The joining of liquid-phase sintered SiC (LPS-SiC) ceramics was conducted using spark plasma sintering (SPS), through solid state diffusion bonding, with Ti-metal foil as a joining interlayer. Samples were joined at 1400 °C, under applied pressures of either 10 or 30 MPa, and with different atmospheres (argon, Ar, vs. vacuum). It was demonstrated that the shear strength of the joints increased with an increase in the applied joining pressure. The joining atmosphere also affected on both the microstructure and shear strength of the SiC joints. The composition and microstructure of the interlayer were examined to understand the mechanism. As a result, a SiC-SiC joining with a good mechanical performance could be achieved under an Ar environment, which in turn could provide a cost-effective approach and greatly widen the applications of SiC ceramic components with complex shape. 相似文献
With the evolution of video surveillance systems, the requirement of video storage grows rapidly; in addition, safe guards and forensic officers spend a great deal of time observing surveillance videos to find abnormal events. As most of the scene in the surveillance video are redundant and contains no information needs attention, we propose a video condensation method to summarize the abnormal events in the video by rearranging the moving trajectory and sort them by the degree of anomaly. Our goal is to improve the condensation rate to reduce more storage size, and increase the accuracy in abnormal detection. As the trajectory feature is the key to both goals, in this paper, a new method for feature extraction of moving object trajectory is proposed, and we use the SOINN (Self-Organizing Incremental Neural Network) method to accomplish a high accuracy abnormal detection. In the results, our method is able to shirk the video size to 10% storage size of the original video, and achieves 95% accuracy of abnormal event detection, which shows our method is useful and applicable to the surveillance industry. 相似文献
Journal of Porous Materials - In recent years, oil spills and industrial organic pollutants have caused irreparable damage to the environment and biological ecosystems. Therefore, the treatment of... 相似文献
Overland flow is an important hydrological response of catchments to rainstorms and contributes to soil erosion and nutrient loss. The kinematic wave model is known to describe the transformation of rainfall to overland flow. Through this, field studies were conducted on a hillslope to simulate water scouring from upstream with a complex surface condition, which was covered with different sizes and percentages of stones. Existing semi-analytical and numerical models were adopted to describe the overland flow in the field. Results indicate that both semi-analytical and numerical models could be applied to describe the process of overland flow. Furthermore, predicted outflow rates by the semi-analytical and the numerical model showed strong correlation with the field measured outflow rates, respectively (NS?=?(0.926, 0.942, 0.992), RE?=?(5.5%, 4.7%, 1.7%) for the semi-analytical model, and NS?=?(0.817, 0.952, 0.992), RE?=?(5.5%, 5.5%, 2.1%) for the numerical model). Besides, hydraulic parameters (Reynolds number-Re, Froude numbers-Fr, Darcy-Weisbach-f, hydraulic shear stress-τ, stream power-ω, water wave celerity-vw) at any time and distance could be described by the semi-analytical method, and the parameter n/h (an important factor indicating the energy of water and wave flow celerity) could successfully characterize the average hydraulic parameters, and all of the hydraulic parameters are fitted to the expression of y?=?a(n/h)b.