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Optical microcavity, which is based on light-matter interaction, has the advantage of high sensitivity as a sensor. It has been widely used in the security, medicine, and environment fields these years. Detection of atoms and molecules at the nanoscale is one of the practical usages of optical microcavity. In this paper, we focus on a ultra-high-quality factor optical microcavity of whispering gallery mode (WGM) to detect the explosive of cyclotrimethylenetrinitramine (RDX). To demonstrate the high sensitivity of the method, we detect the solution at different concentrations. Different types of optical microcavities are suitable for the detection of different matters. Considering the effects of the results and the simplicity of operation, we use silica microspheres chiefly. This is the first time to detect the explosive using highly sensitive optical microcavity. The detection of pure explosives will be helpful for establishing the database of the explosives. [ABSTRACT FROM AUTHOR]

The paper presents a simple yet rigorous analysis of the transient of the spatial distribution of the kinetic energy of a classical ideal monoatomic dilute gas that passes from non-equilibrium to equilibrium. The proposed approach is event-based, in the sense that the evolution of the system is analyzed as a function of the random number of collisions in a given time interval. Taking a very simple yet realistic model of collision, the paper shows that collisions between atoms lead exponentially to energy equipartition. [ABSTRACT FROM AUTHOR]

Motivation Retrosynthesis is a critical task in drug discovery, aimed at finding a viable pathway for synthesizing a given target molecule. Many existing approaches frame this task as a graph-generating problem. Specifically, these methods first identify the reaction center, and break a targeted molecule accordingly to generate the synthons. Reactants are generated by either adding atoms sequentially to synthon graphs or by directly adding appropriate leaving groups. However, both of these strategies have limitations. Adding atoms results in a long prediction sequence that increases the complexity of generation, while adding leaving groups only considers those in the training set, which leads to poor generalization. Results In this paper, we propose a novel end-to-end graph generation model for retrosynthesis prediction, which sequentially identifies the reaction center, generates the synthons, and adds motifs to the synthons to generate reactants. Given that chemically meaningful motifs fall between the size of atoms and leaving groups, our model achieves lower prediction complexity than adding atoms and demonstrates superior performance than adding leaving groups. We evaluate our proposed model on a benchmark dataset and show that it significantly outperforms previous state-of-the-art models. Furthermore, we conduct ablation studies to investigate the contribution of each component of our proposed model to the overall performance on benchmark datasets. Experiment results demonstrate the effectiveness of our model in predicting retrosynthesis pathways and suggest its potential as a valuable tool in drug discovery. Availability and implementation All code and data are available at https://github.com/szu-ljh2020/MARS. [ABSTRACT FROM AUTHOR]

In this paper, the vortices number and the critical atoms number are calculated. Calculations are performed for ultracold trapped Bose gas in two-dimensional deep optical lattice. Hellmann–Feynman theorem is used here to calculate the expectation values of the angular momentum and thermal average of square radius (in situ size). The above-mentioned parameters are calculated from the thermodynamic grand potential q (α , s). The latter is calculated using a conventional semi-classical approximation. This thermodynamic grand potential allows us to investigate the impacts of the finite size and inter-atomic interaction effects. The obtained result for the vortices number has a peak with increase in the rate of rotation. While the critical atoms number has increase in nature with increase in the critical temperature. These parameters show a major dependence on the inter-atomic interaction, depth of optical lattice and number of particles. [ABSTRACT FROM AUTHOR]

Transition rates of a uniformly accelerated atom coupled to a vacuum scalar field are identical with those of one being static in a thermal bath at a temperature proportional to the proper acceleration a, i.e., T U = a 2 π . We discuss in this paper whether there exists such an equivalence in the electromagnetic field case if more atoms are involved. To be specific, we explore the similarities and distinctions between effects of a thermal bath and those of the uniformly accelerated motion by comparing the transition rates of a two-atom system initially in the symmetric or antisymmetric entangled state [ | ψ ± ⟩ ] in two cases, i.e., two static atoms in a thermal bath [the thermal case] and two atoms uniformly accelerated in vacuum [the acceleration case]. We discover that, for some particular orientations of atomic dipole moments, coherent radiation which happens in the acceleration case never occurs in the thermal case. The rates in the acceleration case with a low acceleration which means a low T U can be smaller or larger and even equal to their counterparts in the thermal case; while the rates in the acceleration case with a high acceleration which means a high T U are always much larger than their counterparts in the thermal case. Our results suggest that effects of a thermal bath and those of the uniformly accelerated motion on transition properties of a two-atom system in | ψ ± ⟩ are not necessarily distinctive, but can be equivalent if the acceleration is relatively low, depending on the value of the interatomic separation. [ABSTRACT FROM AUTHOR]

An analytical model of the interaction between Al and C atoms at the interfaces formed by carbon nanoparticles and aluminum is proposed. The model is convenient for practical use in calculating the free energy of the interface, which is essential for nanocomposites and determines their mechanical, thermophysical, and other properties. The paper considers nanoparticles of various structures that are used in the development of aluminum matrix composites: fullerenes of various diameters, single-layer carbon nanotubes of metal and semiconductor types of various radii and chirality, graphene, and graphite. The proposed model employs the Lennard–Jones potential and approximately takes into account the effect of the local structure of the nanoparticle on the interaction of pairs of aluminum and carbon atoms using additional parameters. In this paper, we assume that the average local curvature of the nanoparticle surface determines the depth and location of the potential well. The work is supplemented with the study of interphase interaction in the framework of the density functional theory. The comparison of the results of calculations performed using approximations of various levels of accuracy is used to establish the limits of applicability of the proposed potential, and the possibility of its application in the study of interfacial interaction in nanocomposites based on aluminum and nanocarbon is shown. [ABSTRACT FROM AUTHOR]

This paper investigates the effect of the SiC and triplex thermal aging treatment (TTAT) on the mechanical behavior of compound bars. The bars were fabricated by varying the SiC (2, 4 and 6wt. %) in Al6061. Initially, bars were tested for hardness and compression strength in homogenized conditions. It is observed that as SiC is increased in the matrix, mechanical properties have improved. The bars with composite cores exhibited better properties as compared to bars with composite casing. For the bar having a composite core, with 2 wt. % SiC, the compression strength was 530.70 MPa, for the 4 wt.% SiC core it was 589.35 MPa and for the 6 wt.% SiC it was 691.88 MPa. Failure was progressive, with noticeable signs of failure, and the load-bearing ability was found to be fairly stable up to nearly 218 kN. Later, the bar with a 6 wt. % SiC core was subjected to TTAT, and surface hardness, compression strength, and interfacial shear strength were found to have increased by 11.2, 3.2 and 11.11%, respectively. SiC are the hard particles; reinforcing them in a soft matrix induces strain in the lattice and thus enhances the hardness of the composite. During aging, the diffusion of alloy atoms is blocked by the generated dislocations present around the SiC particles. Hence, the bars with a higher quantity of SiC in the composite core can be used for high load-bearing structural applications due to their superior mechanical properties as an alternative to the simple composite bars with the same SiC quantity. [ABSTRACT FROM AUTHOR]

The aim of this paper is to propose a qualitative approach to the theory of conceptual spaces, in contrast to the usual metric framework. This requires qualitative notions of similarity, simple concepts, prototypes and conceptual categorisation. For this purpose, I will introduce three mathematical models for conceptual spaces. The first one is topological and has been proposed by Mormann. The other two are new and are based on atomistic orders and similarity relations. I will discuss how each of them deals with the Design Principles proposed by Douven and Gärdenfors and with further Adequacy Conditions. Despite being apparently different, I will show that these three models are mathematically equivalent. Finally, I will address three objections to the present approach. The first one says that the qualitative notion of a prototype is a bad analogue of the metric one. The second one suggests that, in contrast to the Voronoi construction, the function qualitatively representing the conceptual categorisation process is arbitrary. The last one appeals to Goodman's companionship and imperfect community problems to show that there is a flaw in defining simple concepts from similarity relations. [ABSTRACT FROM AUTHOR]

In this third of a series on quantum radiation, we further explore the feasibility of using the memories (non-Markovianity) kept in a quantum field to decipher certain information about the early universe. As a model study, we let a massless quantum field be subjected to a parametric process for a finite time interval such that the mode frequency of the field transits from one constant value to another. This configuration thus mimics a statically-bounded universe, where there is an 'in' and an 'out' state with the scale factor approaching constants, not a continuously evolving one. The field subjected to squeezing by this process should contain some information of the process itself. If an atom is coupled to the field after the parametric process, its response will depend on the squeezing, and any quantum radiation emitted by the atom will carry this information away so that an observer at a much later time may still identify it. Our analyses show that (1) a remote observer cannot measure the generated squeezing via the radiation energy flux from the atom because the net radiation energy flux is canceled due to the correlation between the radiation field from the atom and the free field at the observer's location. However, (2) there is a chance to identify squeezing by measuring the constant radiation energy density at late times. The only restriction is that this energy density is of the near-field nature and only an observer close to the atom can use it to unravel the information of squeezing. The second part of this paper focuses on (3) the dependence of squeezing on the functional form of the parametric process. By explicitly working out several examples, we demonstrate that the behavior of squeezing does reflect essential properties of the parametric process. Actually, striking features may show up in more complicated processes involving various scales. These analyses allow us to establish the connection between properties of a squeezed quantum field and details of the parametric process which performs the squeezing. Therefore, (4) one can construct templates to reconstitute the unknown parametric processes from the data of measurable quantities subjected to squeezing. In a sequel paper these results will be applied to a study of quantum radiations in cosmology. [ABSTRACT FROM AUTHOR]

In an additive factorial monoid each element can be represented as a linear combination of irreducible elements (atoms) with uniquely determined coefficients running over all natural numbers. In this paper we develop for a wide class of non-factorial monoids a concept of stratification for atoms which allows to represent each element as a linear combination of atoms where the coefficients are uniquely determined when restricted in a particular way. This wide class includes inside factorial monoids and in particular simplicial affine monoids. In the latter case the question of uniqueness is related to a problem studied by E. B. Elliott in a paper from 1903. For the monoid of all nonnegative solutions of a certain linear Diophantine equation in three variables, Elliott considers "simple sets of solutions" (atoms of the monoid) and looks for a method that gives "every set once only". We show that for simplicial affine monoids in two dimensions a stratification is always possible, which answers to Elliott's problem also for the cases he left open. The results in this paper on the stratification of atoms for monoids in general may be seen also as an answer to a "generalized Elliott problem". This manuscript employs very much the concept of extraction monoid which, as many other tools, stems from discrete geometry but it is less well-known. [ABSTRACT FROM AUTHOR]

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This paper introduces the use of complex Fermi orbital descriptors (FODs) in the Fermi–Löwdin self-interaction-corrected density functional theory (FLOSIC). With complex FODs, the Fermi–Löwdin orbitals (FLOs) that are used to evaluate the SIC correction to the total energy become complex. Complex FLO-SIC (cFLOSIC) calculations based on the local spin density approximation produce total energies that are generally lower than the corresponding energies found with FLOSIC restricted to real orbitals (rFLOSIC). The cFLOSIC results are qualitatively similar to earlier Perdew–Zunger SIC (PZ-SIC) calculations using complex orbitals [J. Chem. Phys. 80, 1972 (1984); Phys. Rev. A 84, 050501(R) (2011); and J. Chem. Phys. 137, 124102 (2012)]. The energy lowering stems from the exchange–correlation part of the self-interaction correction. The Hartree part of the correction is more negative in rFLOSIC. The energy difference between real and complex solutions is greater for more strongly hybridized FLOs in atoms and for FLOs corresponding to double and triple bonds in molecules. The case of N2 is examined in detail to show the differences between the real and complex FLOs. We show that the complex triple-bond orbitals are simple, and physically appealing combinations of π and σg orbitals that have not been discussed before. Consideration of complex FODs, and resulting unitary transformations, underscores the fact that FLO centroids are not necessarily good guesses for FOD positions in a FLOSIC calculation. [ABSTRACT FROM AUTHOR]

We present elemental, lipid biomarker and compound-specific isotope (δ13C, δ²H) data for soils and leaf litter collected in the catchment of Lake Ohrid (Albania, Macedonia), as well as macrophytes, particulate organic matter and sediments from the lake itself. Lake Ohrid provides an outstanding archive of continental environmental change of at least 1.2 M years and the purpose of our study is to ground truth organic geochemical proxies that we developed in order to study past changes in the terrestrial biome. We show that soils dominate the lipid signal of the lake sediments 1r3a ther 2t han the vegetation or aquatic biomass, while compound-specific isotopes (δ13C, δ²H) determined for n-alkanoic acids confirm a dominant terrestrial source of organic matter to the lake. There is a strong imprint of suberin monomers on the composition of total lipid extracts and chain-length distributions of n-alkanoic acids, n-alcohols, ω-hydroxy acids and α,ω-dicarboxylic acids. Our end-member survey identifies that ratios of mid-chain length suberin-derived to long-chain length cuticular-derived alkyl compounds as well as their average chain length distributions can be used as new molecular proxies of organic matter sources to the lake. We tested these for the 8.2 ka event, a pronounced and widespread Holocene climate fluctuation. In SE Europe climate became drier and cooler in response to the event, as is clearly recognizable in the carbonate and organic carbon records of Lake Ohrid sediments. Our new proxies indicate biome modification in response to hydrological changes, identifying two phases of increased soil OM supply, first from topsoils and then from mineral soils. Our study demonstrates that geochemical fingerprinting of terrestrial OM should focus on the main lipid sources, rather than the living biomass. Both can exhibit climate-controlled variability, but are generally not identical. [ABSTRACT FROM AUTHOR]

In this paper, the atomic configuration, electronic structure, and work of adhesion for TiN(111)//B2‐NiTi(110) and TiN(111)//B19′‐NiTi(010) interfaces were investigated by first‐principles calculations based on density functional theory (DFT), which aim to provide a theoretical guidance for analyzing the service reliability of TiN films modified NiTi alloy devices. The results of this paper indicated that a hollow‐site stacking structure was formed on the interface when Ti and N were the terminal atoms on two sides. Such interfaces demonstrated a stronger bonding performance and a more stable structure than that with Ni and Ti as the terminal atoms. The work of adhesion of the TiN(111)//B19′‐NiTi(010) interface was 17.47 J/m2, which is greater than the work of fracture of TiN(111) (6.73 J/m2), whereas the work of adhesion of the TiN(111)//B2‐NiTi(110) interface was found to reach 5.49 J/m2, which is lower than the work of fracture of TiN(111). The models of the work of adhesion between the two interfaces indicate that there are significant bond strength changes in the TiN/NiTi interface, when the NiTi substrate undergoes martensitic transformation. The results of this paper contribute significantly to the service reliability analysis of TiN films coated on NiTi alloy devices. [ABSTRACT FROM AUTHOR]

The article discusses the study of Ulli Eichman and colleagues of Max Born Institute in Berlin, Germany on the acceleration of neutral atoms using a strong laser pulse. It notes that Eichman and colleagues have used helium atoms in their experiment because of its atomic featherweight that can easily be push around with strong forces, and reveals that it has survived the strong laser. It mentions that its survival was because of the ability of helium's electron to oscillate near its ionic core.

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The article discusses that Loma Linda publishing company supports the Academic True Open Model (ATOM).

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The article discusses how Raimund Dutzler, a biochemist at the University of Zurich and his graduate student Ricarda Hilf determine the three-dimensional structures of membrane proteins. At first they could not produce enough protein to make crystals but they fused the channel protein to another protein and obtained crystals. In order to resolve the atomic structure of a protein, one needs numerous sets of extremely precise X-ray-diffraction and fortunately, the team had access to new sensitive X-ray detector called Pilatus at the Swiss Light Source. The team believes that the resulting structure is conserved among all pentameric ligand-gated ion channels and is the first piece of the puzzle.

The article focuses on a study that shows the possibility of creating superatoms from solids. The Bose-Einstein condensate is matter in a phase distinct from solids, liquids and gases. When dropped to a lower temperature, most atoms in such gases drop to the same quantum level and act as one overlapping atom.

The variational approach detailed in the previous paper (Paper I) for the treatment of the Renner–Teller effect in linear tetra-atomic molecules including all degrees of freedom and couplings between angular momenta is applied for HCCH+. The accurate six-dimensional potential energy surfaces of the X 2Πu electronic state, presented in Paper I is incorporated in the variational treatment in order to obtain all rovibronic levels including the spin-orbit coupling for 1/2≤J≤7/2 and up to 2600 cm-1 above the global zero point energy. The “pure” stretching levels are calculated up to 11 000 cm-1 from the stretching zero point energy. The calculated rovibronic energies are compared with previous theoretical and experimental data. The mean agreement with the zero kinetic energy photoelectron measurements of Tang et al. [J. Chem. Phys. 125, 133201 (2006)] is of 16.7 cm-1. The Renner–Teller parameters have been determined at νtrans=690.0 cm-1, εtrans=0.30, νcis=715.0 cm-1, and εcis=-0.063. A detailed analysis of the rovibronic Hund’s cases is presented and the rotational structures of some vibronic bands recorded by Yang and Mo [J. Phys. Chem. A 110, 11001 (2006)] are given. [ABSTRACT FROM AUTHOR]

This study further extends the scope of a previous paper [Y. Ferro and A. Allouche, J. Chem. Phys. 118, 10461 (2003)] on the reactivity of atomic Na with water to some other highly polar molecules known for their solvation properties connected to efficient hydrogen bonding. The solvation mechanisms of ammonia and methanol are compared to the hydration mechanism. It is shown that in the case of ammonia, the stability of the solvated system is only ensured by electrostatic interactions, whereas the methanol action is more similar to that of water. More specific attention is given to the solvation process of the valence 3s Na electron. The consequences on the chemical reactivity are analyzed: Whereas ammonia is nonreactive when interacting with atomic sodium, two chemical reactions are proposed for methanol. The first process is dehydrogenation and yields methoxy species and hydrogen. The other one is dehydration and the final products are methoxy species, but also methyl radical and water. The respective roles of electron solvation and hydrogen bonds network are analyzed in detail in view of the density of states of the reactive systems. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The kinetics and pathway of most catalyzed reactions depend on the existence of interface, which makes the precise construction of highly active single-atom sites at the reaction interface a desirable goal. Herein, we propose a thermal printing strategy that not only arranges metal atoms at the silica and carbon layer interface but also stabilizes them by strong coordination. Just like the typesetting of Chinese characters on paper, this method relies on the controlled migration of movable nanoparticles between two contact substrates and the simultaneous emission of atoms from the nanoparticle surface at high temperatures. Observed by in situ transmission electron microscopy, a single Fe3O4 nanoparticle migrates from the core of a SiO2 sphere to the surface like a droplet at high temperatures, moves along the interface of SiO2 and the coated carbon layer, and releases metal atoms until it disappears completely. These detached atoms are then in situ trapped by nitrogen and sulfur defects in the carbon layer to generate Fe single-atom sites, exhibiting excellent activity for oxygen reduction reaction. Also, sites' densities can be regulated by controlling the size of Fe3O4 nanoparticle between the two surfaces. More importantly, this strategy is applicable to synthesize Mn, Co, Pt, Pd, Au single-atom sites, which provide a general route to arrange single-atom sites at the interface of different supports for various applications. [ABSTRACT FROM AUTHOR]

In this paper, we shed new light on the Flexible Atom Conjecture. We first give finite representation results for relation algebras 3 3 3 7 , 3 5 3 7 , 7 7 8 3 , 7 8 8 3 , 8 0 8 3 , 8 2 8 3 , 8 3 8 3 , 1 3 1 0 1 3 1 6 , 1 3 1 3 1 3 1 6 , 1 3 1 5 1 3 1 6 and 1 3 1 6 1 3 1 6 . Prior to our paper, only 8 3 8 3 and 1 3 1 6 1 3 1 6 were known to be finitely representable. We accomplish this by generalizing the notion of a relation algebra generated by a Ramsey scheme to the directed (antisymmetric) setting, and then showing that each of these algebras embeds into a finite directed anti-Ramsey scheme. The notion of a directed anti-Ramsey scheme may be of independent interest. We complement our upper bounds with some lower bounds. Namely, we show that any square representation of 3 1 3 7 requires at least 14 points, any square representation of 3 3 3 7 requires at least 11 points, and any square representation of 3 5 3 7 requires at least 12 points. Our technique adapts previous work of Alm et al. [Algebra Univ. (2022)], in that we examine the combinatorial structure induced by the flexible atom. [ABSTRACT FROM AUTHOR]

Photoionization of neutral chlorine atom is investigated in this paper in the framework of the screening constant per unit nuclear charge (SCUNC) method. Resonance energies, quantum defects and effective charges of the 3s23p4 (3P2,1,0)ns and 3s23p4 (3P1,0)nd Rydberg series originating from both the 2P03/2 ground state and the 2P01/2 excited state of chlorine atom are reported. The present study believed to be the first theoretical investigation is compared with the recent experimental measurements (Yang et al., Astrophys. J. 810:132, 2015). Good agreements are obtained between theory and experiments. New SCUNC data are tabulated as useful references for interpreting astrophysical spectra from neutral atomic chlorine. [ABSTRACT FROM AUTHOR]

In this paper, we rigorously prove the existence of type-level ordered pairs in Quine's New Foundations with atoms, augmented by the axiom of infinity and the axiom of choice (NFU + Inf + AC). The proof uses the cardinal squaring principle; more precisely, its instance for the (infinite) universe (VCSP), which is a theorem of NFU + Inf + AC. Therefore, we have a justification for proposing a new axiomatic extension of NFU, in order to obtain type-level ordered pairs almost from the beginning. This axiomatic extension is NFU+Inf +AC+VCSP, which is equivalent to NFU + Inf + AC, but easier to reason about. [ABSTRACT FROM AUTHOR]

Biaryl monophosphines are important precursors to active catalysts of palladium-mediated cross-coupling reactions. The efficiency of the phosphine-based transition metal complex catalyst has its origin in the electronic structure of the complex used and the sterical hindrance created by the ligand at an active catalyst site. The aim of this paper is to shed some light on the multiverse of coordination modes of biaryl monophosphine ligands. Here, we present the analysis of the X-ray single crystal structures of palladium(II) complexes of a family of biaryl monophosphine ligands and the first crystallographic report on a related phosphine sulfide. Despite the common biaryl monophosphine ligand motif, they show diverse coordination modes (i) starting from the activation of aromatic C atoms and producing a C,P metallacycle, through (ii) the O,P chelation to Pd(II) ions with a simultaneous demethylation reaction of one of the methoxy groups, ending up with (iii) the monodentate coordination to metal cations via P atoms or (iv) via S atoms in the case of phosphine sulfide. We relate our results to the crystal structures found in the Cambridge Structural Database to show the multiverse of coordination modes in the group of biaryl monophosphine ligands. [ABSTRACT FROM AUTHOR]

This paper focuses on the real-time implementation of an optimal high-performance control applied to an interleaved nonisolated DC/DC converter designed for fuel cell applications. Three-phase interleaved boost converters are utilized to minimize input current undulation, increase efficiency, and provide a high output voltage in order to ensure the performance of the FC stack. The proposed control strategy contains an outer loop that generates the reference current based on a two-degree-of-freedom PID controller. This controller provides a robust setpoint tracking and disturbance rejection, which improves the system's response and efficiency. A fast inner regulation loop based on a super-twisting integral sliding mode (STISM) algorithm is developed to achieve a fixed converter output voltage, equitable phase current sharing, and fast regulation against load disturbances in failure operation. The STISM algorithm exhibits a rapid convergence property of the sliding mode and effectively avoids the chattering phenomena frequently observed in conventional sliding modes. The proposed controller's gains are determined using the atom search optimization algorithm, which ensures exceptional reliability and a high degree of robustness and stability of the controllers under a variety of operational conditions. This method is inspired from the behavior of atoms and their electrons during the excitation process leading to a one-of-a-kind optimization technique which contributes to the controller's reliability. Using Matlab-Simulink simulation tools, the efficacy and performance of the designed control have first been evaluated and assessed and compared with other optimization algorithms, and then with a dual loop based on a PID controller. Then, they have been verified by real-time hardware implementation on a 1.2 KW prototype FC converter driven by the dSPACE-1104 card under a variety of tests. The suggested approach offers impressive experimental results in dynamic and steady states. [ABSTRACT FROM AUTHOR]

Symmetry-deficient two-dimensional (2D) layered materials induce a highly anisotropic optical response due to the anisotropy in their crystal structure, facilitating their application in polarized nanodevices. Intercalation is a new way to tune the optoelectronic properties of materials by inserting guest atoms into layered host materials, and 2D layered structures stacked with van der Waals gaps are a prerequisite for this phase of the technique. In this paper, 2D tellurium nanosheets were synthesized with a hydrothermal method, and copper atoms were inserted with a wet chemical method. The widening of the crystal plane spacing proves the introduction of copper atoms, and polarization−related second-harmonic-generation (SHG) studies reveal the intrinsic anisotropic modes of the two samples, and birefringent properties are found with polarizing light microscopy. We further investigated the electrical properties of the samples, and the embedding of the copper atoms caused the samples to exhibit higher currents, but their devices lost the gate control effect. [ABSTRACT FROM AUTHOR]

Hirshfeld atom refinement studies of hexachloro-cyclo-triphosphazene against high-resolution experimental data revealed the possibility of nitrogen acting simultaneously as a donor and acceptor in interactions with chlorine atoms, resulting in an NCl2 unit equivalent to the X3 synthon reported for halogen (X) bonding. This paper describes the scenarios for the NCl2 unit found in crystals, its stability analysis, and the donor–acceptor features for each case. A similar analysis is also performed for NBr2 and NI2. [ABSTRACT FROM AUTHOR]

Graphene has been widely studied in many fields due to its excellent physical and chemical properties. In this paper, we focus on the electronic structure and adsorption behavior of Al atoms and X (X = B , N, Si, S) atoms co-adsorption on the surface of pure graphene and Al atom adsorption on the surface of X (X = B , N, Si, S) atoms-doped graphene systematically. The adsorption energy, adsorption distance, bond length, bond angle, and electronic structure were studied using density functional theory (DFT) theoretical calculation. The results show that the adsorption capacity of (Al, X) atoms co-adsorbed on the graphene surface is significantly improved compared to the Al atoms on the pure graphene surface. The adsorption energy of Al and B atoms co-adsorbed on the graphene surface is basically the same as that of Al atoms on the B-doped graphene surface. The calculation results also show that the adsorption capacity of Al atoms and X (X = N , Si, S) atoms co-adsorbed on the surface of graphene is better than that of Al atoms on the surface of graphene doped with X (X = N, Si, S) atoms. Compared with N atom and S atom-doped systems, the Si-doped graphene surface has a stronger adsorption capacity for Al atoms than pure graphene. However, due to the doping of N and S atoms, the adsorption capacity of Al atoms on the graphene surface is somewhat reduced. Our calculation results provide a theoretical basis for further selection of Al-based graphene composite materials. [ABSTRACT FROM AUTHOR]

A high-temperature synthetic approach is used to prepare a series of pseudo-binary phases- Co2-xNixZn11. In the structures of Co2-xNixZn11, the statistical distribution between Co and Ni that is suggested by compositional analysis is confirmed by combined refinements of X-ray and neutron powder diffraction (NPD) experimental data. The aforementioned phases adopt a body-centered cubic lattice with a noncentrosymmetric space group I43m (217). Their crystal structures comprise two 26-atom γ-brass clusters. Each γ-cluster is made of four sequential polyhedral shells: inner tetrahedron (IT), outer tetrahedron (OT), octahedron (OH), and distorted cuboctahedron (CO). Diffraction experiments and the computations endorse that the OT site is statistically distributed by Co and Ni atoms, while the other three sites (IT, OH, and CO) are occupied by Zn atoms. The density of states (DOS) curve for Co1.5Ni0.5Zn11 displays a similar feature as binary Co2Zn11, whereas the wide pseudo-gap is formed near EF as Ni-concentration increases in Co2-xNixZn11. Bonding analysis shows that this specific atomic distribution nearly optimizes heteroatomic Co/Ni--Zn contacts in the Co1.0Ni1.0Zn11 and Co0.5Ni1.5Zn11. The Co1.7Ni0.3Zn11 exhibit paramagnetic behavior, whereas Co0.5Ni1.5Zn11 shows distinct diamagnetic behavior. With the increase in Ni concentration in the structure of Co2-xNixZn11, Ni atoms gradually substitute the Co atoms at OT sites; hence, magnetic characteristics change from para- to diamagnetism. [ABSTRACT FROM AUTHOR]

The concept of computability of Boolean algebras is widely used in the theory of constructive and computable models, initiated by A. I. Mal'tsev in the 1960s and actively developed in recent decades. In this paper, we study the long-standing question concerning the decidability of the Fréchet ideal and connections with the decidability of the set of atoms. [ABSTRACT FROM AUTHOR]

When preparing films through magnetron sputtering, atoms of the target material ejected during sputtering adhere, diffuse across the surface, condense, nucleate, and grow on the substrate surface, ultimately forming a film. However, due to the short time scales involved in this process, it is difficult to acquire detailed knowledge about the adsorption, surface diffusion, and film formation of target material atoms on the substrate surface in experimental settings. Therefore, this paper employs first-principles calculation methods to investigate the strongest adsorption sites, optimal diffusion paths, and the impact of diffusion distance of Ti atoms on the Fe(110) and Fe(100) surfaces on the film's microstructure. Through theoretical calculations, this study enriches the theoretical understanding of this process, providing a theoretical basis for the design and analysis of experimental schemes. The calculation results indicate that the adsorption energy of Ti atoms is the highest at the B sites on the Fe(100) surface. The diffusion barrier for Ti atoms on the Fe(100) surface is the lowest, making it easier for Ti atoms to diffuse on this surface. Under the condition of a relative substrate temperature labeled as T s / T m < 0.3 , the average diffusion distance of Ti atoms on the Fe(100) surface is the greatest, facilitating the formation of T-zone structures with superior mechanical properties. [ABSTRACT FROM AUTHOR]

The sequence of events during the photocyclisation of furylfulgides is not fully understood, and there is a significant disparity between ring closing timescales determined with the use of transient absorption spectroscopy [Siewertsen et al., Phys. Chem. Chem. Phys., 2011, 13, 3800] and the timescale estimated on the basis of nonadiabatic molecular dynamics (NAMD) simulations [Kochman et al., Phys. Chem. Chem. Phys., 2022, 24, 18103]. With a view to resolving this issue, in the present study I report NAMD simulations of the photorelaxation process of a model furylfulgide with a bulky alkyl substituent at carbon atom C3. I employed a pattern recognition algorithm in order to automate the analysis of the simulated trajectories. According to the simulation results, the bulky alkyl group causes a substantial increase in the photocyclisation quantum yield, but the timescale of ring closing is only marginally affected. I discuss the implications of these findings in light of the available spectroscopic data. [ABSTRACT FROM AUTHOR]

The exploration of sustainable luminescent compounds has increased economically and globally in recent decades. In this regard, organosamarium complexes have emerged as outstanding luminescent sources in various branches like lighting systems, bio-assays, magnets, organic light-emitting diodes, bioimaging, and material design because of their enhanced optical and thermal features. In this article, we will explore the synthesis, properties, and applications of mononuclear, dinuclear, and polynuclear organosamarium complexes and their luminescence enrichment. The combination of Sm(III) ion with a diversity of organic ligands consisting of hetero-donor atoms and an extensive π-conjugation backbone may prove an effective strategy for designing highly stable complexes. This type of grouping will lead to efficient energy transfer from the coordinated organic ligand via indirectly populating the Sm(III) emitting state. The Sm(III) complexes show emission bands in the visible region at ~ 564, 600, and 646 nm, arising from 4G5/2 → 6H5/2, 6H7/2, and 6H9/2 transitions, respectively. This review paper attempts to furnish an in-depth analysis and highlight the significant outcomes of the recently published organosamarium complexes. Lastly, the key challenges and future perspectives for the design and development of organosamarium complexes in various applications are provided in this review. [ABSTRACT FROM AUTHOR]

A series of cyclometalated (N^C^N) Pt(II)-platinum complexes featuring a terpyridine ligand with a non-coordinating nitrogen atom and a Pt–C bond was synthesized. In the presence of Ag+, the bis(isonitrile)Pt(II) complex formed a remarkable self-assembled helicoidal dimer stabilized by coordination of Ag(I) and metallophilic Pt–Ag interactions. Its assembly was observed in the solid state and maintained in solution. All complexes show strong luminescence and multiple emitting states, which could be rationalized based on solid state X-ray structures and coordinating environment. [ABSTRACT FROM AUTHOR]

This paper presents an analytical solution for the Milburn equation describing the interaction between a 3-level atom in a Ξ -configuration, a cavity field, and a nonlinear Kerr-like medium. The Hamiltonian of the model is presented in the rotating wave approximation (RWA) under specific conditions. The obtained analytical solution accounts for the impact of intrinsic decoherence and nonlinear terms on the dynamics of various physical phenomena. Specifically, we explore the behavior of atomic population, entropy functions, entanglement, negativity, and correlation, highlighting their dependence on the physical parameters of the 3 -level atom-cavity system. [ABSTRACT FROM AUTHOR]

Treatment of [Co(N2)(tBuPNP)] (tBuPNP = anion of 2,5-bis(di-tert-butylphosphinomethyl)pyrrole) with one equivalent of an aryl azide generates the four-coordinate imido complexes [Co(NAr)(tBuPNP)] (Ar = mesityl, phenyl, or 4-tBu-phenyl). X-ray crystallographic analysis of the compounds shows an unusual square-planar geometry about cobalt with nearly linear imido units. In the presence of the hydrogen atom donor, TEMPOH, [Co(NPh)(tBuPNP)] undergoes addition of the H atom to the imido nitrogen to generate the corresponding amido complex, [Co(NHPh)(tBuPNP)], whose structure and composition were verified by independent synthesis. Despite the observation of H atom transfer reactivity with TEMPOH, the imido complexes do not show catalytic activity for C–H amination or aziridination for several substrates examined. In the case of [Co(NPh)(tBuPNP)], addition of excess azide produced the tetrazido complex, [Co(N4Ph2)(tBuPNP)], whose bond metrics were most consistent with an anionic Ph2N4 ligand. Density Functional Theory (DFT) investigations of the imido and tetrazido species suggest that they adopt a ground state best described as possessing a low-spin cobalt(II) ion ferromagnetically coupled to an iminyl radical. [ABSTRACT FROM AUTHOR]

Two dinuclear double oxygen-bridged iron(III) complexes made of the Fe2(μ2-OR)2 diamond-core cluster resulting from the coordination between iron(III) cations with calix[4]arene ligands and bearing two lower-rim-appended salicylideneamine (4) or o-methoxy-salicylideneamine coordinating sites (5), connected to the macrocyclic platform via three methylene bridges and displaying a salen-type coordination pocket, were synthesized and characterized using single-crystal X-ray diffraction (SCXRD), powder X-ray diffraction (PXRD), high-resolution mass spectrometry (HRESI-MS), IR, TG-DSC and EA techniques. Independent of the presence of the o-methoxy group in the salicylideneamine moieties, the as-formed complexes contained two nonequivalent iron(III) atoms, both adopting a distorted octahedral coordination N2O4-environment but differing in the cis and trans positions of the nitrogen atoms within the metal coordination sphere, as attested by single-crystal X-ray diffraction and DFT-B3LYP calculations. The possible reason for the observed coordination mode of the macrocyclic ligands is their conformational behavior upon coordination with Fe(III) cations, as confirmed by DFT-B3LYP analysis. 57Fe Mössbauer spectroscopy study showed that both Fe(III) atoms were present in high spin states at room temperature and at 80 K in the studied coordination compounds. The methoxy groups located at the ortho position of the salicylideneamine coordinating fragments were observed to influence the energy of the frontier orbitals, resulting in an increase in the bandgap energy from 1.97 eV to 2.07 eV, as experimentally established by solid-state voltammetry study of 42-Fe2 exp and 52-Fe2 exp, respectively. The interplay between the steric and electronic factors, emerging from the o-methoxy group within coordinating salicylideneamine moieties, seemed to have a negligible effect on the electronic properties of the prepared clusters but significantly impacted the frontier orbital energy distribution, according to both experimental data and theoretical calculations. [ABSTRACT FROM AUTHOR]

We have studied whether dissociation of the S2B sulfide ligand from one of its two coordinating Fe ions may affect the later parts of the reaction mechanism of nitrogenase. Such dissociation has been shown to be favourable for the E2–E4 states in the reaction mechanism, but previous studies have assumed that S2B either remains bridging or has fully dissociated from the active-site FeMo cluster. We employ combined quantum mechanical and molecular mechanical (QM/MM) calculations with two density-functional theory methods, r2SCAN and TPSSh. To make dissociation of S2B possible, we have added a proton to this group throughout the reaction. We study the reaction starting from the E4 state with N2H2 bound to the cluster. Our results indicate that half-dissociation of S2B is unfavourable in most steps of the reaction mechanism. We observe favourable half-dissociation of S2B only when NH or NH2 is bound to the cluster, bridging Fe2 and Fe6. However, the former state is most likely not involved in the reaction mechanism and the latter state is only an intermittent intermediate of the E7 state. Therefore, half-dissociation of S2B seems to play only a minor role in the later parts of the reaction mechanism of nitrogenase. Our suggested mechanism with a protonated S2B is alternating (the two N atoms of the substrate is protonated in an alternating manner) and the substrate prefers to bind to Fe2, in contrast to the preferred binding to Fe6 observed when S2B is unprotonated and bridging Fe2 and Fe6. [ABSTRACT FROM AUTHOR]

Two lanthanide complexes with formulae [DyIII(LN5)(pentafluoro-PhO)3] (1) and [DyIII(LN5)(2,6-difluoro-PhO)2](BPh4) (2) (LN5 = 2,14-dimethyl-3,6,10,13,19-pentaazabicyclo[13.3.1]nonadecal (19),2,13,15,17-pentaene) were structurally and magnetically characterized. DyIII ions lie in the cavity of a five coordinate nitrogen macrocycle, and in combination with the introduction of multi-fluorinated monodentate phenoxyl coligands a high axiality coordination symmetry is built. Using the pentafluorophenol co-ligand, complex 1 with a D2d coordination environment, is obtained and displays moderate single-molecule magnets (SMMs) behavior. When difluorophenol co-ligands were used, a higher local axisymmetric pentagonal bipyramidal coordination geometry was observed in complex 2, which displays apparent slow magnetic relaxation behavior with a hysteresis temperature of up to 5 K. Further magnetic studies of diluted samples combined with ab initio calculations indicate that the high axiality plays a crucial role in suppressing quantum tunneling of magnetization (QTM) and consequently results in good slow magnetic relaxation behavior. Different fluoro-substituted phenoxyl co-ligands have phenoloxy oxygen atoms with different electrostatic potentials as well as a different number of phenoloxy coligands along the magnetic axis, resulting in different ligand field strengths and coordination symmetries. [ABSTRACT FROM AUTHOR]

Incorporating transition metal atoms into metal–molecule–metal junctions presents opportunities for exploring the electronic properties of coordination complexes, organometallics and metal–organic materials on the single molecule level. Recent single molecule conductance studies have shown that in situ incorporation of electrode metal atoms into coordination chains formed in the junction can occur with deprotonated, negatively charged organic ligands, such as the imidazolate (Im−) anion. However, the mechanism and chemical principles, such as the role of the charge state of the ligand, for the construction of such coordination chains are still debated. Here, we probe the role of the ligand charge state and electronic structure in single-molecule conductance and formation of metal–molecule coordination chains. We perform break junction measurements with triazole isomers, which can bridge junctions both in their neutral and charged forms, and find that prior deprotonation of the ligands is not required for coordination complex assembly, but can affect the molecular conductance and junction formation probability. Our results indicate that coordination chains can form with neutral ligands, as long as the electron density in the frontier MOs is concentrated at the binding sites and along the direction of pulling, promoting ligand binding and incorporation of gold atoms into the junction during elongation. Our findings may provide insight into design principles for in situ assembled molecular wires with transition metal atoms and open the door to electronic and spintronic studies of such materials. [ABSTRACT FROM AUTHOR]

A rigid pentadentate chelating ligand (H2L) has been utilized to synthesize a series of octacoordinate mononuclear complexes, [Dy(L)(Ph3PO)(OOCR)] (where R = C6H5 (1), C(CH3)3 (2), CF3 (3)) and a dinuclear complex, [Dy2(L)2(Ph3PO)2{(OOC)2C6H4}] (4) based on the highly anisotropic Dy(III) ion. All the complexes were structurally characterized by single-crystal X-ray diffraction studies. The complexes were formed by the coordination action of the dianionic pentadentate ligand [L]2−, one phosphine oxide, and carboxylate ligands. DC and AC magnetic measurements were performed on 1–4. Complexes 1–4 show SMM behaviour, under zero DC field for 1 and 4, and under 500 Oe and 1000 Oe DC fields for 2 and 3 respectively, with thermally activated, Raman, and Raman and quantum tunnelling dominant relaxation mechanisms for 1 and 2, 3 and 4, respectively. [ABSTRACT FROM AUTHOR]