2017 Impact factor 5.172
Particles and Fields

EPJ B Highlight - Semantics on the basis of words’ connectivity

Illustration of a tourist walk.

It is now possible to identify the meaning of words with multiple meanings, without using their semantic context

Two Brazilian physicists have now devised a method to automatically elucidate the meaning of words with several senses, based solely on their patterns of connectivity with nearby words in a given sentence – and not on semantics. Thiago Silva and Diego Amancio from the University of São Paulo, Brazil, reveal, in a paper just published in EPJ B, how they modelled classics texts as complex networks in order to derive their meaning. This type of model plays a key role in several natural processing language tasks such as machine translation, information retrieval, content analysis and text processing.


EPJ B Highlight - Averting worse economic collapses

The local separation of one equilibrium surface from another.

A new study shows how specific parameters can help us steer clear of tipping points in dynamic systems, such as entire economies.

By managing macro-economic parameters, scientists believe that—unlike previously thought—it is possible to steer an economy around irreversible changes in its complex dynamics and avert potential economic disasters. These findings, just published in EPJ B, stem from the theoretical work of Michael Harré and colleagues at the Complex Systems Group at the University of Sydney, Australia.


EPJ B Highlight - Predicting collective online behaviour

The visualisation of several clickstream networks.

A team of Chinese scientists evaluates the impact of a website based on the interaction between its users with the entire Web

A new study shows that small websites, in terms of daily user flux based on number of clicks, have a disproportionally high impact when it comes to traffic generation and influence compared to larger websites. These findings, just published in EPJ B, have implications for estimating the value of sites and related advertising revenue. They result from the work of Lingfei Wu from the City University of Hong Kong and Jiang Zhang from the School of Management, at Beijing Normal University, China.


EPJ B Highlight - Coupled particles cross energy wall

Numerically-computed evolution of the coupled particle density function across the potential wall

Model demonstrates that it is possible for two particles to cross an energy barrier together, where a single particle could not

For the first time, a new kind of so-called Klein tunnelling—representing the quantum equivalent of crossing an energy wall— has been presented in a model of two interacting particles. This work by Stefano Longhi and Giuseppe Della Valle from the Institute of Photonics and Nanotechnology in Milan, Italy, has just been published in EPJ B.

Klein tunnelling is a quantum phenomenon referring to the fact that a high-potential barrier can be transparent to a particle moving at a speed nearing that of light, referred to as relativistic. Most of the previous Klein tunnelling models describe the phenomenon for a single particle. However, when two particles are involved, tunnelling can be modified as a result of their mutual interaction. This means, for example, that two electrons hopping on a lattice, or two ultra-cold atoms trapped in an optical lattice can exchange energy when they occupy the same lattice site.


EPJ B Highlight - Promising doped zirconia

Positive (red) and negative (blue) isosurfaces of the magnetisation density of doped zirconia

A new study discusses the electric and magnetic characteristics of a material which could be used in spintronics

Materials belonging to the family of dilute magnetic oxides (DMOs) — an oxide-based variant of the dilute magnetic semiconductors — are good candidates for spintronics applications. This is the object of study for Davide Sangalli of the Microelectronics and Microsystems Institute (IMM) at the National Research Council (CNR), in Agrate Brianza, Italy, and colleagues. They recently explored the effect of iron (Fe) doping on thin films of a material called zirconia (ZrO2 oxide). For the first time, the authors bridged the gap between the theoretical predictions and the experimental measurements of this material, in a paper just published in EPJ B.


EPJ B Highlight - Physicists decipher social cohesion issues

Evolution of individuals into clusters representing social cohesion, under directional migrations. © H. Y. Cheng et al

Studying the effect of migration on cooperation could help to better understand social cohesion

Migrations happen for a reason, not randomly. A new study, based on computer simulation, attempts to explain the effect of so-called directional migration – migration for a reason – on cooperative behaviours and social cohesion. These results appear in a study just published in EPJ B by Hongyan Cheng from Beijing University of Posts and Telecommunications and colleagues.


EPJ B Colloquium - Why heavy doping makes ultrafast plasmonic semiconductors

This EPJB Colloquium reviews the pioneering studies of plasmon resonance in heavily doped semiconductor thin films. It also reports the chemical synthesis and structural properties of heavily doped semiconductor nanocrystals. Their linear plasmonic response (under excitation with weak continuous-wave optical fields) is illustrated both theoretically and experimentally. Finally, the authors review the most recent results on the transient (i.e. nonlinear) ultrafast plasmonic features exhibited by chalcogenide nanocrystals under excitation with ultra-fast optical pulses, including a “gold-like” theoretical model. This model turns out to provide sufficient insights into the first experiments on heavily-doped plasmonic nanoparticles.

Plasmonics in heavily-doped semiconductor nanocrystals. Francesco Scotognella et al., Eur. Phys. J. B (2013) 86: 154, DOI: 10.1140/epjb/e2013-40039-x

EPJ B Highlight - Swarm intelligence

Simulation snapshots of a swarm. © M. Romenskyy and V.Lobaskin

A new study of animal swarms uncovers some new features of their collective behaviour when overcrowding sets in

Swarming is the spontaneous organised motion of a large number of individuals. It is observed at all scales, from bacterial colonies, slime moulds and groups of insects to shoals of fish, flocks of birds and animal herds. Now physicists Maksym Romenskyy and Vladimir Lobaskin from University College Dublin, Ireland, have uncovered new collective properties of swarm dynamics in a study just published in EPJ B. Ultimately, this could be used to control swarms of animals, robots, or human crowds by applying signals capable of emulating the underlying interaction of individuals within the swarm, which could lead to predicted motion patterns elucidated through modelling.


EPJ B Highlight - Unlocking fuel cell conductivity

Temperature dependence of conductivity data of bulk YSZ. © K. L. Ngai et al.

Work on a high-conductivity material demonstrates the role of oxygen ions in enhancing their capabilities

Yttria stabilized zirconia, also known as YSZ, is a material of great interest because of its relatively high oxygen-ion based conductivity. In particular, it finds applications in electrochemical devices, such as solid oxide fuel cells and oxygen sensors. In a study published in EPJ B, Kia Ngai, from the University of Pisa in Italy, and colleagues from the Complutense University in Madrid, Spain, devised a model of the oxygen-ion dynamics that contribute to the conductivity of YSZ.


EPJ B Highlight - Spotting the invisible cracks in wind turbines

Wind turbines can be weakened by unsuspected damages. © kovik

A new approach is available for real-time monitoring of the structural health of wind turbine components during exposure to turbulences.

Physicists have now developed a new method for analysing the elastic characteristics of mechanical structures subjected to disturbances, akin to the turbulences affecting wind turbines. These results have just been published in EPJ B by Philip Rinn and his colleagues at the ForWind Center for Wind Energy Research at the University of Oldenburg, Germany.

A significant percentage of the costs of wind energy is due to wind turbine failures, as components are weakened under turbulent air flow conditions and need to be replaced. The challenge for the team was to find a method for detecting fatigue in the wind turbines’ parts without having to remove each of the components and while the turbine is in operation.


L. Baudis, G. Dissertori, K. Skenderis and D. Zeppenfeld
The author would like to thank two anonymous referees for pointing out several shortcomings in a previous version of this paper and for suggestions to improve its clarity.

J. H. Field

ISSN: 1434-6044 (Print Edition)
ISSN: 1434-6052 (Electronic Edition)

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