Sharpening the predictions of big-bang nucleosynthesis

Motivated by the recent measurement of the primeval abundance of deuterium, we re-examine the nuclear inputs to big-bang nucleosynthesis (BBN). Using Monte-Carlo realization of the nuclear cross-section data to directly estimate the theoretical uncertainties for the yields of D, 3-He and 7-Li, we show that previous estimates were a factor of 2 too large. We sharpen the BBN determination of the baryon density based upon deuterium, rho_B = (3.6 +/- 0.4) * 10^{-31} g/cm^3 (Omega_B h^2 = 0.019 +/- 0.0024), which leads to a predicted 4-He abundance, Y_P = 0.246 +/- 0.0014 and a stringent limit to the equivalent number of light neutrino species: N_nu < 3.20 (all at 95% cl). The predicted 7-Li abundance, 7-Li/H = (3.5 + 1.1 - 0.9) * 10^{-10}, is higher than that observed in pop II stars, (1.7 +/- 0.3) * 10^{-10} (both, 95% cl). We identify key reactions and the energies where further work is needed.Comment: 5 pages, 4 figures (epsfig), REVTeX; submitted to Phys. Rev. Let

Lattice sites of ion-implanted Li in diamond

Published in: Appl. Phys. Lett. 66 (1995) 2733-2735 citations recorded in [Science Citation Index] Abstract: Radioactive Li ions were implanted into natural IIa diamonds at temperatures between 100 K and 900 K. Emission channelling patterns of a-particles emitted in the nuclear decay of 8Li (t1/2 = 838 ms) were measured and, from a comparison with calculated emission channelling and blocking effects from Monte Carlo simulations, the lattice sites taken up by the Li ions were quantitatively determined. A fraction of 40(5)% of the implanted Li ions were found to be located on tetrahedral interstitial lattice sites, and 17(5)% on substitutional sites. The fractions of implanted Li on the two lattice sites showed no change with temperature, indicating that Li diffusion does not take place within the time window of our measurements.

Construction and optical-electrical properties of inorganic/organic heterojunction nanostructures

We have designed and synthesized a series of ordered inorganic/organic hybrid aggregate nanostructures of by self-assembly and self-organizing technique. The process and mechanism of growing hybrid aggregate nanostructures have been studied. The ability to tune the size and morphologies of hybrid aggregate nanostructures has been achieved by controlling reaction conditions. The effects of morphologies and size dependent on electrical and optical properties have been demonstrated. These semiconductor molecular hybrid aggregate nanostructures exhibit interesting electrical, optical, and optoelectronic properties for use in next-generation electronic and optoelectronic devices. REFERENCES [1] Liu, H. B.; Zuo, Z. C.; Guo, Y. B.; Li, Y. J.; Li, Y. L. Angew. Chem. Int. Ed. 2010, 49, 2705. [2] Huang, C. S.; Li, Y. L.; Song, Y. L.; Li, Y. J.; Liu, H. B.; Zhu, D. B. Adv. Mater. 2010, 22, 3532. [3] Wang, K.; Yang, H.; Qian, X. M.; Xue, Z.; Li, Y. J.; Liu, H. B.; Li, Y. L. Dalton Trans. 2014, 43, 11542. [4] Liu, H. B.; Wang, K.; Zhang, L.; Qian, X. M.; Y. J.; Li, Y. L. Dalton Trans. 2014, 43, 432. [5] Guo, Y. B.; Xu, L.; Liu, H. B.; Li, Y. J.; Che, C.-M.; Li, Y. L. Adv. Mater. 2015, 27, 985

Capstone 2019 Art and Art History Senior Projects

This booklet profiles Art Senior Projects by Angelique J. Acevedo, Arin Brault, Bailey Harper, Sue Holz, Yirui Jia, Jianrui Li, Annora B. Mack, Emma C. Mugford, Inayah D. Sherry, Jacob H. Smalley, Laura Grace Waters and Laurel J. Wilson. This booklet profiles Art History Senior Projects by Gabriella Bucci, Melissa Casale, Bailey Harper, Erin O\u27Brien and Laura Grace Waters