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Manju Rajeswaran Thomas N. Blanton David R. Whitcomb Nicholas Zumbulyadis Brian J. Antalek Scott T. Misture 《Journal of solid state chemistry》2006,179(4):1053-1059
In continuation of our interest in solid-state structures of silver complexes of photographic importance, the structure for silver benzotriazole (AgBZT), has now been obtained. The preferred method for solving crystal structures is via single-crystal X-ray diffraction (XRD). However, for some materials, growing single crystals of appropriate size and quality is often difficult or even impossible. AgBZT is an example of such a silver complex with poor solubility. The usual routes to preparing single crystals using recrystallization from a cooperating solvent resulted in polycrystalline powder samples. We propose a crystal structure for AgBZT, solved from synchrotron X-ray powder diffraction data, using a direct-space Monte Carlo simulated annealing approach. AgBZT crystals are monoclinic, (P21/c), with unit cell dimensions, a=14.8052(3) Å, b=3.7498(4) Å, c=12.3495(12) Å, and β=114.200(6)°. The AgBZT complex is constructed from all three of the Benzotriazole (BZT) nitrogens bonding to a separate silver atom. As a consequence of this bonding mode, the structure is a highly cross-linked, coordination polymer. 相似文献
33.
This paper presents results on symmetries of the spectrum of singularities for random cascades found in the statistical theory of turbulence. It is shown that empirical dimension curves possess a natural symmetry whose presence restricts the class of allowable probability distributions of the cascade generator in a simple manner. In particular, necessary and sufficient conditions on the probability distribution of the generator are obtained for symmetry of the singularity spectrum within a large class of cascade models. 相似文献
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L. Sajo-Bohus M. C. Scott E. D. Greaves L. J. Somervaille S. Green T. Avila F. Loaiza L. Foglietta 《Journal of Radioanalytical and Nuclear Chemistry》2004,259(2):251-255
Gamma-ray induced X-ray emission (GIXE) technique for elemental lead in-vivo tibial measurement using a large volume hyper
pure germanium detector is presented with the most convenient source-sample-detector geometry. The system operates advantageously
when several parameters are considered for a lower dead time operation. The detection limit (DL) is better that 3.5 μg/g of
Ca. Results of in-vivo average tibial lead concentration for some of the monitored groups are: control 7 μg of lead per g
of Ca; gasoline filling attendants 6 μg/g of Ca; custom office workers near the DL; industrial workers range from DL up to
84±3 μg/g of Ca, suggesting that lead accumulation in the bone does not represent a major health risk
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
36.
A new flow electrical conductance instrument was constructed and tested on dilute NaCl solutions up to 458 K, and on more
concentrated solutions (maximum 0.436 mol⋅kg−1) at 373 K. The results of the new instrument agreed with those of previous authors within the estimated experimental errors.
The model of Bernard et al. (J. Phys. Chem. 96, 3833–3840 (1992), MSA) was found to represent the high-temperature results without introducing an ion-pairing equilibrium constant. The Fuoss–Hsia
conductance equation as given by Fernandez-Prini was found to represent the dilute concentrations with Λ° (NaCl) as the only adjustable parameter. It was found that Λ° (NaCl) could be expressed as a function of solvent viscosity and density by using three parameters found by regression of
literature results between 278.15 and 523 K. This equation along with the FHFP theory permits the equivalent conductivity
of dilute sodium chloride solutions to be calculated within the accuracy of the existing experimental measurements. 相似文献
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