Metal-directed self-assembly of bimetallic dithiocarbamate transition metal cryptands and their binding capabilities

A novel family of redox-active dinuclear transition metal based cryptands self-assembled from dithiocarbamate ligands has been synthesised; depending upon the nature of the spacer groups these new cryptand systems have been shown to electrochemically recognise the binding of cations or anions.     

Knotted Zeros in the Quantum States of Hydrogen

Complex superpositions of degenerate hydrogen wavefunctions for the n th energy level can possess zero lines (phase singularities) in the form of knots and links. A recipe is given for constructing any torus knot. The simplest cases are constructed explicitly: the elementary link, requiring n6, and the trefoil knot, requiring n7. The knots are threaded by multistranded twisted chains of zeros. Some speculations about knots in general complex quantum energy eigenfunctions are presented.     

Investigation of active structural intensity control in finite beams: theory and experiment

An investigation of structural intensity control is presented in this paper. As opposed to previous work, the instantaneous intensity is completely taken into account in the control algorithm, i.e., all the terms are considered in the real-time control process and, in particular, the evanescent waves are considered in this approach. A finite difference approach using five accelerometers is used as the sensing scheme. A feedforward filtered-X least mean square algorithm is adapted to this energy-based control problem, involving a nonpositive definite quadratic form in general. In this respect, the approach is limited to cases where the geometry is such that the intensity component will have the same sign for the control source and the primary disturbance. Results from numerical simulations are first presented to illustrate the benefit of using a cost function based on structural intensity. Experimental validation of the approach is conducted on a free-free beam covered with viscoelastic material. A comparison is made between classical acceleration control and structural intensity control and the performance of both approaches is presented. These results confirm that using intensity control allows the error sensors to be placed closer to the control source and the primary disturbance, while preserving a good control performance.     

Search for color singlet technicolor particles in p&pmacr; collisions at radicals = 1.8 TeV

We search for color singlet technirho and technipion production in p&pmacr; collisions at sqrt[s] = 1.8 TeV recorded with the Collider Detector at Fermilab. These exotic technimesons are present in a model of walking technicolor. The signatures studied are lepton plus two jets plus E(T) and multijet final states. No excess of events is seen in either final state. We set an upper limit on the technirho production cross section and exclude a region in the technipion mass versus technirho mass plane.     

Diffractive dijets with a leading antiproton in &pmacr;p collisions at sqrt

We report results from a study of events with a leading antiproton of beam momentum fraction 0.9057 GeV. Using the dijet events, we evaluate the diffractive structure function of the antiproton and compare it with expectations based on results obtained in diffractive deep inelastic scattering experiments at the DESY ep collider HERA.     

Mit der volumetrischen Bestimmung von Wasserstoffsuperoxyd und Caroseher S?ure in Gegenwart von Persehwefels?ure

Ohne Zusammenfassung     

Gas chromatographic analysis of phenylethylmalonamide in human plasma

A method is described for the analysis of phenylethylmalonamide in human plasma. Analysis of plasma requires only 200 microliter of sample which is extracted with dichloroethane. After filtration and evaporation of the solvent the residue is reconstituted in 50 microliter of chloroform and 5 microliter are injected onto the gas chromatograph. The column used is a mixture of CDMS/WG11 coated on Chromosorb W HP 100-120 mesh. The method is suitable for use in single-dose pharmacokinetic studies.     

Note sur une formule de M. Schoute

Rendiconti del Circolo Matematico di Palermo Series 1 -     

A C2-symmetric analogue of dppf: synthesis and structures of the indenyl-diphosphine complex 1,3-(Ph2PSe)2(C9H6) and the racemic and meso isomers of the heterobimetallic complex Mo(CO)4(1-PPh2-η-C9H6)2Fe

The preparation, isolation and characterisation of 1,3-bis(diphenylphosphino)indene (1) from indene and chlorodiphenylphosphine is described. The reaction of 1 with selenium gives the diselenide adduct 1,3-bis(diphenylselenophosphino)indene (2) which was characterised crystallographically. Deprotonation of 1 and treatment with ferrous chloride gives the unstable tetraphosphine complex bis(1,3-bis(diphenylphosphino)indenyl)iron(II) (3). Complex 3 decomposes to the diphosphine complex bis(1-diphenylphosphinoindenyl)iron(II) (4) via replacement of one diphenylphosphine substituent per indenyl ligand by a hydrogen atom. Complex 4 was also prepared by treatment of two equivalents of 1-diphenylphosphinoindenide with ferrous chloride. The heterobimetallic complex tetracarbonyl(bis(1-diphenylphosphinoindenyl)iron(II))molybdenum(0) (5) was also prepared and crystal structures of both the meso (5a) and C₂-symmetric racemic (5b) isomers are reported.