XOY Plane Research Articles

High sensitivity and high figure of merit graphene mid-infrared multi-band tunable metamaterial perfect absorber

In the research of this paper, we have devised a mid-infrared band metamaterial perfect absorber made of graphene material. The absorber is composed of a traditional three-layer structure of MPA. The top layer is a graphene layer with a specific structure, with SiO2 as the dielectric layer and the gold film as the substrate. In the wavelength range of 5500 – 13000 nm, the graphene layer generates seven absorption peaks and shows ultra-high absorption efficiency. The respective absorption rates are 91.17%, 99.41%, 99.01%, 95.69%, 94.16%, 96.89%, and 95.01%. By verifying the absorption spectra and the principle of effective impedance matching, analyze the electric field distribution image of the xoy plane based on the principle of surface plasmon resonance, we have proved that it conforms to the classical physical theory and expounded the reason why the absorption peaks were formed. The comparison of different graphene patterns has confirmed the superiority of this structure. By changing the relaxation time and Fermi level of graphene, the tunability of the absorber structure has been verified. Changing the incident angle has proved its insensitivity to the polarization angle (0° - 50°). Finally, by calculating and comparing the figure of merit (FOM) and the sensitivity (S), it is shown that this structure has significant sensitivity and excellent application ability and value. We firmly believe that our absorber can be well applied in high-sensitivity sensors, filters and detectors, and can contribute to fields such as photoelectric detection, optical communication and photoelectric sensing.

Ti-decorated B-doped biphenylene: A hydrogen storage sponge at room temperature

It has always been a difficult problem to design Kubas-type hydrogen storage materials that make hydrogen molecules activate but do not dissociate. Density functional theory calculations confirm that Ti decorated B-doped biphenylene is the first two-dimensional room-temperature hydrogen storage sponge reported so far. The hydrogen adsorption energy of Ti-decorated B-doped biphenylene is in the range of −0.29 ∼ −0.51 eV with hydrogen storage capacity is 6.58–9.13 wt%. What's very interesting and exciting is that the Kubas interaction between Ti sites and H2 can be regulated by changing the electron occupation state of the dx2-y2 orbitals of Ti, and this regulation can be realized through the uniaxial lattice strain in the XOY plane. The average hydrogen adsorption energy of tensile Ti-decorated B-doped biphenylene ranges between −0.34 ∼ −0.66 eV, while −0.22 ∼ −0.48 eV for compressed one. This process makes the reversible hydrogen storage as simple and feasible as a sponge absorbing water. This study provides clear structural for the transformation mechanism to form a folded structure and also provides an important precedent model.

Parametric indoor 3D reconstruction based on binary image feature point extraction

Abstract In recent years, with the rapid advancement of laser scanning technology, indoor 3D modeling technology has significantly developed, becoming a research hotspot in the field of 3D reconstruction. Addressing the issues of high complexity in decoding point cloud surfaces in traditional indoor reconstruction, this paper proposes an indoor 3D reconstruction method based on binary image feature point extraction. The method utilizes point cloud data for semantic segmentation of the indoor environment to accurately extract the ceiling area, which is then projected onto the XOY plane and converted into a binary image, thereby transforming the 3D problem into a 2D problem. Subsequently, key feature points are identified through feature point detection technology, and systematic model construction is carried out based on the sequence of these feature points and their associated parameters. This method effectively simplifies the complexity of traditional 3D modeling, achieving accurate and parametric indoor 3D reconstruction.

Bidirectional beam generation by metasurface for 6G communication

This paper presents a bidirectional metasurface that is polarization dependent and consists of 2-bit coding reflect-transmit (RT) elements. The proposed metasurface can transmit the vertical polarized (VP) incident wave and reflect the horizontal polarized (HP) wave with the same focal length. The 2-bit coding passive RT elements, named UC0 to UC3, have 0°, 90°, 180°, and 270° phase responses for both vertical and horizontal incidences. The array samples were fabricated using standard print circuit board (PCB) technology. The results of both numerical and experimental investigations demonstrate that the proposed metasurface is capable of beam control with an angular range of ±30° in the xoy, xoz, and diagonal planes. The reflected and transmitted beams have been found to exhibit peak gains of 22 dBi at 94.5 GHz with 7% 3-dB gain bandwidth and 22.1 dBi at 93 GHz with 14.8% 3-dB gain bandwidth, respectively. The proposed metasurface shows great potential for use in 6G wireless communication applications.

Velocity inversion of a relativistic electron incident by a vortex beam in a magnetic field

A method is proposed to invert the velocity of a relativistic electron incident by a vector Bessel vortex beam in a magnetic field by analyzing the spectra of the backward scattered echoes. The scattering power and spectra are investigated based on the vector plane wave angular spectrum theory and the Thomson scattering theory. The results indicate that the high velocity of an electron causes the distribution of the scattered power on the xoy plane to shift in the direction of the velocity. Additionally, the spectra of the scattered echoes display periodic bimodality due to the cyclotron motion of the electrons. The velocity of a relativistic electron parallel to the applied magnetic field can be obtained from the spectrum of the scattered echoes and the parameters of the vortex beam. The conclusions suggest that both the magnitude and the direction of the velocity of a relativistic electron can be determined using a set of orthogonal magnetic fields. This work is significant for studying the scattering of vortex beams by plasmas and developing diagnostic techniques of plasmas.

Prediction method of thermal expansion coefficient for 2D composite fabric

In this article, an analytical method for predicting the thermal expansion coefficient of 2D composite fabrics is established. First of all, different from the traditional prediction of thermal expansion coefficient by classical laminate theory, this paper extends the self-consistent method of micromechanics to 2D composite fabrics to improve the accuracy of thickness direction prediction. Analytical Prediction method of Thermal expansion coefficient of 2D Composite fabric (APTC)was established. In the x section of Representative Volume Element(RVE) model, the stress balance equation and deformation coordination equation are applied to derive the internal thermal expansion coefficient. In the z section, the coefficient of thermal expansion is derived from the Poisson effect. Secondly, the formula of thermal expansion coefficient is derived for plain fabric, twill fabric and satin fabric respectively, which is consistent with the APTC method, indicating that the method is representative. Finally, RVE finite element model is established according to the braided structure parameters of 5284/T800 composite fabric. Comparing analytical solution, numerical solution and experimental solution, the α 1 and α 2 of the numerical and experimental solutions is close enough to be considered equal, which is consistent with the transverse isotropy of the composite fabric in xOy plane predicted by theoretical analysis.When predicting α 1 and α 2 , the maximum error between numerical solution and analytical solution is 1.79%, the maximum error between numerical solution and experimental solution is 22.29%, and the error remains at about 4% during predicting α 3 . In general, the APTC method for predicting the thermal expansion coefficient of composite fabrics is accurate and effective, and the simplified formula is more convenient to popularize and apply.

Microstructure and mechanical behaviors of electron beam melted Ta10W alloy

TaW refractory alloys with excellent high-temperature mechanical behaviors up to 2000 ℃ have been intensively researched recently. Such performances herald great potential in industrial applications. In this study, we manufactured a Ta10W refractory alloy using selective electron beam melting with elemental TaW powder. The as-received microstructure shows high chemical homogeneity, and the obtained hardness values are 295±3 HV and 293±3 HV for XOY and XOZ planes, respectively. The yield strength of the compression tests can reach 664±8 MPa. The yield strength, ultimate tensile strength, and strain after fracturing of samples normal to the build direction of the as-deposited Ta10W refractory alloy are 750±5 MPa, 764±4 MPa, and 6.05±2.34, respectively. This study comprehensively investigated the microstructure and mechanical behaviors of the additively manufactured Ta10W refractory alloy, which can provide considerable insight into additive manufacturing of high-melting point refractory alloys.

Inconel 718 alloy reinforced with nano-sized WC particles and graphene nanoplatelets: Microstructure, wear resistance and electrochemical properties

The coarse columnar grain structure of additively manufactured metals diminishes material performance, hence the transition from columnar grains to equiaxed grains is extensively investigated. The microstructure of composite materials and the properties of Inconel 718 are positively influenced by both nano-sized tungsten carbide (nano-WC) and graphene nanoplatelets (GNPs), which act as reinforcing phases. The study employs directed energy deposition (DED) technology for the fabrication of Nano WC/GNPS-IN718 composite materials. Th emicrostructure, wear resistance, and corrosion resistance properties of both Inconel 718 and its composite materials were systemically investigated. The findings discover the microstructure of the composite material consists of γ/M7C3 phases with precipitation of carbides such as (Nb,Ti)C. Utilizing nano WC and graphene as lubricants, and carbides like (Nb,Ti)C as strengthening phases, the composite material exhibits a grain size refinement of approximately 3.36 % compared to IN718. The grain orientation in the XOY plane predominantly aligns along the <001> direction. The Nano WC/GNPS-IN718 composite material exhibited a 1.264-fold increase in average microhardness compared to the IN718 alloy. Notably, the friction coefficient and wear rate were only 77 % and 18.75 %, respectively, of those observed in the IN718 alloy. Furthermore, the corrosion current density of the Nano WC/GNPS-IN718 composite material was 30.8 % of that observed in IN718, with a polarization resistance 4.08 times higher than that of IN718.

Microstructure, compressive performance and wear resistance of pure molybdenum additively manufactured via laser powder bed fusion

Pure molybdenum (Mo) additively manufactured via laser powder bed fusion is challenging due to its high laser reflectivity and sensitivity to cracking. To achieve crack-free pure Mo alloy and enhance production efficiency, this study employs a high-power (350 W) printing process with a layer thickness of 30 μm, resulting in the successful fabrication of pure Mo with a relative density of 99.2%. X-ray diffraction (XRD) and electron backscatter diffraction (EBSD) revealed that the pure Mo specimens prepared by LPBF process exhibited different preferential grain orientations and lattice distortions in various building directions, with higher texture strength on the XOZ plane and greater lattice distortion on the XOY plane. The hardness of the pure Mo specimens reached 208 HV, with uniaxial compressive strength and elongation at 535 MPa and 20.9%, respectively, surpassing existing literature values by 37.2% and 8.0%. Furthermore, the dry friction behavior and mechanism of LPBF-manufactured pure molybdenum were investigated for the first time and compared to traditional powder metallurgy. Consequently, this research offers valuable insights for manufacturing crack-free LPBF pure molybdenum components with 30 μm layer thickness, boasting superior mechanical and wear resistance.

Theoretical and experimental research on the mechanical tests of 3D printed samples from various materials

At this moment, a real industrial, scientific and technological revolution is being discussed worldwide, consisting in the development of Additive Manufacturing AM technologies through the use of 3D printing. The FDM (Fused Deposition Modelling) 3D printing technology consists in the deposition of fusible material layer by layer in the XOY plane, the thickness of the 3D printed layer is g = 0.12 ÷ 0.24 mm, the resolution of 3D printing is r = 0.1mm, while the print head advances vertically on the OZ axis. The purpose of the work is to determine the breaking moment through destructive mechanical bending tests of some samples made by 3D printing from the following materials: ABS+, PETG and PLA. 5 samples were made in 3 printing directions: horizontal, vertical and lateral, resulting in 15 samples for each material. The total number of samples used is 45. Knowing these values, depending on the requirements of the specifications, a certain material and a certain printing position can be used.

High efficiency holographic impedance metasurface for dual circular polarized OAM waves

AbstractThis paper proposes a high aperture efficiency (AE) small size tensor holographic impedance metasurface (THIMS), which has the ability to create circular polarized (CP) high purity orbital angular momentum (OAM) multi‐beams with flexibly independent control of the individual beam direction, polarization and OAM mode. The tensor unit cell is a cross‐slotted circular patch. We design a THIMS at 14.6 GHz for dual CP OAM beams: Beam‐I (LHCP, l = 1, θ1 = 30°, φ1 = 0°), Beam‐II (RHCP, l = −1, θ2 = 30°, φ2 = 180°). The developed tensor dual CP THIMS has the following advantages: high purity in xoy plane at z = 9.73 λ (λ wavelength, measured purity 88.4% for Beam‐I, and 93.5% for Beam‐II), high AE 25.1%, and small size 5.986 λ × 5.986 λ × 0.0618 λ. The calculated, simulated and measured results agree well. The generated dual CP OAM beams have potential applications for high‐capacity wireless communication, radar high resolution imaging, and rotation velocity measurement.

Study on microstructure and properties of selective laser melting formed AlSi10Mg alloy

AbstractThe microstructure and properties of an AlSi10Mg alloy produced by selective laser melting were examined using optical microscopes, scanning electron microscopes, electron backscattered diffraction, and x‐ray diffraction. The results show that the mechanical characteristics of selective laser melting formed AlSi10Mg alloy is superior to those of traditional sand cast AlSi10Mg alloy due to fine grain strengthening and solid solution strengthening. AlSi10Mg alloy formed by selective laser melting is mainly composed of α‐aluminum solid solution, eutectic silicon with network structure and a small amount of Magnesium silicon precipitated phase, and different cross‐sections have unique microstructures and properties. The XOY plane is composed primarily of equiaxed grains with an average grain size of 7.34 μm and a {001} &lt;100&gt; cubic texture, and it has a hardness value of 130.7 HV 0.2. The majority of the YOZ plane, which has a {111}&lt;110&gt; brass R texture and a hardness value of 108.9 HV 0.2, comprises columnar crystals with an average grain size of 8.42 μm.

A temporal correlation coefficient model of grain temperature field cloud maps in horizontal warehouses

The temperature field cloud map (TFCM) is a color temperature contour map that can represent grain temperature distribution of bulk grain in a lagre storage facility (grain warehouse). The analysis of temporal variation characteristics of temperature field cloud maps can assist to analyze the changes of grain temperatures to monitor grain conditions changes. Wherein the temporal correlation coefficient is a type of variation characteristic of temperature field cloud maps at time domain. This research established a temporal correlation coefficients model of grain temperature for different grain warehouses storing paddy, wheat and maize in different provinces of China. That features of TFCM were extracted include the color coherence vector (CCV), LBP feature vector (LBP), gray level co-occurrence matrix vector (GLCMV), RGB feature vector (RGBV) and LAB feature vector (LABV), which were combined successively as the model input. The RMSEs between the correlation coefficients calculated by the model and that calculated by the measured grain temperatures in these planes were analyzed. The results show that the RMSEs of models with different vector combinations as input were different, and the RMSEs were all less than 0.001. Therefore, the five feature combinations could be used as the model input. Afterwards, distribution of temporal correlation coefficients of temperature field cloud maps from different warehouses were analyzed. The results show that in the XOY, XOZ and YOX planes of grain warehouses, temporal correlation coefficients (in the range (0.98, 1)) proportion of temperature field cloud maps were more than 95%, 85% and 82%, respectively.

Improvement of mechanical properties at cryogenic temperature of CoCrNi medium entropy alloy fabricated by hybrid additive manufacturing technology

The emergence of CoCrNi medium-entropy alloys (MEAs) holds great promise for applications in extreme service environments. However, fabricating CoCrNi MEA with an extraordinary combination of strength and ductility is urgently needed. Herein, we adopt a combination of laser direct energy deposition (L-DED) additive manufacturing and ultrasonic impact treatment (UIT) to fabricate CoCrNi additive parts. The optical microscopy results showed that the proportion of equiaxed crystals increased from 7.2% to 42.1% after UIT, while the proportion of columnar crystals with grain sizes greater than 31 μm decreased from 62.8% to 27.4%. The tensile test results at 298 and 77 K showed that the tensile strength increased by 7.0% and 27.6%, respectively, after UIT. Electron backscatter diffraction (EBSD) results indicated that the texture intensity of the XOY and XOZ planes in the additive parts decreased after UIT. The transmission Kikuchi diffraction (TKD) results showed that 29.9% of the FCC phase transformed into the HCP phase after the tensile test. Meanwhile, the volume fractions of the substructured, recrystallization, and deformation zones in the phase transformation zone and in the FCC structure were 21.2%, 58.7%, and 20.1% and 67.7%, 9.0%, and 23.3%, respectively. The enhanced transformation-induced plasticity effect contributed to the higher strength and ductility of the CoCrNi MEA treated by UIT.

Precession of magnetic moments with change of their orientations

In the work the precession of the magnetization vector in nano-sized magnets is induced by a femtosecond laser pulse, the frequency of which lies in the transparency region of the magnet material. It is shown that an alternating magnetic field applied to the XOY plane generates the magnetic equilibrium position vectors and elliptical precession occurs if a constant magnetic field acts along the Z axis. In this case the precession angle changes periodically in time and the precession frequency is determined by the amplitude of the total magnetic field.

Anisotropic response in mechanical and corrosion performances of UNS S31803 duplex stainless steel fabricated by laser powder bed fusion

Mechanical and corrosion behaviors perpendicular to build direction (XOY) and along build direction (XOZ) of UNS S31803 duplex stainless steel (DSS) fabricated by laser powder bed fusion (LPBF) were investigated. With the post-annealing, the steel exhibited a ferrite-austenite microstructure. For XOY plane, austenite displayed a primarily <101> texture while ferrite kept <001> preferred orientation, and mainly held a Nishiyama-Wassermann orientation relationship. However, for XOZ plane, austenite showed a mixed texture. The average size of ferrite grains was larger for XOZ plane than XOY. The austenite in XOY plane was mostly island morphology grains, while in XOZ plane, there were a large number of coarse columnar grains. A higher geometrically necessary dislocation density and proportion of low-angle grain boundaries on XOY plane were observed. The yield strength and ultimate tensile strength values perpendicular to build direction were higher than those along build direction. While the total elongation perpendicular to build direction was lower. Moreover, the XOY plane shows slightly better corrosion resistance than the XOZ.

Optimization of credit scorecard combinations based on quantum annealing algorithm

With the development of the times, the usage of loan-related business is increasing. However, most of the credit score card portfolio methods used nowadays are manually designed and supplemented with computer calculations, so the bank yields are low. Therefore, it is of great interest to study the application of quantum computers in credit score card portfolio optimization for better rating of customer credit ratings. Based on the given credit score card data, a linear programming model is developed. Firstly, the data is processed into two sets of one-dimensional data by Python and the working range of the two sets of data is found. Secondly, after deriving the objective function expressions according to the given conditions, the data were visualized by building a 3D grid matrix with the pass rate and bad debt rate as the XOY plane and the final benefit to the bank as the Z axis. Subsequently, the decision variables in the linear programming model are converted into binary variables, and the original model is transformed into a QUBO model by converting the constraints into binary variables. After analyzing the QUBO model, the quantum annealing method is chosen to solve the optimal solution of the objective function. And based on this, the case of three selected credit score card combinations and any three credit score cards are considered.

Wideband antenna with crescent heads for omnidirectional communications

AbstractThis paper investigates a wideband omnidirectional antenna that possesses 124.7% of fractional bandwidth. The antenna's two crescent‐shaped radiating patches and their ultrawideband matching structures are printed on two laminates that are crossly placed vertically over the ground plane. Simulation shows that the structure on a single laminate radiates an “8”‐shaped pattern on the horizontal plane. The cross formation of the two printed laminates generates an omnidirectional radiation pattern by superimposing two “8”‐shaped patterns perpendicularly. The proposed antenna is fabricated and measured for demonstration. The measured results agree well with the simulation, indicating the omnidirectional antenna works from 1.38 to 5.95 GHz with a return loss of −10 dB. Simulation and measurement also show the gain variation on the xoy plane is 2 dB in the band of interest, which is small if the ultrawide bandwidth is considered. The above features make the proposed antenna a promising candidate for applications in the digital cellular system (DCS1800), long‐term evolution (LTE2300/2600), wireless local area network (WLAN2400), and IEEE 802.11p.

Anisotropy of wear and tribocorrosion properties of L-PBF Ti6Al4V

Additive manufactured Ti6Al4V has shown high tensile anisotropy. The tribocorrosion properties involve the coupling of mechanical wear and surface corrosion, and its anisotropy is unclear. In this study, the corrosion resistance of the horizontal (XOY) plane and the vertical (V) plane was compared by electrochemical tests. The wear resistance and tribocorrosion resistance of different planes of laser powder bed fusion (L-PBF) Ti6Al4V were tested by using zirconia ball as friction pair. The results show that the corrosion resistance of the V plane was better than that of the XOY plane. However, the wear and tribocorrosion resistance recorded for the XOY plane was better than that of the V plane. The columnar crystals along the building direction led to the anisotropy of wear and tribocorrosion of L-PBF Ti6Al4V.

Нетривиальная динамика спинов под действием взаимно перпендикулярных постоянных и переменных магнитных полей

The paper considers the nontrivial dynamics of a spin when it is simultaneously affected by a constant magnetic field directed along the Z axis and a variable one applied to the XOY plane. It is shown that coupled oscillations of all components of the magnetic moment (or magnetization) arise in this case. In other words, it becomes possible to control the orientation of the magnetic moment. Further, it was found that this possibility remains even in the case of two constant magnetic fields – when they are perpendicular to each other. In the latter case, elliptical precessions of magnetic moments occur in planes perpendicular to the applied fields, the amplitudes of which can be changed by means of constant magnetic fields.