Observation of the radiative 2s02p6−2s12p5 transition in NeIII

Ion impact excited spectra of Ne contain a line at 52.82 nm which has been identified as resulting from the decay of double 2s vacancies in NeIII via the transition 2s⁰2p⁶(¹S₀)?2s¹2p⁵(¹P₁).     

Generalization of Fenchel's duality theorem for convex vector optimization

For a vector-valued function f, Sup f and Inf f are defined from the Yu's domination theory and the Pareto's efficiency. A notion of conjugate is proposed for convex vector-valued function, this construction gives once more the usual conjugate function: $\text{f}{}^1\text{(x}{}^1\text{) =}\text{sup}\text{[〈x}{}^1\text{, x〉 ? f(x)]}$ when the function f is scalar. Then, this concept is used to write the Fenchel's problem in convex multiple objective optimization and to prove the associated duality theorem.     

Electron slip influence on quasimolecular X-rays in heavy ion collisions

The rotation of the quasimolecular axis in the heavy ion collision is treated dynamically by taking into account the 2pπ-2pσ electron slip. This is done by the correct quantum mechanical method in the perturbation approximation for low ion velocities. The various radiative processes resulting from initial alignments are discussed. The spectra and anisotropies are calculated. Their dependence on the electron slip is investigated.     

Entrenched time delays versus accelerating opinion dynamics: are advanced democracies inherently unstable?

Modern societies face the challenge that the time scale of opinion formation is continuously accelerating in contrast to the time scale of political decision making. With the latter remaining of the order of the election cycle we examine here the case that the political state of a society is determined by the continuously evolving values of the electorate. Given this assumption we show that the time lags inherent in the election cycle will inevitable lead to political instabilities for advanced democracies characterized both by an accelerating pace of opinion dynamics and by high sensibilities (political correctness) to deviations from mainstream values. Our result is based on the observation that dynamical systems become generically unstable whenever time delays become comparable to the time it takes to adapt to the steady state. The time needed to recover from external shocks grows in addition dramatically close to the transition. Our estimates for the order of magnitude of the involved time scales indicate that socio-political instabilities may develop once the aggregate time scale for the evolution of the political values of the electorate falls below 7–15 months.     

SECM for Studying the Immobilization and Repartition of a Redox Anti-tetracycline Aptamer on Screen-printed Carbon Electrodes

Scanning electrochemical microscopy (SECM) is discussed as a versatile tool to provide a unique approach of localized electrochemical information in the context of biosensing research. The step-by-step immobilization of DNA aptamer with intrinsic redox activity on screen-printed carbon electrode (SPCE) was successfully monitored using SECM imaging tool. Control experiments were performed with a non-electroactive aptamer. After immobilization of these aptamers, SECM images showed the repartition of the electroactive anti-tetracycline aptamer when comparing with images produced for control and for all modification steps of SPCE. The possibility of tetracycline detection was also proved by causing a decrease in recorded current.     

Biological soft X‐ray tomography on beamline 2.1 at the Advanced Light Source

Beamline 2.1 (XM‐2) is a transmission soft X‐ray microscope in sector 2 of the Advanced Light Source at Lawrence Berkeley National Laboratory. XM‐2 was designed, built and is now operated by the National Center for X‐ray Tomography as a National Institutes of Health Biomedical Technology Research Resource. XM‐2 is equipped with a cryogenic rotation stage to enable tomographic data collection from cryo‐preserved cells, including large mammalian cells. During data collection the specimen is illuminated with `water window' X‐rays (284–543 eV). Illuminating photons are attenuated an order of magnitude more strongly by biomolecules than by water. Consequently, differences in molecular composition generate quantitative contrast in images of the specimen. Soft X‐ray tomography is an information‐rich three‐dimensional imaging method that can be applied either as a standalone technique or as a component modality in correlative imaging studies.     

Lifetime measurement of the 2(1)+ state in 20C

Establishing how and when large N/Z values require modified or new theoretical tools is a major quest in nuclear physics. Here we report the first measurement of the lifetime of the 2(1)+ state in the near-dripline nucleus 20C. The deduced value of τ(2(1)+)=9.8±2.8(stat)(-1.1)(+0.5)(syst) ps gives a reduced transition probability of B(E2; 2(1)+→0(g.s.)+)=7.5(-1.7)(+3.0)(stat)(-0.4)(+1.0)(syst) e2 fm4 in good agreement with a shell model calculation using isospin-dependent effective charges.     

Caracterisation et Etude par effet Mössbauer d'une nouvelle variete haute pression de FeOOH

A new high pressure form of FeOOH, isostructural with InOOH, has been prepared by hydrothermal synthesis under very high pressure conditions. Characterization of the new phase was performed by D.T.A., T.G.A., infrared and Mössbauer spectroscopy. The compound behaves as an antiferromagnet with a Néel temperature of approximately 570° K. The hyperfine magnetic field at 0° K is about 525 kOe. Thermal decomposition occurs below the Néel temperature. Comparison with other FeOOH phases is made.     

Synthesis of new luminescent materials activated with divalent samarium

A simple technique for the preparation of powder compounds doped with divalent samarium is described. The reaction is carried out in nickel containers sealed in an inert atmosphere. The samarium impurity is introduced as samarium trifluoride SmF₃, and metallic samarium powder acts as the reducing agent to change Sm³⁺ into Sm²⁺. Using this method, samarium has been stabilized in the divalent state in various fluorides: KMgF₃, BaLiF₃, BaY₂F₈, and KY₃F₁₀. The resulting compounds show under ultraviolet or visible excitation an intense luminescence in the red region characteristic of Sm²⁺-doped materials. The emission and excitation spectra of these phosphors are presented and briefly discussed.