检索结果-内蒙古大学图书馆

arXiv 2024年

作者： Yin, Xin-Zhu Jiao, Na Lu, Jinlian Zheng, Meng-Meng Lu, Hong-Yan Zhang, Ping School of Physics and Physical Engineering Qufu Normal University Qufu273165 China Institute of Applied Physics and Computational Mathematics Beijing100088 China Department of Physics Yancheng Institute of Technology Jiangsu Yancheng224051 China

Two-dimensional (2D) intrinsic superconductors with nontrivial topological band and vertical ferroelectricity exhibit fascinating characteristics to achieving electrostatic control of quantum phases. While, only a few such 2D materials have been theoretically predicted. In this work, based on first-principles calculations, we explore the superconductivity and ferroelectric properties in fluorinated 2D Nb2N. In the stable Nb2NF2, H3-Nb2NF2 breaks the spatial inversion symmetry, exhibiting vertical ferroelectric. More interestingly, it not only possesses intrinsic superconductivity with superconducting transition temperatures (Tc) of 10 K, but also exhibits nontrivial band topology. While, H1-Nb2NF2 shows topological band and superconductivity with Tc of 32 K, surpassing most of 2D conventional topological superconductors’ candidates. Our research has enriched 2D superconducting materials with nontrivial band topology and ferroelectric properties, and provided a theoretical basis for the preparation of devices switching between superconducting and ferroelectric states with external electric field. Copyright © 2024, The Authors. All rights reserved.

关键词： Niobium compounds

来源：评论

学校读者我要写书评

暂无评论

Flexible categorization for auditing using formal concept analysis and Dempster-Shafer theory

arXiv

引用

arXiv 2022年

作者： Boersma, Marcel Manoorkar, Krishna Palmigiano, Alessandra Panettiere, Mattia Tzimoulis, Apostolos Wijnberg, Nachoem School of Business and Economics Vrije Universiteit Amsterdam Netherlands Department of Mathematics and Applied Mathematics University of Johannesburg South Africa College of Business and Economics University of Johannesburg South Africa Faculty of Economics and Business University of Amsterdam Netherlands Computational Science Lab University of Amsterdam Amsterdam Netherlands KPMG Amstelveen Netherlands

Categorization of business processes is an important part of auditing. Large amounts of transnational data in auditing can be represented as transactions between financial accounts using weighted bipartite graphs. We view such bipartite graphs as many-valued formal contexts, which we use to obtain explainable categorization of these business processes in terms of financial accounts involved in a business process by using methods in formal concept analysis. The specific explainability feature of the methodology introduced in the present paper provides several advantages over e.g. non-explainable machine learning techniques, and in fact, it can be taken as a basis for the development of algorithms which perform the task of clustering on transparent and accountable principles. Here, we focus on obtaining and studying different ways to categorize according to different extents of interest in different financial accounts, or interrogative agendas, of various agents or sub-tasks in audit. We use Dempster-Shafer mass functions to represent agendas showing different interest in different set of financial accounts. We propose two new methods to obtain categorizations from these agendas. We also model some possible deliberation scenarios between agents with different interrogative agendas to reach an aggregated agenda and categorization. The framework developed in this paper provides a formal ground to obtain and study explainable categorizations from the data represented as bipartite graphs according to the agendas of different agents in an organization (e.g. an audit firm), and interaction between these through deliberation. © 2022, CC BY.

关键词： Formal concept analysis

来源：评论

学校读者我要写书评

暂无评论

Fruit harvesting: A potential threat to the persistence, spatial distribution, and establishment of plants

arXiv

引用

arXiv 2023年

作者： Mohammed, Mozzamil Brännström, Åke Landi, Pietro Dieckmann, Ulf Institute for Chemistry and Biology of the Marine Environment University of Oldenburg Oldenburg Germany Advancing Systems Analysis Program International Institute for Applied Systems Analysis Laxenburg Austria Department of Mathematics and Mathematical Statistics Umeå University Umeå Sweden Applied Mathematics Division Department of Mathematical Sciences Stellenbosch University Stellenbosch South Africa Okinawa Onna904-0495 Japan

Plant-frugivore interactions play a central role for plant persistence and spatial distribution by promoting the long-range dispersal of seeds by frugivores. However, plant-frugivore interactions are increasingly being threatened by anthropogenic activities. An important anthropogenic threat that could expose plant-frugivore systems to extinction risk is fruit harvesting. Here, we develop an individual-based and a pair-approximation model of plant-frugivore-human interactions to elucidate the effects of human harvesting of fruits on plant establishment, persistence, and spatial distribution. Our results show that frugivores strongly affect global density of plants and gradually shift their spatial distribution from aggregated to random, depending on the attack rate and dispersal efficiency of frugivores. We find that, in the absence of frugivores, plants experiencing intense fruit harvesting cannot persist even if their fecundity is high. In the presence of frugivores, fruit harvesting profoundly affects the global dispersal of seeds and thus changes the spatial distributions of plants from random to aggregated, potentially causing plant extinction. Our results demonstrate that sufficiently efficient frugivores mitigate the negative impact of fruit harvesting on plant populations and enable plant establishment precluded by harvesting. Taken together, these results draw attention to previously underappreciated impacts of fruit harvesting in plant-frugivore-human interactions. Copyright © 2023, The Authors. All rights reserved.

关键词： Spatial distribution

来源：评论

学校读者我要写书评

暂无评论

Electron-hydrogen atom-impact 1s→2s and 1s→2p excitation with screened Coulomb interaction between the n=2 and n=3 excitation thresholds

引用

Physical Review A 2011年第3期83卷 032724-032724页

作者： Song Bin Zhang Jian Guo Wang R. K. Janev Xiang Jun Chen Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics University of Science and Technology of China Hefei 230026 China Key Laboratory of Computational Physics Institute of Applied Physics and Computational Mathematics P. O. Box 8009 Beijing 100088 China Macedonian Academy of Sciences and Arts P. O. Box 428 1000 Skopje Macedonia

The effects of Coulomb interaction screening on electron-hydrogen atom 1S → 2S and 1S → 2p excitation scattering between the n = 2 and n = 3 excitation thresholds have been investigated by using the R-matrix method with pseudostates. The excitation collision strengths show dramatic changes when the interaction screening length D varies from ∞ to 9 a.u., as a result of the convergence of S-type and some p- and D-type Feshbach resonances to the varying 3S or 3p thresholds, and due to the crossover of some other p-, D- and all F-type Feshbach resonances into shape-type resonances when they pass across the 3S or 3p threshold at certain critical values of D. The noncrossover of some p- and D-type Feshbach resonances into shape-type resonances at the 3S (or 3p for those of D-type) threshold is at variance with the behavior of these types of resonances at the 2S (2p for those of D-type) threshold, which results from the threefold splitting of the n = 3 hydrogenic level and, consequently, the more complex nature of the configuration mixing in the n = 3 threshold region. The evolution of the total 1S → 2S, 1S → 2p, and 2S → 2p excitation collision strengths, when the screening strength varies, is presented and discussed.

关键词： COULOMB functions NUCLEAR excitation RESONANCE COLLISIONS (Nuclear physics) NUCLEAR physics

来源：评论

学校读者我要写书评

暂无评论

Transient analysis of a resource-limited recovery policy for epidemics: A retrial queueing approach

Transient analysis of a resource-limited recovery policy for...

引用

IEEE Princeton Section Sarnoff Symposium

作者： Aresh Dadlani Muthukrishnan Senthil Kumar Kiseon Kim Faryad Darabi Sahneh School of EECS Gwangju Institute of Science and Technology Gwangju South Korea Department of Applied Mathematics and Computational Science PSG College of Technology India School of Computer Science Georgia Institute of Technology Atlanta GA USA

ISBN: (纸本)9781509015412

Knowledge on the dynamics of standard epidemic models and their variants over complex networks has been well-established primarily in the stationary regime, with relatively little light shed on their transient behavior. In this paper, we analyze the transient characteristics of the classical susceptible-infected (SI) process with a recovery policy modeled as a state-dependent retrial queueing system in which arriving infected nodes, upon finding all the limited number of recovery units busy, join a virtual buffer and try persistently for service in order to regain susceptibility. In particular, we formulate the stochastic SI epidemic model with added retrial phenomenon as a finite continuous-time Markov chain (CTMC) and derive the Laplace transforms of the underlying transient state probability distributions and corresponding moments for a closed population of size N driven by homogeneous and heterogeneous contacts. Our numerical results reveal the strong influence of infection heterogeneity and retrial frequency on the transient behavior of the model for various performance measures.

关键词： Silicon Peer-to-peer computing Transient analysis Mathematical model Biological system modeling Orbits Numerical models

来源：评论

学校读者我要写书评

暂无评论

K, T and D-like fuzzy Kripke models

K, T and D-like fuzzy Kripke models

引用

Annual Meeting of The North American Fuzzy Information Processing Society

作者： Bedregal, Benjamin Santiago, Regivan H. N. Benevides, Mario Viana, Petrucio Group of Logic Language Information Theory and Applications - LoLITA Department of Informatics and Applied Mathematics Federal University of Rio Grande Do Norte 59072-970 Natal-RN Brazil Program of Engineering of Systems and Computing - PESC Department of Computer Science Federal University of Rio de Janeiro 21941-972 Rio de Janeiro-RJ Brazil Department of Analysis Fluminense Federal University 24020-140 Niterói-RJ Brazil

ISBN: (纸本)9781612849676

The idea of a Kripke semantics endowed with possibility/plausibility information is not new;in fact there are different approaches for that;see: [6], [13], [16], [19]. This paper follows the approach found in [6], but whereas [6] provides a fixed interpretation for connectives into [0,1] here we provide a characterization of a fuzzy semantics for connectives in such a way that the resulting fuzzy frames: K, T and D, are described precisely by the set of statements which also describes, respectively, the usual modal systems K, T and D. © 2011 IEEE.

关键词： Semantics

来源：评论

学校读者我要写书评

暂无评论

引用

Asia International Conference on Modeling & Simulation

作者： Nabaraj Dahal Nanda Nandagopal Bernadine Cocks Naga Dasari Ramasamy Vijayalakshmi Paul Gaertner Division of IT Engineering and Environment University of South Australia Adelaide Australia Department of Applied Mathematics and Computational Science PSG College of Technology Coimbatore Tamil Nadu India Defence Science and Technology Organization Edinburgh South Australia

Accurately identifying cognitive activity from multi-channel EEG data continues to be a challenging task for cognition researchers. Although brain impairments such as epilepsy and ADHD tend to display relatively easy to identify EEG data features, delineating clear patterns of normal cognitive activity within the healthy brain has not yet been satisfactorily achieved. In the current study, the EEG features associated with distraction have been examined. Continuous EEG has been recorded from eight participants as they performed normal and auditory-distraction virtual driving. All pole analysis using the autoregressive model of the EEG data in both conditions has been then carried out, producing interesting and anatomically feasible patterns in temporal lobe regions. Event related synchronization and desynchronization patterns have also been observed at specific brain locations within the alpha, beta and gamma band frequencies. These results clearly distinguish audio-distracted driving from normal driving, suggesting that the techniques used here may provide a new analysis method for brain computer interface research.

关键词： Electroencephalography Brain modeling Mathematical model Data models Kalman filters Temporal lobe Equations

来源：评论

学校读者我要写书评

暂无评论

Laboratorial radiative shocks with multiple parameters and first quantifying verifications to core-collapse supernovae

arXiv

引用

arXiv 2024年

作者： Zhang, Lu Zheng, Jianhua Yang, Zhenghua Song, Tianming Zhang, Shuai Liu, Tong Wei, Yunfeng Kuang, Longyu Jing, Longfei Lin, Zhiwei Li, Liling Li, Hang Zheng, Jinhua Yang, Pin Zhang, Yuxue Zhang, Zhiyu Zhao, Yang He, Zhibing Li, Ping Yang, Dong Yang, Jiamin Zhao, Zongqing Ding, Yongkun Research Center of Laser Fusion China Academy of Engineering Physics Mianyang621900 China Department of Astronomy Xiamen University Fujian Xiamen361005 China Institute of Applied Physics and Computational Mathematics Beijing100088 China

We present experiments to reproduce the characteristics of core-collapsesupernovae with different stellar masses and initial explosion energies in thelaboratory. In the experiments, shocks are driven in 1.2 atm and 1.9 atm xenongas by laser with energy from 1600J to 2800J on the SGIII prototype laserfacility. The average shock velocities and shocked densities are obtained fromexperiments. Experimental results reveal that higher laser energy and lower Xegas density led to higher shock velocity, and lower Xe gas initial density hasa higher compression. Modeling of the experiments using the 2D radiationhydrodynamic codes Icefire shows excellent agreement with the experimentalresults and gives the temperature. These results will contribute to time-domainastrophysical systems, such as gravitational supernovae, where a strongradiative shock propagates outward from the center of the star after the corecollapses. © 2024, CC0.

关键词： Supernovae

来源：评论

学校读者我要写书评

暂无评论

Highly luminescent un-doped carbon nano-dots driven from folic acid and passivated by polyethylene glycol

引用

Materials Today: Proceedings 2020年 33卷 1800-1803页

作者： Yasmin M. Bakier Mohsen Ghali Mohamed Sami Waheed K. Zahra Department of Energy Materials Basic and Applied Science Institute Egypt-Japan University of Science and Technology Borg El-Arab Alexandria 21934 Egypt Physics Department Faculty of Science Kafrelsheikh University 33516 Kafrelsheikh Egypt Departement of Applied and Computational Mathematics Basic and Applied Science Institute Egypt-Japan University of Science and Technology Borg El-Arab Alexandria 21934 Egypt

Carbon nano-dots (CDs) are considered nowadays as one of the most interesting fluorescence nanomaterials with various technological applications in almost all aspects of needs e.g., in medicine, biology and engineering. Yet, as reported in many previous works, un-doped CDs suffer from low quantum yield particularly when synthesized at relatively low temperatures. Here, we report on synthesis and characterization of a small size (4.7 nm in diameter) intentionally un-doped CDs with high fluorescence intensity, from Folic Acid as a single precursor, using hydrothermal process at relatively low temperature 200 °C. By attaching organics species of diamine-terminated oligomeric poly-ethylene glycol (PEG) to the surface of the derived CDs, a much stronger photoluminescence from the passivated dots was observed. Namely, we observe a strong enhancement of the CDs quantum yield from 44.4% to 67.5% by varying the PEG concentrations from 0 to 0.2 mM, respectively.

关键词： Folic Acid-Carbon dots (FA-CDs) Polyethylene glycol (PEG) Photoluminescence quantum yield (QY) Low temperature

来源：评论

学校读者我要写书评

暂无评论

Effect of shapes degrees of freedom on the fusion cross-sections of 16O+154Sm and 18O+148Nd 1

Effect of shapes degrees of freedom on the fusion cross-sect...

引用

1st International Conference on Technologies for Smart Green Connected Society 2021, ICTSGS 2021

作者： Jain, Nishu Rana, Shilpa Joshua, T.M. Kumar, Raj Bhuyan, M. School of Physics and Materials Science Thapar Institute of Engineering and Technology Patiala147004 India Institute of Engineering Mathematics Faculty of Applied and Human Sciences Universiti Malaysia Perlis Perlis Arau02600 Malaysia Center for Theoretical and Computational Physics Department of Physics Faculty of Science University of Malaya Kuala Lumpur50603 Malaysia Institute of Research and Development Duy Tan University Da Nang550000 Viet Nam

ISBN: (纸本)9781607685395

The fusion dynamics of 16O + 154Sm and 18O+148Nd reactions has been investigated to observe the effect of shape degree of freedom on the fusion cross-section using the coupled channel (CC) calculations. The one dimentional barrier penetration model (1-D BPM) is observed to underestimate the experimental data mainly at below barrier energies. The coupled channel calculations including target projectile excitations with 1 phonon of vibrational state and 2+ rotational state of target reproduce the experimental fusion cross-section for 16O + 154Sm reaction at below barrier energies while show some discrepancy for 18O+148Nd reaction. This discrepancy for 18O+148Nd reaction can be addressed with the inclusion of low-lying states with neutron transfer channels and the neck-formation. © The Electrochemical Society

关键词：

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：