Structural modification in swift heavy ion irradiated muscovite mica
Two-layer monoclinic (2M) muscovite mica sheets with a thickness of 12 μm are irradiated with Sn ions at room temperature with electronic energy loss (dE/dx)e of 14.7 keV/nm. The ion fluence is varied between 1×1011 and 1×1013 ions/cm2. Structural transition in irradiated mica is investigated by x-ray diffraction (XRD). The main diffraction peaks shift to the high angles, and the inter-planar distance decreases due to swift heavy ion (SHI) irradiation. Dehydration takes place in mica during SHI irradiation and mica with one-layer monoclinic (1M) structure is thought to be generated in 2M mica after SHI irradiation. In addition, micro stress and damage cross section in irradiated mica are analyzed according to XRD data. High resolution transmission electron microscopy (HRTEM) is used on the irradiated mica to obtain the detailed information about the latent tracks and structural modifications directly. The latent track in mica presents an amorphous zone surrounded by strain contrast shell, which is associated with the residual stress in irradiated mica.
First-principles analysis of the structural, electronic, and elastic properties of cubic organic-inorganic perovskite HC(NH2)2PbI3
The structural, electronic, and elastic properties of cubic HC(NH2)2PbI3 perovskite are investigated by density functional theory using the Tkatchenko-Scheffler pairwise dispersion scheme. Our relaxed lattice parameters are in agreement with experimental data. The hydrogen bonding between NH2 and I ions is found to have a crucial role in FAPbI3 stability. The first calculated band structure shows that HC(NH2)2PbI3 has a direct bandgap (1.02 eV) at R-point, lower than the bandgap (1.53 eV) of CH3NH3PbI3. The calculated density of states reveals that the strong hybridization of s(Pb)-p(I) orbital in valence band maximum plays an important role in the structural stability. The photo-generated effective electron mass and hole mass at R-point along the R-Γ and R-M directions are estimated to be smaller:me*=0.06m0 and mh*=0.08m0 respectively, which are consistent with the values experimentally observed from long range photocarrier transport. The elastic properties are also investigated for the first time, which shows that HC(NH2)2PbI3 is mechanically stable and ductile and has weaker strength of the average chemical bond. This work sheds light on the understanding of applications of HC(NH2)2PbI3 as the perovskite in a planar-heterojunction solar cell light absorber fabricated on flexible polymer substrates.
Comparative study of electrical characteristics for n-type 4H-SiC planar and trench MOS capacitors annealed in ambient NO
The interface properties and electrical characteristics of the n-type 4H-SiC planar and trench metal-oxide-semiconductor (MOS) capacitors are investigated by measuring the capacitance voltage and current voltage. The flat-band voltage and interface state density are evaluated by the quasi-static method. It is not effective on further improving the interface properties annealing at 1250 ℃ in NO ambient for above 1 h due to the increasing interface shallow and fast states. These shallow states reduce the effective positive fixed charge density in the oxide. For the vertical MOS capacitors on the (1120) and (1100) faces, the interface state density can be reduced by approximately one order of magnitude, in comparison to the result of the planar MOS capacitors on the (0001) face under the same NO annealing condition. In addition, it is found that Fowler-Nordheim tunneling current occurs at an oxide electric field of 7 MV/cm for the planar MOS device. However, Poole-Frenkel conduction current occurs at a lower electric field of 4 MV/cm for the trench MOS capacitor. This is due to the local field crowded at the trench corner severely causing the electrons to be early captured at or emitted from the SiO2/SiC interface. These results provide a reference for an in-depth understanding of the mobility-limiting factors and long term reliability of the trench and planar SiO2/SiC interfaces.
The residual C concentration control for low temperature growth p-type GaN
In this work, the influence of C concentration to the performance of low temperature growth p-GaN is studied. Through analyses, we have confirmed that the C impurity has a compensation effect to p-GaN. At the same time we have found that several growth and annealing parameters have influences on the residual C concentration:(i) the C concentration decreases with the increase of growth pressure; (ii) we have found there exists a Ga memory effect when changing the Cp2Mg flow which will lead the growth rate and C concentration increase along the increase of Cp2Mg flow; (iii) annealing outside of metal-organic chemical vapor deposition (MOCVD) could decrease the C concentration while in situ annealing in MOCVD has an immobilization role to C concentration.
Effect of disorder on exciton dissociation in conjugated polymers
By using a multi-configurational time-dependent Hartree-Fock (MCTDHF) method for the time-dependent Schrödinger equation and a Newtonian equation of motion for lattice, we investigate the disorder effects on the dissociation process of excitons in conjugated polymer chains. The simulations are performed within the framework of an extended version of the Su-Schrieffer-Heeger model modified to include on-site disorder, off-diagonal, electron-electron interaction, and an external electric field. Our results show that Coulomb correlation effects play an important role in determining the exciton dissociation process. The electric field required to dissociate an exciton can practically impossibly occur in a pure polymer chain, especially in the case of triplet exciton. However, when the on-site disorder effects are taken into account, this leads to a reduction in mean dissociation electric fields. As the disorder strength increases, the dissociation field decreases effectively. On the contrary, the effects of off-diagonal disorder are negative in most cases. Moreover, the dependence of exciton dissociation on the conjugated length is also discussed.
Simulations of guiding of low-energy ions through a single nanocapillary in insulating materials
Simulations of guiding of low-energy ions through a single nanocapillary in insulating polymers are reported. The nanocapillary has a diameter of 100 nm and a length of 10 μm. Different from previous work, in our simulations a hyperbolic function is used to describe the decay of the charges deposited on the capillary surface. The present simulations reproduce the self-organized charge-up process occurring in the capillary. It is shown that lower-energy ions undergo more oscillations to get guiding equilibrium than those of higher-energy ions, resulting in a longer charging time, which is in good agreement with previous experimental results. Moreover, the experimentally observed mass independence of ion guiding is proved in our simulations. In particular, it is found that the maximum of the repulsive field within the capillary is independent of the ion energy as well as the tilt angle. To counterbalance the increasing of the transversal energy caused by increasing the tilt angle or incident energy, the effective length of the repulsive field is expanded in a self-organizing manner.
Interfacial nanobubbles produced by long-time preserved cold water
Interfacial gaseous nanobubbles which have remarkable properties such as unexpectedly long lifetime and significant potential applications, are drawing more and more attention. However, the recent dispute about the contamination or gas inside the nanobubbles causes a large confusion due to the lack of simple and clean method to produce gas nanobubbles. Here we report a convenient and clean method to effectively produce interfacial nanobubbles based on a pure water system. By adding the cold water cooled at 4 ℃ for more than 48 h onto highly oriented pyrolytic graphite (HOPG) surface, we find that the average density and total volume of nanobubbles are increased to a high level and mainly dominated by the concentrations of the dissolved gases in cold water. Our findings and methods are crucial and helpful for settling the newly arisen debates on gas nanobubbles.
Linear and nonlinear characteristics of time-resolved photoluminescence modulation by terahertz pulse
Local structure-preserving methods for the generalized Rosenau-RLW-KdV equation with power law nonlinearity
An intermediate state of T7 RNA polymerase provides another pathway of nucleotide selection
Phage T7 RNA polymerase is a single-subunit transcription enzyme, transcribing template DNA to RNA. Nucleoside triphosphate (NTP) selection and translocation are two critical steps of the transcription elongation. Here, using all-atom molecular dynamics simulations, we found that between pre-and post-translocation states of T7 RNA polymerase an intermediate state exists, where the O helix C-terminal residue tyrosine 639, which plays important roles in translocation, locates between its pre-and post-translocation positions and the side chain of the next template DNA nucleotide has moved into the active site. NTP selection in this intermediate state was studied, revealing that the selection in the intermediate state can be achieved relying on the effect of Watson-Crick interaction between NTP and template DNA nucleotide, effect of stability of the components near the active site such as the nascent DNA-RNA hybrid and role of tyrosine 639. This indicates that another NTP-selection pathway can also exist besides the main pathway where NTP selection begins at the post-translocation state upon the entry of NTP.
Soliton and rogue wave solutions of two-component nonlinear Schrödinger equation coupled to the Boussinesq equation
Bound states resulting from interaction of the non-relativistic particles with the multiparameter potential
Experimental simulation of violation of the Wright inequality by coherent light
Improving continuous-variable quantum key distribution under local oscillator intensity attack using entanglement in the middle
A modified continuous-variable quantum key distribution (CVQKD) protocol is proposed by originating the entangled source from a malicious third party Eve in the middle instead of generating it from the trustworthy Alice or Bob. This method is able to enhance the efficiency of the CVQKD scheme attacked by local oscillator (LO) intensity attack in terms of the generated secret key rate in quantum communication. The other indication of the improvement is that the maximum transmission distance and the maximum loss tolerance can be increased significantly, especially for CVQKD schemes based on homodyne detection.
Moving bright solitons in a pseudo-spin polarization Bose-Einstein condensate
A note on the mass of Kerr-AdS black holes in the off-shell generalized ADT formalism
Quantum correlations dynamics of three-qubit states coupled to an XY spin chain:Role of coupling strengths
Anomalous boundary deformation induced by enclosed active particles
We simulate a two-dimensional model of a round soft boundary enclosed with self-propelled particles. Persistent motion drives these particles to accumulate near the boundary, thereby dramatically deforming the boundary shape through collisions. Quantitative analyses of the boundary shape and the particle distribution show that there are two typical regimes in the variation of the morphology with the increase of self-propulsion of particles. One is under small forces, characterized by the radially inhomogeneous distribution of particles and the suppression of local fluctuations of the almost round boundary, and the other is under large forces, featured by the angularly inhomogeneous distribution of particles and the global shape deformation of the boundary. These two features are strongly cooperative. We also find different mechanisms in the particle relocation at low and high particle concentrations.
A hybrid strategy to control uncertain nonlinear chaotic system
A novel color image encryption scheme using fractional-order hyperchaotic system and DNA sequence operations
Dynamical energy equipartition of the Toda model with additional on-site potentials
Stochastic bounded consensus of second-order multi-agent systems in noisy environment
Relating Maxwell's demon and quantitative analysis of information leakage for practical imperative programs
Extracting hidden weak sinusoidal signal with short duration from noisy data:Analytical theory and computational realization
Signal detection is both a fundamental topic of data science and a great challenge for practical engineering. One of the canonical tasks widely investigated is detecting a sinusoidal signal of known frequency ω with time duration T:I(t)=Acos ω t+Γ(t), embedded within a stationary noisy data. The most direct, and also believed to be the most efficient, method is to compute the Fourier spectral power at ω:B=|2/T∫0T I(t)eiωtdt|. Whether one can out-perform the linear Fourier approach by any other nonlinear processing has attracted great interests but so far without a consensus. Neither a rigorous analytic theory has been offered. We revisit the problem of weak signal, strong noise, and finite data length T=O(1), and propose a signal detection method based on resonant filtering. While we show that the linear approach of resonant filters yield a same signal detection efficiency in the limit of T→∞, for finite time length T=O(1), our method can improve the signal detection due to the highly nonlinear interactions between various characteristics of a resonant filter in finite time with respect to transient evolution. At the optimal match between the input I(t), the control parameters, and the initial preparation of the filter state, its performance exceeds the above threshold B considerably. Our results are based on a rigorous analysis of Gaussian processes and the conclusions are supported by numerical computations.
Indirect pumping bell-bloom magnetometer
Numerical and experimental analysis of long period gratings in wavelength scale elliptical microfibers
We report the fabrication of long-period gratings (LPGs) in elliptical microfibers with femtosecond laser. Based on the numerical analysis of the modes and the mode coupling condition of elliptical microfibers, an LPG is fabricated with a very short pitch of 10 μm by periodically modifying the fiber surface, which demonstrates very strong polarization-dependent resonances, a very low temperature sensitivity of a few picometers in air, and high temperature sensitivity of -1.62 nm/℃ in refractive index oil.
Nested grazing incidence optics for x ray detection
Correlation between electronic structure and energy band in Eu-doped CuInTe2 semiconductor compound with chalcopyrite structure
Absorption spectra and isotope shifts of the (2, 0), (3, 1), and (8, 5) bands of the A2Πu–X2∑g+ system of 15N2+ in near infrared
The high-resolution absorption spectra of the (2,0),(3,1),and (8,5) bands of the A2Πu-X2∑g+ system of 15N2+ have been recorded by using velocity modulation spectroscopy technique in the near infrared region.The rotational constants of the X2∑g+ and A2Πu states of 15N2+ were derived from the spectroscopic data.The isotope shifts of these bands of the A2Πu-X2∑g+ system of 14N2+ and 15N2+ were also analyzed and discussed.
First principle study of edge topological defect-modulated electronic and magnetic properties in zigzag graphene nanoribbons
Theoretical investigation on forbidden transition properties of fine-structure splitting in 2D state for K-like ions with 26 ≤ Z ≤ 36
Photodetachment dynamics of H- ion in a harmonic potential plus a time-dependent oscillating electric field
Measurement of transient Raman spectrum on gas-gun loading platform and its application in liquid silane
Combining a low temperature liquidizing system with a transient Raman spectroscopy, a new experimental technique is established for the first time on a two-stage light-gas gun, and it is employed to study shock-compressed fluid silane. With this experimental technique, we first obtain a Raman peak shift relating to the Si-H stretching vibration mode of molecular liquid silane under shock loading conditions. The Raman peak of 2184 cm-1 at an initial state of 0 GPa and 85 K moves to 2223.4 cm-1 at a shocked state of 10.5 GPa and 950 K, and its full width of half maximum broadens from 33 cm-1 to 118 cm-1. The shocked temperature, calculated by the thermodynamic equation of state, is well consistent with that estimated by the Doppler broadening function.
Influence of the initial electronic state on minima of high-order harmonic spectrum radiated from hydrogen molecular ion
Combined multi-level quantum mechanics theories and molecular mechanics study of water-induced transition state of OH-+CO2 reaction in aqueous solution
The presence of a solvent interacting with a system brings about qualitative changes from the corresponding gas-phase reactions. A solvent can not only change the energetics along the reaction pathway, but also radically alter the reaction mechanism. Here, we investigated the water-induced transition state of the OH-+CO2→HCO3- reaction using a multi-level quantum mechanics and molecular mechanics method with an explicit water model. The solvent energy contribution along the reaction pathway has a maximum value which induces the highest energy point on the potential of mean force. The charge transfer from OH- to CO2 results in the breaking of the OH- solvation shell and the forming of the CO2 solvation shell. The loss of hydrogen bonds in the OH- solvation shell without being compensated by the formation of hydrogen bonds in the CO2 solvation shell induces the transition state in the aqueous solution. The calculated free energy reaction barrier at the CCSD(T)/MM level of theory, 11.8 kcal/mol, agrees very well with the experimental value, 12.1 kcal/mol.
Wavefront analysis for plenoptic camera imaging
Reflective ghost imaging free from vibrating detectors
Self-compression of 1.8-μm pulses in gas-filled hollow-core fibers
The intensity detection of single-photon detectors based on photon counting probability density statistics
Heterogeneous growth of KDP/KT crystal
Damage threshold influenced by polishing imperfection distribution under 355-nm laser irradiation
Surface plasmon resonance-induced tunable polarization filters based on nanoscale gold film-coated photonic crystal fibers
Performance of thermoelectric generator with graphene nanofluid cooling
Improvement of the heat transfer of the cold side is one of the approaches to enhance the performance of TEG systems. As a new type of heat transfer media, nanofluids can enhance the heat transfer performance of working liquid significantly. Based on a three-dimensional and steady-state numerical model,the heat transfer and thermoelectric conversion properties of TEG systems were studied. Graphene anoplatelet aqueous nanofluids were used as the coolants for the cold side of the TEG system to improve the heat transfer capacity of the cold side. The results showed that the heat absorbed by the hot side, voltage, output power, and conversion efficiency of the TEG system were increased greatly by the nanofluid coolants. The output power and the conversion efficiency using 0.1-wt% graphene nanoplatelet aqueous nanofluid as the coolant are enhanced by 26.39% and 14.74%, respectively.
Simulation on effect of metal/graphene hybrid transparent electrode on characteristics of GaN light emitting diodes
A numerical study of contact force in competitive evacuation
Crowd force by the pushing or crushing of people has resulted in a number of accidents in recent decades. The aftermath investigations have shown that the physical interaction of a highly competitive crowd could produce dangerous pressure up to 4500 N/m, which leads to compressive asphyxia or even death. In this paper, a numerical model based on discrete element method (DEM) as referenced from granular flow was proposed to model the evacuation process of a group of highly competitive people, in which the movement of people follows Newton's second law and the body deformation due to compression follows Hertz contact model. The study shows that the clogs occur periodically and flow rate fluctuates greatly if all people strive to pass through a narrow exit at high enough desired velocity. Two types of contact forces acting on people are studied. The first one, i.e., vector contact force, accounts for the movement of the people following Newton's second law. The second one, i.e., scale contact force, accounts for the physical deformation of the human body following the contact law. Simulation shows that the forces chain in crowd flow is turbulent and fragile. A few narrow zones with intense forces are observed in the force field, which is similar to the strain localization observed in granular flow. The force acting on a person could be as high as 4500 N due to force localization, which may be the root cause of compressive asphyxia of people in many crowd incidents.
A leap-frog discontinuous Galerkin time-domain method of analyzing electromagnetic scattering problems
Diurnal cooling for continuous thermal sources under direct subtropical sunlight produced by quasi-Cantor structure
In this paper, an optical radiative cooler with quasi-Cantor structure is theoretically proposed and analyzed. This simple and symmetrically designed optical structure operates upon continuous thermal sources in diurnal subtropical conditions, and its efficiency is much higher than natural cooling, for instance, when operating upon a typical 323.15 K continuous thermal source with a wind speed at 3 m·-1, it can generate a net cooling power of 363.68 W·m-2, which is 18.26% higher than that of non-radiative heat exchange (natural cooling) under the same conditions. Additionally, several aspects are considered in its design to ensure a low cost in application, which is of great economical and environmental significance.
Near-field characteristics of highly non-paraxial subwavelength optical fields with hybrid states of polarization
Generation of single and multiple dissipative soliton in an erbium-doped fiber laser
Structural evolution study of additions of Sb2S3 and CdS into GeS2 chalcogenide glass by Raman spectroscopy
The structures of pseudo-binary GeS2-Sb2S3, GeS2-CdS, Sb2S3-CdS, and pseudo-ternary GeS2-Sb2S3-CdS chalcogenide systems are systematically investigated by Raman spectroscopy. It is shown that a small number of[S3Ge-GeS3] structural units (SUs) and -S-S-/S8 groups exist simultaneously in GeS2 glass which has a three-dimensional continuous network backbone consisting of cross-linked corner-sharing and edge-sharing[GeS4] tetrahedra. When Sb2S3 is added into GeS2 glass, the network backbone becomes interconnected[GeS4] tetrahedra and[SbS3] pyramids. Moreover, Ge atoms in[S3Ge-GeS3] SUs tend to capture S atoms from Sb2S3, leading to the formation of[S2Sb-SbS2] SUs. When CdS is added into GeS2 glass,[Cd4GeS6] polyhedra are formed, resulting in a strong crystallization tendency. In addition, Ge atoms in[S3Ge-GeS3] SUs tend to capture S atoms from CdS, resulting in the dissolution of Ge-Ge bond. Co-melting of Sb2S3 or CdS with GeS2 reduces the viscosity of the melt and improves the homogeneity of the glass. The GeS2 glass can only dissolve up to 10-mol% CdS without crystallization. In comparison, GeS2-Sb2S3 glasses can dissolve up to 20-mol% CdS, implying that Sb2S3 could delay the construction of[Cd4GeS6] polyhedron and increase the dissolving amount of CdS in the glass.
Two-dimensional thermal illusion device with arbitrary shape based on complementary media
Modulation of absorption manner in helicon discharges by changing profile of low axial magnetic field
Electric ignition energy evaluation and the energy distribution structure of energy released in electrostatic discharge process
Ignition energy is one of the important parameters of flammable materials, and evaluating ignition energy precisely is essential to the safety of process industry and combustion science and technology. By using electric spark discharge test system, a series of electric spark discharge experiments were conducted with the capacitor-stored energy in the range of 10 J, 100 J, and 1000 J, respectively. The evaluation method for energy consumed by electric spark, wire, and switch during capacitor discharge process has been studied respectively. The resistance of wire, switch, and plasma between electrodes has been evaluated by different methods and an optimized evaluation method has been obtained. The electric energy consumed by wire, electric switch, and electric spark-induced plasma between electrodes were obtained and the energy structure of capacitor-released energy was analyzed. The dynamic process and the characteristic parameters (the maximum power, duration of discharge process) of electric spark discharge process have been analyzed. Experimental results showed that, electric spark-consumed energy only accounts for 8%-14% of the capacitor-released energy. With the increase of capacitor-released energy, the duration of discharge process becomes longer, and the energy of plasma accounts for more in the capacitor-released energy. The power of electric spark varies with time as a damped sinusoids function and the period and the maximum value increase with the capacitor-released energy.
Thermoelectric properties of Li-doped Sr0.7Ba0.3Nb2O6-δ ceramics
Thermoelectric properties of Li-doped Sr0.70Ba0.30Nb2O6-δ ceramics were investigated in the temperature range from 323 K to 1073 K. The electrical conductivity increases significantly after lithium interstitial doping. However, both of the magnitudes of Seebeck coefficient and electrical conductivity vary non-monotonically but synchronously with the doping contents, indicating that doped lithium ions may not be fully ionized and oxygen vacancy may also contribute to carriers. The lattice thermal conductivity increases firstly and then decreases as the doping content increases, which is affected by competing factors.Thermoelectric performance is enhanced by lithium interstitial doping due to the increase of the power factor and the thermoelectric figure of merit reaches maximum value (0.21 at 1073 K) in the sample Sr0.70Ba0.30Li0.10Nb2O6.
Optimize the thermoelectric performance of CdO ceramics by doping Zn
The thermoelectric performance of CdO ceramics was enhanced by simultaneously optimizing the electrical and thermal transport properties via a small amount of Zn doping (≤ 3%). The introduction of Zn can obviously increase the electrical conductivity of CdO due to the simultaneous increase of carrier concentration and mobility, and eventually results in an improvement in power factor. Zn doping is also effective in suppressing the thermal conductivity of CdO because of stronger phonon scatterings from point defects, Zn-riched second phase, and grain boundaries. A best ZT of about 0.45 has been achieved in the Cd1-xZnxO systems at about 1000 K, which is comparable to the highest values reported for other n-type oxide TE materials.
Angle-resolved x-ray photoelectron spectroscopy study of GeOx growth by plasma post-oxidation
High resolution inverse synthetic aperture radar imaging of three-axis-stabilized space target by exploiting orbital and sparse priors
Superconducting tunable filter with constant bandwidth using coplanar waveguide resonators
Detailed study of NBTI characterization in 40-nm CMOS process using comprehensive models
Micro-light-emitting-diode array with dual functions of visible light communication and illumination
Improvement in IBC-silicon solar cell performance by insertion of highly doped crystalline layer at heterojunction interfaces
By inserting a thin highly doped crystalline silicon layer between the base region and amorphous silicon layer in an interdigitated back-contact (IBC) silicon solar cell, a new passivation layer is investigated. The passivation layer performance is characterized by numerical simulations. Moreover, the dependence of the output parameters of the solar cell on the additional layer parameters (doping concentration and thickness) is studied. By optimizing the additional passivation layer in terms of doping concentration and thickness, the power conversion efficiency could be improved by a factor of 2.5%, open circuit voltage is increased by 30 mV and the fill factor of the solar cell by 7.4%. The performance enhancement is achieved due to the decrease of recombination rate, a decrease in solar cell resistivity and improvement of field effect passivation at heterojunction interface. The above-mentioned results are compared with reported results of the same conventional interdigitated back-contact silicon solar cell structure. Furthermore, the effect of a-Si:H/c-Si interface defect density on IBC silicon solar cell parameters with a new passivation layer is studied. The additional passivation layer also reduces the sensitivity of output parameter of solar cell to interface defect density.
Effects of rainy weather on traffic accidents of a freeway using cellular automata model
The aim of this work is to investigate the influence of rainy weather on traffic accidents of a freeway. The micro-scale driving behaviors in rainy weather and possible vehicle rear-end and sideslip accidents are analyzed. An improved CA model of two lanes one-way freeway is presented, where some vehicle accidents will occur when the necessary conditions are simultaneously satisfied. The characteristics of traffic flow under different rainfall intensities are discussed and the accident probabilities are analyzed via the simulation experiments by using variable speed limit (VSL) and incoming flow control. The results indicate that the measures are effective especially during heavy rainstorms or short-time heavy rainfall. According to different rainfall intensities, an appropriate strategy should be adopted in order to reduce the probability of vehicle accidents and enhance traffic flux as well.
Time-varying networks based on activation and deactivation mechanisms
A class of models for activity-driven networks is proposed in which nodes vary in two states:active and inactive. Only active nodes can receive links from others which represent instantaneous dynamical interactions. The evolution of the network couples the addition of new nodes and state transitions of old ones. The active group changes with activated nodes entering and deactivated ones leaving. A general differential equation framework is developed to study the degree distribution of nodes of integrated networks where four different schemes are formulated.
Germanene nanomeshes:Cooperative effects of degenerate perturbation and uniaxial strain on tuning bandgap
Based on the detailed first-principles calculations, we have carefully investigated the defect induced band splitting and its combination with Dirac cone move in bandgap opening. The uniaxial strain can split the π -like bands into πa and πz bands with energy interval Estrain to shift the Dirac cone. Also, the inversion symmetry preserved antidot can split πa (πz) into πa1 and πa2 (πz1 and πz2) bands with energy interval Edefect to open bandgap in the nanomesh with Γ as four-fold degenerate Dirac point according to the band-folding analysis. Though the Edefect would keep almost unaffected, the Estrain would be increased by enhancing the uniaxial strain to continuously tune the gap width. Then the bandgap can be reversibly switched on/off. Our studies of the inversion symmetry preserved nanomesh show distinct difference in bandgap opening mechanism as compared to the one by breaking the sublattice equivalence in the (GaAs)6 nanoflake patterned nanomesh. Here, the π-band gap remains almost unchanged against strain enhancing.
High-temperature superconducting filter using self-embedding asymmetric stepped impedance resonator with wide stopband performance and miniaturized size
Injection modulation of p+–n emitter junction in 4H–SiC light triggered thyristor by double-deck thin n-base
Single-shot grating-based x-ray differential phase contrast imaging with a modified analyzer grating
Quadratic interaction effect on the dark energy density in the universe