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181.
Mercère P Zeitoun P Idir M Le Pape S Douillet D Levecq X Dovillaire G Bucourt S Goldberg KA Naulleau PP Rekawa S 《Optics letters》2003,28(17):1534-1536
We report, for the first time to our knowledge, experimental demonstration of wave-front analysis via the Hartmann technique in the extreme ultraviolet range. The reference wave front needed to calibrate the sensor was generated by spatially filtering a focused undulator beam with 1.7- and 0.6-microm-diameter pinholes. To fully characterize the sensor, accuracy and sensitivity measurements were performed. The incident beam's wavelength was varied from 7 to 25 nm. Measurements of accuracy better than lambdaEUV/120 (0.11 nm) were obtained at lambdaEUV = 13.4 nm. The aberrations introduced by an additional thin mirror, as well as wave front of the spatially unfiltered incident beam, were also measured. 相似文献
182.
Mourad?OulmaneEmail author Gordon?W.?Roberts 《Analog Integrated Circuits and Signal Processing》2005,43(3):269-280
In this paper the concept of time amplification in the digital domain is introduced along with a simple CMOS implementation. The time amplifier is presented in the context of a high resolution time-to-digital converter. The issue of limited linearity of the time amplifier is addressed through the utilization of an efficient calibration technique that allows for the correction of such non-ideality. Experimental data validates the design of a resistively loaded time amplifier with a gain of 182 Second/Second. Also, simulations suggest that the time amplifier can be designed for gains up to a few thousands with input dynamic ranges in excess of a few hundred picoseconds. Also, some figures of merit and performance are introduced along with a discussion on some of the trade-offs involved in the design of a time amplifier.Mourad Oulmane received the B.A.Sc. degree from the University of Constantine, Algeria, in 1995, and the M.A.Sc. degree in physics from the Institut National Polytechnique de Grenoble, France, in 1997, the M.Eng. Degree from McGill University in 2001 where he is pursuing a PhD Degree. His research interests include analog/mixed-signal/RF IC design as well as interconnect and semiconductor technologies design and modeling.Gordon W. Roberts received the B.A.Sc. degree from the University of Waterloo, Canada, in 1983, and the M.A.Sc. and Ph.D. degrees from the University of Toronto, Canada, in 1986 and 1989, respectively, all in electrical engineering. He is currently on leave from McGill University as a co-founder of DFT Microsystems, Inc., where he holds the position of Chief Technical Officer. At McGill University he is a full professor where he holds the James McGill Chair in Electrical and Computer Engineering. He has published numerous papers in scientific journals and conferences, and he has contributed chapters to various industrially focused textbooks. In addition, he has co-written five textbooks related to analog IC design and mixed-signal test for undergraduate and graduate engineering programs. Dr. Roberts has held many administration roles within conference organizations; most recently he was the 2003 program chair of the IEEE International Test Conference. Dr. Roberts is a Fellow of the IEEE. 相似文献
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Daoubi M Benharref A Hernandez-Galán R Macías-Sánchez AJ Collado IG 《Natural product research》2004,18(2):177-181
Two novel steroids, 3beta,7alpha-dihydroxy-4alpha,14alpha-dimethyl-5alpha-cholest-8-en-11-one (2) and 3beta,7beta-dihydroxy-4alpha,14alpha-dimethyl-5alpha-cholest-8-en-11-one (3) were isolated from the latex of Euphorbia officinarum. Their structures were established on the basis of NMR and MS studies. 相似文献
186.
K.D. Belfield M.V. BondarO.V. Przhonska K.J. SchaferW. Mourad 《Journal of luminescence》2002,97(2):141-146
Investigations of the absorption, steady-state fluorescence, excitation and excitation anisotropy properties of several fluorene derivatives, (7-benzothiazol-2-yl-9,9-didecylfluoren-2-yl)-diphenylamine, 9,9-didecyl-2,7-bis-(N,N-diphenylamino)fluorene and {4-[2-(7-diphenylamino-9,9-diethylfluoren-2-yl)vinyl]phenyl}phosphoric acid diethyl ester, in liquid solutions have been conducted. Spectral characteristics of these compounds, including fluorescence quantum yields, were measured in acetonitrile, methylene chloride, tetrahydrofuran and hexane at room temperature. Excitation anisotropy spectra provided a means to determine the nature of the short wavelength absorption bands as an electronic transition into a higher excited singlet state. It was found that excitation spectra in the short wavelength region do not correspond to the absorption bands that are correlated with the wavelength dependence of the fluorescence quantum yields. Major reasons of such spectral behavior are discussed. 相似文献
187.
The φ meson productions in Au+Au and/or Pb+Pb collisions at AGS, SPS,
RHIC, and LHC energies have been studied systematically with a hadron and
string cascade model LUCIAE. After considering the energy dependence of the
model parameter α in string fragmentation function and adjusting it
to the experimental data of charged multiplicity to a certain extent,
the model predictions for φ meson yield, rapidity, and
transverse mass distributions are compatible with the experimental data at
AGS, SPS and RHIC energies. A calculation for Pb+Pb collisions at LHC energy
is given as well. The obtained fractional variable in string fragmentation
function shows a saturation in energy dependence. It is discussed that the
saturation of fractional variable in string fragmentation function might be a
qualitative representation of the energy dependence of nuclear transparency. 相似文献
188.
The energy and centrality dependencies of charged particle pseudorapidity density in relativistic nuclearcollisions were studied using a hadron and string cascade model, JPCIAE. Both the relativistic p+p experimental dataand the PHOBOS and PHENIX Au+Au data at RHIC energy could be fairly reproduced within the framework ofJPCIAE model and without retuning the model parameters. The predictions for Pb + Pb collisions at the LHC energywere also given. We computed the participant nucleon distributions using different methods. It was found that thenumber of participant nucleons is not a well defined variable both experimentally and theoretically. Thus it may beinappropriate to use the charged particle pseudorapidity density per participant pair .as a function of the number ofparticipant nucleons for distinguishing various theoretical models. 相似文献
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