Basic Aspects of the Quantum Theory of Solids: Order and Elementary Excitations,by Daniel I. Khomskii

This article briefly surveys the wide variety of applications of radar in meteorology. Microwave radars are used to provide information about the distribution, type and intensity of precipitation in the atmosphere and about wind patterns and turbulence. VHF and UHF radars are used to provide wind profiles. Advances in information technology are enabling the information derived from radars to be processed and made available to users in a timely and convenient fashion. The detailed patterns of precipitation-intensity given by networks of radars are proving to be valuable to weather forecasters and hydrologists alike. Doppler radar enables tornadoes to be detected and aviation will be able to benefit from the detection of other hazardous wind conditions, such as wind shear and microbursts. For the research meteorologist, Doppler radar provides one of the best tools for measuring detailed 3-D fields of air motion within convective storms and frontal weather systems as well as within the planetary boundary layer.     

Understanding Quantum Phase Transitions,edited by Lincoln Carr

The concept of the superdeformed shape is first introduced classically as the most stable configuration of a rapidly rotating deformable body and is then applied to nuclei. The shape of nuclei are determined by a competition between the collective energy of the core, to which classical considerations apply quite well, and the quantal energies of the valence nucleons, which may be evaluated by the Nilsson model. The result of this competition is that slowly rotating nuclei can be either oblate or prolate but rapidly rotating nuclei can have a superdeformed prolate shape, with a 2:1 ratio of axes particularly favoured.

The evidence for superdeformation in nuclei is described under four headings. Firstly, some light nuclei are superdeformed in their ground state or in an excited state. Secondly, some nuclei pass through a well defined superdeformed shape on the way to fission. Thirdly, studies of the excitation functions of elastic and inelastic scattering of identical heavy ions provide evidence of a nuclear molecule in a superdeformed shape. Finally, recent analyses of gamma rays from nuclei formed in a very high spin state by a heavy ion collision provide conclusive evidence for superdeformation.     

Diffraction study of actinides under pressure

Abstract

Uranium and thorium have sufficiently low radioactive dose rates to allow their study at synchrotrons and neutron facilities. Correspondingly, numerous compounds of these two actinides have been studied under pressure by synchrotron x-ray diffraction. The maximum pressures reached were on the order of 60-80 GPa, and 300 GPa in one case.

The situation is much more difficult for all other actinides. Their high level of radioactivity has up to now prevented their study at synchrotrons, except in a few special cases. In contrast, all actinide metals available in sufficient quantities, and a large number of compounds of highly radioactive actinides, have been studied in highpressure laboratory facilities.

Recent examples of in situ high pressure x-ray diffraction work will be described.     

Risk averse elastic shape optimization with parametrized fine scale geometry

Shape optimization of the fine scale geometry of elastic objects is investigated under stochastic loading. Thus, the object geometry is described via parametrized geometric details placed on a regular lattice. Here, in a two dimensional set up we focus on ellipsoidal holes as the fine scale geometric details described by the semiaxes and their orientation. Optimization of a deterministic cost functional as well as stochastic loading with risk neutral and risk averse stochastic cost functionals are discussed. Under the assumption of linear elasticity and quadratic objective functions the computational cost scales linearly in the number of basis loads spanning the possibly large set of all realizations of the stochastic loading. The resulting shape optimization algorithm consists of a finite dimensional, constraint optimization scheme where the cost functional and its gradient are evaluated applying a boundary element method on the fine scale geometry. Various numerical results show the spatial variation of the geometric domain structures and the appearance of strongly anisotropic patterns.     

Binding modes of carboxylate- and acetylacetonate-linked chromophores to homodisperse polyoxotitanate nanoclusters

The binding of carboxylate- and acetylacetonate-linked chromophores to homodisperse polyoxotitanate nanoclusters with 17 Ti atoms or more are surveyed and found to be limited to chelate-bidentate and the bridging modes, the former being dominant for the acetylacetonate-linked chromophores, the latter for the carboxylate linkers. Chromophores with acetylacetonate linking groups invariably bind in the chelate mode, whereas carboxylic acid terminated chromophores more frequently are observed to have the bridging mode, with the exception of three cases in which a strong electron-donating substituent is present on two different sensitizers. The calculations for isonicotinateand nitrophenylacetylacetonate functionalized Ti17 clusters show the observed binding modes to correspond to the lower energy functionalized clusters, but do not predict the difference between the cinnamic acid and dimethylaminocinnamic acid binding to Ti17, which are bridging and chelate respectively. Both binding modes were never observed to occur for a single chromophore, even when synthetic conditions were varied. Density of state calculations show broadening and splitting of the chromophore LUMO on complexation due to interaction with the cluster's conduction band, as well as frequent penetration of sensitizer orbitals into the bandgap of the functionalized nanoparticle.     

Some Remarks on Signs in Functional Equations

We discuss the computation of the sign in certain functional equations.     

Polymeric FAD used as enzyme-friendly mediator in lactate detection

We present the fabrication and properties of lactate biosensors. The novel feature is the use of polymerized flavin adenine dinucleotide (FAD) as mediator for electron transfer. The biosensors were prepared using lactate dehydrogenase (LDH), lactate oxidase (LOX), or baker's yeast (BY) immobilized at the surface of the electrode. The sensors using purified enzymes showed good sensitivity, linearity, and stability. The sensitivity of the BY electrodes was slightly lower. The advantages of this type of sensors are discussed in connection with potential applications.     

Communication network formation with link specificity and value transferability

We model strategic communication network formation with (i) link specificity: link maintenance lowers specific attention and thus value (negative externality previously ignored for communication) and (ii) value transferability via indirect links for informational but not for social value (positive externality modeled uniformly before). Assuming only social value, the pairwise stable set includes many nonstandard networks under high and particular combinations of complete components under low link specificity. Allowing for social and informational value reduces this set to certain fragmented networks under high and the complete network under low link specificity. These extremes are efficient, whereas intermediate link specificity generates inefficiency.     

Surface Plasmon Resonance Coupled with Potential‐step Chronoamperometry: Theory and Applications for Quantitative Measurements of Electrodeposited Thin Films

Cyclic voltammetry (CV) has been combined with surface plasmon resonance (SPR) for probing electrochemical deposition and redox‐initiated film reorganization and conformational changes. However, the varying potential during CV scans leads to unwanted SPR background changes and complicates interpretation of SPR signals. In this work, we show that, when SPR is coupled with CV, the background correction for underpotential deposition of copper and electropolymerization of aniline is either inaccurate or difficult to perform. For accurate thickness measurements of electrodeposited films, potential‐step (PS) chronoamperometry is a method of choice to combine with SPR. The theory that interprets double‐layer charging is used to explain the advantage of PS chronoamperometry over CV in quantifying the thickness of electrodeposited thin films. The influence of the double‐layer charging on the potential‐induced SPR signal change was analyzed, and the results were used to optimize experimental parameters for PS‐SPR. Overall, PS‐SPR is easier to operate, simpler in data interpretation, and more accurate for the film thickness measurement.