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31.
J. Tardy I. Thomas P. Viktorovitch M. Gendry J. L. Perrossier C. Santinelli M. P. Besland P. Louis
G. Post
《Applied Surface Science》1991,50(1-4):383-389Room-temperature bias stress measurements were performed on n-type InP MIS capacitors. A wide range of interface passivation processes and gate dielectrics was investigated. A generally observed behaviour under positive bias stress is a slow trapping - fast detrapping consistent with a trap distribution in the interfacial layer above the conduction band edge of InP. Large variations both in the magnitude and in the time dependence of the flat-band voltage shift ΔVFB are observed. We discuss these drift behaviours in terms of interface traps - rather than bulk dielectric traps - in relation with the physico-chemical properties of the interface. It is shown that devices based on InP treated by annealing under arsenic pressure and controlled oxidation exhibit a very good stability. For any passivation procedure, the drift is strongly diminished if the device is stressed with AC voltage compared to DC voltage. 相似文献
32.
The large difference in S1 → Sn absorption spectrum, fluorescence spectrum and fluorescence decay time of 1,1′-binaphthyl in fluid solution as compared to rigid solution can be related to a change of the molecular conformation of the fluorescent state. 相似文献
33.
Density fluctuations, were observed to have no effect on the classical diffusion of a collisional helium plasma across a poloidal octupole field with an additional weak toroidal field. The implication of these results on tokamak scattering experiments is discussed. 相似文献
34.
In this letter a frequency-doubled frequency-stabilized CW ring dye laser for the wavelength region 292–305 nm is described. 500 μW U.V. power combined with a 2 MHz linewidth and a 7 GHz scanwidth has been obtained by intracavity frequency doubling in an ADA crystal. The set-up has been tested on the hyperfinestructure of the λ = 293.3 nm transition 5p2P → 7s2S in In1. 相似文献
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36.
激光器非线性失真对SCM光波系统的影响 总被引:1,自引:1,他引:0
对于宽带副载波复用(SCM)的光波系统,研究并设法减小光源的非线性所引起的谐波失真和交调失真,是一个重要的理论课题。本文分析激光器的P—I曲线的非线性以及谐振腔里光子和电子相互耦合所引起的固有非线性及其对复用信道的影响。 相似文献
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38.
M. A. Zaki Ewiss W. Hogervorst W. Vassen B. H. Post H. Wijnen 《Zeitschrift für Physik A Hadrons and Nuclei》1985,322(3):371-383
The Stark effect has been studied in the odd-parity 6snf1,3F3 Rydberg series of barium with high-resolution laser-atomic-beam spectroscopy. Scalar and tensor polarizabilities have been measured of 6snf1F3 levels with n=11–30 and of 6snf3F3 levels withn = 12 ? 40. The contributions of the adjacent even-parity Rydberg levels to these polarizabilities have been calculated as far as data are available. This results in important additional information on the only partly known 6sng1,3G4 series and confirms the perturbation of these series atn = 24 by a 5d7dJ= 4 level. A tentative three-channel quantum-defect-theory analysis of the1,3G4 series has been performed. It is shown that reported level energies of the 6snd1,3D2 series are systematically 0.14 cm?1 too high. 相似文献
39.
We develop and implement linear formulations of general Nth order stochastic dominance criteria for discrete probability distributions. Our approach is based on a piece-wise polynomial representation of utility and its derivatives and can be implemented by solving a relatively small system of linear inequalities. This approach allows for comparing a given prospect with a discrete set of alternative prospects as well as for comparison with a polyhedral set of linear combinations of prospects. We also derive a linear dual formulation in terms of lower partial moments and co-lower partial moments. An empirical application to historical stock market data suggests that the passive stock market portfolio is highly inefficient relative to actively managed portfolios for all investment horizons and for nearly all investors. The results also illustrate that the mean–variance rule and second-order stochastic dominance rule may not detect market portfolio inefficiency because of non-trivial violations of non-satiation and prudence. 相似文献
40.
Valero A Post JN van Nieuwkasteele JW Ter Braak PM Kruijer W van den Berg A 《Lab on a chip》2008,8(1):62-67
There is great interest in genetic modification of bone marrow-derived mesenchymal stem cells (MSC), not only for research purposes but also for use in (autologous) patient-derived-patient-used transplantations. A major drawback of bulk methods for genetic modifications of (stem) cells, like bulk-electroporation, is its limited yield of DNA transfection (typically then 10%). This is even more limited when cells are present at very low numbers, as is the case for stem cells. Here we present an alternative technology to transfect cells with high efficiency (>75%), based on single cell electroporation in a microfluidic device. In a first experiment we show that we can successfully transport propidium iodide (PI) into single mouse myoblastic C2C12 cells. Subsequently, we show the use of this microfluidic device to perform successful electroporation of single mouse myoblastic C2C12 cells and single human MSC with vector DNA encoding a green fluorescent-erk1 fusion protein (EGFP-ERK1 (MAPK3)). Finally, we performed electroporation in combination with live imaging of protein expression and dynamics in response to extracellular stimuli, by fibroblast growth factor (FGF-2). We observed nuclear translocation of EGFP-ERK1 in both cell types within 15 min after FGF-2 stimulation. Due to the successful and promising results, we predict that microfluidic devices can be used for highly efficient small-scale 'genetic modification' of cells, and biological experimentation, offering possibilities to study cellular processes at the single cell level. Future applications might be small-scale production of cells for therapeutic application under controlled conditions. 相似文献