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991.
Studies of breakdown threshold intensity for air at various pressures in the range of 24–760 torr using 0.355, 0.532 and 1.06
μm radiation are reported. We observep
−0.8 scaling ofI
th at 1.06 μm and a weak scaling ofp
−0.4 at 0.532 and 0.355 μm radiation. Strong dependence of breakdown spot size on laser power but weak dependence on air pressure
is observed. 相似文献
992.
In this paper a statistical multiplexer that processes a mixture of real-time and non-real-time traffic is studied under bursts of traffic. Different scheduling algorithms are compared under conditions when one of the classes of traffic has a sudden increase in its arrival rate during a short period of time. The results show a difference in the way the scheduling disciplines studied behave under short overloads of traffic even though the scheduling algorithms had been set up to give similar performance under steady-state arrivals. The lifetime of real-time packets is shown to have a great effect on the way in which the performance of the scheduling algorithms compare.Robert Lackman is an IBM employee in the IBM Resident Study Program. 相似文献
993.
M A Alliegro K D Dyer E J Cragoe B M Glaser M C Alliegro 《Journal of chromatography. A》1992,582(1-2):217-223
An assay for amiloride was devised for efficient use with the wide variety of analogues available. Amiloride was extracted from 1-ml plasma samples by elution from a C8 preparative column with 6% acetonitrile-45% methanol-5.4% acetic acid, adjusted to pH 4.0 with trimethylamine. Samples were lyophilized, resuspended in 50% methanol, filtered through 0.22-microns Spin-X cartridges, applied to a reversed-phase C18 column, and eluted in a 0-50% acetonitrile gradient in 0.4% acetic acid, pH 4.5 (1.2 ml/min). Detection by ultraviolet absorbance at 360 nm was linear from 1 to 1000 ng. Versatility of the method was demonstrated with the analogues benzamil, 6-hydro-, 6-iodo-, 5-hexamethylene-, and 5-chlorobenzyl-2',4'-dimethylbenzyl-amiloride. 相似文献
994.
995.
W. D. Hutchison A. V. J. Edge N. Yazidjoglou D. H. Chaplin 《Hyperfine Interactions》1992,75(1-4):291-298
The high resolution hyperfine spectroscopy, modulated adiabatic passage of oriented nuclei (MAPON), has been applied for the
first time to high purity, elemental systems. Detailed comparisons between the electric quadrupole hyperfine interactions
(EQI’s) and, in particular, their distributions, are obtained for60CoCo where the hosts are a single crystal of hcp cobalt and a polycrystalline cobalt foil of predominantly fcc character. For
hcp Co, with the electronic magnetization, M, parallel to the c-axis, the mode value P/h=3e2qQ/4I(2I−1)h=−48.5(5) kHz. This fractional distribution implies the sharpest electric field gradient (efg) measured in a metal
to date, using MAPON spectroscopy, in excess of two times sharper than that of the most dilute impurity efg in a crystallographically
cubic ferromagnetic host. The mode efg is Vzz=−27.3(32)×1019 Vm−2. For the polycrystalline, predominantly fcc foil, prepared by quenching, the EQI mode value is P/h=−6.2(4) kHz with a FWHM
of 12.0(7) kHz yielding a mode efg of Vzz=−3.5(5)×1019 Vm−2. 相似文献
996.
The use of a direct liquid introduction type liquid chromatographic-mass spectrometric interface to study highly thermally labile rifamycin antibiotics is described. Using negative ionization, abundant molecular ions were observed, and the spectra, also contained structurally significant fragments. Variation of the high-performance liquid chromatographic parameters did not change the spectra, thus making it easy to change chromatographic conditions. In quantitative studies, a surprising correlation was found, indicating that the mass spectrometric signal was proportional to the square of the sample concentration. 相似文献
997.
Some hydrodynamic aspects of 3-phase inverse fluidized bed 总被引:2,自引:0,他引:2
Krishna S.V.S.R. Bandaru D.V.S. Murthy K. Krishnaiah 《中国颗粒学报》2007,5(5):351-356
Hydrodynamics of 3-phase inverse fluidized bed is studied experimentally using low density particles for different liquid and gas velocities. The hydrodynamic characteristics studied include pressure drop, minimum liquid and gas fluidization velocities and phase holdups. The minimum liquid fluidization velocity determined using the bed pressure gradient, decreases with increase in gas velocity. The axial profiles of phase holdups shows that the liquid holdup increases along the bed height, whereas the solid holdup decreases down the bed. However, the gas holdup is almost uniform in the bed. 相似文献
998.
C.X. Gao F.C. Yu S.Y. Jeong A.R. Choi P. Parchinskiy D.J. Kim H.J. Kim Y.E. Ihm C.G. Kim C.S. Kim 《Journal of magnetism and magnetic materials》2006
GaMnN and Be-codoped GaMnN were grown via molecular beam epitaxy using a single GaN precursor and their structural and magnetic properties were examined. X-ray diffraction and superconducting quantum interference device (SQUID) measurements revealed that the grown layers are homogeneous without precipitates. The saturation magnetization of GaMnN has increased from ∼4 to ∼16 emu/cm3 via codoping of Be. The d–d exchange interaction between Mn atoms was discussed for the ferromagnetism of GaMnN. 相似文献
999.
B. Zhang S. D. Yao K. Wang D. B. Ding Beijing P.R. China Beijing P.R. China Beijing P.R 《Journal of Radioanalytical and Nuclear Chemistry》2006,269(1):9-13
Summary Department of Technical Physics, School of Physics, Peking Unive 相似文献
1000.
Yu. A. Dobrovolsky P. Jannasch B. Lafitte N. M. Belomoina A. L. Rusanov D. Yu. Likhachev 《Russian Journal of Electrochemistry》2007,43(5):489-501
The 2000–2006 achievements in the field of synthesis, property examination, and application of proton-exchange membranes are reviewed on the basis of more than 120 papers. 相似文献