6 resultados para TERMINOLOGY

em Chinese Academy of Sciences Institutional Repositories Grid Portal


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The advent of nanotechnology has necessitated a better understanding of how material microstructure changes at the atomic level would affect the macroscopic properties that control the performance. Such a challenge has uncovered many phenomena that were not previously understood and taken for granted. Among them are the basic foundation of dislocation theories which are now known to be inadequate. Simplifying assumptions invoked at the macroscale may not be applicable at the micro- and/or nanoscale. There are implications of scaling hierrachy associated with in-homegeneity and nonequilibrium. of physical systems. What is taken to be homogeneous and equilibrium at the macroscale may not be so when the physical size of the material is reduced to microns. These fundamental issues cannot be dispensed at will for the sake of convenience because they could alter the outcome of predictions. Even more unsatisfying is the lack of consistency in modeling physical systems. This could translate to the inability for identifying the relevant manufacturing parameters and rendering the end product unpractical because of high cost. Advanced composite and ceramic materials are cases in point. Discussed are potential pitfalls for applying models at both the atomic and continuum levels. No encouragement is made to unravel the truth of nature. Let it be partiuclates, a smooth continuum or a combination of both. The present trend of development in scaling tends to seek for different characteristic lengths of material microstructures with or without the influence of time effects. Much will be learned from atomistic simulation models to show how results could differ as boundary conditions and scales are changed. Quantum mechanics, continuum and cosmological models provide evidence that no general approach is in sight. Of immediate interest is perhaps the establishment of greater precision in terminology so as to better communicate results involving multiscale physical events.

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In the current paper, we have primarily addressed one powerful simulation tool developed during the last decades-Large Eddy Simulation (LES), which is most suitable for unsteady three-dimensional complex turbulent flows in industry and natural environment. The main point in LES is that the large-scale motion is resolved while the small-scale motion is modeled or, in geophysical terminology, parameterized. With a view to devising a subgrid-scale(SGS) model of high quality, we have highlighted analyzing physical aspects in scale interaction and-energy transfer such as dissipation, backscatter, local and non-local interaction, anisotropy and resolution requirement. They are the factors responsible for where the advantages and disadvantages in existing SGS models come from. A case study on LES of turbulence in vegetative canopy is presented to illustrate that LES model is more based on physical arguments. Then, varieties of challenging complex turbulent flows in both industry and geophysical fields in the near future-are presented. In conclusion; we may say with confidence that new century shall see the flourish in the research of turbulence with the aid of LES combined with other approaches.

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从计算机技术的角度出发,对植物形态学信息处理和应用,构成本文的思想,文中简略同顾了植物形态学术语的标准化的历史发展过程,对当前世界范围内在此领域的工作也作了概要般的总结,论述了计算机技术用十植物学应用和研究的重要性并提出了我国在此领域内开展工作的紧迫性和必要性。计算机的资源限制及植物信息特有的复杂性是这一领域发展的困难。因此,如何贮存植物信息?如何操作加工应用?才能充分利用计算机资源和植物信息资源成为本领域的核心问题。 本文基于上面的考虑,对植物形态学信息从基本的信息单位植物形态学术语出发,探求其分类结构,并从计算机技术的编码理论方面进行探讨.力图求得一个标准化的植物形态学描述分类群的术语编码集,提供一种实现描述的方法,并试验性地给出一种描述规范和格式,简单讨论一下实现语言处理,机器鉴定、数量分类的可能性,最后简单分析和对比了本工作和国际上的类似工作,并对本领域进行了简单的展望。

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The gene of piscidin, an antimicrobial peptide, has been cloned from the mandarin fish, Siniperca chuatsi. From the first transcription initiation site, the mandarin fish piscidin gene extends 1693 nucleotides to the end of the 3' untranslated region and contains four exons and three introns. A predicted 79-residue prepropeptide consists of three domains: a signal peptide (22 aa), a mature peptide (22 aa) and a C-terminal prodomain (35 aa). The shortage of XQQ motif in the prodomain of mandarin fish piscidin and the similar gene structure between moronecidins (piscidins) and pleurocidins may indicate that they are derived from the same ancestor gene. We thus suggest that piscidin should be used as a terminology for these antimicrobial peptides in the future. The mandarin fish piscidin mRNA was abundant in intestine, spleen, pronephros and kidney analysed by real-time polymerase chain reaction. After stimulation with lipopoly saccharides (LPS), a marked increase in transcripts was observed in most tissues, indicating that piscidin is not only a constitutively expressed molecule, but also has an increased response to bacterial infection. The synthetic, amidated mandarin fish piscidin exhibited different antimicrobial activity against different fish bacterial pathogens, especially against species of Aeromonas, which may to certain extent reflect the pathogenicity of these bacteria.

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Eight kinds of pigment-protein complexes were resolved from the thylakoid membrane of the brown alga (Undaria pinnatifida Harv.) by using non-ionic detergent decanoyl-N-methylglucamide and PAGE technique. According to the apparent molecular weights, spectra characteristics, polypeptide compositions and referring to the higher plant spinach, eight pigment-protein complexes were named under Anderson's terminology system as CP I a, CP I, CPa, LHC1, LHC2, LHC3, LHC4, LHC5.

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阐述了可信赖机器翻译( TMT)的基本概念, TMT七原则和七判据, TMT与术语标准化的关系,并讨论了对外来词的音译和双语联合表示法的应用等问题。