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121.
F. Donzelli P. M. Gauthier 《Journal of Contemporary Mathematical Analysis (Armenian Academy of Sciences)》2012,47(3):124-133
There exist perturbations of a rational function which remove zeroes and poles from a prescribed region as well as perturbations which add zeroes and poles to a prescribed region. We employ this to show the instability of the Riemann Hypothesis for zeta-functions of smooth projective varieties over finite fields. 相似文献
122.
Bloch constants for planar harmonic mappings 总被引:3,自引:0,他引:3
Huaihui Chen P. M. Gauthier W. Hengartner 《Proceedings of the American Mathematical Society》2000,128(11):3231-3240
We give a lower estimate for the Bloch constant for planar harmonic mappings which are quasiregular and for those which are open. The latter includes the classical Bloch theorem for holomorphic functions as a special case. Also, for bounded planar harmonic mappings, we obtain results similar to a theorem of Landau on bounded holomorphic functions.
123.
124.
125.
126.
We have synthesized 5H-imidazo[2,1-c]pyrrolo[1,2-a][1,4]benzodiazepine 1 in five steps from 1-(2-amino-methylphenyl) pyrrole 4 . Amidino derivatives 11-12 have also been prepared. 相似文献
127.
Xiaopeng Zhao David G. Schaeffer Carolyn M. Berger Daniel J. Gauthier 《Nonlinear dynamics》2007,48(4):381-389
Various authors have shown that, near the onset of a period-doubling bifurcation, small perturbations in the control parameter
may result in much larger disturbances in the response of the dynamical system. Such amplification of small signals can be
measured by a gain defined as the magnitude of the disturbance in the response divided by the perturbation amplitude. In this
paper, the perturbed response is studied using normal forms based on the most general assumptions of iterated maps. Such an
analysis provides a theoretical footing for previous experimental and numerical observations, such as the failure of linear
analysis and the saturation of the gain. Qualitative as well as quantitative features of the gain are exhibited using selected
models of cardiac dynamics. 相似文献
128.
A. Outhouse P. Lawrence M. Gauthier P. A. Hackett 《Applied physics. B, Lasers and optics》1985,36(2):63-75
The laboratory scale-up of a two-stage laser enrichment process for carbon isotopes, involving infrared multiphoton dissociation of freon-22, is described. Unmodified commercial equipment and materials were used. An initial study of the effect of fluence, laser frequency, freon-22 pressure and pressure of argon, nitrogen and trifluoromethyl chloride was made in short irradiation cells (constant fluence) in order to define optimum process parameters. The process was then scaled to higher throughput in longer cells (1–5 m) in which compensation for beam-energy depletion by absorption was made by reduction in the beam area by focussing. From the scale-up experiments, measurements of yield and enrichment of the tetrafluoroethylene product gave demonstrated production rates. These, coupled with measurements of the absorption, allowed extrapolation to production rates assuming total utilization of the available output energy.Using a 100 W TEA CO2 laser (10 J, 10 Hz) we have demonstrated production rates of 0.20 g h–1 carbon-12 at 99.99% carbon-12, 11 mg h–1 carbon-13 at 72% carbon-13 and 2 kg per annum carbon-13 at 50%. Energy absorption measurements imply a capability to produce 3 kg per annum carbon-13 at over 95% carbon-13 in a two-stage process.The apparatus was used to produce gram quantities of carbon-13 depleted freon-22 (99.99% carbon-12). A comparison of the infrared multiphoton dissociation of this material with that of natural freon-22 (1.11% carbon-13) showed that under the conditions required to give selective dissociation of13CF2HCl that12CF2HCl was excited as a result of a dominantly radiative interaction and that collisional transfer from13CF2HCl molecules played a minor role.Issued as NRCC 23639Summer Student 1983, Acadia University, N.S., Canada 相似文献
129.
A comprehensive review of structure work on high-T
c
oxides as reported during the years 1987 and 1988 is given. Thirteen structures are refined from X-ray single-crystal and/or neutron powder diffraction data:I. (Ba1–x
,K
x
)BiO3 (T
c
=30 K),II. (La2–x
, Sr
x
)CuO4 (T
c
=40 K),III. (Nd, Ce, Sr)2CuO4 (T
c
=28 K),IV. (Nd2–x
, Ce
x
)CuO4 (T
c
=24 K),V. YBa2Cu3O7 (T
c
=90 K),VI. YBa2Cu4O8 (T
c
=80 K),VII. Y2Ba4Cu7O14 (T
c
=40 K),VIII. Pb2Sr2NdCu3O8 (T
c
=70 K),IX. TlBa2CaCu2O7 (T
c
=103 K),X. TlBa2Ca2Cu3O9 (T
c
=120 K),XI. Tl2Ba2CuO6 (T
c
=90 K),XII. Tl2Ba2CaCu2O8 (T
c
=112 K),XIII. Tl2Ba2Ca2Cu3O10 (T
c
=125 K). Except forI (perovskite type),II (K2NiF4 type) andIV (Nd2CuO4 type) they represent new structure types. Structure data, bond distances, structure drawings and calculated X-ray powder diffraction patterns are given for each compound. Structural features and correlations with superconductivity are discussed. The review contains 301 citations. 相似文献
130.
We present a dual-beam multiple exposure technique that can generate complex 2-D and 3-D band gap template structures in a photosensitive material. The system parameters related to the planar interference pattern produced by two laser beams and reorientation effect of the sample relative to these planes is presented. Structures such as the 2-D, square and hexagonal arrays of dielectric “rods” and “holes” and the 3-D, cubic, Yablonovite and other profiles are given. We perform band gap calculations on these structures when the dielectric contrast has been increased using a backfill process and discuss techniques for increasing the band gap by sculpting the dielectric profile. 相似文献