نتایج جستجو برای: laser mass spectrum

تعداد نتایج: 847335  

Journal: :The Journal of chemical physics 2007
Mina Lee Myung Soo Kim

A new technique [mass-analyzed threshold ionization (MATI)-photodissociation yield spectroscopy] to probe bound excited states of a cation was developed, which measures photodissociation yield of the cation generated by mass-analyzed threshold ionization. A vibrational spectrum of vinyl bromide cation in the (~)B state was obtained using this technique. Optical resolution in the low vibrational...

Journal: :Bioorganic & medicinal chemistry 2006
V Sol V Chaleix Y Champavier R Granet Y-M Huang P Krausz

Syntheses of new glycosylated neutral and cationic porphyrin dimers linked at the meso-position via a flexible hydrocarbon chain are described. A detailed 1H and 13C NMR study allows their complete structural elucidation. The UV-visible, fluorescence and MALDI mass spectra are also presented. Photocytotoxicities of these compounds against K562 leukaemia cell line are compared to those of Photof...

2002
Bing Shan Xiao-Min Tong Zengxiu Zhao Zenghu Chang C. D. Lin J. R. Macdonald

High-order harmonic generation has been observed experimentally from O2 molecules at the saturation ionization intensity. The harmonic cutoff extends far beyond the cutoff of Xe despite both have nearly equal ionization potentials. In contrast, the harmonic spectra for N2 and Ar, which have almost the same ionization potentials, are essentially close to each other. We show the extension of harm...

Laser micro-Raman spectroscopy is an ideal tool for assessment and characterization of various types of carbon-based materials. Due to its special optical properties (CrN) coated stainless steel substrates. NCD films have been investigated by laser micro-Raman spectroscopy. The fingerprint of diamond based materials is in the spectral region of 1000-1600 cm-1 in the first order of Raman scatter...

2011
Q. Peter He Jin Wang James A. Mobley Joshua Richman William E. Grizzle

With recent advances in mass spectrometry (MS) technologies, it is now possible to study protein profiles over a wide range of molecular weights in small biological specimens. However, MS spectra are usually not aligned or synchronized between samples. To ensure the consistency of the subsequent analysis, spectrum alignment is necessary to align the spectra such that the same biological entity ...

2014
Kahoko Nishikawa Masahiro Hashimoto Yoshiyuki Itoh Sadayuki Hiroi Akihiko Kusai Fumihiko Hirata Toshihisa Sakamoto Keiichi Iwaya

Matrix-assisted laser desorption/ionisation spiral orbit-type time-of-flight mass spectrometry (MALDI-SpiralTOF) can analyse lipid profiles and characterise lipid structure. Imaging mass spectrometry (IMS) also provides distribution maps of selected m/z values. Here, we investigated triacylglycerol (TG) structure and distribution using these technologies to estimate mouse fatty liver. The distr...

2008
Michael P. Callahan

We have used two-color resonant two-photon ionization (2C-R2PI) mass spectrometry to discriminate between isomers of polycyclic aromatic hydrocarbons in the Murchison meteorite. We measured the 2C-R2PI spectra of chrysene and triphenylene seeded in a supersonic jet by laser desorption. Since each isomer differs in its R2PI spectrum, we can distinguish between isomers using wavelength dependent ...

2003
Kristen Menou

Idealized models are used to illustrate the potential of the Laser Interferometer Space Antenna (LISA) as a probe of the largely unknown population of cosmologically-distant Massive Black Holes (MBHs) and as a tool to measure their masses with unprecedented accuracy. The models suggest that LISA will most efficiently probe a MBH population of lower mass than the one found in bright quasars and ...

2015
Kazuhiko Ohashi Yoshiya Inokuchi Nobuyuki Nishi

Pump-probe photodepletion (hole-burning) experiments are performed on mass-selected cluster ions in the gas phase. An electronic spectrum of (C6H6)2 + in near-infrared region comprises two charge resonance bands at 920 and 1160 nm. Intensities of these two bands monitored by the probe laser are shown to be reduced by the same amount with the introduction of the pump laser. The behavior proves t...

Journal: :The Review of scientific instruments 2014
A Alejo S Kar H Ahmed A G Krygier D Doria R Clarke J Fernandez R R Freeman J Fuchs A Green J S Green D Jung A Kleinschmidt C L S Lewis J T Morrison Z Najmudin H Nakamura G Nersisyan P Norreys M Notley M Oliver M Roth J A Ruiz L Vassura M Zepf M Borghesi

A novel method for characterising the full spectrum of deuteron ions emitted by laser driven multi-species ion sources is discussed. The procedure is based on using differential filtering over the detector of a Thompson parabola ion spectrometer, which enables discrimination of deuterium ions from heavier ion species with the same charge-to-mass ratio (such as C(6+), O(8+), etc.). Commonly used...

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