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排序方式: 共有911条查询结果,搜索用时 15 毫秒
1.
Marco Dall'Aglio Theodore P. Hill 《Journal of Mathematical Analysis and Applications》2003,281(1):346-361
For fair-division or cake-cutting problems with value functions which are normalized positive measures (i.e., the values are probability measures) maximin-share and minimax-envy inequalities are derived for both continuous and discrete measures. The tools used include classical and recent basic convexity results, as well as ad hoc constructions. Examples are given to show that the envy-minimizing criterion is not Pareto optimal, even if the values are mutually absolutely continuous. In the discrete measure case, sufficient conditions are obtained to guarantee the existence of envy-free partitions. 相似文献
2.
Theodore G. Faticoni 《Acta Mathematica Hungarica》1991,57(3-4):265-274
3.
4.
V. I. Burkov E. P. Peredereĭ E. V. Fedotov B. V. Mill’ Yu. V. Pisarevskiĭ 《Crystallography Reports》2008,53(5):843-846
The absorption and circular dichroism spectra of langasite family crystals are studied. Wide bands in the range of 285–500 nm that are related to the structure lattice defects are found. For all the crystals, these bands are in approximately the same spectral region, have identical structures, and can be attributed to one type of defects formed by cation vacancies and excess oxygen atoms in the optically active positions. 相似文献
5.
Daniel C.S. Tse Theodore Kuwana Garfield P. Royer 《Journal of Electroanalytical Chemistry》1979,98(2):345-353
Methylaminopropylviologen (MAV) was covalently attached to glassy carbon electrodes via cyuranic chloride. X-ray photoelectron spectroscopy (XPS) analysis confirmed the presence of bound MAV on the electrode surfaces. Electrochemical experiments of these electrodes indicated that the bound MAV was stable and electrochemically active for extended periods of time in aqueous media. The surface coverage of MAV was in the range, of 2.0–3.0×10?10 mol cm?2. 相似文献
6.
7.
Theodore S. Prokopov 《Mikrochimica acta》1970,58(4):694-701
Summary A non-sulfide scheme of inorganic qualitative microanalysis is presented with solutions of HCl, CH3COONa, H2SO4, and NaOH as group reagents. Color reactions (spot tests) are also included in this scheme. The purpose of this new approach to qualitative analysis is to eliminate disagreeable odor and corosive action of hydrogen sulfide as also to introduce complete group separations leading to more definite analytical results.
Zusammenfassung Ein Schema für die qualitative anorganische Analyse ohne Schwefelwasserstoff mit Salzsäure, Na-Acetat, Schwefelsäure und Natronlauge als Gruppenreagenzien wird vorgelegt. Farbreaktionen (Tüpfelproben) werden im Laufe des Analysenganges verwendet. Die Geruchsbelästigung und die Korrosion durch Schwefelwasserstoff wird vermieden und gleichzeitig eine Gruppentrennung mit eindeutigeren Ergebnissen erzielt.相似文献
8.
We obtain massive and massless vector two-point functions in maximally symmetric spaces (and vacua) of any number of dimensions. These include de Sitter space and anti-de Sitter space, and their Euclidean analogsS
n andH
n. Our method is based on a simple way of constructing every possible maximally symmetric bitensorT
a...bc...d(x, x) which carries tangent-space indicesa...b atx andc...d atx. 相似文献
9.
P. Beneitez V. Correcher A. Millán T. Calderón 《Journal of Radioanalytical and Nuclear Chemistry》1994,185(2):401-410
Thermoluminescence signals of irradiated and unirradiated spices and herbs are due to inorganic matter grains adhering to the surfaces. This study reports the mineral composition of this dust being, mainly quartz, calcite and philosilicates; it shows the differences between samples exposed and non-exposed to -radiation on the basis of TL signals after long storage periods (1–16 months). A saturation process in the TL signal is found when the samples absorb doses higher than 5 kGy. Finally, the TL glow curve intensities do not suffer significant changes with the dose rate of the -source used in the radiation process. 相似文献
10.
Varnavski OP Ostrowski JC Sukhomlinova L Twieg RJ Bazan GC Goodson T 《Journal of the American Chemical Society》2002,124(8):1736-1743
Measurements of ultrafast fluorescence anisotropy decay in model branched dendritic molecules of different symmetry are reported. These molecules contain the fundamental branching center units of larger dendrimer macromolecules with either three (C(3))- or four (T(d), tetrahedral)-fold symmetry. The anisotropy for a tetrahedral system is found to decay on a subpicosecond time scale (880 fs). This decay can be qualitatively explained by F?rster-type incoherent energy migration between chromophores. Alternatively, for a nitrogen-centered trimer system, the fluorescence anisotropy decay time (35 fs) is found to be much shorter than that of the tetramers, and the decay cannot be attributed to an incoherent hopping mechanism. In this case, a coherent interchromophore energy transport mechanism should be considered. The mechanism of the ultrafast energy migration process in the branched systems is interpreted by use of a phenomenological quantum mechanical model, which examines the two extreme cases of incoherent and coherent interactions. 相似文献