bluuebunny/crossref_metadata_2025 huggingface dataset:
Size-dependent dose estimation applied to 177Lu and 90Y -DOTATATE using ICRP Phantoms
Nuclear Science and Engineering
Authors: Jabbari
Published: February 2025

Purpose: radiolabeled peptide has attracted growing interests for neuroendocrine cancer therapy. We aim to calculate S-values of Lu-177, In-111 and Y-90 in different size of International commission of radiation protection (ICRP) male and female phantoms for pre-estimation of absorbed dose in critical target organs using Monte Carlo simulation to see the extent of difference.

Materials and methods: We employed the most advanced hybrid ICRP phantom and used its different male and females BMIs to resemble reality. Twenty different size of ICRP male and female phantoms were generated. GATE code was used to perform dosimetry calculations. Spline, bladder, kidneys, and liver were chosen as the source organs and the S- values were calculated in interested target organs for twenty different body mass indexes (BMIs).

Results: The S-values in both self-absorptions and target organs were dramatically lower for 177Lu -DOTATATE compared to 90Y-DOTATATE. The highest difference between the absorption in kidneys is for BMI of 24.3. The highest S-value in bladder from bladder is 0.01 mGy/MBq.s in BMI of 34.4 for 177Lu-DOTATATE, whereas it is 0.0049 mGy/MBq.s in BMIs of 34.4 for 90Y-DOTATATE. It was found that dose per unit cumulated activity had a tendency to decrease with BMI.
Conclusion: Variability in 177Lu -DOTATATE and 90Y-DOTATATE dosimetry across morphometrically different patients are important in optimizing therapy protocols and research studies. Using size-dependent phantoms for dosimetry, estimations more accurate dose per cumulated activity relative to standard reference dosimetry. To prevent excessive dosage to patients, it is important to consider the relationship between body size and dose.
Thrombosis at Unusual Sites: Focus on Myeloproliferative Neoplasms and Paroxysmal Nocturnal Hemoglobinuria
Authors: Koschmieder Steffen , Panse Jens
Published: February 2025

Patients with thrombosis at an unusual site will need to be explored for rare causes of thrombosis. Two of these rare causes include myeloproliferative neoplasms (MPNs) and paroxysmal nocturnal hemoglobinuria (PNH). It is important not to overlook these causes, since they require specific management, in addition to antithrombotic treatment (anticoagulants, antiplatelet agents). Unusual sites of venous thrombosis include upper extremity veins, splanchnic veins, cerebral veins, and retinal veins, and unusual sites of arterial thrombosis include renal, adrenal, splenic and mesenteric arteries, and intracardiac and aortal locations. Suspicion for MPN and PNH should be raised if there are concomitant abnormalities, such as elevated or decreased blood cell counts or splenomegaly. Diagnosis of MPN and PNH should include JAK2V617F mutational screening as well as flow cytometric assessment of GPI-anchored proteins in the peripheral blood, respectively. Specific treatments for MPN may include phlebotomy or cytoreductive drugs such as hydroxyurea, anagrelide, pegylated interferon-alpha, or Janus kinase inhibitors. Drugs used for PNH treatment include terminal complement inhibitors, such as eculizumab and ravulizumab, as well as proximally acting inhibitors such as pegcetacoplan or iptacopan. Patients with MPN and PNH are at high risk for thrombosis during their entire lifetime and should thus be followed by specialists experienced in the care of these diseases.
Clinical Outcome of Superselective Transarterial Embolization for Acute Colonic Gastrointestinal Bleeding: A Retrospective Single-Center Experience
Authors: Behera Rajendra Kumar , Narang Mohak , Pandey Shivam , Madhusudhan Kumble Seetharama
Published: February 2025

Objective The aim of the study was to assess the safety and efficacy of transarterial embolization in the treatment of acute lower gastrointestinal hemorrhage (LGIH) from colonic origin and to determine factors that influence the treatment outcome.

Methods This retrospective study included 32 patients (mean age: 37.5 years; 24 males) of acute LGIH with a colonic source diagnosed on conventional angiography between March 2014 and May 2023. The clinical characteristics at presentation, laboratory findings, etiology of bleeding, angiographic findings, and embolization details were assessed and correlated with outcomes comprising success rates of embolization, complications, recurrence (immediate and late), and mortality.

Results Embolization was technically successful in 27 patients (84.4%) and clinically successful in 24 patients (75%). Embolic agents used were coils (n = 12), n-butyl cyanoacrylate glue (n = 8), Gelfoam (n = 4), polyvinyl alcohol (PVA) particles (n = 2), and a combination of coils and glue (n = 1). Major complications were seen in five patients (15.6%) including artery dissection (n = 3) and catheter impaction and fracture (n = 2). Sixteen patients (50%) died after a mean period of 8.3 ± 8.8 days mostly due to septic shock related to the underlying cause. Immediate recurrence was observed in five patients (15.6%) after 3.8 ± 1.6 days of embolization and late recurrence in one patient (3.1%) after 76 days. Both univariate and multivariate analyses showed that acute pancreatitis as etiology was significantly associated with mortality (p < 0.05). No other parameters showed any significant association with outcomes.

Conclusion Transarterial embolization is safe and effective in the treatment of acute LGIH due to a colonic source. The etiology of acute pancreatitis is significantly associated with increased mortality.
Large diameter diffractive lens enables detailed imaging in air and space
Authors: Thompson Avery
Published: February 2025

This flat, achromatic diffractive lens provides a lightweight, unobscured alternative to curved lenses and mirrors.
Unstable entropy mode in a current-carrying turbulent plasma and double layer formation
Authors: Kumar Pawan
Published: February 2025

In this manuscript, we developed an analytical model for double layer and unstable entropy formation in current-carrying turbulent plasma. In the presence of a strong axial current, ion acoustic turbulence can give rise to enhanced anomalous resistivity and inhibited thermal conductivity. This state of uniform turbulence is, however, shown to be unstable to a purely growing axial perturbation when v02υ/ve2>k2χ, where v0,ve,υ,and χ are the electron drift velocity, thermal velocity, collision frequency, and thermal conductivity, respectively. The temperature perturbation enhances the local resistivity of electrons and raises their heating rate, further enhancing the temperature perturbation. When this tendency overpowers the opposing effect of thermal conduction, the instability grows. The nonlinear state of this instability has been analyzed and its possible relevance to the experimental results with double layer formation in a long plasma column has been discussed.
High-Q silicon two-dimensional photonic crystal slot nanocavities with asymmetric low-index claddings
Authors: Kim Heungjoon , Song Bong-Shik , Asano Takashi , Noda Susumu
Published: February 2025

Photonic crystal nanocavities with high quality (Q) factors find extensive application in silicon (Si)-integrated photonics owing to their highly selective wavelength filtering, optical buffering, and enhanced nonlinear optical effects in the telecommunication band. High-Q Si photonic nanocavities with asymmetric claddings offer mechanical stability, high functionalities from heterogeneous materials, and vertical integration of optoelectronic devices. However, achieving a high Q factor in an asymmetric structure remains challenging because of the TE–TM coupling loss in the Si slab. To suppress the TE–TM coupling, we designed a high-Q two-dimensional (2D) Si photonic crystal slot cavity by significantly reducing the electric field components in the slab, leveraging a large dielectric discontinuity between Si and the low-index slot. We fabricated 2D Si photonic crystal slot nanocavities with asymmetric claddings consisting of a lower cladding of thermal oxide (nlc = nBOX = 1.45) and an upper cladding of infiltrated spin-on glass (nuc = nSOG = 1.3). The Q factor of this slot cavity is as high as 6.32 × 105, which is the highest Q value ever recorded among nanocavities with asymmetric claddings. Our results are useful for heterogeneous integration of Si photonic crystal nanocavities with various functionalities such as active and nonlinear optical materials, which are unattainable in conventional Si photonics.
The multicomponent generalization for the super modified KP hierarchy of Kac–van de Leur
Authors: Chen Huizhan
Published: February 2025

In this paper, the super modified KP hierarchy of Kac–van de Leur is generalized to multicomponent cases. We utilize the multicomponent super boson-fermion correspondence of type A to bosonize the multicomponent super modified KP hierarchy in the fermionic picture, and we derive bilinear identities of different forms: the super Hirota bilinear form, the super Baker function form, and the super pseudo-differential operator form. Finally, elementary Darboux transformations are presented in the super fermionic Fock space.
Diffusive transport through a double-cone channel under stochastic resetting
Authors: González Gabriel
Published: February 2025

We study three-dimensional diffusive transport of particles through a double-cone channel under stochastic resetting by means of the modified Fick–Jacobs equation. Exact analytical expressions for the unconditional first-passage density and the mean first-passage times in the channel are obtained, and their behavior as a function of the resetting rate is highlighted. Our results show a difference in the mean first-passage times between a narrow–wide–narrow and wide–narrow–wide double-cone geometry. We find in the narrow–wide–narrow double-cone channel with absorbing boundaries a discontinuous transition for the optimal resetting rates, which is not present for the wide–narrow–wide double-cone channel. Furthermore, it is shown how resetting can expedite or slow down the escape of the particle through the double-cone channel. Our results extend the solutions obtained by Jain et al. [J. Chem. Phys. 158, 054113 (2023)].
A novel hybrid spatiotemporal prediction algorithm of solar radiation based on topology and deep learning models
Authors: Wu Mengge , Xue Guixiang , Song Jiancai , Zuo Shixu , Li Ruomeng , Ma Guowei
Published: February 2025

As a renewable energy source, solar energy has become essential to alleviate traditional energy scarcity because of its environmentally friendly characteristics. The intermittence and instability of solar energy bring challenges to energy utilization. Accurate solar radiation prediction models are necessary for the economical and reliable operation of building energy systems. Most existing models predict solar radiation based solely on time-dependent features and neglect the influence of spatial information, resulting in inferior prediction results. A novel hybrid spatiotemporal prediction model based on the graph attention network and bi-directional gated recurrent unit (GAT-BiGRU) is proposed in this paper. The GAT-BiGRU algorithm innovatively adopts the GAT to explore the spatial dependence of solar radiation from the graph topology, while the BiGRU is being applied to capture the temporal dynamic features of solar radiation. Detailed prediction experiments were conducted for the solar radiation of 16 districts in Tianjin. Compared with the state-of-the-art algorithms, the results indicate that the proposed model has a more robust generalization ability and minor prediction errors. Thus, it is expected to provide an effective reference for the actual operation strategy of solar building energy systems.
Tunneling photo-thermoelectric effect in monolayer graphene/bilayer hexagonal boron nitride/bilayer graphene asymmetric van der Waals tunnel junctions
Authors: Park Sabin , Moriya Rai , Zhang Yijin , Watanabe Kenji , Taniguchi Takashi , Machida Tomoki
Published: February 2025

Graphene exhibits a pronounced photo-thermoelectric effect (PTE) in its in-plane carrier transport and has attracted attention toward various optoelectronic applications. In this study, we demonstrate an out-of-plane PTE by utilizing electron tunneling across a barrier, namely, the tunneling photo-thermoelectric effect (TPTE). This was achieved in a monolayer graphene (MLG)/bilayer hexagonal boron nitride (h-BN)/bilayer graphene (BLG) asymmetric tunnel junction. MLG and BLG exhibit different cyclotron resonance (CR) optical absorption energies when their energies are Landau quantized under an out-of-plane magnetic field. We tuned the magnetic field under mid-infrared irradiation to bring MLG into CR conditions, whereas BLG was not in CR. The CR absorption in the MLG generates an electron temperature difference between the MLG and BLG and induces an out-of-plane TPTE voltage across the h-BN tunnel barrier. The TPTE exhibited a unique dependence on the Fermi energy of the MLG, which differed from that of the in-plane PTE of the MLG. The TPTE signal was large when the Fermi energy of the MLG was tuned near the transition between the quantum Hall state (QHS) and non-QHS. The TPTE allows one to measure the PTE on vertically stacked tunnel junctions, thus providing another degree of freedom for probing the electronic and optoelectronic properties of two-dimensional material heterostructures.
Halo formation and emittance growth for an intense sheet beam
Authors: Carlan Antônio H. , Pakter Renato
Published: February 2025

In this paper, halo formation and emittance growth caused by an initial envelope mismatch on high-intensity sheet beams are investigated. An estimate for the maximum energy that a halo particle can achieve is obtained using a nonlinear Hamiltonian approach. Based on a kinetic description of the beam, a theoretical framework is developed to predict the final stationary state achieved after the envelope oscillations are completely damped. The theory allows for the determination of relevant quantities like the final particle distribution and total emittance growth. The results are compared to self-consistent numerical simulations of the sheet beam.
A reconfigurable power electronic system for off-grid residences with V2H capability
Authors: Natarajan Sankar , M. M. Rajan Singaravel
Published: February 2025

Off-grid residences equipped with renewable energy sources (RES), battery storage systems (BSS), and electric vehicles (EVs) constitute a sustainable and self-sufficient ecosystem. This integration helps to achieve energy independence and reduces the reliability on fossil fuels. Existing systems, comprising RES, BSS, and EV, employ an increased number of power conversion stages and power electronic (PE) switches. This paper proposes a reconfigurable power electronic system (RPES) powered by solar photovoltaic (PV) and BSS for charging EVs and supplying residential DC loads (RDCLs) uninterruptedly. With the ability to reconfigure, the proposed system can operate in nine distinct modes with two PE switches and reduced power conversion stages compared to existing systems. The system reconfigures itself using five relays. The proposed system enables vehicle-to-home operation by supplying the RDCLs from EV in the absence of PV and BSS. PV charges the EV during the day, while BSS charges it at night. The dspic30F4011 controller determines the operating mode of the RPES based on the inputs it receives. The controller triggers the relays after the mode selection, which allows the interface to reconfigure automatically. In the same manner, the controller selects the appropriate control logic and transmits triggering pulses to the PE switches in accordance with the operating modes. A laboratory prototype has been created to assess the system's performance under both steady-state and transient conditions. The results indicate an average efficiency of 96.9%.
Qualitative analysis of terpenoid esters based on near-infrared spectroscopy and machine learning
Authors: Bian Haiyi , Huang Ling , Xu Qinxin , Ji Rendong , Wang Jun
Published: February 2025

This study delves into the method of qualitative analysis of terpenoid esters using near-infrared spectroscopy technology. Terpenoid esters are bioactive compounds widely used in the pharmaceutical and cosmetics industries. Near-infrared spectroscopy technology enables rapid and accurate component analysis without compromising the integrity of the sample, which is particularly important for valuable samples that need to be preserved intact or require subsequent analysis. This research combines machine learning techniques, such as K-Nearest Neighbors (K-NN) classifier, Random Forests algorithm, and Back Propagation Neural Networks (BPNN), to analyze terpenoid ester samples extracted from different concentrations of eluents, and compares and evaluates these algorithms. This study results show that in the test set, the prediction accuracy of the K-NN classifier is 96.154% and BPNN is 94.231%, and the Random Forest algorithm performs the best with a prediction accuracy of 100%. Additionally, this study utilizes the Random Forest algorithm to predict the characteristic spectra of terpenoid esters, demonstrating the effectiveness of feature spectrum extraction by ensuring a prediction accuracy of 100% while reducing the number of spectral features.
Machine learning of slow collective variables and enhanced sampling via spatial techniques
Authors: Gökdemir Tuğçe , Rydzewski Jakub
Published: February 2025

Understanding the long-time dynamics of complex physical processes depends on our ability to recognize patterns. To simplify the description of these processes, we often introduce a set of reaction coordinates, customarily referred to as collective variables (CVs). The quality of these CVs heavily impacts our comprehension of the dynamics, often influencing the estimates of thermodynamics and kinetics from atomistic simulations. Consequently, identifying CVs poses a fundamental challenge in chemical physics. Recently, significant progress was made by leveraging the predictive ability of unsupervised machine learning techniques to determine CVs. Many of these techniques require temporal information to learn slow CVs that correspond to the long timescale behavior of the studied process. Here, however, we specifically focus on techniques that can identify CVs corresponding to the slowest transitions between states without needing temporal trajectories as input, instead of using the spatial characteristics of the data. We discuss the latest developments in this category of techniques and briefly discuss potential directions for thermodynamics-informed spatial learning of slow CVs.
Scaling law for the critical voltage of a droplet on a surface in the presence of an external field
Authors: Li Jing , Wen Kaiqiang , Xiao Ke , Chen Xiaoming , Wu Chen-Xu
Published: February 2025

Using external fields to regulate the droplet shape and behavior has attracted considerable attention due to its wide range of practical applications. However, determining the complex flow phenomenon inside a droplet and its deformable boundary shape at equilibrium is a challenging physical and mathematical exercise. In the present work, we employ theoretical and experimental approaches to study the shape deformation of a sessile droplet on a substrate in the presence of an external electric field. Based on the theoretical model we propose, and by combining the finite element method with the gradient descent algorithm, we successfully determine the droplet shape by minimizing the total free energy of the system, viz., a combination of electrostatic energy, surface tension energy, and gravitational potential energy. We also perform scaling analyses and derive an empirical expression for the critical voltage, featuring a universal scaling exponent of 1/2 for the contact angle as a function of normalized volume. The master curve depicted by the empirical expression provides an excellent fit to both the experimental and numerical results.
Label-free 3D optical angiography via time-frequency domain analysis of focal modulated dynamic blood flow
Authors: Yang Shangpan , Yu Yingsi , Chen Huadeng , Liu Zhanpeng , Ding Wenzheng , Zeng Yaguang , Wang Mingyi
Published: February 2025

Accurate three-dimensional (3D) blood flow imaging with high spatiotemporal resolution and significant detection depth is essential for studying vascular structure-related diseases. In this Letter, we introduce a label-free 3D optical angiography technique via time-frequency domain analysis (TFDA) of focal modulated dynamic blood flow. First, a low-magnification telecentric lens is used for sparse axial sampling within a large depth-of-field range to obtain a coarse estimate of vascular depth. Then, based on the frequency-depth characteristics of dynamic blood flow signals, a TFDA-based focusing evaluation function is established in combination with Lambert–Beer's law, achieving a mean absolute percentage error of 2.06%. Finally, validation on a 3-day-old chicken embryo demonstrated a lateral spatial resolution of 2.95 μm and imaging time of 11.5 s for a 4.95 × 4.95 × 0.7 mm3 sample. Our method provides effective blood flow depth localization by assessing focal modulation intensity relative to focal plane and blood flow position, offering promising support for vascular disease research.
Raman signal enhancement via a micro-ring resonator
Authors: Sharma Amis , Li Yuhua , Prasad Madhava Krishna , Ho Wai Lok , Chu Sai Tak , Borzenets Ivan Valerievich
Published: February 2025

This study presents the use of micro-ring resonator (MRR) devices to extract and enhance nonlinear signals. MRRs “trap” incoming light and, therefore, have been shown to achieve extremely high local intensities of light. Thus, they can be used to facilitate highly nonlinear optical signals that are usually weak in intensity and require high excitation power. By embedding materials that host nonlinear optical processes inside the MRR, we expect to observe an enhancement in the strength of the nonlinear optical signals. This concept is demonstrated here by extracting the Raman signature of graphene that is placed inside a MRR device. A highly doped silica MRR featuring an optical bus waveguide coupled to a ring tuned to near-infrared wavelengths is used. Raman signal with an excitation wavelength of 522 nm via third-harmonic generation inside the MRR is observed. The higher-order Raman signal of the embedded graphene is also observed at the 1597.6 nm excitation wavelength. This work demonstrates the feasibility of the MRR as a nonlinear signal enhancer using high-Q MRR device setups.
Semiconductor-to-metal transition in BaFe12−x(Ru, Re)xO19 (x = 0.1) hexaferrite at high temperatures
Authors: Govea-Alcaide E. , Paiva V. S. , Santos C. C. , de Menezes A. S. , Jardim R. F. , Peña Garcia Ramón R. , Guerrero F.
Published: February 2025

Semiconductor-to-metal-like behavior was observed in the BaFe11.9(Ru,Re)0.1O19 ceramic hexaferrite at temperatures above 450 K. X-ray diffraction analysis confirmed its hexagonal structure with minor α-Fe2O3 impurities, while Rietveld refinement revealed significant changes in the lattice parameters, particularly an expansion along the c axis. Atomic positions at the 2b, 4f2, and 12k sites were altered due to the partial substitution of Fe3+ by Ru4+ and Re4+ cations, which have smaller ionic radii than Fe3+. These substitutions modified the bond lengths within the crystal structure, as evidenced by increased Fe–O distances, and led to a partial reduction of Fe3+ to Fe2+, increasing electron density. The AC conductivity, σac(T), showed a transition from semiconducting to metallic-like behavior above ∼450 K. The resistivity, ρac(T), exhibited a plateau near 500 K, indicating a change in the conduction mechanism. The transport mechanism below 450 K was dominated by the non-overlapping small polaron tunneling model, characterized by thermally activated hopping with minimal Coulomb interactions, while above 450 K, the correlated barrier hopping model became dominant. The activation energy for high temperatures, Ea=0.31±0.06 eV, was consistent with the sum of the hopping energy WH=0.20±0.01 eV and half the disorder energy, Ed/2, which increased significantly with temperature. The partial substitution of Ru4+ and Re4+ significantly weakened the magnetic interactions, resulting in reduced saturation magnetization and modifications in coercivity.
Development of interatomic potential suitable for molecular dynamics simulation of Ni oxidation and Ni–NiO interface
Authors: Plummer Gabriel , Tavenner Jacob P. , Mendelev Mikhail I. , Wu Zhigang , Lawson John W.
Published: February 2025

Large-scale molecular dynamics (MD) simulations enabled by computationally efficient semiempirical potentials are an invaluable tool for materials modeling. In the case of metallic alloys, embedded atom method (EAM) and Finnis–Sinclair (FS) potentials are a reasonable choice based on their good balance of quality and computational cost. However, these semiempirical potentials are not suitable for simulating ionic systems, which prevents their use in studying many technologically relevant metal–oxide systems. The charge transfer ionic potential (CTIP), which can utilize EAM/FS potentials available in the literature together with a variable charge representation of electrostatic interactions, should be a reasonable choice for performing reliable and computationally efficient MD simulations of such systems. However, only a few such potentials are available in the literature, and their computational cost is much higher compared to EAM/FS potentials. In the present work, we have attempted to remedy these deficiencies by combining several modifications to the CTIP model proposed in the literature and efficiently implementing them into the widely used Large-scale Atomic/Molecular Massively Parallel Simulator MD code. Using these modifications, we have developed a new Ni–O CTIP parameterization, which has been tested in several different scenarios of interest. First, the early stages of Ni surface oxidation were simulated, demonstrating the nucleation and growth of a crystalline NiO film across the surface. Second, solidification and vitrification in the Ni–O system were investigated, demonstrating that the new CTIP parameterization provides reasonable agreement with the experimentally determined equilibrium phase diagram. Finally, we studied the interaction of dislocations in a Ni matrix with a NiO inclusion using a simulation cell with an unprecedented number of atoms for a variable charge MD simulation. Thus, the approach utilized in the present study is an efficient method to simulate large scale atomic mechanisms in metal–oxide systems.
Transport properties of N + N, O + O, N + O, C + O, C+ + O, C + N, and C + C using an accurate treatment of nonzero spin and electronic angular momentum and including spin–orbit interaction
Authors: Schwenke David W.
Published: February 2025

We have carried out first principles calculations of transport properties of the title atom–atom systems using accurate ab initio electronic structure methods and quantum scattering. We go beyond the Born–Oppenheimer approximation and show how one can properly include the spin and orbital angular momentum of atoms in the calculations. We give the explicit transformation between coupled LS atomic states, where L is the total electron angular momentum and S is the total spin angular momentum, and the diatomic Hund’s case (a) basis. We include both Coulomb spin–orbit interaction as well as the effect of the magnetic-moments of the electrons via the Breit interaction. The relations between the long-range forces of different symmetry electronic states are given for S + P and P + P asymptotes.
A flexible multi-gate organic electrochemical synaptic transistor for image processing
Authors: Wang Jingwen , Xu Yunchao , Jin Chenxing , Zeng Biao , Sun Jia
Published: February 2025

In this study, a P3HT-based multi-gate frequency-dependent synaptic transistor is fabricated, which demonstrates significant advantages in mimicking the transmission characteristics of biological synaptic activities. The proposed device simulates outputs related to frequency and gate voltage modulation. This device can respond differently to inputs ranging from 0.75 to 11.11 Hz, and at the same input frequency, it exhibits different responses by varying the control gate voltage from 0 to −0.8 V. This innovative design can dynamically adjust the cutoff frequency, enhancing edge feature processing in images, thereby significantly improving the recognition accuracy of information in blurry images that can be difficult for humans to distinguish. Our results provide a hardware edge-computing image processing method, overcoming the limitations of traditional single-gate transistors that typically have fixed parameters. The recognition accuracy of information in blurry images preprocessed by this device improved significantly from 80% to 100%. Combined with the multi-gate design, this synaptic device excels not only in edge enhancement and image processing but also offers robust hardware support for future neuromorphic electronics.
Directed transport of particles in coupled fractional-order systems excited by Lévy noise
Authors: Guo Jing , Ning Lijuan
Published: February 2025

This paper investigates the directed transport of particles in a coupled fractional-order system excited by Lévy noise. Numerical simulations reveal the effects of fractional order, Lévy noise and coupling coefficients on the directed transport. It is found that there exists an optimal fractional order, which maximizes the directed transport of particles. The optimal fractional order for the directed transport shifts to the left or right with different noise parameters, which means that the appropriate fractional order and noise parameters should be taken into account to maximize the directed transport. Meanwhile, the increase of the scale and symmetry parameters intensifies the directed transport of the particles, while the increase of the stability index suppresses the directed transport, so appropriate Lévy noise parameters will effectively amplify the directed transport. In addition, strong coupling can also effectively promote the directed transport of particles. These studies may provide a theoretical basis for the design of nanomachines, improving drug delivery across cell membranes and treating diseases of the nervous system.
Combining crystal planes and heterojunctions of ZnS/SnS2 boosts photocatalytic performance
Authors: Jiao Zhengxu , Shuai Xiaofeng , Du Yuxuan , Du Jianping
Published: February 2025

A reasonable construction of hybrid heterogeneous photocatalysts possessing fast charge separation and transfer and visible light utilization ability is of great significance for enhancing and achieving highly efficient photochemical conversion. In this study, a series of ZnS/SnS2 heterojunction photocatalysts were prepared by a morphology-controlled strategy, and the regulation of ZnS/SnS2 heterostructure was realized for the photodegradation of methyl violet (MV) under visible light. The results show that as-prepared ZnS/SnS2 consists of hybrid morphological microparticles and exhibits a nanoparticle/nanosheet interspersed structure. The multi-touch interface of the constructed heterostructures can significantly shorten the carrier transport path and greatly promote the charge separation and transfer under the action of the local electric field at the semiconductor/semiconductor interface. Exposed dual-crystal planes of SnS2 coupled with ZnS enrich the active sites and enhance the performance of pure SnS2 and ZnS material. The degradation rate of MV over the optimal heterojunction material (ZnS/SnS2-50) exceeds 91.4% within 90 min under visible light irradiation, which is about 62 times that of MV compared with pristine ZnS.
Direction-preferred liquid transportation on biomimetic hierarchical gradient microgrooves
Authors: Zhai Xinmeng , Wang Yan , Xie Dongdong , Sun Yunna , Zang Faheng , Yang Zhuoqing , Ding Guifu
Published: February 2025

Conventional understanding holds that droplets on microgrooves flow symmetrically toward both ends, which limits their utility in applications requiring direction-preferred droplet transport, such as vapor chambers. Inspired by the fog-collecting strategies of cactus spines, we propose a bioinspired hierarchical gradient microgroove (BHGM) that achieves the liquid transport in a preferred direction. By combining primary microgrooves with surface nanostructures, BHGM provides a strong initial driving force for liquid transport. Secondary microgrooves are introduced to increase the liquid–solid contact area, further enhancing capillary pressure. Additionally, gradient interfaces at structural discontinuities create unbalanced surface tension, driving direction-preferred liquid transport. This, in combination with the shape variation of the secondary grooves, regulates the meniscus and enables rapid and heterogeneous liquid movement. The BHGM demonstrates forward capillary wicking over a distance of up to 90 mm in just 12.5 s while reducing reverse wicking time by 53.7%. At the two gradient interfaces from bottom to top, speed reduction rates are only 7.7% and 2.3%, respectively. In addition, the BHGM maintains liquid transport capability even at bending angles of 90° and 120°. This hierarchical design enhances heterogeneous capillary transport efficiency while preserving scalability and adaptability, offering promising potential for practical applications, including improved thermal management in vapor chambers and more efficient fluid control in microfluidics.
Thermodynamics of an oblique droplet impinging on stationary water film
Authors: Wang Jingxin , Cao Yan , Guo Rongying , Zhao Ning , Zhu Chunling , Wu Yuan
Published: February 2025

The flow and heat transfer of the oblique impact of a droplet on a stationary liquid film with various dimensionless thicknesses (01.0–0.5) are investigated experimentally and numerically. A superhydrophobic guideway is used to create the oblique impact of a droplet, which causes subsequent asymmetric crown structure and splashing. The thermal level set method is employed to capture the deformation and heat transfer of warm droplets' oblique impact on a cold liquid film. A parameter study of the effect of Weber number, oblique angle, and liquid film thickness on geometrical characteristics and wall heat flux is carried out. The results show that in the downstream direction, during the crown rising period, the radius is independent of the normal Weber number but increases for a larger tangential Weber number and a thinner liquid film. The maximum downstream crown height increases with an increase in the Weber number and exhibits a non-monotonic trend with the liquid film thickness. The heat transfer rate between the liquid film and surface decreases with larger oblique angles and thicker liquid films while having a poor dependence on the Weber number. In addition, the critical oblique angles for prompting splashing at different liquid film thicknesses are presented. Finally, modified thermodynamics models and splashing thresholds for the liquid film are developed to further enhance the understanding of aircraft icing.
Dynamics study of double droplets impacting liquid film based on phase-field lattice Boltzmann method
Authors: Zhou Rui , Guo Xiuya , Cui Shuqi , Zheng Qian , Wang Huili
Published: February 2025

In this paper, we conduct a numerical study on the dynamics of double droplets impacting a liquid film using the phase-field lattice Boltzmann method. The effects of the solid surface roughness, Weber number, Reynolds number, the film thickness, the horizontal distance between the droplets and the density ratio have been investigated systematically. For the flat case (radius of cavity is zero), the droplets with high Weber and Reynolds numbers will lead to a marked increase in the maximum rise height. In addition, the horizontal distance between the droplets also has a significant influence on the dynamic process of the droplets. The maximum rise height first increases and then decreases, with increasing the horizontal distance between the droplets. Conversely, for the rough solid surface, there exists the following relationship between the crown root radius and time, r/(2R)≈α(Ut/(2R))0.25, where r denotes the crown root radius, R represents the initial droplet radius and U is the initial droplet velocity. The numerical results indicate that the effect of the solid surface roughness on the crown root radius is similar to that of a single droplet. Furthermore, we found that the film thickness is inversely proportional to the maximum rise height, which is different from the flat case.
Flow and heat transfer characteristics of a squealer tip with bent rail in turbine blades
Authors: Zhou Haimeng , Luo Lei , Guo Hailong , Du Wei , Yan Han , Wang Songtao
Published: February 2025

Squealer tip is an effective method for reducing heat transfer and leakage losses of blade tips in gas turbines and is currently being extensively researched and developed. In this study, the squealer tip has been innovatively developed by introducing bent rails, and three types of squealer structures with bent rails were proposed: the bent pressure-side rail scheme (Case_P), the bent suction-side rail scheme (Case_S), and the bent double-side rail scheme (Case_PS). This study first compared the performance of the proposed novel schemes with the traditional squealer tip scheme with vertical rails (Baseline) in terms of tip heat transfer and flow control by analyzing parameters such as the tip heat transfer coefficient (h), leakage flow rate (LFR), and total pressure loss (Cpt) under fixed bending values (S). Subsequently, the effects of different bending values (S) on the three novel schemes were investigated. The results show that, in terms of heat transfer, both Case_P and Case_S can effectively reduce the tip h, but their mechanisms are entirely different. Case_P primarily relies on the increasing separation bubble size at pressure-side rail edge and gradually expanded low-energy flow region in the pressure-side rail corner. In contrast, in Case_S, it is mainly because the cavity flow enters the suction-side gap more smoothly due to the bent suction-side rail. In terms of aerodynamics, the bent pressure-side rail of Case_P significantly inhibits the entering velocity of leakage flow, thereby reducing the LFR and Cpt; however, Case_S causes the LFR to increase. In Case_PS, the heat transfer and leakage phenomena resemble a combination of Case_P and Case_S. With the increase in S, the tip h in the three schemes all decreases, and the tip heat transfer in Case_PS is more comprehensively reduced because it incorporates all the flow factors that reduce h from the other two schemes. In Case_PS, the rail types that both hinder and increase LFR coexist, resulting in the LFR remaining relatively stable with varied S.
Soret-driven thermosolutal convection in bidispersive porous medium with vertical throughflow
Authors: Bhavyashree S. M. , Ragoju Ravi , Reddy G. Shivakumar , Siddheshwar P. G.
Published: February 2025

This article investigates thermosolutal convection in bidispersive porous medium with Soret effect and vertical throughflow. The Oberbeck–Boussinesq approximation assumed and fluid flow obeys Darcy's law. Local thermal equilibrium is considered between solid and fluid phases. We analyze the system stability through linear instability, nonlinear stability (energy method), and weak nonlinear analysis. The expression for Ra is derived analytically, using the Galerkin orthogonalization technique. The Ginzburg–Landau equation is derived to get deep insight into convective amplitudes, also we explore the heat and mass transfer in the system by defining Nusselt and Sherwood numbers. The research delves into the influence of various physical parameters on the system's stability. The solutal Rayleigh number and Soret number have destabilizing property, whereas the Lewis number, momentum transfer coefficient, and permeability ratio have the stabilizing nature. The sub-critical region decreases as the Soret number increases. The strong buoyancy force delays the heat transfer and mass transfer by disrupting existing mass transfer. The critical Rayleigh number maintains symmetry over the upward and downward throughflow. The less area under the curve for average Nusselt and Sherwood number over permeability ratio implies total heat and mass transfer alleviating.
Thermal emission modulation of fabrication-friendly, free-form metasurfaces via explainable deep-learning Bayesian optimization
Authors: Chen Jintao , Zhang Zihan , Huang Zhequn , Cui Kehang
Published: February 2025

Free-form metasurfaces with superimposed transformative meta-atoms provide a versatile platform to realize cross-band thermal emission control. However, design and manufacturing of free-form metasurfaces is extremely challenging, owing to the complex and fractal sub-wavelength topology. Here, we address these two issues by proposing an explainable deep-learning Bayesian optimization (DeepBO) framework to realize a library of fabrication-friendly, free-form metasurfaces with different light–matter interaction bandwidths. The DeepBO requires only 50 training data and is capable of screening high-dimensional design space of 1043 thermal photonic structure candidates with bandwidths from 0.3 to 3.2 eV. We unfold the black-box of deep-learning process by pattern recognition and identify the sub-space key features in the high-dimensional design space, which provides insights for thermal photonic metasurface design. We showcase the design and manufacturing of the broadband solar absorber and the narrowband thermophotovoltaic emitter with record-high spectral efficiency. The spectral selectivity of the fabricated free-form metasurface matches well with the design. The fabrication-friendly, free-form metasurfaces realized in this work can be generalized to thermal emitters for broad-ranges applications in energy and sensing.
Experimental research on wind tracking performance of a single-point moored floating offshore wind turbine
Authors: Chen Jiahao , Li Ziqiang , Yin Ziwei , Fan Shaotao , Deng Yanfei
Published: February 2025

Conventional wind turbine yaw systems, which are susceptible to frequent failures, can render the operation and maintenance costs of floating offshore wind turbines unacceptably high. As a result, the concept of a single-point moored floating offshore wind turbine has been introduced to eliminate the need for a wind turbine yaw system. However, the wind tracking characteristics of such turbines under complex marine conditions have not been fully elucidated. To address this gap, a 1:50 scale model of a single-point moored floating offshore wind turbine was tested to gain detailed insights into its wind tracking and wave response behaviors. The findings confirm the feasibility of single-point moored floating wind turbines. Specifically, the wind tracking motion is characterized by an initial acceleration phase followed by deceleration, with an average turning speed ranging from 1.61 to 4.0°/min under the tested cases. However, the rotor's orientation may deviate from the wind direction due to various factors, including gyroscopic moments, wind field uniformity, and hydrodynamic loads. Moreover, the single-point moored floating wind turbine also exhibits wave-following behavior, and the weathervane effect is observed when wind and waves act in different directions. These results offer valuable references for the design and testing of single-point moored floating offshore wind turbines.
Study on the energy harvesting and hydrodynamic stability characteristics of a novel floating bridge with wave energy conversion modules
Authors: Wang Jun , Guo Lei , Wei Changdong , Yan Xianglei , Huang Shuting , Liu Yanjun
Published: February 2025

Integrating floating bridges with wave energy converters can provide a viable option for developing economical wave energy resources, and solving problems of the high cost of wave energy devices and the unstable motion of floating bridges. This paper proposes a novel wave energy floating bridge with an integrated wave energy conversion module (WECM), and its energy capture and hydrodynamic stability problems are investigated. A nonlinear stiffness power take off (PTO) mechanism is used. A hybrid dynamics model for the system is established and the accuracy of numerical model is verified. The energy capture and motion stability of the linear PTO and nonlinear PTO wave energy floating bridge under regular and irregular wave conditions are compared. Results show that WECM can enhance the floating bridge with wave power generation capability and better motion stability in waves. The linear PTO mechanism can reduce the motion response of the floating bridge by choosing the appropriate PTO damping value under regular waves. The nonlinear PTO mechanism increases the double-peak width to broaden the energy capture frequency band. The nonlinear PTO is more suitable for low-frequency wave sea conditions, while the linear PTO is more suitable for high-frequency wave sea conditions. This article can provide favorable reference data for floating bridge design and practical application in the future.
Hydraulic gradient analysis in vertical hydraulic transport for coarse particles
Authors: Wang Yumiao , Zhang Ri , Liu Yong
Published: February 2025

This paper investigates the hydraulic gradient in vertical hydraulic transport (VHT) for coarse particles using a one-dimensional (1D) quasi-fluid model developed in previous work. The hydraulic gradient is divided into three key mechanisms—transport medium, mixture gravity, and particle–wall collisions—each of which is thoroughly analyzed in terms of its contribution to the overall pressure drop. The model's accuracy is validated through comparison with experimental data, yielding a mean absolute percentage error of 13.38%, indicating strong agreement. The study systematically investigates the impact of feed concentration, particle diameter, and mixture velocity on both the values of the individual hydraulic gradient components and their proportions within the total hydraulic gradient. The changes in total pressure drop predicted by the 1D model are also examined across various initial conditions, showing that the total pressure drop increases with higher feed concentration and greater mixture velocity, respectively. Additionally, the total pressure drop is insensitive to the change of particle diameter. This detailed analysis provides key insights into how each mechanism influences pressure loss in VHT systems, offering practical recommendations for enhancing the efficiency and accuracy of hydraulic transport processes in engineering applications.