MOLECULAR-DYNAMIC SIMULATION OF MIXTURES OF MODIFIED FULLERENES AND 1,8-OCTANDITHIOL

В данной работе мы сообщаем о результатах сравнительного атомистического моделирования двух систем, содержащих функцианализированные фуллерены метилового эфира фенил- C-масляной кислоты (PCBM ) и фенил- C-масляной кислоты (PCBM ) в присутствии растворителя 1,8-октандитиола (ODT). Для реализации расчетов использовался метод молекулярной динамики на базе программного пакета LAMMPS. Зафиксировано принципиальное различие в упаковке молекул PCBM и PCBM . В случае систем с PCBM наблюдается тенденция к постепенному разделению растворителя и фуллеренов. При этом в образцах с PCBM наблюдается тенденция к формированию устойчивых трехмерных сетчатых структур, образованных двумя взаимопроникающими фазами: фуллеренами и молекулами ODT. С целью проверки масштабируемости наблюдаемого структурного упорядочения для смеси PCBM с ODT было выполнено моделирование в ячейке с удвоенным размером ребер. В этом случае мы также наблюдаем формирование биконтинуальных структур из фуллеренов и растворителя. In this work, we report on the results of comparative atomistic modeling of two systems containing functionalized fullerenes of phenyl-C-butyric acid methyl ester (PCBM ) and phenyl- C -butyric acid (PCBM ) in the presence of a high-boiling solvent 1,8 -octanedithiol (ODT). The calculations were performed by full atomistic molecular dynamics with using LAMMPS software package. A fundamental difference in the packaging of PCBM and PCBM molecules was detected. In the case of systems with PCBM , there is a tendency towards gradual separation of the solvent and fullerenes. At the same time, in samples with PCBM , there is a tendency to the formation of stable three-dimensional network structures formed by two interpenetrating phases: fullerenes and ODT molecules. In order to check the scalability of the observed structural ordering for the mixture of PCBM with ODT, an additional simulation was performed in a cell with doubled edge size. In this case, we also observe the formation of bicontinual structures from fullerenes and the solvent.

Studies on the Role of circRNAs in Osteoarthritis

Objective. Provide a reference to elucidate the mechanism of circRNAs regulating osteoarthritis (OA) and the clinical treatment. Methods. Herein, articles about circRNAs (hsa-circ) and osteoarthritis in the recent 5 years have been reviewed and the differential expression and regulatory effect of circRNAs in OA deduced. Based on these conclusions and Protein-Protein Interaction (PPI), Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses of the acquired circRNAs, the potential functions and interactions of circRNAs in OA and the involved signaling pathways are discussed. Results. A total of 33 studies meeting the inclusion criteria were included in this study, and 27 circRNAs were upregulated and 8 circRNAs were downregulated in OA. A total of 31 circRNAs were finally included in the PPI, GO, and KEGG analyses. From PPI, 12 map nodes and 7 map edges were interrelated. VWF had the biggest node and edge size. From GO, VWF showed a majority of the functions. From KEGG, circRNAs are enriched in PI3K/AKT, human papillomavirus infection (HPI), and focal adhesion (FA) pathways, and VWF was involved in major pathways. Conclusion. We found that most articles about circRNAs regulating OA in the recent 5 years focused on the mechanism, especially the absorption effect of circ-miRNA as sponges in the recent 2 years, while most of the articles about their functions addressed ECM and PI3K, AKT, and mTOR signaling pathways. Future studies might focus on the functions of circRNAs, and circRNA VWF, with preferable functions, interactions, and involvement, can be used as a biological indicator to detect OA in clinical practice.

SUNTINGAN DOKUMEN BERBASIS WEB

Web-based document editing is a system for making scientific papers without having to adjust the format of writing scientific papers. Where in this system has provided a framework for entering journal contents. Journal article creation must follow the format already in place in the organization, such as font size, edge size, and so on. Often in writing journals, writers experience difficulties or constraints in the format of writing, so they often experience errors in writing journal articles. For this reason, it is necessary to have a standard web journal writing program, which provides a framework for the format of journal writing. The process carried out in designing this application is by looking at the guidelines for journal manuscript writing, with these guidelines the writer can know how the journal format will be translated into a program script. The purpose of this research is to design a standard web program for editing documents in journals and to assist journal authors / journal authors in making scientific papers online. In this research, the writer made a document editing system for scientific journal writing format using PHP and MySQL in the application system. Where in the system designed the author only includes the entries of each input in the journal framework. In this system all the input that is filled in is stored in a database with different tables. And when the author sees the contents of the journal, the display on the journal contents automatically matches the journal template.

Edge length-dependent interlayer friction of graphene

The present work demonstrates the intrinsic dependence of friction on the contact edge size of incommensurate graphene layers.

Identifying Hazardous Shapes in the Plane

This paper explores the problem of identifying the shapes of invisible hazardous entities in R2 by a set S = {s1, s2, . . . , sk} of mobile sensors (autonomous robots). A hazardous entity, H, is a region that affects the operation of robots that either penetrate the area or come in contact with it. In this paper, we propose algorithms for searching a rectangular region for a stationary hazardous entity, where some a priori geometrical knowledge is given (e.g., edge size range), and if such an entity exists, then determine the area that it occupies. We explore entities that are convex in nature such as line segment, circles (discs), and simple convex shapes. The objectives are to minimize the distance travelled by the robots during the search phase, and to minimize the number of robots that are required to identify the region covered by the hazardous entity. The number of robots required to locate H is three or four robots when H is a line segment, two or three robots when H is a circle, and seven robots are sufficient when H is a triangle. Our results extend to n-vertex convex shapes and we show that 2n + 1 robots are sufficient to determine the coverage of H.

Research on Parameter Optimization of Micro-Milling Al7075 Based on Edge-Size-Effect

In the process of micro-milling, the appearance of the edge-size-effect of micro-milling tools cannot be ignored when the cutting parameters are smaller than the cutting edge arc radius (r0) of the micro-milling tool or close to it, and it could easily lead to low cutting efficiency and poor surface quality of the micro-slot. Through micro-milling experiments on Al7075-T6 materials, the change of milling force in the plough zone and shear zone during micro-milling was studied, and the minimum cutting thickness (hmin) range was determined to be 0.2r0–0.4r0 based on r0 of the micro-milling tool. Subsequently, the effect of fz/r0 (fz denotes feed rate per tooth) on the top burr formation of the micro-slot, the surface roughness (Ra) of the micro-slot bottom, and the milling force was studied, and a size-effect band of micro milling was established to determine the strong size-effect zone, transition size-effect zone, and the weak size-effect zone. Finally, two different fz/r0 in the strong size-effect zone and the weak size-effect zone are compared, which proves that the main purpose of the cutting parameters optimization of micro-milling is to avoid cutting parameters locating in the strong edge-size-effect zone. The above conclusions provide a theoretical basis for the selection of micro-milling cutting parameters, and an important reference in improving the surface quality of micro-milling.

Edge, size, and shape effects on WS2, WSe2, and WTe2 nanoflake stability: design principles from an ab initio investigation

The magic nanoflakes, obtained by the evaluation of the relative stability function, are n = 9 and 14 for all chemical compositions, whereas n = 12 is a magic number for WS2 and WSe2.

Improved Growth Estimates for Lethrinus harak: Measuring Increments, Adjusting Ages, and Fitting Flexible Growth Models

Thumbprint emperor (Lethrinus harak) are a widely distributed, tropical species ranging throughout the Indo-Pacific region. In coastal Tanzania, overfishing is likely occurring and thumbprint emperor are commonly represented in catches. The goal of this study was to estimate age and growth to provide basic life history information that may help inform future management. We sampled a total of n = 55 thumbprint emperors from both fishery-dependent and fishery-independent sources. Annular age estimates were improved with measurements of otolith markings. Fish ages ranged from zero to five years. We also evaluated the addition of otolith edge size (a proxy for fractional age) to age estimation, and fit two von Bertalanffy growth models—one for the whole ages and one for the fractional ages—using a flexible Bayesian framework. Growth parameters were similar between the two models, and ultimately, L ∞ (maximum asymptotic size parameter) estimates were comparable to other published values for the species, although our estimates of K (growth coefficient parameter) were smaller. Robust aging techniques for tropical fishes can provide a foundation for basic fishery management, which would help to sustain the future of this widely distributed fish.

Application of Embedded Element in the Short Fiber Reinforced Composite

The finite element analysis (FEA) is a numerical method for predicting the mechanical property of short fiber reinforced composite usefully. However, as we know, there is always a “jamming” limit when generating fiber architecture expecially in the cases of high volume fraction and high aspect ratio of short fiber. Even if the volume fraction and aspect ratio in finite element model meet the practical requirements, the problem of mesh deformity will always occur which would lead to unconverge of numerical computation. In this work, embedded element technique which will help to reduce the probability of the above two problems is employed to establish the finite element model of short fiber reinforced composite. The effect of edge size, thickness and mesh density of FE models on the elastic modulus were investigated. Numerical results show that the value of elastic modulus mainly depend on the edge size and fiber amount of FE model while the effect of thickness can be neglected. The elastic modulus takes to converge for high element number. An inverse method is proposed to calculate volume fraction of short fibers, by which numerical results agree well with the calculation results of empirical formula based on Halpin-Tsai equation.