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<jats:title>Abstract</jats:title> <jats:p>Without dividing the complex-valued systems into two real-valued ones, a class of fractional-order complex-valued memristive neural networks (FCVMNNs) with time delay is investigated. Firstly, based on the complex-valued sign function, a novel complex-valued feedback controller is devised to research such systems. Under the framework of Filippov solution, differential inclusion theory and Lyapunov stability theorem, the finite-time Mittag-Leffler synchronization (FTMLS) of FCVMNNs with time delay can be realized. Meanwhile, the upper bound of the synchronization settling time (SST) is less conservative than previous results. In addition, by adjusting controller parameters, the global asymptotic synchronization of FCVMNNs with time delay can be also realized, which improves and enrich some existing results. At last, some simulation examples are designed to verify the validity of conclusions.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We theoretically investigate the quantum interference theory of magnetotransport of the three-component or spin-1 chiral fermions, which possess two linear Dirac bands and a flat band. For isotropic scalar impurities, the correction of conductivity from the coherent backscatter and non coherent backscatter contributions cancel out in the intravalley scattering, leading to a weak localization correction to the Drude conductivity from the intervalley scattering. For the anisotropic impurities, the above cancellation is removed, we find the approximative quantum interference conductivity in the weak anisotropy case. The contributions from the chiral anomaly and classical Lorentz force are also discussed. Our work reveals some intriguing and detectable transport signatures of the novel spin-1 chiral fermions.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The preparation of surface-enhanced fluorescence (SEF) substrates is often influenced by experimental strategies and factors such as the morphology and size of the nanostructures. In this study, using the natural reed leaves (R.L.) without any special pretreatment as the substrate, metal silver was modified by magnetron sputtering technology to prepare a stable and efficient SEF system. The abundant “hedgehog-like” protrusions on R.L. substrate surface can generate high-density “hot spots”, enhancement factor (EF) is up to 3345 times, and stability and reproducibility have been verified in many measurements. The contribution of the intervention of silver nanostructure to the radiation attenuation process of fluorescent molecules is analyzed with the aid of Jablonski diagrams. 3D finite difference time domain (FDTD) simulate the spatial electric field and “hot spots” distribution of the substrate, “hedgehog-like” protrusions structure generate multiple “hot spots”, which produce an excellent local surface plasmon resonance (LSPR) effect and provide higher fluorescence signal. Finally, R.L./Ag-35 substrate is used to detect crystal violet (CV), the detection limit is as low as 10<jats:sup>-13</jats:sup> M, and this “hedgehog-like” SEF substrate provides a new strategy for the trace detection of CV has good practical application value.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>In this work, based on High Magnetic field Helicon eXperiment (HMHX), HELIC code was used to study the effect of different magnetic fields on the power deposition under parabolic distribution. This paper is divided into three parts: preliminary calculation, actual discharge experiment and calculation. The results of preliminary calculation show that a magnetic field that is too small or too large cannot produce a good power deposition effect. When the magnetic field strength is 1200 Gs, a better power deposition can be obtained. The actual discharge experiment illustrates that the change of the magnetic field will have a certain influence on the discharge phenomenon. Finally, the results of verification calculation successfully verified the accuracy of the results of preliminary simulation. The results show that in the actual discharge experiment, it can achieve the best deposition effect when the magnetic field is 1185 Gs.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We systematically study the evolution of modulated nerve impulses in a myelinated nerve fiber, where both the ionic current and membrane capacitance provides the necessary nonlinear feedbacks. This is achieved by using a perturbation technique, in which the Liénard form of the modified discrete Fitzhugh-Nagumo equation is reduced to the complex Ginzburg-Landau amplitude equation. Three distinct values of the capacitive feedback parameter are considered. At the critical value of the capacitive feedback parameter, it is shown that the dynamics of the system is governed by the dissipative nonlinear Schrödinger equation. Linear stability analysis of the system depicts the instability of plane waves, which is manifested as burst of modulated nerve impulses that fulfills the Benjamin-Feir criteria. Variations of the capacitive feedback parameter generally influences the plane wave stability and hence the type of wave profile identified in the neural network. Results of numerical simulations mainly confirms the propagation, collision, and annihilation of nerve impulses in the myelinated axon.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Evolution of the polarization singularities supported in a one-dimensional periodic plasmonic system is studied. The lateral inversion symmetry of the system, which breaks the in-plane inversion symmetry and up-down mirror symmetry simultaneously, yields abundant polarization states. A complete evolution process for the polarization states with respect to the geometry variation is traced. In the evolution, circularly polarized points (C points) can stem from 3 different processes. In addition to the previously reported ones occur in an isolated band, a new type of C points appearing in two bands simultaneously due to the avoided band crossing, is observed. Different to the dielectric system with similar structure which only support at-Γ Bound states in the continuum (BICs), accidental BICs off the Γ point are realized in this plasmonic system. This work provides a new scheme of polarization manipulation for the plasmonic systems.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Perovskite/silicon(Si) tandem solar cells have been recognized as the next-generation photovoltaic technology with efficiency beyond 30% and low cost. However, the intrinsic instability of traditional three-dimensional (3D) hybrid perovskites seriously hinders the lifetime of tandem devices. In this work, the quasi two-dimensional (2D) (BA)<jats:sub>2</jats:sub>(MA)<jats:sub>n-1</jats:sub>Pb<jats:sub>n</jats:sub>I<jats:sub>3n+1</jats:sub> (n=1, 2, 3, 4, 5) (where MA = methylammonium and BA = butylammonium), with senior stability and wider bandgap, is firstly used as an absorber of semitransparent top perovskite solar cells (PSCs) to construct a four-terminal (4T) tandem devices with a bottom Si-heterojunction cells. The device model has been established by Silvaco Atlas based on experimental parameters. Simulation results show that, in the optimized tandem devices, the top cell (n=4) obtains a power conversion efficiency (PCE) of 17.39% and the Si bottom cell shows a PCE of 11.44%, thus an overall PCE of 28.83%. Furthermore, by introducing a 90 nm LiF anti-reflection layer to reduce the surface reflection loss, the current density (J<jats:sub>SC</jats:sub>) of the top cell is enhanced from 15.56 to 17.09 mA/cm<jats:sup>2</jats:sup>, the corresponding PCE reaches 19.05%, and the tandem PCE increases to 30.58%. Simultaneously, in cases of n=3, 4, and 5, all the tandem PCEs exceed the limiting theoretical efficiency of Si cells. Therefore, the 4T quasi-2D perovskite/Si devices provides a more cost-effective tandem strategy and long-term stability solutions.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>In this paper, the C ion irradiation effect on multilayer ReSe<jats:sub>2</jats:sub> flakes has been studied utilizing different kinds of technology. The domain size, thickness, morphology of the multilayer ReSe<jats:sub>2</jats:sub> flakes on the Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> substrate before and after 1.0 MeV C ion irradiation with different fluence rates was studied by atomic force microscope and scanning electron microscopy. The atomic vibrational spectra of multilayer ReSe<jats:sub>2</jats:sub> flakes were detected by micro-Raman spectra. The redshifts of the Raman modes after 1.0 MeV C ion irradiation were shown by the micro-Raman spectra. The elemental composition and bonding configurations of the multilayer ReSe<jats:sub>2</jats:sub> samples before and after irradiation process were characterized by X-ray photoelectron spectroscopy. Structural properties were also investigated by X-ray diffraction, and it was concluded that after 1.0 MeV C ion irradiation process, multilayer ReSe<jats:sub>2</jats:sub> samples continue to grow on Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> substrate, the increased crystallite size also reveal that the crystallinity improved with increasing layer number after 1.0 MeV C ion irradiation.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The steady-state and transient electron transport properties of β-(Al<jats:sub>x</jats:sub>Ga<jats:sub>1−x</jats:sub>)<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>/Ga<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> heterostructures were investigated by Monte Carlo simulation with the classic three-valley model. In particular, the electronic band structures were acquired by the first-principles calculations, which could provide precise parameters for calculating the transport properties of the 2D electron gas, and the quantization effect was considered in the Γ valley with the five lowest subbands. Wave functions and energy eigenvalues were obtained by iteration of the Schrödinger–Poisson equations to calculate the 2D electron gas scattering rates with five main scattering mechanisms considered. The simulated low-field electron mobilities agree well with the experimental results, thus confirming the effectiveness of our models. Results show that the room temperature electron mobility of the β-(Al<jats:sub>0.188</jats:sub>Ga<jats:sub>0.812</jats:sub>)<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>/Ga<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> heterostructure at 10 kV/cm is approximately 153.669 cm<jats:sup>2</jats:sup>/Vs, and the polar optical phonon scattering would have a significant impact on the mobility property at this time. The region of negative differential mobility, the overshoot of the transient electron velocity, and the negative diffusion coefficients are also observed when the electric field increases to the corresponding threshold value or even exceeds it. This work offers significant parameters of β-(Al<jats:sub>x</jats:sub>Ga<jats:sub>1−x</jats:sub>)<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>/Ga<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> heterostructure which would benefit the design of high-performance β-(Al<jats:sub>x</jats:sub>Ga<jats:sub>1−x</jats:sub>)<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>/Ga<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> heterostructure-based devices.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>For mode selection in a quantum cascade laser (QCL), we demonstrate an anti-symmetric sampled grating (ASG). The wavelength of the −1-th mode of this laser has been blue-shifted more than 75 nm (~10 cm<jats:sup>−1</jats:sup>) compared with that of an ordinary sampled grating laser with an emission wavelength of approximately 8.6 μm, when the periodicity within both the base grating and the sample grating are kept constant. Under this condition, an improvement in the continuous tuning capability of the QCL array is ensured. The ASG structure is fabricated in holographic exposure and optical photolithography, thereby enhancing its flexibility, repeatability, and cost-effectiveness. The wavelength modulation capability of the two channels of the grating is insensitive to variations in channel size, assuming that the overall waveguide width remains constant. The output wavelength can be tailored freely within a certain range by adjusting the width of the ridge and the material of the cladding layer.</jats:p>