bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydrodynamic cloaks with isotropic and homogeneous viscosity for multi-object in collaborative operations
Authors: Yao Neng-Zhi , Wang Bin , Wang Hao , Wu Chen-Long , Wang Xuesheng
Published: October 2024

Although significant efforts have been devoted to advancing hydrodynamic cloaks for a single object, limited exploration has focused on cloaking multiple objects. By cloak, we mean a state of hydrodynamic invisibility achieved by eliminating flow disturbances caused by intrusive objects in the surrounding fluids. These gaps in understanding present challenges in developing effective strategies for achieving hydrodynamic stealth for multiple objects in collaborative operations. To address these issues, we propose a multi-object hydrodynamic cloak with isotropic and homogeneous fluid viscosity in viscous potential flows through a combination of neutral inclusion theory and convection-diffusion-balance method. By effectively transforming the intrusive objects into one single object while maintaining the overall invasive volume unchanged—a critical factor in flow disturbances—we successfully derive the analytical solution of fluid viscosity for multi-object hydrodynamic cloaks. Numerical simulations demonstrate the proposed cloaks considerably minimize the hydrodynamic perturbations generated by objects in groups with symmetric or asymmetric distributions, various sizes, and even arbitrary shapes. In addition, we reveal that the antagonism between the defined boundary effect of flow disturbances and vorticity magnitudes primarily determines the effectiveness of the proposed cloaks, laying the foundation for the future development of multi-object hydrodynamic cloaks involving interactions among objects. Hopefully, this research will advance the fields of hydrodynamic metamaterials for multiple objects in collaborative settings and contribute to the broader understanding of complexity science.
Numerical studies of hydrodynamic relativistic astrophysical jet: The modification of vorticity transport equation
Authors: Pal Ribhu , Roy Arnab
Published: October 2024

In this Letter, we have carried out the two-dimensional numerical simulation of axisymmetric relativistic jet in cylindrical coordinates by employing higher order finite volume method in PLUTO [Mignone et al., “PLUTO: A numerical code for computational astrophysics,” Astrophys. J. Suppl. Ser. 170, 228 (2007)] solver. The modified vorticity transport equation has been proposed for relativistic flow by taking the curl of the momentum equation, which shows significant change in the baroclinic vorticity production term due to relativistic effect. Both mathematical analysis and numerical results show that the vorticity production term due to baroclinic torque is heavily influenced due to the presence of specific enthalpy gradient and square of Lorentz factor gradient in a relativistic fluid flow.
Ionic microsphere therapy for skin trauma
Authors: Feng Jiayin , Wang Fangyan , Pan Xiaoyi , Shao Yunyuan , Jin Anqi , Lei Lanjie , Lin Xiufei
Published: October 2024

The skin is an important barrier for the body. Normal wound healing can be severely impeded by inadequate angiogenesis, excessive inflammation, and increased susceptibility to infection. Therefore, effective wound therapy should focus on accelerating the healing process and providing antimicrobial properties that are essential for wound recovery. Alginate (ALG) is a biocompatible polysaccharide substance capable of forming hydrogel dressings by cross-linking with metal ions, especially with Zn2+, Fe3+, Cu2+, and Ca2+ metal ions. The hydrogel formed by them can gradually release Zn2+, Fe3+, Cu2+, and Ca2+ during the process of wound repair, which has an important role in promoting angiogenesis and collagen deposition. Here, we prepared hydrogel microspheres (MS) based on cross-linking of different ions such as Zn-MS, Fe-MS, Cu-MS, and Ca-MS and investigated the effect of these ions on wound healing. In vitro and in vivo experiments showed that MS formed by Zn2+ enhanced antimicrobial activity, MS formed by Fe3+ and Cu2+ increased the formation of collagen fibers, and MS formed by Zn2+ and Ca2+ promoted the development of capillaries. So, the hydrogel MS formed by cross-linking ALG with these four ions are of great significance and research value in the field of skin wound application.
What’s up with Planet Nine?
Authors: Means Hannah H.
Published: October 2024

The question of whether it exists may soon be resolved.
Linking structure to function: the connection between mesophyll structure and intrinsic water use efficiency
Authors: Schreel Jeroen D. M. , Théroux-Rancourt Guillaume , Roddy Adam B.
Published: October 2024

Climate change-driven drought events are becoming unescapable in an increasing number of areas worldwide. Understanding how plants are able to adapt to these changing environmental conditions is a non-trivial challenge. Physiologically, improving a plant’s intrinsic water use efficiency (WUEi) will be essential for plant survival in dry conditions. Physically, plant adaptation and acclimatisation are constrained by a plant’s anatomy. In other words, there is a strong link between anatomical structure and physiological function. Former research predominantly focused on using 2D anatomical measurements to approximate 3D structures based on the assumption of ideal shapes, such as spherical spongy mesophyll cells. As a result of increasing progress in 3D imaging technology, the validity of these assumptions is being assessed, and recent research has indicated that these approximations can contain significant errors. We suggest to invert the workflow and use the less common 3D assessments to provide corrections and functions for the more widely available 2D assessments. By combining these 3D and corrected 2D anatomical assessments with physiological measurements of WUEi, our understanding of how a plant’s physical adaptation affects its function will increase and greatly improve our ability to assess plant survival.
Identification of a divalent metal transporter required for cellular iron metabolism in malaria parasites
Authors: Loveridge Kade M. , Sigala Paul A.
Published: October 2024

Plasmodium falciparum
malaria parasites invade and multiply inside red blood cells (RBCs), the most iron-rich compartment in humans. Like all cells,
P. falciparum
requires nutritional iron to support essential metabolic pathways, but the critical mechanisms of iron acquisition and trafficking during RBC infection have remained obscure. Parasites internalize and liberate massive amounts of heme during large-scale digestion of RBC hemoglobin within an acidic food vacuole (FV) but lack a heme oxygenase to release porphyrin-bound iron. Although most FV heme is sequestered into inert hemozoin crystals, prior studies indicate that trace heme escapes biomineralization and is susceptible to nonenzymatic degradation within the oxidizing FV environment to release labile iron. Parasites retain a homolog of divalent metal transporter 1 (DMT1), a known mammalian iron transporter, but its role in
P. falciparum
iron acquisition has not been tested. Our phylogenetic studies indicate that
P. falciparum
DMT1 (PfDMT1) retains conserved molecular features critical for metal transport. We localized this protein to the FV membrane and defined its orientation in an export-competent topology. Conditional knockdown of PfDMT1 expression is lethal to parasites, which display broad cellular defects in iron-dependent functions, including impaired apicoplast biogenesis and mitochondrial polarization. Parasites are selectively rescued from partial PfDMT1 knockdown by supplementation with exogenous iron, but not other metals. These results support a cellular paradigm whereby PfDMT1 is the molecular gatekeeper to essential iron acquisition by blood-stage malaria parasites and suggest that therapeutic targeting of PfDMT1 may be a potent antimalarial strategy.
Cell binding tropism of rat hepatitis E virus is a pivotal determinant of its zoonotic transmission to humans
Authors: Guo Hongbo , Xu Jiaqi , Situ Jianwen , Li Chunyang , Wang Xia , Hou Yao , Yang Guangde , Wang Lingli , Ying Dong , Li Zheng , Wang Zijie , Su Jia , Ding Yibo , Zeng Dou , Zhang Jikai , Ding Xiaohui , Wu Shusheng , Miao Weiwei , Tang Renxian , Lu Yihan , Kong Huihui , Zhou Peng , Zheng Zizheng , Zheng Kuiyang , Pan Xiucheng , Sridhar Siddharth , Wang Wenshi
Published: October 2024

Classically, all hepatitis E virus (HEV) variants causing human infection belong to the genus
Paslahepevirus
(HEV-A). However, the increasing cases of rat HEV infection in humans since 2018 challenged this dogma, posing increasing health threats. Herein, we investigated the underlying mechanisms dictating the zoonotic potentials of different HEV species and their possible cross-protection relationships. We found that rat HEV virus-like particles (HEV
VLPs
) bound to human liver and intestinal cells/tissues with high efficiency. Moreover, rat HEV
VLPs
and infectious rat HEV particles penetrated the cell membrane and entered human target cells postbinding. In contrast, ferret HEV
VLPs
showed marginal cell binding and entry ability, bat HEV
VLPs
and avian HEV
VLPs
exhibited no binding and entry potency. Structure-based three-dimensional mapping identified that the surface spike domain of rat HEV is crucial for cell binding. Antigenic cartography indicated that rat HEV exhibited partial cross-reaction with HEV-A. Intriguingly, sera of HEV-A infected patients or human HEV vaccine Hecolin® immunized individuals provided partial cross-protection against the binding of rat HEV
VLPs
to human target cells. In summary, the interactions between the viral capsid and cellular receptor(s) regulate the distinct zoonotic potentials of different HEV species. The systematic characterization of antigenic cartography and serological cross-reactivity of different HEV species provide valuable insights for the development of species-specific diagnosis and protective vaccines against zoonotic HEV infection.
Evolvement and use of stigmatized expressions in computer-mediated communication
Authors: Geng Wenwen
Published: October 2024

A stigmatized expression is featured by its potentially discrediting attributes unwanted by community members. It
is heavily context-dependent, especially in computer-mediated communication (CMC), which is text-based and features abbreviations,
acronyms, and creative use of punctuation. The paper discusses the perception, judgment, and use of stigmatized expressions from
the socio-cognitive approach (SCA) perspective. Our theory- and data-based analysis leads to the following conclusions. First,
stigmatized expressions are considered pervasive and generally detrimental, thus worthy of continuous attention. Second, their
emergence and recognition arise from the mutual effort of societal and individual factors, making them dynamic, ambiguous,
context-dependent, and culture-specific. Third, the mechanism of generating stigmatized expression turns out to be spiral, while
the circulation seems scarcely affected by its divergent interpretations. The sociocultural context serves as a trigger and an
outcome in that it facilitates the processing of stigmatized expressions and is simultaneously modified.
Racing through C. elegans mitosis using cyclin B3
Authors: Boland Andreas , Kamenz Julia
Published: October 2024

Racecar drivers use left-foot braking, i.e., simultaneously engaging brake and throttle, to carefully balance acceleration and traction when navigating chicanes. In this issue, Lara-Gonzalez et al. (https://doi.org/10.1083/jcb.202308034) show that C. elegans embryos employ the molecular equivalent of left-foot braking to faithfully speed through mitosis.
Recombination efficiency in c-plane (In,Ga)N/GaN quantum wells: saturation of localisation sites versus Auger–Meitner recombination
Authors: Barrett R M , Dyer D D , McMahon J M , Schulz S , Kappers M J , Oliver R A , Binks D
Published: October 2024

Light emitting diodes based on c-plane (In,Ga)N/GaN quantum wells (QWs) can have >90% emission efficiency at modest current densities but this drops significantly at higher excitation, an effect known as efficiency droop that limits device efficacy at high brightness. Several explanations for this have been proposed including the saturation of carrier localisation sites at high excitation densities, resulting in a greater exposure of carriers to defects and hence a significant increase in the associated non-radiative recombination processes. Here, power- and temperature-dependent photoluminescence spectroscopy of c-plane (In,Ga)N/GaN QWs is used to investigate the relationship between the saturation of localised states and emission efficiency. For the samples studied, we find that the saturation of localised sites broadly coincides with the onset of efficiency droop. However, it is also found that as the localised states saturate with increasing excitation, the relative contribution of defect-associated non-radiative processes to overall recombination decreases rather than increases. Based on these observations and on modelling of recombination processes in the QW, it is concluded that the saturation of localised states does not significantly contribute to the reduction in emission efficiency at high excitation. Our studies rather suggest that defect-related non-radiative recombination is out-competed by radiative and Auger–Meitner recombination at the carrier densities required for saturation.
On the in-situ determination of the effective secondary electron emission coefficient in low pressure capacitively coupled radio frequency discharges based on the electrical asymmetry effect
Authors: Masheyeva Ranna , Hartmann Peter , Luo Lan-Yue , Dzhumagulova Karlygash , Liu Yong-Xin , Schulze Julian , Donkó Zoltán
Published: October 2024

We present a method for the in-situ determination of the effective secondary electron emission coefficient (SEEC, γ) in a capacitively coupled plasma (CCP) source based on the γ-dependence of the DC self-bias voltage that develops over the plasma due to the electrical asymmetry effect (EAE). The EAE is established via the simultaneous application of two consecutive radio-frequency harmonics (with a varied phase angle) for the excitation of the discharge. Following the measurement of the DC self-bias voltage experimentally, particle-in-cell/Monte Carlo collision simulations coupled with a diffusion-reaction-radiation code to compute the argon atomic excited level dynamics are conducted with a sequence of SEEC values. The actual γ for the given discharge operating conditions is found by searching for the best match between the experimental and computed values of the DC self-bias voltage. The γ ≈ 0.07 values obtained this way are in agreement with typical literature data for the working gas of argon and the electrode material of stainless steel in the CCP source. The method can be applied for a wider range of conditions, as well as for different electrode materials and gases to reveal the effective SEEC for various physical settings and discharge operating conditions.
The CNN-LSTM-attention model for short term prediction of the polar motion
Authors: Wang Leyang , Que Haibo , Wu Fei
Published: October 2024

The accuracy of polar motion (PM) prediction significantly impacts the fields of coordinate frame transformation, satellite orbit determination, and deep space exploration. The present study develops two short term forecasting models based on the EOP 14C04 series. One hybrid approach incorporates convolutional neural networks (CNNs) and long short-term memory networks (LSTM), augmented with an attention mechanism; whereas another baseline model comprises CNN and LSTM. The first model, in contrast to the second model, incorporates an attention mechanism module for a more comprehensive integration of temporal information at each time step. In the initial short-term forecasting experiment, we conducted 360 repeated predictions, and the findings revealed that the parameters suitable for PMX forecasting may not necessarily be applicable to PMY forecasting. In the second experiment, the two models generated a total of 500 forecasts, each encompassing short-term predictions ranging from 1 to 30 d. The experimental results demonstrate that the first model exhibits mean absolute error (MAE) range of 0–7.72 mas for PMX and 0–4.73 mas for PMY, while the second model shows MAE range of 0–7.88 mas for PMX and 0–4.78 mas for PMY. After two exploratory experiments, we discovered the following results: the first model exhibits marginally superior predictive accuracy compared to the second model. Furthermore, this study substantiates the robustness of both models in short-term prediction and affirms the significance of assigning distinct weights to past temporal intervals in forecasting, thereby offering a novel perspective for PM prediction research.
Batch process soft sensing based on data-stacking multiscale adaptive graph neural network
Authors: Yongyong Hui , Kaiwen Sun , Benben Tuo , Xiaoqiang Zhao
Published: October 2024

Soft sensing technology has found extensive application in predicting key quality variables in batch processes. However, its application in batch process is limited by the uneven batch length, the correlation of data and the difficulty in extracting the dependencies between variables and within variables. To address these issues, we propose a data-stacking multiscale adaptive graph neural network (DSMAGNN) soft sensor model. Firstly, Mutual information (MI) is used to selected quality-related variables, the 3D batch data is converted into a time-delay sequence suitable for input to the soft sensor model through the data stacking strategy, and the underlying time correlation at different time scales is preserved by incorporating the multi-scale pyramid network. Secondly, the dependencies between variables are inferred by the adaptive graph learning module, while the dependencies both within and between variables are modeled by the multi-scale temporal graph neural network. Thirdly, collaborative work across different time scales is further facilitated by the scale fusion module. Finally, the feasibility and effectiveness of the model are verified through experiments in the industrial-scale penicillin fermentation process and hot rolling process.
Fabric defect detection method based on multi-scale fusion attention mechanisms
Authors: Liu Chenhui , Zou Hongyan , Lv Peng , Zhu Ruilin
Published: October 2024

Fabric defect detection is extremely important for the development of the textile industry, but the existing traditional image processing algorithms are not good enough to detect fabric defects, and the detection efficiency and accuracy of the classical deep learning model is not satisfactory, so this paper proposes an improved fabric defect detection method based on multi-scale fusion of attention mechanism YOLOv7-PCBS. Based on the YOLOv7 network structure, some of the standard convolutions of the backbone network are replaced with Partial Convolution modules, which reduces the amount of network computation and improves the network detection speed; add coordinate attention to enhance the ability of extracting the positional features of tiny defects in fabrics; reconfiguration of the SPPCSPC module to improve small target detection; optimization of Bidirectional Feature Pyramid Network (BiFPN) and design of Tiny- BiFPN for simple and fast multi-scale feature fusion; finally, a novel loss function SIoU with angular loss is introduced to facilitate the fitting of the true and predicted frames and enhance the accuracy of defect prediction. The results show that the algorithm achieves a mAP value of 94.4% on the detection of defects in solid-colored fabrics of six denim materials, which is an improvement of 15.1% compared to the original YOLOv7 algorithm, while the model achieves a frame rate of 59.5 per second. Compared with other traditional deep learning algorithms SSD and Faster-RCNN, the detection accuracies are improved by 21.6% and 15.2%, and the FPS values are improved by 78.1% and 101.0%, respectively. Therefore, the YOLOv7-PCBS fabric defect detection algorithm proposed in this paper makes the fabric defect detection results more accurate while realizing lightweight, which provides an important technical reference for the subsequent improvement of textile quality.
Simulation optimization and experimental validation of hydraulic impact in pruning machines
Authors: Min Zhao , Bo Yang , Wei Li , Chunguang Lv , Hong Zhang , Weiqiang Zheng
Published: October 2024

This study addresses the instability caused by hydraulic shocks in fruit tree pruning machines during operation and proposes an optimization scheme that combines simulation with experimentation. We investigated the mechanisms of load shock in the hydraulic system through mathematical modeling and LS-DYNA simulation analysis. The optimal operating parameters were determined using mechanical and orthogonal analyses: a forward speed of 4 km h−1, a pruning tool angle of 60°, and a saw blade rotation speed of 1200 r min−1. Additionally, we employed AMESim simulation to optimize the hydraulic system of the pruning machine by designing a dual accumulator configuration to effectively suppress hydraulic shocks. We validated the optimized system through simulations and experimental tests, demonstrating significant reductions in pressure fluctuations, with cutting efficiency improved by 30% and pressure fluctuations reduced by 26.7%. This study not only presents an innovative dual accumulator design but also validates its effectiveness in pruning machines through simulations and experiments, thereby enhancing the operational efficiency and stability of agricultural machinery.
Theory of quasi-ballistic FET: steady-state regime and low-frequency noise
Authors: Yelisieiev M , Kochelap V A
Published: October 2024

We present a theoretical analysis of steady state regimes and low-frequency noise in quasi-ballistic field effect transistors (FETs). The noise analysis is based on the Langevin approach, which accounts for the microscopic sources of fluctuations originating from intrachannel electron scattering. The general formulas for local fluctuations of the carrier concentration, velocity and electrostatic potential, as well as their distributions along the channel, are found as functions of applied voltage/current. Two circuit regimes with stabilized current and stabilized voltage are considered. The noise intensities for devices with different electron ballisticity in the channel are compared. We suggest that the presented analysis allows a better comprehension of the physics of electron transport and fluctuations in quasi-ballistic FETs, improves their theoretical description and can be useful for device simulation and design.
3D-printable Kresling-embedded honeycomb metamaterials with optimized energy absorption capability
Authors: Yang Haiying , Liu Yuheng , Lu Haibao , Tao Ran , Wei Xueyong , Fu Yong-Qing
Published: October 2024

Kresling origami structure has attracted significant interest for achieving extraordinary mechanical properties. In this study, we proposed a new strategy to develop 3D-printable Kresling-embedded honeycombs (KEHs) based mechanical metamaterials and achieve optimized mechanical energy absorption capability. By exploiting the twisted deformation modes and boundary constraints, various KEH reinforced metamaterials were designed, where their deformation behaviors and energy absorption properties were investigated using finite element analysis and quasi-static compression tests. Effects of orientation twisting angle, boundary constraint and crease tilting angle on the deformation behaviors of these KEH reinforced metamaterials were studied to optimize their energy absorption properties. Finally, deformation behaviors and energy absorption properties of KEH reinforced metamaterials incorporated of KEH arrays in both 2D structure and 3D structures were studied. Both experimental and simulation results showed that the proposed KEH reinforced metamaterials achieved much more stable compression behaviors and higher energy absorption capabilities than those of the traditional honeycomb structures. This study provides a novel KEH reinforcement strategy for 3D printed metamaterials with optimized energy absorption capabilities to dramatically expand their practical applications.
A compliant mechanism actuated bistable hybrid mode triboelectric nanogenerator
Authors: Li Zifan , Ee Zhiyin , Pickett William , Patel Bhumik , Gan Wee Chen , Tang Lihua , Su Yufeng , Xia Cuipeng , Yin Peilun , Aw Kean Chin
Published: October 2024

Traditional contact-separation mode triboelectric nanogenerators (CS-TENGs) and lateral sliding mode TENGs exhibit distinct strengths and weaknesses in terms of their charge generation capability and durability. In this study, by leveraging a bistable compliant mechanism (BHM-TENG), we propose a hybrid mode TENG, which synthesizes the features of two traditional working modes to achieve both high durability and satisfactory performance. The proposed design exhibited a 78.6% surge in voltage output and a 142% surge in power density compared to CS-TENG. The design also maintains over 95% power generation capability after 100 000 cycles. Moreover, the compliant bistable mechanism offers a reliable actuation method at low frequencies, validated through experiments supported with a mathematical model. Real-world energy harvesting applications enabled by BHM-TENG are also discussed.
Topological electronic structure and electronic nematicity in candidate kagome superconductors, ATi3Bi5 (A = Rb, Cs)
Authors: Hu Yong , Le Congcong , Wu Xianxin , Shi Ming
Published: October 2024

The newly discovered family of titanium-based kagome metals, ATi3Bi5 (where A can be Rb or Cs), has been found to exhibit non-trivial band topology and fascinating electronic instabilities, including electronic nematicity and potential bulk superconductivity. Distinct from their vanadium-based counterparts (AV3Sb5), which display a charge density wave (CDW) phase that already breaks rotational symmetry, ATi3Bi5 shows no evidence of CDW, providing a unique platform to study nematicity in its pure form and its interplay with other correlated quantum phenomena, such as superconductivity. In this review, we highlight recent progress in both experimental and theoretical research on ATi3Bi5 and discuss the unresolved questions and challenges in this burgeoning field.
Approximate analytic solution of the dissipative semiclassical Rabi model under parametric multi-tone modulations
Authors: Marinho A , Dodonov A V
Published: October 2024

We present an analytic method for obtaining the dynamics of the dissipative time-modulated semiclassical Rabi model, which describes a two-level system (qubit) with time-dependent parameters, coupled to a single-mode bosonic field via the dipole-interaction and to a thermal reservoir. We consider the simultaneous harmonic modulations of the qubit transition frequency and the qubit-field coupling strength, with arbitrary frequencies, and obtain closed analytic expressions for the density operator under the coarse-graining approximation. Our approximate results are in excellent ageement with exact numerical data, and illustrate how the qubit state can be controlled in the dispersive regime by properly adjusting the system parameters.
Molecular dynamics simulation of gradient alloying distribution on the nano-mechanical properties of Nb-Zr alloys
Authors: Fan Zhehang , Ren Junzhao , Li Qinghua , Dai Hao , Tao Xiaoyong , Khan Aqib Mashood , Wu Hongyan
Published: October 2024

In this work, a nano-indentation process of homogeneous Nb-Zr alloy and gradient Nb-Zr alloy was simulated using molecular dynamics simulation. The effects of indentation radius, Zr content and system temperature on the mechanical properties and micro-deformation were investigated. The influence of indentation size on nano-indentation experiments was mainly affected by the curvature of the indented part. Comparing the homogeneous and gradient alloys, it was revealed that the gradient alloy had a smoother mechanical performance. The results showed that the effect of Zr content on the hardness of Nb-Zr homogeneous alloy was not linear. The hardness rose, followed by a decline with increasing Zr content, and the turning point came at 1.5 wt%. Under high temperatures, the Nb-Zr homogeneous alloy and gradient alloy layer retained extremely high hardness, exhibiting excellent mechanical properties. Due to the entanglement of multiple dislocations in gradient Nb-Zr alloy at high temperatures, the hardness still increased with increasing temperature at high temperatures. It was worth noting that gradient alloys could disperse stress faster and reach a stable state during the loading process. The hardness of the Nb-Zr homogeneous alloy layer first increased and then decreased as the Zr content changed from 1.0 wt% to 2.0 wt%, as verified by the experiments. This study provided the reference for the preparation of high-temperature applications alloy by constructing Nb-Zr gradient alloy.
Analysis on density of states and ION/IOFF ratio of GaN/GaN-graphene nanoribbon tunnel FET for enhanced bio-sensing applications
Authors: V N Senthil Kumaran , M Venkatesh , R Shreeshayana , Gudur Manjunath V , P Parthasarathy
Published: October 2024

This research introduces a new analytical model that studies the effect of ferro-dielectric on the operational performance of TFETs doped with halogens. The effect of source and drain depletions, voltage-drain & gate, thickness and capacitance of gate insulator are all investigated in this study. Accurate measurements of the surface potential are required to ascertain the transconductance, gate-to-drain capacitance, and lateral electric field of the device. Our model, which employs Ferroelectric Halo-Doped double gate (FHDD)-gated device designs, has been demonstrated to produce results that nearly match those produced from TCAD simulations. This was accomplished by doing a comparative analysis of the outcomes derived from both sets of simulations. Furthermore, the performance of the suggested structure of TFET, which integrates a dielectric of Fe and GaN heterostructure, surpasses that of other similar devices (fT) in terms of ON current, ON/OFF ratio, transconductance, and cut-off frequency. A ferroelectric dielectric was used to create a ferroelectric heterostructure. This study also centers on the creation and application of a graphene nanoribbon field effect transistor (GNR-TFET) to detect sugar molecules, specifically fructose, xylose, and glucose. The detecting signal is generated by utilizing the fluctuation in the electrical current of the GNR-TFET caused by the presence of individual sugar molecules. The GNR-TFET exhibits noticeable variations in the density of states, transmission spectrum, and current when exposed to individual sugar molecules. The sensor under investigation is being developed and examined using a combination of semi-empirical modeling and non-equilibrium Green’s functional theory (SE + NEGF). According to the research, the modified GNR TFET has the ability to quickly and accurately detect individual sugar molecules in real-time.
DESI dark energy time evolution is recovered by cosmologically coupled black holes
Authors: Croker Kevin S. , Tarlé Gregory , Ahlen Steve P. , Cartwright Brian G. , Farrah Duncan , Fernandez Nicolas , Windhorst Rogier A.
Published: October 2024

Recent baryon acoustic oscillation (BAO) measurements by the Dark Energy Spectroscopic Instrument (DESI) provide evidence that dark energy (DE) evolves with time, as parameterized by aw0waequation of state. Cosmologically coupled black holes (BHs) provide a DE source that naturally evolves with time, because BH production tracks cosmic star-formation. Using DESI BAO measurements and priors informed by Big Bang Nucleosynthesis, we measure the fraction of baryonic density converted into BHs, assuming that all DE is sourced by BH production. We find that the best-fit DE density tracks each DESI best-fitw0wamodel within 1σ, except at redshiftsz≲ 0.2, highlighting limitations of thew0waparameterization. Cosmologically coupled BHs produceH0= (69.94 ± 0.81) km s-1Mpc-1, with the sameχ2as ΛCDM, and with two fewer parameters thanw0wa. This value reduces tension with SH0ES to 2.7σand is in excellent agreement with recent measurements from the Chicago-Carnegie Hubble Program. Because cosmologically coupled BH production depletes the baryon density established by primordial nucleosynthesis, these BHs provide a physical explanation for the “missing baryon problem” and the anomalously low sum of neutrino masses preferred by DESI. The global evolution of DE is an orthogonal probe of cosmological coupling, complementing constraints on BH mass-growth from elliptical galaxies, stellar binaries, globular clusters, the LIGO-Virgo-KAGRA merging population, and X-ray binaries. A DE density that correlates with cosmic star-formation: 1) is a natural outcome of cosmological coupling in BH populations; 2) eases tension between early and late-time cosmological probes; and 3) produces time-evolution toward a late-time ΛCDM cosmology different from Cosmic Microwave Background projections.
Accretion of Vlasov gas onto a black hole in the Kalb–Ramond field
Authors: Zhang Xu-Xin , Jiang Yu-Hao
Published: October 2024

We investigate the accretion of Vlasov gas onto a static, spherically symmetric black hole (BH) influenced by the Kalb–Ramond (KR) field, focusing on the effects of Lorentz symmetry breaking (LSB) parameters. We employ the Maxwell–Jüttner distribution to model the gas at infinity and derive key quantities such as the particle current density and mass accretion rate. Our findings revealed that increasing the LSB parameter results in a decrease in mass accretion rate. We also present explicit formulations of the accretion rate in the high-temperature limit; the result is significantly different from that of the Bumblebee model.
Application of Reciprocity Principle in Ultrasound Bone Tomography
Authors: Shi Qinzhen , Li Yifang , Dai Fei , Zhang Yunyun , Xu Lexiu
Published: October 2024

Full-matrix synthetic aperture imaging (FMSA) is a well-established and widely used modality for ultrasound imaging Nevertheless, the accompanying relatively large amount of data acquisition, storage, and process results in heavy costs of computation and memory, which further hinders FMSA from real-time implementation. Moreover, the most existing FMSAs employed the hypothesis uniform sound velocity to reconstruct the soft tissues, which is not suitable for hard tissue imaging, irrespective of the high acoustic impedance contrast (i.e., the difference of sound velocity) between the bone and soft tissues. To overcome these limitations, a half-matrix ultrasound bone tomography method combining the reciprocity principle and sound velocity estimation was proposed for cortical cross-section imaging. The travel-time inversion was firstly utilized for sound velocity prediction, and then half-matrix synthetic aperture (HMSA) with ray-tracing was conducted to image the cortical cross-section. An ex-vivo bovine femur was used to validate the effectiveness of the method. Compared to the full-matrix capture method, the proposed method was demonstrated to be an accurate and cost-effective modality for cortical bone tomography.
Influence of Mechanical Factors on the Cutting Performance of an Ultrasonic Bone Scalpel
Authors: Luo Xiaoning , Zhang Yuli , Wu Wei , Zhang Pengyuan , Zhen Zhang , Huang Tao , Zhao Li , Zhou Zhaoying , Hu Min
Published: October 2024

The ultrasonic bone scalpel is a cutting-edge surgical instrument that leverages ultrasonic mechanical effects to remove bone tissue with precision, safety, and efficacy. While the adoption of the instrument has surged, the intricate relationship between its mechanical effects and the efficiency of bone removal remains ambiguous. This study aimed to elucidate the quantitative interplay between the mechanical parameters of the instrument and its bone removal performance. To achieve this, we engineered a testing apparatus capable of consistently regulating the scalpel’s cutting force, traversal speed, and depth of cut. The bone removal proficiency of the instrument was then assessed under varying conditions: cutting forces, ultrasonic power outputs, tip traversal speeds, and bone densities. Comprehensive data analysis unveiled a distinct quantitative correlation between the aforementioned parameters and bone removal rates. Furthermore, we identified optimal parameter combinations that maximize cutting efficiency. These insights are pivotal for the design, fabrication, evaluation, and clinical application of ultrasonic bone scalpels, offering a robust reference for future advancements in the field.
Application of ultrasound in the diagnosis, evaluation, and interventional therapy monitoring of patent foramen ovale
Authors: T Miao , Y Wei , M Fei , Z G Xiao , B M T Nur Hartini
Published: October 2024

To explore the impact of pre-intervention ultrasound diagnosis results of PFO and evaluation criteria on the success rate of surgery, intraoperative ultrasound monitoring methods, and postoperative ultrasound follow-up results, and to analyse the results of ultrasound-related examinations and the evaluation value of the success rate of surgery and interventional efficacy. A total of 1617 patients with related symptoms who were diagnosed and treated in our hospital from January 2022 to March 2023 were selected for screening, and transthoracic echocardiography (TTE), contrast transthoracic echocardiography (cTTE), and contrast-enhanced Transcranial Doppler (cTCD) were performed. Positive patients were selected for transesophageal Echocardiography (TEE). And interventional surgery for patent foramen ovale in 70 of these patients. cTTE was performed 3 months and 6 months respectively after surgery to evaluate the therapeutic efficacy. Among the 1617 cases of cTTE, 938 cases were positive, including 538 cases of grade 1, 198 cases of grade 2, and 202 cases of grade 3. TEE was performed in 317 patients with positive cTTE, and 228 patients were diagnosed as PFO with definite shunt. Then selected 76 patients of grade 2-3 in cTTE with positive TEE to perform the closure surgery of the PFO, and 70 cases were successfully operated, with a success rate of 92.11%. cTTE、cTCD and TEE results are correlated with the success rate of interventional surgery. Evaluation using multiple ultrasound techniques can provide guidance for rational selection of treatment in clinical application.
Automatic bony structure segmentation and curvature estimation on ultrasound cervical spine images - a feasibility study
Authors: Ge Songhan , Tian Haoyuan , Zhang Wei , Zheng Rui
Published: October 2024

The loss of cervical lordosis is a common degenerative disorder known to be associated with abnormal spinal alignment. In recent years, ultrasound (US) imaging has been widely applied in the assessment of spine deformity and has shown promising results. The objectives of this study are to automatically segment bony structures from the 3D US cervical spine image volume and to assess the cervical lordosis on the key sagittal frames. In this study, a portable ultrasound imaging system was applied to acquire cervical spine image volume. The nnU-Net was trained on to segment bony structures on the transverse images and validated by 5-fold-cross-validation. The volume data were reconstructed from the segmented image series. An energy function indicating intensity levels and integrity of bony structures was designed to extract the proxy key sagittal frames on both left and right sides for the cervical curve measurement. The mean absolute difference (MAD), standard deviation (SD) and correlation between the spine curvatures of the left and right sides were calculated for quantitative evaluation of the proposed method. The DSC value of the nnU-Net model in segmenting ROI was 0.973. For the measurement of 22 lamina curve angles, the MAD±SD and correlation between the left and right sides of the cervical spine were 3.591±3.432° and 0.926, respectively. The results indicate that our method has a high accuracy and reliability in the automatic segmentation of the cervical spine and shows the potential of diagnosing the loss of cervical lordosis using the 3D ultrasound imaging technique.
Time Series Forecasting for Sparse Ring-shaped Array Photoacoustic Imaging Reconstruction
Authors: Zhu Jing , Zhou Dikui , Chen Feng , Li Chong , Li Chiye , Wang Ruofan , Shi Junhui
Published: October 2024

Photoacoustic computed tomography (PACT), which provides high optical absorption contrast and deep acoustic penetration, plays an important role in non-invasive biomedical imaging area. As the decrease of array elements, the reconstructed image suffers from severe artifacts. Recent studies utilize deep learning methods to improve the imaging quality of PACT based on image network design, but few were reported with raw data. To address this issue, this paper proposes a Wave to Wave Convolution Gate Recurrent-Net (WWCG-Net) to reconstruct photoacoustic image based on time series acoustic signal prediction. Simulation and experiment results show the superiority of our method compared with linear interpolation (LI) and eXtreme Gradient Boosting (XGBoost) in term of suppress artifact and improve resolution.
Reflection Artifacts Removal of Photoacoustic Imaging in Complex Medium
Authors: Nie Shibo , Li Pan , Qi Yuexin , Yang Jiahao , Tian Ye , Yin Guanjun , Guo Jianzhong
Published: October 2024

Photoacoustic (PA) imaging owns a great prospect in medical diagnosis because of its high contrast and capability in functional imaging. While, the detected PA signals are always a mix of direct-arrived signals (DAS) and reflected (scattered) signals (RS) in inhomogeneous and bounded samples such as human tissues. The RS can lead to many artifacts and severely affect the final image, which confuses the artifacts with the real PA sources. This paper employed a spatial singular value decomposition (SVD) filter to abstract the DAS and thus remove the reflection artifacts. We conducted experiments on an agar phantom and an in vitro tissue to verify the method. The results show that the proposed method can effectively remove RS, resulting in fewer reflection artifacts in PA images.
Ultrasound localization microscopy based microvasculature evaluation of spinal cord injury with varying severities
Authors: Yu Junjin , Dong Haoru , Zeng Zhili , Xie Rong , Xu Kailiang
Published: October 2024

The vasculature plays an important role in spinal cord function. Traumatic spinal cord injury (SCI) often results in a vascular disruption after primary insult, following secondary injury in neighbouring tissue. However, standard angiography methods such as digital subtraction angiography (DSA) still have difficulties in microvasculature imaging, especially for spinal cord with small size and non-rigid motion. The ultrasound localization microscopy (ULM) disrupts the compromise between penetration and resolution and provides super-resolution images of microvasculature. In this study, the applicability of the ULM for in vivo SCI evaluation was investigated on rat models with varying severities (different compression time durations correspond to mild and severe injury). Ultrasonic parameters including vessel saturation and blood velocity were measured via ULM. Basso, Beattie, Bresnahan (BBB) locomotion test was applied for injury severity validation and comparison with ultrasonic measurements.
High-resolution ultrasound imaging based on spatio-temporal MUSIC
Authors: Zheng Jie , Zhu Jing , Tagawa Norio
Published: October 2024

Time-reversal MUltiple SIgnal Classification (TR-MUSIC) is known for its super-resolution capability in locating point scatterers. However, a prerequisite for the application of the TR-MUSIC method is a thorough understanding of the properties of the medium and its background Green’s function. In general, it is difficult to obtain an accurate model of the Green’s function in advance for non-uniform or complex media, necessitating the use of approximate Green’s functions. When TR-MUSIC relies on these approximations, the impact on lateral resolution may be minimal, but the axial resolution is significantly reduced. In addition, we have proposed the Range-MUSIC (R-MUSIC) method, which exploits the linear relationship between the rotation of the echo phases and the positions of the scatterers. This approach uses subbands of different frequencies, differentiating multiple point scatterers by the speed of phase rotation associated with each frequency. By analyzing the profile in the time domain of echoes within the noise subspace, R-MUSIC achieves super-resolution in the axial direction without improving lateral resolution. Therefore, our study combines R-MUSIC with TR-MUSIC to improve axial resolution while maintaining lateral resolution. Through simulation and experimental evidence, we have shown that this combined approach yields better imaging performance than either method used independently.
Borehole radiation wavefield for multipole logging while drilling with an eccentric collar
Authors: Rao Bo , Su YuanDa , Li ShengQing , Tang XiaoMing
Published: October 2024

This study investigates the radiation characteristics of the borehole-source in acoustic logging while drilling (ALWD) with an eccentric collar. Understanding these characteristics is crucial for the development of acoustic remote detection technology, which has shown great potential in ALWD. Considering the frequent occurrence of tool eccentricity during drilling, it is essential to take into account its impact on the acoustic wavefield outside the borehole. In this paper, we establish an ALWD model with an eccentric collar in a dual-cylindrical coordinate system. By applying the translational Bessel addition theorem and the steepest descent method, we obtain the far-field asymptotic solution of the problem and model the radiation wavefield. Our findings indicate that the asymmetrical radiation pattern resulting from drill collar eccentricity can effectively resolve ambiguities in determining the reflector azimuth.
Simulation of horizontal refraction of continental slope in the southern continental slope of the South China Sea
Authors: Liu Jin , Hu Chenghao , Wang Kai , Gao Fei , Wei Jiali
Published: October 2024

Sound waves are significantly influenced by boundaries during their propagation in certain environmental conditions. The extent of this impact is related to the complexity of the boundary, such as in the case of slopes and seamounts. In these areas, sound waves may deviate from their original paths, resulting in three-dimensional effects. Recent experiments and simulations have demonstrated that three-dimensional effects occur when sound waves propagate over seamounts in the South China Sea, leading to larger acoustic shadow regions. However, there are limited studies on 3D acoustic propagation based on measured slope topography or database topography. In this study, the topography of the South China Sea area database is selected, and the measured sound velocity profile and seabed acoustic parameters in the South China Sea are taken into considered. The FOR3D sound field calculation model is used to calculate the N×2D and 3D results. The simulation results show that in the southern continental slope region of the South China Sea, when the sound source frequency is 50 Hz, the acoustic wave exhibits significant horizontal refraction with a refraction angle of approximately 13°.