Coordination Shifts Research Articles

Pure-quartic solitons with PT-symmetric nonlinearity

We propose a new, to the best of our knowledge, class of soliton based on the interaction of parity-time (PT) symmetric nonlinearity and quartic dispersion or diffraction. This novel kind of soliton is related to the recently discovered pure-quartic solitons (PQS), which arise from the balance of the Kerr nonlinearity and quartic dispersion, through a complex coordinate shift. We find that the PT-symmetric pure-quartic soliton presents important differences with respect to its Hermitian (Kerr) counterpart, including a nontrivial phase structure, a skewed spectral intensity, and a higher power for the same propagation constant. Further analysis reveals these solitons are linearly stable.

Electrocatalytic properties of transition metal vanadates (T = Ti, Cr, Mn, & Fe) for overall water splitting

In this work, first row transition metal vanadates (TMVs), including titanium vanadate (TiV), chromium vanadate (CrV), manganese vanadate (MnV), and iron vanadate (FeV), were synthesized and investigated their electrocatalytic performance for the alkaline water splitting. The prepared TMVs showed easy electron transfer characteristics and tunable band structures, and among these TMVs, the synthesized FeV demonstrated the best electrocatalytic bifunctional activities for both HER (η100 = 375 mV) and OER (η100 = 260 mV) with a significant electronic and morphological stability over 100 h operation. The examination of electronic structure revealed that the balanced catalyst-intermediate interaction through optimum d-p orbital hybridization in FeV, adhering to the Sabater principle, vouched for such facile redox reaction. The structural stability might be attributed to the synergism between iron and vanadate as the multivalent Fe adjusted the shift in vanadium coordination when the oxidation state of Vn+ (n = 3–5) changed. Moreover, the two-electrode system of FeV || FeV in a single electrolyzer demonstrated superior cell voltage100 of 1.86 V in comparison to commercial Pt/C || IrO2 electrodes (1.91 V). This work offers facile perspective to produce TMVs as the efficient electrocatalysts for green synthesis of fuel gases.

Selective Enhancement of Viewing Angle Characteristics and Light Extraction Efficiency of Blue Thermally Activated Delayed Fluorescence Organic Light-Emitting Diodes through an Easily Tailorable Si3N4 Nanofiber Structure.

We selectively improved the viewing angle characteristics and light extraction efficiency of blue thermally activated delayed fluorescence (TADF) organic light-emitting diodes (OLEDs) by tailoring a nanofiber-shaped Si3N4 layer, which was used as an internal scattering layer. The diameter of the polymer nanofibers changed according to the mass ratio of polyacrylonitrile (PAN) and poly(methyl methacrylate) (PMMA) in the polymer solution for electrospinning. The Si3N4 nanofiber (SNF) structure was fabricated by etching an Si3N4 film using the PAN/PMMA nanofiber as a mask, making it easier to adjust parameters, such as the diameter, open ratio, and height, even though the SNF structure was randomly shaped. The SNF structures exhibited lower transmittance and higher haze with increasing diameter, showing little correlation with their height. However, all the structures demonstrated a total transmittance of over 80%. Finally, by applying the SNF structures to the blue TADF OLEDs, the external quantum efficiency was increased by 15.6%. In addition, the current and power efficiencies were enhanced by 23.0% and 25.6%, respectively. The internal light-extracting SNF structure also exhibited a synergistic effect with the external light-extracting structure. Furthermore, when the viewing angle changed from 0° to 60°, the peak wavelength and CIE coordinate shift decreased from 20 to 6 nm and from 0.0561 to 0.0243, respectively. These trends were explained by the application of Snell's law to the light path and were ultimately validated through finite-difference time-domain simulations.

Study on the influence of pendulum convex plate on the partial value of quartz flexible accelerometer

The partial value is an essential performance index for assessing the stability of quartz flexible accelerometers. By analyzing the structure of the quartz flexural accelerometer and the impact of the pendulum convex plate, the influence of the convex plate on the partial value of the accelerometer is studied by theoretical derivation and modeling simulation methods. The results show that the barycentric coordinate shifts by approximately 10.7678 × 10-12 µm with the change of the coplanarity of the convex plate, which causes mechanical zero position errors, increases the partial value, and affects the stability of the quartz flexural accelerometer. Therefore, the coplanarity of the convex plate should be maintained at ≤0.3 µm and the partial value should be within the error range of ≤ |±2| mg and provide improvement measures to establish a basis for further improving the stability of the quartz flexible accelerometer.

ATOMDANCE: Kernel-based denoising and choreographic analysis for protein dynamic comparison

Comparative methods in molecular evolution and structural biology rely heavily upon the site-wise analysis of DNA sequence and protein structure, both static forms of information. However, it is widely accepted that protein function results from nanoscale nonrandom machine-like motions induced by evolutionarily conserved molecular interactions. Comparisons of molecular dynamics (MD) simulations conducted between homologous sites representative of different functional or mutational states can potentially identify local effects on binding interaction and protein evolution. In addition, comparisons of different (i.e., nonhomologous) sites within MD simulations could be employed to identify functional shifts in local time-coordinated dynamics indicative of logic gating within proteins. However, comparative MD analysis is challenged by the large fraction of protein motion caused by random thermal noise in the surrounding solvent. Therefore, properly denoised MD comparisons could reveal functional sites involving these machine-like dynamics with good accuracy. Here, we introduce ATOMDANCE, a user-interfaced suite of comparative machine learning-based denoising tools designed for identifying functional sites and the patterns of coordinated motion they can create within MD simulations. ATOMDANCE-maxDemon4.0 employs Gaussian kernel functions to compute site-wise maximum mean discrepancy between learned features of motion, thereby assessing denoised differences in the nonrandom motions between functional or evolutionary states (e.g., ligand bound versus unbound, wild-type versus mutant). ATOMDANCE-maxDemon4.0 also employs maximum mean discrepancy to analyze potential random amino acid replacements allowing for a site-wise test of neutral versus nonneutral evolution on the divergence of dynamic function in protein homologs. Finally, ATOMDANCE-Choreograph2.0 employs mixed-model analysis of variance and graph network to detect regions where time-synchronized shifts in dynamics occur. Here, we demonstrate ATOMDANCE’s utility for identifying key sites involved in dynamic responses during functional binding interactions involving DNA, small-molecule drugs, and virus-host recognition, as well as understanding shifts in global and local site coordination occurring during allosteric activation of a pathogenic protease.

Zero coordinate shift: Whetted automatic differentiation for physics-informed operator learning

Automatic differentiation (AD) is a critical step in physics-informed machine learning, required for computing the high-order derivatives of network output w.r.t. coordinates of collocation points. In this paper, we present a novel and lightweight algorithm to conduct AD for physics-informed operator learning, which we call the trick of Zero Coordinate Shift (ZCS). Instead of making all sampled coordinates as leaf variables, ZCS introduces only one scalar-valued leaf variable for each spatial or temporal dimension, simplifying the wanted derivatives from “many-roots-many-leaves” to “one-root-many-leaves” whereby reverse-mode AD becomes directly utilisable. It has led to an outstanding performance leap by avoiding the duplication of the computational graph along the dimension of functions (physical parameters). ZCS is easy to implement with current deep learning libraries; our own implementation is achieved by extending the DeepXDE package. We carry out a comprehensive benchmark analysis and several case studies, training physics-informed DeepONets to solve partial differential equations (PDEs) without data. The results show that ZCS has persistently reduced GPU memory consumption and wall time for training by an order of magnitude, and such reduction factor scales with the number of functions. As a low-level optimisation technique, ZCS imposes no restrictions on data, physics (PDE) or network architecture and does not compromise training results from any aspect.

A geometrical approach for consensus security

Guaranteeing security against eavesdroppers while allowing agents to reach an agreement on some shared variables is an essential feature to foster the adoption of distributed protocols. In the literature, a wide variety of methodologies have been developed in the discrete-time case, and most of them rely on encryption and undirected graphs, often exhibiting quantization or accuracy issues. In this paper, we develop a continuous-time secure consensus algorithm for agents that communicate via a broadcast-only protocol over directed and strongly connected graphs. In detail, the legitimate agents interact by exchanging an extended state, which can be converted into the hidden consensus state via a pre-deployed shared vector, thus preventing eavesdropping. In this paper, we take a geometrical perspective, and we implement our encryption via coordinate shifts. This choice guarantees, on one side, the existence of an uncountable infinity of possible vectors and, on the other side, provides a control-theoretical viewpoint on encryption that naturally blends with a dynamical system. We complement our framework by providing an additional layer of protection against honest but curious legitimate nodes, preventing them from gaining insights into the initial condition of their peers.

Shifts from an extensive to an intensive root nutrient‐acquisition mode with stand development of three Pinus species

Abstract Plant roots employ diverse strategies to acquire soil nutrients, including direct nutrient uptake through absorptive fine roots and root hairs, scavenging nutrients by forming symbioses with mycorrhizal fungi, and mining nutrients by releasing root exudates. However, whether these three strategies are differently coordinated among phylogenetically closely related tree species and how this coordination shifts with stand development remains largely unclear. To fill these knowledge gaps, we measured 13 root morphological, architectural, physiological and mycorrhizal traits tightly related to nutrient‐acquisition of three Pinus species (P. sylvestris var. mongolica, P. densiflora and P. tabuliformis) at young (20‐year‐old) and mature (50‐year‐old) stages planted in nutrient‐impoverished sandy soils, in Northeast China. We found that young trees had thinner absorptive fine roots and a higher specific root length than mature trees across three Pinus species, indicating that roots become morphologically less efficient in ‘do it yourself’ scavenging nutrients during stand development. Moreover, young stands had greater root length density and root area index, and mature stands had faster root‐exudation rates, suggesting that young stands rely more on expanding soil volumes to scavenge nutrients and mature stands depend more on root exudation to ‘mine’ nutrients. The three Pinus species exhibited different nutrient‐acquisition strategies at the mature stage; P. densiflora had higher root length density and root area index, and the other two Pinus species had greater ectomycorrhizal colonization rates. Synthesis. Our findings highlight that phylogenetically closely related tree species may exhibit different nutrient‐acquisition strategies and suggest a shift from an extensive nutrient‐acquisition mode depending more on absorptive fine roots to an intensive nutrient‐acquisition mode relying more on root exudation during stand development.

Conceptualizing Team Disruption Through an Event-System Framework

The success of work teams is often contingent on how they handle disruption. Although research has examined how teams respond to disruptive events, there is surprisingly little clarity about the nature of team disruption as a construct. Through an integration of Event-System Theory (EST) with team-based theories and frameworks, we define team disruption in terms of misalignment of team member coordination relative to task demands due to shifts in coordination, task demands, or both. We describe how event novelty and criticality create team disruption, and explore the temporal and spatial conditions under which team disruption is promoted or mitigated. The proposed conceptualization of team disruption offers a unifying definition of the construct that complements existing research on team adaptability, membership change, team interventions, and related approaches. The framework offers a way to understand past research in new ways, provides specific directions for future research, and contributes actionable guidance for practice.

Luminous characteristics of high-voltage blue mini-light-emitting diodes

The luminous characteristics of flip-chip type high-voltage (HV) blue mini-light-emitting diodes (LEDs), which consist of three serially connected sub-mesas, have been investigated for the first time. The cryogenic electroluminescence below 100 K partially originates from localized excitons. As the driving current reaches 1 μA, the contributions of Shockley–Read–Hall nonradiative recombination and radiative recombination exhibit a remarkably inverse temperature dependence, while the contributions of Auger recombination and carrier leakage are relatively negligible. The mesa corresponding to the anode of the HV blue mini-LED exhibits the lowest temperature among the three sub-mesas due to its smaller thermal resistance. To minimize the temperature-induced shift in chromaticity coordinates, it is necessary to adjust the driving current based on the operating temperature.

Comprehensive Structural Analysis Identifies the Relationships Between the Electrical Characteristics of Environmentally Friendly NBTMn-BAl-NaNb Ceramics

We give an in-depth examination of the structural and electrical features of NBTMn–BAl–NaNb ceramics in the paper. The comprehensive structural investigation indicated an important connection among the phase and polarization mechanisms of the compounds/samples by Nb substitution. The quantitative study of phase contribution shown by Raman spectroscopy is confirmed by structural refinement inquiries. The significant polarization difference in NBTMn–BAl–NaNb was found to be in excellent show with the structural presence of a dual phase contribution, which was confirmed through structural refinement. The substitution of NaNb in NBTMn–BAl led to a significant shift in average grain size (∼1 μm). It was additionally found that the dielectric constant of NBTMn–BAl–NaNb was greater than NBTMn–BAl lowering the depolarization temperature ∼30 °C. This modification resulted in reduced dielectric loss as well as shifts in coordination and structural features. The ferroelectric examines demonstrated that the synthesized compounds exhibited a strong ferroelectric character, Pr slightly increases ΔPr = 4 μC cm−2 and coercive field changes ΔEC=10kV/cm in presence of NaNb. The room temperature bipolar and unipolar strain S(%) ∼1.5, and the fact that the substitution of NaNb leads to an increase in both (bipolar and unipolar), represents structural symmetry modulation. As a result of this, these were discovered to be feasible prospects for current generation applications.

Site preference and local structural stability of Bi(III) substitution in hydroxyapatite using first-principles simulations.

Bismuth (Bi(III)) substitution in hydroxyapatite (HAp) lattice confers unique properties such as antibacterial, catalytic, radiosensitization, and conductive properties while preserving the innate bioactivity. Understanding the local structural changes upon Bi3+ substitution is essential for controlling the stability and optimizing the properties of HAp. Despite numerous experimental studies, the precise substitution behaviors, such as site preference and structural stability, remain incompletely understood. In this study, the substitution behavior of Bi(III) into the HAp lattice with formula of Ca9Bi(PO4)6(O)(OH) was investigated via first-principles simulation by implementing density functional theory. Energy calculations showed that Bi3+ preferentially occupies the Ca(2) site with an energy difference of ∼0.02 eV per atom. Local structure analysis revealed higher bond population values and an oxygen coordination shift from 7 to 6 for the Ca(2) site, attributed to the greater covalent interactions and its flexible environment accommodating the bulky Bi3+ ion and its stereochemically active lone pair. This work provides the first comprehensive investigation on Bi3+ ion substitution site preference in HAp using first-principles simulations.

Coinage metal-ethylene complexes of sterically demanding 1,10-phenanthroline ligands.

Phenanthroline-based ligands with bulky aryl groups flanking the metal binding pocket enabled the synthesis and detailed investigation of ethylene complexes of copper(I), silver(I), and gold(I), including structural data of [{2,9-bis(2,4,6-triisopropylphenyl)-1,10-phenanthroline}M(C2H4)][SbF6] (M = Cu, Ag, Au), Additionally, a related copper(I)-ethylene complex with a highly fluorinated ligand is also reported. Gold(I) affects the ethylene moiety significantly as evident from the notable upfield coordination shifts of ethylene carbon signals in the NMR and lengthening of the ethylene CC bond length. Silver(I) forms the weakest bond with ethylene in this series of isoleptic, group 11 metal-ethylene complexes. Preliminary catalytic investigations underscore the potential of copper complexes, particularly those with weakly coordinating supporting ligands, as effective catalysts for C(sp3)-H functionalization through trifluoromethyl carbene insertion.

Формирование максимума напряженности электрического поля в заданной точке пространства сфокусированной линейной антенной решеткой

The possibility of forming a maximum of the electric field strength at a given point in space with the help of a focused one-dimensional linear antenna array is considered. It is shown that the location of the maximum electric field strength does not coincide with the point of in-phase addition of electromagnetic waves emitted by the elements of the antenna array - the focusing point. The dependence of the shift of the maximum electric field strength on the focus point for various focal lengths and sizes of antenna arrays is presented. It has been found that the value of the shift in the focusing coordinates is determined only by the size of the antenna array and does not depend on the number of its elements. The relationship between a decrease in the intensity of an electromagnetic wave and a shift in the maximum amplitude of the electric field strength is described. The paper presents the dependences of the amplitude of the electric field strength for antenna arrays of various linear sizes and the calculation results confirmed the theoretical concepts. A phase portrait for antenna arrays of various sizes is presented showing the in-phase arrival of waves at a given point in space. According to the family of dependencies presented in the paper, it can be concluded that the greater the ratio of the linear dimensions of the antenna array to the focal length, the smaller the shift in the maximum amplitude of the electric field strength.re frequency plane as a result of an iterative process, which makes it possible to determine the values of the required function.

A novel analysis of the formation and resorption changes in dental hard tissue using longitudinal in vivo micro computed tomography.

This study was to investigate the new analysis manner of dental hard tissue change using in vivo micro-computed tomography (CT) in rat. Scanning, registration, analyzing, and presenting method to track longitudinal in vivo micro-CT data on dental hard tissues were validated in murine models: formative, dentin thickness after direct pulp capping with mineral trioxide aggregate; resorptive, development of apical bone rarefaction in apical periodontitis model. Serial in vivo micro-CT scans were analyzed through rigid-registration, active-contouring, deformable-registration, and motion vector-based quantitative analyses. The rate and direction of hard tissue formation after direct pulp capping was datafied by tracing coordinate shift of fiducial points on pulp chamber outline in formative model. The development of apical periodontitis could be monitored with voxel counts, and quantitatively analyzed in terms of lesion size, bone loss, and mineral density in resorptive model. This study supports the application of longitudinal in vivo micro-CT for resorptive- and formative-phase specific monitoring of dental hard tissues.

Achieving high-precision dual-mode temperature measurement in the photothermal conversion process of SrIn2O4: Er3+, Yb3+ phosphors

Accurate measurement of temperature during photothermal conversion is crucial for the application of up-conversion photothermal conversion fluorescent materials. In this paper, a kind of SrIn2O4: Yb3+, Er3+ up-conversion phosphor with strong photothermal conversion ability and high-precision dual-mode temperature measurement performance was synthesized by high-temperature solid-state method. Under 980 nm laser excitation, a high-precision temperature measurement with a maximum relative sensitivity of Sr = 1.2 %K−1 was achieved by using the fluorescence intensity ratio of the thermally coupled energy level pairs (2H11/2/4S3/2) of Er3+ ions. In addition, we found that the luminescent color of the synthesized phosphor can span a large color gamut interval with the rise of temperature, realizing the optical temperature measurement based on temperature-induced color coordinate shift. On this basis, we realized dual-mode temperature monitoring and temperature self-calibration during the photothermal conversion process of SrIn2O4: Yb3+, Er3+ phosphors. These results are of great practical value for the application of photothermal conversion fluorescent materials in micro-zone heating and temperature self-monitoring.

Design of a trusted shift of Coordination Forms: Supporting Collaboration to handle future non-human intelligent collaborators (NICs)

We introduce principles for designing collaboration among special operation forces (SOF) and future non-human intelligent collaborators (NICs), focusing on interdependence and emergent dynamics of workflow. We discuss a dynamic mixed-initiative human-autonomy teaming (HAT) coordination concept, where multiple military SOF teams collaborate together with autonomous capabilities. We argue that effective tactical actions requires shift of coordination forms, i.e. who is enacting coordination functions, which in military command and control (C2) terminology is formalized as coordination authority. Coordination forms could shift according to a set of requirements and we discuss how to elicit experiences of such coordination from simulated missions where human teammates and/or NICs have had to make choices of coordination form. We formulate a set of hypotheses remaining to be empirically analyzed. We draw on collaboration research investigating socio-technical systems where machine teammates collaborate with human teammates to achieve a common goal.

Luminescence of undoped and Eu3+ activated zinc gallate phosphor: Synthesis, unusual intense 5D0 → 7F4 red emission

A series of Eu3+-doped ZnGa2O4 samples were synthesized via the urea-glycine combustion route. Powder X-ray diffraction (XRD) was used to investigate the crystallinity of the samples, energy dispersive spectroscopy (EDS) to explore the elemental composition, Fourier transform infrared (FTIR), to observe the vibrational modes of the samples, photoluminescence (PL) to determine the luminescence properties. The XRD data prove that the samples remain single cubic structure even at high concentrations of Eu³⁺, enabling the formation of a unique emission spectrum. The active ion concentration was varied to examine the influence of concentration on luminescent properties. This study revealed a 5D0 →7F4 transition located at 700 nm with unusual intensity that has not been documented in the literature, which suggests that the active ion concentration can influence the luminescent characteristics of the phosphors. The increasing Eu3+ content increases the number of Eu3+ ions in ZnGa2O4 host lattice, which enhances the luminescence efficiency of the phosphor. However, beyond a certain level of Eu3+content (i.e., 3 wt% Eu3+), the number of Eu3+ ions becomes excessive, resulting in a reduction in luminescence efficiency due to concentration quenching. The dipole dipole interaction is elucidated to play a prominent role in the mechanism of Eu3+ quenching in the ZnGa2O4. An assessment of color coordinates based on emission spectra reveals that the coordinates shift from blue to the white light region, and then to red as Eu3+ content increases. This suggests that there is a substantial relationship between the Eu3+ concentration and the measured color coordinates.

Linear photogalvanic effect in surface states of topological insulators

The theory of the linear photogalvanic effect is developed for direct optical transitions between surface states of three-dimensional topological insulators. The photocurrent governed by the orientation of the polarization plane of light and caused by the warping of the energy dispersion of two-dimensional carriers is calculated. It is shown that both the shift contribution caused by coordinate shifts of the particle wave packets during the optical transitions and the ballistic contribution caused by interference of the optical absorption and scattering by disorder have generally the same order of magnitude. The ballistic contribution is present owing to electron-hole asymmetry of topological surface states and has a frequency dependence in contrast to the shift photocurrent. In the nonlinear-in-the-light-intensity regime appearing due to saturation of the direct optical transitions, the ballistic contribution dominates. The nontrivial dependence of the photocurrent on the polarization plane orientation in the nonlinear regime appears solely due to the ballistic contribution. Our findings allow separating the ballistic and shift contributions to the Linear photogalvanic current in experiments.

Comment on “Confined Klein–Gordon oscillators in Minkowski spacetime and a pseudo-Minkowski spacetime with a space-like dislocation: PDM KG-oscillators, isospectrality and invariance”

We argue that the analytical energies obtained recently in Mustafa (2022) from a radial eigenvalue equation are incorrect because the truncation method used by the author forces a relationship between two model parameters. This relationship (overlooked by the author) depends on the truncation number and as a result the exact analytical energies do not correspond to a single model but are solutions to different physical models. The reason is that the radial eigenvalue equation is not exactly solvable but conditionally solvable so that one can only obtain some particular exact solutions. We also show that the exact eigenvalues obtained for a particular simpler case are also incorrect because the author overlooked that the shift of the radial coordinate leads to a change in the left boundary condition.