The European Physical Journal B最新文献

{"title":"The charge states in polypropylene doped with ZrO2 nanoparticles and their changes at heat treatment","authors":"Hijran S. Ibrahimova,&nbsp;Tahir D. Ibragimov","doi":"10.1140/epjb/s10051-024-00801-5","DOIUrl":"10.1140/epjb/s10051-024-00801-5","url":null,"abstract":"<p>Charge states of polypropylene doped with zirconium oxide nanoparticles and their changes during heat treatment at different temperatures are studied by the method of thermally stimulated depolarization (TSD) current. It is shown that two peaks associated with the release of charge from different types of traps appear on the TSD thermograms for both pure polypropylene and composites. With an increase in the concentration of the filler, the intensity of the peaks increases up to 3 vol.%. A further increase in concentration leads to a decrease in the intensity of the peaks. The activation energy of charge release from traps, temperature of maximum of the peaks, and the magnitude of the accumulated charge in the traps have also maximal value at nanoparticle concentration of 3 vol.%. The study of charge characteristics of the nanocomposite with concentration of 3 vol.% after heat treatment shows that the intensity of TSD peaks, the temperature of peak maxima, and the activation energy of charge release increase with increasing pre-treatment temperature. The magnitude of the charge accumulated in traps at low treatment temperatures is practically unchanged but has a maximal value at treatment temperature of 140 °C owing to the increase in the number of traps.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"97 10","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142447296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fuels: a key factor to influence the luminescence properties of CaAl2O4: Dy phosphors","authors":"Kabita Ku. Satapathy,&nbsp;Satya N. Tripathy","doi":"10.1140/epjb/s10051-024-00799-w","DOIUrl":"10.1140/epjb/s10051-024-00799-w","url":null,"abstract":"<div><p>Most commercially available phosphors are made from appropriately doped polycrystalline materials while the activation methods have often been examined, the impact of fuels on the host preparation and its effect on the final performance of the products has received less focus. This paper explores the use of various fuels in the synthesis of Dy-doped CaAl₂O₄ phosphors. Dysprosium-doped monoclinic CaAl₂O₄ phosphors were obtained at low temperatures (500 °C) by the process of combustion of the corresponding metal nitrate–fuel mixtures, over a period of 5 min. In this paper, attention has been paid to the influence of fuels on the luminescence properties of the phosphor sample which is prepared by solution combustion method. Dy-activated CaAl₂O₄ phosphor was synthesized by combustion technique using hydrazine, carbohydrazide, and urea as fuels. XRD analysis reveals that introducing a small quantity of rare earth ions into the raw materials did not alter the crystal structure of CaAl₂O₄. XRD result confirms the formation of the sample. Photoluminescence (PL) emission spectrum showed characteristic emission of Dy doped in the CaAl₂O₄ samples. The highest photoluminescence intensity was observed at a 0.02 mol% concentration of Dy. The PL spectrum exhibits wide peaks near 488 and 573 nm when excited at 347 nm. Mechanoluminescence (ML) and Thermoluminescence (TL) properties of the material have been emphasized. Various ML and TL curves have been recorded to assess which of the fuels yields the most efficient CaAl₂O₄: Dy compound. The prepared sample may be useful in TL dosimetry. In the present investigation it is found that urea is a better fuel for preparing CaAl₂O₄: Dy phosphors and enhances the ML and TL intensity of the sample.</p><h3>Graphical abstract</h3><p>PL emission spectra of CaAl2O4: Dy phosphors synthesized by urea, carbohydrazide and hydrazine, where urea provides the highest PL intensity, making it an optimal choice for enhancing optical performance.</p><div><figure><div><div><picture><img></picture></div></div></figure></div></div>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"97 10","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjb/s10051-024-00799-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142443172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Insights from microcanonical thermostatistics into amylin analogues and amyloid-({upbeta }) cross-seeding","authors":"Rafael B. Frigori","doi":"10.1140/epjb/s10051-024-00796-z","DOIUrl":"10.1140/epjb/s10051-024-00796-z","url":null,"abstract":"<p>Growing evidence from population studies and clinical observations strongly suggests a complex connection between major proteinopathies, to know, Type 2 diabetes (T2D) and Alzheimer’s disease (AD). People with T2D face a significantly higher risk of developing AD compared to those without diabetes. These two conditions share several key features, such as inflammation, oxidative stress, metabolic dysfunction, and the buildup of certain proteins known as beta-amyloid (A<span>(upbeta )</span>42) and pancreatic islet amyloid polypeptide (IAPP or amylin). In AD, the brain develops characteristic senile plaques mainly composed of A<span>(upbeta )</span>42. Similarly, in individuals with T2D, the pancreas shows deposits of a protein called human amylin (hIAPP). The accumulation of these aggregated proteins in both the brain and pancreas has been associated with impaired cell function and even cell death. To gain molecular insight in the outset of such complex scenario, we perform microcanonical thermostatistics analysis of Monte Carlo simulations of A<span>(upbeta )</span>42 cross-seeded by hIAPP, or its biotechnological therapeutic analogous as Pramlintide. We find that while A<span>(upbeta )</span>42 is quite prone to cross-seed with hIAPP, and then to aggregate around that critical nuclei, this can be abolished for some of its analogues, which may possibly lead to alternative therapeutic approaches to T2D and AD.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"97 10","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142443248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Majorana bound states and phase transitions in first- and second-order topological superconductors","authors":"Xiang-Nan Yuan,&nbsp;Yue Xie,&nbsp;Guo-Qiao Zha","doi":"10.1140/epjb/s10051-024-00800-6","DOIUrl":"10.1140/epjb/s10051-024-00800-6","url":null,"abstract":"<p>Based on the spin-generalized Bogoliubov–de Gennes theory, we investigate the existence of first- and second-order topological phases in Rashba superconducting ribbon and loop systems. The topological phase transitions driven by the strength of spin-orbit coupling and the spin correlation as well as the temperature are demonstrated. The formation of zero-energy Majorana edge or corner states is highly sensitive to these effects. Due to the modification of the relative strength of competing <i>s</i>- and <i>d</i>-wave pairing symmetries, the number and location of Majorana zero modes in the square loop may be tuned by the introduced spin correlation. Meanwhile, the second-order topological phase and emergent Majorana corner modes can remain robust for finite temperatures. We expect that our theoretical predictions may provide useful information for future experiments.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"97 10","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142434735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heterogeneous hypergraph representation learning for link prediction","authors":"Zijuan Zhao,&nbsp;Kai Yang,&nbsp;Jinli Guo","doi":"10.1140/epjb/s10051-024-00791-4","DOIUrl":"10.1140/epjb/s10051-024-00791-4","url":null,"abstract":"<p>Heterogeneous graph representation learning gains popularity due to its powerful capabilities of feature extraction and numerous related algorithms have emerged for various downstream tasks in graph structural datasets. However, the interactions among nodes for the heterogeneous graphs in the real world often extend beyond individual pairs, excessive attention is payed on isolated pairwise connections. In this paper, we propose a novel framework of Heterogeneous Hypergraph Representation Learning method (HHRL) to capture high-order interactions for learning effective node representations of heterogeneous graphs. The method firstly organizes the heterogeneous connections as different hypergraphs. By modeling the heterogeneous connections, HHRL captures the rich structural and semantic information present in the graphs. Then, the graph neural network (GNN) is applied for each hypergraph to capture the interdependencies between nodes and their associated features. By utilizing GNN, HHRL can effectively learn expressive node representations that encode both the structural and feature information of the network. Finally, we concatenate the vectors from different hypergraphs to obtain the link representations. The experiments are conducted on five real dataset for link prediction and the results demonstrate the well performance of the proposed framework comparing to the existing baselines</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"97 10","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142411144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Empirical analysis of hourly rainfall data in Sicily from 2002 to 2023","authors":"Vera Pecorino,&nbsp;T. Di Matteo,&nbsp;Matteo Milazzo,&nbsp;Luigi Pasotti,&nbsp;Alessandro Pluchino,&nbsp;Andrea Rapisarda","doi":"10.1140/epjb/s10051-024-00792-3","DOIUrl":"10.1140/epjb/s10051-024-00792-3","url":null,"abstract":"<p>Rainfall constitutes an important climatic variable as its lack can lead to severe droughts while its excess can trigger catastrophic events. The Mediterranean basin is one of the European regions most affected by climate change’s effects and Sicily island, for its location in the middle of the Mediterranean sea, represents a very interesting place to study climatic variables. During the last decade, Sicily displayed unusual rainfall behavior and unexpected extreme events. In this paper, we depict how seasonal rainfall characteristics and trends changed since the beginning of twenty-first century. Using an empirical approach, we are able to confirm with a higher resolution previous results obtained through less granular data and detect the emergence of new anomalous behaviors. From our study we see that, after the heavy summer drought during 2009–2012, all seasons recorded a sudden volume variation: increasing during autumn–summer and decreasing in winter–spring. This coupled behavior emerges as an anomaly for the period 2013–2023: the similarity between summer–autumn and winter–spring highlights the passage from a 4 to a 2 season-like cycle,with the occurrence of severe droughts and frequent flash floods. The present contribution adds further evidence that a deep change is occurring and that new strategies for managing risks and resources are urgently needed to reduce human and economic losses.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"97 10","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142411175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Neuronal avalanches in level model under the influence of noisy drive","authors":"Abdul Quadir,&nbsp;Rahul Chhimpa,&nbsp;Haider Hasan Jafri,&nbsp;Avinash Chand Yadav","doi":"10.1140/epjb/s10051-024-00794-1","DOIUrl":"10.1140/epjb/s10051-024-00794-1","url":null,"abstract":"<p>We study a neural-level model (Das and Levina Phys Rev X 9:021062, 2019) that exhibits critical avalanches satisfying power-law distribution. The model recently explained a change in the scaling exponent from 3/2 to 5/4, accounting for a change in the drive condition from no input to moderate strength, along with a relaxed separation of time scale between drive and dissipation. We examine the effect of a class of noisy stimuli in the moderate input regime. Applying the scaling method, we compute scaling functions associated with the avalanche size distribution, revealing striking finite-size scaling. For a class of noisy drives, we find that the scaling exponent can take a value different from 5/4, with an explicit system size dependence.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"97 10","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142410878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sharp detection of the onset of Floquet heating using eigenstate sensitivity","authors":"Sourav Bhattacharjee,&nbsp;Souvik Bandyopadhyay,&nbsp;Anatoli Polkovnikov","doi":"10.1140/epjb/s10051-024-00773-6","DOIUrl":"10.1140/epjb/s10051-024-00773-6","url":null,"abstract":"<p>Chaotic Floquet systems at sufficiently low driving frequencies are known to heat up to an infinite temperature ensemble in the thermodynamic limit. However at high driving frequencies, Floquet systems remain energetically stable in a robust prethermal phase with exponentially long heating times. We propose sensitivity (susceptibility) of Floquet eigenstates against infinitesimal deformations of the drive, as a sharp and sensitive measure to detect this heating transition. It also captures various regimes (timescales) of Floquet thermalization accurately. Particularly, we find that at low frequencies near the onset of unbounded heating, Floquet eigenstates are maximally sensitive to perturbations and consequently the scaled susceptibility develops a sharp maximum. We further connect our results to the relaxation dynamics of local observables to show that near the onset of Floquet heating, the system is nonergodic with slow glassy dynamics despite being nonintegrable at all driving frequencies.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"97 10","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142410979","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of group size and noise on cooperation in population evolution of dynamic groups","authors":"Hong-Bin Zhang,&nbsp;Deng-Ping Tang","doi":"10.1140/epjb/s10051-024-00787-0","DOIUrl":"10.1140/epjb/s10051-024-00787-0","url":null,"abstract":"<p>We consider a large population of <span>(textit{M})</span> agents, who are randomly selected to form size-distributed groups from time to time, and the grouped agents engage in the Public Goods Game (PGG). The size <span>(textit{g})</span> of the group is within <span>(textit{g}_textit{l})</span> and <span>(textit{g}_textit{h})</span>, where <span>(textit{g}_textit{l})</span> and <span>(textit{g}_textit{h})</span> are the lower and upper limits of the group size, respectively. Players have two strategies to choose, i.e., to cooperate (C), or to defect (D). Based on the dynamic grouping, we investigate the cooperative behavior of the system, and the results show that the frequency of cooperation is greatly affected by the noise intensity and group size distribution. In the evolutionary process, the payoffs of the cooperators (defectors) mainly depend on the strategy selection implemented by the death-birth process. For <span>(textit{g}in text {[1,3]})</span>, different noise intensities <span>(textit{K})</span> induce different dynamic behaviors together with the multiplication factor <span>(textit{r})</span>. For <span>(textit{g}in text {[1,5]})</span>, the system may evolve to one of the bistable states (one is the totally cooperative state and the other is a mixed state with cooperators and defectors) starting from different initial concentrations of cooperation. The results of numerical computation seems to fit well with the simulation data. Furthermore, for <span>(K=1.0)</span> and <span>(g in [1,5])</span>, we still observe the phenomenon of hysteresis effect where the system just reaches to the totally cooperative state slowly after a period of delay with increasing multiplication factor <i>r</i>. In addition, when one D-player tries to invade the C-population, there exists a critical game parameter <span>(textit{r}_textit{invade})</span>, below which the C-population will be invaded. We also study how the critical game parameter relies on the noise intensity and the group size distribution.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"97 10","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142410970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An ab-initio study of nodal-arcs, axial strain’s effect on nodal-lines and Weyl nodes and Weyl-contributed Seebeck coefficient in TaAs class of Weyl semimetals","authors":"Vivek Pandey,&nbsp;Sudhir K. Pandey","doi":"10.1140/epjb/s10051-024-00788-z","DOIUrl":"10.1140/epjb/s10051-024-00788-z","url":null,"abstract":"<p>This work establishes the existence of dispersive <i>nodal-arcs</i> and their evolution into Weyl nodes under the effect of spin-orbit coupling (SOC) in NbAs and NbP. The obtained features mimic the observations as reported for TaAs and TaP in our previous work (Pandey in J Phys Condens Matter 35:455501, 2023). In addition, this work reports that the number of nodes in the TaAs class of Weyl semimetals (WSMs) can be altered by creating strain along <i>a</i> or <i>c</i> direction of the crystals. For instance, the number of nodes in NbAs under SOC-effect along with 2% (3%) tensile-strain in <i>a</i> direction is found to be 40 (56) in its full Brillouin zone (BZ). Besides the nodes, such strain are found to have considerable impact on the nodal-lines of these WSMs when effect of SOC is ignored. In the absence of SOC, a 3% tensile (compressive) strain along the <i>a</i> (<i>c</i>) direction leads to the partially merging of nodal-lines in the extended BZ of NbAs and NbP, which is not observed in TaAs and TaP within the range of – 3% to 3% strain. Apart from this, the work discusses the role of Weyl physics in affecting the Seebeck coefficient (<i>S</i>) of any WSM. In this direction, it is discussed that how a symmetric Weyl cone, even if tilted, will have no contribution to the <i>S</i> of WSMs. Furthermore, the work highlights the conditions under which a Weyl cone can contribute to the <i>S</i> of a given WSM. Next, the discussion of Weyl contribution to <i>S</i> is validated over TaAs class of WSMs via investigating the features of their Weyl cones and calculating the contributions of such cones to the <i>S</i> of these semimetals. Weyl-cone contributed <i>S</i> in these WSMs is found to be anisotropic within the temperature range of 0–100 K. The value of <i>S</i> contributed from Weyl cone is found to be as large as <span>(sim )</span>70 <span>(mu )</span><i>V</i>/<i>K</i> below 25 K in case of NbP. Lastly, the expected effect of axial strain and change in SOC-strength on <i>S</i> of TaAs class of WSMs is discussed. The findings of this work present a possibility of engineering the topological properties of TaAs class of WSMs via creating strain in their crystal. It also makes the picture of Weyl physics’  impact on the <i>S</i> of WSMs a more clear.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"97 10","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142410745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}