Possible application of memristors in ESD protection

Memristors as fundamental two-terminal electric circuit elements can be miniaturised to extreme extents. However like other electronic devices memristors can have application in the field of electrical engineering as well, e.g. in the fields of over-current protection, over-voltage protection and EMC. This paper proposes an application opportunity of memristors in ESD protection. Based on their purely dissipative character, these devices can usefully co-operate with ceramic capacitors having no ability to dissipate the energy of ESD surges. A type of structure of memristors for ESD protection purposes and a SPICE model are proposed.     

Which stresses affect the glide of screw dislocations in bcc metals?

By direct application of stress in molecular statics calculations we identify the stress components that affect the glide of 1/2?111? screw dislocations in bcc tungsten. These results prove that the hydrostatic stress and the normal stress parallel to the dislocation line do not play any role in the dislocation glide. Therefore, the Peierls stress of the dislocation cannot depend directly on the remaining two normal stresses that are perpendicular to the dislocation but, instead, on their combination that causes an equibiaxial tension-compression (and thus shear) in the plane perpendicular to the dislocation line. The Peierls stress of 1/2?111? screw dislocations then depends only on the orientation of the plane in which the shear stress parallel to the Burgers vector is applied and on the magnitude and orientation of the shear stress perpendicular to the slip direction.     

An experimental and statistical study of the behavior of the vibration field in two coupled lightweight wooden joist floors

The aim of this study was to evaluate the vibration level attenuation of a common wooden floor structure and to present the results together with the statistical precision of the evaluation. Linear regression was used to determine the attenuation rate in the two main directions of the floor structure. The probability for the attenuation rate to be zero was calculated. The attenuation rate was found to be high in the direction perpendicular to the beams with a probability to be zero lower than 0.001. In the direction parallel to the beams the attenuation rate was found to be close to zero.     

Ultra-intense femtosecond super-heavy ion beams driven by a multi-PW laser

The paper reports the results of numerical studies on the laser-driven acceleration of super-heavy ions by a multi-PW laser pulse of ultra-relativistic intensity attainable with the Extreme Light Infrastructure lasers currently being built in Europe. Using a multi-dimensional (2D3V) particle-in-cell code, it is shown that multi-GeV super-heavy (thorium) ion beams with an intensity of $～{10}^{21}\text{–}{10}^{22}\text{W}/{\text{cm}}^2$, fluence $～{10}^{17}\text{–}{10}^{18}{\text{cm}}^{?2}$ and time duration $～20\text{–}100\text{fs}$ can be produced from a sub-μm thorium target irradiated by a 150-J, 20-fs laser pulse with an intensity of ${10}^{23}\text{W}/{\text{cm}}^2$. Such ion beams are impossible to obtain presently with the use of conventional RF-driven accelerators, so they can open the door to new areas of research in both nuclear and high energy-density physics.     

The argon nuclear quadrupole moments

New standard values -116(2) mb and 76(3) mb are suggested for the nuclear quadrupole moments (Q) of the ³⁹Ar and ³⁷Ar nuclei, respectively. The Q values were obtained by combining optical measurements of the quadrupole coupling constant (B or eqQ/h) of the 3s²3p⁵4s[3/2]₂ (³P^o) and 3s²3p⁵4p[5/2]₃ (³D^e) states of argon with large scale numerical complete active space self-consistent field and restricted active space self-consistent field calculations of the electric field gradient at the nucleus (q) using the LUCAS code, which is a finite-element based multiconfiguration Hartree–Fock program for atomic structure calculations.     

Calculations of Three-Nucleon Reactions

Faddeev calculations using the chiral three-nucleon force in next-to-next-to-next-to-leading-order show that this force is too weak to provide an explanation for the low-energy A _y puzzle. The large discrepancy between data and theory for the neutron–neutron quasi-free-scattering cross section in low energy neutron–deuteron breakup requires a modification of the ${^{1}S_0}$ neutron–neutron force. We discuss the consequences that a bound ${^{1}S_0}$ state of two neutrons has on neutron–deuteron scattering observables. At higher energies we compare the solutions of the non-relativistic three-nucleon Faddeev equations with three-nucleon force included to the solutions of its Poincaré invariant version.     

Determination of the two dimensional distribution of the attempt relaxation times and activation energies from temperature dependence of dielectric dispersion

We present a method for numerical calculation of two dimensional distributions of the attempt relaxation times and activation energies from the temperature dependence of the experimental dielectric permittivity dispersion. We introduce empirical attempts to account for broad and/or asymmetric dispersions with the idea of using a weighted collection of Debye relaxation times. Then we present a modification of the aforementioned idea including attempt relaxation time and activation energy using the Arrhenius law, which significantly complicates the computation of the aforementioned distribution. Incorporating the activation energy and the attempt relaxation time into the equation transforms the discretized matrix equations into tensor equations. We rework the tensor equations into simpler matrix equations, thus permitting us to solve the presented discretized integral equation by using existing Least Distance Problem solving methods. Also, we present a regularization method and a way to choose the regularization parameter based on a best fit criterion. In the end we discuss the method showing some simulated results and experimental results. We then point out some problems involved in the calculations and propose methods to reduce their significance.     

Matter-wave interferometer for large molecules

We demonstrate a near-field Talbot-Lau interferometer for C70 fullerene molecules. Such interferometers are particularly suitable for larger masses. Using three free-standing gold gratings of 1 microm period and a transversally incoherent but velocity-selected molecular beam, we achieve an interference fringe visibility of 40% with high count rate. Both the high visibility and its velocity dependence are in good agreement with a quantum simulation that takes into account the van der Waals interaction of the molecules with the gratings and are in striking contrast to a classical moiré model.