bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation and properties of graphite-based “light–heat–electricity” conversion materials
Authors: Duan Shengzhi , Meng Kaiyue , Wu Xiaowen , Yang Mengyao , Zhong Min , Ao Weihua , Yao Yanbin , Fang Minghao , Huang Zhaohui
Published: December 2024

As a traditional carbon material, natural graphite has excellent electrical properties and huge reserves, making it a potential candidate for thermoelectric materials. By doping Fe, p-type graphite-based thermoelectric materials were prepared. By conjugating with polyethylenimine, the stable n-type graphite-based thermoelectric material was prepared. A thermoelectric device composed of four pairs of p-n graphite units was fabricated by casting process. Under indoor conditions at 305 K, the device was heated by a 333 K heating plate, generating a voltage of 6 mV and a current of 1 nA. The surface temperature of the device rises from room temperature to 333 K in just 1 min under natural light irradiation of 1500 W, producing an output voltage of 4 mV. Additionally, flexible devices can be drawn by using a graphite slurry, and a flexible device composed of four pairs of p-n units can generate a temperature difference of 1.3 K and a voltage of 0.67 mV when curled around a finger.
Unusual salt effects on the time-dependent behavior of charge and shape anisotropic hectorite clay gels: Role of electric double layer (EDL) repulsive force
Authors: Leong Yee-Kwong , Clode Peta
Published: December 2024

Salt strengthened the bond formed and quickened the bonding process of 3–5 wt. % hectorite gels during the structural rejuvenation process. This even occurred at 0.002M KCl. Microstructure showed exfoliated, flexible platelet bonding in (+)edge–(−)face configurations. The display of prominent aging time-dependent behavior is due to the structural rejuvenation process being controlled by the electric double layer (EDL) repulsive force. Salt increased the lower energy paths to bonding in the (+)edge–(−)face configurations and weakened the EDL force to form stronger bonds. The Leong model time constant data supported the faster bonding process. In shear, the gels with a weakened EDL repulsive force caused by 0.01 and 0.1M KCl treatment were unable to display EDL force-control time-dependent behavior in the stepdown shear stress response. This situation was remedied by increasing the negative charge density of platelets with adsorbed P2O74−. The amount of P2O74− needed was higher at 0.1M KCl.
Noncollinear polar magnet Fe2(SeO3)3(H2O)3 with inequivalent Fe3+ sites
Authors: Oyeka Ebube E. , Huai Xudong , Marshall Madalynn , Winiarski Michał J. , Błachowski Artur , Cao Huibo , Tran Thao T.
Published: December 2024

The emergence of novel magnetic states becomes more likely when the inversion symmetry of the crystal field, relative to the center between two spins, is broken. We propose that placing magnetic spins in inequivalent sites in a polar lattice can promote a realization of nontrivial magnetic states and associated magnetic properties. To test our hypothesis, we study Fe2(SeO3)(H2O)3 as a model system that displays two distinct Fe(1) and Fe(2) magnetic sites in a polar structure (R3c space group). At low fields μ0H≤ 0.06 T, the material undergoes an antiferromagnetic ordering with TN1 = 77 K and a second transition at TN2≈ 4 K. At μ0H≥ 0.06 T and 74 K ≤T≤ 76 K, a positive entropy change of ∼0.12 mJ mol−1 K−1 can be associated with a metamagnetic transition to possibly nontrivial spin states. At zero field, Fe(1) is nearly fully ordered at T≈ 25 K, while Fe(2) features magnetic frustration down to T = 4 K. The magnetic ground state, a result corroborated by single-crystal neutron diffraction and 57Fe Mössbauer spectroscopy, is a noncollinear antiparallel arrangement of ferrimagnetic Fe(1)–Fe(2) dimers along the c-axis. The results demonstrate that placing distinct magnetic sites in a polar crystal lattice can enable a new pathway to modifying spin, orbital, and lattice degrees of freedom for unconventional magnetism.
Cavitation onset in an impulsively accelerated liquid column
Authors: Sobral T. , Kokkalis J. , Romann K. , Nedić J. , Higgins A. J.
Published: December 2024

This paper introduces a novel piston-driven apparatus to study the onset of cavitation in an impulsively accelerated liquid column as it compresses a closed gas volume. The experiment is monitored using high-speed videography and piezoelectric pressure transducers. Cavitation onset is observed in the liquid column as it undergoes an abrupt deceleration and is associated with a sudden drop in pressure in the liquid that leads to negative pressure (tension). A novel numerical modeling approach is introduced where the liquid column is treated as a spring-mass system. This approach can reproduce compressibility effects in the liquid column and is used to investigate the wave dynamics responsible for the onset of tension and cavitation in the liquid column. The model is formulated as a coupled set of non-linear differential equations that reproduce the dynamics of an experiment while capturing the pressure wave activity in the liquid column. A parametric study is conducted experimentally and numerically to investigate the behavior behind the onset of cavitation. The mechanism for the onset of cavitation is identified as a series of wave reflections at the boundaries of the liquid column, and this mechanism is found to be well reproduced by the model. While a traditional cavitation number criterion is shown to be unable to predict cavitation onset in our experiment, our numerical model is found to correctly predict the onset of cavitation for a wide range of experimental parameters.
Well location layout of surface drilling for gas extraction in an abandoned gob
Authors: Wang Chenlin , Shen Haoran , Sun Lihui , Li Meng
Published: December 2024

The gob is formed by large-scale voids left after the completion of underground coal mining. A large amount of desorbed gas still remains in the gob. Surface drilling is used to extract gas from abandoned coal mines. The location of surface drilling in abandoned gobs is the key to ensure efficient gas extraction. In this paper, an abandoned gob is divided into the start mining area, the middle area, and the end mining area based on the result of physical similarity simulation experiment. The distribution characteristics of methane concentration in the abandoned gob under the surface drilling extraction are calculated by using the numerical simulation software Ansys. The gas extraction effect in the start mining area, the middle area, and the end mining area is compared. Results show that the methane control range by extraction pipe presents different characteristics along the X-, Y-, and Z-axes of the abandoned gob. When Z = 55 m, the methane control range by extraction pipe reaches the maximum. When Y = 40 m and 60 m, the methane control range by extraction pipe reaches the maximum. In the start and end mining areas, the methane control range by extraction pipe reaches the maximum when X = 70 m and 30 m, respectively. In the middle area, the methane control range by extraction pipe reaches the maximum when X = 100 m and 150 m. The gas extraction effect is the best in the end mining area, followed by the start mining area and finally the middle area. The preferred location of surface drilling is the end mining area of the abandoned gob. The research results provide theoretical basis for gas extraction in abandoned coal mines.
The social leverage effect: Institutions transform weak reputation effects into strong incentives for cooperation
Authors: Lie-Panis Julien , Fitouchi Léo , Baumard Nicolas , André Jean-Baptiste
Published: December 2024

Institutions allow cooperation to persist when reciprocity and reputation provide insufficient incentives. Yet how they do so remains unclear, especially given that institutions are themselves a form of cooperation. To solve this puzzle, we develop a mathematical model of reputation-based cooperation in which two social dilemmas are nested within one another. The first dilemma, characterized by high individual costs or insufficient monitoring, cannot be solved by reputation alone. The second dilemma, an institutional collective action, involves individuals contributing to change the parameters of the first dilemma in a way that incentivizes cooperation. Our model demonstrates that this nested architecture creates a leverage effect. While insufficient on its own to incentivize cooperation in the first dilemma, reputation incentivizes contributions to the institutional collective action, which, in turn, strengthen the initially weak incentives for cooperation in the first dilemma. Just as a pulley system transforms minimal muscular strength into significant lifting capability, institutions act as cooperative pulleys, transforming initially weak reputational incentives into powerful drivers of cooperative behavior. Based on these results, we suggest that institutions have developed as social technologies, designed by humans to exploit this social leverage effect, just as material technologies are designed to exploit physical laws.
Acoustic experimental study on the tone sandhi of the Jino language
Authors: Xiaoyu Zhou
Published: December 2024

This paper combines field investigation and phonetic experiments to study the monosyllabic tone and tone sandhi of
the Jino language as spoken in Baka village. The study found that the phenomenon of tone sandhi in bisyllabic words of Jino
language has describable rules: from a diachronic perspective, morphemes with the same historical origin exhibit the same tone
alternation characteristics when constructing words, while morphemes with different historical origins exhibit different tone
alternation characteristics. Morphemes derived from the *Proto-Lolo Tone 1 reorganize the metrical relationship between morphemes
in word construction, resulting in unstressed and stressed tones. From the perspective of synchronic phonological analysis, the
obligatory contour principle restricts the occurrence of tones in bisyllabic words. In addition, this paper also proposes some new
views on the historical development of tones in Jino language from an empirical perspective.
Crowdsourcing Platforms for Ukrainian Refugees: Meaning Making in Infrastructures of Problem-Solving
Authors: Cheregi Bianca-Florentina , Ciocea Mălina
Published: December 2024

This study focuses on crowdsourcing platforms developed by the Romanian government and civil society for the support of Ukrainian refugees to gain an understanding of the symbolic battles, contested problematizations, and discourses about Ukrainian refugees in the Romanian public sphere. We take these crowdsourcing platforms as dispositives that have a strategic function. They are both infrastructures of problem-solving and discursive fields constituted around the public problem of refugees. Our methodological approach, derived from a semiotic perspective on dispositive analysis, explores how meaning is built on crowdsourcing platforms and what strategies are employed to mobilize the public toward politically significant action. We construct a typology of crowdsourcing initiatives and identify two distinct categories of actors that gain visibility in the public arena: crowdsourcing professionals and aid entrepreneurs. Overall, our analysis highlights that actors employ a variety of semiotic resources and strategies to educate the public and get them involved in humanitarian action.
Picometer sensitive prototype of the optical truss interferometer for LISA
Authors: Jersey Kylan , Hollis Harold , Chia Han-Yu , Sanjuan Jose , Fulda Paul , Mueller Guido , Guzman Felipe
Published: December 2024

The optical truss interferometer (OTI) is a contingent subsystem proposed for the LISA telescopes to aid in the verification of a

1

pm

Hz

optical path length stability. Each telescope would be equipped with three pairs of compact fiber-coupled units, each forming an optical cavity with a baseline proportional to the telescope length at different points around the aperture. Employing a Pound–Drever–Hall approach to maintain a modulated laser field on resonance with each cavity, the dimensional stability of the telescope can be measured and verified. We have designed and developed prototype OTI units to demonstrate the capability of measuring stable structures, such as the LISA telescope, with a

1

pm

Hz

sensitivity using a set of freely mountable fiber-injected cavities. Aside from its initial motivation for the telescope, the OTI can also be readily integrated with other systems to aid in ground testing experiments. In this paper, we outline our experimental setup, measurement results, and analyses of the noise limitations.
A symmetry-oriented crystal structure prediction method for crystals with rigid bodies
Authors: Zhang Qi , Choudhury Amitava , Chernatynskiy Aleksandr
Published: December 2024

We have developed an efficient crystal structure prediction (CSP) method for desired chemical compositions, specifically suited for compounds featuring recurring molecules or rigid bodies. We applied this method to two metal chalcogenides: Li3PS4 and Na6Ge2Se6, treating PS4 as a tetrahedral rigid body and Ge2Se6 as an ethane-like dimer rigid body. Initial trials not only identified the experimentally observed structures of these compounds but also uncovered several novel phases, including a new stannite-type Li3PS4 structure and a potential stable structure for Na6Ge2Se6 that exhibits significantly lower energy than the observed phase, as evaluated by density functional theory calculations. We compared our results with those obtained using USPEX, a popular CSP package leveraging genetic algorithms. Both methods predicted the same lowest energy structures in both compounds. However, our method demonstrated better performance in predicting metastable structures. The method is implemented with Python code which is available at https://github.com/ColdSnaap/sgrcsp.git.
Topology and

PT

symmetry in a non-Hermitian Su–Schrieffer–Heeger chain with periodic hopping modulation
Authors: Mandal Surajit , Kar Satyaki
Published: December 2024

We study the effect of periodic hopping modulation in a Su–Schrieffer–Heeger (SSH) chain with an additional onsite staggered imaginary potential (of strength γ). Such dissipative, non-Hermitian (NH) extension amply modifies the features of the topological trivial phase (TTP) and the topological nontrivial phase (TNP) of the SSH chain, more so with the periodic hopping distribution. Generally a weak NH potential can respect the parity-time (

PT

) symmetry keeping the energy eigenvalues real, while a strong potential breaks

PT

conservation leading to imaginary edge state and complex bulk state energies in the system. We find that the non-zero energy in-gap states, that appear due to periodic hopping modulations even in the γ = 0 limit, take purely real or purely imaginary eigenvalues depending on the strength of both γ and Δ (dimerization parameter). The localization of topological edge states (in-gap states) at the boundaries are investigated that reveals extended nature not only near topological transitions (further away from

|
Δ

/

t

|

=
1

) but also near the unmodulated limit of

Δ
=
0

. Moreover, localization of the bulk states is observed at the maximally dimerized limit of

|
Δ

/

t

|

=
1

, which increases further with γ. These dissipative features can offer additional tunability in modulating the gain-loss contrast in optical systems or in designing various quantum information processing and storage devices.
A high-dimensional neural network potential for Co3O4
Authors: Omranpour Amir , Behler Jörg
Published: December 2024

The Co3O4 spinel is an important material in oxidation catalysis. Its properties under catalytic conditions, i.e. at finite temperatures, can be studied by molecular dynamics simulations, which critically depend on an accurate description of the atomic interactions. Due to the high complexity of Co3O4, which is related to the presence of multiple oxidation states of the cobalt ions, to date ab initio methods have been essentially the only way to reliably capture the underlying potential energy surface, while more efficient atomistic potentials are very challenging to construct. Consequently, the accessible length and time scales of computer simulations of systems containing Co3O4 are still severely limited. Rapid advances in the development of modern machine learning potentials (MLPs) trained on electronic structure data now make it possible to bridge this gap. In this work, we employ a high-dimensional neural network potential (HDNNP) to construct a MLP for bulk Co3O4 spinel based on density functional theory calculations. After a careful validation of the potential, we compute various structural, vibrational, and dynamical properties of the Co3O4 spinel with a particular focus on its temperature-dependent behavior, including the thermal expansion coefficient.
Harnessing orbital and valley thermal transport in 2D materials: the significance of inversion symmetry
Authors: Sharma Shivam , De Sarkar Abir
Published: December 2024

Orbitronics and valleytronics, analogous to spintronics, leverage the orbital degree of freedom and the valley degree of freedom of electrons to carry information, promising significant advancements in information processing. In this study, we disentangle the orbital and valley Nernst effect (VNE) in 2D monolayers, based on the global symmetry of the monolayers. We conduct an in-depth analysis of the orbital (valley) Nernst effect in inversion symmetric (asymmetric) monolayers, using an analytical tight binding model. Furthermore, we elucidate the dependence of the two effects on various inherent materials’ parameters using the prototypical Kane–Mele model. Our calculations show that an inversion symmetric gapped Kagome lattice shows a significant orbital Nernst effect emerging from the interatomic contribution, even in the absence of both spin and VNEs. Furthermore, for the inversion asymmetric 2H-phase of TMDs, we elucidate that the valley degree of freedom encompasses the orbital degree of freedom and the VNE can be more accurately described using the orbital degree of freedom, hence termed as the valley-orbital Nernst effect.
Structural evolution and electronic properties of neutral boron-doped nitrogen clusters
Authors: Chen Meicheng , Huang Shu , Fu Peixin , Chen Bole , Chen Chen , Bi Jie , Ding Kewei , Lu Cheng
Published: December 2024

Clusters represent intermediate states between isolated atoms and bulk solids. They serve as model systems to elucidate the physical properties of compounds from the atomic or molecular scale to the macroscopic bulk phase. Here, we perform thorough structure searches of neutral boron doped nitrogen clusters by crystal structural analysis by particle swarm optimization cluster structural prediction and density functional theory calculations. The calculated results indicate that the ground state structures of BN
n
(n= 4–16) clusters are evolutional from one-dimensional chains to two dimensional rings, and finally to three-dimensional (3D) geometries. Interestingly, the intriguing BN12 cluster, characterized by a 3D configuration with a central boron atom connecting four N3 chains in distinct directions, exhibits exceptional stability. The chemical bonding analysis reveals that the outstanding stability of BN12 cluster is attributed to the strong σ and π interactions between the 2p orbitals of the boron atom and the surrounding nitrogen atoms, as well as the robust σ bonds along the four nitrogen chains. The present findings offer important insights for understanding the geometries and electronic properties of neutral boron doped nitrogen clusters and provide an avenue for the design and synthesis of nitrogen-rich compounds.
Converting a power transistor to an optical transducer as an alternative to a commercial photo-detector for the construction of a simple and low-cost photometer
Authors: Bamdad Farzad , Bamdad Amir Mohammad
Published: December 2024

In this article, design and construction of a low-cost and simple homemade photometer for the determination of iron is described. Affordability and availability of required electronic components are two important factors that have been considered in the design of this photometer. An inexpensive low-wattage light-emitting diode was used as the light source, so there was no need to add a filter for wavelength selection. Instead of using a commercial phototransducer, a readily available NPN power transistor (2N3055) was modified as a proper substitute. To do this, the metallic cover of the transistor was carefully cut and removed so that the semiconductor junction of the transistor was revealed. It should be noted that this part of the transistor is photosensitive and can be used as a photo-sensing device. When the electromagnetic radiation strikes this photosensitive part, a small electric current is developed in the corresponding circuit. As this current is proportional to the radiation intensity, thus it is possible to use the uncovered transistor instead of a commercial phototransducer. The output electrical signal of this homemade phototransducer was amplified by a simple current-to-voltage converter and then measured with a digital voltmeter. As an application, the constructed photometer in this work was applied successfully to the assay of the iron content of vitamin tablets.
Artificial intelligence and undergraduate physics education
Authors: Trout Joseph J , Winterbottom Lauren
Published: December 2024

The latest advances in science and technology have resulted in great advances in artificial intelligence (AI), including the creation of chatbots. Chatbots simulate human conversation and allow humans to ask questions and receive answers based on a large volume of electronically stored information. Faculties of universities around the world are trying to come to grips with the availability of AI tools, such as chatbots, and are debating the ethical and moral questions surrounding the use of AI in education. This paper presents the results of a study which intended to answer three research questions. RQ1: how familiar are students with AI and tools that utilize it? RQ2: are students aware of the ethical issues involving AI and are they familiar with the university’s policies regarding the use of AI? RQ3: can ChatGPT be used as an efficient tool to teach science majors to code in Python? In this project, a chatbot was used to instruct students on the use of the Python programming language. Introductory college physics students were tasked with using an AI chatbot, ChatGPT (chat generative pre-trained transformer), to learn how to effectively code in the coding program, Python. Before using ChatGPT to code, the students were given a pre-test survey to determine their skill level in Python coding and their familiarity of AI and issues pertaining the use of AI. After completing exercises in Python coding using ChatGPT, a post-test survey was conducted to determine how well the students have learned to code in Python as well as how effective ChatGPT was in assisting their study.
Comparative study of a microdosimetric biological weighting function for RBE10 modeling in particle therapy with a solid state SOI microdosimeter
Authors: Pan Vladimir A , Parisi Alessio , Bolst David , Williams Jesse , Inaniwa Taku , Jackson Michael , Ahern Verity , Rosenfeld Anatoly B , Tran Linh T
Published: December 2024

Objective: the recently developed V79-RBE10 biological weighting function (BWF) model is a simple and robust tool for a fast relative biological effectiveness (RBE) assessment for comparing different exposure conditions in particle therapy. In this study, the RBE10 derived by this model (through the particle and heavy ion transport code system (PHITS) simulated d(y) spectra) is compared with values of RBE10 using experimentally derived d(y) spectra from a silicon-on-insulator (SOI) microdosimeter. Approach: experimentally measured d(y) spectra are used to calculate an RBE10 value utilizing the V79-RBE10 BWF model as well as the modified microdosimetric kinetic model (MKM) to produce an RBE10-vs-y

D
trend for a wide range of ions. In addition, a beamline specific PHITS simulation was conducted which replicated the exact experimental conditions that were used with the SOI microdosimeter at the heavy ion medical accelerator in Chiba biological beamline with 12C ions. Main Results: the RBE10-vs-y

D
trend for 1H, 4He, 7Li, 12C, 14N, 16O, 20Ne, 28Si, 56Fe, and 124Xe ions is examined with good agreement found between the SOI microdosimeter derived RBE10 values with the V79-RBE10 BWF model and MKM, as well as the PHITS simulations for 1H, 4He, 7Li, 12C, 16O, and 56Fe ions while some discrepancies were seen for 14N, 20Ne, and 28Si ions. Deviations have been attributed to the difference in the derivation of the d(y) spectra based on the different methods utilized. Good agreement was found between y

D
values and an over estimation was observed for RBE10 values for the beamline specific simulation of the 12
C ion beam. Significance: overall, this study shows that the SOI microdosimeter is a valuable tool that can be utilized for quick and accurate experimental derivation of the d(y) spectra, which can then be convoluted with the weighting function of the V79-RBE10 BWF model to derive RBE10. The SOI microdosimeter is able to derive experimental values of y

D
and RBE10 for various ions in any irradiation condition utilizing other radiobiological models.
Spinless topological chirality from Umklapp scattering in twisted 3D structures
Authors: Chen Cong , Zeng Xu-Tao , Yao Wang
Published: December 2024

Spinless systems exhibit unique topological characteristics compared to spinful ones, stemming from their distinct algebra. Without chiral interactions typically linked to spin, an intriguing yet unexplored interplay between topological and structural chirality may be anticipated. Here we discover spinless topological chiralities solely from structural chiralities that lie in the 3D spatial patterning of structureless units, exemplified using two types of twisted graphite systems. In a 3D screw twisted structure without periodicity in all directions, we find a chiral Weyl semimetal phase where bulk topology and chiral surface states are both determined by the screw direction. And in a 3D periodic structure formed with layer-alternating twist angle signs, a higher-order Dirac semimetal with chiral hinge states is discovered. Underlying these novel topological states is the intervalley Umklapp scattering that captures the chirality of the twisted interfaces, leading effectively to a sign-flipped chiral interlayer hopping, thereby introducing π-flux

Z

2

lattice gauge field that alters the symmetry algebra. Our findings point to a new pathway for engineering topological chirality through patterning twisted arrays of featureless units, which can expand the design principles for topological photonics and acoustics.
Chiral polaritonics: cavity-mediated enantioselective excitation condensation
Authors: Riso Rosario R , Castagnola Matteo , Ronca Enrico , Koch Henrik
Published: December 2024

Separation of the two mirror images of a chiral molecule, the enantiomers, is a historically complicated problem of major relevance for biological systems. Since chiral molecules are optically active, it has been speculated that strong coupling to circularly polarized fields may be used as a general procedure to unlock enantiospecific reactions. In this work, we focus on how chiral cavities can be used to drive asymmetry in the photochemistry of chiral molecular systems. We first show that strong coupling to circularly polarized fields leads to enantiospecific Rabi splittings, an effect that displays a collective behavior in line with other strong coupling phenomena. Additionally, entanglement with circularly polarized light generates an asymmetry in the enantiomer population of the polaritons, leading to a condensation of the excitation on a preferred molecular configuration. These results confirm that chiral cavities represent a tantalizing opportunity to drive asymmetric photochemistry in enantiomeric mixtures.
Improving the microstructure and levitation performance of YBa2Cu3O7−
δ bulks with combined-modified precursor powder for HTS maglev
Authors: Zhang Xiwen , Li Tingting , Zhao Yonghai , Yao Xin , Zhou Difan , Deng Zigang
Published: December 2024

High-temperature superconducting (HTS) pinning magnetic levitation (Maglev) vehicles employ HTS bulk superconductors to achieve its unique levitation and guidance feature above the track, making it a promising Maglev vehicle system. However, few studies consider customizing HTS bulk superconductors for a specific application, particularly in the HTS Maglev system, which hinders its development. In this study, a novel approach is introduced, in which the combined-modified precursor powder (C-MPP) is used to enhance the mechanical and superconducting properties of YBa2Cu3O7−δ
(YBCO or Y123) bulks, which are crucial for HTS pinning Maglev system. The C-MPP method integrates conventional precursor powder (CPP) with MPP in a layered configuration. The large-size YBCO bulks prepared by C-MPP reveal that C-MPP samples exhibit reduced deformation and shrinkage compared to MPP, and alleviate the issue of high porosity. Levitation force measurements indicate that C-MPP can provide superior superconducting properties over CPP. Additionally, in consideration of the realistic application settings, a general method is proposed for comparing the levitation force across samples of different sizes, providing a valuable methodology for evaluating the potential of HTS bulks for researchers and engineers. The findings suggest that the C-MPP technique represents a viable advancement for enhancing the efficiency and reliability of the HTS pinning Maglev system in future high-speed transit solutions.
Solving the fractional nonlinear dispersive K(m, n, 1) partial differential equation: techniques and applications
Authors: Alzahrani Abdulrahman B M
Published: December 2024

This paper presents an in-depth analysis of fractional nonlinear dispersive K(m,n,1) equations using two innovative mathematical techniques: These two are the Mohand transform iterative method (MTIM) and the Mohand residual power series method (MRPSM). These methods are used to formulate approximate analytical solutions in the framework of the Caputo operator. The MTIM offers an iterative type solution for fractional differential equations, and the MRPSM gives a series-based solution where nonlinearities are addressed efficiently. The effectiveness of these methods are illustrated through tables and figures, which can impress with their demonstrable result. They also demonstrate that our approaches of MTIM and MRPSM are adequate for solving the fractional nonlinear dispersive equations, which are enhanced compared with the conventional methods. This work significantly enriches the system's knowledge of applying sophisticated mathematical tools to interdisciplinary fractional differential equation problems with diverse bearings in numerous scientific and engineering disciplines.
Low field-induced significant magnetic entropy change owing to short-range magnetic correlations in a triangular lattice antiferromagnet GdZnAl11O19
Authors: Rani Manshi , Mukherjee K
Published: December 2024

Magnetic refrigeration is the epitome of modern cryogenic refrigeration, where magnetocaloric effect play a crucial role. For feasible practical applications, high-performance materials which exhibit large magnetocaloric effect under a low applied magnetic field are required to resolve the manufacturing and economic challenges. In this context, a highly frustrated system, GdZnAl11O19, where Gd3+ forms a quasi 2D triangular lattice is investigated. In this compound, no long-range ordering prevails down to 1.8 K. Magnetization along with field-dependent magnetic entropy change corroborates the existence of short-range magnetic correlations. Moreover, the calculated values of magnetic entropy change and relative cooling power are significant. Further the high value of mechanical efficiency demonstrates GdZnAl11O19 as a promising magnetocaloric material for magnetic refrigeration technology, particularly at cryogenic temperatures and under low magnetic field change.
Role of twin thickness gradient and grain size gradient in work hardening of gradient nanotwinned metals
Authors: Ding Xiaoyang , Yang Zailin , Yang Yong
Published: December 2024

Gradient nanotwinned (GNT) structures exhibit superior strength and work hardening compared to homogeneous nanotwinned (HNT) structures. However, the relative effectiveness of twin thickness gradient (TTG) versus grain size gradient (GSG) on enhancing material properties remains unclear. In this study, the tensile behavior of various homogeneous, TTG, GSG, and dual gradient (DG) nanotwinned (NT) specimens was investigated using molecular dynamics simulations (MDs). The mechanisms of plastic deformation and the additional dislocation densities in different gradient structures were compared. The results indicate that both TTG and GSG structures facilitate dislocation slip within grains by stabilizing grain boundaries (GBs), dispersing shear bands, and promoting grain rotation. For the components in the DG structure, the extra dislocation density generated by the DG structure is approximately the average of the densities produced by the TTG and GSG structures individually. For the gradient structure as a whole, an appropriately designed DG can yield a higher extra dislocation density than a single gradient. This study contributes to the further enhancement of work hardening in NT metals through microstructural design.
Green’s functions of relativistic oscillators with generalized Dunkl derivative: the (1+1)-dimensional case
Authors: Raber Djamel E M , Benzair Hadjira , Boudjedaa Tahar , Merad Mahmoud
Published: December 2024

The Green’s functions for relativistic oscillators with spin-0 and spin-1/2, within the framework of a new generalization of the Dunkl derivative with three parameters, are calculated using the path integral approach. For simplicity, this derivative is reformulated to depend on only two parameters. As a result, the energy eigenvalues and their corresponding wave functions are determined in both cases as functions of the three deformed parameters. In the limiting cases of the deformed parameters, the standard Dunkl derivative system is recovered, even in the absence of the Dunkl parameters.
Effect of Co substitution for Fe on microstructure and magnetic properties of FeNiSiBCuNb alloy ribbons
Authors: Liu 刘 Wen-Feng 文峰 , Yuan 袁 Ya-Ting 雅婷 , Yu 于 Chang-Jiang 长江 , Kang 康 Shu-Jie 树杰 , Zhu 朱 Qian-Ke 乾科 , Chen 陈 Zhe 哲 , Zhang 张 Ke-Wei 克维 , Zhang 张 Min-Gang 敏刚
Published: December 2024

This work investigated the microstructure, magnetic properties, and crystallization kinetics of the as-spun and annealed alloy ribbons of (Fe40−x
Co
x
Ni40Si6.33B12.66Cu1) 0.97Nb0.03, where x = 0, 6, 7, 8, 9, prepared using the melt-spinning method. The results show that adding a moderate amount of Co can improve the glass forming ability (GFA), the first peak crystallization temperature, and thermal stability of the as-spun alloy ribbons. With x = 7, the two-stage crystallization temperature interval ΔTx
= 90 exhibits optimal thermal stability, and the alloy annealed at 673 K for 10 minutes shows the favorable combined magnetic properties, with H
c = 0.12 A/m, M
s = 88.7 A⋅m2/kg, and μ
e = 13800. The magnetic domain results show that annealing removes numerous pinning points in the magnetic domains of the alloy ribbons, making the domain walls smoother and effectively reducing the pinning effect.
Optical signature of flat bands in topological hourglass semimetal Nb3SiTe6
Authors: Cao 曹 Shize 仕泽 , Zhang 张 Cuiwei 翠伟 , Xu 徐 Yueshan 越山 , Zhao 赵 Jianzhou 建洲 , Shi 石 Youguo 友国 , Long 龙 Yun-Ze 云泽 , Luo 雒 Jianlin 建林 , Chen 谌 Zhi-Guo 志国
Published: December 2024

Flat electronic bands in condensed matter provide a rich avenue for exploring novel quantum phenomena. Here, we report an optical spectroscopy study of a topological hourglass semimetal Nb3SiTe6 with the electric field of the incident light parallel to its crystalline ab-plane. The ab-plane optical conductivity spectra of Nb3SiTe6 single crystals exhibit a remarkable peak-like feature around 1.20 eV, which is mainly contributed by the direct optical transitions between the two ab-initio-calculation-derived flat bands along the momentum direction Z–U. Our results pave the way for investigating exotic quantum phenomena based on the flat bands in topological hourglass semimetals.
How does negative triangularity mitigate ITG turbulence and transport?
Authors: Singh Rameswar , Diamond P.H. , Marinoni A.
Published: December 2024

Improved confinement in negative triangularity (NT) experiments is attributed to reduced fluxes driven by micro-turbulence. The physical mechanism of why thermal confinement improves in NT relative to PT is unknown. This study employs gyrokinetic flux tube simulations using the GENE code with local Miller equilibrium to elucidate the physical mechanisms behind the beneficial effects of NT flux surface shapes. The focus is on collisionless ion temperature gradient (ITG) driven turbulence with adiabatic electrons. The kinetic profiles are held fixed across a scan of triangularity values, thus enabling comparisons on a level playing field. The reduced linear growth rates for NT is shown to be due to a reduced eigenmode averaged magnetic drift frequency and a wider, stronger negative local magnetic shear region about the outboard mid-plane. The nonlinear heat flux is lower for NT than that for PT, due to reduced radial correlation length and increased correlation time (

τ

c

) of fluctuations. These, in turn, are due to a comparatively higher level of self-generated zero-frequency E × B zonal shearing rate ω

E
in NT as compared to PT. Though the linear zonal potential residual is lower for NT, the nonlinearly generated E × B zonal shearing rate is higher for NT than for PT. This outcome is linked to the distinctive features of the radial wavenumber spectra of the zonal potential and the zonal shearing rate. The dimensionless parameter

ω

E

τ

c

is suggested as a figure of merit. This is higher for NT than for PT. Thus, the reduced heat diffusivity for NT is linked to increased

ω

E

τ

c

. Self-generated temperature corrugations (i.e. zonal temperature gradients) are much weaker than the background mean temperature gradient. Nevertheless, temperature corrugations are more pronounced in NT than in PT.
Pt/In2O3/g-C3N4 Composite Materials with Enhanced Visible Light Catalytic Performance for Degradation of Rhodamine B and Tetracycline Hydrochloride
Authors: Wang Linfeng , Su Chunyan , Li Min , Xu Mingyi , Wang Baorui , Yang Jiani
Published: December 2024

Pt/In2O3/g-C3N4 composite photocatalytic nanomaterials were prepared by photodeposition and calcination methods. The structure, morphology and optical properties of composites were characterized by SEM, XRD and UV-Vis DRS, and the degradation experiments of Rhodamine B (RhB) and tetracycline hydrochloride (TCH) were carried out under visible light. The results indicate that the construction of the ternary composite system effectively prevents the recombination of photogenerated electrons and holes in semiconductors, and expands the range of visible light response, so that the photocatalytic performance has been enhanced.
Synthesis and Luminescence Properties of Bi3+ and Re3+ (Re = Eu, Dy, Tm) Co-doped GdVO4 Phosphors for Latent Fingerprint Detection
Authors: Ye Yang , Liang Jinji , Zhang Wei , Xie Wei , Feng Zuyong , Hu Zhengfa , Xiong Guangting , Liu Zhenpeng
Published: December 2024

Rare earth ion doped GdVO4 phosphors have been used in laser, luminaire, luminescent display and other fields, but there are few reports for latent fingerprint. In this paper, a series of Bi3+ and Re3+ (Re = Eu, Dy, Tm) singly doped GdVO4 and Bi3+ and Re3+ double doped GdVO4 phosphors were synthesized by high temperature solid method. The structure and characteristics of luminescence were described by X-ray powder diffraction and photoluminescence spectrum. We tried to apply prepared phosphors to the latent fingerprint detection field, and found that GdVO4: Bi3+, Eu3+ phosphor has lower background interference, and can effectively display latent fingerprint details under different surfaces, wet environments and high temperature conditions. The Bi3+, Eu3+ co-doped GdVO4 phosphor is a promising phosphor material for latent fingerprint identification application.
Compatibility Assessment of High-viscosity Additive and SBS-modified Asphalt
Authors: Li Kuan , Ma Hongpeng , Xie Jianguang , Li Siqi , Pan Youqiang , Zhang Zhixiang , Guan Yongsheng
Published: December 2024

The present study investigates compatibility of high-viscosity additive (HVA) and SBS-modified asphalt (SBSMA). The compatibility between HVA and SBSMA is evaluated through toughness and tenacity of high-viscosity modified asphalt (HVMA) and the Cantabro loss of porous asphalt mixture (PAM), respectively. The results show that the compatibility of HVA and SBSMA is influenced by the crosslinking state of SBS in SBSMA. The compatibility between HVA and SBSMA is adversely affected by excessive or insufficient crosslinking density. The optimal compatibility between HVA and SBSMA can be achieved when the SBSMA contains moderate crosslinked SBS.
Study on the Performance of Grouting Material Modified by Sodium Lignosulfonate
Authors: Zhao Lin , Wang Yang , Wang Youzhi , Liu Jinzhang , Tian Changjin
Published: December 2024

In order to improve the problems of poor stability, low flowability, and weak corrosion inhibition of the grouting material, sodium lignosulfonate (SL) was used as a modified component of the pore grouting material in this paper. The non-uniformity coefficient was introduced to evaluate the stability of the grouting material. And, macro and micro experiments were used to comprehensively evaluate the influence of sodium lignosulfonate on the flowability, stability, strength, and corrosion inhibition of the grouting material, revealing the mechanism of SL’s modification effect on the pore grouting material. The results show that the addition of SL can significantly improve the stability of the grouting material. When the dosage is 4%, the mechanical properties of the grouting material are optimal; The addition of SL can significantly reduce the corrosion products on the surface of steel strand samples, and the research results provide data support and technical guidance for the application of SL in grouting materials.
Microscopic Simulation Study on Orientation Degree of PBO Fiber Macromolecular Chains
Authors: Zhang Haiyun , Wang Danyong , Li Shuhu , Wei Huazhen , An Jing , Xing Wenfang
Published: December 2024

Aiming at the problem that the mechanical properties and preparation efficiency of PBO fiber in China need to be further improved, this study explored the conformation of PBO fiber macromolecular chains and predicted its mechanical properties by using microscopic simulation design technology, which provided basic theoretical and technical support for improving the quality stability of PBO fiber engineering mass production, reducing manufacturing costs and shortening the gap with foreign products.
Study on Freeze-thaw Performance of Improved Subgrade Filler with Large Steel Slag Content
Authors: Liu Jianchao , Zhao Jiahuan , Wang Hongwei , Wei Haibin
Published: December 2024

In order to evaluate the use effect of the modified subgrade filler with large amount of steel slag in the seasonal freezing area, the properties of the filler under the freeze-thaw cycle were studied. On the basis of the optimum mix ratio of improved soil determined by previous geotechnical tests, the variation trend and influence law of various performance parameters of improved soil under different stress and temperature conditions and after multiple freeze-thaw cycles were analyzed through freeze-thaw cycle and temperature control triaxial test. The results show that the failure stress, internal friction angle, shear strength and dynamic elastic modulus of the modified soil with large amount of steel slag decrease significantly after the first freeze-thaw cycle, reaching 7.89%, 6.41%, 13.57%, 30.16%, and then the decreasing amplitude decreases and gradually becomes stable.
Research on Pre-stressed CFRP Plate in the Reinforcement of Composite Box Girder Bridge
Authors: Zhu Kunning
Published: December 2024

Based on the mechanical behavior of Xiuzhen River bridge before and after pre-stressed CFRP plate reinforcement, the finite element model is established, the stress distribution in composite box beams under over load traffic is analyzed, and the crack distribution is compared. The results show that: Overloading is an important cause of cracks in composite box girders; after using pre-stressed CFRP plate reinforcement, the bearing capacity of the girder and the stress meet the requirements of specifications; the pre-stressed CFRP plate has almost no effect on the stiffness of girder; pre-stressed CFRP plate applied a certain degree of pre-stress to the girder, which effectively constrained the development of cracks.
Analysis on Contact Pressure for the Seal Structure of Repair Clamp with Wedge Contact Seals
Authors: Zhao Zhangfan , Shi Xiang
Published: December 2024

Seal pressure is the key performance of repair clamp for subsea pipeline, which is generally designed by analyzing the contact pressure on each sealing surface of the seal structure. Research has shown that the weakest part of the clamp seal is the position where radial seal ring contacts axial seal strip. Usually for clamp seal structure the contact between radial seal ring and axial seal strip is tangent between a cylindrical surface and a plane. In order to improve the contact pressure of the position, a seal structure with wedge contact between seals that is tangent between a conical surface and a plane is proposed. 3D simulation analysis for the seal structure is carried out, and the contact pressures under four different wedge angles of 11°, 13°, 15° and 17° are analyzed. The minimum contact pressure is compared with that of the wedge angle of 0°. Simulation results show that the wedge contact will increase the contact pressure of the original weakest part, and the position of minimum effective contact pressure of the seal structure becomes the contact surface between two seal rings. The minimum contact pressure increases with the increase of the wedge angle. The wedge angle is recommended to be 13 ° more appropriate.
Laboratory and Field Investigations on Flowable Fill with Waste Soils and Fine-Grained Soils
Authors: Huang Zheng , Chen Junjie , Yan Bo , Wang Jun
Published: December 2024

Flowable fill has been widely used as a type of fill materials in engineering practice. However, the adoption of fine-grained soils, especially clay soils, in flowable fills faces difficulties such lack of mixing efficiency and poor engineering performance. In this study, the flowable fill was prepared using waste excavated soil generated from a construction project. Two types of soils, silty clay and silt mixed with silty sand, were used. In the laboratory tests, slump tests, unconfined compressive tests, oedometer compression tests, and drying shrinkage tests were conducted. Within the tested condition (8-10% cement addition and 10-50% water addition), the range of slump was 70-203 mm, and the range the 28d strength was 0.39 -0.67 MPa. For this project and most construction applications, these level of slump and strength are satisfactory. The construction process using the flowable fill has four steps, that is, raw soil filling, cement slurry preparation, flowable fill mixing, and conveying and filling. The details and the problems in the construction are introduced and discussed. Field experiments also confirmed that parameters such as slump, strength, deformation, can meet the design requirements.