bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of the Performance of Pegasos and Traditional Models in the Task of Sentiment Classification of Product Reviews
Authors: Zhu Di
Published: January 2025

Sentiment classification of a large number of commodity reviews is very important for customer selection and market trend prediction. The key to achieving high accuracy of sentiment classification is to select appropriate models for training. However, most of the existing research literature only uses traditional models or does not have a scientific comparison between models, and only provides training steps for a model that can be used for text sentiment analysis. Therefore, in this study, three models (two traditional models and one new model Pegasos) were selected for comparison. The same datasets and data preprocessing methods were selected for the three models to compare the final emotion classification accuracy, and finally, the experimental result with the highest accuracy of the Pegasos model was obtained. The study also analyzed the performance of different models in the experimental results and found the reasons for the poor performance of traditional models in handling sentiment classification tasks and the reasons for the good performance of Pegasos models. In the process of model hyperparameter tuning, the optimal number of iterations is 25 by comparing the classification accuracy under different iterations.
Lung Cancer Prediction Based on K-nearest Neighbor and Other Algorithms
Authors: Ren Yimo
Published: January 2025

Lung cancer is still the most affected type of cancer in the world. The purpose of this study is to achieve a certain accuracy of lung cancer prediction based on a variety of computer algorithms, to effectively reduce the prevalence of cancer in the future. The computer algorithms mainly used in this paper include Random forest, K-nearest neighbours, and Logistic regression. By collecting lung cancer patients and clinical data sets, basic prediction is realized through programming code, and data visualization is finally realized to complete prediction. Finally, it is found that the prediction of lung cancer using a single variable is not accurate, and there are many factors leading to lung cancer. It is necessary to import as many data sets as possible to increase the reliability of prediction. The study found that smoking had the greatest impact on the risk of developing lung cancer. After the study in this paper, it is recommended that all people carry out a healthy life schedule, which can effectively prevent lung cancer. At the same time, the study found that the prediction of lung cancer by computer algorithm is achievable, and more algorithms can be combined to achieve higher precision prediction in the future.
Decoding Consumer Behavior in the Used Car Market: A Machine Learning Approach to Key Decision Factors
Authors: Zhang Minshun
Published: January 2025

This paper analyzes the main factors influencing consumer decision-making in the used car market. With the growing importance of the second-hand vehicle industry, understanding buyer behavior has become crucial for optimizing market strategies. Additionally, the increasing reliance on digital platforms has shifted the dynamics of how consumers evaluate and purchase used cars. The focus is on how online and offline trading platforms affect purchasing behavior. Using machine learning techniques, the paper compares multiple models to predict key purchase factors and visualize the data through various graphs. The findings reveal that factors such as car price, mileage, brand reputation, and online reviews play critical roles in shaping buyer preferences. Specifically, car price and mileage were found to be the most influential factors, with buyers showing a clear preference for vehicles offering better value relative to these parameters. Brand reputation further adds to consumer confidence, often tipping the balance when similar cars are compared. Additionally, online reviews and ratings significantly impact consumer trust, with buyers relying on peer feedback to assess the credibility of the seller and the condition of the vehicle. These factors collectively highlight the interplay between economic considerations and trust-building in consumer decision-making. The analysis provides practical recommendations for both consumers and platforms to optimize decision-making processes.
A mathematical model for coregistered data from electroencephalography and diffusive optical tomography
Authors: Darbas M. , Lohrengel S. , Sulis B.
Published: January 2025

A mathematical model for coregistered time-dependent electroencephalography (EEG) and diffusive optical tomography (DOT) is developed and analysed. Evolution with time is introduced by considering time-dependent dipolar sources in the EEG model and time-dependent optical parameters for DOT. Dimensional analysis shows that time-derivatives can be neglected. A non-linear system of differential equations from literature is used to model the postsynaptic current and hemodynamic parameters at the neuron level. A key point of the full model is to explain how these quantities provide, at the level of the whole head, the moment of the dipolar source term of the EEG problem and the behaviour in time of the optical parameters of the DOT model. The well-posedness of the timedependent EEG problem is proved by the subtraction approach for moments with L2-regularity in time and continuous source trajectories. For the time-dependent DOT model with continuous optical parameters in time, standard results of functional analysis apply. We explain the full pipeline from the stimulation current up to the simulated signals recorded at the electroptodes. Numerical results for a three-dimensional realistic head model illustrate the capacity of simultaneous EEG/DOT measurements to attest neurovascular coupling between the neural activity and changes in the hemodynamic parameters.
Expansion of the known host range of Giardia duodenalis and Cryptosporidium spp. in captive wildlife at Beijing Zoo
Authors: Zhao Qianming , Pei Zhiyang , He Yongqiang , Jia Ting , Zhang Yanzhen , Zheng Mengjun , Zhang Zhenjie , Qi Meng
Published: January 2025

Giardia duodenalis and Cryptosporidium spp. are significant zoonotic parasites that cause diarrhea and affect a diverse range of hosts. This study aimed to investigate the infection rates of these parasites in captive wildlife at Beijing Zoo. A total of 445 fecal samples were collected and analyzed using PCR. The infection rate of G. duodenalis was 3.82% (17/445), with assemblage A (n = 1), assemblage B (n = 13), and assemblage E (n = 3) identified. The infection rate of Cryptosporidium spp. was 0.22% (1/445), with only one instance of C. ryanae identified from cattle (Bos taurus). To the best of our knowledge, this study enhances the understanding of the host range of G. duodenalis in captive wildlife within China, highlighting infections in Corsac Fox (Vulpes corsac), Indian Rhinoceros (Rhinoceros unicornis), and Giraffe (Giraffa camelopardalis). These findings indicate that the infection rates of G. duodenalis and Cryptosporidium spp. in captive wildlife at Beijing Zoo are low, while showing that the known host range of G. duodenalis is expanding.
Multi-instrument Observations of Ionospheric Super Plasma Bubbles in the European Longitude Sector during the 23–24 April 2023 Severe Geomagnetic Storm
Authors: Zakharenkova Irina , Cherniak Iurii , Braun John J. , Wu Qian , Sokolovskiy Sergey , Hunt Douglas , Weiss Jan-Peter
Published: January 2025

This study’s objective is to better specify the rare occurrence of super equatorial plasma bubbles in particular in the European longitude sector, detailing their spatio-temporal evolution, and better understanding pre-conditions for their development. Our comprehensive multi-instrument analysis combined ground-based and space observations from GNSS, ionosondes, and several satellite missions (COSMIC-2, GOLD, Swarm). We have investigated the ionospheric response to the 23–24 April 2023 severe geomagnetic storm and have shown the formation of super plasma bubbles expanding from equatorial latitudes to middle latitudes in the European/African sector during the main phase of the storm. Formation of these super bubbles was associated with storm-induced prompt penetration electric fields. We found that the area affected by the formation of numerous plasma bubbles covered more than 5000 km ranging from 30°W to 30°E in the Atlantic/African sector. The bubbles also had an impressive north-south extension, reaching as far poleward as ~30°–35° latitude in both hemispheres. After 20 UT on 23 April 2023, the zone with equatorial ionospheric irregularities reached Northern Africa, the Iberian Peninsula (Spain, Portugal) and the Mediterranean Sea in southern Europe, including areas of the Canary Islands (Spain) and the Azores and Madeira Islands (Portugal) in the Atlantic Ocean. The ionospheric irregularities persisted for 5–6 hours and began to fade after ~01 UT on 24 April 2023. COSMIC-2 scintillation measurements showed intense amplitude scintillations (S4 above 0.8) across this entire region, indicating presence of small-scale ionospheric irregularities inside the extended plasma bubbles. During this storm, EGNOS (European Geostationary Navigation Overlay Service) experienced degraded performance, with significant navigation errors recorded at its southernmost stations in Northern Africa, Spain, Portugal, and their territories, which were affected by super plasma bubbles. This paper presents conclusive observational evidence showing development of the super plasma bubbles significantly expanding into the southern Europe and northern Africa region under geomagnetically disturbed conditions in April 2023.
Evaluation of Tele-Education in Malawi for Detection of Macular Features Using Optical Coherence Tomography
Authors: Zungu Thokozani , Mdala Shaffi , Twabi Halima Sumayya , Kayange Petros , Gelisken Faik
Published: January 2025

Purpose The study aimed to assess the reliability of tele-education in training a Malawian ophthalmology resident to interpret optical coherence tomography (OCT) images of patients with macular conditions.

Methods This was a retrospective analysis of 1000 macula-centered OCT image series from 1000 eyes of 1000 consecutive patients from Malawi, which involved initial interpretation by a German retina specialist (observer 1) (T0). Observer 1 then trained a Malawian resident (observer 2) via email, and observer 2 independently interpreted images at T1, followed by face-to-face training in Malawi and reinterpretation at T2 and T3 (3-month intervals). The observers had to recognize, on OCT imaging, the normal macular structure, vitreofoveal traction (VFT), absent fovea depression (FD), epiretinal membrane (ERM), lamellar macular hole (LMH), full-thickness macular hole (FTMH), foveoschisis, intraretinal pseudocyst (IPC), intraretinal hyperreflective foci (IHF), subretinal fluid (SRF), pigment epithelial detachment (PED), and drusen. Cohenʼs Kappa statistic measured inter-observer agreement.

Results At T1 post-tele-education, almost perfect agreement (κ = 0.86; 99.6% agreement) was observed for FTMH. Agreement remained high at T2 post-face-to-face training (κ = 0.9; 99.7%) and decreased substantially at T3 (κ = 0.77; 99.4%). Following tele-education (T1), substantial agreement (κ range: 0.77 – 0.86) was found for IPC, PED, IHF, and FD, while ERM showed fair agreement (κ = 0.33; 81%). Face-to-face training notably improved agreement for SRF (T1 κ = 0.6, T2 κ = 0.63), LMH (T1 κ = 0.6, T2 κ = 0.67), and normal macular structure (T1 κ = 0.6, T2 κ = 0.62).

Conclusion There was good agreement in the detection of the majority of the OCT features seen in most of the macular pathologies following training through tele-education and the results did not change significantly following face-to-face teaching. Tele-education could reliably complement training in vitreoretinal diagnostic skills in resource-limited settings.
Interessengesteuertes Framing: Die Sprache der Nikotinindustrie
Authors: Posch Waltraud , Ulbricht Sabina , Hanewinkel Reiner
Published: January 2025

Der Konsum konventioneller Tabakprodukte ist seit Jahren rückläufig. In der Folge hat sich die Tabak- und Nikotinindustrie neue Märkte erschlossen und führt nun eine Reihe verschiedener Nikotinprodukte in ihrem Portfolio. Es soll dargestellt werden, wie die Nikotinindustrie gezielt die Sprache dazu nutzt, Bewusstsein zu schaffen und neue Nikotinprodukte als vermeintlich weniger risikoreich zu charakterisieren als traditionelle Tabakprodukte.

Das interessengesteuerte Framing der Tabak- und Nikotinindustrie wird anhand zentraler Begrifflichkeiten, die die Industrie eingeführt hat, exemplifiziert.

Von der Tabak- und Nikotinindustrie eingeführte Begriffe wie „risikoreduziert“, „rauch- und tabakfrei“, „dampfen“, „alternative Produkte“ können als gezielte Marketingstrategie verstanden werden, die das Risiko, das mit dem Konsum von E-Zigaretten, Tabakerhitzern und anderen Produkten verbunden ist, verharmlosen.

Die Tabak- und Nikotinindustrie hat es erreicht, dass sich für die neu eingeführten Nikotinprodukte eine freundliche und beruhigende Terminologie durchgesetzt hat. Es ist eine große Herausforderung, diese Begriffe durch eine Nomenklatur zu ersetzen, die die Gesundheitsrisiken, insbesondere die Abhängigkeits- und Gesundheitsgefahr des Konsums dieser Nikotinprodukte adäquat beschreibt. Entsprechende Vorschläge werden unterbreitet.
The Vagoaccessory Triangle (VAT): The Arena of ELITE
Authors: Liyadipita Nishanta M. , Uddanapalli Srinivasan S. , Hewage Lakmal K. , Galappaththi Perera M. , Pakshage Ananda Lal C. Dewa
Published: January 2025

Introduction Lesions in the cerebellomedullary angle, anterolateral aspect of lower brainstem, and anterior foramen magnum can be accessed through far lateral approach and extreme lateral infrajugular transcondylar exposure. Detailed anatomical knowledge of this region is of paramount importance to avoid untoward complications.

Objective Comprehensive anatomy of this microsurgical corridor is sparse. Our aim was to define the anatomy of this region with relevance to the surgical approach, which would enable the surgeon to navigate this region with ease during surgery.

Materials and Methods Cadaveric dissection was performed with focus on the various anatomical structures, which are of relevance to the operating surgeon. The same was correlated with the computerized scan and magnetic resonance imaging brain findings and intraoperative findings. The observations are presented.

Discussion Through the far lateral approach, the vagoaccessory triangle (VAT) and three subtriangles within it are exposed. Lateral boundary of the VAT is formed by the spinal accessory nerve, which follows a superolateral trajectory toward the jugular foramen. Medial boundary is formed by the medulla oblongata. Superior boundary is formed by the vagus nerve, which courses horizontally toward the jugular foramen. Rootlets of the hypoglossal nerve divide the VAT into infra-hypoglossal, supra-hypoglossal, and hypoglossal–hypoglossal subtriangles. The floor is formed by the inferior clivus, anterior foramen magnum, occipital condyle, and jugular tubercle. The roof is formed by the dura covering the lower part of the posterior fossa, biventral lobule, and tonsil of the cerebellum. The VAT contains three cisterns compartmentalized by three membranes, three nerves, and a fourth segment of vertebral artery (V4) with its three branches, in three subtriangles. Cisterns are the premedullary, lateral cerebellomedullary, and posterior cerebellomedullary. Membranes are the medial pontomedullary membrane, lateral pontomedullary membrane, and denticulate ligament. Nerves are the rootlets of hypoglossal, cranial accessory, and first cervical nerve. Posterior inferior cerebellar artery, anterior spinal artery, and posterior spinal artery are the three branches of V4.

Conclusion Detailed knowledge of each anatomical structure and its relationship would enable the surgeon to operate safely within the corridors naturally present in this region.
Correlation of low-temperature microplasticity anomalies with structure transformations in C60 crystals
Authors: Fomenko L. S. , Natsik V. D. , Lubenets S. V. , Lirtsman V. G. , Aksenova N. A. , Isakina A. P. , Prokhvatilov A. I. , Strzhemechny M. A. , Ruoff R. S.
Published: January 2025

Structure, microhardness and slip systems were studied in C60 crystals of high purity in the temperature range 30−290 K, which includes the fcc→sc phase transition at Tc = 260 K and the orientational glass region T < 100 K. A step-like change of both the lattice parameter and the microhardness when passing through Tc have been recorded, as well as the formation of slip tracks near the indentations in both phases. The slip system ⟨110⟩{111}, operative at room temperature in the fcc phase, is shown to retain its activity below Tc, in the sc phase. In the region where the orientational glass is formed, we have found a kink-like anomaly on the microhardness vs temperature curve; this anomaly correlates with a weak anomaly in the temperature dependence of the lattice parameter. Assumptions are formulated concerning the character of the dislocation motion in C60 crystals, which make it possible to explain the microplasticity anomalies observed.
Superconducting phase of a highly nonideal electron liquid
Authors: Vavrukh M. V. , Vavrukh N. M.
Published: January 2025

A simple model description is proposed for the superconducting state of a highly correlated, homogeneous electron liquid. The mathematical apparatus is based on the method of the (u,v)-transformation and the basic inclusion of correlation effects. It is demonstrated that the existence of the superconducting phase is attributable to lag effects, which induce an effective attraction between electrons having momenta close to the Fermi momentum. The characteristics of the superconducting phase are investigated as functions of the nonideality parameter.
Structural distortions in Nd2CuO4
Authors: Pashkevich Yu. G. , Pishko V. V. , Tsapenko V. V. , Eremenko A. V.
Published: January 2025

Single-phonon infrared absorption is observed in Nd2CuO4 as a result of magnetic ordering accompanied by cell replication. It is shown that magnetic ordering of the “plane cross” type leads to spin-dependent absorption by phonons corresponding to the boundary of the Brillouin zone of the paramagnetic phase and influences the phonon spectra in a way similar to the influence of structural phase transition. Electric-dipole mechanisms of this absorption are analyzed: from the M-point of the boundary of the Brillouin zone, induced by magnetic ordering, and from the X-point, induced by an external magnetic field. Measurements in a magnetic field exceeding the field at which spin-flip phase transition takes place reveal the onset of single-phonon absorption from the X-point of the Brillouin surface and the suppression of single-phonon absorption from the M-point, and they show that structural distortions do not exist in Nd2CuO4 at temperatures above 150 K.
Critical temperature and limiting concentration of charge carriers in CuO2 planes in copper-based HTS compounds
Authors: Sukharevskiĭ B. Ya. , Vilkova I. V.
Published: January 2025

The δ-n phase diagram of YBa2Cu3 O6+δ is constructed on the basis of analysis of the two-parametric Landau potential Φ (η, ζ) for HTS systems. The physical meaning of the order parameters η and ζ, is determined. Different phases of the yttrium–barium cuprate, which are traditionally called the tetra-I, tetra-II, ortho-I, and ortho-II phases, are identified. The hypothesis that Tc is proportional to the charge carrier concentration nCuO2 in CuO2 planes is confirmed. It is found that nCuO2 corresponds to the position of lability boundaries on the δ–n phase diagram. The calculated dependence of the Néel temperature on δ for YBa2Cu3O6+δ is in good agreement with the experimental data.
Phase field theoretical study of the electrocaloric effect in porous ferroelectric films
Authors: Liu Zenghong , Xiang Yuanjin , Zou Xing , Zhu Zhe , Fang Wenxiao
Published: January 2025

It has been experimentally observed that changes in the nanopore structure have a great impact on the ferroelectric domain structure, and then, the ferroelectric polarization value of the film can be controlled to increase the response of the electrocaloric effect. This phenomenon has great application prospects in refrigeration applications. In this study, the evolution process of the domain structure of porous ferroelectric films of Pb0.7 Sr0.3TiO3 (PST) with different pore shapes was obtained through phase field simulation, and the influence of the pore shape on the performance of electrocaloric was predicted and analyzed. The results show that different shapes of pores can control the magnitude of the adiabatic temperature change. Among them, the anisometric ellipse shaped pore thin film can obtain a maximum adiabatic temperature change of 8 K, which is a significant improvement compared with traditional PST ceramics and PST non-porous films. This large adiabatic temperature change is due to the pore-induced domain switching. Therefore, controlling the pore shapes provides a new idea for optimizing the electrocaloric properties of porous ferroelectric thin films.
Stable magnetocaloric effect over an ultrawide temperature range of 146–320 K via hydrostatic pressure in kagome magnets
Authors: Sheng Junchao , Xu Jiawang , Xi Lei , Xing Shouyuan , Li Shihao , Kan Xucai , Zheng Xinqi , Huang He , Wang Lichen , Han Yuyan , Zhou Shiming , Shen Baogen , Wang Shouguo
Published: January 2025

Solid-state refrigeration leveraging the magnetocaloric effect (MCE) presents a sustainable and energy-efficient alternative to traditional gas compression refrigeration technologies. However, the practical utility of most magnetocaloric materials is restricted by their narrow operational temperature window. In this work, a stable magnetocaloric effect across an ultrawide temperature range of 146–320 K was achieved in Hf0.85Ta0.15Fe2 magnet via the hydrostatic pressure manipulation. Furthermore, the underlying mechanism for the extended and stable MCEs under hydrostatic pressure has been revealed by magnetization measurements and first-principles calculations. The material systems characterized by strong spin–lattice coupling exhibit considerable potential for externally manipulated hybrid-field-tuned magnetic properties and magnetocaloric performance, providing a convenient and practical approach for advancing applications in magnetic refrigeration technologies.
VS2/MoS2 nanocomposite with reverse saturable absorption for optical limiting and nonlinear optical applications
Authors: Dandasena B. , Das S. , Kumar Prabhukrupa C. , Supriya S. , Naik R.
Published: January 2025

Transition metal dichalcogenides (TMDs) have been widely used as nonlinear optical materials. In the current study, hydrothermally prepared VS2/MoS2 nanocomposite was investigated for the non-linear study through the Z-scan technique. Z-scan is a straightforward method for determining how much a laser beam's phase changes when it passes through a nonlinear substance. This phase change, ΔΦ, is simply connected to the change in index of refraction, Δn, and yields both its sign and magnitude. Furthermore, the change in transmission due to nonlinear absorption that is associated with the change in the absorption coefficient, Δα, can also be independently determined using a Z-scan. X-ray diffraction (XRD) resembles the development of the hexagonal phase of VS2 as well as composite. The crystallite size decreased with the increased amount of Mo precursors. The morphological study confirms the formation of a nano-sheet-like structure for VS2 and a flower-like structure of the VS2/MoS2 composite. The high-resolution transmission electron microscopy(HRTEM) images contain both crystallographic planes, confirming the formation of the composite. The prepared material also shows tunable bandgap properties. The direct bandgap value lies in the range from 3.65 to 3.4 eV. The open aperture transmittance data provide information about the nonlinear absorption phenomenon, and the closed aperture transmittance data provide information about the phase shift of the light, that leads to a nonlinear refractive index (n2). The composite shows both self-focusing and self-defocusing nature. From the Z-scan experimental result, it is found that the saturable absorption (SA) properties of the pristine VS2 changed to reverse saturable absorption (RSA) after the formation of the composite with MoS2. The nonlinear absorption coefficient for VS2, VS2/MoS2-1, VS2/MoS2-2, and VS2/MoS2-3 are −(24.15 ± 0.25), 0.183 ± 127 × 10−4, 0.115 ± 3.96 × 10−4, and 0.139 ± 3.084 × 10−5 cm/W, respectively. The composite shows significant optical limiting properties for 100 mW laser source. The increase in nonlinear susceptibility, nonlinear refractive index, and nonlinear absorption coefficient are useful for optical limiting and nonlinear optical device applications.
Onset of phototactic bioconvection in a forward scattering algal suspension placed between rigid walls exposed to diffuse solar flux
Authors: Rajput S. K. , Panda M. K.
Published: January 2025

The proposed work investigates the onset of phototactic bioconvection in a forward-scattering algal suspension exposed to diffuse solar flux only. Additionally, the algal suspension of infinite width is confined between rigid horizontal walls so that the geometry of the proposed problem resembles an experimental chamber. The findings illustrate that the forward scattering enhances the suspension stability with a reduction in pattern wavelength affecting vertical mixing. In addition, an increment in the forward scattering coefficient switches the most unstable solution from a stationary state to an overstable state, or vice versa, depending on the parameter values. Furthermore, both the phase speed and the orbit size (obtained via bifurcation analysis) of the appropriate disturbances are increased at oscillatory bioconvective instability for a higher cell swimming speed. The most striking fact is that the findings of this study show some resemblance to gyrotactic bioconvection pertaining to important ecological implications such as the formation of algal blooms via dismissal of the collimated flux.
Nonlinear dynamics of toroidal Alfvén eigenmodes driven by trapped energetic particles
Authors: Atour Farah , Briguglio Sergio , Wang Xin
Published: January 2025

The nonlinear dynamics of toroidal Alfvén eigenmodes (TAEs) driven unstable by the resonant interaction with trapped energetic particles and, to a lesser extent, with nonstandard copassing particles are analyzed using simulations performed with the HMGC code (Hybrid Magnetohydrodynamic Gyrokinetic Code). The magnetic equilibrium considered is the low-shear configuration from the International Tokamak Physics Activity benchmark. The detailed investigation of the nonlinear mode-particle dynamics is based on the Hamiltonian-mapping approach, where the resonant phase-space structure is sampled by a large number of test particles evolving in the perturbed fields computed in the self-consistent simulations. Several precession-bounce resonances effectively drive the TAE unstable. Around each resonance radius, density mixing occurs as resonant particles form closed-trajectory islands in the (phase, radius) space. It is shown that these islands, whose width increases with the mode amplitude, eventually coalesce, leading to global density mixing. It causes a sudden reduction in the mode-particle power exchange, which is the main saturation mechanism when the energetic-particle density is relatively high. Correspondingly, the scaling of the saturation amplitude with the mode growth rate is slightly weaker than linear, similar to the radial-decoupling scaling observed in previous papers. This result is consistent with the observation that the width of the density-mixing region is limited, at saturation, by the mode width, which is nearly independent of the growth rate. At lower energetic-particle densities, local density mixing around each isolated resonance effectively reduces the power transfer, causing a transition to a stronger scaling, similar to the resonance-detuning regime reported in the literature.
Acoustic emission inversion for hydraulic fracture geometry with geomechanical constraints
Authors: Qin Lin , Zha Fusheng , Wu Shan , Ding Hai , Liu Songyu
Published: January 2025

The evaluation of hydraulic fracturing effectiveness in unconventional oil and gas reservoirs is crucial for production enhancement. Traditional assessments have focused on rock properties, overlooking the influence of external factors such as geostress and fracturing fluid characteristics. Acoustic emission methods, which analyze fracture activities and parameters through inversion, have shown potential in evaluating the fracturing effectiveness by indicating complex fracture networks and the dynamics of microcrack coalescence. However, these methods face challenges in accurately determining fracture parameters due to the inversion's inherent uncertainties. This study introduces a novel inversion method that incorporates geomechanical constraints, aiming to improve the precision of fracturing effectiveness evaluation. By comparing high-viscosity gel and supercritical carbon dioxide (SC-CO2) fracturing techniques, the study demonstrates the novel method has capability to distinguish between varied fracture morphologies. The results show that high-viscosity fracturing leads to fractures with more concentrated propagation directions and larger opening angles, while SC-CO2 fracturing produces fractures with more complex propagation paths and smaller opening angles. This approach marks a significant advancement in the field, allowing for a more accurate and quantitative assessment of hydraulic fracturing operation.
Effects of different water-based fracturing fluids on mechanical properties and energy evolution of deep coal under true triaxial loading
Authors: Hu Huarui , Wang Zepeng , Wang Mengting , Zeng Mengru , Liu Chenguang , Chen Haowen
Published: January 2025

In order to investigate the impact of fracturing fluid invasion on the mechanical degradation of deep coal, coal samples treated with five promising fracturing fluids were used for true triaxial compression tests in deep conditions. Due to water–rock reactions, lubrication, and the water wedge effect, the compressive strength of coal samples decreased. The decrease was most significant for coal samples treated with hydrofluoric (HF). The total energy and elastic strain energy of the coal samples first increased and then decreased. In contrast, the dissipation energy increased gradually, and the energy dissipation ratio exhibited a U-shape, decreasing initially and then increasing, with a turning point at the peak strain. However, the inflection point was delayed to varying degrees following treatment with viscoelastic surfactant fracturing fluid (VESFF) and acidic fracturing fluid (AFF), with the delay being more pronounced for AFF. The coal samples treated with anionic VESFF and hydrochloric acid exhibited the highest peaks of total energy and elastic strain energy, along with the fastest growth rate of dissipated energy and the most rapid decrease in the energy dissipation ratio, whereas the coal samples treated with HF exhibited the opposite behavior. All coal samples primarily exhibited shear damage, with a small number of tensile cracks appearing near the shear surface in the VESFF-treated coal samples. The coal samples treated with two types of AFF exhibited shear-tensile composite damage, while the HF-treated coal samples displayed X-shaped cracks. In summary, VESFF holds significant potential for future applications in the development of deep ECBM.
Realizing p-type InSb with enhanced thermoelectric performance via Cd doping
Authors: Wang Qing , Li Zhiliang , Li Zhipeng , Liu Xinqi , Xue Yuli , Wang Jianglong , Wang Shufang
Published: January 2025

InSb is a promising mid-temperature thermoelectric material, and its n-type thermoelectric properties have been widely studied. For thermoelectric device applications, it is necessary to have p-type counterparts. Here, we report the realization of p-type InSb with enhanced thermoelectric performance via Cd doping. A high-power factor of 1.91 × 10−3 W m−1 K−2 is obtained in p-type In0.93Cd0.07Sb at 723 K due to the increased carrier concentration. Moreover, the lattice thermal conductivity is decreased to 2.0 W m−1 K−1 owing to the significant multiscale phonon scattering and the suppressed bipolar diffusion effect. Ultimately, the peak zT value of 0.40 is achieved at 723 K in p-type In0.93Cd0.07Sb, which surpasses most contemporary p-type InSb materials. This study demonstrates a simple strategy for fabricating p-type InSb with high performance and holds promise in advancing the development of InSb-based TE devices.
Strain tuning of oxygen vacancy channels in SrCoO2.5 thin films
Authors: Mishra Rajan , Choudhary Shivam , Chowdhury Sourav , Ahlawat Anju , Jana Anupam , Giglia Angelo , Nannarone Stefano , Hoesch Moritz , Choudhary Ram Janay
Published: January 2025

Tuning of the oxygen vacancy channels (OVCs) ordering is crucial to control ionic conduction, which has much promise in energy materials and memory devices. Brownmillerite (BM) oxides have been proven to be an ideal playground for exploring the modulation of OVCs through external stimuli. In the BM-SrCoO2.5 thin films, we observed that in-plane compressive strain promotes horizontal OVCs, while in-plane tensile strain facilitates vertical OVCs. The modulation of the OVCs can also be made through electric biasing utilizing the piezo-strain. The selective regulation of the orientation of the OVCs in BM-SrCoO2.5 thin films through strain engineering will significantly enhance the development and implementation of functional features for ion transport and migration-related functionality.
Spreading dynamics of a fluorocarbon surfactant-laden droplet impacting on oil surface at varying Weber numbers
Authors: Zhang Yun , Huang Meiwei , Liu Xingxiang , Zheng Jieqing , Xu Yiming , Guo Yong
Published: January 2025

Effective suppression of flammable liquid fires depends on the rapid formation of a closed water film by aqueous film-forming foam (AFFF) over the oil surface. To investigate the mechanism of film formation on the oil surface with a compounded solution using the fluorocarbon betaine amphoteric surfactant (OC5-Betaine) as the active ingredient, a multi-angle visualization experiment was applied to capture the impact and spreading of the surfactant-laden droplets on a 25 mm deep corn oil pool synchronously, within a Weber number (We) range of 7–168. The results revealed that various characteristic impact phenomena strongly correlate with the We. The critical We for complete floating of a droplet or partial droplet sink to the bottom of oil pool after impact is approximately 155. There are two patterns, “Nipple” and “Mushroom,” when the droplet impacts the oil surface and sinks to the lowest point. When the We exceeds 90, the droplets consistently adopt the Mushroom shape. For a given We, the maximum depth and maximum penetration time of the Nipple type are greater than those of the Mushroom type. There is a high probability of “Rebound static” phenomenon for the Nipple type, which slows spreading. A range of We between 90 and 140 promotes rapid droplet spreading and prevents jet breakup, making it optimal for firefighting. These findings offer insights for developing more effective AFFFs.
Critical parameters of the Jamin effect on the oil droplet passing through an abruptly constricted capillary tube laden with sodium dodecyl sulfate solutions
Authors: Yang Xiaoye , Jiang Lu , Cao Gongqi , He Qingyang , Zhang Menghan , Liu Jianlin
Published: January 2025

The Jamin effect, as a resistance arising from the morphological changes of droplets during two-phases flow in the capillary tube, plays a crucial role in enhancing the oil recovery efficiency (EOR) in petroleum engineering. In the present study, we investigate the critical parameters of the Jamin effect in a sloped capillary tube laden with water and sodium dodecyl sulfate (SDS) solutions, including the critical water velocity and pressure difference. The pinning behavior of the oil droplet is observed in the waterflood with a lower velocity, while depinning and rupturing behavior occur at the higher velocity. Hereto, we build a mechanics model to analyze the underlying mechanism of the Jamin effect in the sloped capillary tube with varying cross sections. Using this theoretical model, we determine the critical velocity required for the depinning of the oil droplet. The results reveal that the critical velocity decreases with the decrease in sloped angles, consistent with the experimental results. Moreover, we find that oil droplets can pass through the entire sloped capillary tube more easily in SDS solutions than in water, and the required time becomes shorter with the decrease in sloped angles and increase in SDS concentrations. To address this, a theoretical model is established to determine the minimum applied pressure difference. These findings provide a deep insight into the mechanisms of oil displacement and contribute to achieving the higher EOR.
Spatio-temporal trends in the abundance of grey kangaroos in Victoria, Australia
Authors: Scroggie Michael P. , Moloney Paul D. , Ramsey David S. L.
Published: January 2025

Context Aerial distance sampling surveys are a widely used approach for estimating the abundance of wildlife populations, including kangaroos and other macropods. When analysing such data, design-based estimates of abundance extrapolate density from the sampled region to the broader area. In contrast, model-based approaches that use relationships between population density and habitat variables can deliver greater precision and ecological insight into population estimates. Aims This study aimed to evaluate recent spatio-temporal trends in the abundance of grey kangaroos (Macropus giganteus and M. fuliginosus) in Victoria, Australia using both design-based and model-based distance sampling. Methods Aerial surveys were conducted in seven management zones spread across the non-forested parts of Victoria on four occasions between 2017 and 2022. Distance sampling data were analysed to obtain design-based and model-based estimates of population size and relative precision across the entire study area, and for each management zone for each of the four surveys. Key results Model-based and design-based estimates of abundance proved to be broadly comparable, but with mostly higher precision for the model-based estimates at both statewide and management zone scales. The model-based approach revealed relationships between transect-level abundance and land-use type, normalised difference vegetation index (NDVI), annual rainfall and the amount of ecotonal habitat in the vicinity of the transects. Between 2017 and 2022 (a period coinciding with a prolonged La Niña event), the total abundance of grey kangaroos increased by approximately 87% (based on the model-based inferences) despite an ongoing harvesting program. Conclusions In addition to improved precision, model based estimation revealed relationships between habitat variables and transect-level abundance, allowing prediction of abundance at small scales. Implications The improved precision of model-based estimates of abundance will provide greater confidence in kangaroo management decisions such as setting of statewide harvest quotas. Model-based estimates at smaller spatial scales will similarly support localised management decisions.
The perceptual primacy of feeling: Affectless visual machines explain a majority of variance in human visually evoked affect
Authors: Conwell Colin , Graham Daniel , Boccagno Chelsea , Vessel Edward A.
Published: January 2025

Looking at the world often involves not just seeing things, but feeling things. Modern feedforward machine vision systems that learn to perceive the world in the absence of active physiology, deliberative thought, or any form of feedback that resembles human affective experience offer tools to demystify the relationship between seeing and feeling, and to assess how much of visually evoked affective experiences may be a straightforward function of representation learning over natural image statistics. In this work, we deploy a diverse sample of 180 state-of-the-art deep neural network models trained only on canonical computer vision tasks to predict human ratings of arousal, valence, and beauty for images from multiple categories (objects, faces, landscapes, art) across two datasets. Importantly, we use the features of these models without additional learning, linearly decoding human affective responses from network activity in much the same way neuroscientists decode information from neural recordings. Aggregate analysis across our survey, demonstrates that predictions from purely perceptual models explain a majority of the explainable variance in average ratings of arousal, valence, and beauty alike. Finer-grained analysis within our survey (e.g. comparisons between shallower and deeper layers, or between randomly initialized, category-supervised, and self-supervised models) point to rich, preconceptual abstraction (learned from diversity of visual experience) as a key driver of these predictions. Taken together, these results provide further computational evidence for an information-processing account of visually evoked affect linked directly to efficient representation learning over natural image statistics, and hint at a computational locus of affective and aesthetic valuation immediately proximate to perception.
Structural insights into glucose-6-phosphate recognition and hydrolysis by human G6PC1
Authors: Xia Zhanyi , Liu Chuanyu , Wu Di , Chen Huiwen , Zhao Jun , Jiang Daohua
Published: January 2025

The glucose-6-phosphatase (G6Pase) is an integral membrane protein that catalyzes the hydrolysis of glucose-6-phosphate (G6P) in the endoplasmic reticulum lumen and plays a vital role in glucose homeostasis. Dysregulation or genetic mutations of G6Pase are associated with diabetes and glycogen storage disease 1a (GSD-1a). Studies have characterized the biophysical and biochemical properties of G6Pase; however, the structure and substrate recognition mechanism of G6Pase remain unclear. Here, we present two cryo-EM structures of the 40-kDa human G6Pase: a wild-type apo form and a mutant G6Pase-H176A with G6P bound, elucidating the structural basis for substrate recognition and hydrolysis. G6Pase comprises nine transmembrane helices and possesses a large catalytic pocket facing the lumen. Unexpectedly, G6P binding induces substantial conformational rearrangements in the catalytic pocket, which facilitate the binding of the sugar moiety. In conjunction with functional analyses, this study provides critical insights into the structure, substrate recognition, catalytic mechanism, and pathology of G6Pase.
Simulated alignment method for suppressing tilt-to-length coupling noise in space gravitational wave telescopes
Authors: Huang Lanjun , Yu Miao , Wu Yanxiong , Li Jiancong , Li Hongbo , Zou Donglan , Liu Yinghong , Lin Lintong
Published: January 2025

Space gravitational wave telescopes are critical in achieving precise interstellar laser interferometry. The coupling coefficient is a key metric for evaluating the ultimate performance of a telescope. However, alignment errors during the assembly phase can degrade the wavefront quality of the telescope, intensify coupling noise, and impair overall performance. Currently, no alignment scheme specifically targets the coupling-noise coefficient of telescopes. To address this, this study proposes a sensitivity matrix model that relates misalignment to the coupling coefficient and establishes clear sampling criteria for coupling noise at the exit pupil of the telescope. The model incorporates second-order correction terms, enabling a more accurate characterisation of the relationship between misalignment and tilt-to-length coupling-noise coefficients. Based on this model, an alignment scheme was developed using the coupling coefficient as the evaluation metric. Owing to the significant differences in the magnitudes of sensitivity among different misalignments and their mutual coupling effects, the predicted alignment parameters often differ substantially from the actual values. To resolve this issue, a misalignment grouping strategy was proposed to reduce prediction errors. Additionally, an iterative algorithm and a sequential adjustment strategy for components were provided to ensure alignment effectiveness. Finally, the feasibility of the proposed method was verified using a typical space gravitational wave telescope model. Experimental results show that the method successfully aligned 500 randomly misaligned samples, with all samples satisfying the requirement of a coupling noise of less than 25 pm μrad−1 after alignment. This method provides new guidance for the alignment of space gravitational wave telescope systems.
Finite element analysis, machine learning, and digital twins for soft robots: state-of-arts and perspectives
Authors: Jin Liuchao , Zhai Xiaoya , Xue Wenbo , Zhang Kang , Jiang Jingchao , Bodaghi Mahdi , Liao Wei-Hsin
Published: January 2025

The current boom in soft robotics development has spurred extensive research into these flexible, deformable, and adaptive robotic systems. However, the unique characteristics of soft materials, such as non-linearity and hysteresis, present challenges in modeling, calibration, and control, laying the foundation for a compelling exploration based on finite element analysis (FEA), machine learning (ML), and digital twins (DT). Therefore, in this review paper, we present a comprehensive exploration of the evolving field of soft robots, tracing their historical origins and current status. We explore the transformative potential of FEA and ML in the field of soft robotics, covering material selection, structural design, sensing, control, and actuation. In addition, we introduce the concept of DT for soft robots and discuss its technical approaches and integration in remote operation, training, predictive maintenance, and health monitoring. We address the challenges facing the field, map out future directions, and finally conclude the important role that FEA, ML, and DT play in shaping the future of soft robots.
Deep neural network for electromechanical impedance analysis and damage detection of laminated rubber bearings
Authors: Zhu Hongping , Shen Zehui , Zhang Ying , Ai Demi , Weng Shun
Published: January 2025

Environmental factors and loads cause potential small cracks in the rubber layers of laminated bearings. Conventional methods for identifying structural damage based on global vibration characteristics are ineffective, and current nondestructive structural damage detection methods based on Piezoelectric ceramic lead Zirconate Titanate (PZT) cannot fully capture deep damage-sensitive features from PZT signals. This study proposes a novel deep learning approach using a convolutional neural network with residual connections to conduct raw electromechanical admittance analysis and automatically extract damage-sensitive features to identify minor cracks in laminated rubber bearings. Numerical models are used to generate a sufficient amount of PZT data under various damage conditions for training the deep neural network, which overcomes the sparsity of damage states in actual laminated rubber bearings. A transfer learning method based on a model fine-tuning strategy was adopted to address the feature differences between the numerical models and actual rubber bearing structure. The fine-tuned model could effectively identify the damage location of actual laminated rubber bearings. The proposed method does not require a complex data preprocessing process when analyzing PZT signals and has a relatively high accuracy in damage localization. The promising results from this work offer a potential paradigm for data-driven PZT signal analysis, which is an appealing approach for identifying minor damage in real-life laminated rubber bearings.