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2022 ◽  
Vol 1049 ◽  
pp. 180-185
Author(s):  
Viktor Mavrinskii ◽  
Evgeniy A. Belenkov

Calculations of the structural and energy parameters, band structure and density of electronic states of new structural varieties of graphyne have been performed by the density functional theory method. The initial structure of the nine polymorphs was theoretically constructed on the basis of the 5-7a graphene layer. As a result of the calculations, the structure of only five graphyne layers was found to be stable: α-L5-7a, β1-L5-7a, β2-L5-7a, β3-L5-7a and β4-L5-7a. The structure of layers γ1-L5-7a, γ2-L5-7a, and γ3-L5-7a is transformed into the structure of graphene layers by geometric optimization, and the graphyne layer γ4-L5-7a is transformed sp+sp2 layer L3-6-13. The sublimation energy of the stable graphyne polymorphs varies from 6.66 to 6.78 eV/atom. The density of electronic states at the Fermi energy level for all α-L5-7a and β-L5-7a layers of graphyne is different from zero, so the new graphyne polymorphs should have metallic properties.


2022 ◽  
Author(s):  
Eugen Hruska ◽  
Ariel Gale ◽  
Xiao Huang ◽  
Fang Liu

The availability of large, high-quality data sets is crucial for artificial intelligence design and discovery in chemistry. Despite the essential roles of solvents in chemistry, the rapid computational data set generation of solution-phase molecular properties at the quantum mechanical level of theory was previously hampered by the complicated simulation procedure. Software toolkits that can automate the procedure to set up high-throughput explicit-solvent quantum chemistry (QC) calculations for arbitrary solutes and solvents in an open-source framework are still lacking. We developed AutoSolvate, an open-source toolkit to streamline the workflow for QC calculation of explicitly solvated molecules. It automates the solvated-structure generation, force field fitting, configuration sampling, and the final extraction of microsolvated cluster structures that QC packages can readily use to predict molecular properties of interest. AutoSolvate is available through both a command line interface and a graphical user interface, making it accessible to the broader scientific community. To improve the quality of the initial structures generated by AutoSolvate, we investigated the dependence of solute-solvent closeness on solute/solvent identities and trained a machine learning model to predict the closeness and guide initial structure generation. Finally, we tested the capability of AutoSolvate for rapid data set curation by calculating the outer-sphere reorganization energy of a large data set of 166 redox couples, which demonstrated the promise of the AutoSolvate package for chemical discovery efforts.


2022 ◽  
Vol 12 (1) ◽  
pp. 440
Author(s):  
Zhanghui Zhai ◽  
Yaguo Zhang ◽  
Shuxiong Xiao ◽  
Tonglu Li

Soil structure has significant influences on the mechanical behaviors of natural soils, although it is rarely considered in previous cavity expansion analyses. This paper presents an undrained elastoplastic solution for cylindrical cavity expansion in structured soils, considering the destructuration effects. Firstly, a structural ratio was defined to denote the degree of the initial structure, and the Structured Cam Clay (SCC) model was employed to describe the subsequent stress-induced destructuration, including the structure degradation and crushing. Secondly, combined with the large strain theory, the considered problem was formulated as a system of first-order differential equations, which can be solved in a simplified procedure with the introduced auxiliary variable. Finally, the significance and efficiency of the present solution was demonstrated by comparing with the previous solutions, and parametric studies were also conducted to investigate the effects of soil structure and destructuration on the cavity expansion process. The results show that the soil structure has pronounced effects on the mechanical behavior of structured soils around the cavity. For structured soils, a cavity pressure that is larger than the corresponding reconstituted soils when the cavity expands to the same radius is required, and the effective stresses first increase to a peak value before decreasing rapidly with soil structure degradation and crushing. The same final critical state is reached for soils with different degrees of the initial structure, which indicates that the soil structure is completely destroyed during the cavity expansion. With the increase of the destructuring index, the soil structure was destroyed more rapidly, and the stress release during the plastic deformation became more significant. Moreover, the present solution was applied in the jacking of a casing during the sand compact pile installation and in situ self-boring pressuremeter (SBPM) tests, which indicates that the present solution provides an effective theoretical tool for predicting the behavior of natural structured soils around the cavity.


Linguaculture ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 145-161
Author(s):  
Alexandra-Maria Vrinceanu

This article is an analysis from a feminist perspective of the two Romanian translations of Margaret Atwood’s The Handmaid’s Tale. By adopting Antoine Berman’s three pronged model of translation criticism, I attempt to identify several differences between the translations. Therefore, it will prove pertinent to see whether the translators adhere to the author’s style, are faithful to the tone, imagery, wordplay and ludic nature of the text, if they prefer to steer clear of more adventurous translation strategies and opt for a source-oriented translation, keeping to the initial structure and employing mostly syntactic strategies. Another important element that surfaces and plays a paramount role is that of the translator’s visibility, more precisely those instances wherein she makes her voice known, be it through an explanatory footnote or, perhaps, a translator’s gloss at the end of the translated text. The translators’ own backgrounds are relevant in the case at hand as well, as their experience and formation influence their preferences for a certain style and translation strategies


Author(s):  
Vitaly Dmitrik ◽  
Igor Kasyanenko ◽  
Alexandr Krakhmalyov

The authors studied the interrelation between the type of structure and the damage rate of the welded joints of steam pipelines made of the heat-resistant pearlitic steels that were operated for a long time, i.e. more than 270 thousand hours in the conditions of creepage and low-cycle fatigue. The purpose of this research was to establish the interrelation between the structural-&-phase condition of the metal used for welded joints of the elements of steam systems and their damageability rate for the service life of welded joints exceeding 270 thousand hours. During the studies, the methods of optical and electron microscopy were used according to the requirements of the guideline documentation and also the methods that are used for the determination of mechanical properties. The level of their reliability has been substantiated and the residual life has been determined. To impart functional performances to welded joints we used well-known methods that were appropriately emended according to the structural changes of above joints. Such changes condition the conversion of the original structure of welded joints into the ferrite-carbide mixture. The availability of the conversion process of the initial structure on the thermal action zone sections (TAZ) of welded joints has essential distinctions due to a different disposition of metal to its own damageability. On the whole, the welded joints are damaged more intensively in comparison to the basic metal of steam pipelines. The analysis of the structural state of welded joints in the steam pipelines of thermal power plants as for the extension of their service life results in a considerable economic effect. Understanding the fact that the metal deterioration in welded joints adheres mainly to the fragile mechanism we managed to establish the level of their damageability that demands the renewal of damaged welded joints. We believe that the damageability level of welded joints that tots up to 0.25 or 0.35 of the volume of their TAZ section should be considered as critical for the service life exceeding 270 thousand hours. The damaged welded joints should be renewed throughout the time period of 15 to 20 thousand hours as soon as the specified damageability level is attained.


2021 ◽  
Vol 13 (1) ◽  
pp. 51-65
Author(s):  
Adriana Mezeg

This article first gives an overview of the different uses of French apposition and then focuses on nominal appositions, a kind of supplementive clause introduced by a nominal group (NG) without an article. Only translations of initial nominal appositions are examined, i.e. those which are placed at the beginning of the sentence and where the content of the initial structure is expressed by an apposition or NG as the subject. In this context, word order and the use of commas are discussed, which are often of importance for Slovenian language users. Based on the FraSloK corpus, the following conclusions can be drawn: (a) sentence-initial position is maintained much more often in novels than in newspaper articles; (b) the expression of the content of initial structures with an apposition and an NG, which functions as a subject, is fairly evenly represented in more than half of the cases from newspaper articles, while in novels the subject function is prominent; (c) apart from the change in sentence position, Slovenian apposition corresponds to the source structure, and when its content is expressed by an NG with subject function, there are changes at different levels compared to French; (d) the (non-)use of the comma cannot be satisfactorily justified on the basis of the present corpus, but the examples suggest that it is based on translators’ personal choices and also depends on the possibilities of expression in the target language. Suggestions have already been made to change the rules and usage examples, which are not tenable in our cases, and would require further consideration.


Author(s):  
Guangqing Cai ◽  
zhefu Liu ◽  
Linzhou Zhang

Automatic molecular design on computers is an emerging technology for the determination of optimal fuel molecules. We developed a computer-aided molecular design framework through a transformation rule-based molecular evolution method. The reaction rule was used as the elementary step to change the molecular structure. A molecule can achieve structural variation continuously using a series of reaction rules. The finding of the optimal molecule can be seen as the evolution of structure in the chemical space, which was guided by using a global optimization algorithm to select the best reaction routine. We showed that the optimized molecule is independent of the input initial structure, proving the robustness of the method. We then applied the method to design gasoline molecules for motor and aviation gasoline. The designed molecules can not only serve as competitive candidate components for high-quality gasoline, but also accelerate the synthesis rate of new molecules in the laboratory.


2021 ◽  
Author(s):  
Yasuto Itoh

The Median Tectonic Line (MTL) along the longstanding convergent margin of eastern Eurasia has been activated intermittently since ca. 100 Ma. In its incipient phase, propagating strike slips on the MTL generated an elongate pull-apart depression buried by voluminous clastics of the Late Cretaceous Izumi Group. In this study, the complicated deformation processes around this regional arc-bisecting fault are unraveled through a series of quantitative analyses. Our geological survey of the Izumi Group was exclusively conducted in an area of diverse fault morphology, such as jogs and steps. The phase stripping method was introduced to elucidate the time sequence of cumulative tectonic events. After stripping away the initial structure related to basin formation, neotectonic signatures were successfully categorized into discrete clusters originating from progressive wrenching near the active MTL fault system, which has been reactivated by the Quaternary oblique subduction of the Philippine Sea Plate. The method presented here is simple and effective for the detection and evaluation of active crustal failures in mobile belts where records of multiphase architectural buildup coexist.


Author(s):  
Tatiana I. Perfilyeva ◽  
Oleg A. Drozhzhin ◽  
Anastasia M. Alekseeva ◽  
Maxim V. Zakharkin ◽  
Andrey V. Mironov ◽  
...  

Abstract Here we introduce a new NASICON-type Na3VSc(PO4)3 positive electrode material for Na-ion batteries demonstrating reversible (de)intercalation of 3 Na cations per formula unit within a wide voltage range with complex voltage-composition dependence. The total electrochemical capacity of the material is 170 mAh/g, which corresponds to the complete three-electron V2+/V3+/V4+/V5+ process. All the (de)sodiation stages follow a predominantly solid-solution mechanism, as shown by operando X-ray powder diffraction. The oxidation of vanadium up to +5 upon the charge of Na3VSc(PO4)3 to 4.5 V vs. Na/Na+ causes the significant transformation of the unit cell. According to ex situ Fourier-transformed infrared spectroscopy it is accompanied by the increasing distortion of the vanadium coordination environment and shortening of the vanadium-oxygen bonds. This leads to the irreversible character of the charge-discharge curve, and the initial structure can be restored after the strong overdischarge to ≈1.5 V vs. Na/Na+.


2021 ◽  
Author(s):  
Rammohan R Yadav ◽  
Mariana Laureano de Souza ◽  
Mariana Lozano Gonzalez ◽  
Shams Ul Mahmood ◽  
Tyler Eck ◽  
...  

The discovery of new targets for treatment of malaria and in particular those aimed at the pre-erythrocytic stage in the life cycle, advanced with the demonstration that orally administered inhibitors of Plasmodium falciparum cGMP-dependent protein kinase (PfPKG) could clear infection in a murine model. This enthusiasm was tempered by unsatisfactory safety and/or pharmacokinetic issues found with these chemotypes. To address the urgent need for new scaffolds, this manuscript presents initial structure-activity relationships in an imidazole scaffold at four positions, representative in vitro ADME, hERG characterization and cell-based anti-parasitic activity. This series of PfPKG inhibitors has good in vitro PfPKG poten-cy, low hERG activity and cell-based anti-parasitic activity against multiple Plasmodium species that appears to correlate with in vitro potency.


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