The process of lithium insertion into thin gold films is studied. It is found that lithium is reversibly inserted with the formation of compounds, which are close to Li
1.5
Au in their average ...composition. The long-term cycling leads to the breakdown of gold layer (and corresponding decrease in the electrode capacity), which is associated with considerable volume changes due to lithium insertion.
Superconducting RF is a key technology for future particle accelerators, now relying on advanced surfaces beyond bulk Nb for a leap in performance and efficiency. The SRF thin film strategy aims at ...transforming the current SRF technology by using highly functional materials, addressing all the necessary functions. The community is deploying efforts in three research thrusts to develop next-generation thin-film based cavities. Nb on Cu cavities are developed to perform as good as or better than bulk Nb at reduced cost and with better thermal stability. Recent results showing improved accelerating field and dramatically reduced Q slope show their potential for many applications. The second research thrust is to develop cavities coated with materials that can operate at higher temperatures or sustain higher fields. Proof of principle has been established for the merit of Nb3Sn for SRF application. Research is now needed to further exploit the material and reach its full potential with novel deposition techniques. The third line of research is to push SRF performance beyond the capabilities of the superconductors alone with multilayered coatings. In parallel, developments are needed to provide quality substrates, cooling schemes and cryomodule design tailored to thin film cavities. Recent results in these three research thrusts suggest that SRF thin film technologies are at the eve of a technological revolution. For them to mature, active community support and sustained funding are needed to address fundamental developments supporting material deposition techniques, surface and RF research, technical challenges associated with scaling and industrialization. With dedicated and sustained investment, next-generation thin-film based cavities will become a reality with high performance and efficiency, facilitating energy sustainable science while enabling higher luminosity, and higher energy.
The Escherichia coli genes encoding purine nucleoside phosphorylase, uridine phosphorylase, and thymidine phosphorylase were cloned into pET plasmids to generate highly effective E. coli BL21(DE3) ...strains producing each of these enzymes. Optimum conditions for biosynthesis of each enzyme as a soluble protein with intact biological activity were found. The crude preparations are approximately 80% pure and can be used immediately for enzymatic transglycosylation. The enzyme preparations were purified to homogeneity by two steps including fractional precipitation with ammonium sulfate and subsequent chromatography on Sephadex G-100 and DEAE-Sephacel.
We report the observation results of the hard radiation flashes which accompanied the lightning discharges above the mountains of Northern Tien Shan. Time series of the counting rate intensity, ...numerical estimations of absolute flux, and energy distribution of accelerated electrons and of (20-2000)keV gamma rays were obtained at the height of 3700m a.s.l., immediately within thunderclouds, and in closest vicinity (\(<\)100m) to discharge region. Two different kinds of radiation emission events are presented here: a relatively prolonged rise of gamma ray intensity with minute-scale duration (the thunderstorm ground enhancement, TGE) which has preceded a negative field variation, and a short sub-millisecond radiation burst, which accompanied a close lightning discharge in thundercloud. It was revealed also an indication to positron generation in thunderclouds at the time of gamma ray emission, as well as modulation of the neutron counting rate in Tien~Shan neutron monitor which was operating at a (1.5-2)km order distance from the region of lightning development.
The ripple transport of fast (suprathermal) ions and electrons in tokamaks is analyzed. This transport, which arises from the drift motion of particles blocked in the ripple of a magnetic field, is ...of the convective type for particles whose energy exceeds a certain value. It is noted that for ions in real tokamaks, this energy region may be close to the bulk of ions having thermal energy. Kinetic equations for the particle distribution function are derived, with consideration given to the ripple drift motion through the magnetic surfaces. In the low-energy (diffusive) limit, the results are found to be in good agreement with the well-known ones; in the case of more energetic particles, convective transport dominates. In particular, a replacement (throught the ripple channel) of fast electrons from the hot periphery is possible; this results in a considerable rise there of the distribution function tail. The importance of the increase in the ripple depth from the chamber center to the periphery is stressed; it causes collisionless adiabatic capture of particles by ripples, which are held there, then drift, and finally escape from the plasma.
In a recent comment arXiv:1405.2978v1 (2014) Romanenko and Grassellino made unsubstantiated statements about our work Appl. Phys. Lett. 104, 092601 (2014) and ascribed to us wrong points which we had ...not made. Here we show that the claims of Romanenko and Grassellino are based on misinterpretation of our Letter and inadequate data analysis in their earlier work *. * A. Romanenko and A. Grassellino, Appl. Phys. Lett. 102, 252603 (2013)
We consider experimentally and theoretically the effect of the thickness on the critical current density ital Jsub ital c of superconducting films. In order to eliminate possible contributions from ...intrinsic pinning, our measurements of ital Jsub ital c(ital cphi) as a function of the amplitude and orientation of the magnetic field bold H with respect to the film plane were performed on isotropic Nb-Ti films having thicknesses ital d ranging from lambda/4 to 4lambda, where lambda is the London penetration depth, and bold Hperpendicularbold J. The angular dependent ital Jsub ital c(ital cphi) has a sharp peak for bold H parallel to the film surface, similar to that observed for high-ital Tsub ital c films. The amplitude of the peak increases as ital d decreases and reaches 20--30 % of the depairing current density (ital Jsub ital d) for the lambda/2 film. The ratio of ital Jsub ital c values for parallel (ital Jsub ital cparallel) and perpendicular (ital Jsub ital cperpendicular) film orientation increases as ital d decreases, so that ital Jsub ital cparallelmuch ltital Jsub ital cperpendicular for the 4lambda film and ital Jsub ital cparallelmuch gtital Jsub ital cperpendicular for the lambda/4 film, the crossover occurring at ital dapprox2lambda. A proposed interpretation of these results is based on our calculations of the vortex behavior in thin (ital dmuch ltlambda) films, which give analytical formulas for the field distribution around a fluxon, the lower critical field, ital Hsub ital c1, the surface barrier, and the vortex-vortex interaction potential.
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