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841.
842.
A new set of matrix addressing schemes for ferroelectric liquid crystal displays is reported. The schemes use the minimum in the response time-voltage characteristic found in certain mixtures and deliver improved operating speed and contrast ratio compared with previously reported schemes operating in this mode. 相似文献
843.
This paper surveys applications of dynamic programming to decisionproblems faced by active participants in sports. 相似文献
844.
B. Vizoso I. R. Matías M. López-Amo M. A. Muriel J. M. López-Higuera 《Optical and Quantum Electronics》1995,27(10):847-857
The design of a double-parallel amplified recirculating optical delay line utilizing an erbium-doped fibre amplifier for a fibre optical bus is described. This structure is used for amplifying, equalizing and filtering multicarrier signals coming from optoelectronic units attached to fibre couplers. The use of this structure for a hybrid multimode-singlemode fibre bus that includes optoelectronic units for sensors is also demonstrated. 相似文献
845.
E. A. Klop B. J. Lommerts J. Veurink J. Aerts R. R. Van Puijenbroek 《Journal of Polymer Science.Polymer Physics》1995,33(2):315-326
Differential scanning calorimetry and high temperature x-ray diffraction were used to study the perfectly alternating copolymer of ethene and carbon monoxide (polyketone; POKC2). It was found that oriented POK-C2 fibers show a crystalline phase transition at a temperature between 110–125°C with a 10% change in crystalline density. At this temperature, the crystal structure reported recently (POK-α) is transformed to a crystal structure that was reported in the past for room temperature imperfectly alternating polyketone. The latter structure will be designated as POK-β. The influence of chain defects on the crystal structure was studied by synthesizing terpolymers (POK-C2/C3), in which small amounts of propylene-CO units are incorporated into the polymer backbone. The resulting terpolymers differ from the copolymer by the presence of methyl groups randomly distributed along the polyketone backbone chain. Evidence is presented that indicates that the methyl groups are built into the crystal lattice as defects. With more than 5 mole-% propene the terpolymer fibers crystallize exclusively in the β-modification. Below this level the α/β ratio (at room temperature) increases with decreasing amounts of propene. Both as-synthesized and as-spun POK-C2 were found to consist of both POK-α and POK-β; the α/β ratio depends on the method of preparation. Because the drawn POK-C2 fibers studied here consist exclusively of POK-α, the process of spinning and drawing leads to the transformation of unoriented β-rich material into oriented POK-α. © 1995 John Wiley & Sons, Inc. 相似文献
846.
M. J. Gaylard G. C. MacLeod D. P. Smits M. E. West D. J. Walt 《Journal of chemical crystallography》1993,23(9):763-763
Future contributions toJournal of Crystallographic and Spectroscopic Research 相似文献
847.
Summary.
We consider a discontinuous Galerkin finite element method
applied in time to a model Volterra equation of the second kind.
A residual-based computable
Galerkin-error estimate is derived
for .
This estimate does not explicitly
contain the time step and therefore the time step
control must be based
on a heuristic criterion, the estimate can then be used to
demonstrate the integrity, or otherwise, of the finite element
solution. After performing some numerical experiments
we conclude that this approach is at least competetive
with classical discretizations since it is
computationally simple to implement,
but has the added advantage of
reliable error feedback.
Received June 25, 1995 相似文献
848.
3-Hydroxybutyramides are obtained in high optical yield from ethyl (±)-3-hydroxybutyrate and aliphatic amines when the reaction is catalyzed by Candida antartica lipase. The chemical reduction of these 3-hydroxybutyramides yields the corresponding 1,3 -aminoalcohols. 相似文献
849.
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
850.
Polarization dynamics are considered in the presence of an anisotropic Kerr non-linearity in the most common semiconductor waveguide geometry. The equations of motion are formulated in terms of Stokes polarization parameters and their Hamiltonian form is derived. Stationary solutions and their stability are found for plane-wave propagation. It is found that the non-integrable problem of mixed-polarization spatial soliton dynamics can be largely explained in terms of the equivalent plane-wave solutions. 相似文献