关键词：
Active control;Anti-synchronization;Pinning control;Synchronization;Three-Scroll Unified Chaotic System (TSUCS)
摘要：
This paper studies the synchronization and anti-synchronization problem of the Three-Scroll Unified Chaotic System (TSUCS), which has nonlinear terms in each subsystem. By virtue of active control, a novel active pinning control strategy is presented, which only needs one or two states of the TSUCS. Under the proposed controller, the synchronization of two TSUCS with parametric uncertainty is achieved and therefore the robust stability of TSUCS synchronization is ensured. Some stability theories about synchronization and anti-synchronization have been given and proved the use of this class of a novel TSUCS and its hyper-unified chaotic system with the active pinning control strategy. Numerical simulations are given to verify the theoretical analysis, which clearly shows that the control strategy can really make the chaotic systems achieve synchronization and anti-synchronization in a quite short time.
通讯机构：
[Guan, Zhihong] H;Huazhong Univ Sci & Technol, Dept Control Sci & Engn, Wuhan 430074, Peoples R China.
关键词：
Fractional-order Hyperchaotic System (FOHCS);Feedback Control (FC);Laplace transform;antisynchronization;Lü-like Hyperchaotic System
摘要：
In this paper, the chaos multiscale-synchronization between two different Fractional-order Hyperchaotic System (FOHCS)s have been investigated. The Lü-like and its FOHCS are also studied. The Lü-like FOHCS is controlled to be multiscale-synchronization with Liu FOHCS and new Lorenz FOHCS, respectively. The analytical conditions for the multiscale-synchronization of these pairs of different FOHCSs are derived by utilizing Laplace transform. Furthermore, multiscale-synchronization between two different FOHCSs is achieved by utilizing the different linear and nonlinear feedback control method in a short period and both remain in chaotic states. Numerical simulations are used to verify the theoretical analysis using different values of the fractional-order parameter and the different linear and nonlinear control functions.
摘要：
In this paper, a versatile complementary metal oxide semiconductor (CMOS) readout integrated circuit (ROIC) for microbolometric infrared focal plane array (IRFPA) is presented. By applying a variable column-shared current mirror (CM) proportional circuit, the ROIC can be used in applications on different occasions from very high background to quite low background. With column-shared blind bolometer, CM proportional circuit and capacitor feedback trans-impedance amplifier (CTIA) integration circuit, the ROIC has high performance such as high gain, low noise, low power dissipation and large output dynamic range while maintaining simple structure. Moreover, a common high correlated double sampling (CDS) circuit is utilized to improve noise performance of the ROIC under low power dissipation. An experimentally prototypical readout chip is designed and fabricated for microbolometric IRFPAs to verify the performance of the ROIC. Theoretical analysis and experimentally measuring results indicate that the proposed CMOS ROIC can be applied to microbolometric IRFPAs. Crown Copyright (C) 2013 Published by Elsevier GmbH. All rights reserved.
关键词：
Diamond nitrogen-vacancy centers;Optical ring cavity;Optical bistability;Elliptically polarized light
摘要：
We explore laser-polarization-dependent and magnetically controlled optical bistability (OB) in an optical ring cavity filled with diamond nitrogen-vacancy (NV) defect centers under optical excitation. The shape of the OB curve can be significantly modified in a new operating regime from the previously studied OB case, namely, by adjusting the intensity of the external magnetic field and the polarization of the control beam. The influences of the intensity of the control beam, the frequency detuning, and the cooperation parameter on the OB behavior are also discussed in detail. These results are useful in real experiments for realizing an all-optical bistate switching or coding element in a solid-state platform. (C) 2013 Elsevier B.V. All rights reserved.
摘要：
The quantum phase crossover in a spin ladder model with four-spin exchange is investigated. Previous studies show that the crossover cannot be detected by the singularity or finite-size analysis of ground-state observables for finite ladders. In this work, we find that the first-excited-state fidelity shows a sudden drop exactly at the crossover point, regardless of the length of the ladder. It suggests that the excited-state fidelity for finite systems is very effective in detecting the crossover in infinite systems. The underlying mechanism is understood through the analysis of re-construction of the low-lying energy levels of the systems.
摘要：
Smart window coating is fabricated by using vanadium dioxide (VO2) thin film. The VO2 thin film is nanocrystal structured and has low phase transition temperature which is about 35 degrees C. This kind of thin film is infrared-optically transparent in the semiconductor phase at low temperatures and highly reflective in the metallic phase at high temperatures. Based on the VO2 thin film, a multilayered structure for smart window is designed and fabricated. The multilayered structure is optically transparent for visible light whether at low temperatures or high temperatures, and is transparent at low temperatures and opaque at high temperatures for infrared light, which is smart for adjusting infrared transmittance. This type of multilayered structure is potential to be applied to green smart windows to realize energy saving function. Crown Copyright (C) 2011 Published by Elsevier GmbH. All rights reserved.
摘要：
The spontaneous emission spectra of a five-level double tripod-type atom embedded in photonic crystals (PCs) are investigated by means of two external fields driving different atomic transitions. We find that due to the quantum interference effects caused by two driving fields, the spontaneous emission spectra exhibit different features from the case of only one driving field. The influences of the parameters of two external driving fields, photonic band-gap (PBG), as well as the atomic initial states on the spectra are analyzed in detail. It is shown that some interesting phenomena such as spectral-line enhancement, spectral-line suppression, spectral-line narrowing, the appearance of dark lines, and multi-peak structures can be observed in the spectra by appropriately modulating the available system parameters. These investigations may find applications in high-precision spectroscopy.
关键词：
Photonic crystals (PCs);Spontaneous emission;Microwave field
摘要：
The spontaneous emission properties of a microwave-field-driven four-level atom embedded in anisotropic double-band photonic crystals (PCs) are investigated. We discuss the influences of the band-edge positions, Rabi frequency and detuning of the microwave field on the emission spectrum. It is found that several interesting features such as spectral-line enhancement, spectral-line suppression, spectral-line overlap, and multi-peak structures can be observed in the spectra. The proposed scheme can be achieved by use of a microwave-coupled field into hyperfine levels in rubidium atom confined in a photonic crystal. These theoretical investigations may provide more degrees of freedom to manipulate the atomic spontaneous emission. (C) 2012 Elsevier B.V. All rights reserved.
摘要：
Nanodomains and grain-size effects in BaTiO3 have been studied theoretically. In this article, we have calculated the long-range Coulomb interaction between ferroelectric nanodomains in a single BaTiO3 grain, and obtained information on the domain structure at various temperatures and grain sizes. The relation between transition temperature and the grain size is obtained by incorporating the domain-wall energy, the surface energy, and the stress energy into the Landau–Ginzburg free-energy density. The results show that 180° domains exist in ferroelectric BaTiO3 nanoceramics. At room temperature, with the decreasing grain size, the domain width does not decrease monotonically; when the grain size reduces to 18 nm, the grain becomes a single domain, and when less than 12 nm, the ferroelectric phase disappears. With the decreasing grain size the temperature of the cubic-tetragonal phase transition is reduced, while the temperatures of the tetragonal–orthorhombic and orthorhombic–rhombohedral phase transitions reach a maximum when the grain sizes are in the vicinity of 200 nm. The theoretical results are compared with experimental data.
摘要：
Writer identification is an important and active branch of biometrics, which means the methods for uniquely recognizing humans based upon their intrinsic physical or behavioral traits. In this paper, we propose one new method for off-line, text-independent writer identification by using the fractal dimension of wavelet subbands in Gabor domain of the handwriting images. In this method, the handwriting images are firstly decomposed into a series of Gabor subbands at different orientations and frequencies. Every Gabor subband is extended into one data sequence. Then, every sequence is decomposed into a series of wavelet subpatterns by wavelet transform. Afterwards, the mesh fractal dimensions of every wavelet subpattern are extracted as the feature for writer identification. Compared to the traditional Gabor method for off-line, text-independent writer identification, our method can extract more effective features to distinguish the handwritings, and hence achieve much better identification results.
