bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of water-in-salt electrolytes on the electrochemical performance of porous N and S co-doped carbon electrodes in supercapacitors
Authors: Thior S. , Kitenge V. N. , Otun Kabir O. , Adam Rashed A. M. , Diop Ndeye F. , Ngom Balla D. , Manyala N.
Published: December 2024

This study demonstrates the benefits of combining water-in-salt electrolytes with co-doped activated carbon electrodes in supercapacitors, enhancing voltage, capacitance, and energy storage performance.
Reducing noble metal dependence: oxygen evolution reaction with a Ru-minimized Bi2Ru2O7@MOF-801 composite
Authors: Sujita P , Gupta Keshav , Gopal V. , Sarmila S. , Vadivel Sethumathavan
Published: December 2024

A noble metal-minimized Bi2Ru2O7@MOF-801 composite delivers high catalytic OER activity and improved durability with the synergy of high conductive Bi2Ru2O7 and high surface area MOF-801.
Fluoride binding-modulated supramolecular chirality of urea-containing triarylamine and its photo-manifestation
Authors: Ma Sijia , Wen Xin , Jiang Yuqian , Jiang Jian , Hao Wenchao , Zhang Li , Liu Minghua
Published: December 2024

The addition of F− led to amplification of the supramolecular chirality of the triarylamine derivative containing a urea unit, and the photoirradiation allowed the F− in the system to be visualized by the naked eye.
Recent breakthroughs in ring-opening annulation reactions of aziridines
Authors: Mishra Deepak Ranjan , Mishra Nilima Priyadarsini
Published: December 2024

Aziridine is a fascinating core which enables synthesis of diverse N-heterocycles comprising natural product analogs and pharmaceutical candidates.
DMSO-promoted α-bromination of α-aryl ketones for the construction of 2-aryl-2-bromo-cycloketones
Authors: Zhai Haojiang , Li Penghui , Wang Hongshuang , Wang Xiaohui
Published: December 2024

A practical regioselective one-step α-bromination reaction of 2-aryl-cycloketones using the NBS–DMSO–CHCl3 system is reported. The desired α-bromination products were isolated in 37% to 97% yields, with a maximum tested scale of 15 mmol.
Enabling preferential Mg (0002) orientation electrodeposition via constructing a SnS2-engineering host for dendrite-free magnesium metal batteries
Authors: Li Feng , Dou Huanglin , Zhao Zhenxin , Li Wenyi , Bai Qiang , Yang Sunbin , Wang Xiaomin
Published: December 2024

SnS2 nanoflower arrays grown on carbon cloth (SnS2@CC) were designed as Mg metal anode host which promote Mg deposition dominated by (0002) basal orientation, thus inhibiting dendrite growth and achieving a high coulomb efficiency of 98%.
Valorisation of citrus waste for sustainable synthesis of carbon-supported copper nanoparticles active in CO2 electroreduction
Authors: De Luca Federica , Demoro Palmarita , Nduka Izuchica , Italiano Cristina , Abate. Salvatore , Arrigo Rosa
Published: December 2024

A microwave-assisted hydrothermal method is used to synthesise carbon-supported Cu2O/Cu electrocatalysts for CO2 conversion using citrus peels as the source of both the carbon support and the Cu cations reducing agent.
Soft template-assisted design and synthesis of anisotropic 2D–3D CuInS2 with a controlled morphology and band gap: exploring photothermal interfacial water evaporation
Authors: Barhoi Ashok , Mahto Bhagirath , Ali Haider , Hussain Sahid
Published: December 2024

Synthesizing I–III–VI2 ternary semiconductor chalcogenide nanostructures with precise control over their shape and bandgap is a major focus of current research.
Size-confined Co nanoparticles embedded in ultrathin carbon nanosheets for enhanced oxygen electrocatalysis in Zn–air batteries
Authors: Liu Yang , Yan Qi , Ge Fayuan , Duan Xinde , Wu Tingting , Zheng Hegen
Published: December 2024

This work demonstrates a composite strategy to modify the MOF structure for the purpose of regulating the size and accessibility of active sites in derived Co@N-CNSs catalyst, enabling enhanced oxygen electrocatalysis in Zn–air batteries.
In situ construction and composition engineering of PbBiO2Br/metal halide perovskite heterojunctions for enhanced interfacial charge transfer and photocatalytic activity
Authors: Qin Qi , Liu Wei-Qi , Xia Zhi-Hua , Chen Hong-Yan , Kuang Dai-Bin
Published: December 2024

Atom-cosharing PbBiO2Br/MHP heterojunction photocatalysts are synthesized via a self-template acid-etching process, which enables precise manipulation of their composition and photoelectrical properties.
Advances in the syntheses, mechanisms and applications of room-temperature phosphorescent carbon dots
Authors: Lu Feng , Xu Xinhuan , Wan Weizheng , Liang Xiumin , Xia Jiajing , Cao Weizhong , Chen Zhaopeng , Hu Min
Published: December 2024

In this review, the structure and luminescence mechanisms of RTP-CDs are clearly demonstrated. Based on the potential strategies to optimize their luminescence performance, the applications and future perspectives of RTP-CD systems are presented.
On homotopy properties of solutions of some differential inclusions in the W1,P-topology
Authors: Caponio Erasmo , Masiello Antonio , Suhr Stefan
Published: December 2024

We consider a differential inclusion on a manifold, defined by a field of open half-spaces whose boundary in each tangent space is the kernel of a one-form ω. We make the assumption that the corank one distribution associated to the kernel of ω is completely nonholonomic of step 2. We identify a subset of solutions of the differential inclusion, satisfying two endpoints and periodic boundary conditions, which are homotopy equivalent in the W1,p-topology, for any p ∈ [1,+∞), to the based loop space and the free loop space respectively.
Sound propagation in superfluid 4He and 3He-A with slip boundary conditions
Authors: Kekutiya Sh. E. , Sanikidze D. G.
Published: December 2024

The propagation of waves in a bounded geometry in superfluid 3He and 4He is investigated under the conditions of slip flow of the normal fluid component and the specular reflection of quasiparticles from the vessel walls. The velocities and absorption coefficients of the propagating waves are calculated. The influence of the boundary condition on the first, second, magnetoacoustic, and spin-temperature sounds is determined.
Photoinduced macroscopic quantum tunneling in superconducting systems
Authors: Golub A. A.
Published: December 2024

The problem of macroscopic quantum coherence in superconducting systems is studied theoretically. A two-level model of a SQUID with phonon-field coupling is considered. The probability of a transition, induced by a periodic perturbation, occurring between the lowest states of the two-well potential, describing the phase dependence of the energy in the SQUID, is calculated for a particular region of this coupling. Use is made of the conformity between this model and the resonance-level model. We also consider the strong-viscosity limit. It is shown that in this case the two-level model cannot be used to describe quantum interferometers.
Magnetic properties of topological solitons in a one-dimensional Peierls chain
Authors: Rozhavskii A. S.
Published: December 2024

We discuss a continuum model of a one-dimensional Peierls dielectric, taking into account the interaction between the electron spins and a magnetic field. We calculate the magnetic moment of the chain when one neutral topological soliton in the order parameter is present. It is shown that in fields μH <Δ the magnetic moment is determined by the contribution of the electronic levels localized at the soliton. We also calculate the EPR absorption due to a soliton.
Ballistic thermal conductivity of a point contact between dielectrics
Authors: Bogachek É. N. , Shkorbatov A. G.
Published: December 2024

The heat fluxes in dielectric point contacts in the pure (ballistic) limit. An anomaly is detected in the temperature dependence of the thermal conductivity. A method is formulated for the determination of the characteristics of the constant-energy surfaces for phonons on the basis of experimental data.
Nonlinear conductivity in island bismuth films
Authors: Butenko A. V. , Bukhshtab E. I. , Pilipenko V. V.
Published: December 2024

The dependence of the conductivity of bismuth island films on the applied voltage has been measured. This dependence is attributed to the singularity caused in the electron density of states by electron–electron interaction (EEI). The experimental dependences σ (V) are in agreement with the theory of electron–electron interaction.
Fluctuation conductivity of granular vanadium films
Authors: Dmitriev V. M. , Solov’ev A. L. , Dmitrenko A. I.
Published: December 2024

The effect of fluctuations on the resistive transitions in thin granular vanadium films at temperatures T ≥ Tc is studied. As the temperature is increased and as a result of the change in the ratio of the coherence length ξ(T) and the average size of the granules g, the dimensionality of the fluctuations changes in all films studied from two [ξ (T) >g] to zero [ξ (T) >g] .Studies of the region of the two-dimensional behavior of the fluctuations showed that the Maki–Thompson mechanism makes the main contribution to the fluctuation conductivity σ′ of such films. The study of critical fluctuations showed that the theory describes well both the behavior of σ′ as a function of temperature and the width of the resistive transitions near Tc. The effect of microwave radiation with frequency ∽ 10 GHz and power P on the resistive transitions and σ′ of such films was studied. It was found that a) the dimensionality of the weak fluctuations changes; b) the region of critical fluctuations decreases as a result of stimulation and then expands as P increases; c) superconductivity is stimulated in the zero-dimensional ensemble of small particles near the temperature of their resistive transition. Most of the observed effects can be explained satisfactorily based on the granular nature of the films.
Anisotropy and phonon-nonequilibrium effects in point-contact spectra of copper
Authors: Akimenko A. I. , Verkin A. B. , Yanson I. K.
Published: December 2024

This is the first combined study of point-contact and noise spectra of single-crystalline point contacts. The high anisotropy and high sensitivity of noise spectra to the presence of impurities in the region of the point contact are used to select point contacts with a given crystallographic direction and given conditions of motion of electrons through the point contact. Copper point contacts were studied in the symmetric directions [100], [111], and [110] for the ballistic (li≫d)and intermediate (li∼ d) states of electron motion through the contact. It turned out that when the smooth background is subtracted out the point-contact (PC) spectra differ from one another for these two states by ∼10% for the [100] and [110] directions and almost coincide for the [111] direction. This difference is in agreement with the spectral correction to the smooth background in the ballistic state, appearing because of the nonequilibrium state of the phonons in the region of the point contact, proposed in the theory. The correlation between the positions of the minima on the energy scale in the noise spectra and the position of the maxima of this correction was observed experimentally. In the intermediate state and for the [111] direction, distinct minima are not observed in the noise spectra in the ballistic state, and the spectral correction to the background is relatively small. For this reason, the experimental PC spectra for symmetric directions, obtained in the intermediate state, are in better agreement with the calculations of anisotropic PC functions in which the nonequilibrium phonons were neglected.
Homogeneous resonance in magnetic materials under nonresonant parallel pumping
Authors: Seminozhenko V. P. , Slezova Zh. V. , Sobolev V. L.
Published: December 2024

A dispersion relation has been obtained for the spectra of spin waves in ferromagnets (FM) and antiferromagnets (AFM) under nonresonant parallel pumping. It is shown that pumping significantly affects the homogeneous resonance frequencies in FM and easy-plane AFM.
Distinctive features of ferromagnetic and helimagnetic ordering in weak itinerant magnets
Authors: Povzner A. A.
Published: December 2024

An approach to the theory of ferromagnetic and helimagnetic ordering in weak itinerant magnets is developed on the basis of the concept of reaction fields. The theory considered in the paper allows the causes of some features of the magnetization and the comparatively high Curie and Néel temperatures of the materials considered to be explained without invoking specific microscopic exchange-interaction models.
Energy excess functions of mixtures of helium isotopes in the supercritical temperature range
Authors: Karnatsevich L. V. , Bogoyavlenskii I. V. , Titar’ L. P. , Lepin I. V. , Konareva V. G.
Published: December 2024

The excess Gibbs potential (GE), excess entropy (SE), and excess enthalpy (HE) of a 3He–4He mixture in the temperature range 4.5–14 K at pressures up 30 atm are calculated on the basis of experimental P–V–T data. The dependences of these functions on the temperature, pressure, and concentration of the mixture are established. The results are compared with calculations by the Prigogine theory. The excess characteristics of the 3He–4He system are calculated within the framework of the gas approximation with allowance for both diffraction and quantum-statistical effects.
The tilt effect in the electron–sound interaction in metals and semimetals in a weak magnetic field
Authors: Fal’ko V. L , Kaner É. A. , Eremenko A. V.
Published: December 2024

A systematic kinetic theory of the tilt effect in sound absorption and the dispersion of the sound velocity in typical metals and semimetals in a relatively weak magnetic field, when the radius of the cyclotron rotation is much larger than the wavelength of the sound wave is developed. The compensation of the basic singularities in the electron–phonon interaction is proved. The oscillation of the absorption and the change in the sound velocity when the tilt angle is increased, owing to the resonant contribution of electrons in noncentral sections of the Fermi surface, are studied in detail.
Anomalous behavior of the Grüneisen coefficient of solid hydrogen on the transition to the quadrupole glass state
Authors: Kokshenev V. B.
Published: December 2024

This paper discusses a hypothetical T–H phase diagram of a quadrupole glass in solid molecular hydrogen. The values of the critical temperature for freezing into the glassy state are identified with the positions of the minima at which a change takes place in the form of the temperature dependence of the Grüneisen coefficient. The temperature–concentration dependence of this latter is obtained from results of specific heat and pressure measurements by Haase et al. in the orientationally disordered phase of an ortho-para hydrogen mixture. The role of a magnetic field is fulfilled by the effective molecular fields characteristic of quadrupole systems. The results of the analysis confirm the validity of the concept of a quadrupole glass being analogous to a spin glass in an external field.
The impact of facilitating conditions on electric vehicle adoption intentions in sub-Saharan Africa: An integrated UTAUT model
Authors: Ajao Qasim , Sadeeq Lanre , Sodiq Oluwatobi Oluwaponmile
Published: December 2024

This research investigates the factors influencing the adoption intentions of electric vehicles (EVs) in sub-Saharan Africa (SSA), focusing on leading countries in EV adoption such as South Africa, Tanzania, Rwanda, Ethiopia, Kenya, and Nigeria. An enhanced version of the Unified Theory of Acceptance and Use of Technology was developed to assess the key determinants of EV adoption. A total of 865 responses were collected and analyzed using structural equation modeling. This paper contributes to the field by showing that facilitating conditions (FC) have a greater impact on EV adoption in SSA compared to other factors typically influencing the adoption of other technologies. The findings further demonstrate that FC can significantly accelerate the widespread adoption of EVs in developing regions. Except for effort expectancy, the results also show that trust, performance expectancy, social influence, and network externalities all positively affect EV adoption. Among these, FC have the strongest effect, increasing influence by 32%. These insights offer valuable guidance for policymakers, industry stakeholders, and researchers to promote EV adoption and support the achievement of Sustainable Development Goals 3.9 and 7.2.
On the transition between autonomous and nonautonomous systems: The case of FitzHugh–Nagumo’s model
Authors: Longo I. P. , Queirolo E. , Kuehn C.
Published: December 2024

This work deals with a parametric linear interpolation between an autonomous FitzHugh–Nagumo model and a nonautonomous skewed problem with the same fundamental structure. This paradigmatic example allows us to construct a family of nonautonomous dynamical systems with an attracting integral manifold and a hyperbolic repelling trajectory located within the nonautonomous set enclosed by the integral manifold. Upon the variation of the parameter the integral manifold collapses, the hyperbolic repelling solution disappears and a unique globally attracting hyperbolic solution arises in what could be considered yet another pattern of nonautonomous Hopf bifurcation. Interestingly, the three phenomena do not happen at the same critical value of the parameter, yielding, thus, an example of a nonautonomous bifurcation in two steps. We provide a mathematical description of the dynamical objects at play and analyze the periodically forced case via rigorously validated continuation.
Desertion of anomalous magnetic transition and emergence of metallic state in Cu doped Eu2Ru2O7 pyrochlore
Authors: Chatterjee Soma , Das I.
Published: December 2024

In this paper, we present a detailed investigation of the structural, magnetic, and electrical transport properties of Eu2−xCuxRu2O7 (x = 0, 0.2, 0.4) pyrochlores. X-ray diffraction measurements confirm the single-phase nature of all samples and also manifest the reduction of lattice parameters with the increase in copper doping concentration. The experimental results of the magnetic measurements indicate that an anomalous magnetic transition around 23 K arises due to the contribution of non-magnetic Eu3+ ions. The strength of this unnatural magnetic transition reduces with decreasing Eu concentration [i.e., with increasing copper doping (x)] and finally disappears for x = 0.4. Moreover, electrical transport measurements reveal a considerable decrease in resistivity for Cu doped samples compared to undoped samples, which indicates the increase in charge carrier concentration with increasing Cu content.
Distinguishing local photoinduced forces from global photoacoustic interactions in homodyne infrared photoinduced force microscopy
Authors: Almajhadi Mohammad A.
Published: December 2024

The rise of tip-based optical force microscopy has transformed nanoscale optical and chemical imaging, enabling sub-10 nm spatial resolution by integrating optical excitation with atomic force microscopy. Photoinduced force microscopy (PiFM) stands out as a key technique, with applications in single-molecule imaging, Raman spectroscopy, and near-field electromagnetic characterization. However, the contrast mechanisms underlying homodyne PiFM, particularly in the infrared regime, remain underexplored. This study provides novel insights into the interpretation of PiF signals, focusing on homodyne IR-PiFM. Contrary to previous assumptions, we demonstrate that the linear dependence of the PiF signal on sample thickness in homodyne mode originates from global photoacoustic forces rather than localized photothermal effects. By minimizing global interactions through power reduction and tip–sample proximity, we achieve a spatial resolution of 11 nm, comparable to heterodyne PiFM. Our findings reveal that both homodyne and heterodyne modes are fundamentally sensitive to tip-enhanced near-field optical intensity, with similar dependencies on sample thickness. This work advances the understanding of the contrast mechanism of PiFM and demonstrates that both homodyne and heterodyne modes can achieve high-resolution imaging, paving the way for broader applications in nanoscale optical and chemical analysis.
Fast axial resolution enhancement microscopy with structured illumination
Authors: Luo Shihang , Gong Ran , Zhang Mingcong , Xu Tao , Ji Wei , Gu Lusheng
Published: December 2024

In this study, we introduce Fast Axial Resolution Enhancement (FARE) microscopy, which employs tilted strip illumination to achieve a near-isotropic three-dimensional resolution with three images per plane. FARE provides an imaging rate of up to 1.5 Hz for 55 × 55 × 3 μm3 with an axial resolution of ∼270 nm. Using this technique, we observed the movement of the endoplasmic reticulum in three dimensions and discovered novel patterns of mitochondrial morphological transitions and their interactions with other organelles under oxidative stress. These findings highlight the significant potential of FARE microscopy for biomedical applications.
Geometric variations in nucleosomal DNA dictate higher-order chromatin structure and enhancer–promoter communication
Authors: Todolli Stefjord , Nizovtseva Ekaterina V. , Clauvelin Nicolas , Maxian Ondrej , Studitsky Vasily M. , Olson Wilma K.
Published: December 2024

The dynamic organization of chromatin plays an essential role in the regulation of genetic activity, interconverting between open and compact forms at the global level. The mechanisms underlying these large-scale changes remain a topic of widespread interest. The simulations of nucleosome-decorated DNA reported herein reveal profound effects of the nucleosome itself on overall chromatin properties. Models that capture the long-range communication between proteins on nucleosome-decorated DNA chains incorporate DNA pathways different from those that were previously proposed based on ultracentrifugation and chemical cross-linking data. New quantitative biochemical assays measuring the rates of communication between interacting proteins bound to a promoter and an enhancer at the ends of saturated, precisely positioned, nucleosome-decorated DNA chains reveal a chromatin architecture with a three-nucleosome repeat, a model inconsistent with the two-start configurations deduced from earlier physical studies. Accompanying computations uncover small differences in the twisting of successive base pairs that seemingly give rise to the observed global properties. These data suggest that the novel state of chromatin determined under physiological conditions differs from that deduced under standard physical conditions, likely reflecting the different salt conditions used in the two types of experiments. This novel chromatin state may be important for a number of DNA transactions that occur in the cell nucleus.
The ordering behaviors of liquid under many-body dissipative particle dynamics potential at solid–liquid interface
Authors: Li Jie , Yu Zhiyuan , Li Luoyi , Zhang Kaixuan , Li Qiliang , Shao Yu , Chen Shuo
Published: December 2024

This study utilizes many-body dissipative particle dynamics to analyze in detail the structural orderings of liquid density, stress, and other physical properties near solid–liquid (S-L) interfaces, examining their relationship with S-L and liquid–liquid (L-L) interaction potentials. By discerning the individual contributions from different phases to the overall force profile, our research reveals that the mutual influence between forces and density variations causes the wall’s impact to extend several multiples beyond the cutoff radius. Through a variety of scenarios involving different potentials, we demonstrate that the stratification period is a fundamental characteristic of the liquid phase, unaffected by the type of solid or the specific S-L interaction potential. Besides, the distance of the first liquid layer from the solid substrate is positively correlated with the position of zero potential (σ) of the S-L potential. Moreover, the oscillation amplitude of the density profiles does not necessarily increase monotonically with hydrophilicity, instead depends on the specific potential form and is a competing outcome of the two S-L potential parameters σ, and ε (the minimum potential energy). Therefore, for cases with the same wettability (e.g., the same liquid but different solids), the density ordering profiles may not completely align.
Machine learning-based estimator for electron impact ionization fragmentation patterns
Authors: Lemishko Kateryna M , Armstrong Gregory S J , Mohr Sebastian , Nelson Anna , Tennyson Jonathan , Knowles Peter J
Published: December 2024

Numerous measurements and calculations exist for total electron impact ionization cross sections. However, knowing electron impact ionization fragmentation patterns is important in various scientific fields such as plasma physics, astrochemistry, and environmental sciences. Partial ionization cross sections can be calculated by multiplying total ionization cross sections with branching ratios for different fragments, which can be deduced from ionization mass spectra. However, the required mass spectrometry data is frequently unavailable. A machine learning-based method to predict mass spectra is presented. This method is used to estimate partial electron impact ionization cross sections using the predicted mass spectra and the appearance thresholds for the ionic fragments. As examples, ammonia and the C2F5 radical are considered: branching ratios derived from the predicted mass spectra and Binary-Encounter Bethe (BEB) total ionization cross sections are used to predict the fragmentation pattern for each species. The machine learning algorithm can also be used to predict mass spectroscopy fragmentation patterns. While effective, the method has key limitations: it does not account for light fragments such as H+, whose peaks are absent in the training data, and its validity is restricted to electron impact energies below 100 eV to minimize the contribution of double ionization, which is not accounted for by the BEB model. Although BEB cross sections are used in this work, the method is not reliant on BEB and can be applied to any set of total ionization cross sections, including experimental measurements.
DEG-SLAM: a dynamic visual RGB-D SLAM based on object detection and geometric constraints for degenerate motion
Authors: Pan Guangen , Cao Songyin , Lv Shuang , Yi Yang
Published: December 2024

Current visual simultaneous localization and mapping (SLAM) systems have demonstrated commendable efficacy in static environments. However, the presence of dynamic objects in real-world settings frequently leads to system discrepancies, significantly impairing the accuracy and robustness of SLAM systems. Conventional visual SLAM approaches typically utilize epipolar constraints to mitigate the impact of outliers; nevertheless, they encounter limitations when confronted with a substantial number of dynamic or planar moving objects. To tackle these issues, this paper introduces a novel dynamic visual SLAM system, termed DEG-SLAM. Initially, the system employs the YOLOv5 object detection network to identify dynamic objects, subsequently relaying the semantic information to the tracking module. During the tracking phase, both semantic information and epipolar constraints are leveraged to filter out dynamic feature points. To address the challenges posed by the malfunctioning of epipolar constraints in degenerate scenes, DEG-SLAM incorporates a degenerate constraint mechanism aimed at further eliminating dynamic feature points. Furthermore, a reprojection constraint has been introduced to enhance the filtering of absent dynamic feature points that lie outside the detection boxes. Experimental findings reveal that DEG-SLAM significantly improves accuracy and robustness when compared to traditional ORB-SLAM3 in dynamic environments. The performance benefits of DEG-SLAM are particularly evident in degenerate scenarios, thereby affirming its practicality and reliability in complex settings.
Co-Existence of Compressive and Rarefactive Dust Acoustic Solitary Structures in Saturn’s Rings with Non-Maxwellian Ions and Electrons
Authors: Zaidi Syed Ahmad Muzammil , Qureshi M. N. S. , Khalid Saba
Published: December 2024

In the present study, we investigated the existence of arbitrary amplitude dust acoustic (DA) solitons by considering the Cairns distributed ions, negatively charged streaming dust grains along with (r,q) distributed electrons in an un-magnetized dusty plasma. We used the pseudopotential technique to obtain the solitary wave solution. It is seen that the coexistence of rarefactive and compressive solitons is possible when ions and electrons are nonthermally distributed. We found that the soliton characteristics are strongly dependent on the choice of velocity distribution function through the nonthermal spectral indices r,q, α as well as on the ion and dust temperatures. For (r,q) distributed electrons, we found that the soliton amplitude increases (decreases) with smaller (higher) values of negative (positive) r. For Cairns distributed ions, we found a transition from negative to positive polarity solitary structures with the coexistence in between as the nonthermal parameter α increases. Our results gave a better explanation for the formation of dust acoustic solitary structures (DASS) and their dependence on high and low energy particles in nonthermal distribution profiles in space environments.
Bremsstrahlung emission from nucleon-nucleus reactions in dense medium of compact stars
Authors: Maydanyuk Sergei P. , Xie 谢 Ju-Jun 聚军 , Shaulskyi Kostiantyn A.
Published: December 2024

Bremsstrahlung photons emitted during nucleon-nucleus reactions in compact stars are investigated. The influence of stellar medium density on emission intensity is studied from a quantum perspective for the first time. A bremsstrahlung model is generalized, where a new term describing the influence of the stellar medium is added to interactions between nucleons and nuclei (in the framework of a nuclear model of deformed oscillatoric shells). Polytropic EOS, Chandrasekar EOS, and Harrison-Wheeler EOS are employed for calculation. Haensel and Potekhin's unified EOS of neutron-star matter based on FPS and SLy EOSs are used for tests. Bremsstrahlung calculations are tested on existing measurements of bremsstrahlung in the scattering of protons off 197Au nuclei at a proton beam energy of

MeV. Many properties of bremsstrahlung emitted from nuclear processes in the stellar medium of compact stars are studied for the first time. In particular, the spectra of photons in the scattering of protons and neutrons off 4He, 8Be, 12C, 16O, 24Mg, 40Ca, 56Fe are estimated based on stellar medium density. The medium of white dwarfs has a small influence on the bremsstrahlung emission from nuclear processes, while bremsstrahlung emission is intensive in neutron stars and it is changed in dependence on stellar medium and structure.
Searching Radio Signals from Two Magnetars and a High-magnetic Field Pulsar and the Serendipitous Discovery of a New Radio Pulsar PSR J1935+2200
Authors: Xie Lang , Han J. L. , Yang Z. L. , Jing W. C. , Zhou D. J. , Su W. Q. , Yan Yi , Wang Tao , Cai Nan-Nan , Wang P. F. , Wang Chen
Published: December 2024

Magnetars are slowly rotating, highly magnetized young neutron stars that can show transient radio phenomena for radio pulses and fast radio bursts. We conducted radio observations from two magnetars SGR J1935+2154 and 3XMM J185246.6+003317 and a high-magnetic field pulsar PSR J1846–0258 using the Five-hundred-meter Aperture Spherical radio Telescope (FAST). We performed single pulse and periodicity searches and did not detect radio signals from them. From the piggyback data recorded by other FAST telescope beams when we observed the magnetar SGR 1935+2154, we serendipitously discovered a new radio pulsar, PSR J1935+2200. We carried out the follow-up observations and obtained the timing solution based on these new observations and the archive FAST data. PSR J1935+2200 is an isolated old pulsar, with a spin period of 0.91 s, a spin-period derivative of 9.19 × 10−15 s s−1, and a characteristic age of 1.57 Myr. It is a weak pulsar with a flux density of 9.8 μJy at 1.25 GHz. Discovery of a new pulsar from the long FAST observations of 30 minutes implies that there may be more weak older pulsars in the Galactic disk to be discovered.
Implementing deep learning-based disruption prediction in a drifting data environment of new tokamak: HL-3
Authors: Yang Zongyu , Zhong Wulyu , Xia Fan , Gao Zhe , Zhu Xiaobo , Li Jiyuan , Hu Liwen , Xu Zhaohe , Li Da , Zheng Guohui , Chen Yihang , Zhang Junzhao , Li Bo , Zhang Xiaolong , Zhu Yiren , Tong Ruihai , Dong Yunbo , Zhang Yipo , Yuan Boda , Yu Xin , He Zongyuhui , Tian Wenjing , Gong Xinwen , Xu Min
Published: December 2024

A deep learning-based disruption prediction algorithm has been implemented on a new tokamak, HL-3. An Area Under receiver-operator characteristic Curve of 0.940 has been realized offline over a test campaign involving 72 disruptive and 240 non-disruptive shots, despite the limited training data available from the initial two campaigns. In addition to the well-documented challenge of insufficient training data, a previously unanticipated issue is addressed that the data distribution of a new device is continuously drifting. The plasma scans across a broad parameter space, bringing a drifting distribution of disruption causes and diagnostic data. This problem is often overlooked in previous implementations on steadily operating tokamaks, necessitating greater attention in future tokamaks like ITER. To address these challenges, innovative modules including predict-first neural network, data augmentation, and pseudo data placeholders are developed and implemented, which promotes the accuracy by up to 20%. A series of advantages are also brought by the modules, including the robustness in handling missing input channels, and the interpretability to identify which parameter of plasma is under abnormal condition. The results demonstrate that, with dedicated data collection and algorithm implementation, the issues of limited data and drifting distribution can be overcome, and further, the deep learning-based algorithm can reliably provide disruption alarms on a new tokamak.
Research on Control Technology of Variable Load Gun Pitch Servo System
Authors: Dai Pu , Du Manli , Yang Bo , Cao Yan
Published: December 2024

The artillery pitch servo system has a significant unbalanced torque within its pitch range, which varies greatly with the change of pitch angle. The conventional control method is designed based on the control model of the controlled object. Due to load changes, the control model of the controlled object in the system changes, resulting in poor consistency of control characteristics in different pitch intervals, and even exceeding the dynamic and static performance and system instability in large unbalanced torque pitch intervals. On the basis of analyzing the composition, working principle, and torque variation of the pitch servo system, this article analyzes the problems of conventional control methods and proposes a control method for artillery pitch servo system based on SMVC control. Through MATLAB simulation and experiments, it is shown that this control method can effectively overcome the impact of variable loads on the pitch servo system, significantly improve the dynamic and static performance of the system, and improve the control effect of the system.
Modeling and Simulation Method of Coordinated Manipulator Based on Robotic Toolbox and ADAMS
Authors: Shenggang Wei , Fengjuan Xie , Liguo Hou , Guangning Li
Published: December 2024

The coordinator was an important component of the automatic ammunition loading system of large-caliber artillery. In this paper, kinematics and dynamics of a coordination manipulator with five degrees of freedom were carried out. The forward and inverse kinematics analysis and motion trajectory planning of the simplified coordination manipulator under different firing angles were carried out with Robotic Toolbox to obtain the motion parameters of angular displacement, angular velocity and angular acceleration at each driving joint of the manipulator. Using the motion parameters obtained from the trajectory planning, the inverse dynamics of the manipulator was analyzed by ADAMS, and the driving torque curves of each joint were calculated, which provided a reference for the subsequent prototype development and simulation control of the manipulator.
Optimization design of a dual 5-phase flux-switching permanent-magnet machine for a direct-drive manipulator in artillery automatic loading applications
Authors: Wang Zhe , Tong Minghao , Zhu Jianlong , Chen Longmiao , Xu Zhiyuan , Huangfu Bingbin
Published: December 2024

Due to the increasing demand for high firing speeds in large-caliber artillery, automatic loading systems have become increasingly important. To enhance the reliability of the automatic loading system, a direct-drive rotary manipulator based on a multi-phase outer-rotor flux-switching permanent-magnet machine is proposed. First, the machine topology is designed, including the type, size, rated parameters, and the stator-tooth/rotor-pole combination. Then, aiming to minimize torque ripple and maximize output torque, the optimization procedure is implemented for the proposed machine. The FEA results compare the original and optimized machines. Finally, the structural design of the entire rotary manipulator is presented.
Enhancing Target Tracking Capability in Weapon Systems Using Target Detection and Sensor Network Mechanisms
Authors: Liu Jiancheng , Qi Wanlong , Hou Gang , Lv Mengen , Wang Zhenming
Published: December 2024

The ability to track targets in weapon systems profoundly impacts the precision and potency of target engagement. Stable and accurate target tracking is pivotal for bolstering military capabilities. This study proposes a framework that integrates a target detection probability model with a wireless sensor network mechanism to address challenges in enhancing the reliability of multi-target tracking in weapon systems. We introduce a closed-loop target tracking framework called MTT-SNM, which integrates multiple-source target tracking modules to improve the system’s capability to capture crucial information for target acquisition. Additionally, we devise a position estimation module and a node collaboration module to achieve smooth, continuous future position estimation with higher precision and reduced uncertainty based on current position estimates. This capability aids in guiding coordinated target tracking within the system and enhancing collaborative tracking capabilities. Furthermore, a target recovery module with a four-phase recovery strategy is introduced to swiftly locate targets after loss, thereby enhancing the stability of target tracking in the system. Extensive experimentation validates the outstanding performance of the MTT-SNM framework in system target tracking.
Research on Cooperative Guidance Technology of Small Tactical Air-to-ground Missile
Authors: Yang K , Wang G P , He Y , Peng Y L
Published: December 2024

To explore the feasibility of collaborative guidance for small tactical air-to-ground missiles and enhance their ability to cope with future complex battlefield systems, this article first elaborated on the principle of multi missile collaborative guidance. Then, based on the operational mission of air-to-ground missiles, several collaborative guidance combat modes were proposed. For specific combat modes, time and angle collaborative guidance laws suitable for air-to-ground missiles were designed and developed. Overcoming the problems of short flight time, fast speed and inability to adjust of air-to-ground missiles, and completing mathematical simulation calculations, the results show that this method can effectively solve the problem of coordinated guidance of air-to-ground missiles, achieve simultaneous attack, rapid attack, and multi target attack, and improve the penetration ability, battlefield survival ability, and strike ability of air-to-ground missiles against targets.
Near-Field Target Detection Method for Vortex Electromagnetic Wave Radar based on Modal Baseline
Authors: Sun Jiayue , Liu Junhao , Chen Qian , Fu Chaowei , Zheng Chengxin
Published: December 2024

Vortex electromagnetic (EM) waves can provide more target information, which is orbital angular momentum (OAM), than traditional plane waves in the field of radar detection. By emitting multiple different OAM modes of vortex EM waves to the same target, the azimuth information of the target can be obtained. The Linear Frequency Modulated (LFM) radar is often used in current OAM radar design. At present, researches on vortex EM wave imaging usually requires the emission of a large number of OAM modes to irradiate the target. Although many achievements have been made to significantly reduce this number, it is often accompanied by problems such as loss of azimuth imaging accuracy or poor real-time performance in practical applications. In response to this issue, this paper proposes a near-field target detection method based on modal baseline using vortex EM waves. By alternately emitting vortex EM waves with least OAM mode difference of 1, the method achieves range-velocity imaging while the OAM mode phase information is not blurred. The target detection task is carried out in the range-Doppler dimension, avoiding the problem of azimuth imaging. Through signal processing, our method achieves 3d point cloud detection of target velocity, range, and azimuth. Simulation results compared with traditional phase comparison azimuth measurement method proved the superiority of our method. The work and results provide suggestions to the development of vortex EM wave target detection.
Analysis of the load distribution law and influencing factors of large-load three-stage synchronous ball screw
Authors: Wen Haoxiang , Wang Jinyuan , Zhao Gaoyang , Yao Jianyong , He Xiansong , Yu Xiaochuan
Published: December 2024

Based on the Hertz contact theory, the contact relationship between adjacent balls and lead screw, and the nut raceways is established for a three-stage synchronous ball screw. A model of axial stiffness for the three-stage synchronous ball screw under large load is established. Considering both the axial stiffness of the screw and the deformation of the screw and nut, the distribution of working contact angles and loads of all balls in the three-stage ball screw is established. Taking a three-hinge-point erection mathematical model as an example, a transmission model of the three-stage synchronous ball screw is established, plan the erection trajectory, and analyze and calculate the deformation and force of the balls in the three-stage synchronous ball screw under different load conditions and the force of a single ball in the erection process. The calculation results show that, during the erection process, the load distribution, the radial clearance, the normal deformation between balls and screw and between balls and nut of different balls in each stage of the ball screw are different.
Research on Structural Parameter Design of High Voltage Plane Switch
Authors: Zhou Mi , Li Jiao , Meng Qingying , Wang Yin , Enyi Chu , Lei Jie , Tong Honghai , Diwu Minjie , Yin Guofu
Published: December 2024

In order to determine the structural parameters of the three electrodes of the high-voltage plane switch, the effects of the main electrode gap distance, trigger electrode width, main electrode radius, electrode thickness and other structural parameters on the static breakdown voltage (SBV) of the high-voltage plane switch were obtained by simulation calculation. The optimized structure parameters of the planar switch are obtained, including primary electrode gap 2.0mm, trigger electrode width 1.2mm, trigger electrode in the center of the two main electrodes, and electrode thickness 4 μ m. The performance of the designed high-voltage planar switch is basically consistent with that of the spark gap switch.
Study on Static Explosion Shock Wave Test and Numerical Simulation of Warhead
Authors: Wang Changli , Qian Bingwen , Ke Ming , Zhang Xin , Wu Zhenghao , Li Kang , Zhang Yusong
Published: December 2024

In order to study the distribution law of free field and ground reflection shock wave overpressure in the static explosion test of warhead, based on high-speed photography and image processing technology, the free field shock wave overpressure test at different blast center distance was carried out, and the ground shock wave overpressure test at different blast center distance was carried out with ground shock wave measuring device. The static value simulation of the battle department was performed through the limited element analysis software. The results show that the measurement value of shock wave overpressure will be disturbed by the ballistic wave produced by the fragment passing over the sensor sensitive surface and the vibration of the measuring device. In the free field and ground shock wave tests, the absolute values of the average relative errors of theoretical and measured data are less than 25% and 20% respectively. In the numerical simulation, the absolute values of the average relative errors of the theoretical data of free field and ground shock wave overpressure and the simulation data are less than 16% and 34% respectively, and the absolute values of the average relative errors of the theoretical data of ground shock wave overpressure and the simulation data are less than 25% and 18% respectively. The shock wave overpressure values obtained by test and numerical simulation show that at the same detonation center distance, the ground and free field shock wave overpressure values increase with the increase of the warhead loading ratio, and the closer the distance to the detonation center, the more obvious the increase of shock wave overpressure value with the increase of the loading ratio.
Experimental and simulation of polyurea/CFRP composite structures were studied under high speed impact of projectile
Authors: Liu Q , Chen P W , Zhai H B , Xiao Y
Published: December 2024

With the development of composite structures, polyurea materials can be used to improve the protective performance of multilayer composite structures subjected to explosion or impact. In order to study the penetration resistance of polyurea sprayed CFRP composites, the fragment penetration loading test was carried out with a 14.5mm ballistic gun. The influence of polyurea coating position on the dynamic response of polyurea/CFRP composite structures were analyzed and discussed by test and numerical simulation. The results showed that polyurea coating on the back surface of CFRP can reduce the damage of CFRP and reduce the residual velocity of fragments compared with bare CFRP. The numerical simulation results were in good agreement with the experimental results, which showed that the numerical method can accurately simulate the penetration of fragment into polyurea/CFRP composites structure. The simulation results showed that the energy absorption of polyurea was increased as polyurea was sprayed on the back of CFRP. The lower the fragment initial velocity, the greater the contribution of polyurea for improving the penetration resistance of structure. The large tensile deformation and damage of fiber under the process of penetration can be seen by numerical simulation, revealing that the anti-ballistic mechanism of polyurea.