bluuebunny/crossref_metadata_2025 huggingface dataset:
Present Status of Musculoskeletal Radiology in Europe: International Survey by the European Society of Musculoskeletal Radiology
Authors: Hebar Timea , Snoj Žiga , Sconfienza Luca Maria , Vanhoenacker Filip Maria H.M. , Shahabpour Maryam , Salapura Vladka , Isaac Amanda , Drakonaki Eleni , Vasilev Yurii , Drape Jean-Luc , Adriaensen Miraude , Friedrich Klaus , Guglielmi Giuseppe , Vieira Alberto , Sanal Hatice Tuba , Kerttula Liisa , Hellund Johan Castberg , Nagy Judit , Heuck Andreas , Rutten Matthieu , Tzalonikou Maria , Hansen Ulrich , Niemunis-Sawicka Joanna , Becce Fabio , Silvestri Enzo , Juan Eva Llopis San , Wörtler Klaus
Published: September 2020

No official data exist on the status of musculoskeletal (MSK) radiology in Europe. The Committee for National Societies conducted an international survey to understand the status of training, subspecialization, and local practice among the European Society of Musculoskeletal Radiology (ESSR) partner societies. This article reports the results of that survey. An online questionnaire was distributed to all 26 European national associations that act as official partner societies of the ESSR. The 24 questions were subdivided into six sections: society structure, relationship with the national radiological society, subspecialization, present radiology practice, MSK interventional procedures, and MSK ultrasound. The findings of our study show a lack of standardized training and/or accreditation methods in the field of MSK radiology at a national level. The European diploma in musculoskeletal radiology is directed to partly overcome this problem; however, this certification is still underrecognized. Using certification methods, a more homogeneous European landscape could be created in the future with a view to subspecialist training. MSK ultrasound and MSK interventional procedures should be performed by a health professional with a solid knowledge of the relevant imaging modalities and sufficient training in MSK radiology. Recognition of MSK radiology as an official subspecialty would make the field more attractive for younger colleagues as well as attracting the brightest and best, an important key to further development of both clinical and academic radiology.

Key Points
Development of Antiarrhythmic Therapy-Resistant Ventricular Tachycardia, Ventricular Fibrillation, and Premature Ventricular Contractions in a 15-Year-Old Patient
Authors: Yozgat Can Yilmaz , Yesilbas Osman , Iscan Akin , Yurtsever Ismail , Temur Hafize Otcu , Bayramova Nigar , Ergun Gokce , Tekin Nur , Yozgat Yilmaz
Published: September 2020

Sudden cardiac arrest (SCA) is the sudden cessation of regular cardiac activity so that the victim becomes unresponsive, with no signs of circulation and no normal breathing. Asystole, ventricular tachycardia (VT), ventricular fibrillation (VF), and pulseless electrical activity are the underlying rhythm disturbances in the pediatric age group. If appropriate interventions (cardiopulmonary resuscitation-CPR and/or defibrillation or cardioversion) are not performed rapidly, this condition progresses to sudden death. There have not been many reported cases of the approach and treatment of cardiac arrhythmias after SCA. Herein, we would like to report a case of a 15-year-old female patient with dilated cardiomyopathy (DCM) who was admitted to our clinic a year ago, and while her left ventricular systolic functions were improved, SCA suddenly occurred. Since the SCA event occurred in another city, intravenous treatment of amiodarone was done immediately and was switch to continuous infusion dose of amiodarone until the patient arrived at our institution's pediatric intensive care unit (PICU) 3 hours later. During the patient's 20-day PICU hospitalization, she developed pulseless VT and VF from time to time. The patient's pulseless VT and VF attacks were brought under control by the use of a defibrillator and added antiarrhythmic drugs (amiodarone, flecainide, esmolol, and propafenone). Intriguingly, therapy-resistance bigeminy with premature ventricular contractions (PVCs) continued despite all these treatments. The patient did not have adequate blood pressure measured by invasive arterial blood pressure monitoring while having bigeminy PVCs. The intermittent bigeminy PVCs ameliorated rapidly after intermittent boluses of lidocaine. In the end, multiple antiarrhythmic therapies and intermittent bolus lidocaine doses were enough to bring her cardiac arrhythmias after SCA under control. This case illustrates that malign PVC's should be taken very seriously, since they may predispose to the development of VT or VF. Also, this case highlights the importance of close vigilance of arterial pressure tracings of patients with bigeminy PVCs which develop after SCA and should not be accepted as normal.
Robotic Transthoracic Repair of a Right-Sided Traumatic Diaphragmatic Rupture
Authors: Kim Jin K. , Desai Anand , Kunac Anastasia , Merchant Aziz M. , Lovoulos Constantinos
Published: September 2020

Introduction Traumatic diaphragm rupture injury repairs are predominately performed through thoracotomy, laparotomy, or a combination of the two approaches. While open surgery is often necessary to follow the fundamentals of damage-control operations in unstable or polytrauma patients, minimally invasive surgery may be an alternative for those with a low injury burden to reduce the postoperative morbidities associated with open operations.

Case Description We describe the first case of a right-sided diaphragm rupture from blunt trauma that was repaired by a robotic transthoracic approach in the index admission.

Conclusion Minimally invasive repair of an acute traumatic diaphragm rupture is feasible in selected trauma patients.
Device improves sensitivity and effectiveness of point-of-care tests
Authors: Mandel Savannah
Published: September 2020

A quick and effective high-pressure preconcentration device improves point-of-care testing sensitivity and effectiveness.
Spectromicroscopic measurements of electronic structure variations in atomically thin WSe2
Authors: Klaproth T. , Habenicht C. , Schuster R. , Büchner B. , Knupfer M. , Koitzsch A.
Published: September 2020

Atomically thin transition metal dichalcogenides (TMDCs) are promising candidates for implementation in next generation semiconducting devices, for which laterally homogeneous behavior is needed. Here, we study the electronic structure of atomically thin exfoliated WSe2, a prototypical TMDC with large spin–orbit coupling, by photoemission electron microscopy, electron energy-loss spectroscopy, and density functional theory. We resolve the inhomogeneities of the doping level by the varying energy positions of the valence band. There appear to be different types of inhomogeneities that respond differently to electron doping, introduced by potassium intercalation. In addition, we find that the doping process itself is more complex than previously anticipated and entails a distinct orbital and thickness dependence that needs to be considered for effective band engineering. In particular, the density of selenium vs tungsten states depends on the doping level, which leads to changes in the optical response beyond increased dielectric screening. Our work gives insight into the inhomogeneity of the electron structure of WSe2 and the effects of electron doping, provides microscopic understanding thereof, and improves the basis for property engineering of 2D materials.
Tunable magnetic focusing using Andreev scattering in superconductor-graphene hybrid devices
Authors: Chaves A. , Moura V. N. , Linard F. J. A. , Covaci L. , Milošević M. V.
Published: September 2020

We perform the wavepacket dynamics simulation of a graphene-based device where propagating electron trajectories are tamed by an applied magnetic field toward a normal/superconductor interface. The magnetic field controls the incidence angle of the incoming electronic wavepacket at the interface, which results in the tunable electron–hole ratio in the reflected wave function due to the angular dependence of the Andreev reflection. Here, mapped control of the quasiparticle trajectories by the external magnetic field not only defines an experimental probe for fundamental studies of the Andreev reflection in graphene but also lays the foundation for further development of magnetic focusing devices based on nanoengineered superconducting two-dimensional materials.
Increasing the length of free-falling path with homogeneous bias field for compact cold atom interferometers by configuring MOT coils
Authors: Zhang Huan-Kai , Wang Ya-Ning , Zhu Ling-Xiao , Li Qi-Xue , Xu Dong-Yang , Zhang Xu , Yan Shu-Hua , Yang Jun
Published: September 2020

In a cold atom interferometer, a bias magnetic field, usually generated by a solenoid or a set of coils, is used to select specific Raman transitions of atoms in the interference region, and its inhomogeneity leads to a Zeeman-effect-induced error for the measurement. To improve the measurement’s accuracy further, we propose a simple method to compensate for the non-uniformity of the bias field by reversing the direction and tuning the value of the current running through the pair of quadrupole coils used for magneto-optical trap (MOT). To smoothen the field with MOT coils, the current applied should be controlled timely and precisely, which was done with a fast-responding electric circuit we designed and built. We also used Raman spectroscopy to characterize the magnetic field profile without and with our method applied, which shows that the length of the homogeneous field (where the fluctuation of magnetic strength is less than 10%) is expanded from 81.87 mm to 101.64 mm. From our calculations, with the free evolution time T of 30 ms, the quadratic Zeeman-effect-induced phase shift Δϕzeeman can be reduced by 76%, which reduces the quadratic Zeeman-effect-induced error of measured gravity Δgzeeman to a quarter of that without our method applied (from 1.745 mGal to 0.418 mGal). Simulation and experiment prove that this method is effective. This method can also be used in other atom interferometers, especially compact systems.
Obesity: a sociological guide for health practitioners
Authors: Grace Samuel G.
Published: September 2020

Obesity is a condition of excess body fat that has been identified as one of the most serious public health problems of the 21st century. Obesity is a leading preventable cause of death globally and increases the likelihood of cardiovascular disease, diabetes and various cancers. Obesity worldwide has tripled in the adult population over the past 40 years, with 13% of the world’s adult population now obese, leading to calls for control of a global obesity epidemic. Causes of obesity can be delineated at individual, societal and systemic levels, highlighting the need for analysis that transcends the biomedical paradigm to explore the sociological influences of this condition. The pathophysiology of why obesity occurs has not changed within recent history, but the way that people live their lives and the cultural understandings that evolve within communities have. This article describes the interaction between obesity and the social environment, explores the meaning of obesity within the context of health and considers the social determinants of obesity within the community. It also discusses the influences of the professional–patient exchange in obesity, the comprehension of obesity as a disease and the challenges of addressing obesity within the healthcare system.
Effects of simultaneous interpreting experience and training on anticipation, as measured by word-translation
latencies
Authors: Chmiel Agnieszka
Published: September 2020

This study aims to investigate the influence of interpreter training and conference interpreting experience on
anticipation, as measured by word-translation latencies in a semantically constrained context. It involved professional conference
interpreters, on the one hand, and, on the other, interpreter trainees being tested at the beginning and at the end of their two-year
training programme. Both groups were asked to translate words embedded at the end of high-context constraint sentences (thus easily
predictable), low-context constraint sentences or those appearing in isolation in both directions (from and to their native language). The
data suggest that word-translation latency improves in the course of interpreter training but it is not enhanced further in the course of
professional experience, whereas anticipation is not improved by either training or experience. All the participants, being late foreign
language learners, manifested an advantage in native language comprehension by anticipating more in an A–B versus a B–A translation
direction. The findings also suggest that professional interpreting experience might facilitate inhibition and lead to the selection of the
appropriate translation equivalent.
Are CLIL texts too complicated?
Authors: Aguirregoitia Martinez Amaia , Bengoetxea Kortazar Kepa , Gonzalez-Dios Itziar
Published: September 2020

This article presents a comparative study of the linguistic characteristics of some materials used to teach English as a foreign language, and Geography and History through English in a Content and Language Integrated Learning (CLIL) experience in the Basque Country with students aged 11–13. This paper analyzes and compares the contents of current textbooks using Coh-Metrix and AzterTest, which calculate stylistic and linguistic metrics regarding lexical and grammatical complexity, readability and coherence. Finally, the study suggests that there are significant differences mainly in vocabulary level, narrativity and cohesion, it identifies the potential difficulties of CLIL texts and offers advice on how to overcome them. Raising awareness of the complexity of some texts used in CLIL can provide a starting point for pedagogical adaptations and contribute to optimizing learning.
Narrative practices in debt collection encounters
Authors: Harrington Leigh
Published: September 2020

Drawing on a corpus of 100 authentic telephone-mediated interactions from a British credit union, this paper is the first to examine narrative practices in debt collection encounters. It demonstrates that the credit union’s debt collector routinely invites and supports indebted individuals’ narratives using alignment and affiliation. Through a small stories approach, the paper therefore highlights that an organisation’s core values and principles can be seen “in action” in the ways that a professional orients to lay-people’s stories in professional-lay discourse. In this case, the collector’s narrative practices are emblematic of the credit union’s consciously ethical, responsible, and debtor-centric approach to collecting debt. The analysis also shows that indebted individuals perform important interactive work through their narrative accounts in terms of mitigating responsibility for their debt, constructing blameless and acceptable identities, and implicitly encouraging (or explicitly instructing) the collector to affiliate with their stance.
The Two-Lens Approach
Authors: Woolf Anneli Rane , Nicolopoulou Ageliki
Published: September 2020

Over the past 30 years we have seen a welcome growth in the understanding of narrative as a complex and broadly defined
set of concepts. While the complexity of children’s narrative development has been brought to light by researchers and theorists across
multiple fields of study, reflecting this growth by comprehensively analyzing narrative complexity still remains a challenge. One reason for
this ongoing challenge is the isolated, disparate focus of the approaches, either in analyzing solely story structure, content, or function.
Few approaches combine these disparate dimensions to comprehensively analyze children’s narratives. In response, we build on research from
the past 30 years to develop the Two-Lens Approach, a holistic theoretical framework for analyzing the form, content, and context of
children’s narratives. This paper presents and applies this approach in an effort to start closing the gaps among the field of narrative
analysis and narrative theory.
The HIDRALERTA system: Application to the ports of Madalena do Pico and S. Roque do Pico, Azores
Authors: Fortes C.J.E.M. , Reis M.T. , Pinheiro L. , Poseiro P. , Serrazina V. , Mendonça A. , Smithers N. , Santos M.I. , Barateiro J. , Azevedo E.B. , Salvador M. , Reis F.V.
Published: September 2020

HIDRALERTA is a forecast and early warning system for coastal and port regions capable of predicting emergency situations, as well as carrying out risk assessment. The system concentrates on evaluating wave overtopping and flooding scenarios. It uses offshore sea-wave and wind forecast data, as well as tide data, as input to determine wave overtopping at specific locations. The calculation of the mean overtopping discharge over a structure is made through artificial neural network tools and/or empirical formulae, which are able to define the spatial distribution of the flow behind the structure. The HIDRALERTA system is composed of four modules developed in Open Source Web Technology, mainly using the Python Language. The Warning System can be configured and adapted for specific scenarios. The system has been successfully tested for the Port and Bay of Praia da Vitória, Terceira Island, Azores, Portugal, and is now under development and being implemented at the ports of Madalena do Pico and S. Roque do Pico. This paper describes the work carried out to date on the system and its application to these two ports in the Pico Island, Azores.
The correlations between physical attributes and golf clubhead speed: A systematic review with quantitative analyses
Authors: Ehlert Alex
Published: September 2020

Clubhead speed (CHS) is a commonly assessed golf performance measure and has been demonstrated to increase in response to physical training. Knowledge of the physical attributes that correlate with CHS will aid in developing effective testing and training protocols for golfers. Thus, the purpose of this review was to identify studies that evaluated the correlation between physical attributes and CHS and synthesise the correlation coefficients using three‐level meta‐analytic methods. Physical attributes were categorised first by general physical attribute categories. Pooled correlations were also estimated for specific attributes (e.g. jump height, body mass) that were evaluated across three or more studies. The results suggested that CHS had the strongest correlations with measures of upper body power/explosiveness (r = 0.51, 95% confidence interval [95CI]: 0.34, 0.67), lower body strength (r = 0.46; 95CI: 0.27, 0.66), upper body strength (r = 0.41; 95CI: 0.18, 0.63), and lower body power/explosiveness (r = 0.38; 95CI: 0.23, 0.53). Muscle endurance (r = 0.18; 95CI: 0.07, 0.28) and anthropometrics (r = 0.27; 95CI: 0.12, 0.42) had small, but significant correlations, while flexibility (r = 0.03; 95CI: −0.08, 0.14) had a trivial correlation. Several specific assessments such as squat strength, estimated jump power, and medicine ball throw outcomes had large pooled correlations with CHS (r = 0.55–0.63). Overall, the results suggest that measures of muscle strength and power/explosiveness have moderate‐large correlations with CHS. Flexibility measures did not have significant associations with CHS, but this may be a result of the specific measures used within the literature.
Brans–Dicke cosmology with a Λ-term: a possible solution to ΛCDM tensions*
Authors: Peracaula Joan Solà , Gómez-Valent Adrià , de Cruz Pérez Javier , Moreno-Pulido Cristian
Published: September 2020

We present a full-fledged analysis of Brans–Dicke cosmology with a cosmological constant and cold dark matter (BD-ΛCDM for short). We extend the scenarios where the current cosmological value of the BD-field is restricted by the local astrophysical domain to scenarios where that value is fixed only by the cosmological observations, which should be more natural in view of the possible existence of local screening mechanism. Our analysis includes both the background and perturbations equations in different gauges. We find that the BD-ΛCDM is favored by the overall cosmological data as compared to the concordance GR-ΛCDM model, namely data on distant supernovae, cosmic chronometers, local measurements of the Hubble parameter, baryonic acoustic oscillations, large-scale structure formation and the cosmic microwave background under full Planck 2018 CMB likelihood. We also test the impact of strong and weak-lensing data on our results, which can be significant. We find that the BD-ΛCDM can mimic effective quintessence with a significance of about 3.0–3.5σ c.l. (depending on the lensing datasets). The fact that the BD-ΛCDM behaves effectively as a running vacuum model (RVM) when viewed from the GR perspective helps to alleviate some of the existing tensions with the data, such as the σ
8 excess predicted by GR-ΛCDM. On the other hand, the BD-ΛCDM model has a crucial bearing on the acute H
0-tension with the local measurements, which is rendered virtually harmless owing to the small increase of the effective value of the gravitational constant with the expansion. The simultaneous alleviation of the two tensions is a most remarkable feature of BD-gravity with a cosmological constant in the light of the current observations, and hence goes in support of BD-ΛCDM against GR-ΛCDM.
Unique determination of fractional order and source term in a fractional diffusion equation from sparse boundary data
Authors: Li Zhiyuan , Zhang Zhidong
Published: September 2020

In this article, for a two dimensional fractional diffusion equation, we study an inverse problem for simultaneous restoration of the fractional order and the source term from the sparse boundary measurements. By using a sequence of harmonic functions, we construct useful quantitative relation between the unknowns and measurements. From Laplace transform and the knowledge in complex analysis, the uniqueness theorem is proved.
Impact of random alloy fluctuations on inter-well transport in InGaN/GaN multi-quantum well systems: an atomistic non-equilibrium Green’s function study
Authors: O’Donovan Michael , Luisier Mathieu , O’Reilly Eoin P , Schulz Stefan
Published: September 2020

Recent experimental studies indicate the presence of ballistic hole transport in InGaN multi quantum well (MQW) structures. Widely used drift–diffusion models cannot give insight into this question, since quantum mechanical effects, such as tunneling, are not included in such semi-classical approaches. Also atomistic effects, e.g. carrier localization effects and built-in field variations due to (random) alloy fluctuations, are often neglected in ballistic transport calculations on InGaN quantum well systems. In this work we use atomistic tight-binding theory in conjunction with a non-equilibrium Green’s function approach to study electron and hole ballistic transport in InGaN MQW systems. Our results show that for electrons the alloy microstructure is of secondary importance for their ballistic transport properties, while for hole transport the situation is different. We observe for narrow barrier widths in an InGaN MQW system that (random) alloy fluctuations give rise to extra hole transmission channels when compared to a virtual crystal description of the same system. We attribute this effect to the situation that in the random alloy case, k
∥-vector conservation is broken/relaxed and therefore the ballistic hole transport is increased. However, for wider barrier width this effect is strongly reduced, which is consistent with experimental studies. Our findings also provide a possible explanation for recent experimental results where alloying the barrier between the wells leads to enhanced ballistic (hole) transport in InGaN MQW systems.
How magnetic field can transform a superconductor into a Bose metal
Authors: Ren Tianhao , Tsvelik Alexei M
Published: September 2020

We discuss whether a simple theory of superconducting stripes coupled by Josephson tunneling can describe a metallic transport, once the coherent tunneling of pairs is suppressed by the magnetic field. For a clean system, the conclusion we reached is negative: the excitation spectrum of preformed pairs consists of Landau levels, and once the magnetic field exceeds a critical value, the transport becomes insulating. As a speculation, we suggest that a Bose metal can exist in disordered systems provided that the disorder is strong enough to localize some pairs. Then the coupling between propagating and localized pairs broadens the Landau levels, resulting in a metallic conductivity. Our model respects the particle–hole symmetry, which leads to a zero Hall response. And intriguingly, the resulting anomalous metallic state has no Drude peak and the spectral weight of the cyclotron resonance vanishes at low temperatures.
Density-density correlation function of strongly inhomogeneous Luttinger liquids
Authors: Danny Babu Nikhil , Das Joy Prakash , Setlur Girish S
Published: September 2020

In this work, we show in pedagogical detail that the most singular contributions to the slow part of the asymptotic density-density correlation function of Luttinger liquids with fermions interacting mutually with only short-range forward scattering and also with localised scalar static impurities (where backward scattering takes place) has a compact analytical expression in terms of simple functions that have second order poles and involve only the scale-independent bare transmission and reflection coefficients. This proof uses conventional fermionic perturbation theory resummed to all orders, together with the idea that for such systems, the (connected) moments of the density operator all vanish beyond the second order—the odd ones vanish identically and the higher order even moments are less singular than the second order moment which is the only one included. This important result is the crucial input to the recently introduced ‘Non-Chiral Bosonization Technique’ (NCBT) to study such systems. The results of NCBT cannot be easily compared with the results obtained using conventional bosonization as the former only extracts the most singular parts of the correlation functions albeit for arbitrary impurity strengths and mutual interactions. The latter, ambitiously attempts to study all the parts of the asymptotic correlation functions and is thereby unable to find simple analytical expressions and is forced to operate in the vicinity of the homogeneous system or the half line (the opposite extreme). For a fully homogeneous system or its antithesis viz. the half-line, all the higher order connected moments of the density vanish identically which means the results of chiral bosonization and NCBT ought to be the same and indeed they are.
The role of velocity derivative skewness in understanding non-equilibrium turbulence*
Authors: Liu Feng , Fang Le , Shao Liang
Published: September 2020

The turbulence governed by the Navier–Stokes equation is paramount in many physical processes. However, it has been considered as a challenging problem due to its inherent nonlinearity, non-equilibrium, and complexity. Herein, we review the connections between the velocity derivative skewness Sk
and the non-equilibrium properties of turbulence. Sk
, a reasonable candidate for describing the non-equilibrium turbulence, which varies during the non-equilibrium procedure. A lot of experimental or numerical evidences have shown that the perturbation of energy spectrum, which associated with the excitation of large scales, results in an obvious variation of Sk
, and Sk
is a negative value in this rapid energy decay process. The variation of positive Sk
is closely related to the perturbation of transfer spectrum, and this corresponds to the backward energy transfer process. In addition, the skewness characterizes the production (or reduction) rate of enstrophy due to vortex stretching (or compression). Using the transport equation of turbulent energy dissipation rate and enstrophy, it is possible to establish a theoretical connection between skewness and the non-equilibrium turbulence. It is expected that this work could trigger the rapid advancement of the future studies of non-equilibrium turbulence, and also the improvement of turbulence models.
Nonperturbative effects of attraction on dynamical behaviors of glass-forming liquids*
Authors: Sun Xiaoyan , Zhang Haibo , Wang Lijin , Zhang Zexin , Ma Yuqiang
Published: September 2020

We investigate systematically the effects of the inter-particle attraction on the structure and dynamical behaviors of glass-forming liquids via molecular dynamics simulations. We find that the inter-particle attraction does not influence the structure, but greatly affects the dynamics and dynamical heterogeneity of the system. After the system changes from a purely repulsive glass-forming liquid to an attractive one, the dynamics slows down and the dynamical heterogeneity becomes greater, which is found interestingly to be associated with larger cooperative rearrangement regions (CRRs). Additionally, the structures of CRRs are observed to be compact in attractive glass-forming liquids but string-like in purely repulsive ones. Our findings constitute an important contribution to the ongoing study of the role of attractions in properties of glasses and glass-forming liquids.
Imprint of transient electron localization in

H2+

using circularly-polarized laser pulse*
Authors: Luo Jianghua , Li Jun , Zhang Huafeng
Published: September 2020

Photoelectron momentum distribution of hydrogen molecular ion in a circularly polarized laser pulse is calculated by solving the three-dimensional time-dependent Schrödinger equation (3D-TDSE). At the intermediate internuclear distance, an unusual multi-peak structure is observed in the angular distribution, which is proved to be a signature of the transient localization of the electron upon alternating nucleus. By tracing the time-dependent ionization rate and bound state populations, we provide a clear evidence that the transient electron localization still exists in circularly polarized pulse and the corresponding multiple ionization bursts are directly mapped onto observable angular distributions. In addition, we introduce an intuitive strong-field approximation model which incorporates laser-induced subcycle internal electron dynamics to isolate the effect of the Coulomb potential of the parent ions. In this way, the timing of each ionization burst can be directly read out from the angular distributions. Our results suggest that the ionization time serves as a sensitive tool encoding intramolecular electron dynamics and can be measured using attoclock technique.
Dynamics of the two-SBT-memristor-based chaotic circuit*
Authors: Guo Mei , Zhang Meng , Dou Ming-Long , Dou Gang , Li Yu-Xia
Published: September 2020

A two-SBT-memristor-based chaotic circuit was proposed. The stability of the equilibrium point was studied by theoretical analysis. The close dependence of the circuit dynamic characteristics on its initial conditions and circuit parameters was investigated by utilizing Lyapunov exponents spectra, bifurcation diagrams, phase diagrams, and Poincaré maps. The analysis showed that the circuit system had complex dynamic behaviors, such as stable points, period, chaos, limit cycles, and so on. In particular, the chaotic circuit produced the multistability phenomenon, such as coexisting attractors and coexisting periods.
Strain and interfacial engineering to accelerate hydrogen evolution reaction of two-dimensional phosphorus carbide*
Authors: Huang Tao , Si Yuan , Wu Hong-Yu , Xia Li-Xin , Lan Yu , Huang Wei-Qing , Hu Wang-Yu , Huang Gui-Fang
Published: September 2020

Hydrogen, regarded as a promising energy carrier to alleviate the current energy crisis, can be generated from hydrogen evolution reaction (HER), whereas its efficiency is impeded by the activity of catalysts. Herein, effective strategies, such as strain and interfacial engineering, are imposed to tune the catalysis performance of novel two-dimensional (2D) phosphorus carbide (PC) layers using first-principle calculations. The findings show that P site in pristine monolayer PC (ML-PC) exhibits higher HER performance than C site. Intriguingly, constructing bilayer PC sheet (BL-PC) can change the coordinate configuration of P atom to form 3-coordination-P atom (3-co-P) and 4-coordination-P atom (4-co-P), and the original activity of 3-co-P site is higher than the 4-co-P site. When an external compressive strain is applied, the activity of the 4-co-P site is enhanced whereas the external strain can barely affect that of 3-co-P site. Interestingly, the graphene substrate enhances the overall activity of the BL-PC because the graphene substrate optimizes the ΔG
H* value of 4-co-P site, although it can barely affect the HER activity of 3-co-P site and ML-PC. The desirable properties render 2D PC-based material promising candidates for HER catalysts and shed light on the wide utilization in electrocatalysis.
Ground-state phases and spin textures of spin–orbit-coupled dipolar Bose–Einstein condensates in a rotating toroidal trap*
Authors: Wang Qing-Bo , Yang Hui , Su Ning , Wen Ling-Hua
Published: September 2020

We investigate the ground-state phases and spin textures of spin–orbit-coupled dipolar pseudo-spin-1/2 Bose–Einstein condensates in a rotating two-dimensional toroidal potential. The combined effects of dipole–dipole interaction (DDI), spin–orbit coupling (SOC), rotation, and interatomic interactions on the ground-state structures and topological defects of the system are analyzed systematically. For fixed SOC strength and rotation frequency, we provide a set of phase diagrams as a function of the DDI strength and the ratio between inter- and intra-species interactions. The system can show rich quantum phases including a half-quantum vortex, symmetrical (asymmetrical) phase with quantum droplets (QDs), asymmetrical segregated phase with hidden vortices (ASH phase), annular condensates with giant vortices, triangular (square) vortex lattice with QDs, and criss-cross vortex string lattice, depending on the competition between DDI and contact interaction. For given DDI strength and rotation frequency, the increase of the SOC strength leads to a structural phase transition from an ASH phase to a tetragonal vortex lattice then to a pentagonal vortex lattice and finally to a vortex necklace, which is also demonstrated by the momentum distributions. Without rotation, the interplay of DDI and SOC may result in the formation of a unique trumpet-shaped Bloch domain wall. In addition, the rotation effect is discussed. Furthermore, the system supports exotic topological excitations, such as a half-skyrmion (meron) string, triangular skyrmion lattice, skyrmion–half-skyrmion lattice, skyrmion–meron cluster, skyrmion–meron layered necklace, skyrmion–giant-skyrmion necklace lattice, and half-skyrmion–half-antiskyrmion necklace.
High-dimensional atomic microscopy in surface plasmon polaritons*
Authors: Munir Akhtar , Wahab Abdul , Jan Munsif
Published: September 2020

We develop a new scheme of two-dimensional (2D) and three-dimensional (3D) atom localization via absorption and gain spectra of surface plasmon polaritons (SPPs) in a closed loop four-level atomic system. For the atom–field interaction, we construct a spatially dependent field by superimposing two (three) standing-wave fields (SWFs) in 2D (3D) atom localization, respectively. We achieve high-precision and high spatial resolution of an atom localization by appropriately adjusting the system parameters such as probe field detuning and phase shifts of the SWFs. The absorption and gain spectra are used to attain information about the position of an atom in SPPs. Our proposed scheme opens up a fascinating way to improve the atom localization that supplies some practical applications in a high-dimensional SPPs.
Field-induced Néel vector bi-reorientation of a ferrimagnetic insulator in the vicinity of compensation temperature*
Authors: Wang Peng , Zhao Hui , Luan Zhongzhi , Xia Siyu , Feng Tao , Zhou Lifan
Published: September 2020

The spin Hall magnetoresistance (SMR) effect in Pt/Gd3Fe5O12 (GdIG) bilayers was systematically investigated. The sign of SMR changes twice with increasing magnetic field in the vicinity of the magnetization compensation point (T
M) of GdIG. However, conventional SMR theory predicts the invariant SMR sign in the heterostructure composed of a heavy metal film in contact with a ferromagnetic or antiferromagnetic film. We conclude that this is because of the significant enhancement of the magnetic moment of the Gd sub-lattice and the unchanged moment of the Fe sub-lattice with a relatively large field, meaning that a small net magnetic moment is induced at T
M. As a result, the Néel vector aligns with the field after the spin-flop transition, meaning that a bi-reorientation of the Néel vector is produced. Theoretical calculations based on the Néel’s theory and SMR theory also support our conclusions. Our findings indicate that the Néel-vector direction of a ferrimagnet can be tuned across a wide range by a relatively low external field around T
M.
Dielectric properties of nucleated erythrocytes as simulated by the double spherical-shell model*
Authors: Xu Jia , Xie Weizhen , Chen Yiyong , Wang Lihong , Ma Qing
Published: September 2020

The dielectric properties of nucleated erythrocytes from bullfrogs were measured in a frequency range of 10 kHz–110 MHz. The complex permittivity (ε
*), complex conductivity (κ
*), and complex resistivity (ρ
*) were analyzed and compared in the 10.63% to 37.58% haematocrit (Hct) range. The relaxation behavior, the passive electrical properties, and the cellular structure parameters, including the cell membrane, the cytoplasm, the nuclear membrane, and the nucleoplasm of the nucleated erythrocyte suspensions were investigated. The method used is based on the binomial Cole–Cole equation and the double spherical-shell physical models. Upon the elimination of the electrode polarization effect, two definite relaxations related to the interfacial polarization are observed on low- and high-frequency dispersions. The permittivity values and the characteristic frequency values differ by one order of magnitude: the low-frequency relaxation increments [Δ ε
1 = (5.63 ± 1.43)× 103] and the characteristic frequency [f
c1 = (297.06 ± 14.48) kHz] derived from the cell membrane, the high-frequency relaxation increments [Δ ε
2 = (5.21 ± 1.20) × 102] and the characteristic frequency [f
c2 = (3.73 ± 0.06) MHz] derived from the dielectric response to the external electric field of the nuclear membrane, respectively. Moreover, the other core dielectric parameters, such as the relative permittivity of the cell membrane [ε
m = (7.57 ± 0.38)] and the nuclear envelope [ε
ne = (23.59 ± 4.39)], the conductivity of the cytoplasm (hemoglobin, κ
Hb = (0.50 ± 0.13) S/m] and the nuclear endoplasm [κ
np = (2.56 ± 0.75) S/m], and the capacitance of the bilayer membranes [C
m: (0.84 ± 0.04) μF/cm2], and C
ne: (0.52 ± 0.10) μF/cm2] were also accurately and reliably measured. This work presents a feasible method to evaluate the dielectric parameters and the cellular structure of the erythrocytes of bullfrogs. Moreover, it paves the way for new studies on the haematology of frogs and the detection of nucleated cells via dielectric impedance spectroscopy.
Interference effect on the liquid-crystal-based Stokes polarimeter*
Authors: Hou Jun-Feng , Wang Dong-Guang , Deng Yuan-Yong , Zhang Zhi-Yong , Sun Ying-Zi
Published: September 2020

The Stokes polarimeter based on liquid crystal variable retarders (LCVRs) is envisaged as a promising novel technique for polarization measurement in space applications due to the inherent advantage of eliminating the need for conventional rotating polarizing optics and increasing the measuring speed. However, the intrinsic multi-beam interference in LCVRs limits its polarization accuracy by several percent. How to eliminate the influence of the interference effect becomes an urgent issue for the liquid-crystal-based Stokes polarimeter. The present study introduces a simplified but effective interference model based on the thin-film optics and polarized light theory to simulate the relationship between the interference effect of the LCVRs-based Stokes polarimeter and the polarization accuracy. The simulation results show that the transmittance variation of LCVR with the derived voltage is caused by multi beam interference between the indium tin oxide (ITO) film and the liquid crystal within LCVR, which produces a few percent of instrumental polarization. The instrumental polarization is about 0.01 and different for different wavelengths. An optimization method was proposed to reduce the instrumental polarization to 0.002, effectively improving the polarization sensitivity of the Stokes polarimeter limited by the interference. In addition, an experimental setup was built up to measure and analyze the influence of the interference effect of the LCVRs-based Stokes polarimeter on the polarization accuracy before and after the optimization. The experiment results are in good agreement with the simulation.
Effect of microstructure of Au80Sn20 solder on the thermal resistance TO56 packaged GaN-based laser diodes
Authors: Lin Hao , Li Deyao , Zhang Liqun , Wen Pengyan , Zhang Shuming , Liu Jianping , Yang Hui
Published: September 2020

Au80Sn20 alloy is a widely used solder for laser diode packaging. In this paper, the thermal resistance of GaN-based blue laser diodes packaged in TO56 cans were measured by the forward voltage method. The microstructures of Au80Sn20 solder were then investigated to understand the reason for the difference in thermal resistance. It was found that the microstructure with a higher content of Au-rich phase in the center of the solder and a lower content of (Au,Ni)Sn phase at the interface of the solder/heat sink resulted in lower thermal resistance. This is attributed to the lower thermal resistance of Au-rich phase and higher thermal resistance of (Au,Ni)Sn phase.
Wireless communication and wireless power transfer system for implantable medical device
Authors: Zhang Zhang , Chen Chao , Fei Tairan , Xiao Hao , Xie Guangjun , Cheng Xin
Published: September 2020

Traditional magnetically coupled resonant wireless power transfer technology uses fixed distances between coils for research, to prevent fluctuations in the receiving voltage, and lead to reduce transmission efficiency. This paper proposes a closed-loop control wireless communication wireless power transfer system with a wearable four-coil structure to stabilize the receiving voltage fluctuation caused by changes in the displacement between the coils. Test results show that the system can provide stable receiving voltage, no matter how the distance between the transmitting coil and the receiving coil is changed. When the transmission distance is 20 mm, the power transfer efficiency of the system can reach 18.5% under the open-loop state, and the stimulus parameters such as the stimulation period and pulse width can be adjusted in real time through the personal computer terminal.
Seasonal impact-based mapping of compound hazards
Authors: Hillier J K , Dixon R S
Published: September 2020

Impact-based, seasonal mapping of compound hazards is proposed. It is pragmatic, identifies phenomena to drive the research agenda, produces outputs relevant to stakeholders, and could be applied to many hazards globally. Illustratively, flooding and wind damage can co-occur, worsening their joint impact, yet where wet and windy seasons combine has not yet been systematically mapped. Here, seasonal impact-based proxies for wintertime flooding and extreme wind are used to map, at 1° × 1° resolution, the association between these hazards across Europe within 600 years as realized in seasonal hindcast data. Paired areas of enhanced-suppressed correlation are identified (Scotland, Norway), and are shown to be created by orographically-enhanced rainfall (or shelter) from prevailing westerly storms. As the hazard metrics used are calibrated to losses, the maps are indicative of the potential for damage.
Impact of ocean model resolution on understanding the delayed warming of the Southern Ocean
Authors: Bilgen Simge I , Kirtman Ben P
Published: September 2020

Currently available historical climate change simulations indicate a relatively delayed Southern Ocean warming, particularly poleward of the Antarctic Circumpolar Current (ACC) compared much of the rest of the globe. However, even this simulated delayed warming is inconsistent with observational estimates which show a cooling trend poleward of the ACC for the period 1979–2014. A fully coupled model run at two resolutions, i.e. ocean eddy parameterized and ocean eddy resolving, driven by historical and fixed CO2 concentration is used to investigate forced trends south of the ACC. We analyze the 1961–2005 Southern Ocean surface and upper ocean temperatures trends simulated by the model and observational estimates to understand the observed trends in the SO. At both resolutions, the models successfully reproduce the observed warming response for the northern flank of the ACC. The eddy resolving simulations, however, are able to reproduce the observed near Antarctic cooling in contrast to the eddy parameterized simulation which shows a warming trend. The cause of this inconsistency between the observations and the ocean eddy parameterized climate models is still a matter of debate, and we show here results that suggest resolved ocean meso-scale processes may be an integral part of capturing the observed trends in the Southern Ocean.
On regular and chaotic dynamics of a non-

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-symmetric Hamiltonian system of a coupled Duffing oscillator with balanced loss and gain
Authors: Ghosh Pijush K , Roy Puspendu
Published: September 2020

A non-

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-symmetric Hamiltonian system of a Duffing oscillator coupled to an anti-damped oscillator with a variable angular frequency is shown to admit periodic solutions. The result implies that

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-symmetry of a Hamiltonian system with balanced loss and gain is not necessary in order to admit periodic solutions. The Hamiltonian describes a multistable dynamical system—three out of five equilibrium points are stable. The dynamics of the model is investigated in detail by using perturbative as well as numerical methods and shown to admit periodic solutions in some regions in the space of parameters. The phase transition from periodic to unbounded solution is to be understood without any reference to

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-symmetry. The numerical analysis reveals chaotic behaviour in the system beyond a critical value of the parameter that couples the Duffing oscillator to the anti-damped harmonic oscillator, thereby providing the first example of Hamiltonian chaos in a system with balanced loss and gain. The method of multiple time-scales is used for investigating the system perturbatively. The dynamics of the amplitude in the leading order of the perturbation is governed by an effective dimer model with balanced loss and gain that is non-

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-symmetric Hamiltonian system. The dimer model is solved exactly by using the Stokes variables and shown to admit periodic solutions in some regions of the parameter space.
A many-body heat engine at criticality
Authors: Fogarty Thomás , Busch Thomas
Published: September 2020

We show that a quantum Otto cycle in which the medium, an interacting ultracold gas, is driven between a superfluid and an insulating phase can outperform similar single particle cycles. The presence of an energy gap between the two phases can be used to improve performance, while the interplay between lattice forces and the particle distribution can lead to a many-body cooperative effect. Since finite time driving of this cycle can create unwanted non-equilibrium dynamics which can significantly impair the performance of the engine cycle, we also design an approximate shortcut to adiabaticity for the many-body state that can be used to achieve an efficient Otto cycle around a critical point.