Metal Chains Research Articles

Dominant superconducting correlations in a Luttinger liquid induced by spin fluctuations

We study spin-fluctuation mediated divergent superconducting fluctuations in a Luttinger liquid proximity-coupled to a spin chain. Our study provides insight into how spin fluctuations can induce superconductivity in a strongly correlated non-Fermi liquid with repulsive electronic interactions only. The electrons in the system are governed by the Extended Hubbard Hamiltonian and are coupled to a chain of localized spins modeled by the spin-$\frac{1}{2}$ $XX$ Hamiltonian. Using a multichannel Luttinger liquid approach, we determine the phase diagram of the metal chain. We find that spin-polarized triplet superconducting correlations persist for repulsive electronic interactions for sufficiently large interchain couplings.

USE OF ELEMENTS OF 3D PRINTING IN MEN’S SUIT DESIGN

The use of innovative methods and constructive solutions, non-typical textural and structural materials and elements of 3 printing in the development of the design of models of products of the fashion industry, and in particular clothes, attracts the attention of fashion industry specialists, starting from interesting and creative ideas, creating collages of inspiration, performing quick black and white sketches of products, selection of materials and components, as well as in the detailed development of elements of men’s suit constructions. Development of an assortment of modern and creative men’s suits from various non-typical materials and elements for the industry is a bold challenge of the designer to society, his idea, vision of the world of emotions, fashion and beauty. This is partly an opportunity to save natural resources and use as decorative elements of the suit 3 printing details imitating metal chains. The article investigates and analyzes the relevance and technological possibility of using 3D printing elements in the form of chains of various weaves for the design of a collection of men’s suits for industrial and individual collections. The issue of fashion trends in the design of men’s suits has been studied and analyzed. An analysis of world brands of clothing manufacturers was conducted, the theoretical feasibility of this development was proved. The results of theoretical and analytical research on the possibility of using bold constructive ideas and solutions in men’s suits are presented. Developed a sketch project, 3D models of chains, made with the help of a 3D printer “Prusa” chain samples for use in the men’s suit collection. Samples-modules of products were made in the material for visualization of the idea. This development was presented at the startup competition of works of young designers, Kyiv KNUTD (2022). The feasibility of this development has been proven theoretically. The collection of products will be presented at the competition “Cave Chestnuts”, Kyiv.

Arsenic Monolayers Formed by Zero-Dimensional Tetrahedral Clusters and One-Dimensional Armchair Nanochains.

One-dimensional (1D) arsenene nanostructures are predicted to host a variety of interesting physical properties including antiferromagnetic, semiconductor-semimetal transition and quantum spin Hall effect, which thus holds great promise for next-generation electronic and spintronic devices. Herein, we devised a surface template strategy in a combination with surface-catalyzed decomposition of molecular As4 cluster toward the synthesis of the superlattice of ultranarrow armchair arsenic nanochains in a large domain on Au(111). In the low annealing temperature window, zero-dimensional As4 nanoclusters are assembled into continuous films through intermolecular van der Waals and molecule-substrate interactions. At the elevated temperature, the subsequent surface-assisted decomposition of molecular As4 nanoclusters leads to the formation of a periodic array of 1D armchair arsenic nanochains that form a (2 × 3) superstructure on the Au(111) surface. These ultranarrow armchair arsenic nanochains are predicted to have a small bandgap of ∼0.50 eV, in contrast to metallic zigzag chains. In addition, the Au-supported arsenic nanochains can be flipped to form a bilayer structure through tip indentation and manipulation, suggesting the possible transfer of these nanochains from the substrate. The successful realization of arsenic nanostructures is expected to advance low-dimensional physics and infrared optoelectronic nanodevices.

Simple approach to current-induced bond weakening in ballistic conductors

We present a simple, first principles scheme for calculating mechanical properties of nonequilibrium bulk systems assuming an ideal ballistic distribution function for the electronic states described by the external voltage bias. This allows for fast calculations of estimates of the current-induced stresses inside bulk systems carrying a ballistic current. The stress is calculated using the Hellmann-Feynman theorem, and is in agreement with the derivative of the nonequilibrium free energy. We illustrate the theory and present results for one-dimensional (1D) metal chains. We find that the susceptibility of the yield stress to the applied voltage agrees with the ordering of break voltages among the metals found in experiments. In particular, gold is seen to be the most stable under strong current, while aluminum is the least stable.

A Double‐Helix Metal‐Chain Metal‐Organic Framework as a High‐Output Triboelectric Nanogenerator Material for Self‐Powered Anticorrosion

AbstractThe development of novel metal organic framework (MOF) friction power generation materials with high stability is important. This paper reports the first example of a double‐helix metal chain organic framework with a network structure (ZUT‐8). ZUT‐8 shows high chemical stability, functional adjustability, and excellent output performance of friction power generation, which is superior to traditional coordination polymer materials. The cathodic protection system with ZUT‐8 can prevent metal corrosion significantly. The output performance can be improved effectively by enhancing the conjugate effect of the linker. The theoretical calculation results showed that an increase in the degree of conjugation could significantly reduce the band gap, thereby affecting the friction power output signal. This study opens the door to constructing MOF materials with a double‐helix metal chain and will promote their potential applications in self‐powered electrochemical cathodic protection.

A Double-Helix Metal-Chain Metal-Organic Framework as a High-Output Triboelectric Nanogenerator Material for Self-Powered Anticorrosion.

The development of novel metal organic framework (MOF) friction power generation materials with high stability is important. This paper reports the first example of a double-helix metal chain organic framework with a network structure (ZUT-8). ZUT-8 shows high chemical stability, functional adjustability, and excellent output performance of friction power generation, which is superior to traditional coordination polymer materials. The cathodic protection system with ZUT-8 can prevent metal corrosion significantly. The output performance can be improved effectively by enhancing the conjugate effect of the linker. The theoretical calculation results showed that an increase in the degree of conjugation could significantly reduce the band gap, thereby affecting the friction power output signal. This study opens the door to constructing MOF materials with a double-helix metal chain and will promote their potential applications in self-powered electrochemical cathodic protection.

Systematic lowering of the scaling of Monte Carlo calculations by partitioning and subsampling

We propose to compute physical properties by Monte Carlo calculations using conditional expectation values. The latter are obtained on top of the usual Monte Carlo sampling by partitioning the physical space in several subspaces or fragments, and subsampling each fragment (i.e., performing side walks) while freezing the environment. No bias is introduced and a zero-variance principle holds in the limit of separability, i.e., when the fragments are independent. In practice, the usual bottleneck of Monte Carlo calculations-the scaling of the statistical fluctuations as a function of the number of particles N-is relieved for extensive observables. We illustrate the method in variational Monte Carlo on the two-dimensional Hubbard model and on metallic hydrogen chains using Jastrow-Slater wave functions. A factor O(N) is gained in numerical efficiency.

Management of foreign bodies in the urinary tract

Introduction: Foreign bodies in the urinary tract may present in various ways. These require a wide range of interventions for retrieval. In this study, we describe our experience in managing foreign bodies in the urinary tract with emphasis on clinical presentation, mechanism of insertion, investigation and treatment of these patients from a South Asian country. Methods: A retrospective analysis of 30 foreign bodies treated by a single urological surgeon in two teaching hospitals in Sri Lanka over 20 years was performed. Data were retrieved from clinical records and follow-up visits focussing on clinical presentation, nature of foreign bodies, mechanism of insertion, investigations, management and complications. Results: The majority were males (73.3%, n=22) with a median age of 34 years (range:14-72). The majority were self-inserted (n=14) or iatrogenic (n=10). X-rays and ultrasound scans were useful in the majority to clinch the diagnosis. The majority were retrieved endoscopically through minimally invasive approaches. Open surgeries were needed for a patient with a large bladder stone associated with a metal chain and retrieval of a retained swab. Common complications associated with foreign bodies included infections (n=9), calcification/ stone formation (n=9) and acute urinary retention (n=4). Among deliberate self- insertions, two had a low intelligent quotient and the majority had no underlying psychiatric condition needing intervention. Conclusions: Simple investigations such as X-ray and ultrasound scans are sufficient to locate and plan interventions in the majority. Minimally invasive approaches are successful in most. The vast majority of the patients with self-insertion had no psychiatric conditions needing intervention.

Novel copper(II) and nickel(II) coordination complexes of 2,4-pentanedione bis-thiosemicarbazone: Synthesis, structural characterization, computational studies, and magnetic properties

• Two new isoformular [Cu(L 1 O)] and [Ni(L 1 O)] complexes structures have been synthesized. • [Cu(L 1 O)] and [Ni(L 1 O)] complexes were characterized by single crystal X-ray, Raman, FTIR and UV–Visible techniques. • Hirshfeld surface analyses of the synthetized complexes were also performed. • For the two coordination complexes, magnetic investigations showed the presence of high antiferromagnetic interactions. The reaction of the proligand thiosemicarbazido 2-pyrazoline (H 2 L 2 ), derived from 2,4-pentanedione bis-thiosemicarbazone (H 2 L 1 ) with Cu(II) and Ni(II) salts, under aerobic conditions, yielded the mononuclear title complexes [M(L 1 O)]. The open form of the ligand, H 2 L 1 , is oxidized at the central CH 2 of the backbone and doubly deprotonated. The obtained complexes were characterized by using single crystal X-ray diffraction, FT-IR and UV–Vis spectroscopic techniques. The structures of the title complexes were determined respectively in monoclinic and triclinic symmetry, where the copper complex [Cu(L 1 O)] and nickel complex [Ni(L 1 O)] crystallize in the centrosymmetric space groups C 2/ c and P 1 ¯ , respectively. The asymmetric unit is formed of M II atom occupying a general position, linked by two sulfur and two nitrogen atoms, to form M II S 2 N 2 square plane environment in both complexes. The crystal structure stabilization of both complexes is ensured by weak interactions hydrogen bonds D–H⋯A with (D = N, C and A = N, O, Sand / or C). This has been confirmed by the three dimensional Hirshfeld surface analysis and the two dimensional fingerprint plots that highlight the dominance of H⋯H, S⋯H/H⋯S and H⋯N/N⋯H intermolecular interactions. The magnetic study revealed that the magnetic chains of Cu and Ni transition metal atoms in square plane environment show two different magnetic interactions in both investigated complexes, with linear and undulating (on zig-zag) metallic chains in Cu and Ni complexes, with antiferromagnetic behaviour for the first complex and ferrimagnetic for the second one.

Ortho-substituent effect on metal coordination geometry, chain microstructure and polymer properties in α-diimine nickel-catalyzed long chain α-Olefin polymerization

The tuning of polyolefin microstructure, including the branching density and branching distribution, through the ligand modification in transition metal-based catalysts has received considerable interest. In this work, we present the synthesis and characterization of a series of α-diimine Ni(II) catalysts containing bulky diarylmethyl moiety and varied steric substituents, and a systematic investigation on the catalytic behavior of these catalyst for 1-octene and 1-decene polymerization. Ni3 with ortho-diisopropyl substituents adopts a common distorted tetrahedral geometry, while a rare square planar geometry is observed for Ni4 with ortho-phenyl substituents. The ortho-substituent effect on the preference of insertion fashion (1,2 or 2,1-insertion) and chain-walking in long chain α-olefin polymerization is also established. Highly branched amorphous polyolefin can be obtained by the unsymmetrical catalyst with ortho-alkyl substituents (H, Me, iPr) in which the major 1,2-insetion pathway was observed, whereas moderate branched semicrystalline polyolefin can be produced by the unsymmetrical catalyst with ortho-phenyl substituents, which showed a significant increase in 2,1-insertion. Most interestingly, the branching distribution analysis through 13C NMR indicated that the polymer obtained by Ni3 gave the higher percentage of long-chain branches relative to methyl branches, while Ni4 afforded the polymer with methyl branches being predominant. These significant differences in coordination geometry and catalytic behavior between Ni3 and Ni4 may be associated with the unique steric congestion of the ortho-phenyl substituents. In particular, the comparative investigation of the mechanical properties of the polymers obtained by Ni3 and Ni4 was also performed.

Unified treatment for photoluminescence and scattering of coupled metallic multi-nanostructures

We present a multimer coupling classic harmonic oscillator model to reveal the scattering and photoluminescence (PL) properties of metallic nanoparticle chains. Taking particle number from 1 to 6 as examples, we compare the calculated spectra with the experimental ones from other researchers’ work, and they agree well with each other. Furthermore, scattering and PL properties are analyzed carefully varying with particle number n, coupling strength g, and effective free electron number N. Results indicates larger red-shift and smaller full width at half maximum (FWHM) of the scattering spectra with larger n or/and larger g. Particularly, the limitation of the red-shift is obtained in the limit of n→∞. Meanwhile, the splitting of PL modes increases as g increases, and the amplitudes are dependent on the excitation wavelength. This classic model is simple and shows a unified treatment for understanding the scattering and PL properties of multimer coupled systems.

Observation of dimension-crossover of a tunable 1D Dirac fermion in topological semimetal NbSixTe2

Condensed matter systems in low dimensions exhibit emergent physics that does not exist in three dimensions. When electrons are confined to one dimension (1D), some significant electronic states appear, such as charge density wave, spin-charge separations, and Su-Schrieffer-Heeger (SSH) topological state. However, a clear understanding of how the 1D electronic properties connects with topology is currently lacking. Here we systematically investigated the characteristic 1D Dirac fermion electronic structure originated from the metallic NbTe2 chains on the surface of the composition-tunable layered compound NbSixTe2 (x = 0.40 and 0.43) using angle-resolved photoemission spectroscopy. We found the Dirac fermion forms a Dirac nodal line structure protected by the combined widetilde {M_y} and time-reversal symmetry T and proves the NbSixTe2 system as a topological semimetal, in consistent with the ab-initio calculations. As x decreases, the interaction between adjacent NbTe2 chains increases and Dirac fermion goes through a dimension-crossover from 1D to 2D, as evidenced by the variation of its Fermi surface and Fermi velocity across the Brillouin zone in consistence with a Dirac SSH model. Our findings demonstrate a tunable 1D Dirac electron system, which offers a versatile platform for the exploration of intriguing 1D physics and device applications.

Tetranuclear Pd4, PtnPd4‐n (n=1–3), and Pt4 Chains Supported by rac‐ and meso‐Ph2PCH2P(Ph)N(Ar)P(Ph)CH2PPh2 Tuned by Changing N‐Substituents, P‐Configuration, and Terminal Ligands

AbstractWith the hope of tuning structural and electronic properties of the metal chains by changing the N‐substituent group and P‐chiral configurations, a series of PNP bridged tetraphosphines, rac‐ and meso‐Ph2PCH2P(Ph)N(Ar)P(Ph)CH2PPh2 (Ar=4‐RC6H4, R=F (rac‐dpmppanF), CH3 (rac‐dpmppanMe), H (meso‐dpmppan), OMe (meso‐dpmppanOMe); Ar=2,4‐xylyl (rac‐dpmppanMe2)), were synthesized, and utilized to prepare the Pd4 and Pt2Pd2 chains with XylNC terminal ligands, [M4(rac‐dpmppanR)2(XylNC)2](PF6)2 (M4=Pd4, R=F (1F), Me (1Me); M4=Pt2Pd2, R=F (4F), Me (4Me)) and [M4(meso‐dpmppanR)2(XylNC)2](PF6)2 (M4=Pd4, R=H (6), OMe (6OMe); M4=PdPt2Pd, R=OMe (9OMe)). While the M4 metal chains with rac‐dpmppanR (R=H, F, Me) ligands showed only marginal effects on the tetranuclear metal chains, the meso stereoisomer of meso‐dpmppanOMe afforded a new series of Pd4 (6OMe), PtPd3 (7OMe), PtPd2Pt (8OMe), PdPt2Pd (9OMe), Pt3Pd (10OMe), and Pt4 (11OMe) chains that exhibited a characteristic electronic absorption band tunable by the number and positions of incorporated Pt atoms from 628 nm to 473 nm. Especially, 11OMe is the first example of Pt4 chains supported by tetraphosphines. The coordinatively unsaturated Pd4 strings, [Pd4(rac‐dpmppan)2(CH3CN)](BF4)2 (12) and [Pd4(meso‐dpmppanOMe)2](BF4)2 (13), were also synthesized and 12 was utilized in axial ligand exchange reactions with PPh2Me, and PPh3 to disclose their successive incorporation into [Pd4(rac‐dpmppan)2(L)2](BF4)2 (L=PPh2Me (14 a), PPh3 (14 b)) and remarkable red‐shift (713–718 nm) of the HOMO‐LUMO transition of the Pd4 chains. The linear Pd4, PtnPd4‐n (n=1–3), and Pt4 complexes obtained in the present study could be useful 1D building blocks for assembling through metal−metal interaction.

Electron Transport in N-functionalised Armchair Graphene Nanoribbons: Computational Insight

Density functional theory (DFT) theoryhas been used to explore the electronic and transport properties of (3, 0) pristine armchair graphene nanoribbons (AGNR) and its Nitrogen (N) doped counterparts. The analysis has been performed for four different Nitrogen doping concentrations i.e., 6.25%, 12.5%, 18.75% and 25% by replacing the carbon atoms of the pristine AGNR. The computed formation energy (Eform) confirms that the stability of N-doped AGNR is comparable to pristine AGNR. Band structure and density of states profile shows that pristine AGNRs havea band gap of 1.06 eV and introduction of N doping changes its behavior to n-type semiconductor. Interestingly, in N doped AGNR, its metallic character remains intact with increasing concentration of N and shows superior current-voltage characteristics compared to linear atomic chains of metals, with 25% doping concentration. This interesting behavior of N doped AGNR can be exploited for its application as electrodes or interconnects in electronic devices.

Assessment of the drinker type on water intake and toy type on behaviour of nursery piglets

This study was conducted to assess the effect of two types of drinkers on water intake (WI) and two types of toys on behavioural observations of piglets in the nursery phase. A total of 72 crossbred entire male piglets (Landrace × Large White, Agroceres♂ and DanBred♀), weaned at 21 days of age, with an average initial body weight (AIBW) of 6.75 ± 0.19 kg were used. Two statistical models were fitted for WI. In model I, animals were distributed in a completely randomized design (CRD) with a split-plot in time, composed of six treatments (2 types of drinkers × 3 experimental phases), eight replications (days of sampling), and 36 animals/experimental unit (EU), without using AIBW as a covariate. In model II, animals were distributed in a CRD with two treatments (fixed or pendular nipple drinkers), eight replications (days of sampling) and 36 animals/EU, with use of AIBW as a covariate. For assessment of behavioural observations, the model was adjusted in a randomized block design, consisting of four treatments [two types of toys (metal chain and plastic bottle) × two daytime periods (morning and afternoon)], nine replications and three blocks constituted in time (days), totalling four pigs/EU. The results indicated an effect on animal daily WI in the starter phase in model I (p < 0.000) and II (p = 0.006). There was an effect (p ≤ 0.05) of toy type for behavioural observations, in which pigs showed a greater proportion of fighting and belly nosing when they had the bottle toy. However, animals spent more time (p ≤ 0.05) eating, drinking water, overlapping, and playing with the toy when they had access to the chain toy. There was an increase (p ≤ 0.05) in sleeping behaviour in the morning period, as well as greater (p ≤ 0.05) behavioural activity in the afternoon period. In conclusion, WI of nursery piglets was positively influenced by growth phase, and the fixed drinker stimulated greater WI in piglets in the starter phase. In addition, the metal chain, as an environmental enrichment, promoted improvements in feeding behaviour and WI, reducing fighting events, and the afternoon period had increased behavioural observations overall.

Элементы культового комплекса домашнего очага в погребальной практике населения Предкавказья в скифский и сарматский периоды

The article discusses the cult objects found in the burials of the Scythian and Sarmatian times of the Central Ciscaucasia: metal chains, vessels with pebbles and chains, bronze cauldrons, cauldron-shaped pendants, etc. Using the legends of the Nart sagas about Batraz, the God of Thunderstorms and the Lightning, and ethnographic data on the above cult objects, the author reconstructs elements of a complex cult of hearth. Two different variants for cauldron-shaped pendants and chains finds both on the sites of steppe cultures of Scythians and Sarmatians and in the autochthonous burials of Koban culture in the territory of the Central Ciscaucasia indicate the coexistence in the region of two substantially similar hearth cults: steppe (Indo-European) origin, first brought by the Scythians, later by the Sarmatians, and autochthonous (Indo-European) origin, known from the Middle Bronze Age (finds of bronze pot-shaped pendants), cultivated by the population of Koban culture. Finds of vessels with pebbles and chains, cauldron-shaped pendants and other objects associated with the hearth cult in the burials of the last centuries BC in the foothill areas of the Central Ciscaucasia — the area with the mixed population, suggest a symbiosis of the two cults, similar by type, but different by their origin.

The impacts of marking on bats: mark-recapture models for assessing injury rates and tag loss

AbstractThe individual identification of animals is essential for long-term population ecology studies. Injuries and tag loss can negatively impact animal welfare and parameter estimates. We used time-to-failure curves and multistate mark-recapture models to estimate injury rates, body condition decline, tag loss and survival probabilities associated with two tags commonly used in bats: metallic arm bands and steel ball chain collars. We monitored two colonies of Carollia perspicillata at União Biological Reserve, southeastern Brazil, from 2013 to 2019. Every other month, we marked individuals with arm bands, collars or both. Collars did not cause noticeable injuries, but were lost at a higher rate than arm bands (1.5–2.5 times). The arm band-related injury probability between captures was ~ 0.2, and after 17 months half the marked animals developed injuries. Animals marked as juveniles were less likely to get injured than adults. Injuries were associated with a lower body condition in females. Body condition was positively associated with apparent survival; however, a direct effect of arm band injuries on survival estimates was not observed. The tag loss rates caused a negative bias in survival estimates. Mark-recapture studies should evaluate the efficacy of the marking technique, accounting for potential animal injury, tag loss, and bias in parameter estimation. Marking individuals should be limited to studies that monitor species with high recapture probability, using the least harmful tags possible, and balancing the burden to the animals with the potential to generate knowledge.

Two novel luminescent metal-organic frameworks based on the thioether bond modification: The selective sensing and effective CO2 fixation

Two new complexes {[Cd3L2(4,4'-bipy)(H2O)2]·2H2O}n (1) and {[Zn3L2(4,4'-bipy)(H2O)]·H2O}n (2), were synthesized successfully based on 5-((carboxy-3-thio) methyl)isophthalic acid (H3L) and 4,4'-bipyridine (4,4'-bipy) auxiliary ligands under solvothermal conditions. Complexes 1 and 2 have the three-dimensional (3D) crystal structures, which contain infinitely extended one-dimensional (1D) metal chains decorated by open metal sites (OMSs). 1 and 2 both show good thermal stability and excellent water resistance. Fluorescence tests showed that complex 1 has high selectivity and sensitivity to detect Fe3+, Cr2O72− and CrO42− ions in aqueous solution. In addition, complex 1 is an excellent heterogeneous catalyst for the cycloaddition of CO2 and epoxides that catalytic efficiency of epichlorohydrin is higher than 99% under mild conditions.

رؤیة تشکیلیة جدیدة للکروشیه الفیلیة على النول الیدوی والاستفادة منها فى إثراء مکملات الملابس

رؤیة تشکیلیة جدیدة للکروشیه الفیلیة على النول الیدوی والاستفادة منها فى إثراء مکملات الملابس

Unearthing of a new science from nanostructured carbons

Graphene, single-wall carbon nanotubes, and porous carbons have zero-dimensional nanowindows, one-dimensional (1D) pores, and three-dimensional pores consisting of two-dimensional (2D) unit pores, respectively. A molecular dynamics simulation study on nanowindows shows that they enable the efficient separation of O2 from N2 and Ar at an extremely high permeance. Intense confinement of sulfur atoms in 1D-carbon nanotube pore spaces in vacuo leads to the formation of metallic 1D-sulfur chains. Evidence of the partial breaking of the Coulombic law for ionic liquids confined as monolayers in 2D pores, which is caused by an evident image charge effect of conductive carbon-pore walls, was provided by hybrid-reverse Monte Carlo simulation-aided X-ray scattering. The solid-like structural formation of oxygen molecules in 2D carbon pores induces highly efficient and rapid adsorption separation of 18O2 from 16O2 near 112 K, which is the boiling point of methane. Abundant water vapor can be adsorbed on microporous carbon through cluster-associated hydrophobic-hydrophilic transformations. Water molecules form aggregated clusters on the adsorbed branch, which transforms into a continuous structure at a relative pressure of 1, giving rise to obvious adsorption hysteresis. Logical and challenging studies to improve our fundamental understanding, along with new approaches, produce completely new findings, even for carbon materials that have been thoroughly studied.