bluuebunny/crossref_metadata_2025 huggingface dataset:
Integrative taxonomy in Syllis prolifera (Annelida, Syllidae): from a unique cosmopolitan species to a complex of pseudocryptic species
Authors: del Olmo Irene , Roma-Cavagliani Josep , Martín-Hervás María del Rosario , Langeneck Joachim , Cervera Juan Lucas , Álvarez-Campos Patricia
Published: June 2024

Syllis prolifera (Syllidae, Syllinae) is an abundant species of marine annelids commonly found in warm to temperate waters worldwide. Although morphological variability occurs among populations, S. prolifera has long been considered a cosmopolitan species, widely distributed in coastal environments, including acidified and polluted areas. However, the increasing number of cases of cryptic and pseudocryptic speciation in several polychaete families in recent years has led us to question whether S. prolifera represents a single globally distributed taxon or is a species complex. To address this question, we conducted an integrative study, combining morphological, ecological and molecular data of 52 S. prolifera specimens collected in different localities across the western Mediterranean Sea and the Gulf of Cadiz. Our phylogenetic and species delimitation analyses that included two mitochondrial DNA markers (COI and 16S rRNA) were congruent in not considering S. prolifera a unique entity. Five distinct lineages that can also be recognised by certain morphological and ecological traits were identified from these analyses instead. Overall, our study does not support the homogeneity of S. prolifera across the Mediterranean Sea, providing a new example of pseudocrypticism in marine invertebrates.
Valence Bands Convergence in p-Type CoSb3 through Electronegative Fluorine Filling
Authors: Huang 黄 Xiege 写格 , Li 李 Jialiang 家良 , Ma 马 Haoqin 浩钦 , Li 李 Changlong 昌隆 , Liu 刘 Tianle 天乐 , Duan 段 Bo 波 , Zhai 翟 Pengcheng 鹏程 , Li 李 Guodong 国栋
Published: June 2024

Band convergence is considered to be a strategy with clear benefits for thermoelectric performance, generally favoring the co-optimization of conductivity and Seebeck coefficients, and the conventional means include elemental filling to regulate the band. However, the influence of the most electronegative fluorine on the CoSb3 band remains unclear. We carry out density-functional-theory calculations and show that the valence band maximum gradually shifts downward with the increase of fluorine filling, lastly the valence band maximum converges to the highly degenerated secondary valence bands in fluorine-filled skutterudites. The effective degeneracy near the secondary valence band promotes more valleys to participate in electric transport, leading to a carrier mobility of more than the threefold and nearly twofold effective mass for F0.1Co4Sb12 compared to Co4Sb12. This work provides a new and promising route to boost the thermoelectric properties of p-type skutterudites.
Robustness analysis for the vibration control performance of energy-harvesting tuned mass damper with uncertainties
Authors: Qinlin Cai , Ping Lu , Yuanbin Chen , Xiang Shi
Published: June 2024

Energy-harvesting vibration control strategy has been proposed and applied in different applications, including but not limited to automotive, mechanical, and civil engineering. However, when facing uncertainties from both internal and external environments, the robustness of its performance has rarely been evaluated. The energy-harvesting tuned mass damper (EHTMD) is a representative vibration control device integrated with the energy-harvesting function. This study investigates the robustness of an EHTMD installed on a structure with multi-uncertainties. First, the EHTMD modeling, the interval model, and the robustness evaluation framework are introduced. Uncertainties are considered for all parameters of an EHTMD, including the mechanical units, electromagnetic damper, and energy harvesting circuit. Subsequently, a series of dynamic simulations are performed on a damped benchmark single-degree-of-freedom frame with an EHTMD. The lower- and upper-bound structural vibration and generated power are estimated under free-vibration, harmonic-excitation, and random-excitation scenarios. The EHTMD performance robustness is evaluated through the interval response by incorporating the first-passage theory. The key factors in EHTMD that influence its robustness are identified. Results indicate promising robustness when using the energy-harvesting vibration control strategy to replace the conventional dampers, addressing one of the often-questioned issues of the energy-harvesting vibration control strategy.
Intelligent surrogate model of a high-temperature superconducting cable for reliable energy delivery: short-circuit fault performance
Authors: Sadeghi Alireza , Song Wenjuan , Yazdani-Asrami Mohammad
Published: June 2024

High-temperature superconducting (HTS) cables are promising solutions for electric power transmission of renewable energy resources, where their fault performance study is vital to avoid power interruptions in the grid. In this study, a fast intelligent surrogate model was presented to estimate the fault performance of a 22.9 kV/50 MW HTS cable to make fast fault performance analysis of the HTS cables possible during the design stage. Different fault scenarios were considered under different fault durations, fault resistances, and types of faults. Then, the fault energy, fault current, fault type, fault duration, and fault resistance were fed into the surrogate model as inputs. The outputs were the temperature of the rare-earth barium copper oxide (ReBCO) tapes, the former temperature, the ReBCO layer current, and the total resistance of each phase. For surrogate modelling, cascade forward neural networks (CFNNs) were used. The results show that the CFNN-based model estimated the fault performance of the cable with an average accuracy of 99.1%. Finally, the impact of considering fault energy, fault current, and both, as the inputs of the models, on the final accuracy were explored. The results show that by considering the fault energy, the accuracy of the surrogate model can be increased.
Elementary proof of QAOA convergence
Authors: Binkowski Lennart , Koßmann Gereon , Ziegler Timo , Schwonnek René
Published: June 2024

The quantum alternating operator ansatz (QAOA) and its predecessor, the quantum approximate optimization algorithm, are one of the most widely used quantum algorithms for solving combinatorial optimization problems. However, as there is yet no rigorous proof of convergence for the QAOA, we provide one in this paper. The proof involves retracing the connection between the quantum adiabatic algorithm and the QAOA, and naturally suggests a refined definition of the ‘phase separator’ and ‘mixer’ keywords.
Enhanced nonlinear optical properties and optical limiting performance of graphene modified polyaniline composite under pulsed laser regime
Authors: Mathew Roshan Joseph , Chandran Arun R , K S Syam Kishor , Kumar K V Arun , Saji K J , Sajeev U S
Published: June 2024

Polyaniline (PANI) and its graphene-doped composite (PANI-GNP) were subjected to open-aperture (OA) z-scan studies to investigate their nonlinear optical (NLO) properties and optical limiting (OL) behavior. The z-scan experiments were carried out using a nanosecond pulsed Nd:YAG laser at a wavelength of 532 nm. The z-scan studies revealed that PANI and PANI-GNP composites exhibited a reverse saturable absorption (RSA), and graphene doping modified the NLO behaviour and improved the OL property. The nonlinear absorption coefficient (β), OL threshold, and imaginary part of nonlinear susceptibility (

χ

i

(
3
)

) of PANI and PANI-GNP were calculated for three different laser input pulse energies and found to be in the order of 10−9 cm W−1, 106 W cm−2, and 10−10 esu, respectively. These results qualify the PANI-GNP composite as having potential applications in OL and optoelectronic devices. The successful incorporation of graphene into PANI in PANI-GNP composite was confirmed by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR). Linear optical properties were analysed using UV–visible absorption spectroscopy. To the best of our knowledge, the present work is the first attempt to explore the intensity-dependent NLO properties, OL behaviour and the calculation of their related NLO parameters of PANI-GNP composites.
Effects of different Ti concentrations doping on Li2MnO3 cathode material for lithium-ion batteries via density functional theory
Authors: Thajitr W , Busayaporn W , Sukkabot W
Published: June 2024

Li2MnO3 is extensively studied for a cathode material in lithium-ion batteries because of its high voltage and specific capacity. Nevertheless, it has the disadvantages due to low conductivity and Li-ion diffusion. To modify its performance, we determine the structure stability and electronic properties of Li2MnO3 cathodes doped with different Ti-ion concentrations using the spin-polarized density functional theory including the Hubbard term (DFT + U). For the calculations, cell parameters, formation energies, band gaps, total density of states, partial density of states and stability voltages are determined. The results highlight that the expansion of the cell volumes by Ti-ion impurities has a positive effect on the diffusion of Li ions in these cathodes. Because of the minor voltage changes, Li2MnO3 cathode doped with a Ti-ion concentration of 0.250 exhibits the highest voltage stability. Overall, these results are effective for the lithium-ion battery application based on Ti-doped Li2MnO3 cathodes.
On a one-dimensional time-fractionally damped wave equation with a singular potential
Authors: Jleli Mohamed , Samet Bessem
Published: June 2024

A nonlinear time-fractionally damped wave equation with an inverse-square potential posed on the interval (0, 1) is investigated. The time-fractionally derivative is considered in the Caputo sense. A weight function of the form x
−σ
(

σ
∈
R

) is allowed in front of the nonlinearity ∣u(t, x)∣
p
(p > 1). The problem is studied under certain initial conditions and a homogeneous boundary condition. Namely, we obtain sufficient conditions under which the considered problem admits no weak solution. The cases u(0, · ) ≡ 0 and u(0, · ) ≢ 0 are studied separately.
Probing the twist angle of confined prominence eruption using SDO/AIA data
Authors: Khaled Safinaz A , Shaltout Abdelrazek M K , Abdelkawy Ali G A , Hassanin A , Semeida Mohamed A , Ghitas Ahmed
Published: June 2024

In this context, we utilized a simplified representation of the curved cylinder flux tube to approximate the helical structure of the prominence. By considering the bright helical features as indicators of the magnetic field, we measured the average twist angle of the prominence legs. To gather the necessary data, we obtained image data with a wavelength of 171 Å from the Solar Dynamic Observatory (SDO)/Advanced Imaging Assembly (AIA) archive. We employed some IDL routines within the SolarSoft (SSW) package to determine the flux rope’s total twist angle for a confined prominence eruption. Specifically, we focus on a confined prominence eruption that occurred at the south-east limb of the Sun for an active region (AR) NOAA (AR 11 117) observed on October 21, 2010. The eruption commenced on 2010-10-21 at 21:56:18 UT and lasted until 2010-10-22 at 01:24:58 UT. During this event, a B2.6 flare class that occurred on 2010-10-21 at 23:17 UT, located at heliographic position of N20E84. Our results indicate that the distance between the two footpoints is up to 18 670 km. Initially, when the event began the height (h) was found to be 21 162.1 km, but the height was increased to reach 80 362.4 km at the end of eruption. The flux rope’s average twist angle (ϕ, in radian) at the beginning of eruption was ϕ = 13.4π. As the prominence ascended to higher levels, the twist angle was decreased gradually due to the magnetic field relaxation reached to ϕ = 3.6π. We determined that the flux ropes average twist angle (ϕ) that exceed the threshold for the helical kink instability. Therefore, we conclude that the eruption was caused by helical kink instability, as a result it is in consistent with other investigations.
Interruption characteristic of 3%C5F10O/97%CO2 gas mixture in a 40.5 kV circuit breaker
Authors: Cui Zhaoxuan , Lin Xin , Xia Yalong , Xu Jianyuan
Published: June 2024

The C5F10O/CO2 gas mixture is one of the most promising SF6 alternative gases at the present stage, which was initially applied in high-voltage electrical equipment. This paper mainly studies the interruption performance of 3%C5F10O/97%CO2 gas mixture (k = 3%) with a charging pressure of 0.6 MPa in high-voltage circuit breakers. First, the thermodynamic parameters, transport coefficient, and net radiation coefficient were calculated for k = 3%. On this basis, a 40.5 kV circuit breaker was used as a prototype to establish the magnetohydrody-namic model for breaking 20 kA short-circuit current, and the arc temperature and pressure distribution in the arc extinguishing chamber of the circuit breaker were calculated. The LC oscillation circuit was used to build an arc-extinguishing characteristic test platform to verify the accuracy of the numerical calculation. Finally, based on the Mayr arc model and the critical electric field strength, the post-arc thermal breakdown and electrical breakdown characteristics of SF6, CO2, and k = 3% were quantitatively analyzed. The results show that under 0.6 MPa, the thermal breakdown performance of k = 3% is about 89.7% of SF6, which is nearly twice higher than that of CO2 and has better thermal breaking ability. The electrical breakdown performance of k = 3% is about 20.4% of SF6, and the probability of electrical breakdown in the front end of the fixed contact is high. This problem should be paid attention to in the design of high-voltage circuit breakers. This study can provide a reference for the development and optimization of environmentally friendly high-voltage circuit breakers.
Effect of non-square potential profile on three subband electron mobility in AlGaAs quantum well structures
Authors: Sahu Ajit Kumar , Sahoo Narayan , Swain Raghunandan , Sahu Trinath
Published: June 2024

This work analyses the effect of the non-square structure potentials, such as V-shaped (V), parabolic (P), cubic (C), semi-V (SV), semi-parabolic (SP), and semi-cubic (SC) on the low temperature electron mobility (μ) as a function of doping concentrations (N

d
= 0.1 to 3.0 × 1018 cm−3) in modulation δ-doped quantum well (QW) structures. We calculate μ by adopting screened ionized impurity (ii-) and alloy disorder (al-) scatterings. We consider higher subband occupancy up to three and show that the intersubband effects influence the screened scattering potentials differently, such that μ

ii
increases while μ

al
decreases, leading to nonlinear enhancement of μ. Further, there are sudden drops in μ, near the transition of occupation of subbands due to the intersubband effects, and the magnitude of the drop is reduced at the third subband occupancy. The number of occupied subbands (nos), for the considered range of N

d
, differs with NSQW structures, e.g., nos = 3 in the case of VQW, CQW, and PQW, nos = 2 in SCQW and SPQW, and nos = 1, in SVQW structures. Interestingly, in VQW, the occupation of the second subband starts at a higher N

d
, compared to CQW and PQW, while, the third subband occupancy shows an opposite trend. Furthermore, the dissimilarity in electron charge distributions in the NSQW structures influences the ii-scattering potential differently, causing μ

ii
(VQW) > μ

ii
(PQW) > μ

ii
(CQW), while for al-scattering the order of μ

al
reverses.
Quantum secure multiparty computing XOR protocol based on single photons and its application in quantum secure communications for intelligence agents
Authors: Li Huijie , Shi Run-Hua , Jia Qianqian
Published: June 2024

In this paper, we consider an interesting and important privacy-preserving issue, i.e., how to implement anonymous and secure communications for several intelligence agents, hiding in n participants. To solve this issue, we first propose a quantum Secure Multiparty Computing XOR (SMC_XOR) protocol based on single photons, which can guarantee the unconditional security of the protocol. By implementing rotation encryption, the practicality of quantum SMC_XOR protocol can be significantly improved without other complex quantum techniques. Security analysis shows that the proposed protocol can resist various types of attacks. Furthermore, a special network model is designed to solve this issue, using hash function to verify the identity of the communication parties and key recycling to reduce resource consumption. Finally, the proposed quantum SMC_XOR protocol is simulated in IBM Qiskit, and the simulation results show that the protocol is correct and feasible.
Dielectric terahertz metasurface governed by symmetry-protected BIC for ultrasensitive sensing
Authors: Yan Hui , Fan Wen-Hui , Jiang Xiao-Qiang , Chen Xu , Qin Chong , Wu Qi
Published: June 2024

The non-radiative bound states in the continuum (BIC) have attracted much attention in achieving theoretically infinite quality (Q) factor. In this paper, a dielectric terahertz metasurface with C
4v symmetry is proposed, and a toroidal dipole resonance is easily obtained under incident plane wave. Moreover, by slightly tuning the asymmetry parameter δ to break the in-plane symmetry of the structure (side length perturbation), a magnetic dipole BIC mode radiates as quasi-BIC (QBIC) with extremely narrow linewidth and ultrahigh Q of 1.2 × 104 at δ = 0.4 μm. It shows significant performance in THz sensing with the sensitivity around 446 GHz/RIU and figure of merit (FoM) up to 2267. The designed metasurface in the case of symmetry-breaking by position perturbation also achieves ultrasensitive sensing. Additionally, the effects of geometric parameters on the resonance modes have been comprehensively investigated. Our work provides a route to design symmetry-protected BIC metasurface with simple structure, and the Q factor as well as resonant frequency can be controlled using a single geometric parameter, which may facilitate designing high-performance metasurface in sensing applications.
Investigation of pressure-driven superconductivity in TlInTe2: an ab initio study
Authors: Renskers Christopher , Margine Elena R
Published: June 2024

The Zintl compound TlInTe2 is an intriguing material because of its outstanding thermoelectric properties at ambient pressure. Interestingly, it has recently been found that TlInTe2 exhibits a V-shape dependence of the superconducting critical temperature (T
c) under increasing pressure, which has been linked to the reversed behavior of the Raman active Ag phonon mode and anharmonic effects. In this study, we have performed first-principles calculations of the electron-phonon interactions and the superconducting properties of TlInTe2 in order to understand this unusual pressure-induced response. In contrast to experiment, we find a dome-shaped pressure-induced dependence of T

c
with a maximum value of 0.23 K at 18 GPa, significantly lower than the experimental results. Electron doping has the potential to adjust the T
c to fall within the experimental range, but it necessitates considerably high levels of doping. Furthermore, our analysis of the phonon spectra and phonon lifetimes, including anharmonic effects, show that anharmonicity is unlikely to influence the superconducting properties of TlInTe2. It remains an open question whether there is indeed an unusual V-shape T
c dependence with pressure or whether the phonon-mediated theory of superconductivity used here breaks down in this system.
Light management in hole transport layer-free perovskite solar cell by SPP and LSPR
Authors: Batoo Khalid Mujasam , Ibrahim Ahmed Ahmed , Naeem Youssef Ali , Abdulameer Maha Khalid , Zazoum Bouchaib , Khuder Shahad Abdulhadi , Ward Zahraa Hassan , F Ramadan Montather , Al-Tameemi Ahmed Read , Hasan Kadhum Eftikhaar , Alzubaidi Laith H
Published: June 2024

In recent years, light management based on localized surface plasmon resonance (LSPR) effects in perovskite solar cells (PSCs) has received significant attention. However, the use of surface plasmon polariton (SPP) excitations in PSCs has been less studied. Meanwhile, hole transport layer-free perovskite solar cells (HTL-free PSCs) have garnered interest due to their lower cost. In this study, we improve light absorption in HTL-free PSCs by simultaneously utilizing LSPR and SPP effects. Au nanotriangles are employed on the surface of the back electrode to excite SPPs. The thickness of the perovskite layer is varied from 100 nm to 400 nm. The optimal periodicity and dimensions of the triangular nanoparticles are determined for each perovskite layer thickness. In the optimal structures with perovskite layer thicknesses of 100 nm, 200 nm, 300 nm, and 400 nm, absorption enhancements of 25%, 12.4%, 13%, and 4.3% are achieved, respectively. The interaction of light with SPP and LSP modes leads to improved solar cell performance. Furthermore, the short circuit current density (JSC) in structures with layer thicknesses of 100 nm and 200 nm increased from 16.7 mA cm−2 to 20.71 mA cm−2 and from 19.8 mA cm−2 to 21.86 mA cm−2, respectively. Other photovoltaic characteristics of the solar cell were obtained through optical-electrical numerical analysis. For the improved solar cell with a perovskite thickness of 100 nm, the values of open circuit voltage, efficiency, and fill factor were 0.847 V, 0.81, and 14.24%, respectively, representing increases of 1.1%, 2.4%, and 28.7% compared to the bare device. Additionally, in the solar cell with a thickness of 200 nm, an efficiency of 17.03% was achieved, showing a 12.5% improvement compared to the bare structure. Our research results facilitate the design of high-performance, ultra-thin, semi-transparent solar cells.
The shot noise in quasi-one-dimensional single spin filter magnetic heterojunctions
Authors: Lü Hou-Xiang , Fang Tian-Hai , Xie Zheng-Wei , Tang Ming-Jun
Published: June 2024

Based on the free electronic model and Büttike’s theory on shot noise, we investigated the shot noise of spin electrons in ferromagnetic/non-ferromagnetic insulator/spin filter layer/normal metal (FM/I/SF/NM) quasi-one-dimensional single spin filter tunneling junctions. The calculation results show that the barrier heights and thicknesses of the insulator and spin filter layers strongly affect the values and phases of the Fano factors of spin electrons. Compared with the traditional sandwich structures of ferromagnetic/spin filter layer/normal metal (FM/SF/NM) and ferromagnetic/non-ferromagnetic insulator/normal metal (FM/I/NM), when the thicknesses of the insulator and spin filter layers are very small, in single spin filter magnetic heterojunctions (FM/I/SF/NM), the insulator layer can suppress the Fano factors, while the spin filter layer is easier to separate the Fano factors of electrons whose spin directions are different. Further analysis shows that whether the Rashba coupling in the spin filter layer has an obvious influence on the Fano factors of spin electrons depends on the thickness of the spin filter layer. On the other hand, the Fano factors are strongly dependent on the sizes and directions of the molecular fields of the ferromagnet and spin filter layers. In addition, the electrons are incident with low energy or high energy, and the barrier heights and thicknesses of the spin filter layer and the thicknesses of the insulation layer have a significant effect on the spin-direction-dependent Fano factors of electrons.
Exploring the NANOGrav signal and planet-mass primordial black holes through Higgs inflation
Authors: Yi Zhu , You Zhi-Qiang , Wu You , Chen Zu-Cheng , Liu Lang
Published: June 2024

The data recently released by the North American Nanohertz Observatory for Gravitational
Waves (NANOGrav) provides compelling evidence supporting the existence of a stochastic signal that
aligns with a gravitational-wave background. We show that the scalar-induced gravitational waves
from the Higgs inflation model with the parametric amplification mechanism can explain this
signal. Such a gravitational-wave background naturally predicts the substantial existence of
planet-mass primordial black holes, which can be planet 9 in our solar system and the lensing
objects for the ultrashort-timescale microlensing events observed by the Optical Gravitational
Lensing Experiment. Therefore, the NANOGrav signal, the potential Planet 9 in our solar system,
and the Optical Gravitational Lensing Experiment can be explained within the framework of Higgs
inflation.
Density dependent displaced vertex signatures as a novel probe of light dark sector scalars at the LHC
Authors: Argyropoulos Spyros , Burrage Clare , Englert Christoph
Published: June 2024

Dynamical theories of dark energy predict new degrees of freedom with particular environmental sensitivity to avoid constraints on fifth forces. We show that the similar, yet complementary multi-purpose detector setup of the ATLAS
and CMS experiments provides a unique opportunity to place sensitivity on such scenarios in a narrow, yet relevant parameter range. Furthermore, our investigation gives rise to a novel phenomenological signature that the LHC experiments
can pursue to exploit their complementary detector design from a BSM perspective.
Suggestions of decreasing dark energy from supernova and BAO data
Authors: Raamsdonk Mark Van , Waddell Chris
Published: June 2024

The potential energy from a time-dependent scalar field provides a possible explanation for the observed cosmic acceleration. In this paper, we investigate how data from supernova and bary acoustic oscillation surveys constrain the possible evolution of a single scalar field over the period of time (roughly half the age of the universe) for which these data are available. Taking a linear approximation to the scalar potential V(ϕ) = V
0 + V
1
ϕ around the present value, a likelihood analysis appears to significantly prefer models with a decreasing potential energy at present, with approximately 99.99 % of the exp(-χ
2/2) distribution having V
1 > 0 in a convention where ϕ̇ ≤ 0 at present. The models favoured by the distribution typically have an order one decrease 〈|Range[V(ϕ(t))]/V(t
0)|〉 ≈ 0.36 in the scalar potential energy over the time frame corresponding to z < 2. According to the likelihood analysis, the ΛCDM model with no variation in dark energy appears to be significantly disfavoured in the context of the linear potential model, but this should be interpreted cautiously since model selection criteria that make use of Δχ
2 while ignoring parameter space volumes still favour ΛCDM. Working with a second order approximation to the potential, the supernova data can be fit well for a wide range of possible potentials, including models where the universe has already stopped accelerating.
Influence of electron–phonon interaction on linear and nonlinear magneto-optical absorption properties in monolayer transition metal dichalcogenides
Authors: Bich Tran N , Dinh Le , Phuc Huynh V
Published: June 2024

In this study, we investigate the linear and non-linear magneto-optical properties of TMDC monolayer semiconductors MX2 (M = Mo/W, X = S/Se) in a perpendicular magnetic field by evaluating the magneto-optical absorption coefficients (MOACs) and the refractive index changes (RICs) subject to the influence of electron–phonon interaction (EPI). Our results are achieved by considering the influence of electron couplings with acoustic (AC) and optical (OP) phonons via the absorption (AB) and emission (EM) mechanisms. When compared to the neglected EPI case, the intensity of the linear MOAC and RIC increases about 2.6–4 times and 5.3–10.5 times, respectively. The absorption peaks exhibit the blue-shifts, with the largest blue-shift observed for the OP-EM phonon scatterings, followed by the AC phonons and the smallest for the OP-AB phonon scatterings. Meanwhile, the greatest contribution to MOAC and RIC comes from the OP-AB phonons, which is followed by that of the AC phonons and the OP-EM phonons, respectively. The MoX2 group is more significantly affected by the scattering mechanism compared to the WX2 one. Although the OP-EM phonons contribution for the MoX2 group is much smaller than that of the other two interaction mechanisms, it nevertheless produces a very noticeable blue-shift. Meanwhile, for the WX2 group, all three mechanisms erect comparable results. The biggest (smallest) value of the linear MOAC and RIC are both founded in MoSe2 (MoS2). Notably, the absolute values of the non-linear MOAC and RIC terms increase by tens to hundreds of times, leading to the total MOAC terms being negative, contrary to when EPI is not taken into account, while the characteristics of the non-linear RIC curves also undergo considerable changes. Among the four TMDC materials, MoX2 is more significantly affected by the EPI effect than WX2.
Cauchy matrix approach for H1
a
equation in the torqued Adler–Bobenko–Suris lattice list
Authors: Wang Jing , Zhao Song-lin , Shen Shoufeng
Published: June 2024

As a torqued version of the lattice potential Korteweg–de Vries equation, the H1
a
is an integrable nonsymmetric lattice equation with only one spacing parameter. In this paper, we present the Cauchy matrix scheme for this equation. Soliton solutions, Jordan-block solutions and soliton-Jordan-block mixed solutions are constructed by solving the determining equation set. All the obtained solutions have jumping property between constant values for fixed n and demonstrate periodic structure.
Lewis acid-doped transition metal dichalcogenides for ultraviolet–visible photodetectors
Authors: Yang 杨 Heng 恒 , Ma 马 Mingjun 明军 , Pei 裴 Yongfeng 永峰 , Kang 康 Yufan 雨凡 , Yan 延 Jialu 嘉璐 , He 贺 Dong 栋 , Jiang 蒋 Changzhong 昌忠 , Li 李 Wenqing 文庆 , Xiao 肖 Xiangheng 湘衡
Published: June 2024

Ultraviolet photodetectors (UV PDs) are widely used in civilian, scientific, and military fields due to their high sensitivity and low false alarm rates. We present a temperature-dependent Lewis acid p-type doping method for transition metal dichalcogenides (TMDs), which can effectively be used to extend the optical response range. The p-type doping based on surface charge transfer involves the chemical adsorption of the Lewis acid SnCl4 as a light absorption layer on the surface of WS2, significantly enhancing its UV photodetection performance. Under 365 nm laser irradiation, WS2 PDs exhibit response speed of 24 ms/20 ms, responsivity of 660 mA/W, detectivity of 3.3 × 1011 Jones, and external quantum efficiency of 226%. Moreover, we successfully apply this doping method to other TMDs materials (such as MoS2, MoSe2, and WSe2) and fabricate WS2 lateral p–n heterojunction PDs.
Preparation and performance study of polyurethane/ kaolinite nanocomposite insulation materials
Authors: Dai Jun , Tang Peiduo , Wu Zhiding , Chen Bin
Published: June 2024

Polyurethane foam insulation materials exhibit excellent noise reduction, shock absorption and vibration damping capabilities while being cost-effective and easily moldable. They have found widespread applications in diverse fields such as automotive, machinery, packaging, insulation, healthcare and construction. However, the application range of this traditional organic material is limited by issues related to thermal stability and flame retardancy. By achieving uniform dispersion of nanoparticles, composite materials exhibit enhanced comprehensive properties in terms of flame retardancy, oxidation resistance, physicochemical stability and structural performance. Polyurethane/Kaolinite nanocomposite insulation materials were prepared by using the in situ intercalation compounding method. X-ray diffractometer, Fourier infrared spectrophotometer, thermogravimetric analyzer and scanning electron microscope were used to characterize the thermal stability of the composite material obtained under different preparation conditions and the state of the nanomaterial in the system. The results showed that the composite material with good dispersion of kaolinite in the matrix was obtained by effective surface modification through dimethyl sulfoxide. The doping of low-concentration kaolinite can improve the thermal stability of polyurethane. When the mass fraction of nano-kaolinite is 5%, the initial decomposition temperature of the composite system is 47°C higher than that of pure polyurethane and the system achieves the highest thermal stability.
Comparative analysis of experimental and simulation results of composite circular tube
Authors: Qin Yuhang , Zhang Yu , Fan Zhaoyang , Zheng Jian , Xiong Chao
Published: June 2024

In this work, the internal pressure of the composite pipe is analysed and studied when transporting liquid or gas. The quasi-static hydraulic test is designed to simulate the internal pressure of the composite pipe. By using the ABAQUS finite element method, a numerical model of the composite pipe under hydraulic load is established. The strain curves and final failure modes of the test and simulation are compared to verify the feasibility of the finite element method model. Finally, the damage mechanism of the composite tube is analysed according to the numerical model, and it is found that the carbon fibre composite material has an important effect on the bearing capacity of the composite tube.
Effect of coal tar pitch as carbon source on the electrochemical performance of silicon-carbon composites
Authors: Wang Ning , Zhang Wei , Feng Zongyu , Zhang Jianhua , Zhang Xiaobao , Yang Juanyu
Published: June 2024

Silicon-carbon composites (SCCs) represent a pivotal class of silicon-based negative electrode materials, exhibiting immense potential for commercial applications. The inclusion of carbon serves to restrict the expansion of silicon and establishes a reliable conductive framework. Pitch, as a carbonaceous precursor, can be utilized for the preparation of SCC exhibiting exceptional electrochemical performance. However, the structural and compositional variations in the carbon pyrolyzed from the pitch with varying softening points result in distinct impacts on the electrochemical properties of SCC, particularly their cycle performance. The coal tar pitch (CTP) with softening points of 80°C and 250°C was selected for synthesizing SCC in this research. The impact of utilizing CTP as a carbon source on the electrochemical performance of SCC and its accompanying structural modifications during cycling were investigated. The pyrolytic carbon with an enhanced graphitization level could be obtained from the CTP and exhibited a softening point of 250°C. The SCC prepared using this CTP revealed superior structural stability and electrochemical performance, with a specific capacity of 1413.4 mAh/g and a capacity retention rate of 76.70% after 100 cycles. The CTP with a softening point of 250°C was further combined with silicon and graphite composites and used as negative electrode materials. The initial reversible specific capacity of 546.1 mAh/g was demonstrated, and it maintained 93.53% of its capacity after 200 cycles. The CTP with a softening point of 250°C can be chosen for the preparation of SCC, ensuring excellent structural stability and electrochemical performance.
In-situ growth of MoSe2 on N-doped Ti3C2Tx for electrocatalytic hydrogen evolution in alkaline media
Authors: Zhou Xingliao , Liu Jinhua , Chen Jing
Published: June 2024

Serious environmental contamination and the energy crisis have heightened public desire for new renewable energy sources. Because of its high energy content and non-polluting qualities, hydrogen energy has emerged as a viable alternative to fossil fuels. Currently, high-purity hydrogen is typically produced through water electrolysis. The sensible use of electrocatalysts in this process can significantly minimize power usage in the electrolysis of water, which is of great significance to industrial production. However, the electrocatalyst that is inexpensive, has abundant reserves and performs well has yet to be discovered, severely restricting the promotion and application of hydrogen energy. In this paper, a MoSe2/N-doped Ti3C2TX heterostructure with notable electrocatalytic hydrogen evolution activity in an alkaline environment was fabricated via nitrogen doping and in-situ growth of molybdenum selenide. When the current density is 10 mA·cm-2, its overpotential and Tafel slope are 321.87 mV and 139.97 mV·dec-1, respectively. This work serves as a valuable experimental reference for the development of non-noble metal electrocatalysts based on two-dimensional materials.
Study of chemically deposited magnetic materials of NiTi memory alloys and their magnetothermal properties
Authors: Zhang Yanhui , Cui Yaning
Published: June 2024

NiTi alloy has good mechanical properties and biocompatibility, as well as unique shape memory properties. Therefore, it is commonly used to make metal stents in clinical practice. In this study, the substrate used is a NiTi memory alloy, which has been coated with CoNiFeP magnetic material through an electroless plating. The morphology, composition, and magnetic properties of the coating were analyzed using SEM, XRD, and VSM. The magneto-thermal properties were studied by high-frequency alternating magnetic field (AMF) induction equipment. The results showed that after determining a reasonable plating application process, the prepared coatings had certain soft magnetic properties and could exceed 43°C in a short time at different field intensities (Happl×fappl=M×109 Aꞏm−1ꞏs−1, M=1.0, 2.0, 3.0, 4.0, and 5.0) to reach the temperature required for tumor ablation, which can be used to prepare magnetic scaffolds for magnetothermal therapy.
Experimental study of synthesis of N-2-Hydroxypropyltrimethylammonium chloride chitosan and carboxymethyl chitosan nanoparticles by ultrasonic microreactor
Authors: Qu Chang , Zhao Xiuzheng , Jin Zheng , Zhao Kai
Published: June 2024

To overcome the technical limitations of current batch reactors for synthesizing N-2-HACC/CMCS NPs, an ultrasonic microreactor was designed and fabricated to continuously prepare N-2-HACC/CMCS NPs, which were characterized by SEM, laser particle sizing instrument, and FTIR. The findings indicate that the granular size of the NPs can be precisely regulated by changing the conditions of reaction temperature, ultrasonic power, reactant flux ratio, and reactant concentration. Compared with the batch reactor, ultrasonic microreactors can continuously prepare NPs with smaller and more uniform particle sizes.
Enhancing anticorrosive properties of low-zinc composite epoxy coatings with graphene
Authors: Pan Kai , Lin Yijun , Xi Zhiwei , Wang Lijie , Huang Chunfang , Zhang Guangzhao
Published: June 2024

Traditional zinc-rich coatings face challenges such as high zinc powder content, brittle film formation, poor adhesion, high porosity, and low zinc powder utilization. In this study, graphene was introduced into an epoxy coating with a 30% zinc powder content to develop a graphene-modified low-zinc coating with exceptional corrosion resistance and mechanical properties. The primary objective was to determine the optimal graphene addition for enhanced corrosion resistance and mechanical performance. Characterization of the coating included assessing pull-off adhesion, flexibility, impact resistance, saltwater resistance, and resistance to acids and alkalis. Concurrently, the corrosion resistance of coatings was thoroughly examined through electrochemical testing and salt spray experiments. Our findings indicate that the coating demonstrated optimal overall performance with a graphene content of 1%, achieving superior corrosion resistance as well as enhanced physical and mechanical properties.
Study on seawater corrosion resistance of copper alloy
Authors: Gong Kaifei , Zheng Chuanbo , Zhang Dongwei , Lv Tianyi , Ju Xiang
Published: June 2024

The Marine environment is a very complex and corrosive environment. Marine corrosion environment can be generally divided into Marine atmospheric environment and seawater environment. Because the seawater is rich in a variety of free ions mixed with corrosive media, the main component is sodium chloride, in addition to containing magnesium, potassium, iodine, bromine, and other elements of salt, which has strong corrosion to metal materials, if serious, it will cause safety accidents. Therefore, ensuring the effectiveness of the anticorrosion system is very important for the safe and reliable operation of the offshore platform. pulse plating is used and the metal nickel coating and metal nickel-chromium coating are prepared to analyze the microstructure and corrosion resistance of each film layer. From the macroscopic, it can be found that three coatings have more or less corrosion phenomenon, there is obviously no nickel-chromium and nickel layer on the surface of nickel-chromium corrosion defects, and through scanning electron microscopic observation, microscopic level nickel chromium corrosion after corrosion phenomenon is the least of three layers, which suggests that nickel chromium seawater corrosion resistance is strong. The three layers are then electrochemical corroded to study the corrosion resistance of the three layers. The results show that the corrosion resistance of the nickel-plated layer, nickel-chromium coating, and nickel-iron chromium coating prepared in the copper substrate is improved successively, which shows the influence of different membrane elements on the corrosion resistance of copper substrate against seawater medium. Although the composition parameters of the various membrane layers vary, they experience the same corrosion mechanism-pitting; Nickel chromium and chromium, iron and other atoms are present in the nickel matrix in the form of solid solution and finally form the solid solution alloy coating. For nickel-chromium coating, the content of iron and chromium in the surface layer has a certain influence on the corrosion resistance of the metal coating. The electrochemical parameters of nickel plating are studied separately, and the comparison with the nickel-chromium alloy coating and the coating is conducted. The equivalent circuit is fitted and determines the largest impedance value and the largest phase Angle among the three membrane layers, which finally has the strongest seawater corrosion resistance.
A comparison of three modification methods for polyvinylidene fluoride membrane grafting
Authors: Jiang Qin , Xu Luo-peng , Zhou Ning , Nie Mingyu , Chen Xin , Fan Tao , Lu Ziling , Mao Xin , Liang Zhenyu
Published: June 2024

UV-induced covalent bonding, UV-benzophenone (BP) embedding, and ozone-activated grafting methods were respectively used to graft 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) on polyvinylidene fluoride (PVDF) hollow fiber membrane surfaces via orthogonal test. The rejection rate, permeating flux, and pure water flux were chosen as comprehensive evaluation indexes to optimize the modification conditions. The optimal experimental conditions for UV-induced covalent bonding, UV-BP embedding, and ozone-activated grafting methods were obtained. Subsequently, three membranes were prepared by these three methods under their optimal modification conditions to compare their properties. The PVDF-g-AMPS-2 membrane obtained by the UV-BP embedding method exhibited the highest hydrophilicity and lipophobicity, and its water and underwater oil contact angles were respectively 66.0° and 146.6°. Besides, The PVDF-g-AMPS-2 membrane can resist the adhesion of oil with the underwater oil adhesion force of zero. What’s more, the PVDF-g-AMPS-2 membrane possessed the largest pure water flux (544.5 L/(m2·h·bar)), permeation flux (66.5 L/(m2·h·bar)), and recovered flux (205.7 L/(m2·h·bar)). By comparison, UV-BP embedding with simpler procedures can fabricate the AMPS modified PVDF membrane with superior performance, which has better application prospects in industrial scale-up production.
Giant asymmetric proximity-induced spin–orbit coupling in twisted graphene/SnTe heterostructure
Authors: Milivojević Marko , Gmitra Martin , Kurpas Marcin , Štich Ivan , Fabian Jaroslav
Published: June 2024

We analyze the spin–orbit coupling effects in a 3∘-degree twisted bilayer heterostructure made of graphene and an in-plane ferroelectric SnTe, with the goal of transferring the spin–orbit coupling from SnTe to graphene, via the proximity effect. Our results indicate that the point-symmetry breaking due to the incompatible mutual symmetry of the twisted monolayers and a strong hybridization has a massive impact on the spin splitting in graphene close to the Dirac point, with the spin splitting values greater than 20 meV. The band structure and spin expectation values of graphene close to the Dirac point can be described using a symmetry-free model, triggering different types of interaction with respect to the threefold symmetric graphene/transition-metal dichalcogenide heterostructure. We show that the strong hybridization of the Dirac cone’s right movers with the SnTe band gives rise to a large asymmetric spin splitting in the momentum space. Furthermore, we discover that the ferroelectricity-induced Rashba spin–orbit coupling in graphene is the dominant contribution to the overall Rashba field, with the effective in-plane electric field that is almost aligned with the (in-plane) ferroelectricity direction of the SnTe monolayer. We also predict an anisotropy of the in-plane spin relaxation rates. Our results demonstrate that the group-IV monochalcogenides MX (M = Sn, Ge; X = S, Se, Te) are a viable alternative to transition-metal dichalcogenides for inducing strong spin–orbit coupling in graphene.
A superhydrophobic/photothermal synergistic anti-icing mesh with active/passive anti-icing function
Authors: Cao Zhanguo , Gong Zeweiyi , Ma Xianlong , Peng Jing , Xiong Yanmei , Nie Yongjie , Duan Yuting , Li Hao , Zhou Shuai , Rao Tong , Chen Qizhi , Wang Peng
Published: June 2024

The ice covering of transmission lines tends to cause flashover along the surface, and even topple the tower in serious cases, which seriously threatens the safe operation of the power grid. Here, a dual active and passive anti-icing strategy was designed. The active deicing was achieved by photothermal effect, and passive anti-icing was based on superhydrophobicity. On the one hand, the semi-embedded candle ash gives the surface excellent photothermal characteristics, which can quickly melt the ice through sunlight; On the other hand, the superhydrophobic coating based on candle ash demonstrates excellent passive anti-icing performance, which reduces ice adhesion as small as 3.0 kPa and delayed freezing time as long as 1096 s. Furthermore, the semi-embedded structure enables the superhydrophobic coating excellent anti-abrasion ability and outstanding self-cleaning property. This combination of active and passive anti-icing strategies provides a reference for the current anti-icing and deicing methods of transmission lines.
Influence of scanning speed on microstructures and mechanical properties of SLM produced Hastelloy X: as-built and solution-treated
Authors: Li Sai , Zhang Yunlong , Wang Yasong , Liu Ji , Cheng Liang , Wang Yajun , Bai Jie , Ma Rui
Published: June 2024

Hastelloy X (HX) alloys with ideal strength and ductility match can be obtained by selective laser melting (SLM) and a proper follow-up heat treatment. This work studies the influence of scanning speed on grain size, grain boundary distribution, recrystallization and mechanical properties of as-built HX. These influences are reevaluated after a solution treatment at 1175 °C for 4h. The results reveal that the average grain size decreases, while the aspect ratio, texture intensity and the proportion of high-angle grain boundaries (HAGBs) increases with the increase of scanning speed. A small amount of recrystallization has occurred in the as-built alloys due to the cyclic thermal effect of SLM scanning. The finer grains and larger aspect ratio imply the higher energy storage during SLM, which will increase the recrystallizing nucleation rate. Solution treatment eliminates the fiber texture of 〈100〉//BD, significantly increases the HAGBs fraction and recrystallization fraction, reduces the grain aspect ratio, and coarsens the grains. With the increase of scanning speed, the strength of the Hastelloy X increases and the elongation decreases. The decrease of grain size is the main reason for the increase of yield strength.