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91.
We present a new algorithm for continuation of limit cycles of autonomous systems as a system parameter is varied. The algorithm
works in phase space with an ordered set of points on the limit cycle, along with spline interpolation. Currently popular
algorithms in bifurcation analysis packages compute time-domain approximations of limit cycles using either shooting or collocation.
The present approach seems useful for continuation near saddle homoclinic points, where it encounters a corner while time-domain
methods essentially encounter a discontinuity (a relatively short period of rapid variation). Other phase space-based algorithms
use rescaled arclength in place of time, but subsequently resemble the time-domain methods. Compared to these, we introduce
additional freedom through a variable stretching of arclength based on local curvature, through the use of an auxiliary index-based
variable. Several numerical examples are presented. Comparisons with results from the popular package, MATCONT, are favorable
close to saddle homoclinic points. 相似文献
92.
93.
H R Morris A Chatterjee M Panico B N Green M A Almeida da Silva B S Hartley 《Rapid communications in mass spectrometry : RCM》1989,3(4):110-116
Two-sector linked-scan analysis of an unpurified proteolytic digest of a pyruvate decarboxylase enzyme (60,000 Da) has allowed the discovery and assignment of an amino-terminal post-translational modification and processing event. A difference in amino acid sequence from that predicted by a recently published nucleotide sequence has also been found. These results illustrate both the use and considerable potential of linked-scan methods for the analysis of complex biopolymer mixtures. 相似文献
94.
Experimental measurements of power spectra of a single longitudinal and transverse mode ring dye laser are presented that reveal the critical slowing down of the laser near threshold. External pump noise serves as a probe of the frequency response of the dye laser. Detailed comparisons of the spectral characteristics with computer simulations and an approximate analytic theory are given. The dynamics of spatial pattern formation in a multimode dye laser is examined through measurements of first-passage-time distributions. A comparison of the experiments with computer simulations based on a simple theoretical model of the two-mode laser shows qualitative agreement. These measurements indicate that there are a variety of complex phenomena associated with the transverse mode pattern formation dynamics that need to be addressed theoretically and studied further experimentally. 相似文献
95.
Alpha particle and deuteron impactL-subshell ionization cross-sections of Ar, Cu, Ge, Br, Zr and Ag have been computed using Vriens’ expressions for ionization
cross-section of atoms due to impact of heavy charged particles. The effects of Coulomb deflection of the projectile and increase
in binding of the target electron in the presence of projectile have been incorporated. Hartree-Fock velocity distributions
for the target electrons have been used in the present calculations. The simple binary encounter approximation model is found
to give results which are in satisfactory agreement with those obtained from experiments and from other theories. 相似文献
96.
The basic principle that has been used in the application of superheated drops in neutron spectrometry is its dependence of threshold energy of nucleation on temperature. In the present work, superheated drops of R114 suspended in a visco-elastic gel were irradiated at different temperatures by neutrons obtained from an 241Am–Be source. The temperature of the detector was converted to the energy of the incident neutrons following the method developed by us to unfold the neutron energy spectrum. The threshold energy obtained by us agrees well with other results obtained using monochromatic neutron sources, clearly demonstrating the validity of our principle of spectrometry. 相似文献
97.
98.
S. K. Das R. K. Chatterjee S. K. Saha 《Journal of Radioanalytical and Nuclear Chemistry》2002,251(1):145-147
Hafnium ion forms a strong complex with nitrilotriacetic acid (NTA). But there is a controversy about the nature of the complex on whether it is a 1:1 or a 1:2 complex. We have carried out an electrophoresis experiment and supplemented data to establish the nature of the complex. Our data indicates that it is a 1:2 complex i.e. [Hf(NTA)2]2- in which the coordination number 8 has been satisfied for hafnium. 相似文献
99.
The diastereoselective synthesis of the macrolactone core of amphidinolide W was successfully accomplished using Evans’ asymmetric alkylation, Aldol reaction, Julia-Kocienski olefination, and Kita’s macrocyclization protocol. 相似文献
100.
A. Chatterjee A. Sarkar Sourav Bhattacharya P. Mukherjee N. Gayathri P. Barat 《Physics letters. A》2008,372(22):4016-4020
Tensile tests were carried out by deforming polycrystalline samples of substitutional Al–2.5%Mg alloy at room temperature for a range of strain rates. The Portevin–Le Chatelier (PLC) effect was observed throughout the strain rate regime. The deformation bands in this region are found to be of type A in nature. From the analysis of the experimental stress time series data we could infer that the dynamics of type A dislocation band propagation is a Markov process. 相似文献