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Gert W. Wolf 《International journal of geographical information science》2014,28(7):1401-1424
This article demonstrates how the generalisation of topographic surfaces has been formalised by means of graph theory and how this formalised approach has been integrated into an ISO standard that is employed within nanotechnology. By applying concepts from higher-dimensional calculus and topology, it is shown that Morse functions are those mappings that are ideally suited for the formal characterisation of topographic surfaces. Based on this result, a data structure termed weighted surface network is defined that may be applied for both the characterisation and the generalisation of the topological structure of a topographic surface. Hereafter, the focus is laid on specific issues of the standard ISO 25178-2; within this standard change trees, a data structure similar to weighted surface networks, are applied to portray the topological information of topographic surfaces. Furthermore, an approach termed Wolf pruning is used to simplify the change tree, with this pruning method being equivalent to the graph-theoretic contractions by which weighted surface networks can be simplified. Finally, some practical applications of the standard ISO 25178-2 within nanotechnology are discussed. 相似文献
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Michael F. Hochella Jr.Author Vitae 《Earth and Planetary Science Letters》2002,203(2):593-605
Nanoscience and technology are not exactly new, but nevertheless rapidly expanding fields that are providing revolutions in all sciences on the scale of what genomics and proteomics have done in recent years for the biological sciences. Nanoscience is based on the fact that properties of materials change as a function of the physical dimension of that material, and nanotechnology takes advantage of this by applying selected property modifications of this nature to some beneficial endeavor. The prefix ‘nano’ is used because the property dependence on physical size is generally observed close to the nanoscale, somewhere around 10−9 m. The dimensions at which changes are observed depend on the specific material and the property in question, as well as which of the three dimensions are restricted in real space (e.g. small particles vs. thin films vs. ‘one-dimensional’ phases). Properties change in these confined spaces because the electronic structure (i.e. the distribution of electron energies) of the material is modified here in the gray area between the bulk and atomistic/molecular realms, or equivalently between the continuum and strictly quantum domains. Earth materials with at least one dimension in the nanorange are essentially ubiquitous. Many have been known for several decades and more are being discovered all the time. But the scientific emphasis has now shifted to that of measuring, understanding and ultimately predicting the property changes from the bulk to nanodomains, and to the understanding of the significant ways that Earth processes are affected by these changes. In addition, where possible, Earth scientists are using nanoscience to develop nanotechnology that should play important roles in Earth sustainability issues of the future. 相似文献
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Ben Anderson 《Area》2007,39(2):156-165
This paper describes how hopes can be, and have been, placed in nanotechnology. Focusing on two recent UK government reports into the future of nanotechnology, by the DTI/OST and MoD, the paper describes how the disclosure of the nanoscale as a place subject to intervention, the act that is taken to define nanotechnology, can be understood in the context of anticipatory knowledge practices that create futures. Because the object of such practices are virtualities, such as opportunities and threats, the paper argues that affect is transversal to both nano-technoscience and anticipatory governance. In conclusion, I open up a set of questions about anticipatory knowledges and argue that the ground that enables hope to be placed in nanotechnology is the event that defines nano – to simultaneously reduce 'life' to matter and to multiply 'life' into a limitless set of materialities. 相似文献
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李虹 《成都信息工程学院学报》2010,25(6)
首先从人们的日常生活的场景入手,定义了物联网的概念,对物联网科学和物联网技术进行了详细的讲解.然后系统地讲解了物联网的前沿应用--物联网新能源技术、物联网空间探测技术、物联网智慧云计算技术、物联网智慧纳米技术,阐述了从传统的方法到物联网技术的转变过程,物联网如何改变人们的生活. 相似文献
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单链环状DNA在纳米技术、分子生物学和医药学等领域具有广泛的应用前景,但难以大量制备一直是制约其研究和应用的难题之一。本文针对一种高效大量制备单链环状DNA的方法-逐步添加法,系统地探究了逐步添加法中各主要条件对制备单链环状DNA的影响,确定了逐步添加法中的主要关键条件为:T4DNA连接酶Buffer浓度、单链DNA浓度、添加间隔时间、温度和Splint GC含量。以72nt的核酸链为例,使用逐步添加法将单链环状DNA的制备得率提高至99%,产量与常用的一步法相比提高至4.9倍。本研究为高效、大量制备单链环状DNA提供了指导,为以单链环状DNA为基础的研究奠定了基础。 相似文献
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Organizing accountability: co-production of technoscientific and social worlds in a nanoscience laboratory 总被引：1，自引：0，他引：1
Robert Doubleday 《Area》2007,39(2):166-175
Nanotechnology exemplifies the intensification of policy concerns both with relations between science and innovation, and with the public authority of scientific knowledge. This paper focuses on the negotiation of accountability by a nanoscience laboratory both to the state for public funds and to wider society for the social aspects of nanotechnology. This paper argues that geographical approaches can address questions of accountability by paying attention to the laboratory as a site for the co-production of scientific, technological and social orders. In particular, this paper focuses on how concepts of innovation and citizenship are configured through particular moments of laboratory accounting. 相似文献
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Colloform pyrite is a special form of nano-micro polycrystalline aggregation growth, for which a suitable term is "aggregates of nano-micro crystals". This kind of colloform texture is observed in various geological bodies, such as ancient sedimentary rocks, modern marine and lake sediments, various types of ore deposits, and modern seafloor hydrothermal vents. This paper summarizes the latest developments and research into the definition, formation mechanisms, and environmental indications of colloform pyrite. There appears to be three main formation mechanisms of colloform pyrite: pseudomorphic replacement; biogenic precipitation; and inorganic precipitation. The morphology, particle size, trace element content and preferential growth orientations of colloform pyrite microcrystals can be important indicators for sedimentary environments, hydrothermal activity, and ore-forming processes. We suggest that the microscopic features of nano-micro crystals in colloform pyrite and their aggregation growth patterns need further investigation. The relationships between formation mechanisms of colloform pyrite, organic activity and depositional environments require further exploration. To reveal the nature of nano-micro grain aggregation growth in colloform pyrite and analyse its growth environment and evolutionary history, it is supposed to apply nanoscientific and nanotechnological methods, further integrate consideration of macroscopic geological backgrounds and microscopic mineral growth phenomena, combine high-resolution imaging systems and in situ quantitative microanalysis methods and constitute a mergence of earth science, thermodynamics and kinetics, life science, material science, and chemistry in the study. 相似文献
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