Non perturbative approach for a polar and polarizable linear molecule in an inhomogeneous electric field: Application to molecular beam deviation experiments

A non perturbative approach is used to solve the problem of a rigid linear molecule with both a permanent dipole moment and a static dipole polarizability, in a static electric field. Eigenenergies are obtained and compared to perturbative low field and high field approximations. Analytical expressions for the orientation parameters and for the gradient of the energy are given. This non perturbative approach is applied to the simulation of beam deviation experiments in strong electric field. Results of simulations are given for inhomogeneous alkali dimers. For LiNa, the simulations are compared to experimental data. For LiK, deviation profiles have been simulated in order to prepare future experiments on this molecule. Received 21 July 1999 and Received in final form 22 September 1999     

The action of a few permutations on r-tuples is quickly transitive

We prove that for every r and d≥2 there is a C such that for most choices of d permutations π₁, π₂,…,π_d of S_n, the following holds: for any two r-tuples of distinct elements in {1,…,n}, there is a product of less than C log n of the π_is which map the first r-tuple to the second. Although we came across this problem while studying a rather unrelated cryptographic problem, it belongs to a general context of which random Cayley graph quotients of S_n are good expanders. © 1998 John Wiley & Sons, Inc. Random Struct. Alg., 12: 335–350, 1998     

On the validity of crystallization kinetics parameters derived from the depolarized light intensity (DLI) technique: An experimental study of polyvinylidene fluoride

Although the depolarized light intensity technique has been known for some decades, the time dependence of light intensity does not yet seem to be well understood. In this article, devoted to the crystallization kinetics of polyvinylidene fluoride (PVDF), we present some of the problems associated with quantitative analysis. Parameters such as incident light intensity—in combination with the detection system—and specimen thickness are shown to dramatically affect the apparent kinetics. Experiments on single spherulites grown in very thin films can help interpret the intensity–time curve. Our results demonstrate that care should be taken when comparison is made between DLI and differential scanning calorimetry. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 997–1008, 1999     

Synthetic Utility of Stable Phosphanylcarbenes: Synthesis and Crystal Structure of an α‐(Lithiomethylene)phosphorane

The first crystallographically characterized phosphonium yldiide 2 was obtained in a simple reaction by addition of n‐butyllithium to the stable phosphanyl(silyl)carbene 1 . R=cHex₂N.     

Entire Solution in Cylinder-Like Domains for a Bistable Reaction–Diffusion Equation

We construct nontrivial entire solutions for a bistable reaction–diffusion equation in a class of domains that are unbounded in one direction. The motivation comes from recent results of Berestycki et al. (Calc Var Partial Differ Equ 55(3):1–32, 2016) concerning propagation and blocking phenomena in infinite domains. A key assumption in their study was the “cylinder-like” assumption: their domains are supposed to be straight cylinders in a half space. The purpose of this paper is to consider domains that tend to a straight cylinder in one direction. We need a different approach based on the long time stability of the bistable wave in heterogeneous media. We also prove the existence of an entire solution for a one-dimensional problem with a non-homogeneous linear term.     

Magnetodielectric coupling in Ca3Co2O6 triangular Ising lattice

Geometric frustration in magnetic systems is a key ingredient for magnetodielectric coupling. Ca₃Co₂O₆ system is a model of triangular Ising lattice and presenting exotic magnetic properties. With a partially disordered antiferromagnetic ground state and two steps in magnetisation to a ferrimagnetic state and to a ferromagnetic state, this oxide is a good system for studying the effect of frustration in magnetodielectric coupling. Dielectric constant measurements of single crystals of Ca₃Co₂O₆ have been done showing the sensitivity of this technique to frustration.     

On Bell,Suarez-Scarani,and Leggett Experiments: Reply to a Comment by Marek Żukowski in [Found. Phys. 38:1070, 2008]

It is shown that the before-before (or Suarez-Scarani) experiment refutes hidden variable models with a deterministic (“realistic”) nonlocal part, whereas experiments violating Leggett-type inequalities refute models with biased random local part. Therefore the claim that Gröblacher et al. (Nature 446:871–875, 2007) present “an experimental test of nonlocal realism” is misleading, and Marek ?ukowski’s (Found. Phys. 38:1070, 2008) comment misses the point. A new experiment is suggested.     

A stereoselective synthetic entry to β-substituted α-[(trans)-vinyl] phosphonamides

α-(trans-Vinyl) phosphonamides with different substituents at the β-position were stereoselectively synthesized in high yields by treatment of β-substituted α-epoxy-α-trimethylsilyl phosphines with oxidizing agents. The corresponding phosphonamides were unstable in most cases and underwent reductive elimination affording desilylated vinyl derivatives. In turn, α-epoxy phosphines resulted from the [1+2] addition of [bis(diisopropylamino)phosphino](trimethylsilyl)carbene 2 to aliphatic, aromatic, and heteroaromatic aldehydes. In this way, a great variety of vinyl compounds have been efficiently prepared through one-pot procedure.     

Hybrid Flow-Shop: a Memetic Algorithm Using Constraint-Based Scheduling for Efficient Search

The paper considers the hybrid flow-shop scheduling problem with multiprocessor tasks. Motivated by the computational complexity of the problem, we propose a memetic algorithm for this problem in the paper. We first describe the implementation details of a genetic algorithm, which is used in the memetic algorithm. We then propose a constraint programming based branch-and-bound algorithm to be employed as the local search engine of the memetic algorithm. Next, we present the new memetic algorithm. We lastly explain the computational experiments carried out to evaluate the performance of three algorithms (genetic algorithm, constraint programming based branch-and-bound algorithm, and memetic algorithm) in terms of both the quality of the solutions produced and the efficiency. These results demonstrate that the memetic algorithm produces better quality solutions and that it is very efficient.