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DART mass spectrometry commonly uses helium as the DART gas. With the looming helium shortage, other gases are being evaluated for DART.

The power-dependent transfer characteristics of spin currents at the interface of the permalloy/Pt bilayer device were investigated over a wide power range

In this work we used msFineAnalysis to compare Vinyl Acetate Resins that were measured by using Pyrolysis (Py)-GC-MS.

In this work, we compare sensitivity levels when using the combination EI/FI and EI/PI ion sources when He and N2 are used as the GC carrier gas.

This research demonstrates the effect of Li and Ni co-doping in P2-type layered materials and suggests a new strategy of using Mn-rich cathode materials.

This primer article introduces a practical guide for setting up 1H detection solid-state NMR experiments under fast MAS conditions for small molecules.

In this guidebook, we will introduce polymeric material analysis solutions that make full use of JEOL's high-performance mass spectrometers.

The JMS-S3000 SpiralTOF™-plus Ultra-High Mass Resolution MALDI-TOFMS System time-of-flight optics design utilizes a figure-eight ion trajectory to allow a 17m flight path to fit in an extremely small console.

Magic angle spinning (MAS) nuclear magnetic resonance (NMR) experiments at ultra low temperature (ULT) ( 100 K) have demonstrated clear benefits for obtaining large signal sensitivity gain and probing spin dynamics phenomena at ULT. ULT NMR is furthermore a highly promising platform for solid-state dynamic nuclear polarization (DNP). However, ULT NMR is not widely used, given limited availability of such instrumentation from commercial sources. In this paper, we present a comprehensive study of hydrated [U-C]alanine, a standard bio-solid sample, from the first commercial 14.1 Tesla NMR spectrometer equipped with a closed-cycle helium ULT-MAS system. The closed-cycle helium MAS system provides precise temperature control from 25 K to 100 K and stable MAS from 1.5 kHz to 12 kHz. The C CP-MAS NMR of [U-C]alanine showed 400% signal gain at 28 K compared with at 100 K. The large sensitivity gain results from the Boltzmann factor, radio frequency circuitry quality factor improvement, and the suppression of its methyl group rotation at ULT. We further observed that the addition of organic biradicals widely used for solid-state DNP significantly shortens the H T1 spin lattice relaxation time at ULT, without further broadening the C spectral linewidth compared to at 90 K. The mechanism of H T1 shortening is dominated by the two-electron-one-nucleus triple flip transition underlying the Cross Effect mechanism, widely relied upon to drive solid-state DNP. Our experimental observations suggest that the prospects of MAS NMR and DNP under ULT conditions established with a closed-cycle helium MAS system are bright.

High-capacity Li1+x(Ni0.3Mn0.7)1-xO2, (0 < x < 1/3) samples were synthesized by the coprecipitation–calcination method. Both electrochemical cycle and high-rate performances were drastically improved by selecting an N2 atmosphere as final calcination. Scanning transmission electron microscopy—energy dispersive X-ray spectroscopy analysis showed that the sample calcined in an N2 atmosphere had a more homogeneous transition metal distribution into primary particles than that calcined in air. The solid-state 7Li nuclear magnetic resonance data showed that electrochemically inactive domains were only diminished for the sample calcined in an N2 atmosphere after electrochemical activation. X-ray Rietveld analysis revealed that the suitable transition metal distribution and content of the samples were different from those of typical layered rock-salt materials. Only that calcined in an N2 atmosphere had no spinel formation during charging and no oxide ion insertion reaction during discharging. No positive Co substitution effect was observed under the optimized preparation conditions. At the 100th cycle, the discharge capacity was 216 mAh g−1, which corresponds to 87% of the initial capacity (251 mAh g−1) at optimizing synthetic condition.

Other Resources

Image Gallery
  • View a selection of NMR and MS spectra
  • Walkup NMR
  • See how the Delta NMR software allows users to just "walk up" and start NMR experiments
  • Mass Spec Reference Data
  • View our page of useful molecular references for Mass Spec
  • Tutorials (Mass Spec)
  • Documents on the basics of mass spectrometry
  • Delta NMR software Tutorials
  • Videos on how to use the Delta NMR software
  • No-D NMR
  • Description of No-D NMR and how it can be used to eliminate the need for deuterated solvents
  • Non Uniform Sampling (NUS)
  • Description of how NUS is used to greatly reduce the time needed for running NMR experiments
  • NMR Basics
  • Overview of the Basics of NMR Theory
  • NMR Magnet Destruction
  • See our presentation of the slicing open of a JEOL Delta-GSX 270 MHz NMR Magnet
  • Media

    Corona - Glow Discharge (DART Ion Source)

    January 28, 2022
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