bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gravitational fields of rotating disks and black holes
Authors: Meinel R. 
Published: May 2022

AbstractThe two known exact solutions of Einstein's field equations describing rotating objects of physical significance – a black hole and a rigidly rotating disk of dust – are discussed using a single mathematical framework related to Jacobi's inversion problem. Both solutions can be represented in such a form that they differ in the choice of a complex parameter and a real solution of the axisymmetric Laplace equation only.A recently found family of solutions describing differentially rotating disks of dust fits into the same scheme.
Singularity structure of the two point function of the free Dirac field on a globally hyperbolic spacetime
Authors: Kratzert Kai 
Published: May 2022

AbstractWe give an introduction to the techniques from microlocal analysis that have successfully been applied in the investigation of Hadamard states of free quantum field theories on curved spacetimes. The calculation of the wave front set of the two point function of the free Klein‐Gordon field in a Hadamard state is reviewed, and the polarization set of a Hadamard two point function of the free Dirac field on a curved spacetime is calculated.
Early Gedanken experiments of quantum mechanics revisited
Authors: Shi Yu 
Published: May 2022

AbstractThe famous gedanken experiments of quantum mechanics have played crucial roles in developing the Copenhagen interpretation. They are studied here from the perspective of standard quantum mechanics, with no ontological interpretation involved. Bohr's investigation of these gedanken experiments, based on the uncertainty relation with his interpretation, was the origin of the Copenhagen interpretation and is still widely adopted, but is shown to be not consistent with the quantum mechanical view. We point out that in most of these gedanken experiments, entanglement plays a crucial role, while its buildup does not change the uncertainty of the concerned quantity in the way thought by Bohr. Especially, in the gamma ray microscope and recoiling double‐slit gedanken experiments, we expose the entanglement based on momentum exchange. It is shown that even in such cases, the loss of interference is only due to the entanglement with other degrees of freedom, while the uncertainty relation argument, which has not been questioned up to now, is not right.
Laser‐ and collision‐induced nonadiabatic wave‐packet dynamics in sodium molecules
Authors: Grossmann F. , Saalmann U. , Schmidt R. 
Published: May 2022

AbstractWe investigate nonadiabatic dynamics of molecular sodium in two alternative approximate ways. Firstly, the semiclassical mapping formalism is used to study the decisive step in resonant two photon ionization of Na2, where the Rabi oscillations of the occupation probability of the resonantly excited intermediate state are reproduced with a high degree of accuracy. Secondly, nonadiabatic quantum molecular dynamics is combined with the surface hopping approach of Tully in order to take into account quantum effects on the nuclear dynamics in collisionally excited sodium molecular ions. Their importance is demonstrated by comparing the results with experimental fragment correlations of kinematically complete experiments.
Optical tests of quantum nonlocality: from EPR‐Bell tests towards experiments with moving observers
Authors: Gisin N. , Scarani V. , Tittel W. , Zbinden H. 
Published: May 2022

AbstractPast, present and future experimental tests of quantum nonlocality are discussed. Consequences of assuming that the state‐vector collapse is a real physical phenomenon in space‐time are developed. These lead to experiments feasible with today's technology.
The interpretation of quantum mechanics through1935
Authors: Cushing J.T. 
Published: May 2022

AbstractI first define what I mean by the term ‘interpretation’, then trace some of the major developments in attempts to fashion an interpretation of quantum mechanics from its early mathematical formulation (ca. 1925) up through the Einstein‐Podolsky‐Rosen paper, Bohr's response to it, and Schrödinger's insights on entanglement, in 1935. In the process, I question some of the conventional wisdom about how a unified interpretation emerged.
Plasma immersion ion implantation for silicon processing
Authors: Yankov Rossen A. , Mändl Stephan 
Published: May 2022

AbstractPlasma Immersion Ion Implantation (PIII) is a technology which is currently widely investigated as an alternative to conventional beam line implantation for ultrashallow doping beyond the 0.15 μm technology. However, there are several other application areas in modern semiconductor processing. In this paper a detailed discussion of the PIII process for semiconductors and of actual as well as future applications is given. Besides the well known advantages of PIII — fast process, implantation of the whole surface, low cost of ownership — several peculiarities — like spread of the implantation energy due to finite rise time or collisions, no mass separation, high secondary electron emission — must be mentioned. However, they can be overcome by adjusting the system and the process parameters. Considering the applications, ultrashallow junction formation by PIII is an established industrial process, whereas SIMOX and Smart‐Cut by oxygen and hydrogen implantation are current topics between research and introduction into industry. Further applications of PIII, of which some already are research topics and some are only investigated by conventional ion implantation, include seeding for metal deposition, gettering of metal impurities, etch stop layers and helium implantation for localized lifetime control.
Inertial mass and the quantum vacuum fields
Authors: Haisch Bernard , Rueda Alfonso , Dobyns York 
Published: May 2022

AbstractEven when the Higgs particle is finally detected, it will continue to be a legitimate question to ask whether the inertia of matter as a reaction force opposing acceleration is an intrinsic or extrinsic property of matter. General relativity specifies which geodesic path a free particle will follow, but geometrodynamics has no mechanism for generating a reaction force for deviation from geodesic motion. We discuss a different approach involving the electromagnetic zero‐point field (ZPF) of the quantum vacuum. It has been found that certain asymmetries arise in the ZPF as perceived from an accelerating reference frame. In such a frame the Poynting vector and momentum flux of the ZPF become non‐zero. Scattering of this quantum radiation by the quarks and electrons in matter can result in an acceleration‐dependent reaction force. Both the ordinary and the relativistic forms of Newton's second law, the equation of motion, can be derived from the electrodynamics of such ZPF‐particle interactions. Conjectural arguments are given why this interaction should take place in a resonance at the Compton frequency, and how this could simultaneously provide a physical basis for the de Broglie wavelength of a moving particle. This affords a suggestive perspective on a deep connection between electrodynamics, the origin of inertia and the quantum wave nature of matter.
Semiclassical trace formulae using coherent states
Authors: Mehlig Bernhard , Wilkinson Michael 
Published: May 2022

AbstractWe derive semiclassical trace formulae including Gutzwiller's trace formula using coherent states. This formulation has several advantages over the usual coordinate‐space formulation. Using a coherent‐state basis makes it immediately obvious that classical periodic orbits make separate contributions to the trace of the quantum‐mechanical time evolution operator. In addition, our approach is manifestly canonically invariant at all stages, and leads to the simplest possible derivation of Gutzwiller's formula.
Spindynamics in thulium van Vleck paramagnets
Authors: Weizenecker Jürgen 
Published: May 2022

AbstractThree different thulium hydrides (TmH2, Tm0.06La0.94H2, TmH2.73 have been investigated by means of nuclear magnetic resonance and static magnetic susceptibility measurements in a temperature range 4–300 K. A careful analysis of the data facilitates the determination of the various crystal field splittings and the type of microscopic magnetic interactions among and between the nuclear subsystems as well as those with the electrons. The selection of the samples used was made in order to clarify a transversal relaxation maximum of the protons at about 35 K. The measured relaxation rates and the resonance positions will be compared to theoretical results obtained by computing the relevant electronic and nuclear spectral densities as function of temperature.
On the generalized Tomimatsu‐Sato solutions
Authors: Hoenselaers C. 
Published: May 2022

AbstractWe consider stationary axisymmetric vacuum gravitational fields. We use the factor structure of rational solutions to derive two second order equations for two functions. From the solutions of those equations the Ernst potential can be found by quadrature. Non‐rational solutions generalize the Tomimatsu‐Sato solutions.
Canonical transformations and exact invariants for time‐dependent Hamiltonian systems
Authors: Struckmeier Jürgen , Riedel Claus 
Published: May 2022

AbstractAn exact invariant is derived for n‐degree‐of‐freedom non‐relativistic Hamiltonian systems with general time‐dependent potentials. To work out the invariant, an infinitesimalcanonical transformation is performed in the framework of the extended phase‐space. We apply this approach to derive the invariant for a specific class of Hamiltonian systems. For the considered class of Hamiltonian systems, the invariant is obtained equivalently performing in the extended phase‐space a finitecanonical transformation of the initially time‐dependent Hamiltonian to a time‐independent one. It is furthermore shown that the invariant can be expressed as an integral of an energy balance equation.The invariant itself contains a time‐dependent auxiliary function ξ (t) that represents a solution of a linear third‐order differential equation, referred to as the auxiliary equation. The coefficients of the auxiliary equation depend in general on the explicitly known configuration space trajectory defined by the system's time evolution. This complexity of the auxiliary equation reflects the generally involved phase‐space symmetry associated with the conserved quantity of a time‐dependent non‐linear Hamiltonian system. Our results are applied to three examples of time‐dependent damped and undamped oscillators. The known invariants for time‐dependent and time‐independent harmonic oscillators are shown to follow directly from our generalized formulation.
Electronic correlation in the quantum Hall regime
Authors: Kasner Marcus 
Published: May 2022

AbstractTwo‐dimensional interacting electron systems become strongly correlated if the electrons are subject to a perpendicular high magnetic field. After introducing the physics of the quantum Hall regime the incompressible many‐particle ground state and its excitations are studied in detail at fractional filling factors for spin‐polarized electrons. The spin degree of freedom whose importance was shown in recent experiments is considered by studying the thermodynamics at filling factor one and near one.
Acceleration‐induced nonlocality: kinetic memory versus dynamic memory
Authors: Chicone C. , Mashhoon B. 
Published: May 2022

AbstractThe characteristics of the memory of accelerated motion in Minkowski spacetime are discussed within the framework of the nonlocal theory of accelerated observers. Two types of memory are distinguished: kinetic and dynamic. We show that only kinetic memory is acceptable, since dynamic memory leads to divergences for nonuniform accelerated motion.
Screw dislocations in the field theory of elastoplasticity
Authors: Lazar Markus 
Published: May 2022

AbstractA (microscopic) static elastoplastic field theory of dislocations with moment and force stresses is considered. The relationship between the moment stress and the Nye tensor is used for the dislocation Lagrangian. We discuss the stress field of an infinitely long screw dislocation in a cylinder, a dipole of screw dislocations and a coaxial screw dislocation in a finite cylinder. The stress fields have no singularities in the dislocation core and they are modified in the core due to the presence of localized moment stress. Additionally, we calculated the elastoplastic energies for the screw dislocation in a cylinder and the coaxial screw dislocation. For the coaxial screw dislocation we find a modified formula for the so‐called Eshelby twist which depends on a specific intrinsic material length.
Hydrodynamics from Grad's equations: What can we learn from exact solutions?
Authors: Karlin I.V. , Gorban A.N. 
Published: May 2022

AbstractA detailed treatment of the classical Chapman‐Enskog derivation of hydrodynamics is given in the framework of Grad's moment equations. Grad's systems are considered as the minimal kinetic models where the Chapman‐Enskog method can be studied exactly, thereby providing the basis to compare various approximations in extending the hydrodynamic description beyond the Navier‐Stokes approximation. Various techniques, such as the method of partial summation, Padé approximants, and invariance principle are compared both in linear and nonlinear situations.
Numerical and analytical treatment of the smoothed Tamm problem
Authors: Afanasiev G.N. , Shilov V.M. , Stepanovsky Y.P. 
Published: May 2022

AbstractWe study the motion of an electric charge in a medium over a finite spatial distance. We consider at first the motion described by continuous functions of time, that is, its velocity and all its time derivatives are continuous. If the velocity v of the charge is greater than the velocity cn of light in the medium, then the intensity of the radiation is proportional to the frequency in some angular region and decreases exponentially outside of it. If the motion has no jumps in the velocity but jumps in the acceleration, the exponential decrease changes to a reciprocal one with 1/ω. For a purely decelerated motion, when both the initial and the final velocities are greater than cn, the intensity of the radiation contains a plateau. For practical application, the case with a vanishing final charge velocity is important: the intensity of the radiation is then maximal at the Cherenkov angle θc that corresponds to the initial charge velocity whereas it decreases sharply for θ>θc. For this case, provided the velocity of the charge exceeds cn, the total intensity (obtained by integrating the angular intensity of the radiation over the solid angle) is a linear function of the frequency, even though the Tamm condition is strongly violated.
Exact eigenstates for a Hamiltonian which represents a first order perturbative approximation of the periodic Anderson model
Authors: Mertins F.W. 
Published: May 2022

AbstractWe consider a two‐band model with strong correlations derived from the Periodic Anderson Model by means of first order perturbation theory with respect to 1/U (U is the local interaction for f‐sites). We show that at half‐filling the Gutzwiller ansatz is an exact solution of that model for special parameters, generalizing a result of Brand and Giesekus. We use an exponential representation of the wave function, which allows for the derivations to use a terminating multi‐commutator expansion. The latter motivates a generaliztion of the Gutzwiller wave function for the half‐filled case. The combination of the Bardeen Cooper Schrieffer wave function and the Gutzwiller ansatz leads to exact solutions for further two‐band models with strong correlations.
DNA‐Mediated Membrane Fusion and Its Biological Applications: Sensing, Reaction Control and Drug Delivery
Authors: Wang Caihui , Yan An , Wang Hui , Su Yingying , Li Di 
Published: May 2022

AbstractMembrane fusion plays a fundamental role in various biological processes, such as endocytosis, exocytosis, neurotransmission, and viral infections. These processes involve a highly selective recognition mechanism controlled by functional proteins, which inspire the development of sensitive and selective biosensors and other biomedical devices. By mimicking the nature membrane fusion mechanism, various artificial membrane fusion systems have been developed. In particular, DNA‐mediated membrane fusion holds great potential for spatiotemporal control of fusion events owing to the inherent programmability of DNA hybridization. Moreover, the biocompatibility of DNA enables it possible in vivo applications. In this Review, we illustrate different anchoring strategies of DNA‐mediated membrane fusion and discuss several factors that affect fusion efficiency. Subsequently, we highlight the biosensing application of the DNA‐mediated membrane fusion. In addition, we outline the significant progress made in other biological applications, including nanoreactor construction, protocell communication and drug delivery. Finally, we present major challenges and opportunities for DNA‐mediated membrane fusion.
Electrospinning synthesis of few‐layer hexagonal antimonene nanosheets as anode for lithium‐ion batteries
Authors: Sun Haibin , Zheng Wenrui , Liu Congcong , Liang Shuangshuang , Huang Mingyue , Li Ya , Gao Shasha , Feng Minghai , Liu Shenghong , Xie Wenhe 
Published: May 2022

AbstractTwo‐dimensional (2D) antimonene (Sb) is regarded as a promising anode candidate for lithium‐ion batteries owing to its theoretical capacity (660 mAh g−1). Preparing hexagonal Sb nanosheets (H‐SbNs) has been addressed an effective strategy to resolve the drastic volume expansion and the pulverization issues. Here, we present a facile method to prepare the few‐layer H‐SbNs on the surface of carbon fibers via the electrospinning with a thermal annealing process. When evaluated as an anode for lithium storage, the H‐SbN electrode delivers a high rate performance and excellent cycling stability. Electrochemical analysis reveals that the H‐SbN electrode displays the mainly diffusion‐controlled capacitive contributions and excellent lithium‐ion and electron transport. Our findings demonstrate that 2D materials are superior to use as the Sb‐based anodes for electrochemical lithium storage.
Effects of trehalose and ergosterol on pinene stress of Candida glycerinogenes
Authors: Ma Tengfei , Cai Haowen , Zong Hong , Lu Xinyao , Zhuge Bin 
Published: May 2022

AbstractPinene is a commercially important monoterpene that can be prepared using engineered bacterial and yeast species; however, high pinene levels can adversely affect the stability and permeability of microbial membranes leading to significantly reduced growth yields. This study reports that the fluidities and permeabilities of cell membranes of Candida glycerinogenes decrease as pinene levels increase resulting in adverse effects on cell growth. Exposure of cells to pinene results in upregulation of the genes encoding ergosterol and trehalose whose production helps stabilize their cell membranes. Exogenous addition of ergosterol and trehalose to pinene‐treated cells also reduces the fluidity and permeability of the cell membrane, whilst also reducing production of intracellular reactive oxygen species. This led to the finding that the biomass of yeast cells cultivated in shake flask systems are improved by exogenous addition of trehalose and ergosterol. Overexpression of genes that encode trehalose and ergosterol produced a recombinant C. glycerinogenes strain that was found to tolerate higher concentrations of pinene.
Recombinant human carbonic anhydrase VII: Purification, characterization, inhibition, and molecular docking studies
Authors: Duran Hatice Esra , Beydemir Şükrü 
Published: May 2022

AbstractHuman carbonic anhydrase VII (hCA VII), a cytosolic enzyme, defends against oxidative stress by preventing reactive oxygen species from forming. In our study, first, hCA VII was cloned into Escherichia coli (One Shot Mach1‐T1R) strain by using cDNA of the human brain and successfully expressed. The integrity of the plasmid generated by colony PCR was checked, and after, for protein expression, the plasmid was transformed into E. coli BL21 (DE‐3) strain. hCA VII expression was observed after 6 h of isopropyl‐D‐1‐thiogalactopyranoside (IPTG) induction. The fusion protein containing hexahistidine (6xHis) was purified with 7.02 EU/mg of specific activity, had 48.07% of purification yield, and approximately 21‐folds using a ProbondTM nickel chelating resin affinity column. Then, both molecular mass determination and purity control of the purified recombinant enzyme was done by SDS‐PAGE (sodium dodecyl sulfate‐polyacrylamide gel electrophoresis). The mass of the SUMO‐hCA VII fusion protein was calculated as 46.77 kDa. As a result of Western blot analysis using anti‐His G‐HRP antibody, the fusion protein was detected as approximately 45 kDa. Furthermore, the characterization assays and in vitro inhibition studies were done for the recombinant enzyme. KI values of these agents were found between 0.29 μM and 157.6 mM. Finally, molecular docking investigations of these antibiotics were undertaken to understand further the binding interactions on the active site of this recombinant enzyme.
Quantum dot‐based fluorescence immunosorbent assay for the rapid detection of bacitracin zinc in feed samples
Authors: Zhou Jingming , Wang Zhuoyang , Qian Wenjing , Liang Chao , Chen Yumei , Liu Hongliang , Liu Yankai , Zhu Xifang , Wang Aiping 
Published: May 2022

AbstractBacitracin zinc (BAC), a polypeptide antibiotic, is utilized as a feed additive due to its ability to promote growth in animals. However, the abuse of BAC can lead to a great threat to food safety. Therefore, there is an urgent need to develop a rapid and sensitive detection method. In this study, a monoclonal antibody (mAb) against BAC with excellent sensitivity and specificity was obtained. For the first time, quantum dots (QDs) were conjugated with the prepared mAb against BAC and rabbit anti‐mouse antibody to fabricate a direct and an indirect competitive fluorescence‐linked immunosorbent assay (dc‐FLISA and ic‐FLISA) to detect BAC. The IC50 of dc‐FLISA and ic‐FLISA were 0.28 ng/ml and 0.17 ng/ml, respectively. The limits of detection were 0.0016 ng/ml and 0.001 ng/ml, respectively, and the detection ranges were 0.0016–46.50 ng/ml and 0.001–35.65 ng/ml, respectively. In addition, the recovery rate of the two methods ranged from 93.5% to 112.0%, and the coefficient of variation (CV) was less than 10%. Therefore, the methods developed in this work have the merits of low cost, simple operation, and high sensitivity, which provide an effective analytical tool for BAC residue detection in feed samples.
Determination of isoscoparin in mouse blood using UPLC–MS/MS and its pharmacokinetics
Authors: Huang Xueli , Jiang Haodong , Liang Qishun , Ma Yizhe , Wang Xianqin 
Published: May 2022

AbstractThis study developed a UPLC–MS/MS method to detect isoscoparin in mouse blood, determined the pharmacokinetics of isoscoparin in mice after intravenous (5 mg/kg) and intragastric (20 mg/kg) administration, and calculated the absolute bioavailability. A HSS T3 column was used for separation, and the column temperature was set at 40°C. The mobile phases were acetonitrile and 0.1% formic acid, and the gradient elution procedure was used. The blood sample was treated with protein precipitant with acetonitrile–methanol (9:1, v/v). Multiple reaction monitoring mode was used for quantitative analysis in electrospray positive‐ion mode. It showed a good linear relationship in the range of 1–4000 ng/mL (r > 0.998); the intra‐day and inter‐day precision was <12%, and the accuracy was 86–112%. The recovery was >68%, and the matrix effect was 86–90%. The half‐life of isoscoparin was relatively short in mice, and the bioavailability was 2.6%. The developed UPLC–MS/MS method was rapid, sensitive, and suitable for the pharmacokinetics of isoscoparin in mice.