bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tunable Hydroxyapatite/Magnetite Nanohybrids with Preserved Magnetic Properties
Authors: Jahoushi Khaula A. Al , Ayesh Ahmad I. , El‐Maghraby Hesham F. , Alnoush Wajdi , Higgins Drew , Hassan Fathy M. , Greish Yaser E. 
Published: April 2022

AbstractMagnetic nanoparticles (MNPs) have been extensively investigated in a wide range of biomedical applications. Controlled coating of the MNPs is commonly utilized to protect and maintain their magnetic properties and to improve their biocompatibility, hydrophilicity, colloidal stability and overall biodistribution. Hydroxyapatite (HAp), a highly biocompatible material, is considered for the functionalization of MNPs. In this study, two simple chemical approaches are used to prepare nanohybrid MNPs‐on‐HAp and HAp‐on‐MNPs composites. The effect of heat treatment on the phase composition, morphology, and magnetic properties of both types of magnetic composites is extensively evaluated. In the presence of HAp, MNPs are segregated onto their surfaces and their transformation to hematite upon heat treatment is delayed. On the other hand, needle‐shaped HAp nanocrystallites preferentially grow onto the hydroxylated MNPs surfaces, leading to a synergistic enhancement in the magnetic properties of the produced nanocomposites, with preserved magnetic properties. Compared with a saturation magnetization (Ms) value of 80 emu g−1 of pure MNPs, a MNPs‐on HAp nanohybrid shows a maximum of 14 emu g−1, while nanohybrids based on HAp‐on‐MNPs show Ms values in the range of 43–78 emu g−1. These findings demonstrate the ability to fine‐tune the magnetic properties of the HAp/MNPs nanohybrids via optimizing their processing conditions.
Upconversion‐Enabled In Situ Growth of Silver Nanostructures Mediated by Cavity Resonance in Single Microrod
Authors: He Huilin , Liu Jianxun , Li Ke , Xu Yiwei , Cai Wenfeng , Wang Jiawei , Cen Mengjia , Liu Yan Jun 
Published: April 2022

AbstractSolution‐based photochemical reaction is widely utilized in the syntheses of metallic nanocrystals. Although seedless photochemical reaction can avoid pre‐treatments, it relies on long, high‐energy radiation. Here, this work demonstrates an upconversion‐enabled seedless photochemical approach to synthesize grating‐like silver nanostructures on a hexagonal NaYF4 microrod via a near‐infrared laser excitation. Experimental results show that upconversion emission enables the nucleation and growth of Ag nanoparticles. Meanwhile, the emission can be also precisely tuned and enhanced by in situ growth of silver nanoparticles on the NaYF4 and NaYF4@SiO2 microrods. The maximum enhancement factor of 2 in overall emissions is achieved for the NaYF4@SiO2 microrod. This fabrication approach and results visually confirm the cavity resonance of excitation light inside the microrod via the distribution of Ag nanostructures. Moreover, the in situ grown Ag nanostructures provide a tunable far‐field upconversion emission via the plasmonic effect, which is potentially useful for tunable microlasers, biosensing, antibacterial, and catalytic applications.
Air Cushion Storing Energy Promoting Droplets Retraction and Flow on Engineering Porous Bionic Lotus Surfaces
Authors: Zhu Zewei , Li Jingbo , Luo Yimin , Tan Sheng , Wei Manjun , Lai Ziming , Luo Zhuangzhu 
Published: April 2022

AbstractPorous bionic self‐cleaning surfaces with low contact time of droplets show good potentials in anti‐icing, drag reduction, antifouling, etc. However, the reason of asymmetric and fast retraction on inclined surfaces after droplet impact is not clear. Here, it is reported that the fast retraction is mainly ascribed to the “air cushion” in porous surface acting as “energy reservoir” that stores excess kinetic energy of droplet during spread and returns it back promoting droplets retraction with contact time 20–40% off. Besides, the pinning effect and wetting state transition result in the asymmetric morphology evolution and suddenly stretch along tangential. A physical model of droplet asymmetric retraction including the influence of dynamic wetting angle fDCA, pinning effect fPin, and air cushion fAir is innovatively proposed to describe droplet morphologic evolution. The fundamental understanding of droplets impact dynamic on inclined surfaces is beneficial for engineering applications of extremely wettable surfaces.
Soybean management for seed composition: The perspective of U.S. farmers
Authors: Borja Reis Andre F. , Rosso Luiz , Davidson Dan , Kovács Péter , Purcell Larry C. , Below Frederick E , Casteel Shaun , Kandel Hans J. , Naeve Seth , Archontoulis Sotirios V. , Ciampitti Ignacio A. 
Published: April 2022

AbstractThe soybean [Glycine max (L.) Merr.] compositional quality is mainly provided by the seed concentration of protein and oil. These traits are critical for sustaining global use, and although there is demand for high protein soybean, no mechanism to differentiate production is in place. At the opposite end of the supply chain, farmers are remunerated on a mass basis without having any incentive regarding seed composition. This study evaluated farmers' perspectives and knowledge on soybean quality and their propensity to adopt quality improvement technologies. Farmers from the main U.S. producing regions (n = 271) were investigated with a self‐administrated survey containing 21 questions during 2020 and 2021. Our results show that 84% are unaware of the current protein and oil levels from their own production. A small portion (1.4%) make management decisions (e.g., choice of genotypes or monitor quality) based on the implications on seed quality. However, practices already in place are likely to enhance the quality of seed, namely N nutrition (via rhizobia [12.9%] or fertilizer [5.9%]) and late‐season crop protection (17.1%). If farmers are financially rewarded by US$0.50 per bushel, a mindset change may occur. Based on these results, we concluded that shifts in the U.S. production system targeting protein or oil markets are possible, and the constraints are mainly related to on‐farm management. However, the challenges for improving the U.S. soybean competitiveness in global or niche markets also rely upon other segments of the production chain, specifically breeders, technology suppliers, and logistical structure.
Toward clinical and molecular dissection of frontonasal dysplasia with facial skin polyps: From Pai syndrome to differential diagnosis through a series of 27 patients
Authors: Lehalle Daphné , Bruel Ange‐Line , Vitobello Antonio , Denommé‐Pichon Anne‐Sophie , Duffourd Yannis , Assoum Mirna , Amiel Jeanne , Baujat Geneviève , Bessieres Bettina , Bigoni Stefania , Burglen Lydie , Captier Guillaume , Dard Rodolphe , Edery Patrick , Fortunato Fernanda , Geneviève David , Goldenberg Alice , Guibaud Laurent , Héron Delphine , Holder‐Espinasse Muriel , Lederer Damien , Lopez Grondona Fermina , Grotto Sarah , Marlin Sandrine , Nadeau Gwenaël , Picard Arnaud , Rossi Massimiliano , Roume Joëlle , Sanlaville Damien , Saugier‐Veber Pascale , Triau Stéphane , Valenzuela Palafoll Maria Irene , Vanlerberghe Clémence , Van Maldergem Lionel , Vezain Myriam , Vincent‐Delorme Catherine , Zivi Einat , Thevenon Julien , Vabres Pierre , Thauvin‐Robinet Christel , Callier Patrick , Faivre Laurence 
Published: April 2022

AbstractUnique or multiple congenital facial skin polyps are features of several rare syndromes, from the most well‐known Pai syndrome (PS), to the less recognized oculoauriculofrontonasal syndrome (OAFNS), encephalocraniocutaneous lipomatosis (ECCL), or Sakoda complex (SC). We set up a research project aiming to identify the molecular bases of PS. We reviewed 27 individuals presenting with a syndromic frontonasal polyp and initially referred for PS. Based on strict clinical classification criteria, we could confirm only nine (33%) typical and two (7%) atypical PS individuals. The remaining ones were either OAFNS (11/27—41%) or presenting with an overlapping syndrome (5/27—19%). Because of the phenotypic overlap between these entities, OAFNS, ECCL, and SC can be either considered as differential diagnosis of PS or part of the same spectrum. Exome and/or genome sequencing from blood DNA in 12 patients and from affected tissue in one patient failed to identify any replication in candidate genes. Taken together, our data suggest that conventional approaches routinely utilized for the identification of molecular etiologies responsible for Mendelian disorders are inconclusive. Future studies on affected tissues and multiomics studies will thus be required in order to address either the contribution of mosaic or noncoding variation in these diseases.
First order metal‐insulator transition in two‐dimensional disordered systems
Authors: Xiong Shi‐Jie , Katomeris G.N. , Evangelou S.N. 
Published: April 2022

AbstractIn the absence of magnetic field or spin‐orbit coupling the one‐parameter scaling theory predicts localization of all states in two‐dimensional (2D) disordered systems, for any amount of disorder. However, a 2D metallic phase has been recently reported in high mobility Si‐MOS and GaAs‐based materials without magnetic field. We study numerically a recently proposed 2D model which consists of a compactly coupled pure‐random plane structure. This allows to obtain exactly a continuum of one‐dimensional ballistic extended states which can lead to a marginal metallic phase of finite conductivity σ0 = 2e2/h, in a wide energy range whose boundaries define the mobility edges of a first‐order metal‐insulator transition. We present numerical diagonalization results and the conductivity of the system in perpendicular magnetic field, which verify the above analytical predictions. The model is also discussed in connection to recent experiments.
Many‐body spectral statistics of interacting fermions
Authors: Pascaud M. , Montambaux G. 
Published: April 2022

AbstractWe have studied the appearance of chaos in the many‐body spectrum of interacting Fermions. The coupling of a single state to the Fermi sea is considered. This state is coupled to a hierarchy of states corresponding to one or several particle‐hole excitations. We have considered various couplings between two successive generations of this hierarchy and determined under which conditions this coupling can lead to Wigner‐Dyson correlations. We have found that the cross‐over from a Poisson to a Wigner distribution is characterized not only by the ratio V = Δc, but also by the ratio Δc = δ. V is the typical interaction matrix element, δ is the energy distance between many‐body states and Δc is the distance between many‐body states coupled by the interaction.
Level repulsion in excitonic spectra of disordered systems and local relaxation kinetics
Authors: Runge Erich , Zimmermann Roland 
Published: April 2022

AbstractA thorough understanding of the excitonic spectra from quantum wells with rough interfaces or alloy disorder requires large‐scale numerical simulations with detailed modeling of the underlying quantum mechanics of exciton localization and relaxation. We discuss various numerical aspects of the calculation of wave functions, phonon transition rates and radiative lifetimes, as well as absorption and luminescence spectra. We argue, that spatially and energetically resolved spectra yield information on wave function size and localization character and discuss phonon scattering between disorder eigenstates for the limit of small energy transfer which is relevant at low temperatures.
Quantum diffusion of interacting particles in a random potential
Authors: Halfpap O. , Kawarabayashi T. , Kramer B. 
Published: April 2022

AbstractWe simulate the quantum diffusion of n interacting particles in a one dimensional disordered system by solving the time dependent n‐particle Schrödinger equation numerically. The influence of the interaction on the diffusion is studied. The mean extensions of the n‐particle wave packets (n ≤ 3) in the asymptotic limit of infinite time are investigated as functions of the disorder and the interaction strength. Our findings are consistent with interaction‐induced delocalization which is considerably enhanced when increasing the number of particles.
Energy barriers of spin glasses from multi‐overlap simulations
Authors: Janke Wolfhard , Berg Bernd A. , Billoire Alain 
Published: April 2022

AbstractWe report large‐scale simulations of the three‐dimensional Edwards‐Anderson Ising spin glass system using the recently introduced multi‐overlap Monte Carlo algorithm. In this approach the temperature is fixed and two replica are coupled through a weight factor such that a broad distribution of the Parisi overlap parameter q is achieved. Canonical expectation values for the entire q‐range (multi‐overlap) follow by reweighting. We present an analysis of the performance of the algorithm and in particular discuss results on spin glass free‐energy barriers which are hard to obtain with conventional algorithms. In addition we discuss the non‐trivial scaling behavior of the canonical q‐distributions in the broken phase.
Energy balance and energy transport velocity in dispersive media
Authors: Diener G. 
Published: April 2022

AbstractThe energy balance equation is considered for an electromagnetic wave in a medium with frequency dispersion. It is shown that the energy density consists of two parts representing the field energy and the energy stored in the medium, respectively. The energy transport is carried solely by the field energy. A corresponding transport velocity is introduced. It differs from the group velocity and is always smaller than (or equal to) the vacuum speed of light, even in the case of superluminal group velocities.
Superluminal electromagnetic waves in free space
Authors: Capelas de Oliveira E. , Rodriguez W.A. 
Published: April 2022

AbstractRecently it has been shown that all relativistic wave equations possess families of undistorted progressive waves (UPWs) which can travel with arbitrary speeds 0 ≤ v < ∞. In this paper we present the theory of how to generate UPW solutions of the Maxwell equation and discuss the particular case of the superluminal electromagnetic X‐wave (SEXW), clarifying its extraordinary properties. The theory of how it is possible to launch finite aperture approximations for the SEXW in free space is also discussed in detail. The theory is illustrated by computer simulations showing the birth of a finite aperture approximation for a SEXW and its superluminal propagation without appreciable distortion up to a 100 km. We discuss also the experimental evidence available and discuss if SEXWs can be used to transmit information.
Instantaneous spreading and Einstein causality in quantum theory
Authors: Hegerfeldt G.C. 
Published: April 2022

AbstractIn nonrelativistic quantum mechanics the wave‐function of a free particle which initially is in a finite volume immediately spreads to infinity. In a nonrelativistic theory this is of no concern, but we show that the same instantaneous spreading can occur in relativistic quantum theory and that transition probabilities in widely separated systems may instantaneously become nonzero. We discuss how this affects Einstein causality.
Superluminal microwave propagation and special relativity
Authors: Recami E. , Hernández F. H.E. , Pablo A. , Barbero L. 
Published: April 2022

AbstractIn the first part of this paper we verify, on the basis of the numerical solution of Maxwell equations, that waves propagating down a microwave guide can travel with superluminal group velocity, thus confirming experimental results previously reported in the literature. Then, we have to face the question of superluminal motions within the theory of Special Relativity. It is not widely recognized that all such theoretical and experimental results do not place relativistic causality in jeopardy. For instance, it seems possible to solve also the known causal paradoxes devised for “faster than light” motion. Here we show, in detail and rigorously, how to solve the oldest causal paradox, originally proposed by Tolman, which is the kernel of many further tachyon paradoxes. The key to the solution is a careful application of tachyon mechanics, as it unambiguously follows from Special Relativity.
Hamilton formalism and variational principle construction
Authors: Ván P. , Nyíri B. 
Published: April 2022

AbstractIt is widely accepted that a variational principle cannot be constructed for an arbitrary differential equation; a rigorous mathematical condition shows which equations can have a variational formulation. On the other hand, the importance for variational principles in various fields of physics resulted in several methods to circumvent this condition and to construct another type of variational principles for any differential equation. In this paper the common origin of the considered methods is investigated, and a generalized Hamiltonian formalism is formulated. Additionally, constructive algorithms are given by different methods to construct variational principles. Simple examples are presented to make construction methods more transparent: several Lagrangians are constructed for the different forms of the Maxwell equations and for the extended heat conduction equation.
Perturbation treatment of non‐linear transport via the Robertson statistical formalism
Authors: Nettleton R.E. 
Published: April 2022

AbstractA perturbation solution is found for the differential equation defining an operator Tˆ used by Robertson to relate the information‐theoretic phase‐space distribution σ to the solution ρ of the classical Liouville equation. This relation provides a closure, used in obtaining an exact equation for σ. Multiplying the latter equation by F, a phase‐space function odd under momentum reversal, of which heat and diffusion fluxes are among the examples, one gets an exact equation for ∂〈F〉/∂t. 〈F〉 is the phase space integral of ρF. The dissipative terms in ∂〈F〉/∂t can be expanded, like Tˆ, in successive orders O(〈F〉n). For a model in which equilibrium ensemble fluctuations relax exponentially, terms linear and O(〈F〉3) are calculated. The non‐linear terms exhibit an explicit time‐dependence for short times. In a steady state induced by external driving forces, the explicit time‐dependence disappears, in agreement with existing phenomenology. For simplicity, spatial uniformity is assumed. A generalization is required for large temperature or velocity gradients.
Magnetic field dependencies of the critical current and of the resonant modes of dc SQUIDs fabricated from superconductors with s + id order‐parameter symmetries
Authors: Chesca Boris 
Published: April 2022

AbstractThe magnetic field dependencies of the critical current and of the self‐induced resonant modes of dc SQUIDs fabricated from superconductors with s + id order parameter symmetries are calculated. Combining the complementary results of the two dependencies, an unambiguous determination of the ratio of the s and d wave components is possible. Two cases of SQUID configurations are analyzed for which the flux coupled to the two Josephson junctions of the dc SQUID is either negligible or significant.
Ground state properties of disordered and dimerized spin chains
Authors: Schuster C. , Eckern U. 
Published: April 2022

AbstractConcerning the question of the (spin‐)Peierls mechanism in the presence of disorder we present a detailed analysis of the ground state phase diagram of the dimerized anisotropic Heisenberg‐XXZ chain containing one impurity. It is obtained by studying the destruction of the quantum coherence by the perturbations. The stability of the Peierls phase, i. e. the occurence of a stable dimerization, is determined by the energy gain and gap due to the coupling to the static phonons. The extension of the paramagnetic phase, found already in the clean dimerized chain, grows by adding the impurity, because the distortions weaken each other. The Peierls phase is reduced for two reasons: First, the energy gain of the spin‐system decreases, which leads to a smaller stable dimerization and second, the energy gap itself is reduced.
Metal‐insulator transition in nanocomposites of glass and RuO2
Authors: Kusy A. , Stadler A.W. , Mleczko K. , Żak D. , Pawłowski S. , Szałański P. , Zawiślak Z. , Grabecki G. , Plesiewicz W. , Dietl T. 
Published: April 2022

AbstractWe report on studies of interplay between percolation and quantum localization in mixtures consisting of glass grains and RuO2 metal particles of average diameters 550 and 10 nm, respectively. A weak temperature dependence of conductivity σ(T) = a + bTα, where α ≅ 0.20, is found in the temperature region 0.04 < T < 1 K. Similarly, an anomalously small magnitude of magnetoconductivity is observed in the studied magnetic field range up to 5 T. These observations demonstrate that percolation nature of electron transport leads to a significant modification of quantum corrections to conductivity at the localization boundary. The conductivity at criticality obeys a dynamic scaling equation with the conductivity exponent μ = 1.65 as expected for one‐electron Anderson localization.
Quantum critical behavior of itinerant ferromagnets
Authors: Vojta Thomas , Belitz D. , Kirkpatrick T.R. , Narayanan R. 
Published: April 2022

AbstractWe investigate the quantum phase transition of itinerant ferromagnets. It is shown that correlation effects in the underlying itinerant electron system lead to singularities in the order parameter field theory that result in an effective long‐range interaction between the spin fluctuations. This interaction turns out to be generically antiferromagnetic for clean systems. In disordered systems analogous correlation effects lead to even stronger singularities. The resulting long‐range interaction is, however, generically ferromagnetic.We discuss two possibilities for the ferromagnetic quantum phase transition. In clean systems, the transition is generically of first order, as is experimentally observed in MnSi. However, under certain conditions the transition may be continuous with non‐mean field critical behavior. In disordered systems, one finds a very rich phase diagram showing first order and continuous phase transitions and several multicritical points.
The quantized Hall insulator
Authors: Hilke M. , Shahar D. , Song S.H. , Tsui D.C. , Shayegan M. , Xie Y.H. 
Published: April 2022

AbstractThe quantized Hall insulator is characterized by vanishing conductivities and a quantized Hall resistance. For low mobility samples, the quantized Hall insulator is obtained when the magnetic field is increased well above the ν = 1 quantum Hall state. For higher mobility samples, a similar quantization is observed when the magnetic field is increased above the ν = 1/3 fractional quantum Hall states. This quantization, throughout the quantum Hall liquid‐to‐insulator transition, leads to a perfect semicircle relation for the diagonal and Hall conductivities. The measurements were performed in Ge/SiGe quantum Wells and in n‐type InP/InGaAs and GaAs/AlGaAs heterostuctures.
Scaling analysis of the low temperature conductivity in neutron‐transmutation‐doped 70Ge:Ga
Authors: Itoh K.M. , Watanabe M. , Ootuka Y. , Haller E.E. 
Published: April 2022

AbstractWe report on the scaling analysis of low temperature electron transport properties of nominally uncompensated neutron‐transmutation‐doped 70Ge:Ga samples in the critical regime for the metal‐insulator transition. Ga concentration (N) and temperature (T) dependent conductivities σ(N, T) are shown to collapse onto a single universal curve using finite temperature scaling of a form σ(N, T) ∝ Tx f(|N/Nc — 1|/Ty) with x ≈︂ 0.38 and y ≈︂ 0.32 for the very small region of N = Nc ± 0.004Nc. The conductivity critical exponent μ = x/y = 1.2 ± 0.2 found from this analysis is significantly larger than μ ≈︂ 0.5 found from the analysis we performed previously on the same series of samples covering the much larger region of the concentration Nc < N < 1.4Nc. Determination of the true critical region, either N = Nc ± 0.4% or N = Nc ± 40%, is necessary in the future for the reliable determination of μ in Ge:Ga.