bluuebunny/crossref_metadata_2025 huggingface dataset:
Machine learning based charge mobility prediction for organic semiconductors
Authors: Tan Tianhao , Wang Dong
Published: February 2023

Transfer integral is a crucial parameter that determines the charge mobility of organic semiconductors, and it is very sensitive to molecular packing motifs. The quantum chemical calculation of transfer integrals for all the molecular pairs in organic materials is usually an unaffordable task; fortunately, it can be accelerated by the data-driven machine learning method now. In this work, we develop machine learning models based on artificial neutral networks to predict transfer integrals accurately and efficiently for four typical organic semiconductor molecules: quadruple thiophene (QT), pentacene, rubrene, and dinaphtho[2,3-b:2′,3′-f]thieno[3,2-b]thiophene (DNTT). We test various forms of features and labels and evaluate the accuracy of different models. With the implementation of a data augmentation scheme, we have achieved a very high accuracy with the determination coefficient of 0.97 and mean absolute error of 4.5 meV for QT, and similar accuracy for the other three molecules. We apply these models to studying charge transport in organic crystals with dynamic disorders at 300 K and obtain the charge mobility and anisotropy in perfect agreement with the brutal force quantum chemical calculation. If more molecular packings representing the amorphous phase of organic solids are supplemented to the dataset, the current models can be refined to study charge transport in organic thin films with polymorphs and static disorders.
Electron transfer in strong-field three-body fragmentation of ArKr2 trimers
Authors: Lu Chenxu , Shi Menghang , Pan Shengzhe , Zhou Lianrong , Qiang Junjie , Lu Peifen , Zhang Wenbin , Wu Jian
Published: February 2023

We experimentally studied the three-body fragmentation dynamics of a noble gas cluster (ArKr2) upon its multiple ionization by an intense femtosecond laser pulse. The three-dimensional momentum vectors of correlated fragmental ions were measured in coincidence for each fragmentation event. A novel comet-like structure was observed in the Newton diagram of the quadruple-ionization-induced breakup channel of ArKr24+→ Ar+ + Kr+ + Kr2+. The concentrated head part of the structure mainly originates from the direct Coulomb explosion process, while the broader tail part of the structure stems from a three-body fragmentation process involving electron transfer between the distant Kr+ and Kr2+ ion fragments. Due to the field-driven electron transfer, the Coulomb repulsive force of the Kr2+ and Kr+ ions with respect to the Ar+ ion undergoes exchange, leading to changes in the ion emission geometry in the Newton plot. An energy sharing among the separating Kr2+ and Kr+ entities was observed. Our study indicates a promising approach for investigating the strong-field-driven intersystem electron transfer dynamics by using the Coulomb explosion imaging of an isosceles triangle van der Waals cluster system.
Hydrological changes caused by the construction of dams and reservoirs: The CECP analysis
Authors: Daniel de Carvalho Barreto Ikaro , Stosic Tatijana , Cezar Menezes Rômulo Simões , Alves da Silva Antonio Samuel , Rosso Osvaldo A. , Stosic Borko
Published: February 2023

We investigated the influence of the construction of cascade dams and reservoirs on the predictability and complexity of the streamflow of the São Francisco River, Brazil, by using complexity entropy causality plane (CECP) in its standard and weighted form. We analyzed daily streamflow time series recorded in three fluviometric stations: São Francisco (upstream of cascade dams), Juazeiro (downstream of Sobradinho dam), and Pão de Açúcar station (downstream of Sobradinho and Xingó dams). By comparing the values of CECP information quantifiers (permutation entropy and statistical complexity) for the periods before and after the construction of Sobradinho (1979) and Xingó (1994) dams, we found that the reservoirs’ operations changed the temporal variability of streamflow series toward the less predictable regime as indicated by higher entropy (lower complexity) values. Weighted CECP provides some finer details in the predictability of streamflow due to the inclusion of amplitude information in the probability distribution of ordinal patterns. The time evolution of streamflow predictability was analyzed by applying CECP in 2 year sliding windows that revealed the influence of the Paulo Alfonso complex (located between Sobradinho and Xingó dams), construction of which started in the 1950s and was identified through the increased streamflow entropy in the downstream Pão de Açúcar station. The other streamflow alteration unrelated to the construction of the two largest dams was identified in the upstream unimpacted São Francisco station, as an increase in the entropy around 1960s, indicating that some natural factors could also play a role in the decreased predictability of streamflow dynamics.
Theoretical analysis on macro-mesoscopic gas flow performances in gas dynamic bearing with three pads
Authors: Zhang Chuanbing , Dang Yongjie , Wang Yongliang , Ao Hongrui , Jiang Hongyuan
Published: February 2023

The Reynolds equation based on the continuum medium assumption fails to meet the accuracy requirements of numerical simulation for mesoscale gas flow. In this research, the gas flow performances and bearing performances of gas dynamic bearing with three pads (GDBTPs) are theoretically analyzed from macroscopic to mesoscopic perspectives. A modified lattice Boltzmann equation is exploited considering the wall effect ψ(y/λ) with gas density ratio ρ/ρref, and the dimensionless gas flow velocity is analyzed for smooth, square cavity, half-sine asperity, triangular asperity, and a combination of surface morphologies. A modified Reynolds equation considering the gas compressibility and gas rarefaction effect is developed to study the static bearing performances of GDBTPs. Results show that the relative roughness Δh and asperities geometries are key factors to affect the mesoscale gas flow characteristics. The load-carrying capacity of GDBTPs increases with the growth of length-to-diameter ratio L/D, rotational speed ω, and eccentricity ratio ɛ and decreases with the increase of gas film thickness hg.
Study on surface thermal oxidation of silicon carbide irradiated by pulsed laser using reactive molecular dynamics
Authors: An Haojie , Wang Jinshi , Fang Fengzhou
Published: February 2023

Pulsed lasers are a powerful tool for fabricating silicon carbide (SiC) that has a hard and brittle nature, but oxidation is usually unavoidable. This study presents an exploration of the oxidation mechanism of 4H–SiC in oxygen and water under different temperatures via reactive force field molecular dynamics. Single pulse irradiation experiments were conducted to study the oxygen content of the laser-affected zone through energy dispersive x-ray spectrometry. The results show that laser-induced thermal oxidation is a complex dynamic process with the interactions among H, C, O, and Si atoms. The oxidation zone includes an oxide layer, a graphite layer, and a C-rich layer. With an increase in oxygen concentration, the amorphous oxide layer changes from silicon oxide to silicon dioxide. In addition, the formation of carbon clusters at the interface between SiOx and C-rich layers promotes the desorption of the oxide layer. The mechanism revealed in this study provides theoretical guidance for high-quality processing of 4H–SiC at atomic and close-to-atomic scales.
Modified nonlinear Schrödinger equation for gravity waves with the influence of wind, currents, and dissipation
Authors: Liao Bo , Dong Guohai , Ma Yuxiang , Ma Xiaozhou , Perlin Marc
Published: February 2023

A new modified nonlinear Schrödinger (MNLS) equation is derived for gravity waves with the presence of wind, dissipation, and shear currents in finite water depth. Horizontal surface currents are assumed stationary and slowly varying spatially. Using the MNLS equation, the modulational instability (MI) of deep-water gravity wave trains affected by wind and dissipation is considered. It was demonstrated that the modulational perturbation of waves is unstable or becomes unstable after several wave periods, whereas the dissipation will suppress the MI. Then, a new theoretical formula for predicting the maximum amplitude is derived to take into account the effect of vorticity, dissipation, and wind. The effect of dissipation becomes significant in strong currents, while wind can increase the height amplification. Furthermore, an explicit analytical Peregrine breather (PB) solution that considers the effect of vorticity, dissipation, and wind is presented. Opposing currents and winds will increase the height of PB. However, following currents and dissipation have opposite effects. The effects of the shear current, dissipation, and wind on nondimensional maximum amplitudes during the evolution of the Akhmediev breather are similar to PB solution.
On solutions of a class of neutral evolution equations with discrete nonlocal conditions
Authors: Cao Nan , Fu Xianlong
Published: February 2023

This paper studies the existence, regularity, and asymptotic properties of solutions for a class of neutral differential evolution equations with nonlocal initial conditions on an infinite interval. The existence and regularity of solutions of the considered equation are, respectively, investigated by the theory of fractional power operators and fixed point theorems under some assumptions for nonlinear functions. Then, under suitable conditions, asymptotic properties, including stability and existence of global attracting sets and quasi-invariant sets of mild solutions, are also discussed in the context. Finally, an example is presented to illustrate the applications of the obtained abstract results.
Multi-timescale operations of nuclear-renewable hybrid energy systems for reserve and thermal product provision
Authors: Rahman Jubeyer , Zhang Jie
Published: February 2023

In this paper, an optimal operation strategy of a nuclear-renewable hybrid energy system (N-R HES), in conjunction with a district heating network, is developed within a comprehensive multi-timescale electricity market framework. The grid-connected N-R HES is simulated to explore the capabilities and benefits of N-R HES of providing energy products, different reserve products, and thermal products. An N-R HES optimization and control strategy is formulated to exploit the benefits from the hybrid energy system in terms of both energy and ancillary services. A case study is performed on the customized NREL-118 bus test system with high renewable penetrations, based on a multi-timescale (i.e., three-cycle) production cost model. Both day-ahead and real-time market clearing prices are determined from the market model simulation. The results show that the N-R HES can contribute to the reserve requirements and also meet the thermal load, thereby increasing the economic efficiency of N-R HES (with increased revenue ranging from 1.55% to 35.25% at certain cases) compared to the baseline case where reserve and thermal power exports are not optimized.
Enhancing cation storage performance of layered double hydroxides by increasing the interlayer distance
Authors: Ge Chengxuan , Mao Chenghui , Zhao Jie , Li Guochang , Yang Lijun , Wu Qiang , Wang Xizhang , Hu Zheng
Published: February 2023

Layered double hydroxides (LDH) can be transformed from alkaline supercapacitor material into metal-cation storage cathode working in neutral electrolytes through electrochemical activation. However, the rate performance for storing large cations is restricted by the small interlayer distance of LDH. Herein, the interlayer distance of NiCo-LDH is expanded by replacing the interlayer nitrate ions with 1,4-benzenedicarboxylic anions (BDC), leading to the enhanced rate performance for storing large cations (Na+, Mg2+, and Zn2+), whereas almost the unchanged one for storing small-radius Li+ ions. The improved rate performance of the BDC-pillared LDH (LDH-BDC) stems from the reduced charge-transfer and Warburg resistances during charge/discharge due to the increased interlayer distance, as revealed by in situ electrochemical impedance spectra. The asymmetric zinc-ion supercapacitor assembled with LDH-BDC and activated carbon presents high energy density and cycling stability. This study demonstrates an effective strategy to improve the large cation storage performance of LDH electrodes by increasing the interlayer distance.
Fick diffusion coefficients probed by the shadowgraph method considering confinement and advection
Authors: Schmidt P. S. , Wu W. , Rausch M. H. , Fröba A. P.
Published: February 2023

The present work contributes to the development of the shadowgraph method for its routine application for an accurate determination of the Fick diffusion coefficient D11 of binary fluid mixtures. In this context, measurement and data evaluation strategies for thermodiffusion experiments where confinement and advection are potentially present are elaborated by studying two binary liquid mixtures with positive and negative Soret coefficients, i.e., 1,2,3,4-tetrahydronaphthalene/n-dodecane and acetone/cyclohexane. For obtaining accurate D11 data, the dynamics of non-equilibrium fluctuations in concentration is analyzed considering recent theory by data evaluation procedures that are demonstrated to be suitable for different experimental configurations.
Secreted metabolome of porcine blastocysts encapsulated within
Authors: Walsh Sophie C. , Miles Jeremy R. , Broeckling Corey D. , Rempel Lea A. , Wright-Johnson Elane C. , Pannier Angela K.
Published: February 2023

Context The exact mechanisms regulating the initiation of porcine conceptus elongation are not known due to the complexity of the uterine environment. Aims To identify contributing factors for initiation of conceptus elongation in vitro, this study evaluated differential metabolite abundance within media following culture of blastocysts within unmodified alginate (ALG) or Arg-Gly-Asp (RGD)-modified alginate hydrogel culture systems. Methods Blastocysts were harvested from pregnant gilts, encapsulated within ALG or RGD or as non-encapsulated control blastocysts (CONT), and cultured. At the termination of 96 h culture, media were separated into blastocyst media groups: non-encapsulated control blastocysts (CONT); ALG and RGD blastocysts with no morphological change (ALG− and RGD−); ALG and RGD blastocysts with morphological changes (ALG+ and RGD+) and evaluated for non-targeted metabolomic profiling by liquid chromatography (LC)–mass spectrometry (MS) techniques and gas chromatography–(GC–MS). Key results Analysis of variance identified 280 (LC–MS) and 1 (GC–MS) compounds that differed (P < 0.05), of which 134 (LC–MS) and 1 (GC–MS) were annotated. Metabolites abundance between ALG+ vs ALG−, RGD+ vs RGD−, and RGD+ vs ALG+ were further investigated to identify potential differences in metabolic processes during the initiation of elongation. Conclusions This study identified changes in phospholipid, glycosphingolipid, lipid signalling, and amino acid metabolic processes as potential RGD-independent mechanisms of elongation and identified changes in lysophosphatidylcholine and sphingolipid secretions during RGD-mediated elongation. Implications These results illustrate changes in phospholipid and sphingolipid metabolic processes and secretions may act as mediators of the RGD-integrin adhesion that promotes porcine conceptus elongation.
Cloud transition across the daily cycle illuminates model responses of trade cumuli to warming
Authors: Vial Jessica , Albright Anna Lea , Vogel Raphaela , Musat Ionela , Bony Sandrine
Published: February 2023

The response of trade cumulus clouds to warming remains a major source of uncertainty for climate sensitivity. Recent studies have highlighted the role of the cloud–convection coupling in explaining this spread in future warming estimates. Here, using observations from an instrumented site and an airborne field campaign, together with high-frequency climate model outputs, we show that i) over the course of the daily cycle, a cloud transition is observed from deeper cumuli during nighttime to shallower cumuli during daytime, ii) the cloud evolution that models predict from night to day reflects the strength of cloud sensitivity to convective mass flux and exhibits many similarities with the cloud evolution they predict under global warming, and iii) those models that simulate a realistic cloud transition over the daily cycle tend to predict weak trade cumulus feedback. Our findings thus show that the daily cycle is a particularly relevant testbed, amenable to process studies and anchored by observations, to assess and improve the model representation of cloud–convection coupling and thus make climate projections more reliable.
Drying of tundra landscapes will limit subsidence-induced acceleration of permafrost thaw
Authors: Painter Scott L. , Coon Ethan T. , Khattak Ahmad Jan , Jastrow Julie D.
Published: February 2023

We used a model for permafrost hydrology informed by detailed measurements of soil ice content to better understand the potential risk of abrupt permafrost thaw triggered by melting ground ice, a key open question associated with permafrost response to a warming Arctic. Our spatially resolved simulations of a well-characterized site in polygonal tundra near Utqiaġvik, Alaska, agree well with multiple types of observations in the current climate. Projections indicate 63 cm of bulk subsidence from 2006 to 2100 in the strong-warming Representative Concentration Pathway 8.5 climate. Permafrost thaw as measured by the increase in active layer thickness (ALT)—the thickness of the soil layer that thaws each summer—is accelerated by subsidence, but the effect is relatively small. The ALT increases from the current-day value of approximately 50 cm to approximately 180 cm by 2100 when subsidence is included compared to about 160 cm when it is neglected. In these simulations, previously identified positive feedbacks between subsidence and thaw are self-limiting on decadal time frames because landscape runoff and increasing evapotranspiration result in drier tundra with weaker surface/atmosphere coupling. These results for a tundra site that is representative of large swathes of the Alaska North Slope suggest that subsidence is unlikely to lead to abrupt thaw over large areas. However, subsidence does have significant effects on the hydrology of polygonal tundra. Specifically, subsidence increases landscape runoff, which helps maintain streamflow in the face of increased evapotranspiration but also causes drier tundra conditions that could have deleterious effects on sensitive Arctic wetland ecosystems.
Evolutionary analysis of a complete chicken genome
Authors: Huang Zhen , Xu Zaoxu , Bai Hao , Huang Yongji , Kang Na , Ding Xiaoting , Liu Jing , Luo Haoran , Yang Chentao , Chen Wanjun , Guo Qixin , Xue Lingzhan , Zhang Xueping , Xu Li , Chen Meiling , Fu Honggao , Chen Youling , Yue Zhicao , Fukagawa Tatsuo , Liu Shanlin , Chang Guobin , Xu Luohao
Published: February 2023

Microchromosomes are prevalent in nonmammalian vertebrates [P. D. Waters
et al.
,
Proc. Natl. Acad. Sci. U.S.A.
118
(2021)], but a few of them are missing in bird genome assemblies. Here, we present a new chicken reference genome containing all autosomes, a Z and a W chromosome, with all gaps closed except for the W. We identified ten small microchromosomes (termed dot chromosomes) with distinct sequence and epigenetic features, among which six were newly assembled. Those dot chromosomes exhibit extremely high GC content and a high level of DNA methylation and are enriched for housekeeping genes. The pericentromeric heterochromatin of dot chromosomes is disproportionately large and continues to expand with the proliferation of satellite DNA and testis-expressed genes. Our analyses revealed that the 41-bp CNM repeat frequently forms higher-order repeats (HORs) at the centromeres of acrocentric chromosomes. The centromere core regions where the kinetochore attaches often encompass telomeric sequence (TTAGGG)n, and in a one of the dot chromosomes, the centromere core recruits an endogenous retrovirus (ERV). We further demonstrate that the W chromosome shares some common features with dot chromosomes, having large arrays of hypermethylated tandem repeats. Finally, using the complete chicken chromosome models, we reconstructed a fine picture of chordate karyotype evolution, revealing frequent chromosomal fusions before and after vertebrate whole-genome duplications. Our sequence and epigenetic characterization of chicken chromosomes shed insights into the understanding of vertebrate genome evolution and chromosome biology.
Bayes factor functions for reporting outcomes of hypothesis tests
Authors: Johnson Valen E. , Pramanik Sandipan , Shudde Rachael
Published: February 2023

Bayes factors represent a useful alternative toP-values for reporting outcomes of hypothesis tests by providing direct measures of the relative support that data provide to competing hypotheses. Unfortunately, the competing hypotheses have to be specified, and the calculation of Bayes factors in high-dimensional settings can be difficult. To address these problems, we define Bayes factor functions (BFFs) directly from common test statistics. BFFs depend on a single noncentrality parameter that can be expressed as a function of standardized effects, and plots of BFFs versus effect size provide informative summaries of hypothesis tests that can be easily aggregated across studies. Such summaries eliminate the need for arbitraryP-value thresholds to define “statistical significance.” Because BFFs are defined using nonlocal alternative prior densities, they provide more rapid accumulation of evidence in favor of true null hypotheses without sacrificing efficiency in supporting true alternative hypotheses. BFFs can be expressed in closed form and can be computed easily fromz,t,χ2, andFstatistics.
Evolution of bitter receptor genes and ontogenetic dietary shift in a frog
Authors: Hao Xiangyu , Jiao Hengwu , Zou Dahu , Li Qiyang , Yuan Xiangqun , Liao Wenbo , Jiang Peihua , Zhao Huabin
Published: February 2023

Vertebrate Tas2r taste receptors detect bitter compounds that are potentially poisonous. Previous studies found substantial variation in the number of
Tas2r
genes across vertebrates, with some frog species carrying the largest number. Peculiar among vertebrates, frogs undergo metamorphosis, often associated with a dietary shift between tadpoles and adults. A possible explanation for the large size of frog
Tas2r
families could be that distinct sets of
Tas2r
genes are required for tadpoles and adults, suggesting differential expression of
Tas2r
genes between tadpoles and adults. To test this hypothesis, we first examined 20 amphibian genomes and found that amphibians generally possess more
Tas2r
genes than do other vertebrate clades. We next focused on the American bullfrog (
Lithobates catesbeianus
) to examine the expression of its
Tas2r
genes in herbivorous tadpoles and insectivorous adult frogs. We report that close to one fifth of its 180
Tas2r
genes are differentially expressed (22 genes enriched in adults and 11 in tadpoles). Tuning properties were determined for a subset of differentially expressed genes by a cell-based functional assay, with the adult-enriched
Tas2r
gene set covering a larger range of ligands compared to the tadpole-enriched subset. These results suggest a role of
Tas2r
genes in the ontogenetic dietary shift of frogs and potentially initiate a new avenue of ontogenetic analysis of diet-related genes in the animal kingdom.
Assessing interactional competence
Authors: Lam Daniel M. K. , Galaczi Evelina , Nakatsuhara Fumiyo , May Lyn
Published: February 2023

This paper is positioned at the interface of second/foreign language (L2) assessment and Conversation Analysis-Second Language Acquisition (CA-SLA). It explores challenges of ratability in assessing interactional competence (IC) from three dimensions: an overview of the conceptual and terminological convergence/divergence in the CA-SLA and L2 assessment literature, a micro-analytic Conversation Analysis of test-taker interactions, and the operationalisation of IC construct features in rating scales across assessment contexts. It draws insights from these dimensions into a discussion of the nature of the IC construct and the challenges of IC ratability, and concludes with suggestions on ways in which insights from CA research can contribute to addressing these issues.
Assessing interactional competence in secondary schools
Authors: Barth-Weingarten Dagmar , Freitag-Hild Britta
Published: February 2023

Interactional competence (IC) is a crucial component of teaching and assessing speaking in second/foreign languages in general. However, SLA research based on Conversation Analysis (CA) has shown that IC is a complex phenomenon, and while a qualitative approach to assessing IC is needed, it is time-consuming. At the same time, assessment in the foreign-language classroom has to be both manageable for teachers and it should provide learners with reliable and supportive feedback about their specific strengths and weaknesses. This paper offers some solutions for these issues. It will draw on previous proposals in CA to employ generic organizations of practice as a way to manage the complexity of the IC concept. Second, it will show how one of these organizations – action accomplishment – can be operationalized for assessment purposes in public-school classrooms. This includes a discussion of the CEFR Companion’s approach to ‘action’. Finally, it will present a possible rubric for action accomplishment. Our approach to assessing will be illustrated through the analysis of a sample role play with two foreign-language learners from a corpus of 14 2–4 minute role plays, recorded with beginning-to-intermediary-level learners of English as a foreign language in two German secondary schools.
Fan translation and film criticism in China
Authors: Guo Ting
Published: February 2023

Film criticism in China has been changing due to a growing fan community and their active participation in online
film reviewing. While social media has democratized who can write reviews, there remain distinct hierarchies of professional and
amateur reviewers. Drawing upon Henry Jenkins’ (2006b) concept of “knowledge community”
and Alex Bruns’ “produsage” model (2008), this article will explore how Chinese film
fans use translation to shape the online reception of a film and participate in the debates over film criticism in the digital
age. Through a case study of the Chinese translations of an English review of The Wandering Earth (2019), a
Chinese sci-fi blockbuster, it argues that translation, as an alternative form of self-expression, constitutes both an
important cinematic experience for fans and a response by grassroots consumers to the existing reviewing system influenced by
media capital.
Bidirectional vortex stabilization of a supersonic inductively coupled plasma torch
Authors: Pascale A , Lafleur T , Corr C S
Published: February 2023

Radio-frequency (RF) inductively coupled plasma (ICP) torches using a supersonic nozzle have many industrial materials processing applications and have also been proposed as novel electrothermal plasma thrusters for space propulsion. The gas injection method in plasma torches plays an important role in both gas heating dynamics and overall discharge stabilization. Here, we investigate reverse vortex gas injection into a supersonic ICP torch for RF powers up to 1 kW, argon mass flow rates between 15 and 180 mg s−1, and plasma torch pressures from ∼270 Pa to ∼50 kPa. In this configuration, gas is injected tangentially just upstream of the nozzle inlet. This produces a bidirectional vortex flow field where gas first spirals upwards along the outer edge of the plasma torch walls, before then reversing direction at the torch end and spiralling back down through the central plasma region towards the nozzle exit. Results are compared to a more conventional forward vortex configuration where gas is instead injected tangentially from the upstream end of the torch, and which forms a unidirectional vortex that spirals towards the downstream nozzle. While performance is similar for gas flows below 80 mg s−1, we show that at higher mass flow rates both the effective torch stagnation temperature and thermal efficiency can be increased by almost 50% with reverse vortex injection. Considering that the measured RF antenna-plasma power transfer efficiency is similar for both configurations, this enhancement occurs because of the unique bidirectional vortex flow field which leads to reduced gas-wall heat losses and consequently an increased enthalpy flow leaving the torch.
Ag2SO4-Ag2S transformation in SnO2-based nanofibers for high selectivity and response H2S sensors
Authors: Wang Weiming , Li Ji , Hu Bo , Zhou Shiqiang , Cai Yong , Zhang Ming
Published: February 2023

Tin-based gas sensors have been developed for many years owing to their advantages of low price, high response and stability. However, selectivity remains a significant issue. Herein, Ag-SnO2 nanofibers are synthesized using AgCl as the doping reagent. The 3%Ag-SnO2 nanofibers sensors show a high response of 68 toward 1 ppm H2S at 90 °C. Besides, the sensor with 3% AgCl possesses the shortest response time about 136 s at 150 °C which is only 30% value of the sensor without AgCl doping. It is also demonstrated that the nanofibers show a high selectivity towards H2S. According to the ex situ x-ray photoelectron spectrum and x-ray diffraction results, AgCl was transferred to Ag2S after Ag-SnO2 was exposed to H2S, and reversible transformation between Ag2SO4 and Ag2S was the main mechanism for H2S detection. Compared with pure SnO2 nanofiber sensors, the presence of Ag2S with high conductivity greatly affects the resistance to H2S, resulting in high selectivity and response. This mechanism differs from that of the transformation between Ag2O and Ag2SO4. This study may provide a new strategy for the design and investigation of sensors with high selectivity.
Rare-earth orthovanadate nanoparticles trigger Ca2+-dependent eryptosis
Authors: Yefimova Svetlana , Onishchenko Anatolii , Klochkov Vladimir , Myasoedov Valeriy , Kot Yurii , Tryfonyuk Liliya , Knigavko Oleksandr , Maksimchuk Pavel , Kökbaş Umut , Kalashnyk-Vakulenko Yuliia , Arkatov Andrii , Khanzhyn Vladyslav , Prokopyuk Volodymyr , Vyshnytska Iryna , Tkachenko Anton
Published: February 2023

Introduction. Rare-earth orthovanadate nanoparticles (ReVO4:Eu3+, Re = Gd, Y or La) are promising agents for photodynamic therapy of cancer due to their modifiable redox properties. However, their toxicity limits their application. Objective. The aim of this research was to elucidate pro-eryptotic effects of GdVO4:Eu3+ and LaVO4:Eu3+ nanoparticles with identification of underlying mechanisms of eryptosis induction and to determine their pharmacological potential in eryptosis-related diseases. Methods. Blood samples (n = 9) were incubated for 24 h with 0–10–20–40–80 mg l−1 GdVO4:Eu3+ or LaVO4:Eu3+ nanoparticles, washed and used to prepare erythrocyte suspensions to analyze the cell membrane scrambling (annexin-V-FITC staining), cell shrinkage (forward scatter signaling), reactive oxygen species (ROS) generation through 2′,7′-dichlorodihydrofluorescein diacetate (H2DCFDA) staining and intracellular Ca2+ levels via FLUO4 AM staining by flow cytometry. Internalization of europium-enabled luminescent GdVO4:Eu3+ and LaVO4:Eu3+ nanoparticles was assessed by confocal laser scanning microscopy. Results. Both nanoparticles triggered eryptosis at concentrations of 80 mg l−1. ROS-mediated mechanisms were not involved in rare-earth orthovanadate nanoparticles-induced eryptosis. Elevated cytosolic Ca2+ concentrations were revealed even at subtoxic concentrations of nanoparticles. LaVO4:Eu3+ nanoparticles increased intracellular calcium levels in a more pronounced way compared with GdVO4:Eu3+ nanoparticles. Our data disclose that the small-sized (15 nm) GdVO4:Eu3+ nanoparticles were internalized after a 24 h incubation, while the large-sized (∼30 nm) LaVO4:Eu3+ nanoparticles were localized preferentially around erythrocytes. Conclusions. Both internalized GdVO4:Eu3+ and non-internalized LaVO4:Eu3+ nanoparticles (80 mg l−1) promote eryptosis of erythrocytes after a 24 h exposure in vitro via Ca2+ signaling without involvement of oxidative stress. Eryptosis is a promising model for assessing nanotoxicity.
Derivation of the fractional porous medium equation from a microscopic dynamics
Authors: Cardoso Pedro , Paula Renato de , Gonçalves Patrícia
Published: February 2023

In this article we derive the fractional porous medium equation for any power of the fractional Laplacian as the hydrodynamic limit of a microscopic dynamics of random particles with long range interactions, but the jump rate highly depends on the occupancy near the sites where the interactions take place.
Stereotactic body radiation therapy (SBRT) following Yttrium-90 (90Y) selective internal radiation therapy (SIRT): a feasibility planning study using 90Y delivered dose
Authors: Mee Stephen F , Polan Daniel F , Dewaraja Yuni K , Cuneo Kyle C , Gemmete Joseph J , Evans Joseph R , Lawrence Theodore S , Dow Janell S , Mikell Justin K
Published: February 2023

Objective. 90Y selective internal radiation therapy (SIRT) treatment of hepatocellular carcinoma (HCC) can potentially underdose lesions, as identified on post-therapy PET/CT imaging. This study introduces a methodology and explores the feasibility for selectively treating SIRT-underdosed HCC lesions, or lesion subvolumes, with stereotactic body radiation therapy (SBRT) following post-SIRT dosimetry. Approach. We retrospectively analyzed post-treatment PET/CT images of 20 HCC patients after 90Y SIRT. Predicted tumor response from SIRT was quantified based on personalized post-therapy dosimetry and corresponding response models. Predicted non-responding tumor regions were then targeted with a hypothetical SBRT boost plan using a framework for selecting eligible tumors and tumor subregions. SBRT boost plans were compared to SBRT plans targeting all tumors irrespective of SIRT dose with the same prescription and organ-at-risk (OAR) objectives. The potential benefit of SIRT followed by a SBRT was evaluated based on OAR dose and predicted toxicity compared to the independent SBRT treatment. Main results. Following SIRT, 14/20 patients had at least one predicted non-responding tumor considered eligible for a SBRT boost. When comparing SBRT plans, 10/14 (71%) SBRTboost and 12/20 (60%) SBRTalone plans were within OAR dose constraints. For three patients, SBRTboost plans were within OAR constraints while SBRTalone plans were not. Across the 14 eligible patients, SBRTboost plans had significantly less dose to the healthy liver (decrease in mean dose was on average ± standard deviation, 2.09 Gy ± 1.99 Gy, ) and reduced the overall targeted PTV volume (39% ± 21%) compared with SBRTalone. Significance. A clinical methodology for treating HCC using a synergized SIRT and SBRT approach is presented, demonstrating that it could reduce normal tissue toxicity risk in a majority of our retrospectively evaluated cases. Selectively targeting SIRT underdosed HCC lesions, or lesion subvolumes, with SBRT could improve tumor control and patient outcomes post-SIRT and allow SIRT to function as a target debulking tool for cases when SBRT is not independently feasible.
Reverberant magnetic resonance elastographic imaging using a single mechanical driver
Authors: Kabir Irteza Enan , Caban-Rivera Diego A , Ormachea Juvenal , Parker Kevin J , Johnson Curtis L , Doyley Marvin M
Published: February 2023

Reverberant elastography provides fast and robust estimates of shear modulus; however, its reliance on multiple mechanical drivers hampers clinical utility. In this work, we hypothesize that for constrained organs such as the brain, reverberant elastography can produce accurate magnetic resonance elastograms with a single mechanical driver. To corroborate this hypothesis, we performed studies on healthy volunteers (n= 3); and a constrained calibrated brain phantom containing spherical inclusions with diameters ranging from 4–18 mm. In both studies (i.e. phantom and clinical), imaging was performed at frequencies of 50 and 70 Hz. We used the accuracy and contrast-to-noise ratio performance metrics to evaluate reverberant elastograms relative to those computed using the established subzone inversion method. Errors incurred in reverberant elastograms varied from 1.3% to 16.6% when imaging at 50 Hz and 3.1% and 16.8% when imaging at 70 Hz. In contrast, errors incurred in subzone elastograms ranged from 1.9% to 13% at 50 Hz and 3.6% to 14.9% at 70 Hz. The contrast-to-noise ratio of reverberant elastograms ranged from 63.1 to 73 dB compared to 65 to 66.2 dB for subzone elastograms. The average global brain shear modulus estimated from reverberant and subzone elastograms was 2.36 ± 0.07 kPa and 2.38 ± 0.11 kPa, respectively, when imaging at 50 Hz and 2.70 ± 0.20 kPa and 2.89 ± 0.60 kPa respectively, when imaging at 70 Hz. The results of this investigation demonstrate that reverberant elastography can produce accurate, high-quality elastograms of the brain with a single mechanical driver.
Electrical characterization of Au/Ni Schottky contacts on GaN synthesized using electrodeposition
Authors: Ali Abdulraoof I , Omotoso Ezekiel , Nel Jacqueline M , Meyer Walter E
Published: February 2023

Gallium nitride thin films have attracted attention due to their prospects in semiconductor devices and technology. In this study, we investigate the electrical properties and perform deep level transient spectroscopy (DLTS) on Au/Ni Schottky diodes fabricated on gallium nitride thin films that were synthesized by electrodeposition on a Si(111) substrate from a solution containing gallium nitrate (Ga(NO3)3) and ammonium nitrate (NH4(NO3)) using current densities of 1 and 3 mA cm−2. The thin films were found to crystallize in the wurtzite hexagonal structure with crystallite sizes of approximately 20 nm. Scanning electron microscopy and atomic force microscopy were used to characterize the microstructure of the GaN thin films. The Schottky diodes had good rectifying properties, corresponding to n-type material. The diodes had a IV barrier heights of 0.76 eV and 0.60 eV; a CV barrier heights of 0.92 eV and 0.71 eV; and carrier densities of 1.2 × 1016 cm−3, and 1.7 × 1016 cm−3, for material deposited under 1 mA cm−2 and 3 mA cm−2, respectively. By fitting a model taking both thermionic emission as well as conduction through the polycrystalline bulk into account, it was found that the grain boundary potential of the GaN crystallites was 0.29 V. The DLTS study revealed different dominant DLTS peaks in each as-grown sample with activation energies of 0.49 and 0.48 eV with capture cross-sections of 9 × 10−15 and 4 × 10−16 cm2, in the material grown under 1 mA cm−2 and 3 mA cm−2 current density, respectively. The defects seem to be similar to defects found in heavily damaged GaN and GaN grown on highly mismatched or cracked substrates, and are probably not simple defects.
Thickness dependence of resistive switching characteristics of the sol–gel processed Y2O3 RRAM devices
Authors: Kim Kyoungdu , Kim Hae-In , Lee Taehun , Lee Won-Yong , Bae Jin-Hyuk , Kang In Man , Lee Sin-Hyung , Kim Kwangeun , Jang Jaewon
Published: February 2023

In this study, yttrium oxide (Y2O3)-based resistive random-access memory (RRAM) devices were fabricated using the sol–gel method. The fabricated Y2O3 RRAM devices exhibited conventional bipolar RRAM device characteristics and did not require a forming process. The Y2O3 film thickness was controlled by varying the liquid-phase precursor concentration. As the concentration increased, thicker Y2O3 films were formed. In addition, the concentration of oxygen vacancies increased. The RRAM device properties were not observed for thin Y2O3 films, which had the lowest oxygen vacancy concentration. Moreover, RRAM devices, which consisted of the thickest Y2O3 films with the largest oxygen vacancy concentration, showed poor non-volatile properties. The optimized Y2O3-based RRAM devices with a thickness of 37 nm showed conventional bipolar RRAM device characteristics, which did not require an initial forming process. The fabricated RRAM devices showed a high resistance state to low resistance state ratio of over 104, less than +1.5 V of SET voltage, and −15.0 V of RESET voltage. The RRAM devices also showed promising non-volatile memory properties, without significant degradation after 103 s retention and 102 cycle endurance tests.
Orbital-free approach for large-scale electrostatic simulations of quantum nanoelectronics devices
Authors: Svejstrup Waldemar , Maiani Andrea , Van Hoogdalem Kevin , Flensberg Karsten
Published: February 2023

The route to reliable quantum nanoelectronic devices hinges on precise control of the electrostatic environment. For this reason, accurate methods for electrostatic simulations are essential in the design process. The most widespread methods for this purpose are the Thomas-Fermi (TF) approximation, which provides quick approximate results, and the Schrödinger-Poisson (SP) method, which better takes into account quantum mechanical effects. The mentioned methods suffer from relevant shortcomings: the TF method fails to take into account quantum confinement effects that are crucial in heterostructures, while the SP method suffers severe scalability problems. This paper outlines the application of an orbital-free approach inspired by density functional theory. By introducing gradient terms in the kinetic energy functional, our proposed method incorporates corrections to the electronic density due to quantum confinement while it preserves the scalability of a theory that can be expressed as a functional minimization problem. This method offers a new approach to addressing large-scale electrostatic simulations of quantum nanoelectronic devices.
A novel image encryption scheme based on Logistic cosine cascade maps
Authors: Ma Wenzheng , Yu Tingting , Wang Zhuang , Li Xianli
Published: February 2023

A two-dimensional Logistic cosine cascade map (2D-LCCM) and a three-dimensional Logistic cosine cascade map (3D-LCCM) are proposed based on a logistic map and infinite collapse cascade model. We analyze the chaotic properties of 2D-LCCM and 3D-LCCM, such as Lyapunov exponential spectrum, attractors, and complexity, which show that the 2D-LCCM and 3D-LCCM are hyperchaotic and have large chaotic regions. We also proposed a DNA encryption algorithm based on double chaotic maps. 2D-LCCM was used for scrambling and 3D-LCCM for diffusion. First, the sequence no-duplicate zigzag transform (SNZT) is used to scramble the plaintext. Z-transform is applied to the permutation sequence to make the sequence more random. Then a repetition-free permutation associated with the plaintext is applied to each block, and the pixel position is effectively scrambled. Finally, DNA diffusion is performed using DNA coding to diffuse pixel values. Simulation results show that the algorithm has a good encryption effect, high efficiency and anti-interference performance. Therefore, the proposed new hyperchaotic map and DNA encryption algorithm can be effectively applied to the process of image encryption.
Enhancing the spectrum of timed Dicke state via squeezing a cavity mode
Authors: Zhou Chunxiao , Cao Binfang , Yang Guang , Shang Xue
Published: February 2023

In this work we present transmission spectra of a two atom timed Dicke state in an optical cavity which is subject to the parametric driving. In the proposed scheme, the parametric driving can squeeze the cavity mode and exponentially enhance the atom-cavity interaction. We show that the interaction between the timed Dicke state and squeezed cavity mode induces the quantum interference and normal mode splitting on the transmission spectra. In addition, we demonstrated that the spectra intensities are exponential quadratic enhanced under the parametric driving, which may provide a feasible scheme for sensitivity enhancement of the single photon measurement.
First-principles study of the strain effect with half-metallic ferromagnetism in Cd
1−x

V

x

Te alloys: supercell approaches
Authors: Essebbahi L , Goumrhar F , Drissi L B , Es-Semyhy M , Ahl Laamara R
Published: February 2023

In this work, we study the effect of vanadium (V) dopantson the structural, electronic, and magnetic properties of the CdTe alloys using density functional theory (DFT). The calculations are performed as a function of the concentration of V in the host CdTe semiconductor using a 2 × 2 × 1 tetragonal supercell and a 2 × 2 × 2 cubic supercell. The lattice constants and bulk modulus of Cd
1−x

V

x

Te alloys are determined. The analysis of the density of states shows that the Cd0.75 V0.25Te alloys in both supercells present a total polarization of 100% at the Fermi level, which confirms a stable half-metallic ferromagnetism phase in these materials, in contrast to the Cd
0.9375
V
0.0625
Te and Cd
0.875
V
0.125
Te alloys, which have a polarizability that does not reach 100%. In addition, the electronic band structures are used to estimate the s(p) − d exchange constants mainly resulting from the p − d hybridization between V- 3d and Te-p. Furthermore, the local magnetic moment of V of its free space charge value decreases, leading to the appearance of a small magnetic moment on the Cd and Te sites. Besides, the magnetic stability at different doping concentrations in the ferromagnetic (FM) and anti-ferromagnetic (AFM) states is examined, where the total energy of the systems is considered as a stability criterion. The robustness of the half-metallicity and the curie temperatures under the strain effect are also investigated. Finally, we rely on the binding energy to evaluate the energetic stability of the vanadium in the intrinsic compound CdTe under external deformations.
The

sl2(R)

coalgebra symmetry and the superintegrable discrete-time systems
Authors: Gubbiotti Giorgio , Latini Danilo
Published: February 2023

In this paper, we classify all the variational discrete-time systems in quasi-standard form in N degrees of freedom admitting coalgebra symmetry with respect to the generic realisation of the Lie–Poisson algebra

sl

2

(
R
)

. This approach naturally yields several quasi-maximally and maximally superintegrable discrete-time systems, both known and new. We conjecture that this exhausts the (super)integrable cases associated with this algebraic construction.
Non-perturbative production of fermionic dark matter from fast preheating
Authors: Klaric J. , Shkerin A. , Vacalis G.
Published: February 2023

We investigate non-perturbative production of fermionic dark matter in the early universe.
We study analytically the gravitational production mechanism accompanied by the coupling of
fermions to the background inflaton field. The latter leads to the variation of effective fermion
mass during preheating and makes the resulting spectrum and abundance sensitive to its parameters.
Assuming fast preheating that completes in less than the inflationary Hubble time and no
oscillations of the inflaton field after inflation, we find an abundant production of particles
with energies ranging from the inflationary Hubble rate to the inverse duration of preheating.
The produced fermions can account for all observed dark matter in a broad range of parameters. As
an application of our analysis, we study non-perturbative production of fermionic dark matter in
the model of Palatini Higgs inflation.