bluuebunny/crossref_metadata_2025 huggingface dataset:
Anisotropy of losses in grain-oriented Fe–Si
Authors: Ferrara E. , Appino C. , Ragusa C. , de la Barrière O. , Fiorillo F.
Published: November 2021

Comprehensive assessment of the magnetic behavior of grain-oriented steel (GO) Fe–Si sheets, going beyond the conventional characterization at power frequencies along the rolling direction (RD), can be the source of much needed information for the optimal design of transformers and efficient rotating machines. However, the quasi-monocrystal character of the material is conducive, besides an obviously strong anisotropic response, to a dependence of the measured properties on the sample geometry whenever the field is applied along a direction different from the rolling and the transverse (TD) directions. In this work, we show that the energy losses, measured from 1 to 300 Hz on GO sheets cut along directions ranging from 0° to 90° with respect to RD, can be interpreted in terms of linear composition of the same quantities measured along RD and TD. This feature, which applies to both the DC and AC properties, resides on the sample geometry-independent character of the RD and TD magnetization and on the loss separation principle. This amounts to state that, as substantiated by magneto-optical observations, the very same domain wall mechanisms making the magnetization to evolve in the RD and TD sheets, respectively, independently combine and operate in due proportions in all the other cases. By relying on these concepts, which overcome the limitations inherent to the semi-empirical models of the literature, we can consistently describe the magnetic losses as a function of cutting angle and stacking fashion of GO strips at different peak polarization levels and different frequencies.
Nonlinear optical properties of Au@Ag coreshell nanospheres excited by femtosecond laser
Authors: Wang Jun , Jiang Jijuan , Shao Yabin , Wu Wenzhi , Kong Degui , Gao Yachen
Published: November 2021

The nonlinear optical properties and ultrafast dynamics process of Au@Ag coreshell nanospheres (NSs) are reported in this paper. We researched the optical nonlinear absorption property of Au@Ag coreshell NSs excited by 800 nm laser at different energies by open-aperture Z-scan technology. The experimental results demonstrated that the Au@Ag coreshell NSs exhibited two-phone absorption (TPA) behavior, the degree of which was intensity-dependent. The TPA coefficients of Au@Ag coreshell NSs excited by different energies were obtained by fitting. By using pump-probe technology, we studied the ultrafast dynamics process of Au@Ag coreshell NSs. The results indicated that the relaxation process contained a fast and a slow process, which depended strongly on the laser intensity. By numerical fitting, we got the relaxation times of the sample excited at different laser powers.
Heat transport in a flowing complex plasma in microgravity conditions
Authors: Nosenko V. , Zhdanov S. , Pustylnik M. , Thomas H. M. , Lipaev A. M. , Novitskii O. V.
Published: November 2021

Heat transport in a three-dimensional complex (dusty) plasma was experimentally studied in microgravity conditions using a Plasmakristall-4 (PK-4) instrument on board the International Space Station (ISS). An extended suspension of microparticles was locally heated by a shear flow created by applying the radiation pressure force of the manipulation-laser beam. Individual particle trajectories in the flow were analyzed, and from these, using a fluid heat transport equation that takes viscous heating and neutral gas drag into account, the complex plasma's thermal diffusivity and kinematic viscosity were calculated. Their values are compared with previous results reported in ground-based experiments with complex plasmas.
Comment on “Mathematical constraints on the scaling exponents in the inertial range of fluid turbulence” [Phys. Fluids 33(3), 031703 (2021)]
Authors: Kopyev A. V. , Il'yn A. S. , Sirota V. A. , Zybin K. P.
Published: November 2021

The paper [Djenidi et al., Phys. Fluids 33(3), 031703 (2021)] considers a classical issue of an anomalous scaling of velocity structure functions in a high-Reynolds number turbulent flow. The paper offers a mathematical proof of the ground-breaking result: the intermittency is an artifact of the Reynolds number finiteness. However, the proof contains a technical error that makes this conclusion ungrounded.
Plasma reflectivity behavior under strong subpicosecond excitation of liquids
Authors: Ponomareva E. , Ismagilov A. , Putilin S. , Tcypkin A. N.
Published: November 2021

Emerging laser plasma-based technologies require new knowledge on the optical pump optimization and underlying physics of laser–matter interaction. Plasma in liquid jets is still largely unexplored, although this configuration is actively used as a part of optical devices. Hereby, in this work, we report on the reflectivity-based approach to study the optical properties of the induced plasma and quasi-free electron temporal dynamics. The single-shot experiments provide plasma characteristics relative to the laser pump parameters. A strong angular dependence of the plasma absorptivity, which affects rigorously the reflectivity curve, is demonstrated. Furthermore, twofold higher plasma reflectivity in ethanol is revealed and explained through the theoretical model of ultrashort laser pulse interaction with a thin dielectric surface layer. Finally, the time-resolved fundamental and third harmonic reflection measurements and associated analytical study provide the new insight into the electron density dynamics in the case of optical breakdown in water and ethanol. We believe that these findings are of particular significance for the development of highly efficient plasma-based x rays and THz radiation sources.
Trends of complete anion substitution on electronic, ferroelectric, and optoelectronic properties of BiFeX3 (X = O, S, Se, and Te)
Authors: Jin Heng , Huang Bing
Published: November 2021

BiFeO3 is one of the most important perovskite ferroelectric materials. It is known that cation substitution in BiFeO3 can greatly modulate its fundamental physical properties for various applications. However, the role of anion substitution in BiFeO3 is still largely unknown. In this article, using first-principles calculations, we have systematically investigated the trends of electronic, ferroelectric, and optoelectronic properties of BiFeX3 as a function of complete anion evolution. Interestingly, the calculated bandgaps of BiFeX3, in the favorable G-type antiferromagnetic configuration, decrease from 3.32 eV (X = O) to 1.27 eV (X = S) to 0.75 eV (X = Se) and to 0.27 eV (X = Te) due to the enhanced Fe d and X p orbital hybridization at the bottom of the conduction band of BiFeX3, providing an insight to explore narrow bandgap ferroelectrics. Meanwhile, it is found that the value of spontaneous polarization of BiFeX3 decreases along with the increase in dipole moment from X = O to X = Te. In addition, the ferroelectric reversal barrier of BiFeX3 increases from X = O to X = Te, indicating that an increased external field is required to flip the opposite ferroelectric phases. The role of covalency of Bi–X bonds is revealed in the formation of spontaneous polarization. Furthermore, in the visible-light energy range, the increased absorption coefficient has been observed for larger anions and significant optical anisotropy has been found in different energy ranges for different BiFeX3 systems. Our work provides a fundamental understanding on the electronic, ferroelectric, and optoelectronic properties of complete anion substitution in BiFeO3.
The Challenges of Teaching
Authors: Lock Frank
Published: November 2021

This chapter details strategies used to deal with teaching challenges. The 17 editorials, and the appreciations written by this author, address specific issues in physics education as well as education in general.

“A Good and Demanding Life” and “Wealth and the Physics Teacher” present the benefits of a career spent teaching physics. Included is information about teaching salaries, summer institutes, and the responsibilities of teaching. “New Fad, Old Fraud” is a discussion of teaching innovations. “On Teaching What We Do Not Know” is about the pleasure of finding out about things. “Specialists” identifies the dual-specialist responsibility teachers have.

“The Text for Today” and “Downhill Thoughts” describe challenges teachers face in making decisions about student resources and student expectations. “How Many B's Make an A?,” “The Variety of Learning Experiences,” and “Mid-Winter Grouch” describe some of the most challenging situations teachers face. “Salus ex Machina” deals with problems in education created by past events and future needs. “The Rumpelstiltskin Factor” includes details about how funds budgeted to improve education do not always do that. “A Quantitative Misconception,” “Listen!,” “Lo, The Vanishing Physics Teacher,” “No One Kissed the Physics Teacher,” and “Judgement Day” all explain challenges faced by teachers throughout their careers.
Challenges Faced by Students
Authors: Lock Frank
Published: November 2021

This chapter details challenges faced by students and provides suggestions for how teachers might deal with them. There are eight editorials written by Cliff Swartz and appreciations written by this author for each editorial. These address specific issues in physics education as well as education in general. Students in every science class typically are encouraged to compete in a science competition, which provides them with the opportunity to use science strategies to investigate a problem. In the editorial “How to Win the Science Project Contest,” Swartz's suggestions for assisting students in being successful at a project are insightful. This sets the tone for the other editorials in the chapter. In “The Facts of Life,” careful consideration of decisions that have far-reaching implications are addressed. “What the Student Saw” encourages teachers to consider the perspective of the student when presenting concepts. In “Quantitative Conceptual Physics,” the relationship between those two courses is examined. “True Confessions” examines student learning strategies from the teacher's perspective. “Is This Generation Different?,” addresses the important idea that student culture changes over the course of a teacher's career. The final editorial in the chapter addresses the challenge of student attitudes as courses are completed.
Curriculum and Instruction
Authors: Lock Frank
Published: November 2021

Chapter 5 includes information about the teaching strategies use used by instructors and how they are utilized. “An Elementary Proposal for Elementary School Science” addresses the turnover rate of elementary school teachers. “Ex Cathedra Editoris” describes approaches that might be used to increase enrollment in high school physics, and “More Sage Advice—The High School Physics Course” analyzes the history of the course and makes proposals for improving it. “What Do College Professors Want?” identifies the expectations our society has for high school graduates, and “Impedance Matching” examines the relationship between high school and college physics courses. “The Bottom Lines” delves into student characteristics. “Homely Physics” postulates for investigating the concepts involved in everyday physics, and “The Great American New Math Swindle” castigates the problems with math pedagogy. “Modest Proposals” focuses on technology and making teaching careers attractive.
Increase in the output power of radiation with a wavelength of about 1650 nm using dual-polarised Raman amplification
Authors: Grigorievsky V.I. , Tezadov Ya.A.
Published: November 2021

Nonlinear distortions of radiation at the Raman amplifier output in the regimes with one and two orthogonal polarisations (single- and dual-polarised amplification) in an extended optical fibre are compared. At an output power of 3.5 W and a wavelength of 1650 nm the nonlinear distortions for dual-polarised amplification are smaller, due to which a narrower spectrum can be provided for output radiation. As a result, one can measure more exactly, for example, the methane concentration using a remote lidar system. A somewhat higher power of an undistorted signal (∼4 W) without deteriorating the spectral properties of output radiation is obtained in the dual-polarised amplification regime at the aforementioned wavelength.
Increasing the pump current range of a single-frequency laser diode tuned to the caesium D2 line
Authors: Bagaeva O.O. , Ivanov A.V. , Drozdovskii V.N. , Kurnosov V.D. , Kurnosov K.V. , Romantsevich V.I. , Simakov V.A. , Chernov R.V.
Published: November 2021

It is shown experimentally and theoretically that increasing the pump current of a laser diode and simultaneously lowering its temperature can ensure an order of magnitude increase in the range of pump currents where the diode emission frequency is tuned to the caesium D2 line. The results are compared to the case where the laser diode and fibre Bragg grating temperatures are maintained constant and only the laser pump current is varied.
Cumulation and mixing of ions in a tubular focus of a high-power laser pulse
Authors: Kovalev V.F. , Bychenkov V.Yu.
Published: November 2021

As applied to laser acceleration of ions, we have constructed an analytical solution to the Cauchy problem for the kinetic equation, which describes the radial motion of particles under the action of a ponderomotive force in a tubular focus of a high-power laser beam propagating in a transparent plasma. For axisymmetric geometry, we have obtained the time and spatial dependences of the ion distribution function and have found their integral characteristics, such as density, average velocity, and energy spectrum. The appearance of ion density peaks inside the laser caustics, the cumulation of ions on the axis, and the effect of the formation of a multi-flux regime of ion motion are described analytically. The efficiency of the generation of neutron bursts by a laser pulse in the focal region in the case of cylindrical cumulation of ions is estimated.
Effects of dietary supplementation with Artemisia argyi alcohol extract on growth performance, blood biochemical properties and small intestinal immune markers of broilers challenged with lipopolysaccharide
Authors: Yang Shuo , Zhang Jing , Jiang Yang , Xu Yuanqing , Jin Xiao , Yan Sumei , Shi Binlin
Published: November 2021

Context Broilers are prone to immunological stress when subjected to unsuitable environmental conditions (such as virus attack, nutrient deficiency and high stocking density), lowering immunity and resulting in inflammatory bowel diseases. The herb-feed additive Artemisia argyi has been applied in poultry production, and its extract may improve small intestinal immune capacity. Aims This study was conducted to investigate the effect of A. argyi alcohol extract (AAAE) on growth performance and blood biochemical and small intestinal immune markers of broilers challenged with a proinflammatory substance, lipopolysaccharide (LPS). The study also examined possible mechanisms of action, and aimed to clarify whether AAAE could be applied as a feed additive. Methods In total, 192 one-day-old Arbor Acres broilers were allocated to four groups following a 2 × 2 factorial arrangement (including six replicates with eight birds per replicate) with two dietary AAAE rates (0 or 750 mg/kg) and two immune stress treatments (LPS or saline injection). Blood and small intestine were sampled on Days 21 and 35. Key results Dietary AAAE alleviated the LPS-induced decrease in bodyweight, average daily gain and average daily feed intake, and mitigated the elevated serum alanine aminotransferase, triglyceride, low-density lipoprotein cholesterol, adrenocorticotropic hormone and corticosterone concentrations at Day 21 and/or Day 35 in LPS-challenged broilers. AAAE significantly (P < 0.05) attenuated LPS-induced increases in intestinal immunoglobulin (IgA, IgG and IgM) and interleukin (IL-1β and IL-6) concentrations. Moreover, the small intestinal mRNA abundances of the genes TLR4, MyD88, NF-κBp65, IL-1β and IL-6 in LPS-challenged broilers were decreased (P < 0.05) in response to dietary AAAE treatment. Conclusions These results further demonstrated that AAAE at 750 mg/kg enhanced small intestinal tissue immune capacity of broilers, thereby alleviating LPS-induced immune stress damage in broilers. Its mechanism of action may be related to the mediating of TLR4/NF-κB pathways. Implications Dietary AAAE can be used to improve the immune function of broilers, and to provide a new scientific theoretical basis for the development of new anti-stress feed additives.
‘Be nice to us, we’re still learning’: an online survey of young people in Hawkes Bay, New Zealand, about unmet need for sexual health care and improving access to services
Authors: Rose Sally B. , Garrett Susan M. , McKinlay Eileen M. , Morgan Sonya J.
Published: November 2021

Background Young people need equitable access to high-quality sexual and reproductive health care to enjoy good sexual health. Methods This online survey of people aged 15–24 years in a defined region of New Zealand asked about unmet need for sexual health care and sought views on improving access to sexual health care. Results Five hundred participants took part in the study between August and October 2020, of whom 60% were female, 25% were of Māori (indigenous) ethnicity, and 21.4% were gender and/or sexuality diverse. Sixty percent had ever received sexual health care (300/500), and 74.3% received it from a general practice clinic (223/300). Overall, 41% (204/500) reported they needed, but had not received sexual health care in the past (‘unmet need’). Reasons for unmet need included being shy, embarrassed or ashamed (74.5%, 152/204), fear of judgment by clinic staff (42.6%, 87/204), cost (32.8%, 67/204), concerns about confidentiality (28.9%, 59/204), and not knowing where to go (24%, 49/204). Māori participants were more likely to report not knowing where to go (32.1% vs 20%, P = 0.04). Participants identified the need to reduce stigma, normalise sexual health care, improve convenience, affordability and awareness of services as key to improving access. Reassurance about confidentiality and being treated with kindness, empathy and respect were deemed critical to service acceptability. Conclusions Action is urgently needed at policy, funding and practice levels to improve access to services by: reducing societal stigma, normalising discussions around sexual health, improving affordability and raising awareness of services. Quality improvement is also needed in general practice to ensure young people can routinely access youth-friendly sexual and reproductive health care.
Ubiquitin-specific proteases UBP12 and UBP13 promote shade avoidance response by enhancing PIF7 stability
Authors: Zhou Yu , Park Su-Hyun , Soh Miao Yi , Chua Nam-Hai
Published: November 2021

Significance

For plants grown in a crowded environment, PHYTOCHROME INTERACTING FACTOR 7 (PIF7) plays a critical role by initiating a series of adaptive growth responses. Here, we demonstrate that, in addition to transcription activity and subcellular localization, the PIF7 protein level, which is stringently regulated, is also important for shade avoidance responses. We identified two ubiquitin-specific proteases, UBP12 and UBP13, which positively regulate rapid plant growth in response to shade light. These two ubiquitin proteases directly interact with PIF7 and protect the latter from destruction by 26S proteasomes. The dynamic changes of PIF7 abundance regulated by UBP12 and UBP13 provide insight into the roles of posttranslational modifications of PIF7 in integrating environmental changes with endogenous responses.
Peptide nucleic acid–dependent artifact can lead to false-positive triplex gene editing signals
Authors: Ho Pui Yan , Zhang Zhen , Hayes Mark E. , Curd Andrew , Dib Carla , Rayburn Maire , Tam Sze Nok , Srivastava Tumul , Hriniak Brandon , Li Xiao-Jun , Leonard Scott , Wang Lan , Tarighat Somayeh , Sim Derek S. , Fiandaca Mark , Coull James M. , Ebens Allen , Fordyce Marshall , Czechowicz Agnieszka
Published: November 2021

Significance

Many current gene editing techniques rely on use of a donor template to elicit correction. While functional correction remains the strongest indicator of successful editing, many candidates are initially screened via in vitro–based outcomes. Our work here indicates that peptide nucleic acids have an intrinsic capability to aggregate with single-stranded DNA donor templates, which may lead to false positives in PCR-based readouts. To mitigate this issue, we have validated several methods including size exclusion, nuclease digestion, and purification columns, which reversed the appearance of false signals. This is critical to enable efficient development of optimal gene editing agents, which could impact the treatment of many diseases ranging from severe combined immunodeficiencies to sickle cell anemia to cystic fibrosis.
Time-dependent ab initio approaches for high-harmonic generation spectroscopy
Authors: Coccia Emanuele , Luppi Eleonora
Published: November 2021

High-harmonic generation (HHG) is a nonlinear physical process used for the production of ultrashort pulses in XUV region, which are then used for investigating ultrafast phenomena in time-resolved spectroscopies. Moreover, HHG signal itself encodes information on electronic structure and dynamics of the target, possibly coupled to the nuclear degrees of freedom. Investigating HHG signal leads to HHG spectroscopy, which is applied to atoms, molecules, solids and recently also to liquids. Analysing the number of generated harmonics, their intensity and shape gives a detailed insight of, e.g., ionisation and recombination channels occurring in the strong-field dynamics. A number of valuable theoretical models has been developed over the years to explain and interpret HHG features, with the three-step model being the most known one. Originally, these models neglect the complexity of the propagating electronic wavefunction, by only using an approximated formulation of ground and continuum states. Many effects unravelled by HHG spectroscopy are instead due to electron correlation effects, quantum interference, and Rydberg-state contributions, which are all properly captured by an ab initio electronic-structure approach. In this review we have collected recent advances in modelling HHG by means of ab initio time-dependent approaches relying on the propagation of the time-dependent Schrödinger equation (or derived equations) in presence of a very intense electromagnetic field. We limit ourselves to gas-phase atomic and molecular targets, and to solids. We focus on the various levels of theory employed for describing the electronic structure of the target, coupled with strong-field dynamics and ionisation approaches, and on the basis used to represent electronic states. Selected applications and perspectives for future developments are also given.
Investigation of vacancy defects and substitutional doping in AlSb monolayer with double layer honeycomb structure: a first-principles calculation
Authors: Bafekry A , Faraji M , Karbasizadeh S , Jappor H R , Sarsari I Abdolhosseini , Ghergherehchi M , Gogova D
Published: November 2021

The experimental knowledge of the AlSb monolayer with double layer honeycomb structure is largely based on the recent publication (Le Qin et al 2021 ACS Nano
15 8184), where this monolayer was recently synthesized. Therefore, the aim of our research is to consequently explore the effects of substitutional doping and vacancy point defects on the electronic and magnetic properties of the novel hexagonal AlSb monolayer. Besides experimental reports, the phonon band structure and cohesive energy calculations confirm the stability of the AlSb monolayer. Its direct bandgap has been estimated to be 0.9 eV via the hybrid functional method, which is smaller than the value of 1.6 eV of bulk material. The majority of vacancy defects and substitutional dopants change the electronic properties of the AlSb monolayer from semiconducting to metallic. Moreover, the MgSb impurity has demonstrated the addition of ferromagnetic behavior to the material. It is revealed through the calculation of formation energy that in Al-rich conditions, the vacant site of VSb is the most stable, while in Sb-rich circumstances the point defect of VAl gets the title. The formation energy has also been calculated for the substitutional dopants, showing relative stability of the defected structures. We undertook this theoretical study to inspire many experimentalists to focus their efforts on AlSb monolayer growth incorporating different impurities. It has been shown here that defect engineering is a powerful tool to tune the properties of novel AlSb two-dimensional monolayer for advanced nanoelectronic applications.
Weighted total least squares–Bayes filter-based estimation of relative pose for a space non-cooperative unknown target without a priori knowledge
Authors: Zhu Chengguang , Gao Zhongpai , Zhao Jiankang , Long Haihui , Liu Chuanqi
Published: November 2021

The estimation of relative pose of a space non-cooperative target is an attractive yet challenging task due to the complexity of the target background and illumination, and the lack of a priori knowledge. Unfortunately, these negative factors have a grave impact on the accuracy of the estimation and the robustness of the filter algorithms. In response, this paper proposes a novel filter algorithm for estimating relative pose to improve robustness based on a stereovision system. First, to obtain a coarse relative pose, the weighted total least squares (WTLS) algorithm is adopted to estimate the relative pose based on several feature points. The resulting relative pose is fed into the subsequent filter scheme as an observation quantity. Second, the classic Bayes filter is exploited to estimate the relative state except for moment-of-inertia ratios. Additionally, the one-step prediction results are used as feedback for WTLS initialization. The proposed algorithm successfully eliminates the dependence on continuous tracking of several fixed points. Finally, comparison experiments demonstrate that the proposed algorithm presents a better performance in terms of robustness and convergence time.
Non-volatile multi-level cell storage via sequential phase transition in Sb7Te3/GeSb6Te multilayer thin film
Authors: Xu Zhehao , Su Xiao , Hua Sicong , Zhai Jiwei , Song Sannian , Song Zhitang
Published: November 2021

For high-performance data centers, huge data transfer, reliable data storage and emerging in-memory computing require memory technology with the combination of accelerated access, large capacity and persistence. As for phase-change memory, the Sb-rich compounds Sb7Te3 and GeSb6Te have demonstrated fast switching speed and considerable difference of phase transition temperature. A multilayer structure is built up with the two compounds to reach three non-volatile resistance states. Sequential phase transition in a relationship with the temperature is confirmed to contribute to different resistance states with sufficient thermal stability. With the verification of nanoscale confinement for the integration of Sb7Te3/GeSb6Te multilayer thin film, T-shape PCM cells are fabricated and two SET operations are executed with 40 ns-width pulses, exhibiting good potential for the multi-level PCM candidate.
Droplet epitaxy of InAs/InP quantum dots via MOVPE by using an InGaAs interlayer
Authors: Sala Elisa M , Godsland Max , Na Young In , Trapalis Aristotelis , Heffernan Jon
Published: November 2021

InAs quantum dots (QDs) are grown on an In0.53Ga0.47As interlayer and embedded in an InP(100) matrix. They are fabricated via droplet epitaxy (DE) in a metal organic vapor phase epitaxy (MOVPE) reactor. Formation of metallic indium droplets on the In0.53Ga0.47As lattice-matched layer and their crystallization into QDs is demonstrated for the first time in MOVPE. The presence of the In0.53Ga0.47As layer prevents the formation of an unintentional non-stoichiometric 2D layer underneath and around the QDs, via suppression of the As-P exchange. The In0.53Ga0.47As layer affects the surface diffusion leading to a modified droplet crystallization process, where unexpectedly the size of the resulting QDs is found to be inversely proportional to the indium supply. Bright single dot emission is detected via micro-photoluminescence at low temperature, ranging from 1440 to 1600 nm, covering the technologically relevant telecom C-band. Transmission electron microscopy investigations reveal buried quantum dots with truncated pyramid shape without defects or dislocations.
Microwave and furnace annealing in oxygen ambient for performance enhancement of p-type SnO thin-film transistors
Authors: Mohanty Srikant Kumar , Wu Chien Hung , Chang Shih-Ho , Chang Kow Ming
Published: November 2021

In this study, we investigated the effect of microwave-irradiation annealing (MWA) and thermal furnace annealing (FA) in oxygen ambient on the active channel layer of p-type tin-oxide (SnO) thin-film transistors. At very low source-drain voltage of −0.1 V, the MWA at 1200 W and FA at 300 °C samples have exhibited significant improvement in the electrical characteristics such as subthreshold swing (SS) of 0.93 and 0.485 V dec−1, the I
on/I
off ratio of 1.65 × 104 and 3.07 × 104, the field-effect mobility (μ
FE) of 0.16 and 0.26 cm2 V−1 s and ultra-low off-state current of 1.9 and 2.0 pA respectively. The observed performance enhancement was mainly attributed to the reduction of interface trap density (N
t) by tuning the power of MWA and optimizing the temperature in FA. From the result, we observed the optical band gap (E
g) increased by 6% in FA, and 12% in MWA, which confirms improved crystallinity and reduction of defect states. Additionally, a low thermal budget microwave anneal process has shown high transmittance of more than 86% in the visible region (380–700 nm). The physical characterization indicates the partial phase transformation of SnO to SnO2 with retaining p-type conductivity in both annealing processes. The results demonstrate that both the annealing process could be highly promising to be used in the complementary logic circuits of new generation flexible/transparent displays.
Anisotropic critical current density and flux pinning mechanism of Fe

1+y

Te0.6Se0.4 single crystals
Authors: Pan Yongqiang , Zhou Nan , Lin Bencheng , Wang Jinhua , Zhu Zengwei , Zhou Wei , Sun Yue , Shi Zhixiang
Published: November 2021

Fe

1
+
y

Te0.6Se0.4 has considerable application potential due to its large critical current density (J
c) and high upper critical magnetic field (

H

c2

). However, the uncertainty of the anisotropy of J
c and the unclear flux-pinning mechanism have limited the application of this material. In this study, the J
c in three directions were obtained from magnetic hysteresis loop measurements. A large anisotropy of

J

c

a
b

/

J

c

c

∼

10 was observed, and the origin of the anisotropy was discussed in details. Flux pinning force densities (F
p) were obtained from J
c, and a non-scaling behavior was found in the normalized pinning force

f

p

[

F

p

/

F

p-max

]

versus the normalized field h[H/

H

c2

]. The peaks of pinning force shift from a high h to a low h with increasing temperature. Based on the vortex dynamics analysis, the peak shift was found to originate from the magnetization relaxation. The J
c and F
p at critical states free from the magnetic relaxation were regained. According to the Dew-Hughes model, the dominant pinning type in Fe

1
+
y

Te0.6Se0.4 clean single crystals was confirmed to be normal point pinning.
A methodological approach for the optimal design of the toroidal field coils of a tokamak device using artificial intelligence
Authors: Tomassetti Giordano , de Marzi Gianluca , Fiamozzi Zignani Chiarasole , Giorgetti Francesco , Della Corte Antonio
Published: November 2021

As prototypes of future commercial tokamaks, DEMOs nuclear fusion power plants are expected to be able to produce cost-effective electrical power. In this view, an optimized design becomes crucial in the whole engineering workflow. Up to now, the design of one of the most critical components, the cross-section of each of the toroidal field coils inner leg winding pack, was performed using a sequential trial-and-error procedure. In this work, a novel comprehensive approach is proposed to include all the main design aspects into a unified tool taking advantage of artificial neural networks for faster computation in finding optimal design configurations. This procedure overcomes several difficulties including dealing with both real-valued and discrete design variables, the significant CPU-time of magneto-structural analysis and also guarantees the optimality for the winding pack configuration. The proposed methodology was demonstrated for the 2019 ENEA DEMO configuration which includes 16 toroidal field coils, made-up of 6 Nb3Sn double layers and a Wind and React manufacturing technique.
Screening current induced field characteristics of HTS quasi-isotropic and simply stacked strands in alternating magnetic field
Authors: Liu Yating , Wang Yinshun , Zhang Guangyi , Chen Yuheng
Published: November 2021

The screening current induced field (SCIF) in the flat REBCO coated conductors so called the second generation high temperature superconducting tapes cause undesirable effects in multiple applications. Their existence reduces the spatial uniformity and temporal stability of magnetic fields for applications of superconducting magnets. In this paper, we numerically and experimentally investigate the characterization of the screening current and SCIF of quasi-isotropic strand (Q-IS) and simply stacked strand (SSS) under external alternating magnetic field with various amplitudes, orientations, and excitation rates. The two-dimensional finite element method based on
T-A
formulation is adopted for simulation, the Q-IS and SSS samples are fabricated for experiments. The field angle is in the range of 0°–90° at intervals of 15°, the excitation rate varies from 20 mT s−1 to 800 mT s−1. We display the distribution of screening current in both strands under various field amplitudes and orientations. Then the dependence of the SCIF on the amplitude and orientation of the external field is studied, respectively. The spatial distribution of SCIF of both strands with different amplitudes and angles of the external field are also discussed. Besides, we analyze the properties of SCIF under various excitation rates. As a result, the SCIF of Q-IS is much smaller and has quasi-isotropic distribution compared to SSS, which represents that Q-IS has a relative smaller screening effect. The spatial point with the largest SCIF of Q-IS locates at the corner of the strand and is independent of the external field, but the corresponding point in SSS varies with the angle and amplitude. The Q-IS is also less susceptible to the change of rate. Therefore, Q-IS has more advantages when the screening effect is considered in superconducting applications.
Quantification of hydrogen isotopes by CF-LIBS in a W-based material (WZr) at atmospheric pressure: from ns towards ps
Authors: Roldán A Marín , Dwivedi V , Veis M , Atikukke S , van der Meiden H , Držík M , Veis P
Published: November 2021

Tungsten-based materials are possible candidates as PFCs in future fusion devices. LIBS is one of the most suitable techniques for monitoring erosion and deposition processes including fuel retention, due to its versatility and ability to perform in situ measurements. By deploying ps-LIBS, instead of ns, the laser ablation occurs with fewer melting effects. This work compares ns- and ps- (CF)-LIBS characterization of WZr(D) samples, at the linear plasma generator at Magnum-PSI at the DIFFER. The laser energy has been optimized for both laser regimes, lowering the laser energy for the ns regime (from 19.9 mJ pulse−1 to 7.4 mJ pulse−1) to approximate to ps regime (0.3 mJ pulse−1). All the experimental measurements have been performed at Patm. The pure WZr samples have been analyzed in ambient air, while the WZrD sample measurements have been performed under Ar gas flow. The retained deuterium content varies from 4 at% to 0.3 at%.
Heavy-tailed distributions in a stochastic gene autoregulation model
Authors: Bokes Pavol
Published: November 2021

Synthesis of gene products in bursts of multiple molecular copies is an important source of gene expression variability. This paper studies large deviations in a Markovian drift-jump process that combines exponentially distributed bursts with deterministic degradation. Large deviations occur as a cumulative effect of many bursts (as in diffusion) or, if the model includes negative feedback in burst size, in a single big jump. The latter possibility requires a modification in the WKB solution in the tail region. The main result of the paper is the construction, via a modified WKB scheme, of matched asymptotic approximations to the stationary distribution of the drift-jump process. The stationary distribution possesses a heavier tail than predicted by a routine application of the scheme.
Flow-signal correlation in seal whisker array sensing
Authors: Liu Geng , Jiang Weili , Zheng Xudong , Xue Qian
Published: November 2021

Phocid seals detect and track artificial or biogenic hydrodynamic trails based on mechanical signals of their whisker arrays. In this paper, we investigated the correlations between flow structures and whisker array signals using a simplified numerical model of fluid–structure interaction (FSI). Three-dimensional (3D) wakes of moving paddles in three different shapes (rectangular plate, undulated plate, and circular cylinder) were simulated using an in-house immersed-boundary-method-based computational fluid dynamics solver. One-way FSI was then simulated to obtain the dynamic behavior and root signal of each whisker in the two whisker arrays on a seal head in each wake. The position, geometry, and material properties of each whisker were modeled based on the measurements reported in literatures. The correlations between the wake structures and whisker array signals were analyzed. It was found that the patterns of the signals on the whisker arrays can reflect the strength, timing, and moving trajectories of the jets induced by the vortices in the wakes. Specifically, the rectangular plate generates the strongest starting vortex ring as well as the strongest jets, while the undulated plate generates the weakest ones. These flow features are fully reflected by the largest whisker signal magnitude in the rectangular plate sensing and the smallest one in the undulated plate sensing. Moreover, the timing of the signal initiation and the maximum signal agree well with the timing of the jet reaching the arrays and the maximum flow speed, respectively. The correlation coefficient between the moving trajectories of the jet and the movement of the high signal level region in the array was found to be higher than 0.9 in the rectangular plate case. The results provide a physical insight into the mechanisms of seal whisker flow sensing.
Monitoring decellularization via absorbance spectroscopy during the derivation of extracellular matrix scaffolds
Authors: Mora-Navarro Camilo , Garcia Mario E , Sarker Prottasha , Ozpinar Emily W , Enders Jeffrey R , Khan Saad , Branski Ryan C , Freytes Donald O
Published: November 2021

Extracellular matrix (ECM) is a complex structure composed of bioactive molecules representative of the local tissue microenvironment. Decellularized ECM biomaterials harness these biomolecules for regenerative medicine applications. One potential therapeutic application is the use of vocal fold (VF) specific ECM to restore the VFs after injury. ECM scaffolds are derived through a process of decellularization, which aims to remove unwanted immunogenic biomolecules (e.g. DNA) while preserving the composition of the ECM. The effectiveness of the decellularization is typically assessed at the end by quantifying ECM attributes such as final dsDNA content. However, batch-to-batch variability in ECM manufacturing remains a significant challenge for the standardization, cost-effectiveness, and scale-up process. The limited number of tools available for in-process control heavily restricts the uncovering of the correlations between decellularization process parameters and ECM attributes. In this study, we developed a technique applicable to both the classical batch method and semi-continuous decellularization systems to trace the decellularization of two laryngeal tissues in real-time. We hypothesize that monitoring the bioreactor’s effluent absorbance at 260 nm as a function of time will provide a representative DNA release profile from the tissue and thus allow for process optimization. The DNA release profiles were obtained for laryngeal tissues and were successfully used to optimize the derivation of VF lamina propria-ECM (auVF-ECM) hydrogels. This hydrogel had comparable rheological properties to commonly used biomaterials to treat VF injuries. Also, the auVF-ECM hydrogel promoted the down-regulation of CCR7 by THP-1 macrophages upon lipopolysaccharide stimulation in vitro suggesting some anti-inflammatory properties. The results show that absorbance profiles are a good representation of DNA removal during the decellularization process thus providing an important tool to optimize future protocols.
Virtual nitrogen and phosphorus flow associated with interprovincial crop trade and its effect on grey water stress in China
Authors: Ren Dandan , Liu Wenfeng , Yang Hong , Zhuo La , Tong Yindong , Liu Yilin , Yang Yonghui , Zhou Lingfeng
Published: November 2021

The grey water footprint (GWF) is defined as freshwater requirements for diluting pollutants in receiving water bodies. It is widely used to measure the impact of pollutant loads on water resources. GWF can be transferred from one area to another through trade. Although pollution flow has previously been investigated at the national level, there has been no explicit study on the extent to which crop trade affects GWF across regions and the associated changes in grey water stress (GWS). This study analyzes pollution flow associated with interprovincial crop trade based on nitrogen (N) and phosphorus (P) loss intensity of three major crops, namely, maize, rice and wheat, which is simulated by a grid-based crop model for the period 2008–2012, and evaluates the spatial patterns of GWS across China. The results indicate that the integrated national GWF for N and P was 1271 billion m3 yr−1, with maize, rice, and wheat contributing 39%, 37%, and 24%, respectively. Through interprovincial crop trade, southern China outsourced substantial N and P losses to the north, leading to a 30% GWS increase in northern China and 66% GWS mitigation in southern China. Specifically, Jilin, Henan, and Heilongjiang Provinces in the northern China showed increases in GWS by 161%, 114%, and 55%, respectively, while Fujian, Shanghai, and Zhejiang in the south had GWS reductions of 83%, 85%, and 80%, respectively. It was found that the interprovincial crop trade led to reduced national GWF and GWS. Insights into GWF and GWS can form the basis for policy developments on N and P pollution mitigation across regions in China.
Financing climate change mitigation in agriculture: assessment of investment cases
Authors: Khatri-Chhetri Arun , Sapkota Tek B , Sander Bjoern O , Arango Jacobo , Nelson Katherine M , Wilkes Andreas
Published: November 2021

More than one-quarter of the world’s greenhouse gas emissions come from agriculture, forestry, and land-use change. As with other sectors of the economy, agriculture should also contribute to meeting countries’ emission reduction targets. Transformation of agriculture to low-carbon food systems requires much larger investments in low emission development options from global climate finance, domestic budgets, and the private sector. Innovative financing mechanisms and instruments that integrate climate finance, agriculture development budgets, and private sector investment can improve and increase farmers’ and other value chain actors’ access to finance while delivering environmental, economic, and social benefits. Investment cases assessed in this study provide rich information to design and implement mitigation options in agriculture through unlocking additional sources of public and private capital, strengthening the links between financial institutions, farmers, and agribusiness, and coordination of actions across multiple stakeholders. These investment cases expand support for existing agricultural best practices, integrate forestry and agricultural actions to avoid land-use change, and support the transition to market-based solutions.
Statistics and optimization of random pan stacking
Authors: Talbot J , Antoine C
Published: November 2021

We consider a minimal model of random pan stacking. A single pan consists of a V-shaped object characterized by its internal angle α. The stack is constructed by piling up N pans with different angles in a given, random order. The set of pans is generated by sampling from various kinds of distributions of the pan angles: discrete or continuous, uniform or optimized. For large N the mean height depends principally on the average of the distance between the bases of two consecutive pans, and the effective compaction of the stack, compared with the unstacked pans, is 2 log 2/π. We also obtain the discrete and continuous distributions that maximize the mean stack height. With only two types of pans, the maximum occurs for equal probabilities, while when many types of pans are available, the optimum distribution strongly favours those with the most acute and the most obtuse angles. With a continuous distribution of angles, while one never finds two identical pans, the behaviour is similar to a system with a large number of discrete angles.
Non-abelian anyons and some cousins of the Arad–Herzog conjecture
Authors: Buican Matthew , Li Linfeng , Radhakrishnan Rajath
Published: November 2021

Long ago, Arad and Herzog (AH) conjectured that, in finite simple groups, the product of two conjugacy classes of length greater than one is never a single conjugacy class. We discuss implications of this conjecture for non-abelian anyons in 2 + 1-dimensional discrete gauge theories. Thinking in this way also suggests closely related statements about finite simple groups and their associated discrete gauge theories. We prove these statements and provide some physical intuition for their validity. Finally, we explain that the lack of certain dualities in theories with non-abelian finite simple gauge groups provides a non-trivial check of the AH conjecture.