OALib Journal期刊

ISSN: 2333-9721




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匹配条件: “Araújo” ,找到相关结果约24431条。
Idempotent Generated Endomorphisms of an Independence Algebra
Jo?o Araújo
Mathematics , 2011, DOI: 10.1007/s00233-002-0020-6
Abstract: The aim of this note is to give a direct proof for the following result proved by Fountain and Lewin: {\em Let $\alg$ be an independence algebra of finite rank and let $a$ be a singular endomorphism of $\alg $. Then $a=e_1... e_n$ where $e^2_i=e_i$ and $rank(a)=rank(e_i)$.}
On idempotent generated semigroups
Jo?o Araújo
Mathematics , 2011, DOI: 10.1007/s002330010089
Abstract: We provide short and direct proofs for some classical theorems proved by Howie, Levi and McFadden concerning idempotent generated semigroups of transformations on a finite set.
A Theoretical Study of Binary and Ternary Hydride-Bonded Complexes N(Beh2)...X with N = 1 or 2 and X = K+ or Ca+2  [PDF]
Regiane Araújo, Boaz Galdino de Oliveira
Open Journal of Physical Chemistry (OJPC) , 2011, DOI: 10.4236/ojpc.2011.13018
Abstract: A theoretical study of hydride bonds formed between beryllium hydride and alkaline earth metal cations is presented. B3LYP/6-311++G(d,p) calculations were used for determining the optimized geometries of the BeH2...K+, BeH2...Ca+2, BeH2...K+...BeH2, and BeH2...Ca+2...BeH2 hydride-bonded complexes, where among them the first are binaries, whereas the last ones are ternaries with the calcium (Ca+2) and potassium (K+) ions mediating the interactions with the beryllium hydride (BeH2). A detailed structural analysis were performed, by which the yielded profiles are in good agreement with results of the infrared vibrational spectrum, mainly in regards to the existence of red-shifted modes followed by enlarged absorption intensity ratios of the B-H bonds of the binary complexes. The capability of either donating or accepting of protons among BeH2, K+, and Ca+2, is currently treated in conformity with Lewis’s acid/base theory, but is also interpreted through the application of the Quantum Theory of Atoms in Molecules (QTAIM), whose formalism consents in the molecular modeling of concentrations and depletions of charge density ruled by the Laplacian shapes, charge transference fluxes, as well as by the local virial theorem of the electronic density with quantification of the kinetic and potential energies along the bonds and interactions.
Phase Transformations in PZT Thin Films Prepared by Polymeric Chemical Method  [PDF]
Elton C. Lima, Eudes Borges Araújo
Advances in Materials Physics and Chemistry (AMPC) , 2012, DOI: 10.4236/ampc.2012.23027
Abstract: Lead zirconate titanate Pb(Zr0.50Ti0.50)O3 (PZT) thin films were deposited by a polymeric chemical method on Pt(111)/ Ti/SiO2/Si substrates to understand the mechanisms of phase transformations in these films. PZT films pyrolyzed at temperatures higher than 350℃ present a coexistence of pyrochlore and perovskite phases, while only perovskite phase is present in films pyrolyzed at temperatures lower than 300℃. For films where the pyrochlore and perovskite phase coexists the amount of pyrochlore phase decreases from top surface to the bottom film-electrode interface and the PZT structure near top surface are Ti-rich compositions while near the bottom film-electrode interface the compositions are Zr-rich. For pyrochlore-free PZT thin film, a small (100) orientation tendency near the film-electrode interface was observed.
The cross-correlation between output and nominal variables in new keynesian models calibrated to Brazil and the U.S.
Araújo, Eurilton;
Economia Aplicada , 2011, DOI: 10.1590/S1413-80502011000400001
Abstract: this paper investigates if the interaction between habit formation and a forward-looking taylor rule can mimic the observed dynamic correlations between output and nominal variables (inflation and interest rates) in brazil and in the u.s. i carry out the analysis in a new keynesian model under sticky price or sticky information. the empirical cross-correlation pattern, obtained from the data, for brazil is different from the u.s. pattern. for both countries, the models that i considered cannot replicate with a fair amount of accuracy the dynamic correlations between output and nominal variables, though sticky price models and sticky information models imply different propagation mechanisms for macroeconomic shocks.
Qualifica??o e reestrutura??o das rela??es industriais: uma nova moeda-de-troca?
Castro, Nadya Araújo;
Educa??o & Sociedade , 1997, DOI: 10.1590/S0101-73301997000400003
Abstract: this article deals with the rol of managerial policies on training and skills in contexts of instable institutional conditions (like market overture, new state regulations related to privatization processes, and changing patterns in industrial relations). i argue that, under these conditions, consent negotiation relies upon manipulation of institutional resources for negotiating qualification policies toward the core labor force. empiral analysis takes into account the experience of market deregulation, privatization and restructuring of industrial relations in brazilian petrochemical industry.
Escola, democracia e a constru??o de personalidades morais
Araújo, Ulisses F.;
Educa??o e Pesquisa , 2000, DOI: 10.1590/S1517-97022000000200007
Abstract: this article intends to discuss the relationship between morality, democracy and education within the perspective of the complex thinking, pointing to paths and proposals for its effective implementation in the educational routine, under the conviction that this is an imperative of the new social demands presented to the contemporary schooling. understanding that one of the purposes of education is the ethical development, the author proposes intentional actions such that through them the school practices can offer to the subjects of education the necessary tools to build their cognitive, affective, cultural, and organic competence, thereby enabling them to act morally in the world. to that effect, seven aspects of school reality that hamper or contribute to school democratization are identified and discussed, which must be understood from the paradigm of complexity: school contents, classroom methodology, the nature of interpersonal relationships, the values, self-esteem and self-knowledge of the school community, as well as the school management processes.
As marcas da violência na constitui??o da identidade de jovens da periferia
Araújo, Carla;
Educa??o e Pesquisa , 2001, DOI: 10.1590/S1517-97022001000100010
Abstract: this work deals with the school experiences of young pupils living in vila da luz - a neighborhood on the outskirts of belo horizonte, brazil - whose daily life is characterized by violence, public insecurity, and social exclusion. the exploratory study examined how experiences outside school, particularly in vila da luz, infringe on their daily lives and reorient pupil?s attitudes and behaviors among themselves and towards teachers and other school workers. the school environment was sociologically characterized as a space of complex interactions, in which symbolic violence and physical aggression intersect, giving rise to a school experience based on fear and anxiety. the experiences and social representations of young pupils were emphasized with a view to understand how they build their identities when their group and interpersonal relations take place against a background of violence. thus, the investigation offered possibilities to think the school as a space for the mediation of conflicts and the coexistence of social and cultural diversity. centered on a participative research methodology with emphasis on the interpretative model, this study permitted developing issues concerning education and subjectivity under the optics of some important theorists such as anthony giddens, norbert elias, and erik erikson.
A história da maconha no Brasil
Carlini, Elisaldo Araújo;
Jornal Brasileiro de Psiquiatria , 2006, DOI: 10.1590/S0047-20852006000400008
Abstract: the present study describes of history of cannabis sativa l. (marihuana) since the arrival in brazil in the portuguese discovers, in 1500. during the following centuries cannabis cultivation was stimulated by the portuguese crown, which included sending seeds to brazil; the medicinal use of cannabis was also common, mostly during the second part of 19th century, being the cigarros índios (cannabis cigarettes) imported from france, and advertised in brazilian medical journals up to the first years of the 20th century. the repression against cannabis use reached proportion only in the 20th century. this probably happened because the brazilian representatives at the ii international conference on opium and coca/cocaine flatly declared that in brazil cannabis was "more dangerous than opium". the condemnation of cannabis in that conference was seemingly extended up to the 1961 single convention of narcotic drugs, united nations, in which cannabis was considered a "particularly dangerous drug" and as such was included together with heroine in the schedule iv of that convention. possibly, as a consequence the repression started seriously in the beginning of the 1930 decade; and according to the brazilian law 6.368/1976, the recreational and medical uses of cannabis products are prohibited. such uses are criminal offenses and as such the users may face prison penalties. however a new law is under discussion in the brazilian congress. according to it the possession of a certain quantity of marihuana (and other drugs) is no longer a criminal offense and will be subject to administrative sanctions.
Raz?o e emo??o: uma leitura analítico-comportamental de avan?os recentes nas neurociências
Darwich, Rosangela Araújo;
Estudos de Psicologia (Natal) , 2005, DOI: 10.1590/S1413-294X2005000200008
Abstract: recent findings of the neurosciences present an integrated view of the human functioning, one that encompasses the relationships among the great organic systems, between physiological and cognitive states and between reason and emotion. the aim of this paper is to contrast such studies with central aspects of the skinnerian explanatory system, highlighting the role of relations between respondent and operant processes for an understanding of the interdependence between reason and emotion. the importance of emotional responses and verbal behavior for rational responding and, moreover, for the selection of verbal and non-verbal behavioral repertoire, is discussed. it is argued that the current movement in the neurosciences towards overcoming dualistic views of the human being is compatible with the behavior-analytic approach to overt and covert responses in the context of individual-environment relations.

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