Efficient Time Propagation Technique for MAS NMR Simulation: Application to Quadrupolar Nuclei

The quantum mechanical Floquet theory is investigated in order to derive an efficient way of performing numerical calculations of the dynamics of nuclear spin systems in MAS NMR experiments. Here, we take advantage of time domain integration of the quantum evolution over one period as proposed by Edenet al.(1). But a full investigation of the propagatorU(t,t₀), and especially its dependence with respect totandt₀within a formalized approach, leads to further simplifications and to a substantial reduction in computation time when performing powder averaging for any complex sequence. Such an approximation is suitable for quadrupolar nuclei (I> 1/2) and can be applied to the simulation of the RIACT (rotational induced adiabatic coherence transfer) phenomenon that occurs under special experimental conditions in spin locking experiments (2–4). The present method is also compared to the usual infinite dimensional Floquet space approach (5, 6), which is shown to be rather inefficient. As far as we know, it has never been reported for quadrupolar nuclei withI≥ 3/2 in spin locking experiments. The method can also be easily extended to other areas of spectroscopy.     

Lipschitz continuity ofV-subdifferentials of convex operators

It is proved that theV-subdifferential of a convex operator is locally Lipschitzian on the set of points at which it is continuous and subdifferentiable.Proposition 2.2 was originally stated for Holder continuity ofV-subdifferentials. The author would like to thank J. P. Penot for a very helpful suggestion which led to the present form of this proposition.     

High-spin structure in154Er

High spin states in the nucleus¹⁵⁴Er have been reinvestigated using the¹²³Sb(³⁵Cl, 4n) reaction and a variety of spectroscopic techniques including excitation functions,γ-γ coincidences,γ angular distribution and linear polarization measurements. From the measured energies, relative intensities and transition multipolarities a new level scheme has been deduced up to an excitation energy of ～12 MeV and spin 36. An interpretation of the experimental results is given in terms of the deformed Woods-Saxon orbitals. Gigantic backbending (superdeformation) effect is studied theoretically within the cranking model.     

Beta-delayed two-neutron emission from 30,31,32Na

Beta-delayed two-neutron emission from mass-separated samples of short-lived sodium isotopes has been detected both by n-n time correlations with a 4π neutron counter and by γ-spectroscopic identification of daughter products with mass A ? 2. The observed cases (intensities per beta decay) are ${}^{30}\text{Na}\text{(1.2 ± 0.2\%),}{}^{31}\text{Na}\text{(0.70 ± 0.25\%)}\text{and}{}^{32}\text{Na}\text{(5.1 ± 1.8\%)}$. The results are in good agreement with a simple model of beta-particle emission.     

Multipolarity of the continuum γ-rays in 152Dy and 160Er via linear polarisation measurements

The multipolarity of the continuum transitions in ¹⁵²Dy and ¹⁶⁰Er has been deduced from γ-ray linear polarisation and angular distribution measurements. The yrast part for ¹⁶⁰Er agrees with the predicted stretched E2 cascade. The statistical parts for both ¹⁵²Dy and ¹⁶⁰Er consist of a mixture of dipolar stretched and non-stretched transitions, predominantly of electrical character. Below 1.5 MeV, the data of ¹⁵²Dy exhibit a different structure, and reveal a stretched M1 component in the low-energy region.     

Variational Convergence of Composed Convex Functions

In this paper we introduce a concept of variational convergence for mappings taking values in order topological vector spaces. This variational convergence notion is shown to be well adapted to the (epi)-convergence of composed convex functions, in the sense that it is preserved after composition with nondecreasing functions. It is proved how this stability result can be applied to the continuity of multipliers under perturbations associated with a family of constrained optimization problems. Other applications are also given.     

Integrated microfluidic devices with enhanced separation performance: application to phosphoproteome analyses of differentiated cell model systems

This work reports on the application of a microfluidic device integrating nanoscale LC to nanoelectrospray MS (nano-LC-chip-MS) for the analysis of complex protein digests. Peak profile analyses of more than 700 peptide ions, reproducibly detected across replicate nano-LC-chip-MS runs (n = 5), indicated that the system provided RSD values of 0.24% on retention time, +/- 30 ppm on m/z measurement and +/- 30% variation on intensity over three orders of magnitude. RP adsorbant media with different alkyl chains and particle size packed in both trapping and separation channels were investigated to improve the chromatographic performance of this system. A two-fold improvement in chromatographic peak capacity was achieved using microfluidic devices comprising a 5 mircrom C3 trap with 2.5 microm C18 trap separation channel compared to the traditional 5 microm C18 stationary phase. Enhanced sample selectivity for the identification of phosphopeptides was obtained by combining immobilized metal affinity media prior to peptide separation on the RP microfluidic device. This system was evaluated in the context of differential phosphoproteome analyses to identify changes in signaling events and protein expression of human monocytes following the administration of phorbol ester.     

On proto-differentiability and strict proto-differentiability of multifunctions of feasible points in perturbed optimization problems

This paper is concerned with the study of the proto-differentiability of the multifunction associated with the feasible points of optimization problems. It is proved under some natural conditions that the proto-differentiability of the data multifunctions ensure that of the resulting multifunctions of feasible points.