Effects of Vacuum Annealing on the Conduction Characteristics of ZnO Nanosheets

This paper is open acess and available in full at http://www.nanoscalereslett.com/content/10/1/368 .ZnO nanosheets are a relatively new form of nanostructure and have demonstrated potential as gas-sensing devices and dye sensitised solar cells. For integration into other devices, and when used as gas sensors, the nanosheets are often heated. Here we study the effect of vacuum annealing on the electrical transport properties of ZnO nanosheets in order to understand the role of heating in device fabrication. A low cost, mass production method has been used for synthesis and characterisation is achieved using scanning electron microscopy (SEM), photoluminescence (PL), auger electron spectroscopy (AES) and nanoscale two-point probe. Before annealing, the measured nanosheet resistance displayed a non-linear increase with probe separation, attributed to surface contamination. Annealing to 300 °C removed this contamination giving a resistance drop, linear probe spacing dependence, increased grain size and a reduction in the number of n-type defects. Further annealing to 500 °C caused the n-type defect concentration to reduce further with a corresponding increase in nanosheet resistance not compensated by any further sintering. At 700 °C, the nanosheets partially disintegrated and the resistance increased and became less linear with probe separation. These effects need to be taken into account when using ZnO nanosheets in devices that require an annealing stage during fabrication or heating during use

Клинически значимые варианты анатомии ветвления чревного ствола и прилежащих к нему лимфоузлов

ЛИМФАТИЧЕСКИЕ УЗЛЫ /АНАТОМАНГИОГРАФИЯ /ИСПАРТЕРИОГРАФИЯ /ИСПВАЗОГРАФИЯ /ИСПРЕНТГЕНОАНГИОГРАФИЯ /ИСПМАГНИТНОГО РЕЗОНАНСА ИЗОБРАЖЕНИЕ /ИСПМР-ТОМОГРАФИЯ /ИСПТОМОГРАФИЯ, ЯМР /ИСПЯМР-ИЗОБРАЖЕНИЕ /ИСПЯМР-ТОМОГРАФИЯ /ИСПМАГНИТНО-РЕЗОНАНСНАЯ АНГИОГРАФИЯ /ИСПАНГИОГРАФИЯ МАГНИТНО-РЕЗОНАНСНАЯ /ИСПМРИ-АНГИОГРАФИЯ /ИСПАРТЕРИИ /АНАТОМПЕЧЕНОЧНАЯ АРТЕРИЯ /АНАТОМСЕЛЕЗЕНОЧНАЯ АРТЕРИЯ /АНАТОМДИАГНОСТИКАКРОВЕНОСНЫЕ СОСУДЫ /АНАТОМ /АНОМАЛАОРТА БРЮШНАЯ /АНАТОМСЕРДЕЧНО-СОСУДИСТАЯ СИСТЕМА /АНАТОМЛЕВАЯ ЖЕЛУДОЧНАЯ АРТЕРИЯЛУЧЕВАЯ ВИЗУАЛИЗАЦИЯСИНДРОМ КОМПРЕССИИ ЧРЕВНОГО СТВОЛАВЕТВЛЕНИЯ ЧРЕВНОГО СТВОЛАЧРЕВНЫЙ СТВО

Potential cellular and biochemical mechanisms of exercise and physical activity on the ageing process

Exercise in young adults has been consistently shown to improve various aspects of physiological and psychological health but we are now realising the potential benefits of exercise with advancing age. Specifically, exercise improves cardiovascular, musculoskeletal, and metabolic health through reductions in oxidative stress, chronic low-grade inflammation and modulating cellular processes within a variety of tissues. In this this chapter we will discuss the effects of acute and chronic exercise on these processes and conditions in an ageing population, and how physical activity affects our vasculature, skeletal muscle function, our immune system, and cardiometabolic risk in older adults