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Patrik U. Andersson Leif Holmlid Stephan Fuelling 《Journal of Superconductivity and Novel Magnetism》2012,25(4):873-882
Ultra-dense deuterium D(?1) is expected to be both a superfluid and a superconductor as shown by recent theoretical research. Condensed D(?1) can be deposited on surfaces by a source which produces a stream of clusters. A magnetic field strongly influences the type of material formed. Very little of D(?1) and of the form D(1), which is strongly coupled to D(?1), exists on the magnet surface or within several mm from the magnet surface. Even the formation of D(?1) on the source emitter is strongly influenced by a magnetic field, with a critical field strength in the range 0.03?C0.07 T. Higher excitation levels D(2) and D(3) dominate in a magnetic field. The excitation level D(2) is now observed for the first time. The removal of D(?1) and D(1) in strong magnetic fields is proposed to be due to a Meissner effect in long D(?1) clusters by large-orbit electron motion. The lifting of long D(?1) clusters above the magnet surface is slightly larger than expected, possibly due to the coupling to D(1). The previously reported oscillation between D(?1) and D(1) in an electric field is proposed to be due to destruction of D(?1). 相似文献
43.
Driven by promising recent results, there has been a revived interest in the thermoelectric properties of organic (semi)conductors. Concomitantly, there is a need to probe the Seebeck coefficient S of modestly conducting materials in thin film geometry. Here we show that geometries that seem desirable from a signal-to-noise perspective may induce systematic errors in the measured value of S, Sm, by a factor 3 or more. The enhancement of Sm by the device geometry is related to competing conduction paths outside the region between the electrodes. We derive a universal scaling curve that allows correcting for this and show that structuring the semiconductor is not needed for the optimal electrode configuration, being a set of narrow, parallel strips. 相似文献
44.
Nathaniel A. Riordan Chaturvedi Gogineni Shane R. Johnson Xianfeng Lu Tom Tiedje Ding Ding Yong-Hang Zhang Rafael Fritz Kolja Kolata Sangam Chatterjee Kerstin Volz Stephan W. Koch 《Journal of Materials Science: Materials in Electronics》2012,23(10):1799-1804
Bulk and quantum well GaAs1?xBix/GaAs layers with Bi mole fractions from 0.02 to 0.10 are grown by molecular-beam epitaxy at temperatures ranging from 280 to 320?°C. The samples are characterized using temperature and pump-power dependent photoluminescence measurements covering 8–300?K and 1–250?mW (7–1,800?W/cm2), respectively. The results indicate that there is strong reduction in bandgap energy with the incorporation of small amounts of Bi and that GaAsBi most likely forms a weak type-I band alignment with GaAs. 相似文献
45.
Alexander Gredner Christoph Gerhard Stephan Wieneke Kai Schmidt Wolfgang Viol 《材料科学与工程:中英文B版...》2013,(6):346-351
In this work, a novel atmospheric pressure plasma-assisted excimer laser annealing method for increasing the generation efficiency of poly-crystalline silicon from amorphous silicon layers is presented. Here, both the plasma and the laser propagate coaxially in order to generate energetic synergies. The influence of different process gases and plasma discharge modes as well as the working distance were investigated. Depending on the particularly applied plasma, the crystalline area was increased by a factor of approx. 1.1 to 1.9, where the highest efficiency was observed when introducing an argon plasma beam to the annealing process. 相似文献
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Dmitry V. Volodkin Stephan Schmidt Paulo Fernandes Natalia I. Larionova Gleb B. Sukhorukov Claus Duschl Helmuth Möhwald Regine von Klitzing 《Advanced functional materials》2012,22(9):1914-1922
Formulation of therapeutic proteins into particulate forms is a main strategy for site‐specific and prolonged protein delivery as well as for protection against degradation. Precise control over protein particle size, dispersity, purity, as well as mild preparation conditions and minimal processing steps are highly desirable. It is, however, hard to fit all these criteria with conventional preparation techniques. Here a one‐step hard‐templating synthesis of microparticles composed of functional, non‐denatured protein is reported. The method is based on filling porous CaCO3 microtemplates with the protein near to its isoelectric point (pI) followed by pH‐ or EDTA‐mediated dissolution of the tempplates. In principle, a wide variety of proteins can be converted into microparticles using this approach. The main requirement is an overlap of the protein insolubility and a template solubility for a certain parameter (here pH or EDTA). Here the formulation of insulin particles is studied in detail and it is shown that particles consisting of high molecular weight protein (catalase) can also be prepared. In this context, the synthesis of CaCO3 templates with controlled size, the mechanism of the protein microparticle formation and mechanical properties of the microparticles are discussed. For the first time, the fabrication of mesoporous monodispersed CaCO3 microtemplates with identical porocity but tuned diameter from 3 to 20 μm is demonstrated. The protein particle diameter can be adjusted by choosing the appropriate template size that is critical for successful pulmonary delivery of insulin. As a first step towards insulin delivery, the in vitro release of insulin at physiological conditions is studied. 相似文献
48.
Profile accuracy, no burning and residual compressive stresses at the tooth root fillet are required for the durability of highly stressed gears. This paper reveals the challenges for continuous generating grinding with corundum and CBN. For this purpose, material removal simulations and experimental investigations were carried out to gain knowledge of the tool–workpiece contact conditions. The potential of CBN tools was analysed due to the fact that the mechanical loads at the grinding worm tip result in high profile wear of the corundum tools. In this context, especially the interrelationship between the dressing strategy and the workpiece quality was investigated in detail. 相似文献
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