发布求助
文献互助 智能选刊 最新文献

EPL (Europhysics Letters)最新文献

筛选
英文 中文
Formulation of an electrostatic field with a charge density in the presence of a minimal length based on the Kempf algebra 基于Kempf代数的最小长度条件下带电荷密度的静电场公式
EPL (Europhysics Letters) Pub Date : 2012-06-01 DOI: 10.1209/0295-5075/98/50001
S. K. Moayedi, M. Setare, H. Moayeri
{"title":"Formulation of an electrostatic field with a charge density in the presence of a minimal length based on the Kempf algebra","authors":"S. K. Moayedi, M. Setare, H. Moayeri","doi":"10.1209/0295-5075/98/50001","DOIUrl":"https://doi.org/10.1209/0295-5075/98/50001","url":null,"abstract":"In a series of papers, Kempf and co-workers (J. Phys. A: Math. Gen., 30 (1997) 2093; Phys. Rev. D, 52 (1995) 1108; Phys. Rev. D, 55 (1997) 7909) introduced a D-dimensional (β, β′)-two-parameter deformed Heisenberg algebra which leads to a nonzero minimal observable length. In this work, the Lagrangian formulation of an electrostatic field in three spatial dimensions described by Kempf algebra is studied in the case in which β′ =2β up to first order over the deformation parameter β. It is shown that there is a similarity between electrostatics in the presence of a minimal length (modified electrostatics) and higher-derivative Podolsky's electrostatics. The important property of this modified electrostatics is that the classical self-energy of a point charge becomes a finite value. Two different upper bounds on the isotropic minimal length of this modified electrostatics are estimated. The first upper bound will be found by treating the modified electrostatics as a classical electromagnetic system, while the second one will be estimated by considering the modified electrostatics as a quantum field-theoretic model. It should be noted that the quantum upper bound on the isotropic minimal length in this paper is near to the electroweak length scale (ℓelectroweak∼10− 18 m).","PeriodicalId":171520,"journal":{"name":"EPL (Europhysics Letters)","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125530227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 15
Active Brownian particles in two-dimensional traps 二维阱中的活跃布朗粒子
EPL (Europhysics Letters) Pub Date : 2012-06-01 DOI: 10.1209/0295-5075/98/50004
A. Pototsky, H. Stark
{"title":"Active Brownian particles in two-dimensional traps","authors":"A. Pototsky, H. Stark","doi":"10.1209/0295-5075/98/50004","DOIUrl":"https://doi.org/10.1209/0295-5075/98/50004","url":null,"abstract":"We consider a population of self-propelled Brownian particles in 2D traps. For non-interacting particles the stationary distribution for position and orientation is found analytically for small and large rotational diffusivities. These results are used to map the system of interacting active particles onto a system of passive particles in a modified trapping potential which we then formulate as a dynamic density functional theory. Our approach is supported by Brownian dynamics simulations of the original and the effective model.","PeriodicalId":171520,"journal":{"name":"EPL (Europhysics Letters)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115807355","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 82
Some non-linear effects of stationary heat conduction in 3D domains through extended thermodynamics 用扩展热力学的方法研究三维领域中稳态热传导的非线性效应
EPL (Europhysics Letters) Pub Date : 2012-06-01 DOI: 10.1209/0295-5075/98/54004
E. Barbera, F. Brini, G. Valenti
{"title":"Some non-linear effects of stationary heat conduction in 3D domains through extended thermodynamics","authors":"E. Barbera, F. Brini, G. Valenti","doi":"10.1209/0295-5075/98/54004","DOIUrl":"https://doi.org/10.1209/0295-5075/98/54004","url":null,"abstract":"We describe stationary heat conduction in an ideal gas at rest between three-dimensional manifolds. To this aim, we refer to the field equations of extended thermodynamics. The solution is determined through a 3rd-order asymptotic expansion with respect to the Knudsen number. As illustrative examples, we show the results for a gas enclosed between two non-coaxial circular cylinders or two confocal elliptical cylinders. With respect to the classical thermodynamics, we obtain corrections on the temperature, stress tensor and heat flux, that give rise to more complex behaviors of these variables. The dependence on the parameters is also analyzed.","PeriodicalId":171520,"journal":{"name":"EPL (Europhysics Letters)","volume":"115 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131749847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 17
Elementary and collective excitations as probes for order parameter symmetry in Fe-based superconductors 作为铁基超导体序参量对称探测的初等激发和集体激发
EPL (Europhysics Letters) Pub Date : 2012-06-01 DOI: 10.1209/0295-5075/98/57012
H. Ghosh, H. Purwar
{"title":"Elementary and collective excitations as probes for order parameter symmetry in Fe-based superconductors","authors":"H. Ghosh, H. Purwar","doi":"10.1209/0295-5075/98/57012","DOIUrl":"https://doi.org/10.1209/0295-5075/98/57012","url":null,"abstract":"We show that the superconducting quasiparticle energy of Fe-based superconductors would be different for a sign-changing order parameter than that for a non–sign-changing order parameter. This particularly happens in the low-doping region when the electron and hole Fermi surfaces nest and superconductivity coexists with either magnetic or orbital or both density waves. This difference in the nature of superconducting quasiparticles is also detectable from collective mode excitations. We further show that while the magnetic spin density wave order competes with superconductivity, the orbital density wave grows when the superconductivity order parameter changes sign accross the electron-hole Fermi surface. However, when the superconducting order parameter does not change sign both the density waves compete with superconductivity. Irrespective of the nature of the superconducting order parameter the spin and orbital density waves are concurrent indicating simultaneous magnetic and structural transition. The significance of the various results is discussed comparing the various experimental observations.","PeriodicalId":171520,"journal":{"name":"EPL (Europhysics Letters)","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131883001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 9
Reply to the Comment by D. Spemann et al. 回复D. Spemann等人的评论。
EPL (Europhysics Letters) Pub Date : 2012-06-01 DOI: 10.1209/0295-5075/98/57007
M. Sepioni, Rahul Nair, I-Ling Tsai, Andre K. Geim, I. Grigorieva
{"title":"Reply to the Comment by D. Spemann et al.","authors":"M. Sepioni, Rahul Nair, I-Ling Tsai, Andre K. Geim, I. Grigorieva","doi":"10.1209/0295-5075/98/57007","DOIUrl":"https://doi.org/10.1209/0295-5075/98/57007","url":null,"abstract":"This article is a reply to the Comment by D. Spemann et al (arXiv:1204.2992) in response to our paper 'Revealing common artifacts due to ferromagnetic inclusions in highly oriented pyrolytic graphite' (EPL, 97 (2012) 47001).","PeriodicalId":171520,"journal":{"name":"EPL (Europhysics Letters)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126474892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 5
Phonon-roton modes in liquid 4He coincide with Bose-Einstein condensation 液体4He中的声子-光子模式与玻色-爱因斯坦凝聚一致
EPL (Europhysics Letters) Pub Date : 2012-06-01 DOI: 10.1209/0295-5075/98/56008
J. Bossy, J. Ollivier, H. Schober, H. Glyde
{"title":"Phonon-roton modes in liquid 4He coincide with Bose-Einstein condensation","authors":"J. Bossy, J. Ollivier, H. Schober, H. Glyde","doi":"10.1209/0295-5075/98/56008","DOIUrl":"https://doi.org/10.1209/0295-5075/98/56008","url":null,"abstract":"We present neutron scattering measurements of the phonon-roton (P-R) and layer modes of liquid 4He confined in MCM-41 under pressure up to 38 bar. The data shows unambiguously that the P-R mode exists at low temperature only. As temperature is increased, there is a gradual transfer of intensity from the P-R mode to the normal liquid response, which lies at a lower energy at higher pressure. The transfer takes place with no observable mode broadening. The loss of P-R modes is identified with the loss of Bose-Einstein condensation (BEC). The mode giving rise to the specific heat, cV, of liquid 4He in porous media (e.g., gelsil) at higher temperature is the layer mode since the energy of the mode extracted from cV and the layer mode energy are the same.","PeriodicalId":171520,"journal":{"name":"EPL (Europhysics Letters)","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132650235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 10
Self-diffusion in nanopores studied by the NMR pulse gradient spin echo 用核磁共振脉冲梯度自旋回波研究纳米孔中的自扩散
EPL (Europhysics Letters) Pub Date : 2012-06-01 DOI: 10.1209/0295-5075/98/57009
J. Stepišnik, B. Fritzinger, U. Scheler, A. Mohorič
{"title":"Self-diffusion in nanopores studied by the NMR pulse gradient spin echo","authors":"J. Stepišnik, B. Fritzinger, U. Scheler, A. Mohorič","doi":"10.1209/0295-5075/98/57009","DOIUrl":"https://doi.org/10.1209/0295-5075/98/57009","url":null,"abstract":"NMR pulse gradient spin echo is the most efficient method for non-invasive elucidation of molecular transport in heterogeneous media. With a proper interpretation of experimental data, the method can also be applied to investigate molecular self-diffusion in pores small enough that the characteristic diffusion times are much shorter than time, needed to build up the spin phase structure by the pulse of magnetic field gradient. This is demonstrated by the analysis of restricted self-diffusion measurement of water molecules trapped in a polyamide membrane. The results are presented as a distribution of spin-relaxation rates and pore sizes in this nanoporous system that also present the method in its true colors as a useful tool in the bio-nanotechology.","PeriodicalId":171520,"journal":{"name":"EPL (Europhysics Letters)","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132214746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 3
Effective medium of periodic fluid-solid composites 周期性流固复合材料的有效介质
EPL (Europhysics Letters) Pub Date : 2012-06-01 DOI: 10.1209/0295-5075/98/54001
Jun Mei, Ying Wu, Zhengyou Liu
{"title":"Effective medium of periodic fluid-solid composites","authors":"Jun Mei, Ying Wu, Zhengyou Liu","doi":"10.1209/0295-5075/98/54001","DOIUrl":"https://doi.org/10.1209/0295-5075/98/54001","url":null,"abstract":"An analytic solution of the effective mass density and bulk modulus of a periodic fluid-solid composite is obtained by using the multiple-scattering theory in the long-wavelength limit. It is shown that when the concentration of solid inclusions is high, the effective mass density is structure dependent and differs significantly from the leading-order dipole solution, whereas Wood's formula is accurately valid, independently of the structures. Numerical evaluations from the analytic solution are shown to be in excellent agreement with finite-element simulations. In the vicinity of the tight-packing limit, the critical behavior of the effective mass density is also studied and it is independent of the lattice symmetry.","PeriodicalId":171520,"journal":{"name":"EPL (Europhysics Letters)","volume":"86 1-2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132062374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 9
Size-induced transition from non–Griffiths-like to Griffiths-like clustered phase above the Curie temperature 在居里温度以上，由非类格里菲思相到类格里菲思簇相的尺寸诱导转变
EPL (Europhysics Letters) Pub Date : 2012-06-01 DOI: 10.1209/0295-5075/98/57004
S. Zhou, Y. Guo, J. Zhao, L. F. He, L. Shi
{"title":"Size-induced transition from non–Griffiths-like to Griffiths-like clustered phase above the Curie temperature","authors":"S. Zhou, Y. Guo, J. Zhao, L. F. He, L. Shi","doi":"10.1209/0295-5075/98/57004","DOIUrl":"https://doi.org/10.1209/0295-5075/98/57004","url":null,"abstract":"Recent studies on several pervoskite oxides such as Sm0.5Sr0.5MnO3, La0.7Sr0.3CoO3, and La2NiMnO6, reveal that their inverse susceptibilities exhibit an upward deviation from Curie-Weiss behavior above TC, indicating the existence of a non–Griffiths-like clustered phase due to the dominance of antiferromagnetic interactions in this regime. Here, we study the magnetic behaviors of their nanoparticles and find that the deviation becomes sharply downward, which is a typical characteristic of a Griffiths-like phase. This suggests that reducing the particle size induces a phase transition from non–Griffiths-like to Griffiths-like. We propose that the weakening of the antiferromagnetic interactions by size reduction is responsible for this transition.","PeriodicalId":171520,"journal":{"name":"EPL (Europhysics Letters)","volume":"134 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127370327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 11
Structures in fully differential cross-sections for proton impact ionization of helium 氦质子碰撞电离的全微分截面结构
EPL (Europhysics Letters) Pub Date : 2012-06-01 DOI: 10.1209/0295-5075/98/53001
X. Ma, X. Li, S. Sun, X. Jia
{"title":"Structures in fully differential cross-sections for proton impact ionization of helium","authors":"X. Ma, X. Li, S. Sun, X. Jia","doi":"10.1209/0295-5075/98/53001","DOIUrl":"https://doi.org/10.1209/0295-5075/98/53001","url":null,"abstract":"The three-Coulomb wave (3C) model is applied to study single ionization of helium by 75 keV proton impact. Fully differential cross-sections (FDCS) are calculated in both the scattering plane and the perpendicular plane. The results are compared with experimental data and other theoretical predictions and we find that the present 3C results qualitatively reproduce the experimental peak structure, especially in the perpendicular plane. Furthermore, the contributions of various scattering amplitudes to FDCS in the present model are discussed. It turns out that the cross-section is strongly influenced by the interference of these amplitudes. In particular, the theory predicts the minimum at the largest momentum transfer in the perpendicular plane due to the interference.","PeriodicalId":171520,"journal":{"name":"EPL (Europhysics Letters)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115273776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 17
首页 上一页 下一页 尾页
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整，为了账户安全，请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
请完成安全验证×
相关产品
×
本文献相关产品
联系我们：info@booksci.cn Book学术提供免费学术资源搜索服务，方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号：481959085
Book学术官方微信