- 标题
- 摘要
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- 实验方案
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Artificial association of memory events by optogenetic stimulation of hippocampal CA3 cell ensembles
摘要： Previous gain-of-function studies using an optogenetic technique showed that manipulation of the hippocampal dentate gyrus or CA1 cell ensembles is important for memory reactivation and to generate synthetic or false memory. However, gain-of-function study manipulating CA3 cell ensembles has not been reported. The CA3 area of the hippocampus comprises a recurrent excitatory circuit, which is thought to be important for the generation of associations among the stored information within one brain region. We investigated whether the coincident firing of cell ensembles in one brain region, hippocampal CA3, associates distinct events. CA3 cell ensembles responding to context exploration and during contextual fear conditioning were labeled with channelrhodopsin-2 (ChR2)-mCherry. The synchronous activation of these ensembles induced freezing behavior in mice in a neutral context, in which a foot shock had never been delivered. The recall of this artificial associative fear memory was context specific. In vivo electrophysiological recordings showed that 20-Hz optical stimulation of ChR2-mCherry-expressing CA3 neurons, which is the same stimulation protocol used in behavioral experiment, induced long-term potentiation at CA3-CA3 synapses. Altogether, these results demonstrate that the synchronous activation of ensembles in one brain region, CA3 of the hippocampus, is sufficient for the association of distinct events. The results of our electrophysiology potentially suggest that this artificial association of memory events might be induced by the strengthening of synaptic efficacy between CA3 ensembles via recurrent circuit.
关键词： CA3,Synaptic plasticity,Artificial association,Optogenetics,Recurrent circuit,Long-term potentiation (LTP),Hippocampus
更新于2025-09-23 15:22:29
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The Automatic Measuring System Suitable for the Simplified Very Small Phase Difference Measurement Circuit
摘要： In order to implement the measurement and evaluation of analog signals in high accuracy, to detect not only amplitude level but also phase information is necessary. Particularly, measurement of very small phase difference is desired in fields such as electric power and organism-related. Therefore, we have proposed the simplified very small phase difference measurement circuit with automatic measuring system using microcontroller (Arduino) and automatic amplitude adjustment program. In this paper, we examine a new automatic measuring system in order to improve the measurement accuracy.
关键词： very small phase difference measurement circuit,automatic measuring system,automatic amplitude adjustment program
更新于2025-09-23 15:22:29
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Equivalent-Circuit Model with Retarded Electromagnetic Coupling for Meta-Atoms of Wired Metallic Spheres
摘要： This paper describes the equivalent-circuit model of a metamaterial composed of conducting spheres and wires. This model involves electromagnetic coupling between the conductors, with retardation. The lumped-parameter equivalent circuit, which imports retardation to the electromagnetic coupling, is developed in this paper from Maxwell’s equation. Using the equivalent-circuit model, we clarify the relationship between the retardation and radiation loss; we theoretically demonstrate that the electromagnetic retardation in the near-field represents the radiation loss of the meta-atom in the far-field. Furthermore, this paper focuses on the retarded electromagnetic coupling between two meta-atoms; we estimate the changes in the resonant frequencies and the losses due to the distance between the two coupled meta-atoms. It is established that the dependence characteristics are significantly affected by electromagnetic retardation.
关键词： meta-atom,equivalent-circuit model,metamaterial,electromagnetic coupling,radiation,retardation
更新于2025-09-23 15:22:29
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Corrosion Resistance of Aluminum against Acid Activation: Impact of Benzothiazole-Substituted Gallium Phthalocyanine
摘要： This study describes the adsorption behavior of organic inhibitors at the aluminum-HCl solution interface and their corrosion inhibition performance. The organic inhibitors employed are: 4-(benzo [d]thiazol-2ylthio)phthalonitrile (BTThio) and tetrakis[(benzo[d]thiazol-2-yl-thio)phthalocyaninato]gallium(III) chloride (ClGaBTThioPc). The corrosion behavior of these inhibitors is investigated using electrochemical and computational techniques. Open circuit potential results reveal predominant cathodic character for the mechanism of aluminum corrosion inhibition by the inhibitors. Inhibition efficiency values from potentiodynamic polarization measurements increase from 46.9 to 70.8% for BTThio and 59.7 to 81.0% for ClGaBTThioPc within the concentration range of 2 to 10 μM. Scanning electron microscopy (SEM) measurements reveal protection of the metal surface from acid attack, in the presence of the inhibitors and energy dispersive X-ray (EDX) measurements show that the most probable way by which the inhibitors protect the metal surface would be by shielding it from the corrosion attacks of Cl? from the acid. Quantum chemical parameters corroborate well with experimental findings.
关键词： open circuit potential,cyclic voltammetry,potentiodynamic polarization,corrosion inhibition
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE International Workshop on Electromagnetics: Applications and Student Innovation Competition (iWEM) - Nagoya (2018.8.29-2018.8.31)] 2018 IEEE International Workshop on Electromagnetics:Applications and Student Innovation Competition (iWEM) - E-Plane Beam-Forming Performance of Rotman-Lens in Multi-Layer Substrate
摘要： A two-dimensional Rotman-lens feeding circuit was proposed for planar two-dimensional multi-beam antenna using multi-layer substrate integrated waveguide in the millimeter-wave band. In this work, an E-plane Rotman-lens for two-dimensional Rotman-lens was designed and the E-plane beam-forming performance was evaluated by array factors from the simulated S-parameters.
关键词： multi-beam antenna,feeding circuit,multi-layer substrate,millimeter-wave,Rotman-lens
更新于2025-09-23 15:22:29
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A unified figure of merit for interband and intersubband cascade devices
摘要： By exploring a semi-empirical model, the saturation current density J0 is identified to manifest the significant difference in carrier lifetime between interband cascade devices (ICDs) and intersubband quantum cascade devices (QCDs). Based on this model, the values of J0 have been extracted for a large number of ICDs and QCDs from their current-voltage characteristics at room temperature. By analyzing and comparing available ICD and QCD data, we demonstrate how J0 can be used as a unified figure of merit to evaluate both interband and intersubband cascade configurations for their device functionality. The significance of J0 on the performances of mid-infrared detectors and photovoltaic cells is illustrated by comparing the measured detectivity (D*) and the estimated open-circuit voltage (Voc), respectively. From extracted values of J0, which are more than one order of magnitude lower in ICDs than that in QCDs with similar transition energies in active regions, and discussion of the consequences on device performance, the advantages of interband cascade configurations over intersubband quantum cascade configurations have been clearly revealed based on the same framework. The overall picture for both QCDs and ICDs sheds light from the perspective of a united figure of merit, which will provide useful guidance and stimulation to the future development of both ICDs and QCDs.
关键词： Saturation current density,Interband cascade,Quantum cascade,Open-circuit voltage
更新于2025-09-23 15:22:29
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Effect of the Diamagnetic term in the ultra-strong coupling regime
摘要： We consider a set of two level atoms interacting with a single quantized bosonic mode governed by the Dicke model. In this model it is well known that under a critical value of the light-matter coupling a spontaneous radiation process takes place. In the present work, we investigate the dynamics of the system and we study the Wigner distribution function to visualize the effect of the minimal coupling on the ground state wavefunction from the normal phase to the superradiant one. We show also that the entanglement of Bi-partite model is limited by the presence of the diamagnetic term.
关键词： diamagnetic term,Circuit QED,Cavity QED,Entanglement
更新于2025-09-23 15:22:29
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Quantum-dot circuit-QED thermoelectric diodes and transistors
摘要： Recent breakthroughs in quantum-dot circuit-quantum-electrodynamics systems are promising both from fundamental perspectives and from the point of view of quantum photonic devices. However, understanding such setups as potential thermoelectric devices has been missing. In this paper, via the Keldysh nonequilibrium Green’s function approach, we show that cavity-coupled double quantum-dots can serve as excellent quantum thermoelectric diodes and transistors. Using an enhanced perturbation approach based on the exact polaron transformation, we find dependencies of thermoelectric transport properties on the electron-photon interaction beyond the predictions from the conventional second-order perturbation theory. In particular, strong light-matter interaction leads to pronounced rectification effects for both charge and heat, as well as thermal transistor effects in the linear transport regime, which opens up a cutting-edge frontier for quantum thermoelectric devices.
关键词： rectification,light-matter interaction,circuit-QED,diode,transistor,thermoelectric,thermal transistor,quantum-dot
更新于2025-09-23 15:22:29
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Research on Image Smoothing Diffusion Model with Gradient and Curvature Features
摘要： In this paper, two image smoothing models are proposed for the visual inspection of high-density flexible IC package substrates with strict requirements on line-width and line distance which are applied to the de-noising of high-density flexible IC package substrate images. First of all, the two models proposed in this paper combines the level set curvature feature of the image with gradient threshold, using more abundant second-order differential information as the detection factor to remove noise in image. Secondly, theoretical analysis shows that the de-noised image obtained by the two models proposed can retain more detailed texture information and edge information of the original image. What is more, the experimental analysis shows that the proposed models have the highest structural similarity and peak signal-to-noise ratio, and have a relatively high edge-preserving index and the lowest mean squared error compared with other models. In particular, the de-noised image through Model 1 has the highest structural similarity and peak signal to noise ratio, as well as the lowest mean squared error. The de-noised image through Model 2 has a relatively high edge retention index. The methods proposed in this paper can effectively remove the noise of the image of the high-density flexible IC package substrate, and can retain the original details and edges information of the image.
关键词： Image de-noising,Flexible integrated circuit substrate image,Gradient,Curvature
更新于2025-09-23 15:22:29
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A Novel Transmitting Module Self-Monitoring Protection System Based On MEMS Sensors and Actuators
摘要： Design, fabrication, and measurements of a novel transmitting module self-monitoring protection system are presented in this letter. Such a system is based on micro-electromechanical systems (MEMS) sensors and actuators for monitoring and protecting the microwave amplifier circuit. The transmitting module self-monitoring protection system consists of the RF MEMS switches, the directional coupler, and the MEMS power sensors. When the microwave amplifier circuit is at an abnormal state ("open," "short," or "overload"), the transmitting module self-monitoring protection system can isolate the microwave amplifier circuit out of order and reconfigure the transmitting module into impedance matching within 36 ms. When the microwave amplifier circuit is at the overload state, the error between the set switching power and the actual switching power is less than 9%. The measured results agree well with the theory.
关键词： Microelectromechanical systems (MEMS) power sensor,microwave amplifier circuit,RF MEMS switch,self-monitoring protection
更新于2025-09-23 15:22:29