bluuebunny/crossref_metadata_2025 huggingface dataset:
She has a stadium named after her
Authors: Johannsen Berit
Published: August 2022

In English, sequences consisting of the verb have, a noun phrase and a past participle vary in meaning. This meaning variation has been discussed both in the context of grammatical description and language change, mostly based on a handful of examples. This study seeks to combine theoretical and methodological approaches from construction grammar and interactional linguistics in the description of this meaning variation. Theoretically, this implies distinguishing between abstracted meaning potential and situated meaning of linguistic elements. Methodologically, this means taking both a coarse-grained view by means of a quantitative corpus-based approach that abstracts over a number of instances and a fine-grained view by means of qualitative analysis of talk-in-interaction.
Emerging into your family of constructions
Authors: Haegen Flor Vander , Bossuyt Tom , Leuschner Torsten
Published: August 2022

Starting from the term “family of constructions”, the present article investigates lexical and syntactic variation in a subtype of German concessive conditionals which is marked bywas(‘what’) in combination with expressions of irrelevance likeegal(‘no matter’). 12,894 examples from the DeReKo corpus (Deutsches Referenzkorpus) are analysed manually for seven variables. Both the quantitative and the qualitative results suggest that combinations ofwaswith an expression of irrelevance, or “[IRRwas]” for short, form part of a recently entrenched constructional schema [IRRw-] of concessive-conditional subordinators which are emerging into the family of concessive-conditional constructions in present-day German.
Variation and Grammaticalization of Verbal Constructions
Authors: Diewald Gabriele , Czicza Dániel
Published: August 2022

Construction grammar – most notably Cognitive Construction Grammar (Goldberg 2006), Radical Construction Grammar (Croft 2001) and Cognitive Grammar (Langacker 2008) – has been extremely inspiring in providing tools for modelling gradience in variation and change. Verbal constructions have been investigated within the paradigm of construction grammar from a number of angles including idiomaticization processes as well as argument structure constructions (Boas 2003;Engelberg 2009;Faulhaber 2011;Goldberg 1995;Rostila 2007). Usage-based approaches (Barlow & Kemmer 2000;Bybee & Hopper 2001;Diessel 2015,2019;Langacker 1988;Tomasello 2003) have pointed out that usage is the place to look for variation and change. Data-driven, corpus-based approaches have introduced quantitative methods for analyzing constructional functionality and variety synchronically (Stefanowitsch & Gries 2003;Gries 2006;Glynn 2014) and diachronically (Hilpert 2006). These techniques have given rise to detailed studies of verbal constructions, lexicalization and idiomaticization.

This volume presents papers which in their majority have arisen in connection with the workshop “Variation and Grammaticalization of Verbal Constructions”, held at the 51st SLE Annual Meeting at Tallinn, 29th August – 1st September 2018. Its focus is on verbal constructions inGermaniclanguages, constructional variation and degrees of polyfunctionality between lexical, idiomatic and grammaticalized usages. The major object of this volume is to investigate the conditions and interdependencies of such variations and polyfunctionalities. The theoretical and conceptual foundations of the studies united here rest upon grammaticalization theory, usage-based constructional approaches, and frame semantics, allway in combination with empirical testing. The scope of interest comprises synchronic as well as diachronic phenomena in various registers and communicative types.
Pacing and packing behaviour in elite and world record performances at Berlin marathon
Authors: Muñoz‐Pérez Iker , Lago‐Fuentes Carlos , Mecías‐Calvo Marcos , Casado Arturo
Published: August 2022

The aim of this study was to compare pacing and packing behaviours between sex and performance level at elite Berlin marathon races. Official electronic split and finishing times from 279 (149 male and 130 female) marathon performances, including 5 male world records, were obtained from 11 Berlin marathon races held from 2008 to 2018, and from two previous world records and the second world all‐time fastest performance also achieved at that same Berlin course. Male performances displaying an even pacing behaviour were significantly faster than those adopting a positive behaviour (p < 0.001; d = 0.75). Male world records were characterized by even profiles with fast endspurts, being especially remarkable at world all‐time two fastest performances which were assisted by the use of a new shoe technology. Female marathon runners decreased their speed less than men during the second half marathon and especially from the 35th km onwards (p < 0.001; 0.51 ≤ d ≤ 0.55). The latest race stages were usually run individually in both sexes. Significant pace differences between performance groups at every race segment were found in women (p < 0.01; 1.0 ≤ d ≤ 2.0), who also covered an important part of the race alone. Prior to participation in meet marathon races such as Berlin marathon, elite runners should select the group that they will join during the race according to their current performance level as a preassigned pace set by a pacemaker will be adopted. Therefore, they could follow an even rather than positive pacing behaviour which will allow them to achieve a more optimal performance.
Multi-level images around Kerr–Newman black holes
Authors: Hou Yehui , Liu Peng , Guo Minyong , Yan Haopeng , Chen Bin
Published: August 2022

We study the lensing effects of Kerr–Newman (KN) black holes and the multi-level images of luminous sources around the black holes. We obtain the analytic forms of the lens equations in KN spacetime and derive approximately their limiting forms for photon emissions near the bounded photon orbits. After deriving the expressions of three key parameters γ, δ and τ, we investigate the primary, the secondary and the higher-order images of spherical sources and equatorial disk-like sources. In particular, we find that the charge of KN black hole has a significant effect on the higher-order images.
A brief review on the spin valve magnetic tunnel junction composed of 2D materials
Authors: Elahi Ehsan , Dastgeer Ghulam , Sharma Pradeep Raj , Nisar Sobia , Suleman Muhammad , Iqbal Muhammad Waqas , Imran Muhammad , Aslam Muhammad , Imran Ali
Published: August 2022

Two-dimensional (2D) materials including graphene, hexagonal boron nitride, and transition metal dichalcogenides have revolutionized electronic, optoelectronic and spintronic devices. Recent progress has been made in the knowledge of spin injection, detection, and manipulation utilizing spintronic devices based on 2D materials. However, some bottlenecks still need to be addressed to employ spintronic devices for logical applications. Here, we review the major advances and progress in vertical magnetic tunnel junctions (MTJs) made of various 2D materials as spacer layers between distinct ferromagnetic electrodes. Spin transportation characteristics depending on the magnetic field are investigated by considering the magnetoresistance (MR) and tunneling MR ratio in vertically stacked structures. This review examines the important features of spin transfer through the various spacer 2D materials in MTJs by carefully analyzing the temperature-dependent phenomena. The underlying physics, reliance of spin signals on temperature, quality of junction, and various other parameters are discussed in detail. Furthermore, newly discovered 2D ferromagnets introduce an entirely new type of van der Waals junction enabling effective dynamic control and spin transport across such heterojunctions. Finally, the challenges and prospects of 2D materials-based spin-valve MTJs for improving spintronic devices are discussed in detail.
Generated four-wave mixing in temperature controlled mixtures of carbon disulfide and benzene
Authors: Li Shuang , Liang Han , Liu Xiaofeng , Fang Wenhui , Sun Chenglin , Men Zhiwei
Published: August 2022

Generated four-wave mixing (FWM) from the Cascaded stimulated Raman scattering (SRS) process of the mixtures of carbon disulfide and benzene on temperature was investigated. At the low temperature conditions, the stimulated Brillouin scattering can be significantly suppressed, the beam distortion caused by thermal self-defocusing effect can be reduced, thereby improving the energy conversion efficiency of SRS. Not only the multi-order Stokes and anti-Stokes SRS of CS stretching vibration, CC ring skeleton vibration and CH stretching vibration were obtained, but also the 1st (∼583 nm) and 2nd -order (∼646 nm) FWM was generated by the Stokes light, anti-Stokes light and pump laser. At 20 °C, the highest conversion efficiency is 32%, and the peak intensity of FWM is also the intensest. The results are of great significance for the multi-wavelength Raman laser in liquid medium.
A review of metal–semiconductor contacts for β-Ga2O3
Authors: Lu Chao , Ji Xueqiang , Liu Zeng , Yan Xu , Lu Nianpeng , Li Peigang , Tang Weihua
Published: August 2022

β-Gallium oxide (β-Ga2O3) has been studied extensively in recent decades due to its excellent usability in fabricating a variety of devices, such as solar-blind photodetectors and power devices. However, as an important part of a device, related investigations of β-Ga2O3–metal contacts, especially for Schottky contacts, are rare. In this review, we summarize recent research progress on β-Ga2O3–metal contacts, including related theories, measurements, fabrication processes, control methods, etc. This review will provide insights for both theoretical understanding of the metal/semiconductor interface, as well as the fabrication process for engineering applications of Ga2O3-based devices.
The nature of excitons in PPDT2FBT:PCBM solar cells: Role played by PCBM
Authors: Sahoo Subhamoy , Barah Dhruvajyoti , Kumar S Dinesh , Xavier Nithin , Dutta Soumya , Ray Debdutta , Bhattacharyya Jayeeta
Published: August 2022

In organic semiconductor-based bulk heterojunction solar cells, the presence of an acceptor increases the formation of charge-transfer (CT) excitons, thereby leading to higher exciton dissociation probabilities. In this work we used steady-state electroabsorption (EA) measurements to probe the change in the nature of excitons as the blend composition of the solar cell active layer material was varied. We investigated blends of poly[(2,5-bis(2-hexyldecyloxy)phenylene)-alt-(5,6-difluoro-4,7-di(thiophen-2-yl)benzo[c]-[1,2,5]thiadiazole)] (PPDT2FBT) and (6,6)-phenyl C71 butyric acid methyl ester (PCBM). Analysis of the EA spectra showed that in the presence of a fullerene-based acceptor, like PCBM, CT characteristics of the excitons were modified, though no new CT signature was observed in the blend. Enhancement in the CT characteristics in the blend was reflected in photoluminescence (PL) measurements of the blends, where PL quenching of ∼63% was observed for 1% PCBM. The quenching reaches saturation at about 20% PCBM. However, efficiency of the device increased with a PCBM percentage beyond 20%. Maximum efficiency was obtained for the blend with 50% PCBM, among the blend compositions studied in this work, indicating the optimum concentration of PCBM for best power conversion efficiency to be around that value. When we compared the experimental results with simulations, the variation of the device efficiency with PCBM percentage was shown to arise from multiple factors, such as an increase in the polarizability and dipole moment of excitons, and the efficiency of the carrier collection from the bulk of the active layer.
Sustainable carbon coated ZrO2 electrodes with high capacitance retention for energy storage devices
Authors: Singh Nirbhay , Tanwar Shweta , Kour Simran , Sharma A L , Yadav B C
Published: August 2022

The rapid development of modern technology starves for future research to attain high-energy, high-power, and high cyclic stable energy-storage devices. Carbonaceous electrodes in supercapacitors provide a large-power device, which stores the charge between the surface of the carbonaceous electrode and the electrolyte layer. The commercially available electrode based on pure carbon suffers from low energy density. To overcome the mentioned issue, major efforts have been dedicated to enhancing the charge storage of carbonaceous electrodes by the addition of both pure capacitive material (such as Carbon and its derivative) and pure battery-type material (transition-metal oxide, hydroxides, etc). Mesoporous carbon due to its advanced feature along with ZrO2 good fit on performance and environmental aspect parameters. In this report, we have prepared environmentally friendly mesoporous carbon ZrO2 composite by the facile method, initially, ZrO2 is prepared hydrothermally after that mixing is done at room temperature to obtain the final product mesoporous carbon@ZrO2. The material structural, and microstructural examinations are done by x-ray diffraction analysis, and field emission scanning electron microscopy. The galvanostatic charging-discharging (GCD) analysis shows the specific capacitance of the device is 125 F g−1 and the energy density of the device is 25 Wh kg−1 at a current density of 0.5 A g−1. The GCD shows an extreme power density of 1201 W kg−1 at 1 mA. The cyclic voltammetry analysis shows the maximum specific capacitance of 54.5 F g−1 at 10 mV s−1. The long-term cyclic stability of up to 10 000 cycles is tested through GCD. The device shows high capacitance retention and Coulombic efficiency till the last GCD cycle at 82% and 100% respectively. The capacitive contribution is 55% for optimized electrodes. The prototype device formation and load light emitting diode (LED) testing are done at the laboratory. Based on experimental findings we have proposed a charge storage mechanism for a better understanding of readers.
Radiation exposure to extremities in medical applications and its implications for the radiation protection of workers in the Philippines
Authors: Romallosa Dean Kristine Marie , Panlaqui Angelo , Betos Christy Mae , Acha Jericissa Amberrose
Published: August 2022

In medical applications, non-homogeneous radiation exposure conditions may be encountered and whole-body monitoring alone may not be an adequate assessment of doses received by workers. This paper investigated the exposure to extremities in medical applications in the Philippines in terms of personal dose equivalent Hp(0.07). Profiles of monitored workers, dose levels, implications on optimization of occupational exposures, and factors affecting the extremity monitoring implementation were studied. The results show that <3% of workers are monitored for extremities, and there is no monitoring of eye lens dose. There is no extremity monitoring in diagnostic radiology, particularly interventional radiology. Dose levels to extremities were higher and more varied than whole-body doses. In nuclear medicine, the median annual extremity dose is 1.2 mSv, the interquartile range (IQR) is 7.6 mSv (Q1 = 0.5 mSv, Q3 = 8.1 mSv), and the maximum dose is 35 mSv. These median and IQR dose values are four and eight times higher, respectively, compared to the whole-body dose. In radiopharmaceutical distribution, the extremity median annual dose is five times higher than the whole-body dose, and the IQR value is 12 times higher where IQR is 12.1 mSv (Q1 = 0.1 mSv, Q3 = 12.2 mSv). Most notable is in cyclotron operations where <40% of workers were monitored on their extremities; however, the median dose is 100 times higher than the whole-body dose, with a maximum dose of 148 mSv. The results imply that there may be an underassessment of occupational exposure of workers in medical applications. As monitoring results are used for the establishment of a radiation protection program, lack of consideration of extremity doses can lead to inadequate measures in the optimization of worker protection. This study thus shows the need to enhance the implementation of extremity and eye lens dose monitoring in the Philippines to further strengthen the radiation protection of workers in medical applications.
In situ off-axis electron holography of real-time dopant diffusion in GaAs nanowires
Authors: Balasubramanian Ganapathi Prabhu Sai , Lebedkina Elizaveta , Goktas Nebile Isik , Wagner Jakob Birkedal , Hansen Ole , LaPierre Ray , Semenova Elizaveta , Mølhave Kristian , Beleggia Marco , Fiordaliso Elisabetta Maria
Published: August 2022

Off-axis electron holography was used to reveal remote doping in GaAs nanowires occurring during in situ annealing in a transmission electron microscope. Dynamic changes to the electrostatic potential caused by carbon dopant diffusion upon annealing were measured across GaAs nanowires with radial p-p+ core–shell junctions. Electrostatic potential profiles were extracted from holographic phase maps and built-in potentials (Vbi
) and depletion layer widths (DLWs) were estimated as function of temperature over 300–873 K. Simulations in absence of remote doping predict a significant increase of Vbi
and DLWs with temperature. In contrast, we measured experimentally a nearly constant Vbi
and a weak increase of DLWs. Moreover, we observed the appearance of a depression in the potential profile of the core upon annealing. We attribute these deviations from the predicted behavior to carbon diffusion from the shell to the core through the nanowire sidewalls, i.e. to remote doping, becoming significant at 673 K. The DLW in the p and p+ regions are in the 10–30 nm range.
Designing boron-cluster-centered zwitterionic Y-shaped clocked QCA molecules
Authors: Liza Nishattasnim , Lu Yuhui , Blair Enrique P
Published: August 2022

Quantum-dot cellular automata (QCA) is a nanoscale, transistor-less device technology. A single molecule may provide an elementary QCA device known as a cell. Molecular redox centers function as quantum dots, and the configuration of mobile charge on the dots encodes device states useful for classical computing. Molecular QCA may support ultra-high device densities and THz-scale switching speeds at room temperature. An applied electric field may be used to clock molecular QCA, providing power gain to boost weakened signals, as well as quasi-adiabatic device operation for minimal power dissipation in QCA devices and circuits. A zwitterionic, Y-shaped, three-dot molecule may function as a field-clocked QCA cell. We focus on the design of a counterion built into the center of the cell. Ab initio computations demonstrate that choice of counterion determines the number of mobile charges for encoding the device state on the three quantum dots. We use

B

5

H

5

2
−

or

B

4

CH

5

−

as the central counterionic linker for two different Y-shaped, three-dot QCA molecules. While both molecules support the desired device states, the number of trapped charges in the counterion determines the number of mobile holes on the molecular quantum dots. This, in turn, determines whether the device state is encoded by a hole or an electron. This choice of encoding determines how the molecular QCA cell responds to a clocking field. The two counterions studied here lead to two QCA molecules with opposite responses to the clock, similar to the complementary responses of PMOS and NMOS transistors to gated voltage control.
Large-area vertically aligned 2D MoS2 layers on TEMPO-cellulose nanofibers for biodegradable transient gas sensors
Authors: Yoo Changhyeon , Yoon Jaesik , Kaium Md Golam , Osorto Brandon , Han Sang Sub , Kim Jung Han , Kim Bo Kyoung , Chung Hee-Suk , Kim Dong-Joo , Jung Yeonwoong
Published: August 2022

Crystallographically anisotropic two-dimensional (2D) molybdenum disulfide (MoS2) with vertically aligned (VA) layers is attractive for electrochemical sensing owing to its surface-enriched dangling bonds coupled with extremely large mechanical deformability. In this study, we explored VA-2D MoS2 layers integrated on cellulose nanofibers (CNFs) for detecting various volatile organic compound gases. Sensor devices employing VA-2D MoS2/CNFs exhibited excellent sensitivities for the tested gases of ethanol, methanol, ammonia, and acetone; e.g. a high response rate up to 83.39% for 100 ppm ethanol, significantly outperforming previously reported sensors employing horizontally aligned 2D MoS2 layers. Furthermore, VA-2D MoS2/CNFs were identified to be completely dissolvable in buffer solutions such as phosphate-buffered saline solution and baking soda buffer solution without releasing toxic chemicals. This unusual combination of high sensitivity and excellent biodegradability inherent to VA-2D MoS2/CNFs offers unprecedented opportunities for exploring mechanically reconfigurable sensor technologies with bio-compatible transient characteristics.
Janus Ga2SSe nanotubes as efficient photocatalyst for overall water splitting
Authors: Li Lijian , Zhao Chen , Zhang Yujiao , Zhang Long , Zhu Yingtao
Published: August 2022

Using sunlight to decompose water into hydrogen and oxygen is one of the most important ways to solve the current global environmental issues and energy problems. In this paper, we use density functional theory to predict the photocatalytic performance of Janus Ga2SSe nanotubes (JGSSe NTs) for the first time. The result shows that the small formation energy and strain energy ensure the stability of the nanotubes. Compared with monolayers, the visible light absorption range of JGSSe NTs is wider, and the large radius (>26.60 A) nanotubes all meet the hydrolysis potential. Surprisingly, the hole mobility of JGSSe NT was estimated to be as high as 2.89 × 104 cm2 V−1 S−1. In conclusion, JGSSe nanotubes are expected to be an excellent photocatalyst due to their low electron–hole recombination rate, high hole mobility, solar absorption in the visible light range, and good oxidation capacity. In addition, the nanotube band gap can be effectively regulated by applying strain. It is hoped that our research will provide meaningful progress in the development of novel and efficient photocatalysts. We hope that our research will provide a possible way to develop novel and efficient photocatalysts.
Pre-service physics teachers’ developing views on the role of mathematics in the teaching and learning of physics
Authors: de Winter James , Airey John
Published: August 2022

This qualitative, questionnaire and interview-based study explores how pre-service physics teachers think about the role that mathematics plays in the teaching and learning of physics at university and school level and whether these views change during their pre-service teacher education. Many of the pre-service teachers were aware of the complex relationship between these two subjects at university level, noting that success in mathematics can often mask a lack of conceptual understanding in physics and that there can be a disconnect between the physics and mathematical aspects of undergraduate courses. At school level, many stressed the importance of a focus on conceptual understanding and that technical competence in mathematics lessons does not always transfer to physics lessons. Almost all the pre-service physics teachers changed their views during the year, often in response to their classroom experiences. As they became more attuned to the difficulties students faced with respect to the mathematical challenges involved in learning physics, many took a more pragmatic position that balanced the role of mathematics in physics with acceptance that they must respond to student needs. We suggest that these changing views can be framed in terms of two re-orientations. A disciplinary re-orientation where the role that mathematics plays in order to be successful in physics is reassessed, and a pedagogical re-orientation that attends to pragmatic, teaching considerations. We recommend that direct attention to the role of mathematics in school physics should be an integral part of pre-service physics teacher education in order to encourage these re-orientations.
An online astronomy activity embedded with REACT strategy for preservice primary school teachers
Authors: Oktay Ozlem , Avci Zeynep , Sen Ahmet Ilhan
Published: August 2022

The purpose of this study was to provide an online astronomy activity using the Stellarium program as a virtual planetarium. The implementation was conducted with 30 preservice primary school teachers (PPTs) who participated in a non-formal workshop that included interactive, technology-based astronomy practices embedded with the Relate, Engage, Applying, Cooperating, Transferring strategy. The activity featured in the implementation covers the zodiac constellations and common related misconceptions, the duration of the Sun in the constellations, and the concepts of astronomy, astrology, and star clusters. At the end of the implementation, an online-survey was conducted to elicit feedback from the PPTs. According to the results of this study, PPTs enjoyed using Stellarium as a virtual planetarium. The PPTs were aware of certain astronomical concepts and misconceptions, stated that the activity content related to daily life, and that they gained skills related to astronomy teaching. The PPTs reported being satisfied with working in groups, and actively communicating actively with their peers. They suggested adding mythological stories while teaching the constellations. In addition, they proposed increased preliminary preparation and practice prior to the activity so as to gain basic pre-skills in using a virtual environment.
Numerical modelling of a charged pendulum above a grounded conducting surface
Authors: Secrest Jeffery A , Jarra Ibrahim
Published: August 2022

The problem of an electrically charged pendulum above a grounded conducting surface is examined using traditional analyses, such as forces, energy, and torque. The system was numerically modelled using a finite difference method and analysed. A number of classroom activities have been suggested.
Deep learning method for reducing metal artifacts in dental cone-beam CT using supplementary information from intra-oral scan
Authors: Hyun Chang Min , Bayaraa Taigyntuya , Yun Hye Sun , Jang Tae-Jun , Park Hyoung Suk , Seo Jin Keun
Published: August 2022

Objective.Recently, dental cone-beam computed tomography (CBCT) methods have been improved to significantly reduce radiation dose while maintaining image resolution with minimal equipment cost. In low-dose CBCT environments, metallic inserts such as implants, crowns, and dental fillings cause severe artifacts, which result in a significant loss of morphological structures of teeth in reconstructed images. Such metal artifacts prevent accurate 3D bone-teeth-jaw modeling for diagnosis and treatment planning. However, the performance of existing metal artifact reduction (MAR) methods in handling the loss of the morphological structures of teeth in reconstructed CT images remains relatively limited. In this study, we developed an innovative MAR method to achieve optimal restoration of anatomical details.Approach.The proposed MAR approach is based on a two-stage deep learning-based method. In the first stage, we employ a deep learning network that utilizes intra-oral scan data as side-inputs and performs multi-task learning of auxiliary tooth segmentation. The network is designed to improve the learning ability of capturing teeth-related features effectively while mitigating metal artifacts. In the second stage, a 3D bone-teeth-jaw model is constructed with weighted thresholding, where the weighting region is determined depending on the geometry of the intra-oral scan data.Main results.The results of numerical simulations and clinical experiments are presented to demonstrate the feasibility of the proposed approach.Significance.We propose for the first time a MAR method using radiation-free intra-oral scan data as supplemental information on the tooth morphological structures of teeth, which is designed to perform accurate 3D bone-teeth-jaw modeling in low-dose CBCT environments.
Dedicated convolutional neural network for noise reduction in ultra-high-resolution photon-counting detector computed tomography
Authors: Huber Nathan R , Ferrero Andrea , Rajendran Kishore , Baffour Francis , Glazebrook Katrina N , Diehn Felix E , Inoue Akitoshi , Fletcher Joel G , Yu Lifeng , Leng Shuai , McCollough Cynthia H
Published: August 2022

Objective. To develop a convolutional neural network (CNN) noise reduction technique for ultra-high-resolution photon-counting detector computed tomography (UHR-PCD-CT) that can be efficiently implemented using only clinically available reconstructed images. The developed technique was demonstrated for skeletal survey, lung screening, and head angiography (CTA). Approach. There were 39 participants enrolled in this study, each received a UHR-PCD and an energy integrating detector (EID) CT scan. The developed CNN noise reduction technique uses image-based noise insertion and UHR-PCD-CT images to train a U-Net via supervised learning. For each application, 13 patient scans were reconstructed using filtered back projection (FBP) and iterative reconstruction (IR) and allocated into training, validation, and testing datasets (9:1:3). The subtraction of FBP and IR images resulted in approximately noise-only images. The 5-slice average of IR produced a thick reference image. The CNN training input consisted of thick reference images with reinsertion of spatially decoupled noise-only images. The training target consisted of the corresponding thick reference images without noise insertion. Performance was evaluated based on difference images, line profiles, noise measurements, nonlinear perturbation assessment, and radiologist visual assessment. UHR-PCD-CT images were compared with EID images (clinical standard). Main results. Up to 89% noise reduction was achieved using the proposed CNN. Nonlinear perturbation assessment indicated reasonable retention of 1 mm radius and 1000 HU contrast signals (>80% for skeletal survey and head CTA, >50% for lung screening). A contour plot indicated reduced retention for small-radius and low contrast perturbations. Radiologists preferred CNN over IR for UHR-PCD-CT noise reduction. Additionally, UHR-PCD-CT with CNN was preferred over standard resolution EID-CT images. Significance. CT images reconstructed with very sharp kernels and/or thin sections suffer from increased image noise. Deep learning noise reduction can be used to offset noise level and increase utility of UHR-PCD-CT images.
Comprehensive analysis of optoelectronic performance of ultraviolet phototransistors based on AlGaN/GaN heterostructure
Authors: Chen Dingbo , Chen Yu-Chang , Zeng Guang , Li Yu-Chun , Li Xiao-Xi , Peng Bo-Fang , Lu Hong-Liang
Published: August 2022

Optoelectronic performance of ultraviolet phototransistors (UVPTs) based on AlGaN/GaN high-electron-mobility transistor (HEMT) configuration is comprehensively studied under different illumination wavelengths, light power densities, gate biases, and drain voltages. A special photoresponse mechanism combining photovoltaic effect and photoconductive effect is proposed to explain the variation of detection performance with the optical and electrical conditions. By comparing the photoreponse characteristics under typical illumination wavelengths of 310 and 360 nm, the optoelectronic properties of the HEMT-based UVPTs are deeply revealed and summarized. This work can provide suggestions and guidelines for designing of AlGaN/GaN-based UVPTs in III–V integrated photonic systems.
Electrical-performance and reliability improvement of flexible low-temperature polycrystalline silicon thin-film transistors via post-annealing process
Authors: Im Hwarim , Ahn Jeong Hyun , Kim Won-Young , Ha Tae Eun , Jo Eun Kyung , Oh Yunjung , Cha Myoung Geun , Choi Sanggun , Lim Jun Hyung , Kim Yong-Sang
Published: August 2022

We investigated the improvement methods of the electrical characteristics and reliability of flexible low-temperature polycrystalline silicon (LTPS) thin-film transistors (TFTs) by optimizing the annealing process. We investigated the effect of annealing on the device properties via electrical measurement and density-of-state (DOS) analysis. The annealing temperature should be reduced for flexible LTPS TFTs compared to rigid devices because the range of the thermal stability of flexible substrate is narrower than that of the glass substrate. As the activation annealing temperature (T
a) decreased, the threshold voltage and field-effect mobility (μ
FE) decreased, and the subthreshold swing (SS) increased. When the post-annealing temperature (T
pa) decreased, μ
FE increased, and the changes in the other parameters were negligible. The DOS decreased with an increase in T
a and a reduction in T
pa. These results originated from ineffective dopant activation and defect curing due to the lower T
a and the enhanced hydrogen defect passivation at the lower T
pa. Therefore, flexible LTPS TFTs with reduced T
a values exhibited similar μ
FE values and lower SS values when the post-annealing process was omitted. Furthermore, removing the post-annealing process improved the reliability of the flexible LTPS TFTs with reduced T
a values under electrical stress. According to a hot-carrier instability analysis, defect passivation by hydrogen was more stable than defect curing with a higher T
a. Consequently, although T
a was low for flexible LTPS TFTs, the electrical performance and reliability could be improved by optimizing the post-annealing process.
Experimental and numerical studies on SMA-viscoelastic hybrid self-centering braces
Authors: Ping Yiwei , Fang Cheng , Shi Fei , Wu Honglei , Yam Michael C H , Chen Yiyi
Published: August 2022

This study presents a novel hybrid self-centering solution, namely, shape memory alloy (SMA)-viscoelastic hybrid brace (SVHB), to enhance structural seismic resilience and meanwhile, to overcome some shortcomings of existing self-centering braces. The study commences with a detailed introduction of the working principle of the SVHB, followed by a series of tests on individual SMA cables and viscoelastic dampers (VEDs). After gaining a basic understanding of the behavior of the critical components, a comprehensive experimental study on SVHB specimens considering different design parameters and loading conditions is carried out. Numerical models are subsequently developed and validated, followed by a parametric study providing a more in-depth insight into the influence of varying brace parameters. The individual SMA cables show stable flag-shaped hysteretic curves, with a fracture strain of around 15%. The individual VED displays typical parallelogram-shaped hysteretic responses, with a slight hardening effect at large shear strain. The SVHB specimen shows anticipated axial deformation mode with almost zero residual deformation upon unloading. The hysteretic response of the SVHB is the summation of that of the SMA cables and VEDs working in parallel. The average initial stiffness of the SVHB specimen is 87.4 kN mm−1, and the equivalent viscous damping ratio is up to 14.4%. Following the experimental study, a multiple spring-based modelling strategy is proposed which can accurately capture the complex nonlinear behavior of the SVHB. The influences of various parameters, such as rate sensitivity of VED and proportion of critical components, on the behavior of SVHBs are finally revealed.
In-vitro and in-vivo studies of 4D printed shape memory scaffolds with bioactive fillers and coating for enhanced bone tissue regeneration
Authors: Zhou Wanmei , Dong Xueming , He Yang , Zheng Wei , Leng Jinsong
Published: August 2022

Bone tissue engineering is considered one of the pivotal treatments for bone defects in patients. However, the conventional strategies for repairing irregular and complex bone defects are highly unsatisfactory, and appropriate repairing of bone defects remains a challenge. In recent years, smart scaffolds integrated with multiple functions have emerged as promising alternatives for the treatment of various bone defects. In this study, 4D printed shape memory polymer (SMP) scaffolds containing bioactive fillers (hydroxyapatite and alendronate) and collagen–dexamethasone (Col–Dex) coating were fabricated, and their microstructures, porosity, mechanical properties, and biological functions were thoroughly investigated. The SMP scaffolds manufactured in this study could be programmed into temporary shapes of small sizes and then recovered to working sizes and shapes under an alternating magnetic field to fill bone defects. In addition, the biological studies including cytotoxicity tests, osteogenesis-related gene expressions, fluorescence staining imaging, and animal experiments demonstrated the effective biological activities and osteogenic effects of the 4D printed SMP scaffolds, with potential applications in bone tissue regeneration. In other words, the prepared 4D printed scaffolds with bioactive fillers and the Col–Dex coating will provide an efficient approach for personalized bone tissue repair as well as enhanced bone tissue regeneration.
The effect of facet lines on critical current density and trapped field in bulk RE–Ba–Cu–O single grains
Authors: Shi Y , Mousavi T , Dennis A R , Ainslie M D , Speller S C , Grovenor C R H , Durrell J H , Cardwell D A
Published: August 2022

Bulk, single grain RE–Ba–Cu–O (where RE = rare earth or yttrium) [(RE)BCO] high temperature superconductors could potentially be used to generate stable magnetic fields for magnetic resonance imaging (MRI) and nuclear magnetic resonance (NMR). In these applications, however, the homogeneity of the magnetic field is of critical importance. As a result, the spatial distribution of critical current density, J
c, within the bulk single grain and the effects of the magnetisation process, which are primary drivers of the uniformity of the achievable trapped magnetic field, are fundamental to assessing the performance of these technologically important materials. This paper reports the systematic measurement of the distribution of J
c–B at 77 K over a vertical cross-section of a single grain along a facet line and through the seed crystal [(110)-F] at 20 positions within a 20 mm diameter Gd–Ba–Cu–O sample in an attempt to understand and assess the distribution of J
c along this microstructural feature. A comparison of the data within the whole vertical plane across the seed measured along the a or b direction within the [(100)-a] plane shows that J
c–B at 77 K at the facet line is more than 10% higher for applied fields between 0.2 T and 2.5 T. The effect of the J
c–B relationship of the facet line on the overall trapped field measured in an individual bulk sample was investigated by measuring the magnitudes of trapped fields and their contour maps for sections cut from four single grain samples of GdBCO–Ag at different sizes and shapes parallel to the ab-plane from the top to the bottom of the bulk sample. Based on the results reported here, we demonstrate a method to achieve more uniform trapped fields through an optimal arrangement of an assembly of sections of individual GdBCO single grains.
Improvement on Faraday rotation measurement affected by the stray lights on the HL-2A tokamak
Authors: Wang Z H , Li Y G , Li Y , Wang H X , Yi J , Wen R N , Shi Z B
Published: August 2022

Formic-acid (HCOOH, λ = 432.5 μm) laser
P
olarimeter-
I
nterferomet
er
(
PIer
) has been developed on the HL-2A tokamak, which provides 4 channels of line-integrated electron densities and 4 channels of Faraday rotation angles, respectively. Affected by the stray lights arising from the reflection of the probe waves in the optical system, the measurement of Faraday rotation angles was drastically contaminated during the HL-2A experiments, showing an obvious oscillation modulation during the electron density ramp-up/down. This paper introduces an effective correction approach used to improve the accuracy of Faraday rotation measurement on the HL-2A tokamak. Based on the method, the deviation term originating from the stray lights can be effectively subtracted from the contaminated Faraday rotation measurement. The preliminary result indicates that the interference amplitude on Faraday rotation angle is reduced by about 80%, and the corrected data is consistent with the experimental measurement by using the optical isolator that consists of a λ/4 wave-plate and polarizer under the similar discharges.
Color image encryption algorithm based on 3D spiral transform and radial diffusion
Authors: Zhang Xiaoqiang , Yang Xiaochang
Published: August 2022

While digital image information is convenient to transmit in Internet, there is a great risk of information leakage in practice. To satisfy the demands for image content security and real-time communication, we propose a color image encryption algorithm based on a three-dimensional (3D) spiral transform and radial diffusion. Firstly, a 3D spiral transform is designed by combining the R, G and B channels of the color image with the traditional spiral transform; secondly, after the randomly selecting the spiral starting point by the chaotic sequence, the plained image is scrambled by the 3D spiral transform; thirdly, after randomly selecting the method of radial diffusion by the chaotic sequence, the scrambled image is radially diffused by chaotic sequences to obtain the cipher image. Simulation results and theoretical analyses show that the proposed algorithm not only has an excellent encryption effect, but also has the strong security to resist common attacks. Thus, the proposed algorithm can be suitable for the color image transmission under the network platform with the high-security requirement.
Moving boundary problems for a canonical member of the WKI inverse scattering scheme: conjugation of a reciprocal and Möbius transformation
Authors: Rogers Colin
Published: August 2022

Reciprocal links between certain solitonic systems and their hierarchies are well-established. Moreover, the AKNS and WKI inverse scattering schemes are known to be connected by a composition of gauge and reciprocal transformations. Here, a reciprocal transformation allied with a Möbius-type mapping is applied to a class of Stefan-type problems for the solitonic Dym equation to generate a novel exact parametric solution to a class of moving boundary problems for a canonical member of the WKI system.
Nonparametric Bayesian inference for meta-stable conformational dynamics
Authors: Köhs Lukas , Kukovetz Kerri , Rauh Oliver , Koeppl Heinz
Published: August 2022

Analyses of structural dynamics of biomolecules hold great promise to deepen the understanding of and ability to construct complex molecular systems. To this end, both experimental and computational means are available, such as fluorescence quenching experiments or molecular dynamics simulations, respectively. We argue that while seemingly disparate, both fields of study have to deal with the same type of data about the same underlying phenomenon of conformational switching. Two central challenges typically arise in both contexts: (i) the amount of obtained data is large, and (ii) it is often unknown how many distinct molecular states underlie these data. In this study, we build on the established idea of Markov state modeling and propose a generative, Bayesian nonparametric hidden Markov state model that addresses these challenges. Utilizing hierarchical Dirichlet processes, we treat different meta-stable molecule conformations as distinct Markov states, the number of which we then do not have to set a priori. In contrast to existing approaches to both experimental as well as simulation data that are based on the same idea, we leverage a mean-field variational inference approach, enabling scalable inference on large amounts of data. Furthermore, we specify the model also for the important case of angular data, which however proves to be computationally intractable. Addressing this issue, we propose a computationally tractable approximation to the angular model. We demonstrate the method on synthetic ground truth data and apply it to known benchmark problems as well as electrophysiological experimental data from a conformation-switching ion channel to highlight its practical utility.
Pattern Recognition Using SVM for the Classification of the Size and Distance of Trans-Neptunian Objects Detected by Serendipitous Stellar Occultations
Authors: Hernández-Valencia B. , Castro-Chacón J. H. , Reyes-Ruiz M. , Lehner M. J. , Guerrero C. A. , Silva J. S. , Hernández-Águila J. B. , Alvarez-Santana F. I. , Sánchez E. , Nuñez J. M. , Calvario-Velásquez L. T. , Figueroa Liliana , Huang C.-K. , Wang Shiang-Yu , Alcock C. , Chen W.-P. , Granados Contreras Agueda Paula , Geary J. C. , Cook K. H. , Kavelaars J. J. , Norton T. , Szentgyorgyi A. , Yen W.-L. , Zhang Z.-W. , Olague G.
Published: August 2022

We present a new pipeline based on the Support Vector Machine algorithm to confirm the detection and perform classification of small solar system objects by serendipitous stellar occultations. This pipeline is designed to analyze light curves and to identify the occultation events and the classification of the occulting bodies according to their size, typically from a fraction to a few kilometers, and their distance from the Sun, typically a few tens of astronomical units. The input light curves for this pipeline were obtained from the event simulator for the Trans-Neptunian Automated Occultation Survey (TAOS II). We explore parameters affecting occultation light curves such as spectral type, apparent magnitude and finite angular size of the occulted star, angle from opposition, and readout cadence for the observations; also we assumed a Poisson noise distribution as expected from the TAOS II project. We find that occultation events, especially by trans-Neptunian objects with diameters ≥2 km are detected with 99.99%, 99.53%, and 86% efficiency for stars with a visual apparent magnitude of 12, 14, and 16, respectively at 0.05 s of exposure time. In terms of size and distance classification the overall accuracy is 94%. However, for smaller objects the confirmation and classification depends mostly upon the signal-to-noise ratio.
Realization of phase dependent optical bistability in a quantum dot molecule via three-wave mixing
Authors: Wang Donghui
Published: August 2022

In this paper, we have proposed a new model based on the electron tunneling effect for controlling the optical bistability (OB) and optical multistability (OM) in a defect slab structure with a quantum dot molecule (QDM). Due to the presence of the electron tunneling effect, an additional weak signal beam can be generated in the system which makes the medium becomes phase dependent. We have studied the refractive index properties of the QDM via optical susceptibility of the propagated probe light. We have discussed the relative phase effect on negative refractive index (NRI) of the QDM nanostructure due to presence of electron tunneling. Then, by using the transfer matrix method, we have studied the transmission coefficient for NRI of the QDM nanostructure. Then, we have investigated the properties of transmitted light versus incident light for realizing the OB and OM. We have considered the relative phase effect on OB and OM properties of the transmitted beam and find that the switching between them is possible when electron tunneling is present in the quantum dot. Moreover, the optical thickness of the defect layer is also investigated on OB and OM in resonance and non-resonance conditions.