Different Degrees Of Localization Research Articles

Correlation research on visual behavior and cognition of impression against localized church facades in China

Churches in China are material witnesses of cultural dissemination, and their architectural forms are in the process of localization. In order to determine the optimal degree of localization of church facades as well as to study the correlation between visual behavior and subjective cognition, five church facades with different degrees of localization were selected in present study, and the questionnaire survey as well as eye-tracking technology were used to collect data from two aspects: subjective cognition (the impression and acceptance levels) and objective eye movement (the first fixation duration, total fixation duration, fixation count, and visit count). The results showed the differences in public perceptions of church facades, and the impression of participants was continuously enhanced with the increasing of localization degree of church facade, while the acceptance level showed a U-shaped change. What's more, the correlation between the impression level and the first fixation duration was found to be 0.910, the Pearson coefficient between the acceptance level and the total fixation duration was found to be 0.928, indicating that eye-tracking indicators could accurately reflect the subjective cognition of the public. Performed analyses demonstrated that eye-tracking technology would provides an important technical mean for the design, conservation, and renewal of building facades.

The Degree and Generation of Localization in Marketing: An Empirical Study Based on Coca-Colas Localization Strategy

In a world where development is no longer limited by geography, globalization has become the slogan and goal of many companies. However, not many have noticed that companies that have achieved international sales, such as Coca-Cola, have adopted a localization strategy. This study aspires to examine the existing cases of localization in the market, how localization is implemented, and the impact of implementing localization, from both macro and micro perspectives. This paper identifies the marketing strategies used by the multinational beverage company Coca-Cola through an analysis of its advertising in China in the process of achieving global sales. Based on the marketing mix, this paper analyzes and compares countries with vastly different degrees of localization to determine the decisive factors for using localization strategies in the four areas of product, price, promotion, and place. Current marketing research on the success of Coca-Cola is still narrow, with studies limited to how marketing success is accomplished in a specific location but does not identify the underlying strategy that had led to such success, localization. Meanwhile, the market lacks practical guidance on localization strategies due to inadequate research and this study fills these currently identified limitations.

Compositions of localized fractional derivatives and integrals of a different degree of localization

The article considers the compositions of localized fractional Marchaud type derivatives and localized fractional integrals of a different degree of localization. The author obtained non-local uniqueness conditions for the solution homogeneous differential equations with such compositions. New property of hypergeometrical functions is proved.

Decentralized Control of Large Collaborative Swarms Using Random Finite Set Theory

Controlling large swarms of robotic agents presents many challenges including but not limited to computational complexity due to a large number of agents, uncertainty in the functionality of each agent in the swarm, and uncertainty in the swarm's configuration. The contribution of this work is to decentralize random finite set (RFS)-based control of large collaborative swarms for controlling individual agents. The RFS-based control formulation assumes a Gaussian mixture probability hypothesis density approximation and a complete topology for centralized swarm control. To generalize the control topology in a localized or decentralized manner, a sparse linear quadratic regulator (LQR) is used to sparsify the RFS-based control gain matrix obtained using iterative LQR. This allows agents to use information of agents near each other (localized topology) or only the agent's own information (decentralized topology) to make a control decision. Sparsity and performance for decentralized RFS-based control are compared for different degrees of localization in feedback control gains which show that the stability and performance compared to centralized control do not degrade significantly in providing RFS-based control for large collaborative swarms.

Combining Single-Molecule Fluorescence and MD-Simulations to Delineate the Kinetics and Regulation of Proteins

Protein conformational kinetics and its regulation occur on many time- and length-scales. While for example post-translational modifications act very locally, specific protein-protein interaction typically affect larger domains, and global changes (like crowding) affect the whole protein (complex) non-specifically. In a first part we use a combination of single-molecule FRET, FRET-FCS, ns-FCS and MD simulations to delineate the timescales for information transfer from the hydrolysis event in the nucleotide binding site of the heat shock protein 90 (Hsp90) to large conformational changes in the Hsp90 dimer[1]. This allosteric process occurs via a hierarchical mechanism that involves timescales from pico- to microseconds. In a second part we show protein regulation under different degrees of localization, and present the effects on the Hsp90 chaperone system. Interestingly using single-molecule FRET, we find that similar functional and conformational steady states are caused by completely different underlying kinetics. We will introduce a new mechanistic concept, namely functional stimulation through conformational confinement[2]. Finally, we use a network of distance distributions obtained with single molecule FRET to investigate a Hsp90 - model client interaction[3]. We find negligible effects of the client on the open-close equilibrium of Hsp90, but strong effects on Hsp90's conformational fluctuations. This hints towards an additional (orthogonal) regulation mechanism. Altogether, these applications demonstrate that a combination of (single-molecule) methods is ideal to investigate the biophysics of multi-component (protein) systems. [1] S. Wolf et al., Allosteric action of nucleotides on Hsp90 across several time- and length scales. BioRxiv, 2020.02.15.950725 (2020); https://doi.org/10.1101/2020.02.15.950725 [2] S. Schmid and T. Hugel, Controlling protein function by fine-tuning conformational flexibility. eLife, 9, 1013 (2020); https://doi.org/10.7554/eLife.57180 [3] Hellenkamp et al., Multidomain structure and correlated dynamics determined by self-consistent FRET networks. Nat Methods, 14 (2), 174 (2017). https://doi.org/10.1038/nmeth.4081

Edge mode manipulation through commensurate multifrequency driving

We explore the impact of commensurate multifrequency driving protocols on the stability of topological edge modes in topological 1D systems of spinless fermions. Using Floquet theory, we show that all the topological phase transitions can be mapped to their single-frequency counterparts in terms of effective driving parameters. This drastic simplification can be explained by considering the gap closures in the quasienergy dispersion. These gap closures are pinned to high-symmetry points, where all the effective Floquet Hamiltonians collapse to the same form. While for all protocols all topological phase transitions coincide, the gap size and the number of edge modes in the quasienergy spectra vary considerably depending on the chosen driving pattern. This gives rise to a full range of edge states with different degrees of localization, from highly localized to completely delocalized. Switching between different driving protocols then suggests a dynamical control of the localization and stability of topological edge modes, with possible applications in quantum computation. We illustrate our findings on three paradigmatic fermionic systems -- namely the Kitaev chain, the Su-Schrieffer-Heeger model, and the Creutz ladder, and demonstrate how to control the localization length of the corresponding edge states.

Controlling protein function by fine-tuning conformational flexibility.

In a living cell, protein function is regulated in several ways, including post-translational modifications (PTMs), protein-protein interaction, or by the global environment (e.g. crowding or phase separation). While site-specific PTMs act very locally on the protein, specific protein interactions typically affect larger (sub-)domains, and global changes affect the whole protein non-specifically. Herein, we directly observe protein regulation under three different degrees of localization, and present the effects on the Hsp90 chaperone system at the levels of conformational steady states, kinetics and protein function. Interestingly using single-molecule FRET, we find that similar functional and conformational steady states are caused by completely different underlying kinetics. We disentangle specific and non-specific effects that control Hsp90's ATPase function, which has remained a puzzle up to now. Lastly, we introduce a new mechanistic concept: functional stimulation through conformational confinement. Our results demonstrate how cellular protein regulation works by fine-tuning the conformational state space of proteins.

Photon Echo from Localized Excitons in Semiconductor Nanostructures

An overview on photon echo spectroscopy under resonant excitation of the exciton complexes in semiconductor nanostructures is presented. The use of four-wave-mixing technique with the pulsed excitation and heterodyne detection allowed us to measure the coherent response of the system with the picosecond time resolution. It is shown that, for resonant selective pulsed excitation of the localized exciton complexes, the coherent signal is represented by the photon echoes due to the inhomogeneous broadening of the optical transitions. In case of resonant excitation of the trions or donor-bound excitons, the Zeeman splitting of the resident electron ground state levels under the applied transverse magnetic field results in quantum beats of photon echo amplitude at the Larmor precession frequency. Application of magnetic field makes it possible to transfer coherently the optical excitation into the spin ensemble of the resident electrons and to observe a long-lived photon echo signal. The described technique can be used as a high-resolution spectroscopy of the energy splittings in the ground state of the system. Next, we consider the Rabi oscillations and their damping under excitation with intensive optical pulses for the excitons complexes with a different degree of localization. It is shown that damping of the echo signal with increase of the excitation pulse intensity is strongly manifested for excitons, while on trions and donor-bound excitons this effect is substantially weaker.

Formation and dynamics of small polarons on the rutile TiO2 (110) surface

Charge trapping and formation of polarons is a pervasive phenomenon in transition metal oxide compounds, in particular at the surface, affecting fundamental physical properties and functionalities of the hosting materials. Here we investigate via first-principle techniques the formation and dynamics of small polarons on the reduced surface of titanium dioxide, an archetypal system for polarons, for a wide range of oxygen vacancy concentrations. We report how the essential features of polarons can be adequately accounted in terms of few quantities: the local structural and chemical environment, the attractive interaction between negatively charged polarons and positively charged oxygen vacancies, and the spin-dependent polaron-polaron Coulomb repulsion. We combined molecular dynamics simulations on realistic samples derived from experimental observations with simplified static models, aiming to disentangle the various variables at play. We find that depending on the specific trapping site, different types of polarons can be formed, with distinct orbital symmetries and different degree of localization and structural distortion. The energetically most stable polaron site is the subsurface Ti atom below the undercoordinated surface Ti atom, owing to a small energy cost to distort the lattice and a suitable electrostatic potential. Polaron-polaron repulsion and polaron-vacancy attraction determine the spatial distribution of polarons as well as the energy of the polaronic in-gap state. In the range of experimentally reachable oxygen vacancy concentrations the calculated data are in excellent agreement with observations, thus validating the overall interpretation.

Analysis of Bloch Surface Waves at the Interface Between Two Semi-infinite Rugate Filters with Symmetric Refractive Index Profiles

Surface electromagnetic waves are representation of Maxwell’s frequency domain equations at the interface of two dissimilar materials. In this article, two canonical boundary value problems have been formulated to analyze the multiplicity of electromagnetic surface waves at the interface between two dissimilar materials. In the first problem, interface between two semi-infinite rugate filters having symmetric refractive index profiles is considered and in the second problem, to enhance the multiplicity of surface electromagnetic waves, a homogeneous dielectric slab is included between two semi-infinite symmetric rugate filters. Multiplicity has been observed by varying the size of dielectric material from 0 to 1000 nm. Numerical results show that the number of Tamm waves of different phase speeds, different polarization states, different degrees of localization, and different field profiles that are being propagated at interface between two semi-infinite rugate filters having symmetric refractive profile is almost twice as when asymmetric refractive index profile is used. Having two interfaces when a homogeneous dielectric layer is placed between two semi-infinite rugate filters has increased the multiplicity of electromagnetic surface waves.

Multiple Bloch surface waves in visible region of light at the interfaces between rugate filter/rugate filter and rugate filter/dielectric slab/rugate filter

Surface electromagnetic waves are the solution of Maxwell’s frequency domain equations at the interface of two dissimilar materials. In this article, two canonical boundary-value problems have been formulated to analyze the multiplicity of electromagnetic surface waves at the interface between two dissimilar materials in the visible region of light. In the first problem, the interface between two semi-infinite rugate filters having symmetric refractive index profiles is considered and in the second problem, to enhance the multiplicity of surface electromagnetic waves, a homogeneous dielectric slab of 400 nm is included between two semi-infinite symmetric rugate filters. Numerical results show that multiple Bloch surface waves of different phase speeds, different polarization states, different degrees of localization and different field profiles are propagated at the interface between two semi-infinite rugate filters. Having two interfaces when a homogeneous dielectric layer is placed between two semi-infinite rugate filters has increased the multiplicity of electromagnetic surface waves.

On the optical polarization properties of semipolar (202¯1) and (202¯1¯) InGaN/GaN quantum wells

In the framework of k·p-theory, semipolar (202¯1) and (202¯1¯) InGaN/GaN quantum wells (QWs) have equivalent band structures and are expected to have identical optical polarization properties. However, (202¯1) QWs consistently exhibit a lower degree of linear polarization (DLP) than (202¯1¯) QWs. To understand this peculiarity, we investigate the optical properties of (202¯1) and (202¯1¯) InGaN/GaN single QW light-emitting diodes (LEDs) via resonant polarization-resolved photoluminescence microscopy. LEDs were grown on bulk substrates by metal organic vapor phase epitaxy with different indium concentrations resulting in emission wavelengths between 442 nm and 491 nm. We discuss the origin of their DLP via k·p band structure calculations. An analytical expression to estimate the DLP in the Boltzmann-regime is proposed. Measurements of the DLP at 10 K and 300 K are compared to m-plane LEDs and highlight several discrepancies with calculations. We observe a strong correlation between DLPs and spectral widths, which indicates that inhomogeneous broadening affects the optical polarization properties. Considering indium content fluctuations, QW thickness fluctuations, and the localization length of charge carriers, we argue that different broadenings apply to each subband and introduce a formalism using effective masses to account for inhomogeneous broadening in the calculation of the DLP. We conclude that the different DLP of (202¯1) and (202¯1¯) QWs might be related to different effective broadenings of their valence subbands induced by the rougher upper QW interface in (202¯1), by the larger sensitivity of holes to this upper interface due to the polarization field in (202¯1), and/or by the different degrees of localization of holes.

Фотонное эхо на локализованных экситонах в полупроводниковых наноструктурах

AbstractAn overview on photon echo spectroscopy under resonant excitation of the exciton complexes in semiconductor nanostructures is presented. The use of four-wave-mixing technique with the pulsed excitation and heterodyne detection allowed us to measure the coherent response of the system with the picosecond time resolution. It is shown that, for resonant selective pulsed excitation of the localized exciton complexes, the coherent signal is represented by the photon echoes due to the inhomogeneous broadening of the optical transitions. In case of resonant excitation of the trions or donor-bound excitons, the Zeeman splitting of the resident electron ground state levels under the applied transverse magnetic field results in quantum beats of photon echo amplitude at the Larmor precession frequency. Application of magnetic field makes it possible to transfer coherently the optical excitation into the spin ensemble of the resident electrons and to observe a long-lived photon echo signal. The described technique can be used as a high-resolution spectroscopy of the energy splittings in the ground state of the system. Next, we consider the Rabi oscillations and their damping under excitation with intensive optical pulses for the excitons complexes with a different degree of localization. It is shown that damping of the echo signal with increase of the excitation pulse intensity is strongly manifested for excitons, while on trions and donor-bound excitons this effect is substantially weaker.

Hybrid-DFT + Vw method for band structure calculation of semiconducting transition metal compounds: the case of cerium dioxide

Hybrid functionals’ non-local exchange-correlation potential contains a derivative discontinuity that improves on standard semi-local density functional theory (DFT) band gaps. Moreover, by careful parameterization, hybrid functionals can provide self-interaction reduced description of selected states. On the other hand, the uniform description of all the electronic states of a given system is a known drawback of these functionals that causes varying accuracy in the description of states with different degrees of localization. This limitation can be remedied by the orbital dependent exact exchange extension of hybrid functionals; the hybrid-DFT + Vw method (Ivády et al 2014 Phys. Rev. B 90 035146). Based on the analogy of quasi-particle equations and hybrid-DFT single particle equations, here we demonstrate that parameters of hybrid-DFT + Vw functional can be determined from approximate theoretical quasi-particle spectra without any fitting to experiment. The proposed method is illustrated on the charge self-consistent electronic structure calculation for cerium dioxide where itinerant valence states interact with well-localized 4f atomic like states, making this system challenging for conventional methods, either hybrid-DFT or LDA + U, and therefore allowing for a demonstration of the advantages of the proposed scheme.

Formation of Vacancies in Si- and Ge-based Clathrates: Role of Electron Localization and Symmetry Breaking.

The formation of framework vacancies in Si- and Ge-based type-I clathrates is studied using density-functional theory as a function of filling the cages with K and Ba atoms. Our analysis reveals the relevance of structural disorder, geometric relaxation, and electronic saturation as well as vibrational and configurational entropy. In the Si clathrates, we find that vacancies are unstable, but very differently, in Ge clathrates, up to three vacancies per unit cell can be stabilized. This contrasting behavior is largely driven by the different energy gain on populating the electronic vacancy states, which originates from the different degree of localization of the valence orbitals of Si and Ge. This also actuates a qualitatively different atomic relaxation of the framework.

Multi-scale crystal plasticity finite element method (CPFEM) simulations for shear band development in aluminum alloys

Abstract Multi-scale Crystal Plasticity Finite Element Method (CPFEM) simulations including macro-, meso- and microscale are applied to study the shear band development in cold-rolled AA5182-H28 aluminum alloy sheets under simple shear along various directions with respect to the rolling direction. The resolution and the computational cost in predicting the development of shear bands are compared among the three simulation scales. In macro-, meso- or microscale, each element represents an aggregate of polycrystal, a single crystal or part of a grain, respectively. The constitutive response of an integration point is thus described by the Taylor-type polycrystalline model in the macroscale, or by the single crystal constitutive model in the two finer scales. A common feature predicted by simulations at the three scales is that the development of shear bands is highly anisotropic. This is most clearly revealed by simulations at the microscale: (1) no shear band forms along RD (Rolling Direction); (2) some shear bands develop then delocalize afterwards along RD20 (20° from RD); (3) severe shear bands develop along RD45 (45° from RD) and (4) some weak and discrete shear bands form along TD (Transverse Direction). However, the capability to capture the development of shear bands with different degrees of localization is not the same for the three simulation scales: for cases with severe/no shear band forming, simulations in all the three scales can capture the features, however, for cases with weak shear banding, only the microscale simulations can give right predictions. The cost of the three scales is also quite different: the computation time increases nearly an order of magnitude when the simulation runs at a lower scale. Therefore, in view of both the resolution and the cost, appropriate simulation scale can be chosen to study the development of shear bands according to the degree of localization: for cases with severe/no shear band forming, a macroscale simulation with Taylor-type model is sufficient to give good predictions; but for cases with weak shear bands formation, a microscale simulation is needed. For this strategy to work, a quick estimation is needed first for the extent of shear band development for all cases of concern, which can be accomplished using the one-element method proposed by Wu et al. [29].

The size dependence recombination luminescence of hydrophilic colloidal CdS quantum dots in gelatin

The recombination photoluminescence (PL) properties of hydrophilic colloidal CdS quantum dots (QDs) dispersed in gelatin were investigated. The average size of QDs varies from 2.4 to 4.4nm. The size dependence of the emission peak position is defined in the range from 1.65 to 2.27eV. The PL decay (0.3–4·103ns) is accompanied by the red shift of its maximum. It is interpreted as the radiative recombination via the donor-acceptor pairs. The analysis of the half-width and shape of the observed PL spectra was performed taking into account the QDs size distribution and the Coulomb interaction of donor and acceptor uniformly distributed in QD volume. The deviation of the theoretical PL spectra from experimental data on the half-width was determined, which amounted of the order 0.4eV. It is concluded that to describe the PL spectra of CdS QDs it is necessary to consider a different degree of localization of the wave functions and the variation of the binding energy of the donor and acceptor versus their depth in the QD volume.

Effect of electron-hole separation on optical properties of individual Cd(Se,Te) quantum dots

Cd(Se,Te) Quantum Dots (QD) in ZnSe barrier typically exhibit a very high spectral density, which precludes investigation of single dot photoluminescence. We design, grow and study individual Cd(Se,Te)/ZnSe QDs of low spectral density of emission lines achieved by implementation of a Mn-assisted epitaxial growth. We find an unusually large variation of exciton-biexciton energy difference (3 meV $\leq$ $\Delta \mathrm{E_{X-XX}}$ $\leq$ 26 meV) and of exciton radiative recombination rate in the statistics of QDs. We observe a strong correlation between the exciton-biexciton energy difference, exciton recombination rate, splitting between dark and bright exciton, and additionally the exciton fine structure splitting $\delta_1$ and Land\'e factor. Above results indicate that values of the $\delta_1$ and of the Land\'e factor in the studied QDs are dictated primarily by the electron and hole respective spatial shift and wavefunctions overlap, which vary from dot to dot due to a different degree of localization of electrons and holes in, respectively, CdSe and CdTe rich QD regions.

Histological and histochemical characterization on stomach of Mystus cavasius (Hamilton), Oreochromis niloticus (Linnaeus) and Gudusia chapra (Hamilton): Comparative study

The histological features and histochemical characterization of the stomach were investigated in Mystus cavasius (Hamilton), Oreochromis niloticus (Linnaeus) and Gudusia chapra (Hamilton) having different feeding habits. Histologically the stomach of all the three fishes was made up of mucosa, submucosa, muscularis and serosa. The mucosa of superficial epithelium consists of a single layer of compactly arranged columnar epithelial cells. Prominent gastric glands are present in M. cavasius whereas in G. chapra the gastric glands are totally absent in the gizzard like stomach. However, in O. niloticus tubular gastric glands are present in the glandular epithelium of caecal like stomach. The distribution and chemical nature of mucopolysaccharides in the aforementioned fishes were studied histochemically by employing Periodic Acid Schiff’s in combination with the Alcian Blue (PAS–AB) technique. Columnar epithelial cells lining the mucosa of the stomach including mucosal border were provided with exclusively neutral mucin which was probably involved in the protective functions against acid and enzymes. The different intensities of reaction of Best Carmine (BC) for glycogen in the epithelial lining and gastric glands of the stomach of the aforesaid three fish species under study were discussed. The intense reaction for protein and tryptophan was noticed in the gastric epithelium and gastric glands of M. cavasius probably due to accumulation of zymogen granules in the gastric glands. On the contrary, moderate reaction for protein and tryptophan was associated with the epithelial cells and gastric glands of O. niloticus and G. chapra. The cytoarchitecture and different degrees of localization of mucopolysaccharides, glycogen, protein and tryptophan in the stomach of M. cavasius, O. niloticus and G. chapra were correlated with the functional significance of the region concerned.

Theoretical unification of hybrid-DFT andDFT + Umethods for the treatment of localized orbitals

We formulate the on-site occupation dependent exchange correlation energy and effective potential of hybrid functionals for localized states and connect them to the on-site correction term of the DFT+U method. Our derivation provides a theoretical justification for adding a DFT+U-like onsite potential in hybrid DFT calculations to resolve issues caused by overscreening of localized states. The resulting scheme, hybrid- DFT+Vw, is tested for chromium impurity in wurtzite AlN and vanadium impurity in 4H-SiC, which are paradigm examples of systems with different degree of localization between host and impurity orbitals.