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991.
Chaos control of a spinning disk model via delayed feedback method is presented. The feedback gain is obtained and adapted according to a minimum entropy (ME) algorithm. In this method, stabilizing an unstable fixed point of the system Poincare map is achieved by minimizing the entropy of point distribution on the Poincare section. Simulation results show the feasibility of the proposed method in applying the delayed feedback technique for chaos control of spinning disks. 相似文献
992.
993.
994.
Carbon disulfide (CS2) was determined at trace levels by its induction effect on the reaction of triiodide with azide in acidic media. The reaction was monitored spectrophotometrically by the decreased absorbance of triiodide over a period of 30 - 180 s from the initiation of the reaction at 350 nm, with calibration linear range of 0.020 - 1.870 microg/ml CS2. The limit of detection is 0.013 microg/ml CS2. A carbon-active column was used for sample solution clean up. The proposed method was successfully applied to the determination of trace carbon disulfide in natural water. 相似文献
995.
A. Sh Ghazal M. S. M. Nour El-Din M. Y. M. Hassan 《The European Physical Journal A - Hadrons and Nuclei》2004,19(2):221-229
A linear form of density-dependent total nucleon-nucleon (NN) cross-section that depends on the coordinates of the projectile and target is applied in the Glauber phase shift formula. The only free parameter in these calculations is the density-dependent parameter
, which is adjusted to obtain an agreement between the calculated angular distribution of the elastic-scattering cross-section and the corresponding experimental one. The elastic scattering of the 12C ion on the 12C ion target has been studied at incident energies of 300, 360, 1016, 1441 and 2400 MeV. The total reaction cross-section
is also calculated with the obtained value of
for the same reactions. The obtained values of
are compared with those obtained from the optical-model analysis as well as those of the experimental value. Nuclear transparency effects are also discussed. Generally, the density-dependent NN cross-section improves the calculated results.Received: 11 February 2003, Revised: 8 July 2003, Published online: 26 January 2004PACS:
24.10.-i Nuclear-reaction models and methods - 25.70.-z Low and intermediate energy heavy-ion reactions 相似文献
996.
Ultrathin films of chiral polyelectrolyte complex, prepared by the multilayering process, exhibit selectivity in the membrane separations of optically active compounds, such as l- and d-ascorbic acid. The flux through these polyelectrolyte multilayers, PEMUs, is exceptionally high and may be controlled by the concentration of salt present in the permeating solutions. Both in-situ ATR-FTIR and chiral capillary electrochromatography indicate that flux selectivity is mainly kinetically controlled, stemming from a difference in diffusion rates of various enantiomers through PEMUs, rather than a difference in partitioning. 相似文献
997.
We propose an interaction-induced cooling mechanism for two-component cold fermions in an optical lattice. It is based on an increase of the spin entropy upon localization, an analogue of the Pomeranchuk effect in liquid helium 3. We discuss its application to the experimental realization of the antiferromagnetic phase. We illustrate our arguments with dynamical mean-field theory calculations. 相似文献
998.
A. H. Khater M. M. Hassan E. V. Krishnan Y. Z. Peng 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,50(2):177-184
New several classes of exact solutions are obtained in terms of the
Weierstrass elliptic function for some nonlinear partial
differential equations modeling ion-acoustic waves as well as dusty
plasmas in laboratory and space sciences. The Weierstrass elliptic
function solutions of the Schamel equation, a fifth order dispersive
wave equation and the Kawahara equation are constructed. Moreover,
Jacobi elliptic function solutions and solitary wave solutions of
the Schamel equation are also given. The stability of some periodic
wave solutions is computationally
studied. 相似文献
999.
1000.
M. Amin H. H. Hassan G. M. Nasr 《Journal of polymer science. Part A, Polymer chemistry》1983,21(12):3353-3360
Following a series of experiments on the effect of different factors of the electrical conductivity of carbon-black-loaded styrene butadiene rubber, an attempt was made to study the effect on electrical conduction of changing the sulfur content. It was found that an optimum sulfur content leads to a swelling-resistant composite with good electrical insulation. This was done for dry as well as wet specimens of rubber. 相似文献