first time we derive that the probability of the atom being in the α-th （α = j ＋ 1 -jz, j is the angular momentum quantu...We study the long-time limit behavior of the solution to an atom＇s master equation. For the first time we derive that the probability of the atom being in the α-th （α = j ＋ 1 -jz, j is the angular momentum quantum number, jz is the z-component of angular momentum） state is {（1 - K/G）/[1 - （K/G）2j＋1]}（K/G）^α-1 as t → ＋∞, which coincides with the fact that when K/G 〉 1, the larger the a is, the larger the probability of the atom being in the α-th state （the lower excited state） is. We also consider the case for some possible generaizations of the atomic master equation.展开更多
在受端交流侧发生故障时,现有依赖耗能装置的基于模块化多电平换流器的多端柔性直流(modular multilevel converter based multi-terminal direct current,MMC-MTDC)输电系统,其盈余功率处理方案存在经济性差和能量浪费等问题。为充分发...在受端交流侧发生故障时,现有依赖耗能装置的基于模块化多电平换流器的多端柔性直流(modular multilevel converter based multi-terminal direct current,MMC-MTDC)输电系统,其盈余功率处理方案存在经济性差和能量浪费等问题。为充分发挥MMC-MTDC系统自有盈余功率消纳能力,减少对耗能装置的依赖,文中提出一种基于主从能量控制的多站极间交互消纳策略。首先,建立相应的MMC-MTDC控制模型,并对其通过能量控制实现盈余功率消纳的可行性进行分析。随后,引入MMC三维度模型,实现换流站各极能量解耦控制,并通过构建的MMC-MTDC系统简化模型,对各类型换流站开展主动能量控制设计。在此基础上,类比主从控制思想,构建适用于不同受端站极交流故障及两类盈余功率情况的主从能量时序控制逻辑,以实现各站极之间的能量裕度协调利用。最后,在PSCAD/EMTDC平台搭建MMC-MTDC系统仿真模型进行实验验证。仿真结果表明,所提控制策略能够在不依赖耗能装置的前提下,有效协调多站极之间的能量控制,适应多种盈余功率故障情况,成功实现故障穿越。展开更多
Nonlinear viscoelastic creep properties of poly （methyl methacrylate） at various temperatures and stress levels were measured in short-term tests to check the applicability of time-temperature-stress superposition p...Nonlinear viscoelastic creep properties of poly （methyl methacrylate） at various temperatures and stress levels were measured in short-term tests to check the applicability of time-temperature-stress superposition principle, which is the combined form of time-temperature superposition principle and time-stress superposition principle. A unified master creep compli- ance curve was constructed from the short-term tests by joint application of time-temperature superposition and time-stress superposition. The unified master curve establishes the creep com- pliance over two years, which is 4.2 decades longer than the test duration. Moreover, it is verified that in nonlinear viscoelastic cases, the time-temperature shift factors are dependent on stresses at which the shifts are applied, while the time-stress shift factors are dependent on temperatures.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.11074072)
文摘We consider the population and decay of a qubit under the electromagnetic environment. Employing the time- convolutionless master equation, we investigate the Markovian and non-Markovian behaviour of the corresponding perturbation expansion. The Jaynes-Cummings model on resonance is investigated. Some figures clearly show the different evolution behaviours. The reasons are interpreted in the paper.
文摘The approach proposed in the study is based on the revision of the concept of time as a point on the real axis. It uses the concept of fuzzy time as the set of real numbers with a finite, but not equal to one, function of membership to the time set, i.e. the fuzzy time concept. It is postulated that in fuzzy time t the system dynamics follows from the standard variational principle of the least action and is ordinary Hamilton-Jacobi mechanics. This validates the passage to the limit from fuzzy mechanics to ordinary variational conservative mechanics. The Liouville equation is solved by the method of successive approximations in the time domain of a much larger characteristic scale of fuzziness, using interaction as a small parameter. A standard diagram technique is used. It can be shown that the defuzzification of the Liouville equation inevitably reduces the reversible part in the description to the irreversible evolutionary equation. The latter leads to the second law of thermodynamics. Generalization to the quantum case is possible, i.e. the so-called fuzzy Pauli equation can be drawn.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11605003 and 11547231
文摘The generalized master equation for the space-time coupled continuous time random walk is derived analytically, in which the space-time coupling is considered through the correlated function 9（t） ～ t^γ, 0 ≤ γ 〈 2, and the probability density function ω（t） of a particle＇s waiting time t follows a power law form for large t： ω（t） ～t^-（1＋α）, 0 〈 α 〈 1. The results indicate that the expressions of the generalized master equation are determined by the correlation exponent 7 and the long-tailed index α of the waiting time. Moreover, the diffusion results obtained from the generalized master equation are in accordance with the previous known results and the numerical simulation results.
基金Project supported by the National Natural Science Foundation of China (Grant No. 11105133)
文摘We study the long-time limit behavior of the solution to an atom＇s master equation. For the first time we derive that the probability of the atom being in the α-th （α = j ＋ 1 -jz, j is the angular momentum quantum number, jz is the z-component of angular momentum） state is {（1 - K/G）/[1 - （K/G）2j＋1]}（K/G）^α-1 as t → ＋∞, which coincides with the fact that when K/G 〉 1, the larger the a is, the larger the probability of the atom being in the α-th state （the lower excited state） is. We also consider the case for some possible generaizations of the atomic master equation.
文摘在受端交流侧发生故障时,现有依赖耗能装置的基于模块化多电平换流器的多端柔性直流(modular multilevel converter based multi-terminal direct current,MMC-MTDC)输电系统,其盈余功率处理方案存在经济性差和能量浪费等问题。为充分发挥MMC-MTDC系统自有盈余功率消纳能力,减少对耗能装置的依赖,文中提出一种基于主从能量控制的多站极间交互消纳策略。首先,建立相应的MMC-MTDC控制模型,并对其通过能量控制实现盈余功率消纳的可行性进行分析。随后,引入MMC三维度模型,实现换流站各极能量解耦控制,并通过构建的MMC-MTDC系统简化模型,对各类型换流站开展主动能量控制设计。在此基础上,类比主从控制思想,构建适用于不同受端站极交流故障及两类盈余功率情况的主从能量时序控制逻辑,以实现各站极之间的能量裕度协调利用。最后,在PSCAD/EMTDC平台搭建MMC-MTDC系统仿真模型进行实验验证。仿真结果表明,所提控制策略能够在不依赖耗能装置的前提下,有效协调多站极之间的能量控制,适应多种盈余功率故障情况,成功实现故障穿越。
基金supported by NSFC(No. 11172256)NCET (No. NCET-08-0685)+1 种基金Key Project of Chinese Ministry of Education (No. 209085)Aid Program for Science and Technology Innovative Research Team in Higher Educational Institutions of Hunan Province
文摘Nonlinear viscoelastic creep properties of poly （methyl methacrylate） at various temperatures and stress levels were measured in short-term tests to check the applicability of time-temperature-stress superposition principle, which is the combined form of time-temperature superposition principle and time-stress superposition principle. A unified master creep compli- ance curve was constructed from the short-term tests by joint application of time-temperature superposition and time-stress superposition. The unified master curve establishes the creep com- pliance over two years, which is 4.2 decades longer than the test duration. Moreover, it is verified that in nonlinear viscoelastic cases, the time-temperature shift factors are dependent on stresses at which the shifts are applied, while the time-stress shift factors are dependent on temperatures.
