64,359 research outputs found
Spectroscopic properties of Yb3+-doped TeO2-BaO-BaF2-Nb2O5-based oxyfluoride tellurite glasses
No full text
A series of oxyfluoride glasses with the compositions of 75 mol% TeO2, 10 mol% Nb2O5, (15 mol%-x) BaO, x BaF2 (x = 0 mol%, 5 mol%, 10 mol%, 15 mol%) doped with Yb2O3 were prepared by the melt-quenching method. Their emission cross-sections, fluorescence lifetimes, and gain properties were investigated by using the absorption spectra and the fluorescence decay curves. The results show that by substituting BaF2 for BaO, the emission cross-section decreases from 1.37 pm(2) to 1.21 pm(2), and the fluorescence lifetime increases from 0.71 ms to 0.96 ms. These properties indicate that this oxyfluoride tellurite glass may have potential uses as the Yb2O3-doped gain medium in a solid laser.</p
El Tlacuache Núm. 386 (2009). 386 Año 9 (2009) octubre. El Tlacuache
No full textCarlos Illades y Las otras ideas en México: 1850-1935 por Ricardo Melgar Bao
Obtenção, caracterização físico química de vidros e vitro-cerâmicos baseados no sistema Li2-ZrO2-BaO-SiO2
No full textDissertação (Mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas. Curso de Pós-Graduação em QuímicaNeste trabalho encontra-se descrita a preparação de vidros e vitro-cerâmicos de composição 29 % Li2O - 1% ZrO2 - x% BaO - (70 - x %) SiO2, onde x = 0, 2, 3, 5, e 6 % em mol de BaO, obtidos pelo método clássico de fusão. Os materiais foram caracterizados por Difração de Raios-X, Espectroscopia Raman, Espectroscopia no Infravermelho, Espectroscopia de Fotoelétrons Excitados por Raio-X, Microscopia Eletrônica de Varredura e Análise Térmica Diferencial. Determinaram-se o mecanismo e a cinética de cristalização dos vidros, além das propriedades físico-químicas microdureza e durabilidade química
Deborah Lin oral history interview and transcript
No full textThis recording and transcript form part of a collection of oral history interviews conducted by the Chao Center for Asian Studies at Rice University. This collection includes audio recordings and transcripts of interviews with Asian Americans native to or living in Houston.Dr. Deborah Ho Lin, originally born in Taiwan, came to Atlanta, Georgia with her family when she was 17. She attended Georgia Tech for an undergraduate degree and later, Emory University for medical school. She is an accomplished pediatrician and writer, as well as the loving wife of Jimmy Lin and mother of Lara Lin. The family lived in New York since the couple got married, moved to Houston in 2008 when her husband
obtained a professorship post at Rice University, and stayed here since. In this second interview with HAAA, Dr. Lin spoke of her childhood memories, her family and her role in the family as the eldest sister, and the important people in her lives during her upbringing. Dr. Lin also spoke briefly about her experience growing up in Georgia as the only non-caucasian family there 40 years ago. She reflected on her medical career as a woman of color in a male-dominated field, and her writing career during which, she covered the story of Nobel Prize winner, Chien-Shiung Wu’s story immediately after the award
El Tlacuache Núm. 373 (2009). 373 Año 9 (2009) julio. El Tlacuache
No full textEl impacto actual de la Revolución Popular Sandinista en América Latina por Gilberto López y Rivas. - Palabras y entretiemPosLa olvidada réplica de Fayad a los militares colombianos por Ricardo Melgar Bao
El Tlacuache Núm. 436 (2010). 436 Año 10 (2010) octubre. El Tlacuache
No full textMaya Aguiluz y Zygmunt Bauman:La ambivalencia, el Holocausto y la cuestión gitana por Ricardo Melgar Bao. -Gitanos: el pueblo de Dios,olvidado por la humanidad por Perla Jaimes Navarro
El Tlacuache Núm. 451 (2011). 451 Año 11 (2011) enero. El Tlacuache
No full textRecepción y redes anarquistas de la Revolución Mexicana en los Andes por Ricardo Melgar Bao. -“Ni Dios, ni amo, ni marido”: feminismo anarquista peruano en los albores del siglo XX por Perla Jaimes Navarro
Ya pian shi lüe
No full text林則徐. 鴉片事略 / 李圭 ; [編輯者 中國歷史硏究社]Lin Zexu. Ya pian shi lüe / Li Gui ; [bian ji zhe Zhongguo li shi yan jiu she
Jiao hui xin bao.
No full textOn vol. 10 A: With editor's presentation inscription on final page.Also available in photocopy by Hua wen shu chü, Taipei, 1968. in series of Chʻing mo min chʻu pao kʻan tsʻung pien chih 3.Superseded by Wan kuo kung pao, 1874-1907.Ed. by Young John Allen.Mode of access: Internet.Adrian A. Bennett. Research guide to the Chiao hui hsin pao (The church news)
Does Downloading PowerPoint Slides Before the Lecture Lead to Better Student Achievement?: Reply
No full textThis reply responds to a comment by Cannon (2011) that opens the debate on consistency of the effect of downloading PowerPoint slides before lectures on students’ exam performance. Cannon (2011) points out potential endogeneity problems in Chen and Lin (2008) and attempts to explore the unconditional mean effect of downloading PowerPoint slides for the full sample. In this reply, we firstly argue that the estimates in our original article are consistent since the effect of interest is the “conditional†treatment effect but not the unconditional mean effect. We provide explanations for our rationale of estimating the “conditional†treatment effect. Secondly, we propose a modified downloading variable to replicate Cannon’s analysis. Our results suggest that downloading PowerPoint slides before the exam does not produce a significant effect on absent students’ exam performance which is different from the results in Cannon (2011). Our analysis does support Cannon’s argument that students fixed effects are different across different attendance status.
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