bluuebunny/crossref_metadata_2025 huggingface dataset:
Phrenic Nerve Reconstruction in Pediatric Diaphragm Paralysis: Outcomes and Techniques
Authors: Kaufman Matthew , Lu Charles , Staab Victoriya , Bauer Thomas
Published: February 2025

Background: Symptomatic diaphragm paralysis in the pediatric patient is an uncommon condition. This study aims to evaluate the outcomes and technique of phrenic nerve reconstruction and its application to pediatric patients with unilateral and bilateral diaphragm paralysis at a single institution. The objective of this study is to demonstrate the application of a well-studied reconstructive technique in a population of patients not previously studied.
Methods: A retrospective review of pediatric patients between 2012 and 2022 with symptomatic diaphragm paralysis treated with phrenic nerve reconstruction. 9 patients with a median age of 10 years old were offered surgical treatment. The etiology of their paralysis include: birth trauma, congenital cervical anomaly, mediastinal neoplastic disease, cervical spinal cord injury, and acute flaccid myelitis. Measures of postoperative improvement include fluoroscopic sniff testing, pulmonary function testing, electromyography/nerve conduction testing, ultrasound evaluation and ventilator requirements.
Results: 100% patients with unilateral paralysis demonstrated improvement, defined as improvements in dyspnea, orthopnea, fatigability, and decreased respiratory infections. This was corroborated by sniff testing, pulmonary function testing, and electrodiagnostic evaluation. In 80% of patients, there was recovery of diaphragm excursion on the chest fluoroscopy, and a 10% or greater improvement on pulmonary spirometry (Forced Expiratory Volume in 1 Second, FEV1, and Forced Vital Capacity, FVC) percent predicted values. In patients with bilateral diaphragm paralysis, 75% demonstrated improvement in sniff testing, ultrasound findings and ventilator requirements. 25% of the patients did not improve. There were no post-operative complications defined as hematoma, wound infection, pleural effusion, pneumonia, sepsis, nerve injury, or hardware malfunction seen during follow-up.
Conclusion: Phrenic nerve reconstruction in pediatric patients demonstrates potential as a safe and effective surgical option for symptomatic diaphragm paralysis. In patients with unilateral paralysis, this intervention consistently improved respiratory function. In patients with bilateral paralysis, the results were variable but showed promise in facilitating ventilator weaning when performed early. These findings underscore the importance of early surgical intervention. Larger, multicenter studies are needed to validate its long-term potential.
Identifying risk factors for left ventricular thrombus in patients with ischemic left ventricular aneurysm using cardiac MRI
Authors: Wu Yanfang , Wang Hui , Wang Zhiyan , Hua Chang , Xiong Rang , Fu Hao , Lv Qiang , Xu Lei , Du Xin , Dong Jian-Zeng
Published: February 2025

Background: Ischemic left ventricular (LV) aneurysm is associated with LV thrombus and subsequent embolic events. However, there is currently no evidence-based recommendation for anticoagulation in these patients.
Objective: To determine the characteristics of LV aneurysms associated with a high risk of thrombus formation.
Methods: This retrospective study included all hospitalized patients with ischemic LV aneurysm who underwent cardiac magnetic resonance (CMR) from September 2015 to June 2023. Baseline characteristics and CMR parameters were compared between patients with and without LV thrombus. Factors associated with LV thrombus were identified using univariable and multivariable logistic regression analyses.
Results: Among the 317 patients included in this study, 88 (27.8%) had LV thrombus. Patients with LV thrombus demonstrated a higher prevalence of heart failure, lower left ventricular ejection fraction, and greater volume, mass, and global extent of late gadolinium enhancement (LGE). They also exhibited distinct LV aneurysm characteristics, such as a larger maximum transverse dimension (maximum width), a wider aneurysm neck, and a higher aneurysm shape index (ratio of maximum length to neck width). Multivariable logistic regression analyses identified aneurysm neck width (OR 1.33 per 5 mm, 95% CI 1.00–1.77, P = 0.047), shape index (OR 1.63 per 20%, 95% CI 1.23–2.16, P = 0.001), and LGE global extent > 50% (OR 6.58, 95% CI 3.04–14.27, P < 0.001) as significant predictors of LV thrombus.
Conclusions: A wider aneurysm neck, a higher aneurysm shape index, and LGE global extent > 50% are associated with LV thrombus in patients with ischemic LV aneurysm.
A Retrospective Analysis Comparing Technical Difficulty and Safety between Right and Left-sided Percutaneous Transhepatic Biliary Drainage in a Nondilated Biliary System
Authors: Patel Ranjan Kumar , Tripathy Taraprasad , Pattnaik Bramhadatta , Dutta Tanmay , Gupta Sunita , Nayak Hemant Kumar , Panigrahi Manas Kumar , Das Deepak , Barik Sandip Kumar , Mohakud Sudipta , Naik Suprava , Deep Bag Nerbadyswari
Published: February 2025

Objective The aim of this study was to compare the technical difficulty and safety between right-sided percutaneous transhepatic biliary drainage (R-PTBD) and left-sided percutaneous transhepatic biliary drainage (L-PTBD) in patients with nondilated bile ducts.

Materials and Methods Forty-two patients (22 males and 20 females with a mean age of 46.2 ± 13.7 years) who received PTBD in nondilated bile ducts (from September 2021 to January 2024) were dichotomized into the R-PTBD (n = 22) and L-PTBD (n = 20) groups. The number of needle punctures, successful biliary punctures, technical success, difficulty in catheter placement, total fluoroscopic time, total procedure time, overall complications, and hemorrhagic complications were evaluated and compared between the groups.

Results The R-PTBD group had significantly fewer needle punctures for biliary access (3.9 ± 1.3 vs. 4.3 ± 1.3; p = 0.004) and a shorter procedure duration (21 ± 8.5 vs. 29.9 ± 13.2 minutes; p = 0.021) than the L-PTBD group. The successful biliary puncture (20 [90.9%] vs. 15 [75%]; p = 0.229) and technical success rate (20 [90.9%] vs. 14 [70%]; p = 0.123) were also higher for the R-PTBD group than for the L-PTBD group, while R-PTBD required less fluoroscopic time (5.83 [3.5–8.13] vs. 8.16 [4.34–12.9] minutes; p = 0.113). However, these differences did not reach statistical significance (p > 0.05). Further, difficulty during catheter placement was more frequently encountered in the L-PTBD group (02 [9%] vs. 04 [20%]; p = 0.367). The overall complication and hemorrhagic complication rates were comparable between both groups.

Conclusion When both approaches are equally suitable for patients with nondilated bile ducts, R-PTBD may be favored over L-PTBD, given the evidence demonstrating less technical difficulty in the right-sided approach than in the left-sided approach.
Enlarged Iliopsoas Bursa Compressing the Femoral Nerve Resulting in Femoral Mononeuropathy and Denervation Edema
Authors: Shirodkar Kapil , Pilania Khushboo , Jankharia Bhavin G. , Botchu Rajesh
Published: February 2025

Iliopsoas bursitis, although not rare, may manifest clinically as a detectable mass in the groin area. This condition has the potential to apply pressure on the adjacent femoral neurovascular bundle, leading to isolated mononeuropathy.

We present an uncommon case of femoral mononeuropathy in a 46-year-old female patient caused by an enlarged iliopsoas bursa. The case is noteworthy due to its rarity and the clinical and diagnostic challenges associated with assessing individuals with a groin mass, hip flexor weakness, and femoral nerve palsy.
A Cadaveric Study of the Anatomical Characteristics of the Superficial Circumflex Iliac Artery Perforator
Authors: Rao Tanvi , Jaganathan Vijay , Victor Jonathan , Lingam Pappu Paramartha
Published: February 2025

Background The superficial circumflex iliac artery perforator flap (SCIP flap) is an evolution of the conventional free groin flap. Even though the anatomical basis for SCIP flap is well established in general, the same is not described in a South Indian population.

Objectives The objectives of our study were to determine the anatomical variations of the superficial circumflex iliac artery perforators (SCIA perforators) and describe them in relation to the nearby bony landmarks like anterior superior iliac spine (ASIS) and pubic tubercle (PT).

Materials and Methods This observational study was done between October 2020 and December 2021. Cadaveric dissection was done and the required anatomic data were collected.

Results The mean diameter of SCIA was 0.99 mm and the mean pedicle length was 2.97 cm. The average diameters of the medial and lateral perforators were 0.63 and 0.55 mm, respectively. The pedicle lengths of the medial and lateral perforators were 3.03 and 4.31 cm, respectively. The medial perforator was 5.63 cm lateral and 1.66 cm superior to the PT. It was 5.37 cm medial and 5.99 cm inferior to the ASIS. The lateral perforator was 7.97 cm lateral and 2.73 cm superior to the PT. It was 2.86 cm medial and 4.11 cm inferior to the ASIS.

Conclusion Finding the exact location of the medial and the lateral perforators with respect to permanent bony landmarks and having an idea about their average pedicle length are useful for preoperative planning of the SCIP flap.
Advancing Varicocele Management: A Comprehensive Study on the Efficacy and Outcomes of Endovascular Techniques in a Tertiary Health Care Setting
Authors: Suresh Adheeni , M.V Bhaskar , Govindaraju Aswath , Soman Suresh
Published: February 2025

Objective The aim of the study is to report the clinical outcomes of embolization for symptomatic varicoceles.

Materials and Methods In this institutional review board approved prospective study, 126 patients (median age: 30.58 ± 6.13 years) with 43 bilateral and 83 unilateral varicoceles were included. The majority of patients had pain as the major complaint, while 21 patients had associated infertility. The technical and clinical success and complications were studied.

Results The technical success was 100% (169/169 varicoceles). There was a significant reduction in the grading of varicocele on ultrasound postprocedure (p < 0.001). Ninety-eight percent had a reduction in their pain score. The preprocedural mean pain score was 6.4 ± 1.30, which decreased to 1.3 following the procedure. An overall satisfaction score of 9 of 10 was also noted. Out of 126 patients, 94.5% patients had uneventful recovery, while 7 patients had few minor complications. One patient had recurrence and received a repeat embolization.

Conclusion Embolization is safe and effective in the treatment of varicocele.
Light–matter interaction Hamiltonians in cavity quantum electrodynamics
Authors: Taylor Michael A. D. , Mandal Arkajit , Huo Pengfei
Published: February 2025

When matter is strongly coupled to an optical cavity, new hybrid light–matter states are formed, the so-called polariton states. These polaritons can qualitatively change the physical properties of the matter coupled to the cavity by completely altering its energy eigenspectrum. Fueled by experimental innovations in recent years, much progress has been made in simulating the intrinsic quantum behavior of these hybrid states. At the heart of each simulation is the choice of Hamiltonian to represent the total light–matter hybrid system. Even at this fundamental level, there has been significant progress in developing new gauges and representations for this Hamiltonian, whether exact or under approximations. As such, this review aims to discuss several different forms of Hamiltonians for the researcher trying to enter this field by clearly and concisely deriving each different representation from the fundamental Minimal Coupling Hamiltonian. In addition, this review provides commentary on the optimal usage and extent of approximations for each individual representation to assist the reader in choosing the appropriate Hamiltonian for their work.
Peculiar spin Hall magnetoresistance in polycrystalline WTe2/Ni80Fe20 heterostructures
Authors: Tian Zong-kui , Luo Zi-yan , Guo Jun-jie , Ding Jin-min , Nie Yao-zhuang , Xia Qing-lin , Zhou Yu , Guo Guang-hua
Published: February 2025

Charge–spin interconversion is a key issue in spintronics. It gives rise to a series of new phenomena, such as spin Hall magnetoresistance (SMR). In the present work, we report the peculiar SMR behaviors in heterostructures composed of polycrystalline WTe2 nanoplate and Ni80Fe20(Py) film. We observe a negative SMR, which is contrary to the positive SMR usually measured in heavy metal/ferromagnet bilayers. We further observe a transition from negative to positive SMR with increasing thickness of the WTe2 layer, as well as SMR sign reversal with increasing temperature in heterostructures with thicker WTe2. The peculiar SMR behaviors in polycrystalline WTe2/Py heterostructures are attributed to the interface-induced spin current and its competition with the spin Hall-induced spin current. The findings in this work offer a fundamental input for the future exploitation of heterostructures based on two-dimensional transition metal dichalcogenides.
On the Czochralski growth of SixGe1−x crystals as substrates for strained Ge quantum well heterostructures
Authors: Subramanian Aravind N. , Richter Carsten , Gybin Alexander , Kabukcuoglu Merve P. , Hamann Elias , Zuber Marcus , Oezkent Maximilian , Guguschev Christo , Juda Uta , Schroeder Thomas , Abrosimov Nikolay V. , Sumathi R. Radhakrishnan , Gradwohl Kevin-P.
Published: February 2025

This investigation showcases the viability of producing SixGe1−x bulk single crystals via the Czochralski technique. A high Si content in Ge-rich SiGe wafers is highly desirable for various applications in quantum technology, particularly as strain-relaxed buffers for the realization of hole spin qubits in strained Ge quantum well heterostructures. The focus lies on the bulk crystal growth of such materials and their chemical and structural quality. For this, the Czochralski process, starting from a highly pure Ge seed and melt, utilizing continuous feeding by dissolution of Si rods was performed.Si0.16Ge0.86 wafers with a diameter of up to 15 mm obtained from the bulk crystal exhibited homogeneous structural quality in contrast to the conventionally used epitaxial strain-relaxed SiGe buffers. The compositional fluctuations of Si measured throughout the wafer were below 0.4 at. % in addition to a dislocation density below 3 × 106 dislocations/cm2. Interestingly, the central region of the wafer displayed no measurable compositional fluctuations and contained less than 105 dislocations/cm2. Furthermore, the difficulties and limits of growing such SiGe crystals are discussed, such as the continuous dissolution of Si during growth and the formation of oxides in the melt during growth. The current observations indicate significant potential for further enhancement of the crystal quality and to realize higher Si concentrations using the Czochralski technique.
Spin wave propagation in YIG waveguides with magnetic microvolcanoes: Experiment and simulation
Authors: Khutieva A. B. , Sadovnikov A. V. , Garanin F. E. , Anisimov R. A. , Kalinova A. E. , Chen X. , Song Y. , Sheshukova S. E. , Lomova M. V.
Published: February 2025

Control of spin wave transport in polymer 3D films was realized by magnetic microvolcanoes embedded in waveguides, fabricated by soft-matter specific techniques. Propagate of the spin wave signal excited in yttrium iron garnet (YIG) with 3D self-standing microvolcanoes chambers on top filled by the magnetic nanoparticles was evaluated by Brillouin light scattering and microwave spectroscopy. The magnetic moment of the polymer microvolcanoes varied with the change of the magnetic field bias direction inside the YIG films, which was shown by 2D mapping of the outer surface of the films. The good correlation of micromagnetic modeling and experimental data of spin wave propagation in the multistructure as a function of the applied magnetic field was clarified by the convergence parameters of the obtained polymer 3D magnetic microvolcanoes fields and the standard theory of spin wave propagation. The uniqueness of the soft materials object—polymer magnetic 3D films on conductive YIG film—lies in the application of the magnon network properties, which may find application in biomedical high-sensitivity feedback sensors.
An effective strategy to search for 2D piezoelectric materials
Authors: Wu Jiarui , Hu Ziyu , Shao Xiaohong
Published: February 2025

Two-dimensional (2D) piezoelectric materials have a great potential for device applications by utilizing their remarkable electromechanical coupling. In this study, we propose a sure independence screening and sparsifying operator algorithm to search for 2D piezoelectric materials, which is culminating in the identification of a novel 2H-MoS2-like crystalline structure. Utilizing first-principles calculations grounded in density-functional theory, we systematically conducted a thorough analysis of their mechanical properties, electronic properties, and piezoelectric responses. The results indicate that 2H-MoS2-like crystalline structures exhibit the most superior piezoelectric characteristics and have an e11 coefficient of up to 5.09 and a d11 coefficient reaching 10.87, showing remarkable piezoelectric performance. Employing Kendall correlation analysis and polynomial regression, we analyzed the relations between physical parameters and piezoelectric properties, yielding empirical equation that encapsulate the piezoelectric nature of this new class of materials, which mostly related to their lattice structures and bandgaps. Then, we investigated the stress, system energy, and piezoelectric response of these materials under various strain conditions, a d11 coefficient reaching 12.07 for WMo3Se8. Our work may broaden the horizon of low-dimensional piezoelectric materials, offering a pathway to tailor materials with desired properties through our proposed effective strategy.
Integration of electrically detected magnetic resonance on a chip (EDMRoC) with charge pumping for low-cost and sensitive defect characterization in silicon carbide metal–oxide–semiconductor field-effect transistors
Authors: Lettens Jan , Avramenko Marina , Vandevenne Ilias , Chu Anh , Hengel Philipp , Kern Michal , Anders Jens , Moens Peter , Goovaerts Etienne , Cambré Sofie
Published: February 2025

Electrical detection of magnetic resonance (EDMR), a variant of electron paramagnetic resonance (EPR) in which the magnetic resonance effect is detected via changes in the electrical properties of materials or devices, is of high interest for studying electrically active defects in SiC metal–oxide–semiconductor field-effect transistors (MOSFETs), but requires dedicated instrumentation that is not widely available. Integration of microwave sources and detection circuits has led to the design of very compact EPR instruments, the so-called EPR-on-a-chip (EPRoC), which also offers opportunities for EDMR-on-a-chip (EDMRoC). Here, we report the demonstration of EDMRoC on lateral SiC MOSFETs under charge pumping (CP) conditions. The detected CP current gives direct access to microscopic information about the recombination centers within the transistor gate inversion region under the gate dielectric. Efficient and selective microwave excitation of the region of interest of the device can be obtained by only modest modifications to both the MOSFET and the EPRoC electronic board. A comparative study between EDMRoC and a traditional resonant cavity configuration reveals comparable signal-to-noise ratios for CP-detected EDMR spectra. In addition to space- and cost-efficiency, EDMRoC offers alternative detection modes with scanning and modulation of the microwave frequency, as well as potentially easier sample mounting and exchange. We end with a discussion of the advantages, limitations, and perspectives of the EDMRoC setup compared to EDMR in a conventional EPR spectrometer, offering promise for widespread integration of EDMR in semiconductor laboratories.
Giant persistent photoconductivity at room temperature in Sn-based perovskites
Authors: Euvrard Julie , Pournia Sadaf , Gunawan Oki , Mitzi David B.
Published: February 2025

Long avoided due to adverse effects in traditional optoelectronic devices, persistent photoconductivity (PPC) is now sought-after for emerging technologies, including artificial synapses and coupled solar batteries. We report on a giant PPC effect at room temperature in the mixed Sn/Pb-based perovskite MAPb0.5Sn0.5I3 (MA = methylammonium). Using Hall and photo-Hall measurements, we identify macroscopic separation of negative and positive carriers as the most likely origin for delayed photoconductivity decay, with a strong electron localization expected at grain boundaries or cracks within the polycrystalline films. Additionally, measurements on perovskite films with varying morphology and SnF2 additive content reveal that large apparent grain size (>5 μm) and effective passivation of recombination centers combine to provide a path for achieving PPC extending over 100 h at room temperature.
Parameter-free multiscale analysis of hydrogen solubility in Pd nanofilms under hydrogen gas using density functional theory
Authors: Ishii Akio , Nakamura Nobutomo
Published: February 2025

A parameter-free multiscale analysis of hydrogen solubility, hydrogen coverage, and hydrogen bulk concentration for face-centered-cubic Pd nanofilms with a (111) surface under hydrogen gas conditions is proposed using density functional theory and a simple kinetic model. The calculated solubility is quantitatively comparable to that obtained via experimental observations. Although the Pd surface is fully covered by hydrogen in a short time (microseconds to milliseconds) under exposure to 10–10000 ppm hydrogen gas pressure (1.0 atm), the hydrogen concentration in the subsurface or bulk changes significantly on the experimental time scale depending on gas pressure. We confirmed that the hydrogen concentration in the bulk or subsurface of Pd nanofilms (not the Pd surface) plays a role in the resistance change of Pd through comparison between the calculated hydrogen concentration and experimental observations of an electric resistance change caused by exposure to hydrogen gas. A hydrogen sensor requires a 0.1% change in the hydrogen concentration in the bulk to observe a significant change in the electric resistance. Furthermore, we calculated the time-dependent diffusion coefficient of hydrogen in a Pd nanofilm and compared it with the experimental observed one. We also investigated temperature dependency of the solubility and confirmed that the hydrogen gas pressure determines hydrogen solubility in Pd nanofilms at the equilibrium state, whereas the temperature controls the speed to reach the equilibrium state.
Frequency-domain proper orthogonal decomposition for efficient reconstruction of unsteady flows
Authors: Gu Xiaojiang , Xu Chen , Liu Min , Mao Yijun
Published: February 2025

Proper orthogonal decomposition (POD) is a widely used data-driven, reduced-order method for feature extraction and field reconstruction of unsteady flows. The number of modes required in the POD varies greatly with the flow characteristics, and a high number of modes is a significant challenge to effective multiscale flow analysis. The first part of this study shows that the number of modes required for flow field reconstruction increases almost linearly with the energy proportion of the stochastic fluctuation, making it costly to accurately reconstruct the stochastic fluctuation in unsteady flows. To address this issue, the second part of this study proposes a frequency domain proper orthogonal decomposition (FDPOD) method, which reduces the number of modes required for accurate reconstruction while preserving key spectral characteristics of the unsteady flow. Three case studies, i.e., cylinder flow, jet flow, and fan flow, are employed to illustrate the advantage of the developed FDPOD method, which provides a more accurate and efficient tool for turbulence analysis, especially for multiscale flows dominated by stochastic fluctuations.
An efficient resistance assessment method for the porous and upright roughness arrays
Authors: Song Yanhong , Pei Binbin , He Kan , Zhang Jie , Huang Ning
Published: February 2025

Sand fences and shelterbelts are often combined to form porous and upright roughness arrays (PURAs) to mitigate soil erosion and land degradation. However, the efficient resistance assessment for these massive arrays remains unresolved. This paper develops a novel method quantifying the resistance of the PURAs using computational fluid dynamics technology, which brings the drag term and the source term in the Navier–Stokes (N–S) equations to simulate the resistance of PURAs to airflow. Then, the equivalent boundary is conducted to accurately assess the drag coefficient of PURAs. Furthermore, the computational methods for the drag coefficients specific to sand fences and shelterbelts are presented, which are regarded as the functions of the porosity, the height, the number of belts, and the spacing of these arrays. Utilizing these insights, an efficient resistance assessment method is formed, with the threshold of wind pressure required to drive to sand movement serving as the evaluation criterion. Finally, the model's performance is validated against wind tunnel test results, demonstrating good accuracy. The findings show that the combination of sand fences and shelterbelts has a higher obstructive effect and the arrangement of shelterbelts in the narrow belt with multiple strips pattern can achieve higher resistance. This resistance assessment method of the PURA is superior to enhancing the design efficiency of sand and wind control engineering in intense wind-blown sand environments.
Two-dimensional temperature field prediction of rotary kiln based on graph neural networks
Authors: Xu Yue , Guo Feng , Wang Yaozu , Liu Zhengjian , Zhang Jianliang
Published: February 2025

Sensing and optimizing the temperature distribution in rotary kilns is key to improve energy efficiency and reduce production costs. Traditional computational fluid dynamics (CFD) solvers are computationally expensive and cannot meet the demand for real-time performance in industrial sites. With the continuous development of deep learning, graph neural networks (GNNs) have emerged as a potentially effective method for accelerating CFD unstructured grid simulations. In order to accurately predict the whole temperature field in a rotary kiln, a novel GNN model is designed in this study, and the CLJPNet model is proposed for fast prediction of the whole temperature field in a rotary kiln. Compared with the traditional GNN, this study is able to accurately predict the rotary kiln temperature field by using the Cleary-Luby-Jones-Plassmann Coarsening coarsening algorithm in the multi-algebraic lattice to sparsify the graph topology to accelerate the inference speed while maintaining a high accuracy. Finally, the model proposed in this paper is compared with the other three models to verify the effectiveness of the model. The experimental results indicate that the model proposed in this study achieves a coefficient of determination (R2) of 0.99, mean squared error of 710.63, mean absolute percentage error of 1.64, and mean relative error in the region of interest of 0.02 on the test set, and all evaluation metrics are superior to other models, demonstrating better prediction performance. In addition, the proposed model runs 3 orders of magnitude faster than the CFD model. The rapid prediction method for temperature fields proposed in this paper provides a novel approach to the intelligent advancement of rotary kiln production.
Two-degree-of-freedom swimming of the seahorse in a vertical plane
Authors: Chen Gong , Li Xiaohu , Gao Yang , Mei Jianwei
Published: February 2025

The seahorse exhibits a special upright posture during swimming, which is different from the horizontal propulsion of other fish. Seahorses can swim simultaneously in both horizontal and vertical directions and change their movement path in the vertical plane by adjusting the inclination angle of the body. Thus, the two-degree-of-freedom (2-DoF) swimming of the seahorse is numerically analyzed to reveal its propulsive mechanism when the inclination angles α of its body are 85° and 30°. The research results indicate that hydrodynamic force can be decomposed into horizontal and vertical components on the vertical plane, and changes in the inclination angle can cause adjustments for both components, ultimately affecting their swimming speed and trajectory. Although the resultant speeds are nearly identical, it is more conducive to upward swimming at α = 85°, while it is more effective for horizontal motion at α = 30°. Unlike the backward diffusion appearing in the wake of other fish, the strip vortex generated by the seahorse dorsal fin diffuses simultaneously in both horizontal and vertical directions, indicating the generation of forward and heaving forces. Compared to the one-degree-of-freedom propulsion, the diffusion direction of the strip vortex and the position of the attachment vortex in the 2-DoF swimming have changed, especially at α = 85°. This study is beneficial for expanding the design of the propulsion mode of innovative robotic fish.
Monte Carlo study of the electron emission yields of germanium
Authors: Imtiaz H. I. , Zou Y. B. , Mao S. F. , Khan M. S. S. , Ding Z. J.
Published: February 2025

Though extensive experiments have been performed in the past to measure electron emission properties under electron beam bombardment, reliable measured data for clean and smooth surfaces are still lacking for most elemental solids. In this study, we have conducted a comprehensive Monte Carlo simulation to examine electron emission yields, including secondary electron yield (SEY), backscattering coefficient (BSC), and total electron yield (TEY), for germanium. The uncertainties associated with theoretical calculations have also been assessed with a total of 4608 scattering models by considering several dominant factors that can influence the calculated yields, i.e., optical energy loss function dataset, work function data, dielectric function model for electron inelastic scattering, and scattering potential for electron elastic scattering. Our results indicate that the work function value significantly affects the simulated SEY, and the energy loss function dataset and elastic scattering potential moderately influence both SEY and BSC. Our simulated BSC data are somewhat higher than most of the experimental measurements, while the simulated SEY data are mostly lower than the experimental data within the estimated theoretical uncertainty. This study highlights the critical need for establishing an accurate database of electron emission yields using theoretical modeling, considering particularly the unreliability of the previous experimental data caused by surface contamination during measurements.
Vortex dynamics analysis of an energy loss mechanism in a centrifugal pump impeller
Authors: Jiang Lei , Wang Weijun , Shi Yuhui , Chen Jie , Bai Ling , Zhou Ling
Published: February 2025

Centrifugal pumps play a vital role in industrial production, particularly for the transportation of viscous liquids, where they often incur significant energy losses. This study investigates the energy loss mechanisms in centrifugal pump impellers, focusing on the dynamics of vortices under varying viscosities and rotational speeds through numerical simulation. The proportion and distribution of entropy production under different viscosities and rotational speeds are discussed, and the influence of different terms of the vorticity transport equation on vorticity changes is analyzed. The results show that turbulent dissipation entropy production is the main entropy production at low viscosities. As the viscosity increases, the proportion of wall entropy production rises and becomes the main source of energy loss in the pump. Under high rotating speed condition, the Coriolis force source term is the main reason for vorticity changes. As the viscosity increases, the Coriolis force source term decreases sharply, and the relative vortex stretching term also decreases. Meanwhile, the viscosity diffusion term increases and becomes the main reason for the reduction of unstable flow in the impeller of a centrifugal pump for high-viscosity fluid media. This study combines the vorticity transport equation with entropy production analysis to analyze the energy conversion process and loss generation mechanism in a centrifugal pump, and deeply explore the relationship between the vorticity field and energy loss in the impeller. It has theoretical and practical significance for improving the efficiency of centrifugal pumps in transporting viscous fluids and providing support for related designs.
Numerical simulation of evaporation of droplet impacting on tubular wall with different wettability based on smoothed particle hydrodynamics method
Authors: Ma Xiaojing , Fan Mengyao , Cui Jie , Zhao Linjiao
Published: February 2025

In this paper, the evaporation numerical model of droplet impinging on the tubular wall with different wettability is established based on the smoothed particle hydrodynamics (SPH) method. The liquid phase mass fraction is introduced and integrated with the particle merging technique to address the phase change processes effectively. The flow spreading and heat transfer processes accompanying the phase change during droplet impact on a tubular wall are simulated. Meanwhile, five tubular walls with different wettability are prepared by sanding method and surface active material modification. The corresponding contact angles are 11°, 36°, 58°, 78°, and 112°, respectively. The experimental study of droplet impacts on tubular walls with different wettability is conducted. The reliability and validity of the SPH model are verified by comparing the simulation results with the experimental results. The dynamic process of flow spreading and evaporation of droplets impacting different wettability tubular walls are simulated, and the effects of surface wettability, wall temperature, and impact Weber number on the droplet evaporation process are further discussed and explored. It is found that poor surface wettability hinders droplet spreading and discourages the evaporation process. The spreading factor of the droplet increases with the tubular wall temperature and the impact Weber number. However, the increase in the impact Weber number promotes droplet spreading more significantly than the increase in tube temperature. Enhancing the wall wettability, increasing the tubular wall temperature, and enhancing the impact Weber number are beneficial to the evaporation of the liquid.
Dynamic graph learning-based higher-order graph convolutional networks for fluid classification in oil and gas exploration
Authors: Li Hengxiao , Sun Youzhuang , Qiao Sibo
Published: February 2025

In the field of oil and gas exploration, well-logging data is essential for predicting subsurface fluids. However, the classification of fluids remains a challenging task due to the inherent complexity of well-logging signals and the noise interference that distorts the data. Traditional machine learning techniques, while effective in extracting local features from these signals, often struggle to capture the spatial and topological relationships between data points. This limitation hinders their performance in fluid classification. To address these issues, we propose the deep dynamic higher-order graph convolutional network (DynGraph-FluidNet), a model that leverages dynamic graph learning to reduce the impact of noise and improve classification accuracy. Our approach integrates a higher-order graph convolutional network to extract multi-scale features embedded within the data's connectivity structure. Additionally, we utilize an edge pooling-based downsampling strategy to optimize the feature aggregation process, which further enhances classification performance. A residual convolution module is also incorporated to capture local information from individual well-logging samples more effectively, thereby improving the model's ability to represent intricate patterns. Experimental results demonstrate that DynGraph-FluidNet outperforms traditional models, achieving significantly higher fluid classification accuracy.
Inductive effect of charge transfer in ferroelectrics and plasmonic Ag heterojunctions for enhanced CO2 photoreduction
Authors: Liu Xiao , Wang Jicong , Tian Wenchao , Li Yanrui , Shi Jing
Published: February 2025

Converting carbon dioxide into fuel and chemicals by utilizing solar energy represents a cutting-edge approach to carbon recovery and energy renewal. The transfer behavior of photogenerated electrons and built-in electric field of photocatalysts greatly affect the efficiency of the photoreduction reaction. Herein, the heterostructures composed of bismuth sodium titanate (BNT) ferroelectrics and silver nanoparticles (Ag NPs) are constructed to promote the photocatalytic CO2 performance. The large spontaneous polarization of BNT optimizes the transfer dynamics of photoinduced electrons and holes and causes energy band bending with strong intrinsic electric field. With the aid of Ag NPs, the BNT@xAg heterojunctions exhibit intensified light absorption due to the phenomenon of localized surface plasmon resonance (LSPR), which extends the visible light absorption spectrum and strengthens charge transfer. The modified catalysts demonstrate improved charge separation capacity and notably prolonged electron lifetime up to 40.95 ns. The synergistic effect of LSPR and intrinsic polarization significantly boosts the photocatalytic efficiency together with ultrahigh CO product selectivity, which is outstanding among the ferroelectric and other representative photocatalysts. This study elucidates the photocatalytic enhancement mechanism of plasmonic Ag decorated BNT and offers an alternative route for the design of efficient catalysts.
Enhanced power-line energy harvesting by capacitance compensation for remote self-powered CO2 monitoring
Authors: Qian Jieying , Xu Jiawen
Published: February 2025

Aiming at carbon neutrality and compliance, it is necessary to monitor carbon emissions in remote areas. In this study, we proposed a remote self-powered CO2 monitoring system powered by a capacitance compensation enhanced power line energy harvester. The harvester consists of a magnetic core, a 4000-turn coil, and a matching capacitance. The coils would generate electrical energy due to the flux variation around the power lines. Besides, we demonstrate experimentally that the introduction of capacitance compensation would enhance the power output of the energy harvester and hence boost the overall efficiency of the system. Experimental studies of the proposed system revealed a capacitance compensation output power of 103.8 mW with a resistance load of 55 kΩ under 219 mArms current at 50 Hz. A microcontroller-based wireless sensor node was built for evaluation. The proposed system would ensure reliable remote CO2 monitoring mounted on power lines.
Research of magnetic properties of nanocrystalline materials considering temperature effects
Authors: Wang Ning , Zhang Pengning , Cheng Hong
Published: February 2025

Nanocrystalline materials are increasingly used in high-frequency transformer cores due to their advantages, including high permeability, high saturation flux density, and low loss characteristics. Measuring the magnetic properties of these materials at various temperatures is essential for accurately simulating loss distributions in high-frequency transformers and developing effective models. However, previous research on the measurements of nanocrystalline materials typically considered only a limited number of influencing factors and magnetic characteristic parameters, making it difficult for the findings to accurately reflect the impact of temperature on these materials. Therefore, this paper introduces a temperature-variable magnetic property measurement system for nanocrystalline magnetic rings based on a temperature-controlled chamber. This system is specifically designed to measure multiple property parameters, including saturation flux density, relative permeability, coercivity, and remanence, while accounting for several influencing factors, such as temperature, frequency, flux density, and excitation signals. Experimental measurements revealed positive correlations between the core loss, coercivity, and phase angle of the nanocrystalline material with temperature, while its saturation flux density and relative permeability showed negative correlations with temperature. In addition, a complex relationship was observed between the remanence and temperature across different flux density ranges, and the variation trends of magnetic properties in the saturation range were further identified. These results provide valuable data for developing loss models and optimizing the design of high-frequency transformers.
Structural characterization of influenza group 1 chimeric hemagglutinins as broad vaccine immunogens
Authors: Nguyen Yen Thi Kim , Zhu Xueyong , Han Julianna , Rodriguez Alesandra J. , Sun Weina , Yu Wenli , Palese Peter , Krammer Florian , Ward Andrew B. , Wilson Ian A.
Published: February 2025

Chimeric hemagglutinins (cHA) appear to be promising for the design and development of universal influenza vaccines. Influenza A group 1 cHAs, cH5/1, cH8/1, and cH11/1, comprising an H1 stem attached to either an H5, H8, or H11 globular head, have been used sequentially as vaccine immunogens in human clinical trials and induced high levels of broadly protective antibodies. Using X-ray crystallography and negative-stain electron microscopy, we determined structures of cH5/1, cH8/1, and cH11/1 HAs in their apo (unliganded) and antibody Fab-bound states. Stem-reactive antibodies 3E1 and 31.b.09 recognize their cognate epitopes in cH5/1, cH8/1, and cH11/1 HAs. However, with cH5/1, the head domains are rotated by 35 to 45° around the threefold axis of the HA trimer compared to native HA with a more splayed-open conformation at the stem base. cH11/1 with 3E1 is structurally more native-like but resembles cH5/1 with 31.b.09, whereas cH8/1 with 31.b.09 exhibited a range of closed-to-open stem configurations with some separation of head and stem domains. Furthermore, all of these group 1 cHAs effectively bound a broad head trimer interface antibody and other broad stem antibodies. Thus, the cHAs exhibit structural plasticity without compromising the stem and head trimer interface epitopes for elicitation of influenza A group 1 cross-reactive antibodies.
Longitudinal-lateral coupling control and global sensitivity analysis method for intelligent vehicles under heterogeneous disturbances
Authors: Guan Longxin , Guo Lie , Wu Xiaojian , Liu Weidong
Published: February 2025

Intelligent vehicles motion control system is a kind of nonlinear system with many het-erogeneous disturbances such as modeling inaccuracies, model coupling, parameters perturbation, speed fluctuation and external environmental disturbance. This paper ac-cordingly proposes a nonlinear longitudinal-lateral coupling model predictive control (LLMPC) method. Firstly, to effectively describe the inherent nonlinearity and coupling of the vehicle dynamic model, an approximate nonlinear longitudinal-lateral coupling model with a paradigm bounded uncertainty is established using linear fractional trans-formation (LFT) formulation. Secondly, a final-value theorem-based constrained feed-forward compensation strategy and a speed compensation are designed to obtain the longitudinal-lateral coupling control law, which can effectively handle heterogeneous disturbances of the system. Thirdly, a Sobol-based global sensitivity analysis method is designed to analyse and quantify the extent to which different disturbances affect the control performance of the system. Finally, the recursive feasibility of the closed-loop system is analysed and system asymptotic stability is proved through Lyapunov theorem. The simulation results of Carsim-Simulink and the statistical comparison analysis show the superiority of the proposed controller, which can effectively ensure the stability margin and has good tracking accuracy, robustness. Further, real-vehicle experimental results also show good accuracy and real-time performance.
Transient measurement of the discharge termination field in an atmospheric pressure pulse discharge based on electric field induced second harmonic generation
Authors: Wang Xinyan , Yang Xin , Wang Wei , Lv Zepeng , Wu Kai
Published: February 2025

Motivated by the need for precise control of plasma parameters of atmospheric non-equilibrium plasma, we present an approach for the transient measurement of the electric field for discharge termination (i.e. the discharge termination fields, DTFs) based on the electric field induced second harmonic generation method. This approach utilizes a custom-designed electrode structure and introduces the integration system as the connection between the electric field and the response signals according to the superposition theorem of electric fields. Considering the electric field profile, the effect of the undesired electric field outside the copper foils on second harmonic generation is eliminated, leading to more accurate DTF measurement results. The DTFs for positive discharges decrease with increasing voltage amplitude or gap height, while the DTFs for negative discharges display the opposite trend, both of which are closely related to the discharge magnitude. Moreover, the higher measurement accuracy of the proposed method is further demonstrated in the experimental measurement of electric field evolution. The presented quantitative measurement results can be used to validate high-fidelity modeling predictions and facilitate a deeper understanding of the physical mechanisms of discharge extinction.
Experiences and lessons learned from the End-of-Substructure card production of the ATLAS ITk Strip upgrade
Authors: Bauckhage L. , Boebel A.L. , Ceslik H. , Dam M. , da Silva A. , Diez Cornell S. , Garvey C.M. , Gotfredsen R.S. , Göttlicher P. , Gregor I.M. , Keaveney J.M. , Palmelund A. , Ruiz Daza S. , Schmitt S. , Stanitzki M. , Strom L.R.
Published: February 2025

The silicon tracker of the ATLAS experiment will be upgraded for the upcoming
High-Luminosity Upgrade of the LHC. The main building blocks of the new strip tracker are
modules that consist of silicon sensors and hybrid PCBs hosting the read-out ASICs. The modules
are mounted on rigid carbon-fiber substructures, known as staves in the central barrel region and
petals in the end-cap regions, that provide common services to all the modules. At the end of
each stave or petal side, a so-called End-of-Substructure (EoS) card facilitates the transfer of
data, power, and control signals between the modules and the off-detector systems. The EoS
connects up to 28 data lines to one or two lpGBT chips that provide data serialization and uses a
10 Gbit s-1 versatile optical link to transmit signals to the off-detector
systems. To meet the tight integration requirements in the detector, several different EoS card
designs are needed. The power to the EoS is provided by a dedicated dual-stage DC-DC package
providing 2.5 V and 1.2 V to the EoS cards. As the EoS production of almost 2000 EoS
cards and accompanying DC-DC converters is getting close to completion, the production experience
including detailed QC statistics and design validation (QA) results is reported on.