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161.
Line-integral representations for the solution of the elastostatic traction boundary-value problem of the half space are derived for the case of polyharmonic surface loading. For load regions of essentially arbitrary shape, bearing uniform tractions, these line-integral representations are applied to the analysis of the stress singularities present at the edges of the load region.
Resume On dérive des représentations par intégrales curvilignes de la solution du problème aux conditions limites de traction élasto-statique dans le demi espace.On applique, pour des régions de charge de forme essentiellement arbitraire, ces représentations par intégrales curvilignes à l'analyse des singularités de tension qui apparaissent aux bords de la région de charge.相似文献
162.
163.
Ana N. Nunes Alexandra Borges Ana A. Matias Maria Rosrio Bronze Joana Oliveira 《Molecules (Basel, Switzerland)》2022,27(2)
Anthocyanins are natural pigments displaying different attractive colors ranging from red, violet, to blue. These pigments present health benefits that increased their use in food, nutraceuticals, and the cosmetic industry. However, anthocyanins are mainly extracted through conventional methods that are time-consuming and involve the use of organic solvents. Moreover, the chemical diversity of the obtained complex extracts make the downstream purification step challenging. Therefore, the growing demand of these high-value pigments has stimulated the interest in designing new, safe, cost-effective, and tunable strategies for their extraction and purification. The current review focuses on the potential application of compressed fluid-based (such as subcritical and supercritical fluid extraction and pressurized liquid extraction) and deep eutectic solvents-based extraction methods for the recovery of anthocyanins. In addition, an updated review of the application of counter-current chromatography for anthocyanins purification is provided as a faster and cost-effective alternative to preparative-scale HPLC. 相似文献
164.
A study concerning the valence space dependence of neutrinoless doubleβ
− decay observables is performed for several nuclei in the framework of QRPA using the multiple commutator method (MCM). Calculations
and comparison to earlier results show that at least for the ground state to ground state transition the dependence is much
weaker than in the two neutrino doubleβ
− decay. It is still a difficult task to extract the parameters of the neutrinoless doubleβ
− decay since the half-life expression contains products of the parameters 〈m
ν
〉 〈η〉 and 〈λ〉.
Presented by M. Aunola at the Workshop on calculation of double-beta-decay matrix elements (MEDEX’97), Prague, May 27–31,
1997. 相似文献
165.
166.
J. P. Hugonin P. Lalanne I. Del. Villar I. R. Matias 《Optical and Quantum Electronics》2005,37(1-3):107-119
This work contains new materials relative to the use of Fourier expansion techniques, also called plane-wave expansion techniques, for modelling normal modes of optical waveguides. Two rigorous fully vectorial methods are presented and benchmarked for a classical rib waveguide geometry well studied in the literature. The first method relies on a pole extraction and on a one-dimensional expansion scheme. A four-digit accuracy for the normalized propagation constant B is obtained for the dominant TE and TM modes of the benchmark problem and for a small number of retained Fourier harmonics. Better accuracy is anticipated for larger truncation ranks. The second method relies on a two-dimensional expansion scheme in Fourier space and provides a three-digit accuracy for the normalized propagation constant. 相似文献
167.
Femtosecond pump-probe spectra show direct evidence for ultrafast solvent-induced spin flip in photodissociation-recombination events of ClF, a light diatomic molecule, for which the spin-orbit coupling is weak. The bound triplet states ((3)Pi) of ClF are probed and the dynamics for excitation to the singlet state ((1)Pi(1)) is compared with excitation to the triplet state B((3)Pi(0)). The population initially excited to the singlet state (1)Pi(1) is transferred to the bound triplet states (3)Pi within tau(f)=0.5 ps. Oscillations in the spectra indicate wave packet dynamics with the triplet state period of 300 to 400 fs in both cases. According to simulations of F(2)/Ar, most of the initially excited singlet state population is converted to repulsive and weakly bound triplet states within approximately 60 fs. In the first ps, 40% of the triplet population accumulates in the weakly bound (3)Pi states, in good accord with the experiment. 相似文献
168.
The problem of sorting n integers from a restricted range [1…m], where m is a superpolynomial in n, is considered. An o(n log n) randomized algorithm is given. Our algorithm takes O(n log log m) expected time and O(n) space. (Thus, for m = npolylog(n) we have an O(n log log n) algorithm.) The algorithm is parallelizable. The resulting parallel algorithm achieves optimal speedup. Some features of the algorithm make us believe that it is relevant for practical applications. A result of independent interest is a parallel hashing technique. The expected construction time is logarithmic using an optimal number of processors, and searching for a value takes O(1) time in the worst case. This technique enables drastic reduction of space requirements for the price of using randomness. Applicability of the technique is demonstrated for the parallel sorting algorithm and for some parallel string matching algorithms. The parallel sorting algorithm is designed for a strong and nonstandard model of parallel computation. Efficient simulations of the strong model on a CRCW PRAM are introduced. One of the simulations even achieves optimal speedup. This is probably the first optimal speedup simulation of a certain kind. 相似文献
169.
Manuel Norte JosJ. fern
ez Rafael Gonzz Matias L. Rodríguez Catalina Ruiz-Prez Victor Rodriguez-Romero 《Tetrahedron》1990,46(24):8237-8242
(+)-Lepidozene 1, a new sesquiterpene possessing a trans-fused (8,1,0) undecane system, has been isolated from the gorgonia Lophogorgia ruberrima. Its structure and absolute configuration have been determined by spectroscopical methods and X-ray diffraction analysis. 相似文献
170.
Zhavoronkov N Gritsai Y Bargheer M Woerner M Elsaesser T Zamponi F Uschmann I Förster E 《Optics letters》2005,30(13):1737-1739
We demonstrate a subpicosecond 1 kHz femtosecond x-ray source with a well-accessible quasi-point size (10 microm diameter) providing Cu K(alpha) emission with a maximum flux of 6.8 x 10(10) photons/s for continuous operation of 10 h. A new geometry that essentially facilitates the adjustment and diminishes the temporal jitter between the x-ray probe and the laser pump pulse is implemented for time-resolved diffraction experiments. 相似文献