bluuebunny/crossref_metadata_2025_split huggingface dataset:
Layer‐by‐Layer Electrodeposition of FTO/TiO2/CuxO/CeO2 (1 <x< 2) Photocatalysts with High Peroxidase‐Like Activity by Greatly Enhanced Singlet Oxygen Generation
Authors: Shao Mingzhe , Liu Dapeng , Yan Baolin , Feng Xilan , Zhang Xiaojuan , Zhang Yu 
Published: June 2021

AbstractInorganic nanomaterials have attracted much attention as enzyme mimics because of simple and stable spatial conformation of those artificially synthesized nanocatalysts. Cu2O, as an important kind of narrow band gap semiconductor, is identified as effective as visible‐light‐driven photocatalysts, which can catalyze decomposition of H2O2 into reactive oxygen species. Moreover, after forming CuxO/CeO2 hybrids, the strongly coupled interface between the two components will further improve their catalytic performance. In this paper, the authors try to construct FTO/TiO2/CuxO/CeO2 (1 < x < 2) nanohybrids with such a kind of active interface via a layer‐by‐layer electrodeposition strategy by aid of the following surface etching process. It is found that FTO/TiO2/CuxO/CeO2 exhibits good peroxidase mimic activity in the dark but much better performance under visible light irradiation (λ ≥ 420 nm) during catalytic oxidation of 3,3′,5,5′‐tetramethylbenzidine substrates in the presence of H2O2. Detailed characterizations disclose that the construction of TiO2/Cu2O pn‐heterojunctions do effectively accelerate separation of photogenerated carriers, and the formation of a highly active CuxO/CeO2 interface is synergistically favorable for selectively generating singlet oxygen to boost the catalytic performance of FTO/TiO2/CuxO/CeO2.
Uniformly Dispersed Ru Nanoparticles Constructed by In Situ Confined Polymerization of Ionic Liquids for the Electrocatalytic Hydrogen Evolution Reaction
Authors: Zhang Yong‐Ya , Zhang Nan , Peng Peng , Wang Rui , Jin Yan , Lv Ya‐Kun , Wang Xin , Wei Wei , Zang Shuang‐Quan 
Published: June 2021

AbstractDesign and development of cost‐effective electrocatalysts with high efficiency and stability for scalable and sustainable hydrogen production through water splitting is still challenging. Herein, with the aid of divinyl functionalized ionic liquids, uniformly distributed Ru nanoparticles (NPs) on nitrogen‐doped carbon frameworks are obtained via an in situ confined polymerization strategy. Attributed to the unique lamellar structure and confinement effect of carbon supports, the optimized homo‐PIL‐Ru/C‐600 (with Ru 10 wt%) catalyst exhibits superior catalytic efficiency for the hydrogen evolution reaction with the overpotential of only 16 mV at a current density of 10 mA cm−2 and the corresponding Tafel slope of only 42 mV dec−1. Moreover, the performance can be well reserved even after 10 000 cycles, demonstrating excellent stability and promising potentials for industrial application. This work not only provides a facile approach for the preparation of highly efficient Ru‐based catalysts, but also guides the synthesis of other highly dispersed metallic NPs for special applications.
Ruthenium Complexes Featuring Unsymmetrical N‐Heterocyclic Carbene Ligands–Useful Olefin Metathesis Catalysts for Special Tasks
Authors: Monsigny Louis , Kajetanowicz Anna , Grela Karol 
Published: June 2021

AbstractThis review describes a distinct class of ruthenium olefin metathesis catalysts featuring unsymmetrical N‐heterocyclic carbene (uNHC) ligands, from its historical beginning to the present state of the art. Thanks to advantageous traits, such as pronounced thermodynamic stability, chemical latency, outstanding selectivity, and compatibility with green solvents, these catalysts led to good results in a number of specialized metathesis transformations. Therefore, while being a niche, the uNHC complexes can potentially be implemented in a number of industrial processes, such as valorization of Fischer‐Tropsch olefin fractions, ethenolysis of renewable products, and modern pharmaceutical production.
Genome‐wide association mapping of seedling and adult plant response to stem rust in a durum wheat panel
Authors: Megerssa Shitaye H. , Sorrells Mark E. , Ammar Karim , Acevedo Maricelis , Bergstrom Gary C. , Olivera Pablo , Brown‐Guedira Gina , Ward Brian , Degete Ashenafi G. , Abeyo Bekele 
Published: June 2021

AbstractMany of the major stem rust resistance genes deployed in commercial wheat (Triticum spp.) cultivars and breeding lines become ineffective over time because of the continuous emergence of virulent races. A genome‐wide association study (GWAS) was conducted using 26,439 single nucleotide polymorphism (SNP) markers and 280 durum wheat [Triticum turgidum L. subsp. Durum (Desf.) Husnot] lines from CIMMYT to identify genomic regions associated with seedling resistance to races TTKSK, TKTTF, JRCQC, and TTRTF and field resistance to TKTTF and JRCQC. The phenotypic data analysis across environments revealed 61–91 and 59–77% of phenotypic variation was explained by the genotypic component for seedling and adult plant response of lines, respectively. For seedling resistance, mixed linear model (MLM) identified eight novel and nine previously reported quantitative trait loci (QTL) while a fixed and random model circulating probability unification (FarmCPU) detected 12 novel and eight previously reported QTL. For field resistance, MLM identified 12 novel and seven previously reported loci while FarmCPU identified seven novel and nine previously reported loci. The regions of Sr7a, Sr8155B1, Sr11, alleles of Sr13, Sr17, Sr22/Sr25, and Sr49 were identified. Novel loci on chromosomes 3B, 4A, 6A, 6B, 7A, and 7B could be used as sources of resistance to the races virulent on durum wheat. Two large‐effect markers on chromosome 6A could potentially be used to differentiate resistant haplotypes of Sr13 (R1 and R3). Allelism tests for Sr13, breaking the deleterious effect associated with Sr22/Sr25 and retaining the resistance allele at the Sr49 locus, are needed to protect future varieties from emerging races.
Ultrasonographic approach and findings in calves with hydranencephaly
Authors: Gorjidooz Morteza , Rahimabadi Peyman Dehghan , Raoofi Afshin , Masoudifard Majid , Mardjanmehr Seyed Hossein 
Published: June 2021

BackgroundTeratogenic viral infections may proceed to hydranencephaly in cattle. Post‐mortem and antemortem diagnosis can be achieved by necropsy or ultrasonography, CT‐scan and MRI techniques.ObjectivesThe aim of this study was to determine how effective ultrasonography approach is in detecting hydranencephaly in calves.MethodsIn this study, ultrasonography images were obtained from brains of nine Holstein claves, of the same age, with neurological signs (due to Akabane virus infection), approaching from the caudal part of the temporal bone. To confirm the obtained images, the same approach was used to obtain images from a normal calf of the same age. The thickness of the temporal bone was measured and compared in seven affected and the healthy calves, using CT‐scan images.ResultsIn ultrasonographic images, temporal bone (as a hyperechoic structure) and temporal cortical mantle (as an echogenic structure) were noted in the right and left side of the skull. The medial part of the image showed presence of fluid in an anechoic region, instead of brain parenchyma. Falx cerebri was also seen as a floating hyperechoic line in the middle part in all patients. There was no statistically significant difference between the thickness of temporal bone in normal and affected calves (p = 0.502). All findings were confirmed by necropsy.ConclusionsTranstemporal approach is a novel and easy approach to study the brain in calves. This is the first study on the hydranencephalic brains of claves, using ultrasonography by transtemporal approach.
Use of a polyethylene glycol solution for the management of sand impaction in three dogs
Authors: Johnson Randi , Wigglesworth Samantha , Moyle Rachel , Lynch Alex 
Published: June 2021

AbstractThree dogs were hospitalized for management of acute gastrointestinal signs secondary to sand impaction. Hospitalized care with administration of a polyethylene glycol (PEG) solution via nasogastric tube. Variable PEG solution doses were used in these dogs (range 72–109 ml/kg). All patients tolerated PEG administration without adverse effects. Two dogs had additional radiographs performed, consistent with radiographic improvement of impaction. Each dog had marked clinical improvement and was successfully discharged from the hospital.
An Homage to Otto Stern
Authors: Herschbach Dudley 
Published: June 2021

AbstractThis chapter outlines an International Symposium held at Frankfurt on 1–5 September 2019. It marked the centennial of quantitative experiments with molecular beams, pioneered by Otto Stern. The European Physical Society declared Stern’s original laboratory a Historic Site, the fifth in Germany. As a graduate student in 1955, I learned about Otto Stern (1888–1969) and the impact of his molecular beams on quantum physics. I was intrigued and undertook crossed-beam experiments at Berkeley. In 1960 Otto came to a seminar that I gave. Later I met him, and heard some of his stories. The rest of the chapter describes his Nobel Prize and other Fests. In 1958 his long-term colleague, Immanuel Estermann, organized a celebration and Festschrift for Otto’s 70th birthday. In 1988, as a guest editor, I organized a Festschift for the centennial of Otto’s birth. That year, the German Physical Society established the Stern-Gerlach Prize as its highest award for experimental physics. Bretislav Friedrich and I wrote three papers about Stern. Since 2000, Horst Schmidt-Böcking at Frankfurt and colleagues have produced historical articles, along with a book about Otto, edited and bound all of his research papers into books, and diligently pursued letters to and from Otto, collecting them into large volumes.
Wilhelm Heinrich Heraeus—Doctoral Student at the University Frankfurt
Authors: Jorda S. , Schmidt-Böcking H. 
Published: June 2021

AbstractWilhelm Heinrich Heraeus (*1900 – †1985), the founder of the Wilhelm and Else Heraeus Foundation, wrote his doctoral thesis at the University of Frankfurt in 1922–23 under the supervision of Richard Wachsmuth and Walther Gerlach. Thereby, he became a witness of the Stern-Gerlach experiment, completed in Frankfurt in 1922. In his thesis, Heraeus investigated “The dependence of the thermoelectrical force of iron on its structure” and was able to show that earlier measurements by G. Borelius were incorrect and irreproducible. On 23 July 1923, Heraeus passed his doctoral examination in Frankfurt under Wachsmuth’s auspices.
Quantum or Classical Perception of Atomic Motion
Authors: Briggs John S. 
Published: June 2021

AbstractAn assessment is given as to the extent to which pure unitary evolution, as distinct from environmental decohering interaction, can provide the transition necessary for an observer to perceive quantum dynamics as classical. This has implications for the interpretation of quantum wavefunctions as a characteristic of ensembles or of single particles and the related question of wavefunction “collapse”. A brief historical overview is presented as well as recent emphasis on the role of the semi-classical “imaging theorem” in describing quantum to classical unitary evolution.
The Precision Limits in a Single-Event Quantum Measurement of Electron Momentum and Position
Authors: Schmidt-Böcking H. , Eckart S. , Lüdde H. J. , Gruber G. , Jahnke T. 
Published: June 2021

AbstractA modern state-of-the-art “quantum measurement” [The term “quantum measurement” as used here implies that parameters of atomic particles are measured that emerge from a single scattering process of quantum particles.] of momentum and position of a single electron at a given time [“at a given time” means directly after the scattering process. (It should be noticed that the duration of the reaction process is typically extremely short => attoseconds).] and the precision limits for their experimental determination are discussed from an experimentalists point of view. We show—by giving examples of actually performed experiments—that in a single reaction between quantum particles at a given time only the momenta of the emitted particles but not their positions can be measured with sub-atomic resolution. This fundamental disparity between the conjugate variables of momentum and position is due to the fact that during a single-event measurement only the total momentum but not position is conserved as function of time. We highlight, that (other than prevalently perceived) Heisenberg’s “Uncertainty Relation” UR [1] does not limit the achievable resolution of momentum in a single-event measurement. Thus, Heisenberg’s statement that in a single-event measurement only either the position or the momentum (velocity) of a quantum particle can be measured with high precision contradicts a real experiment. The UR states only a correlation between the mean statistical fluctuations of a large number of repeated single-event measurements of two conjugate variables. A detailed discussion of the real measurement process and its precision with respect to momentum and position is presented.
Precision Physics in Penning Traps Using the Continuous Stern-Gerlach Effect
Authors: Blaum Klaus , Werth Günter 
Published: June 2021

Abstract“A single atomic particle forever floating at rest in free space” (H. Dehmelt) would be the ideal object for precision measurements of atomic properties and for tests of fundamental theories. Such an ideal, of course, can ultimately never be achieved. A very close approximation to this ideal is made possible by ion traps, where electromagnetic forces are used to confine charged particles under well-controlled conditions for practically unlimited time. Concurrently, sensitive detection methods have been developed to allow observation of single stored ions. Various cooling methods can be employed to bring the trapped ion nearly to rest. Among different realisations of ion traps we consider in this chapter the so-called Penning traps which use static electric and magnetic fields for ion confinement. After a brief discussion of Penning-trap properties, we consider various experiments including the application of the “continuous Stern-Gerlach effect”, which have led recently to precise determinations of the masses and magnetic moments of particles and antiparticles. These serve as input for testing fundamental theories and symmetries.
Stern-Gerlach Interferometry with the Atom Chip
Authors: Keil Mark , Machluf Shimon , Margalit Yair , Zhou Zhifan , Amit Omer , Dobkowski Or , Japha Yonathan , Moukouri Samuel , Rohrlich Daniel , Binstock Zina , Bar-Haim Yaniv , Givon Menachem , Groswasser David , Meir Yigal , Folman Ron 
Published: June 2021

AbstractIn this invited review in honor of 100 years since the Stern-Gerlach (SG) experiments, we describe a decade of SG interferometry on the atom chip. The SG effect has been a paradigm of quantum mechanics throughout the last century, but there has been surprisingly little evidence that the original scheme, with freely propagating atoms exposed to gradients from macroscopic magnets, is a fully coherent quantum process. Specifically, no full-loop SG interferometer (SGI) has been realized with the scheme as envisioned decades ago. Furthermore, several theoretical studies have explained why it is a formidable challenge. Here we provide a review of our SG experiments over the last decade. We describe several novel configurations such as that giving rise to the first SG spatial interference fringes, and the first full-loop SGI realization. These devices are based on highly accurate magnetic fields, originating from an atom chip, that ensure coherent operation within strict constraints described by previous theoretical analyses. Achieving this high level of control over magnetic gradients is expected to facilitate technological applications such as probing of surfaces and currents, as well as metrology. Fundamental applications include the probing of the foundations of quantum theory, gravity, and the interface of quantum mechanics and gravity. We end with an outlook describing possible future experiments.
Inducing Enantiosensitive Permanent Multipoles in Isotropic Samples with Two-Color Fields
Authors: Ordonez Andres F. , Smirnova Olga 
Published: June 2021

AbstractWe find that two-color fields can induce field-free permanent dipoles in initially isotropic samples of chiral molecules via resonant electronic excitation in a one-$$3\omega $$

3
ω

-photon versus three-$$\omega $$
ω
-photons scheme. These permanent dipoles are enantiosensitive and can be controlled via the relative phase between the two colors. When the two colors are linearly polarized perpendicular to each other, the interference between the two pathways induces excitation sensitive to the molecular handedness and orientation, leading to uniaxial orientation of the excited molecules and to an enantio-sensitive permanent dipole perpendicular to the polarization plane. We also find that although a corresponding one-$$2\omega $$

2
ω

-photon versus two-$$\omega $$
ω
-photons scheme cannot produce enantiosensitive permanent dipoles, it can produce enantiosensitive permanent quadrupoles that are also controllable through the two-color relative phase.
Ultra-fast Dynamics in Quantum Systems Revealed by Particle Motion as Clock
Authors: Schöffler M. S. , Schmidt L. Ph. H. , Eckart S. , Dörner R. , Czasch A. , Jagutzki O. , Jahnke T. , Ullrich J. , Moshammer R. , Schuch R. , Schmidt-Böcking H. 
Published: June 2021

AbstractTo explore ultra-fast dynamics in quantum systems one needs detection schemes which allow time measurements in the attosecond regime. During the recent decades, the pump & probe two-pulse laser technique has provided milestone results on ultra-fast dynamics with femto- and attosecond time resolution. Today this technique is applied in many laboratories around the globe, since complete pump & probe systems are commercially available. It is, however, less known or even forgotten that ultra-fast dynamics has been investigated several decades earlier even with zeptosecond resolution in ion-atom collision processes. A few of such historic experiments, are presented here, where the particle motion (due to its very fast velocity) was used as chronometer to determine ultra-short time delays in quantum reaction processes. Finally, an outlook is given when in near future relativistic heavy ion beams are available which allow a novel kind of “pump & probe” experiments on molecular systems with a few zeptosecond resolution. However, such experiments are only feasible if the complete many-particle fragmentation process can be imaged with high momentum resolution by state-of-the-art multi-particle coincidence technique.
Manipulation and Control of Molecular Beams: The Development of the Stark-Decelerator
Authors: Meijer Gerard 
Published: June 2021

AbstractState-selective manipulation of beams of atoms and molecules with electric and magnetic fields has been crucial for the success of the field of molecular beams. Originally, this manipulation only involved the transverse motion. In this Chapter, the development of the Stark-decelerator, that allows to also manipulate and control the longitudinal motion of molecules in a beam, is presented.
Quantum Effects in Cold and Controlled Molecular Dynamics
Authors: Koch Christiane P. 
Published: June 2021

AbstractThis chapter discusses three examples of quantum effects that can be observed in state-of-the-art experiments with molecular beams—scattering resonances as a probe of interparticle interactions in cold collisions, the protection of Fano-Feshbach resonances against decay despite resonant coupling to a scattering continuum, and a circular dichroism in photoelectron angular distributions arising in the photoionization of randomly oriented chiral molecules. The molecular beam setup provides molecules in well-defined quantum states. This, together with a theoretical description based on first principles, allows for excellent agreement between theoretical prediction and experimental observation and thus a rigorous understanding of the observed quantum effects.
From Hot Beams to Trapped Ultracold Molecules: Motivations, Methods and Future Directions
Authors: Fitch N. J. , Tarbutt M. R. 
Published: June 2021

AbstractOver the past century, the molecular beam methods pioneered by Otto Stern have advanced our knowledge and understanding of the world enormously. Stern and his colleagues used these new techniques to measure the magnetic dipole moments of fundamental particles with results that challenged the prevailing ideas in fundamental physics at that time. Similarly, recent measurements of fundamental electric dipole moments challenge our present day theories of what lies beyond the Standard Model of particle physics. Measurements of the electron’s electric dipole moment (eEDM) rely on the techniques invented by Stern and later developed by Rabi and Ramsey. We give a brief review of this historical development and the current status of eEDM measurements. These experiments, and many others, are likely to benefit from ultracold molecules produced by laser cooling. We explain how laser cooling can be applied to molecules, review recent progress in this field, and outline some eagerly anticipated applications.
Otto Stern and Wave-Particle Duality
Authors: Peter Toennies J. 
Published: June 2021

AbstractThe contributions of Otto Stern to the discovery of wave-particle duality of matter particles predicted by de Broglie are reviewed. After a short introduction to the early matter-vs-wave ideas about light, the events are highlighted which lead to de Broglie’s idea that all particles, also massive particles, should exhibit wave behavior with a wavelength inversely proportional to their mass. The first confirming experimental evidence came for electrons from the diffraction experiments of Davisson and Germer and those of Thomson. The first demonstration for atoms, with three orders of magnitude smaller wave lengths, came from Otto Stern’s laboratory shortly afterwards in 1929 in a remarkabletour de forceexperiment. After Stern’s forced departure from Hamburg in 1933 it took more than 40 years to reach a similar level of experimental perfection as achieved then in Stern’s laboratory. Today He atom diffraction is a powerful tool for studying the atomic and electronic structure and dynamics of surfaces. With the advent of nanotechnology nanoscopic transmission gratings have led to many new applications of matter waves in chemistry and physics, which are illustrated with a few examples and described in more detail in the following chapters.
Grating Diffraction of Molecular Beams: Present Day Implementations of Otto Stern’s Concept
Authors: Schöllkopf Wieland 
Published: June 2021

AbstractWhen Otto Stern embarked on molecular-beam experiments in his new lab at Hamburg University a century ago, one of his interests was to demonstrate the wave-nature of atoms and molecules that had been predicted shortly before by Louis de Broglie. As the effects of diffraction and interference provide conclusive evidence for wave-type behavior, Otto Stern and his coworkers conceived two matter-wave diffraction experiments employing their innovative molecular-beam method. The first concept assumed the molecular ray to coherently scatter off a plane ruled grating at grazing incidence conditions, while the second one was based on the coherent scattering from a cleaved crystal surface. The latter concept allowed Stern and his associates to demonstrate the wave behavior of atoms and molecules and to validate de Broglie’s formula. The former experiment, however, fell short of providing evidence for diffraction of matter waves. It was not until 2007 that the grating diffraction experiment was retried with a modern molecular-beam apparatus. Fully resolved matter-wave diffraction patterns were observed, confirming the viability of Otto Stern’s experimental concept. The correct explanation of the experiment accounts for quantum reflection, another wave effect incompatible with the particle picture, which was not foreseen by Stern and his contemporaries.