bluuebunny/crossref_metadata_2025 huggingface dataset:
Direct comparison of molecular-beam vs liquid-phase pump–probe and two-dimensional spectroscopy on the example of azulene
Authors: Solowan Hans-Peter , Malý Pavel , Brixner Tobias
Published: June 2022

Although azulene’s anomalous fluorescence originating from S2 rather than from S1 is a textbook example for the violation of Kasha’s rule, an understanding of the underlying processes is still a subject of investigation. Here, we use action-based coherent two-dimensional electronic spectroscopy (2DES) to measure a single Liouville-space response pathway from S0 via S1 to the S2 state of azulene. We directly compare this sequential excitation in the liquid phase detecting S2 fluorescence and in a molecular beam detecting photoionized cations, using the S2 anomalous emission to our advantage. We complement the 2DES study with pump–probe measurements of S1 excitation dynamics, including vibrational relaxation and passage through a conical intersection. A direct comparison of the liquid and gas phase allows us to assess the effect of the solvent and the interplay of intra- and intermolecular energy relaxation.
Simultaneous improvement of magnetic-field-induced working temperature and mechanical properties in Ni–Mn–In shape memory alloy
Authors: Ma Tianyou , Zhang Kun , Han Binglun , Zhao Lei , Zhao Wenbin , Wang Cheng , Liu Rui , Tian Xiaohua , Tan Changlong
Published: June 2022

Ni–Mn–In magnetic shape memory alloys, which can be stimulated by an external magnetic field, exhibit a fast response and have aroused wide attention in the field of electro-mechanical actuators. However, the low working temperature and the inherent brittleness severely limit their application scenarios. Here, an effective strategy is proposed to improve the magnetic-field-induced working temperature and mechanical properties in Ni–Mn–In shape memory alloys. We predict that the Ni16Mn12In4 alloy with Pt doping can solve the problems simultaneously through a comprehensive first-principles study. The calculations show that Pt occupying Ni sites can increase the martensitic temperature (TM) and Curie temperature (TC) simultaneously. TM and TC of Ni14Mn12In4Pt2 are predicted to be as high as 440 and 476 K, respectively. This is mainly due to the increased phase stability of the martensite and Pt–Mn bonds having stronger ferromagnetic exchange effects than Ni–Mn bonds after Pt doping. Moreover, according to the increase of B/G and v after Pt doping, it can be concluded that the mechanical properties of the alloy have been improved.
Melting points of water models: Current situation
Authors: Blazquez S. , Vega C.
Published: June 2022

By using the direct coexistence method, we have calculated the melting points of ice Ih at normal pressure for three recently proposed water models, namely, TIP3P-FB, TIP4P-FB, and TIP4P-D. We obtained Tm = 216 K for TIP3P-FB, Tm = 242 K for TIP4P-FB, and Tm = 247 K for TIP4P-D. We revisited the melting point of TIP4P/2005 and TIP5P obtaining Tm = 250 and 274 K, respectively. We summarize the current situation of the melting point of ice Ih for a number of water models and conclude that no model is yet able to simultaneously reproduce the melting temperature of ice Ih and the temperature of the maximum in density at room pressure. This probably points toward our both still incomplete knowledge of the potential energy surface of water and the necessity of incorporating nuclear quantum effects to describe both properties simultaneously.
Multiple AUUV cooperative area target searching method based on distributed model
Authors: Zhang Honggang , Sun Yuchen , Wang Peng , Zhang Hu
Published: June 2022

Underwater unmanned vehicle cluster cooperative area target searching is an inexpensive and efficient effort for salvaging and vigilance at sea. In order to realize the autonomous area searching of the attacking underwater unmanned vehicle (AUUV) cluster, a multiple AUUV cooperative area target searching method is put forward and simulated in this paper. The proposed method combines the AUUV with an underwater environment to create an environmental model, an AUUV motion model, a target probability and update model, and an object optimization function. Moreover, the global-best difference-mutation brain storm optimization algorithm is adopted to test the multiple AUUV cooperative area target searching path planning. The results of the simulation experiment verify the effectiveness of the proposed method and models. Hence, a new scheme is advanced to realize multiple AUUV cooperative area target searching and expand multiple AUUV applications.
Insect detection from imagery using YOLOv3-based adaptive feature fusion convolution network
Authors: Amrani Abderraouf , Sohel Ferdous , Diepeveen Dean , Murray David , Jones Michael G. K.
Published: June 2022

Context Insects are a major threat to crop production. They can infect, damage, and reduce agricultural yields. Accurate and fast detection of insects will help insect control. From a computer algorithm point of view, insect detection from imagery is a tiny object detection problem. Handling detection of tiny objects in large datasets is challenging due to small resolution of the insects in an image, and other nuisances such as occlusion, noise, and lack of features. Aims Our aim was to achieve a high-performance agricultural insect detector using an enhanced artificial intelligence machine learning technique. Methods We used a YOLOv3 network-based framework, which is a high performing and computationally fast object detector. We further improved the original feature pyramidal network of YOLOv3 by integrating an adaptive feature fusion module. For training the network, we first applied data augmentation techniques to regularise the dataset. Then, we trained the network using the adaptive features and optimised the hyper-parameters. Finally, we tested the proposed network on a subset dataset of the multi-class insect pest dataset Pest24, which contains 25 878 images. Key results We achieved an accuracy of 72.10%, which is superior to existing techniques, while achieving a fast detection rate of 63.8 images per second. Conclusions We compared the results with several object detection models regarding detection accuracy and processing speed. The proposed method achieved superior performance both in terms of accuracy and computational speed. Implications The proposed method demonstrates that machine learning networks can provide a foundation for developing real-time systems that can help better pest control to reduce crop damage.
Hans Charles Freeman 1929–2008
Authors: Hambley Trevor W. , Rae Ian D.
Published: June 2022

Hans Freeman was born in Germany and arrived in Australia with his parents in 1938. A brilliant student at the University of Sydney, he spent a seminal year at the California Institute of Technology before joining the staff at Sydney and initiating research on bioinorganic chemistry, studying metal ion complexes of compounds of biological significance such as amino acids, peptides and proteins. In his use of X-ray crystallography he was a pioneer in Australia, constructing his first crystallographic apparatus and mastering the necessary computing, at first by hand but soon with electronic computers. The culmination of his work with a series of collaborators was the structure of the blue, copper-containing metalloprotein, plastocyanin. Freeman also employed another advanced technique—X-ray spectroscopy and the study of X-ray absorption fine structure. He was a leading figure in Australia and internationally, and played an important role in gaining access for Australian scientists to international facilities such as synchrotron radiation sources at the dawning of the era of ‘Big Science’.
Opportunistic datasets perform poorly in Ecological Niche Modelling: a case study from a polymorphic lizard
Authors: Sacchi Roberto , Mangiacotti Marco , Scali Stefano , Donati Elisa , Coladonato Alan J. , Zuffi Marco A. L.
Published: June 2022

Context Among processes involved in colour polymorphism, geographic variation in morph composition and frequency has been attracting interest since it reflects morph local adaptation. A recent study in the Pyrenees associated the pattern of geographic variation in morph frequency of the common wall lizard with the divergence in climatic niches, supporting the hypothesis that morphs represent alternative local climatic adaptations. However, the Pyrenees represent only a small portion of the species range. Aims We modelled the ecological niches of Italian morphs using the same procedure adopted for the Pyrenees to check whether the effects detected at local scales (i.e. the Pyrenees) were repeatable at regional scales (i.e. Italy). This generalisation is needed to investigate how natural selection maintains locally adapted polymorphisms. Methods We classified each locality (120 populations) according to the presence/absence of morphs, and independent Ecological Niche Models (ENMs) against the same background were fitted. Receiver Operating Curves accounting for sampling biases, equivalency and similarity tests were used to check and compare models accounting for spatial distribution of data. Key results Morph-specific ENMs did not reproduce any of the patterns detected in the Pyrenees. Any difference among morphs disappeared after controlling for morph spatial distribution. Since occurrence points of the rarest morphs were a subsample of the occurrence points of the most common morph, it is not possible to separate the effects of true ecological differences among morphs from the effects of the spatial distribution patterns of morph occurrence. Conclusions Using presence data not specifically collected for ENM comparisons does not allow reliable assessments of morph niche segregation. Our analysis points out the need to be very cautious in ecological interpretations of ENMs built on presence/background or presence-only data when occurrences are spatially nested. Implications When dealing with data not specifically collected according to a targeted design, it is not legitimate to compare ENMs with completely nested occurrence points, because this approach can not exclude the possibility that ENM differences were the result of a spatial subsampling. This type of bias is probably largely underestimated, and it may lead to serious misinterpretations as shown in this study.
Power of faecal pellet count and camera trapping indices to monitor mammalian herbivore activity
Authors: Davis Naomi E. , Di Stefano Julian , Whelan Jim , Wright John , Taylor Lorraine , Coulson Graeme , Sitters Holly
Published: June 2022

Context Monitoring spatial and temporal change in relative abundance using statistically powerful designs is a critical aspect of wildlife management. Many indices of relative abundance are available, but information regarding their influence on statistical power is limited. Aims We compared the statistical power associated with occurrence-based and frequency-based indices derived from faecal pellet counts and camera trapping to detect changes in the activity of five mammalian herbivores. Methods We deployed camera traps and counted faecal pellets in native vegetation subjected to four management treatments in south-eastern Australia. We used simulation coupled with generalised linear mixed models to investigate the statistical power associated with a range of effect sizes for each combination of species, survey method and data type. Key results The index derived from camera frequency data provided the greatest statistical power to detect species’ responses and was the only index capable of detecting small effect sizes with high power. The occurrence index from camera trapping did not provide the same level of statistical power. Indices derived from faecal pellet frequency data also detected spatial and temporal changes in activity levels for some species, but large numbers of plots were required to detect medium to large effect sizes. High power to detect medium to large effects could be achieved using occurrence indices derived from pellet presence–absence data, but required larger sample sizes compared to the camera frequency index. Conclusions Both camera trapping and pellet counts can be applied to simultaneously monitor the activity of multiple mammalian herbivore species with differing activity patterns, behaviour, body size and densities, in open and closed habitat. However, using frequency indices derived from camera trapping may improve management outcomes by maximising the statistical power of monitoring programs to detect changes in abundance and habitat use. Implications Frequency indices derived from camera trapping are expected to provide the most efficient method to detect changes in abundance. Where the use of cameras is cost prohibitive, occurrence indices derived from pellet presence–absence data can be used to detect medium to large effect sizes with high power. Nonetheless, the cost-effectiveness of camera trapping will improve as equipment costs are reduced and advances in automated image recognition and processing software are made.
Myeloid caspase-8 restricts RIPK3-dependent proinflammatory IL-1β production and CD4 T cell activation in autoimmune demyelination
Authors: Kim Sunja , Lu Hsueh Chung , Steelman Andrew J. , Li Jianrong
Published: June 2022

Caspase-8 functions at the crossroad of programmed cell death and inflammation. Here, using genetic approaches and the experimental autoimmune encephalomyelitis model of inflammatory demyelination, we identified a negative regulatory pathway for caspase-8 in infiltrated macrophages whereby it functions to restrain interleukin (IL)-1β–driven autoimmune inflammation. Caspase-8 is partially activated in macrophages/microglia in active lesions of multiple sclerosis. Selective ablation of
Casp8
in myeloid cells, but not microglia, exacerbated autoimmune demyelination. Heightened IL-1β production by caspase-8–deficient macrophages underlies exacerbated activation of encephalitogenic T cells and production of GM-CSF and interferon-γ. Mechanistically, IL-1β overproduction by primed caspase-8–deficient macrophages was mediated by RIPK1/RIPK3 through the engagement of NLRP3 inflammasome and was independent of cell death. When instructed by autoreactive CD4 T cells in the presence of antigen, caspase-8–deficient macrophages, but not their wild-type counterparts, released significant amount of IL-1β that in turn acted through IL-1R to amplify T cell activation. Moreover, the worsened experimental autoimmune encephalomyelitis progression in myeloid
Casp8
mutant mice was completely reversed when
Ripk3
was simultaneously deleted. Together, these data reveal a functional link between T cell-driven autoimmunity and inflammatory IL-1β that is negatively regulated by caspase-8, and suggest that dysregulation of the pathway may contribute to inflammatory autoimmune diseases, such as multiple sclerosis.
陈述句的语篇角色
Authors: Zhenhua Wang , Chunhui Zhang
Published: June 2022

提要

在社会互动中，不管是口语还是书面语，语篇总是有起始、发展和终结。语篇分析或语类研究对语篇的起始、发展与终结的研究成果丰硕。语法学研究陈述句时主要关注语法结构及其意义，很少将陈述句置于语篇中讨论它们扮演的起始、发展和终结的语篇角色。本文在陈述句语法功能的基础上，在系统功能语言学框架下，将陈述句置于大语篇中进行研究，从语篇语义视角讨论陈述句的语篇角色，探索它们的生成机制以及对语篇组织策略的贡献，以此为不同句类的语篇角色研究带来启示。
Similitudes y diferencias en la expresión del sujeto pronominal en una misma comunidad de habla
Authors: Manjón-Cabeza Cruz Antonio , Granados Romero Isabel
Published: June 2022

Abstracto

Granada y Málaga pertenecen a la misma comunidad: Andalucía. Basándonos en PRESEEA, analizamos la expresión variable de los sujetos pronominales en ambas ciudades. Observamos que hay similitudes en la expresión de los factores lingüísticos, aunque la tasa pronominal es diferente: 17,7% para Granada y 27,4% para Málaga. Estas diferencias porcentuales no se explican por la ambigüedad fonética que se deriva de la pérdida de /-s/. La expresión deltúinespecífico proporciona solo una explicación parcial, que ha de completarse con la existencia de diferentes estilos comunicativos en la expresión de los pronombres sujetos que representan a los participantes en la entrevista (tú, yo, nosotros). A ello se suma la situación de cambio lingüístico por convergencia con la variedad centro-norte de la variedad peninsular, aún en proceso en Málaga.
Spatial prepositions min and ʕan in Traditional Negev Arabic
Authors: Henkin Roni , Cerqueglini Letizia
Published: June 2022

The Arabic prepositions min and ʕan in their prototypical spatial use relate to
the Source domain, translating as ‘(away) from’. In many contemporary dialects ʕan is absent or limited to
secondary, non-spatial meanings. In Traditional Negev Arabic, however, both prepositions are used complementarily. The proto-scene
of ablative min is a Figure (F) exiting from a 3-dimensional Ground (G)-source, with ‘containment’ and
‘boundary-crossing’ typical components of the scene. The preposition ʕan prototypically fulfils a separative
function, denoting separation from a Source with no relevance to dimensions, and has developed secondary modal functions. Both
also have perlative functions and may appear in static scenes. Only min heads prepositional complexes, where it
typically restores the nominal origin of the following element as a bounded region. So ‘min behind the house’ may
denote ‘in the back zone of the house’; these complexes characterize multiple axes, when F crosses G’s path.
Representation of sublexical structure of the word among bilingual and monolingual kindergartners
Authors: Zaretsky Elena
Published: June 2022

Early spelling development is an important area of research as it presents an opportunity for our understanding of how children begin to represent sounds within words through application of letter-sound mapping. The development of spelling is often characterized by stage-like theories, although it has been suggested that children may draw on different patterns of representations (Integration of Multiple Patterns). This study examined early spelling acquisition among monolingual English-speaking and ELL kindergartners with Spanish as L1. ELLs receive all academic instruction, including written language, in English (L2) while continuously using oral L1 for all other communications. As languages differ in their linguistic and structural composition, our aim was to identify possible influences of oral L1 on spelling abilities in L2. We were particularly interested in representation of sublexical units within the words, as English and Spanish differ in their intrasyllabic awareness. Our results showed expected differences in psycholinguistic profiles of language groups as well as differences in allocation of resources in spelling attempts. While there were no statistically significant differences in representation of sublexical units between language groups, there were notable differences in percentage of correct responses pointing to language specific influences. These findings support theDual System Modelof phonological representations development among bilingual individual and suggests that in the early stages of spelling acquisition in L2, L1 Spanish kindergartners are still influenced by their native language although they use it in their oral modality only.
Predictors of adult spelling in an orthography of intermediate depth
Authors: Mesquita Ana B. , Morais Inês Salomé , Faísca Luís , Reis Alexandra , Castro São Luís
Published: June 2022

What is the hallmark of a good speller? Spelling is a critical component in learning to become literate, but how
it works in literate adults remains poorly explored. We examined word and pseudoword spelling in 214 adults in relation to general
cognitive abilities, vocabulary, reading history, reading performance, phonological processing and rapid automatized naming. We
conducted hierarchical multiple regression analyses to uncover predictors of spelling performance and compared a subsample of good
and poor spellers to identify patterns of cognitive and language abilities associated with high vs. low spelling ability. In the
regression model under test, which progressed from general cognitive and language abilities to specific reading-related skills,
the most important predictor for word spelling was vocabulary, and for pseudoword spelling phonological processing (phoneme
deletion). The model explained 20% of word spelling, and 8% of pseudoword spelling, variance. Good spellers outperformed poor
spellers in reading connected text and pseudowords, and in phonological processing; poor spellers typically had a history of
reading difficulties but similar levels of cognitive ability, word reading and RAN performance. Overall, our findings indicate
that adult spelling relies more strongly on word knowledge than on reading proficiency and that, as in literacy acquisition, good
phonology-related abilities are a hallmark of proficient adult spellers.
Cannabis and Cocaine Use, Drinking Outcomes, and Quality of Life in General Hospital Inpatients with Alcohol use Disorder
Authors: Romero-Rodríguez Esperanza , Chen Clara A. , Dukes Kimberly A. , Hartlage Kaitlin , Palfai Tibor P. , Magane Kara M. , Samet Jeffrey H. , Saitz Richard
Published: June 2022

Background: While associations between cannabis and cocaine use, and heavy drinking and quality of life (QOL), are well-established in the general population, it is unclear whether they are present in hospital inpatients with alcohol use disorder (AUD). The aim of the study was to assess associations between cannabis and cocaine use and two outcomes [heavy drinking days (HDDs) and QOL] among hospital inpatients with AUD. Methods: Hospitalized patients with AUD and at least one past-month HDD participated in this cross-sectional study. Cannabis and cocaine use were assessed using the Alcohol, Smoking, and Substance Involvement Screening Test. HDDs were assessed using the Timeline Followback. QOL was assessed by the WHOQOL–BREF instrument. Multivariable regression models assessed associations. Results: Of 248 participants, 225 (91%) had severe AUD. There were no statistically significant associations between: recent cannabis use and HDDs [Incidence Rate Ratio (IRR) = 0.95; 95% Confidence Interval (95% CI): 0.80, 1.14], cocaine use and HDDs [IRR = 0.88; 95% CI: 0.66, 1.18], or both cannabis and cocaine use and HDDs [IRR = 0.87; 95%CI: 0.70, 1.09], as compared to use of neither cannabis nor cocaine. Use of cannabis, cocaine, and both, were not associated with QOL [(odds ratio (OR) = 0.98; 95% CI:0.55, 1.74), (OR = 0.76; 95% CI:0.30, 1.93), (OR = 1.00; 95%CI: 0.49, 2.03), respectively]. Conclusions: Among hospital inpatients with AUD, there were no significant associations between cannabis and cocaine use, heavy drinking, or QOL. Our findings raise questions regarding how drug use affects AUD and whether similar results would be found among those with milder AUD and in prospective studies.
Quantum Spin Liquid Phase in the Shastry-Sutherland Model Detected by an Improved Level Spectroscopic Method
Authors: Wang Ling , Zhang Yalei , Sandvik Anders W.
Published: June 2022

We study the spin-1/2 two-dimensional Shastry–Sutherland spin model by exact diagonalization of clusters with periodic boundary conditions, developing an improved level spectroscopic technique using energy gaps between states with different quantum numbers. The crossing points of some of the relative (composite) gaps have much weaker finite-size drifts than the normally used gaps defined only with respect to the ground state, thus allowing precise determination of quantum critical points even with small clusters. Our results support the picture of a spin liquid phase intervening between the well-known plaquette-singlet and antiferromagnetic ground states, with phase boundaries in almost perfect agreement with a recent density matrix renormalization group study, where much larger cylindrical lattices were used [J. Yang et al., Phys. Rev. B 105, L060409 (2022)]. The method of using composite low-energy gaps to reduce scaling corrections has potentially broad applications in numerical studies of quantum critical phenomena.
Analysis of notch-δ-doped GaAs-based Gunn diodes
Authors: Mohd Akhbar Siti Amiera , Ong Duu Sheng
Published: June 2022

The performances of GaAs-based Gunn diodes with notch-δ-doped structures are studied in this work. The δ-doped effect is analysed using Monte Carlo modelling in terms of temporal evolution of current density, electric field profile, electron energy, mean velocity and occupancy in the Γ and higher valleys. The presence of a δ-doped layer after the notch causes a significant increase in the harmonic current amplitude of the device, where the growth of the high field domain can be attributed to a slow electron track due to the well-known Gunn effect and an additional fast electron track which appears over a short time window when the domain is reaching the anode. An optimised GaAs notch-δ-doped structure with a 700 nm device length including a 100 nm notch and a 5 nm δ-doped layer can generate signals at a fundamental frequency of 262 GHz with a current harmonic amplitude of 29.4 × 107 A m−2, which is almost twice of that without a δ-doped layer. Its second and third harmonic signals are found to be substantial, reaching into the terahertz range of 512 GHz and 769 GHz.
Plasmon-enhanced Raman spectroscopy of two-dimensional semiconductors
Authors: Rahaman Mahfujur , Zahn Dietrich R T
Published: June 2022

Two-dimensional (2D) semiconductors have grown fast into an extraordinary research field due to their unique physical properties compared to other semiconducting materials. The class of materials proved extremely fertile for both fundamental studies and a wide range of applications from electronics/spintronics/optoelectronics to photocatalysis and CO2 reduction. 2D materials are highly confined in the out-of-plane direction and often possess very good environmental stability. Therefore, they have also become a popular material system for the manipulation of optoelectronic properties via numerous external parameters. Being a versatile characterization technique, Raman spectroscopy is used extensively to study and characterize various physical properties of 2D materials. However, weak signals and low spatial resolution hinder its application in more advanced systems where decoding local information plays an important role in advancing our understanding of these materials for nanotechnology applications. In this regard, plasmon-enhanced Raman spectroscopy has been introduced in recent time to investigate local heterogeneous information of 2D semiconductors. In this review, we summarize the recent progress of plasmon-enhanced Raman spectroscopy of 2D semiconductors. We discuss the current state-of-art and provide future perspectives on this specific branch of Raman spectroscopy applied to 2D semiconductors.
Thermoelectric transport in two-terminal topological nodal-line semimetals nanowires
Authors: Yang Ning-Xuan , Liao Hui , Song Chun-Yan , Wang Rui , Tang Guang-Hui
Published: June 2022

Recently discovered topological nodal-line semimetals (TNLSMs) have received considerable research interest due to their rich physical properties and potential applications. TNLSMs have the particular band structure to lead to many novel properties. Here we theoretically study the thermoelectric transport of a two-terminal pristine TNLSM nanowires and TNLSMs p–n–p junctions. The Seebeck coefficients S

c
and the thermoelectrical figure of merit ZT are calculated based on the Landauer-Büttiker formula combined with the nonequilibrium Green’s function method. In pristine TNLSM nanowires, we discuss the effect of the magnetic fields φ, the disorder D, the on-site energy µ

z
, and the mass term m on the thermoelectric coefficient and find that the transport gap can lead to a large S

c
and ZT. When transmission coefficient jumps from one integer plateau to another, S

c
and ZT show a series of peaks. The peaks of S

c
and ZT are determined by the jump of the transmission coefficient plateau and are not associated with the plateau itself. For TNLSMs p–n–p junctions, S

c
and ZT strongly depend on the parameter ξ of potential well. We can get a large ZT by adjusting the parameter ξ and magnetic field φ. In TNLSMs p–n–p junctions, ZT has the large value and is easily regulated. This setup has promising application prospects as a thermoelectric device.
Towards the establishment of national diagnostic reference levels in Tunisia: a multicentre survey in paediatric CT
Authors: Bouaoun Abir , Ben Omrane Latifa , Douira Khomssi Wièm
Published: June 2022

This work focuses on the determination of the radiation doses for a total sample of 916 children, categorised into four age groups (<1, 1–5, <5–10, <10–15 years) undergoing the most frequent paediatric CT scans performed in different scan facilities in Tunisia in order to establish the national diagnostic reference levels (DRLs). Dose evaluation concerned the dosimetric indicators: volume computed tomography dose index (CTDIvol) and dose–length product (DLP). The different paediatric CT protocols and practices were also evaluated. The results show a large variation in doses between different radiology departments. For head scans, the respective DRLs for children aged <1, 1–5, 5–10 and 10–15 years were 26, 38, 51 and 51 mGy, respectively, for CTDIvol and 384, 664, 873 and 978 mGy cm, respectively, for DLP. For the chest, the equivalent respective DRLs were 8, 10, 12 and 15 mGy for CTDIvol and 118, 330, 442 and 526 mGy cm for DLP. For the abdomen, the respective DRLs were 9, 13, 19 and 18 mGy for CTDIvol and 353, 485, 592 and 1073 mGy cm for DLP. This study shows that the optimisation of paediatric CT procedures should be a priority, especially within regional hospitals. The implementation of corrective actions will take place after the initial DRLs. These actions, including recommendations and guidelines to good practice, should be a joint effort of all stakeholders, including health authorities, the radiation protection regulator, professional societies and universities.
Optimal gate selection method for simultaneous lifetime-based measurement of PSP and TSP
Authors: Kasai Miku , Nagata Takayuki , Nonomura Taku , Saito Yuji , Asai Keisuke
Published: June 2022

In this study, a new method that optimizes a measurement condition in a lifetime-based simultaneous measurement of a pressure-sensitive paint (PSP) and a temperature-sensitive paint (TSP) is proposed for the improvement of the accuracy of the pressure measurement. An optimal gate is selected based on a pressure measurement error when calculating the pressure and the temperature simultaneously from measurement values of a PSP and a TSP. A shot noise of a PSP, a temperature error, and a fluctuation in an emission intensity ratio due to blurring were considered error factors of the PSP measurement. The pressure measurement error propagated from each error source was considered as an evaluation index in an optimization of a measurement condition. We evaluated 17 types of TSP characteristics and selected an optimal TSP and a measurement condition for the PSP measurement. Further, the optimized measurement condition was evaluated in a PSP/TSP simultaneous measurement using a coupon-based test. The optimal measurement condition obtained based on the proposed method and an empirical selection method were compared by a PSP/TSP simultaneous measurement using a coupon-based test. A small-pressure measurement error, i.e. high pressure-measurement accuracy, was realized by the proposed method in the simultaneous lifetime-based method of a PSP and a TSP. In addition to the analyses above, the blurring effects were found to be minor and briefly summarized in appendices.
A carbon nanosphere nanofluid for improving the toughness and thermal properties of epoxy composites
Authors: Li Peipei , Qu Danyao , Zhang Lu , Su Chen , Ma Jie , Wang Qi , Liu Chao , Wang Yongkun , Feng Huanran , Li Cong , Wu Weiwei
Published: June 2022

A carbon nanosphere nanofluid (CNS-nanofluid) was successfully prepared through the non-covalent modification of carbon nanosphere (CNS) with the specific ionic liquid (i.e. [M2070][VBS]) at first. The resulting CNS-nanofluid is a homogeneous and stable fluid with liquid-like behaviour at room temperature, and which shows better dispersion stability in its good solvents and improved processability than the pristine CNS. Subsequently, this CNS-nanofluid was used as a kind of novel functional filler and incorporated into epoxy matrix to prepare the CNS-nanofluid filled epoxy composites (CNS-nanofluid/EP composites). The toughness and thermal properties of those CNS-nanofluid/EP composites were carefully characterized and analysed. And it was found that this CNS-nanofluid could respectively improve the impact toughness and glass transition temperature of the CNS-nanofluid/EP composites to 19.8 kJ m−2 and 122.5 °C at the optimum amount, demonstrating that this CNS-nanofluid is a kind of promising functional filler to achieve robust epoxy composites, and thus opening up new possibilities with great significance for epoxy composites in high-performance applications.
Intrinsic variation effect in memristive neural network with weight quantization
Authors: Park Jinwoo , Song Min Suk , Youn Sangwook , Kim Tae-Hyeon , Kim Sungjoon , Hong Kyungho , Kim Hyungjin
Published: June 2022

To analyze the effect of the intrinsic variations of the memristor device on the neuromorphic system, we fabricated 32 × 32 Al2O3/TiO
x
-based memristor crossbar array and implemented 3 bit multilevel conductance as weight quantization by utilizing the switching characteristics to minimize the performance degradation of the neural network. The tuning operation for 8 weight levels was confirmed with a tolerance of ±4 μA (±40 μS). The endurance and retention characteristics were also verified, and the random telegraph noise (RTN) characteristics were measured according to the weight range to evaluate the internal stochastic variation effect. Subsequently, a memristive neural network was constructed by off-chip training with differential memristor pairs for the Modified National Institute of Standards and Technology (MNIST) handwritten dataset. The pre-trained weights were quantized, and the classification accuracy was evaluated by applying the intrinsic variations to each quantized weight. The intrinsic variations were applied using the measured weight inaccuracy given by the tuning tolerance, RTN characteristics, and the fault device yield. We believe these results should be considered when the pre-trained weights are transferred to a memristive neural network by off-chip training.
Failure mechanism of graphene kirigami under nanoindentation
Authors: Zhang Henin , Ma Jun , Zhang Yingyan , Yang Jie
Published: June 2022

Though graphene is the strongest material in nature, its intrinsic brittleness hinders its applications where flexibility is the key figure of merits. In this work, we report the enhanced flexibility of graphene under nanoindentation by using kirigami technique. Based on molecular dynamics simulations, we find that graphene kirigami designed at the optimal cut parameter can sustain more than 45% larger out-of-plane deformation than its pristine counterpart while the maximum impact load is reduced by 20% due to the flexible cut edges. This trade-off between flexibility and strength in a graphene kirigami can be overcome by adding a pristine graphene as a supporting substrate. This double-layer structure consisting of one graphene kirigami and one pristine graphene can stand the maximum impact load three times larger than the single-layer graphene kirigami but its maximum indentation depth is merely 8% smaller. Our simulation results provide useful insights into the failure mechanism of the graphene kirigami under nanoindentation and useful guidelines to enhancing the flexibility of graphene for its applications as protection materials.
Gevrey estimates for asymptotic expansions of Tori in weakly dissipative systems*
Authors: Bustamante Adrián P , De la Llave Rafael
Published: June 2022

We consider a singular perturbation for a family of analytic symplectic maps of the annulus possessing a KAM torus. The perturbation introduces dissipation and contains an adjustable parameter. By choosing the adjustable parameter, one can ensure that the torus persists under perturbation. Such models are common in celestial mechanics. In field theory, the adjustable parameter is called the counterterm and in celestial mechanics, the drift. It is known that there are formal expansions in powers of the perturbation both for the quasi-periodic solution and the counterterm. We prove that the asymptotic expansions for the quasiperiodic solutions and the counterterm satisfy Gevrey estimates. That is, the nth term of the expansion is bounded by a power of n!. The Gevrey class (the power of n!) depends only on the Diophantine condition of the frequency and the order of the friction coefficient in powers of the perturbative parameter. The method of proof we introduce may be of interest beyond the problem considered here. We consider a modified Newton method in a space of power expansions. As is custumary in KAM theory, each step of the method is estimated in a smaller domain. In contrast with the KAM results, the domains where we control the Newton method shrink very fast and the Newton method does not prove that the solutions are analytic. On the other hand, by examining carefully the process, we can obtain estimates on the coefficients of the expansions and conclude the series are Gevrey.
First-principles prediction of the half-metallicity in quaternary Heusler CoRhCrAl thin films
Authors: Muhammad Iltaf , He Yu , Ali Anwar , Zhang Wen , Wong Ping Kwan Johnny
Published: June 2022

Magnetic thin films are essential building blocks for spintronic devices. Whether the spin-dependent properties associated with a parental bulk can be preserved at the surface or interface with a lowered symmetry represents an important topic to be addressed. In the work, theoretical calculations are performed to study the structural, electronic and magnetic properties of the bulk CoRhCrAl quaternary Heusler alloy and its (111)-, (001)- and (110)-oriented thin films by using the VASP package based on the first-principles density functional theory. Our results indicate that the bulk structure of CoRhCrAl alloy is half-metallic (HM) in character with 100% spin-polarization, and its spin-down bandgap and total magnetic moment are

E

g

↓

=
0.3
0

eV and 3.00 μ
B, respectively. For the thin film structures with different orientations and terminations, half-metallicity only exists in the (111)-oriented thin film with Al-termination, but is lost in the Co-, Rh- or Cr-terminations. On the other hand, both the (001)- and (110)-oriented thin films are partially or nearly HM. Interestingly, the half-metallicity is lost on introducing U parameter in the calculations.
Exploring neutrinos from proton decays catalyzed by GUT monopoles in the Sun
Authors: Hu Hang , Cheng Jie , Guo Wan-Lei , Wang Wei
Published: June 2022

We explore the neutrino signals from proton decays catalyzed by GUT monopoles in the Sun. Three typical proton decay modes, p ⟶ e
+ + (ρ
0, η, ω… ) ⟶ π
+, p ⟶ μ
+
K
0 and p ⟶ ν̅eπ+
, have been analyzed for the Super-Kamiokande experiment. The monopole-induced neutrinos arise from interactions and subsequent decays of the proton decay products. To obtain the neutrino energy spectra, we use the Geant4 software to simulate propagations of daughter particles in the highly-dense solar center. It is found that K
0 can produce a large amount of 236 MeV monoenergetic νμ
neutrinos through the charge exchange process K
0 + p ⟶ K
+ + n and the subsequent decay K
+ ⟶ μ
+
ν
μ at rest. Based on this interesting feature, p ⟶ μ
+
K
0 can give the best discovery potential among three decay modes for most of the parameter space. In addition, we present the Super-Kamiokande sensitivities to the monopole flux for three proton decay modes.
Cosmological constraints on the gravitational constant
Authors: Ballardini Mario , Finelli Fabio , Sapone Domenico
Published: June 2022

We study the variation of the gravitational constant on cosmological scales in scalar-tensor theories
of gravity. We focus on the simplest models of scalar-tensor theories with a coupling to the Ricci
scalar of the form F(σ) = N
2
pl + ξσ
2, such as extended Jordan-Brans-Dicke
(N
pl = 0), or a non-minimally coupled scalar field with N
pl = M
pl, which permits
the gravitational constant to vary self-consistently in time and space. In addition, we allow the
effective gravitational constant on cosmological scales to differ from the Newton's measured constant
G, i.e. G
eff(z = 0) = G(1+Δ)2.
We study the impact of this imbalance Δ jointly with the coupling ξ into anisotropies of the
cosmic microwave background and matter power spectrum at low-redshift.
Combining the information from Planck 2018 CMB temperature, polarization and lensing, together with a compilation of BAO measurements from the release DR12 of the Baryon Oscillation Spectroscopic
Survey (BOSS), we constrain the imbalance to Δ = -0.022 ± 0.023 (68% CL) and the coupling parameter to 103
ξ < 0.82 (95% CL) for Jordan-Brans-Dicke and for a non-minimally coupled scalar
field with F(σ) = M
2
pl + ξσ
2 we constrain the imbalance to Δ > -0.018 (< 0.021) and the coupling parameter to ξ < 0.089 (ξ > - 0.041) both at 95% CL. With current data, we observe that the degeneracy between Δ, the coupling ξ to the Ricci scalar,
and H
0 allows for a larger value of the Hubble constant increasing the consistency between the
distance-ladder measurement of the Hubble constant from supernovae type Ia by the SH0ES team and its
value inferred by CMB data.
We also study how future cosmological observations can constrain the gravitational Newton's constant.
Future data such as the combination of CMB anisotropies from LiteBIRD and CMB-S4, and large-scale
structures galaxy clustering from DESI and galaxy shear from LSST reduce the uncertainty in Δ
to σ(Δ) ≃ 0.004.
A high power 1030 nm ytterbium doped fiber laser with a near diffraction limited quality using a 20/400 μm active fiber
Authors: Tabatabaei Jafari N , Batebi S , Sarikhani S , Eyni Chenar R
Published: June 2022

A 1030 nm ytterbium doped fiber laser (YDFL), made by using a 20/400 μm YDF, was studied both theoretically and experimentally in this article. From the theoretical point of view, it is found that the optimum length for the active fiber with higher than 30 dB suppression of amplified spontaneous emission (ASE) effect is about 7.3 m. However, an output beam with a diffraction limited quality (M
2 = 1.16) and 735 W power with a slope efficiency of 77% and over 30 dB of signal to noise ratio without any sign of ASE was extracted from this YDFL.
Detection and identification of faults in clock ensembles with the generalized likelihood ratio test
Authors: Trainotti Christian , Giorgi Gabriele , Günther Christoph
Published: June 2022

In this paper we propose an approach for performing fault detection and identification in clock ensembles based on the generalized likelihood ratio test. We show that by applying a set of purposefully-designed statistical tests, one can successfully detect faults occurring in a clock of the ensemble, and identify which measurement in the ensemble is most likely to have triggered the detection. We first develop the theoretical framework for the characterization of the detectors and their performance, and validate the derivations via Monte Carlo simulations. Then, we apply the statistical tests to an ensemble of cesium clocks, aiming at detecting and identifying three types of non-nominal behaviors. The faulty conditions are obtained by injecting a pattern of phase steps, a phase and frequency drift, and an oscillatory phase component.
Precise density measurement and its uncertainty evaluation for refractory liquid metals over 3000 K using electrostatic levitation
Authors: Jeon Sangho , Ganorkar Shraddha , Cho Yong Chan , Lee Joohyun , Kim Minju , Lee Jonghyun , Lee Geun Woo
Published: June 2022

Accurate density measurement of molten refractory metals over 3000 K is very challenging, and difficult to achieve with conventional methods. Although containerless techniques have been the most effective and well-established methods to measure the density of molten metals at such high temperatures, a large discrepancy in the containerlessly measured density values has been reported. Here, we identify the uncertainty factors of the density measurement and their influence on the measured density of molten refractory metals over 3000 K using an electrostatic levitator (ESL). We find that intensely focused laser beams can cause rotation-induced deformation of a levitated droplet and thus the large uncertainty in the measured density. Moreover, the combination of sample rotation and precession seriously affects the measurements of density and temperature dependence of density (i.e., volume thermal expansion). By minimizing such rotation and precession, we successfully measure the density and volume expansion coefficient of refractory liquids (tantalum, molybdenum, and niobium) with significantly improved reproducibility and accuracy, and evaluate the uncertainties associated with the density measurement using ESL.
Anomalies of motor unit amplitude and territory after botulinum toxin injection
Authors: Chandra Sourav , Suresh Nina L , Afsharipour Babak , Rymer William Zev , Holobar Ales
Published: June 2022

Objective. Botulinum toxin (BT) induced cholinergic denervation of hyperactive motor units (MUs) is a clinically accepted and extensively practiced way of managing focal spasticity after stroke. The denervation potentially initiates a temporary reorganization of the MU activation patterns and structures by inducing the emergence of a large number of newly innervated muscle fibers. In this study, we quantify the effect of the BT on MU action potential (MUAP) amplitudes and on the MU territory areas (MUTAs) as seen on the surface of the skin over the biceps brachii (BB) muscle. Approach. We have used a 128-channel high-density surface electromyography (HDsEMG) grid on the spastic and contralateral BB muscle and recorded the myoelectric activity along with the contraction force during isometric contraction of the elbow muscles. We have decomposed the recorded EMG signal into individual MU potentials and estimated the MUAP amplitudes and territory areas before and two weeks after a BT injection. Main result. There were significantly larger median (47 ± 9%) MUAP amplitudes as well as reduction of MUTA (20 ± 2%) two weeks after the injection compared to the respective pre-injection recording. Significance. The observed covariation of the amplitude and the territory area indicates that the large amplitude MUs that appeared after the BT injection have a relatively smaller territory area. These results provide a rare insight into the BT-induced changes of MU characteristics and have the potential to improve spasticity treatment. We discuss the potential contributing factors to these changes subsequent to the injection in the context of the investigated subject cohort.
First experimental results with new ICRF antenna in EAST
Authors: Zhang X.J. , Yang H. , Qin C.M. , Yuan S. , Zhao Y.P. , Wang Y.S. , Liu L.N. , Mao Y.Z. , Cheng Y. , Gong X.Z. , Xu G.S. , Song Y.T. , Li J.G. , Wan B.N. , Zhang K. , Zhang B. , Ai L. , Wang G.X. , Guo Y.Y.
Published: June 2022

A new ion cyclotron range of frequency (ICRF) antenna, instead of a B-port antenna, is installed at the N-port to improve the power coupling in the 2021 experimental advanced superconducting tokamak (EAST) experimental campaign. In all the experiments, a frequency of 37 MHz is used, corresponding to hydrogen minority heating of deuterium plasma at B
0 = 2.5 T. The maximum coupling resistance is up to 10 Ω, which is close to two times the resistance of the original two antennas in EAST. The plasma stored energy is increased by 30 kJ MW−1, and significant core ion and electron heating are observed. For long pulse operation, we have achieved 1.5 MW/41 s and 1.1 MW/61 s with the new antenna in the high poloidal beta plasma discharge. ICRF power up to 1.8 MW is routinely coupled to the plasma for pulse lengths up to 21 s.