Thermodynamics Modeling for Actinide Monocarbides and Mononitrides from First Principles

The high-temperature thermodynamical properties for the actinide monocarbides and mononitrides ThC, ThN, UC, UN, PuC, and PuN are calculated from first-principles electronic-structure theory. The electronic structure is modeled with density-functional theory (DFT) and is fully relativistic, including the spin-orbit interaction. Furthermore, the DFT is extended to account for orbital–orbital interactions, by means of a parameter-free orbital-polarization (OP) technique, that has proven to be essential for the 5f electrons in plutonium. Strong anharmonicity and the temperature dependence of the lattice vibrations are captured with the self-consistent ab initio lattice dynamics (SCAILD) method. The calculated free energies and heat capacities are compared to published results from quasi-harmonic (QH) theory, and experiments, where available. For the uranium and plutonium compounds, we make use of CALPHAD assessments to help evaluate the theory. Generally, our anharmonic relativistic approach compares well with both CALPHAD and experiments. For the thorium compounds, our theory is in good accord with QH modeling of the free energy at lower temperatures but for the heat capacity the comparison is less favorable.

Dispersion Size-Consistency

A multivariate adiabatic connection (MAC) framework for describing dispersion interactions in a system consisting of non-overlapping monomers is presented. By constraining the density to the physical ground-state density of the supersystem, the MAC enables a rigorous separation of induction and dispersion effects. The exact dispersion energy is obtained from the zero-temperature fluctuation-dissipation theorem and partitioned into increments corresponding to the interaction energy gained when an additional monomer is added to a -monomer system. The total dispersion energy of an -monomer system is independent of any partitioning into subsystems. This statement of dispersion size consistency is shown to be an exact constraint. The resulting additive separability of the dispersion energy results from multiplicative separability of the generalized screening factor defined as the inverse generalized dielectric function. Many-body perturbation theory (MBPT) is found to violate dispersion size-consistency because perturbative approximations to the generalized screening factor are nonseparable; on the other hand, random phase approximation-type methods produce separable generalized screening factors and therefore preserve dispersion size-consistency. This result further explains the previously observed increase in relative errors of MBPT for dispersion interactions as the system size increases. Implications for electronic structure theory and applications to supramolecular materials and condensed matter are discussed.

A Computer-Assisted Writing Tool for an Extended Variety of Leichte Sprache (Easy-to-Read German)

Leichte Sprache (LS; easy-to-read German) defines a variety of German characterized by simplified syntactic constructions and a small vocabulary. It provides barrier-free information for a wide spectrum of people with cognitive impairments, learning difficulties, and/or a low level of literacy in the German language. The levels of difficulty of a range of syntactic constructions were systematically evaluated with LS readers as part of the recent LeiSA project (Bock, 2019). That study identified a number of constructions that were evaluated as being easy to comprehend but which fell beyond the definition of LS. We therefore want to broaden the scope of LS to include further constructions that LS readers can easily manage and that they might find useful for putting their thoughts into words. For constructions not considered in the LeiSA study, we performed a comparative treebank study of constructions attested to in a collection of 245 LS documents from a variety of sources. Employing the treebanks TüBa-D/S (also called VERBMOBIL) and TüBa-D/Z, we compared the frequency of such constructions in those texts with their incidence in spoken and written German sources produced without the explicit goal of facilitating comprehensibility. The resulting extension is called Extended Leichte Sprache (ELS). To date, text in LS has generally been produced by authors proficient in standard German. In order to enable text production by LS readers themselves, we developed a computational linguistic system, dubbed ExtendedEasyTalk. This system supports LS readers in formulating grammatically correct and semantically coherent texts covering constructions in ELS. This paper outlines the principal components: (1) a natural-language paraphrase generator that supports fast and correct text production while taking readership-design aspects into account, and (2) explicit coherence specifications based on Rhetorical Structure Theory (RST) to express the communicative function of sentences. The system’s writing-workshop mode controls the options in (1) and (2). Mandatory questions generated by the system aim to teach the user when and how to consider audience-design concepts. Accordingly, users are trained in text production in a similar way to elementary school students, who also tend to omit audience-design cues. Importantly, we illustrate in this paper how to make the dialogues of these components intuitive and easy to use to avoid overtaxing the user. We also report the results of our evaluation of the software with different user groups.

Text as tautology: an exploration in inference, transitivity, and logical compression

Rhetorical structure theory (RST) and relational propositions have been shown useful in analyzing texts as expressions in propositional logic. Because these expressions are systematically derived, they may be expected to model discursive reasoning as articulated in the text. If this is the case, it would follow that logical operations performed on the expressions would be reflected in the texts. In this paper the logic of relational propositions is used to demonstrate the applicability of transitive inference to discourse. Starting with a selection of RST analyses from the research literature, analyses of the logic of relational propositions are performed to identify their corresponding logical expressions and within each expression to identify the inference path implicit within the text. By eliminating intermediary relational propositions, transitivity is then used to progressively compress the expression. The resulting compressions are applied to the corresponding texts and their compressed RST analyses. The application of transitive inference to logical expressions results in abridged texts that are intuitively coherent and logically compatible with their originals. This indicates an underlying isomorphism between the inferential structure of logical expressions and discursive coherence, and it confirms that these expressions function as logical models of the text. Potential areas for application include knowledge representation, logic and argumentation, and RST validation.

Boeing: surviving business turbulence after black swan cataclysms

Theoretical basis Capital structure theory. Research methodology The case is meant for teaching and class discussion, and uses only secondary data based on published sources. The interpretation and perspectives presented are based solely on the secondary data. Case overview/synopsis This paper aims to help current and future managers understand capital structure theory and the various equity and debt finance options available for raising capital. It also examines the financial analysis and strategic management of black swan events. After the class discussion, students will understand how to financially and strategically manage a company during black swan events and also have a deep dive into capital structure analysis of a large company. Complexity academic level MBA/postgraduate/undergraduate courses on corporate finance or advanced corporate finance. Executive/management development programs and short duration Massive Open Online Courses on investment decision-making and advanced corporate finance. MBA/postgraduate/undergraduate courses on corporate strategy and economic environment and planning.

Comprehensive Evaluation of Functional Diversity of Urban Commercial Complexes Based on Dissipative Structure Theory and Synergy Theory: A Case of SM City Plaza in Xiamen, China

Urban commercial complex is an architectural form formed in the high-density urban building environment based on the diversified concentration of human consumption behavior and the composite utilization of space. It can effectively cope with the problem of tight land resources and insufficient development capacity in urban centers and promote sustainable urban development. Additionally, the diversity of functions is the key to ensure its healthy operation. Based on the homogenization phenomenon of commercial complex development in some big cities in China in recent years, this study applies dissipative structure theory and synergistic effect theory to the study of functional diversity system of urban commercial complexes, and proposes a Shannon–Weiner biodiversity index model and calculation indexes based on the functional diversity measurement model. At the same time, correlation analysis and comparative analysis were conducted between the measurement results of spatial vitality and the calculation results of the diversity model to verify the scientificity and rationality of the proposed model. Finally, the SM City Plaza commercial complex in Xiamen was selected as a representative research object to measure the functional diversity of its weekdays and holidays and the coupling relationship between functional diversity and changes in spatial vitality. The calculation results show that although the comprehensive index of functional diversity of SM commercial complex is in a dynamic state of change, the overall level is high. The reasonable proportion of the six functional formats shows a high level of diversity, which effectively promotes the generation of commercial vitality and enhances the comprehensive benefits of the commercial complex; the change trends of functional diversity in time and space dimensions are in line with the actual situation, indicating that the proposed model has certain scientific and application values. On the basis of the completed empirical work, the scope of application and limitations of the calculation model and evaluation method, as well as the optimization of the index system are further pointed out.

Research on the Model of Interaction and Coupling Relationship between Standard System Construction and Process Management

The fundamental motivation for enterprises to build a standard system is to meet the subjective needs of the unique use nature of standards, such as benchmarking and criteria, from input to output in the baseline relationship of all their business processes. How to guess the credibility and value of the standard system requires collaborative and mature processes to mediate cognition. Firstly, this paper clarifies the philosophical relationship between standard system construction and process management by using the general system structure theory. Secondly, it systematically summarizes the interaction mechanism between the two from the perspective of methodology. Finally, it designs a conceptual model with the "human regulation" composite system as the core and the coupling between standard system construction and the outer edge of process management, and combed the three mechanism characteristics that affect the fit of the coupling model. In order to provide a new integration idea for enterprise standardization management and process management to jointly realize the optimal value utility.

Recent Developments of Computational Methods for pKa Prediction Based on Electronic Structure Theory with Solvation Models

The protonation/deprotonation reaction is one of the most fundamental processes in solutions and biological systems. Compounds with dissociative functional groups change their charge states by protonation/deprotonation. This change not only significantly alters the physical properties of a compound itself, but also has a profound effect on the surrounding molecules. In this paper, we review our recent developments of the methods for predicting the Ka, the equilibrium constant for protonation reactions or acid dissociation reactions. The pKa, which is a logarithm of Ka, is proportional to the reaction Gibbs energy of the protonation reaction, and the reaction free energy can be determined by electronic structure calculations with solvation models. The charge of the compound changes before and after protonation; therefore, the solvent effect plays an important role in determining the reaction Gibbs energy. Here, we review two solvation models: the continuum model, and the integral equation theory of molecular liquids. Furthermore, the reaction Gibbs energy calculations for the protonation reactions require special attention to the handling of dissociated protons. An efficient method for handling the free energy of dissociated protons will also be reviewed.