Environmental Molecular Sciences Laboratory

About: Environmental Molecular Sciences Laboratory is a facility organization based out in Richland, Washington, United States. It is known for research contribution in the topics: Mass spectrometry & Ion. The organization has 1471 authors who have published 3010 publications receiving 169961 citations.

Experimental Observation of Pentaatomic Tetracoordinate Planar Carbon-Containing Molecules

Abstract: The first neutral pentaatomic tetracoordinate planar carbon molecules, CAl 3Si and CAl3Ge, as well as their anions, CAl3Si - and CAl3Ge - , were experimentally observed in the gas-phase and characterized by ab initio calculations and anion photoelectron spectroscopy. A four-center bond involving ligand -ligand interactions was found to be critical in stabilizing the planar structures of the 17-valence-electron CAl 3Si and CAl3Ge and 18-valence-electron CAl3Si - and CAl3Ge - . These species violate the conventional expectation of tetrahedral structure for tetracoordinate carbon atoms and thus extend our concept of the range of chemical bonds that carbon can form.

Characterization of the human blood plasma proteome

Abstract: We describe methods for broad characterization of the human plasma proteome. The combination of stepwise immunoglobulin G (IgG) and albumin protein depletion by affinity chromatography and ultrahigh-efficiency capillary liquid chromatography separations coupled to ion trap-tandem mass spectrometry enabled identification of 2392 proteins from a single plasma sample with an estimated confidence level of > 94%, and an additional 2198 proteins with an estimated confidence level of 80%. The relative abundances of the identified proteins span a range of over eight orders of magnitude in concentration (< 30 pg/mL to approximately 30 mg/mL), facilitated by the attomole-level sensitivity of the analysis methods. More than 80% of the observed proteins demonstrate interactions with IgG and/or albumin, and the human plasma protein loss in the affinity chromatography/strong cation exchange/reversed-phase liquid chromatography-tandem mass spectrometry methodology was investigated in detail. The results of this study provide a basis for a wide range of plasma proteomics studies, including broad quantitation of relative abundances in comparative studies of the identification of novel protein disease markers, as well as further studies of protein-protein interactions.

Development of high-temperature ferromagnetism in Sn O 2 and paramagnetism in SnO by Fe doping

Abstract: We report the development of room-temperature ferromagnetism in chemically synthesized powder samples of ${\mathrm{Sn}}_{1\ensuremath{-}x}{\mathrm{Fe}}_{x}{\mathrm{O}}_{2}$ $(0.005\ensuremath{\leqslant}x\ensuremath{\leqslant}0.05)$ and paramagnetic behavior in an identically synthesized set of ${\mathrm{Sn}}_{1\ensuremath{-}x}{\mathrm{Fe}}_{x}\mathrm{O}$. The ferromagnetic ${\mathrm{Sn}}_{0.99}{\mathrm{Fe}}_{0.01}{\mathrm{O}}_{2}$ showed a Curie temperature ${T}_{C}=850\phantom{\rule{0.3em}{0ex}}\mathrm{K}$, which is among the highest reported for transition-metal-doped semiconductor oxides. With increasing Fe doping, the lattice parameters of $\mathrm{Sn}{\mathrm{O}}_{2}$ decreased and the saturation magnetization increased, suggesting a strong structure-magnetic property relationship. When the ${\mathrm{Sn}}_{0.95}{\mathrm{Fe}}_{0.05}{\mathrm{O}}_{2}$ was prepared at different temperatures between 200 and $900\phantom{\rule{0.2em}{0ex}}\ifmmode^\circ\else\textdegree\fi{}\mathrm{C}$, systematic changes in the magnetic properties were observed. Combined M\"ossbauer spectroscopy and magnetometry measurements showed a ferromagnetic behavior in ${\mathrm{Sn}}_{0.95}{\mathrm{Fe}}_{0.05}{\mathrm{O}}_{2}$ samples prepared at and above $350\phantom{\rule{0.2em}{0ex}}\ifmmode^\circ\else\textdegree\fi{}\mathrm{C}$, but the ferromagnetic component decreased gradually as preparation temperature approached $600\phantom{\rule{0.2em}{0ex}}\ifmmode^\circ\else\textdegree\fi{}\mathrm{C}$. All ${\mathrm{Sn}}_{0.95}{\mathrm{Fe}}_{0.05}{\mathrm{O}}_{2}$ samples prepared above $600\phantom{\rule{0.2em}{0ex}}\ifmmode^\circ\else\textdegree\fi{}\mathrm{C}$ were paramagnetic. X-ray photoelectron spectroscopy, magnetometry, and particle induced x-ray emission studies showed that the Fe dopants diffuse towards the surface of the particles in samples prepared at higher temperatures, gradually destroying the ferromagnetism. M\"ossbauer studies showed that the magnetically ordered ${\mathrm{Fe}}^{3+}$ spins observed in the ${\mathrm{Sn}}_{0.95}{\mathrm{Fe}}_{0.05}{\mathrm{O}}_{2}$ sample prepared at $350\phantom{\rule{0.2em}{0ex}}\ifmmode^\circ\else\textdegree\fi{}\mathrm{C}$ is only $\ensuremath{\sim}24%$ of the uniformly incorporated ${\mathrm{Fe}}^{3+}$. No evidence of any iron oxide impurity phases were detected in ${\mathrm{Sn}}_{1\ensuremath{-}x}{\mathrm{Fe}}_{x}{\mathrm{O}}_{2}$ or ${\mathrm{Sn}}_{1\ensuremath{-}x}{\mathrm{Fe}}_{x}\mathrm{O}$, suggesting that the emerging magnetic interactions in these systems are most likely related to the properties of the host systems $\mathrm{Sn}{\mathrm{O}}_{2}$ and SnO, and their oxygen stoichiometry.

Origin of lithium whisker formation and growth under stress.

Abstract: Lithium metal has the lowest standard electrochemical redox potential and very high theoretical specific capacity, making it the ultimate anode material for rechargeable batteries. However, its application in batteries has been impeded by the formation of Li whiskers, which consume the electrolyte, deplete active Li and may lead to short-circuit of the battery. Tackling these issues successfully is dependent on acquiring sufficient understanding of the formation mechanisms and growth of Li whiskers under the mechanical constraints of a separator. Here, by coupling an atomic force microscopy cantilever into a solid open-cell set-up in environmental transmission electron microscopy, we directly capture the nucleation and growth behaviour of Li whiskers under elastic constraint. We show that Li deposition is initiated by a sluggish nucleation of a single crystalline Li particle, with no preferential growth directions. Remarkably, we find that retarded surface transport of Li plays a decisive role in the subsequent deposition morphology. We then explore the validity of these findings in practical cells using a series of carbonate-poisoned ether-based electrolytes. Finally, we show that Li whiskers can yield, buckle, kink or stop growing under certain elastic constraints.