A review on some classes of algebraic systems

ABSTRACT

In this paper, we review some algebraic control system. Precisely, linear and bilinear systems on Euclidean spaces and invariant and linear systems on Lie groups. The fourth classes of systems have a common issue: to any class, there exists an associated subgroup. From this object, we survey the controllability property. Especially, from those coming from our contribution to the theory.     

Material design and development: From classical thermodynamics to CALPHAD and ICME approaches

This paper presents an overview and examples of material design and development using (1) classical thermodynamics; (2) CALPHAD (calculation of phase diagrams) modeling; and (3) Integrated Computational Materials Engineering (ICME) approaches. Although the examples are given in lightweight aluminum and magnesium alloys for structural applications, the fundamental methodology and modeling principles are applicable to all materials and engineering applications. The examples in this paper have demonstrated the effectiveness and limitations of classical thermodynamics in solving specific problems (such as nucleation during solidification and solid-state precipitation in aluminum alloys). Computational thermodynamics and CALPHAD modeling, when combined with critical experimental validation, have been used to guide the selection and design of new magnesium alloys for elevated-temperature applications. The future of material design and development will be based on a holistic ICME approach. However, key challenges exist in many aspects of ICME framework, such as the lack of diffusion/mobility databases for many materials systems, limitation of current microstructural modeling capability and integration tools for simulation codes of different length scales.     

Molecular dynamics studies of a model polymer-catalyst-carbon interface

Classical molecular dynamics simulations are performed to obtain insights into structural and dynamical behavior of water and O₂ transport through a model polymer membrane, and at the interface of such hydrated polymer with graphite-supported nanocatalyst platinum particles. Water clustering is observed near the membrane hydrophilic sites constituted by sulfonic groups, which due to their affinity with platinum, are located near the metallic surface. It is found that the diffusion of water through the model hydrated polymer membrane depends strongly on the level of membrane hydration due to contribution from various mechanisms whose relative weights change with the degree of hydration. Possible scenarios for O₂ diffusion are also analyzed.     

动态描述逻辑的可拓集合扩展

通过对可拓集合与经典集合、模糊集合的分析比较,说明可拓集合的特点和优点,用可拓集合代替经典集合或模糊集合作为动态描述逻辑DDL的集合论基础,对DDL进行扩展,生成了一种新的描述逻辑DDES,并给出了DDLES中概念、关系和实例的描述形式以及它们的语义解释,最后对传统描述逻辑ALC、模糊DDL和DDES中的Abox形式进行了比较.     

从古典诗词中“花”意象旷观中国传统美学中的人与自然

＂意象＂是中国传统美学的核心要素,是中国古典诗歌的灵魂。＂意象＂生成的基础是人的审美体验。而＂花意象＂在古典诗词中俯拾皆是。＂花＂美丽的表象经过诗人词客主观的情感关照被赋予丰富的情感内涵,纷纷借＂花＂抒发情志,寄寓对生命的深切体悟。中国古典诗词中对＂花＂的描写,体现了中国人心灵深处人与自然交感互融的宇宙观和自然观,这种自然观直接导致了中国人审美化的人生态度。本文拟从古典诗词中的＂花意象＂探查中国传统美学中人与自然的关系,即中国古典美学的精神内核。     

Cognitive ergonomics: it's all in the mind

In this paper a distinction is made between classical ergonomics as dealing with the quality of working and cognitive ergonomics as dealing with the quality of work including the joint system products. It is argued that classical ergonomics can be seen as embracing a dualism, where the effects of work on the body are considered separately from the effects of work on the mind. This continues the mechanistic tradition of Western psychology. The aim of cognitive ergonomics is to describe (1) how work affects the mind, as well as (2) how the mind affects work. Work is all in the mind in the sense that the quality of work depends on the person's understanding of the situation (goals, means, constraints) and in the sense that the design of a worksystem depends on the designer's understanding, in particular the conceptualization of the people in the system. In cognitive ergonomics, the reliability of performance—and in particular the reliability of cognition—become central issues. The differences between classical and cognitive ergonomics are illustrated by considering two typical areas: risks at work and human-computer interaction. It is concluded that classical and cognitive ergonomics represent two complementary views of work that must be combined to meet the challenges of present day work environments.     

The dielectric constant and quality factor calculation of the microwave dielectric ceramic solid solutions

The dielectric constant of the microwave dielectric ceramic solid solution is usually predicted by the Clausius-Mosotti equation but the quality factor (Q) cannot be precisely calculated. In this paper, it finds that the dielectric constant of the solid solutions also could be well calculated by the Maxwell-Wagner formula, and that the Q of solid solutions can be precisely calculated, by assuming a solid solution as a two or more materials’ mixture.     

水淘洗法分离镍基高温合金粉末中陶瓷类夹杂物

详细介绍了水淘洗方法分离固体颗粒的原理,从实践上建立了镍基高温合金粉末陶瓷类夹杂物的分级分离法,进行实验验证,并分析了水淘洗方法的可靠性。