7,819 research outputs found

    Possible Way to Synthesize Superheavy Element Z=117

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    Within the framework of the dinuclear system model, the production of superheavy element Z=117 in possible projectile-target combinations is analyzed systematically. The calculated results show that the production cross sections are strongly dependent on the reaction systems. Optimal combinations, corresponding excitation energies and evaporation channels are proposed in this letter, such as the isotopes ^{248,249}Bk in ^{48}Ca induced reactions in 3n evaporation channels and the reactions ^{45}Sc+^{246,248}Cm in 3n and 4n channels, and the system ^{51}V+^{244}Pu in 3n channel.Comment: 10 pages, 4 figures, 1 tabl

    NMF-Based Comprehensive Latent Factor Learning with Multiview da

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    Multiview representations reveal the latent information of the data from different perspectives, consistency and complementarity. Unlike most multiview learning approaches, which focus only one perspective, in this paper, we propose a novel unsupervised multiview learning algorithm, called comprehensive latent factor learning (CLFL), which jointly exploits both consistent and complementary information among multiple views. CLFL adopts a non-negative matrix factorization based formulation to learn the latent factors. It learns the weights of different views automatically which makes the representation more accurate. Experiment results on a synthetic and several real datasets demonstrate the effectiveness of our approach

    Mutual-learning sequence-level knowledge distillation for automatic speech recognition

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    Automatic speech recognition (ASR) is a crucial technology for man-machine interaction. End-to-end models have been studied recently in deep learning for ASR. However, these models are not suitable for the practical application of ASR due to their large model sizes and computation costs. To address this issue, we propose a novel mutual-learning sequence-level knowledge distillation framework enjoying distinct student structures for ASR. Trained mutually and simultaneously, each student learns not only from the pre-trained teacher but also from its distinct peers, which can improve the generalization capability of the whole network, through making up for the insufficiency of each student and bridging the gap between each student and the teacher. Extensive experiments on the TIMIT and large LibriSpeech corpuses show that, compared with the state-of-the-art methods, the proposed method achieves an excellent balance between recognition accuracy and model compression

    A P300-speller based on event-related spectral perturbation (ERSP)

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    A brain-computer interface (BCI) P300 speller is a novel technique that helps people spell words using the electroencephalography (EEG) without the involvement of muscle activities. However, only time domain ERP features (P300) are used for controlling of the BCI speller. In this paper, we investigated the time-frequency EEG features for the P300-based brain-computer interface speller. A signal preprocessing method integrated ensemble average, principal component analysis, and independent component analysis to remove noise and artifacts in the EEG data. A time-frequency analysis based on wavelet transform was carried out to extract event-related spectral perturbation (ERSP) and inter-trial coherence (ITC) features. Results showed that the proposed signal processing method can effectively extract EEG time-frequency features in the P300 speller, suggesting that ERSP and ITC may be useful for improving the performance of BCI P300 speller. © 2012 IEEE.published_or_final_versio

    Extending the first-order post-Newtonian scheme in multiple systems to the second-order contributions to light propagation

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    In this paper, we extend the first-order post-Newtonian scheme in multiple systems presented by Damour-Soffel-Xu to the second-order contribution to light propagation without changing the virtueof the scheme on the linear partial differential equations of the potential and vector potential. The spatial components of the metric are extended to second order level both in a global coordinates (qij/c4q_{ij}/ c^4) and a local coordinates (Qab/c4Q_{ab}/ c^4). The equations of qijq_{ij} (or QabQ_{ab}) are obtained from the field equations.The relationship between qijq_{ij} and QabQ_{ab} are presented in this paper also. In special case of the solar system (isotropic condition is applied (qij=δijqq_{ij} = \delta_{ij} q )), we obtain the solution of qq. Finally, a further extension of the second-order contributions in the parametrized post-Newtonian formalism is discussed.Comment: Latex2e; 6 pages PS fil

    Operator Quantum Geometric Tensor and Quantum Phase Transitions

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    We extend the quantum geometric tensor from the state space to the operator level,and investigate its properties like the additivity for factorizable models and the splitting of two kinds contributions for the case of stationary reference states. This operator-quantum-geometric tensor (OQGT) is shown to reflect the sensitivity of unitary operations against perturbations of multi parameters. General results for the cases of time evolutions with given stationary reference states are obtained. By this approach, we get exact results for the rotated XY models, and show relations between the OQGT and quantum criticality.Comment: One more reference added. 6 pages,2 figs. Accepted by EP

    Studying arsenic trioxide-induced apoptosis of Colo-16 cells with two-photon and confocal laser scanning microscopy

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    With two-photon and confocal laser scanning microscopy in combination with fluorescent probes Hoechst 33342, 2′,7′-dichlorofluorescin diacetate (DCFH-DA) and Fluo 3-AM, we simultaneously observed arsenic trioxide (As2O3)-induced changes in nuclear morphology, reactive oxygen species (ROS) and intracellular calcium concentration (Ca2+)i within human skin squamous carcinoma cells (Colo-16 cells). Our results indicated that As2O3 induced (Ca2+)i elevation and ROS production within Colo-16 cells, and both (Ca2+)i elevation and ROS production were involved in the apoptosis of Colo-16 cells. These results suggested that two-photon and confocal laser scanning microscopy might provide a real-time, sensitive and noninvasive method for simultaneously multi-parameter observation of As2O3- induced apoptosis at the single cell level.Key words: Two-photon laser scanning microscopy, confocal laser scanning microscopy, human skin squamous carcinoma cells (Colo-16 cells), arsenic trioxide, apoptosi

    On the Convergence of Ritz Pairs and Refined Ritz Vectors for Quadratic Eigenvalue Problems

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    For a given subspace, the Rayleigh-Ritz method projects the large quadratic eigenvalue problem (QEP) onto it and produces a small sized dense QEP. Similar to the Rayleigh-Ritz method for the linear eigenvalue problem, the Rayleigh-Ritz method defines the Ritz values and the Ritz vectors of the QEP with respect to the projection subspace. We analyze the convergence of the method when the angle between the subspace and the desired eigenvector converges to zero. We prove that there is a Ritz value that converges to the desired eigenvalue unconditionally but the Ritz vector converges conditionally and may fail to converge. To remedy the drawback of possible non-convergence of the Ritz vector, we propose a refined Ritz vector that is mathematically different from the Ritz vector and is proved to converge unconditionally. We construct examples to illustrate our theory.Comment: 20 page
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