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131.
Laser-induced desorption of proteins 总被引:1,自引:0,他引:1
M Salehpour I Perera J Kjellberg A Hedin M A Islamian P H?kansson B U Sundqvist 《Rapid communications in mass spectrometry : RCM》1989,3(8):259-263
Laser-induced desorption mass spectrometry has been applied to a number of proteins in the mass range 5000-150,000 u. The beam from an excimer-laser-pumped dye-laser at 266 nm has been focused to a spot of about 50 microns in diameter with irradiances in the 10(7) W/cm2 region. A linear time-of-flight mass spectrometer has been used for mass spectrometric measurements, where positive and negative secondary ions of large proteins have been studied. The effect of different experimental parameters on the protein ion-signal intensities are discussed. 相似文献
132.
The Mechanisms of Rectification in Au|Molecule|Au Devices Based on Langmuir–Blodgett Monolayers of Iron(III) and Copper(II) Surfactants
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Lanka D. Wickramasinghe Dr. Shivnath Mazumder Sunalee Gonawala Meeghage Madusanka Perera Habib Baydoun Bishnu Thapa Li Li Lingxiao Xie Prof. Guangzhao Mao Prof. Zhixian Zhou Prof. H. Bernhard Schlegel Prof. Cláudio N. Verani 《Angewandte Chemie (International ed. in English)》2014,53(52):14462-14467
Langmuir–Blodgett films of metallosurfactants were used in Au|molecule|Au devices to investigate the mechanisms of current rectification. 相似文献
133.
The development of techniques to study the liquid–liquid interface is a major challenge. Spectroscopy in all its forms provides
a powerful method of investigation, especially when combined with other optical techniques. Over the last 30 years, there
have been significant developments in the methods for studying heterogeneous interfaces. As technology progresses, the sensitivity
of existing techniques has been improved but there are major challenges still to be met, such as the measurement of interfacial
dielectric constant and viscosity. This paper aims to summarise the use of spectroscopy to study molecular interactions at
the liquid–liquid interface. 相似文献
134.
135.
Bias-, frequency- and temperature-dependent capacitance characteristics of p-GaAs homojunction interfacial work-function internal
photoemission (HIWIP) far-infrared detectors are reported. A strong negative capacitance phenomenon has been observed. The
origin of this effect is believed to be due to the carrier capture and emission at interface states, and has been confirmed
by a comparison study of capacitance characteristics on p-GaAs HIWIP detectors with different interface state densities. A
fitting data based on charging–discharging current and the inertial conducting current model show good agreement with the
experimental observations.
Received: 15 November 1999 / Accepted: 20 April 2000 / Published online: 5 October 2000 相似文献
136.
Karunarathne K. A. Janani K. Perera Kumudu S. Vidanapathirana Kamal P. Pitawela Jagath C. 《Journal of Solid State Electrochemistry》2019,23(7):2165-2171
Journal of Solid State Electrochemistry - Super capacitors have emerged as a promising substitute for batteries and conventional capacitors which have played a key role as energy storage devices.... 相似文献
137.
Kanishka Perera 《Journal of Mathematical Analysis and Applications》2008,338(2):1397-1400
We obtain multiple positive solutions of multiparameter semipositone p-Laplacian problems using the sub- and supersolution method and the mountain pass lemma. 相似文献
138.
139.
A. Nakaruk C. Y. Lin D. S. Perera C. C. Sorrell 《Journal of Sol-Gel Science and Technology》2010,55(3):328-334
Essentially fully dense titania thin films were spin coated on fused quartz substrates under identical conditions and subjected
to annealing over the range 750°–900°C. The films were of a consistent ~400 nm thickness. The anatase → rutile phase transformation
temperature was between 750°C and 800°C, with first-order kinetics; annealing at 900°C yielded single-phase rutile. Silicon
contamination from the fused quartz substrate was considered to be critical since it suppressed both titania grain growth
(maintaining constant grain size) and the phase transformation (occurring at an unusually high temperature); its presence
also was considered to be responsible for the formation of lattice defects, which decreased the transmittances and the band
gaps. 相似文献
140.
Magana D Perera SC Harter AG Dalal NS Strouse GF 《Journal of the American Chemical Society》2006,128(9):2931-2939
Mn ion doping of CdSe and other semimagnetic quantum dot (QDs) alloys has been an area of active speculation for over a decade. We report evidence of Mn(II) doping of CdSe grown from a cubic single source precursor that is superparamagnetic (SPM) with a blocking temperature of 40 K following thermal annealing. Prior to thermal annealing the 4 nm Mn/CdSe (1% Mn) QDs exhibit mainly paramagnetic behavior between 300 and 2 K, with a weak antiferromagnetic exchange. Following thermal annealing of the sample, high-temperature ferromagnetic exchange is observed in the magnetization data with the onset of an SPM phase at 40 K that exhibits a coercivity of 0.1 T at 2 K. The switching-on of SPM behavior is believed to be linked to ion migration with formation of (Se-Mn-Se-Mn-Se-Mn)n centers within the nanocrystal that exhibit coupled magnetic moments. Electron paramagnetic resonance (EPR) provides evidence of two distorted T(d) Mn core sites, a clustered site (dipolar broadened), and a localized Mn site (hyperfine-split). The ratio of the EPR signature for the dipolar broadened site increases following annealing and shows a hysteretic response around the blocking temperature. These observations suggest that thermal annealing results in enhanced cluster formation explaining the onset of the SPM phase in these nanoscale materials. Evidence of SPM behavior is evident in the field-dependent non-Langevin magnetization with a tangential loss in the ac-magnetic susceptibility and the Mydosh parameter (phi = 0.16). 相似文献