Railway Engineering Science - Emerging technologies of wireless and mobile communication enable people to accumulate a large volume of time-stamped locations, which appear in the form of a... 相似文献
Ca3Co4O9 ceramics were prepared using the sol-gel process with ordinary pressing sintering and their thermoelectric properties were
measured from room temperature to 673 K. The experimental results show that single phase Ca3Co4O9 can be fabricated at 750–900 °C in different citrate acid molar proportions for 0.2–1.0. For all the oxides, both the Seebeck
coefficients S and the electrical conductivities κ increase with the increasing temperature. The Seebeck coefficients S are all positive. The thermal conductivities k increase with the increasing temperature also and the lattice thermal conductivity
κl plays an important role to the thermal conductivity κ. The citrate acid molar proportions have a large influence on the particle sizes, which influences the thermoelectric properties
of the ceramics. The figure of merit increases with the increasing temperature and reaches 4.5×10−5 K−1 at 573 K for the sample in the citrate acid molar proportion of 0.46. 相似文献
Multimedia Tools and Applications - New mobile applications need to estimate user activities by using sensor data provided by smart wearable devices and deliver context-aware solutions to users... 相似文献
Numerous visual notations are present in technical and business domains. Notations have to be cognitively effective to ease the planning, documentation, and communication of the domains’ concepts. Semantic transparency (ST) is one of the elementary principles that influence notations’ cognitive effectiveness. However, the principle is criticized for not being well defined and challenges arise in the evaluations and applications of ST. Accordingly, this research’s objectives were to answer how the ST principle is defined, operationalized, and evaluated in present notations as well as applied in the design of new notations in ICT and related areas. To meet these objectives, a systematic literature review was conducted with 94 studies passing the selection process criteria. The results reject one of the three aspects, which define semantic transparency, namely “ST is achieved with the use of icons.” Besides, taxonomies of related concepts and research methods, evaluation metrics, and other findings from this study can help to conduct verifiable ST-related experiments and applications, consequently improving the visual vocabularies of notations and effectiveness of the resulting diagrams.
ZrC coatings were deposited on graphite substrates by low pressure chemical vapor deposition (LPCVD) with the Br2-Zr-C3H6-H2-Ar system. The effects of deposition time on the microstructures and growth behavior of ZrC coatings were investigated. ZrC coating grew in an island-layer mode. The formation of coating was dominated by the nucleation of ZrC in the initial 20 minutes, and the rapid nucleation generated a fine-grained structure of ZrC coating. When the deposition time was over 30 min, the growth of coating was dominated by that of crystals, giving a column-arranged structure. Energy dispersive X-ray spectroscopy showed that the molar ratio of carbon to zirconium was near 1:1 in ZrC coating, and X-ray photoelectron spectroscopy showed that ZrC was the main phase in coatings, accompanied by about 2.5mol% ZrO2 minor phase. 相似文献