bluuebunny/crossref_metadata_2025 huggingface dataset:
Nanocodelivery of 5‐Fluorouracil and Curcumin by RGD‐Decorated Nanoliposomes Achieves Synergistic Chemotherapy for Breast Cancer
Authors: Mahmoudi Reza , Mohammadi Somayeh , Mahmoudi Rouzbeh , Fouani Mohamad Hassan , Ardakani Maryam Tajali , Hadi Amin , Nikseresht Mohsen , Barmak Mehrzad Jafari , Karimpour Farzad , Bardania Hassan
Published: November 2024

In the present study, arginine–glycine–aspartic acid peptide (RGD) surface functionalized liposomes (Lips) were formulated for the concomitant targeted delivery of two antineoplastic drugs, namely curcumin (Cur) and 5‐fluorouracil (5FU) to breast cancer cells. The Lips’ measured size values where 50–100 nm by transmission electron microscopy (TEM) and 169 ± 10.2 nm by dynamic light scattering (DLS), which fall within the desired range required for drug delivery purposes. In this study, we assessed the antineoplastic effects of various liposomal formulations for the codelivery of Cur and 5FU to MCF‐7 breast cancer cells. We evaluated two liposomal formulations (Lip–Cur–5FU) and (Lip–Cur–5FU–RGD). The treatment of MCF‐7 cells with 32 µg/mL of Cur exhibited a significant (p < 0.0001) drop in cell viability among the three formulations, namely Cur and 5Fu in the free form (Lip–Cur–5FU) and liposomal form (Lip–Cur–5FU–RGD); the least viability rate (9.91% ± 1.65%) corresponded to the RGD functionalized concomitantly Cur and 5Fu loaded Lips (Lip–Cur–5FU–RGD) formulation. On the other hand, liposomal Cur increased the rate of early apoptotic cell by 4.88% without altering the rate of late apoptotic cells. Furthermore, the concomitant treatment of MCF‐7 cells with Cur and 5FU enhanced the overall apoptosis rate, where Cur–5FU in the RGD functionalized‐liposomal form induced the highest (16.8%) apoptosis rate, while other Cur–5FU formulations, free and nonfunctionalized liposomal form, induced lower apoptosis rates (10.4% and 10.9%, respectively). Collectively our results demonstrated that the implementation of RGD‐functionalized Lips for the concomitant delivery of Cur and 5FU enhanced their therapeutic efficacy against this breast cancer model.
An efficient hybrid algorithm based on particle swarm optimisation and teaching‐learning‐based optimisation for parameter estimation of photovoltaic models
Authors: Wang Dianlang , Qiu Zhongrui , Yin Qi , Wang Haifeng , Chen Jing , Zeng Chengbi
Published: November 2024

In recent years, many meta‐heuristic algorithms have been investigated to estimate the parameters of photovoltaic (PV) models. However, the accuracy of the estimated parameters still needs to be concerned, especially for some complex PV models with many unknown parameters. In order to estimate the unknown parameters of the PV models more precisely and reliably, an efficient hybrid algorithm based on particle swarm optimisation and teaching‐learning‐based optimisation (PSOTLBO) is proposed in this paper. In PSOTLBO, inspired by the learner phase of teaching‐learning‐based optimisation (TLBO), an improved learner phase is designed and introduced into the basic PSO to enhance the global search ability and the ability to get rid of local optimum. The improved learner phase divides the population into four groups according to three values, which are the average fitness values of the overall population, the population in the first half of the fitness ranking and the population in the second half of the fitness ranking. Typically, each group has its particular movement pattern concentrating on exploration or exploitation respectively to improve the search efficiency of the algorithm. Furthermore, to deal with individuals beyond the boundary, a new designed probabilistic rebound strategy is introduced, which increases the diversity of population and avoids population aggregation at the search boundary. Then, the proposed PSOTLBO is applied to estimate the parameters of the single diode model, double diode model and PV module model. The comparative results between PSOTLBO and other 14 advanced algorithms show that the average root mean square error values of different PV models obtained by PSOTLBO are 9.86021878E−04, 9.82630511E−04, 2.42507487E−03, 1.72981371E−03, and 1.66006031E−02, respectively, which indicate that PSOTLBO can provide more accurate and stable parameter estimation results than other compared algorithms. Furthermore, the convergence experimental results demonstrate that PSOTLBO has outstanding performance in convergence speed and stability.
Predicting high-fidelity data from coarse-mesh computational fluid dynamics corrected using hybrid twins based on optimal transport
Authors: Torregrosa Sergio , Champaney Victor , Ammar Amine , Herbert Vincent , Chinesta Francisco
Published: November 2024

Nowadays, numerical simulation, such as computational fluid dynamics (CFD), has become an essential tool for scientific investigation and analysis of complex systems in engineering allowing high-fidelity Navier-Stokes resolution for realistic turbulent flows which cannot be solved analytically. However, although all the studies and development conducted to improve its accuracy and computational cost, CFD remains either not to be trusted completely or too expensive to run. Moreover, with the present data-based revolution, artificial intelligence and machine learning (ML) are acquiring indisputable importance in every field leading to data, theory, and simulation working together for computational efficiency and to increase accuracy. Among the very different applications of data in CFD, here we focus on data-driven correction of coarse simulations based on the knowledge of the error gap between coarse and high-fidelity simulations, also known as the "hybrid twin" rationale. On the one hand, coarse numerical simulations are computed as fast and cheap data, assuming their inherent error. On the other hand, some high-fidelity (HF) data is gathered to train the ML correction model which fills the coarse-HF gap. However, modeling this ignorance gap might be difficult in some fields such as fluids dynamics, where a regression over the localized solutions can lead to non physical interpolated solutions. Therefore, the Optimal Transport theory is followed, which provides a mathematical framework to measure distances between general objects. Such an OT-based "hybrid twin" methodology was already proposed in a previous article by the authors. However, even if in this article the methodology remains the same, the problem solved is conceptually different since we correct no longer the gap between experimental and numerical data but between coarse and high-fidelity simulations.
Prediction of the Survival Status, Immunotherapy Response, and
Medication of Lung Adenocarcinoma Patients Based on Hypoxia- and
Apoptosis-Related Genes
Authors: Shi Ziliang , Sang Zi , Xiao Junmeng , Hou Jianbin , Geng Mingfei
Published: November 2024

To predict patient survival prognosis, we aimed to establish a novel set of gene
features associated with hypoxia and apoptosis. RNA-seq and clinical data of
LUAD were sourced from The Cancer Genome Atlas (TCGA) and Gene Expression
Omnibus (GEO) databases, while hypoxia and apoptosis-related genes were obtained
from the Molecular Signatures Database (MsigDB). A 13-gene-prognostic model
incorporating hypoxia and apoptosis genes was developed using
univariate/multivariate Cox regression, Nonnegative Matrix Factorization (NMF)
clustering, and LASSO regression. Patients were divided into high-risk (HR) and
low-risk (LR) groups according to the median risk score. Gene Ontology (GO) and
Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses revealed
distinct biological processes between HR and LR groups, including hormone
regulation and lipid metabolism pathways. Single sample gene set enrichment
analysis (ssGSEA) indicated elevated cell infiltration levels of Neutrophils and
T_helper_cells in the LR group, while NK cells and Th1cells were higher in the
HR group. Immunophenoscore (IPS) and tumor immune dysfunction and exclusion
(TIDE) analyses suggested potential benefits of immunotherapy for LR group
patients. In conclusion, this prognostic feature integrating hypoxia- and
apoptosis-related genes offers insights into predicting survival, immune status,
and treatment response in LUAD patients, paving the way for personalized
treatment strategies.
The rare reason for massive lactic aciduria and mitochondrial
disorders: combined oxidative phosphorylation deficiency type 23
(COXPD23)
Authors: Akar Halil Tuna , Akduman Hasan , Kolkıran Abdülkerim , Taşadelen Elifcan , Aycan Nur
Published: November 2024

Mitochondrial respiratory chain dysfunction and impaired oxidative
phosphorylation are rare but significant causes of mitochondrial diseases in
children, presenting with diverse clinical features. Combined oxidative
phosphorylation deficiency type 23 (COXPD23), an autosomal recessive disorder
due to GTPBP3 gene mutations, typically manifests as lactic acidosis,
hypertrophic cardiomyopathy, and encephalopathy. This case report describes a
male infant born at 35 weeks gestation, who exhibited severe lactic aciduria and
hypotonia but no cardiomyopathy, which is atypical for COXPD23. Genetic analysis
revealed a novel homozygous missense variant in the GTPBP3 gene. Despite
intensive metabolic and supportive treatments, the patientʼs condition worsened,
leading to death on the 23rd day. This case emphasizes the need to consider
mitochondrial cytopathies in neonates with persistent metabolic acidosis and
hyperlactatemia and highlights the importance of early genetic screening for
accurate diagnosis and management.
Contilistat, a New Multitarget Small Polyfunctionalized Indole Derivative
Authors: Hansen Finn K. , Marco-Contelles José , Toledano-Pinedo Mireia , Diez-Iriepa Daniel , Porro-Pérez Alicia , Schäker-Hübner Linda , Hanl Maria , Samadi Abdelouahid , Almendros Pedro , Iriepa Isabel , Rodríguez-Fernández M. Mercedes , Griñán-Ferré Christian , Siwek Agata , Wolak Małgorzata , Satała Grzegorz , Bojarski Andrzej J. , Doroż-Płonka Agata , Handzlik Jadwiga , Godyń Justyna , Knez Damijan , Gobec Stanislav , Więckowska Anna
Published: November 2024

We describe the design, synthesis, and in vitro biological evaluation of contilistat, a novel polyfunctionalized indole derivative designed as a hybrid of contilisant and vorinostat containing key pharmacophoric groups of both parent ligands.
Microcontact spectroscopy of electron–phonon interaction in zinc and cadmium
Authors: Yanson I. K.
Published: November 2024

The nonlinear current–voltage characteristics of microscopic (d≃10–100 Å) zinc and cadmium point contacts are measured at 1.5°K. It is shown that the second derivatives of the characteristics are proportional to the density of phonon states and permit the maxima in the phonon spectrum to be located more precisely. The microcontact spectra display seven features: five maxima at eV = 7.6 ± 0.2, 10.1 ± 0.7, 15.2 ± 0.7, 19.5 ± 1.0 and 23.3 ± 0.5 MeV for zinc and 4.8 ± 0.3, 6.6 ± 0.1, 10.5 ± 0.3, 13.3 ± 0.8 and 17.0 ± 0.5 MeV for cadmium as well as two additional maxima, observed more rarely, at eV = 12.5 and 26.5 MeV for zinc and 8.5 and 20 MeV for cadmium. All of these values are fairly consistent with the position of the singular points ∂ω/∂q = 0 on the phonon dispersion curves. Slight energy shifts and redistribution of line strength observed in the spectra of different samples are interpreted as being due to the different orientation of crystallites in the region of the contact. The effect of temperature on the spectral linewidth is studied and an empirical method is proposed for taking account of the background observed in the spectra of most contacts.
Ultrasound propagation velocity in liquid hydrogen and deuterium
Authors: Pashkov V. V. , Konovodchenko E. V.
Published: November 2024

The speed of ultrasound propagation is measured in liquid hydrogen and deuterium by the impulse method at a frequency of 5 MHz over the temperature range T = 18.25−32.28°K for hydrogen, and T = 22−35°K for deuterium at pressures of up to 150 atm. The values obtained are compared with values calculated by the multistructure theory.
Surface impedance oscillations in a metal plate in a perpendicular magnetic field
Authors: Zherebchevskii D. É. , Naberezhnykh V. P.
Published: November 2024

A theory of oscillatory effects in the surface impedance of a metal plate in a magnetic field normal to its surface has been developed for the “corrugated cylinder” model of the Fermi surface. It is shown that in the case of nonspecular electron reflection from the plate surfaces with antisymmetric excitation, the main contribution to the impedance oscillations comes from modulation of the field in the skin layer. This modulation is due to two causes: first, surface current oscillations which result from diffuse electron reflection and which are an rf analog of the dc Sondheimer effect and, second, excitation of a weakly attenuated standing wave, i.e., a doppleron. The relative contributions of both effects depend on the magnetic field, the wave frequency, the plate thickness, and the reflection specularity. The amplitude of the Gantmakher-Kaner oscillations is small in comparison with that of the oscillations set up by these effects.
Effect of tension on the Fermi surface of antimony
Authors: Brandt N. B. , Bogdanov E. V. , Minina N. Ya.
Published: November 2024

The effect of tension along the binary and bisector axes on the Fermi surface is studied in antimony. Deformations of the order of 0.24% were obtained using a special method. The deformation changes the crystal symmetry and destroys the equivalence of the electron and hole ellipsoids, causing a redistribution of carriers among the extrema.
A Josephson junction in a nonhomogeneous field
Authors: Zharkov G. F. , Zaikin A. D.
Published: November 2024

The problem is solved of the static field and current distributions in a Josephson junction of finite width L in a nonhomogeneous magnetic field of intensities H(x = 0) = 0 and H(x = L) = HL. The boundary-value problem involving a nonlinear differential equation which describes the field distribution over the junction is reduced to the equivalent Cauchy problem. All possible kinds of solutions to the problem are shown. The solutions given here are tested for stability. The dynamics of stable solutions as well as nonstationary self-oscillatory solutions which correspond to a traveling vortex structure are analyzed on the basis of an equation in time. Numerical calculations have been carried out on a computer.
Hot electrons at the free surface of liquid helium
Authors: Monarkha Yu. P. , Sokolov S. S.
Published: November 2024

The nonlinear effects originating in a two-dimensional electron gas at the surface of liquid helium, during the action on it of a low-frequency attractive electric field, are studied theoretically. It follows from the results obtained, that under conditions of electron-ripplon scattering with increase of amplitude of the guiding field, the mobility of the electrons at the first surface level decreases at first, and then very slowly increases. As a result of this, the electrons existing in the ground surface level, in a quite large range of guiding fields can be easily heated up to relatively high temperatures (Te ⪢ T), almost without change of mobility, until electron transitions to subsequent energy levels start to be affected. It is shown that electron transitions in the region of the quasicontinuous spectrum lead to a strong nonlinear dependence of the average mobility of the electrons on the amplitude of the guiding field.
Quantum interference and the characteristics of Josephson junctions
Authors: Shnyrkov V. I. , Khlus V. A. , Tsoi G. M. , Chetaev M. P.
Published: November 2024

A single-junction superconducting quantum interferometer with external high-frequency excitation is considered, in which the weak coupling is described within the framework of the resistive model. An analysis for the hysteresis-free state serves to define the parameters characterizing the Josephson junction, including the current as a function of the phase difference at the junction, as well as the interference term in the dissipative component of the current. The theoretical results are compared with experiment to define certain parameters of the Josephson junction and the sign of the interference term.
A compensated-moment structure in the noncollinear phase of antiferromagnetic CsMnF3
Authors: Gredeskul V. M. , Mil’ner A. A.
Published: November 2024

A four-sublattice model for an antiferromagnet has been used to examine the possible magnetic states of hexagonal CsMnF3. It is shown that the orientation of the sublattice moments in the basal plane determines whether the magnetic structure of the crystal is collinear or slightly noncollinear. A model for a noncollinear antiferromagnet is presented in which the magnetic moment is compensated on all the sublattices. An estimate is made of the sixth-order anisotropy.
Thermal conductivity of krypton and xenon at constant density and pressures up to 2700 atm. Law of corresponding states
Authors: Slyusar’ V. P. , Tret’yakov V. M. , Rudenko N. S.
Published: November 2024

The thermal conductivity coefficients of krypton and xenon are studied by the heated filament method. Measurements were performed over the range 120−300°K (Kr) and 180−330°K (Xe), at densities of 0.344−2.424 g/cm3 (Kr) and 0.200−2.845 g/cm3 (Xe), and pressures of 1−2730 atm (Kr) and 1−1380 atm (Xe). The results obtained are analyzed, compared with the data of other authors, with calculations using the theories of Eyring, Enskog, and Prigogine, and with values calculated by the molecular dynamics method. The thermal conductivities of krypton, xenon, argon, and nitrogen are described with the aid of the law of corresponding states, which is also used to calculate the thermal conductivities of neon and radon along the saturation line and at constant density.
VUV luminescence from doped argon crystals
Authors: Poltoratskii Yu. B. , Fugol’ I. Ya.
Published: November 2024

The effect of nitrogen and oxygen impurities in neon and argon crystals on the VUV emission spectra has been studied. It is demonstrated that the broad molecular bands in argon (centered at 6.2 and 7.6 eV) are due to emission from ArO* and ArN* excimers. Information about the excitonic nature of the energy transfer in argon crystals is obtained from the concentration and temperature dependences of the intensities in the excimer bands.
Temperature and magnetic-field dependence of the vortex-pinning force with wide variation of j
c
Authors: Borka S. , Goncharov I. N. , Khukhareva I. S.
Published: November 2024

The behavior of the pinning forces in cold-deformed strips of Nb−80% Zr alloy was investigated for different angles between the sample plane and the magnetic-field direction (with j⊥H) over practically the whole region of existence of the mixed state. The strong angular dependence of the critical current permitted controlled changes to be made in the pinning force Fc over a broad range. The transition from curves of Fc(h)t,φ with a peak close to Hc2 to the dome-like curves corresponding to small angles φ was investigated. The temperature dependence of the pinning force was found. In discussing the results, it was assumed that the change in the shape of Fc(h)t,φ with change in φ is associated with a transition from the “lattice” approximation (in moderate magnetic fields) to the “liquid” approximation.
Effect of electron–phonon interactions on retarded cyclotron resonance
Authors: Makarov N. M. , Sodin S. L.
Published: November 2024

Effects of electron–phonon interactions on cyclotron resonance line shapes are investigated under conditions of strong retardation effects. The resonance line shape is found in the case of “sharp” resonance. Anomalous and normal skin effects are considered. Equations are obtained for the resonance frequency shift and for the effective electron relaxation frequency with external electromagnetic wave frequencies much higher and much lower than the Debye frequency. It is shown that for frequencies low in comparison with the Debye frequency the resonance frequency shift exceeds the effective electron relaxation frequency.
Magnetostriction of antiferromagnetic iron and chromium garnet single crystals
Authors: Pronin V. N. , Sokolov V. I. , Shevaleevskii O. I.
Published: November 2024

The static magnetostriction of antiferromagnetic garnet single crystals Ca3Fe2Ge3O12 and Ca3Cr2Ge3O12 is measured at 4.2°K. It is shown that the angular dependences of the magnetostriction are characterized by equilibrium spin configurations occurring in cubic antiferromagnets in spin-flop fields. The magnetostriction fields H1 and H2, whose magnitudes confirm the existence of a significant magnetoelastic gap in the AFMR spectrum of the iron and chromium garnets investigated, are computed on the basis of the values obtained for λ100 and λ111.
Self-localization of high-frequency triplet excitations in crystal nitrogen
Authors: Fugol’ I. Ya. , Poltoratskii Yu. B. , Rybalko Yu. I.
Published: November 2024

The radiation of crystalline nitrogen corresponding to the transition between two high-lying triplet states C3→ B3Πg is discovered. The spectrum of this transition in the crystal possesses an interesting feature–the agreement between the frequencies of the electron-vibrational-rotational transitions and those in the gas. The effect of free molecule rotation in the lattice is observed in both excited states. A possible mechanism for the formation of self-localized states C3Πu and B3Πg in the nitrogen lattice is discussed.
Resistivity of the Pd–Fe–H system in the temperature range 4.2−300°K
Authors: Dekhtyar I. N. , Nishchenko M. M. , Shevchenko V. I.
Published: November 2024

The temperature dependence of the resistivity was studied in hydrogenated palladium alloys with 1, 5, and 10 at.% Fe. The hydrogenated alloy with 1 at.% Fe displayed an anomaly in the ρ(T) curve near 50°K and a shallow minimum in the region of 25°K. In the case of alloys with 5 at.% Fe, the slope of the ρ(T) curve changed sharply (by a factor of approximately 25) near the temperature anomaly. The change in the ρ(T) curve for Pd alloy with 5 at.% Fe was also investigated under hydrogen desorption.
Superconductive properties of the system gallium–dielectric, produced by shock compression
Authors: Alekseevskii V. P. , Balbanov E. I. , Bespalov B. P. , Gakel’ V. R. , Kostromin A. S. , Mikheev V. A. , Pechentkovskaya L. E. , Titov V. V. , Yarosh V. V.
Published: November 2024

A finely dispersed modification of gallium which transforms to the superconductive state at T ≤ 6.1°K was produced by shock compression of the systems Ga-[Qn-TCNQ2] and Ga-glass. By comparing the superconductive parameters of the modification obtained with corresponding parameters of similar finely dispersed systems the modification was identified as the gallium β-phase. This β-phase, obtained by shock compression of a gallium–dielectric system, is stable with respect to repeated heating and lengthy maintenance at room temperature.
Intermediate-radius excitons in rare gas crystals
Authors: Ratner A. M. , Tarasova E. I.
Published: November 2024

A simple scheme is suggested for constructing exciton states of intermediate radius rs in rare gas crystals. The applicability condition of this approach is a small band width in comparison with binding energies of valence electrons. The states of an atom placed in the crystal field are used as the zeroth approximation. In the limiting cases of small and large rs the dispersion law obtained here reduces to the dispersion laws of Frenkel and hole excitons. A suitable interpolation formula is suggested.
Structure of solid H2–D2 mixtures
Authors: Krupskii I. N. , Kovalenko S. I. , Krainyukova N. V.
Published: November 2024

The structure of solid H2–D2 mixtures deposited from the gaseous phase is studied by the transmission electron-diffraction method in the concentration range 0–100 mole %. The experiments were carried out in the range from 2.3°K to the temperature of sublimation of the specimens, which usually occured at T≈ 5°K in the case of H2 and T≈ 7°K in the case of D2. It is established that with low-temperature condensation, solid films of pure components form an fcc structure which is metastable for the given temperature range and which has the parameters aH2=5.310±0.01Å and aD2=5.100±0.005Å. In the case of two-component condensates, a continuous series of solid solutions is observed to form. The reasons why there is no decomposition in the H2–D2 system are considered.
The thickness of films of He3–He4 liquid solutions
Authors: Ivantsov V. G. , Shcherbachenko R. I.
Published: November 2024

The thickness of films of He3−He4 liquid solutions is calculated on the basis of permittivity data for these solutions by using the conclusions of the theory of Dzyaloshinskii, Lifshitz, and Pitaevskii. It is shown that the values of the thickness of films of He3−He4 solutions and pure He4 practically coincide under identical conditions. Consideration is given to the effect of possible mechanisms which may lead to a difference in the He3 concentration in the film and in the bulk liquid.
Low-temperature internal stresses in niobium films on dielectric substrates
Authors: Shermergor T. D. , Tumanova L. A. , Makhov V. I. , Dyuzhev N. A.
Published: November 2024

Internal stresses in niobium films on crystal glass sitall substrates are investigated experimentally in the 4.2–300° K temperature range. It is shown that the stresses depend on the film thickness and the test temperature, where the thinner the film and the lower the temperature, the greater the stresses which occur. In order to estimate the contribution of the thermal stresses in the specimens investigated, the coefficient of thermal expansion of the sitall was measured for the 6–300°K temperature range. Graphs of the dependence of the thermal stresses on the test temperature are constructed according to the data obtained. An analysis of the experimental data showed that stress relaxation processes can proceed at low temperatures. A mechanism is proposed for these processes.
Thermal conductivity of rare-earth metals of the cerium subgroup at low temperatures
Authors: Feher A. , Jánoš Š. , Petrovič P. , Flachbart K. , Reiffers M.
Published: November 2024

The paper reports on investigations on the thermal conductivity of polycrystalline specimens of Ce, Pr, Nd, Sm, and Eu in the temperature range 0.5–10° K and discusses possible mechanisms of heat transfer. Experimental results show that the main contribution to the thermal conductivity in the temperature range investigated is made by electrons. An additional contribution, due to the magnetic system, was observed in one Nd specimen at temperatures below 6°K.
Nonlocal hydrodynamics of phonon gas in dielectrics
Authors: Gurzhi R. N. , Maksimov A. O.
Published: November 2024

It is shown that for certain dispersion laws of transverse vibrations, realizable in dielectric crystals of high and low symmetry, the nature of hydrodynamic effects in these dielectric crystals changes considerably. Thermal phonons, as usual, are the carriers of energy and momentum, whereas “viscosity” is determined by the longitudinal, long-wave phonons, carrying energy and momentum over distances comparable with the characteristic dimension of the system. Under these conditions the hydrodynamic variables obey an integral equation, whose structure depends on the dispersion law properties of transverse vibrations. The calculated temperature dependences of the thermal conductivity and second sound attenuation coefficients are close to the experimental observations.
Study of plastic deformation to the temperature ∼0.4°K
Authors: Kuz’menko I. N. , Parkhomenko T. A. , Pustovalov V. V.
Published: November 2024

The first investigations of the plastic deformation of aluminum in the normal and superconducting states have been performed at temperatures to 0.44° K by using an original apparatus for the study of strain in a liquid He3 medium.
Electrical properties of thin bismuth-antimony films. IV. Temperature dependence
Authors: Nikitin Yu. V. , Bukhshtab E. I. , Komnik Yu. F.
Published: November 2024

Thin film samples of Bi1−xSbx alloys of various thicknesses and compositions have been measured for electrical resistivity, for their coefficient of magnetoresistivity, and for their Hall coefficient in the temperature range 4.2–300 °K. The density and mobility of the charge carriers have been calculated. It is shown that the nonuniform film-potential model used in parts I–III [Sov. J. Low Temp. Phys. 4, 000 (1978); 4, 000 (1978); 4, 000 (1978)] to explain the absence of a semimetal–semiconductor Bi1−xSbx alloys for x = 0.065 and the anomalous size effect in the film conductivity is confirmed by the data obtained in the present study. Because of the increase in charge-carrier density with temperature, the influence of the size effect of the film potential is weakened and the anomalies observed in parts I–III disappear. Various features are observed in the temperature dependences. There is a maximum in the resistivity of very thin films and a minimum in the magnetoresistance coefficient. A general observation is that as the antimony content of the film is increased, the effect is similar to reducing film thickness.
Nonequilibrium states of normal metal films during tunneling injection of electrons
Authors: Seminozhenko V. P.
Published: November 2024

The nonequilibrium states of a metal film in the normal (N) state in an S-I-N-I-S structure (S is a bulk superconductor and I is an insulator) are studied when a voltage V > Δ/e is applied to each tunnel diode in the same direction (Δ is the energy gap of the S electrode and e is the electron charge). Conditions are found in which the energy distribution of electrons near the Fermi surface of the N film is inverted.
Analysis of circularity metrology of small cylindrical workpiece with a segmenting scan method
Authors: Li Qiaolin , Zeng Chuang , Zhao Jiali , Wu Dan , Zhang Liang
Published: November 2024

Owing to eccentricity and inclination, circularity of a cylindrical workpiece cannot be measured precisely by a circularity measuring machine when the workpiece has a small dimension (diameter ≤ 3 mm). In this paper, with the aim of solving this problem, circularity metrology of a small cylindrical workpiece using a segmenting scanning method is analyzed. The cross-sectional circle of the cylinder is segmented into several equivalent arcs for measurement by a two-dimensional coordinate measuring machine (profilometer). The circularity contour is obtained by stitching together arc contours obtained by data processing of the coordinates. Different segmenting patterns for coordinate scanning are considered. Measurement results are presented for three segmentation patterns, with 8, 10, and 12 equal segments, respectively. These results are evaluated in terms of the matching coefficient between neighboring arc contours on circumferential stitching, the Euclidean distance between neighboring arc contours on radial stitching, and the curvature of the arcs. From these evaluations, it is found that as the number of segments is increased, the matching coefficient increases from 0.14 to 0.50, the Euclidean distance decreases from 32 nm to 26 nm, and the curvature becomes close to the standard value.
Catalyst development for electrochemical hydrogenation of biomass-derived platform molecules
Authors: Zhang Kaidi , Sun Yiwei , Chen Ziyao , Dong Mengyang , Fu Huaiqin , Xu Yiming , Zou Yu , Hu Mengqing , Fu Bo , Wang Xinyu , Ahmad Waseem , Wang Liang , Zhang Lei , Zhou Ming , Wang Yun , Yin Huajie , Liu Porun , Zhao Huijun
Published: November 2024

In recent decades, economic growth and the growing demand for limited resources have prompted a global search for more environmentally friendly and sustainable raw materials for the production of chemicals, materials, and fuels. Compared with traditional fossil fuel feedstocks, whose upgrading features high temperature, high pressure and sever greenhouse gas footprint, the upgrading of biomass-derived platform molecules with various functional groups are achievable at room temperature and ambient pressure with the emerging electrocatalytic hydrogenation (ECH) technology. The selectivity and conversion rate of ECH can be manipulated by adjusting and optimizing the electrode material and the composition of the electrolyte. This review summarizes the progress made in the ECH of various biomass platform molecules with different functional groups (such as 5-hydroxymethylfurfural, furfural, and levulinic acid) into chemicals and fuels across different electrocatalytic systems. It introduces the two mechanisms of ECH reaction and systematically reviews those on both noble metal electrocatalysts (Pt, Pd, Ag, Ru, etc.) and non-noble metal electrocatalysts (Cu, Pb, Sn, etc.). Finally, the current challenges and unresolved issues for the ECH of biomass-derived platform molecules are presented. This review will provide useful insights and guideline for the rational design of high-performance electrocatalysts for selective ECH of biomass platform molecules.
Size-dependent atomic strain localization mechanism in Nb/amorphous CuNb nanolayered composites
Authors: Chen Yangheng , Wang Yaodong , Li Jianjun
Published: November 2024

Experiments have shown that crystalline–amorphous nanolayered composites show a strong size dependence in strength and plasticity. However, the underlying mechanism remains unknown. Here, the layer thickness (h)-dependent compressive strength and plastic deformation of Nb/amorphous CuNb nanolayered composites with h ranging from 2.8 to 20 nm have been studied by molecular dynamics simulations. It is found that the strength increases monotonically with the decrease of h, which can be well captured by the refined confined layer slip model. Furthermore, the shear banding-induced strain localization was analyzed in detail based on the evolution of the von Mises strain distribution with the applied strain and a strain localization parameter that represents the deviation of the specific atomic Mises strain from the average one of all atoms. The results show that the strain localization of the composite shows a significant size dependence and its magnitude increases with the decrease in the layer thickness. The prevention of shear band propagation in thicker layer samples is attributed to that the amorphous phase is capable of forming an atomic vortex to alleviate the strain concentration caused by dislocation absorption. The thicker amorphous layers accommodate enhanced homogeneous plasticity than the thinner ones by forming a larger vortex. Note that the above size dependence of strength and strain localization in the composite agrees well with existing experimental measurements and observations in the layer thickness range considered. As a result, the present work gives a deeper insight into the understanding of the size-dependent strengthening and strain localization mechanism in the amorphous/crystalline composites.
Search for promising structures and superconductivity in high-pressure Sr through first-principles calculations
Authors: Geshi Masaaki , Funashima Hiroki , Hettiarachchi Gayan Prasad
Published: November 2024

In the high-pressure phases of Sr, the Sr-V phase is considered an incommensurate host–guest structure. However, just as a low-temperature phase Ba-VI exists in the pressure region of the Ba-IV phase of high-pressure Ba, Sr also has a Sr-VI phase on the low-temperature region of the Sr-V phase according to experiments. We investigated the pressure range from 40 to 2400 GPa using first-principles calculations and found a group of promising candidate structures for the Sr-VI phase. At higher pressures, the lowest-enthalpy structure became hexagonal close-packed (hcp) around 160 GPa and is consistent with experiments for the Sr-VII phase, and the hcp structure transformed to a double hcp (dhcp) structure around 1000 GPa, and then, the dhcp structure changed to a face-centered cubic structure around 2200 GPa. The superconducting state remained intact through these structural phase transitions, although with a decreasing Tc with increasing pressure.
Double-barrier magnetic tunnel junctions with enhanced tunnel magnetoresistance
Authors: Zheng Xiaohong , Yang Shili , Zheng Zhifan , Liu Chun-Sheng , Wang Weiyang , Zhang Lei
Published: November 2024

Tunnel magnetoresistance (TMR) ratio is a key parameter characterizing the performance of a magnetic tunnel junction (MTJ), and a large TMR ratio is essential for the practical application of it. Generally, the traditional solutions to increasing the TMR ratio are to choose different material combinations as the ferromagnetic (FM) leads and nonmagnetic tunnel barrier. In this work, we study an architecture of MTJs of “FM/barrier/FM/barrier/FM” with double barriers, in contrast to the traditional single barrier structure “FM/barrier/FM.” We first analytically show that double barrier MTJ will generally have much higher TMR ratio than the single barrier MTJ and then substantiate it with the well-known example of “Fe/MgO/Fe” MTJ. Based on density functional calculations combined with nonequilibrium Green's function technique for quantum transport study, in the single barrier “Fe/MgO/Fe” MTJ, the TMR ratio is obtained as 122%, while in the double barrier “Fe/MgO/Fe/MgO/Fe” MTJ, it is greatly increased to 802%, suggesting that double barrier design can greatly enhance the TMR and can be taken into consideration in the design of MTJs.
Density functional theory and material databases in the era of machine learning
Authors: Kashyap Arti
Published: November 2024

This perspective article presents the density functional theory and traces its evolution. With the advancement in density functional theory-based computations and the efforts to collate the data generated through density functional theory, the field now has a good repository/database of materials and their properties. This repository, though not as substantial as generally used for machine learning, has nonetheless made it possible to combine density functional theory and machine learning. This article highlights current research challenges and presents an optimistic outlook for the future of “Density Functional Theory with Machine Learning” by discussing some specific examples.
Resistive switching and artificial synapses performance of co-evaporated Cs3Cu2I5 films
Authors: Zhang Yi , Mao Xiaojun , Chang Xi , Xie Jinghao , Niu Yueping , Gong Shangqing , Qian Min
Published: November 2024

Perovskite memristors have garnered significant interest for their potential simulating artificial synapses; however, the presence of the toxic lead-based perovskites has hindered advancements in this field. In this work, a nontoxic, thickness-controllable Cs3Cu2I5 perovskite functional layer is synthesized through a dual-source vapor deposition for the Ag/Cs3Cu2I5/ITO memristor. The co-evaporation method shows advantages of various element, controllable atomic ratio and thickness, free impurity, and continuously uniform film. This device demonstrates an operating voltage of 1.2 V, a low power consumption of 0.013 W, a retention time exceeding 104 s, and an endurance of over 400 cycles. The synaptic behavior is emulated using the memristor, focusing on phenomena such as short-term potentiation and depression, paired-pulse facilitation, and spike-time-dependent plasticity. The migration of Na+ and Cl− ions, which occurs between the synaptic cleft and the postsynaptic membrane in biological synapses, is analogously represented by the movement of Ag+ ions between functional layer and the bottom electrode of the memristor. This process is further analyzed using the Hodgkin–Huxley neuron model. The Cs3Cu2I5-based memristor shows considerable promise for applications in storage systems and artificial synapses.
The Kob–Andersen model crystal structure: Genetic algorithms vs spontaneous crystallization
Authors: Fomin Yu. D. , Chtchelkatchev N. M.
Published: November 2024

The crystal structure of the Kob–Andersen mixture has been probed by genetic algorithm calculations. The stable structures of the system with different molar fractions of the components have been identified, and their stability at finite temperatures has been verified. It has been found that the structures of composition ABn, where n = 2, 3, or 4, can be formed in the system. Metastable structures with compositions AB0.4 and AB0.58 have also been identified. Molecular dynamics simulations of spontaneous crystallization from liquid have been performed.
Operando Li-ion distribution measurement of all-solid-state batteries by Compton-scattered x rays
Authors: Nakamura Kazuki , Suzuki Kosuke , Utsuno Futoshi , Takano Kodai , Ando Tomoya , Hoshi Kazushi , Tsuji Naruki , Sakurai Hiroshi
Published: November 2024

We report operando measurements of the Li-ion distribution in the anode and cathode of a coin-type all-solid-state battery in the charged and discharged states via Compton scattering using high-energy synchrotron radiation x-ray analysis. From the line shape pattern analysis of the Compton scattering x-ray spectrum, we accurately observed the Li-ion distribution within the cathode and anode during the charging/discharging of a real coin-shaped battery in an SUS casing. This study discusses the difference in Li-ion distribution between the cathode and anode and compares the Li-ion distribution of the battery after 20 charge–discharge cycles with those of a fresh battery.
Organic ferroelectric transistors with composite dielectric for efficient neural computing
Authors: Li Changqing , Tian Fuguo , Luo Zhongzhong , Luo Haoyang , Yan Jie , Xu Xiangdong , Wan Xiang , Zhu Li , Tan Chee Leong , Yu Zhihao , Xu Yong , Sun Huabin
Published: November 2024

Organic ferroelectric field-effect transistors (Fe-OFETs) exhibit exceptional capabilities in mimicking biological neural systems and represent one of the primary options for flexible artificial synaptic devices. Ferroelectric polymers, such as poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)), given their strong ferroelectricity and facile solution processing, have emerged as the preferred choices for the ferroelectric dielectric layer of wearable devices. However, the solution processed P(VDF-TrFE) films can lead to high interface roughness, prone to cause excessive gate leakage. Meanwhile, the ferroelectric layer in neural computing and memory applications also faces a trade-off between storage time and energy for read/write operations. This study introduces a composite dielectric layer for Fe-OFETs, fabricated via a solution-based process. Different thicknesses of poly(N-vinylcarbazole) (PVK) are shown to significantly alter the ferroelectric hysteresis window and leakage current. The optimized devices exhibit synaptic plasticity with a transient current of 3.52 mA and a response time of approximately 50 ns. The Fe-OFETs with the composite dielectric were modeled and integrated into convolutional neural networks, achieving a 92.95% accuracy rate. This highlights the composite dielectric's advantage in neuromorphic computing. The introduction of PVK optimizes the interface and balances device performance of Fe-OFETs for neuromorphic computing.
Characterizing the non-Hermitian route to higher-order topology via fractional mode charges in acoustic systems
Authors: Lv Wenbin , Zheng Taotao , Cao Han , He Jinyang , Xu Chudong , Lu Ming-Hui
Published: November 2024

Non-Hermitian factors play a key role in introducing changes to the topology of acoustic systems, by significantly expanding the classification of topological phases beyond traditional Hermitian theory and presenting challenges to the conventional bulk–boundary correspondence. Traditional Hermitian theory cannot fully describe the complicated behavior of systems interacting with their environment, thus non-Hermitian theory emerged. Currently, most non-Hermitian topological systems derive their phases from Hermitian components, which entails concurrently considering the gain and loss of the system. In the study of higher-order topological insulators, higher-order topological states are usually achieved by modulating coupling strengths. While traditionally it is viewed that dissipation in topological systems is detrimental to the topological states, recent research studies have challenged this perspective. The nontrivial topology can arise by introducing loss of a specific configuration in a trivial phase. In this study, through finite-element simulations of coupled acoustic cavity systems from one-dimensional to three-dimensional structure, it is illustrated how intentionally introducing non-Hermitian loss can induce the higher-order topology. More crucially, we have simulated the acoustic local density of states (LDOS) and calculated fractional charge modes and can directly observe and prove through LDOS that introducing loss can convert a trivial system into a topological one. Both theoretical and simulated results show that the LDOS can be used to calculate fractional charge modes, effectively characterizing higher-order topological states in non-Hermitian acoustic systems. This study carves out a research pathway for the future of non-Hermitian acoustic topology.
Polyelectrolyte brush in a cylindrical pore: A Poisson–Boltzmann theory
Authors: Popova Tatiana O. , Laktionov Mikhail Y. , Zhulina Ekaterina B. , Borisov Oleg V.
Published: November 2024

The conformation of a polyelectrolyte (PE) brush grafted to the inner surface of a long cylindrical mesopore was described within analytical Poisson–Boltzmann strong stretching approximation. The internal structure of the PE brush, including brush thickness and radial density profile of monomer units, and radial distribution of electrostatic potential were analyzed as functions of the pore radius, degree of polymerization, and grafting density of the brush-forming PE chains as well as ionic strength of the solution. It is demonstrated that narrowing of the pore leads to a non-monotonous variation of the brush thickness, which passes through a maximum when the brush thickness becomes equal to the pore radius. Variation in the salt concentration triggers conformational transition that leads to the opening or closing of the hollow (PE-free) channel in the pore center that potentially allows controlling of the pore-selective permeability for charged nanocolloidal particles (e.g., globular proteins or viruses). The predictions of the analytical theory were validated by numerical calculations using the Scheutjens–Fleer self-consistent field modeling method. These theoretical findings may be used for the design of highly selective smart mesoporous membranes with PE brush-functionalized pores for, e.g., protein separation and purification.
Magnetic textures and perpendicular anisotropy in asymmetric multilayers with Ta and W
Authors: Shukaili S. Al , Berrai I. , Ma'Mari F. Al , Ramu M. , Bhatti S. , Zar Myint M. T. , Harthi S. Al , Cherif S. M. , Piramanayagam S. N. , Sbiaa R.
Published: November 2024

Asymmetric (Pt/Co/X) multilayers where X is Ta or W have been investigated. Both structures showed a tailed hysteresis loop indicating the existence of skyrmions. The interfacial Dzyaloshinskii–Moriya interaction (iDMI) extracted from Brillouin light scattering revealed that sample with W has a value of −0.52 mJ/m2, which is ∼2.5 times larger than Ta case. In addition to iDMI, the perpendicular magnetic anisotropy is also stronger for W case due to the orbital hybridization at the interface. From magnetic force microscopy, W sample showed a change from unusual rod-like domains to skyrmions, while the change was from labyrinth domains to skyrmions in Ta-based structure.