From Blanché’s Hexagonal Organization of Concepts to Formal Concept Analysis and Possibility Theory

The paper first introduces a cube of opposition that associates the traditional square of opposition with the dual square obtained by Piaget??s reciprocation. It is then pointed out that Blanché??s extension of the square-of-opposition structure into an conceptual hexagonal structure always relies on an abstract tripartition. Considering quadripartitions leads to organize the 16 binary connectives into a regular tetrahedron. Lastly, the cube of opposition, once interpreted in modal terms, is shown to account for a recent generalization of formal concept analysis, where noticeable hexagons are also laid bare. This generalization of formal concept analysis is motivated by a parallel with bipolar possibility theory. The latter, albeit graded, is indeed based on four graded set functions that can be organized in a similar structure.     

Preface

正It is with pleasure that we accepted the invitation of Tatsien Li,the Editor in chief of Chinese Annals of Mathematics(CAM),to act as guest editors of this journal for two special issues dedicated to Haim Brezis.The present issue and the next one are the result of this     

Matrix probing: A randomized preconditioner for the wave-equation Hessian

This paper considers the problem of approximating the inverse of the wave-equation Hessian, also called normal operator, in seismology and other types of wave-based imaging. An expansion scheme for the pseudodifferential symbol of the inverse Hessian is set up. The coefficients in this expansion are found via least-squares fitting from a certain number of applications of the normal operator on adequate randomized trial functions built in curvelet space. It is found that the number of parameters that can be fitted increases with the amount of information present in the trial functions, with high probability. Once an approximate inverse Hessian is available, application to an image of the model can be done in very low complexity. Numerical experiments show that randomized operator fitting offers a compelling preconditioner for the linearized seismic inversion problem.     

Synthesis of α‐alkenyl‐β‐hydroxy adducts by α‐addition of unprotected 4‐bromocrotonic acid and amides with aldehydes and ketones by chromium(II)‐mediated reactions

The regioselective and diastereoselective chromium(II)‐mediated reactions of 4‐bromocrotonic acid or amides with aldehydes and ketones can proceed without the need to protect protic sites to generate the respective α‐alkenyl‐β‐hydroxy adducts, i.e. formally the addition of the α‐anion of a carboxylic acid or amide to an oxo‐compound is featured. Copyright © 2016 John Wiley & Sons, Ltd.     

Topical Issue on Thermal Non-Equilibrium Phenomena in Soft Matter

The European Physical Journal E - The transmission and the reflection of a shock wave by one or several impurities in viscoelastic bead chains is studied in the present paper. There is only one...     

Thermal analysis and high heat flux testing of unidirectional carbon–carbon composite for infrared imaging diagnostic

Carbothermic reduction of chromite in the presence of nickel as the alloying element was investigated in a wide temperature range up to 1500 °C using thermogravimetric analysis coupled with continuous off-gas analysis (TG-DSC-MS). Both isothermal and non-isothermal linear heating tests were performed for the kinetic study with the calculation of activation energies. In order to further elucidate the reduction mechanism, the reduced products were characterized by SEM–EDS and XRD. It was concluded that the reduction sequence followed a multi-stage mechanism, reflected partly by the dependency of the activation energy on the extent of reduction. With the progress of reduction, refractory oxide layers gradually formed on/close to the surface of each chromite particle, causing the shift of the rate-limiting factor from chemical control to diffusion control. The promoting effect from the addition of Ni was evident at temperatures higher than 1300 °C due to the formation of alloys of lower melting point.     

Influence of Strong Transannular N→P Interaction on Acidity of Cyclenphosphine Sulfide

The acid-base behavior of cyclenphosphine sulfide (cyclenPS) is appreciably different from that of cyclamphosphine sulfide (cyclamPS). The cyclenPS shows five acid functionalities compared to four for cyclamPS. The fifth acidic group in cyclenPS corresponds to the formation of a stable amidure in aqueous solution (pK=12.3). This behavior is due to the strong transannular N→P interaction. The deprotonation sequences were established by ³¹P-NMR and confirmed by modelling of cyclenPS.     

Routes to reduce aluminium co-catalyst content for zirconocene activation in olefin polymerization

In this paper, we investigate different routes to lower drastically the amount of methylaluminoxane (MAO) required to activate racEt(Ind)₂ZrX₂ catalysts towards olefin polymerization. A first approach consists in replacing Cl ligands by more easily extractable X groups such as Me, CH₂Ph or NMe₂ groups. A second method focuses on the preparation of TMA-depleted MAO either by pumping off TMA from commercial MAO or by exploring new synthetic source to MAO via non-hydrolytic processes such as the reaction of TMA with benzophenone. Both methods allowed us to produce polyolefins with a maximal catalytic activity for Al/Zr ratios not exceeding 150, i.e. ratio 20 times lower than those required in the presence of commercial MAO.