bluuebunny/crossref_metadata_2025 huggingface dataset:
On the nature of the Schottky anomaly in endohedral water
Authors: Serwatka Tobias , Yim Spencer , Ayotte Patrick , Roy Pierre-Nicholas
Published: March 2023

In this work, we study the heat capacity contribution of a rigid water molecule encapsulated in C60 by performing six-dimensional eigenstate calculations with the inclusion of its quantized rotational and translational degrees of freedom. Two confinement model potentials are considered: in the first, confinement is described using distributed pairwise Lennard-Jones interactions, while in the second, the water molecule is trapped within an eccentric but isotropic 3D harmonic effective confinement potential [Wespiser et al., J. Chem. Phys. 156, 074304 (2022)]. Contributions to the heat capacity from both the ortho and para nuclear spin isomers of water are considered to enable the effects of their interconversion to be assessed. By including a symmetry-breaking quadrupolar potential energy term in the Hamiltonian, we can reproduce the experimentally observed Schottky anomaly at ∼2 K [Suzuki et al., J. Phys. Chem. Lett. 10, 1306 (2019)]. Furthermore, our calculations predict a second Schottky anomaly at ∼0.1 K resulting from the H configuration, a different orientational arrangement of the fullerene cages in crystalline solid C60. Contributions from the H configuration to CV also explain the second peak observed at ∼7 K in the experimentally measured heat capacity.
Charophytes of Australia’s Northern Territory – I. Tribe Chareae
Authors: Casanova Michelle T. , Karol Kenneth G.
Published: March 2023

This study of Northern Territory charophytes documents 22 species in 3 of the genera in tribe Chareae, family Characeae, including 15 previously described species (Chara benthamii, C. erythrogyna, C. globularis, C. karolii, C. lucida, C. porteri, C. protocharoides, C. setosa, C. submollusca, C. wightii, C. zeylanica, Lamprothamnium capitatum, L. compactum, L. stipitatum, Lychnothamnus barbatus) of which 2 are new for the Australian flora (C. erythrogyna and C. wightii), as well as 5 varieties raised to species rank (C. aridicola, C. arnhemensis, C. bancroftii, C. behriana, C. duriuscula), and 2 newly described species (C. lamprothamniformis, C. schultae). Three previously reported species in the tribe (C. braunii, C. corallina, C. fibrosa) are not recorded from the Northern Territory in this study, as previous records were based on erroneous identifications or localities. Although Northern Territory specimens of Lychnothamnus barbatus have not been seen, it has been included in this treatment, because it occurs in south-eastern Queensland, the Gulf of Carpentaria, Papua New Guinea and Timor-Leste. A key, illustrations and descriptions of all the species are provided.
Mechanochemical upcycling of spent LiCoO
2
to new LiNi
0.80
Co
0.15
Al
0.05
O
2
battery: An atom economy strategy
Authors: Yu Jiadong , Li Ju , Zhang Shang , Wei Fan , Liu Yanjun , Li Jinhui
Published: March 2023

The use of strong acids and low atom efficiency in conventional hydrometallurgical recycling of spent lithium-ion batteries (LIBs) results in significant secondary wastes and CO
2
emissions. Herein, we utilize the waste metal current collectors in spent LIBs to promote atom economy and reduce chemicals consumption in a conversion process of spent Li
1-

x

CoO
2
(LCO) → new LiNi
0.80
Co
0.15
Al
0.05
O
2
(NCA) cathode. Mechanochemical activation is employed to achieve moderate valence reduction of transition metal oxides (Co
3+
→Co
2+,3+
) and efficient oxidation of current collector fragments (Al
0
→Al
3+
, Cu
0
→Cu
1+,2+
), and then due to stored internal energy from ball-milling, the leaching rates of Li, Co, Al, and Cu in the ≤4 mm crushed products uniformly approach 100% with just weak acetic acid. Instead of corrosive precipitation reagents, larger Al fragments (≥4 mm) are used to control the oxidation/reduction potential (ORP) in the aqueous leachate and induce the targeted removal of impurity ions (Cu, Fe). After the upcycling of NCA precursor solution to NCA cathode powders, we demonstrate excellent electrochemical performance of the regenerated NCA cathode and improved environmental impact. Through life cycle assessments, the profit margin of this green upcycling path reaches about 18%, while reducing greenhouse gas emissions by 45%.
Altered plasma membrane abundance of the sulfatide-binding protein NF155 links glycosphingolipid imbalances to demyelination
Authors: McKie Shannon J. , Nicholson Alex S. , Smith Emily , Fawke Stuart , Caroe Eve R. , Williamson James C. , Butt Benjamin G. , Kolářová Denisa , Peterka Ondřej , Holčapek Michal , Lehner Paul J. , Graham Stephen C. , Deane Janet E.
Published: March 2023

Myelin is a multilayered membrane that tightly wraps neuronal axons, enabling efficient, high-speed signal propagation. The axon and myelin sheath form tight contacts, mediated by specific plasma membrane proteins and lipids, and disruption of these contacts causes devastating demyelinating diseases. Using two cell-based models of demyelinating sphingolipidoses, we demonstrate that altered lipid metabolism changes the abundance of specific plasma membrane proteins. These altered membrane proteins have known roles in cell adhesion and signaling, with several implicated in neurological diseases. The cell surface abundance of the adhesion molecule neurofascin (NFASC), a protein critical for the maintenance of myelin-axon contacts, changes following disruption to sphingolipid metabolism. This provides a direct molecular link between altered lipid abundance and myelin stability. We show that the NFASC isoform NF155, but not NF186, interacts directly and specifically with the sphingolipid sulfatide via multiple binding sites and that this interaction requires the full-length extracellular domain of NF155. We demonstrate that NF155 adopts an S-shaped conformation and preferentially binds sulfatide-containing membranes in
cis
, with important implications for protein arrangement in the tight axon-myelin space. Our work links glycosphingolipid imbalances to disturbance of membrane protein abundance and demonstrates how this may be driven by direct protein–lipid interactions, providing a mechanistic framework to understand the pathogenesis of galactosphingolipidoses.
NAMPT-dependent NAD
+
biosynthesis controls circadian metabolism in a tissue-specific manner
Authors: Basse Astrid L. , Nielsen Karen N. , Karavaeva Iuliia , Ingerslev Lars R. , Ma Tao , Havelund Jesper F. , Nielsen Thomas S. , Frost Mikkel , Peics Julia , Dalbram Emilie , Dall Morten , Zierath Juleen R. , Barrès Romain , Færgeman Nils J. , Treebak Jonas T. , Gerhart-Hines Zachary
Published: March 2023

Molecular clocks in the periphery coordinate tissue-specific daily biorhythms by integrating input from the hypothalamic master clock and intracellular metabolic signals. One such key metabolic signal is the cellular concentration of NAD
+
, which oscillates along with its biosynthetic enzyme, nicotinamide phosphoribosyltransferase (NAMPT). NAD
+
levels feed back into the clock to influence rhythmicity of biological functions, yet whether this metabolic fine-tuning occurs ubiquitously across cell types and is a core clock feature is unknown. Here, we show that NAMPT-dependent control over the molecular clock varies substantially between tissues. Brown adipose tissue (BAT) requires NAMPT to sustain the amplitude of the core clock, whereas rhythmicity in white adipose tissue (WAT) is only moderately dependent on NAD
+
biosynthesis, and the skeletal muscle clock is completely refractory to loss of NAMPT. In BAT and WAT, NAMPT differentially orchestrates oscillation of clock-controlled gene networks and the diurnality of metabolite levels. NAMPT coordinates the rhythmicity of TCA cycle intermediates in BAT, but not in WAT, and loss of NAD
+
abolishes these oscillations similarly to high-fat diet-induced circadian disruption. Moreover, adipose NAMPT depletion improved the ability of animals to defend body temperature during cold stress but in a time-of-day-independent manner. Thus, our findings reveal that peripheral molecular clocks and metabolic biorhythms are shaped in a highly tissue-specific manner by NAMPT-dependent NAD
+
synthesis.
Epitranscriptic regulation of
HRAS
by
N
6
-methyladenosine drives tumor progression
Authors: Pan Yongbo , Gu Yinmin , Liu Tihui , Zhang Qingqing , Yang Facai , Duan Liqiang , Cheng Shuwen , Zhu Xiaofeng , Xi Yibo , Chang Xiaoli , Ye Qinong , Gao Shan
Published: March 2023

Overexpression of Ras, in addition to the oncogenic mutations, occurs in various human cancers. However, the mechanisms for epitranscriptic regulation of
RAS
in tumorigenesis remain unclear. Here, we report that the widespread
N
6
-methyladenosine (m
6
A) modification of
HRAS
, but not
KRAS
and
NRAS
, is higher in cancer tissues compared with the adjacent tissues, which results in the increased expression of H-Ras protein, thus promoting cancer cell proliferation and metastasis. Mechanistically, three m
6
A modification sites of
HRAS
3′ UTR, which is regulated by FTO and bound by YTHDF1, but not YTHDF2 nor YTHDF3, promote its protein expression by the enhanced translational elongation. In addition, targeting
HRAS
m
6
A modification decreases cancer proliferation and metastasis. Clinically, up-regulated H-Ras expression correlates with down-regulated FTO and up-regulated YTHDF1 expression in various cancers. Collectively, our study reveals a linking between specific m
6
A modification sites of
HRAS
and tumor progression, which provides a new strategy to target oncogenic Ras signaling.
Lexical development of Spanish heritage and L2 learners in a study abroad setting
Authors: Marqués-Pascual Laura , Checa-García Irene
Published: March 2023

This study investigates the effects of an immersion experience on the lexical development of Spanish heritage
language learners (HLLs) and second language learners (L2Ls) abroad. Data were collected from 21 Spanish HLLs and 33 L2Ls who
spent a semester abroad. Lexical development was assessed based on written narratives collected before and after the semester. The
narratives were analyzed to determine the impact of study abroad on three measures of lexical development: density, diversity, and
sophistication. Lexical sophistication was assessed based on Spanish frequency data from the Corpus del Español
(Davies, 2006) using the log-transformed frequency count. Results indicate a
significant increase over time in lexical density for HLLs but not L2Ls, and a significant decrease in lexical sophistication for
both groups. Findings are discussed in light of previous research on study abroad and the analysis of lexical development.
Swirling currents
Authors: Junker Christine R. , Cubberley Mark S. , Jacquemin Stephen J.
Published: March 2023

Understanding how humans relate to and think about nonhuman nature has never been more important. To begin
exploring that question, our study compares literature (nature-writing) that explicitly addresses this relationship with
literature of the same genre that does not address nonhuman nature (creative nonfiction) using the tools of digital humanities and
ecological analysis. We used Linguistic Inquiry and Word Count (LIWC) and Meaning Extraction Method (MEM) to examine 228 texts.
Resulting scores were then examined for gradients, patterns, and trends across texts using principal components analysis (PCA).
Overall, we found that nature writing texts scored higher in analytical and authenticity scores; were associated with
psychological processes such as perception, cognition, politics, and power; and were typified by individual word
choice clouds associated with clusters of text such as tree/human/see/time/form/place than non-nature creative nonfiction. This
analysis serves as a foundation for understanding the genre of nature-writing and the ways that humans think about nonhuman
nature.
Verbal past inflection in Nigerian English
Authors: Bohmann Axel , Babalola Adesoji
Published: March 2023

We analyze variation in Nigerian English verbal past inflection on the basis of 2,989 verbs with past-time reference. Observations were extracted from the spontaneous conversations category of the International Corpus of English Nigeria and from two sets of sociolinguistic interviews. In contrast to the previous literature, our analysis shows rich systematicity in the constraints governing verbal past inflection, but also significant differences between the data sets. The latter concern both the overall frequency of past inflection and the number and strength of linguistic conditioning variables. At the level of method, we argue for ‘sociolinguistic compound vision,’ i.e. an active effort to include diverse data sets in order to avoid homogenizing accounts of New Englishes.
Analysing the speech rhythm of New Englishes
Authors: Fuchs Robert
Published: March 2023

Most New Englishes are classified as syllable-timed and many L1 varieties of English as stress-timed. However, much empirical work on varieties of English and other languages has shown that a categorical distinction between discrete rhythm classes is not commensurate with the empirical evidence. Moreover, the comparability of published research is hampered by a lack of methodological standardization. This chapter provides a step-by-step guide for researchers and charts new avenues for future enquiries, illustrated with a case study comparing Pakistani, Nigerian, Philippine, and British English. Results indicate that the first three can be described as more syllable-timed than British English, but also that a binary classification of syllable- vs. stress-timed does not fully do justice to the results.
Mixed methods in the mapping of accent perceptions in Indian varieties of English
Authors: Regnoli Giuliana
Published: March 2023

This paper discusses the benefits of a mixed-methods approach designed for the investigation of language attitudes towards accent variation in Indian English. The study was carried out in a transient community of Indian university students in Heidelberg, Germany in 2018. Methods from language attitude research were combined with those from perceptual dialectology with the aim of eliciting both overt and covert attitudes. The paper critically assesses the current methods used in language attitude research in New Englishes, which often neglect the mapping of perceptual landscapes and mostly rely on Verbal Guise Tests and direct questions. The results show that a mixed-methods approach helps to depict the perceptual heterogeneity of language users in New Englishes contexts.
Mapping perceptions in New Englishes
Authors: Schmalz Mirjam
Published: March 2023

This chapter presents a case study illustrating the validity of employing a mixed-methods approach based on a draw-a-map task and semi-structured sociolinguistic interviews in language attitude research of a New Englishes context. This is illustrated by the analysis of two data sets. First, 49 participants drew perceptual maps of St Kitts and Nevis. The analysis of these maps shows that the participants exhibit complex perceptual landscapes, including areas with varying degrees of fine-grained subdivisions. In addition, interview data from sociolinguistic interviews allows for triangulation of the data and furthermore provides additional information. Thus, this chapter shows how a mixed-methods approach, including map-drawing tasks, can enrich the toolbox of research in New Englishes.
A PI3K-calcium-Nox axis primes leukocyte Nrf2 to boost immune resilience and limit collateral damage
Authors: Clemente Giuliana D. , Weavers Helen
Published: March 2023

Phagosomal reactive oxygen species (ROS) are strategically employed by leukocytes to kill internalized pathogens and degrade cellular debris. Nevertheless, uncontrolled oxidant bursts could cause serious collateral damage to phagocytes or other host tissues, potentially accelerating aging and compromising host viability. Immune cells must, therefore, activate robust self-protective programs to mitigate these undesired effects, and yet allow crucial cellular redox signaling. Here, we dissect in vivo the molecular nature of these self-protective pathways, their precise mode of activation, and physiological effects. We reveal Drosophila embryonic macrophages activate the redox-sensitive transcription factor Nrf2 upon corpse engulfment during immune surveillance, downstream of calcium- and PI3K-dependent ROS release by phagosomal Nox. By transcriptionally activating the antioxidant response, Nrf2 not only curbs oxidative damage but preserves vital immune functions (including inflammatory migration) and delays the acquisition of senescence-like features. Strikingly, macrophage Nrf2 also acts non-autonomously to limit ROS-induced collateral damage to surrounding tissues. Cytoprotective strategies may thus offer powerful therapeutic opportunities for alleviating inflammatory or age-related diseases.
Magnetoelectrics and multiferroics: theory, synthesis, characterisation, preliminary results and perspectives for all-optical manipulations
Authors: Bossini D , Juraschek D M , Geilhufe R M , Nagaosa N , Balatsky A V , Milanović M , Srdić V V , Šenjug P , Topić E , Barišić D , Rubčić M , Pajić D , Arima T , Savoini M , Johnson S L , Davies C S , Kirilyuk A
Published: March 2023

Solid state compounds exhibiting multiple and coupled macroscopic orders, named multiferroics, represent a challenge for both theoretical and experimental modern condensed-matter physics. Spins and the electric polarisation in conventional magnetic and ferroelectric materials can be manipulated on their fundamental timescales, by means of femtosecond laser pulses. In view of the resounding success and popularity of the all-optical approach, it is only natural to wonder about the application of this scheme to study the intrinsic coupling between spins and charges in multiferroics. Deeply fundamental questions arise: can ultrashort laser pulses deterministically activate, enhance or suppress the magnetoelectric coupling on the femtosecond timescale? Can these processes be triggered in a fully coherent fashion, thus being unrestrained by any thermal load? Which mechanism of spin-charge coupling is most favourable to overcome these overarching and daunting challenges? This problem is interdisciplinary in nature, requiring contributions from materials science and condensed matter physics from both theoretical and experimental perspectives. High-quality materials suitable for optical investigations have to be identified, synthetized and characterised. General and valid models offer then a guide to the plethora of possible light-induced processes, resulting in the desired ultrafast multiferroic manipulations. Finally, healthy experimental schemes, able to unambiguously track the ultrafast dynamics of either the ferroelectric or the magnetic order parameter have to be developed and implemented. Our motivation to write this review is to lay a broad and multidisciplinary foundation, which may be employed as a starting point for non-equilibrium approaches to the manipulation of the multiferroicity on the femtosecond timescale. This was also one of the main goals of the COST Action MAGNETOFON, whose network constitutes the core of the authors of this review. The present work thus represents a part of the scientific legacy of MAGNETOFON itself.
Optimization of fs + ps double-pulse sequence parameters for laser-assisted chemical etching of microchannels in fused silica
Authors: Yao Qian , Song Juan , Yin Weiyi , Shi Huiqiang , Yao Heng , Su Zihuai , Dai Ye
Published: March 2023

Developing laser fabricating technology to improve the etching rate of microchannels is of great significance for the development of microfluidic devices. In this paper, the laser processing parameters of the fs + ps double-pulse sequence, including temporal delay and pulse energy ratio, have been investigated to optimize the fabrication of microchannels, in order to obtain a high etching rate. As a result, the optimal energy ratio could be obtained at
Efs:Eps

= 2:1 in negative delays. Furthermore, the etching rate of microchannels was significantly improved by 40.8% compared with those written by fs + fs double-pulse sequence with an energy ratio of 1:1. This improvement is possibly because fs sub-pulse excited seed electron may trigger impact ionization via an efficient energy absorption process within the following ps sub-pulse, this energy accumulation and subsequent thermal diffusion lead to an increase of the modified area. The aforementioned results possibly offer an effective route to improve the etching rate of microchannels which is in favor of accelerating the fabrication of three-dimensional microfluidic devices.
Particle size distribution measurements of widely distributed carbonyl iron powder particles in concentrated suspensions using ultrasonic attenuation
Authors: Wei Qilong , Yang Qiang , Gao Wei
Published: March 2023

In this paper, particle size distribution (PSD) of widely distributed carbonyl iron powder (CIP) particles in concentrated suspensions was measured using the ultrasonic attenuation technology to analyze their dispersion behaviors. Importantly, their zeta potential was measured using electroacoustic technology. Both visco-inertial and scattering mechanisms were considered while measuring the PSD of these particles with primary sizes ranging from about 100 nm to 10 μm. As a result, the opposite evolution of the PSD curves was observed for nanoscale particles and microparticles, namely, d
01 increased and d
99 decreased when the concentration increased from 15 wt% to 35 wt%, whereas the trend was reversed when the concentration increased from 35 wt% to 75 wt%. This outcome means that changes in concentration cause small and large particles to have opposite dispersion behaviors. The zeta potential of the particles was negative, with absolute values not higher than 22 mV, whereas particle concentration and carrier liquids exerted some effects. This opposite evolution was found first while measuring PSD in concentrated suspensions, where non-Derjaguin, Landau, Verwey, and Overbeek interactions could markedly influence the dispersion behaviors of the widely distributed CIP particles. These results might bring forward some challenges to disperse these particles fully for some advanced applications.
Global well-posedness of 3D inhomogeneous Navier–Stokes system with small unidirectional derivative
Authors: Paicu Marius , Zhu Ning
Published: March 2023

In Liu and Zhang (2020 Arch. Ration. Mech. Anal.
235 1405–44); Liu et al (2020 Arch. Ration. Mech. Anal.
238 805–43), the authors proved that as long as the one-directional derivative of the initial velocity is sufficiently small in some scaling invariant spaces, then the (anisotropic) Navier–Stokes (NS) system has a unique global solution. The goal of this paper is to extend this type of result to the 3D inhomogeneous (density-dependent) NS system. More precisely, given initial density such that

a
0

≜

1

ρ
0

−
1
∈

B

p
,
1

3
p

(

R

3

)

and the initial velocity

u
0

=
(

u
0
h

,

u
0
3

)
∈

B

p
,
1

−
1
+

2
p

,

1
p

(

R

3

)
,

with

u
0
h

belonging to

H
1

(

R

3

)

, then the inhomogeneous NS system has a unique global solution provided that

(

∥

a
0

∥

B

p
,
1

3
p

+
∥

Λ
h

−
1

∂
3

u
0

∥

B

p
,
1

−
1
+

2
p

,

1
p

)

⋅
f
(

u
0

)

being sufficiently small for some bounded function f depending on

∥

u
0

∥

p
,
1

−
1
+

2
p

,

1
p

and

∥

u
0
h

∥

H
1

. This provide a more general result that of Chemin et al (2014 Commun. Math. Phys.
272 529–66); Chemin and Zhang (2015 Commun. PDE
40 878–96).
The outflow problem for the radiative and reactive gas: existence, stability and convergence rate
Authors: Yin Haiyan , Zhu Changjiang
Published: March 2023

In this paper, we show that the small-amplitude stationary solutions are time-asymptotically stable to the half-space problem for the one-dimensional radiative and reactive gas (pressure

p
=
R
ρ
θ
+

a
3

θ

4

, internal energy

e
=

C

v

θ
+

a
ρ

θ

4

) provided that the initial perturbation is sufficiently small in some weighted Sobolev spaces. We also obtain the convergence rate of global solutions toward corresponding stationary solutions. The proofs are given by a weighted energy method. A key point is to capture the positivity of the energy dissipation functional and boundary terms with suitable space weight functions and using the precise estimates about stationary solutions.
Fluid compartments influence elastography of the aging mouse brain
Authors: Ge Gary R , Rolland Jannick P , Song Wei , Nedergaard Maiken , Parker Kevin J
Published: March 2023

Objective. Elastography of the brain has the potential to reveal subtle but clinically important changes in the structure and composition as a function of age, disease, and injury. Approach. In order to quantify the specific effects of aging on mouse brain elastography, and to determine the key factors influencing observed changes, we applied optical coherence tomography reverberant shear wave elastography at 2000 Hz to a group of wild-type healthy mice ranging from young to old age. Main results. We found a strong trend towards increasing stiffness with age, with an approximately 30% increase in shear wave speed from 2 months to 30 months within this sampled group. Furthermore, this appears to be strongly correlated with decreasing measures of whole brain fluid content, so older brains have less water and are stiffer. Rheological models are applied, and the strong effect is captured by specific assignment of changes to the glymphatic compartment of the brain fluid structures along with a correlated change in the parenchymal stiffness. Significance. Short-term and longer-term changes in elastography measures may provide a sensitive biomarker of progressive and fine-scale changes in the glymphatic fluid channels and parenchymal components of the brain.
Uncertainty quantification in the assessment of human exposure to pulsed or multi-frequency fields
Authors: Giaccone Luca
Published: March 2023

Objective: pulsed fields or waveforms with multi-frequency content have to be assessed with suitable methods. This paper deals with the uncertainty quantification associated to these methods. Approach: among all possible approaches, the weighted peak method (WPM) is widely employed in standards and guidelines, therefore, in this paper, we consider its implementation both in time domain and frequency domain. For the uncertainty quantification the polynomial chaos expansion theory is used. By means of a sensitivity analysis, for several standard waveforms, the parameters with more influence on the exposure index are identified and their sensitivity indices are quantified. The output of the sensitivity analysis is used to set up a parametric analysis with the aim of evaluating the uncertainty propagation of the analyzed methods and, finally, also several measured waveforms generated by a welding gun are tested. Main results: it is shown that the time domain implementation of the weighted peak method provides results in agreement with the basilar mechanisms of electromagnetic induction and electrostimulation. On the opposite, the WPM in frequency domain is found to be too sensitive to parameters that should not influence the exposure index because its weight function includes sharp variations of the phase centered on real zeros and poles. To overcome this issue, a new definition for the phase of the weight function in frequency domain is proposed. Significance: it is shown that the time domain implementation of the WPM is the more accurate and precise. The standard WPM in frequency domain has some issues that can be avoided with the proposed modification of the phase definition of the weight function. Finally, all the codes used in this paper are hosted on a GitHub and can be freely accessed at https://github.com/giaccone/wpm_uncertainty.
A tomographic reconstruction algorithm for cross-sectional imaging of IMRT beams from six projections
Authors: Pivot Odran , Pittet Patrick , Clackdoyle Rolf , Desbat Laurent , Rit Simon
Published: March 2023

Objective. Patient-specific Quality Assurance (QA) measurements are of key importance in radiotherapy for safe and efficient treatment delivery and allow early detection of clinically relevant errors. Such QA processes remain challenging to implement for complex Intensity Modulated Radiation Therapy (IMRT) radiotherapy fields delivered using a multileaf collimator (MLC) which often feature small open segments and raise QA issues similar to those encountered in small field dosimetry. Recently, detectors based on long scintillating fibers have been proposed to measure a few parallel projections of the irradiation field with good performance for small field dosimetry. The purpose of this work is to develop and validate a novel approach to reconstruct MLC-shaped small irradiation fields from six projections. Approach. The proposed field reconstruction method uses a limited number of geometric parameters to model the irradiation field. These parameters are iteratively estimated with a steepest descent algorithm. The reconstruction method was first validated on simulated data. Real data were measured with a water-equivalent slab phantom equipped with a detector made of 6 scintillating-fiber ribbons placed at 1 m from the source. A radiochromic film was used to acquire a reference measurement of a first dose distribution in the slab phantom at the same source-to-detector distance and the treatment planning system (TPS) provided the reference for another dose distribution. In addition, simulated errors introduced on the delivered dose, field location and field shape were used to evaluate the ability of the proposed method to efficiently identify a deviation between the planned and delivered treatments. Main results. For a first small IMRT segment, 3%/3 mm, 2%/2 mm and 2%/1 mm gamma analysis conducted between the reconstructed dose distribution and the dose measured with radiochromic film exhibited pass rates of 100%, 99.9% and 95.7%, respectively. For a second and smaller IMRT segment, the same gamma analysis performed between the reconstructed dose distribution and the reference provided by the TPS showed pass rates of 100%, 99.4% and 92.6% for the 3%/3 mm, 2%/2 mm and 2%/1 mm gamma criteria, respectively. Gamma analysis of the simulated treatment delivery errors showed the ability of the reconstruction algorithm to detect a 3% deviation between the planned and delivered doses, as well as shifts lower than 7 mm and 3 mm when considering an individual leaf and a whole field shift, respectively. Significance. The proposed method allows accurate tomographic reconstruction of IMRT segments by processing projections measured with six scintillating-fiber ribbons and is suitable for water-equivalent real-time small IMRT segments QA.
Fusion reactivities with drift bi-Maxwellian ion velocity distributions
Authors: Xie Huasheng , Tan Muzhi , Luo Di , Li Zhi , Liu Bing
Published: March 2023

The calculation of fusion reactivity involves a complex six-dimensional integral that takes into account the fusion cross section and velocity distributions of two reactants. However, a more simplified one-dimensional integral form can be useful in certain cases, such as for studying fusion yield or diagnosing ion energy spectra. This simpler form has been derived in a few special cases, such as for a combination of two Maxwellian distributions, a beam-Maxwellian combination, and a beam-target combination, and can greatly reduce computational costs. In this study, it is shown that the reactivity for two drift bi-Maxwellian reactants with different drift velocities, temperatures, and anisotropies can also be reduced to a one-dimensional form, unifying existing derivations into a single expression. This result is used to investigate the potential enhancement of fusion reactivity due to the combination of beam and temperature anisotropies. For relevant parameters in fusion energy, the enhancement factor can be larger than 20%, which is particularly significant for proton-boron (p–B11) fusion, as this factor can have a significant impact on the Lawson fusion gain criteria.
SOLPS-ITER simulations of a vapour box design for the linear device Magnum-PSI
Authors: Gonzalez J , Westerhof E , Morgan T W
Published: March 2023

A vapour box (VB) is a physical device currently being considered to reduce the high heat and particle fluxes typically impacting the divertor in tokamaks. This system usually consists of a series of boxes that retains neutral particles to increase the amount of collision events with the impacting plasma. The neutral particles come from recycling and recombination of the plasma, gas puffing inside the box and by the evaporation of a liquid metal, typically Li or Sn. Currently, an VB is being constructed for testing in the linear plasma generator Magnum-PSI, operated at DIFFER. Its modular design will allow for open (not enclosing the target) and closed (enclosing the target) configurations, as well as evaporating a liquid metal to create a vapour cloud inside the box. The experiments carried out with this device will investigate its capabilities to reduce the plasma flux towards the target. This work presents a numerical study performed with SOLPS-ITER about the effectiveness of the current VB design in its open configuration to retain neutrals and its effect on the plasma beam properties. This is a first step before validation against experiments and studying closed configurations to ensure that the VB can successfully operate in a wide range of plasma parameters. Simulations show that the VB is capable of retaining neutrals and reducing fluxes to the target without requiring additional gas puffing in High and Low plasma flux scenarios. When lithium is evaporated from inside the box, the hydrogen plasma is completely extinguished and replaced by a low temperature Li plasma with lower flux. The fraction of Li and Li+ transported upstream the VB is three orders of magnitude below the amount evaporated form the central box, as most of the lithium is condensed in the side boxes and another small portion (two orders of magnitude below the amount evaporated) is deposited on the target. The VB design in its open configuration can mitigate incoming plasma peak heat flux by

0.6
 

M
W

m

−
2

, which represents a fraction of

75
%

and

81
%

for the High and Low flux scenarios. This effect is expected to be higher when a closed configuration is employed, which could result in a significant reduction of heat fluxes on the divertor of tokamaks once that this design is extrapolated to the toroidal geometry, with just a minimal amount of Li and Li+ reaching the core.
Multiple-image encryption algorithm based on Sarrus rule and 3D Fibonacci matrix
Authors: Zhang Xiaoqiang , Liu Mi , Tian Jingxi
Published: March 2023

Using images to transmit information becomes more common in the new era, but the image information can easily be stolen and tampered with the malicious damage during transmission. In this paper, firstly, inspired by the famous Sarrus rule the theory of linear algebra theory, the Sarrus model is established to scramble images; secondly, the pixel positions of plain images are scrambled with the established Sarrus model to obtain the stereo scrambled matrix; thirdly, two-dimensional Fibonacci matrix is extended to three-dimensional (3D) space; finally, the image matrix is divided into cubes which are diffused by the 3D Fibonacci matrix. Experimental analyses indicate that the new algorithm has the characteristics of large key space, high key sensitivity, high efficiency and can resist to the plaintext attacks, statistical attacks, etc.
MHD effects of liquid metal flows through multiple electrically coupling ducts with U-turn bends in fusion blankets
Authors: Lv Xinting , Zhang Xiujie , Wang Lei
Published: March 2023

The investigation of liquid metal (LM) magnetohydrodynamic (MHD) flows through multiple electrically coupling ducts with U-turn bends is of crucial importance for accurately predicting the thermal-hydraulic performance of LM blankets in fusion reactors. Moreover, this duct configuration is often adopted in liquid blanket designs. Here, the combination effects of the MHD coupling, 3D MHD and inclined external magnetic fields on LM MHD flows through the multiple coupling ducts with different aspect ratios and wall conductance ratios are systematically investigated by numerical simulations. The results indicate that the MHD pressure gradient caused by MHD coupling effect decreases but the 3D MHD pressure gradient increases firstly and then decreases as the inclined angles of external magnetic fields increase. In addition, the results also indicate that the normalized pressure gradient can be reduced by increasing the wall conductance ratio (

C

w

) through the increase of the wall thickness. Furthermore, an important finding is that the pressure gradients caused by the MHD coupling decrease with the increases of aspect ratios (b/a) of ducts, while the 3D MHD pressure gradient when b/a = 16 increases to an excessive large degree about 40 times of the pressure gradient in a single conductive duct. The related investigation results will provide a theoretical support for the liquid blanket designs in fusion reactors and deepen our understanding on the LM MHD effects.
Ultra wideband bandstop plasmonic filter in the NIR region based on stub resonators
Authors: Zegaar Imane , Hocini Abdesselam , Bensalah Hocine , Harhouz Ahlam , Khedrouche Djamel , Lahoubi Mahieddine
Published: March 2023

In this study, we propose an ultra-wideband bandstop filter (UWB-BSF) using a plasmonic MIM waveguide coupled with a stub cavity that is investigated using finite-difference time-domain (FDTD). Air and silver are used as insulators and metals, respectively; silver is characterized by the Drude model. The structure can filter the optical telecommunication wavelengths of 1550 nm and 1310 nm. The transmission peak and the resonance wavelength of the basic structure can be tuned by varying the stub resonator’s length and width. In order to improve the filtering function of the bandstop filter at broad bandwidth in the NIR region with maximum transmission peak, the number of stub resonators is increased to two, three, and four stubs with properly studied lengths and a proper horizontal distance between each two stubs. The bandwidth is enhanced from 350 nm, with two stubs, to 620 nm, with three stubs, and 770 nm, with four stubs, respectively. The corresponding filtered wavelength ranges are [1600 nm–1950 nm], [1330 nm–1950 nm] and [1180 nm–1950 nm] respectively. Moreover, with the increase in the number of stubs, the center wavelength achieves a blue shift to lower wavelengths. Further, the paper provides significant applications for plasmonic bandstop filters in highly integrated optical circuits.
Multidirectional galloping-based wind energy harvester based on a cylindrical cantilever beam and multi-tooth blunt body
Authors: Lu Caijiang , Wu Gang , Xu Changbao , Jiang Xueling , Tian Fei , Liu Jie , Wang Tao , Wang Xi , Fu Guoqiang
Published: March 2023

To improve the response-ability of the energy harvester to multi-directional wind, this paper proposes a galloping-based wind energy harvester by fixing a multi-tooth blunt body at the free end of a cylindrical cantilever beam, which consists of a long-straight FeGa thin cylinder and a piezoelectric tube. Combining the structural symmetry advantages of the multi-tooth blunt body and piezoelectric cylinder cantilever, the harvester can respond well to the wind from all directions of the two-dimensional plane. In the simulation and experiment, detailed comparative studies are carried out on the harvesters with square (four-tooth), six-tooth, eight-tooth, ten-tooth, and twelve-tooth blunt bodies. Within the wind speed range of 1.5 ∼ 8 m s−1, the results show that the harvester with a six-tooth blunt body has the best multidirectional wind response performance. When the wind speed is 8 m s−1, the output power of the harvester with a six-tooth blunt body improves by ∼43% more than that of the harvester with a traditional square blunt body. The design idea of the proposed harvester provides a direction for the future in-depth study of multidirectional piezoelectric wind energy harvesting.
Analytical workload dependence of self-heating effect for SOI MOSFETs considering two-stage heating process
Authors: Li 李 Yi-Fan 逸帆 , Ni 倪 Tao 涛 , Li 李 Xiao-Jing 晓静 , Wang 王 Juan-Juan 娟娟 , Gao 高 Lin-Chun 林春 , Bu 卜 Jian-Hui 建辉 , Li 李 Duo-Li 多力 , Cai 蔡 Xiao-Wu 小五 , Xu 许 Li-Da 立达 , Li 李 Xue-Qin 雪勤 , Wang 王 Run-Jian 润坚 , Zeng 曾 Chuan-Bin 传滨 , Li 李 Bo 博 , Zhao 赵 Fa-Zhan 发展 , Luo 罗 Jia-Jun 家俊 , Han 韩 Zheng-Sheng 郑生
Published: March 2023

Dynamic self-heating effect (SHE) of silicon-on-insulator (SOI) MOSFET is comprehensively evaluated by ultrafast pulsed I–V measurement in this work. It is found for the first time that the SHE complete heating response and cooling response of SOI MOSFETs are conjugated, with two-stage curves shown. We establish the effective thermal transient response model with stage superposition corresponding to the heating process. The systematic study of SHE dependence on workload shows that frequency and duty cycle have more significant effect on SHE in first-stage heating process than in the second stage. In the first-stage heating process, the peak lattice temperature and current oscillation amplitude decrease by more than 25 K and 4% with frequency increasing to 10 MHz, and when duty cycle is reduced to 25%, the peak lattice temperature drops to 306 K and current oscillation amplitude decreases to 0.77%. Finally, the investigation of two-stage (heating and cooling) process provides a guideline for the unified optimization of dynamic SHE in terms of workload. As the operating frequency is raised to GHz, the peak temperature depends on duty cycle, and self-heating oscillation is completely suppressed.
Nonlinearity Correction of Fourier Transform Spectrometer in Solar Observation Using Simulated Annealing
Authors: Dong Ze-Yin , Bai Xian-Yong , Feng Song , Deng Yuan-Yong , Yu Zi-Hang , Ao Wen-Tong , Yang Xiao , Zhang Zhi-Yong , Feng Zhi-Wei
Published: March 2023

A Fourier transform spectrometer (FTS) has been used to observe solar activities due to its ultra-high spectral resolution. However, the FTS in-band spectra are usually distorted and some artifacts appear in out-of-band regions due to nonlinear effects. Therefore, the FTS nonlinear problem must be corrected. In this study, we proposed a novel method to correct the nonlinear effects using simulated annealing. We simulated several nonlinear spectra to evaluate the performance of our method. The calculated quadratic coefficients are extremely close to the given values, demonstrating that the method is effective and accurate. The proposed method is further used to correct the blackbody and solar spectra with nonlinearity obtained by Bruker IFS-125HR installed at the Huairou Solar Observing Station, which is a pathfinder for the accurate infrared magnetic field measurements of the Sun project. To the blackbody spectra, the nonlinearity in low- and high-frequency regions are corrected by 89.09% and 60.84%. The nonlinear correction of the solar spectra in the low- and high-frequency regions have reached 65.34% and 81.04%, respectively. These results prove that our method can correct the nonlinear problem to improve the data accuracy.
Detection of ADHD from EEG signals using new hybrid decomposition and deep learning techniques
Authors: Esas Mustafa Yasin , Latifoğlu Fatma
Published: March 2023

Objective. Attention deficit hyperactivity disorder (ADHD) is considered one of the most common psychiatric disorders in childhood. The incidence of this disease in the community draws an increasing graph from the past to the present. While the ADHD diagnosis is basically made with the psychiatric tests, there is no active clinically used objective diagnostic tool. However, some studies in the literature has reported development of an objective diagnostic tool that facilitates the diagnosis of ADHD. Approach. In this study, it was aimed to develop an objective diagnostic tool for ADHD using electroencephalography (EEG) signals. In the proposed method, EEG signals were decomposed into subbands by robust local mode decomposition and variational mode decomposition techniques. These subbands and the EEG signals were fed as input data to the deep learning algorithm designed in the study. Main results. As a result, an algorithm has been put forward that distinguishes over 95% of ADHD and healthy individuals through using a 19-channel EEG signal. In addition, a classification accuracy of over 87% was obtained by the proposed approach of EEG signal decomposition followed by data processing in the designed deep learning algorithm. Significance. The findings of the current research enrich the literature based on originality and proposed method can be used as a clinical diagnostic tool in the near future.
Review of Human-exoskeleton Control Strategy for Lower Limb Rehabilitation Exoskeleton
Authors: Long Yi , Guo Hexiao , Chi Yutian , Mo Duncheng
Published: March 2023

The research on exoskeleton robots has been widely carried out for many years around the world, especially the development of new-style lower limb exoskeletons for rehabilitation and assistance is one of the key research directions. The focus on the control system of lower limb exoskeletons for rehabilitation is discussed. Based on the public literature in recent years, it is summarized from three aspects, i.e., movement mode switching, human gait recognition and human-exoskeleton interaction control. Finally, the technical issues of the current lower limb rehabilitation exoskeleton control strategy are discussed. The future development prospects and research directions of the lower limb rehabilitation exoskeleton are prospected, and some suggestions on how to achieve a more efficient and accurate control are given.
A Task Allocation Strategy based on Hungarian Algorithm in RoboCup Rescue Simulation
Authors: Wang Zijin , Wang Yibin , Chen Ming , Yuan Tingyu , Chen Haibo , Yang Yingze
Published: March 2023

In the multi-agent cooperation of RoboCup Rescue Agent Simulation, as one of the three agents, the agent with the task of clearing roadblocks plays a significant role. The clearing behavior help other agents to work promptly and provide a highly efficient operation to the entire simulation system. However, considering the cost of all agents in a limited time, it is not easy to carry out flexible task allocation, which leads to the current strategy is not perfect, and finally leads to the low efficiency of rescue operations. Therefore, it is necessary to make sure the high efficiency of clearing behavior. In order to maximize the resources of agents, this article puts forward a task allocation strategy based on Hungarian algorithm, which has substantially enhanced the agents’ efficiency through experimental verification at last.
Classification of CMT Additive Manufacturing Defects based on Statistical Features
Authors: Wang Hongmin , Wu Longhua , Jiang Meng , Liang Yanyang , Wang Tianlei , Pan Zengxi , Ye Haohuai , Song Yingying
Published: March 2023

Aiming at the problem of the CMT(cold metal transfer) additive manufacturing process defect monitoring method being susceptible to environmental influence, this paper proposes a classification method for additive manufacturing process defects with current as the research object. By setting up three sets of experiments, experimenting and collecting the current parameters of each group, using the statistical feature method to pretreat the current, and then classifying the pretreated data into random forests, to highlight the superiority of statistical characteristics plus random forests, two sets of control groups are also set up for comparison. It was concluded that the principal component analysis method could not classify the non-defective group and the non-protective gas group, while the use of random forest could achieve two by two classifications of the three working conditions; After the statistical feature method treatment, the random forest classification is compared with the original current direct random forest classification, and the accuracy of the training set, verification set, and test set has been improved.