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271.
Test examples for nonlinear programming codes 总被引:3,自引:0,他引:3
The increasing importance of nonlinear programming software requires an enlarged set of test examples. The purpose of this note is to point out how an interested mathematical programmer could obtain computer programs of more than 120 constrained nonlinear programming problems which have been used in the past to test and compare optimization codes. 相似文献
272.
U. K.?Sapaev J.?KutznerEmail author K.?Finsterbusch 《Optical and Quantum Electronics》2005,37(6):515-527
Type-II frequency doubling of short Gaussian laser pulses is studied theoretically. The situation is analysed when the group velocity mismatch and the walk-off angle of the interacting waves limit the frequency conversion efficiency. It is shown that with collinear ‘o’ and ‘e’ polarized fundamental waves a temporal and spatial separation of the fundamental beams is necessary to compensate for both effects. Results of the presented model are discussed for KDP crystals. 相似文献
273.
274.
We briefly describe the contents of the authors PhD thesis (see Colson 2003) discussed on July 2003 at the University of Namur (Belgium) and supervised by Philippe L. Toint. The contributions presented in this thesis are the development of trust-region methods for solving two particular classes of mathematical programs, namely derivative-free optimization (DFO) problems and nonlinear bilevel programming problems. The thesis is written in English and is available via the author.Received: July 2003, AMS classification:
65D05, 90C30, 90C56, 90C59 相似文献
275.
276.
In the past years extensive studies have been conducted on porphyrin-type photosensitizers because of their photosensitive activity. With regard to their interaction with many important macromolecules such as nucleic acids, proteins and lipids, porphyrin-type photosensitizers are capable of damaging numerous cells. They damage DNA via oxidation of four bases, especially guanine and cytosine pairs[1], damage protein by oxidation of (at least) two amino acids——cysteine and tryptophan residues… 相似文献
277.
Boyer RD Johnson R Krishnamurthy K 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2003,165(2):253-259
Use of adiabatic pulses in broadband inversion and decoupling is well known. Replacement of the rectangular pi pulses in the INEPT and rev-INEPT parts of the HSQC and gHSQC experiments with adiabatic pulses substantially improves the sensitivity of these experiments. However, modulation of cross peak intensity in multiplicity-edited HSQC or gHSQC experiments can be quite severe. These modulations arise during the multiplicity-editing periods due to the inefficient refocusing of the spin-echo caused by the mismatch of the echo delay with the one-bond coupling constant. These modulations (which we call echo modulations) are field strength (and hence spectral width) independent. Use of adiabatic pulses with the inversion sweep synchronized to the 1H-13C coupling constant range typically observed in a 13C spectrum will provide substantial improvement in sensitivity. The inversion profile problems associated with rectangular pi pulses can be moderately compensated by composite pulse schemes and these schemes could prove to be reasonable alternatives to adiabatic pulses. However, the adiabatic sweep provides a unique method to compensate the echo modulations for multiplicity-edited experiments. The origin and the compensation of refocusing inefficiency with synchronized inversion sweep (CRISIS) method to minimize these modulations is described. 相似文献
278.
We have obtained theoretically an expression for the nuclear free precession signal in an inhomogeneously broadened spin system with a complex structure of the NMR spectrum. It is shown that in this case in the nuclear precession signal there appear maxima the moments of whose formation depend on the detuning of the pulse carrier frequency from the central frequencies of the NMR lines, their widths, and the Rabi frequency. The theoretical results are in good agreement with the experimental data on the observation of proton free precession in toluene. We have constructed a physical model explaining the appearance of maxima in the free precession signal of the spin system. 相似文献
279.
The rf pulse response of I=3/2 spin system experiencing first order quadrupolar splitting is studied using density matrix approach. A general expression is derived in terms of spin populations, quadrupole splitting and duration and amplitude of the rf pulse for calculating the NMR signal arising due to the centre line and satellite resonances for the situation where the impressed rf pulse excites the resonances selectively as well as non-selectively. The necessary 4×4 transformation matrix obtained analytically by diagonalyzing the Hamiltonian are used to get the expression for the centre line response. The satellite signals are obtained in the same way but by using the numerical values of the roots of the related quartics. The widths of the corresponding π/2-pulses are calculated for different initial spin populations. The variations of this pulse-width and the corresponding signal amplitude as a function of satellite splitting are studied. 相似文献
280.
The mechanism and kinetics of energy transfer from highly excited Xe states (E
ex > 9.5 eV), generated by a 12-ns electron beam, to chlorine donor molecules were deduced from time-resolved spectra of fluorescence in the region 240–340 nm. The emissions at 240–250 nm were assigned to Xe2** excimers, and those at 308 and 340 nm to XeCl(B) and XeCl(C) states. Kinetic analysis of the recorded spectra for Xe–CCl4 and Xe–SOCl2 gas mixtures at constant xenon pressure and various pressures of molecular admixtures (0.1–1 Torr) allowed us to find the rate constants for the reactions (5) Xe** + RCI products, (6a) Xe** + RCl XeCl(B) + R*, and (6b) Xe** + RCl XeCl(C) + R*, where R is any radical. 相似文献