能量循环利用是汽车电子产业发展的主要研究方向之一,基于车辆发动机工作原理为辅助设备(如制冷系统和液压泵)提供动力,从而降低车辆燃料消耗,达到节能的效果。车辆再生辅助动力系统(Regenerative auxiliary power System,RAPS)以货车...能量循环利用是汽车电子产业发展的主要研究方向之一,基于车辆发动机工作原理为辅助设备(如制冷系统和液压泵)提供动力,从而降低车辆燃料消耗,达到节能的效果。车辆再生辅助动力系统(Regenerative auxiliary power System,RAPS)以货车为研究对象,通过增加一个额外电池,将车辆变为混合动力车。为了追求较高的总体效率,设计了一种整体控制器,用于确定如何以及何时为电池充电,同时将辅助系统的功耗降至最低。研究结果表明,与传统服务车辆的燃油消耗相比,提出的RAPS可节省约7%的燃油。展开更多
The＇entanglement capacity of general two-qubit unitary operators is studied when auxiliary systems are allowed, and the analytical results based on linear entropy when input states are disentangled are given. From th...The＇entanglement capacity of general two-qubit unitary operators is studied when auxiliary systems are allowed, and the analytical results based on linear entropy when input states are disentangled are given. From the results the condition for perfect entangler, α1 = α2 = π/4, is obtained. Contrary to the case without auxiliary system, the parameter α3 may play active role to the entanglement capacity when auxiliary systems are allowed.展开更多
The explicit transformations of the 1→ 3 optimal universal quantum cloning and the optimal phase-covariant quantum cloning in d-dimensions are presented, and the dimensionalities of their ancillary systems are both d...The explicit transformations of the 1→ 3 optimal universal quantum cloning and the optimal phase-covariant quantum cloning in d-dimensions are presented, and the dimensionalities of their ancillary systems are both d-dimensions. As d→∞ , their clone fidelities move toward 1/3, showing a classical limit for the fidelity of quantum cloning. Based on the reduction of the unitary transformation of quantum cloning, the transformation of the 1→M=d+1 optimal economical phase-covariant quantum cloning in d-dimensions is derived, and the clone fidelity is covered by the theoretical value.展开更多
An unknown state of a quantum system S is usually determined by repeatedly measuring a set of non-commuting observables. The state can also be obtained from the repeated measurements of a single separable observable w...An unknown state of a quantum system S is usually determined by repeatedly measuring a set of non-commuting observables. The state can also be obtained from the repeated measurements of a single separable observable when the system S interacts with an assistant system A in a known state. In this paper, we study the quantum state tomography of a three-level atom （the system S） interacting with two radiation fields as the assistant system A. We obtain the initial state of S by repeatedly measuring a separable observable O = Sz n1 n2, in which Sz is the atom operator, and hi and h2 are the photon number operators of the two radiation fields. We achieve the one-to-one mapping M between the initial density matrix of the system S and the measured results of the single separable observable. We also give a concrete numerical example.展开更多
文摘能量循环利用是汽车电子产业发展的主要研究方向之一,基于车辆发动机工作原理为辅助设备(如制冷系统和液压泵)提供动力,从而降低车辆燃料消耗,达到节能的效果。车辆再生辅助动力系统(Regenerative auxiliary power System,RAPS)以货车为研究对象,通过增加一个额外电池,将车辆变为混合动力车。为了追求较高的总体效率,设计了一种整体控制器,用于确定如何以及何时为电池充电,同时将辅助系统的功耗降至最低。研究结果表明,与传统服务车辆的燃油消耗相比,提出的RAPS可节省约7%的燃油。
基金The project supported by National Natural Science Foundation of China under Grant No. 60433050
文摘The＇entanglement capacity of general two-qubit unitary operators is studied when auxiliary systems are allowed, and the analytical results based on linear entropy when input states are disentangled are given. From the results the condition for perfect entangler, α1 = α2 = π/4, is obtained. Contrary to the case without auxiliary system, the parameter α3 may play active role to the entanglement capacity when auxiliary systems are allowed.
基金supported by the National Natural Science Foundation of China (Grant No.10704001)the Natural Science Foundation of the Education Department of Anhui Province of China (Grant Nos.KJ2010ZD08 and KJ2010B204)the Doctor Research Start-Up Program of Huainan Normal University
文摘The explicit transformations of the 1→ 3 optimal universal quantum cloning and the optimal phase-covariant quantum cloning in d-dimensions are presented, and the dimensionalities of their ancillary systems are both d-dimensions. As d→∞ , their clone fidelities move toward 1/3, showing a classical limit for the fidelity of quantum cloning. Based on the reduction of the unitary transformation of quantum cloning, the transformation of the 1→M=d+1 optimal economical phase-covariant quantum cloning in d-dimensions is derived, and the clone fidelity is covered by the theoretical value.
基金the National Natural Science Foundation of China (Grant Nos. 60978009 and 91121023)the National Basic Research Program of China (Grant No. 2011CBA00200)
文摘An unknown state of a quantum system S is usually determined by repeatedly measuring a set of non-commuting observables. The state can also be obtained from the repeated measurements of a single separable observable when the system S interacts with an assistant system A in a known state. In this paper, we study the quantum state tomography of a three-level atom （the system S） interacting with two radiation fields as the assistant system A. We obtain the initial state of S by repeatedly measuring a separable observable O = Sz n1 n2, in which Sz is the atom operator, and hi and h2 are the photon number operators of the two radiation fields. We achieve the one-to-one mapping M between the initial density matrix of the system S and the measured results of the single separable observable. We also give a concrete numerical example.
