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21.
D.J. Pikas S.M. Kirkpatrick D.W. Tomlin L. Natarajan V. Tondiglia T.J. Bunning 《Applied Physics A: Materials Science & Processing》2002,74(6):767-772
Two-photon holographic photopolymerization was used to form switchable Bragg gratings composed of layers of phase-separated
liquid-crystal (LC) domains interspersed with cured, crosslinked polymer. These holographic polymer-dispersed liquid crystals
form a periodic structure which diffracts red light due to nanostructured planes ∼250 nm in spacing. These structures were
formed by interfering two 90-fs pulses coherently upon a reactive syrup consisting of acrylate monomer, liquid crystal, and
a two-photon dye. The large two-photon cross-section allows excitation of the two-photon dye that results in electron transfer
between this dye and the monomer. Diffraction efficiencies of approximately 10% were obtained, which can be modulated using
an electric field applied across the film. Switching speeds below 1 ms were observed due in part to the small size of the
LC domains.
Received: 10 April 2001 / Accepted: 1 July 2001 / Published online: 2 October 2001 相似文献
22.
A structural failure problem was solved using an integrated and iterative program of testing and analysis. The steps taken in solving the problem were: analytical calculations; operational testing; qualifications of analytical results; problem identification; design of corrective action; and confirmatory testing. 相似文献
23.
J. A. Tomlin 《Mathematical Programming》1974,6(1):42-47
In this paper we re-examine some of the available methods for pricing out the columns in the simplex method and point out their potential advantages and disadvantages. In particular, we show that a simple formula for updating the pricing vector can be used with some advantage in the standard product form simplex algorithm and with very considerable advantage in two recent developments: P.M.J. Harris' dynamic scaling method and the Forrest—Tomlin method for maintaining triangular factors of the basis. 相似文献
24.
D. W. Tomlin C. M. Roland L. I. Slutsker 《Journal of Polymer Science.Polymer Physics》1993,31(10):1331-1337
X-ray scattering from a series of poly(ethylene terephthalate) (PET) fibers spun at differet speeds is analyzed to probe the morphology in the direction transverse to the fiber axis. Both the apparent crystal modulus, determined from the change in wide-angle X-ray scattering angle with fiber stretching, and the transverse degree of crystallinity indicate there is a substantial interfiberillar amorphous content. In the PET fiber spun at conventional speeds, only roughly one-quarter of the fiber cross-section is actually occupied by fibrils. The transverse crystallinity increases for fibers spun at speeds sufficient to cause crystallization in the spin line. The X-ray moduli and fibril diameters are correspondingly larger in these high speed spun fibers. © 1993 John Wiley & Sons, Inc. 相似文献
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27.
Rick L. Paul Elizabeth A. Mackey Rolf Zeisler Rabia O. Spatz Bryan E. Tomlin 《Journal of Radioanalytical and Nuclear Chemistry》2009,282(3):945-950
A combination of instrumental neutron activation analysis (INAA) and prompt gamma-ray activation analysis (PGAA) was used
to value assign 35 elements in SRM soil 2709a (San Joaquin Soil). INAA with counting of short-lived radioisotopes was used
for determination of Al, Au, Ca, Dy, K, Mg, Mn, Na, Ti, and V. Elements determined by INAA with counting of intermediate and
long-lived radioisotopes included As, Ba, Ce, Co, Cr, Cs, Eu, Fe, Hf, La, Lu, Nd, Rb, Sb, Sc, Sm, Sr, Ta, Tb, Yb, Zn, and
Zr. Thermal neutron PGAA was used for the determination of H, B, Si, K, Ti, Mn, Fe, Cd and Gd. Expanded uncertainties were
determined for all values reported. 相似文献
28.
A picowatt cryogenic radiometer (PCR) has been fabricated at the microscale level for electrical substitution optical fiber power measurements. The absorber, electrical heater, and thermometer are all on a micromachined membrane less than 1 mm on a side. Initial measurements with input powers from 50 fW to 20 nW show a response inequivalence between electrical and optical power of 8%. A comparison of the response to electrical and optical input powers between 15 pW to 70 pW yields a repeatability better than ±0.3% (k=2). From our first optical tests, the system has a noise equivalent power of ≈5×10(-15) W/√Hz at 2 Hz, but simple changes to the measurement scheme should yield an NEP 2 orders of magnitude lower. 相似文献
29.
Steffen JH Upadhye A Baumbaugh A Chou AS Mazur PO Tomlin R Weltman A Wester W 《Physical review letters》2010,105(26):261803
We report results from a search for chameleon particles created via photon-chameleon oscillations within a magnetic field. This experiment is sensitive to a wide class of unexplored chameleon power-law and dark energy models. These results exclude 5 orders of magnitude in the coupling of chameleons to photons covering a range of 4 orders of magnitude in chameleon effective mass and, for individual models, exclude between 4 and 12 orders of magnitude in chameleon couplings to matter. 相似文献
30.
Global sensitivity analysis of chemical-kinetic reaction mechanisms: construction and deconstruction of the probability density function 总被引:1,自引:0,他引:1
This paper investigates global sensitivity analysis as applied to reaction mechanisms. It uses the HDMR (high-dimensional model representation) expansion and the features of the sensitivity indices to explore the probability density function (pdf) of predicted target outputs that results from the uncertainties in the rate coefficients. We study the autoignition of H(2)/O(2) mixtures, where the pdf describes the uncertainty in ignition delay times due to the uncertainties in the rate coefficients. The global sensitivity analysis in conjunction with the HDMR expansion allows for the deconstruction of the pdf in several different ways. These deconstructions allow the features of the pdf to be understood in terms of the constitute reactions in much finer detail than the study of a variance decomposition alone. 相似文献