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71.
Ohne Zusammenfassung 相似文献
72.
The optimum conditions for the photometric determination of tantalum with pyrogallol in sulphuric acid solution at 405 nm have been elaborated. The method has been checked statistically. 相似文献
73.
Arnošt Bergstein 《Czechoslovak Journal of Physics》1956,6(2):164-168
Zusammenfassung Es wurden einige dielektrische Eigenschaften polykristalliner gesinterter Bleioxydproben gemessen. Aus den Ergebnissen wird auf zwei Polarisationsvorgänge geschlossen, die bei niedrigen Frequenzen und Temperaturen zwischen 20–60 °C gleichzeitig die Werte der Dielektrizitätskonstante beeinflussen. Einer von ihnen ist mit dem Auftreten orientierter Bereíche verbunden, die spontane Polarisierung aufweisen, deren Sinn durch ein äusseres elektrisches Feld um 180° gedreht werden kann. 相似文献
74.
The ground state of a double-exchange model for orbitally degenerate e(g) electrons with Jahn-Teller lattice coupling and weak disorder is found to be spatially inhomogeneous near half filling. Using a real-space Monte Carlo method we show that doping the half-filled orbitally ordered insulator leads to the appearance of hole-rich disordered regions in an orbitally ordered environment. The doping driven orbital order to disorder transition is accompanied by the emergence of metallic behavior. We present results on transport and optical properties along with spatial patterns for lattice distortions and charge densities, providing a basis for an overall understanding of the low-doping phase diagram of La1 - xCaxMnO3. 相似文献
75.
Arno Fehm 《Journal of Algebra》2010,323(6):1738-1744
76.
Arno Kret 《Mathematische Annalen》2013,356(2):487-518
Under simplifying hypotheses we prove a relation between the $\ell $ -adic cohomology of the basic stratum of a Shimura variety of PEL-type modulo a prime of good reduction of the reflex field and the cohomology of the complex Shimura variety. In particular we obtain explicit formulas for the number of points in the basic stratum over finite fields. We obtain our results using the trace formula and truncation of the formula of Kottwitz for the number of points on a Shimura variety over a finite fields. 相似文献
77.
Yoshitake Yamazaki Arno Holz Herbert Gleiter Yoshiichi Fukuda Moyuru Ochiai 《Phase Transitions》2013,86(1-4):109-144
We shall focus on extended defect systems and review their critical behavior. Primarily, with two aims, one of which is to understand phase transitions and how to derive effective dimension of extended defects with various structures, and the other is to propose a new research-method for defect systems, we let extended defects grow on a triangular lattice with frustration in a similar fashion to diffusion-limited aggregation, and discuss the situation. The existence of phase transitions, phase diagram, effective defect dimension, etc. will be shown. Furthermore, we shall summarize theoretical studies of extended defect systems on phase diagrams, critical behavior, tricritical behavior, and crossover behavior as static properties, and on nonconserved systems and conserved systems as dynamic properties. 相似文献
78.
Ammonium formate aided catalytic transfer hydrogenation has been employed in the cleavage, and concommitant deprotection, of the pentapeptide leucine enkephalin from the Merrifield peptide resin under ambient conditions of temperature and pressure in a neutral medium. 相似文献
79.
Arno F. Stassen Huub Kooijman Anthony L. Spek Jaap G. Haasnoot Jan Reedijk 《Journal of chemical crystallography》2001,31(6):307-314
The compounds hexakis(1-(2-chloroethyl)-tetrazole-N4)copper(II) tetrafluoroborate mono(1-(2-chloroethyl)-tetrazole) (1) and hexakis(1-(2-chloroethyl)-tetrazole-N4) copper(II) perchlorate mono(1-(2-chloroethyl)-tetrazole) (2) were obtained from the crystallization of 1-(2-chloroethyl)-tetrazole (teec) with the respective copper salt. The X-ray structures are reported. Both compounds crystallize in the monoclinic space group C2/c for 1: a = 25.754(3) Å, b = 18.162(3) Å, c = 10.298(2) Å = 104.294(7)° and Z = 4 and for 2: a = 25.745(3) Å, b = 18.197(3) Å, c = 10.29355(3) Å = 104.512(10)° and Z = 4. The CuII ions are octahedrally surrounded by six teec ligands. One free teec ligand is present in the structures. The Cu–N distances in the centrosymmetrical units are 2.01, 2.04, and 2.39 Å in both compounds, consistent with a Jahn–Teller elongated octahedron. The ligand field spectra of both compounds show a signal in the visible range at about 15.200 cm–1 and by an EPR spectrum the following values are found: g
| = 2.29 and g = 2.03. The compounds are both paramagnetic and the T value of 0.37 cm–1 K mol–1, which is associated with S = 1/2, is what would be expected for a mononuclear CuII complex. 相似文献
80.
Receptors and , incorporating two heterocyclic recognition units as well as oxime- or hydroxymethyl-based hydrogen-bonding sites, were prepared, and their binding properties toward neutral sugars were determined. The design of these receptors was inspired by the binding motifs observed in the crystal structure of protein-carbohydrate complexes. The receptors and are able to recognize both mono- and disaccharides, with a strong preference for the disaccharides. Both hydrogen-bonding and interactions of the sugar CH's with the phenyl rings of the receptor contribute to the stabilisation of the receptor-sugar complexes. Molecular modeling calculations, synthesis and binding studies are described. 相似文献