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Communications out of the container and cooled in air. For examination and processing, the capillaries were cast in epoxy resin. A thin film of water-free paraffin oil was enough to protect the fiber ends from attack by moisture for several days.

The polymerization experiments were carried out in a calorimeter modified for UV irradiation [22]. The samples were prepared by adding 1 wt.-% photoinitiator, Irgacure 651 (Ciba-Geigy), and 200 ppm of inhibitor p-methoxyphenol to the monomer to avoid thermal polymerization (81.To prepare the polymer films, the monomers, provided with initiator and inhibitor, are pressed at 120-125°C between glass plates coated with polyimide. They are left at this temperature until a defect-free homeotropic alignment, with disks parallel to the substrate, is obtained (black films between crossed polarizers in optical microscopy). The films, from 4 to 15 pm thick, are then exposed to UV radiation for 15 min at varied polymerization temperatures. The resulting materials are defect-free, transparent and colorless.The ordinary (no) and extraordinary (n,) refractive indices of 2 and poIy(2) are measured with an Abbe refractometer. Wide-angle X-ray diffraction experiments were carried out on a Siemens Hi-Star Area Detector, using CuKa radiation.

Let the sun shine in: Hocheffiziente und stabile Heterokontakt‐Solarzellen werden durch Einführung von vertikal ausgerichteten, vernetzten Polymernanostäben erhalten (siehe Bild). Die Solarzelle zeigt einen Rekordwert für den Konversionswirkungsgrad von 7.3 %.

Cognitive radio allows radio devices to access the idle spectrum opportunistically, thus alleviates the huge demand for spectrum. Rendezvous, where two radios complete handshaking in an idle channel, is a key step for cognitive radios to start communication. Radios may have the same (homogeneous) or different (heterogeneous) spectrum sensing capabilities. Currently, there is a "gap" between the rendezvous algorithms for homogeneous and heterogeneous cognitive radios-existing homogeneous algorithms incur high delay when applied to heterogeneous radios; while heterogeneous algorithms incur high congestion when applied to homogeneous radios. Since mixtures of these two types of radios appear commonly in practice, it is crucial to bridge the gap between the respective rendezvous algorithms. In this paper, we propose a new rendezvous algorithm, named the ICH scheme, for arbitrary mixtures of radios with homogeneous or heterogeneous spectrum sensing capabilities. Rigorous analysis and extensive simulations are conducted and show that ICH is the first rendezvous scheme that guarantees rendezvous for arbitrary mixtures of homogeneous and heterogeneous radios without incurring large delay and congestion.

The spin Hall effect (SHE) is found to be strong in heavy transition metals (HM), such as Ta and W, in their amorphous and/or high resistivity form. In this work, we show that by employing a CuTa binary alloy as buffer layer in an amorphous Cu100-xTax-based magnetic heterostructure with perpendicular magnetic anisotropy (PMA), the SHE-induced damping-like spin-orbit torque (DL-SOT) efficiency DL  can be linearly tuned by adjusting the buffer layer resistivity. Currentinduced SOT switching can also be achieved in these Cu100-xTax-based magnetic heterostructures, and we find the switching behavior better explained by a SOT-assisted domain wall propagation picture. Through systematic studies on Cu100-xTax-based samples with various compositions, we determine the lower bound of spin Hall conductivity