991 resultados para 537.1


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计算了GaN二维光子晶体的能带结构,并利用常规工艺在国内首次制备出了GaN基二维平板结构的光子晶体蓝光LED。经过器件测试表明,与没有制作光子晶体的器件相比,光子晶体使器件的有效出光效率达到了原来的1.5倍以上。另外,还对感应耦合等离子体刻蚀(ICP)的制备光子晶体LED的刻蚀工艺进行了分析。

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研究了光子晶体作为谐振腔端面反射镜的应用.利用有效折射率法和2D PWE以及2D FDTD方法结合对构成谐振腔的两个端面反射镜进行了设计,得到左端面反射镜的最佳光子晶体晶格周期数为11×11,而右端面反射镜的最佳光子晶体晶格周期数为3×11,这为实验工作提供了良好的理论依据.

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近年来硅基光电子材料和器件受到高度的重视.利用外延生长和键合技术成功研制出硅基应变赝衬底、GexSi1-x/Si量子阱、高密度锗量子点、硅基InGaAsP/Si异质结,这些进展为硅基光电子器件提供了坚实的材料基础.同CMOS工艺相结合,实现了硅量子点1.17 μm的受激发射,研制出硅基Raman激光器、1.55 μm混合型激光器、高灵敏度的Si/Ge探测器、谐振腔增强型的SiGe光电二极管、调制频率30 GHz的SOI CMOS光学调制器和16×16的SOI光开关阵列等.硅光电子学将在光通信、光计算等领域获得重要应用.本文综述了国内外硅基光电子材料和器件的进展、我们的研究结果和硅基光电子学的发展趋势.

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En este documento presentamos algunos de los resultados de un estudio que aporta evidencias de la capacidad de los alumnos de tercer grado para desarrollar pensamiento relacional y para comprender el significado del signo igual trabajando en un contexto de igualdades numéricas.

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Identificar y explicar las coordenadas básicas que troquelan la imagen que la mentalidad social española se forja durante el primer tercio del siglo XX, acerca de la infancia, la familia y la escuela. Comprobar posibles procesos de diferenciación y ruptura en relación a modelos mentales. Análisis e interpretación de los diferentes paradigmas mentales tomando como fuente textos literarios, y en concreto, novelas escritas entre los años 1900 y 1930. El resultado es una muestra que comprende 75 escritores, 200 obras y más de 20.000 páginas literarias. Aplicando una metodología semántico-estuctural (método de los campos léxicos), se procedió en la siguiente forma: A. Determinación de 'palabras-base'. B. Extracción de textos literarios relacionados con la palabra-base. C. Articulación de 'redes léxicas'. D. Construcción de los 'cuadros léxicos', como modelos articuladores de las redes o campos léxicos, y a partir de los cuales se efectuan las inferencias acerca de las líneas-eje de la mentalidad social en torno a los temas estudiados. Análisis de contenido. Metodología semántico-estructural. Método de los campos léxicos. En relación a los temas propuestos (infancia, familia y escuela) se constata: A. Dualidad de modelos mentales según clase social y ubicación geográfica. B. Fenómenos de homogeneidad y heterogeneidad en cada modelo mental. C. Procesos de identidad entre ambos modelos respecto a ciertas imágenes. D. Procesos de influencia entre ambos modelos. E. Ruptura de modelos mentales a partir de 1920. El trabajo de investigación pretende acercarse interdisciplinarmente a la interpretación de las coordenadas de mentalidad de una época y de una sociedad determinada en torno a cuestiones como la infancia, la familia y la escuela. La conexión entre una historia de la educación y una historia de las mentalidades resulta necesaria teóricamente y posible metodológicamente. La incardinación de ambas en el dominio más amplio de una historia socio-cultural, resulta asimismo evidente.

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Existe otro ejemplar con registro 75450 con edición de 1991

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El CD anexo contiene la convocatoria de 2007 en Andalucía más la legislación actual y la correspondiente a la secuenciación de contenidos 'logse', información sobre oposiciones procedente de la Comunidad Autónoma de Murcia y que complementa a la anterior, y ejemplo-tipo de una programación didáctica

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Cooperation is the fundamental underpinning of multi-agent systems, allowing agents to interact to achieve their goals. Where agents are self-interested, or potentially unreliable, there must be appropriate mechanisms to cope with the uncertainty that arises. In particular, agents must manage the risk associated with interacting with others who have different objectives, or who may fail to fulfil their commitments. Previous work has utilised the notions of motivation and trust in engendering successful cooperation between self-interested agents. Motivations provide a means for representing and reasoning about agents' overall objectives, and trust offers a mechanism for modelling and reasoning about reliability, honesty, veracity and so forth. This paper extends that work to address some of its limitations. In particular, we introduce the concept of a clan: a group of agents who trust each other and have similar objectives. Clan members treat each other favourably when making private decisions about cooperation, in order to gain mutual benefit. We describe mechanisms for agents to form, maintain, and dissolve clans in accordance with their self-interested nature, along with giving details of how clan membership influences individual decision making. Finally, through some simulation experiments we illustrate the effectiveness of clan formation in addressing some of the inherent problems with cooperation among self-interested agents.

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One of the most important problems in the elderly is a nutritional deficiency. Several physiological changes and the use of multiple drugs interfere with appetite, food intake and absorption of nutrients, which can lead to the risk and malnutrition in the elderly, especially among institutionalized. The present study aimed to evaluate the prevalence of malnutrition and risk for malnutrition and its associated factors in institutionalized elderly. The same can be characterized by the type individual, observational and cross-sectional. Obtaining the sample was through the records of individuals of long-stay institutions for the elderly in the city of Natal, RN. The elderly were evaluated through the Mini Nutritional Assessment (MNA) and triceps skinfold (TSF) and each senior or caregiver answered a questionnaire about information like type and dietary restrictions, accessibility to food, use of alcohol and tobacco, practice physical activity and appetite. Variables such as age, gender, education, marital status, time that the elderly living in the institution, the reason for the institutionalization and comorbidities were taken from the records of each senior. The frequency of food consumption of various food groups was assessed from the questionnaire frequency of feeding study Health, Wellbeing and Aging (HWA). Data were presented as means and standard deviations, absolute and relative frequencies. To analyze the frequency of consumption, there was a factor analysis with extraction of factors from the principal components analysis with varimax rotation. A bivariate analysis was performed using the chi-square and the magnitude of the effect observed by prevalence ratio (95% CI). The Poisson regression assessed the net effect of independent variables on the two outcomes, considering a significance level of 5%. We studied twelve Homes for the Aged totaling 381 seniors eligible for the study. The prevalence of risk of malnutrition was 46.1% (45.9 to 46.2) and malnutrition was 31.4% (31.2 to 31.5). The risk of malnutrition was significantly associated with the presence of urinary incontinence (RP = 1.444, 1.113 to 1.874) was associated with malnutrition and lack of appetite (RP = 1.757, 1.246 to 2.476), the fact that the individuals do not have access to food outside the institution (RP = 0.565, 0.337 to 0.946), low water consumption (RP = 1.646, 1.101 to 2.459) and dementia (PR = 1.537, 1.072 to 2.204). The high prevalence of malnutrition and risk of malnutrition in the study suggests that we should pay attention to information related to eating habits and the presence of comorbidities, as these can influence the nutritional status of this population

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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IL TESTO SVILUPPA IL RAPPORTO TRA ANTROLOGIA CULTURALE E TURISMO, IN PARTICOLARE LA FORMAZIONE DI OPERATORI TURISTICI IN CAMBOGIA.