10,000 publications from this institution
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
The photoelectrochemical properties of n‐Si in with and without are explored using photoelectrochemical impedance spectroscopy to define a transfer function as the ratio between the modulated output voltage of a fast photodiode (proportional to the incident light intensity) and the modulated photocurrent response. We show that the transfer function transforms correctly according to the K‐K relations, demonstrating that the system satisfies the linearity, causality, and stability constraints of linear system theory. Accordingly, the transfer function may be identified with the system impedance and may be analyzed in terms of passive electrical analogs or reaction models that employ Heaviside algebra.
Summary This paper develops a procedure to select unscaled ground motions for estimating seismic demand hazard curves (SDHCs) in performance‐based earthquake engineering. Currently, SDHCs are estimated from a probabilistic seismic demand analysis, where several ensembles of ground motions are selected and scaled to a user‐specified scalar conditioning intensity measure (IM). In contrast, the procedure developed herein provides a way to select a single ensemble of unscaled ground motions for estimating the SDHC. In the context of unscaled motions, the proposed procedure requires three inputs: (i) database of unscaled ground motions, (ii) I M , the vector of IMs for selecting ground motions, and (iii) sample size, n ; in the context of scaled motions, two additional inputs are needed: (i) a maximum acceptable scale factor, S F m a x , and (ii) a target fraction of scaled ground motions, γ . Using a recently developed approach for evaluating ground motion selection and modification procedures, the proposed procedure is evaluated for a variety of inputs and is demonstrated to provide accurate estimates of the SDHC when the vector of IMs chosen to select ground motions is sufficient for the response quantity of interest. Copyright © 2015 John Wiley & Sons, Ltd.
Steam gasification was performed on both graphite and demineralized char. Mixtures of earth alkali with potassium as catalysts exhibited good gasification characteristics. K-Mg is the most active and only somewhat less active than K-Ni. K-Ca is less active than K-Mg. The alkali-earth alkali catalysts show less initial deactivization and greater stability than K-Ni. The alkali-earth alkali mixtures can dissociate water at the operating temperatures (>800k). An additional factor in catalyst activity is the ability of the catalyst to wet and spread over the carbon surface. This is dependent on the melting point of the mixture which is lower for K-Mg and for K-Ni than for a Mg-Ni mixture. A previously proposed reaction scheme is expanded and is supported by experimental work. 4 refs., 5 figs., 2 tabs.
The best and worst organizational practices found in this study can be used by ICU leaders as a checklist for improving ICU management.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
The functionalization of amines at C-H bonds beyond the α-position could generate valuable difunctional products, but such transformations with readily accessible amine derivatives remain underdeveloped. We report the iridium-catalyzed, regio- and stereoselective silylation of primary and secondary C(<i>sp</i><sup>3</sup>)-H bonds in primary amine derivatives to afford silapyrrolidines and 1,2-amino alcohols after oxidation. The use of sulfonamides as protecting groups on the alkyl amines enables alkylation of the resulting sulfonamide with halomethylsilanes and subsequent silylation of the C(<i>sp</i><sup>3</sup>)-H bonds with broad scope. This reaction also enables the functionalization of both primary and secondary C(<i>sp</i><sup>3</sup>)-H bonds with high regioselectivity and stereoselectivity. Reactions with iridium complexes of new chiral nitrogen-based ligands occur with high enantioselectivity.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Abstract The effects of plan‐wise distribution of stiffness and strength‐as determined by the number, location, orientation and yield deformations of resisting elements‐on the inelastic response of one‐storey systems are evaluated. In particular, various systems are investigated for wide ranges of parameters involved, with the objective of establishing how the response is influenced by: (i) the presence of resisting elements perpendicular to the direction of ground motion; (ii) the number of resisting elements along the direction of ground motion; (iii) the overstrength typical of code‐designed buildings; (iv) the relative values of strength and stiffness eccentricities; and (v) whether the asymmetry of the system is due to eccentricity in stiffness or in mass. The results presented for a simple excitation make it possible to explain the inconsistencies in conclusions from various earlier investigations, and to evaluate their applicability to actual buildings.
