bluuebunny/crossref_metadata_2025_split huggingface dataset:
Highly Sensitive Tungsten Oxide Thin Film‐Based Field‐Effect Transistor for Real‐Time Monitoring of Dissolved Ammonia in Human Plasma
Authors: Sharma Sumit , Moudgil Akshay , Singh Sanjay , Das Samaresh , Mishra Prashant 
Published: June 2022

AbstractField‐effect transistors (FETs) based on metal‐oxide thin film have the advantage of excellent sensitivity, fast response, miniaturized size, and compatibility with bio‐analytes. In this work, a highly responsive FET biosensor is fabricated based on tungsten trioxide (WO3) thin film to detect the physiological concentration of total ammonia (ammonium NH4+ and NH3) in human body fluids. The elevated level of ammonia in the body fluids indicates damage or improper functioning of organs mainly the liver. Thus, real‐time monitoring of ammonia concentration in human body fluid acts as a prognostic marker for liver disorders. The fabricated FET device shows reliable and accurate results for ammonia sensing with the highest response of 498 at 100 µM and a limit of detection of 6 µM. This device measures the ammonia in body fluid faster than available techniques and shows a high response towards ammonia in commercially available human plasma. This is also capable of real‐time detection of very low concentrations of ammonia (2 µM) with a wide range from 2 to 100 µM. Also, the prospect of the device's batch fabrication is demonstrated with consistent and high stability performance. This study demonstrates a unique and stable sensing platform, capable of direct detection of ammonia concentration in human plasma for point of care applications.
Smooth or with a Snap! Biomechanics of Trap Reopening in the Venus Flytrap (Dionaea muscipula)
Authors: Durak Grażyna M. , Thierer Rebecca , Sachse Renate , Bischoff Manfred , Speck Thomas , Poppinga Simon 
Published: June 2022

AbstractFast snapping in the carnivorous Venus flytrap (Dionaea muscipula) involves trap lobe bending and abrupt curvature inversion (snap‐buckling), but how do these traps reopen? Here, the trap reopening mechanics in two different D. muscipula clones, producing normal‐sized (N traps, max. ≈3 cm in length) and large traps (L traps, max. ≈4.5 cm in length) are investigated. Time‐lapse experiments reveal that both N and L traps can reopen by smooth and continuous outward lobe bending, but only L traps can undergo smooth bending followed by a much faster snap‐through of the lobes. Additionally, L traps can reopen asynchronously, with one of the lobes moving before the other. This study challenges the current consensus on trap reopening, which describes it as a slow, smooth process driven by hydraulics and cell growth and/or expansion. Based on the results gained via three‐dimensional digital image correlation (3D‐DIC), morphological and mechanical investigations, the differences in trap reopening are proposed to stem from a combination of size and slenderness of individual traps. This study elucidates trap reopening processes in the (in)famous Dionaea snap traps – unique shape‐shifting structures of great interest for plant biomechanics, functional morphology, and applications in biomimetics, i.e., soft robotics.
Interatomic Electronegativity Offset Dictates Selectivity When Catalyzing the CO2 Reduction Reaction
Authors: Hao Jican , Zhuang Zechao , Hao Jiace , Wang Chan , Lu Shuanglong , Duan Fang , Xu Fangping , Du Mingliang , Zhu Han 
Published: June 2022

AbstractAchieving efficient efficiency and selectivity for the electroreduction of CO2 to value‐added feedstocks has been challenging, due to the thermodynamic stability of CO2 molecules and the competing hydrogen evolution reaction. Herein, a dual‐single‐atom catalyst consisting of atomically dispersed CuN4 and NiN4 bimetal sites is synthesized with electrospun carbon nanofibers (CuNi‐DSA/CNFs). Theoretical and experimental studies reveal the strong electron interactions induced by the electronegativity offset between the Cu and Ni atoms. The delicately averaged and compensated electronic structures result in an offset effect that optimizes the adsorption strength of the *COOH intermediate and boosts the CO2 reduction reaction (CO2RR) kinetics, notably promoting the intrinsic activity and selectivity of the catalyst. The CuNi‐DSA/CNFs catalyst exhibits an outstanding FECO of 99.6% across a broad potential window of −0.78– −1.18 V (vs the reversible hydrogen electrode), a high turnover frequency of 2870 h–1, and excellent durability (25 h). Furthermore, an aqueous Zn‐CO2 battery for CO2 power conversion is constructed. This atomic‐level electronegativity offset of the dual‐atom structures provides an appealing direction to develop advanced electrocatalysts for the CO2RR.
The first second of the Universe
Authors: Schwarz D.J. 
Published: June 2022

AbstractThe history of the Universe after its first second is now tested by high quality observations of light element abundances and temperature anisotropies of the cosmic microwave background. The epoch of the first second itself has not been tested directly yet; however, it is constrained by experiments at particle and heavy ion accelerators. Here I attempt to describe the epoch between the electroweak transition and the primordial nucleosynthesis. The most dramatic event in that era is the quark‐hadron transition at 10 μs. Quarks and gluons condense to form a gas of nucleons and light mesons, the latter decay subsequently. At the end of the first second, neutrinos and neutrons decouple from the radiation fluid. The quark‐hadron transition and dissipative processes during the first second prepare the initial conditions for the synthesis of the first nuclei. As for the cold dark matter (CDM), WIMPs (weakly interacting massive particles) – the most popular candidates for the CDM – decouple from the presently known forms of matter, chemically (freeze‐out) at 10 ns and kinetically at 1 ms. The chemical decoupling fixes their present abundances and dissipative processes during and after thermal decoupling set the scale for the very first WIMP clouds.
The distinction of integer and fractional Quantum Hall Effect is a mathematical artifact without physical merit
Authors: Post E.J. 
Published: June 2022

AbstractMany body wave function assessments of the quantum Hall effect are compared with a global assessment using Aharonov‐Bohm and Gauss‐Ampère period‐integrals as counters of flux and charge quanta. Experiment pleads in favor of a two quanta unified description in terms of flux and charge numbers.
Antiferromagnetic and superconducting gaps and their interrelation in high‐Tc cuprates
Authors: Arrigoni E. , Zacher M.G. , Eckl T. , Hanke W. 
Published: June 2022

AbstractWe propose a phenomenological model, comprising a microscopic SO(5) model plus the on‐site Hubbard interaction U (projected SO(5) model) to understand the interrelation between the d‐wave‐gap modulation observed by recent angle‐resolved photoemission experiments in the insulating antiferromagnet Ca2CuO2Cl2 and the d‐wave gap of high‐Tc superconducting materials. The on‐site interaction U is important in order to produce a Mott gap of the correct order of magnitude, which would be absent in an exact SO(5) theory. The projected SO(5)‐model explains the gap characteristics, namely both the symmetry and the different order of magnitude of the gap modulations between the AF and the SCc phases. Furthermore, it is shown that the projected SO(5) theory can provide an explanation for a recent observation [E. Pavarini et al., Phys. Rev. Lett. 87, 47003 (2001)], i. e. that the maximum Tc observed in a large variety of high‐Tc cuprates scales with the next‐nearest‐neighbor hopping matrix element t′.
Radion‐induced gravitational wave oscillations and their phenomenology
Authors: Barvinsky A.O. , Kamenshchik A.Yu. , Rathke A. , Kiefer C. 
Published: June 2022

AbstractWe discuss the theory and phenomenology of the interplay between the massless graviton and its massive Kaluza‐Klein modes in the Randall‐Sundrum two‐brane model. The equations of motion of the transverse traceless degrees of freedom are derived by means of a Green function approach as well as from an effective nonlocal action. The second procedure clarifies the extraction of the particle content from the nonlocal action and the issue of its diagonalization. The situation discussed is generic for the treatment of two‐brane models if the on‐brane fields are used as the dynamical degrees of freedom. The mixing of the effective graviton modes of the localized action can be interpreted as radion‐induced gravitational‐wave oscillations, a classical analogy to meson and neutrino oscillations. We show that these oscillations arising in M‐theory‐motivated braneworld setups could lead to effects detectable by gravitational‐wave interferometers. The implications of this effect for models with ultra‐light gravitons are discussed.
A new look at the derivation of the Schrödinger equation from Newtonian mechanics
Authors: Fritsche L. , Haugk M. 
Published: June 2022

AbstractWe present a modified version of Nelson's seminal paper on the derivation of the time‐dependent Schrödinger equation which draws on the equation of motion of a particle that moves under the influence of a classical force field and additional stochastic forces. The emphasis of our elaboration is focused on the implication of allowing stochastic forces to occur, viz. that the energy E of the particle is no longer conserved on its trajectory in a conservative force field. We correlate this departure Δ E from its classical energy with the energy/time uncertainty relation where Δ t is the average time for Δ E to persist. The stability of atoms, the zero‐point energy of oscillators, the tunneling effect and the diffraction at slits are shown to be directly connected with the occurrence of such energy fluctuations. We discuss and rederive Nelson's theory entirely from this point of view and generalize his approach to systems of N particles which interact via pair forces. Achieving reversibility in a description of particle motion that is akin to Brownian motion, represents a salient point of the derivation. We demonstrate that certain objections raised against Nelson's theory are without substance. We also try to put the particular worldview of this version of stochastic quantum mechanics into perspective with regard to the established Copenhagen interpretation.
Influence of surface roughness on subdominant pairing in d‐wave superconductors
Authors: Lück T. 
Published: June 2022

AbstractWe study a d‐wave superconductor with dominant d‐wave order parameter and subdominant pairing in either the s‐ or the dxy‐wave channel near a surface. In particular we analyze the influence of surface roughness on the mixed order parameter which may break the time‐reversal symmetry. We find that the subdominant component is suppressed by the roughness independent of its pairing symmetry; for very rough surfaces the subdominant component may even vanish completely. Additionally we discuss a possible real‐valued admixture which counteracts the suppression of the d‐wave order parameter at the surface.
Uniqueness of conserved currents in quantum mechanics
Authors: Holland P. 
Published: June 2022

AbstractIt is proved by a functional method that the conventional expression for the Dirac current is the only conserved 4‐vector implied by the Dirac equation that is a function of just the quantum state. The demonstration is extended to derive the unique conserved currents implied by the coupled Maxwell‐Dirac equations and the Klein‐Gordon equation. The uniqueness of the usual Pauli and Schrödinger currents follows by regarding these as the non‐relativistic limits of the Dirac and Klein‐Gordon currents, respectively. The existence and properties of further conserved vectors that are not functions of just the state is examined.
The fifth dimension: Theodor Kaluza's ground‐breaking idea
Authors: Wuensch D. 
Published: June 2022

AbstractTheodor Kaluza (1885–1954) attracted the attention of the physical community since 1921 with his unified field theory of gravitation and electromagnetism in five dimensions. Despite Einstein's great interest in Kaluza's theory, 50 years elapsed before it contributed toward a paradigm shift in modern theoretical physics. The biography of this still unknown scientist is briefly presented along with an outline of his work in physics. A short history of the theories of unification and the dimensionality of space‐time is followed by a discussion of the significance of Kaluza's five‐dimensional unified theory in modern physics from the point of view of superstring and M‐theory.
Interference of probabilities and number field structure of quantum models
Authors: Khrennikov A. 
Published: June 2022

AbstractWe study the probabilistic consequences of the choice of the basic number field in the quantum formalism. We demonstrate that by choosing a number field for a linear space representation of quantum model it is possible to describe various interference phenomena. We analyse interference of probabilistic alternatives induced by real, complex, hyperbolic (Clifford) and p‐adic representations.
Mechanics with variable‐order differential operators
Authors: Coimbra C.F.M. 
Published: June 2022

AbstractThis work presents the novel concept of Variable‐Order (VO) Calculus through the description of a simple problem in Mechanics. A mathematical definition for the VO‐differential operator that is suitable to mechanical modelling is proposed, and an example concerning the effect of nonuniform viscoelastic frictional forces is described. A numerical method for the solution of Variable Order Differential Equations (VODEs) is proposed. The physical model under study requires mathematical tools that lie beyond the traditional methods of Constant‐Order (CO) differential equations. The VO‐Calculus formulation is compared to a CO‐Calculus model in order to show the limitations of the latter in resolving the transition between the relevant dynamic regimes.
Growth and characterization of La0.8Sr0.2MnO3/Pb(Zr0.2Ti0.8)O3/La0.8Sr0.2MnO3heterostructures for three‐dimensional circuit studies
Authors: Hong X. , Xiao F. , Reiner J.W. , Posadas A. , Ahn C.H. 
Published: June 2022

AbstractThe structural and electronic properties of epitaxial colossal magnetoresistive oxide (CMR) / ferroelectric / CMR trilayers have been examined to investigate the feasibility of building all‐oxide three‐dimensional (3D) circuits. Epitaxial Pb(Zr0.2Ti0.8)O3(PZT) films sandwiched by ultrathin La0.8Sr0.2MnO3(LSMO) layers have been fabricated using off‐axis magnetron sputtering, with high crystalline quality and smooth surfaces having been obtained. Both the top and bottom layers of LSMO exhibit CMR behavior.
Cathodoluminescence of selected single ZnO nanowires on sapphire
Authors: Lorenz M. , Lenzner J. , Kaidashev E.M. , Hochmuth H. , Grundmann M. 
Published: June 2022

AbstractCathodoluminescence (CL) investigations of selected single ZnO nanowires grown by a thermal vapor‐liquid‐solid process demonstrate their very good structural quality. The low temperature CL of the ZnO nanowires of about 100 nm diameter shows in the spectral range of the donor bound exciton three main peaks at 3.366, 3.362, and 3.358 eV. The full width at half maximum of the bound exciton peak is 1.1 meV for ZnO nanowires at 9 K. In comparison, the peak widths of epitaxial ZnO PLD thin films and a ZnO bulk single crystal (Eagle Picher) are 1.2 meV and 0.7 meV, respectively. In contradiction to ZnO nanowires grown by MOCVD at 750°C, the CL spectra of the thermally (915°C) grown ZnO nanowires show no additional peaks from donor or acceptor transitions or phonon replica.
Transport properties of reduced SrTiO3 single crystal “thin films”
Authors: Takahashi K.S. , Matthey D. , Jaccard D. , Triscone J.‐M. 
Published: June 2022

AbstractSrTiO3 single crystal surfaces were reduced using an hydrogen plasma cleaning method at room temperature. Transport measurements show that the reduced SrTiO3 surfaces are metallic with mobilities as high as 2.4 × 103 cm2/Vs at 10 K, comparable to those of bulk single crystals. The average carrier concentration is deduced to be ∼ 1 × 1018 cm‐3 and the reduced thickness ∼ 0.65 µm.
Difference in individual layer properties in cuprate/manganite structures deposited by laser ablation
Authors: Chakalov R.A. , Jeynes C. , Mikheenko P. , Allsworth M.D. , Darlington C.N.W. , Colclough M.S. , Muirhead C.M. 
Published: June 2022

AbstractWe report measurements of the electrical and magnetic properties of bilayers of YBa2Cu3O7 (YBCO) and La2/3Ca1/3MnO3 (LCMO) deposited on SrTiO3 substrates by Pulsed Laser Deposition. We find distinct differences in the properties depending on the order of the deposition, with the lower layer always being degraded. In particular, the YBCO has a Tc suppressed to ∼ 60 K when it is covered by LCMO. We argue that the effect is not due to an electronic interaction, but results from a reduction in the oxygen content of the YBCO by the LCMO.
Influence of gamma radiation on the electrical properties of MnO and MnO/TeO2 thin films
Authors: Arshak K. , Korostynska O. 
Published: June 2022

AbstractThe pure and mixed oxide materials, such as manganese oxide (MnO) and tellurium dioxide (TeO2), in the form of thermally deposited thin films were studied in terms of their susceptibility to gamma radiation exposure. Radiation‐induced changes in their electrical properties indicated the level of radiation damage. These thin film devices showed increase in values of current by the increase in the radiation dose. The dose response was found to be composition‐ and thickness‐dependant.
Leakage current through high permittivity thin films
Authors: Schroeder H. , Schmitz S. 
Published: June 2022

AbstractFor the leakage current through high‐permittivity, low‐electronic mobility, perovskite‐type thin films a bulk‐limited conduction mechanism is suggested, in contrast to the often assumed interface injection limitation. This model can successfully describe measured leakage data of field, temperature, thickness and electrode dependence in SrTiO3 and Ba0.7Sr0.3TiO3 thin films.
Proximity effect in oxide superconductor/ferromagnet films
Authors: Bacca E. , Pérez F. , Gross K. , Prieto P. , Morán O. , Hott R. 
Published: June 2022

AbstractWe fabricated high‐quality YBa2Cu3O7‐δ/La2/3Ca1/3 MnO3 bilayers with 10 monolayers (∼ 12 nm) thin superconducting YBa2Cu3O7‐δ (YBCO)layers on top of ferromagnetic La2/3Ca1/3MnO3 (LCMO) layers with a thickness varied between 5 and 35 monolayers (∼ 2–13 nm). We measured the transport properties of the YBCO layers and the magnetic properties of the LCMO layers as a function of the LCMO layer thickness. We observed a smooth linear increase of the Curie temperature TC of the LCMO layer in the investigated thickness range, but a sudden strong decrease of the superconducting critical temperature Tc of the YBCO layer at a critical LCMO thickness of ∼ 12 nm. Since no dramatic change of the structural quality of the YBCO layers is observed we conclude that the increasing magnetization strength in the LCMO layer is responsible for the Tc suppression in the YBCO layer via proximity effect.
Fabrication and characterisation of La0.67Sr0.33MnO3 submicron grain boundary junctions
Authors: Gunnarsson R. , Charlebois S. , Liljenfors T. , Ivanov Z. , Olsson E. 
Published: June 2022

AbstractWe have successfully fabricated LSMO grain boundary bicrystal junctions with widths down to 200 nm. The grain boundaries are symmetric with misorientation angles of 24° or 36.8°, and the microbridges are positioned across those with a precision better than ±0.5 µm. Grain boundary magnetoresistance is observed in the wider junctions but not in the most narrow junction.
Temperature and electric field response of a dielectric (Ba,Sr)TiO3 layer between perovskite‐type manganite electrodes
Authors: Khamchane K. , Boikov Yu.A. , Ivanov Z.G. 
Published: June 2022

AbstractEpitaxial films of ferroelectric (00l)Ba0.25Sr0.75TiO3 (BSTO) and ferromagnetic half metal La0.67Sr0.33MnO3 were grown by laser ablation, forming a trilayer heterostructure with combined ferroelectric and magnetic properties, on (001)(LaAlO4)0.3 + (Sr2AlTaO6)0.7 substrates. Maxima TM in the dielectric permittivity of ϵ of the BSTO film were 30–50 K lower than in bulk and ϵ follows a Curie‐Weiss law above TM. The ϵ was suppressed up to 50% at ±2.5 V between the electrodes. Below 100 K, loss function tan δ was found to be 0.005–0.01 at 1 kHz and 100 kHz.
Peculiar relics from Primordial Black Holes in the inflationary paradigm
Authors: Barrau A. , Blais D. , Boudoul G. , Polarski D. 
Published: June 2022

AbstractDepending on various assumptions on the energy scale of inflation and assuming a primordial power spectrum of a step‐like structure, we explore new possibilities for Primordial Black Holes (PBH) and Planck relics to contribute substantially to Cold Dark Matter in the Universe. A recently proposed possibility to produce Planck relics in four‐dimensional string gravity is considered in this framework. Possible experimental detection of PBHs through gravitational waves is also explored. We stress that inflation with a low energy scale, and also possibly when Planck relics are produced, leads unavoidably to relics originating from PBHs that are not effectively classical during their formation, rendering the usual formalism inadequate for them.
Harmonium
Authors: Karwowski J. , Cyrnek L. 
Published: June 2022

AbstractThe eigenvalue problem of a Hamiltonian describing two interacting particles confined by an external harmonic‐oscillator potential is analyzed. If the particles are identical, the system is referred to as harmonium. Harmonium belongs to very few non‐trivial two‐particle systems for which the Schrödinger equation is not only separable but also, for several interaction potentials and for a set of the coupling constants, quasi‐exactly solvable. In particular, the complete spectrum of harmonium has been obtained and analyzed. Also some aspects or relativistic generalizations of the model are briefly discussed.
Reduced density matrices, their spectral resolutions, and the Kimball‐Overhauser approach
Authors: Ziesche P. , Tasnádi F. 
Published: June 2022

AbstractRecently, it has been shown, that the pair density of the homogeneous electron gas can be parametrized in terms of 2‐body wave functions (geminals), which are scattering solutions of an effective 2‐body Schrödinger equation. For the corresponding scattering phase shifts, new sum rules are reported in this paper. These sum rules describe not only the normalization of the pair density (similar to the Friedel sum rule of solid state theory), but also the contraction of the 2‐body reduced density matrix. This allows one to calculate also the momentum distribution, provided that the geminals are known from an appropriate screening of the Coulomb repulsion. An analysis is presented leading from the definitions and (contraction and spectral) properties of reduced density matrices to the Kimball‐Overhauser approach and its generalizations. Thereby cumulants are used. Their size‐extensivity is related to the thermodynamic limit.See erratum Ann. Phys. (Leipzig) 13, 624 (2004)
Pattern formation in semiconductors: control of spatio‐temporal dynamics
Authors: Schöll E. 
Published: June 2022

AbstractSemiconductors driven far from thermodynamic equilibrium by an applied dc voltage exhibit a variety of spatio‐temporal electronic instabilities including complex and chaotic scenarios. We study stabilization of chaotic spatio‐temporal patterns in spatially extended semiconductor models by time delayed feedback control. Different control schemes, e.g., a diagonal control matrix, or global control, or combinations of both, are compared. Specifically, we use two models of semiconductor nanostructures which are of particular current interest: (i) superlattice, (ii) double‐barrier resonant‐tunneling diode.