An interactive system to assist mineral identification in ore microscopy     

Tetsuya Shoji  Hiroaki Kaneda 《Mathematical Geology》1994,26(8):961-972

An interactive computer system has been developed to assist the mineral identification in ore microscopy. The reference file of the system consists of optical, mechanical, and chemical properties of about 130 ore minerals. The properties are name, chemical formula, color, bireflectance, anisotropism, internal reflection, reflectance at wavelengths of 470, 546, 589, and 650 nm, and polishing hardness and micro-indentation hardness. All the properties except reflectance and microindentation hardness are qualitative or semi-qualitative. Most of the properties are given as characters relative to the more common minerals. This implies that most of the identification processes advance on the basis of the comparison between a subject mineral and coexisting minerals. For this reason, the system asks a user at first to input already identified mineral names. This is quite different from the mineral identification procedures used in petrographic microscopy. To reduce the number of possible minerals, the system presents a series of questions to a user, and the user selects any of the prepared answers according to his observation. The user can also choose any desired question independently of the sequence. The user is expected to be able to recognize some common minerals, such as pyrite, chalcopyrite, galena, and hematite, without the assistance of the system.  相似文献   

泰国的地震活动及地震工作的现状     

郑斯华  叶洪 《国际地震动态》1995,(3):24-27

应泰国气象厅的邀请，固定地震局派遣了由郑斯华、叶洪组成的中国国家地震局专家组，于１９９４年８月１７日至９月４日访问考察了泰国。访问期间，泰国地震专家们向专家组介绍了泰国的地震活动性和地震工作现状；专家组访问了泰国Ｃｈｕｌａｌｏｎｇｋｏｒｎ大学的土木工程系，了解了泰国地震工程研究的情况。本文介绍了泰国的地震构造和地震活动性以及泰国的地震工作现状等。  相似文献   

Pastoralists’ perceptions and realities of vegetation change and browse consumption in the northern Kalahari, Namibia     

M. Katjiua  D. Ward   《Journal of Arid Environments》2007,69(4):716-730

Pastoral production around artificial watering points in semi-arid environments affects the density and composition of plant communities. In the Kalahari desert of southwestern Africa, bush encroachment is often regarded as the major form of land degradation resulting from pastoral production around watering points. We investigated the OvaHerero pastoralists’ perceptions of the extent of vegetation change since the establishment of artificial watering points in the northern Kalahari desert of Namibia, and related this to ecological data on vegetation change. We determined the utility of woody vegetation to pastoralists’ livelihoods in terms of provision of construction material, fuel wood and browse. We quantified local knowledge of cattle browse consumption and correlated this with field data. We also assessed the purposes for which major livestock types were used. Our results showed that: (1) pastoral knowledge of bush encroachment and browse consumption was consistent with concurrently collected field data, (2) the current level of bush encroachment was perceived to be beneficial for pastoral production, and (3) cattle played an important role in the production of milk and milk by-products for domestic use, and served as a source of cash income, while sheep and goats were primarily kept for meat consumption. This result contrasts with historical studies that mainly portray cattle as a symbol of social status among OvaHerero pastoralists.  相似文献   

Time, idealisation and international development: promoting Canadian co-management in northern Russia     

Elana Wilson 《Area》2007,39(3):323-330

In this article, I trace the efforts of a development team working to promote a Canadian approach to natural resources management in the Russian North. These development workers used two communication strategies related to time and history to render Canadian knowledge mobile and applicable to a new location: (1) imagining today's Russian North as equivalent to the Canadian northern past and (2) reframing and idealising the Canadian past and present to make the governance export less discursively 'messy' for an outside audience. The relative failure of these communicative strategies points to the need for richer dialogue in efforts to move knowledge cross-culturally.  相似文献   

National and institutional productivity and collaboration in Antarctic science: an analysis of 25 years of journal publications (1980–2004)     

Prabir G. Dastidar 《Polar research》2007,26(2):175-180

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The role and value of local knowledge in Jamaican agriculture: adaptation and change in small-scale farming     

CLINTON BECKFORD  DAVID BARKER† 《The Geographical journal》2007,173(2):118-128

Local knowledge has played an active role in the lives of rural communities in virtually every part of the world. In Jamaica, traditional cropping systems based on local informal knowledge have been practiced since the days of slavery and play a vital role in meeting food security. Yet, some negative attitudes remain about the legitimacy and relevance of small-scale farmers' local and traditional knowledge. This paper discusses some conceptual and empirical issues related to the application of local knowledge among small-scale food farmers in central Jamaica. The paper argues that contextually speaking, local and traditional knowledge is valuable, adaptable and necessary in coping with risk and uncertainty in a changing world, while cautioning against a misguided notion of traditional knowledge as a panacea to all the ills of local agriculture.  相似文献   

Awkward geographies: Spatializing academic responsibility, encountering Sri Lanka     

Tariq Jazeel 《Singapore journal of tropical geography》2007,28(3):287-299

This paper responds to recent postcolonial geographical scholarship that sets forth transformative agendas in order to create more cosmopolitan theoretical projects within the discipline. For many geographers the challenges they face are located within not only their own disciplinary parameters, but also those of other specific research communities within which their work situates them. By bringing geography and area studies into productive conversation, this paper explores the tensions between negotiating one's academic voice, position and responsibility within geography as well as within a specific area studies community. More specifically, as a UK-based geographer I reflect on some of my own fairly unremarkable, yet extremely awkward, encounters during the course of scholarly praxis in Sri Lanka in order to raise questions over the spatialities of responsibility and political engagement in such academic praxis. I seek to theorize the chasms that open in such awkward encounters between notionally situated 'local' and 'foreign' scholars respectively and, in particular, develop ways of engaging and reorienting those chasms in ways that might enable the production of theoretically rich, yet richly contextualized postcolonial knowledges committed to the site of one's scholarly praxis – not just to the advancement of a more cosmopolitan theoretical project within geography.  相似文献   

论防震减灾科普宣传与培训教育工作     

孙国学  孙晶岩 《山西地震》2007,(4):34-36,39

文章从如何做好防震减灾科普知识的宣传与培训教育工作,提高群众在地震发生时的自救、互救能力和抢险救灾能力等方面进行了论述,并提出了相应的想法和建议。对切实提高社会公众防灾减灾的能力、普及防震减灾知识有一定的参考价值。  相似文献   

论空间数据挖掘和知识发现的理论与方法   总被引：114，自引：0，他引：114  

李德仁  王树良  李德毅  王新洲 《武汉大学学报(信息科学版)》2002,27(3):221-233

首先分析了空间数据挖掘和知识发现（SMDKD）的内涵和外延；然后分别研究了用于SDMKD的概率论，证据理论，空间统计学，规则归纳，聚类分析，空间分析，模糊集，云理论，粗集，神经网络，遗传算法，可视化，决策树，空间在线数据挖掘等理论和方法及其进展；最后展望了SDMKD的发展前景。  相似文献   

The Spatial Characteristics of a Line and Their Application to Line Simplification     

GUOQingsheng  ChristophBrandenberger 《地球空间信息科学学报》2002,5(1):62-67

This paper discusses the spatial knowledge related to a line,and the characteristic points of lines is detected.According to the requirements of line generalization,new algorithms for identifying characteristic line points are presented.These characteristic points are used to improve the algorithms of line generalization.An algorithm for identifying bends is shown.In this paper,improved algorithms based on those by Douglas-Peucker,Visvalingam and Whyatt are shown.In this test,the progressive process of line generalization is emphasized.  相似文献