Symmetric Layer Research Articles

Generation of pseudo-nondiffracting symmetrical Layer beams using cylindrical lenses

The pseudo-nondiffracting behavior of optical caustic beams makes them potentially useful in precise component alignment at CERN. This paper introduces an innovative method for generating one and two-dimensional symmetrical Airy-like beams, known as Layer beams, utilizing a specific configuration of plano-convex cylindrical lenses. Simulations and experimental results have validated this method, demonstrating its potential for scalable and cost-effective beam production with tunable properties, making it practical for a wide range of scientific applications.

Buckling of Thin-Walled Angle Column Made of Hybrid Laminate Under Axial Compression

This paper presents the investigation of eigenproblem for angle columns made flax, carbon laminates. The first three eigenmodes were determined and corresponding critical load values for columns subjected to axial compression. The analysis was made for six configurations. Each of them had the same arrangement of layers. The effect of changing the material of individual layers on bifurcation load values was analyzed. The obtained values were related to the K1 configuration, for carbon and flax-carbon configurations the differences in the values of bifurcation load in relation to the all-flax configuration were determined for all 3 modes. Interpreting the achieved results, it was concluded that replacing the relevant layers of flax laminate with carbon layers could increase the operating range of the system in the linear area. Moreover, for hybrid configurations, the effect of using a single carbon layer versus using a pair of carbon layers on the critical load value was investigated. Analysis of the results showed that for the selected configurations, a higher bifurcation load value was obtained with the use of a single carbon layer compared to the use of a pair of symmetric carbon layers. The conducted research indicates the need to study this topic in more depth, due to the possibility of increasing the work of the system in the linear range while reducing the cost and environmental impact of the material used.

A symmetric heterogate dopingless electron-hole bilayer TFET with ferroelectric and barrier layers

In this paper, a symmetric heterogate dopingless electron–hole bilayer tunnel field-effect transistor with a ferroelectric layer and a dielectric barrier layer (FBHD-EHBTFET) is proposed. FBHD-EHBTFET can not only avoid random doping fluctuation and high thermal budget caused by doping, but also solve the issue that conventional EHBTFETs are unable to use the self-alignment process during device manufacturing. The simultaneous introduction of the symmetric heterogate and dielectric barrier layer can significantly suppress off-state current (I off). Ferroelectric material embedded in the gate dielectric layer can enhance electron tunneling, contributing to improving on-state current (I on) and steepening average subthreshold swing (SS avg). By optimizing various parameters related to the gate, ferroelectric layer, and dielectric barrier layer, FBHD-EHBTFET can obtain the I off of 1.11 × 10–18 A μm−1, SS avg of 12.5 mV/dec, and I on of 2.59 × 10–5 A μm−1. Compared with other symmetric dopingless EHBTFETs, FBHD-EHBTFET can maintain high I on while reducing its I off by up to thirteen orders of magnitude and SS avg by at least 51.2%. Moreover, investigation demonstrates that both interface fixed charge and interface trap can increase I off, degrading the off-state performance of device. The study on FBHD-EHBTFET-based dynamic random access memory shows that it has the high read-to-current ratio of 1.1 × 106, high sense margin of 0.42 μA μm−1, and long retention time greater than 100 ms, demonstrating that it has great potential in low-power applications.

Dispersion control and radiation based on glide-symmetric spoof surface plasmon polaritons

Glide symmetry transmission line (TL) is a highly symmetric TL with characteristics such as reduced frequency dispersion and merged passband. The dispersion characteristics and field distribution of single-layer and double-layer spoof surface plasmon polaritons (SSPPs) unit with glide symmetry are studied in this paper. It is found that the double layer structure with stronger slow wave effect is more suitable for frequency scanning radiation with higher scanning rates. Thus, T-shaped glide symmetric double-layer unit is proposed. Such unit exhibits stronger field confinement and higher degrees of freedom in modulating dispersion characteristics. Besides the basic transmission characteristic, additional radiation characteristic based on such T-shaped glide symmetric double-layer units performs well with continuously beam scanning in a large frequency and angle range. Experimental results agree well with numerical simulations, demonstrating the superior performance of T-shaped glide symmetric double-layer SSPPs. The radiation method of such T-shaped glide symmetric double layer SSPPs can be applied to antenna design, which is conductive to the development of highly compact plasmonic integrated circuits and systems.

Conical-Shaped Shells of Non-Uniform Thickness Vibration Analysis Using Higher-Order Shear Deformation Theory

Conical-Shaped Shells of Non-Uniform Thickness Vibration Analysis Using Higher-Order Shear Deformation Theory

Well-Posedness in Gevrey Function Space for the 3D Axially Symmetric MHD Boundary Layer Equations Without Structural Assumption

Well-Posedness in Gevrey Function Space for the 3D Axially Symmetric MHD Boundary Layer Equations Without Structural Assumption

High Thermal Performance Ultraviolet (368 nm) AlGaN-Based Flip-Chip LEDs with an Optimized Structure

In this study, we have fabricated a 368 nm LED with an epitaxial Indium Tin Oxide (ITO) contact layer. We analyze the thermal performance of the flip-chip LED with a symmetric electrode and metal reflective layer, applying ANSYS to build a coupled electro-thermal finite element model (FEM) of the temperature distribution in the multiple quantum wells (MQWs). We compare our system with the traditional Au-bump flip-chip LED and a flip-chip LED with a Distributed Bragg Reflector (DBR) layer. The simulation results have shown that the flip-chip LED with a metal reflective layer and symmetric electrode exhibits better heat dissipation performance, particularly at high input power. The influence of the insulating layer on the LED chip junction temperature is also examined. The simulation data establish an effect due to the thermal conductivity of the insulating layer in terms of heat dissipation, but this effect is negligible at an insulation layer thickness ≤1 µm.

Interfacial engineering of Si anodes by confined doping of Co toward high initial coulombic efficiency.

A Si/Si-Co multilayer film, with Co confined doping in the silicon anode, was successfully fabricated by alternating magnetron sputtering, achieving both metal doping and surface coating. Operando magnetometry revealed the stability of the Si-Co layers during cycling. The symmetrical Si-Co layers can protect the overall structure of the Si anodes and facilitate electron conduction. Consequently, the resultant Si anode delivers an impressive initial coulombic efficiency of 93.4% with large capacity retention of 85.07% after 100 cycles.

Ionic Polymer-Metal Composites: From Material Engineering to Flexible Applications.

ConspectusIonic polymer-metal composites (IPMCs) are one kind of artificial muscles that can realize energy conversions in response to external stimulus with merits of lightweight, scalability, quick response, and flexibility and have been treated as an important platform in artificial intelligence, such as bionic robotics, smart sensors, and micro-electromechanical systems. It is well-known that IPMC devices are mainly composed of one electrolyte layer laminated with symmetric electrode layers and realize energy conversion based on ion migration and redistribution inside the devices. However, several critical issues have greatly impeded the practical applications of IPMC devices, including metal electrode cracks, metal-polymer interface detachment, and water loss in the electrolyte. In the past decade, our group and collaborators have made attempts to address the mentioned critical issues with the purpose of accelerating practical applications of IPMC devices. First, in order to address the metal electrode cracks, we have developed various electrode materials to replace the metal electrode material, such as black phosphorus and graphdiyne. These materials display superior electrical and mechanical properties with enhanced material stability without cracking. Second, to address metal-polymer interface detachment, we have designed robust interfaces for IMPC devices with vertical array structures. The as-prepared interfaces present high ionic conductivity with excellent mechanical stability under bending states. As a result, the IPMC devices deliver high working stability exceeding a million cycles under air conditions. Third, in order to avoid water loss in the electrolyte, especially at ambient conditions, we have developed ionogel electrolytes containing highly stable ionic liquids as active ion sources. The ionogel electrolytes effectively prevent water loss in conventional water-containing electrolytes, just like Nafion electrolytes and greatly improve the working stability of IPMC devices. After addressing the key issues of IPMC devices, we finally obtained many high-performing IPMC devices and explored various intelligent applications of them. For instance, we have demonstrated the smart functions of IPMC devices as sensitive strain sensors, such as sign language recognition, handwriting detection, and human muscle monitoring. In addition, we have developed bionic flying robots with a vibration frequency as high as 30 Hz with the aid of high-performance IPMC actuators. A medical catheter based on IPMC actuators has been put forward by our group and can realize multiple degrees of freedom deformation under a low driving voltage of 2.5 V, which presents great potential for application in medical instruments. Lastly, a perspective on critical challenges and future research directions on IPMC materials and devices is highlighted for accelerating practical application.

Observational energy transfers of a spiral cold filament within an anticyclonic eddy

The ocean surface mixed layer represents a critical interface linking the ocean and atmosphere. The physical processes determining the surface mixed layer properties and mediate atmosphere–ocean exchange. Submesoscale processes play a key role in cross-scale oceanic energy transformation and the determination of surface mixed-layer properties, includingthe enhancement of vertical nutrient transport, leading to increased primary productivity. Herein, we presented observations ofthe spiral chlorophyll-a filament and its influence on turbulence within an anticyclonic eddy in thewestern South China Sea during August 2021. The filament had a negative Ertel potential vorticity associated with strong upwelled/downward currents (approximately 20–40 m/day). Across-filament sections of the in-situ profiles showed turbulent dissipation rates enhanced inthe filament. We suggested this enhancement values can be attributed tosubmesoscale processes, which accounted for 25 % of the total parameterized turbulent dissipation rates. The present parametrized submesoscale turbulent scheme overestimated the in-situ values. The filament transferred kinetic energy upward to anticyclonic eddy via barotropic instability and gained energy from the anticyclonic eddy via baroclinic instability. After kinetic energy budget diagnostic, we suggested besides symmetric instability, centrifugal instability and mixed layer baroclinic instability should also be included in the turbulence scheme to overcome the overestimation. The observeddual energy transfers between the anticyclonic eddy and filament, and the observed high turbulent energy dissipation within the filament, emphasized the need for these processes to be accurately parameterized regional and climate models.

Architecture of the baculovirus nucleocapsid revealed by cryo-EM

Baculovirus Autographa californica multiple nucleopolyhedrovirus (AcMNPV) has been widely used as a bioinsecticide and a protein expression vector. Despite their importance, very little is known about the structure of most baculovirus proteins. Here, we show a 3.2 Å resolution structure of helical cylindrical body of the AcMNPV nucleocapsid, composed of VP39, as well as 4.3 Å resolution structures of both the head and the base of the nucleocapsid composed of over 100 protein subunits. AcMNPV VP39 demonstrates some features of the HK97-like fold and utilizes disulfide-bonds and a set of interactions at its C-termini to mediate nucleocapsid assembly and stability. At both ends of the nucleocapsid, the VP39 cylinder is constricted by an outer shell ring composed of proteins AC104, AC142 and AC109. AC101(BV/ODV-C42) and AC144(ODV-EC27) form a C14 symmetric inner layer at both capsid head and base. In the base, these proteins interact with a 7-fold symmetric capsid plug, while a portal-like structure is seen in the central portion of head. Additionally, we propose an application of AlphaFold2 for model building in intermediate resolution density.

Symmetrical dialkyl-benzotriazolium as gel polymer electrolyte for energy storage and their alkyl chain trend on their electrochemical property

This work is on reporting development of symmetrically dialkylated series of benzotriazolium ionic liquids with tetrafluoroborate and hexafluorophosphate anion and their electrochemical properties. Also fabrication, and testing of ionic liquid as solid state gel polymer electrolyte using poly (vinylidenefluoride co hexa-fluoropropylene) as host polymer and testing their efficiency in electrical double layer capacitor. Structural characterizations done with 1H NMR, and 13C NMR and their property characterizations like electrochemical properties and the thermal properties of salts were done. All ionic liquids shows a potential window of ∼4.0 V. Cytotoxicity studies for understanding environmental friendliness of benzotriazolium ILs also studied using MTT assay which proved their alkyl chain effect on toxicity. The series of 1,3-dialkyl-1,2,3-benzotriazolium cationic and BF4ˉand PF6ˉ anionic ionic liquids shows are promising efficiency for energy storage application. Solid state gel polymer electrolyte using 1,3-dipropBTBF4 tested with symmetrical electrical double layer capacitor which shows 0–7.0 V excellent operating window. And at 0–3.5 V shows a good specific capacitance of 56.96 Fg−1 at scan rate of 2 mVs−1, and at a current density of 0.45 Ag−1 from galvanostatic charge discharge cycle a specific capacitance of 1.78 Fg−1 with energy density of 3.09 mWh and 509.45 mWg−1 power density. The prototype retains capacitance of 91.89 % even after 2000 cycles. Even after 2000 cycles the film stability is not much affected and resistance is not varied drastically. Single Swagelok cell charged at 2 V for 20 min was able to light red (1.7 V, 20 mA) LED brightly for 8 min, using two Swagelok cell charged individually up to 2 V for 20 min was enough to lit a blue LED of 2.7 V connected in series for 7 min brightly, which demonstrated its practical applicability. The unused IL remaining in the gel polymer electrolyte is easily and completely recovered out of the polymer host after studies which found to be advantages towards environmental friendliness in line with their disposal.

Compact plasmon modulator based on the spatial control of carrier density in indium tin oxide.

To keep pace with the demands of semiconductor integration technology, a semiconductor device should offer a small footprint. Here, we demonstrate a compact electro-optic modulator by controlling the spatial distribution of carrier density in indium tin oxide (ITO). The proposed structure is mainly composed of a symmetrical metal electrode layer, calcium fluoride dielectric layer, and an ITO propagating layer. The carrier density on the surface of the ITO exhibits a periodical distribution when the voltage is applied on the electrode, which greatly enhances the interaction between the surface plasmon polaritons (SPPs) and the ITO. This structure can not only effectively improve the modulation depth of the modulator, but also can further reduce the device size. The numerical results indicate that when the length, width, and height of the device are 14µm, 5µm, and 8µm, respectively, the modulation depth can reach 37.1dB at a wavelength of 3.66µm. The structure can realize a broadband modulation in theory only if we select a different period of the electrode corresponding to the propagating wavelength of SPPs because the modulator is based on the scattering effect principle. This structure could potentially have high applicability for optoelectronic integration, optical communications, and optical sensors in the future.

Плазмонные резонансы золотой нано нити, покрытой слоем кварца

In this work, a two-dimensional problem of diffraction of a plane H polarized wave in the light range 300 nm < λ < 900 nm (λ – is the wavelength) by a nanostructure formed by a gold nanocylinder coved with a symmetric quartz layer is considered. The frequency characteristics of the scattering cross-section and plasmon’s resonances are calculated by rigorous numerical methods. The influence of the cylinder’s radius and radius of the quartz layer, relative permittivity and gold loss on the spectra of the scattering cross-section is investigated.

SimpleClick: Interactive Image Segmentation with Simple Vision Transformers.

Click-based interactive image segmentation aims at extracting objects with a limited user clicking. A hierarchical backbone is the de-facto architecture for current methods. Recently, the plain, non-hierarchical Vision Transformer (ViT) has emerged as a competitive backbone for dense prediction tasks. This design allows the original ViT to be a foundation model that can be finetuned for downstream tasks without redesigning a hierarchical backbone for pretraining. Although this design is simple and has been proven effective, it has not yet been explored for interactive image segmentation. To fill this gap, we propose SimpleClick, the first interactive segmentation method that leverages a plain backbone. Based on the plain backbone, we introduce a symmetric patch embedding layer that encodes clicks into the backbone with minor modifications to the backbone itself. With the plain backbone pretrained as a masked autoencoder (MAE), SimpleClick achieves state-of-the-art performance. Remarkably, our method achieves 4.15 NoC@90 on SBD, improving 21.8% over the previous best result. Extensive evaluation on medical images demonstrates the generalizability of our method. We provide a detailed computational analysis, highlighting the suitability of our method as a practical annotation tool.

Security and data encryption effect of high ciphertext based on improved RC6 algorithm for WSN

Along with the continuous growth and improvement of computer and communication technologies, wireless sensors are needed in more and more places to fulfil specific tasks. A lightweight data encryption mechanism is designed for the limited processing power, storage space and energy of wireless sensor networks. The mechanism improves the RC6 algorithm and adds the “symmetric layer” operation. In order to further improve the security of the ciphertext and the strength of the data encryption, the AES-128 encryption algorithm is used in the data link layer, the network layer, and the application layer, respectively. The experiment is based on the STM32L series of ultra-low-power ARM processors, and the operating frequency of the STM32L controller is tuned to 64 MHz to obtain faster efficiency; three groups of experiments on the encryption mechanism are carried out by using the original RC6 algorithm and the improved algorithm, and the lengths of the keys used in the experiments are 16 bytes, 24 bytes, and 32 bytes, respectively, and the data-receiving and transmitting functions are tested separately. This avoids the delay of transceiver mode switching when using a single module for communication, and improves the quality and stability of multi-machine bidirectional communication.

Passive damping of the beam elements of antenna systems

Beams are one of the most common elements of antennas - they can be used both as elements for receiving and transmitting radio signals, and as design solutions for various purposes. The paper considers a hinged-supported composite beam consisting of symmetrical layers reinforced with fiber with a viscoelastic coating. The representative element forming the beam layer consists of a fiber, a viscoelastic layer and a matrix. To assess the effect of the volumetric content of reinforcing fiber with a viscoelastic coating on the loss coefficient of a layered composite beam, the viscoelastic analogy method is used, within which the properties of a viscoelastic material are specified by complex quantities. And to evaluate the effect of the volumetric content of reinforcing fiber with a viscoelastic coating on the loss modulus of the composite material, the three-phase method extended to a multiphase medium and the viscoelastic analogy method are used. A study is also carried out to study the influence of the ratio of the real parameter of the loss modulus of the viscoelastic layer to the shear modulus of the reinforcing fiber on the effective transverse loss modulus of the composite material and on the loss coefficient of the laminated composite beam. Numerical values of the effective transverse loss moduli for the composite material under study and the loss coefficients of a simply supported beam are given depending on the thickness of the viscoelastic layer. For the parameters under study, the nature of the peak values is analyzed and ways of influencing their position and shape are discussed. It is assumed that such beams can find wide application in antenna technology, since they will significantly reduce mechanical resonant vibrations of antenna system structures, while maintaining their rigidity and strength.

Cessation of Labrador Sea Convection Triggered by Distinct Fresh and Warm (Sub)Mesoscale Flows

Abstract By ventilating the deep ocean, deep convection in the Labrador Sea plays a crucial role in the climate system. Unfortunately, the mechanisms leading to the cessation of convection and, hence, the mechanisms by which a changing climate might affect deep convection remain unclear. In winter 2020, three autonomous underwater gliders sampled the convective region and both its spatial and temporal boundaries. Both boundaries are characterized by higher subdaily mixed layer depth variability sampled by the gliders than the convective region. At the convection boundaries, buoyant intrusions—including eddies and filaments—instead of atmospheric warming primarily trigger restratification by bringing buoyancy with a comparable contribution from either fresh or warm intrusions. At the edges of these intrusions, submesoscale instabilities, such as symmetric instabilities and mixed layer baroclinic instabilities, seem to contribute to the decay of the intrusions. In winter, enhanced lateral buoyancy gradients are correlated with strong destabilizing surface heat fluxes and alongfront winds. Consequently, winter atmospheric conditions and buoyant intrusions participate in halting convection by triggering restratification while surface fluxes are still destratifying. This study reveals freshwater anomalies in a narrow area offshore of the Labrador Current and near the convective region; this area has received less attention than the more eddy-rich West Greenland Current, but is a potential source of freshwater in closer proximity to the region of deep convection. Freshwater fluxes from the Arctic and Greenland are expected to increase under a changing climate, and our findings suggest that they may play an active role in the restratification of deep convection.

Hydrodynamic Modeling of Calender Forming (Pressing) of Sheet and Roll Composites

Statement of the problem. The problem of production of sheet and roll composites necessary for the construction industry in the conditions of roll-calender processing and pressing of polymer materials and reinforcing tape is investigated. The solution of this problem is carried out within the framework of a hydrodynamic model of a stationary, isothermal flow of a viscous, incompressible medium in a flat symmetrical layer between two ideal cylinders (calenders) rotating in opposite directions with equal speeds. The purpose of such a statement is to analyze the stress-strain obtained under calendering conditions, as well as to obtain at the design stage of the molding process the results of calculating a complex of energy-power parameters that allow controlling the calendering process. Results and conclusions. Using the approximate Reynolds equations in the part of the deformable medium in direct contact with the cylinders, assuming that its rheological properties correspond to a Newtonian fluid, analytical expressions are obtained for the force and kinematic parameters of pressing, depending on the thickness of the formed layer and the speed of rotation of the rollers. Based on the equilibrium condition, an expression is obtained for the magnitude of the thrust force that ensures the molding process. It is shown that the value of the rolling friction coefficient decreases with a decrease in the thickness of the layer, the specific spacer force, as well as the angular velocity of rotation.

Comparative study on damping performance of different shape memory polymers

Vibration analysis using an unconstrained layer damping for surface damping treatment is presented in the paper. The layer made of viscoelstic material is applied over the structure on single side known as an unsymmetrical unconstrained layer damping treatment is discussed along with the same material is glued on two sides of the surface called as symmetrical unconstrained layer damping treatment. In the present investigation, based on UTM and DMA tests, different analytical studies were carried out using shape memory polymers such as polyurethane, silicone, and butyl rubbers as damping materials for symmetrical and unsymmetrical configurations with damping layer thicknesses of 10 mm to evaluate the damping performance of unconstrained layer damped specimens. The feasibility studies of all the selected shape memory polymers revealed that the structure layered with butyl rubber gives better results than others in reducing vibration amplitude when the possibility of rectangular and cylindrical cavities in the layer are considered and discussed. The extensional damped samples were modeled using the modeling software tool, i.e. Solid Works, and modal analysis was carried out on the ANSYS workbench. Finally, the whole structure’s damping is predicted using RKU (Ross-Kerwin-Ungar) analysis, and the optimum values of system’s loss factor are obtained using Python programming.