1,720,957 research outputs found
Organic ionic electro-optic crystals grown by specific interactions on templates for THz wave photonics
No full textWe demonstrate the growth of organic ionic electro-optic crystals with an optimal morphology (large area and suitable thickness) for efficient THz-wave photonics. The nucleation is induced by local supersaturation on a template and nucleates grow following the surface of the template based on secondary bonds
Bawool Yoo
No full text학위논문(석사)--아주대학교 일반대학원 :분자과학기술학과,2015. 2Ι. Introduction 1
II. Experiments 6
II.1 Chemical Structure 6
II.2 Synthesis 8
II.2.1 Materials 8
II.2.2 Scheme of HMQ-VBS Synthesis 8
II.2.3 Scheme of OHQ-VBS Synthesis 9
II.3 General Characterization 10
II.3.1 1H NMR Analysis 10
II.3.1.1 1H NMR Analysis of intermediates 10
II.3.1.2 1H NMR Analysis of HMQ-VBS and OHQ-VBS 11
III. Results and Discussion 15
III.1 Design and Synthesis 15
III.2 Thermal Analysis 17
III.3 Second Harmonic Generation (SHG) Test 20
III.4 Crystal Growth and Structure 22
IV. Conclusions 34
V. References 35MasterDerivatives of highly nonlinear optical ionic salt organic crystal HMQ-T (2-(4-hydroxy-3-methoxystyryl)-1-methylquinolinium 4-methylbenzenesulfonate) with 2-(4-hydroxy-3-methoxystyryl)-1-methylquinolinium 4-vinylbenzenesulfonate (HMQ-VBS) replacing the 4-methylbenzenesulfonate of HMQ-T have been synthesized and characterized. In addition we synthesized and characterized derivatives of another highly nonlinear optical ionic salt organic crystal OHQ-T (2-(4-hydroxystyryl)-1-methylquinolinium 4-methylbenzenesulfonate) with 2-(4-hydroxystyryl)-1-methylquinolinium 4-vinylbenzenesulfonate (OHQ-VBS) replacing same counteranion. OHQ-VBS crystal exhibits a highly macroscopic nonlinear optical properties with highly second harmonic generation (SHG) efficiency. The cations of OHQ-VBS constitutes strong head-to-tail hydrogen bonds, and they exhibits acentric crystal structure of cations and counteranion layers. Therefore HMQ-VBS crystal exhibits a centrosymmetric crystal structure. X-ray crystallographic analysis revealed that the crystal structure of OHQ-VBS is monoclinic Pn, which is similar to that of OHQ-T, however HMQ-VBS exhibits a centrosymmetric P21/c structure compare to other three molecules
New acentric core structure for organic electrooptic crystals optimal for efficient optical-to-THz conversion
No full textOrganic electrooptic crystals based on a new acentric core structure 2‐(4‐hydroxystyryl)‐1‐methylquinolinium provide optimal molecular packing for maximizing the electrooptic response. They allow intense broadband terahertz generation with over 30 times higher terahertz generation efficiency compared to the widely used inorganic ZnTe
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Variations on the Author
Full text link“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
Full text linkWe 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
Full text linkWe 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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