The method of chaos identifying for time series is introduced. By virtue of the predictability of chaotic time series,the distortion detective method for chaotic time series based on neural network is presented.The practical example demonstrate that the distortion data of chaotic time series can be detected and recovered correctly by this kind of method.The method is not only a detective process but also a recovering process,and the application prospect in the field of data processing is optimistic.
The determination of wind friction velocity from satellite-derived wind data will take an important role of key factors for computation of C02 flux transfer. It is necessary for relation between wind speed and wind friction velocity to determine that of relation between nondimensional roughness length and wave age, included with all parameters (wind, wave). In this study, we proposed a new method to estimate u„, which is based on the new relationship between non-dimensional roughness and wave velocity, after considering fetch and wave directionality. Consequently, we obtained the new relationship between friction velocity and wind speed. Using this relationship, we estimated the wave frequency from two methods: 3 per 2 powers law (Toba, 1972) and WAM model (WAMDI, 1988). The results arc compared with the results estimated from Charnock formula (1955) and the above influence of wave effects on the wind stress is also discussed. A new relationship was established to determine CO. exchange coefficient based on whitecap model (Monahan and Spillane 1984), using U|0-u, relationship in North Pacific Ocean, satellite data of NOAA-AVHRR (SST) and DMSP-SSM-I (wind speed) in Oct., Nov., and Dec. 1991. The C02 exchange coefficient estimated by other models (Wanninkhof, 1992; Liss and Merlivat, 1986; Tans et al., 1990) are also compared with these results. The results show the importance of wave breaking effect. Key words: wind waves, friction velocity, C02 exchange coefficient, roughness length, wave age.
Abstract. In this study, a framework to project the potential future climate change impacts on extreme hydrological drought events in the Weihe River basin in North China is presented. This framework includes a large-scale hydrological model driven by climate outputs from a regional climate model for historical streamflow simulations and future streamflow projections, and models for univariate drought assessment and copula-based bivariate drought analysis. It is projected by the univariate drought analysis that future climate change would lead to increased frequencies of extreme hydrological drought events with higher severity. The bivariate drought assessment using copula shows that future droughts in the same return periods as historical droughts would be potentially longer and more severe, in terms of drought duration and severity. This trend would deteriorate the hydrological drought situation in the Weihe River basin. In addition, the uncertainties associated with climate models, hydrological models, and univariate and bivariate drought analysis should be quantified in the future research to improve the reliability of this study.
This paper describes a kinetic study of the decomposition of waste printed circuit boards (WPCB) under conventional and microwave-induced pyrolysis conditions. We discuss the heating rates and the influence of the pyrolysis on the thermal decomposition kinetics of WPCB. We find that the thermal degradation of WPCB in a controlled conventional thermogravimetric analyzer (TGA) occurred in the temperature range of 300 °C–600 °C, where the main pyrolysis of organic matter takes place along with an expulsion of volumetric volatiles. The corresponding activation energy is decreased from 267 kJ/mol to 168 kJ/mol with increased heating rates from 20 °C/min to 50 °C/min. Similarly, the process of microwave-induced pyrolysis of WPCB material manifests in only one stage, judging by experiments with a microwave power of 700 W. Here, the activation energy is determined to be only 49 kJ/mol, much lower than that found in a conventional TGA subject to a similar heating rate. The low activation energy found in microwave-induced pyrolysis suggests that the adoption of microwave technology for the disposal of WPCB material and even for waste electronic and electrical equipment (WEEE) could be an attractive option.
High permittivity materials have been required to replace traditional SiO 2 to be gate dielectric to extend Moore’s law. However, growth of a thin SiO 2 -like interfacial layer (IL) is almost unavoidable during the deposition or subsequent high temperature anneal. This limits the scaling benefits of incorporating high-k dielectrics into transistors. A promising approach, in which O-scavenging metal layer and a barrier layer preventing scavenging metal diffusing into high-k gate dielectric are used to engineer the thickness of the IL, is reported in this paper. Using a Ti scavenging layer and TiN barrier layer on HfO 2 dielectric, the equivalent oxide thickness (EOT) decreased due to the effect of O-scavenging indicated by the C-V measurement results. From high resolution transmission electron microscopy (HRTEM) pictures and X-ray photoelectron spectroscopy (XPS), the removal of interfacial layer (IL) has been seen clearly.
As is well known, the ocean plays a key role in global ecological environment. In this paper, we introduced the basic principle of monitoring oil spill by using SAR images. On the basis of that, we systematically analyzed the applicability of various methods for monitoring oil spill by using SAR images. The conclusion shows that the ANN method and the OTSU method have the advantages of timeliness and efficiency in oil spill monitoring, while the Markov Chain method cost more time due to its capability in reducing the effect of internal ocean wave.
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