New Insights into The Photoactivity of Shape-Tailored BiVO4 Semiconductors via Photocatalytic Degradation Reactions and Classical Reduction Processes

In the present study, additive-free, pH-driven, hydrothermal crystallization was used to obtain shape-tailored monoclinic BiVO4 photocatalysts. The as-prepared BiVO4 products were systematically characterized, uncovering their crystallographic, morphologic and optical properties, while their applicability was verified in the visible light-driven photodegradation of oxalic acid and rhodamine B. Monoclinic clinobisvanite was obtained in most cases, with their band gap values located between 2.1 and 2.4 eV. The morphology varied from large, aggregated crystals, individual microcrystals to hierarchical microstructures. It was found that the degradation efficiency values obtained in the case of oxalic acid were directly related to the presence of (040) crystallographic plane, while the degradation of rhodamine B was partially independent by the presence of this structural feature. The importance of (040) crystallographic plane was also demonstrated via the reduction of Cu2+ to Cu, by analyzing the Raman spectra of the Cu containing samples, the mean primary crystallite size of Cu and Cu content. Furthermore, the presence of (040) crystallographic plane was directly proportional with the hydrodynamic properties of the powders as well.

Hydrogenation of carboxylic acid derivatives with bifunctional ruthenium catalysts

This paper focuses on recent advances in the chemistry of bifunctional Ru catalysts with chelate protic amine ligands effective for hydrogenation of polar carbonyl compounds. The rational design of the cooperating amine ligand that adjusts the balance of the electronic factors on the M/NH units in the bifunctional catalysts is crucial to exploit the characteristic catalytic performance with a wide scope and high practicability. These bifunctional molecular catalysts offer a great opportunity to develop new fundamental processes for the straightforward hydrogenation of carboxylic acid derivatives as a powerful alternative for classical reduction using stoichiometric amounts of metal hydride reagents.

Can One Validly Use Classical Statistical Inference in Open Quantum Systems?

A major problem to perform statistical inference in open quantum systems is the perturbation induced by the measurement process. However, at least theoretically, a suitable choice of the measurement process could provide a consistent approach through classical stochastic processes. This work proposes a method to perform statistical inference on open quantum systems represented by quantum Markov semigroups having a suitable classical reduction. The method is based on measurements associated to observables generating invariant abelian algebras.

Switched Systems Reduction Framework Based on Convex Combination of Generalized Gramians

A general method for model-order reduction of switched linear dynamical systems is presented. The proposed technique uses convex generalized gramian which is a convex combination of the generalized gramians. It is shown that different classical reduction methods can be developed into the generalized gramian framework for model reduction of linear systems and further for the reduction of switched systems by construction of the convex generalized gramian. Balanced reduction within specified frequency bound is taken as an example which is developed within this framework. In order to avoid numerical instability and also to increase the numerical efficiency, convex generalized gramian-based Petrov-Galerkin projection is constructed instead of the similarity transform approach for reduction. It is proven that the method preserves the stability of the original switched system at least for stabilizing switching signal and it is also less conservative than the method which is based on the common generalized gramian. Some discussions on the coefficient of the vertices of the convex variables are presented. The performance of the proposed method is illustrated by numerical examples.

Reduction formulae from the factorization Theorem of Littlewood-Richardson polynomials by King, Tollu and Toumazet

International audience The factorization theorem by King, Tollu and Toumazet gives four different reduction formulae of Littlewood-Richardson coefficients. One of them is the classical reduction formula of the first type while others are new. Moreover, the classical reduction formula of the second type is not a special case of KTT theorem. We give combinatorial proofs of reduction formulae in terms of tableaux or hives. The proofs for the cases $r=1, 2, n-2$ in terms of tableaux and the proof for the classical reduction formula of the second type in terms of hives are new. Le Théorème de factorisation par King, Tollu, et Toumazet donne quatre formules différentes de réduction des coefficients de Littlewood-Richardson. L'une d'entre eux est la formule classique de réduction du premier type alors que les trois autres sont nouvelles. De plus, la formule classique de réduction du deuxième type n'est pas un cas spécial du KTT théorème. Nous donnons preuves combinatoires des formules de réduction en termes de tableaux ou $\textit{hives}$. Les preuves pour les cas $r = 1, 2, n-2$ en termes de tableaux et la preuve pour la formule classique de réduction du deuxième type en termes de $\textit{hives}$ sont nouvelles.