Inverse Structure Research Articles

Resilience of quantum spin fluctuations against Dzyaloshinskii-Moriya interaction.

In low-dimensional systems, the lack of structural inversion symmetry combined with the spin-orbit coupling gives rise to an anisotropic antisymmetric superexchange known as the Dzyaloshinskii-Moriya interaction (DMI). Various features have been reported due to the presence of DMIs in quantum systems. We here study the one-dimensional spin-1/2 transverse field XY chains with a DMI at zero temperature. Our focus is on the quantum fluctuations of the spins measured by the spin squeezing and the entanglement entropy. We find that these fluctuations are resistant to the effect of the DMI in the system. This resistance will fail as soon as the system is placed in the chiral phase where its state behaves as a squeezed state, suggesting the merit of the chiral phase to be used for quantum metrology. Remarkably, we prove that the central charge vanishes on the critical lines between gapless chiral and ferromagnetic/paramagnetic phases where there is no critical scaling versus the system size for the spin squeezing parameter. Our phenomenal results provide a further understanding of the effects of the DMIs in the many-body quantum systems which may be testable in experiments.

Tuning benzene activity of cobalt-based spinel catalysts with cation substitution

Cobalt-based spinel oxides are promising low-cost catalysts for volatile organic compounds (VOCs) elimination. Herein, we prepared the cobalt-based spinel oxides (MCo2O4: M = Ni, Cu, Co, Zn) by a one-step solvothermal method to evaluate the influence of cation substitution on benzene combustion. The cation distribution on tetrahedral and octahedral sites could influence the degree of inversion in cobalt-based spinel oxides, thus achieving the regulation of Co-O bond strength. NiCo2O4 catalyst with the inverse spinel structure had the weak Co-O bond strength, which is conducive to the activation of lattice oxygen to improve the activity of benzene degradation. This work provides deep insights into the influence of the cation substitution on the cobalt-based spinel catalysts for the efficient benzene oxidation.

Temperature Structure Inversion of Mesoscale Eddies in the South China Sea Based on Deep Learning

Mesoscale eddies are common in global oceans, playing crucial roles in ocean dynamics, ocean circulation, and heat transport, and their vertical structures can affect the water layers from tens to thousands of meters. In this study, we integrated sea surface height and sea surface temperature data into deep learning methods to study the mesoscale eddy subsurface temperature structure and to explore the relationship between sea surface data and eddy subsurface layers. In this study, we introduce Dual_EddyNet, a deep learning algorithm designed to invert the subsurface temperature structure of mesoscale eddies. Using this algorithm, we explore the impact of the sea surface height and sea surface temperature on the subsurface temperature structure inversion of mesoscale eddies. Furthermore, we compare different data fusion strategies, namely single-stream neural networks and dual-stream neural networks, to validate the effectiveness of the dual-stream model. To capture the interrelations among surface data and integrate feature information across various dimensions, we introduce the Triplet Attention Mechanism. The experimental results demonstrate that the proposed Dual_EddyNet performs well in reconstructing the three-dimensional structure of mesoscale eddies in the South China Sea (within a depth of 1000 m), with an inversion accuracy of 91.44% for cyclonic eddies and 95.25% for anticyclonic eddies. This algorithm provides a new method for inverting the subsurface temperatures of mesoscale eddies, and can not only be directly deployed in systems, embedded in ship moving platforms, etc., but can also provide a data reference for assimilations and numerical simulations, demonstrating its rich application potential.

Absolute Structures of a Mirror Pair of Infinite Na(H2O)4 + -Connected ε-Keggin-Al13 Species.

The absolute structures of a pair of infinite Na(H2O)4+-connected ε-Keggin-Al13 species (Na-ε-K-Al13) that were inversion structures and mirror images of each other were determined. Single crystals obtained by adding A2SO4 (A = Li, Na, K, Rb, or Cs) solution to NaOH-hydrolyzed AlCl3 solution were subjected to X-ray structure analyses. The statistical results for 36 single crystals showed that all the crystals had almost the same unit cell parameter, belonged to the same F4̅3m space group, and possessed the same structural formula [Na(H2O)4AlO4Al12(OH)24(H2O)12](SO4)4·10H2O. However, the crystals had two inverse absolute structures (denoted A and B), which had a crystallization ratio of 1:1. From Li+ to Cs+, with increasing volume of the cation coexisting in the mother solution, the degree of disorder of the four H2O molecules in the Na(H2O)4+ hydrated ion continuously decreased; they became ordered when the cation was Cs+. Absolute structures A and B are the first two infinite aluminum polycations connected by statistically occupied [(Na1/4)4(H2O)4]+ hydrated ions. The three-dimensional structure of the infinite Na-ε-K-Al13 species can be regarded as the assembly of finite ε-K-Al13 species linked by [(Na1/4)4(H2O)4]+ in a 1:1 ratio. In this assembly, each [(Na1/4)4(H2O)4]+ is connected to four ε-K-Al13 and each ε-K-Al13 is also connected to four [(Na1/4)4(H2O)4]+ in tetrahedral orientations to form a continuous rigid framework structure, which has an inverse spatial orientation between absolute structure A and B. This discovery clarifies that the ε-K-Al13 (or ε-K-GaAl12) species in Na[MO4Al12(OH)24(H2O)12](XO4)4·nH2O (M = Al, Ga; X = S, Se; n = 10-20) exists as discrete groups and deepens understanding of the formation and evolution process of polyaluminum species in forcibly hydrolyzed aluminum salt solution. The reason why Na+ statistically occupies the four sites was examined, and a formation and evolution mechanism of the infinite Na-ε-K-Al13 species was proposed.

Interplay of positive structural inversion and salt tectonics: The case study of the central Algerian margin, Western Mediterranean

Convergence between African and European plates generates compressional strain, primarily concentrated along the northern African margin. This is testified on the Algerian margin by numerous earthquakes (e.g. Bougrine et al., 2019) and by the presence of active folds and thrusts. Multi-channel seismic reflection profiles from the MARADJA I survey reveal north-verging thrusts rooted below the Messinian units, and the geometries of the Messinian salt structures. This study examines the characteristics of salt tectonics offshore Algiers and Dellys, focusing on the effect of the positive structural inversion of the former passive margin on geometries, timing, and mechanisms of salt deformation. The interpretation of seismic reflection and multi-beam bathymetric data of the MARADJA I survey, along with its comparison with analogue models, allowed us to reconstruct the salt tectonics processes on the margin and to identify the predominant role of a plateau uplift on salt deformation. Early and ubiquitous salt deformation by downbuilding was followed by a major phase of plateau uplift (end of Messinian Crisis), leading to westward gravity gliding and a slowdown of the salt deformation above the plateau. Km-tall salt structures were developed and thick minibasins deposited. Salt tectonics is nowadays active only where the relationship between salt and overburden thickness is favorable.

Analisis Struktur Batin Pada Puisi Selamat Ulang Tahun Buku Karya Joko Pinurbo

Poetry is one of the most interesting forms of literary work but is full of meaning. Poetry is a medium for conveying feelings and ideas with beautiful words. Poetry as a meaningful aesthetic work is also a recording and interpretation of human experience composed in the most memorable form. Poetry can make us laugh, cry, smile, think, reflect, be moved and even get emotional and angry. Until now, poetry can be an illustration of the cultural progress of society. How the writer of the poem views his world is a real picture of the culture that surrounds him. Because the progress of society from time to time always increases, bringing changes in the style, nature and form of poetry. Poetry changes following developments in taste, ever-changing aesthetic concepts, and intellectual progress. The aim of the research is stated in a sentence that explores or deepens the inner structure of poetry. The inner structure intended is: theme, tone, feeling and message. The method used in this research is descriptive analytical method. This method also attempts to describe facts logically. Through this method, the researcher tries to analyze the inner structure of Joko Pinurbo's poem entitled "Happy Birthday, Book", while the analysis of this poem is described in his own words and language.

High-performance magnetic refrigeration materials: Prediction and realization

Magnetic refrigeration technology based on the magnetocaloric effect provides an optimal replacement for conventional refrigeration technology. However, an efficient approach to developing superior magnetic refrigeration materials to satisfy practical requirements is still lacking. Here, a feasible approach to develop magnetic refrigeration materials with a superior magnetocaloric effect is designed. Based on this screening rule, the 23 rare-earth-based compounds with inverse perovskite structures were revealed in space group Pm3̅m (No. 221). The First principle calculations are used to predict the magnetism, and electronic structure of candidate compounds, and there are 13 rare earth-based compounds in the candidate materials that have a ferromagnetic magnetic ground state. The Er3SnC, Ho3SnC, Gd3SnC, and Gd3AlC compounds were realized, and the magnetism, magnetocaloric effects were investigated. The experimental results demonstrate that the magnetic ground states of the prepared compounds are in agreement with theoretical predictions. The Er3SnC, Ho3SnC and Gd3SnC compounds with ferromagnetic states exhibit superior magnetocaloric effects.

An inverse data envelopment analysis model for solving time substitution problems

This paper proposes new inverse data envelopment analysis (DEA) models considering input and output efficiency measures for the time substitution problem. We compare our DEA model with existing models in the literature. We show that existing models in the literature overestimate the required resources, and on the other hand, these are a special case of our models. We show that our models are unit invariant. We also describe another appealing characteristic of our model, that is, efficiency invariant, as a consequence of inverse structure. An illustrative example is provided to explain the proposed model and provide a comparison of our models and existing models in the literature. We also used our models in a real-world application, the selected economic sectors in Iran. The results show some potential improvements during the period of study.

Adjoint sensitivity kernels for free oscillation spectra

SUMMARY We apply the adjoint method to efficiently calculate sensitivity kernels for long-period seismic spectra with respect to structural and source parameters. Our approach is built around the solution of the frequency-domain equations of motion using the direct solution method (DSM). The DSM is currently applied within large-scale mode coupling calculations and is also likely to be useful within finite-element type methods for modelling seismic spectra that are being actively developed. Using mode coupling theory as a framework for solving both the forward and adjoint equations, we present numerical examples that focus on the spectrum close to four eigenfrequencies (the low-frequency mode, 0S2, and higher frequency modes, namely 2S2, 0S7 and 0S10 for comparison). For each chosen observable, we plot sensitivity kernels with respect to 3-D perturbations in density and seismic wave speeds. We also use the adjoint method to calculate derivatives of observables with respect to the matrices occurring within mode coupling calculations. This latter approach points towards a generalization of the two-stage splitting function method for structural inversions that does not rely on inaccurate self-coupling or group-coupling approximations. Finally, we verify through direct calculation that our sensitivity kernels correctly predict the linear dependence of the chosen observables on model perturbations. In doing this, we highlight the importance of non-linearity within inversions of long-period spectra.

Chloroplast genome of Ecbolium viride (Forssk.) Alston: plastome evolution and phylogenomics of Justiceae (Acanthaceae, Acanthoideae).

Justicieae is the most taxonomically complex tribe in Acanthaceae. Here, we sequenced the plastome of Ecbolium viride, a medicinally important species. The genome was analyzed with previously reported plastome of Justiceae. The plastome of E. viride has quadripartite structure with a length of 151 185bp. The comparative genomic analyses revealed no structural inversion in Justiceae and some regions (rpoC2, ycf2, ycf1, ndhH rps16-trnQ-UGG, and trnL-CAA-ycf15) exhibiting a significant level of nucleotide divergence. The positive selection analyses revealed that some species in the tribe have undergone adaptive evolution. The visualization of the boundaries between the single copy and inverted repeat regions revealed that Justiceae chloroplast genome experienced some levels of variation, which give an insight into the evolution of the species. The longest genome was in the earliest diverged taxa of the tribe Pseuderanthemum haikangense and from this genome, a series of contraction and expansion occurred contributing to the evolution of other lineages. The plastome-based phylogeny revealed and confirmed the monophyly of Justiceae, polyphyly of Justicia and supported the tribal classification Graptophyllinae, Tetrameriinae, and Isoglossinae. We proposed that Declipterinae should be treated as subtribe and the status of Justiciinae can only be confirmed after the resolution of the polyphyletic Justicia.

Engineering Spin-Orbit Interactions in Silicon Qubits at the Atomic-Scale.

Spin-orbit interactions arise whenever the bulk inversion symmetry and/or structural inversion symmetry of a crystal is broken providing a bridge between a qubit's spin and orbital degree of freedom. While strong interactions can facilitate fast qubit operations by all-electrical control, they also provide a mechanism to couple charge noise thereby limiting qubit lifetimes. Previously believed to be negligible in bulk silicon, recent silicon nano-electronic devices have shown larger than bulk spin-orbit coupling strengths from Dresselhaus and Rashba couplings. Here, it is shown that with precision placement of phosphorus atoms in silicon along the [110] direction (without inversion symmetry) or [111] direction (with inversion symmetry), a wide range of Dresselhaus and Rashba coupling strength can be achieved from zero to 1113 × 10-13eV-cm. It is shown that with precision placement of phosphorus atoms, the local symmetry (C2v, D2d, and D3d) can be changed to engineer spin-orbit interactions. Since spin-orbit interactions affect both qubit operation and lifetimes, understanding their impact is essential for quantum processordesign.

Strength-Ductility Mechanism of CoCrFeMnNi High-Entropy Alloys with Inverse Gradient-Grained Structures.

The microstructures and mechanical properties of equiatomic CoCrFeMnNi high-entropy alloys (HEAs) treated with various processing parameters of laser surface heat treatment are studied in this paper. The typical inverse gradient-grained structure, which is composed of a hard central layer and a soft surface layer, can be obtained by laser surface heat treatment. A much narrower gradient layer leads to the highest yield strength by sacrificing ductility when the surface temperature of the laser-irradiated region remains at ~850 °C, whereas the fully recrystallized microstructure, which exists from the top surface layer to the ~1.05 mm depth layer, increases the ductility but decreases the yield strength as the maximum heating temperature rises to ~1050 °C. Significantly, the superior strength-ductility combination can be acquired by controlling the surface temperature of a laser-irradiated surface at ~1000 °C with a scanning speed of ~4 mm/s due to the effect of hetero-deformation-induced strengthening and hardening, as well as the enhanced interaction between dislocation and nanotwins by the hierarchical nanotwins. Therefore, retaining the partial recrystallized microstructure with a relatively high microhardness in the central layer, promoting the generation of hierarchical nanotwins, and increasing the volume proportion of gradient layer can effectively facilitate the inverse gradient-grained CoCrFeMnNi HEAs to exhibit a desirable strength-ductility synergy.

Hepatocellular carcinoma biomarkers screening based on hydrogel photonic barcodes with tyramine deposition amplified ELISA

Hepatocellular carcinoma (HCC), as one of the most lethal cancers, significantly impacts human health. Attempts in this area tends to develop novel technologies with sensitive and multiplexed detection properties for early diagnosis. Here, we present novel hydrogel photonic crystal (PhC) barcodes with tyramine deposition amplified enzyme-linked immunosorbent assay (ELISA) for highly sensitive and multiplexed HCC biomarker screening. Because of the abundant amino groups of acrylic acid (AA) component, the constructed hydrogel PhC barcodes with inverse opal structure could facilitate the loading of antibody probes for subsequent detection of tumor markers. By integrating tyramine deposition amplified ELISA on the barcode, the detection signal of tumor markers has been enhanced. Based on these features, it is demonstrated that the hydrogel PhC barcodes with tyramine deposition amplified ELISA could realize highly sensitive and multiplexed detection of HCC-related biomarkers. It was found that this method is flexible, sensitive and accurate, suitable for multivariate analysis of low abundance tumor markers and future cancer diagnosis. These features make the newly developed PhC barcodes an innovation platform, which possesses tremendous potential for practical application of low abundance targets.

Understanding color variation with site distribution in inverse spinel structure via neutron diffraction, magnetism, and optical studies

Chromophores at different coordinations can give rise to different colors; usually, chromophores at non-centrosymmetric coordinations are preferred for intense pigments. Different solid solutions M2-xCoxM’O4 (M = Mg/Zn, and M’ = Ti/Sn) with inverse spinel structure were synthesized with the goal of understanding color variation with site distribution, as the chromophore Co2+ in these solid solutions can occupy either the tetrahedral or octahedral sites or both depending on the composition. Another goal was to develop environmentally friendly and cheap blue pigments by reducing the carcinogenic cobalt to obtain a similar color to that of commercially available cobalt blue, which uses a significant amount of Co2+ (33.31 % by mass). For Mg2-xCoxTiO4 series, turquoise blue hues were observed for low cobalt content, and different shades of blue were observed for Mg2-xCoxSnO4 series with a color similar to cobalt blue, including just 4.90% of cobalt by mass. While for Zn2-xCoxTiO4, and Zn2-xCoxSnO4 series, different shades of brown and different shades of green, respectively, were observed. One of the main reasons behind the major difference in color for the Mg and Zn containing solid solutions, regardless of the same chromophore in the same structure is related to the chromophore site distribution in the system. For the Mg-containing solid solutions, different shades of blue are observed as Mg has no preference for any of the sites, Co2+ mostly goes to tetrahedral sites. In contrast, for the Zn-containing solid solutions, no blue shades were observed because of the strong preference of Zn for the tetrahedral sites owing to the sp3 hybridization, which in turn forces Co2+ to occupy the octahedral sites. Neutron refinement proves that Co2+ occupies mainly tetrahedral sites in the Mg-containing solid solutions and mostly octahedral sites in the Zn-containing solid solutions.

Production of Green energy via Water Splitting mechanism by Mn- doped Cobalt Ferrites [Co1-xMnxFe2O4] based Hydroelectric Cells

In our current study, we have investigated the impact of manganese (Mn) doping on the structural, magnetic properties, and hydroelectric cell properties of cobalt ferrite with chemical formula [Co1-xMnxFe2O4, x=0.00, 0.125]. The solid-state approach has been utilized to synthesize the material. XRDmeasurements revealed the formation of an inverse spinel cubic structure with the space group Fd-3m. FTIR spectra hold a shift in the octahedral and tetrahedral bands with the increase in Mn content in cobalt ferrites. The subsequent rise in ferroelectric behavior has been observed with the net maximum saturation polarization of 1.08μC/cm2. The variation in the permittivity values has been also studied with the increase in Mn content for dry as well as wet hydroelectric cells. The impedance measurements helped us understand the contribution of grains/grain boundaries in the prepared ferrites. The enhanced value of magnetization has been noticed from 48.258 emu/g to 73.089 emu/g upon doping of Mn ions in cobalt ferrite spinel structure lattice.The Mndoped CFO exhibited enhanced performance in hydroelectric cells which demonstrates the great ionic diffusion mechanism with the incorporation of Mn ions. The obtained output makes Mn doped CFO a suitable material for studying microelectronic and hydroelectric cell applications. The purpose of this study is to enhance both ferroelectric as well as ferromagnetic behavior along with the improved value of current in hydroelectric cells.

Bandgap engineering of spinel-structured oxide semiconductor alloys

We investigated bandgap engineering of spinel-structured MgB 2O4 (B = Al, Ga, In) alloys. The trend of bandgap change was tunable from approximated 7.8–3.6 eV by substituting group III cation atoms in MgB 2O4. To evaluate the doping possibility, we have calculated the natural band alignment and doping pinning energy of the normal and inverse spinel structures of MgB 2O4 alloys. The calculated doping pinning energies show that spinel-structured MgB 2O4 alloys can potentially control the electron concentration, but hole doping is difficult. Our computational results are expected to provide new insights into the doping control of ultra-wide bandgap semiconductors.

Unraveling the effect of annealing on the structural and microstructural evolution of NiFe2O4@SiO2 core-shell type nanocomposites

The comparison between as-received and multistage annealed NiFe2O4@SiO2 (NFO@SiO2) core-shell nanoparticles is presented. The studied ferrites were synthesized by co-precipitation followed by microemulsion. The presence of cubic inverse spinel ferrite structure with tetrahedral and octahedral iron occupancy is confirmed in all analyzed samples. The structural characterization revealed the gradual crystallization of NFO cores up to about 12 nm crystallite size at the last annealing stage. Simultaneously, a partial crystallization of the silica matrix is evidenced. The superparamagnetic (SPM) behaviour is demonstrated based on complex magnetic performance and confirmed by Mössbauer spectrometry. The spin-canting phenomenon on the surface dead magnetic layer (MDL) is revealed based on the Yafet-Kittel model. A slight change in MDL thickness versus heat treatment is proved. The X-ray photoemission and absorption studies confirmed the complex nature of the Fe-based states. The Si–O–Ni/Fe intermixing on the NFO – SiO2 nanoparticles interface is revealed by the core-level lines analysis, proving the existence of a disordered layer on the NFO surface.

ZnxFe3-xO4–ZnO heterojunction interfaced with poly(L-DOPA) electron transfer mediator layer for enhanced visible light photocatalytic activity

Z-scheme heterojunctions comprising ZnxFe3-xO4@poly(L-DOPA)@ZnO (ZF@PD@ZnO) were synthesized using solvothermal and precipitation techniques. The study aimed to investigate the impact of the poly(L-DOPA) electron transfer mediator on the photocatalytic performance of ZnxFe3-xO4@ZnO (ZF@ZnO) nanocomposites under visible light irradiation. X-ray diffraction (XRD) and HRTEM analysis confirmed the formation of heterostructures, identifying the crystalline phases of both ZnO and zinc ferrite. BFTEM images revealed a polyhedral shape for all samples, with a tendency toward mild agglomeration. The partial inversion of the zinc ferrite cubic spinel structure was evidenced by FT-IR, XPS, and VSM analyses. Zinc ferrite was found to be ferromagnetic, with cation distributions between tetrahedral (A) and octahedral (B) positions as [Zn0.62+Fe0.43+]A[Fe0.42+Fe1.63+]BO4. The samples exhibited notable photocatalytic activity against Rhodamine B, serving as a model contaminant. Furthermore, the stability and reusability of the samples were examined. Additionally, the study elucidated the photocatalytic mechanism produced by the ternary Z-scheme ZF@PD@ZnO, involving spin-polarized charge carriers. Energy band alignment was evaluated by combining ultraviolet photoelectron spectroscopy (UPS) with UV-Vis spectroscopy. The interplay between band alignment and reactive oxygen species (ROS) generation was discussed in correlation with EPR results. Enhanced ROS generation under visible light illumination, observed in the ZF@PD@ZnO nanocomposite, is mainly due to the addition of the conductive poly(L-DOPA) layer, acting as an electron transfer mediator in the Z-scheme heterojunction, ensuring enhanced charge separation.

Driven electron g-factor anisotropy in layered III–V semiconductors: Interfacing, tunnel coupling, and structure inversion asymmetry effects

A key piece for spintronic applications, the so-called electron g-factor engineering is still predominantly based on the semiconductor bulk g factor and its dependence on the bandgap energy. In nanostructures, however, the mesoscopic confinement introduces exclusive anisotropies, transforming scalar g factors into tensors, enabling different renormalization mechanisms as routes for fine-tuning the electron g factor. These questions we address in this comparative theoretical analysis between the obtained electron g-factor (tensor) anisotropies for realistic InAs|AlSb- and In0.53Ga0.47As|InP-based multilayers. The electron g-factor anisotropy, i.e., the difference between g factors for magnetic fields parallel and perpendicular to the interfaces, is analytically calculated via perturbation theory using the envelope-function approach based on the eight-band Kane model. Effects from bulk, interfacing, tunnel coupling, and structure inversion asymmetry are systematically introduced within a transparent comparative view; differences between obtained anisotropies, such as in the magnitude, sign, and other fine details, are analyzed in terms of the heterostructure parameters, mapped over different confining and tunnel-coupling regimes without requiring elaborated numerical computations.

A Route to Two-Dimensional Room-Temperature Organometallic Multiferroics: The Marriage of d-p Spin Coupling and Structural Inversion Symmetry Breaking.

Two-dimensional (2D) room-temperature multiferroic materials are highly desirable but still very limited. Herein, we propose a potential strategy to obtain such materials in 2D metal-organic frameworks (MOFs) by utilizing the d-p direct spin coupling in conjunction with center-symmetry-breaking six-membered heterocyclic rings. Based on this strategy, a screening of 128 2D MOFs results in the identification of three multiferroics, that is, Cr(1,2-oxazine)2, Cr(1,2,4-triazine)2, and Cr(1,2,3,4-trazine)2, simultaneously exhibiting room-temperature ferrimagnetism and ferroelectricity/antiferroelectricity. The room-temperature ferrimagnetic order (306-495 K) in these MOFs originates from the strong d-p direct magnetic exchange interaction between Cr cations and ligand anions. Specifically, Cr(1,2-oxazine)2 exhibits ferroelectric behavior with an out-of-plane polarization of 4.24 pC/m, whereas the other two manifest antiferroelectric characteristics. Notably, all three materials present suitable polarization switching barriers (0.18-0.31 eV). Furthermore, these MOFs are all bipolar magnetic semiconductors with moderate band gaps, in which the spin direction of carriers can be manipulated by electrical gating.