1,721,218 research outputs found
Post-développementisme ou néolibéralisme à Taïwan ?
No full textCet article propose une réflexion approfondie, combinant théorie et politique, sur le rôle de l’État dans le développement, appliquée au cas particulier et complexe de Taïwan. Il analyse les formes singulières qu’a pu prendre le néolibéralisme à Taïwan, mais également les forces de résistance populaires qui lui font face.Hsiu-Mei Chung. Post-développementisme ou néolibéralisme à Taïwan ?. In: Recherches Internationales, n°86, 2009. L’Asie chez elle. pp. 101-123
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
The study on the physical properties of multiferroic RMnO3 (R=Ho, Er, Tm, Yb, Lu and Y)
No full text在固態反應合成下，稀土錳氧化物RMnO3 ( R = 稀土元素或釔 )依據R3+ 離子半徑的大小可形成二種晶體結構，分別為：（1）當R為半徑較大的La、Ce、Pr、Nd、Sm、Eu、Gd、Tb、Dy時，則會形成正方結構的RMnO3；（2）當R為半徑較小的Ho、Er、Tm、Yb、Lu、Y，則會形成六方結構的RMnO3。這個研究利用固態反應法備製了一系列六方結構的RMnO3（R = Ho、Er、Tm、Yb、Lu、Y）的樣品，藉由X光繞射儀斷定其結構，繼而測量其磁性、電性和比熱的特性，探討不同R3+離子對於整個化合物的物性影響。
研究發現，在磁性的數據中顯示，只有在YMnO3、YbMnO3和LuMnO3清楚出現了反鐵磁的轉變溫度，分別為73 K、87 K和83 K；而由比熱的量測發現，磁性轉變溫度清楚的反應在比熱的性質中，由比熱的轉變溫度可以歸納出，轉變溫度隨R的離子半徑變小而增高。在介電常數的量測中，發現在所有磁轉變溫度附近都出現不正常的轉折現象，證實磁和電性的強關聯性。综而言之，我們的這個研究提供了重要的實驗數據，有助於未來多磁體的理論發展。The rare earth manganites RMnO3 (R = rare earth element or Y) exhibit strong magnetic exchange interactions between the magnetic moments of the Mn3+ ions as well as some of the magnetic R3+. Depending on the size of rare earth ion, RMnO3 crystallizes into two different structures：（1） orthorhombic phase for R = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, or Dy which has a larger ionic radius compared with that of Ho；and （2）hexagonal phase for R = Ho, Er, Tm, Yb, Lu or Y which possesses a smaller ionic radius. In this work, we have prepared a series of hexagonal RMnO3 with R = Ho, Er, Tm, Yb, Lu and Y and employed the techniques of X-ray powder diffraction, magnetic susceptibility, heat capacity and dielectric permeability in order to systematically study their R-dependent structural, magnetic and electric properties.
In the data of magnetic susceptibility of these six samples, only YMnO3, YbMnO3 and LuMnO3 show antiferromagnetic transitions near 73 K, 87 K and 83 K respectively. However, the magnetic transition temperatures of all samples are clearly observed in the data of specific heat. It is found that the transition temperature increases with decreasing the radius of R-ion, which is attributed to the enhancement of exchange interaction between Mn3+-ions. In the data of temperature dependent dielectric permeability vs. temperature, anomalies appear near TN in all samples, implying a strong coupling between ferroelectric and magnetic orders in the hexagonal RMnO3 compounds. The results of this study provide important information for the future development of theoretical model for multiferroism.Contents
口試委員審定書 i
致謝 ii
Abstract (in Chinese) iii
Abstract (in English) iv
Contents v
List of figures vi
List of tables viii
Chapter 1. Introduction 1
Chapter 2. Experimental 5
2-1 Experiment flow chart 5
2-2 Sample preparation 6
2-3 Measurements 8
2-3-1 Structure analysis 8
2-3-2 Magnetic analysis 8
2-3-3 Specific heat analysis 8
2-3-4 Dielectric analysis 9
Chapter 3. Results and Discussion 10
3-1 Structures of hexagonal RMnO3 10
3-2 Magnetic properties of hexagonal RMnO3 10
3-3 Specific heat properties of hexagonal RMnO3 12
3-4 Dielectric properties of hexagonal RMnO3 14
Chapter 4. Conclusion 17
References 18
List of figures
Fig. 1-1 View of the ferroelectric phase from the perpendicular to the c axis, showing the layered nature of the hexagonal RMnO3. 19
Fig. 1-2 Schematic representation of the magnetic structure of YMnO3. 19
Fig. 2-1 X-ray diffraction machine Bruker D8. 20
Fig. 2-2 JEOL 6700 Scanning Electron Microscopy. 20
Fig. 2-3 Superconducting quantum interference device (SQUID) Quantum Design. 21
Fig. 2-4 PPMS (Quantum Design Model 6000). 21
Fig. 2-5 The set-up of thermal relation measurement. (a) view from the side; (b) view from the top. 22
Fig. 2-6 (a) LCR-Meter Agilent 4294A); (b) home-made probe. 22
Fig. 3-1 X-ray diffraction patterns of RMnO3 samples with R= Ho, Er, Tm, Yb, Lu and Y. 23
Fig. 3-2 Lattice parameter of RMnO3 as a function of the size of the rare earth (RE). 23
Fig. 3-3 Scanning electron micrographs of a sintered pellet of HoMnO3 taken at a magnification of 5.000 times. 24
Fig. 3-4 Scanning electron micrographs of a sintered pellet of ErMnO3 taken at a magnification of 2000 times. 24
Fig. 3-5 Scanning electron micrographs of a sintered pellet of TmMnO3 taken at a magnification of 5000 times. 25
Fig. 3-6 Scanning electron micrographs of a sintered pellet of YbMnO3 taken at a magnification of 5000 times. 25
Fig. 3-7 Scanning electron micrographs of a sintered pellet of LuMnO3 taken at a magnification of 5000 times. 26
Fig. 3-8 Scanning electron micrographs of a sintered pellet of YMnO3 taken at a magnification of 5000 times. 26
Fig. 3-9 Inverse susceptibility of HoMnO3 in the zero-field-
cooled and the field-cooled. 27
Fig. 3-10 Inverse susceptibility of ErMnO3 in the zero-field-
cooled and the field-cooled. 27
Fig. 3-11 Inverse susceptibility of TmMnO3 in the zero-field-
cooled and the field-cooled. 28
Fig. 3-12 Inverse susceptibility of YbMnO3 in the zero-field-
cooled and the field-cooled. 28
Fig. 3-13 Inverse susceptibility of LuMnO3 in the zero-field-
cooled and the field-cooled. 29
Fig. 3-14 Inverse susceptibility of YMnO3 in the zero-field-
cooled and the field-cooled. 29
Fig. 3-15 Magnetization isotherms of YMnO3. 30
Fig. 3-16 Magnetization isotherms of TmMnO3. 30
Fig. 3-17 Specific heat v.s. temperature of YMnO3 at zero magnetic field. The solid line is the lattice contribution. 31
Fig. 3-18 Specific heat v.s. temperature of HoMnO3 at zero magnetic field. The solid line is the lattice contribution. 31
Fig. 3-19 Specific heat v.s. temperature of ErMnO3 at zero magnetic field. The solid line is the lattice contribution. 32
Fig. 3-20 Specific heat v.s. temperature of TmMnO3 at zero magnetic field. The solid line is the lattice contribution. 32
Fig. 3-21 Specific heat v.s. temperature of YbMnO3 at zero magnetic field. The solid line is the lattice contribution. 33
Fig. 3-22 Specific heat v.s. temperature of LuMnO3 at zero magnetic field. The solid line is the lattice contribution. 33
Fig. 3-23 Excess specific heat of YMnO3 after subtraction of the lattice contribution. 34
Fig. 3-24 Excess specific heat of HoMnO3 after subtraction of the lattice contribution. 34
Fig. 3-25 Excess specific heat of ErMnO3 after subtraction of the lattice contribution. 35
Fig. 3-26 Excess specific heat of TmMnO3 after subtraction of the lattice contribution. 35
Fig. 3-27 Excess specific heat of YbMnO3 after subtraction of the lattice contribution. 36
Fig. 3-28 Excess specific heat of LuMnO3 after subtraction of the lattice contribution. 36
Fig. 3-29 Temperature dependence of the dielectric constant (ε) of YMnO3. 37
Fig. 3-30 Temperature dependence of the dielectric constant (ε) of HoMnO3. 37
Fig. 3-31 Temperature dependence of the dielectric constant (ε) of ErMnO3. 38
Fig. 3-32 Temperature dependence of the dielectric constant (ε) of TmMnO3. 38
Fig. 3-33 Temperature dependence of the dielectric constant (ε) of YbMnO3. 39
Fig. 3-34 Temperature dependence of the dielectric constant (ε) of LuMnO3. 39
Fig. 3-35 Frequency dependence of the dielectric constant of RMnO3 at room temperature. 40
Fig. 3-36 Frequency dependence of the tanδ of RMnO3 at room temperature. 40
List of table
Table 1. Lattice parameters and magnetic transition temperature in RMnO3. 4
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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