Local Structure and Coordination Define Adsorption in a Model Ir1/Fe3O4 Single‐Atom Catalyst

Single‐atom catalysts (SACs) bridge homo‐ and heterogeneous catalysis because the active site is a metal atom coordinated to surface ligands. The local binding environment of the atom should thus strongly influence how reactants adsorb. Now, atomically resolved scanning‐probe microscopy, X‐ray photoelectron spectroscopy, temperature‐programmed desorption, and DFT are used to study how CO binds at different Ir₁ sites on a precisely defined Fe₃O₄(001) support. The two‐ and five‐fold‐coordinated Ir adatoms bind CO more strongly than metallic Ir, and adopt structures consistent with square‐planar Ir^I and octahedral Ir^III complexes, respectively. Ir incorporates into the subsurface already at 450 K, becoming inactive for adsorption. Above 900 K, the Ir adatoms agglomerate to form nanoparticles encapsulated by iron oxide. These results demonstrate the link between SAC systems and coordination complexes, and that incorporation into the support is an important deactivation mechanism.     

Nonwoven Releasing Propolis as a Potential New Wound Healing Method—A Review

Wound healing poses a serious therapeutic problem. Methods which accelerate tissue regeneration and minimize or eliminate complications are constantly being sought. This paper is aimed at evaluation of the potential use of biodegradable polymer nonwovens releasing propolis as wound healing dressings, based on the literature data. Propolis is honeybee product with antioxidant, antibacterial, antifungal, anticancer, anti-inflammatory, analgesic, and regenerative properties. Controlled release of this substance throughout the healing should promote healing process, reduce the risk of wound infection, and improve aesthetic effect. The use of biodegradable aliphatic polyesters and polyester carbonates as a propolis carrier eliminates the problem of local drug administration and dressing changes. Well-known degradation processes and kinetics of the active substance release allows the selection of the material composition appropriate to the therapy. The electrospinning method allows the production of nonwovens that protect the wound against mechanical damage. Moreover, this processing technique enables adjusting product properties by modifying the production parameters. It can be concluded that biodegradable polymer dressings, releasing a propolis, may find potential application in the treatment of complicated wounds, as they may increase the effectiveness of treatment, as well as improve the patient’s life quality.     

A Machine Learning Approach for Gearbox System Fault Diagnosis

This study proposes a fully automated gearbox fault diagnosis approach that does not require knowledge about the specific gearbox construction and its load. The proposed approach is based on evaluating an adaptive filter’s prediction error. The obtained prediction error’s standard deviation is further processed with a support-vector machine to classify the gearbox’s condition. The proposed method was cross-validated on a public dataset, segmented into 1760 test samples, against two other reference methods. The accuracy achieved by the proposed method was better than the accuracies of the reference methods. The accuracy of the proposed method was on average 9% higher compared to both reference methods for different support vector settings.     

РЕАКЦИЯ (γ, р) НА КАДМИИ И ОЛОВЕ

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(, p) Reaction on cadmium and tin

A study is made of the nuclear photoeffect on Sn and Cd where, in contrast to most of the experiments with this effect up to now, discrete rays were used. The paper complements paper [3], the experimental arrangement of which it has taken over. Several interesting results were obtained — particularly the discreteness of the energy spectrum and the unconventional form of the angular distribution. With tin, the top proton shell of which is completely occupied, the shape of the energy spectrum corresponds to the Wilkinson theory of gigant resonance; with cadmium the energy spectrum is similar to the evaporation spectrum. The angular distributions of the photoprotons of both elements do not satisfy the commonly used relations corresponding to existing theories of nuclear photoeffect. They can, however, be described quite well by empirical equations which contain associated Legendre polynomials of different orders. With both elements the results have features of both a direct and a collective process. The paper gives results, a satisfactory explanation of which would require a new theory including both types of processes.

     

Hydrogen implantation in semiconductors

Proton implantation is presented as a versatile tool for hydrogen-doping of semiconductors. The paper shows the advantages as well as disadvantages of this technique: precise spatial distribution and hydrogen concentrations obtained up to the non-equilibrium states are possible because of the damages introduced during the slowing down of protons. Some examples of experimental results obtained by proton implantation are discussed in detail. The review is also intended to serve as a source of key references in the field.     

On Some Interpolation Rules for Lattice Ordered Groups

Let be an infinite cardinal. In this paper we define an interpolation rule IR() for lattice ordered groups. We denote by C() the class of all lattice ordered groups satisfying IR(), and prove that C() is a radical class.     

On the Affine Completeness of Lattice Ordered Groups

In the paper it is proved that a nontrivial direct product of lattice ordered groups is never affine complete.     

Nondispersive wave packets as solitonic solutions of level dynamics

We discuss the analogy between nondispersive wave packets in periodically driven hydrogen atoms and solitons as solitary wave solutions of nonlinear dynamical systems. Whereas the wave packet eigenstates should not be considered as solitons propagating in real space, they are shown to display the essential features of solitonic solutions as they propagate through the irregular lattice of quasienergy levels evolving with a fictitious time like the strength or the frequency of the driving force.     

Radiation damage distributions for 300 keV antimony ions implanted into silicon

Two well-known theories of Brice and of Winterbon and one simplified theory of radiation damage distributions are statistically compared with RBS data for room temperature 300 keV antimony ion implantation of silicon.