Fear extinction is an important form of emotional learning, and affects neural plasticity. Cue fear extinction is a classical form of inhibitory learning that can be used as an exposure-based treatment for phobia, bec...Fear extinction is an important form of emotional learning, and affects neural plasticity. Cue fear extinction is a classical form of inhibitory learning that can be used as an exposure-based treatment for phobia, because the long-term extinction memory produced during cue fear extinction can limit the over-expression of fear. The expression of this inhibitory memory partly depends on the context in which the extinction learning occurs. Studies such as transient inhibition, electrophysiology and brain imaging have proved that the hippocampus - an important structure in the limbic system - facilitates memory retrieval by contextual cues. Mediation of the hippocampus-medial prefrontal lobe circuit may be the neurobiological basis of this process. This article has reviewed the role of the hippocampus in the learning and retrieval of fear extinction. Contextual modulation of fear extinction may rely on a neural network consisting of the hippocampus, the medial prefrontal cortex and the amygdala.展开更多
We propose a new scheme to enhance the performance of the Gussian-modulated coherent-state continuous-variable measurement-device-independent quantum key distribution(CV-MDI-QKD)system via quantum scissors(QS)operatio...We propose a new scheme to enhance the performance of the Gussian-modulated coherent-state continuous-variable measurement-device-independent quantum key distribution(CV-MDI-QKD)system via quantum scissors(QS)operation at Bob's side.As an non-deterministic amplifying setup,we firstly introduce the QS-enhanced CV-MDI-QKD protocol and then investigate the success probability of the QS operation in accordance with the equivalent one-way scheme.Afterwards,we investigate the effect of the QS operation on the proposed scheme and analyze the performance of the QS-enhanced CV-MDI-QKD system under the extreme asymmetric circumstance.Simulation results show that the QS operation can indeed improve the performance of the CV-MDI-QKD system considerably.QS-enhanced CV-MDI-QKD protocol outperforms the original CV-MDI-QKD protocol in both the maximum transmission distance and the secret key rate.Moreover,the better the performance of QS operation,the more significant the improvement of performance of the system.展开更多
When developing a practical continuous-variable quantum key distribution(CVQKD),the detector is necessary at the receiver's side.We investigate the practical security of the CVQKD system with an unbalanced heterod...When developing a practical continuous-variable quantum key distribution(CVQKD),the detector is necessary at the receiver's side.We investigate the practical security of the CVQKD system with an unbalanced heterodyne detector.The results show that unbalanced heterodyne detector introduces extra excess noise into the system and decreases the lower bound of the secret key rate without awareness of the legitimate communicators,which leaves loopholes for Eve to attack the system.In addition,we find that the secret key rate decreases more severely with the increase in the degree of imbalance and the excess noise induced by the imbalance is proportional to the intensity of the local oscillator(LO)under the same degree of imbalance.Finally,a countermeasure is proposed to resist these kinds of effects.展开更多
基金the National Natural Science Foundation of China, No. 30670704
文摘Fear extinction is an important form of emotional learning, and affects neural plasticity. Cue fear extinction is a classical form of inhibitory learning that can be used as an exposure-based treatment for phobia, because the long-term extinction memory produced during cue fear extinction can limit the over-expression of fear. The expression of this inhibitory memory partly depends on the context in which the extinction learning occurs. Studies such as transient inhibition, electrophysiology and brain imaging have proved that the hippocampus - an important structure in the limbic system - facilitates memory retrieval by contextual cues. Mediation of the hippocampus-medial prefrontal lobe circuit may be the neurobiological basis of this process. This article has reviewed the role of the hippocampus in the learning and retrieval of fear extinction. Contextual modulation of fear extinction may rely on a neural network consisting of the hippocampus, the medial prefrontal cortex and the amygdala.
基金Project supported by the National Natural Science Foundation of China(Grant No.62001383)the Scientific Research Plan Project of Shaanxi Education Department(Natural Science Special Project)(Grant No.19JK0847).
文摘We propose a new scheme to enhance the performance of the Gussian-modulated coherent-state continuous-variable measurement-device-independent quantum key distribution(CV-MDI-QKD)system via quantum scissors(QS)operation at Bob's side.As an non-deterministic amplifying setup,we firstly introduce the QS-enhanced CV-MDI-QKD protocol and then investigate the success probability of the QS operation in accordance with the equivalent one-way scheme.Afterwards,we investigate the effect of the QS operation on the proposed scheme and analyze the performance of the QS-enhanced CV-MDI-QKD system under the extreme asymmetric circumstance.Simulation results show that the QS operation can indeed improve the performance of the CV-MDI-QKD system considerably.QS-enhanced CV-MDI-QKD protocol outperforms the original CV-MDI-QKD protocol in both the maximum transmission distance and the secret key rate.Moreover,the better the performance of QS operation,the more significant the improvement of performance of the system.
基金the National Natural Science Foundation of China(Grant No.62001383)the Natural Science Basic Research Plan in Shaanxi Province of China(Grant No.2019JM-591)。
文摘When developing a practical continuous-variable quantum key distribution(CVQKD),the detector is necessary at the receiver's side.We investigate the practical security of the CVQKD system with an unbalanced heterodyne detector.The results show that unbalanced heterodyne detector introduces extra excess noise into the system and decreases the lower bound of the secret key rate without awareness of the legitimate communicators,which leaves loopholes for Eve to attack the system.In addition,we find that the secret key rate decreases more severely with the increase in the degree of imbalance and the excess noise induced by the imbalance is proportional to the intensity of the local oscillator(LO)under the same degree of imbalance.Finally,a countermeasure is proposed to resist these kinds of effects.
