bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigating bio-based solvents as a sustainable alternative in the formulation and fabrication of superhydrophobic surfaces
Authors: Garcia-Gonzalez Reyna I. , Crick Colin R.
Published: October 2023

Organic solvents can be highly toxic to humans, causing damage to the tissues and toxin metabolizing systems. Petroleum-based solvents (such as n-hexane) are likely to trigger endocrine disruption in humans regularly exposed to them. Given this, there is still a high demand for petroleum-based solvents, as they can be used to fabricate materials for various high-performance products. In addition, extensive environmental damage is also caused by petroleum-based solvents. This biological and environmental harm has been the main cause of the demand for sustainable and cost-effective development of environmentally non-hazardous solvent systems. An area targeted to achieve this is bio-based solvent alternatives. In this report, 2-methyltetrahydrofuran (2-MeTHF), a bio-based solvent, is explored as an alternative solvent in the development of superhydrophobic surfaces, replacing n-hexane. This model system explores the factors considered when exploring the implementation of bio-based solvents in the development of highly advanced materials. In this research, both 2-MeTHF/n-hexane are used in the formulation/deposition of superhydrophobic polymer–nanoparticle composites (SPNCs). SPNCs developed using 2-MeTHF have water repelling functionality like those developed using n-hexane, while also demonstrating performance enhancements. Overall, this solvent exchange is aimed to serve as an example of what can be achieved in similar systems to enhance the sustainability of chemical processes that require organic solvents.
Building up a view and understanding of the multifunctional activity of black phosphorous nanosheet modified with the metal atom
Authors: Zhang Hongyu , Xue Xiong-Xiong , Guo Gencai , Meng Haiyu , Qi Xiang , Zhong Jianxin , Huang Zongyu
Published: October 2023

Constructing metal-semiconductor interfaces by loading metal atoms onto two-dimensional material to build atomically dispersed single-atom catalysts (SACs) has emerged as a new frontier for improving atom utilization and designing multifunctional electrocatalysts. Nowadays, studies on black phosphorus nanosheets in electrocatalysis have received much attention and the successful preparation of metal nanoparticle/black phosphorus (BP) hybrid electrocatalysts indicates BP nanosheets can serve as a potential support platform for SACs. Herein, by using large-scale ab initio calculations, we explored a large composition space of SACs with transition metal atoms supported on BP monolayer (M-BP) and built a comprehensive picture of activity trend, stability, and electronic origin towards oxygen reduction and evolution reaction (ORR and OER) and hydrogen evolution reaction (HER). The results show that the catalytic activity can be widely tuned by reasonable regulation of metal atoms. Ni-, Pd-, and Pt-BP could effectively balance the binding strength of the target intermediates, thus achieving efficient bifunctional activity for OER and ORR. Favorable bifunctional catalytic performance for OER and HER can be realized on Rh-BP. Especially, Pt-BP exhibits promising trifunctional activity towards OER, ORR, and HER. Multiple-level corrections among overpotential, Gibbs free energy, orbital population, and d-band center reveal that the trend and origin of catalytic activity are intrinsically determined by the d-band center of metal sites. The thermodynamic and dynamic stability simulations demonstrate that the active metal centers are firmly anchored on BP substrate with intact M-P bonds. These findings provide a theoretical basis for the rational design of BP-based SACs toward promising multifunctional activity.
Effect of fluid viscoelasticity, shear stress, and interface tension on the lift force in lubricated contacts
Authors: Hu Shiyuan , Meng Fanlong , Doi Masao
Published: October 2023

We consider a cylinder immersed in viscous fluid moving near a flat substrate covered by an incompressible viscoelastic fluid layer, and study the effect of the fluid viscoelasticity on the lift force exerted on the cylinder. The lift force is zero when the viscoelastic layer is not deformed, but becomes non-zero when it is deformed. We calculate the lift force by considering both the tangential stress and the normal stress applied at the surface of the viscoelastic layer. Our analysis indicates that as the layer changes from the elastic limit to the viscous limit, the lift force decreases with the decrease of the Deborah number (De). For small De, the effect of the layer elasticity is taken over by the surface tension and the lift force can become negative. We also show that the tangential stress and the interface slip velocity (the surface velocity relative to the substrate), which have been ignored in the previous analysis, give important contributions to the lift force. Especially for thin elastic layers, they give dominant contributions to the lift force.
Laboratory study of the PFRC-2's initial plasma densification stages
Authors: Cohen S. A. , Evans E. S. , David L. , Jandovitz P. , Vinoth S. P. , Palmerduca E. , Swanson C. P. S. , Jusino-Gonzalez G. , Dogariu A.
Published: October 2023

Initial plasma densification by odd-parity rotating magnetic fields (RMFo) applied to the linear magnetized Princeton field-reversed configuration (PFRC-2) device with fill gases at pressures near 1 mTorr proceeds through two phases: a slow one, characterized by a rise time τslow∼100μs, followed by a fast one, characterized by τfast∼10μs. The transition from slow to fast occurs at a line-integral-averaged electron density, tne, near 2×1011 cm−3, independent of magnetic field. Over most of the range of experimental parameters investigated, as the PFRC-2 axial magnetic field strength was increased, RMFo power decreased, gas fill pressure lowered, or lower atomic mass unit (AMU) fill gas used, the duration of the slow phase lengthened from 50 μs to longer than 10 ms after the RMFo power began. The post-fast-phase maximum ne increases with the fill-gas AMU, exceeding 5 × 1013 cm−3 for Ar. The slow phase is consistent with atomic physics processes and field-parallel sound-speed losses. The fast phase may be explained by improved axial confinement, possibly augmented by radial or axial contraction of the plasma. Another possible explanation, a large increase in electron temperature, is inconsistent with x-ray emission. The ne behavior is discussed in relation to the E to H transition.
Material characteristics governing in-plane phonon-polariton thermal conductance
Authors: Minyard Jacob , Beechem Thomas E.
Published: October 2023

The material dependence of phonon-polariton-based in-plane thermal conductance is investigated by examining systems composed of air and several wurtzite and zinc-blende crystals. Phonon-polariton-based thermal conductance varies by over an order of magnitude (∼0.5–60 nW/K), which is similar to the variation observed in the materials corresponding to bulk thermal conductivity. Regardless of the material, phonon-polaritons exhibit similar thermal conductance to that of phonons when layers become ultrathin (∼10 nm), suggesting the generality of the effect at these length-scales. A figure of merit is proposed to explain the large variation of in-plane polariton thermal conductance that is composed entirely of easily predicted and measured optical phonon energies and lifetimes. Using this figure of merit, in-plane phonon-polariton thermal conductance enlarges with increases in (1) optical phonon energies, (2) splitting between transverse and longitudinal mode pairs, and (3) phonon lifetimes.
Alleviation of salinity stress in zinc oxide nanoparticle-treated Lagenaria siceraria L. by modulation of physiochemical attributes, enzymatic and non-enzymatic antioxidative system
Authors: Javeed Ayesha , Ahmed Shakil , Sardar Rehana
Published: October 2023

Salt stress is a major abiotic stress that affects the world’s agricultural soils and crop yield, the system that ensures food production. In the present study, three different concentrations of zinc oxide nanoparticles (250, 500 and 750 ZnO NPs mg L−1) were applied by soil drenching. The treatments aimed to improve the phytochemical characteristics of Lagenaria siceraria L. (bottle gourd) by lowering the oxidative stress brought on by salinity stress (200 ppm NaF). Green synthesised ZnO NPs were prepared, having hexagonal and spherical shapes and sizes 16–35 nm. Salt stress reduced fresh and dry biomass of plants and improved production of proline. ZnO NPs improved antioxidant response by enhancing catalase, ascorbate peroxidase, superoxide dismutase and peroxidase activities, and protecting cellular structures by eliminating free radicals and reactive oxygen species. The 500 mg L−1 ZnO NPs treatment improved total chlorophyll (31%), total soluble sugars (23%) and maintained the gas exchange parameters under salt stress. This treatment also enhanced the biosynthesis of osmotic regulators (proline) by 19%, Na+ by 22% and Zn2+ by 17%, assisting mitigation of salt stress-mediated toxicity in plants. This study demonstrates that ZnO NP-treated seedlings show improved growth attributes, suggesting that ZnO NPs could be advantageous for L. siceraria cultivation in salt polluted areas and could be utilised in place of conventional Zn fertiliser for better crop yield.
Bugs in floods
Authors: Blaskovich Mark A. T. , Harris Patrick N. A.
Published: October 2023

Floods are natural disasters that affect millions of people every year, with escalating impact due to a combination of factors that include increasing urbanisation of previously uninhabited land, deforestation, and climate change. Floods do not discriminate between lower–middle income countries (LMICs) and high-income countries, though the types of damage can differ. As a ‘fire or flood’ country, Australia is no exception. Apart from the obvious physical damage to infrastructure and direct impact on human health due to injury and drowning, there is a more insidious danger lurking in floodwaters – a range of microbial pathogens that can opportunistically cause additional morbidity and mortality. These health effects can be both acute, and longer term. This review focuses on bacterial infections that can be attributed to floods, divided into sections that summarise opportunistic infections by commonly seen human pathogens, versus infections caused by more unusual microbes that are normally not encountered until they are released by floods.
Effect of tree wood density on energy release and charcoal reflectance under constant heat exposure
Authors: Crawford Alastair J. , Feldpausch Ted R. , Marimon Junior Ben Hur , de Oliveira Edmar A. , Belcher Claire M.
Published: October 2023

Background Charcoal increases in reflectance with increased intensity and/or duration of heating, and this has been proposed as a potential quantitative metric for fire severity. Because fuel properties also influence reflectance, relationships between heat exposure and reflectance must currently be considered fuel-specific, limiting the application of the method. Aims We assessed the effect of wood density on charcoal reflectance, to test whether it could be used as a proxy for overall variation in wood properties. Methods Wood samples from 25 tree species were charred under constant conditions in a microcalorimeter, and reflectance measured by microphotometry. Key results A positive linear relationship was found between wood density and charcoal reflectance (r = 0.53). Wood density was highly correlated with total heat release per unit volume (r = 0.94). Conclusions Wood density accounts for a substantial component of the variation in charcoal reflectance under constant heat exposure. Implications The relationship of density to reflectance shown here is relevant to the assessment of charcoals formed anaerobically, where endogenous heating (combustion of the sample itself) does not occur. In fire-produced chars, an additional increase in reflectance from endogenous heating should produce a stronger correlation, and density might account for a large component of the variation in reflectance under such conditions.
Visual event boundaries restrict anchoring effects in decision-making
Authors: Ongchoco Joan Danielle K. , Walter-Terrill Robert , Scholl Brian J.
Published: October 2023

Research on higher-level thought has revealed many principles of reasoning and decision-making but has rarely made contact with how we perceive the world in the first place. Here we show how a lower-level property of perception—the spontaneous and task-irrelevant segmentation of continuous visual stimulation into discrete events—can restrict one of the most notorious biases in decision-making: numerical anchoring. Subjects walked down a long room in an immersive three dimensional (3D) animation and then made a numerical judgment (e.g., of how much a suitcase is worth, or of how many hours of community service a minor crime deserved). Critically, some subjects passed through a doorway (a visual event boundary) during their virtual walk, while others did not—equating time, distance traveled, and visual complexity. The anchoring manipulation was especially innocuous, not appearing to be part of the experiment at all. Before the online trial began, subjects reported the two-digit numerical value from a visually distorted “CAPTCHA” (“to verify that you are human”)—where this task-irrelevant anchor was either low (e.g., 29) or high (e.g., 92). With no doorway, we observed reliable anchoring effects: Higher CAPTCHA values produced higher estimates. With the doorway, however, such effects were attenuated or even eliminated. This generalized across tasks involving item valuations, factual questions, and legal judgments and in tests of both incidental and explicit anchoring. This demonstrates how spontaneous visual event segmentation can have profound consequences for higher-level thought.
Downregulation of a transcription factor associated with resistance to Bt toxin Vip3Aa in the invasive fall armyworm
Authors: Jin Minghui , Shan Yinxue , Peng Yan , Wang Wenhui , Zhang Huihui , Liu Kaiyu , Heckel David G. , Wu Kongming , Tabashnik Bruce E. , Xiao Yutao
Published: October 2023

Transgenic crops producing insecticidal proteins from
Bacillus thuringiensis
(Bt) have revolutionized control of some major pests. However, more than 25 cases of field-evolved practical resistance have reduced the efficacy of transgenic crops producing crystalline (Cry) Bt proteins, spurring adoption of alternatives including crops producing the Bt vegetative insecticidal protein Vip3Aa. Although practical resistance to Vip3Aa has not been reported yet, better understanding of the genetic basis of resistance to Vip3Aa is urgently needed to proactively monitor, delay, and counter pest resistance. This is especially important for fall armyworm (
Spodoptera frugiperda
), which has evolved practical resistance to Cry proteins and is one of the world’s most damaging pests. Here, we report the identification of an association between downregulation of the transcription factor gene
SfMyb
and resistance to Vip3Aa in
S. frugiperda
. Results from a genome-wide association study, fine-scale mapping, and RNA-Seq identified this gene as a compelling candidate for contributing to the 206-fold resistance to Vip3Aa in a laboratory-selected strain. Experimental reduction of
SfMyb
expression in a susceptible strain using RNA interference (RNAi) or CRISPR/Cas9 gene editing decreased susceptibility to Vip3Aa, confirming that reduced expression of this gene can cause resistance to Vip3Aa. Relative to the wild-type promoter for
SfMyb
, the promoter in the resistant strain has deletions and lower activity. Data from yeast one-hybrid assays, genomics, RNA-Seq, RNAi, and proteomics identified genes that are strong candidates for mediating the effects of
SfMyb
on Vip3Aa resistance. The results reported here may facilitate progress in understanding and managing pest resistance to Vip3Aa.
Longitudinal study of endodontic and periapical status of an adult Danish population examined in 2009, 2014, and 2019: a repeated cohort study
Authors: Razdan Ankur , Schropp Lars , Væth Michael , Kirkevang Lise-Lotte
Published: October 2023

Objective: To describe endodontic changes in an adult Danish population (C2;2009–2014–2019) and compare them with a similar cohort (C1;1997–2003–2008).
Material and methods: A randomly selected cohort (C2) with three full-mouth radiographic examinations. The frequencies of teeth, apical periodontitis (AP), root filled teeth, and lost teeth in C2 were compared to a similar cohort (C1) using regression analyses; effect of age, cohort, and period was assessed.
Results: C1 had 330 and C2, 170 participants (mean age, C1: 42.9; C2: 47.3 years, p < .001). The proportion of individuals with no AP was similar in C1 and C2 (p = .46). C2 had a higher proportion of individuals with no root filled teeth (p < .001) and no tooth loss (p = .02) than C1. The proportion of AP and root filled teeth increased with age in both cohorts. C2 had fewer root filled teeth and lost teeth, fewest lost teeth in the youngest age groups.
Conclusions: In C2, the prevalence of teeth with AP and root fillings increased with age, and few teeth were lost. Change in proportion of AP was similar in two cohorts; fewer root filled teeth and lost teeth in C2. The proportion of lost teeth in C2 showed cohort effect for older age groups.
Determining the viscosity of the Navier–Stokes equations from observations of finitely many modes
Authors: Biswas Animikh , Hudson Joshua
Published: October 2023

In this work, we ask and answer the question: when is the viscosity of a fluid uniquely determined from spatially sparse measurements of its velocity field? We pose the question mathematically as an optimization problem using the determining map (the mapping of data to an approximation made via a nudging algorithm) to define a loss functional, the minimization of which solves the inverse problem of identifying the true viscosity given the measurement data. We give explicit a priori conditions for the well-posedness of this inverse problem. In addition, we show that smallness of the loss functional implies proximity to the true viscosity. We then present an algorithm for solving the inverse problem and provide a priori verifiable conditions that ensure its convergence.
Invertible residual networks in the context of regularization theory for linear inverse problems
Authors: Arndt Clemens , Denker Alexander , Dittmer Sören , Heilenkötter Nick , Iske Meira , Kluth Tobias , Maass Peter , Nickel Judith
Published: October 2023

Learned inverse problem solvers exhibit remarkable performance in applications like image reconstruction tasks. These data-driven reconstruction methods often follow a two-step procedure. First, one trains the often neural network-based reconstruction scheme via a dataset. Second, one applies the scheme to new measurements to obtain reconstructions. We follow these steps but parameterize the reconstruction scheme with invertible residual networks (iResNets). We demonstrate that the invertibility enables investigating the influence of the training and architecture choices on the resulting reconstruction scheme. For example, assuming local approximation properties of the network, we show that these schemes become convergent regularizations. In addition, the investigations reveal a formal link to the linear regularization theory of linear inverse problems and provide a nonlinear spectral regularization for particular architecture classes. On the numerical side, we investigate the local approximation property of selected trained architectures and present a series of experiments on the MNIST dataset that underpin and extend our theoretical findings.
Supersensitive phase estimation for hybrid interferometer using balanced homodyne detection
Authors: Shao Tao , Zhang Minyang , Li Chenlu , Wang Yuanxiang , Hu Youyou , Zhang Mingming , Liu Jun
Published: October 2023

We have theoretically investigated the phase sensitivity of the hybrid interferometer with two coherent beams using the method of balance homodyne detection. The measurement device is a nonlinear–linear hybrid interferometer consisting of an optical parametric amplifier and a beam splitter. We prove that the phase sensitivity can beat the shot noise limit in the optimal conditions. Furthermore, we derive the quantum Cramér–Rao bound of the hybrid interferometer. The effects of transmission loss and detection loss on the measurement accuracy are discussed. The detection accuracy of this scheme is compared with that of the conventional SU (1,1) interferometer. Our results show that this scheme outperforms the conventional SU (1,1) interferometer scheme at high parametric strength. This scheme can be implemented with existing experimental techniques and will have important applications in quantum precision measurements.
A non-volatile optical filter based on a Ge2Sb2Te5-assisted microring with a tunable bandwidth and extinction ratio
Authors: Zhang Yujia , He Yu , Guo Xuhan , Su Yikai
Published: October 2023

A novel non-volatile optical filter with a large bandwidth (BW) and extinction ratio (ER) tunability is first experimentally demonstrated by introducing an all-optical phase change of Ge2Sb2Te5 (GST). The Si-GST hybrid device promises flexible multi-level regulation of essential filter parameters in an ultra-compact footprint of 30 μm × 13 μm. Ultra-low power consumption is realised on account of the saving of external static power that is required in other electric-optic or optic-optic-driven filters. The GST is loaded onto two triple-waveguide directional couplers located at the coupling regions of an add-drop microring resonator. By initiating the GST phase transition with pump optical pulses, the transmitted optical power to the cross port of the triple-waveguide coupler is adjustable, hence influencing the coupling efficiency states of the microring filter. Consequently, a tunable on-off ER from 0.7 dB to 18.2 dB and a tunable BW from 0.6 nm to 3.3 nm are experimentally obtained with the aid of optically manipulating the crystallization degree of GST. Our device potentially enables the realisation of high-density photonic integrated circuits, especially in dense wavelength division multiplexing networks.
An enhanced chromatic dispersion probe for simultaneous measurement of dual-axis absolute and relative displacement with nanometric resolutions
Authors: Zhao Ran , Chen Chong , Xiong Xin , Chen YuanLiu , Ju BingFeng
Published: October 2023

This paper presents an enhanced chromatic dispersion probe for simultaneous measurement of dual-axis absolute and relative displacement with nanometric resolutions based on a 4f optical system and a signal processing algorithm. In the 4f optical system, a light source is generated by a pinhole in such a way that the employed pinhole is placed on the focal planes of the two achromatic lenses, aimed at generating a low-pass filter in the frequency domain. With a smaller pinhole, side lobes of the measured spectra are effectively suppressed and the signal-to-noise ratio is optimized, resulting in an expanded absolute measurement range and improved resolution of the two axes, and an enhanced relative measurement resolution of the dual-axis. A signal processing algorithm is proposed in such a way that in the spectral curvature region of the dual-axis output spectra, the original fitted spectrum is replaced by a linear fitting line and a newly-intersected wavelength can be obtained, resulting in an expanded measurement range of the relative displacement of the dual-axis. Numerical simulation and experiments have indicated that the absolute measurement range has been expanded to 225 μm with an enhanced resolution of 40 nm, and the measurement range of the relative displacement of the dual-axis has been expanded to 370 μm with an enhanced relative measurement resolution of 90 nm.
The transient concept of bearings: a novel strategy for RUL prediction
Authors: Zhang Xu , Guo ChenXia , Yang RuiFeng , Li Kun
Published: October 2023

Bearings serve as integral components in mechanical devices, providing stability during mechanical transmission and reducing friction coefficients. Hence, the precise prediction of bearing remaining useful life (RUL) is paramount for the health monitoring of mechanical systems. However, traditional techniques which utilize linear degradation processes for constructing health index models often fail to adequately portray the complex relationship between degradation and time. To rectify this, we introduce The Transient Concept of Bearings and determine the degradation rate predicated on this novel concept. We construct a degradation rate model for bearings using a K-means-transformer network and leverage transfer learning methodologies to predict the RUL of bearings. Validation of the proposed concepts and demonstration of their accuracy are achieved using the PHM2012 challenge dataset, even amidst incomplete data scenarios. When compared to existing RUL prediction models, our approach not only significantly improves prediction accuracy but also sheds valuable insights into the bearing degradation process.
Functional gradient piezoelectric composite nanogenerator for self-powered touch sensor
Authors: Shi Xiaoquan , Sun Yazhou , Tian Haiying , Li Dekai , Liu Haitao
Published: October 2023

Touch sensors play a pivotal role in the domain of human-machine interfaces. To streamline the complexity of array electrodes, this paper presents a novel functional gradient piezoelectric composite nanogenerator touch sensor by utilizing only a pair of electrodes for touch position detection through voltage measurements. The rheological characteristics of the BaTiO3/PDMS composites were evaluated, and the functional gradient nanogenerator was successfully fabricated by extrusion 3D printing. Finite element simulations revealed a significant concentration of stress in the vicinity of the touch position, which gradually diminished farther away. The output voltage demonstrated substantial variation across different touch positions, which was validated by experimental results exhibiting a similar trend. Comparing voltage values enabled the distinction of touch positions, as confirmed by both simulation and experimental findings. The nanogenerator can realize the function of human-machine interfaces.
Favorable features of a calcium phosphate cement based on a metastable α ̅-tricalcium phosphate and reinforced by hydroxyapatite whiskers
Authors: Zyman Z , Epple M , Goncharenko A , Onyshchenko O , Rokhmistrov D , Prymak O , Loza K
Published: October 2023

The composition, impurities, ion substitutions, structure, peculiarities in crystallization and compressive strength were studied in the initial stage of setting (for 15 min) of a new cement based on a metastable

α

̅

-tricalcium phosphate and reinforced by various amounts (up to 15 wt%) of hydroxyapatite whiskers. The set cements were apatitic, highly nonstoichiometric with a Ca/P ratio below 1.5. The compressive strength increased more than twice (up to 8 MPa) at a whisker content of 4 wt% and then decreased again with increasing whisker content. The decline was associated with the growth of nanocrystals on the surface planes of whiskers and formation of micropores in the whisker vicinity caused by the consumption of the surrounding mother phase for the growth. It is expected that the micropores are favorable for the surrounding tissue to grow into enhancing the effectiveness of the set cement. The cement can primarily be used as accessible remedies for treatment of slightly-loaded bone defects.
Topological properties and anomalous transport in van der Waals ferromagnets Fe
n
GeTe2: a comparative study
Authors: Sau Jyotirmoy , Hassan S R , Kumar Nitesh , Kumar Manoranjan
Published: October 2023

Recently synthesized topological van der Waals (vdW) Fe
n
GeTe2 (n=3,4, and 5) series of compounds have drawn a lot of research interest due to their interesting magnetic properties and anomalous transport behavior. However, understanding the topological aspect of these materials’ electronic band structure is either scant or absent in the literature. In this work, we perform a comparative study of the electronic structure of all three materials to understand their topological properties and their effect on transport properties using the first-principles calculations and to derive the effective tight-binding model for these systems. All three systems exhibit ferromagnetic behavior, and the contribution of various Fe d-orbitals are also studied. Spin-orbit coupling (SOC) causes the degeneracy to be lifted and results in a finite Berry curvature (BC). Finite BC contributes to the intrinsic anomalous Hall conductivity (AHC) and Nernst conductivity (ANC) of these systems. We show that Fe3GeTe2 and Fe5GeTe2 have similar nodal line formations, while Fe4GeTe2 exhibits nodal points close to Fermi energy E

F
. We calculate AHC (σ

xy
) at zero temperature and ANC (α

xy
) at room temperature for n = 3, 4 and 5 and find that our values are consistent with transport and magnetic measurement.
Research on electron and positron spectrum in the high-energy region based on the gluon condensation model
Authors: Wu Jin-tao , Feng Ming-jun , Ruan Jian-hong
Published: October 2023

Electron (positron), proton and nuclei can be accelerated to very high energy by local supernova remnants (SNR). The famous excesses of electron and proton (nuclei) potentially come from such kind of local sources. Recently, the DAMPE experiment measured the electron spectrum (including both electrons and positrons) of cosmic rays with high-accuracy. It provides an opportunity to further explore the excess of electrons. According to the gluon condensation (GC) theory, once GC occurs, huge number of gluons condense at a critical momentum, and the production spectra of electron and proton showing typical GC characteristics. There are exact correlations between the electron and proton spectrum from a same GC process. It is possible to interpret the power-law break of cosmic rays in view of GC phenomenon, and predict one from another based on the relations between electron and proton spectrum. In this work, we point out the potential existence of a second excess in the electron spectrum, the characteristics of this excess is derived from experimental data of proton. We hope that the future DAMPE experiments will confirm the existence of this second excess and support the result of GC model.
Topological states switching and group velocity control in two-dimensional non-reciprocal Hermitian photonic lattice
Authors: Lin 林 Yu 宇 , Wang 王 Yuandan 元旦 , Yang 杨 Junhao 俊豪 , Fu 符 Yixuan 艺萱 , Qi 齐 Xinyuan 新元
Published: October 2023

We proposed a model with non reciprocal coupling coefficients, in which the imaginary parts γ indicate the phase delay or exceed term. The distributions of band structure and the group velocity are both characterized as a function of the coupling. we studied the system’s topological states and group velocity control. The results show that the movement and breaking of Dirac points exist in the energy band of the system. By changing the coupling coefficients, the conversion between any topological states corresponds to different Chern number. Topological edge states exist in topological non-trivial systems that correspond to the two different Chern numbers. Besides, it is also found that both the coupling coefficient and the wave vector can cause the oscillation of the pulse group velocity. At the same time, the topological state can suppress the amplitude of the group velocity profiles. Our findings enrich the theory of light wave manipulation in high-dimensional photonic lattices and provide a novel view for realizing linear localization and group velocity regulation of light waves, which has potential application in high-speed optical communication and quantum information fields.
Analytical solution to incident angle quasi-phase-matching engineering for second harmonic generation in a periodic-poled lithium niobate crystal
Authors: Hong 洪 Li-Hong 丽红 , Qiu 邱 Ya-Ting 雅婷 , Li 李 Xiao-Ni 晓霓 , Chen 陈 Bao-Qin 宝琴 , Li 李 Zhi-Yuan 志远
Published: October 2023

Phase matching or quasi-phase matching (QPM) is of significant importance to the conversion efficiency of second harmonic generation (SHG) in artificial nonlinear crystals like lithium niobate (LN) crystal or microstructured nonlinear crystals like periodic-poled lithium niobate (PPLN) crystals. In this paper, we propose and show that the incident angle of pump laser light can be harnessed as an alternative versatile tool to engineer QPM for high-efficiency SHG in a PPLN crystal, in addition to conventional means of period adjusting or temperature tuning. A rigorous model is established and analytical solution of the nonlinear conversion efficiency under the small and large signal approximation theory is obtained at different incident angles. The variation of phase mismatching and walk-off length with incident angle or incident wavelength are also explored. Numerical simulations for a PPLN crystal with first order QPM structure are used to confirm our theoretical predictions based on the exact analytical solution of the general large-signal theory. The results show that the narrow-band tunable SHG output covers a range of 532 nm–552.8 nm at the ideal incident angle from 0° to 90°. This theoretical scheme, fully considering the reflection and transmission at the air-crystal interface, would offer an efficient theoretical system to evaluate the nonlinear frequency conversion and help to obtain the maximum SHG conversion efficiency by selecting an optimum incident wavelength and incident angle in a specially designed PPLN crystal, which would be very helpful for the design of tunable narrow-band pulse nanosecond, picosecond, and femtosecond laser devices via PPLN and other microstructured LN crystals.
Coherent optical frequency transfer via 972-km fiber link
Authors: Deng 邓 Xue 雪 , Zhang 张 Xiang 翔 , Zang 臧 Qi 琦 , Jiao 焦 Dong-Dong 东东 , Wang 王 Dan 丹 , Liu 刘 Jie 杰 , Gao 高 Jing 静 , Xu 许 Guan-Jun 冠军 , Dong 董 Rui-Fang 瑞芳 , Liu 刘 Tao 涛 , Zhang 张 Shou-Gang 首刚
Published: October 2023

We demonstrate coherent optical frequency dissemination over a distance of 972 km by cascading two spans where the phase noise is passively compensated for. Instead of employing a phase discriminator and a phase locking loop in the conventional active phase control scheme, the passive phase noise cancellation is realized by feeding double-trip beat-note frequency to the driver of the acoustic optical modulator at the local site. This passive scheme exhibits fine robustness and reliability, making it suitable for long-distance and noisy fiber links. An optical regeneration station is used in the link for signal amplification and cascaded transmission. The phase noise cancellation and transfer instability of the 972-km link is investigated, and transfer instability of 1.1 × 10−19 at 104 s is achieved. This work provides a promising method for realizing optical frequency distribution over thousands of kilometers by using fiber links.
Improved decoy-state quantum key distribution with uncharacterized heralded single-photon sources
Authors: Xu 徐 Le-Chen 乐辰 , Zhang 张 Chun-Hui 春辉 , Zhou 周 Xing-Yu 星宇 , Wang 王 Qin 琴
Published: October 2023

Encoding system plays a significant role in quantum key distribution (QKD). However, the security and performance of QKD systems can be compromised by encoding misalignment due to the inevitable defects in realistic devices. To alleviate the influence of misalignments, a method exploiting statistics from mismatched basis is proposed to enable uncharacterized sources to generate secure keys in QKD. In this work, we propose a scheme on four-intensity decoy-state quantum key distribution with uncharacterized heralded single-photon sources. It only requires the source states are prepared in a two-dimensional Hilbert space, and can thus reduce the complexity of practical realizations. Moreover, we carry out corresponding numerical simulations and demonstrate that our present four-intensity decoy-state scheme can achieve a much higher key rate compared than a three-intensity decoy-state method, and meantime it can obtain a longer transmission distance compared than the one using weak coherent sources.
Dynamics and synchronization in a memristor-coupled discrete heterogeneous neuron network considering noise
Authors: Yan 晏 Xun 询 , Li 李 Zhijun 志军 , Li 李 Chunlai 春来
Published: October 2023

Research on discrete memristor-based neural networks has received much attention. However, current research mainly focuses on memristor–based discrete homogeneous neuron networks, while memristor-coupled discrete heterogeneous neuron networks are rarely reported. In this study, a new four-stable discrete locally active memristor is proposed and its nonvolatile and locally active properties are verified by its power-off plot and DC V–I diagram. Based on two-dimensional (2D) discrete Izhikevich neuron and 2D discrete Chialvo neuron, a heterogeneous discrete neuron network is constructed by using the proposed discrete memristor as a coupling synapse connecting the two heterogeneous neurons. Considering the coupling strength as the control parameter, chaotic firing, periodic firing, and hyperchaotic firing patterns are revealed. In particular, multiple coexisting firing patterns are observed, which are induced by different initial values of the memristor. Phase synchronization between the two heterogeneous neurons is discussed and it is found that they can achieve perfect synchronous at large coupling strength. Furthermore, the effect of Gaussian white noise on synchronization behaviors is also explored. We demonstrate that the presence of noise not only leads to the transition of firing patterns, but also achieves the phase synchronization between two heterogeneous neurons under low coupling strength.
Sharing quantum nonlocality in the noisy scenario
Authors: Yang 杨 Shu-Yuan 舒媛 , Hou 侯 Jin-Chuan 晋川 , He 贺 Kan 衎
Published: October 2023

It was showed in [Phys. Rev. Lett.
125 090401 (2020)] that there exist unbounded number of independent Bobs who can share quantum nonlocality with a single Alice by performing sequentially measurements on the Bob’s half of the maximally entangled pure two-qubit state. However, from practical perspectives, errors in entanglement generation and noises in quantum measurements will result in the decay of nonlocality in the scenario. In this paper, we analyze the persistency and termination of sharing nonlocality in the noisy scenario. We first obtain the two sufficient conditions under which there exist n independent Bobs who can share nonlocality with a single Alice under noisy measurements and the noisy initial two qubit entangled state. Analyzing the two conditions, we find that the influences on persistency under different kinds of noises can cancel each other out. Furthermore, we describe the change patterns of the maximal nonlocality-sharing number under the influence of different noises. Finally, we extend our investigation to the case of arbitrary finite-dimensional systems.
Holographic Schwinger effect in spinning black hole backgrounds*
Authors: Cai 蔡 Yi-Ze 镒泽 , Zhang 张 Zi-Qiang 自强
Published: October 2023

We perform a potential analysis for the holographic Schwinger effect in spinning Myers-Perry black holes. We compute the potential between the produced pair by evaluating the classical action of a string attached on a probe D3-brane at an intermediate position in the AdS bulk. We find that increasing the angular momentum reduces the potential barrier, thus enhancing the Schwinger effect, consistent with previous findings obtained via the local Lorentz transformation. In particular, these effects are more visible for the particle pair lying in the transversal plane compared with that along the longitudinal orientation. In addition, we discuss how the Schwinger effect changes with the shear viscosity to entropy density ratio at strong coupling under the influence of angular momentum.
The influence of temperature on the properties of anti - ice materials
Authors: Gan Gan
Published: October 2023

The results of experimental research and practical application of anti-icing surface fully show that its performance is greatly affected by temperature. The anti-icing measures of anti-icing surface can be divided into three stages: before icing, during icing and after icing. In these three stages, the influence brought by temperature change is respectively reflected in: the adhesion of water droplets to the surface, the time it takes for ice nucleation, the adhesion of ice to the surface. Surface anti-ice technology has important application in aviation and aerospace field. The surface temperature of aircraft will change greatly when the aircraft is sailing at different altitudes and passing through different climatic environments. If ice accumulates in some parts of the aircraft, even if it is small, it may lead to a decrease in the climbing force of the aircraft and an increase in flight resistance, thus leading to the deterioration of aerodynamic performance such as the maneuverability and stability of the aircraft. Studying the influence of these temperature changes on the anti-icing performance of aircraft surface can avoid the air disaster caused by surface icing. Starting from these three stages, this paper analyzes the influence of temperature on material surface and the liquid itself successively in these three stages, so as to further explore the influence of temperature on ice suppression performance.
Use of fibre reinforced polymer (FRP) in new construction and in strengthening of existing structures
Authors: Li Renjie
Published: October 2023

Concrete is the primary construction material for most building projects today owing to its versatility, moldability and superior strength in compression. Concrete however is an inherently brittle material with quite poor tensile strength and has very low resistance to cracks and their propagation throughout the medium. In this research paper, a thorough compilation of previous work on the development of FRPs, their performance under various conditions through traditional structural loading techniques such as 4-point loading and their implementation is provided. Fibre reinforced polymers (FRP) allow alterations in concrete’s structural behaviour under tensile loading as well as expansions during exposures to extreme temperatures and routine shrinkage cracks through addition of small fibres that act as anchors preventing the widening of cracks as well as behaving in a similar fashion to the conventional steel reinforcement. FRP not only comes from small hair like fibres but also in the form of wraps which provide confinement on beams and columns increasing the compressive strength of the element as well as reducing the tensile loads, similar to how prestressing tendons alter the behaviour of prestressed concrete.
Advances in E-Skin research: materials, functions and applications
Authors: Cheng Zhijin
Published: October 2023

The need for long-term physiological signal surveillance during everyday life is brought on by the ageing of the population and the rise in health-related worries. Electronic skin is a system that replicates the properties of human skin as well as performs comparable sensory tasks. It has recently demonstrated significant promise in the fields of health monitoring, human-machine interface, and machine perception as a result of its high abrasion resistance and adaptability. The material qualities, functional aspects, as well as typical applications of contemporary electronic skin research are reviewed in this paper. The goal of the project is to make e-skins stretchable, self-healing, and bio-compatible while simultaneously monitoring physical, chemical, and electrophysiological signals in real-time. Finally, the difficulties and potential solutions for e-development skin’s are examined. In order to realize its full potential, e-skin requires the scientists collaboration from multiple areas, including materials, information, engineering, and life, to realize its full potential.
Bi2MoO6 photocatalyst: structure, preparation, modification method and application in water cleaning
Authors: Lyu Peishan
Published: October 2023

Humans widely utilize solar energy as a green and sustainable resource. Furthermore, semiconductor photocatalysis can use sunlight for reaction without other additional energy, so it has received wide attention. Bi2MoO6 shows excellent potential in visible photocatalysis due to its narrow band gap, high stability, and non-toxicity. This review focuses on the modification methods of Bi2MoO6 photocatalysts. By adjusting the treatment of Bi2MoO6 with different modifications, the photogenerated electron-hole complexation can be retarded, and its specific surface area increases, thus enhancing its photocatalytic performance. This article begins with describing the current state of photocatalysts, the mechanism of the photocatalytic process, as well as important bottlenecks and affecting factors. Then, three techniques for making Bi2MoO6 photocatalysts are provided, and their attributes are compared in various ways. Four approaches for enhancing the photocatalytic performance of the material are outlined and addressed. Then, the organic pollutant degradation performance of Bi2MoO6 photocatalysts generated by various modification techniques is studied. Finally, the existing issues with Bi2MoO6 photocatalysts and ways to improve them are explored.
Recent progress in electrochemical immunosensors for SARS-CoV-2 detection
Authors: Liao Ruoheng
Published: October 2023

SARS-CoV-2 has been threatening the human’s health which caused numerous infections and deaths since its outbreak in 2020. Various techniques for its detection have been researched and published for early diagnosis of SARS-CoV-2 to reduce infections. Currently, most methods target on the RNA using the PCR. It is reliable to the laboratory and professional staffs, but is inconvenient and untouchable for citizens to do the rapid test these days. In this review, the recent progress of design for SARS-CoV-2 detection using the electrochemical immunosensors, a kind of biosensors, has been introduced. Unlike the other skills, it targets on the antigen of the virus and the diagnostic results can be obtained through the current or potential changes caused by the redox reaction of the immunocomplex. In addition, this review would focus on the selection of the bio-receptor, the assay format and the modification of the electrode. This paper will hopefully shed light on pathogen detection with electrochemical immunosensors.
Recent progress in diluted ferromagnetism for spintronic application
Authors: Fan Yan
Published: October 2023

With the continuous in-depth research of spintronics, the manufacture of high-performance magnetic random access memory devices and electronic devices that are more energy-efficient and generate less heat has received extensive attention. The traditional ferromagnet TbMnO3 is basically Tc at room temperature, which seriously limits its application. Since the discovery of diluted magnetic semiconductor materials at room temperature, such as AlNTiO2, ZnO, SnO2, etc., they have received increasing attention. Although these dopants can form ferromagnetism above-room temperature, the ferromagnetic mechanism and ferromagnetic properties are different. In this regard, we reviewed the current progress in the research on above room temperature dilute magnetic semiconductor materials; discussed the ferromagnetic mechanism of dilute magnetic semiconductors; summarized the problems and challenges, and advantages and disadvantages of different kinds of dilute magnetic semiconductor materials used in new memory devices; and prospected the application potential of spintronic devices.