bluuebunny/crossref_metadata_2025 huggingface dataset:
A Jacobian-free pseudo-arclength continuation method for phase transitions in inhomogeneous thermodynamic systems
Authors: Varner Samuel , Balzer Christopher , Wang Zhen-Gang
Published: August 2024

Developing phase diagrams for inhomogeneous systems in thermodynamics is difficult, in part, due to the large phase space and the possibility of unstable and metastable solutions arising from first-order phase transitions. Pseudo-arclength continuation (PAC) is a method that allows one to trace out stable and unstable solutions of nonlinear systems. Typically, PAC utilizes the Jacobian in order to implement Newton (or quasi-Newton) steps. In this work, we present a Jacobian-free PAC method that is amenable to the usual workflows in inhomogeneous thermodynamics. We demonstrate our method in systems that have first-order phase transitions, including a novel example of polyelectrolyte complex coacervation in confinement, where multiple surface phase transitions occur and can overlap with one another.
Femtosecond laser-produced heterogeneous wettability surfaces for turning Leidenfrost drop spinning
Authors: Liu Yao , Yin Kai , Yang Pengyu , Yan Duanhong , Arnusch Christopher J.
Published: August 2024

Liquid droplets on superheated surfaces produce the Leidenfrost effect. This phenomenon might lead to droplet manipulation and control strategies in microfluidics and thermal management. However, Leidenfrost droplets move randomly and irregularly on superheated surfaces and the manufacturing of special surfaces to control Leidenfrost droplet movement poses great challenges. Here, we propose a simple and environment-friendly method to create heterogeneously wetting surface structures to control the spin motion of droplets on superheated brass using femtosecond laser patterning. The water contact angle of the superhydrophobic area on the surface was ∼160°, and the superhydrophilic area showed ∼7°. A z-shaped pattern was fabricated, which segmented the vapor film and influenced gas flow, and it resulted in the spinning of oval-shaped droplets analogous to a spinning egg. We used simulation to explain this phenomenon and also expanded the application of this droplet control in accelerating dissolution of solids and mechanical driving. This study provides the basis for a creative control method using the Leidenfrost droplet phenomenon, which has broad implications in steam-driven droplet motion and future fluid manipulation.
Policy-guided Monte Carlo on general state spaces: Application to glass-forming mixtures
Authors: Galliano Leonardo , Rende Riccardo , Coslovich Daniele
Published: August 2024

Policy-guided Monte Carlo is an adaptive method to simulate classical interacting systems. It adjusts the proposal distribution of the Metropolis–Hastings algorithm to maximize the sampling efficiency, using a formalism inspired by reinforcement learning. In this work, we first extend the policy-guided method to deal with a general state space, comprising, for instance, both discrete and continuous degrees of freedom, and then apply it to a few paradigmatic models of glass-forming mixtures. We assess the efficiency of a set of physically inspired moves whose proposal distributions are optimized through on-policy learning. Compared to conventional Monte Carlo methods, the optimized proposals are two orders of magnitude faster for an additive soft sphere mixture but yield a much more limited speed-up for the well-studied Kob–Andersen model. We discuss the current limitations of the method and suggest possible ways to improve it.
Bandgap tuning in ZnxCd1−xTe superlattices through variable atomic ordering
Authors: Barone V. , Ellingson R. J. , Khare S. V.
Published: August 2024

We explore the entire search space of 32-layer ZnxCd1−xTe superlattices to find the structures that minimize and maximize the bandgap at each possible zinc concentration. The searching is accomplished through an accurate and efficient combination of valence force field dynamics, the empirical pseudopotential method, and the folded spectrum method. We also describe the use of an alternate preconditioner that improves the robustness and efficiency of the locally optimal preconditioned conjugate gradient’s solutions to the folded spectrum method. The physical properties of these superlattices, such as their formation energies, bandgaps, densities of states, effective masses, and optical response functions, are investigated with density functional theory paired with hybrid functionals and compare well to available experimental measurements. It is revealed that the bandgap of ZnxCd1−xTe may change by up to 0.2 eV depending on how the layers in the superlattice are ordered. Stacking order has a large, irregular effect on the effective masses, but optical response functions seem insensitive to it.
Nonadiabatic dynamics of molecules interacting with metal surfaces: Extending the hierarchical equations of motion and Langevin dynamics approach to position-dependent metal–molecule couplings
Authors: Mäck Martin , Thoss Michael , Rudge Samuel L.
Published: August 2024

Electronic friction and Langevin dynamics is a popular mixed quantum–classical method for simulating the nonadiabatic dynamics of molecules interacting with metal surfaces, as it can be computationally more efficient than fully quantum approaches. In this work, we extend the theory of electronic friction within the hierarchical equations of motion formalism to models with a position-dependent metal–molecule coupling. We show that the addition of a position-dependent metal–molecule coupling adds new contributions to the electronic friction and other forces, which are highly relevant for many physical processes. Our expressions for the electronic forces within the Langevin equation are valid both in and out of equilibrium and for molecular models containing strong interactions. We demonstrate the approach by applying it to different models of interest.
Surface chlorination of IrO2(110) by HCl
Authors: Pope Connor , Yun Jungwon , Reddy Rishikishore , Jamir Jovenal , Kim Dongjoon , Kim Minkyu , Asthagiri Aravind , Weaver Jason F.
Published: August 2024

The ability to controllably chlorinate metal-oxide surfaces can provide opportunities for designing selective oxidation catalysts. In the present study, we investigated the surface chlorination of IrO2(110) by HCl using temperature programmed reaction spectroscopy (TPRS), x-ray photoelectron spectroscopy (XPS), and density functional theory (DFT) calculations. We find that exposing IrO2(110) to HCl, followed by heating to 650 K in ultrahigh vacuum, produces nearly equal quantities of on-top and bridging Cl atoms on the surface, Clt and Clbr, where the Clbr atoms replace O-atoms that are removed from the surface by H2O formation. After HCl adsorption at 85 K, only H2O desorbs at low Cl coverages during TPRS, but HCl begins to desorb in increasing yields as the Cl coverage is increased above about 0.5 monolayer (ML). The desorption of Cl2 was not observed under any conditions, in good agreement with the high barrier for this reaction predicted by DFT. A maximum Cl coverage of 1 ML, with nearly equal coverages of Clt and Clbr atoms, could be generated by reacting HCl with IrO2(110) in UHV. Our results suggest that a kinetic competition between recombinative HCl and H2O desorption under the conditions studied limits the saturation Cl coverage to a value less than the 2 ML maximum predicted by thermodynamics. XPS further shows that the partitioning of Cl between the Clt and Clbr states can be altered by subjecting partially chlorinated IrO2(110) to reductive or oxidative treatments, demonstrating that the Cl site population can change dynamically in response to the gas environment. Our results provide insights for understanding the chlorination of IrO2(110) by HCl and can enable future experimental studies to determine how Cl-modification alters the surface chemical reactivity of IrO2(110) and potentially enhances selectivity toward partial oxidation chemistry.
Stable high energy density in orthogonal layered cathode achieved by trace-substitution strategy
Authors: Guo Chengran , Wang Dongxiao , Guo Zhiqiang , Lyu Yingchun , Xu Shuyin , Zhu Chengjun
Published: August 2024

P′2-type Na0.67MnO2 is considered as one of the most promising cathode materials due to its high theoretical capacities and the low cost of sodium-ion batteries (SIBs). However, the multiple phase transitions and distortion of MnO6 octahedron during Na+ extraction/insertion cause poor structural stability and electrochemical properties. Here, a trace-substitution strategy of electronegative Zn2+ and Ti4+ was applied to balance the high capacity and structural stability. The obtained Na0.67Zn0.04Ti0.06Mn0.9O2 (NZTM4) maintains a high capacity of up to 204.3 and 109 mAh g−1 at 0.1 and 10 C rate, respectively, simultaneously achieving excellent capacity retention of 90.6% after 300 cycles. The Mn-O-Zn-O-Ti local structure formed after Zn incorporation inhibits the distortion of MnO6 octahedron and provides lower activation barrier for Na+ diffusion. With the addition of sodium supplements, this enables a high energy density of 241 Wh kg−1 and satisfactory cycle performance in full cells. These findings provide a promising strategy for designing high-capacity layered cathodes of SIBs.
Cooperative coupling of microscopic enhanced electric field and macroscopic efficient bubble traffic for industrial hydrogen evolution
Authors: Ou-Yang Zhen-Yang , Nie Jianhang , Xia Sheng-Xuan , Xie Meng-Yuan , Xian Ming-Hua , Wan Hui , Huang Gui-Fang , Huang Wei-Qing
Published: August 2024

The alkaline hydrogen evolution reaction (HER) for industrial hydrogen generation is a promising way to achieve intermittent energy storage. However, challenges, such as the insufficient supply of adsorbed hydrogen atoms (*H) and slow bubble dynamics, hinder the development of industrial HER. Here, we report a cooperative strategy by leveraging both microscopic enhanced electric field and macroscopic efficient bubble traffic for industrial hydrogen evolution, demonstrated through the NiCoP nanotips on NiP nanorods (NiCoP-tip@NiP). Specifically, during the HER process, the nanotips can accumulate a large number of electrons, enhancing the electric field of the Stern layer. This enhanced electric field accelerates the dissociation of water, resulting in favorable *H for HER. Simultaneously, the confined space between the nanotips hinders the growth of bubbles generated at the tips. Newly formed bubbles will push out the existing bubbles, thus accelerating gas release. As a result, NiCoP-tip@NiP exhibits a low overpotential of 300 mV at 1000 mA cm−2 and maintains stable operation over 90 h at approximately 300 mA cm−2 during HER processes. This cooperative strategy provides profound insights for industrial hydrogen generation.
Effect of egg weight and maternal flock age on egg characteristics, incubation traits, and offspring performance
Authors: Moreno Filipe Augusto , Dahlke Fabiano , Kuritza Leandro Nagae , Alvarez Marcus Vinícius Niz , Dias Isabella de Camargo , Maiorka Alex
Published: August 2024

Context There are pre-hatch factors that can influence performance during the growing phase, such as the egg size and breeder age. Aims Investigate the influence of egg weight and flock age separately on egg characteristics, hatching traits, hatchling weight, and initial offspring performance. Methods Treatments consisted of eggs laid by 28-week-old (Y), 42-week-old (M), or 61-week-old (O) broiler breeder hens and different egg-weight classes, light (L, 56.6–62.2 g), average (A, 62.3–67.9 g), or heavy (H, 68–73.6 g). Eggs of a similar weight from hens of different ages (treatments YA/ML, YH/MA/OL, and MA/OA) were selected, which allowed us to assess specifically the effect of maternal flock age on the following variables: egg characteristics (eggshell, yolk, and albumen), incubation traits (egg weight loss (EWL), and hatchability), hatchling weight, and live performance of the progeny (7, 14 and 21 days). When data satisfied homogeneity of variance, they were submitted to the one-way ANOVA, and means were compared by Tukey’s test at 5% probability level. Key results Eggshell thickness and albumen height were lower, but albumen weight, yolk weight, and percentage of yolk were higher in eggs produced by older flocks. When eggs of the same weight were evaluated, the variables were also affected by flock ages. EWL increased with the hen age. The age of the hen and egg weight significantly affect the hatchability and hatchling weight. The maximum hatchability was recorded in eggs from broiler breeders at the age of 42 weeks (90.53%). In the average egg-size group (62.3–67.9 g), the young hens produced the lightest chick, and the old flock had the worst hatchability. Broiler’s performance was influenced both by flock age and egg weight. Conclusions The eggshell thickness is mainly influenced by the egg size. However, other egg features are affected by flock age. EWL and chick weight are reduced in young flocks. The oldest flocks produced heavier chicks and the positive effect on feed intake and bodyweight remained until 14 days of age. Implications Egg size and broiler breeder age can influence the egg traits and performance of broilers.
Modifications to the soft-walled Thomas trap
Authors: Meek P. D. , Collingridge L. , Smith D. , Thomas N.
Published: August 2024

We provide some recommended methods of modifying and using the Thomas trap to assist future use by field practitioners and to facilitate manufacture improvements. These recommendations are based on the original designer’s and author’s experience, and discussions with other practitioners.
AlphaFold two years on: Validation and impact
Authors: Kovalevskiy Oleg , Mateos-Garcia Juan , Tunyasuvunakool Kathryn
Published: August 2024

Two years on from the initial release of AlphaFold, we have seen its widespread adoption as a structure prediction tool. Here, we discuss some of the latest work based on AlphaFold, with a particular focus on its use within the structural biology community. This encompasses use cases like speeding up structure determination itself, enabling new computational studies, and building new tools and workflows. We also look at the ongoing validation of AlphaFold, as its predictions continue to be compared against large numbers of experimental structures to further delineate the model’s capabilities and limitations.
Decline in carbon emission intensity of global agriculture has stagnated recently
Authors: Bai Zhaohai , Zhang Nannan , Winiwarter Wilfried , Luo Jiafa , Chang Jinfeng , Smith Pete , Ledgard Stewart , Wu Yan , Hong Chaopeng , Conchedda Giulia , Ma Lin
Published: August 2024

Using global data for around 180 countries and territories and 170 food/feed types primarily derived from FAOSTAT, we have systematically analyzed the changes in greenhouse gas (GHG) emission intensity (GHGi) (kg CO2eqper kg protein production) over the past six decades. We found that, with large spatial heterogeneity, emission intensity decreased by nearly two-thirds from 1961 to 2019, predominantly in the earlier years due to agronomic improvement in productivity. However, in the most recent decade, emission intensity has become stagnant, and in a few countries even showed an increase, due to the rapid increase in livestock production and land use changes. The trade of final produced protein between countries has potentially reduced the global GHGi, especially for countries that are net importers with high GHGi, such as many in Africa and South Asia. Overall, a continuous decline of emission intensity in the future relies on countries with higher emission intensity to increase agricultural productivity and minimize land use changes. Countries with lower emission intensity should reduce livestock production and increase the free trade of agricultural products and improve the trade optimality.
Digital multimodal composing as a translanguaging space
Authors: Wang Danping
Published: August 2024

Multimodality and translanguaging are groundbreaking concepts that researchers and teachers in second language
education have increasingly embraced over the past decade. Despite their potential to transform traditional monolingual and
monomodal approaches to assessment design, these concepts remain largely unexplored in Chinese language teaching, particularly as
legitimate assessment strategies. This study was conducted with a large group of ab initio beginners of Chinese at a Western
university. It first analyses students’ digital multimodal composing (DMC) projects, a video assessment designed to enable
students to showcase their learning achievements multimodally and multilingually. It then discusses the challenges students
encountered when engaging with this novel assessment approach for the first time. Findings demonstrate that in this DMC project
students created a translanguaging space with rich trans-semiotic resources, actively engaging in communication through their
newly acquired language despite being absolute beginners in their first few weeks of learning. Furthermore, due to the novelty of
the assessment design, the study also found that some students encountered challenges such as uneven technical skills and the
complexity of the assessment design. The study suggests that teachers should reconceptualise their approach to teaching Chinese in
the digital age, focusing on empowering learners to apply their language skills in real-life communication contexts. Building
ownership of their L2 learning can strengthen their motivation to learn Chinese more effectively and creatively.
The endolysosomal system in conventional and unconventional protein secretion
Authors: Néel Eloïse , Chiritoiu-Butnaru Marioara , Fargues William , Denus Morgane , Colladant Maëlle , Filaquier Aurore , Stewart Sarah E. , Lehmann Sylvain , Zurzolo Chiara , Rubinsztein David C. , Marin Philippe , Parmentier Marie-Laure , Villeneuve Julien
Published: August 2024

Most secreted proteins are transported through the “conventional” endoplasmic reticulum–Golgi apparatus exocytic route for their delivery to the cell surface and release into the extracellular space. Nonetheless, formative discoveries have underscored the existence of alternative or “unconventional” secretory routes, which play a crucial role in exporting a diverse array of cytosolic proteins outside the cell in response to intrinsic demands, external cues, and environmental changes. In this context, lysosomes emerge as dynamic organelles positioned at the crossroads of multiple intracellular trafficking pathways, endowed with the capacity to fuse with the plasma membrane and recognized for their key role in both conventional and unconventional protein secretion. The recent recognition of lysosomal transport and exocytosis in the unconventional secretion of cargo proteins provides new and promising insights into our understanding of numerous physiological processes.
Emergence of cosmic space and horizon thermodynamics from Kaniadakis entropy
Authors: Prasanthan Pranav , Nelleri Sarath , Poonthottathil Navaneeth , E K Sreejith
Published: August 2024

Utilizing Kaniadakis entropy associated with the apparent horizon of the Friedmann–Robertson–Walker Universe and applying the emergence of cosmic space paradigm, we deduce the modified Friedmann equation for a non-flat (n+1)-dimensional Universe. Employing the first law of thermodynamics, we arrive at the same modified Friedmann equation, showing the connection between emergence of cosmic space and first law of thermodynamics. We also establish the condition to satisfy the generalized second law of thermodynamics within the Kaniadakis framework. Our study illuminates the intricate connection between the law of emergence and horizon thermodynamics, offering a deeper insight through the lens of Kaniadakis entropy.
The water bottle flipping experiment: a quantitative comparison between experiments and numerical simulations
Authors: Nassoy Julie , Huu Margot Nguyen , Rembotte Léon , Trebbia Jean-Baptiste , Nassoy Pierre
Published: August 2024

The water bottle flip experiment is a recreational, non-conventional illustration of the conservation of angular momentum. When a bottle partially filled with water is thrown in a rotational motion, water redistributes throughout the bottle, resulting in an increase of moment of inertia and thus a decrease in angular velocity, which increases the probability of it falling upright on a table as compared with a bottle filled with ice. The investigation of this phenomenom is accessible to undergraduate students and should allow them to gain better understanding of combined translational and rotational motions in classical mechanics. We report a series of detailed experiments that are quantitatively compared with numerical calculations based on a simple theoretical framework in which the water volume is decomposed into thin slices of a rigid body that are subjected to fictitious forces in the non-inertial frame of the spinning bottle. This model also allows us to capture and predict other experimental configurations. Finally, we discuss additional counter-intuitive effects that contribute to bottle stabilization on landing.
Optical fiber shape reconstruction algorithm based on 3D Euler spiral model
Authors: Tian Ye , Zhu Shicheng , Duan Chao , Tan Tao , Mu Daolu , Chen Wenli , Zhang Jianzhong
Published: August 2024

This paper presents a reconstruction algorithm that uses a 3D Euler spiral model to construct the microsegment of a 3D space curve to improve the reconstruction efficiency. Euler spiral is a curve whose shape information changes linearly with arc length, which improves the current assumption of the reconstruction algorithms that the shape information of the micro-segment is constant, and effectively reduces the number of interpolations required, and thus improves the efficiency of the shape algorithm. To verify the effectiveness of this algorithm, a method for constructing random space curves is proposed. Three random space curves of different lengths are reconstructed and the results are compared with the reconstruction algorithms based on the homogeneous transformation matrix and Bishop frame. The results show that this model can significantly improve the efficiency of the algorithm. Under the random space curves of 1 m, 10 m, and 100 m, the efficiency is enhanced by about 15, 27, and 30 times respectively. Prepare a shape sensor with a length of 1465 mm to verify the highest reconstruction accuracy of 3D Euler spiral model, which is consistent with the simulation results. The results provide a solid foundation for further research in the field of shape sensing, and show potential for promoting the development of applications that rely on real-time shape measurements.
A novel method for the classification of 3D point clouds based on the improved PointNet++
Authors: Liu Ziming , Li Guoguang , Wang Beibei , Yan Bin , Gao Ruizhen
Published: August 2024

In deep learning, point clouds are used as the primary input format for 3D data, which can provide detailed geometric information about objects in the original 3D space. PointNet++ is a deep learning network that uses point cloud data as an input format, which avoids the losses associated with the previous conversion of point cloud into 3D voxelization and a collection of 2D images. Although PointNet++ can directly process point cloud data in various ways, due to the disordered, irregular, and unevenly distributed nature of point cloud data, the effect of extracting point cloud features could be better. The large amount of point cloud data also leads to the training model falling into the local optimal solution, which affects the training results. In recent years, some effective methods and strategies have emerged to address these problems. In this study, three methods are proposed based on the PointNet++ network: feature similarity-based attention pooling, small kernel convolution, and diverse branch block method to improve the performance of the PointNet++ network. Experiments show that the improvement methods proposed in this paper effectively improve the feature extraction accuracy, which improves the accuracy of the PointNet++ network for classification on the ModelNet40_Normal_Resampled dataset, with an overall improvement of 1% compared with PointNet++.
Electromagnetic and thermal performance study on a canted stack of REBCO tapes
Authors: Wang Mingyang , Meng Xuan’ang , Wang Xueliang , Ye Haosheng , Zhou Xuan , Sheng Jie , Li Zhuyong , Jin Zhijian
Published: August 2024

Due to the critical current limitation of a single rare-earth barium copper oxide (REBCO) tape, stacking methods are generally employed to increase the current carrying capacity in practical high-temperature superconducting (HTS) applications. However, the overall critical current is strongly dependent on the self-magnetic field, which is influenced by the geometrical arrangement of conductors in the stack. Due to their brittle ceramic properties, REBCO tapes are conventionally bent along the thickness side of the tape. However, the difference in bending radii of the outer and inner tape surfaces in the stack may lead to fracture deformation, thereby limiting the stacking number of REBCO tapes. To balance the stacking number with the bending issue, a canted stack is proposed as a variant of the normal stack for REBCO tapes. As a potential HTS intermediate component, it is imperative to conduct a comprehensive study on the electromagnetic and thermal performance of the canted stack. The unique geometrical arrangement of the canted stack introduces new factors that affect the critical current and transport AC loss. This paper concludes with the special influencing factors of canted stacks, including canted angle, stacking number, tape width, and spatial structure. The metal interleaving method is introduced for spatial distribution changing and thermal stability. Furthermore, orthogonal analysis is performed to elucidate the comprehensive correlation among these multiple factors. This study provides insights into the overall critical current and transport AC loss for different combinations of canted stack and establishes a predicting function for critical current to support the structural design of canted stacks. Based on the specific case study, the improved capability of the canted stack is confirmed by both experiments and simulations.
Fast current discharging using self-coupling energy absorption for insulated high temperature superconductor magnets
Authors: Liu Jingyi , Lu Zhen , Wang Yawei , Yang Qingqing , Fu Yutong , Zhao Yue , Jin Zhijian
Published: August 2024

Quench protection has always been challenging for high-temperature superconductor (HTS) coils. Fast current discharge after quench detection is important for a successful coil protection. The copper plates initially intended for cooling can significantly accelerate the discharging process for HTS coils through electromagnetic coupling between coils and copper plates. However, the underlying physical mechanism of this technique has not been studied thoroughly. Here we present a detailed study on the electromagnetic and thermal characteristics of HTS coils coupled with copper plates through experiments and simulations. The results show that a considerable current rebound occurs after an accelerating current drop in the early stage of the fast-discharging process. This coil current rebound is induced by temperature rise as well as the resistivity of copper plates, which are heated by induced eddy current. The heat transfer from copper plates can uniformly heat the whole coil rapidly, which speeds up the discharging process, meanwhile it can also induce overcurrent quench risk. A 30 T@20 K HTS magnet with 36 single pancakes is analyzed. The coupling copper plates can make the coil current drop to 36.9% within the initial 8 ms. The temperature rise induced by copper plates shows a considerable nonuniform distribution among the multiple coil systems. The protection can be enhanced by optimizing the resistivity of copper plates and magnetic coupling strength between plates and coils. This technique has great potential for the protection of insulated HTS magnets.
D-nontrilocality of sparse probability tensors and the triangle network
Authors: Zhao Xue-Yan , Chen Zheng-Li , Wang Wen-Hua , Cao Huai-Xin
Published: August 2024

Bell’s inequalities are linear and apply for cases of two entangled bodies. In this work, we consider the case of entanglement among three bodies as previously discussed in [Renou, et al Phys. Rev. Lett., 123, 140 401 (2019)] and based on triangle network. By discussing the question whether a sparse probability tensor (SPT) can be represented by a discrete trilocal hidden variable model (D-triLHVM), we show that every SPT having a D-triLHVM satisfies a set of concrete equalities and a nonlinear inequality, which can be used to detect whether a D-triLHVM can describe the network completely. As an application, we re-explore the D-nontrilocality of the correlations studied by Renou et al and that of the triangle network with shared entangled pure states. We also leave open questions about the closednees of the set of all D-trilocal probability tensors and the description with a continuous trilocal hidden variable model.
Large scale massively parallel numerical simulation for blast effects on structures
Authors: Liu N , Zeng F , Wang J , Wang J T , Zhang P , Li K , Yu Y Q
Published: August 2024

An efficient large-scale parallel computing program for blast effects on structures is developed based on software platform mode, which adopts component-based three-layer software architecture to achieve disciplinary hierarchy. The parallel layer encapsulates high-performance data structures and shields large-scale parallel computing technology, enabling efficient mesh adaptivity. The common numerical algorithm layer encapsulates fluid, structural, and coupling algorithm processes providing standardized interfaces for extending numerical schemes. The physical model layer provides extension interfaces for state equations, source terms, initial boundary values, etc, to facilitate quick customization of large-scale parallel software for blast effects on structures. Typical examples verify the correctness, effectiveness and high precision of the proposed program in fluid-structure coupling problems. The parallel efficiency of 300,000 processor cores with hundreds of millions of grids reach 60.84% for the shock wave transmission. Finally, the dynamic behavior of multi-storey buildings under blast waves is simulated to reveal the damage model of the overall collapse. These results show that the software has a broad application prospect in the field of explosion. The results suggest that the software holds significant potential for application in the field of explosion, particularly in intricate and large-scale scenarios.
Research on integrated LiDAR and multi-parameter detection of atmospheric transmittance, turbulence, and wind
Authors: Hu Yalin , Xie Chenbo , Zhou Hui , Xing Kunming , Wang Bangxin , Wang Yingjian
Published: August 2024

An integrated LiDAR system has been reported, which can be used for simultaneous detection of atmospheric transmittance, turbulence, and wind along the same path. Through the integrated design of optics and mechanics, the size and weight of the system were effectively reduced. The comprehensive detection distance of atmospheric transmittance, atmospheric coherence length, and radial wind had also been achieved at least 4 kilometers. Comparative experiments have demonstrated that the detection results of the integrated LiDAR system and the near-surface meteorological observation system have standard deviations of less than 0.03 km−1 for extinction coefficient, 0.2 m/s for wind velocity, and 7.15 × 10−14 m−2/3 for C

2

n
(atmospheric refractive index structure parameter), thus verifying the accuracy of the system detection. The reliability of the integrated LiDAR system was validated through six consecutive nights of continuous detection experiments, measuring three parameters simultaneously. Through analysis, the influence laws among atmospheric transmittance, coherence length, and wind were preliminarily explored. Significant variations in wind velocity can induce substantial fluctuations in atmospheric coherence length, and it is positively correlated with atmospheric transmittance. The integrated LiDAR system can provide a variety of reliable real-time detection data for further research on the laser transmission process in the atmosphere.
Extreme ultraviolet emission spectra of a low-pressure microwave neon discharge
Authors: Ye Zeyi , Yu Yue , Li Wenbin , Qi Runze , Wang Zhanshan
Published: August 2024

In this paper, in order to reveal the discharge mechanism and optimize the extreme ultraviolet (EUV) emission lines in intensity of a low-pressure microwave (MW) neon discharge, the EUV neon spectra is carefully characterized under varied MW powers and neon pressures. The corona balance is verified to be valid for the neon upper levels of the measured EUV lines, and the electron temperature T

e
is derived by the modified Boltzmann plot method and the line-ratio method. Both results of the methods present a decreasing trend of T

e
with growing neon pressure, but the values in a range of 1.87-5.77 eV deduced by the former method is in general lower than that calculated by the latter with a range of 2.23–5.58 eV in similar neon pressure range. It is also found that the increase of MW power from 90 to 135 W only leads to a slight increasing of T

e
. A global model is applied to estimate the electron density n

e
, which is found to lie in the order of magnitude of 1010 cm−3. The dependence of the plasma parameters on different discharge conditions is analysed in detail, which in turn provide a favourable basis for further optimization of the promising low-pressure MW discharge radiation source.
Viscous modified Chaplygin gas with spherical top-hat collapse in modified theories of gravity
Authors: Kundu Rownak , Debnath Ujjal , Pradhan Anirudh
Published: August 2024

The work explores the dynamics of a spherically symmetric perturbation of viscous modified Chaplygin gas (VMCG) in different gravity theories within the spherical top hat collapse framework (SC-TH). The study investigates the behaviour of perturbed quantities such as the δ, θ, w, w

c
, c
s

2, c
e

2, and h using numerical and graphical analysis. Our findings reveal that VMCG generates quintessential dark energy without crossing over to the phantom barrier in most of the gravity models considered here. Further, in all the gravity models considered here, VMCG remained classically stable. This research offers new insights into the evolution of VMCG in different gravitational contexts. In this paper, we have examined the collapse of viscous modified Chaplygin gas in the context of (i) Einstein’s gravity, (ii) Loop quantum cosmology, (iii) generalised Rastall gravity, and (iv) the fractal universe. We have also addressed their comparative analysis.
Bulk properties of nuclear matter in a modified relativistic dirac formalism
Authors: Panda A K , Panda S , Panda B K
Published: August 2024

In this study, we employ a phenomenologically modified relativistic Dirac framework coupled with the σ - ω quark-meson coupling model to look into the properties of nuclear matter. By combining scalar and vector linear potential forms and incorporating perturbative adjustments for various factors such as centre-of-mass motion, gluonic, and pionic effects, we aim to find the nucleon’s mass in a vacuum. Then, we consider nucleon-nucleon interactions are constructed within a mean-field approximation. Our methodology systematically explores key characteristics of nuclear matter, including equations of state, compressibility, binding energy, and pressure. Furthermore, we compute essential parameters such as the nucleon charge radius, axial-vector coupling constant, pion coupling constant, nuclear sigma term, sensitivity, and potential strengths. And also, we calculate symmetry energy, density slop (L) and incompressibility (

K
0

). In addition, we compute the mass and radius of a neutron star and provide a graphical representation illustrating the relationship between mass and radius. To validate our results, we comprehensively compare them with other theoretical models and quark-meson coupling approaches, confirming the precision and reliability of our theoretical paradigm. Overall, our study enhances our understanding of the fundamental properties of nuclear matter and underscores their relevance in elucidating complex astrophysical phenomena.
Investigating the dielectric and ferromagnetic behaviour of Ni and Co dual doped ZnO for diluted magnetic semiconductor
Authors: Kant Ravi
Published: August 2024

Herein, Ni/Co co-doped ZnO nanoparticles (NPs) were successfully prepared via chemical co-precipitation process. The structural, purity and crystallite size of as-prepared particles were confirmed by using x-ray diffraction (XRD). The results revealed the hexagonal wurtzite structure of ZnO without any impurity phase of as-prepared samples. The crystallite size decreased from 34.9 to 9.6 nm, whereas lattice strain reduced to 0.00086. The change in crystallite size, lattice parameters, strains and dislocation density further indicates the successful incorporation of dopants in ZnO host lattice. The dielectric properties, ac conductivity, and magnetic behaviour were steadily examined. The dielectric constant has been found to be 1070 with 5wt% at low frequency and become constant at higher frequency. It was revealed that dopant additions lead to attain high dielectric constant and low loss possibly attributed to interface polarization, and dipole polarization due to oxygen vacancy defects. M-H measurement observed that ferromagnetism at room temperature pure and doped ZnO samples. The ferromagnetic behaviour of pure ZnO NPs with Ms = 0.17 emu g−1, Mr = 0.11 emu g−1 and Hc = 67 which was increased to Ms = 0.85 emu g−1 and Mr = 0.65 emu/g for 5wt% Co. This improvement with increasing Co concentration indicates that oxygen defects may stabilize the ferromagnetic order. These interesting features encouraging to use this material for ultrahigh dielectric materials and spintronics.
The de Broglie-Einstein-Rosen gravitational wave
Authors: D’Errico Luca
Published: August 2024

de Broglie gravitational waves are solutions of the linearized Einstein's field equations in vacuum, with intriguing properties. They are axially symmetric and have an effective mass, which is responsible for longitudinal effects that are absent in standard gravity waves. Moreover, they represent a classical realization of a form of dynamics proposed for quantum particles by de Broglie one hundred years ago. In this paper we will show that this perturbation field can be obtained, apart from a proportionality constant, in the weak field limit of a particular Einstein-Rosen field, which we call the de Broglie-Einstein-Rosen wave. Some properties of this exact solution are also discussed.
Structural, electronic, and optical properties of Zn-doped V2O5 thin films
Authors: Ikhlaq Uzma , Sami Samiullah , Khalil Maria , Ullah Farman , Ramay Shahid M , Ali Shahzad Akhtar , Saleem Murtaza
Published: August 2024

V2O5 shows a diverse range of applications due to its remarkable electronic and optical properties. This research is designed to tune the electronic and optical properties of V2O5 through modification in the energy band profile by varying Zn doping concentration. Density functional theory (DFT) calculations were used to investigate the Density of States (DOS) spectra for pure V2O5, exhibiting the prominent contribution of V-d and O-p orbitals, representing the p-d hybridized orbitals along with additional Zn-d orbital contribution in Zn-doped compositions. The effects of doping on the structural, morphological, elemental, and optical properties of the developed thin films were investigated employing x-ray diffraction (XRD), scanning electron microscope (SEM), x-ray dispersive spectroscopy (EDX), and spectroscopic ellipsometry (SE), respectively. x-ray diffraction analysis revealed the orthorhombic crystal structure in thin films. Surface morphology depicts the uniformly distributed compact rod-like features. The experimentally calculated band gap was found to decrease with Zn doping from 2.77 eV for pure V2O5 to 2.45 eV for maximum doping content. A significant variation is recorded in optical parameters like the increase in absorption coefficient and optical conductivity, which makes these more favorable for optoelectronic devices, particularly focusing on photovoltaics.
An improved YOLOv8 model enhanced with detail and global features for underwater object detection
Authors: Zhai Zheng-Li , Niu Niu-Wang-Jie , Feng Bao-Ming , Xu Shi-Ya , Qu Chun-Yu , Zong Chao
Published: August 2024

Underwater object detection is significant for the practical research of mastering existing marine biological resources. In response to the challenges posed by complex underwater environments such as water scattering and variations in object scales, researchers have developed YOLOv8 for object detection, driven by the rising popularity and iteration of deep learning. Building upon this model, we propose an enhanced underwater object detection model named YOLOv8-DGF. Firstly, we replace the convolutional layers of Spatial Pyramid Pooling Fusion (SPPF) with Invertible Neural Networks to further augment the fusion capacity of detailed features, facilitating the preservation of pivotal information while mitigating the impact of noise. Additionally, we introduce a global attention mechanism into Convolution to Fully Connected (C2f), which weights the input features, thereby emphasizing or suppressing feature information from different locations. Through our ‘Detail to Global’ strategy, the model achieved mAP@0.5 scores of 87.7% and 84.8% on the RUOD and URPC2020 datasets, respectively, with improved processing speed. Extensive ablation experiments on the Pascal VOC dataset demonstrate that YOLOv8-DGF outperforms other methods, achieving the best overall performance.
Observation of dielectric anomaly at magnetic transition temperature in NdMn1xZnxO3/SNTO (x = 0.00, 0.05, 0.10) films
Authors: Vyas Brinda , Ravalia Ashish , Udeshi Malay , Kuberkar D G
Published: August 2024

We report our observation of dielectric anomaly from temperature–dependent dielectric study near the antiferromagnetic transition (TN) in pure and Zn–doped NdMnO3/SNTO (SrNb0.002Ti0.998O3) epitaxial films. Structural and microstructural studies showed the presence of compressive strain along the a–axis and changes in grain size due to Zn–substitution. The variation in the elemental concentration of Zn was confirmed by RBS measurements led to amend Mn–Mn exchange interactions in doped films. Alteration in TN due to Zn–doping, obtained from D.C. magnetization is consistent with the dielectric anomaly temperatures, indicating the presence of magnetoelectric effect in pure and Zn–doped NdMnO3/SNTO system.
Noether symmetries and conservation laws in some analytic spherically symmetric spacetimes of f(R, L

m
) gravity
Authors: Dalal Preeti , Singh Karanjeet , Kumar Sachin , Malik Sandeep
Published: August 2024

In general relativity, dark energy is usually illustrated by a cosmological constant(Λ), but f(R, L

m
) gravity provides a different approach to cosmic acceleration by modifying the gravitational theory. In the present paper, the non-static spherically symmetric spacetimes have been derived by taking into account f(R, L

m
) = f
1(R) + H(L

m
)f
2(R). Lie symmetry approach is operated to reduce the order of the partial differential equations corresponding to the field equations, which are further solved. Killing and Noether symmetries provides insights into the conservation laws. So, the obtained spacetimes have been investigated to obtain the Killing and Noether symmetries. The Lagrangian approach have been used to obtain the Noether symmetries. This study is well-structured, as it provides a justification for the well-established result that Noether symmetries encompass Killing symmetries [1]. Also the conserved quantities and commutators of Noether symmetries have been calculated.
CMB spectral distortions from enhanced primordial perturbations: the role of spectator axions
Authors: Putti Margherita , Bartolo Nicola , Bhattacharya Sukannya , Peloso Marco
Published: August 2024

Primordial scalar and tensor modes can induce Cosmic Microwave Background spectral distortions during horizon re-entry. We investigate a specific mechanism proposed for this purpose, characterized by the coupling of an SU(2) gauge field to an axion undergoing a momentary stage of rapid evolution during inflation. Examining in details the perturbations produced by this model, we find that spectral distortions from the scalar modes significantly dominate those arising from the tensors. This holds true also for an earlier version of the model based on a U(1) gauge field. The scalar-induced distortions might be observed in future experiments, and the current COBE/FIRAS constraints already limit the parameter space of these models. Additionally, we find that delaying the onset of fast roll in the SU(2) scenario (to enhance the modes at the scales relevant for spectral distortions, while respecting the CMB constraints at larger scales) poses a greater challenge compared to the U(1) case. We propose a way to control the axion speed by varying the size of its coupling to the gauge fields.
String theory and the first half of the universe
Authors: Apers Fien , Conlon Joseph P. , Copeland Edmund J. , Mosny Martin , Revello Filippo
Published: August 2024

We perform a detailed study of stringy moduli-driven cosmologies between the end of inflation and the commencement of the Hot Big Bang, including both the background and cosmological perturbations: a period that can cover half the lifetime of the universe on a logarithmic scale. Compared to the standard cosmology, stringy cosmologies with vacua that address the hierarchy problem motivate extended kination, tracker and moduli-dominated epochs involving significantly trans-Planckian field excursions. We analyse the cosmology within the framework of the Large Volume Scenario but explain how analogous cosmological features are expected in other string theory models characterized by final vacua located in the asymptotic regions of moduli space. Conventional effective field theory is unable to control Planck-suppressed operators and so such epochs require a stringy completion for a consistent analysis. Perturbation growth in these stringy cosmologies is substantially enhanced compared to conventional cosmological histories. The transPlanckian field evolution results in radical changes to Standard Model couplings during this history and we outline potential applications to baryogenesis, dark matter and gravitational wave production.