bluuebunny/crossref_metadata_2025_split huggingface dataset:
Numerical simulation on high quality anapole resonator with large electric field concentration in all-dielectric metasurface
Authors: Liu Xiangpeng , Wang Junqiao , Xiong Jing , Wang Qiaoqiao , Zhang Hao , Sun Jingyi 
Published: April 2024

Abstract
In the field of nanophotonics, the manipulation of light using high refractive index dielectric materials has garnered significant attention in recent years. This occurs because dielectric materials with a high refractive index demonstrate lower losses in comparison to metallic plasmonic materials. Furthermore, the interference between internal toroidal dipole moment and electric dipole moment leads to destructive interference in the radiation field, resulting in the formation of an anapole state and localization of energy in the near-field. In this work, we initially excite the anapole state in a silicon nanodisk with a periodic nanostructured disk. By introducing a cross slit and adjusting the structural parameters, the anapole state is further optimized, and achieving highly concentrated near-field energy within the cross air slit of the silicon nanodisk. Specially designed, with a full width at halfmaximum (FWHM) of the transmitted spectrum of only 0.09 nm, and a Q factor of up to 9745, close to 104. Additionally, the structure can produce up to 571 times the electric field enhancement. The remarkable performance of a high Q factor and localized near-field energy holds great potential for various applications, including enhancing nonlinear effects, surface enhanced Raman scattering (SERS) and designing nanolasers.
The CIPM list ‘Recommended values of standard frequencies’: 2021 update
Authors: Margolis H S , Panfilo G , Petit G , Oates C , Ido T , Bize S 
Published: April 2024

Abstract
This paper gives a detailed account of the analysis underpinning the 2021 update to the list of standard reference frequency values recommended by the International Committee for Weights and Measures. This update focused on a subset of atomic transitions that are secondary representations of the second (SRS) or considered as potential SRS. As in previous updates in 2015 and 2017, methods for analysing over-determined data sets were applied to make optimum use of the worldwide body of published clock comparison data. To ensure that these methods were robust, three independent calculations were performed using two different algorithms. The 2021 update differed from previous updates in taking detailed account of correlations among the input data, a step shown to be important in deriving unbiased frequency values and avoiding underestimation of their uncertainties. It also differed in the procedures used to assess input data and to assign uncertainties to the recommended frequency values, with previous practice being adapted to produce a fully consistent output data set consisting of frequency ratio values as well as absolute frequencies. These changes are significant in the context of an anticipated redefinition of the second in terms of an optical transition or transitions, since optical frequency ratio measurements will be critical for verifying the international consistency of optical clocks prior to the redefinition. In the meantime, the reduced uncertainties for optical SRS resulting from this analysis significantly increases the weight that secondary frequency standards based on these transitions can have in the steering of International Atomic Time.
SET sensitivity of a VCRO-based PLL for HL-LHC ATLAS HGTD
Authors: Taille Christophe De La , Dinaucourt Pierrick , Ky Beng-Yun , Morenas Maxime , Seguin-Moreau Nathalie , Thienpont Damien , Vernazza Elena 
Published: April 2024

Abstract
We report the characterization of the Single Effect Transient (SET) sensitivity of an analogue Phase Locked Loop (PLL) based on a Voltage Controlled Ring Oscillator (VCRO) under a proton beam. The clock generator is embedded in a front-end ASIC, namely ALTIROC designed in CMOS 130 nm, reading out Low-Gain Avalanche Diode (LGAD) matrices for the High-Luminosity Large Hadron Collider (HL-LHC). We detail the methodology developed to study such events that could degrade the targeted time resolution of 35 ps per hit. Observed SET-induced phase jumps allow the estimation of the total cross-section of the PLL. The results are extrapolated to the HL-LHC radiation conditions.
Specialized spatially-arranged non-circular fibers enhance filtration performance of African shrimp (Atya gabonensis)
Authors: Liao Yifeng , Lyu Jun , Zhang Yujia , Hong Yuhe , Ding Shuoshuo , Wu Zhigang , Liu Hao , Wu Jianing 
Published: April 2024

Abstract
African shrimp (Atya gabonensis) inhabit clear freshwaters, where the notably low concentration of food may pose a challenge to the efficacy of filter fibers on the chela for filter-feeding. Here, we investigate how the distinctive cross-sectional characteristics and spatial arrangement of the African shrimp’s non-circular fibers contribute to the enhanced filtration performance of these specialized fibers. The unilateral thickening of the wall along the long axis of the elliptical cross-section of African shrimp fibers markedly enhances the filtration performance. The staggered and twisted arrangement of the fibers optimizes the surrounding flow field, achieving a favorable balance between pressure drop and collection efficiency, consequently improving their filtration performance in collecting fine particles (diameter: 2–10 μm). Moreover, the arrangement of the fibers substantially increases the effective flow-facing filtering area of the fiber bundles, thus facilitating their efficiency in collecting larger particles (diameter > 10 μm). The unique fiber properties of the African shrimp offer novel insights for the design and optimization of new fiber-filtering robots, presenting a wide range of potential applications, such as marine in-situ resource extraction, medical filtration, and industrial filtration.
Towards humanlike grasp in robotic hands: mechanical implementation of force synergies
Authors: Teng Zhicheng , Xu Guanghua , Pei Jinju , Li Baoyu , Zhang Sicong , Li Dongwang 
Published: April 2024

Abstract
In the field of robotic hands, finger force coordination is usually achieved by complex mechanical structures and control systems. This study presents the design of a novel transmission system inspired from the physiological concept of force synergies, aiming to simplify the control of multifingered robotic hands. To this end, we collected human finger force data during six isometric grasping tasks, and force synergies (i.e. the synergy weightings and the corresponding activation coefficients) were extracted from the concatenated force data to explore their potential for force modulation. We then implemented two force synergies with a cable-driven transmission mechanism consisting of two spring-loaded sliders and five V-shaped bars. Specifically, we used fixed synergy weightings to determine the stiffness of the compression springs, and the displacements of sliders were determined by time-varying activation coefficients. The derived transmission system was then used to drive a five-finger robotic hand named SYN hand. We also designed a motion encoder to selectively activate desired fingers, making it possible for two motors to empower a variety of hand postures. Experiments on the prototype demonstrate successful grasp of a wide range of objects in everyday life, and the finger force distribution of SYN hand can approximate that of human hand during six typical tasks. To our best knowledge, this study shows the first attempt to mechanically implement force synergies for finger force modulation in a robotic hand. In comparison to state-of-the-art robotic hands with similar functionality, the proposed hand can distribute humanlike force ratios on the fingers by simple position control, rather than resorting to additional force sensors or complex control strategies. The outcome of this study may provide alternatives for the design of novel anthropomorphic robotic hands, and thus show application prospects in the field of hand prostheses and exoskeletons.
Vertical structures and drivers of marine heatwaves and cold-spells in the Kuroshio Extension region
Authors: Xu Qiang , Liu Kai , Wang Haiyan , Chen Xingrong 
Published: April 2024

Abstract
Marine heatwaves (MHWs) and marine cold-spells (MCSs) are prolonged oceanic extreme temperature events that can severely impact large-scale ecosystems, fisheries, and human activities with consequent socioeconomic impacts. Although some studies have contributed valuable insights into the vertical structure and related mechanisms of MHWs, equivalent research on MCSs remains unclear. Thus, comprehensive and systematic analysis of the vertical structures and related mechanisms of MHWs and MCSs remains area of an active research. In this study, we classified MHWs/MCSs into two types in the Kuroshio Extension region: extended MHWs/MCSs that can extend through more than 70% of the water column and shallow MHWs/MCSs that are restricted from the surface layer to less than 70% of the water column. Analysis revealed that shallow events are characterized by stronger intensity and shorter duration compared with extended events. All shallow events are driven by surface heat flux anomalies, with shortwave radiation (latent heat flux) mostly inducing those in MHWs (MCSs). However, extended MHWs/MCSs are primarily driven by ocean anticyclonic/cyclonic eddies. These findings provide deeper understanding of the statistical characteristics, vertical structures, and physical drivers of MHWs and MCSs.
Seismic Response of a Tall Reinforced Concrete Frame Structure Subjected to both Horizontal and Vertical Strong Motions
Authors: Toma A M , Movila M , Rosca O V , Toma I O 
Published: April 2024

Abstract
The continuous development of urban areas coupled with the ageing of built-stock and the variety of structures built following different design code recommendations may result in different behaviours during seismic events. Hence, reliable information is needed in order to assess the risk of severe damage or collapse during earthquakes. Accurate numerical simulations coupled with analytical models provide essential information on the seismic performance of civil engineering structures. The results obtained from realistic numerical simulations may serve as entries in data-bases designed to train and calibrate early warning systems (EWS). Their continuous development is of paramount importance taking into account their potential to save lives and prevent economic loses in case of a severe seismic event. The paper presents the preliminary results obtained from numerical simulations on the seismic response of a tall reinforced concrete (RC) frame structure subjected to both horizontal and vertical string motions produced by an earthquake. The obtained results, in terms of response spectra in terms of accelerations, may be used for training EWS sensors to identify a seismic event and transmit warning messages at local, regional and even national level.
Comparative analysis of two strengthening solutions for the structural rehabilitation of a historical masonry building
Authors: Taranu G , Olteanu I , Entuc I-S , Colt O-E , Bunea G , Toma I-O 
Published: April 2024

Abstract
The paper presents a comparative analysis based on the Finite Element Method (FEM) for a masonry building located in Iasi, the North-Eastern side of Romania. This specific region is known to be found in a seismic area having a design peak ground acceleration of 0.25g. The building was assessed as being in the 1st seismic risk class, according to the Romanian norms, with a high probability of collapse in case of future earthquakes. Being a historical monument, the structural strengthening solutions are very limited. The study consists of modal and seismic analyses for the masonry structure. A comparison of the advantages and disadvantages of two approaches of structural rehabilitation solutions is done. The structural strengthening solution “A” consists of the addition of reinforced concrete thin wall elements, while the other - called solution “B” - consists of an interior steel profile skeleton mechanically and chemically connected to the adjacent masonry walls.
Case study on reinforced concrete frame structure adaptability
Authors: Olteanu I , Anton C-I , Țăranu G 
Published: April 2024

Abstract
The limited space to build from scratch significantly increased the need to rehabilitate for the re-functionalization of different buildings. The reinforced concrete frame structure is easily adaptable and has several advantages in this direction. When changing the function of a building an evaluation of the existing damages is done as well as a numerical simulation with the new loads. The article presents the case of changing a neighbourhood clinic into a kindergarten. The seismic risk coefficients are computed (R1, R2 and R3) in order to establish the seismic risk class for the existing building and also an evaluation of the damage state. A comparison between the seismic force computed when the building was designed and according to current codes is performed. In order to identify the failure mechanism pushover analysis was performed in both X and Y direction.
Fiber reinforced polymers in pervious concrete - a state of the art review
Authors: Chiriac R D , Kiss Z I 
Published: April 2024

Abstract
Porous concrete, entitled also as permeable or pervious concrete, is a type of concrete that has interconnected voids that allow water and also air to go across it. It is widely used in the construction of pavements, parking lots, and sidewalks, among other applications, because of its ability to reduce stormwater drainage, better quality of the water, and decrease urban heat island effects. The addition of fibers to porous concrete has been the subject of numerous studies in recent years, with researchers examining the effects of diversified types and amounts of fibers on the material’s properties. Fiber reinforcement can enhance the strength, durability, and ductility of porous concrete, making it more suitable for use in structural applications. Polymer fibers, in particular, have shown promise in improving the properties of porous concrete. They can increase the material’s resistance to cracking, improve its flexural strength, and enhance its heat-absorbing property. However, the characteristics of polymer-reinforced porous concrete are not yet fully understood, and more research is needed to determine the optimal types and amounts of fibers for specific applications. Despite the potential benefits of fiber-reinforced porous concrete, there are also some challenges associated with its use. The addition of fibers can increase the material’s cost and complexity of production, and it may also affect its permeability and drainage capacity.
Fiber-reinforced porous concrete represents an exciting area of research and development in the field of civil engineering. While the addition of fibers can enhance the material’s properties, more research is needed to determine the optimal types and amounts of fibers for specific applications. By addressing these challenges and continuing to refine the material’s properties, fiber-reinforced porous concrete has the potential to expand its use in a large spectrum of applications, including structural engineering, transportation infrastructure, and environmental protection.
Enhanced circular dichroism of an X-shaped nanostructure by asymmetric surface plasmon interference
Authors: Abdukerim Abduweli , Abdusattar Haximjan 
Published: April 2024

Abstract
A plasmonic chiral structure, which is a nanostructure composed of noble metals that lacks planar symmetry, demonstrates significant potential for various applications in bio-sensing, optical forces, switching and controlling the photoluminescence, and detecting chiral light. Understanding its fundamental property of circular dichroism (CD) is critical for these applications. Although the surface plasmon resonance (SPR) mode at a specific moment can explain the CD properties of chiral structures, to gain a better understanding of chirality, the mode shape of the SPR on a nanostructure must be analyzed throughout an entire period. Our study proposes an X-shaped nanostructure to investigate the temporal evolution of plasmon resonance in chiral structures. The simulation results demonstrated that our structure exhibited a significant temporal evolution in plasmonic oscillations, providing new insights into the nature of chirality. In addition, we provided a comprehensive theoretical explanation of CD using the Born–Kuhn model. Furthermore, we discovered that the CD in the X-shaped structure was intensified by the asymmetric interference between the structure and underlying gold film substrate.
Design of ultra-compact thin-film lithium niobate edge coupler based on micro–nano structure
Authors: Qin Yan-Yan , Xue Xiao-Mei , Shi Lei , Zhang Xiao-Yang , Zhang Tong 
Published: April 2024

Abstract
High coupling loss due to fiber-to-chip mode mismatch is considered as one of the main hindrances to thin-film lithium niobate (TFLN) devices to replace their bulk counterparts in engineering applications. In this work, we introduce subwavelength micro–nano structure and slot-strip mode coupling to design an efficient and ultra-compact edge coupler to solve the mismatch issue. The total device length is 130 μm, which is only 43% of the lengths of general TFLN edge couplers and even 35% shorter than the shortest one while maintaining low coupling loss (0.47 dB/0.38 dB per facet @1550 nm for TE/TM mode). This work provides a case study for the design of integrated photonic devices on the TFLN platform.
Precise structure and energy of group 6 transition metal dichalcogenide homo- and heterobilayers in high-symmetry configurations
Authors: Emrem Birkan , Joswig Jan-Ole , Heine Thomas 
Published: April 2024

Abstract
Two-dimensional group 6 transition metal dichalcogenide (2D TMDC) bilayers show various high-symmetry stacking configurations, which have also been observed in extended domains formed in their twisted homo- and heterobilayers. The interlayer energy varies for these stacking configurations, and the energy differences determine the relative size of the stacking domains. Therefore, the precise prediction of the composition- and stacking-dependent interlayer energy is crucial to model the domain structure of 2D TMDCs in their twisted bilayer homo- and heterostructures. For the validation of approximate methods that are necessary to tackle these systems encompassing thousands of atoms precise reference data is still lacking. Here, we employ the random phase approximation (RPA) on previously validated SCAN-rVV10 geometries to obtain interaction energies of state-of-the-art accuracy on the six high-symmetry stacking configurations (

H

h

h

,

H

h

M

,

H

h

X

,

R

h

h

,

R

h

M

, and

R

h

X

) of MX2 (M = Mo, W; X = S, Se) bilayers and compare them with the dispersion-corrected density-functional theory (DFT) functionals Perdew–Burke–Ernzerhof (PBE)+D3(BJ), PBE-rVV10L, and SCAN-rVV10. We identify SCAN-rVV10 as most reliable DFT variant with an average deviation of 1.2 meV/atom in relative energies from the RPA reference, and a root mean squared error of less than 2 meV/atom for interlayer interaction energies. We find interlayer distances obtained by PBE+D3(BJ) as being too short, with an impact on the electronic structure, resulting in the incorrect prediction of the band gap character in some cases. A further result of this work is the significant lowering of the interlayer energy and increasing of the interlayer distance in the high-energy stacking configurations. These stackings can be accessible via shear strain and promote exfoliation.
Electrically tunable correlated domain wall network in twisted bilayer graphene
Authors: Wang Hao-Chien , Hsu Chen-Hsuan 
Published: April 2024

Abstract
We investigate the domain wall network in twisted bilayer graphene (TBG) under the influence of interlayer bias and screening effect from the layered structure. Starting from the continuum model, we analyze the low-energy domain wall modes within the moiré bilayer structure and obtain an analytic form representing charge density distributions of the two-dimensional structure. By computing the screened electron–electron interaction strengths both within and between the domain walls, we develop a bosonized model that describes the correlated domain wall network. We demonstrate that these interaction strengths can be modified through an applied interlayer bias, screening length and dielectric materials, and show how the model can be employed to investigate various properties of the domain wall network and its stability. We compute correlation functions both without and with phonons. Including electron–phonon coupling in the network, we establish phase diagrams from these correlation functions. These diagrams illustrate electrical tunability of the network between various phases, such as density wave states and superconductivity. Our findings reveal the domain wall network as a promising platform for the experimental manipulation of electron–electron interactions in low dimensions and the study of strongly correlated matter. We point out that our investigation not only enhances the understanding of domain wall modes in TBG but also has broader implications for the development of moiré devices.
Local resetting in non-conserving zero-range processes with extensive rates
Authors: Grange Pascal 
Published: April 2024

Abstract
A non-conserving zero-range process with extensive creation, annihilation and hopping rates is subjected to local resetting. The model is formulated on a large, fully-connected network of states. The states are equipped with a (bounded) fitness level: particles are added to each state at a rate proportional to the fitness level of the state. Moreover, particles are annihilated at a constant rate, and hop at a fixed rate to a uniformly-drawn state in the network. This model has been interpreted in terms of population dynamics: the fitness is the reproductive fitness in a haploid population, and the hopping process models mutation. It has also been interpreted as a model of network growth with a fixed set of nodes (in which particles occupying a state are interpreted as links pointing to this state). In the absence of resetting, the model is known to reach a steady state, which in a certain limit may exhibit a condensate at maximum fitness. If the model is subjected to global resetting by annihilating all particles at Poisson-distributed times, there is no condensation in the steady state. If the system is subjected to local resetting, the occupation numbers of each state are reset to zero at independent random times. These times are distributed according to a Poisson process whose rate (the resetting rate) depends on the fitness. We derive the evolution equation satisfied by the probability law of the occupation numbers. We calculate the average occupation numbers in the steady state. The existence of a condensate is found to depend on the local behavior of the resetting rate at maximum fitness: if the resetting rate vanishes at least linearly at high fitness, a condensate appears at maximum fitness in the limit where the sum of the annihilation and hopping rates is equal to the maximum fitness.