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91.
M. I. Kolybaeva V. I. Salo I. M. Pritula Yu. N. Velikhov A. P. Voronov V. F. Tkachenko V. M. Puzikov 《Crystallography Reports》2004,49(2):266-270
The influence of various technological parameters of crystallization (acidity of growth solutions, crystallization temperature, growth rate, degree of solution purification) on the optical absorption of large KDP single crystals has been studied in the UV range of the spectrum. It is shown that the method of solvent recirculation with the use of the starting material with the microimpurity content not exceeding 5 × 10?5 wt % and solution ultrafiltration under the optimum crystallization conditions (tcr = 80°C, Vcr ~ (0.8–1.6) × 10?6 cm/s, pH 4) enables one to grow KDP single crystals with cross sections up to 300 × 300 mm2 and the transmission in the vicinity of the fundamental absorption edge λ = 200 nm) equal to 86%. 相似文献
92.
Valeriy Brytik Maarten V. de Hoop Mikko Salo 《Journal of Fourier Analysis and Applications》2010,16(4):544-589
Earthquakes, viewed as passive sources, or controlled sources, like explosions, excite seismic body waves in the earth. One detects these waves at seismic stations distributed over the earth’s surface. Wave-equation tomography is derived from cross correlating, at each station, data simulated in a reference model with the observed data, for a (large) set of seismic events. The times corresponding with the maxima of these cross correlations replace the notion of residual travel times used as data in traditional tomography. Using first-order perturbation, we develop an analysis of the mapping from a wavespeed contrast (between the “true” and reference models) to these maxima. We develop a construction using curvelets, while establishing a connection with the geodesic X-ray transform. We then introduce the adjoint mapping, which defines the imaging of wavespeed variations from “finite-frequency travel time” residuals. The key underlying component is the construction of the Fréchet derivative of the solution to the seismic Cauchy initial value problem in wavespeed models of limited smoothness. The construction developed in this paper essentially clarifies how a wavespeed model is probed by the method of wave-equation tomography. 相似文献
93.
We establish a sharp integrability condition on the partial derivatives of a Sobolev mapping to guarantee that sets of measure
zero get mapped to sets of measure zero. This condition is sharp also for continuity and differentiability almost everywhere.
Received: 6 January 1999 / Revised version: 5 May 1999 相似文献
94.
95.
We show that a dilute two-species gas of Fermi-Dirac alkali-metal atoms in a periodic optical lattice may exhibit fractionalization of the particle number when the two components are coupled via a coherent electromagnetic field with a topologically nontrivial phase profile. This results in fractional eigenvalues of the spin operator with vanishing fluctuations. The fractional part can be accurately controlled by modifying the effective detuning of the electromagnetic field. 相似文献
96.
Tero Taipale Monika Österberg Antti Nykänen Janne Ruokolainen Janne Laine 《Cellulose (London, England)》2010,17(5):1005-1020
Different types of microfibrillated cellulose (MFC) and fines suspensions were produced, characterized, and then added to
a papermaking pulp suspension. High and medium molar mass cationic polyelectrolytes were used as fixatives. The drainage behavior
of the pulp suspensions with additives were evaluated against the strength properties of hand sheets made thereof. The effects
of salt concentration, pH, fixative type, dosage and type of fibrillar material on drainage were examined. All the MFC and
fines samples produced had clearly different properties due to their dissimilar production methods, and they also introduced
specific responses on the measured drainage and paper strength. Generally, the addition of MFC decreased the drainage rate
of pulp suspension and increased the strength of paper. However, it was shown that by optimum selection of materials and process
conditions an enhancement of the strength properties could be achieved without simultaneously deteriorating the drainage. 相似文献
97.
98.
Robust portfolio modeling with incomplete cost information and project interdependencies 总被引:1,自引:0,他引:1
Robust portfolio modeling (RPM) [Liesiö, J., Mild, P., Salo, A., 2007. Preference programming for robust portfolio modeling and project selection. European Journal of Operational Research 181, 1488–1505] supports project portfolio selection in the presence of multiple evaluation criteria and incomplete information. In this paper, we extend RPM to account for project interdependencies, incomplete cost information and variable budget levels. These extensions lead to a multi-objective zero-one linear programming problem with interval-valued objective function coefficients for which all non-dominated solutions are determined by a tailored algorithm. The extended RPM framework permits more comprehensive modeling of portfolio problems and provides support for advanced benefit–cost analyses. It retains the key features of RPM by providing robust project and portfolio recommendations and by identifying projects on which further attention should be focused. The extended framework is illustrated with an example on product release planning. 相似文献
99.
Janne Kauhanen Pekka Koskela Jan Malý 《Archive for Rational Mechanics and Analysis》2001,160(2):135-151
We establish a sharp integrability condition on the partial derivatives of a mapping with L p -integrable distortion for some p>n? 1 to guarantee discreteness and openness. We also show that a mapping with exponentially integrable distortion and integrable Jacobian determinant is either constant or both discrete and open. We give an example demonstrating the preciseness of our criterion. 相似文献
100.
The reaction of stabilized Peterson reagents (alpha-silyl ester enolates) with ketones has been studied theoretically and experimentally. Enolate geometry was studied by trapping experiments and NMR spectroscopy and was found to differ markedly with the nature of the base (LiHMDS vs LDA vs KHMDS). The chelating effect of the lithium counterion was found to be critical for the reaction. For the two ketones studied, the combined weight of experimental and computational data assigns geometrical selectivity to the initial addition transition state, though in general there appears to be a fine balance between three possible choices for the rate-determining step. 相似文献