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排序方式: 共有833条查询结果,搜索用时 15 毫秒
91.
Birkel CS Kieslich G Bessas D Claudio T Branscheid R Kolb U Panthöfer M Hermann RP Tremel W 《Inorganic chemistry》2011,50(22):11807-11812
Understanding how solids form is a challenging task, and few strategies allow for elucidation of reaction pathways that are useful for designing the synthesis of solids. Here, we report a powerful solution-mediated approach for formation of nanocrystals of the thermoelectrically promising FeSb(2) that uses activated metal nanoparticles as precursors. The small particle size of the reactants ensures minimum diffusion paths, low activation barriers, and low reaction temperatures, thereby eliminating solid-solid diffusion as the rate-limiting step in conventional bulk-scale solid-state synthesis. A time- and temperature-dependent study of formation of nanoparticular FeSb(2) by X-ray powder diffraction and iron-57 M?ssbauer spectroscopy showed the incipient formation of the binary phase in the temperature range of 200-250 °C. 相似文献
92.
We put forward an approximate method to locate the fluid-solid (freezing) phase transition in systems of classical particles interacting via a wide range of Lennard-Jones-type potentials. This method is based on the constancy of the properly normalized second derivative of the interaction potential (freezing indicator) along the freezing curve. As demonstrated recently it yields remarkably good agreement with previous numerical simulation studies of the conventional 12-6 Lennard-Jones (LJ) fluid [S.A.Khrapak, M.Chaudhuri, G.E.Morfill, Phys. Rev. B 134, 052101 (2010)]. In this paper, we test this approach using a wide range of the LJ-type potentials, including LJ n-6 and exp-6 models, and find that it remains sufficiently accurate and reliable in reproducing the corresponding freezing curves, down to the triple-point temperatures. One of the possible application of the method--estimation of the freezing conditions in complex (dusty) plasmas with "tunable" interactions--is briefly discussed. 相似文献
93.
Haas W Rath T Pein A Rattenberger J Trimmel G Hofer F 《Chemical communications (Cambridge, England)》2011,47(7):2050-2052
Cu(2)ZnSnSe(4) nanoparticles have high potential to be used as ink for printable solar cells. Using transmission electron microscopy we show that these nanoparticles exhibit a broad range of chemical heterogeneity. These results are contrary to the interpretation of previous experimental work and will have considerable impact on the development of these nanoparticles. 相似文献
94.
95.
Recursive fault-tolerance of Fibonacci cube in hypercubes 总被引:1,自引:0,他引:1
Petr Gregor 《Discrete Mathematics》2006,306(13):1327-1341
Fibonacci cube is a subgraph of hypercube induced on vertices without two consecutive 1's. If we remove from Fibonacci cube the vertices with 1 both in the first and the last position, we obtain Lucas cube. We consider the problem of determining the minimum number of vertices in n-dimensional hypercube whose removal leaves no subgraph isomorphic to m-dimensional Fibonacci cube. The exact values for small m are given and several recursive bounds are established using the symmetry property of Lucas cubes and the technique of labeling. The relation to the problem of subcube fault-tolerance in hypercube is also shown. 相似文献
96.
97.
Gregor Masbaum 《manuscripta mathematica》1996,91(1):495-509
A method for computing spin refined skein modules of 3-manifolds from Heegaard splittings is described, and the spin refined
skein modules of the lens spacesL(p, r) (includingL(0,1)=S
1×S
2) are computed explicitly. 相似文献
98.
Gregor Kovačič Thomas A. Wettergren 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1996,47(2):221-264
We present a plethora of homoclinic and heteroclinic orbits that exist in the phase space of a weakly nonlinear model describing small oscillations of two resonantly driven coupled pendula. These orbits connect equilibria in a resonance band, which is contained in an invariant plane, and is born under perturbation out of a circle of equilibria. Their existence is shown by using a combination of the Melnikov method and singular perturbation techniques. 相似文献
99.
Highly porous interpolymer ion-exchange membranes of poly(styrene sulfonic acid) and poly(vinylidene fluoride) have been investigated under pressure filtration with KCI, Na2SO4, erythrosin, and bovine serum albumin as solutes in the feed solution. The rejection of the ionic solutes is governed by a Donnan exclusion of electrolyte from the membrane phase. A model for the transport behavior is proposed that includes both diffusive and convective salt transport. The calculated rejections agree adequately with the observed data. 相似文献
100.
Hellmut Haberland Bernd von Issendorff Ji Yufeng Thomas Kolar Gregor Thanner 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1993,26(1):8-12
The change of the cohesive energy and the optical absorption spectra of small singly sized Hg clusters is discussed. The cohesive energy allows one to determine the different regimes of chemical bonding. The optical spectra show an abrupt transition to a collective, plasmon-like absorption as a function of increasing cluster size. The position of the one plasmon peak is: 1) independent of the charge state, 2) nearly independent of cluster size, and 3) agrees with that of the classical Mie plasmon calculated from the experimental dielectric constants. The width of the plasmon peaks is discussed. A strong influence of electronic correlations on the cluster size dependence of the oscillator strength is observed. 相似文献