bluuebunny/crossref_metadata_2025 huggingface dataset:
Transmission spectroscopy and Rossiter-McLaughlin measurements of the young Neptune orbiting AU Mic
Authors: Palle E. , Oshagh M. , Casasayas-Barris N. , Hirano T. , Stangret M. , Luque R. , Strachan J. , Gaidos E. , Anglada-Escude G. , Plavchan P. , Addison B.
Published: September 2020

AU Mic b is a Neptune-sized planet on an 8.47-day orbit around the nearest pre-main sequence (~20 Myr) star to the Sun, the bright (V = 8.81) M dwarf AU Mic. The planet was preliminary detected in Doppler radial velocity time series and recently confirmed to be transiting with data from the TESS mission. AU Mic b is likely to be cooling and contracting and might be accompanied by a second, more massive planet, in an outer orbit. Here, we present the observations of the transit of AU Mic b using ESPRESSO on the Very Large Telescope. We obtained a high-resolution time series of spectra to measure the Rossiter-McLaughlin effect, to constrain the spin-orbit alignment of the star and planet, and to simultaneously attempt to retrieve the planet’s atmospheric transmission spectrum. These observations allowed us to study, for the first time, the early phases of the dynamical evolution of young systems. We applied different methodologies to derive the spin-orbit angle of AU Mic b, and all of them retrieve values consistent with the planet being aligned with the rotation plane of the star. We determined a conservative spin-orbit angle λ value of −2.96−10.30+10.44 degrees, indicative that the formation and migration of the planets of the AU Mic system occurred within the disc. Unfortunately, and despite the large signal-to-noise ratio of our measurements, the degree of stellar activity prevented us from detecting any features from the planetary atmosphere. In fact, our results suggest that transmission spectroscopy for recently formed planets around active young stars is going to remain very challenging, if at all possible, for the near future.
Production yields of micro-second isomers populated in 252Cf(SF)
Authors: Gaudefroy Laurent , Ebran Adeline
Published: September 2020

A twin Frisch grid ionization chamber loaded with an ultra-thin 252 Cf sample is used in order to detect spontaneous fission events. The chamber is surrounded by 8 HPGe detectors allowing to perform γ-spectroscopic measurements. We are interested in the decay of isomeric states populated in fission fragments. In this contribution we report on preliminary results on production yields of isomeric states with half-lives ranging from few nanoup to few micro-seconds.
Bragg curve spectroscopy for improved fission fragment identification
Authors: Fulsom Bryan
Published: September 2020

We report on the development of Bragg curve spectroscopy techniques to improve fission fragment identification in the measurement of independent fission product yields. The NIFFTE collaboration’s fissionTPC detector provides ionization energy and particle tracking information from neutroninduced fission targets. A joint effort between PNNL, LLNL, LANL, and the Colorado School of Mines is investigating the ionization profiles deposited by U-235, U-238, and Pu-239 fission products in this detector, with the goal of including additional stopping power information beyond a standard 2E analysis. The aim is to improve the determination of fragment atomic and mass numbers with this information, via methods such as parametric fits and machine learning techniques.
Completeness Check of Experimental Fission Product Yield Data in EXFOR Database
Authors: Okumura Shin
Published: September 2020

The IAEA conducted the completeness assessment of fission product yield (FPY) data in EXFOR database against two bibliographies that were used in ENDF/B-VI and UKFY3.0 library evaluations. We found that 194 articles are found to be relevant for new entry.
Description of the Fission Process: Nuclear Models for Fission Dynamics
Authors: Verriere M. , Mumpower M.R. , Kawano T. , Schunck N.
Published: September 2020

Nuclear fission is the splitting of a heavy nucleus into two or more fragments, a process that releases a substantial amount of energy. It is ubiquitous in modern applications, critical for national security, energy generation and reactor safeguards. Fission also plays an important role in understanding the astrophysical formation of elements in the universe. Eighty years after the discovery of the fission process, its theoretical understanding from first principles remains a great challenge. In this paper, we present promising new approaches to make more accurate predictions of fission observables.
Phonologische Prozesse in der deutschen Sprache türkisch-deutsch bilingualer Kinder
Authors: Fox-Boyer Annette , Fricke Silke , Albrecht Katharina Margareta
Published: September 2020

Hintergrund Kenntnisse über den typischen Ausspracheerwerb sind notwendig, um Aussprachestörungen identifizieren zu können. Hierbei spielt die phonologische Prozessanalyse eine wichtige Rolle. Informationen zum Ausspracheerwerb bilingualer Kinder sind bislang rar, sodass eine Diagnosestellung erschwert ist.

Methode Mit Hilfe eines Bilderbenenntests wurden die phonologischen Prozesse im Deutschen von 84 türkisch-deutsch bilingualen Kindern im Alter von 3;0–5;5 Jahren untersucht.

Ergebnis Bis auf wenige Ausnahmen (z. B. Vokalfehler) wurden nur phonologische Prozesse im Deutschen beobachtet, die denen monolingualer Kinder entsprechen. Diese wurden meist später als von monolingualen Kindern überwunden. Simultan und sukzessiv bilingual aufwachsende Kinder unterschieden sich hier kaum.

Diskussion Die Ergebnisse bestätigen bisherige Pilotstudien zum türkisch-deutschen Phonologieerwerb und können zur Orientierung in der sprachtherapeutischen Aussprachediagnostik herangezogen werden.
Sports and Metabolic Bone Disease
Authors: Aparisi Gómez Maria Pilar , Weidekamm Claudia , Aparisi Francisco , Bazzocchi Alberto
Published: September 2020

Physical activity (PA) increases bone mass and bone strength through different mechanisms and also reduces the risk of falls in the elderly, through proprioception and balance training. The benefits seen in adolescence continue into adulthood. Exercise delays and attenuates the effects of osteoporosis, and particular sports activities may be recommended to improve bone mineral density (BMD) of the spine or regional BMD, improve balance, and prevent falls. Stress injuries related to exercise are more common in osteopenic and osteoporotic individuals.

Sports activity may in some cases be detrimental for bone health, with nutrition restriction a frequent cause for negative effects of the practice of PA on bone. The examples are the so-called female athlete triad of menstrual dysfunction resulting in reduced estrogen levels, low energy due to malnutrition, and decreased BMD. A similar triad is described in male athletes. This review analyzes the effects of sport on bone metabolism and in particular its relationship with metabolic bone disease.
Stress Injuries of the Spine in Sports
Authors: Wong Jenn Shiunn , Lalam Radhesh , Cassar-Pullicino Victor N. , Tyrrell Prudencia N.M. , Singh Jaspreet
Published: September 2020

Spine sports stress injuries account for a significant amount of time loss at play in athletes, particularly if left unrecognized and allowed to progress. Spondylolysis makes up most of these stress injuries. This article focuses on spondylolysis, bringing together discussion from the literature on its pathomechanics and the different imaging modalities used in its diagnosis. Radiologists should be aware of the limitations and more importantly the roles of different imaging modalities in guiding and dictating the management of spondylolysis. Other stress-related injuries in the spine are also discussed including but not limited to pedicle fracture and apophyseal ring injury.
Glioblastoma Multiforme in the Cerebellopontine Angle in a Pediatric Patient
Authors: Pregúntegui-Loayza Ivethe , Céspedes Erland , Saal-Zapata Giancarlo
Published: September 2020

Posterior fossa tumors are frequently diagnosed in children compared to their adult counterparts, representing 54 to 70% of the cases. Tumors located in the cerebellopontine angle are rare and represent 10% of the posterior fossa lesions in children. In addition, glioblastoma multiforme is a malignant primary tumor of the central nervous system and represents 3% of the tumors in children. We present the fourth reported case of a glioblastoma multiforme, confirmed by histopathology and located in the cerebellopontine angle in a 6-year old child, which was treated with surgery and subsequently with radiotherapy and chemotherapy. Thus, the presence of a glioblastoma multiforme in the cerebellopontine angle is extremely rare and needs a high-index of suspicion in children.
Knee Dislocation with Ipsilateral Tibial Fracture Treated with an Intramedullary Locked Nail and Simultaneous Transtibial Tunnel Knee Ligament Reconstruction: A Case Report of Autografts and Limited Resources
Authors: Campos Túlio Vinícius de Oliveira , Moraes Marcelo Nacif , Andrade Marco Antônio Percope de , Schenck Robert C. , Donell Simon T.
Published: September 2020

Knee dislocations associated with ipsilateral tibial shaft fracture represent one of the most challenging injuries in trauma surgery. This injury occurs in only 2% of all tibial fractures in several series. With the use of intramedullary nail (IMN) of the tibia, current practice paraments suggest that transtibial tunnels should be avoided and ligamentous knee surgery be delayed until healing of the shaft fracture occurs. We report a novel case which was successfully managed by delayed IMN and multiligamentous transtibial posterior cruciate ligament (PCL) and posterolateral corner (PLC) autograft reconstructions. A 27-year-old male sustained a Gustilo-Anderson grade IIIa tibial shaft fracture and a Schenck IIIL knee dislocation (KD3L) in the ipsilateral knee. At 2 weeks, the patient was then taken back to the operating theater to undergo definitive bone fixation and ipsilateral simultaneous knee ligamentous reconstruction. The knee was stabilized by open reconstruction of the PCL under fluoroscopic control using an ipsilateral quadriceps autograft fixed with metallic interference screws. The PLC was reconstructed with ipsilateral semitendinosus autograft harvested through a separate 1.5-cm standard anteromedial incision using the technique described by Stannard et al. After graft fixation, the 90 degree posterior and posterolateral drawer and 0 and 30 degrees varus stress tests were negative. After 12 months follow-up, the patient had no complaints regarding pain or instability. The tibial fracture had healed and no knee axis deviation could be noted. The patient had returned to recreational low demand activities and motorcycle riding. Treatment of a combined tibial shaft fracture with an ipsilateral knee dislocation may be satisfactorily accomplished with an IMN for the tibia and transtibial tunnel fixation for knee ligament reconstruction allowing for a single rehabilitation course and a shorter recovery without having to use a third stage for knee ligamentous reconstruction.
Surgical Interventions for Functional Constipation: An Update
Authors: Vilanova-Sanchez Alejandra , Levitt Marc A.
Published: September 2020

Chronic idiopathic constipation, also known as functional constipation, is defined as difficult and infrequent defecation without an identifiable organic cause. Medical management with laxatives is effective for the majority of constipated children. However there is a subset of patients who may need evaluation by a surgeon. As constipation progresses, it can lead to fecal retention and rectal and sigmoid distension, which impairs normal colorectal motility. Surgical interventions are influenced by the results of: a rectal biopsy, transit studies, the presence of megacolon/megarectum on contrast enema, the degree of soiling/incontinence, anorectal manometry findings, and colonic motility evaluation. In this review, we describe the different surgical options available (intestinal diversion, antegrade enemas, sacral nerve stimulation, colonic resections, and Botulinum toxin injection) and provide guidance on how to choose the best procedure for a given patient.
Hilar Fibropolycystic Liver Disease of Unknown Etiology: A Revelation from the Explant Liver
Authors: Menon Jagadeesh , Vij Mukul , Shanmugam Naresh , Hakeem Abdul , Reddy Mettu Srinivas , Kaliamoorthy Ilankumaran , Rela Mohamed
Published: September 2020

Fibropolycystic diseases of the liver comprise a spectrum of disorders affecting bile ducts of various sizes and arise due to an underlying ductal plate malformation (DPM). We encountered a previously unreported variant of DPM, the hilar fibropolycystic disease which we diagnosed in the explant liver. A 2-year-old boy was referred for liver transplantation with a diagnosis of biliary atresia (BA) and failed Kasai portoenterostomy (KPE). He had cirrhosis with portal hypertension along with synthetic failure indicated by coagulopathy and hypoalbuminemia. The child underwent liver transplant successfully. The explant liver had fibropolycystic disease confined to the perihilar liver and hilum. No pathogenic mutation was detected by whole exome sequencing. Fibropolycystic liver disease may represent a peculiar anatomical variant, which can be diagnosed by careful pathological examination of the explant liver. The neonatal presentation of hilar fibropolycystic liver disease can be misdiagnosed as BA.
Concepts for historical and geographical thinking in Sweden’s and Spain’s Primary Education curricula
Authors: Moreno-Vera Juan Ramón , Alvén Fredrik
Published: September 2020

The goal of this study is to compare the presence of concepts for historical and geographical thinking in the national curricula for Primary Education in Spain and Sweden in order to analyze if these thinking concepts can enable new active learning methodologies in the Social Science classroom. The comparative study is based on a qualitative investigation using a horizontal evaluation instrument (international compared analysis). Compared items were divided in four dimensions: 1. curriculum structure—subjects, timetable, compulsory, ratio, etc.-, 2. educational methodologies—project-based learning, research, practical lessons-, 3. Objectives and evaluation—aims, evaluation criteria, standards-, and 4. Contents—conceptual, procedural, and attitudinal. The results show that, despite a different structure for the history and geography subjects in Primary Education, neither of the two curricula present historical and geographical thinking concepts as a fundamental aim for Primary Education and, at the same time, the low presence of these thinking concepts is linked to traditional teaching models still based on positivism and memorization.
Ultrafast photoemission electron microscopy: Capability and potential in probing plasmonic nanostructures from multiple domains
Authors: Sun Quan , Zu Shuai , Misawa Hiroaki
Published: September 2020

The near-field properties and dynamics of plasmonic nanostructures play a crucial role in several fundamental concepts in physics and chemistry, and they are widely relevant in plasmonic applications. Ultrafast photoemission electron microscopy (PEEM) is a novel approach that has been widely applied to probe plasmonic nanostructures from multiple domains. Furthermore, PEEM is the only technique that provides nanometer spatial resolution, sub-femtosecond temporal resolution, and tens to hundreds of millielectron volt energy resolution. This allows for extremely sensitive observations of plasmonic field oscillations, field dephasing, and hot electrons. This Perspective provides a brief overview of the basic principles and main applications of ultrafast PEEM. The research progress of ultrafast PEEM in plasmonics is highlighted from three points of view: near-field imaging, near-field spectroscopy, and ultrafast dynamics. Future applications of PEEM in plasmonics for the probing of plasmonic hot electron dynamics in the energy and time domains are proposed and discussed.
Comparison of hot carrier generation between self-assembled gold and silver nanoparticle arrays tailored to the same hybrid plasmon resonance
Authors: Fujita Tetsuya , Takeuchi Yuki , Yamaguchi Kenzo , Yano Taka-aki , Tanaka Takuo , Takeyasu Nobuyuki
Published: September 2020

We evaluated the properties of hot carrier generation on Au and Ag nanoparticle (NP) 2D arrays by monitoring chemical transformation. The arrays were fabricated by assembling the Au and AgNPs, respectively, with a diameter of ∼30 nm. The plasmon resonance peaks of both the arrays were tuned to around 671 nm, where the intraband transition was the dominant pathway for the surface plasmon excitation since the incident photon energy is below the interband transition threshold for both Au and Ag. Time-resolved surface-enhanced Raman scattering (SERS) spectroscopy was utilized to monitor the changes in the molecular structure sensitively. We selected para-aminothiophenol as the molecule, which was well known to transform to 4,4′-dimercaptoazobenzene (DMAB) by hot carriers generated from the plasmonic excited surface. It was observed that the peak intensity of DMAB increased as the total exposure increased due to the increase in the number of DMAB molecules for both metals, similar to our previous reports. The analysis of the SERS spectra showed that larger laser intensity progressed the transformation more rapidly. The analysis also clarified that the chemical transformation occurs more efficiently on the AgNP array compared to the AuNP array. The superiority in the efficiency for Ag may be derived from contribution of more hot carriers generated in the material with the smaller plasmon damping constant.
Restricted configuration path integral Monte Carlo
Authors: Yilmaz A. , Hunger K. , Dornheim T. , Groth S. , Bonitz M.
Published: September 2020

Quantum Monte Carlo (QMC) belongs to the most accurate simulation techniques for quantum many-particle systems. However, for fermions, these simulations are hampered by the sign problem that prohibits simulations in the regime of strong degeneracy. The situation changed with the development of configuration path integral Monte Carlo (CPIMC) by Schoof et al. [Contrib. Plasma Phys. 51, 687 (2011)] that allowed for the first ab initio simulations for dense quantum plasmas [Schoof et al., Phys. Rev. Lett. 115, 130402 (2015)]. CPIMC also has a sign problem that occurs when the density is lowered, i.e., in a parameter range that is complementary to traditional QMC formulated in coordinate space. Thus, CPIMC simulations for the warm dense electron gas are limited to small values of the Brueckner parameter—the ratio of the interparticle distance to the Bohr radius—rs=r¯/aB≲1. In order to reach the regime of stronger coupling (lower density) with CPIMC, here we investigate additional restrictions on the Monte Carlo procedure. In particular, we introduce two different versions of “restricted CPIMC”—called RCPIMC and RCPIMC+—where certain sign changing Monte Carlo updates are being omitted. Interestingly, one of the methods (RCPIMC) has no sign problem at all, but it introduces a systematic error and is less accurate than RCPIMC+, which neglects only a smaller class of the Monte Carlo steps. Here, we report extensive simulations for the ferromagnetic uniform electron gas with which we investigate the properties and accuracy of RCPIMC and RCPIMC+. Furthermore, we establish the parameter range in the density–temperature plane where these simulations are both feasible and accurate. The conclusion is that RCPIMC and RCPIMC+ work best at temperatures in the range of Θ = kBT/EF ∼ 0.1…0.5, where EF is the Fermi energy, allowing to reach density parameters up to rs ∼ 3…5, thereby partially filling a gap left open by existing ab initio QMC methods.
Near-infrared free carrier absorption enhancement of heavily doped silicon in all-dielectric metasurface
Authors: Yu Honghao , Xiong Qing , Wang Hong , Zhang Ye , Wang Yi , Lai Jianjun , Chen Changhong
Published: September 2020

As the hole mobility increases with free carrier absorption (FCA), heavily doped p-type silicon has emerged as a promising candidate for detecting near-infrared (NIR) light with photonic energy below the semiconductor bandgap, and the hot-carrier photodetector is capable of high responsivity approaching commercially available devices. To enhance performance-related FCA of the semiconductor, here we demonstrate an all-silicon metasurface absorber designed in nanohole arrays and present an in-depth analysis on the electromagnetic resonance mechanism in the NIR spectral of interest. Multipole decomposition under a Cartesian coordinate system reveals that combining with the dielectric loss introduced by the doping, magnetic dipole resonances contribute predominantly to the absorption enhancement. This simple and easy-fabricated architecture has great potential for silicon hot-carrier photodetectors.
Orbital-fluctuation freezing and magnetic-nonmagnetic phase transition in α-TiBr3
Authors: Pei Shenghai , Tang Jiangke , Liu Cai , Mei Jia-Wei , Guo Zenglong , Lyu Bingbing , Zhang Naipeng , Huang Qiaoling , Yu Dapeng , Huang Li , Lin Junhao , Wang Le , Huang Mingyuan
Published: September 2020

We present a detailed study on the structural phase transition in α-TiBr3, which is deeply connected with the lattice and orbital degree of freedoms. A chemical vapor transport method is adopted to synthesize the α-TiBr3 single crystal samples, and the structural phase transition at about 180 K is characterized by x-ray diffraction (XRD), magnetic susceptibility, and specific heat capacity. To further the understanding in the physical nature of this phase transition, a systematic Raman spectroscopic study is performed on α-TiBr3 crystals. With temperature decreasing, a large frequency blue shift and peak width narrowing are observed in the vibrational mode associated with Ti in-plane relative movement, which indicates the formation of Ti–Ti bonding and orbital-fluctuation freezing at low temperatures. These results are fully consistent with magnetic–nonmagnetic phase transition resolved by the measurement of magnetic susceptibility and lattice changes by XRD.
Fermi level dependence of gas–solid oxygen defect exchange mechanism on TiO2 (110) by first-principles calculations
Authors: Jeong Heonjae , Seebauer Edmund G. , Ertekin Elif
Published: September 2020

In the same way that gases interact with oxide semiconductor surfaces from above, point defects interact from below. Previous experiments have described defect–surface reactions for TiO2(110), but an atomistic picture of the mechanism remains unknown. The present work employs computations by density functional theory of the thermodynamic stabilities of metastable states to elucidate possible reaction pathways for oxygen interstitial atoms at TiO2(110). The simulations uncover unexpected metastable states including dumbbell and split configurations in the surface plane that resemble analogous interstitial species in the deep bulk. Comparison of the energy landscapes involving neutral (unionized) and charged intermediates shows that the Fermi energy EF exerts a strong influence on the identity of the most likely pathway. The largest elementary-step thermodynamic barrier for interstitial injection trends mostly downward by 2.1 eV as EF increases between the valence and conduction band edges, while that for annihilation trends upward by 2.1 eV. Several charged intermediates become stabilized for most values of EF upon receiving conduction band electrons from TiO2, and the behavior of these species governs much of the overall energy landscape.
Consequences of sp2–sp3 boron isomerization in supercooled liquid borates
Authors: Alderman O. L. G. , Benmore C. J. , Weber J. K. R.
Published: September 2020

Time-resolved high-energy synchrotron x-ray total scattering measurements on supercooled molten lithium metaborate (LiBO2) reveal an isomerization reaction involving conversion of trigonal sp2 boron to tetrahedral sp3 boron during quenching and glass formation. Van't Hoff analysis yields an accurate enthalpy change, ΔH = 21(1) kJ mol−1 boron, from which we develop an analytical model for the sp3 isomer fraction and its contribution to configurational heat capacity (Cpconf) and entropy as a function of temperature and composition. Isomerization constitutes 40% of the total calorimetric Cpconf at the glass transition for LiBO2 and directly contributes to the observed rise in liquid fragility with the lithium content.
Generation of a large-scale uniform plasma plume through the interactions between a pair of atmospheric pressure argon plasma jets
Authors: Li Xuechen , Wu Jiacun , Jia Boyu , Wu Kaiyue , Kang Pengcheng , Zhang Furong , Zhao Na , Jia Pengying , Wang Long , Li Shouzhe
Published: September 2020

In this Letter, a uniform air plasma plume with a fairly large scale is generated downstream of an air flow through interactions between a pair of argon plasma jets excited by a direct current power supply. With increasing power voltage, two separated plumes are first generated downstream of the pair of jets, which transit to the uniform planar plume with a fairly large scale. The planar plume elongates with the increasing air flow rate or power voltage. Moreover, the temperature of the planar plume is comparatively low with a maximum of about 80 °C, which is symmetrically distributed perpendicular to the pair of jets. For the separated plumes, discharge current is intermittently pulsed under a time-invariant gap voltage. However, both gap voltage and discharge current are periodically pulsed for the planar plume. High-speed video images reveal that the planar plasma plume stems from two discrete plumes flushing out of the pair of jets, which are soon merged together by a cathode-directed streamer due to interactions between them, leading to the generation of an arc-shaped filament. Due to the air flow, the arc-shaped filament keeps moving away from the jet vicinity until it quenches at last, which belongs to a glow discharge regime. In addition, surface modification of polyethylene terephthalate (PET) is performed with our planar plasma plume, which reveals that the hydrophilicity of the PET surface can be improved greatly.
Effect of defocusing on the quality of quantum ghost images
Authors: Belinsky A.V.
Published: September 2020

The effect of defocusing due to the finite thickness of the crystal, in which parametric scattering occurs, on the spatial resolution of ghost images is considered. The necessary relationships are presented, and methods of levelling this distorting factor and improving the quality of ghost images are proposed.
Acousto-optic modulators for fibre-optic lines
Authors: Epikhin V.M. , Karnaushkin P.V.
Published: September 2020

The specific features of efficient matching of acousto-optic devices with single-mode fibres for the cases of isotropic and anisotropic diffraction are considered. The acousto-optic interaction geometry, optimal for modulating an arbitrarily polarised light beam with a possibility of tuning its frequency shift in the range up to ∼10 MHz, is chosen. Acousto-optic modulators/frequency shifters based on paratellurite (TeO2), pigtailed with polarisation-maintaining and non-polarisation-maintaining fibres, have been developed for wavelengths of 1064 and 1550 nm, and their main technical parameters are investigated.
Efficient lasing in mixtures of helium and fluorine in diffuse discharges formed by runaway electrons
Authors: Tarasenko V.F. , Panchenko A.N. , Kozhevnikov V.V.
Published: September 2020

The parameters of stimulated lasing in diffuse discharges formed in mixtures of helium and fluorine in a strongly inhomogeneous electric field are investigated. Lasing is obtained in the visible and VUV spectral regions on the transitions of fluorine atoms and molecules. It is shown that lasing in He – F2 mixtures at a wavelength of 157 nm continues for several half-periods of the discharge current. Due to the homogeneity of the diffuse discharge, the maximum lasing efficiency of the F2 laser is 0.15 %, which corresponds to the efficiency of this type of lasers pumped by pre-ionised transverse volume discharges.
A narrative to support the future of the Australian Outback
Authors: Traill B. J. , Stafford-Smith Mark
Published: September 2020

Stories matter: as powerful frames for policy and public understanding, but the current narratives about Outback Australia are both confused and often negative. We illustrate this power of stories, including how deliberate framing and story-telling to create a better narrative on some rangeland issues has had positive policy outcomes. Moving to a more intuitive name is one key issue – we suggest that talking of the ‘Modern Outback’ is a powerful change in this regard. We then draw on discussions to provide a set of guiding principles for how to frame writings about the Outback, and give an example of their use.
L2 learning of opaque Chinese compounds through elaborative encoding
Authors: Gao Zhe
Published: September 2020

Chinese compounds consist of two to four characters but function as single word. If the compounds are semantically opaque and contain unfamiliar characters, learners will resort to learning them individually by rote. However, given the large number of Chinese compounds, rote learning can place an excessive burden on memory. To facilitate L2 learning of opaque Chinese compounds, the present study proposes a method called elaborative encoding. In this study, L2 learners were given a booklet with 26 two-character opaque compounds. With elaborative encoding, participants learned the English meanings of the compounds through short metaphorical explanations. With rote memorization, participants learned the compounds’ English meanings without any explanation. To test the effects of elaborative encoding, a Chinese-to-English translation task was conducted immediately after training, five days later, and 14 days later. The results showed elaborative encoding was superior to rote memorization in retaining the meanings of the opaque compounds.
Narrative accounts and their influence on treatment recommendations in medical interviews
Authors: Fioramonte Amy
Published: September 2020

Previous research exploring the use of narratives in medical interviews has primarily examined the history-taking phase to illustrate the ways in which physicians and patients discursively collaborate to organize and interpret patients’ illness experiences (Eggly, 2002;Halkowski, 2006;Stivers & Heritage, 2001). In this paper, the scope will be expanded to demonstrate that narrative accounts are interwoven and unfold across various phases of the medical interview, not only the history-taking phase, and are utilized in a variety of ways to collaboratively accomplish specific social practices. A narrative as talk-in-interaction approach is used to examine narrative accounts using audio-recordings of naturally occurring medical interview data (US, American English). This paper examines the ways in which narratives are locally occasioned todoa variety of things (e.g., raise difficult topics, actively resist treatment, reinforce identities), including influencing the treatment decision making process.
Twisted and coiled bamboo artificial muscles for moisture responsive torsional and tensile actuation*
Authors: Hu Xiaoyu , Leng Xueqi , Jia Tianjiao , Liu Zunfeng
Published: September 2020

Smart textiles responding to the ambient environment like temperature, humidity, and light are highly desirable to improve the comfortability and realize multifunctions. The bamboo yarn has merits like air permeability, biodegradability, and excellent heat dissipation performance, but it has not been prepared for responsive materials and smart textiles. In this paper, the moisture-responsive twisted bamboo yarns were plied to form a self-balanced torsional actuator and wrapped around a mandrel to form a coil, followed by water immersion and evaporation to fix the shape and serve as a tensile actuator. A torsional actuation of 64.4°⋅ mm−1 was realized for the twisted actuator in 4.2 s; a maximum elongation of 133% or contraction of 50% was achieved for a coiled tensile actuator with good cyclability. The porous structure of bamboo yarns helped improve the water absorbance speed and decrease the response time of moisture. The self-balanced two-ply physical structure and reversible generation of chemical phase after soaking in aqueous solution fixed internal stress and provided good cyclability. With the unique properties including aqueous water-induced shape fixation and moisture-induced actuation, the application of tensile actuation of bamboo yarns was demonstrated, showing promising prospects on smart textiles.
Thermal entanglement in a spin-1/2 Ising–Heisenberg butterfly-shaped chain with impurities*
Authors: Ma Meng-Ru , Zheng Yi-Dan , Mao Zhu , Zhou Bin
Published: September 2020

We investigate the effect of impurities on the thermal entanglement in a spin-1/2 Ising–Heisenberg butterfly-shaped chain, where four interstitial Heisenberg spins are localized on the vertices of a rectangular plaquette in a unit block. By using the transfer-matrix approach, we numerically calculate the partition function and the reduced density matrix of this model. The bipartite thermal entanglement between different Heisenberg spin pairs is quantified by the concurrence. We also discuss the fluctuations caused by the impurities through the uniform distribution and the Gaussian distribution. Considering the effects of the external magnetic field, temperature, Heisenberg and Ising interactions as well as the parameter of anisotropy on the thermal entanglement, our results show that comparing with the case of the clean model, in both the two-impurity model and the impurity fluctuation model the entanglement is more robust within a certain range of anisotropic parameters and the region of the magnetic field where the entanglement occurred is also larger.
Surface states modulated exchange interaction in Bi2Se3/thulium iron garnet heterostructures*
Authors: Shi Hai-Bin , Yan Li-Qin , Su Yang-Tao , Wang Li , Cao Xin-Yu , Bi Lin-Zhu , Meng Yang , Sun Yang , Zhao Hong-Wu
Published: September 2020

We investigate the modulation of magnetic anisotropy of thulium iron garnet (TmIG) films by interfaced Bi2Se3 thin films. High quality epitaxial growth of Bi2Se3 films has been achieved by molecular beam epitaxy on TmIG films. By the method of ferromagnetic resonance, we find that the perpendicular magnetic anisotropy (PMA) of TmIG can be greatly strengthened by the adjacent Bi2Se3 layer. Moreover, the competition between topological surface states and thickness dependent bulk states of Bi2Se3 gives rise to the modulation of PMA of the Bi2Se3/TmIG heterostructures. The interfacial interaction can be attributed to the enhanced exchange coupling between Fe3+ ions of TmIG mediated by topological surface electrons of Bi2Se3.
Understanding defect production in an hcp Zr crystal upon irradiation: An energy landscape perspective
Authors: Tian Jiting
Published: September 2020

Primary radiation damage in hcp Zr, including both defect production in a single collision cascade and damage buildup through cascade overlap, is investigated using molecular dynamics (MD) simulations from a potential energy landscape (PEL) perspective. It is found that the material’s response to an energetic particle can be understood as a trajectory in the PEL comprising a fast uphill journey and a slow downhill one. High-temperature-induced damage reduction and the difference in the radiation tolerance between metals and semiconductors can be both qualitatively explained by the dynamics of the trajectory associated with the topographic features of the system’s PEL. Additionally, by comparing irradiation and heating under a nearly identical condition, we find that large atomic displacements stemming from the extreme locality of the energy deposition in irradiation events are the key factor leading to radiation damage in a solid. Finally, we discuss the advantages of the PEL perspective and suggest that a combination of the PEL and the traditional crystallographic methods may provide more insights in future work.
Multiple reversals of vortex ratchet effects in a superconducting strip with inclined dynamic pinning landscape*
Authors: He An , Xue Cun
Published: September 2020

Using time-dependent Ginzburg–Landau formalism, we investigate the multiple reversals of ratchet effects in an unpatterned superconducting strip by the tilted dynamic pinning potential. In the case of collinear sliding potential and Lorentz force, vortices are always confined in the channels induced by sliding potential. However, due to the inclination angle of sliding pinning potential with respect to the Lorentz force, vortices could be driven out of the channels, and unexpected results with multiple reversals of vortex rectifications are observed. The mechanism of multiple reversals of vortex rectifications is explored by analyzing different vortex motion scenarios with increasing ac current amplitudes. The multiple reversals of transverse and longitudinal ratchet effects can be highly controlled by ac amplitude and dynamic pinning velocity. What’s more, at certain large current the ratchet effect reaches strongest within a wide range of pinning sliding velocity.
Effect of recombination process in femtosecond laser-induced modification on Ge crystal*
Authors: Ju Jia-Qi , Qin Zi-Yao , Liu Ju-Kun , Zhao Hong-Wei , Huang Yao-Qing , Hu Rong-Rong , Wu Hua
Published: September 2020

The dynamics of produced excited carriers under the irradiation of Ge crystal is investigated theoretically by using femtosecond laser pulse. A two-temperature model combined with the Drude model is also used to study the nonequilibrium carrier density, carrier and lattice temperatures, and optical properties of the crystal. The properties of the surface plasmon wave when excited are also studied. The influences of non-radiation and radiative recombination process on the photoexcitation of the semiconductor during pulse and the relaxation after the pulse are described in detail. The results show that the effects of Auger recombination on the nonequilibrium carrier density and optical properties of the crystal and the properties of the surface plasmon polariton are great, whereas the effect of radiative recombination is extremely small.
Modularity-based representation learning for networks*
Authors: He Jialin , Li Dongmei , Liu Yuexi
Published: September 2020

Network embedding aims at learning low-dimensional representation of vertexes in a network and effectively preserving network structures. These representations can be used as features for many complex tasks on networks such as community detection and multi-label classification. Some classic methods based on the skip-gram model have been proposed to learn the representation of vertexes. However, these methods do not consider the global structure (i.e., community structure) while sampling vertex sequences in network. To solve this problem, we suggest a novel sampling method which takes community information into consideration. It first samples dense vertex sequences by taking advantage of modularity function and then learns vertex representation by using the skip-gram model. Experimental results on the tasks of community detection and multi-label classification show that our method outperforms three state-of-the-art methods on learning the vertex representations in networks.
Thermal stability and thermoelectric properties of Cd-doped nano-layered Cu2Se prepared using NaCl flux method*
Authors: Lu Jianhua , Li Decong , Liu Wenting , Shen Lanxian , Chen Jiali , Ge Wen , Deng Shukang
Published: September 2020

Cu2Se is a promising “phonon liquid–electron crystal” thermoelectric material with excellent thermoelectric performance. In this work, Cd-doped Cu2–x
SeCd
x
(x = 0, 0.0075, 0.01, and 0.02) samples were prepared using NaCl flux method. The solubility of Cd in Cu2Se at room temperature was less than 6%, and a second phase of CdSe was found in the samples with large initial Cd content (x = 0.01 and 0.02). Field-emission scanning electron microscopic image showed that the arranged lamellae formed a large-scale layered structure with an average thickness of approximately 100 nm. Transmission electron microscopy demonstrated that doping of Cd atoms did not destroy the crystal integrity of Cu2Se. A small amount of Cd in Cu2Se could reduce the electrical and thermal conductivities of the material, thus significantly enhancing its thermoelectric performance. With the increase in Cd content in the sample, the carrier concentration decreased and the mobility increased gradually. Thermogravimetric differential thermal analysis showed that no weight loss occurred below the melting point. Excessive Cd doping led to the emergence of the second phase of CdSe in the sample, thus significantly increasing the thermal conductivity of the material. A maximum ZT value of 1.67 at 700 K was obtained in the Cu1.9925SeCd0.0075 sample.
Analysis of the decrease of two-dimensional electron gas concentration in GaN-based HEMT caused by proton irradiation*
Authors: Tang Jin-Jin , Liu Gui-Peng , Song Jia-Yu , Zhao Gui-Juan , Yang Jian-Hong
Published: September 2020

Gallium nitride (GaN)-based high electron mobility transistors (HEMTs) that work in aerospace are exposed to particles radiation, which can cause the degradation in electrical performance. We investigate the effect of proton irradiation on the concentration of two-dimensional electron gas (2DEG) in GaN-based HEMTs. Coupled Schrödinger’s and Poisson’s equations are solved to calculate the band structure and the concentration of 2DEG by the self-consistency method, in which the vacancies caused by proton irradiation are taken into account. Proton irradiation simulation for GaN-based HEMT is carried out using the stopping and range of ions in matter (SRIM) simulation software, after which a theoretical model is established to analyze how proton irradiation affects the concentration of 2DEG. Irradiated by protons with high fluence and low energy, a large number of Ga vacancies appear inside the device. The results indicate that the ionized Ga vacancies in the GaN cap layer and the AlGaN layer will affect the Fermi level, while the Ga vacancies in the GaN layer will trap the two-dimensional electrons in the potential well. Proton irradiation significantly reduced the concentration of 2DEG by the combined effect of these two mechanisms.
A phononic rectifier based on carbon schwarzite host–guest system*
Authors: Zhangz Zhongwei , Ouyang Yulou , Chen Jie , Volz Sebastian
Published: September 2020

Thermal rectification is a promising way to manipulate the heat flow, in which thermal phonons are spectrally and collectively controlled. As phononic devices are mostly relying on monochromatic phonons, in this work we propose a phononic rectifier based on the carbon schwarzite host–guest system. By using molecular dynamic simulations, we demonstrate that the phononic rectification only happens at a specific frequency of the hybridized mode for the host–guest system, due to its strong confinement effect. Moreover, a significant rectification efficiency, ∼ 134 %, is observed, which is larger than most of the previously observed efficiencies. The study of length and temperature effects on the phononic rectification shows that the monochromaticity and frequency of the rectified thermal phonons depend on the intrinsic anharmonicity of the host–guest system and that the on-center rattling configuration with weak anharmonicity is preferable. Our study provides a new perspective on the rectification of thermal phonons, which would be important for controlling monochromatic thermal phonons in phononic devices.
Electronic structure and optical properties of Ge- and F-doped α-Ga2O3: First-principles investigations*
Authors: Shu Ti-Kang , Miao Rui-Xia , Guo San-Dong , Wang Shao-Qing , Zhao Chen-He , Zhang Xue-Lan
Published: September 2020

The prospect of α-Ga2O3 in optical and electrical devices application is fascinating. In order to obtain better performance, Ge and F elements with similar electronegativity and atomic size are selected as dopants. Based on density functional theory (DFT), we systematically research the electronic structure and optical properties of doped α-Ga2O3 by GGA+U calculation method. The results show that Ge atoms and F atoms are effective n-type dopants. For Ge-doped α-Ga2O3, it is probably obtained under O-poor conditions. However, for F-doped α-Ga2O3, it is probably obtained under O-rich conditions. The doping system of F element is more stable due to the lower formation energy. In this investigation, it is found that two kinds of doping can reduce the α-Ga2O3 band gap and improve the conductivity. What is more, it is observed that the absorption edge after doping has a blue shift and causes certain absorption effect on the visible region. Through the whole scale of comparison, Ge doping is more suitable for the application of transmittance materials, yet F doping is more appropriate for the application of deep ultraviolet devices. We expect that our research can provide guidance and reference for preparation of α-Ga2O3 thin films and photoelectric devices.
Polarization-independent silicon photonic grating coupler for large spatial light spots*
Authors: Yang Lijun , Hu Xiaoyan , Li Bin , Cao Jing
Published: September 2020

We design and demonstrate a one-dimensional grating coupler with a low polarization-dependent loss (PDL) for large spatial light spots. Based on current fabrication conditions, we first utilize genetic algorithms to find the optimal grating structure including the distributions of duty and periods, making the effective refractive index of transverse electric mode the same as that of transverse magnetic mode. The designed grating coupler is fabricated on the common silicon-on-insulator platform and the PDL is measured to be within 0.41 dB covering the C-band.
Study of electrophysical properties of metal–semiconductor contact by the theory of complex systems
Authors: Askerov Sh. G. , Abdullayeva L. K. , Hasanov M. G.
Published: September 2020

The purpose of this work is to analyze the electrical properties of the metal–semiconductor contact (MSC) in the framework of the theory of complex systems. The effect of inhomogeneity of the different microstructures: polycrystalline, monocrystalline, amorphous metal–semiconductor contact surface is investigated, considering a Schottky diode (SD) as a parallel connection of numerous subdiodes. It has been shown that the polycrystallinity of the metal translates a homogeneous contact into a complex system, which consists of parallel connected numerous elementary contacts having different properties and parameters.
First principles study of the electronic structure and photovoltaic properties of β-CuGaO2 with MBJ + U approach
Authors: Luo Guoping , Bian Yingmei , Wu Ruifeng , Lai Guoxia , Xu Xiangfu , Zhang Weiwei , Chen Xingyuan
Published: September 2020

Based on the density functional theory, the energy band and electronic structure of β-CuGaO2 are calculated by the modified Becke-Johnson plus an on-site Coulomb U (MBJ + U) approach in this paper. The calculated results show that the band gap value of β-CuGaO2 obtained by the MBJ + U approach is close to the experimental value. The calculated results of electronic structure indicate that the main properties of the material are determined by the bond between Cu-3d and O-2p energy levels near the valence band of β-CuGaO2, while a weak anti-bond combination is formed mainly by the O-2p energy level and Ga-4s energy level near the bottom of the conduction band of β-CuGaO2. The β-CuGaO2 thin film is predicted to hold excellent photovoltaic performance by analysis of the spectroscopic limited maximum efficiency (SLME) method. At the same time, the calculated maximum photoelectric conversion efficiency of the ideal CuGaO2 solar cell is 32.4%. Relevant conclusions can expand β-CuGaO2 photovoltaic applications.