Imaging delocalized electron clouds: photoionization of C(60) in Fourier reciprocal space

The dynamics of the photoionization of the two outermost orbitals of C(60) has been studied in the oscillatory regime from threshold to the carbon K edge. We show that geometrical properties of the fullerene electronic hull, such as its diameter and thickness, are contained in the partial photoionization cross sections by examining ratios of partial cross sections as a function of the photon wave number in the Fourier conjugated space. Evaluated in this unconventional manner photoemission data reveal directly the desired spatial information.     

Systematic event generator tuning for the LHC

In this article we describe Professor, a new program for tuning model parameters of Monte Carlo event generators to experimental data by parameterising the per-bin generator response to parameter variations and numerically optimising the parameterised behaviour. Simulated experimental analysis data is obtained using the Rivet analysis toolkit. This paper presents the Professor procedure and implementation, illustrated with the application of the method to tunes of the Pythia 6 event generator to data from the LEP/SLD and Tevatron experiments. These tunes are substantial improvements on existing standard choices, and are recommended as base tunes for LHC experiments, to be themselves systematically improved upon when early LHC data is available.     

Decomposition of the optical transfer function: wavefront coding imaging systems

We describe the mapping of the optical transfer function (OTF) of an incoherent imaging system into a geometrical representation. We show that for defocused traditional and wavefront-coded systems the OTF can be represented as a generalized Cornu spiral. This representation provides a physical insight into the way in which wavefront coding can increase the depth of field of an imaging system and permits analytical quantification of salient OTF parameters, such as the depth of focus, the location of nulls, and amplitude and phase modulation of the wavefront-coding OTF.     

The structure of solid salt eutectics — – Why lamellar or conglomerate?

Using KCl/ZnSO₄ eutectic it has been shown that cooling the melt into a room temperature enclosure forms a lamellar structure, whereas cooling into a heated enclosure (225 °C) forms a conglomerate structure, while an enclosure temperature of 125 °C gave a partially conglomerate structure with some lamellae in process of forming conglomerates.Consideration of the thermal gradients imposed on solidification and consequently the relative time available during which the ions are sufficiently mobile to rearrange their positions, can explain the observation that lamellar structures are formed by higher melting point eutectics, whereas eutectics of lower melting point form conglomerate structures.     

Smooth Nb surfaces fabricated by buffered electropolishing

It was demonstrated that smooth Nb surfaces could be obtained through buffered electropolishing (BEP) employing an electrolyte consisting of lactic, sulfuric, and hydrofluoric acids. Parameters that control the polishing process were optimized to achieve a smooth surface finish. The polishing rate of BEP was determined to be 0.646 μm/min which was much higher than 0.381 μm/min achieved by the conventional electropolishing (EP) process widely used in the superconducting radio frequency (SRF) community. Root mean square measurements using a 3D profilometer revealed that Nb surfaces treated by BEP were an order of magnitude smoother than those treated by the optimized EP process. The chemical composition of the Nb surfaces after BEP was analyzed by static and dynamic secondary ion mass spectrometry (SIMS) systems. SIMS results implied that the surface oxide structure of Nb might be more complicated than what usually believed and could be inhomogeneous. Preliminary results of BEP on Nb SRF single cell cavities and half-cells were reported. It was shown that smooth and bright surfaces could be obtained in 1800 s when the electric field inside a SRF cavity was uniform during a BEP process. This study showed that BEP is a promising technique for surface treatment on Nb SRF cavities to be used in particle accelerators.     

Palladium-free Suzuki-Miyaura cross-coupling at elevated pressures

Elevated pressure (15 kbar) in the liquid phase improves yields and permits the use of cheaper Fe(III), Co(II), and Ni(II) metal salts as catalysts for the Suzuki-Miyaura cross-coupling of aryl halides and aryl boronic acids.     

Software Reviews

Micro Messenger One World Countries Database The Math Machine USA Social and Geographical Database Central United States Adventure Construction Set Green Globs and Graphing Equations Success With Math: Geometric Construction Gnee or Not Gnee     

Substituted metal carbonyls. Part 25: Unidentate,intramolecular, and intermolecular bridging modes of 1,1′-bis(diphenylphosphino)ferrocene inM 3S2(CO)9 (M = Fe,Ru) cluster derivatives

Carbonyl exchange of Fe₃(₃-S)₂(CO)₉ wioth1,1-bis(diphenylphosphino)ferrocene (dppf) in refluxing THF gives a cluster ligand with a pendant phosphine moiety, Fe₃(₃-S)₂(CO)₈ (gn¹-Ph₂PlC₅H₄)Fe(C₅H₄)P⁴ MePh₂)]1 ^–,4. Addition of 1 to AuCl(SMe₂) gives ClAu(-dppf) Fe₄(₃-S)₂(CO)₈,8 (45%). Spectroscopic evidence is also obtained for (OC)₈ (₃-S)₂Fe₃(-dppf) Os₃(CO)₁₁,7 and PdCl₂[(-dppf)Fe₃(₃-D)₂(CO)₈]₂,9, from1 and Os₃(CO)₁₁(CH₃CN) and PdCl₂CN)₂, respectively. Crystal data dor3: space group P2₁/n,a = 10.891(3) Å,b = 19.939(3) Å,c = 20.443(2) Å, 100.17(2)°.Z = 4, 3917 reflections,R = 0.049.