When implementing Markov Chain Monte Carlo (MCMC) algorithms, perturbation caused by numerical errors is sometimes inevitable. This paper studies how perturbation of MCMC affects the convergence speed and Monte Carlo ...
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Static friction, a ubiquitous physical phenomenon, plays a significant role in natural processes and industrial applications. Its influence is particularly notable in the field of controlled micromanipulation and prec...
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Static friction, a ubiquitous physical phenomenon, plays a significant role in natural processes and industrial applications. Its influence is particularly notable in the field of controlled micromanipulation and precision manufacturing, where static friction often exceeds kinetic friction and leads to material damage and unpredictable behaviors. In this study, we report the first experimental observation of the elimination of static friction peak in sliding micrometer contacts of layered materials, achieved through a technique involving selective etching of the amorphous edges of single crystalline surfaces. Our findings are consistent with theoretical models and simulations that predicted the absence of static friction between two atomically flat, pristine, weakly interacting, incommensurate solid surfaces. In this state, thermally induced spontaneous actuation in graphite homogeneous junctions was observed at temperatures slightly above room temperature (around 40 °C), with contact sizes up to 100 μm2. These results have significant implications for improving our understanding and control of static friction, opening up promising opportunities for the application of micromechanical devices and precision mechanical systems.
Flexible supercapacitor electrodes with high mass loading are crucial for obtaining favorable electrochemical performance but still challenging due to sluggish electron and ion ***,rationally designed CNT/MnO2/graphen...
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Flexible supercapacitor electrodes with high mass loading are crucial for obtaining favorable electrochemical performance but still challenging due to sluggish electron and ion ***,rationally designed CNT/MnO2/graphene-grafted carbon cloth electrodes are prepared by a“graft-deposit-coat”*** to the large surface area and good conductivity,graphene grafted on carbon cloth offers additional surface areas for the uniform deposition of MnO2(9.1 mg cm?2)and facilitates charge ***,the nanostructured MnO2 provides abundant electroactive sites and short ion transport distance,and CNT coated on MnO2 acts as interconnected conductive“highways”to accelerate the electron transport,significantly improving redox reaction *** from high mass loading of electroactive materials,favorable conductivity,and a porous structure,the electrode achieves large areal capacitances without compromising rate *** assembled asymmetric supercapacitor demonstrates a wide working voltage(2.2 V)and high energy density of 10.18 mWh cm?3.
Noble metal-based surface-enhanced Raman spectroscopy(SERS)has emerged as an ultrasensitive technique capable of detecting single molecules through their unique vibrational ***,achieving robust SERS nano-materials tha...
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Noble metal-based surface-enhanced Raman spectroscopy(SERS)has emerged as an ultrasensitive technique capable of detecting single molecules through their unique vibrational ***,achieving robust SERS nano-materials that combine significant enhancement factors,scalable reproducibility,and superior chemical stability remains a significant *** present an oxygen-free vapor deposition technique for wafer-scale fabrication of nanocrystalline NbSe_(2)(NC-NbSe_(2))films on SiO2/Si substrates,which is compatible with batch *** NC-NbSe_(2)films exhibit remarkable chemical stability across both crystalline domains(average size~8.1 nm)and grain *** stability,combined with enhanced surface adsorption and a high density of states near the Fermi level,enables superior SERS *** 6G detection demonstrates a sensitivity of 1×10^(-10)M,comparable to noble metal-based SERS ***,the NC-NbSe_(2)film maintains stable SERS signals under harsh thermal and chemical *** scalable approach enables the creation of uniform,reproducible SERS atomic thin film,advancing applications in microelectronics and sensing technologies.
Chaotic dynamics in optical microcavities, governed dominantly by manifolds, is of great importance for both fundamental studies and photonic applications. Here, we report the experimental observation of a stable mani...
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Chaotic dynamics in optical microcavities, governed dominantly by manifolds, is of great importance for both fundamental studies and photonic applications. Here, we report the experimental observation of a stable manifold characterized by energy and momentum evolution in the nearly chaotic phase space of an asymmetric optical microcavity. By controlling the radius of a fiber coupler and the coupling azimuth of the cavity, corresponding to the momentum and position of the input light, the injected light can in principle excite the system from a desired position in phase space. It is found that once the input light approaches the stable manifold, the angular momentum of the light experiences a rapid increase, and the energy is confined in the cavity for a long ***, the distribution of the stable manifold is visualized by the output power and the coupling depth to high-Q modes extracted from the transmission spectra, which is consistent with theoretical predictions by the ray model. This work opens a new path to understand the chaotic dynamics and reconstruct the complex structure in phase space, providing a new paradigm of manipulating photons in wave chaos.
Co@C core–shell nanospheres highly dispersed on carbon supports were rationally designed to improve the microwave absorbing property of the composite material, and fabricated by one pot thermal decomposition and simp...
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Co@C core–shell nanospheres highly dispersed on carbon supports were rationally designed to improve the microwave absorbing property of the composite material, and fabricated by one pot thermal decomposition and simple annealing process. The Co nanospheres were completely encapsulated with thin carbon shells, which can effectively prevent the oxidation of the Co surface. Additionally, the particle size of Co nanospheres were properly controlled to optimize the electromagnetic property of the composite material. As a result, the lightweight Co@C/C composites with the particle size of 20 nm exhibited much enhanced microwave absorption properties. The improved microwave absorption performance is attributed mainly to the enhanced isotropic ratio and impedance matching of magnetic composites via tuning the Co particle size. Therefore, the welldesigned core-shell Co@C composite structure will provide a new insight for the development of high performance microwave absorbers.
The sensory nervous system in animals enables the perception of external stimuli. Developing an artificial sensory nervous system has been widely conducted to realize neuro-inspired robots capable of effectively respo...
The sensory nervous system in animals enables the perception of external stimuli. Developing an artificial sensory nervous system has been widely conducted to realize neuro-inspired robots capable of effectively responding to external stimuli. However, it remains challenging to develop artificial sensory nervous systems that possess sophisticated biological functions, such as habituation and sensitization, enabling efficient responses without bulky peripheral circuitry. Here, we introduce a memristor device with third-order switching complexity, emulating an artificial synapse that inherently possesses habituation and sensitization properties. Incorporating an additional resistive switching TiO layer into the HfO memristor exhibits third-order switching complexity and non-volatile habituation characteristics. Based on the third-order memristor, we propose a robotic system equipped with a memristor-based artificial sensory nervous system for optimizing the robot arm's response to external stimuli without the aid of processors. It is experimentally demonstrated that the robot arm with the developed memristor-based artificial sensory nervous system ignores approximately 71% of safe and familiar stimuli while sensitively responding to threatening and significant stimuli, similar to the habituation and sensitization of biological sensory nervous systems. Our findings can be a stepping stone for energy-efficient and intelligent robotic systems with reduced hardware burden.
We study the simplest quantum lattice spin model for the two-dimensional (2D) cubic ferromagnet by means of mean-field analysis and tensor network calculation. While both methods give rise to similar results in detect...
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We study the simplest quantum lattice spin model for the two-dimensional (2D) cubic ferromagnet by means of mean-field analysis and tensor network calculation. While both methods give rise to similar results in detecting related phases, the 2D infinite projected entangled-pair state (iPEPS) calculation provides more accurate values of transition points. Near the phase boundary, moreover, our iPEPS results indicate that it is more difficult to pin down the orientation of magnetic easy axes, and we interpret it as the easy-axis softening. This phenomenon implies an emergence of continuous U(1) symmetry, which is indicated by the low-energy effective model and has been analytically shown by the field theory. Our model and study provide a concrete example for utilizing iPEPS near the critical region, showing that the emergent phenomenon living on the critical points can already be captured by iPEPS with a rather small bond dimension.
A parallel screening of 27 different flavonoids and chalcones was conducted using 6 artificial naringenin-activated riboswitches(M1,M2,M3,O,L and H).A quantitative structure-property relationship approach was applied ...
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A parallel screening of 27 different flavonoids and chalcones was conducted using 6 artificial naringenin-activated riboswitches(M1,M2,M3,O,L and H).A quantitative structure-property relationship approach was applied to understand the physicochemical properties of the flavonoid structures resulting in specificity differences relied on the fluorescence intensity of a green fluorescent protein *** models of riboswitches M1,M2 and O that had good predictive power were constructed with descriptors selected for their high *** electronegativity and hydrophilicity of the flavonoids structures were identified as two properties that increased binding affinity to RNA *** groups at the C-3′and C-4’positions of the flavonoid molecule were strictly required for ligand-activation with riboswitches M1 and *** O and L preferred multi-hydroxylated flavones as *** on the A ring of the flavonoid molecule were not important in the molecular recognition process.O-glycosylated derivatives were not recognized by any of the riboswitches,presumably due to steric *** the challenges of detecting RNA conformational change after ligand binding,the resulting models elucidate important physicochemical features in the ligands for conformational structural studies of artificial aptamer complexes and for design of ligands having higher binding specificity.
We theoretically study the tunnel magnetoresistance (TMR) effect in (111)-oriented magnetic tunnel junctions (MTJs) with SrTiO3 barriers, Co/SrTiO3/Co(111) and Ni/SrTiO3/Ni(111). Our analysis combining the first-princ...
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We theoretically study the tunnel magnetoresistance (TMR) effect in (111)-oriented magnetic tunnel junctions (MTJs) with SrTiO3 barriers, Co/SrTiO3/Co(111) and Ni/SrTiO3/Ni(111). Our analysis combining the first-principles calculation and the Landauer formula shows that the Co-based MTJ has a high TMR ratio over 500%, while the Ni-based MTJ has a smaller value (290%). Since the in-plane lattice periodicity of SrTiO3 is about twice that of the primitive cell of fcc Co (Ni), the original bands of Co (Ni) are folded in the kx−ky plane corresponding to the ab plane of the MTJ supercell. We find that this band folding gives a half-metallic band structure in the Λ1 state of Co (Ni) and the coherent tunneling of such a half-metallic Λ1 state yields a high TMR ratio. We also reveal that the difference in the TMR ratio between the Co- and Ni-based MTJs can be understood by different s-orbital weights in the Λ1 band at the Fermi level.
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