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991.
992.
C. D. Schaper Y. M. Cho T. Kailath 《Applied Physics A: Materials Science & Processing》1992,54(4):317-326
A low-order model of rapid thermal processing (RTP) of semiconductor wafers is derived. The first-principles nonlinear model describes the static and dynamic thermal behavior of a wafer with approximate spatial temperature uniformity undergoing rapid heating and cooling in a multilamp RTP chamber. The model is verified experimentally for a range of operating temperatures from 400° C to 900° C and pressures of 1 Torr and 1 atmosphere in an inert N2 environment. Theoretical predictions suggest model validity over a still wider range of operating conditions. One advantage of the low-order model over previous high-order and statistical models is that the proposed model contains a small number of fundamental parameters and functions that, if necessary, are easily identifiable. Furthermore, because of reduced computational complexity, the low-order model can be used in real-time predictive applications including signal processing and process control design. In studying and verifying the model, the dynamic behavior of a semiconductor wafer undergoing rapid temperature changes is characterized. Close comparison between theory and experiment in terms of the wafer eigenvalue and dc gain is demonstrated; the strong nonlinear effects of temperature are shown. Convective heat transfer losses are also examined and are shown to increase with radial position on the wafer. 相似文献
993.
Mathematical Notes - 相似文献
994.
J. Odeurs R. Coussement C. L'abbé G. Neyens G.R. Hoy E.E. Alp W. Sturhahn T. Toellner C. Johnson 《Hyperfine Interactions》1998,113(1-4):455-463
A new time integrated method for the study of resonant nuclear scattering of synchrotron radiation in the forward direction
or in Bragg directions is introduced. This method gives in principle similar information as the well known time differential
method. A brief comparison of both methods is presented. The idea is to excite coherently the nuclei incorporated in two absorbers,
one moving with respect to the other. The fields radiated by the nuclei from both absorbers interfere and each time the nuclear
energy in one absorber matches, by Doppler modulation, the nuclear energy of the other, an extremum in the time integrated
intensity is observed. The results of the first experiments at the Advanced Photon Source at the Argonne National Laboratory
will be presented.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
995.
D. A. Ténné V. A. Gaisler N. T. Moshegov A. I. Toropov A. P. Shebanin 《JETP Letters》1998,68(1):53-58
Experiments on Raman scattering in the “forward” geometry, permitting observation of anisotropy of the optical phonons, are
performed on specially prepared short-period GaAs/AlAs superlattice structures with the substrates removed and the surfaces
covered with an antireflective layer. The experimental data agree well with the computational results obtained for the angular
dispersion of optical phonons in superlattices on the basis of a modified continuum model.
Pis’ma Zh. éksp. Teor. Fiz. 68, No. 1, 50–55 (10 July 1998) 相似文献
996.
Naba K. Mondal 《Pramana》1998,51(1-2):65-76
In this article, we review some of the recent results from CDF and DØ experiments at the Tevatron and their prospects at the upgrade. Among the topics discussed are top quark physics, electroweak physics, qcd physics and new physics beyond standard model. 相似文献
997.
H Akiyama H Toyoda S Yamanashi Y Sagehashi T Toida T Imanari 《Biomedical chromatography : BMC》1991,5(5):189-192
A high performance liquid chromatographic (HPLC) system is described for determination of the unsaturated disaccharide (delta Di-HA) derived from hyaluronic acid (HA) in human urine by digestion with hyaluronidase SD. The effects of eluents on the separation of delta Di-HA and delta Di-0S, which is derived from the reaction of chondroitin with the enzyme, have been studied. The established chromatographic conditions were as follows--column: a stainless steel tube (4 mm i.d. x 250 mm) packed with TSKgel NH2-60; eluent: a mixture of acetonitrile and 0.1 M Tris-HCl buffer containing 0.1 M boric acid and 10 mM sodium sulphate, pH 7.0 (64:36, v/v). The strong fluorescence of unsaturated disaccharide after the reaction with 2-cyanoacetamide in alkaline medium was used for post-column detection. The calibration curve for delta Di-HA was linear in the range 5 pmol-5nmol with a practical detection limit of 2 pmol. The assay coefficients of variation (n = 5) at 200 pmol for delta Di-HA and delta Di-0S were 1.7 and 1.5%, respectively. This HPLC system has been applied to the determination of HA in human urine. 相似文献
998.
A commercial baker’s yeast was subjected to selection in a continuous turbidostat cultivation with increasing concentration of acetic acid. The final acetic acid content in fresh medium was 0.6% or 0.8% v/v. Two of seven selected variants were stable over 15 sequential shake flask cultivations without selection pressure. After laboratory scale production of baker’s yeast, one of the variants also showed increased acetic acid tolerance in sour dough. The overall raising power (mL CO2/h) in sour dough was improved 36%. 相似文献
999.
The 351 nm laser-damage thresholds (at 0.7 nm pulse length) of monomeric liquid crystals are reported and results from aromatic-core samples are compared with those from fully saturated systems. The role of π-electron conjugation is examined and identified as the key cause for laser damage. For UV laser compatibility of devices, the damage behaviour of an alignment-layer polymer (nylon 6/6) was also investigated. 相似文献
1000.
Y2BaCuO5 (211) inclusions are prominent microstructural features found in melt-textured YBa2Cu3Ox (123) superconductors. These particles are of interest because the 123/211 interfaces and the interface-associated defects have been proposed to be flux pinning centers. In addition, the 211 particles are believed to be heterogeneous nucleation centers of dislocation which can increase the critical current density of 123. Unfortunately, only limited studies have been performed on these particles to ascertain their roles in flux pinning. In this investigation, 211 particles, the interfacial structure and defects in undeformed and mechanically deformed melt-textured 123 have been studied by transmission electron microscopy. It was found that there appears to be a preferred orientation between large oblong 211 particles and the 123 matrix. In addition, while the 123/211 interfaces in undeformed 123 are sharp and relatively undistorted, the interfaces in deformed 123 samples are much thicker. Also, the distribution of strained regions and dislocations around oblong 211 particles in undeformed 123 is nonuniform; the interfaces of low surface curvature are relatively free of defects while the surfaces of high curvature are abundant in dislocations. In contrast, the 123/211 interfaces in deformed 123 samples contain high density of dislocations regardless of interface curvature. 相似文献