Detonation behavior in vapor-deposited 34-bis(4-nitro-125-oxadiazol-3-yl)-125-oxadiazole 2-oxide (BNFF)
Abstract not provided.
Publications
Ultrafast Shock-Induced Reactions in Pentaerythritol Tetranitrate Thin Films
Abstract not provided.
Ultrafast Shock Interrogation and Ultrafast Spectroscopy of Shocked Thin-Film Explosives
Abstract not provided.
Experimental and Theoretical Investigation of Shock-Induced Reactions in Energetic Materials
In this work, shock-induced reactions in high explosives and their chemical mechanisms were investigated using state-of-the-art experimental and theoretical techniques. Experimentally, ultrafast shock interrogation (USI, an ultrafast interferometry technique) and ultrafast absorption spectroscopy were used to interrogate shock compression and initiation of reaction on the picosecond timescale. The experiments yielded important new data that appear to indicate reaction of high explosives on the timescale of tens of picoseconds in response to shock compression, potentially setting new upper limits on the timescale of reaction. Theoretically, chemical mechanisms of shock-induced reactions were investigated using density functional theory. The calculations generated important insights regarding the ability of several hypothesized mechanisms to account for shock-induced reactions in explosive materials. The results of this work constitute significant advances in our understanding of the fundamental chemical reaction mechanisms that control explosive sensitivity and initiation of detonation.
Emissivity corrected pyrometry of reactive multilayers
Abstract not provided.
Ultrafast Shock Interrogation of Polycrystalline Energetic Materials
Abstract not provided.
Ultrafast Shock Interrogation (USI) of Energetic Materials
Abstract not provided.
Bandgap Inhomogeneity of a PbSe Quantum Dot Ensemble from Two-Dimensional Spectroscopy and Comparison to Size Inhomogeneity from Electron Microscopy
Nano Letters
Femtosecond two-dimensional Fourier transform spectroscopy is used to determine the static bandgap inhomogeneity of a colloidal PbSe quantum dot ensemble. It is shown that the absorption bandgap inhomogeneity is robustly determined by the slope of the nodal line separating positive and negative peaks in the 2D spectrum around the bandgap transition; this nodal line slope is independent of excited state parameters not known from the absorption and emission spectra. The absorption bandgap inhomogeneity is compared to a size and shape distribution determined by electron microscopy. The electron microscopy images are analyzed using new 2D histograms that correlate major and minor image projections to reveal elongated nanocrystals, a conclusion supported by grazing incidence small angle X-ray scattering and high resolution transmission electron microscopy. Lastly, the absorption bandgap inhomogeneity quantitatively agrees with the bandgap variations calculated from the size and shape distribution, placing upper bounds on any surface contributions.
Matter in Extreme Conditions: Probing Shock-Induced Reactions in Explosive Materials
Abstract not provided.
The Initial Pump-Probe Polarization Anisotropy of Colloidal PbS Quantum Dots
Abstract not provided.
The initial pump-probe polarization anisotropy of colloidal PbS quantum dots
OSA Technical Digest (Online)
Pump-probe polarization anisotropy measurements with 15 fs pulses are employed to investigate the electronic structure of PbS quantum dots. Here, the initial anisotropy at the bandgap is anomalously low (<0.1) and suggests large electronic couplings.
In situ study of Surface-mediated Explosive Degradation Using Heterodyne IR-Vis Sum Frequency Generation (SFG)
Abstract not provided.
12 Results