bluuebunny/crossref_metadata_2025_split huggingface dataset:
Theoretical understanding on all-solid frustrated Lewis pair sites of C2N anchored by single metal atom
Authors: Zhu Yijia , Jian Changping , Xue Ruifang , Zhang Wei , Guo Rou , Gao Yijing , Chen De-Li , Zhang Fumin , Zhu Weidong , Wang Fang-Fang 
Published: July 2022

The design of all-solid heterogeneous catalysts with frustrated Lewis pairs (FLPs) has attracted much attention recently because of their appealing low dissociation energy for H2 molecules due to which a promotion of hydrogenation reaction is expected. The sterically encumbered Lewis acid (metal site) and base (nitrogen site) in the cavity of single transition metal atom-doped M/C2N sheets make them potential candidates for the design of catalysts with FLPs, while a comprehensive understanding of their intrinsic property and reactivity is still lacking. Calculations show that the complete dissociation of the H2 molecule into two H* states at the N sites requires two steps: heterolytic cleavage of the H2 molecule and the transfer of H* from the metal site to the N site, which are strongly related to the acidity of the metal site. Ni/C2N and Pd/C2N, which outperform the other eight transition metal atom (M) anchored M/C2N candidates, possess low energy barriers for the complete dissociation of H2 molecules, with values of only 0.30 and 0.20 eV, respectively. Furthermore, both Ni/C2N and Pd/C2N catalysts can achieve semi-hydrogenation of C2H2 into C2H4, with overall barriers of 0.81 and 0.75 eV, respectively, which are lower than those reported for many other catalysts. It is speculated that M/C2N catalysts with intrinsic FLPs may also find applications in other important hydrogenation reactions.
YouTube
Authors: Pelttari Sanna 
Published: July 2022

AbstractThis case study discusses audiences’ emotional reactions and convergent alignment in YouTube comment threads observed on four videos of Spanish YouTubers with affective narratives on sensitive topics. The analysis reveals that most single-comment threads are generally positive and that utterances are fairly equally divided in their focus on YouTubers or narratives. The act of taking a stance follow consists of a versatile process in which the convergent alignment or agreement with the YouTubers’ stance lead occurs not just by positively evaluating YouTubers or the story, but also by revealing something highly private concerning the stance topic. The four affective narratives evoke not only compliments, but also the convergent alignment the YouTubers presumably seek with their stories.
Evaluating multiword unit word lists for academic purposes
Authors: Nguyen Thi My Hang , Coxhead Averil 
Published: July 2022

Abstract
Word lists play a critical role in English for Academic Purposes (EAP) teaching and learning, and recent
developments include lists of academic collocations (e.g., vast majority, ultimate goal). There is however still
a gap in evaluating lists focusing on a similar group of lexis. This paper evaluates two lists of academic collocations by Ackermann and Chen (2013) and Lei and Liu
(2018) using three different methods: applying an evaluation framework adapted from Nation (2016), comparing the lexical constituents, and analysing the lexical coverage. The evaluation results give
implications for EAP teachers to select the list that best suits their needs. By modelling the practice of evaluating word lists,
this study highlights the importance of this work and encourages similar attempts in wordlist development studies.
Anti-fraud measures in Western Africa and commentary on research findings across the three regions analysed
Authors: Mykhalchenko Nataliya , Wiegratz Jörg 
Published: July 2022

SUMMARY
This briefing explores anti-fraud measures (AFMs) in Ghana, Nigeria and Sierra Leone. This is the last of three Briefings which examine the characteristics of AFMs across Africa. The findings confirm our earlier analyses concerning major anti-fraud measure drivers, actors, tools and controversies. These measures link matters of corporate competition, branding, consumer protection, industrial policy, capitalism and national politics, and are by now a component of economic policy and governance of various African states. A reflection on the data presented across the three Briefings concludes, and marks the end of the series.
Unveiling the structural, dynamical, elastic, and electronic properties of cuboid silver tetrathiotungstate by means of ab initio calculations
Authors: Ould-Mohamed Mounir , Ouahrani Tarik , Muñoz Alfonso , Errandonea Daniel 
Published: July 2022

Abstract
We present for the first time a theoretical study of the structural stability and physical properties of the newly synthesized Ag2WS4. The study contributes to a better understanding of its electronic and vibrational properties, which is fundamental for the optimization of the technological applications of Ag2WS4. Calculations have been carried out by means of density-functional theory. The obtained results support that Ag2WS4 is thermodynamically, mechanically, and dynamically stable in a tetragonal layered structure, in good agreement with experiments. Calculations have also been used to obtain phonon frequencies, their assignments, and the Raman scattering spectrum. Furthermore, we show that Ag2WS4 has a brittle structure, that is governed by van der Waals interactions, which favors its exfoliation as a low-dimensional structure. Additionally, the results show that Ag2WS4 has a band gap of 2.02 eV with a favorable band-edge diagram for water splitting as well as for optoelectronic applications.
Magnetic phase transition of monolayer chromium trihalides investigated with machine learning: toward a universal magnetic Hamiltonian
Authors: Zhang F , Zhang J , Nan H , Fang D , Zhang G-X , Zhang Y , Liu L , Wang D 
Published: July 2022

Abstract
The prediction of magnetic phase transitions often requires model Hamiltonians to describe the necessary magnetic interactions. The advance of machine learning provides an opportunity to build a unified approach that can treat various magnetic systems without proposing new model Hamiltonians. Here, we develop such an approach by proposing a novel set of descriptors that describes the magnetic interactions and training the artificial neural network (ANN) that plays the role of a universal magnetic Hamiltonian. We then employ this approach and Monte Carlo simulation to investigate the magnetic phase transition of two-dimensional monolayer chromium trihalides using the trained ANNs as energy calculator. We show that the machine-learning-based approach shows advantages over traditional methods in the investigation of ferromagnetic and antiferromagnetic phase transitions, demonstrating its potential for other magnetic systems.
Influence of gyro axis sequence configuration on the accuracy of alignment and navigation in a nested rotation inertial navigation system
Authors: Wang Meng , Wang Lei 
Published: July 2022

Abstract
It is analyzed that for a nested rotation inertial navigation system (NRINS) constructed from three ring fiber optic gyros nested within each other the main residual errors after rotation modulation are gyro angle random walk (ARW) and non-modulated gyro drift. It is pointed out that different orientations of the gyro sensitive axis lead to different equivalent ARWs, and the non-modulated gyro drift caused by the nested installation of three ring gyros is also different. The mechanism of generation of non-modulated drift in the embedded system and the general relationship with the axis sequence configuration are expounded. The equivalent ARW and non-modulated gyro drift in the inner frame rotation modulation mode and their influence on the alignment and navigation of the system are analyzed and deduced. Finally, taking the two typical applications of short-time and long-time navigation as examples, the influence of different gyro axis sequence configuration schemes on the navigation accuracy of the NRINS is verified through static navigation experiments, and the best axis sequence configuration scheme under the two applications is determined. By optimizing the gyro axis sequence configuration, the accuracy of navigation can be improved by about two times, which is of great significance. This work has important reference value for further improving the accuracy of NRINS and maximizing the accuracy advantage of gyros in different applications.
An equivalent parameter geometric shape representation using independent coordinates of cubic Bézier control points
Authors: Zhenwei Wang , Ziyu Zhang , Shuro Nakajima , Hong Chen 
Published: July 2022

Abstract
Bézier surface has been commonly applied to represent the complex geometric shape. Generally, all control points are dealt with by the same blending functions, regardless of the effect of independent coordinate. It causes to lack the modeling flexibility. Therefore, this paper proposes an equivalent parameter geometric shape representation method using the independent coordinates of control points. Since the coordinate components of control points are independent, the geometric modeling becomes more flexible. Firstly, a general Bézier curve is described in detail. Related expression is brought out in the form of independent coordinates by introducing two parameters. Then, their geometric meanings are analyzed in detail. Since both parameters are independent to parametric variables u and v, Bézier curve possess the same interval in the discrete parametric space, namely equivalent parameter. Next, a bicubic Bézier subsurface patch representation is discussed, including regular and non-regular subsurface patch. A general surface expression is given out in the form of independent coordinates, as well as the parameter structure and the geometric transformations. Finally, an example of ‘Bézier tree branch’ is constructed by using the proposed method. Results shows that the proposed method is feasible and reasonable.
Modeling the propagation of tumor fronts with shortest path and diffusion models—implications for the definition of the clinical target volume
Authors: Bortfeld Thomas , Buti Gregory 
Published: July 2022

Abstract

Objective. The overarching objective is to make the definition of the clinical target volume (CTV) in radiation oncology less subjective and more scientifically based. The specific objective of this study is to investigate similarities and differences between two methods that model tumor spread beyond the visible gross tumor volume (GTV): (1) the shortest path model, which is the standard method of adding a geometric GTV-CTV margin, and (2) the reaction-diffusion model. Approach. These two models to capture the invisible tumor ‘fire front’ are defined and compared in mathematical terms. The models are applied to example cases that represent tumor spread in non-uniform and anisotropic media with anatomical barriers. Main results. The two seemingly disparate models bring forth traveling waves that can be associated with the front of tumor growth outward from the GTV. The shape of the fronts is similar for both models. Differences are seen in cases where the diffusive flow is reduced due to anatomical barriers, and in complex spatially non-uniform cases. The diffusion model generally leads to smoother fronts. The smoothness can be controlled with a parameter defined by the ratio of the diffusion coefficient and the proliferation rate. Significance. Defining the CTV has been described as the weakest link of the radiotherapy chain. There are many similarities in the mathematical description and the behavior of the common geometric GTV-CTV expansion method, and the definition of the CTV tumor front via the reaction-diffusion model. Its mechanistic basis and the controllable smoothness make the diffusion model an attractive alternative to the standard GTV-CTV margin model.
Issues in the automated classification of multilead ecgs using heterogeneous labels and populations
Authors: Reyna Matthew A , Sadr Nadi , Perez Alday Erick A , Gu Annie , Shah Amit J , Robichaux Chad , Bahrami Rad Ali , Elola Andoni , Seyedi Salman , Ansari Sardar , Ghanbari Hamid , Li Qiao , Sharma Ashish , Clifford Gari D 
Published: July 2022

Abstract

Objective. The standard twelve-lead electrocardiogram (ECG) is a widely used tool for monitoring cardiac function and diagnosing cardiac disorders. The development of smaller, lower-cost, and easier-to-use ECG devices may improve access to cardiac care in lower-resource environments, but the diagnostic potential of these devices is unclear. This work explores these issues through a public competition: the 2021 PhysioNet Challenge. In addition, we explore the potential for performance boosting through a meta-learning approach. Approach. We sourced 131,149 twelve-lead ECG recordings from ten international sources. We posted 88,253 annotated recordings as public training data and withheld the remaining recordings as hidden validation and test data. We challenged teams to submit containerized, open-source algorithms for diagnosing cardiac abnormalities using various ECG lead combinations, including the code for training their algorithms. We designed and scored the algorithms using an evaluation metric that captures the risks of different misdiagnoses for 30 conditions. After the Challenge, we implemented a semi-consensus voting model on all working algorithms. Main results. A total of 68 teams submitted 1,056 algorithms during the Challenge, providing a variety of automated approaches from both academia and industry. The performance differences across the different lead combinations were smaller than the performance differences across the different test databases, showing that generalizability posed a larger challenge to the algorithms than the choice of ECG leads. A voting model improved performance by 3.5%. Significance. The use of different ECG lead combinations allowed us to assess the diagnostic potential of reduced-lead ECG recordings, and the use of different data sources allowed us to assess the generalizability of the algorithms to diverse institutions and populations. The submission of working, open-source code for both training and testing and the use of a novel evaluation metric improved the reproducibility, generalizability, and applicability of the research conducted during the Challenge.
Breakdown voltage in long tubes: the effect of surface charge
Authors: Meshchanov A V , Shishpanov A I , Bazhin P S , Ionikh Y Z 
Published: July 2022

Abstract
The study focuses on ignition processes in long discharge tubes (the length of which is large compared to the diameter) in rare gases Ne, Ar, and their mixture at a low pressure (∼1 Torr). Gas breakdown was caused by ramp voltage pulses of positive or negative polarity applied to the active electrode. The breakdown voltage was determined by the voltage drop at breakdown. The emission of the ionization wave (IW) preceding the breakdown was explored. The discharge tubes were exposed to two types of external influences. The first was illumination of the tube cathode with visible spectrum light, while the second was the constant or pulsed bias of the cathode potential by a value lower than that of maintaining discharge. In both cases the breakdown voltage increased up to doubling under some conditions. The observation of the IW revealed the presence of extra waves preceding the regular pre-breakdown IW. The extra wave velocity and emission intensity differed from those of the regular waves. Their main feature is that they do not overcome the entire inter-electrode gap, but weaken and disappear in between. It is assumed that the extra waves deposit the wall surface charge, which in turn affects the breakdown voltage. The increased breakdown voltage value remains for tens of minutes, which could indicate the surface charge lifetime of the same order. This was confirmed by direct wall-potential measurements using an electrostatic voltmeter.
Dynamical fluctuations in fragmentation reactions in a Boltzmann–Langevin approach
Authors: Li Bing , Tang Na , Zhang Feng-Shou 
Published: July 2022

Abstract
Based on the isospin-dependent Boltzmann–Langevin model, the dynamical fluctuations in the fragmentation reaction of 112Sn+112Sn are investigated. The quadrupole moment and octupole moment with zero magnetic quantum number have large fluctuations in the early time of the collisions. The dynamical fluctuations in momentum space show a strong dependence on the incident energy. The effects of using different fluctuations on the fragment cross sections are also studied in the fragmentation reactions. The results by using Q
20 + Q
30 fluctuation have a better agreement with the experimental data. Calculations using Q
20 + Q
30 fluctuation produce more proton-rich and neutron-rich nuclei than those using Q
20 fluctuation only. Besides, the difference between the production cross sections of fragments calculated by using Q
20 and Q
20 + Q
30 fluctuations is larger in the vicinity of the projectile. These results present that the dynamical fluctuations may affect the whole dynamical process of fragmentation reactions including the production of fragments, due to the nonlinear nature of the Boltzmann–Langevin equation.
Tighter monogamy relations of entanglement measures based on fidelity
Authors: Zhang Meiming , Jing Naihuan 
Published: July 2022

Abstract
We study the Bures measure of entanglement and the geometric measure of entanglement as special cases of entanglement measures based on fidelity, and find their tighter monogamy inequalities over tri-qubit systems as well as multi-qubit systems. Furthermore, we derive the monogamy inequality of concurrence for qudit quantum systems by projecting higher-dimensional states to qubit substates.
Investigating color screening in proton-nucleus collisions with complex potentials*
Authors: Wen Liuyuan , Du Xiaojian , Shi Shuzhe , Chen Baoyi 
Published: July 2022

Abstract
Color screening and parton inelastic scattering modify the heavy-quark antiquark potential in mediums consisting of particles from quantum chromodynamics (QCD), leading to the suppression of quarkonium production in relativistic heavy-ion collisions. Owing to the small charm/anti-charm (

) pair production number in proton-nucleus (pA) collisions, the correlation between different

pairs is negligible, which makes the Schrödinger equation viable for tracking the evolution of only one

pair. We employ the time-dependent Schrödinger equation with an in-medium

potential to study the evolution of charmonium wave functions in a hydrodynamic-like QCD medium produced in pA collisions. We explore different parametrizations of real and imaginary parts of the

potential and calculate the nuclear modification factors (

) of

and

in

TeV energy p-Pb collisions at the Large Hadron Collider (LHC). Comparing strong and weak screening scenarios with experimental data in this approach, we arrive at the conclusion that color screening is weak at temperatures close to the deconfined phase transition. Moreover, the imaginary part of the potential is crucial in describing the experimental data, which is consistent with widely studied semi-classical approaches, where dissociation rates are essential.
Systematic study on α-decay half-lives of uranium isotopes with a screened electrostatic barrier*
Authors: Xu Yang-Yang , Zhu De-Xing , Zou You-Tian , Wu Xi-Jun , He Biao , Li Xiao-Hua 
Published: July 2022

Abstract
In the present work, we systematically study the α-decay half-lives of uranium (Z=92) isotopes based on the Gamow model with a screened electrostatic barrier. There are only two adjustable parameters in our model i.e. the parameter g and the screening parameter t in the Hulthen potential for considering the screened electrostatic effect of the Coulomb potential. The calculated results are in good agreement with experimental data, and the corresponding root-mean-square (rms) deviations of uranium isotopes with α transition orbital angular momentum l=0 and l=2 are 0.141 and 0.340, respectively. Moreover, we extend this model to predict α-decay half-lives of uranium isotopes whose α decay is energetically allowed or observed but not yet quantified in NUBASE2020. For comparison, the modified Hatsukawa formula (XLZ), the unified Royer formula (DZR), the universal decay law (UDL) and the Viola–Seaborg–Sobiczewski formula (VSS) are also used. The predictions are basically consistent with each other. Meanwhile, the results also indicate that N=126 shell closure is still robust at Z=92 and the spectroscopic factor

is almost the same for uranium isotopes with the same l.
Time stability and connectivity analysis with an intracortical 96-channel microelectrode array inserted in human visual cortex
Authors: Grani Fabrizio , Soto-Sanchez Cristina , Farfan Fernando Daniel , Alfaro Arantxa , Grima Maria Dolores , Rodil Doblado Alfonso , Fernández Eduardo 
Published: July 2022

Abstract

Objective. Microstimulation via electrodes that penetrate the visual cortex creates visual perceptions called phosphenes. Besides providing electrical stimulation to induce perceptions, each electrode can be used to record the brain signals from the cortex region under the electrode which contains brain state information. Since the future visual prosthesis interfaces will be implanted chronically in the visual cortex of blind people, it is important to study the long-term stability of the signals acquired from the electrodes. Here, we studied the changes over time and the repercussions of electrical stimulation on the brain signals acquired with an intracortical 96-channel microelectrode array implanted in the visual cortex of a blind volunteer for 6 months. Approach. We used variance, power spectral density, correlation, coherence, and phase coherence to study the brain signals acquired in resting condition before and after the administration of electrical stimulation during a period of 6 months. Main results. Variance and power spectral density up to 750 Hz do not show any significant trend in the 6 months, but correlation coherence and phase coherence significantly decrease over the implantation time and increase after electrical stimulation. Significance. The stability of variance and power spectral density in time is important for long-term clinical applications based on the intracortical signals collected by the electrodes. The decreasing trends of correlation, coherence, and phase coherence might be related to plasticity changes in the visual cortex due to electrical microstimulation.
Nonlinear impact of the porous nanostructure on the net tungsten erosion in the linear plasma device PISCES-A
Authors: Yang K.R. , Dai S.Y. , Doerner R.P. , Liu D.H. , Chen J.Y. , Wang D.Z. 
Published: July 2022

Abstract
The tungsten fuzz growth under non-erosive and erosive helium plasmas in the linear plasma device PISCES-A has been investigated by experiments and simulations. The simulation results benchmarked against the experimental measurements indicate a decayed net physical sputtering yield during fuzz growth under the erosive helium plasma. Further, a nonlinear dependence of the net tungsten erosion on the ‘effective’ porous nanostructure that can be sputtered by incident helium particles has been found.