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991.
Peng Sun Lucas P. Veelenturf Said Dabia Tom Van Woensel 《European Journal of Operational Research》2018,264(3):1058-1073
We introduce the time-dependent capacitated profitable tour problem with time windows and precedence constraints. This problem concerns determining a tour and its departure time at the depot that maximizes the collected profit minus the total travel cost (measured by total travel time). To deal with road congestion, travel times are considered to be time-dependent. We develop a tailored labeling algorithm to find the optimal tour. Furthermore, we introduce dominance criteria to discard unpromising labels. Our computational results demonstrate that the algorithm is capable of solving instances with up to 150 locations (75 pickup and delivery requests) to optimality. Additionally, we present a restricted dynamic programing heuristic to improve the computation time. This heuristic does not guarantee optimality, but is able to find the optimal solution for 32 instances out of the 34 instances. 相似文献
992.
Lucas?Ambrozio Alessandro?CarlottoEmail author Ben?Sharp 《Calculus of Variations and Partial Differential Equations》2018,57(1):22
We investigate compactness phenomena involving free boundary minimal hypersurfaces in Riemannian manifolds of dimension less than eight. We provide natural geometric conditions that ensure strong one-sheeted graphical subsequential convergence, discuss the limit behaviour when multi-sheeted convergence happens and derive various consequences in terms of finiteness and topological control. 相似文献
993.
Lucas Dahinden 《Israel Journal of Mathematics》2018,224(1):367-383
Let S*Q be the spherization of a closed connected manifold of dimension at least two. Consider a contactomorphism φ that can be reached by a contact isotopy that is everywhere positively transverse to the contact structure. In other words, φ is the time-1-map of a time-dependent Reeb flow. We show that the volume growth of φ is bounded from below by the topological complexity of the loop space of Q. Denote by ΩQ0(q) the component of the based loop space that contains the constant loop. 相似文献
994.
The application of ultrasonics in metal forming applications has been shown to reduce the forming load significantly in many research studies. The load reduction has been related to the stress superposition effect, rise in temperature and change in the friction condition between the specimen and die interfaces. This paper reports an investigation into the effects of superimposed ultrasonic oscillation of the die in compression tests on aluminium specimens. In particular, a finite element model is developed to simulate uniaxial compression and to model the effects of a change in the friction boundary condition when ultrasonic excitation is applied to the lower platen. The model predictions of the stress-strain relationship can be compared with test data to provide some insights into the effects of the interfacial condition. The paper shows how the analysis of the test data, combined with finite element models of ultrasonic compression test simulations, allows some initial conclusions to be drawn regarding the influence of the interfacial friction during ultrasonic compression. 相似文献
995.
María Consuelo Casabán Rafael Company Vera N. Egorova Lucas Jódar 《Mathematical Methods in the Applied Sciences》2020,43(14):8223-8236
Random coupled parabolic partial differential models are solved numerically using random cosine Fourier transform together with non-Gaussian random numerical integration that captures the highly oscillatory behaviour of the involved integrands. Sufficient condition of spectral type imposed on the random matrices of the system is given so that the approximated stochastic process solution and its statistical moments are numerically convergent. Numerical experiments illustrate the results. 相似文献
996.
Pirahi da Silva Chagas Naiara de Paula Amantes Bruno Galhardo Pimenta Tienne Lucas da Silva Figueiredo André Ben-Hur Vieira Marques Maria de Fátima 《Journal of Thermal Analysis and Calorimetry》2019,138(2):1279-1286
Journal of Thermal Analysis and Calorimetry - The aim of the present study was to prepare and characterize composites of ultra-high-molar mass polyethylene reinforced with varied amounts of jute... 相似文献
997.
Lucas Mors Ana Cristine da Silva Josias Merib Adriana Neves Dias Eduardo Carasek 《Journal of separation science》2019,42(7):1404-1411
This study proposes an efficient analytical methodology using a biosorbent (cork) as an extraction phase in disposable pipette extraction technique for the rapid determination of the emerging contaminants methyl paraben, ethyl paraben, benzophenone, 3‐(4‐methylbenzylidene) camphor and 2‐(ethylhexyl)‐4‐(dimethylamino) benzoate in lake water samples using high‐performance liquid chromatography with diode array detection. The optimized conditions were comprised of 800 μL of sample, three cycles of 30 s each for the extraction, pH 6, addition of 30% w/v of NaCl. For the desorption step, the optimized desorption conditions were achieved with 100 μL of a mixture comprised of 50% methanol and 50% acetonitrile v/v, using one cycle of 30 s. Excellent analytical performance was achieved with limits of detection of 0.6 μg/L for methyl paraben to 1.4 μg/L for 3‐(4‐methylbenzylidene) camphor, and the limit of quantitation varied from 2 μg/L for methyl paraben to 4.3 μg/L 3‐(4‐methylbenzylidene) camphor, respectively. The correlation coefficients ranged from 0.9962 for ethyl paraben to 0.9980 for methyl paraben. The method accuracy varied from 71–132%, and the intraday precision ranged from 3 to 23% (n = 3) and interday from 9 to 23% (n = 9). The robustness was evaluated through Youden and Lenth's methods and indicated no significant variations in the results. 相似文献
998.
Thomas B. J. Hall Bryce R. Hoggard Christopher B. Larsen Nigel T. Lucas 《化学:亚洲杂志》2019,14(8):1106-1110
Hexa‐peri‐hexabenzocoronenes with a bay‐fused five‐membered ring are synthesized from fluorenyl precursors. The key oxidative cyclodehydrogenation step is accompanied by regioselective chlorination that is enhanced by methylation at the cyclopenta‐ring or increased reaction concentration. The CpHBC products undergo mild electrophilic aromatic bromination, without catalyst, to afford adducts suitable for π‐extension by cross‐coupling. 相似文献
999.
E. Mergel C.M. Petrache G. Lo Bianco H. Hübel J. Domscheit D. Roßbach G. Schönwaßer N. Nenoff A. Neußer A. Görgen F. Becker E. Bouchez M. Houry A. Hürstel Y. Le Coz R. Lucas Ch. Theisen W. Korten A. Bracco N. Blasi F. Camera S. Leoni F. Hannachi A. Lopez-Martens M. Rejmund D. Gassmann P. Reiter P.G. Thirolf A. Astier N. Buforn M. Meyer N. Redon O. Stezowski 《The European Physical Journal A - Hadrons and Nuclei》2002,15(4):417-420
The even-even nucleus 136Nd was studied via in-beam γ-ray spectroscopy using the 16O + 125Te reaction at 100 MeV and the EUROBALL array. One new dipole band was observed. Together with a previously identified dipole
band, whose position in the level scheme is revised, the new band forms a doublet structure similar to the recently observed
chiral bands in the odd-odd neighboring nuclei. This would be the first case of a chiral doublet in an even-even nucleus.
Received: 23 May 2002 / Accepted: 30 September 2002 / Published online: 27 November 2002
RID="a"
ID="a"e-mail: costel.petrache@unicam.it
RID="b"
ID="b"Present address: Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
RID="c"
ID="c"Present address: Gesellschaft für Schwerionenforschung D-64291 Darmstadt, Germany.
Communicated by C. Signorini 相似文献
1000.
Lucas LH Cerny MA Koen YM Hanzlik RP Larive CK 《Analytical and bioanalytical chemistry》2004,380(4):627-631
We recently attempted to generate an affinity chromatography adsorbent to purify cytochrome P450 4A1 by coupling 11-(1-imidazolyl)-3,6,9-trioxaundecanoic acid to Toyopearl AF-Amino 650 M resin. Variations in ligand density for several resin batches were quantified by high-resolution magic-angle spinning (HR-MAS) NMR spectroscopy using a novel resin internal standard. The uniquely designed ImQ internal resin standard yields its signature resonance in a transparent region of the analyte spectrum making suppression of the polymer background unnecessary. This method enabled us to target a reasonable ligand density for enzyme purification and provides an advantageous alternative to quantitation against soluble standards or protonated solvent. 相似文献