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991.
R. Schneider 《偏微分方程通讯》2013,38(8-9):1263-1286
992.
This is a review of the literature on variants and extensions of the standard location-routing problem published since the last survey, by Nagy and Salhi, appeared in 2006. We propose a classification of problem variants, provide concise paper excerpts that convey the central ideas of each work, discuss recent developments in the field, and list promising topics for further research. 相似文献
993.
994.
Friedrich Martin Schneider Sebastian Kerkhoff Mike Behrisch Stefan Siegmund 《Semigroup Forum》2013,87(3):590-598
In this paper we propose and explore a general notion of chaos in the abstract context of continuous actions of topological semigroups and show that any chaotic action on a Hausdorff uniform space is sensitive to initial conditions. 相似文献
995.
Abstract Since the circulation, in 1974, of the first draft of “The construction D + XD S [X], J. Algebra 53 (1978), 423–439” a number of variations of this construction have appeared. Some of these are: The generalized D + M construction, the A + (X)B[X] construction, with X a single variable or a set of variables, and the D + I construction (with I not necessarily prime). These constructions have proved their worth not only in providing numerous examples and counter examples in commutative ring theory, but also in providing statements that often turn out to be forerunners of results on general pullbacks. The aim of this paper will be to discuss these constructions and the remarkable uses they have been put to. I will concentrate more on the A + XB[X] construction, its basic properties and examples arising from it. 相似文献
996.
997.
A number of amines are of the utmost importance to the normal function of the nervous system; numerous relationships also exist between certain diseases of the nervous system and the metabolism of these amines. Noradrenaline, serotonin, and histamine are taken as examples to offer some idea of the possibilities and methods of biochemical research that help to elucidate the physiological and pathological processes in the nervous system. The article shows that our knowledge of the functioning of the nervous system, even in a field that has been studied as thoroughly as the transmission of nerve stimuli at synapses, is still in its infancy. 相似文献
998.
Surface Brillouin spectroscopy (SBS) has been widely used for elastic property characterization of thin films. For films thicker than 500 nm, however, the wavelength of surface acoustic wave in the frequency range available for SBS is smaller than film thickness, and the SBS measures only the Rayleigh wave of the film. The laser-SAW technique, on the other hand, measures only the low-frequency portion of the surface acoustic wave dispersion and can estimate only one elastic modulus of the film (typically Young's modulus). In this work, we have combined the two methods to determine both Young's modulus and Poisson's ratio of a diamond-like carbon (DLC) film. It was found that reasonable estimates can be obtained for the longitudinal wave velocity, shear wave velocity, and Young's modulus of the film. The Poisson's ratio, however, still has a relatively large measurement error. 相似文献
999.
H. Prade L. Käubler U. Hagemann H.U. Jäger M. Kirchbach L. Schneider F. Stary Z. Roller V. Paar 《Nuclear Physics A》1980,333(1):33-66
High-spin states of 143Pm have been studied in the reactions 141Pr(α, 2n)143Pm and 143Nd(d, 2n)143Pm by means of in-beam spectroscopy. The level scheme, spin and parity assignments are based on results obtained from singles γ-ray spectra, conversion electron spectra, prompt and delayed γ-γ coincidences, γ-ray angular distribution and linear polarization measurements. Positive- and negative-parity states with energies up to 4580 keV and spins up to have been established including 22 new levels. For two nanosecond isomeric states the nuclear spin precession in an external magnetic field was observed providing the following g-factors: The experimental results are well understood by calculations which have been performed in the framework of the shell model (for positive-parity states of 11 valence protons above a Z = 50, N = 82 core) and of the cluster-vibration model (for 3 holes in a Z = 64, N = 82 core). In the case of positive-parity states no evidence for particle-core coupling could be found, while the negative-parity states could qualitatively be understood within the particle-core coupling picture. 相似文献
1000.
Diacetone Alcohol as Complex Ligand. Crystal Structures of [MnBr2{O=C(Me)CH2–C(Me)2OH}2] and [M{O=C(Me)CH2–C(Me)2OH}2][MCl4] with M = Fe, Co, and Zn The metal halides MnBr2 and MCl2 (M = Fe, Co, Zn) react with diacetone alcohol (4-hydroxy-4-methyl-2-pentanon) forming the title compounds, which are characterized by IR spectroscopy and crystal structure analyses. [MnBr2{O=C(Me)CH2–C(Me2)OH}2] ( 1 ): Space group C2/c, Z = 4, lattice dimensions at 293 K: a = 1189.2(4), b = 1317.2(3), c = 1200.0(3) pm, β = 102.25(3)°, R1 = 0.0256. In 1 the manganese atom is coordinated in a distorted octahedral fashion by the two cis bromine atoms and by the four oxygen atoms of the two diacetone alcohol chelating molecules. The distances Mn–[OH] (223.8 pm) and Mn–[O=C] (222.1 pm) are only slightly different. [M{O=C(Me)CH2–C(Me)2OH}2][MCl4] [M = Fe ( 2 ), Co ( 3 ), Zn ( 4 )]: 2 and 3 crystallize isotypically with each other in the space group Pc, Z = 4. Lattice dimensions for 2 at 293 K: a = 865.8(3), b = 926.3(2), c = 1401.5(1) pm, β = 104.19(2)°, R1 = 0.0421. Lattice dimensions for 3 at 293 K: a = 872.3(1), b = 925.7(1), c = 1394.2(3) pm, β = 104.79(2)°, R1 = 0.0481. As in 1 , the metal atoms of the [M{O=C(Me)CH2–C(Me)2OH}2]2+ ions in 2 and 3 are chelated in a distorted octahedral fashion by two diacetone alcohol molecules and associated cis via two μ-Cl atoms of the [MCl4]2– anions to form strands. [Zn{O=C(Me)CH2–C(Me)2OH}2][ZnCl4] ( 4 ): Space group C2/c, Z = 4. Lattice dimensions at 213 K: a = 1582.27(13), b = 1356.15(13), c = 941.93(7) pm, β = 107.283(10)°, R1 = 0.0328. The zinc atom of the dication in 4 is associated in a distorted octahedral fashion by the two diacetone alcohol chelating molecules in the equatorial positions and trans by two μ-Cl atoms of the [ZnCl4]2– ions to form strands. 相似文献