Showing papers by "South China University of Technology published in 2008"
TL;DR: In this article, the antioxidant capacities of 45 medicinal plants were evaluated using ferric reducing antioxidant power (FRAP) and Trolox equivalent antioxidant capacity (TEAC) assays, respectively, and the total phenolic contents of these plants were measured by the Folin-Ciocalteu method.
Abstract: In order to find out new sources of safe and inexpensive antioxidants, the antioxidant capacities of 45 selected medicinal plants were evaluated using ferric reducing antioxidant power (FRAP) and Trolox equivalent antioxidant capacity (TEAC) assays, respectively, and the total phenolic contents of these plants were measured by the Folin–Ciocalteu method. Most of these plants were analyzed for the first time for their antioxidant activities. It was found that the plants Sargentodoxa cuneata Rehd. Et Wils, Fraxinus rhynchophylla Hance, Paeonia lactiflora Pall, Paeonia suffruticosa Andr and Scutellaria baicalensis Ceorgi possessed the highest antioxidant capacities and thus could be potential rich sources of natural antioxidants. A strong correlation between TEAC values and those obtained from FRAP assay implied that antioxidants in these plants were capable of scavenging free radicals and reducing oxidants. A high correlation between antioxidant capacities and their total phenolic contents indicated that phenolic compounds were a major contributor of antioxidant activity of these plants.
487 citations
TL;DR: In this paper, a planar ultrawideband (UWB) antenna with 3.4/5.5 GHz dual band-notched characteristics is proposed, which consists of a beveled rectangular metal patch and a 50 Omega coplanar waveguide (CPW) transmission line.
Abstract: We propose a compact planar ultrawideband (UWB) antenna with 3.4/5.5 GHz dual band-notched characteristics. The antenna consists of a beveled rectangular metal patch and a 50 Omega coplanar waveguide (CPW) transmission line. By etching two nested C-shaped slots in the patch, band-rejected filtering properties in the WiMAX/WLAN bands are achieved. The proposed antenna is successfully simulated, designed, and measured showing broadband matched impedance, stable radiation patterns and constant gain. An equivalent circuit model of the proposed antenna is presented to discuss the mechanism of the dual band-notched UWB antenna. A UWB antenna and a single band-notched one are also provided for references.
448 citations
TL;DR: In this article, the authors proposed a solution to store hydrogen efficiently on board hydrogen fuel-cell vehicles, which can be used for a large-scale hydrogen production from renewable sources.
397 citations
19 Dec 2008
TL;DR: This paper describes an effective method to detect copy-move forgery in digital images by first extracting SIFT descriptors of an image, which are invariant to changes in illumination, rotation, scaling etc.
Abstract: As result of powerful image processing tools, digital image forgeries have already become a serious social problem. In this paper we describe an effective method to detect copy-move forgery in digital images. This method works by first extracting SIFT descriptors of an image, which are invariant to changes in illumination, rotation, scaling etc. Owing to the similarity between pasted region and copied region, descriptors are then matched between each other to seek for any possible forgery in images. Experiments have been performed to demonstrate the efficiency of this method on different forgeries and quantify its robustness and sensitivity to post image processing, such as additive noise and lossy JPEG compression etc, or even compound processing.
389 citations
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TL;DR: In this paper, the typical managerial and operational practices of reverse logistics are discussed in detail based on qualitative and quantitative case study methods, and possible directions for further investigations on this subject are presented.
Abstract: Environmental concerns and rapid development of e-commerce bring a new focused field in reverse logistics. In order to avoid return losses and add customerspsila value, there is a need for companies to find proper ways to reduce wastes and recover the value from used products for further utilities. All these challenges make reverse logistics a contemporary area of interest among managers and researchers of this field. The paper proposed the reasons of practicing reverse logistics and the implications of reverse logistics. The differences between reverse logistics and traditional forward logistics; and green logistics and closed-loop supply chain are analyzed. Moreover, reverse logisticspsila distinct characteristics such as supply uncertainty and operational difficulties are pointed out. Based on qualitative and quantitative case study methods, the typical managerial and operational practices of reverse logistics are discussed in detail in this paper. By concluding, the paper presented possible directions for further investigations on this subject.
381 citations
TL;DR: In this paper, an amperometric glucose biosensor based on MnO2/MWNTs electrode was reported, which showed high electrocatalytic activity towards the oxidation of glucose in alkaline solution, showing about 0.30-V negative shift in peak potential with oxidation starting at ca. −0.20
362 citations
TL;DR: Results clearly indicate that the carbohydrate-derived catalysts, especially the starch-derived catalyst, are highly effective, recyclable, eco-friendly and promising solid acid catalysts that are highly suited to the production of biodiesel from waste oils containing high FFAs.
361 citations
TL;DR: Effects of medium components and culture conditions on biomass and lipid production of Trichosporon fermentans were studied and addition of various sugars to the pretreated molasses could efficiently enhance the accumulation of lipid and the lipid content reached as high as above 50%.
344 citations
TL;DR: In this article, the effect of pH and sodium dodecylbenzenesulfonate (SDBS) surfactant on thermal conductivity of nanofluids was measured by a Hot Disk Thermal Constants Anlyser.
330 citations
TL;DR: It was found that basic peptides had greater capacity to scavenge hydroxyl radical than acidic or neutral peptides and that hydrophobic peptides contributed more to the antioxidant activities of hydrolysates than the hydrophilic peptides.
327 citations
TL;DR: Dry water stores 175 v(STP)/v methane at 2.7 MPa and 273.2 K in a hydrate form which is close to the Department of Energy volumetric target for methane storage.
Abstract: Dry water stores 175 v(STP)/v methane at 2.7 MPa and 273.2 K in a hydrate form which is close to the Department of Energy volumetric target for methane storage. Dry water is a silica-stabilized free-flowing powder (95% wt water), and fast methane uptakes were observed (90% saturation uptake in 160 min with no mixing) as a result of the relatively large surface-to-volume ratio of this material.
TL;DR: In this paper, both substitutional and interstitial nitrogen-doped titanium dioxides (N-TiO2) were prepared and their surface states were clarified by XPS spectra of N 1s, O 1s and Ti 2p.
TL;DR: In this paper, a cascaded microstrip open-loop resonator filter with controllable electric and magnetic mixed coupling is presented to have one or more transmission zeros, which can be produced in the lower stopband, upper stopband or both.
Abstract: A novel cascaded microstrip open-loop resonator filter with controllable electric and magnetic mixed coupling is presented to have one or more transmission zeros. For two coupled resonators, the coupled sides with the maximum magnetic field are combined with their open gaps with the maximum electric field, creating the electric and magnetic mixed coupling. By adjusting the distances between resonators and the positions of open gaps in a mixed coupled filter, the coupling coefficients can be changed, and controllable transmission zeros can be produced in the lower stopband, upper stopband, or both. Design and fabrication of the proposed second-and fourth-order filters show the advantages: such as a smaller number of resonators, higher rejection level, as well as asymmetrical response; moreover, the location of the transmission zeros can be precisely controlled.
TL;DR: In this article, the authors apply geographical tools in an examination of the geographical distribution of sites and their spatial relationship to tourist origin cities to identify three major sources of threat that may compromise the protection of the heritage sites.
TL;DR: The empirical results suggest that the new adaptive tradeoff model (ATM) outperforms or performs similarly to other state-of-the-art techniques referred to in this paper in terms of the quality of the resulting solutions.
Abstract: In this paper, an adaptive tradeoff model (ATM) is proposed for constrained evolutionary optimization. In this model, three main issues are considered: (1) the evaluation of infeasible solutions when the population contains only infeasible individuals; (2) balancing feasible and infeasible solutions when the population consists of a combination of feasible and infeasible individuals; and (3) the selection of feasible solutions when the population is composed of feasible individuals only. These issues are addressed in this paper by designing different tradeoff schemes during different stages of a search process to obtain an appropriate tradeoff between objective function and constraint violations. In addition, a simple evolutionary strategy (ES) is used as the search engine. By integrating ATM with ES, a generic constrained optimization evolutionary algorithm (ATMES) is derived. The new method is tested on 13 well-known benchmark test functions, and the empirical results suggest that it outperforms or performs similarly to other state-of-the-art techniques referred to in this paper in terms of the quality of the resulting solutions.
TL;DR: In this paper, the effects of high pressure (HP) treatment on physicochemical and functional properties of soy protein isolates (SPI) were investigated, including surface hydrophobicity, free sulfhydryl content, differential scanning calorimetry characteristics, protein solubility, emulsifying activities, and heat-induced gelling property.
TL;DR: In this paper, the authors applied the Box-Behnken design to evaluate the effects of three independent variables (ultrasonic power, time and temperature) on the recovery and 1,1′-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity of longan fruit pericarp (PLFP).
TL;DR: Redox-responsive gel-sol/sol-gel transition in aqueous PAA system containing Fe( III)-citrate complex was realized by switching the redox states of Fe(III)/F(II) ions conjugated with photoreduction and oxidation.
Abstract: Redox-responsive gel-sol/sol-gel transition in aqueous PAA system containing Fe(III)-citrate complex was realized by switching the redox states of Fe(III)/F(II) ions conjugated with photoreduction and oxidation. This reversible transition can be indicated chromatically by the Fe(III) ions and repeated many times as long as there is sufficient citric acid.
TL;DR: In this article, a co-coagulation process was used to prepare carboxylated butadiene-styrene rubber (xSBR)/halloysite nanotube (HNT) nanocomposites.
TL;DR: Carotenogenic mechanism in Dunaliella is described, which revealed that relation may exist between enhanced beta-carotene accumulation and lipid metabolism, and suggested that ROS trigger massive carotenoids accumulation in DunAliella.
TL;DR: In this article, the authors measured the phenolic contents of methanolic extracts of emblica from six regions in China, and evaluated the antioxidant activities of these extracts were also evaluated.
TL;DR: Phylogenetic analyses resulted in the identification of three major clusters of orthologous genes that contain members belonging to both species, which must have been represented in their common ancestor before the taxonomic splitting of the angiosperms.
TL;DR: Hydrogen is gaining more and more attention because it is regarded as an important future fuel and recently several new processes, such as photovoltaic–photoelectrochemical water splitting and one-step or multistep thermochemical water splitting based on focused solar or nuclear heat, have been developed.
Abstract: Hydrogen is gaining more and more attention because it is regarded as an important future fuel. Today, hydrogen is mainly produced from nonrenewable natural gas and petroleum. With concerns over worldwide energy demands and global climate change, alternative sources must be found. Obviously, water is recommended as the ideal source for the generation of large amounts of hydrogen. In addition to electrolysis, recently several new processes, such as photovoltaic–photoelectrochemical water splitting and one-step or multistep thermochemical water splitting 6] based on focused solar or nuclear heat, have been developed. Although water dissociation into oxygen and hydrogen is conceptually simple [Eq. (1)], efficient hydrogen production
TL;DR: The tutorial review summarizes the recent research advances in the field of bimetallic dendrimer-encapsulated nanoparticles (DENs) with a focus on the application in homogeneous and heterogeneous catalysis.
Abstract: Bimetallic dendrimer-encapsulated nanoparticles (DENs) are important materials, because they have demonstrated improvement in performance compared to the monometallic DENs in many systems when they are used as catalysts. This tutorial review focuses on the recent research advances in bimetallic DENs with respect to their synthesis, characterization, and applications as catalysts. Bimetallic DENs can be made mainly via three routes: co-complexation, sequential loading, and partial displacement. The research in bimetallic DENs has been significantly promoted by the advancement of characterization instruments. The performances of bimetallic DENs as homogeneous and heterogeneous catalysts in organic synthesis have been compared with both monometallic DENs and their physical mixtures. It is concluded that the synergistic electronic effect in bimetallic nanoparticles enhances their catalytic activities.
TL;DR: Electron spin resonance (ESR) signals of spin-trapped paramagnetic species with 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) evidenced that the OH* radicals were indeed formed in the PFT/ZnO system under visible light irradiation.
TL;DR: In this paper, the gas-sensing properties of the SnO2 nanoparticles, ZnO microrods and the nanocomposite of SnO 2 nanoparticles doped with 5-15% Zn O microrod were investigated.
Abstract: SnO2 nanoparticles and ZnO microrods were prepared and characterized by X-ray diffraction (XRD) and a field emission scanning electron microscope (FESEM). The results showed that the mean grain size of the SnO2 nanoparticles was 40 nm; the diameter of ZnO microrods was about 1–1.5 μm with a length between 8 and 10 μm. The gas-sensing properties of the SnO2 nanoparticles, ZnO microrods and the nanocomposite of SnO2 nanoparticles doped with 5–15 wt% ZnO microrods were investigated. The gas-sensing properties of the SnO2 nanoparticles were greatly improved by doping with the ZnO microrods. The SnO2–ZnO nanocomposite sensor showed high and quick response to trimethylamine (TMA) at 190–330 °C. This sensor showed the advantages of high selectivity, excellent sensitivity, strong stability and prompt response/recovery characteristics in detecting TMA at 330 °C. It could be used to detect the freshness of fishes.
TL;DR: In this article, a nanoencapsulated PCM with polystyrene as the shell and n -octadecane as the core was synthesized by the ultrasonic-assistant miniemulsion in-situ polymerization, and its morphology, structure and thermal properties were characterized by TEM, FT-IR, XRD, DSC and TG.
TL;DR: In this article, a method of separating variables is effectively implemented for solving a time-fractional telegraph equation (TFTE), and the analytical solution of the TFTE with three kinds of nonhomogeneous boundary conditions, namely, Dirichlet, Neumann and Robin boundary conditions.
01 Jun 2008
TL;DR: The proposed ACO-based edge detection approach is able to establish a pheromone matrix that represents the edge information presented at each pixel position of the image, according to the movements of a number of ants which are dispatched to move on the image.
Abstract: Ant colony optimization (ACO) is an optimization algorithm inspired by the natural behavior of ant species that ants deposit pheromone on the ground for foraging. In this paper, ACO is introduced to tackle the image edge detection problem. The proposed ACO-based edge detection approach is able to establish a pheromone matrix that represents the edge information presented at each pixel position of the image, according to the movements of a number of ants which are dispatched to move on the image. Furthermore, the movements of these ants are driven by the local variation of the imagepsilas intensity values. Experimental results are provided to demonstrate the superior performance of the proposed approach.