6H-SiC single crystals were grown by sublimation method. It is found that foreign grains occur frequently on the facets of the crystals. To characterize the foreign grain, a longitudinal and a sectional cut samples we...6H-SiC single crystals were grown by sublimation method. It is found that foreign grains occur frequently on the facets of the crystals. To characterize the foreign grain, a longitudinal and a sectional cut samples were prepared by standard mechanical processing method. Raman spectrum confirms that the foreign grain is actually a mis-oriented 6H-SiC grain. The surface structure of the foreign grain was studied by chemical etching and optical microscopy. It is shown that etch pits in foreign grain region take the shape of isosceles triangle, which are different from those in mono-crystalline region, and high density stacking faults are observed on the surface of the foreign grain. The orientation of foreign grain surface is determined to be （10]-4） plane by back-scattering X-ray Laue image. The X-ray powder diffraction reveals that the powder is partly graphitized after a long crystal growth rim. Therefore it is believed that the loss of Si results in the formation of C inclusions, which is responsible for the nucleation of foreign grain in the facet region.展开更多
Farmer-managed irrigation systems(FMIS) in the high altitude valleys of the Karakorum,Pakistan, continue to be managed effectively despite increased pressure on the social arrangements that sustain them. Colonial era ...Farmer-managed irrigation systems(FMIS) in the high altitude valleys of the Karakorum,Pakistan, continue to be managed effectively despite increased pressure on the social arrangements that sustain them. Colonial era records shows that over a century ago government agencies undertook irrigation support projects. In the past three decades,government agencies and the non-government agency Aga Khan Rural Support Programme(AKRSP), which channels foreign funds into the region, have actively engaged in the provision of irrigation support. This article seeks to explore whether such projects support or undermine farmer-managed irrigation systems and the complex institutional arrangements that underpin them. Field research using ethnographic and participatory methods was conducted in spring 2013 in the upper Shigar valley, Skardu district, GilgitBaltistan. The findings show that irrigation development is a political activity that involves village-based actors, religious leaders, local politicians,and government and non-government agencies.Government agencies operate in a largely top-down,engineering mode, their larger projects limited to villages suffering water scarcity. The local government provides small funds for renovation work of FMIS,though allocation of funds is highly politicized. Nongovernment agencies, for a variety of reasons including donor-funding cycles, apply a one-size-fitsall ‘participatory' model in an attempt to socially engineer rules and institutions. In communities divided by factionalism the use of such external models that stress formation of committees are unlikely to yield positive results, and could instead contribute to undermining the very systems they seek to support. This research argues that irrigation interventions should take care to build upon the rich and complex social arrangements that have sustained FMIS through the centuries.展开更多
The public power and the private enterprise, the main agents of national economic and social development, when cooperating strategically, promote increased functional efficiency of their activities. In order to highli...The public power and the private enterprise, the main agents of national economic and social development, when cooperating strategically, promote increased functional efficiency of their activities. In order to highlight the relevance of such partnership, this article aims to analyze the potential of actions jointly developed by private organizations and Brazilian universities. The research problem is lined in the field of health, which hosted actions developed between the Federal University of Rio Grande do Norte （UFRN） and the Hospital Maternity Guiomar Fernandes （HMGF）, located in the city of Alexandria, in Rio Grande do Norte. The study emphasizes the shortcomings of this organization, the resolving power of the university in this scenario, and performs the analysis of the effects of this cooperation. The methodology used in this research was the case study in HMGF. With emphasis on fundraising and improving the informational management system, funding sources for projects of restructuring and expansion of the hospital were sought, as well as initiatives for developing hospital management softwares for small- and medium-sized organizations. As a result, the articulation between the university and the hospital provided the elaboration of a project for software development and the production of a project for physical restructuring and technological investment, aiming to expand the supply and quality of the hospital＇s services. The implementation of information systems, associated with investments in hospital infrastructure, providing increased efficiency in public assistance to the population, bringing both local and regional benefits, besides, providing the authorities with relevant data on the development of public policies.展开更多
基金Projects(2006AA03A145,2007AA03Z405) supported by the National High-Tech Research and Development Program of ChinaProjects(50721002,50802053) supported by the National Natural Science Foundation of ChinaProject (707039) supported by the Cultivation Fund of the Key Scientific and Technical Innovation Project,Ministry of Education of China
文摘6H-SiC single crystals were grown by sublimation method. It is found that foreign grains occur frequently on the facets of the crystals. To characterize the foreign grain, a longitudinal and a sectional cut samples were prepared by standard mechanical processing method. Raman spectrum confirms that the foreign grain is actually a mis-oriented 6H-SiC grain. The surface structure of the foreign grain was studied by chemical etching and optical microscopy. It is shown that etch pits in foreign grain region take the shape of isosceles triangle, which are different from those in mono-crystalline region, and high density stacking faults are observed on the surface of the foreign grain. The orientation of foreign grain surface is determined to be （10]-4） plane by back-scattering X-ray Laue image. The X-ray powder diffraction reveals that the powder is partly graphitized after a long crystal growth rim. Therefore it is believed that the loss of Si results in the formation of C inclusions, which is responsible for the nucleation of foreign grain in the facet region.
基金funded by the Federal Ministry of Education and Research (BMBF), Germany
文摘Farmer-managed irrigation systems(FMIS) in the high altitude valleys of the Karakorum,Pakistan, continue to be managed effectively despite increased pressure on the social arrangements that sustain them. Colonial era records shows that over a century ago government agencies undertook irrigation support projects. In the past three decades,government agencies and the non-government agency Aga Khan Rural Support Programme(AKRSP), which channels foreign funds into the region, have actively engaged in the provision of irrigation support. This article seeks to explore whether such projects support or undermine farmer-managed irrigation systems and the complex institutional arrangements that underpin them. Field research using ethnographic and participatory methods was conducted in spring 2013 in the upper Shigar valley, Skardu district, GilgitBaltistan. The findings show that irrigation development is a political activity that involves village-based actors, religious leaders, local politicians,and government and non-government agencies.Government agencies operate in a largely top-down,engineering mode, their larger projects limited to villages suffering water scarcity. The local government provides small funds for renovation work of FMIS,though allocation of funds is highly politicized. Nongovernment agencies, for a variety of reasons including donor-funding cycles, apply a one-size-fitsall ‘participatory' model in an attempt to socially engineer rules and institutions. In communities divided by factionalism the use of such external models that stress formation of committees are unlikely to yield positive results, and could instead contribute to undermining the very systems they seek to support. This research argues that irrigation interventions should take care to build upon the rich and complex social arrangements that have sustained FMIS through the centuries.
文摘The public power and the private enterprise, the main agents of national economic and social development, when cooperating strategically, promote increased functional efficiency of their activities. In order to highlight the relevance of such partnership, this article aims to analyze the potential of actions jointly developed by private organizations and Brazilian universities. The research problem is lined in the field of health, which hosted actions developed between the Federal University of Rio Grande do Norte （UFRN） and the Hospital Maternity Guiomar Fernandes （HMGF）, located in the city of Alexandria, in Rio Grande do Norte. The study emphasizes the shortcomings of this organization, the resolving power of the university in this scenario, and performs the analysis of the effects of this cooperation. The methodology used in this research was the case study in HMGF. With emphasis on fundraising and improving the informational management system, funding sources for projects of restructuring and expansion of the hospital were sought, as well as initiatives for developing hospital management softwares for small- and medium-sized organizations. As a result, the articulation between the university and the hospital provided the elaboration of a project for software development and the production of a project for physical restructuring and technological investment, aiming to expand the supply and quality of the hospital＇s services. The implementation of information systems, associated with investments in hospital infrastructure, providing increased efficiency in public assistance to the population, bringing both local and regional benefits, besides, providing the authorities with relevant data on the development of public policies.
