bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on Effect of Obstacle Shapes on Filling Process in Pulse Detonation Rocket Engine
Authors: Wang Yun , Fan Wei , Jiang Jintao , Zhang Peng
Published: October 2020

In order to explore the influence of obstacle shapes on the filling process of pulse detonation rocket engine under valveless self-adaptive working mode, the numerical simulations of two-phase single filling process and multi-cycle experiment were carried out, in which gasoline was utilized as fuel, and oxygen-enriched air as oxidizer. The effects of four kinds of obstacles with different shapes on the filling process of PDRE were studied. The results showed that the existence of obstacles blocks the filling of fuel into the tail of detonation tube, resulting in a great non-uniformity of filling results in the axial and radial directions. Fuel droplets collect near the head and wall of detonation tube, and droplets are seriously blocked by orifice plates. The detonation initiation and stable propagation can be achieved by Shchelkin spirals, annular grooves and spiraling grooves, while the detonation initiation cannot be achieved by orifice plates.
Research of Small Sheet-Type Laminar Flow Meter
Authors: Wang Xiaolu , Chen Yuchun , Jiang Yuxiang , Zhang Kai
Published: October 2020

A small sheet-type LFM is proposed to solve the problems of leakage and deformation in the design of traditional sheet-type LFM. The pressure tap is set in the middle of the laminar flow channel to extract pressure from the fully developed laminar flow. The design value Remax·de/l is 5.81, which is much higher than the 2~2.5 required by the traditional design. Experimental results show that the linearity factor ξL of small sheet-type LFM can reach 0.81% and the accuracy is up to 1%, which shows that the present design can effectively overcome the nonlinear effects caused by sudden expansion and contraction. In addition, when the flow rate is above 20% designed maximum valve, the calculation error of pressure drop can be controlled below 5.42%.
Dynamic Reliability Model for Airborne Systems Based on Stochastic Petri Net
Authors: Zhuang Lu , Lu Zhong , Zhang Ziwen
Published: October 2020

The reliability of the airborne systems have a significant influence on the safety of aircraft. The modern airborne systems have a high degree of automation and integration, which lead to obvious dynamic failure characteristics. Namely, system failure is not only dependent on the combination of units' failures but also related to their sequence. A dynamic reliability method for modeling airborne systems is proposed based on the stochastic Petri nets. Stochastic Petri nets are applied in reliability modeling for typical dynamic structures including warm standby, cold standby and load sharing, which are widely used in airborne systems. In this way, the dynamic (time-dependent) failure behaviors of the airborne system can be represented. In terms of the stochastic Petri net based reliability model, a reliability analysis method based on Monte Carlo simulation is proposed by generating system life samples for system reliability parameter calculation. Finally, an electrical power system is used as a case to illustrate the application and effectiveness of the present approaches. The results show that the difference by using the present method and the analytical method is below 2×10-7, which can be neglected in practice.
Conditional Expression Fault Classification and Repair Method of Aviation Control Software
Authors: Xie Wenguang , Li Qi , Wang Kenian , Ma Chunyan , Zhang Tao , Zhang Guoqun
Published: October 2020

Aviation control software has become the core control decision-making unit of the aviation system. The Boolean conditional expressions are the main parts of the branch and loop control logic of aviation control software. This paper studies the fault classification and repair method of conditional expression of aviation control software. 1) a two-level Boolean conditional expression fault classification method is proposed; 2) based on the design of mutation operator, repair solution and stop condition of mutation repair, an automatic repair method of conditional expression is proposed; 3) a repair assistant tool for conditional expression is designed and implemented, and 155 fault expressions are repaired. The results show that 55.5% of fault expressions can achieve accurate repair, 44.5% of fault expressions can generate multiple correct versions after a repair, and some versions have operation redundancy, so it is necessary to select the optimal version manually.
Mechanical Analysis of Shape Memory Alloy Beams under Asymmetric Bending
Authors: Yang Jingning , Wang Yongxiang , Ma Liansheng
Published: October 2020

Based on the bending theory of beams, combining with the constitutive relationship of shape memory alloy materials, the asymmetric bending of shape memory alloy beams under concentrated load was studied. Considering tension-compression asymmetry on both sides of the tension and compression in the process of bending, tension-compression asymmetry coefficient was introduced, by using the step-by-step method. The stress distribution, neutral axis displacement, curvature and phase boundary of the beam sections of the I-shaped cross-section shape memory alloy beam were analyzed. The results show that under the same load, the maximum offset of the neutral axis displacement increases with the increase of tension-compression asymmetry coefficient. Under the same tension-compression asymmetry coefficient, the displacement and curvature of the neutral axis increased with the increase of load; as tension-compression asymmetry coefficient increased, the proportion of mixed phase increased gradually, the proportion of martensite phase decreased, and the asymmetry of phase boundary became more obvious. Under the same conditions, the rectangular section is more suitable. The cross section of I shaped cross section was prone to occur phase transformation.
Open-Hole 3D Braided Composites Strength Prediction and Stress Analysis
Authors: Liang Shuangqiang , Zhang Chenglong , Chen Ge , Zhou Qihong , Ko Frank
Published: October 2020

The stress concentration caused by notches is a common engineering issue for composite structure application. 3D braided composite possess excellent damage tolerance compared to common laminates. The tensile properties of 3D braided composite with open-hole and un-notched were experimentally examined. The mechanic properties of 3D braided composite in other directions are predicted using FGM (Fabric Geometry Model) and finite element analysis. The stress distributions around the hole and perpendicular to the loading direction are analyzed based on Abaqus software. The simulation results were compared with Lekhnitskii's analytical study. The open-hole strength of 3D braided composite was predicted respectively using Average stress failure criteria, Point stress failure criteria (PSC), and also the progressive failure analysis based on different failure criteria. The predicted strength results were compared to the experimental values. The results show the PSC predicted strength matched the experiment, while the progressive failure analysis can predict the failure initiation, propagation and final failure mode.
Les Français et la perception des risques et de la sécurité
Authors: Le Gros Gaïc
Published: October 2020

L’Institut de radioprotection et de sûreté nucléaire (IRSN) publie chaque année le « baromètre sur la perception des risques et de la sécurité par les Français » qui suit l’évolution des attitudes et des opinions du grand public en la matière, grâce à des sondages réalisés par des instituts spécialisés. Ce travail permet d’éclaircir et d’ordonner, avec méthode, les préoccupations des Français et leurs représentations.
Bienvenue dans la société du récit
Authors: de Beistegui Charles
Published: October 2020

Sans que l’on s’en aperçoive de façon évidente et sans toujours en tirer toutes les conséquences pour la communication, nous sommes passés de la société de l’information à la société du récit.
Was ist neu bei der Diagnostik und Therapie des Mammakarzinoms? – Aktuelle Standards in der Behandlung von Brustkrebs
Authors: Albert Anna , Stüber Tanja , Bauer Jonas , Wöckel Achim
Published: October 2020

Was ist neu?

Vorsorge, Früherkennung und familiärer Brustkrebs Mit dem Mammografie-Screening für Frauen ab dem 50. Lebensjahr steht in Deutschland eine etablierte Früherkennungsmaßnahme zur Verfügung. Eine Reduktion der Mortalität ist gesichert. Das Screening kann mittlerweile auch bei Frauen über 70 fortgeführt werden. Durch intensive Forschung im Bereich des familiären Mammakarzinoms kann das Hochrisikopatientenkollektiv präziser bestimmt und einer intensivierten Früherkennung zugeführt werden.

Therapie lokal begrenzter Stadien – Senkung der Radikalität Die Behandlung erfolgt zielgerichtet und so wenig radikal wie möglich. Nach neoadjuvanter Chemotherapie kann immer öfter auf eine Brustamputation verzichtet werden. Die axilläre Lymphknotendissektion (ALND) bleibt wenigen Fällen vorbehalten. Die molekulare Subtypisierung ermöglicht individualisierte medikamentöse Therapien in der kurativen Absicht.

Rekonstruktive Chirurgie Das BIA-ALCL stellt eine seltene Brustimplantat-assoziierte Erkrankung dar, bei der in den meisten Fällen eine Heilung möglich ist. Trotz steigender Inzidenz ist von Implantateinlagen nach adäquater Aufklärung der Patientin in Deutschland nicht abzuraten.

Therapie des metastasierten Karzinoms Zur Behandlung des metastasierten Mammakarzinoms sollte wenn möglich eine gut verträgliche Therapie zur Erhaltung der Lebensqualität gewählt werden. Auch hier stehen immer mehr individualisierte Optionen zur Verfügung.

Nachsorge Der Zeitraum der Nachsorge weitet sich aufgrund der Tumorbiologie auf 10 Jahre aus.

Ausblick Eine ESR1-Mutation kann zukünftig möglicherweise als prädiktiver Marker hinsichtlich einer antihormonellen Therapie in der Metastasierung genutzt werden. Für eine PD-1-Blockade gibt es vielversprechende Ergebnisse in der neoadjuvanten Behandlung des triple-negativen Mammakarzinoms (TNBC).
Menschen mit Alzheimer im Alltag unterstützen – Empfehlungen für Angehörige
Authors: Höglinger Nadine
Published: October 2020

In ihrer Bachelorarbeit erarbeitete Nadine Höglinger Handlungsempfehlungen für pflegende Angehörige von Menschen mit Morbus Alzheimer. Dabei legte sie insbesondere Wert auf die gemeinsame Alltagsbewältigung sowie die größtmögliche Selbstständigkeit der Betroffenen.
Sinnvoll auswählen – Assessments in der Neuroreha
Authors: Sporrer Wiebke
Published: October 2020

Standardisierte Testverfahren gehören in der Neurorehabilitation zur systematischen Evaluation. Es ist allerdings nicht immer einfach, das passende Assessment zu finden. Wiebke Sporrer zeigt mithilfe der ICF- Ebenen, wie man Tests sinnvoll auswählt und praktisch in den Therapiealltag integriert.
Fall für Drei Zurück in den Stall
Authors: Schäfer Mirjam , Wildi Samantha , Staubli Stefan
Published: October 2020

Für den Landwirt Herrn Schneider war es ein Schock: Nach einem schweren Unfall ist er Paraplegiker. Sein Ziel war es, seinen Bauernhof wieder möglichst selbstständig zu betreiben. Dabei unterstützten ihn eine Ergotherapeutin, ein Physiotherapeut sowie ein Jobcoach.
Jeder hat das Recht auf die eigene Sexualität – Sexualberatung von Menschen mit geistiger Behinderung
Authors: Heitkamp Janne
Published: October 2020

Menschen mit einer geistigen Behinderung sind in unterschiedlichem Maße auf ihre Eltern oder Betreuer angewiesen. Und nicht immer ist es leicht, ihre Bedürfnisse zu verstehen oder zu deuten. Janne Heitkamp kommt ins Spiel, wenn es um die sexuelle Entwicklung und die sexuelle Autonomie geistig behinderter Menschen geht.
Eltern gesucht – Kolumne
Authors: Schiewack Michael
Published: October 2020

Michael Schiewack hat in seiner Praxis schon alles erlebt. Dachte er. Bis ein herrenloser Junge auftaucht – ohne Verordnung und ohne Ansprechpartner. Da geht die Detektivarbeit los.
Articular Cartilage Repair in the Knee: Postoperative Imaging
Authors: Yang Brian W. , Brusalis Christopher M. , Fabricant Peter D. , Greditzer Harry G.
Published: October 2020

Diagnostic and therapeutic advancements have improved clinical outcomes for patients with focal chondral injuries of the knee. An increased number and complexity of surgical treatment options have, in turn, resulted in a commensurate proliferation of patients requiring postoperative evaluation and management. In addition to patient-reported clinical outcomes, magnetic resonance imaging (MRI) offers clinicians with noninvasive, objective data to assist with postoperative clinical decision making. However, successful MRI interpretation in this setting is clinically challenging; it relies upon an understanding of the evolving and procedure-specific nature of normal postoperative imaging. Moreover, further research is required to better elucidate the correlation between MRI findings and long-term clinical outcomes. This article focuses on how specific morphologic features identified on MRI can be utilized to evaluate patients following the most commonly performed cartilage repair surgeries of the knee.
Impact of Preoperative Opioid Use on 2-Year Patient-Reported Outcomes in Knee Surgery Patients
Authors: Aneizi Ali , Sajak Patrick M. J. , Alqazzaz Aymen , Weir Tristan , Burt Cameran I. , Ventimiglia Dominic J. , Leong Natalie L. , Packer Jonathan D. , Henn R. Frank
Published: October 2020

The objectives of this study are to assess perioperative opioid use in patients undergoing knee surgery and to examine the relationship between preoperative opioid use and 2-year postoperative patient-reported outcomes (PROs). We hypothesized that preoperative opioid use and, more specifically, higher quantities of preoperative opioid use would be associated with worse PROs in knee surgery patients. We studied 192 patients undergoing knee surgery at a single urban institution. Patients completed multiple PRO measures preoperatively and 2-year postoperatively, including six patient-reported outcomes measurement information system (PROMIS) domains; the International Knee Documentation Committee (IKDC) questionnaire, numeric pain scale (NPS) scores for the operative knee and the rest of the body, Marx's knee activity rating scale, Tegner's activity scale, International Physical Activity Questionnaire, as well as measures of met expectations, overall improvement, and overall satisfaction. Total morphine equivalents (TMEs) were calculated from a regional prescription monitoring program. Eighty patients (41.7%) filled an opioid prescription preoperatively, and refill TMEs were significantly higher in this subpopulation. Opioid use was associated with unemployment, government insurance, smoking, depression, history of prior surgery, higher body mass index, greater comorbidities, and lower treatment expectations. Preoperative opioid use was associated with significantly worse 2-year scores on most PROs, including PROMIS physical function, pain interference, fatigue, social satisfaction, IKDC, NPS for the knee and rest of the body, and Marx's and Tegner's scales. There was a significant dose-dependent association between greater preoperative TMEs and worse scores for PROMIS physical function, pain interference, fatigue, social satisfaction, NPS body, and Marx's and Tegner's scales. Multivariable analysis confirmed that any preoperative opioid use, but not quantity of TMEs, was an independent predictor of worse 2-year scores for function, activity, and knee pain. Preoperative opioid use and TMEs were neither independent predictors of met expectations, satisfaction, patient-perceived improvement, nor improvement on any PROs. Our findings demonstrate that preoperative opioid use is associated with clinically relevant worse patient-reported knee function and pain after knee surgery.
Comparison of Acorn and Fluted Reamers on Tibial Tunnel Outer Aperture Dimensions in ACL Reconstruction
Authors: Gerrard Adam D. , Jump Chris M. , Sutton Paul , Charalambous Charalambos P.
Published: October 2020

The aim of this study was to determine if the type of reamer used in tibial tunnel creation during anterior cruciate ligament (ACL) reconstruction influences the dimensions of the tunnel's outer aperture. Tibial tunnels were created in tibial saw bones by reaming over a guidewire using an 8 mm acorn or fluted reamer in an antegrade manner. Reaming was aimed either in line with the guidewire, or with 10-degree inferior/superior deviation in relation to the wire. The shape and size of the outer aperture of the tibial tunnel were compared between the two reamers. When using the acorn reamer, a 10-degree deviation in relation to the guidewire resulted in minimal change in outer aperture length (mean 13.6 vs. 15.6 mm, p = 0.11) and width (11.6 vs. 11.1 mm, p = 0.51). However, when using the fluted reamer, although the aperture width showed no substantial change with reamer/guidewire deviation (11.4 vs. 11.2 mm, p = 0.71), the mean length almost doubled (14.7 vs. 28.1 mm, p = 0.002). The use of a fluted reamer when reaming the tibial tunnel creates a distal aperture which is inconsistently sized, larger, and of oblong shape compared with an acorn-shaped reamer. This should be taken in consideration when using a fluted reamer for creating the tibial tunnel in ACL reconstruction.
Managing supply chain uncertainty by building flexibility in container port capacity: a logistics triad perspective and the COVID-19 case
Authors: Russell Dawn , Ruamsook Kusumal , Roso Violeta
Published: October 2020

The contemporary supply chains in which container ports logistics operate are characterized by increased uncertainties driven by a range of factors such as socioeconomic factors and changing supply chain strategies in response to market dynamics. Recently, the occurrences and effects of these factors on global economic activities, and thus container port logistics, have been intensified by the COVID-19 pandemic. Enabling flexibility in port logistics is more important than ever to navigate uncertainties, now and in the post-COVID-19 world. This paper seeks to develop a conceptual framework to holistically capture different dimensions of container port logistics capacity. A systematic literature review method is employed to formulate a conceptual framework depicting the structure of various elements of capacity and the interplay among the logistics triad of transport carriers, port operators, and logistics service providers whose interactions and service capacities constitute the overall capacity of the system. The study reveals four dimensions of port logistics capacity, namely seaside interface, platform, landside interface, and system-wide, each of which consists of subelements that can be distinguished into static or adjustable. The proposed framework provides insights corresponding to the logistics triad roles and interactions within the system for understanding uncertainty characteristics, assessing various elements of capacity, and identifying potential levers to build flexibility into these interrelated capacity elements.
Experimental observation of the effect of electron attachment and detachment reactions on the electron energy distribution in an inductive oxygen discharge
Authors: Jung Jiwon , Lee Moo-Young , Kim Kyung-Hyun , Chung Chin-Wook
Published: October 2020

Electron energy distribution functions (EEDFs) are measured with varying radio-frequency (RF) power in an oxygen inductive discharge. At a pressure of 10 mTorr, the EEDF has a Maxwellian distribution, and the low-energy (1–5 eV) electron temperature, Te,low, monotonically decreases with RF power. However, at a pressure of 100 mTorr, Te,low increases at low RF power (80–150 W) and decreases at high RF power (150–300 W), and the EEDF has a Druyvesteyn-like distribution. These changes in Te,low are attributed to electron attachment and detachment reactions, which are the main creation and loss reactions of negative ions. To investigate this relationship between Te,low and collisional reactions, the reaction coefficients of several reactions are calculated, and the electronegativity (α) is measured with varying RF power. The EEDF is modified by electron attachment and detachment reactions, which lead to a change in Te,low; this modification of EEDF is supported by calculated reaction coefficients and measured α.
Numerical simulation of Ne-like Ar plasma dynamics and laser beam characteristics of 46.9 nm laser excited by capillary discharge
Authors: Khan Muhammad Usman , Zhao Yongpeng , Zhao Dongdi , Cui Huaiyu , Cao Ziyue , An Bo , Zhang Feifei
Published: October 2020

In this work, we performed computer modeling of high electrical discharge in an Ar filled alumina capillary in order to investigate the parameters of the discharge system that may lead to achieve an intense laser beam. One-dimensional magnetohydrodynamics (MHD) simulations were used to study the parameters of discharge produced Ar plasma. The radial evolution of plasma parameters such as electron temperature, electron density, and Ne-like argon density was estimated from MHD simulations. Additionally, the influence of the main discharge current on the pinching time and plasma radius was analyzed with the one-dimensional MHD model. The active medium for lasing is created by a high amplitude main pulse and pre-pulse. Specifically, we investigated the optimum main discharge current and Ar filling pressure. The main discharge current of 30 kA was declared as the best current to obtain the 46.9 nm laser with a 4 mm alumina capillary. The influence of the main discharge current and lasing pressure on laser beam intensity and beam characteristics has been studied theoretically and experimentally. The saturated laser intensity was obtained with a main discharge current of 30 kA. A severe reduction in laser intensity was observed above the main discharge current of 30 kA due to capillary wall ablation. The laser beam divergence was observed to be less than 3.5 mrad. The theoretical results obtained from MHD simulations are in good agreement with the experimental results of laser intensity and laser beam characteristics.
Hydrogen embrittlement in ferritic steels
Authors: Martin May L. , Connolly Matthew J. , DelRio Frank W. , Slifka Andrew J.
Published: October 2020

Hydrogen will be a crucial pillar in the clean-energy foundation, and therefore, the development of safe and cost-effective storage and transportation methods is essential to its success. One of the key challenges in the development of such storage and transportation methods is related to the interaction of hydrogen with structural materials. Despite extensive work, there are significant questions related to the hydrogen embrittlement of ferritic steels due to challenges associated with these steels, coupled with the difficulties with gauging the hydrogen content in all materials. Recent advancements in experimental tools and multi-scale modeling are starting to provide insight into the embrittlement process. This review focuses on a subset of the recent developments, with an emphasis on how new methods have improved our understanding of the structure–property–performance relationships of ferritic steels subjected to mechanical loading in a hydrogen environment. The structure of ferritic steels in the presence of hydrogen is described in terms of the sorption and dissociation processes, the diffusion through the lattice and grain boundaries, and the hydrogen–steel interactions. The properties of ferritic steels subjected to mechanical loading in hydrogen are also investigated; the effects of test conditions and hydrogen pressure on the tensile, fracture, and fatigue properties of base metal and welds are highlighted. The performance of steels in hydrogen is then explored via a comprehensive analysis of the various embrittlement mechanisms. Finally, recent insights from in situ and high-resolution experiments are presented and future studies are proposed to address challenges related to embrittlement in ferritic steels.
Full InGaN red light emitting diodes
Authors: Dussaigne A. , Barbier F. , Damilano B. , Chenot S. , Grenier A. , Papon A. M. , Samuel B. , Ben Bakir B. , Vaufrey D. , Pillet J. C. , Gasse A. , Ledoux O. , Rozhavskaya M. , Sotta D.
Published: October 2020

The full InGaN structure is used to achieve red light emitting diodes (LEDs). This LED structure is composed of a partly relaxed InGaN pseudo-substrate fabricated by Soitec, namely, InGaNOS, a n-doped buffer layer formed by a set of InxGa1−xN/GaN superlattices, thin InyGa1−yN/InxGa1−xN multiple quantum wells, and a p doped InxGa1−xN area. p-doped InGaN layers are first studied to determine the optimal Mg concentration. In the case of an In content of 2%, an acceptor concentration of 1 × 1019/cm3 was measured for a Mg concentration of 2 × 1019/cm3. Red electroluminescence was then demonstrated for two generations of LEDs, including chip sizes of 300 × 300 μm2 and 50 × 50 μm2. The differences between these two LED generations are detailed. For both devices, red emission with a peak wavelength at 620 nm was observed for a pumping current density of 12 A/cm2. Red light-emission is maintained over the entire tested current range. From the first to the second LED generation, the maximum external quantum efficiency, obtained in the range of 17–40 A/cm2, was increased by almost one order of magnitude (a factor of 9), thanks to the different optimizations.
Fabrication of durable superhydrophilic silicon surfaces using nanosecond laser pulses
Authors: Verma Nancy , Anoop K. K. , Dominic Priya , Philip Reji
Published: October 2020

In this work, we report the fabrication and characterization of large area micro-/nano-textured silicon surfaces using laser pulses of nanoseconds duration. An area of 6×6mm2 has been textured by the parallel line scanning method to create hierarchical structures, consisting of microscale channels and self-organized surface nano-capillaries decorated with randomly distributed silicon nanoparticles. The combination of micro-channels and nano-capillaries results in a superhydrophilic silicon surface, with the contact angle reduced substantially from about 80° to nearly 5°. In contrast to most of the reports given in the literature, the superhydrophilicity of the surface remains stable without a shift to hydrophobicity, even after exposure to the atmosphere for about three months. Thus, long-lasting and durable superhydrophilic silicon has been obtained by using maskless, compact, and cost-effective nanosecond laser writing, without the need to employ any chemical post-processing. Potential applications of these surfaces include heat exchangers, biosensors, cell adhesives, and self-cleaning solar cells.
Wall effect on interaction and coalescence of two bubbles in a vertical tube
Authors: Gui Yuteng , Shan Chengjun , Zhao Jiaquan , Wu Jie
Published: October 2020

While most studies on bubble dynamics are carried out in unconfined geometries, less attention has been paid to investigate confined bubbles and wall effects. This paper numerically investigates interaction and coalescence of two buoyancy-driven inline bubbles in a confined cylindrical vessel to study wall effects. An improved volume-of-fluid method is adopted, and high mesh resolution is achieved by dynamic adaptive mesh refinement. The confinement ratio, CR (the ratio of the radius of the cylindrical tube to the radius of the bubble), is introduced to quantitatively describe the wall proximity. In this paper, the interaction between bubbles is divided into three regimes according to the strength of the liquid influx behind the trailing bubble during bubble interaction (i.e., “weak interaction,” “intermediate interaction,” and “strong interaction”). If the CR is larger than a critical value (CR = 4 in this study), the wall effect can be neglected. It is found that wall proximity reduces the strength of the liquid influx behind the trailing bubble, which causes regime transition. In “strong interaction” and “intermediate interaction” regimes, if the CR is below another critical value, which is termed the second critical CR, “strong interaction” is degraded to “intermediate interaction,” and “intermediate interaction” can be degraded to “weak interaction.” A broader range of parameters is studied to explore the effect of confinement on bubble coalescence, and we further discovered that decreasing the CR does not necessarily postpone coalescence. This work provides insights into bubble motion and interaction influenced by the side wall.
Electrically tunable optical devices based on graphene-split-ring-resonator periodic multilayers at mid-infrared frequencies
Authors: Zhang Yan , Zhu Wen-Huan
Published: October 2020

In this work, we demonstrate that photonic crystals made with alternating layers of graphene and nanometer-scale split-ring-resonator metamaterials can be treated as single negative-index materials with broad zero-ϕeff gaps in the mid-IR frequency range. These provide a versatile platform for the fabrication of anti-interference multichannel filters whose tunability can be realized flexibly by adjusting the conductivity of the graphene layer. Specifically, by inserting dielectric defects into the periodic system, one can obtain tunable tunneling modes inside the zero-ϕeff gap, which are highly robust against scaling and structural disorder. Moreover, without altering the structure of the system, the number of defect modes multiplies as the graphene chemical potential is decreased appropriately. In addition, the tunneling modes are nearly invariant with the incident angle in the range of 0°–5°. Also, the bandwidths of the tunneling modes are compressed by decreasing the chemical potential, which could be utilized to improve the Q values of the filters. Furthermore, THz amplification could also be accomplished when taking into account the damping constant of the permittivity of graphene. As a result, these characteristics may facilitate the design of optical devices in the mid-IR range, especially leading to more practical applications of these filters.
Algebra, coherent states, generalized Hermite polynomials, and path integrals for fractional statistics—Interpolating from fermions to bosons
Authors: Ramakrishna Satish
Published: October 2020

This article constructs the Hilbert space for the algebra αβ − eiθβα = 1 that provides a continuous interpolation between the Clifford and Heisenberg algebras—this particular form is inspired by the properties of anyons. We study the eigenvalues of a generalized number operator (N=βα) and construct the Hilbert space, classified by values of a complex coordinate (λ0): the eigenvalues lie on a circle. For θ being an irrational multiple of 2π, we get an infinite-dimensional representation; however, for a rational multiple (MN) of 2π, it is finite-dimensional, parameterized by the complex coordinate λ0. The case for N = 2, θ = π is the usual Clifford algebra for fermions, while the case for N = ∞, θ = 0 is the Heisenberg algebra of bosons, albeit with two copies for positive and negative eigenvalues. We find a smooth transition from the fermion to the boson situation as N → ∞ from N = 2. After constructing the Hilbert space from the algebra, the cases for N = 2, 3 can be mapped to the “fuzzy sphere” of SU(2), while for general N, the “fuzzy pancake” is found to be the correct representation. Then, we motivate the study of coherent states, which are the eigenstates of α (the lowering operator), labeled by complex numbers for non-zero λ0. We specialize the study of coherent states to the very interesting case of λ0 = 0 and construct a calculus of the generalized Grassmann variables that result, applying it to compute a partition function for these particles. We then make some remarks about extending this study to that of anyons.
Equality conditions of data processing inequality forα-zRényi relative entropies
Authors: Zhang Haonan
Published: October 2020

The α–z Rényi relative entropies are a two-parameter family of Rényi relative entropies that are quantum generalizations of the classical α-Rényi relative entropies. In the work [Adv. Math. 365, 107053 (2020)], we decided the full range of (α, z) for which the data processing inequality (DPI) is valid. In this paper, we give algebraic conditions for the equality in DPI. For the full range of parameters (α, z), we give necessary conditions and sufficient conditions. For most parameters, we give equivalent conditions. This generalizes and strengthens the results of Leditzky et al. [Lett. Math. Phys. 107, 61–80 (2017)].
Wireless strain sensor based on the magnetic strain anisotropy dependent ferromagnetic resonance
Authors: Chen Yicheng , Hu Chaojie , Wang Zhiguang , Li Yaojin , Zhu Shukai , Su Wei , Hu Zhongqiang , Zhou Ziyao , Liu Ming
Published: October 2020

Wireless strain sensors have received extensive attention owing to their wide application prospects in structural health monitoring, industrial automation, human activity monitoring, and intelligent robotic systems. Here, a wireless strain sensor prototype based on the magnetoelectric heterostructure of ferromagnetic thin films on a piezoelectric substrate has been developed. The ferromagnetic resonance (FMR) frequency of the sensor is strongly dependent on external strain due to the large magnetostriction of the film. The piezoelectric substrate with a programmable voltage has been used as a strain source for the characterization of the wireless strain sensor. The limit of detection of the wireless strain sensor is 0.54 με, which is comparable with that of commercial metal-foil sensors that need connection wires. More importantly, the FMR strain sensor shows a sensitivity of 65.46 ppm/με, indicating more than a 60 fold improvement than that of traditional wireless strain sensors based on patch antenna and RLC resonators whose frequency shift is mainly due to the strain induced dimension change.
Transition to the dynamical chaos and anomalous transport of a passive scalar in the annular Kolmogorov flow
Authors: Reutov V. P. , Rybushkina G. V.
Published: October 2020

In this paper, we are concerned with the transition to dynamical chaos and related anomalous transport of a passive scalar in the annular Kolmogorov flow, which is considered as a model of the barotropic zonal flows in the Earth’s atmosphere and ocean or their laboratory analogs. The investigation of the anomalous transport is conducted within a dynamically consistent flow model describing the saturation of barotropic instability. The analysis is based on the numerical solution of equations of a quasi-two-dimensional flow in an annular channel with rigid walls taking into account the beta-effect and external (bottom) friction. It is supposed that the sinusoidal velocity profile of the Kolmogorov flow has three periods inside a channel and the sticking condition on the channel walls is satisfied. Four basic regimes arising with increasing flow supercriticality, the last of which corresponds to dynamical chaos, are distinguished. It is found that five modulated chains of wave-vortex structures with closed streamlines are formed in the channel and their temporal behavior is studied by making videos. The frequency–wavenumber spectra of the longitudinal velocity at certain values of radial coordinates are drawn and the largest Lyapunov exponent is determined in the regime of dynamical chaos. The relationship between the streamlines behavior and the discrete peaks of frequency–wavenumber spectra is elucidated. The occurrence of anomalous transport of a passive scalar is confirmed by drawing trajectories of tracer particles, as well as by determining exponents of the time dependence of mean particle displacement and its variance.
Quantification of interfacial spin-charge conversion in hybrid devices with a metal/insulator interface
Authors: Sanz-Fernández Cristina , Pham Van Tuong , Sagasta Edurne , Hueso Luis E. , Tokatly Ilya V. , Casanova Fèlix , Bergeret F. Sebastián
Published: October 2020

We present and experimentally verify a universal theoretical framework for the description of spin-charge interconversion in non-magnetic metal/insulator structures with interfacial spin–orbit coupling (ISOC). Our formulation is based on drift-diffusion equations supplemented with generalized boundary conditions. The latter encode the effects of ISOC and relate the electronic transport in such systems to spin loss and spin-charge interconversion at the interface. We demonstrate that the conversion efficiency depends solely on these interfacial parameters. We apply our formalism to two typical spintronic devices that exploit ISOC: a lateral spin valve and a multilayer Hall bar, for which we calculate the non-local resistance and the spin Hall magnetoresistance, respectively. Finally, we perform measurements on these two devices with a BiOx/Cu interface and verify that transport properties related to the ISOC are quantified by the same set of interfacial parameters.
Cavity magnon polariton based precision magnetometry
Authors: Crescini N. , Braggio C. , Carugno G. , Ortolan A. , Ruoso G.
Published: October 2020

A photon-magnon hybrid system can be realized by coupling the electron spin resonance of a magnetic material to a microwave cavity mode. The quasiparticles associated with the system dynamics are the cavity magnon polaritons, which arise from the mixing of strongly coupled magnons and photons. We illustrate how these particles can be used to probe the magnetization of a sample with a remarkable sensitivity, devising suitable spin-magnetometers, which ultimately can be used to directly assess oscillating magnetic fields. Specifically, the capability of cavity magnon polaritons of converting magnetic excitations to electromagnetic ones allows for translating to magnetism the quantum-limited sensitivity achieved by state-of-the-art microwave detectors. Here, we employ hybrid systems composed of microwave cavities and ferrimagnetic spheres to experimentally implement two types of novel spin-magnetometers.
Improved output performance of triboelectric nanogenerators based on polydimethylsiloxane composites by the capacitive effect of embedded carbon nanotubes
Authors: Liu Zhanqi , Muhammad Mir , Cheng Li , Xie Erqing , Han Weihua
Published: October 2020

Conductive carbon fillers were commonly used to mix with polydimethylsiloxane to improve the output performance of polydimethylsiloxane-based triboelectric nanogenerators. In this work, we focused on the mechanism underlying the unpredictable output performance influenced by adding conductive fillers. We selected multiwall carbon nanotubes as conductive fillers and investigated their electronegative performance in triboelectric nanogenerators. An optimized performance was achieved when the weight concentration of carbon nanotubes was about 0.4%. The open-circuit voltage can reach up to 720 V, the short-circuit current was about 18.28 μA, and a power density of 4.65 mW (11.62 W/m2) was obtained at the load resistance of 55.15 MΩ and a stimulus frequency of 2.0 Hz. The attractive performance was attributed to the appropriate balance of the capacitive effect and the leakage effect of carbon nanotubes to triboelectric charges. A model based on alternative current impedance analysis has been proposed, which may be helpful for future triboelectric nanogenerator design and investigation.
Short-wavelength soliton in a fully degenerate quantum plasma
Authors: Lashkin Volodymyr M.
Published: October 2020

We present a novel one-dimensional nonlinear evolution equation governing the dynamics short-wavelength longitudinal waves in a nonrelativistic fully degenerate quantum plasma using kinetic equation for the Wigner function. The linear dispersion of the equation has a form of “zero sound” ∼k exp (−k2), where k is the wave number, and it strongly differs from previously known nonlinear evolution equations. We numerically find the corresponding soliton solutions and demonstrate that the collisions between three solitons turn out to be elastic, resulting only in phase shifts.
The secret life of Fairy Terns: breeding chronology and life history observations of Sternula nereis nereis in south-western Australia
Authors: Greenwell C. N. , Dunlop J. N. , Admiraal R. , Loneragan N. R.
Published: October 2020

This research describes the breeding ecology, behaviour and substrate preferences of the Australian Fairy Tern, Sternula nereis nereis, in four colonies around Perth, Western Australia between 2018 and 2020. Extensive field observations, supported by a bird banding study and sunrise to sunset video recording were used at colony and roosting sites to determine the processes of mating, colony formation, egg-laying and incubation periods, post-hatching care and breeding success (fledglings per pair). At a colony in North Fremantle, the median nest spacing was 0.71m (mean± s.e.= 0.89±0.05m), which increased over time. Birds establishing nests within a week of the first eggs being laid selected sites with significantly higher percentage beach shell cover (73.5±4.5%) than those laying later in the season (58.2±7.9%) and on average, birds selected sites with higher shell cover (64.9±2.8%, n=114) than a random sample of sites within the colony (53.7±4.4%, n=44). Incubation periods ranged from 17 to 26 days (n=86, mean=21±0.17 days). Incubation shift duration was highly variable, with both sexes contributing, almost equally to the care of the brood (mean=1.27±6.11h). Chicks fledged 21–23 (mean=22±0.21, n=10) days following hatching, with all banded juveniles leaving the colony site within 8 days of fledgling. The information gained from this research helps inform conservation strategies for this vulnerable species, where management interventions are frequently necessary to prevent population decline.
Pushing the conductance and transparency limit of monolayer graphene electrodes for flexible organic light-emitting diodes
Authors: Ma Lai-Peng , Wu Zhongbin , Yin Lichang , Zhang Dingdong , Dong Shichao , Zhang Qing , Chen Mao-Lin , Ma Wei , Zhang Zhibin , Du Jinhong , Sun Dong-Ming , Liu Kaihui , Duan Xiangfeng , Ma Dongge , Cheng Hui-Ming , Ren Wencai
Published: October 2020

Significance

Although graphene shows great promise as a generational flexible transparent electrode (FTE), its development has been severely limited by the intrinsic trade-off between electrical conductance and transparency with the performance metrics inferior to that of the state-of-the-art ITO electrodes. We report a straightforward approach to break previous limit in graphene FTEs and yield an unprecedented performance that rivals the best commercial ITO electrode. Using the tailored monolayer graphene FTE, we further demonstrate high-performance flexible green organic light-emitting diodes (OLEDs) with the efficiencies outperforming all comparable flexible OLEDs and surpassing that with rigid ITO anode. This simple strategy will boost the development of next-generation flexible optoelectronics beyond the dominant rigid platforms.
Designing electrolytes with polymerlike glass-forming properties and fast ion transport at low temperatures
Authors: Zhao Qing , Liu Xiaotun , Zheng Jingxu , Deng Yue , Warren Alexander , Zhang Qiyuan , Archer Lynden
Published: October 2020

Significance

Liquid electrolytes with thermophysical properties analogous to solid polymers, but with exceptional liquidlike ionic conductivities, are formed spontaneously when moderate amounts (≤1 M) of inorganic salts coordinate strongly with small molecules in a conventional aprotic solvent. Specifically, we report that electrolytes composed of the cyclic liquid ether, dioxolane (DOL), and containing the simple salt LiNO
3
are able to completely bypass the liquid → crystalline solid thermal transition, and to exhibit abnormally high bulk and interfacial ionic conductivities down to temperatures as low as −50 °C. Through physical, spectroscopic, and ion-transport measurements it is shown that strong interactions between LiNO
3
and DOL distort bonds in DOL, couple motions of individual solvent molecules, and lower the thermodynamic activity of the electrolyte.
Nonlocal elastic metasurfaces: Enabling broadband wave control via intentional nonlocality
Authors: Zhu Hongfei , Patnaik Sansit , Walsh Timothy F. , Jared Bradley H. , Semperlotti Fabio
Published: October 2020

Significance

The practical application of passive elastic metasurfaces is severely hindered by its intrinsic narrow-band performance due to the underlying locally resonant nature. In this study, we present the concept of “intentional nonlocality” as the fundamental mechanism to design broadband elastic metasurfaces for the control of stress waves in solid media. The nonlocal design breaks the strict dependence on the local resonance of the unit cells and allows crafting an elaborate frequency-wavenumber-dependent response that guarantees remarkable broadband performance. This approach eliminates the most significant barrier to the development of elastic metasurface-based devices and paves the way to a wide range of practical applications.
Neuroadaptations in the dorsal hippocampus underlie cocaine seeking during prolonged abstinence
Authors: Werner Craig T. , Mitra Swarup , Auerbach Benjamin D. , Wang Zi-Jun , Martin Jennifer A. , Stewart Andrew F. , Gobira Pedro H. , Iida Madoka , An Chunna , Cobb Moriah M. , Caccamise Aaron , Salvi Richard J. , Neve Rachael L. , Gancarz Amy M. , Dietz David M.
Published: October 2020

Significance

Achieving abstinence is difficult for individuals with cocaine use disorder but the greater challenge is avoiding relapse. Relapse vulnerability is provoked by exposure to drug-associated cues that evoke drug craving. Cue-induced drug craving persists during prolonged abstinence and is mediated by neuroadaptations in the brain. We found that activin A is increased in the dorsal hippocampus (DH) during prolonged, but not acute, abstinence and regulates phosphorylation of NMDA receptor subunit GluN2B. Both activin A and GluN2B-containing NMDA receptors in the DH regulate cocaine seeking during prolonged abstinence. Hippocampal synaptic strength is increased during prolonged abstinence and DH projections to lateral septum regulate cocaine seeking. Together, the DH acquires an abstinent-dependent role in regulating cocaine seeking during prolonged abstinence.
Rewiring of B cell receptor signaling by Epstein–Barr virus LMP2A
Authors: Fish Kamonwan , Comoglio Federico , Shaffer Arthur L. , Ji Yanlong , Pan Kuan-Ting , Scheich Sebastian , Oellerich Angelika , Doebele Carmen , Ikeda Masato , Schaller Samantha J. , Nguyen Hang , Muppidi Jagan , Wright George W. , Urlaub Henning , Serve Hubert , Staudt Louis M. , Longnecker Richard , Oellerich Thomas
Published: October 2020

Significance

B cell development and function depend on BCR signaling. Infection of primary B cells by EBV relies on the EBV-encoded protein LMP2A, which is currently thought to mimic BCR signaling. We revise this model based on systematic comparison of BCR and LMP2A signaling at the phosphoproteome and transcriptome levels. Our study identifies LMP2A signaling modules that are not shared by BCR signaling and elucidates their impact on gene expression in primary B cells. We describe a mechanism by which LMP2A interferes with apoptosis and cell-cycle checkpoints to cooperate with oncogenes in promoting cell survival and proliferation. These insights provide a framework in which to understand how EBV promotes malignant transformation of B cells.
Natural variability of the Arctic Ocean sea ice during the present interglacial
Authors: de Vernal Anne , Hillaire-Marcel Claude , Le Duc Cynthia , Roberge Philippe , Brice Camille , Matthiessen Jens , Spielhagen Robert F. , Stein Ruediger
Published: October 2020

Significance

Arctic sea ice is an important component of the Earth’s climate system, but prior to its recent reduction, its long-term natural instabilities need to be better documented. In this study, information on past sea-ice conditions across the Arctic Ocean demonstrates that whereas its western and central parts remained occupied by perennial sea ice throughout the present interglacial, its southeastern sector close to the Russian margin experienced, at least, sporadic seasonal sea-ice-free conditions during the warmer part of the present interglacial until ∼4,000 y ago. Sea-ice-free conditions during summer in the southeastern Arctic Ocean seem, therefore, to be a recurrent feature linked to its natural variability during warm episodes of the past.