DEM simulation of the mechanical properties of SiC ceramic under pre-stressing

In this paper, the method of discrete element model (DEM) simulation was used to investigate the mechanical properties of SiC ceramic materials under the action of pre-stress. Using the bonded particle model (BPM), several different numerical tests (such as UCT, TPB, SENB tests) of SiC ceramic were established. Different pre-stress values were applied on the lateral surface of the ceramic specimen during the numerical simulation process, all tests were carried out at least 5 times with different random number, and the average mechanical properties results were calculated. It was showed that the existence of pre-stress has a significant effect on the mechanical properties of materials. It can enhance the strength of materials, while the force action on material in machining process force or action force the crack’s initiation and propagation was limited

Analysis and design of power management scheme for an on-board solar energy storage system

This paper investigates the power management issues in a mobile solar energy storage system. A multi-converter based energy storage system is proposed, in which solar power is the primary source while the grid or the diesel generator is selected as the secondary source. The existence of the secondary source facilitates the battery state of charge detection by providing a constant battery charging current. Converter modeling, multi-converter control system design, digital implementation and experimental verification are introduced and discussed in details. The prototype experiment indicates that the converter system can provide a constant charging current during solar converter maximum power tracking operation, especially during large solar power output variation, which proves the feasibility of the proposed design

Numerical Simulation-Based Optimization of Contact Stress Distribution and Lubrication Conditions in the Straight Worm Drive

Tooth contact area optimization/meshing of the straight worm pair is vital for improving its operation efficiency. Geometric parameters of a worm helicoid were derived via the gear meshing theory using the equations of the instantaneous contact line. The visualization function and powerful computing capability of MATLAB are used for the numerical analysis where the instantaneous contact line distribution is simulated for particular worm drive parameters, which yields the induced curvature and slip angle in the direction of the line. The above results are used for further optimization of the meshing performance of the straight worm gear and identification of its influencing factors. A case study of the particular cylindrical worm gear in compliance with the GB 10085-1988 Standard of China demonstrate that a reasonable selection of worm gear parameters can extend the contact line and the working range of the tooth surface of the worm gear and/or make the contact line distribution along the worm wheel more uniform, thus improving the local meshing performanceОптимизация зубчатой контактной поверхности/зацепление прямолинейной червячной пары определяют повышение эффективности ее эксплуатации. Геометрические параметры червячного геликоида получены с использованием теории зацепления зубчатых колес и уравнения линии мгновенного контакта. Численный анализ основан на функции визуализации и вычислительных возможностях программы MATLAB, что позволяет моделировать распределение на линии мгновенного контакта для специфических параметров червячного привода, создавая вынужденную кривизну и угол скольжения в направлении этой линии. Полученные результаты обеспечивают последующую оптимизацию параметров зацепления прямолинейной червячной передачи и установление определяющих факторов. Пример использования специфической цилиндрической червячной передачи в соответствии со стандартом Китая (GB 10085-1988) показывает, что рациональный выбор параметров этой передачи может увеличить линию контакта, а также расширить рабочий диапазон ее зубчатой поверхности и/или обеспечить более равномерный контакт по червячному колесу, повышая тем самым эффективность локального зацепления

Thermo-elasticity for anisotropic media in higher dimensions

In this note we develop tools to study the Cauchy problem for the system of thermo-elasticity in higher dimensions. The theory is developed for general homogeneous anisotropic media under non-degeneracy conditions. For degenerate cases a method of treatment is sketched and for the cases of cubic media and hexagonal media detailed studies are provided.Comment: 33 pages, 5 figure

Graphene-stablized lipid monolayer heterostructures: a novel biomembrane superstructure

Supramolecular & Biomaterials Chemistr

Contact angle measurement of free-standing square-millimeter single-layer graphene

Supramolecular & Biomaterials Chemistr

Genome-wide association study for flour color-related traits and polyphenol oxidase activity in common wheat

This study aimed to clarify the genetic mechanisms behind wheat flour color. Flour colorrelated traits (L*, a*, and b*) and polyphenol oxidase (PPO) activity are important parameters that influence the end-use quality of wheat. Dissecting the genetic bases and exploring important chromosomal loci of these traits are extremely important for improving wheat quality. The diverse panel of 205 elite wheat varieties (lines) was genotyped using a highdensity Illumina iSelect 90K single-nucleotide polymorphisms (SNPs) assay to disclose the genetic mechanism of flour color-related traits and PPO activity. In 2 different environments and their mean values (MV), 28, 30, 24, and 12 marker-trait associations (MTAs) were identified for L*, a*, b* traits, and PPO activity, respectively. A single locus could explain from 5.52% to 20.01% of the phenotypic variation for all analyzed traits. Among them, 5 highly significant SNPs (P ≤ 0.0001), 11 stable SNPs (detected in all environments) and 25 multitrait MTAs were identified. Especially, BS00000020_51 showed pleiotropic effects on L*, a*, and b*, and was detected in all environments with the highest phenotypic contribution rates. Furthermore, this SNP was also found to be co-associated with wheat grain hardness, ash content, and pasting temperature of starch in previous studies. The identification of these significantly associated SNPs is helpful in revealing the genetic mechanisms of wheat colorrelated traits, and also provides a reference for follow-up molecular marker-assisted selection in wheat breeding

Sensing at the surface of graphene field-effect transistors

Supramolecular & Biomaterials Chemistr