bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tri-band metasurface absorber based on square rotational symmetry
Authors: Wang Zizheng , Shen Zhaoyang , Liu Han , Xiang Tianyu 
Published: June 2023

Abstract
In this paper, a multi-band metasurface absorber is designed, measured and investigated. There are four centrosymmetric two-tangent copper trapezoids that make up its unit cell. The parameters of the unit cell have great influence on the frequency of absorption peaks, with optimized parameters leading to absorptivity of 99.4%, 93.9% and 99.7% at 4.80GHz, 8.68GHz and 10.92GHz, respectively. The physical mechanism of absorption is further analyzed based on the distributions of surface current, electric and magnetic field, as well as the impedance matching. Furthermore, the absorber exhibits characteristics of polarization insensitivity and incident sensitivity, which are demonstrated through experiment. In addition, the proposed absorber is able to monitor different environments that the sensitivities are 0.15 GHz/PIU, 0.50 GHz/PIU and 1.53 GHz/PIU at three absorption peaks. In addition, the FOM of the proposed sensors at corresponding resonant frequencies are 0.68, 1.61 and 4.78, respectively. The result reflects that the proposed metasurface shows effective sensing abilities. The designed metasurface absorber has potential applications in both military and civil fields.
Broaden the sound absorption band by using micro-perforated plate back cavities with different cross-sectional areas
Authors: Yan Shanlin , Wu Fei , Zhang Xiao , Hu Man , Ju Zegang , Zhao Jiang 
Published: June 2023

Abstract
In finite size micro-perforated plate structure, the cross-sectional area size of back cavity will affect the resonant frequency of structure. Based on transfer matrix and the characteristics of acoustic propagation in variable cross-section channel, the sound absorption characteristics of the double-layer micro-perforated plate structure with variable cross-section back cavity are studied and analyzed, and a theoretical analysis model of the variable cross-section back cavity micro-perforated plate structure is established. By comparing the theoretical model with the finite element model, the effect of abrupt changes in the cross-sectional area of the back cavity on the noise reduction performance is obtained. As for the double-layer micro-perforated plate in this paper, the bigger the cross-sectional area of back cavity of inner micro-perforated plate, the lower the frequency of first peak absorption coefficient of structure will be and the higher the frequency corresponding to second absorption coefficient peak of structure. Utilizing this feature, a combined micro-perforated plate structure is designed, which has back cavities with different inner cross-sectional areas, and ultimately broadening the structural sound absorption band. Additionally, through using 3D printing technology to produce samples and conducting experimental tests in the impedance tube. Experiments show that the structure can achieve an absorption coefficient of more than 0.8 within the frequency range of 500–1650 Hz, which further improving the noise reduction performance of the MPP structure. The feasibility of variable-sectional back cavity structure for the design of low-frequency and broadband noise reduction absorber is verified.
Broadband dielectric behaviour and structural characterization of PVDF/PMMA/OMMT polymer nanocomposites for promising performance nanodielectrics in flexible technology advances
Authors: Kumar Naresh , Sengwa R J 
Published: June 2023

Abstract
Characterization of broadband dielectric behaviour of polymer nanocomposites (PNCs) is vital for the exploration of efficient nanodielectrics as energy storage, flexible dielectric substrates, and insulators in a wide range of advanced electronic device technologies. Accordingly, herein, PNC films based on poly(vinylidene fluoride) (PVDF)/ poly(methyl methacrylate) (PMMA) blend matrix (80/20 wt/wt%) dispersed with 0, 2.5, 5, and 10 wt% organo-modified montmorillonite (OMMT) nanoclay are developed by state-of-the-art homogenized solution casting method. These PVDF/PMMA/OMMT compositions based flexible PNC films are characterized in detail by employing a scanning electron microscope (SEM) equipped with energy dispersive x-ray (EDX) device, x-ray diffractometer (XRD), Fourier transform infrared (FTIR) spectrometer, differential scanning calorimeter (DSC), inductance-capacitance-resistance (LCR) meter, and impedance/material analyzer (IMA). The SEM microimages, XRD traces, and FTIR spectra evidenced appreciable homogeneity and surface morphology, intercalated and exfoliated OMMT structures, and the α, β and γ-phase crystallites of the PVDF in these complex semicrystalline PNCs. The DSC thermograms confirmed a significant alteration in the melting temperature and degree of crystallinity of the PVDF crystallites with the increased amount of OMMT in the 80PVDF/20PMMA blend host matrix. The broadband dielectric dispersion spectra over the frequency range of 20 Hz−1 GHz explained the contribution of interfacial polarization in the complex dielectric permittivity at lower experimental frequencies, whereas at higher frequencies permittivity is ruled by dipolar polarization in these composites at 27 °C. The dielectric loss angle tangent and electric modulus spectra revealed an intense structural dynamics relaxation process in the upper radio frequency region. The influence of OMMT concentration on the dielectric permittivity and electrical conductivity is explored. The detailed dielectric and electrical characterization of these innovative semicrystalline composites with important structural and thermal properties revealed their immense potential as high-performance nanodielectrics for highlighting current applications of broadband frequency range electrical and electronic device technologies.
Independently tunable refractive index sensor based on metal-insulator-metal waveguide with key-shaped resonator and application in human blood plasma detection
Authors: Zhao Shiyu , Qi Yunping , Chen Haowen , Wen Yujiao , Wang Li , Zhou Zihao , Zhang Shu , Wang Xiangxian 
Published: June 2023

Abstract
In this paper, a metal-insulator-metal waveguide structure based on a key-shaped resonator is proposed. Firstly, the structure is simulated using the finite difference in time domain (FDTD) method, revealing the generation of three resonant peaks. And the theoretical results are then analyzed using multimode interference coupled mode theory (MICMT), demonstrating a high level of agreement with the simulation results. Then the parameters of the structure are adjusted, so that the resonant peaks can be tuned independently. Notably, the structure exhibits a maximum sensitivity of 1520 nm RIU−1 with a figure of merit (FOM*) of 195.89, highlighting its exceptional sensing capabilities. Additionally, an analysis of the asymmetric structure reveals the emergence of a new Fano resonance. Due to its outstanding sensing performance, the structure holds potential for applications blood plasma concentration testing. Feasibility is assessed in terms of blood plasma concentration detection, achiveing a maximum sensitivity of 3.07 nm l g−1. As a result, this structure offers promising opportunities in the field of on-chip optical integration and the biomedical field, among others.
Conversion of carbon dioxide in atmospheric pressure dielectric barrier discharges with different electrode configurations
Authors: Wang Chao , Wang Hai-Xing , Liu Chang-Yu , Meng Xian , Jin Guang-Yuan , Huang He-Ji , Cao Jin-Wen , Sun Su-Rong , Yan Cong 
Published: June 2023

Abstract
The choice of electrode configuration and dielectric material is critical to the discharge process and plasma characteristics of a dielectric barrier discharge (DBD) reactor. In this study, a new electrode configuration of DBD reactor with copper mesh as electrode inserted between dielectrics is proposed, which has a much higher capacitance than the conventional double-dielectric layer DBD reactor. Two materials with different relative dielectric permittivities, alumina and zirconia, are chosen as dielectrics for an experimental comparison of CO2 decomposition. The experimental results show that the conversion rate of CO2 for the reactor with copper mesh inserted between dielectrics are higher than that of the corresponding double dielectric layer reactor under the same discharge power, and the conversion rate of CO2 with zirconia as a dielectric material is higher than the case of alumina as a dielectric. Further analysis of discharge characteristics shows that for the reactor with copper mesh inserted between dielectrics, the applied voltage required for discharge is significantly reduced, the amount of transferred charge is significantly increased, and the number of micro-discharge current pulses as well as the average lifetime during a single voltage cycle are also considerably increased, leading to an increase in the CO2 discharge efficiency and conversion rate.
Multi-Watt cavity for 266 nm light in vacuum
Authors: Brand Christian , Knobloch Christian , Simonović Ksenija , Arndt Markus 
Published: June 2023

Abstract
Intense coherent ultraviolet radiation is gaining increasing importance in advanced quantum technologies—from optical clocks and quantum computers to matter-wave interferometry—as well as in photochemistry, life sciences, semiconductor industry, and space applications. Since the preparation of multi-Watt light sources is still an open challenge for many ultraviolet wavelengths, resonant enhancement in a cavity is an attractive alternative. However, many experiments with atoms, molecules or nanoparticles require isolation in high vacuum where UV optics often show fast degradation. Here, we present stable performance of a cavity for 266 nm light with several Watt of intra-cavity power in high vacuum despite the presence of hydrocarbons. Comparing two sets of cavity mirrors indicates that this feat is connected to the micro-chemical environment at the topmost coating layer. Our study emphasizes the need for further developments in this direction to facilitate robust, compact, and high-performing devices employing UV radiation.
Bionic Porous Design and Mechanical Response of Short Implants
Authors: Zhang Xiao , Zhang Jinyang , Chen Jianyu , Chen Xianshuai 
Published: June 2023

Abstract
Due to the material itself and the traditional geometric design, short implants have the problems of high stiffness, less osseointegrated area, and lower long-term reliability in clinical application. In this research, short implants with various porous structures were constructed and their biomechanical responses were evaluated, including biomechanical properties, compression capability, and stress distribution of surrounding bone tissue. Thus, three types of short implants were built: the diamond-like porous short implant (5.0 × 5.0 mm), the hexahedral porous short implant (5.0 × 5.0 mm), and the solid short implant (5.0 × 5.0 mm). Three implant-supported prosthetic models were built based on the above three implants, and their static mechanical properties were assessed. Besides, the average stiffness of regular cylindrical samples was calculated by compression test simulation. The result confirmed that hexahedral porous short implants showed minimum peak stress compared with the diamond-like porous and solid short implants. Similarly, the value of stress peaks in the bone-implant interface for the hexahedral porous short implant appeared lower than the other two short implants. Compression simulation indicated the average stiffness of cylinders after diamond-like and hexahedral porous design was 92.2% and 56.3% lower than the solid cylinder. Compared with the other two designs, the hexahedral porous short implant obtained better stress distribution, even avoiding bone overstress.
Mechanical behaviors and failure mechanisms of CMDB propellant under wide strain rate tension loading
Authors: Yin Jianping , Li Meng , Du Wenxuan , He Xuanfu , Song Jun , Hu Bowen , Huang Meng , Li Yang , Miao Yinggang 
Published: June 2023

Abstract
Composite modified double-base (CMDB) is a sort of mature propellant with a stable structure and high performance. Its tensile mechanical properties should be considered in the structural integrity design of solid propellant charges. The tensile tests were performed on the CMDB by a quasi-static measurement machine. The Hopkinson tension bar (SHTB) under strain rates from 0.0001s−1 to 2500s−1 was modified for structural integrity evaluation, and the stress-strain curves were accurately obtained. After comparing under different strain rates, the results show that the initial modulus of elasticity and stress level are significantly affected by the level of strain rate. Furthermore, the strain hardening becomes more distinct with increasing strain rates. Failure specimens were observed by scanning electron microscopy (SEM). It is indicated that the failure under a low strain rate is mainly debonding of filled particles from the matrix. However, it is mainly caused by their embrittlement under dynamic loading.
Mechanical properties of carbon steel under uniaxial static tension
Authors: Wang Zhuolin 
Published: June 2023

Abstract
With the continuous development of science and technology, carbon steel is widely used in production and life. Especially at the practical application level, in the engineering application, the analysis of the mechanical properties of carbon steel materials has become increasingly prominent. The tensile test is a mechanical property test in which a standard tensile specimen is pulled to fracture at a specified tensile speed under the continuous action of static axial tensile force. The force and elongation are continuously recorded during the tensile process so as to obtain its strength criterion and plasticity criterion. In this paper, the characteristics of mechanical properties of the high, medium, and low carbon steels under uniaxial static tension are discussed. The reasons for the different mechanical properties of steels with different carbon content are explained from a microscopic perspective. The study provides some basic assistance to those who need relevant information.
Mechanical Properties of Seawater Sea-sand Recycled Concrete in Sulfate Attack Environment
Authors: Tian Xiangsheng , Huang Yijie , Zhang Jingxue , Ma Xiaoli 
Published: June 2023

Abstract
Seawater sea-sand recycled concrete (SSRAC) is a new sort of green concrete, it has good environmental and economic benefits. In this paper, the dry-wet cycle and full immersion erosion environments is simulated. The change characteristics of mechanical properties of SSRAC under sulfate attack are studied and compared with ordinary concrete (OC) and freshwater river sand recycled concrete (RAC). The test shows that compared with immersion erosion, the dry-wet cycle significantly accelerates the deterioration rate of concrete. For the concrete in full immersion condition, the strength is still in the rising stage when the immersion corrosion to 120 d, and there is no obvious change of appearance. In dry-wet cycles, apparent damage gradually extends from the diagonal to the surrounding. The damage deterioration starts from the surface layer and gradually deepens. The prismatic compressive strength and corrosion resistance coefficient of SSRAC show the same law as OC and RAC, which increases first and then decreases. The corrosion resistance coefficient is lower than 75% at 120 cycles. The sulfate resistance of SSRAC is significantly inferior to OC and slightly greater than RAC.
An investigation on the effect of thread pitch on the self-loosening of bolted joint caused by fretting wear
Authors: Zhang Mingyuan , Huang Yuanzhe , Liu Haining , Li Fajia , Cai Yuquan 
Published: June 2023

Abstract
To study the effect of thread pitch on the bolt loosening behavior with consideration of fretting wear, the loosening experiments and finite element analysis were carried out to the bolts with different thread pitches. The experimental results demonstrate that fretting wear existed on the thread surface. It caused a slow bolt loosening without the nut rotation. With the thread pitch increases, the clamping force will become smaller, so that the fretting wear on the thread surface will also decrease, indicating that lager thread pitch could increase the anti-loosening ability through alleviating the fretting wear. The FE (Finite Element) results show that the decrease of sliding distance on thread surface had more beneficial effects than the increase of contact stress on the reduction in the fretting wear for the bolt with larger thread pitch.
Simulation study of nanomaterials in heat pipe enhanced high power LED heat sink
Authors: Huang Haibo , Huang Xiaohua , Cheng Zaijun , Wang Yuanzhang 
Published: June 2023

Abstract
To facilitate the simulation of heat dissipation of high-power LED lamps, a set of simplified models for tubular heat pipes and carbon nanotube arrays were first established to estimate their thermal conductivity. Then several kinds of radiators were designed. The application of nanomaterials and heat pipes in the heat dissipation of lamps was studied by the finite element method. It is found that the radiator with vertical suspended fins strengthened by a heat pipe and heat dissipation coating has a better heat dissipation effect than other radiators. Finally, the simulation study of thermal interface materials and heat dissipation coatings for lamps and lanterns heat dissipation is carried out. The results show that the thermal interface materials of carbon nanotubes and carbon nano coatings can enhance the heat dissipation performance of lamps.
Straight recycled green fibre pull-out behaviour in an ultrahigh performance concrete composite matrix UHPC
Authors: Li Yan , Nyathi Tinashe Daniel , Dong Wenyang 
Published: June 2023

Abstract
This article presents the study of the pull-out method and the behavior of the cementitious matrix under loading. Using finite element analysis to investigate the interfacial debonding performance allows us to grasp the experiment’s estimated values. The mechanical bonding is determined using a Scanning Electron Microscopy SEM image. The slippage during the pull-out load varies depending on the cementitious matrix grade and whether the recycled steel strand is hooked at specific angles (Inclination angle). The relationship between monotonic loading and steel fiber diameter was found to be a direct proportion. To comprehend the bonding and debonding between surfaces, as well as the shear experience under loading, both studies find the correlation between theoretical and experimental results to be satisfactory. All aspects were discussed in relation to the effective use of a finite element method in analysis.
Exact solutions for compact stars in general relativity
Authors: Raghoonundun A , Bell R , Hobill D 
Published: June 2023

Abstract
Complete, exact, analytic solutions to the spherically symmetric Einstein equations have been constructed. Beginning with the Tolman VII solution we first “complete” the solution by computing an expression for the pressure and subsequently the equation of state. The Tolman VII solution is then extended to include non-zero mass densities at the fluid-vacuum interface. The method developed to construct these solutions is extended to include transverse pressures and charge. Furthermore the quadratic density profile of the Tolman VII type solutions is modified to include quartic density profiles that lead to expressions in terms of Jacobi elliptic integrals. It is shown that, depending on the outer boundary conditions placed on the mass density, the equations of state lead to either a set of polytropes or behaviour that mimics strange quark matter.
The Importance of the Pressure Anisotropy Induced by Strong Magnetic Fields on Neutron Star Physics
Authors: Ferrer Efrain J , Hackebill Aric 
Published: June 2023

Abstract
In this paper we discuss in some detail how the pressures determined from semi-classical statistical averaging of the energy momentum tensor in the presence of a uniform background magnetic field are anisotropic with different pressures arising along and perpendicular to the magnetic field direction. Hence, we analyze how this result can affect two important characteristics of dense magnetized systems: (i) The hadron-quark phase transition in the presence of a magnetic field, (ii) The behavior of the speed of sound in dense magnetized systems. Taking into account that large magnetic fields are expected to be present in the interior of neutron stars, we will stress the role the pressure anisotropy plays in the physics of these compact astronomical objects.
Readout Electronics for Spatial Distribution Measurement of Neutron Beam Flux in BNCT
Authors: Jiang W. , Cao P. , Liu X. , Fang Z. , Zhang Z. , An Q. , Shi B. , Chen J. 
Published: June 2023

Abstract
Boron neutron capture therapy (BNCT) is a promising cancer
treatment that selectively destroys tumor cells using a neutron
beam. However, accurately and fast measuring the spatial
distribution of neutron flux is critical to ensuring effective
treatment. To address this challenge, Micromegas detectors are
applied for the first time to measure the spatial distribution of
neutron beam flux in BNCT. Due to the high flux, large area, and
multiple components of the BNCT beam, the design of readout
electronics that can handle high counting rate, large channel
numbers, high integration, and discrimination of multiple beam
components is challenging. This paper proposes a targeted readout
electronics system to overcome this challenge. A modular readout
structure based on the PCI Express (PXIe) platform is designed for
384-channel readout. A fully parallel readout structure is developed
and fast shaper parameters are optimized to achieve high counting
rate for each readout channel. A multi-channel high-speed,
large-capacity caching technique is developed to address the
high-speed data storage problem. Digital shapers are implemented in
field-programmable gate array (FPGA) to achieve high
integration. Tests demonstrate that each readout channel can support
a counting rate of 800 kHz and achieve an excellent position
resolution of 1.4 mm. Furthermore, final tests on the BNCT beam
confirm that our system can successfully measure the flux spatial
distribution of different neutron components.
The effect of farmer’s characteristics to arabica coffee farmer’s performances
Authors: Rico  , Darma R , Salman D , Mahyuddin  
Published: June 2023

Abstract
Characteristics of farmers show the performance of farmers in running better and more sustainable farming. This study aims to analyze farmer characteristics’ effect on Arabica coffee farmers’ performance in North Toraja Regency. This study used a survey method with a quantitative descriptive approach. This research was conducted in North Toraja Regency on March 2022. The effect of farmer characteristics on farmer performance was analyzed using multiple linear regression analysis. Investigating the impact of farmer characteristics on farmer performance, it was found that farmer characteristics (gender, age, education, farming experience, family responsibilities, and income) had a positive influence on farmer performance.