M2B5 or M2B4? A Reinvestigation of the Mo/B and W/B System

The literature states different compositions (M/B = 1:2 vs. 2:5) and structures for diborides of molybdenum and tungsten. Using X‐ray and neutron powder diffraction as well as energy and wavelength dispersive electron microprobe analysis, the Mo/B and W/B systems were now reinvestigated. Molybdenum diboride crystallizes as a stoichiometric compound Mo₂B₄ (formerly described as Mo₂B₅) in space group (No. 166, a, b = 3.01375(2) Å, c = 20.9541(3) Å), and as a non‐stoichiometric compound MoB_2?x (formerly described as MoB₂) in P6/mmm (No. 191, a, b = 3.043(2) Å, c = 3.067(2) Å), whereas stoichiometric tungsten diboride W₂B₄ (formerly described as W₂B₅) is found to crystallize in space group P6₃/mmc (No. 194, a, b = 2.9864(4) Å, c = 13.896(2) Å). These results seem to be supported by DFT calculations which show the instability of a hypothetic W₂B₅.     

Transparent Interconnection of Metro Access and Metro Core Networks Including Protection

We proposed and demonstrated a solution for the transparent interconnection of metro access and metro core networks enabling end-to-end wavelength provisioning including the protection.     

A new friedelane triterpenoid and saponin with moderate antimicrobial activity from the stems of Drypetes laciniata

A new friedelane-type triterpene named 3β-hydroxyfriedelane-7,12,22-trione,as well as nine known compounds were isolated from the whole stems of Drypetes laciniata Hutch.(Euphorbiaceae).Their structures were established on the basis of spectroscopic methods.The new triterpene derivative and a known saponin were tested for antimicrobial and antifungal activities and they appeared to be moderate active.     

THE RANDOM BATCH METHOD FOR N-BODY QUANTUM DYNAMICS

This paper discusses a numerical method for computing the evolution of large inter-acting system of quantum particles.The idea of the random batch method is to replace the total interaction of each particle with the N-1 other particles by the interaction with p ＜＜ N particles chosen at random at each time step,multiplied by (N-1)/p.This re-duces the computational cost of computing the interaction potential per time step from O(N2) to O(N).For simplicity,we consider only in this work the case p =1 — in other words,we assume that N is even,and that at each time step,the N particles are orga-nized in N/2 pairs,with a random reshuffling of the pairs at the beginning of each time step.We obtain a convergence estimate for the Wigner transform of the single-particle reduced density matrix of the particle system at time t that is both uniform in N ＞ 1 and independent of the Planck constant h.The key idea is to use a new type of distance on the set of quantum states that is reminiscent of the Wasserstein distance of exponent 1 (or Monge-Kantorovich-Rubinstein distance) on the set of Borel probability measures on Rd used in the context of optimal transport.     

Control of a separated boundary layer: reduced-order modeling using global modes revisited

The possibility of model reduction using global modes is readdressed, aiming at the controlling of a globally unstable separation bubble induced by a bump geometry. A combined oblique and orthogonal projection approach is proposed to design an estimator and controller in a Riccati-type feedback setting. An input?Coutput criterion is used to appropriately select the modes of the projection basis. The full-state linear instability dynamics is shown to be successfully controlled by the feedback coupling with controllers of moderate degrees of freedom.