Showing papers on "Valency published in 2020"

Design of higher valency in covalent organic frameworks.

Abstract: The valency (connectivity) of building units in covalent organic frameworks (COFs) has been primarily 3 and 4, corresponding to triangles and squares or tetrahedrons, respectively. We report a strategy for making COFs with valency 8 (cubes) and "infinity" (rods). The linker 1,4-boronophenylphosphonic acid-designed to have boron and phosphorus as an isoelectronic combination of carbon-group elements-was condensed into a porous, polycubane structure (BP-COF-1) formulated as (-B4P4O12-)(-C6H4-)4 It was characterized by x-ray powder diffraction techniques, which revealed cubes linked with phenyls. The isoreticular forms (BP-COF-2 to 5) were similarly prepared and characterized. Large single crystals of a constitutionally isomeric COF (BP-COF-6), composed of rod units, were also synthesized using the same strategy, thus propelling COF chemistry into a new valency regime.

Photoelectron diffraction for probing valency and magnetism of 4 f -based materials: A view on valence-fluctuating EuIr 2 Si 2

Abstract: We present and discuss the methodology for modeling $4f$ photoemission spectra, $4f$ photoelectron diffraction (PED) patterns, and magnetic dichroism effects for rare-earth-based materials. Using PED and magnetic dichroism in photoemission, we explore the electronic and magnetic properties of the near-surface region of the valence-fluctuating material ${\mathrm{EuIr}}_{2}{\mathrm{Si}}_{2}$. For the Eu-terminated surface, we found that the topmost Eu layer is divalent and exhibits a ferromagnetic order below 10 K. The valency of the next Eu layer, that is the fifth atomic layer, is about 2.8 at low temperature that is close to the valency in the bulk. The properties of the Si-terminated surface are drastically different. The first subsurface Eu layer (fourth atomic layer below the surface) behaves divalently and orders ferromagnetically below 48 K. Experimental data indicate, however, that there is an admixture of trivalent Eu in this layer, resulting in its valency of about 2.1. The next deeper lying Eu layer (eighth atomic layer below the surface) behaves mixed valently, but the estimated valency of 2.4 is notably lower than the value in the bulk. The presented approach and obtained results create a background for further studies of exotic surface properties of $4f$-based materials, and allow us to derive information related to valency and magnetism of individual rare-earth layers in a rather extended area near the surface.

Os4+ Instability in the Pyrochlore Structure: Tl2–xBixOs2O7–y

Abstract: Osmium-containing oxides are rare due to the difficulty in stabilizing complex structures with a fixed stoichiometry and metastability of the phases. Bismuth-substituted thallium osmate pyrochlore samples, Tl2-xBixOs2O7-y, were synthesized using solid-state reactions where the solubility limit was found to be approximately x = 1.4. Members of this solid solution were characterized by their structural, electronic, magnetic, and thermal properties to understand the influence of Bi3+ substitution on the ground state. The Os-containing pyrochlores crystallize in the ideal cubic pyrochlore structure (Fd3m), and the lattice parameter a was found to slightly increase as a function of Bi content. A possible interplay between structure and cation valence states was explored using both neutron powder diffraction and X-ray absorption spectroscopy, suggesting that a combination of Os4+/Os5+ and Tl1+/Tl3+ mixed valency throughout the solid solution allows for the stabilization of the pyrochlore structure. The system is metallic for the entire solid solution and predominantly exhibits temperature-independent paramagnetism. Specific heat measurements show an enhanced Sommerfeld coefficient, a possible flat-band signature. This system gave insight into the bonding preferences of Os, indicating a dependence on high oxidation states and mixed valence for the stability of complex structures.

DFT investigations on the electronic structure, magnetism, thermodynamic and elastic properties of newly predicted cobalt based antiperovskites: Co3XN (X = Pd, Pt & Rh)

Abstract: In this report, we have applied the muffin tin orbital method within full-potential linearized augmented plane wave approximation to investigate the intricate details of the electronic structure, elastic properties and magnetism of antiperovskite compounds Co3XN with X = Rh, Pd and Sn. The detailed analysis of the electronic structure calculations using various chemical bonding indicators suggest the covalent hybridization of the electronic states associated with Co (the high valency transition element) and the X atom (low valency transition element) as the significant interaction liable for the exhibition of the octahedral symmetry by these alloys. The large magnetic moments of Co3RhN, Co3PdN and Co3PtN are observed to be 6.20 μB, 5.20 μB and 6.21 μB, respectively; with a net magnetic moment of around 4.7 μB contributed by Co atoms in each compound. The direct exchange between Co and X atoms and indirect interaction between Co and Co via N atoms is responsible for its ferromagnetic character. The influence of the strain on the overall magnetism and relative atomic moments in the unit cell is also investigated. The anisotropic nature of these alloys and the mechanical properties like ductility increases from Rh > Pd > Pt. Also, the Debye temperatures of Co3RhN, Co3PdN and Co3PtN are calculated to be 702 K, 689 K and 606 K, respectively.

Optional valency complementations in Czech light verb constructions

Abstract: This paper addresses Czech light verb constructions, partly revising principles of their syntactic structure formation formulated within the Functional Generative Description. It argues that obligatoriness of valency complementations should be reflected in these principles. Namely, the role of optional valency complementations of light verbs played in this process has been analyzed. This analysis has shown that in the cases where light verbs do not provide a sufficient number of valency complementations for the surface expression of semantic participants of predicative nouns, semantic participants of nouns make use of optional verbal complementations; namely ORIGin, LOCative and BENefactor have been attested in the VALLEX lexicon. In such cases, semantic participants can be expressed on the surface, either as optional verbal complementation or as nominal complementation. The distribution of verbal and nominal complementations have been observed in 1,600 light verb constructions extracted from the Czech National Corpus, with the result that the surface expression of these participants through the optional verbal complementations is strongly preferred (88% of verbal complementations and 12% of nominal ones). The semantic analysis has indicated that the optional verbal complementations are overrepresented as they cover broader semantic contexts than the corresponding nominal ones.

Frame-Constructional Verb Classes: Change and Theft Verbs in English and German

Abstract: While verb classes are a mainstay of linguistic research, the field lacks consensus on precisely what constitutes a verb class. This book presents a novel approach to verb classes, employing a bottom-up, corpus-based methodology and combining key insights from Frame Semantics, Construction Grammar, and Valency Grammar. On this approach, verb classes are formulated at varying granularity levels to adequately capture both the shared semantic and syntactic properties unifying verbs of a class and the idiosyncratic properties unique to individual verbs. In-depth analyses based on this approach shed light on the interrelations between verbs, frame-semantics, and constructions, and on the semantic richness and network organization of grammatical constructions.This approach is extended to a comparison of Change and Theft verbs, revealing unexpected lexical and syntactic differences across semantically distinct classes. Finally, a range of contrastive (German–English) analyses demonstrate how verb classes can inform the cross-linguistic comparison of verbs and constructions.

Transitivity and Case Assignment in Ígálâ

Abstract: Insight on transitivity is derived cross-linguistically in terms of description of formal and functional features in the morphosyntax of token languages. This paper on transitivity and case assignment in Ígálâ describes transitivity in the language from both formal and functional accounts. Structurally, transitive features of a syntactic string are checked off via the ordering of arguments after the verb and features of agreement appear between verbs and their objects to § This is a revised version of a paper presented at the 31st Annual National Conference of the Nigeria English Studies Association (NESA) held 25th-29th October 2015 at Federal University, Lokoja, Nigeria, with the support of the Association of Commonwealth Universities (ACU), London, United Kingdom, which graciously awarded the researcher the Early Careers Academic Grant. Salem Ochala Ejeba Lecturer, Department of Linguistics and Communication Studies, University of Port Harcourt, Nigeria Email: salem.ejeba@gmail.com Received 24 January, 2020; Revised 12 February, 2020; Accepted 11 March, 2020 Copyright © 2020 Language Research Institute, Sejong University Journal of Universal Language is an Open Access Journal. All articles are distributed online under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. 2 Transitivity and Case Assignment in Ígálâ validate the object status of arguments in object position. The functional account of transitivity in Ígálâ shows that some technically intransitive verbs may be rendered transitively in causative constructions, causativization being a valency changing and enhancing process in the language. Morphologically, nominal elements in the language are not lexically distinguished for morphological case. On the basis of this observation, this paper ascribes the transitive feature of object to functional properties of verb as governor of object, to check off the syntactic case of this argument.

Stimuli-responsive Mixed-valence Architectures: Synthetic Design and Interplay between Mobile and Introduced Charges

Abstract: Mixed valency is a well-known phenomenon in which charge distributions can change via intervalence charge transfer. In addition, there are many other ubiquitous phenomena for charges such as proton...

The Skewed Frequency Hypothesis and the identification of valent nouns in English

Abstract: I propose the Skewed Frequency Hypothesis, according to which the distribution of corpus types following immediately after the occurrences of a valent noun is significantly skewed, unlike with avalent nouns. The question explored in this paper is whether this observation can be used to retrieve a list of valent nouns from a corpus. Two simple ratios are used to measure the skewness of the distribution of types, and it is shown that the two ratios are correlated and serve as somewhat reliable cues of noun valency. The cases are discussed in which the two ratios suggest conflicting results, and it is argued that these cases serve as one of the arguments for viewing noun valency in English as a scalar phenomenon rather than a binary possibility (valent vs. avalent). Finally, I also discuss some other issues concerning noun valency in English, and based on the data, I suggest treating noun valency in terms of Construction Grammar.

Dynamical Bonding Driving Mixed Valency in a Metal Boride

Abstract: Samarium hexaboride is an anomaly, having many exotic and seemingly mutually incompatible properties. It was proposed to be a mixed-valent semiconductor, and later a topological Kondo insulator, and yet has a Fermi surface despite being an insulator. We propose a new and unified understanding of SmB6 centered on the hitherto unrecognized dynamical bonding effect: the coexistence of two Sm-B bonding modes within SmB6 , corresponding to different oxidation states of the Sm. The mixed valency arises in SmB6 from thermal population of these distinct minima enabled by motion of B. Our model simultaneously explains the thermal valence fluctuations, appearance of magnetic Fermi surface, excess entropy at low temperatures, pressure-induced phase transitions, and related features in Raman spectra and their unexpected dependence on temperature and boron isotope.

Błędy walencyjne w tekstach obcokrajowców uczących się języka polskiego w świetle korpusu PoLKo

Abstract: The present article addresses valency errors in writings of non-native speakers learning Polish as a foreign language. Valency is a key element in a foreign language acquisition, and yet there are no studies on valency errors based on empirical data for Polish as a foreign language. Therefore, this study presents the firstattempt to examine valency errors based on data from the Polish Learner Corpus PoLKo. The pilot analysis deals with different proficiency levels (A1–C1) and nationalities (Slavic and non-Slavic) of learners. The corpus material has shown that valency errors are present across all language levels and for different nationalities. Nevertheless, valency errors are more common in prepositional phrases among learners with uninflected mother tongue. Further investigation into the subject is obviously needed, and it may be expected that it will bring new results and new conclusions, along with the development of PoLKo.

Valency Dictionaries and Chinese Vocabulary Acquisition for Foreign Learners

Abstract: Valency is a major source of lexical errors in foreign language learning. Accordingly, the research question is how the syntactic and semantic properties of a word can be retrieved from the corpora and represented in a Chinese valency dictionary to facilitate foreign learners' vocabulary acquisition. Within the three aspects of the valency framework — logical-semantic, syntactic and semantic-pragmatic valency — this study examines 60 cases of Chinese lexical misuse extracted from the HSK (Chinese Language Proficiency Test) Dynamic Compositions Corpus. The results suggest that the majority of cases of misuse occur in the dimension of semantic-pragmatic valency and that this semantic-pragmatic misuse can be ascribed to various factors such as semantic collocations, emotive variables, text styles, registers, and other contextual factors. The results are then utilized as syntactic, semantic and pragmatic information to be presented in a Chinese valency dictionary. Specifically, the results obtained from a case study of a misused word by referring to a large-scale native Chinese speaker corpus help retrieve a relatively full list of complementation patterns, based on which the study designs a Chinese valency entry that embodies three basic elements — quantitative valency, qualitative valency and valency patterns.

Numerical Approach in Superconductivity

Abstract: The dependence of the critical temperature of high temperature superconductors of various families on their composition and structure is proposed. A clear dependence of the critical temperature of high temperature superconductors on the sequence number of the constituent elements, their valency, and the structure of the crystal lattice is revealed.

On Valency Problems of Saxl Graphs.

Abstract: Let $G$ be a permutation group on a set $\Omega$ and recall that a base for $G$ is a subset of $\Omega$ such that its pointwise stabiliser is trivial. In a recent paper, Burness and Giudici introduced the Saxl graph of $G$, denoted $\Sigma(G)$, with vertex set $\Omega$ and two vertices adjacent if they form a base. If $G$ is transitive, then $\Sigma(G)$ is vertex-transitive and it is natural to consider its valency (which we refer to as the valency of $G$). In this paper we present a general method for computing the valency of any finite transitive group and we use it to calculate the exact valency of every primitive group with stabiliser a Frobenius group with cyclic kernel. As an application, we calculate the valency of every almost simple primitive group with an alternating socle and soluble stabiliser and we use this to extend results of Burness and Giudici on almost simple primitive groups with prime-power or odd valency.

Verb valency in interlanguage: An extension to valency theory and new perspective on L2 learning

Abstract: Valency theory has been applied to investigate various languages, such as German, Chinese and English. However, most studies in this field were based on the linguistic materials produced by native speakers. The current research aimed to examine the valency structures in the interlanguage. Based on the English writing produced by L2 Chinese learners, we adopted the quantitative approach, trying to find out whether the distributional features of verb valency in the interlanguage also had regular probability distributions as those in the native languages, and whether there was a relationship between these valency distributional characteristics and L2 learners’ language competence. It was found that (1) verb valency in the interlanguage followed distributional regularities which had been identified in the native languages; (2) the valency features showed differences in the diversity of valency patterns, the use of valences and the complexity of forms of complements between the interlanguage and the target language; (3) the distribution functions and parameters related to verb valency could manifest the development of students’ language competence. The current research has extended valency theory to the study of interlanguage and the valency perspective has profound methodological and pedagogical implications for L2 learning. Its item-specific property and the integration of grammatical and lexical factors are conducive to analyzing the way various words combine with each other.

X-ray photoelectron spectroscopy study of a layered tri-chalcogenide system LaTe3

Abstract: By employing x-ray photoelectron spectroscopy, we present a detailed study of the core level spectra of LaTe3 in its charge density wave phase at room temperature. The analysis of the Te 3d spectrum by curve fitting using least square error minimization reveals that the Te atoms exist in two different charge states: the two Te atoms in the Te-Te layer has a valency of −0.5, whereas the Te atom in La-Te layer has a valency of −2. The La 3d spectrum shows three peaks for each spin orbit component, where the main peak and the satellite peaks appear due to different final states related to charge transfer from different ligand Te states.

A Comparative Analysis of Verb Synonyms from the Perspective of Valency Structure in the Context of 'Provide and Offer'

Abstract: This article reported a study of verb synonym’s valency structure based on corpus data, which clearly shows the affiliation between the word item and its governing member. This study analyzed ‘provide’ and ‘offer’ in British National Corpus from the perspective of types and frequency distribution of valency structures, action elements, the relevance between valency structure and its meaning. The results indicate the valency structure is characteristic and closely interrelated with word’s meaning. Therefore, this can give us some enlightenment in h distinguishing verb synonyms effectively and promoting the English vocabulary teaching.

Spracovanie valencie substantív v Slovníku súčasného slovenského jazyka

Abstract: The article deals with noun valency and its processing in the Contemporary Dictionary of Slovak Language (2006, 2011, 2015). Based on the data from the prepared fourth volume, it presents the rules and lexicographic conventions of processing noun valency within the grammatical apparatus of nominal units. It also describes lexicalization processes yielding deverbal nouns, which are no more treated as grammatical forms within the verbal paradigm, but represent separate lexicographic units processed in the dictionary as independent heads. The indicators of these lexicalization processes are presented too, including specific types of valency modifications that the nouns undergo, as compared with valency frames of their motivating units. In the final part of the study the most frequent valency complementations of nouns are described, on the basis of dictionary data and source corpus Omnia Slovaca III Maior.

Reflexive and Reciprocal as Valency Decrease: A Morpho-syntax Study in Sasak

Abstract: This research is a descriptive study that examines the constructions of reflexive and reciprocal of valency decrease using linguistic typological theory proposed by Dixon (2012). The results of data analysis revealed that in Sasak Kuto-Kute dialect, reflexive constructions can be formed through two techniques; namely verb derivation and combination techniques. The verb derivation technique involved the addition of a nasal prefix (N) to the verb functioning as reflexive marker (REF), whilst, the combination technique employed the addition of confix n- -in followed by the pronoun diriqnya ‘him/herself’. The formation of reciprocal construction is carried out through three techniques: the use of reciprocal verbs, verb derivation and the use of reciprocal adverbs. The reciprocal verb used in the data is tempur 'meet'. Meanwhile, for verb derivation the addition of confix meng- -an on the verb kaol 'hug' makes the verb’s meaning reciprocal. In the technique of using adverbs, the sentences that bear reciprocal meaning are formed by adding the word saling ‘each other’ appearing before the bases (affixless), verbs with suffix -in and confix ke- -n. From the overall data, it was found that the verb derivation techniques for reflexive is more preferred, while for reciprocals, the technique of using adverbs is more often used compared to the other two.

Predictive Modelling of Type Valency in Word Formation Grammar

Abstract: This paper explores different regression models for predicting the type valency of Persian suffixes within a usage-based approach. Usage-based models treat the type frequency of a suffix as a key p...

Condensation of Rodlike Counterions on a Charged Cylinder

Abstract: We study the condensations of dumbbell-like counterions onto an oppositely charged cylinder at weak and strong electrostatic coupling strengths. Performing extensive Monte Carlo simulations, we show that the condensation characteristics of the dumbbell ions can be understood by viewing dumbbell ions of length d as point ions with an effective valency depending on the radial distance r from the cylinder’s axis. In terms of the condensation behavior, dumbbell ions behave as two independent point ions if r ≪ d, but act as a single point ion with twofold valency when r ≫ d. Such a distance-dependent effective valency as a characteristic of ions of extended structures explains a unique feature in the condensed counterion fraction and heat capacity at both weak and strong coupling strengths.

Towards a Single Chemical Model for Understanding Lanthanide Hexaborides.

Abstract: Lanthanide hexaborides (LnB6 ) have disparate and often anomalous properties, from structurally homogeneous mixed valency, to superconductivity, spectral anomalies, and unexplained phase transitions. It is unclear how such a diversity of properties may arise in the solids of identical crystal structures and seemingly very similar electronic structures. Building on our previous model for SmB6 (mixed valent, with a peak in specific heat, and pressure induced magnetic phase transitions), we present a unifying dynamic bonding model for LnB6 that explains simultaneously EuB6 (possessing an anomalous peak in specific heat at low T, magnetic phase transitions, and no mixed valency), YbB6 (mixed valent topological insulator), and rather ordinary LaB6 . We show that Ln can engage in covalent bonding with boron, and, in some members of the LnB6 family, also easily access alternative bonding states through the electron-phonon coupling. The accessibility, relative energetics, and bonding nature of the states involved dictate the properties.

On quasiprimitive edge-transitive graphs of odd order and twice prime valency

Abstract: Abstract A graph is edge-transitive if its automorphism group acts transitively on the edge set. In this paper, we investigate the automorphism groups of edge-transitive graphs of odd order and twice prime valency. Let Γ{\varGamma} be a connected graph of odd order and twice prime valency, and let G be a subgroup of the automorphism group of Γ{\varGamma}. In the case where G acts transitively on the edge set and quasiprimitively on the vertex set of Γ{\varGamma}, we prove that either G is almost simple, or G is a primitive group of affine type. If further G is an almost simple primitive group, then, with two exceptions, the socle of G acts transitively on the edge set of Γ{\varGamma}.