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1.
Alloys of the systems Fe–Al (mixable over the whole concentration range) and Fe–Mg (insoluble with each other) were produced by implantation of Fe ions into Al and Mg, respectively. The implantation energy was 200 keV and the ion doses ranged from 1 × 1014 to 9 × 1017cm-2The obtained implantation profiles were determined by Auger electron spectroscopy depth profiling. Maximum iron concentrations reached were up to 60 at.% for implantation into Al and 94 at.% for implantation into Mg. Phase analysis of the implanted layers was performed by conversion electron Mössbauer spectroscopy and X‐ray diffraction. For implantation into Mg, two different kinds of Mössbauer spectra were obtained: at low doses paramagnetic doublets indicating at least two different iron sites and at high doses a dominant ferromagnetic six‐line‐pattern with a small paramagnetic fraction. The X‐ray diffraction pattern concluded that in the latter case a dilated αiron lattice is formed. For implantation into Al, the Mössbauer spectra were doublet structures very similar to those obtained at amorphous Fe–Al alloys produced by rapid quenching methods. They also indicated at least two different main iron environments. For the highest implanted sample a ferromagnetic six‐line‐pattern with magnetic field values close to those of Fe3Al appeared. 相似文献
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F. Richter 《Analytical and bioanalytical chemistry》1940,119(3-4):109-118
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K. H. Geib J. Reitstötter R. E. Liesegang Thomas M. Richter Thierbach P. Krais 《Colloid and polymer science》1938,84(1):119-122
Ohne Zusammenfassung 相似文献
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P. Santhana Gopala Krishnan Chaobin He Christine Tay Shang Shang 《Journal of polymer science. Part A, Polymer chemistry》2004,42(16):4036-4046
Two ladder‐like polysilsesquioxanes (LPS) containing side‐chain maleimide groups have been synthesized successfully by reacting N‐(4‐hydroxyphenyl)maleimide (HPM) with LPS containing 100 mol % of chloropropyl groups (Ladder A ) and 50 mol % of each methyl and chloropropyl group (Ladder B ). HPM was synthesized by reacting maleic anhydride with 4‐aminophenol, and the resulting amic acid was imidized using p‐toluenesulfonic acid as a catalyst (Scheme 1 ). The LPSs were characterized by Fourier transform infrared (FTIR), 1H nuclear magnetic resonance (NMR), proton‐decoupled 13C NMR, 29Si NMR, wide‐angle X‐ray diffraction (WAXD), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). Characterization indicated that these polymers had ordered ladder‐like structures with possible defects. These polymers were soluble in common solvents at ambient temperature, which suggested that they were not crosslinked. Both the polymers and the HPM were cured, and their kinetics were followed by dynamic DSC. The Ozawa and Kissinger methods were used to calculate activation energies for curing. Curing increased the temperature at which both 5% weight loss and maximum rate of weight loss were observed. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4036–4046, 2004 相似文献
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For a graph G and a positive integer m, G(m) is the graph obtained from G by replacing every vertex by an independent set of size m and every edge by m2 edges joining all possible new pairs of ends. If G triangulates a surface, then it is easy to see from Euler's formula that G(m) can, in principle, triangulate a surface. For m prime and at least 7, it has previously been shown that in fact G(m) does triangulate a surface, and in fact does so as a “covering with folds” of the original triangulation. For m = 5, this would be a consequence of Tutte's 5‐Flow Conjecture. In this work, we investigate the case m = 2 and describe simple classes of triangulations G for which G(2) does have a triangulation that covers G “with folds,” as well as providing a simple infinite class of triangulations G of the sphere for which G(2) does not triangulate any surface. © 2003 Wiley Periodicals, Inc. J Graph Theory 43: 79–92, 2003 相似文献
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YoungJu Choie Olav K. Richter 《Proceedings of the American Mathematical Society》2007,135(8):2309-2315
We determine a class of functions spanned by theta series of higher degree. We give two applications: A simple proof of the inversion formula of such theta series and a classification of skew-holomorphic Jacobi forms.