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Monsoon Circulation Related to ENSO phase-locking

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Advances in Atmospheric Sciences 1998年第2期15卷 134-143页

作者：徐建军朱乾根周铁汉 LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing Nanjing Institute of Meteorology Nanjing

The relation of interannual anomaly of East Asian monsoon to the ENSO cycle is investigated in terms of even and odd symmetry analysis over a tropical heating field based on the past 30-year data. Evidence suggests that odd and even symmetry components related to the monsoon and Walker heating, respectively, effectively describe the East Asian monsoon circulation and Pacific Walker analog, with the monsoon intensity index corresponding to its heating vigor and western Pacific Walker heating vigor to ENSO phase change, both types of heating marked by pronounced seasonal variation and phase-locking; the key region for linking monsoon-ENSO interaction is the western Pacific warm pool; the monsoon effect upon ENSO cycle is affected jointly by the seasonal evolution and interannual anomaly of the heating components; the superimposition of an anti-Walker circulation phase produced by interannual winter monsoon perturbation upon a weaker Walker phase on a seasonal basis leads to an El Nino happening in March-April and plays a significant role in maintaining a warm ENSO phase.

关键词： Monsoon heating Walker heating ENSO cycle phase locking

phase-locked single-mode terahertz quantum cascade lasers array

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Journal of Semiconductors 2024年第6期45卷 87-91页

作者： Yunfei Xu Weijiang Li Yu Ma Quanyong Lu Jinchuan Zhang Shenqiang Zhai Ning Zhuo Junqi Liu Shuman Liu Fengmin Cheng Lijun Wang Fengqi Liu Key Laboratory of Semiconductor Materials Science Institute of SemiconductorsChinese Academy of SciencesBeijing Key Laboratory of Low Dimensional Semiconductor Materials and DevicesBeijing100083China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Division of Quantum Materials and Devices Beijing Academy of Quantum Information SciencesBeijing 100193China

We demonstrated a scheme of phase-locked terahertz quantum cascade lasers(THz QCLs)array,with a single-mode pulse power of 108 mW at 13 *** device utilizes a Talbot cavity to achieve phase locking among five ridge lasers with first-order buried distributed feedback(DFB)grating,resulting in nearly five times amplification of the single-mode *** to the optimum length of Talbot cavity depends on wavelength,the combination of Talbot cavity with the DFB grating leads to better power amplification than the combination with multimode Fabry-Perot(F-P)*** Talbot cavity facet reflects light back to the ridge array direction and achieves self-imaging in the array,enabling phase-locked operation of *** set the spacing between adjacent elements to be 220μm,much larger than the free-space wavelength,ensuring the operation of the fundamental supermode throughout the laser's dynamic range and obtaining a high-brightness far-field *** scheme provides a new approach for enhancing the single-mode power of THz QCLs.

关键词： quantum cascade lasers phase locking terahertz single mode

Interaction function of coupled bursting neurons

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Chinese Physics B 2016年第6期25卷 95-100页

作者：石霞张佳栋 School of Science Beijing University of Posts and Telecommunications

The interaction functions of electrically coupled Hindmarsh–Rose（HR） neurons for different firing patterns are investigated in this *** applying the phase reduction technique,the phase response curve（PRC） of the spiking neuron and burst phase response curve（BPRC） of the bursting neuron are *** the interaction function of two coupled neurons can be calculated numerically according to the PRC（or BPRC） and the voltage time course of the *** show that the BPRC is more and more complicated with the increase of the spike number within a burst,and the curve of the interaction function oscillates more and more frequently with ***,two certain things are unchanged：Φ = 0,which corresponds to the in-phase synchronization state,is always the stable equilibrium,while the anti-phase synchronization state with Φ = 0.5 is an unstable equilibrium.

关键词： phase response curve burst phase response curve interaction function phase locking

Propagation of phase-locked truncated Gaussian beam array in turbulent atmosphere

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Chinese Physics B 2010年第2期19卷 266-273页

作者：周朴刘泽金许晓军储修祥 College of Optoelectric Science and Engineering National University of Defense Technology

Truncation manipulation is a simple but effective way to improve the intensity distribution properties of the phase-locked Gaussian beam array at the receiving plane. In this paper, the analytical expression for the propagation of the phase-locked truncated Gaussian beam array in a turbulent atmosphere is obtained based on the extended Huygens--Fresnel principle. Power in the diffraction-limited bucket is introduced as the beam quality factor to evaluate the influence of different truncation parameters. The dependence of optimal truncation ratio on the number of beamlets, the intensity of turbulence, propagation distance and laser wavelength is calculated and discussed. It is revealed that the optimal truncation ratio is larger for the laser array that contains more lasers, and the optimal truncation ratio will shift to a larger value with an increase in propagation distance and decrease in intensity of atmosphere turbulence. The optimal truncation ratio is independent of laser wavelength.

关键词： laser array phase locking truncation propagation turbulence

Spiking patterns of a hippocampus model in electric fields

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Chinese Physics B 2011年第12期20卷 484-489页

作者：门聪王江秦迎梅魏熙乐车艳秋邓斌 School of Electrical Engineering and Automation Tianjin University Tianjin Key Laboratory of Information Sensing and Intelligent Control Tianjin University of Technology and Education

We develop a model of CA3 neurons embedded in a resistive array to mimic the effects of electric fields from a new perspective. Effects of DC and sinusoidal electric fields on firing patterns in CA3 neurons are investigated in this study. The firing patterns can be switched from no firing pattern to burst or from burst to fast periodic firing pattern with the increase of DC electric field intensity. It is also found that the firing activities are sensitive to the frequency and amplitude of the sinusoidal electric field. Different phase-locking states and chaotic firing regions are observed in the parameter space of frequency and amplitude. These findings are qualitatively in accordance with the results of relevant experimental and numerical studies. It is implied that the external or endogenous electric field can modulate the neural code in the brain. Furthermore, it is helpful to develop control strategies based on electric fields to control neural diseases such as epilepsy.

关键词： electric field Pinsky-Rinzel neuron phase locking firing pattern

Measure Synchronization on Symplectic Map

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Communications in Theoretical Physics 2004年第6期41卷 886-894页

作者： CHENShao-Ying XUHai-Bo WANGGuang-Rui CHENShi-Gang DepartmentofPhysics HulunbuirCollegeHailaer021008China InstituteofAppliedPhysicsandComputationalMathematics P.O.Box8009Beijing100088China

Measure synchronization in coupled Hamiltonian systems is a novel synchronization phenomenon. The measure synchronization on symplectic map is observed numerically, for identical coupled systems with different parameters. We have found the properties of the characteristic frequency and the amplitude of phase locking in regular motion when the measure synchronization of coupled systems is obtained. The relations between the change of the largest Lyapunov exponent and the course of phase desynchronization are also discussed in coupled systems, some useful results are obtained. A new approach is proposed for describing the measure synchronization of coupled systems numerically,which is advantage in judging the measure synchronization, especially for the coupled systems in nonregular region.

关键词： symplectic map measure synchronization phase locking Lyapunov exponent

Resonant current in coupled inertial Brownian particles with delayed-feedback control

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Frontiers of physics 2017年第6期12卷 33-41页

作者： Tian-Fu Gao Zhi-Gang Zheng Jin-Can Chen College of Physical Science and Technology Shenyang Normal University Shenyang 110034 China College of Information Science and Engineering Huaqiao University Xiamen 361021 China Department of Physics Xiamen University Xiamen 361005 China

The transport of a walker in rocking feedback-controlled ratchets is investigated. The walker consists of two coupled ＂feet＂ that allow the interchange of the order of particles while the walker moves. In the underdamped case, tile deterministic dynamics of the walker in a tilted asymmetric ratchet with an external periodic force is considered. It is found that delayed feedback ratchets with a switching-on- and-off dependence of the states of the system can lead to absolute negative mobility. In such a novel phenomenon, the particles move against tile bias. Moreover, the walker can acquire a series of resonant steps for different values of the current. It is interesting to find that the resonant currents of the walker are induced by tile phase locked motion that corresponds to the synchronization of the motion with the change in the frequency of the external driving. These resonant steps can be well predicted in terms of time-space symmetry analysis, which is in good agreement with dynamics simulations. The transport performances can be optimized and controlled by suitably adjusting the parameters of tile delayed-feedback ratchets.

关键词： delayed-feedback control absolute negative mobility resonant steps phase locking

Emulation of auditory senses depending on chaotic dynamics of threshold switching memristor

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InfoMat 2023年第10期5卷 53-63页

作者： Junwei Yu Fei Zeng Qin Wan Ziao Lu Feng Pan Key Laboratory of Advanced Materials(MOE) School of Materials Science andEngineeringTsinghua UniversityBeijingthe People's Republic of China2Center for Brain Inspired ComputingResearch(CBICR)Tsinghua UniversityBeijingthe People's Republic of China

Emulating the auditory sense is a significant challenge in terms of both integration and energy consumption for handling complicated spatiotemporal ***,we demonstrate how to utilize the chaotic dynamics of a threshold switching memristor,which usually acts as a leaky integrate and fire neuron in the neuromorphic network,to encode the frequency and amplitude in auditory *** fabricate a Pd/Nb/NbOx/Nb/Pd memristor domi-nated by the Poole-Frankel conduction mechanism,set its state at the edge of chaos,and stimulate it using periodic *** memristor's responses to the perturbation frequencies can be categorized into three *** are phase locking with linear phase-frequency rela tionships,and one has a hyper-bolic spike number-frequency *** memristor system also enables intensity coding and tonotopy by modulating the response spikes in either the locked phase or spike *** on the emulation of these two features,the memristor system demonstrates sound location and frequency *** study suggests a novel routine for handling the auditory and visual senses using threshold-switching memristor arrays to enhance the efficiency of neuromorphic networks.

关键词： auditory senses chaotic dynamics intensity coding phase locking sound location thresholdswitching memristor

Historical phase-Locked El Nino Episodes

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Atmospheric and Climate Sciences 2017年第1期7卷 48-64页

作者： David H.Douglass Robert S.Knox Scott Curtis Benjamin S.Giese Sulagna Ray Department of Physics and Astronomy University of RochesterRochesterNYUSA Department of Geography Planningand EnvironmentEast Carolina UniversityGreenvilleNCUSA Department of Oceanography Texas A&M UniversityCollege StationTXUSA Atmospheric and Ocean Sciences Program Princeton UniversityPrincetonNJUSA

Using a newly reported Pacific sea surface temperature data set, we extend a prior study that assigned El Niño episodes to distinct sequences. Within these sequences the episodes are phase-locked to subharmonics of the annual solar irradiance cycle having two- or three-year periodicity. There are 40 El Niño episodes occurring since 1872, each found within one of eighteen such sequences. Our list includes all previously reported events. Three El Niño episodes have already been observed in boreal winters of 2009, 2012 and 2015, illustrating a sequence of 3-year intervals that began in 2008. If the climate system remains in this state, the next El Niño is likely to occur in boreal winter of 2018.

关键词： Climate Climatology Solar Forcing Seasonal Effects El Nino phase locking