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121.
Luis Barreira Claudia Valls 《Nonlinear Analysis: Theory, Methods & Applications》2011,74(18):7210-7225
We give a simple and direct proof of the Grobman–Hartman theorem for nonautonomous differential equations obtained from perturbing a nonuniform exponential dichotomy. In particular, we do not need to pass through discrete time and obtain the result as a consequence of a corresponding result for maps. To the best of our knowledge, this is the first direct approach for nonuniform exponential dichotomies. We also show that the conjugacies are continuous in time and Hölder continuous in space. In addition, we describe the dependence of the conjugacies on the perturbation, and we obtain a reversibility result for the conjugacies of reversible differential equations. We emphasize that the additional work required to consider nonuniform exponential dichotomies is substantial. 相似文献
122.
123.
Guasch L Sala E Valls C Blay M Mulero M Arola L Pujadas G Garcia-Vallvé S 《Journal of computer-aided molecular design》2011,25(8):717-728
Peroxisome Proliferator-Activated Receptor γ (PPARγ) full agonists are molecules with powerful insulin-sensitizing action
that are used as antidiabetic drugs. Unfortunately, these compounds also present various side effects. Recent results suggest
that effective PPARγ agonists should show a low transactivation activity but a high binding affinity to inhibit phosphorylation
at Ser273. We use several structure activity relationship studies of synthetic PPARγ agonists to explore the different binding
features of full and partial PPARγ agonists with the aim of differentiating the features needed for binding and those needed
for the transactivation activity of PPARγ. Our results suggest that effective partial agonists should have a hydrophobic moiety
and an acceptor site with an appropriate conformation to interact with arm II and establish a hydrogen bond with Ser342 or
an equivalent residue at arm III. Despite the fact that interactions with arm I increase the binding affinity, this region
should be avoided in order to not increase the transactivation activity of potential PPARγ partial agonists. 相似文献
124.
We study the existence of local analytic first integrals of a class of analytic differential systems in the plane, obtained from the Chua?s system studied in L.O. Chua (1992, 1995), N.V. Kuznetsov et al. (2011), G.A. Leonov et al. (2012) , , and . The method used can be applied to other analytic differential systems. 相似文献
125.
Toyoda H Trischuk W de Troconiz JF Truitt S Tseng J Turini N Ukegawa F Valls J Vejcik S Velev G Vidal R Vilar R Vologouev I Vucinic D Wagner RG Wagner RL Wahl J Wallace NB Walsh AM Wang C Wang CH Wang MJ Watanabe T Waters D Watts T Webb R 《Physical review letters》2000,84(10):2094-2099
We have reconstructed the radiative decays chi(b)(1P)-->Upsilon(1S)gamma and chi(b)(2P)-->Upsilon(1S)gamma in p&pmacr; collisions at sqrt[s] = 1.8 TeV, and measured the fraction of Upsilon(1S) mesons that originate from these decays. For Upsilon(1S) mesons with p(Upsilon)(T)>8.0 GeV/c, the fractions that come from chi(b)(1P) and chi(b)(2P) decays are [27.1+/-6.9(stat)+/-4. 4(syst)]% and [10.5+/-4.4(stat)+/-1.4(syst)]%, respectively. We have derived the fraction of directly produced Upsilon(1S) mesons to be [50.9+/-8.2(stat)+/-9.0(syst)]%. 相似文献
126.
127.
We obtain a C1 center manifold theorem for perturbations of delay difference equations in Banach spaces with infinite delay. Our results extend in several directions the existing center manifold theorems. Besides considering infinite delay equations, we consider perturbations of nonuniform exponential trichotomies and generalized trichotomies that may exhibit stable, unstable and central behaviors with respect to arbitrary asymptotic rates ecρ(n) for some diverging sequence ρ(n). This includes as a very special case the usual exponential behavior with ρ(n)=n. 相似文献
128.
129.
Enis Oguz Oriol T. Valls Gene F. Mazenko J. Luscombe Steven J. Heilig 《Surface science》1982,118(3):572-584
The diffusive motion of adsorbates on crystal planes is studied by means of a lattice gas model with stochastic dynamics, in the disordered phase and at half coverage. The diffusion coefficient and the time-correlation functions measured in field-emission experiments are calculated. These correlation functions are shown to have the proper hydrodynamic power law decay at long times. It is pointed out that if experiments are done at times before the onset of the hydrodynamic regime the value of the diffusion coefficient obtained will be too small. Our results show also that correlations among the adsorbed particles persist for times longer than predicted by a hydrodynamical approximation. 相似文献
130.
Tseng J Turini N Ukegawa F Vaiciulis T Valls J Vejcik S Velev G Vidal R Vilar R Volobouev I Vucinic D Wagner RG Wagner RL Wahl J Wallace NB Walsh AM Wang C Wang CH Wang MJ Watanabe T Waters D Watts T Webb R Wenzel H Wester WC Wicklund AB 《Physical review letters》2000,85(7):1378-1383
Events collected by the Collider Detector at Fermilab (CDF) with an energetic jet plus large missing transverse energy can be used to search for physics beyond the standard model. We see no deviations from the expected backgrounds and set upper limits on the production of new processes. We consider in addition the production of light gravitinos and set a limit at 95% confidence level on the breaking scale sqrt[F]>/=217 GeV, which excludes gravitino masses smaller than 1.1x10(-5) eV/c(2). 相似文献