International Journal of Chemistry and Materials Research

Published by: Conscientia Beam
Online ISSN: 2311-763X
Print ISSN: 2312-0991
Quick Submission    Login/Submit/Track

No. 8

Randic Index and Edge Eccentric Connectivity Index of Certain Special Molecular Graphs

Pages: 81-87
Find References

Finding References


Randic Index and Edge Eccentric Connectivity Index of Certain Special Molecular Graphs

Search :
Google Scholor
Search :
Microsoft Academic Search
Cite

Citation: 3

Yun Gao , Li Liang , Wei Gao

Export to    BibTeX   |   EndNote   |   RIS

  1. L. Yan, Y. Li, W. Gao, and J. Li, "On the extremal hyper-wiener index of graphs," Journal of Chemical and Pharmaceutical Research, vol. 6, pp. 477-481, 2014.
  2. W. Gao and L. Shi, "Wiener index of gear fan graph and gear wheel graph," Asian Journal of Chemistry, vol. 26, pp. 3397-3400, 2014.
  3. L. Yan, Y. Li, W. Gao, and J. Li, "PI index for some special graphs," Journal of Chemical and Pharmaceutical Research, vol. 5, pp. 260-264, 2013.
  4. I. G. Yero and J. A. R. Velazquez, "On the randic index of corona product graphs," ISRN Discrete Mathematics, vol. 2011, pp. 1-7, 2011.
  5. M. Randic, "On characterization of molecular branching," J. Am. Chem. Soc., vol. 97, pp. 6609–6615, 1975.
  6. B. Bollobas and P. Erdos, "Graphs of extremal weights," Ars Combin., vol. 50, pp. 225–233, 1998.
  7. B. Li and W. Liu, "The smallest randic index for trees," Proc. Indian Acad. Sci. (Math. Sci.), vol. 123, pp. 167–175, 2013.
  8. H. Liu, M. Lu, and F. Tian, "On the randic index," Journal of Mathematical Chemistry, vol. 38, pp. 345-354, 2005.
  9. Y. Yang and L. Lu, "The randic index and the diameter of graphs," Discrete Mathematics, vol. 311, pp. 1333-1343, 2011.
  10. H. Liu, Z. Yan, and H. Liu, "Extremal chemical (n, m, k)-graphs with maximum randic index," MATCH Commun. Math. Comput. Chem., vol. 60, pp. 513-522, 2008.
  11. G. Yu and L. Feng, "Randic index and eigenvalues of graphs," Rocky Mountain J. Math., vol. 40, pp. 713-721, 2010.
  12. H. Liu, X. Pan, and J. Xu, "On the randic index of unicyclic conjugated molecules," Journal of Mathematical Chemistry, vol. 40, pp. 135-143, 2006.
  13. X. Xu and Y. Guo, "The edge version of eccentric connectivity index," International Mathematical Forum, vol. 7, pp. 273-280, 2012.
  14. Z. N. Odaba?, "The edge eccentric connectivity index of dendrimers," Journal of Computational and Theoretical Nanoscience, vol. 10, pp. 783-784, 2013.
No any video found for this article.
Yun Gao , Li Liang , Wei Gao (2014). Randic Index and Edge Eccentric Connectivity Index of Certain Special Molecular Graphs. International Journal of Chemistry and Materials Research, 2(8): 81-87. DOI:
In this paper, we determine the Randic index and edge eccentric connectivity index of fan molecular graph, wheel molecular graph, gear fan molecular graph, gear wheel molecular graph, and their r-corona molecular graphs.
Contribution/ Originality

Photoluminescence Characteristics of the Caal2o4: Eu2+ Co-Doped With Ion Dy3+ Synthesized By Combustion Method

Pages: 75-80
Find References

Finding References


Photoluminescence Characteristics of the Caal2o4: Eu2+ Co-Doped With Ion Dy3+ Synthesized By Combustion Method

Search :
Google Scholor
Search :
Microsoft Academic Search
Cite

Citation: 2

Nguyen Ngoc Trac , Nguyen Manh Son , Phan Tien Dung

Export to    BibTeX   |   EndNote   |   RIS

  1.  Lin, Z. Zhang, Z. Tang, J. Zhang, Z. Zheng, and X. Lu, "The characterization and mechanism of long afterglow in alkline earth aluminates phosphors co-doped by Eu2O3 and Dy2O3," Materials Chemistry and Physics, vol. 70, pp. 156-159, 2001.
  2. N. M. Son, L. T. T. Vien, L. V. K. Bao, and N. N. Trac, "Synthesis of SrAl2O4: Eu2+, Dy3+ phosphorescence nanosized powder by combustion method and its optical properties," Journal of Physics: Conference Series, vol. 187, p. 012-017, 2009.
  3. M. Mothudi, J. R. Ntwaeborwa, Botha, and H. C. Swart, "Photoluminescence and phosphorescence properties of MAl2O4: Eu2+, Dy3+ (M: Ca, Ba, Sr) phosphors prepared at an initiating combustion temperature 500oC," Journal of Physica, vol. 404, pp. 4440-4444, 2009.
  4. S. H. Choi, N. H. Kim, Y. H. Yun, and S. C. Choi, "Photoluminescence properties of SrAl2O4 and CaAl2O4 long-phosphorescent phosphors synthesized by an oxalate coprecipitation method," Journal of Ceramic Processing Research, vol. 7, pp. 62-65, 2006.
  5. H. Ryu and K. S. Bartwal, "Photoluminescent spectra of Nd3+ codoped CaAl2O4: Eu2+ blue phosphor," Research Letter in Materials Science, Article ID 23643, vol. 2007, p. 4, 2007.
  6. T. Matsuzawa, Y. Aoki, N. Takeuchi, and Y. Murayama, "A new long phosphorescent phosphor with high brightness, SrAl2O4: Eu2+, Dy3+," J. Electrochem. Soc., vol. 143, pp. 2670-2673, 1996.
  7. N. Avci, K. Korthout, M. A. Newton, P. F. Smet, and D. Poelman, "Valence state of Europium in CaAl2O4: Eu phosphors," Optical Materials Express, vol. 2, pp. 321-330, 2012.
  8. K. C. Patil, M. S. Hegde, T. Rattan, and S. T. Aruna, Chemistry of  nanocrystalline oxide materials – combustion synthesis: Properties and Applications, World Scientific, 2008.
  9. H. Choi, C. H. Kim, C. H. Pyun, and S. J. Kim, "Luminescence of (Ca, La)S: Dy," J. Luminescence, vol. 82, pp. 25-32, 1999.
  10. J. Kuang, Y. Liu, and J. Zhang, "White-light-emitting long-lasting phosphorescence in Dy3+-doped SrSiO3," Journal of Solid State Chemistry, vol. 179, pp. 266-269, 2006.
No any video found for this article.
Nguyen Ngoc Trac , Nguyen Manh Son , Phan Tien Dung (2014). Photoluminescence Characteristics of the Caal2o4: Eu2+ Co-Doped With Ion Dy3+ Synthesized By Combustion Method. International Journal of Chemistry and Materials Research, 2(8): 75-80. DOI:
The phosphors of CaAl2O4: Eu2+, Dy3+ with varying concentrations were synthesized by combustion method. The monoclinic single phase structure of CaAl2O4 was investigated by X-ray diffraction. The emission spectra of phosphors had a broad band with maximum at 444 nm due to electron transition from the 4f65d1 to the 4f7 of Eu2+ ion and a small peak at 575 nm due to 4F9/2  6H13/2 transition of Dy3+ ions. The excitation spectra and the decay time of phosphors were investigated also. The phosphors of CaAl2O4: Eu2+, Dy3+ had long persistence luminescence. In these phosphors, Eu2+ ions play the role of activators. Whereas, Dy3+ ions generate the hole traps that lead to the long persistent phosphorescence and act as the activators in the phosphors simultaneously. The concentration of Dy3+ ion co-doped has strong influence on the luminescence of phosphor.


Contribution/ Originality