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In the course of this work, fluorinated catalysts MoO3/Al2O3-F for the olefins metathesis have been synthesized. The materials have been characterized by various physicochemical methods and tested in the propylene metathesis reaction. It has been shown that the support fluorination leads to partial replacement of surface hydroxyl groups by F, which is accompanied by an increase in the strength of both Lewis acid sites and residual bridging OH groups. Increasing the fluorine content on γ-Al2O3 up to 3 wt. % leads to an increase in the conversion of propylene in the metathesis reaction by 1.5 times (WHSV = 1.1 h-1, Т = 100 °С, р = 9 atm.) with a selectivity of more than 95%. However, when the reaction is carried out at atmospheric pressure, fluorinated samples show lower activity than unpromoted ones. The results of this work show that the support acidity plays an important role in propylene metathesis. The proposed method of catalyst modification opens up new possibilities for improving classical metathesis catalysts.

The article provides a semantic analysis of the general concept of “progress”. The author shows that the objective meaning of this concept is a series of successive changes of a certain object. Still, the meaning of the con-cept of “progress” also includes an assess-ment of these changes from the observer’s viewpoint, who can assess these changes as a transition from lower to higher, from less perfect to more perfect, that is as progressive changes, or on the contrary – as a transition from perfect to less perfect, that is as regres-sive changes. It seems clear that these esti-mates depend on the observers’ value sys-tem, that is from their ideas about the high, the perfect, and the useful. Different people have different value systems, which is why so often people disagree in their assessments of some changes as progressive or regressive. The article discusses the question of whether a certain system of universal values exists, which assumes that a generally valid assess-ment of some changes as progressive is possible. Modern sociological research demonstrates the absence of such system. The author, in his turn, suggests a hypothesis about what could serve as the basis for the formation of such a universal human value system.

This paper suggests brief answers to the criticism given on the article “On the meaning and significance of the concept of ‘progress’”. This article depicts progress as an evaluative concept, and since the value systems of dif-ferent people are different, it argues that the assessments about progress or regression will always differ. Critics’ comments, however, clarify that there are criteria for evaluating some changes on which there is real general agreement. The author notes that the critical comments support the fact that the notion of progress is still vague and unclear and a spe-cial consideration of its various aspects seems important.

Book Review: Steven Pinker, Luchshee v nas: pochemu nasiliya v mire stalo men’she [The Better Angels of Our Nature: Why Violence has Declined] (Moscow, 2021) (in Russian).

Ore-controlling factors determine the patterns of formation and localization of mineralization within ore regions and deposits. The need for this study arises from the importance of integrated assessment of mineral resources and improvement of metasomatic formation techniques. This is especially important for geological materials which are mined for their direct commercial value (industrial materials). This article is devoted to the study of the ore control of complex industrial minerals. The Khizovaara structure belongs to the Tikshozero greenstone belt. Within the structure, a multistage metamorphism and metasomatism processes are manifested. The totality of lithological, structural and petrologic ore control factors determines the existence within the structure of several deposits. These are deposits of industrial minerals, such as garnet, quartz, muscovite, kyanite, staurolite. In almost all cases, the ores are complex. The following objects were studied: Southern Lens (kyanite + quartz) deposit, Northern lens (kyanite + quartz) deposit, East Khizovaara (muscovite + quartz) deposit, Vysota-181 (garnet + staurolite + kyanite + muscovite + quartz) deposit, ore occurence Fuxit (decorative rocks). For the ores of each site, the processes of regional metamorphism of the amphibolite facies of kyanite-biotite and muscovite-chlorite-kyanite subfacies are important. Metamorphism, tectonic regime and geological connection with rocks has been studied as a ore control factor, based on this, data on the quantitative distribution of industrial minerals of metamorphic genesis have been obtained. Acidic and alkaline metasomatites of each site are considered. On the basis of these data, metasomatic processes that lead to the formation of complex ores are revealed. The process of superposition of metasomatosis products of the late stage on the products of early stage metasomatosis was studied. This process leads to the formation of complex ores of three or four minerals. The result of the work is a general scheme of metamorphic and metasomatic ores control

WOS:000361155700013; International audience; Conical intersections are perhaps the most significant mechanistic features of chemical reactions occurring through excited states. By providing funnels for efficient non-adiabatic population transfer, conical intersections govern the branching ratio of products of such reactions, similar to what the transition states do for ground-state reactivity. In this regard, intersections between the ground and the lowest excited states play a special role, and the correct description of the potential energy surfaces in their vicinity is crucial for understanding the mechanism and dynamics of excited-state reactions. The methods of density functional theory, such as time-dependent density functional theory, are widely used to describe the excited states of large molecules. However, are these methods suitable for describing the conical intersections or do they lead to artifacts and, consequently, to erroneous description of reaction dynamics? Here we address the first part of this question and analyze the ability of several density functional approaches, including the linear-response time-dependent approach as well as the spin-flip and ensemble formalisms, to provide the correct description of conical intersections and the potential energy surfaces in their vicinity. It is demonstrated that the commonly used linear-response time-dependent theory does not yield a proper description of these features and that one should instead use alternative computational approaches.

Two new light-driven molecular rotary motors based on the N-alkylated indanylidene benzopyrrole frameworks are proposed and studied using quantum chemical calculations and nonadiabatic molecular dynamics simulations. These new motors perform pure axial rotation, and the photochemical steps of the rotary cycle are dominated by the fast bond-length-alternation motion that enables ultrafast access to the S1/S0 intersection. The new motors are predicted to display a quantum efficiency higher than that of the currently available synthetic all-hydrocarbon motors. Remarkably, the quantum efficiency is not governed by the topography (peaked versus sloped) of the minimum-energy conical intersection, whereas the S1 decay time depends on the topography as well as on the energy of the intersection relative to the S1 minimum. It is the axial chirality (helicity), rather than the point chirality, that controls the sense of rotation of the motor.

WOS:000342844100027; International audience; Quantum-chemical computational methods are benchmarked for their ability to describe conical intersections in a series of organic molecules and models of biological chromophores. Reference results for the geometries, relative energies, and branching planes of conical intersections are obtained using ab initio multireference configuration interaction with single and double excitations (MRCISD). They are compared with the results from more approximate methods, namely, the state-interaction state-averaged restricted ensemble-referenced Kohn-Sham method, spin-flip time-dependent density functional theory, and a semiempirical MRCISD approach using an orthogonalization-corrected model. It is demonstrated that these approximate methods reproduce the ab initio reference data very well, with root-mean-square deviations in the optimized geometries of the order of 0.1 angstrom or less and with reasonable agreement in the computed relative energies. A detailed analysis of the branching plane vectors shows that all currently applied methods yield similar nuclear displacements for escaping the strong non-adiabatic coupling region near the conical intersections. Our comparisons support the use of the tested quantum-chemical methods for modeling the photochemistry of large organic and biological systems. (C) 2014 AIP Publishing LLC.

For thermal neutron experiments at ESS very high resolution and fast hybrid microstrip gas chamber (MSGC) detectors are being developed at HMI, which lend themselves for setting up large-area detector arrays comprising detector cells of 285 mm x 285 mm size. These detectors utilize a composite 157 Gd/CsI foil converter and novel robust multilayer microstrip glass plates, which are optimized for a low-pressure two-stage gas amplification mode. Using a delay-line based, interpolating readout mode with sub-segmentation on the plates, the detectors have the potential to combine position resolutions of 0.1-0.3 mm FWHM, time-of-flight (TOF) resolutions of less than 10 ns and a counting rate capability in the range of Mevents/s per cell, which is limited by the present version of the data acquisition system. To handle these high data rates a PCI-bus board has been developed comprising four 8-channel multihit TDC chips (~150 ps LSB) of the F1 type, one digital signal processor (1 GFLOP DSP) for online data processing and a histogram memory (HM) of 256 MB. By means of the DSP the data of the registered coordinates X, Y, TOF and pulse-height, measured by means of time-over-threshold discriminators in the TDCs, can either be calibrated and transformed online into 2D spectra accumulated in the HM or read out in list-mode.

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