Dai X.,Southwest University |
Gao Z.,Northumbria University
IEEE Transactions on Industrial Informatics | Year: 2013
This review paper is to give a full picture of fault detection and diagnosis (FDD) in complex systems from the perspective of data processing. As a matter of fact, an FDD system is a data-processing system on the basis of information redundancy, in which the data and human's understanding of the data are two fundamental elements. Human's understanding may be an explicit input-output model representing the relationship among the system's variables. It may also be represented as knowledge implicitly (e.g., the connection weights of a neural network). Therefore, FDD is done through some kind of modeling, signal processing, and intelligence computation. In this paper, a variety of FDD techniques are reviewed within the unified data-processing framework to give a full picture of FDD and achieve a new level of understanding. According to the types of data and how the data are processed, the FDD methods are classified into three categories: model-based online data-driven methods, signal-based methods, and knowledge-based history data-driven methods. An outlook to the possible evolution of FDD in industrial automation, including the hybrid FDD and the emerging networked FDD, are also presented to reveal the future development direction in this field. © 2013 IEEE.
Zhang J.,Nanyang Technological University |
Li C.M.,Nanyang Technological University |
Li C.M.,Southwest University |
Li C.M.,Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energies
Chemical Society Reviews | Year: 2012
Nanoporous metals, a representative type of nanostructured material, possess intriguing properties to generate enormously promising potentials for various important applications. In particular, with the advances of fabrication strategies, nanoporous metals with a variety of superior properties including unique pore structure, large specific surface area and high electrical conductivity have fuelled up great interests to explore their electrocatalytic properties and greatly extend their emerging applications in electrochemical sensing and energy systems. This tutorial review attempts to summarize the recent important progress towards the development of nanoporous metals, with special emphasis on fabrication methods and advanced electrochemical applications, such as electrocatalysts, chemical sensors and energy systems. Key scientific issues and prospective directions of research are also discussed. © 2012 The Royal Society of Chemistry.
Zhang P.,Southwest University
Talanta | Year: 2013
In this contribution, an organic small molecule (OSM)-participating interaction between its aptamer and graphene oxide (GO) is investigated by taking coralyne as an example. Based on their interactions, a simple, rapid, highly sensitive and selective fluorometric method for the detection of coralyne is developed. GO can effectively quench the fluorescence of dye-labeled aptamer, while stronger binding of the aptamer and its target can make the fluorescence be recovered, which have been well demonstrated by the studies of the fluorescence spectra, fluorescence anisotropy, and circular dichroism spectra. In this case, the coralyne can be quantificationally detected by the variation of the fluorescence intensity, where GO acts as an efficient signal-to-background enhancer. With the increase of the coralyne, the fluorescence intensity increases gradually and linearly proportional to the concentration of the coralyne in the range of 10-700 nmol L(-1). This method is reliable, and has been successfully applied for the detection of coralyne in complicated matrixes. Copyright © 2013 Elsevier B.V. All rights reserved.
Zhou J.,Southwest University
Zeitschrift fur Angewandte Mathematik und Physik | Year: 2014
In this paper, we consider a diffusive Leslie-Gower predator-prey model with Bazykin functional response and zero Dirichlet boundary condition. We show the existence, multiplicity and uniqueness of positive solutions when parameters are in different regions. Results are proved by using bifurcation theory, fixed point index theory, energy estimate and asymptotical behavior analysis. © 2013 Springer Basel.
Cao H.,Southwest University
The Analyst | Year: 2013
We investigated the suitability of dithiocarbamate (DTC) capped Ag nanoparticles (NPs) as resonance light scattering (RLS) probes for the simultaneous sensing of Pb(2+) and cysteine. The DTC capping ligands are generated by a very simple in situ method through reaction of carbon disulfide with diethanolamine as primary precursor molecules under ultrasonic irradiation. This strategy was based on the fact that Pb(2+) could induce the aggregation of DTC-Ag NPs due to the strong metal affinity of DTC along with an enhanced RLS signal. After optimizing some experimental conditions (including the pH value of the solution, concentration of DTC-Ag NPs, and ion strength), a very simple and facile sensing system has been developed for the detection of Pb(2+) in water based on RLS technology. The proposed system promises excellent selectivity, a wide linear response range and high sensitivity for Pb(2+). The linear response range for Pb(2+) was from 0.01 μM to 60 μM. The limit of detection (S/N = 3σ) for Pb(2+) was as low as 4 nM. The proposed method was successfully used to detect Pb(2+) in river and tap water samples, indicating the potential of this new, sensitive and selective method in water quality monitoring. Meanwhile, due to the strong binding preference of cysteine toward Pb(2+) by the formation of Pb(2+)-S bonds, Pb(2+) was removed from the surfaces of the DTC-Ag NPs, leading to redispersion of DTC-Ag NPs, along with a decreased RLS signal. The possibility of the proposed system for the sensing of cysteine was also investigated.