A5089826499- X-ray Spectroscopy and Fluorescence Analysis
- Electron and X-Ray Spectroscopy Techniques
- Machine Learning in Materials Science
- Nuclear Physics and Applications
- Analytical chemistry methods development
- X-ray Diffraction in Crystallography
- 2D Materials and Applications
- Electronic and Structural Properties of Oxides
- Neurotransmitter Receptor Influence on Behavior
- Neuroscience and Neuropharmacology Research
- Nicotinic Acetylcholine Receptors Study
- Computational Drug Discovery Methods
- Chalcogenide Semiconductor Thin Films
- Electrochemical Analysis and Applications
- Quantum Dots Synthesis And Properties
- Advancements in Battery Materials
- Chemical Thermodynamics and Molecular Structure
- Advanced X-ray and CT Imaging
- Radiation Detection and Scintillator Technologies
- Military and Defense Studies
- Radioactive element chemistry and processing
- Winter Sports Injuries and Performance
- Polymer crystallization and properties
- Fluoride Effects and Removal
- Coral and Marine Ecosystems Studies
University of Washington
2010-2023
University of Vermont
2022
University of Pennsylvania
2018-2020
Seattle University
2020
Advanced Photon Source
2018
Argonne National Laboratory
2018
Abstract Black phosphorus (BP) is a promising anode material in lithium‐ion batteries (LIBs) owing to its high electrical conductivity and capacity. However, the huge volume change of BP during cycling induces rapid capacity fading. In addition, unclear electrochemical mechanism hinders development rational designs preparation high‐performance BP‐based anodes. Here, nanostructured BP–graphite–carbon nanotubes composite (BP/G/CNTs) synthesized using ball‐milling method reported. The BP/G/CNTs...
Synthetic efforts to prepare indium phosphide (InP) quantum dots (QDs) have historically generated emissive materials with lower than unity yields. This property has been attributed structural and electronic defects associated the InP core as well chemistry of shell used overcoat passivate surface. Consequently, uniformity core–shell interface plays a critical role. Using X-ray emission spectroscopy (XES) performed recently developed benchtop spectrometer, we studied evolution oxidized...
X-ray absorption fine structure (XAFS) and x-ray emission spectroscopy (XES) are advanced spectroscopies that impact a wide range of disciplines. However, unlike the majority other spectroscopic methods, XAFS XES accompanied by an unusual access model, wherein dominant use technique is for premier research studies at world-class facilities, i.e., synchrotron light sources. In this paper, we report design performance improved spectrometer based on general conceptual Seidler et al. [Rev. Sci....
Adolescent smoking is associated with pathological drinking later in life, but the biological basis for this vulnerability unknown. To examine how adolescent nicotine exposure influences subsequent ethanol intake, was administered during adolescence or adulthood, and responses to alcohol were measured 1 month later. We found that adolescent, not adult, altered GABA signaling within ventral tegmental area (VTA) led a long-lasting enhancement of self-administration. detected depolarizing...
An extensive experimental and theoretical study of the Kα Kβ high-resolution X-ray emission spectroscopy (XES) sulfur-bearing systems is presented. This encompasses a wide range organic inorganic compounds, including numerous spectra from both prior published work new measurements. Employing linear-response time-dependent density functional theory (LR-TDDFT) approach, strong quantitative agreement found in calculation energy shifts core-to-core as well full spectral features valence-to-core...
X-ray emission spectroscopy is emerging as an important complement to x-ray absorption fine structure spectroscopy, providing a characterization of the occupied electronic density states local species interest. Here, we present details design and performance compact spectrometer that uses dispersive refocusing Rowland (DRR) circle geometry achieve excellent for 2-2.5 keV range, i.e., especially K-edge from sulfur phosphorous. The DRR approach allows high energy resolution even unfocused...
Abstract Surface functionalization of two‐dimensional crystals is a key path to tuning their intrinsic physical and chemical properties. However, synthetic protocols experimental strategies directly probe bonding in modified surfaces are scarce. Introduced herein mild, surface‐specific protocol for the surface few‐layer black phosphorus nanosheets using family photolytically generated nitrenes (RN) from corresponding azides. By embedding spectroscopic tags organic backbone, multitude...
We analyze an ensemble of organophosphorus compounds to form unbiased characterization the information encoded in their X-ray absorption near-edge structure (XANES) and valence-to-core emission spectra (VtC-XES). Data-driven emergence chemical classes via unsupervised machine learning, specifically cluster analysis Uniform Manifold Approximation Projection (UMAP) embedding, finds spectral sensitivity coordination, oxidation, aromaticity, intramolecular hydrogen bonding, ligand identity....
The analytical chemistry of sulfur-containing materials poses substantial technical challenges, especially due to the limitations 33S NMR and time-intensive preparations required for wet-chemistry analyses. A number prior studies have found that synchrotron-based X-ray absorption near edge structure (XANES) measurements can give detailed speciation sulfur in such cases. However, obvious access limitations, synchrotron XANES cannot be part routine practice across chemical sciences community....
We report a compact laboratory-based, high resolution X-ray emission spectrometer installed in glovebox for simultaneous measurement of phosphorus Kα and Kβ spectra air-sensitive materials.
There are several reports in the scientific literature of use mass-produced charge coupled device or complementary metal oxide semiconductor (CMOS) sensors as x-ray detectors that combine high spatial resolution with significant energy resolution. Exploiting a relatively new especially favorable ambient-temperature back-illuminated CMOS sensor, we report development spectroscopic camera having particularly impressive performance for 2–6 keV photons. This instrument has beneficial...
Abstract We tested for density‐dependent reproduction in a small coral reef fish using field manipulations of density and observational data. Males the study species, bridled goby ( Coryphopterus glaucofraenum Gill), defend benthic nest sites, within which they spawn with females, females can repeatedly over an extended breeding season. In areas, usually only single male nested at any one time regardless how many males were present, so probability nesting was inversely proportional to...
We demonstrate that vacuum forming of 10-cm diameter silicon wafers various crystallographic orientations under an x-ray permeable, flexible window can easily generate spherically bent crystal analyzers and toroidally with ∼1-eV energy resolution a 1-m major radius curvature. In applications at synchrotron light sources, free electron lasers, laboratory spectrometers, these characteristics are generally sufficient for many absorption fine structure (XAFS), emission spectroscopy (XES),...
Coupling lab-based XES measurements with computations amenable to solid-state systems revealed the valence band behavior of several vanadium-based electronic materials.
Abstract Nicotine use increases the risk for subsequent abuse of other addictive drugs, but biological basis underlying this remains largely unknown. Interactions between nicotine and drugs may arise from nicotine-induced neural adaptations in mesolimbic dopamine (DA) system, a common pathway reinforcing effects many substances. Previous work identified neuroadaptations that alter inhibitory transmission ventral tegmental area (VTA). Here, we test whether dysregulation GABAergic signaling...
There is a growing body of evidence demonstrating the benefits diversity across many domains. However, neurosurgery consistently lags most medicine in aspects diversity. Any inability to make progress this arena likely due multifactorial and complex nature issue, which makes it difficult meaningfully measure track within workforce. The goal pilot study was assess utilization multidimensional statistical model quantify neurosurgery. authors sought 1) residents using Simpson's Diversity Index...
Indium phosphide (InP) is the leading Cd‐free quantum dot material for application in photoluminescence downconversion display and lighting technologies. To date performance of InP dots (QDs) has lagged behind cadmium selenide terms both luminescence line width yield. Extensive studies our lab have implicated kinetically persistent magic‐sized cluster intermediates as a contributor to polydispersity these samples, providing new opportunities achieving high color purity. Now, using...
X-ray absorption spectroscopy (XAS) beamlines worldwide are steadily increasing their emphasis on full photon-in/photon-out spectroscopies, such as resonant inelastic scattering (RIXS), emission (RXES) and high energy resolution fluorescence detection XAS (HERFD-XAS). In cases, each beamline must match the choice of spectrometer to scientific mission its users. Previous work has recently reported a miniature tender using dispersive Rowland refocusing (DRR) geometry that functions with even...
Abstract X-ray emission spectroscopy (XES), as a complementary technique to x-ray absorption (XAS), is powerful in the analysis of electronic structure materials by probing occupied density states with high energy resolution. Recently, an XES spectrometer optimized for tender region (2–5 keV) was successfully installed into inert atmosphere glovebox, and entire system integrated SXRMB (soft microcharacterization beamline) at Canadian Light Source. Here, technical design performance...
Identification of oxidation state and ligand species is often challenging, requiring arduous preparation destructive analytical techniques which inhibit rapid analyses. Advancements in laboratory-based X-ray emission spectrometers (XES) are addressing this issue, facilitating consistent access to element-specific bulk chemical analysis speciation users’ own labs. Intended simplify expand powerful technique for both new existing members the XAS community, everyday a game-changer enables...
Abstract Surface functionalization of two‐dimensional crystals is a key path to tuning their intrinsic physical and chemical properties. However, synthetic protocols experimental strategies directly probe bonding in modified surfaces are scarce. Introduced herein mild, surface‐specific protocol for the surface few‐layer black phosphorus nanosheets using family photolytically generated nitrenes (RN) from corresponding azides. By embedding spectroscopic tags organic backbone, multitude...
We demonstrate that vacuum forming of 10-cm diameter silicon wafers various crystallographic orientations under an x-ray permeable, flexible window can easily generate spherically bent crystal analyzers (SBCA) and toroidally (TBCA) with ~1-eV energy resolution a 1-m major radius curvature. In applications at synchrotron light sources, free electron lasers, laboratory spectrometers these characteristics are generally sufficient for many absorption fine structure (XAFS), emission spectroscopy...