间同1,2-聚丁二烯的结构和结晶动力学研究

间同1,2-聚丁二烯(s-PB)由丁二烯用Fe(2-EHA)3/Al(i-Bu)3/DEP作催化剂,在己烷溶剂中50℃下聚合制备.用13C NMR谱方法测定的1,2-结构含量为89.3%,间同结构为86.5%;X射线测得聚合物的结晶度约为68%.非等温结晶动力学研究采用DSC方法,改进的Avrami方程可以很好地分析s-PB非等温结晶过程的主期结晶,表明其结晶过程是自成核,三维球形生长.Ozawa方程不适合分析s-PB非等温结晶动力学;Avrami和Ozawa方程结合的方法可以很好地描述s-PB非等温结晶过程,指数a为1.138,F(θ)随着结晶度的提高而增大;并计算了s-PB的结晶活化能.

Effects of crystal growth conditions on morphology of crystalline syndiotactic 1,2-polybutadiene

The crystalline syndiotatic 1,2-polybutadiene was synthesized with a catalyst consisting of iron acetylacetonate (Fe(acac)(3))-triisobutylaluminum (Al(i-Bu)(3))-diethyl phosphite (DEP), and the effects of crystal growth conditions on morphology of thin films of the polymer were investigated by transmission electron microscopy (TEM) and electron diffraction (ED) techniques. The polymer with melting point 179 degreesC was found to have 89.3% 1,2-content and 86.5% syndiotacticity by C-13 NMR measurement. The results of electron microscopic studies indicate that the solution-cast thin films of the syndiotatic 1,2-polybutadiene consist of lath-like lamellae with the c-axis perpendicular to the film plane, while a- and b-axes are in the film plane. The morphology of isothermally crystallized thin films of the polymer is temperature dependent. At lower crystallization temperatures (130 degreesC), a spherulitic structure consisting of flat-on lamellae is formed. With an increase in the crystallization temperature (e.g., at 140 degreesC), the spherulites and single faceted crystals coexist. At higher crystallization temperatures (150 degreesC), single crystals with a hexagonal prismatic shape are produced.

间同立构1,2-聚丁二烯的合成和形态结构研究

间同立构1,2-聚丁二烯自1955年问世以来 ,引起人们的广泛关注 ,但绝大多数研究工作集中在聚合物的合成方面[1～3] ,对其形态结构方面的研究却很少报道[4] ,原因是该聚合物分子侧链含有大量双链 ,在较高温度下 (>150℃ )很容易产生热交联 ,这给结构研究造成了很大困难 .间同立构1,2-聚丁二烯的性能取决于间规度 ,低间规度聚合物呈现弹性体特征 ,而高间规度聚合物则是一种半结晶性塑料 ,其结晶为平面锯齿链正交堆砌 ,Pacm空间群[4] .本文采用一种新的催化体系 ,使合成的1,2-聚丁二烯间规度可以调控.同时首次报道了结晶性间规1,2-聚丁二烯稀溶液浇铸薄膜形成具有单晶取向的板条状片层结构,并应用电子显微学和电子衍射技术确定其晶体结构.1.实验部分1.1样品及试剂　乙酰基丙酮铁 [(Fe(acac) 3)纯度为 99.9% ],使用时配成0.2mol/ L的甲苯溶液 ;三异丁基铝 [Al(i-Bu) 3]由 Aldrich公司提供 ;氢化亚磷酸二乙酯 (DEP)及丁二烯由锦州化学公司提供 ;丁二烯通过蒸馏进行纯化 ;己烷使用前在 Na/ K合金...

(Des)encontros com a realidade: a trajectória profissional dos licenciados em ensino básico : 1º ciclo formados pelas instituições de ensino superior público do Alentejo entre os anos de 2001 e 2003

A problemática que constitui o ponto de partida do presente estudo evidencia a importância de se conhecer e compreender a forma como se processa a inserção profissional dos recém-diplomados em Ensino Básico - 1º Ciclo. De entre distintas ópticas possíveis, considerou-se importante assumir, como elemento estratégico deste processo, e na linha do pensamento de M. Alves (2001), o entendimento de que o processo de inserção profissional assume um carácter dinâmico, que envolve três actores fundamentais: os diplomados, os empregadores e os estabelecimentos de ensino superior. É tendo como base de trabalho esta perspectiva (conceito de inserção profissional articulado com o paradigma da aprendizagem ao longo da vida) que se edifica o presente estudo, estruturando-se em quatro partes. A primeira delas visa, embora não de forma exclusiva, a explanação dos principais referenciais teóricos relativos à temática em questão; a segunda parte explicita as opções metodológicas adoptadas; a terceira debruça-se sobre a análise e interpretação dos resultados e a quarta remete para algumas conclusões que emergiram de todo o processo de investigação empreendido. Procurando desenvolver-se uma investigação descritiva assente numa metodologia integrada e complementar com abordagens qualitativas e quantitativas, a recolha de dados incide num questionário e numa entrevista, tendo-se sempre em consideração os objectivos subjacentes ao estudo e optando-se, para tal, como sujeitos, pelos licenciados em Ensino Básico - 1.° Ciclo que realizaram a sua formação nas instituições formadoras do Alentejo (Escolas Superiores de Beja e Portalegre e Universidade de Évora), no período compreendido entre 2001 e 2003. As trajectórias profissionais destes licenciados ficam marcadas por sentimentos de ilusão, incerteza e indignação, mas também por um forte sentimento de frustração. Não foi pacífico, para muitos deles, aceitar que a realização do curso não lhes conferiu o acesso ao emprego esperado. A sua maioria encontrava-se integrada em sectores profissionais que não estavam directamente relacionados com o curso ou, então, permaneciam desempregados. A esperança de virem a exercer a profissão docente parecia ser cada vez mais ténue. /***Abstract - The problem that constitutes the start of the present study emphasizes the importance of knowing and understanding the way it proceeds the professional insertion of the new graduates of the Ensino Básico — V Ciclo (primary school).Between several visions, it has been important, as a strategic element of this process and following the line of M. Alves (2001), the understanding that the professional insertion assumes a dynamic character, that envolves three fundamental elements: the graduates, the employers and. the universities. This study, structured in four parts, is based in the concept that links profession insertion with life long learning. The purpose of the first part is to expose, not in an exclusive way, the several theories connected with the theme in question the second part explains the methodology used; the third consists of the analysis and interpretation of the results and the fourth and. last one, exposes some conclusions that carne out of the investigation process. It has been tried in this study to develop a descriptive investigation, based on an integrated and complementary methodology that includes a qualitative and quantitative analysis. Therefore, the gathering of data is based on a questionnaire and an interview. Always considering the underlying objectives of the study, we have chosen, as subjects, the graduates in Ensino Básico - 1º Ciclo that performed their formation in the institutes of Alentejo (Escola Superior de Educação de Beja, Escola Superior de Educação de Portalegre e Universidade de Évora), in the period between 2001 and. 2003. The professional trajectory of these graduates is full of uncertainty, indignation and also full of strong feelings of frustration. It was not easy for many of them to accept that the course they have completed doesn't open the doors for the job they've dreamed of and expected. The majority was integrated in professional areas not directly connected with their course or then remained unemployed. The hope of becoming teachers was turning more and more tenuous.

Escola e diversidade cultural dos alunos: Um estudo no 1º ciclo do ensino básico

Portugal não foi exceção à globalização do mundo e hoje é procurado por povos de toda a parte. A diferença cultural destes povos/minorias reflete-se nas escolas a partir do 1.° Ciclo do Ensino Básico (CEB). No enquadramento teórico de vários autores sobre educação inter/ multicultural para as minorias, abordámos questões sobre a "Sociedade Inter/ Multicultural, Escola Multicultural”, a "Educação Multicultural", e a "Autonomia da escola e gestão do Currículo”. Focalizámos o estudo na "Escola e Minorias étnicas”, na relação da escola com, "estereótipos, preconceitos e atitudes” na sua inter ação com a comunidade e estudámos o caso concreto da escola e a etnia cigana. No estudo empírico, através de um questionário, recolhemos a opinião dos docentes de seis concelhos do distrito de Évora de Escolas do 1.° CEB, sobre as ”Práticas Educativas Desejáveis" e “Existentes” nas escolas em relação a estes alunos. Os resultados obtidos levam-nos a concluir que as práticas educativas existentes não respeitam totalmente a cultura dos alunos de minorias/ciganos mas que existe uma sensibilização para práticas educativas que transformem a escola numa escola multicultural. /ABSTRACT - School and Student's Cultural Diversity Portugal was not exception to the world's globalization and today is looked by peoples (ethnic minorities) of all different places. The cultural difference of these peoples/minorities reflects in the schools since 1.st degree (1. ° Ciclo do Ensino Básico). In the theoretical part of several authors on inter/multicultural education for the minorities, we approached questions on the "Inter/Multicultural Society,” Multicultural School", "School and multicultural education", the "School’s autonomy, curriculum management and multicultural education". We focused the study on the "gypsies" (ethnic minority) approaching questions of´Minority ethnic and school” and "School, Preconceptions and Stereotypes". In the empirical study, through a questionnaire, we collected the opinion of the professors of 1.st degree, from six councils (concelhos) of Évora's district, on "Desirable Educative Practice" and "the Existing ones" in the schools in relation to these pupils. The gotten results take us to conclude that the existing educative practice do not totally respect the culture of the pupils of minorities/gypsies but that exists a sensibilization for educative practice that transform the school into a multicultural school.

Avaliar o impacto das novas medidas de política educativa para o 1º ciclo do ensino básico e educação de adultos na oferta local dos ambientes de aprendizagem (Anos lectivos de 2004-2005 e 2006-2007) : o caso do Concelho de Gavião

Tendo como principal fio condutor a pergunta de partida (Qual o impacto das novas medidas de política educativa para o 1° Ciclo do Ensino Básico e Educação de Adultos na oferta local dos ambientes de aprendizagem?) procuramos encontrar uma resposta para a problemática na qual se centra esta investigação. A partir desta questão inicial delineámos o corpo da dissertação em duas partes: a primeira referente ao enquadramento teórico e a segunda respeitante ao estudo empírico. No âmbito do enquadramento teórico, procedemos a uma reflexão cruzada entre educação e território, no sentido de perceber as suas potenciais (inter) ligações, bem como à análise de alguns dos normativos que dão suporte legal a esta problemática, finalizando com a apresentação do campo de estudo. Ao nível do estudo empírico, seguimos uma metodologia partilhada (qualitativa quantitativa), apoiada essencialmente numa aproximação conceptual ao estudo de caso. Os dados recolhidos, por melo de inquérito por questionários aplicados, permitiram-nos conceber várias leituras do território: Cartografia Institucional do Concelho de Gavião e Cartografia Educacional do Concelho de Gavião referente aos anos Ietivos de 2004-2005 e 2006-2007, respetivamente, dado o estuda ter decorrido ao Iongo de um período de três anos Ietivos. Da análise dos dados disponíveis, centramos as nossas conclusões em, pelo menos, duas dimensões totalmente opostas. Por um lado, o novo paradigma de “escola a tempo inteiro” assume, atualmente, neste território um papel preponderante, devolvendo aos ambientes formais de educação uma clara liderança no que concerne à quantidade e diversidade de aprendizagens desenvolvidas; por outro, assistimos a um claro abandono das aprendizagens realizadas em espaços não formais, as quais eram dirigidas quase exclusivamente às faixas etárias mais avançadas, que agora vêm as várias possibilidades de aprender, o que quer que seja, como uma oportunidade cada vez mais distante. Face à problemática em estudo, a nossa dissertação termina com a formulação das sugestões e recomendações que nos parecem mais oportunas. /ABSTRACT - The main question of this work is: "Which is the impact of new rules of education politics and rules, in first level (6-10years old) and adult education, in local offers into learning contexts?” we look for an answer to this problematic which is the matter of our research. Throughout this question, this essay was divided into two parts: the first one refers the theoretic frame, and the second one is about the empiric study. On the theoretic frame, we made a profound consideration between education and district, in order to understand its potentials (inter) connections, as well as the analysis of some normatives, which Iegally supports this problematic, ending with a presentation of the subject. On the empiric study, our approach is a mix methodology (qualitative and quantitative one) mainly supported on the concept of the “case study” Data collected by inquiry and questionnaire, allowed us to realize several knowledge of the municipality: Institutional Cartography of Gavião's Municipality and Educational Cartography of Gavião's Municipality, it refers to the academic years 2004-2005 and 2006-2007, because the study was done during those two years. From data analyses, we centered our conclusions into, at least, two opposite ways. On one hand, a new paradigm of “full time school” (from 9:00am to 5:30pm) claims, actually, in this municipality an important rule, it restores in the formal educational environment a great control, concerning the quantity and diversity of developed learning, on the other hand, we saw a destitution of developed learning on no formal environment, which were almost exclusively direct to the elder one, now this population felt learning possibilities rather far away. Our essay ends with some suggestions and recommendations which seams to us proper into this context.

Escola e diversidade: os desafios da diversidade cultural na gestão do currículo : alunos imigrantes nas escolas do 1º ciclo do ensino básico de Abrantes: um estudo de caso

Partindo do objeto de estudo: a gestão do currículo para a diversidade cultural é nossa intenção compreender a forma como o discurso do multiculturalismo se encontra presente nos principais documentos definidores de uma política de escola e na postura desta e dos professores, através das decisões e práticas adotadas perante uma realidade diversificada, na presença de culturas de imigrantes. A construção do saber e a análise que fazemos da forma como o currículo é gerido, seguiram um percurso assente num quadro teórico nos campos curricular e da educação intercultural, bem como nas opções metodológicas em que o estudo assenta, e às quais recorremos para a realização da componente empírica. Nesta, analisamos a forma como as escolas-alvo de estudo e os professores respondem à presença dos alunos imigrantes através das representações dos próprios alunos, seus professores e responsáveis pelas escolas; ou seja, analisamos a forma como é gerido o currículo para a diversidade cultural. /ABSTRACT - Taking the subject under study: curricular management for cultural diversity, as our starting point, our aim is to gain an understanding of the nature of multiculturalism as portrayed in the main documents that define school policy as well as in the position taken both by the school and the teachers, in the light of the decisions and practices adopted in the presence of a culturally diverse reality, immigrant cultures. The construction of a body of knowledge and the assessment we make of how the curriculum is managed, has been based on a theoretical framework in the areas of intercultural curricula and education, as well as on the choice of methodology for the study used in carrying out the empirical component In the latter, We have analysed the way in which the schools and the teachers under study responded to the presence of immigrant pupils, seen in the descriptions given by the pupils themselves, their teachers and those responsible for the schools, that is to say, we have analysed the way in which the curriculum for cultural diversity has been managed.

Contribuiçã ao estudo de caracterizaçã de depó formados no papel

Deposits formed on the surface of. paper were analysed in order to identify the sources of the defects, as well as to solve the problems associated with performance and adjustments at the wet end of the paper forming process. Standard paper samples containing deposits were collected and analysed by comparing the microstructure and composition of the deposit with paper regions adjacent to it. Optical microscopy (OM). energy dispersive X-ray microanalysis (EDX) X-ray powder diffraction (XRD). thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) were the techniques used in this study. The results obtained from the EDX, XRD. and TG techniques allowed concluding that the calcium carbonate content in the farm of calcite is 1.6 times higher in the formed deposit them the quantity expected in the standard paper composition. The paper sample microstructure revealed by the SEM images indicates the presence of irregular spherical aggregates up to 20μm in diameter in the deposit region. containing larger amount of calcium carbonate as well as in the regions adjacent to the deposit. These spherical aggregates seem to be absorbed and integrated into the pulp fibres and present characteristics similar to those of partially cooked cationic starch. The analysed deposits are characterised by a dense and thick substance, forming a plate with highly adhesive property. This adhesive substance has a characteristic similar to glue with a large amount of organic matter due to the high weight loss shown by the TG curve. The results are consistent with the interaction ofparticles of negatively charged calcium carbonate and cationic starch, forming sterically stabilized deposits, which firmly adhere to the paper microstructure.

Dielectrophoresis (dep) and electrowetting (ewod) as an anti-fouling process for antibacterial surfaces

Nowadays the medical field is struggling to decrease bacteria biofilm formation which leads to infection. Biomedical devices sterilization has not changed over a long period of time. This results in high costs for hospitals healthcare managements. The objective of this project is to investigate electric field effects and surface energy manipulation as solutions for preventing bacteria biofilm for future devices. Based on electrokinectic environments 2 different methods were tested: feasibility of electric gradient through mediums (DEP) reinforced by numerical simulations; and EWOD by the fabrication of golden interdigitated electrodes on silicon glass substrates, standard ~480 nm Teflon (PTFE) layer and polymeric gasket to contain the bacteria medium. In the first experiment quantitative analysis was carried out to achieve forces required to reject bacteria without considering dielectric environment limitations as bacteria and medium frequency dependence. In the second experiment applied voltages was characterized by droplets contact angle measurements and put to the live bacteria tests. The project resulted on promising results for DEP application due to its wide range of frequency that can be used to make a “general” bacteria rejecting; but in terms of practicality, EWOD probably have higher potential for success but more experiments are needed to verify if can prevent biofilm adhesion besides the Teflon non-adhesive properties (including limitations as Teflon breakthrough, layer sensitivity) at incubation times larger than 24 hours.

DEP-derived density from two snow trenches from Kohnen Station, Dronning Maud Land, Antarctica from the 2012/13 field season

The density of firn is an important property for monitoring and modeling the ice sheet as well as to model the pore close-off and thus to interpret ice core-based greenhouse gas records. One feature, which is still in debate, is the potential existence of an annual cycle of firn density in low-accumulation regions. Several studies describe or assume seasonally successive density layers, horizontally evenly distributed, as seen in radar data. On the other hand, high-resolution density measurements on firn cores in Antarctica and Greenland showed no clear seasonal cycle in the top few meters. A major caveat of most existing snow-pit and firn-core based studies is that they represent one vertical profile from a laterally heterogeneous density field. To overcome this, we created an extensive dataset of horizontal and vertical density data at Kohnen Station, Dronning Maud Land on the East Antarctic Plateau. We drilled and analyzed three 90 m long firn cores as well as 160 one meter long vertical profiles from two elongated snow trenches to obtain a two dimensional view of the density variations. The analysis of the 45 m wide and 1 m deep density fields reveals a seasonal cycle in density. However, the seasonality is overprinted by strong stratigraphic noise, making it invisible when analyzing single firn cores. Our density dataset extends the view from the local ice-core perspective to a hundred meter scale and thus supports linking spatially integrating methods such as radar and seismic studies to ice and firn cores.