On Si-implanted n-type GaN, a nonalloyed Ti/Al metallization has been found to form an Ohmic contact that has a specific contact resistance as low as 1.0×10−5 Ω cm2. The Ohmic character is believed to be caused by the 1120 °C implant activation anneal which generates nitrogen vacancies that leave the surface heavily n type. This theory is indirectly confirmed on unimplanted n-type GaN by comparing the rc of nonalloyed Ti/Al on unannealed GaN with that of nonalloyed Ti/Al on 1120 °C annealed GaN. The former has rectifying electrical characteristics, while the latter forms an Ohmic contact with an rc=1.3×10−3 Ω cm2.

The hairs on the wings of Locusta migratoria were observed and mapped using light microscopy, as well as by scanning and transmission electron microscopy. Based on their ultrastructure, we can distinguish four main types of hairs on the wings of adult L. migratoria, viz, short, medium and long hairs, and sensilla chaetica. The long hairs are located only on the ventral surface of the hindwing, whereas the other three types are present both on the dorsal and ventral surfaces of forewing and hindwing in both sexes. Medium hairs and sensilla chaetica are significantly more abundant on the dorsal surface of forewings in both females and males, than on the ventral surface, whereas the opposite was observed for short hairs (P < 0.01). No significant difference between males and females was observed in the density of any type of hairs (P > 0.1). Several dendritic branches, enveloped by a dendrite sheath, are situated in the lymph cavity of sensilla chaetica. Instead, no dendritic structure was observed in the cavity of the other three types of hairs. Immunocytochemical localization of chemosensory proteins (CSPs) was performed on ultrathin sections of hairs on wings. The antiserum against chemosensory proteins from L. migratoria (LmigCSP‐II) strongly labelled sensilla chaetica, with gold granules only found in the outer sensillum lymph. In addition, the epidermal cell membrane of the wing was stained by the antiserum against LmigCSP‐II. The other three types of hairs were never labelled. The results indicate that the wings might involve in contact chemoreception process.

Ag nanoparticles (NPs) formed in situ by the photochemical reduction of phosphotungstic acid (H 3 PW 12 O 40 , PTA) under UV-irradiation in polyelectrolyte multilayer nanoreactors composed of poly(ethyleneimine)-silver ions (PEI-Ag + ) and PTA fabricated on solid substrates by alternating adsorption, wherein the PTA plays the role of a UV-switchable reducing agent and an assembly reagent. Transmission electron microscopy (TEM) images show the formation of sphere-like silver NPs with sizes smaller than 12 nm in the multilayer films. Atomic force microscopy (AFM) and field emission scanning microscopy (FESEM) imply a film with a rough surface. The UV-vis characteristic absorbances of PTA and Ag NPs increase almost linearly with the number of bilayers, suggesting that the deposition process was regular and highly reproducible from layer to layer. X-Ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) confirm the incorporation of PEI-Ag and PTA into the films. The multilayer films also exhibit good electrocatalytic activity for the oxidation of uric acid, which may be used in electrochemical biosensors.

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