Showing papers by "Jiangxi University of Science and Technology published in 2009"
TL;DR: In this article, a simple method for preparing nanocrystalline C-N-codoped TiO2 photocatalyst was developed by annealing titanium carbonitride.
Abstract: A simple method for preparing nanocrystalline C–N-codoped TiO2 photocatalyst was developed by annealing titanium carbonitride. The prepared C–N-codoped TiO2 powders were characterized by TGA, XRD, XPS, UV–Vis, PL, SEM, and BET surface areas. The photocatalytic activity was evaluated by the photocatalytic degradation of methylene blue in an aqueous solution under visible-light radiation. Results showed that the annealing temperatures and time affected the crystal composition and structure and activity of the catalyst. The most promoting effect of C–N-codoping in activity was obtained over C–N-codoped TiO2 prepared by annealing titanium carbonitride at 400 °C for 8 h. The high photocatalytic activity could be attributed to the synergetic effects in light absorption and the suppression of recombination of electrons/holes pairs.
138 citations
TL;DR: In this paper, a sonochemical-hydrothermal method for preparing fluorinated mesoporous TiO2 microspheres was developed, which was achieved by sonication and then hydrothermal treatment of a solution containing titanium isopropoxide, template, and sodium fluoride.
109 citations
TL;DR: In this paper, a ZnWO4 nanocrystal catalyst with rod-like structure was first synthesized by powerful ultrasonic irradiation method at room temperature and then, Ag was introduced to the nanorods by a photodeposited method, and the results show that the prepared samples have good crystallinity and Ag addition can improve the photocatalytic performance of ZnwO4 in degradation of rhodamine-B under UV light irradiation.
Abstract: A ZnWO4 nanocrystal catalyst with rod-like structure was first synthesized by powerful ultrasonic irradiation method at room temperature. Then, Ag was introduced to ZnWO4 nanorods by a photodeposited method. The as-synthesized Ag/ZnWO4 catalysts have been investigated by photocatalytic reaction tests and some physicochemical characterizations like XRD, BET, IR, TEM, EDX, XPS, PL, and UV–vis DRS. The results show that the prepared samples have good crystallinity and Ag addition can improve the photocatalytic performance of ZnWO4 in degradation of rhodamine-B (RhB) under UV light irradiation. The deposition of 1 wt% Ag over ZnWO4 leads to about a one-time increase in the photocatalytic performance with the reference of ZnWO4. The high performance of Ag/ZnWO4 could be attributed to the fact that the high dispersed Ag particles could act as electron traps promoting the electron–hole separation then enhancing the photocatalytic reaction.
97 citations
TL;DR: In this paper, the AWO 4 :Tm 3+ (A = Ca, Sr and Ba) blue phosphors were prepared via a mild and facile hydrothermal route.
87 citations
TL;DR: Tb 3+ :NaGd(WO 4 ) 2 (Tb:NGW) phosphors have been synthesized by a mild hydrothermal process directly without further sintering treatment.
82 citations
TL;DR: In this article, the authors used hydrochloric acid as lixivant with characteristics of faster leaching rate and being recycled easily, and the results showed that the dissolution yields of Ni, Co and Mn can be 95.5% at least.
80 citations
TL;DR: In this article, the effect of pre-roasting on leaching of gamierite laterite ore, obtained from Yunnan province, China, was investigated with X-ray powder diffraction (XRD).
70 citations
TL;DR: Magnetic property studies indicated that complexes 1 and 2 show not only intrachain but also interchain field-induced metamagnetic transitions from an antiferromagnetic to a ferromagnetic state and exhibit an antferromagnetic long-range ordering.
Abstract: Two couples of enantiomerically pure chiral cyano-bridged heterobimetallic chain coordination polymers, [Mn((R,R)-Salcy)Fe(Tp)(CN)3·H2O·1/2CH3CN]n (1), [Mn((S,S)-Salcy)Fe(Tp)(CN)3·H2O·1/2CH3CN]n (2), [Mn((R,R)-Salcy)Fe(bpca)(CN)3·H2O]n (3), and [Mn((S,S)-Salcy)Fe(bpca)(CN)3·H2O]n (4) [(R,R)-Salcy or (S,S)-Salcy = (R,R)- or (S,S)-N,N′-(1,2-cyclohexanediylethylene)bis(salicylideneiminato) dianion, Tp = tris(pyrazolyl)hydroborate, bpca = bis(2-pyridylcarbonyl)amidate anion], were synthesized using the modified cyanometalate building blocks [Fe(L)(CN)3]− (L = Tp, bpca) and the chiral polydentate Schiff base manganese(III) complex fragments. The circular dichroism measurements showed Cotton effects of the opposite sign at the same wavelength for each pair of enantiomers. Magnetic property studies indicated that complexes 1 and 2 show not only intrachain but also interchain field-induced metamagnetic transitions from an antiferromagnetic to a ferromagnetic state and exhibit an antiferromagnetic long-range order...
62 citations
TL;DR: In this article, green-phosphor spherical microparticles of CaWO 4 :Tb 3+ (CWO:Tb) exhibiting excellent emission at 545-nm have been synthesized by a conventional hydrothermal process directly without further sintering treatment.
55 citations
TL;DR: In this paper, a series of lithium-iron-vanadium-phosphate compositions that can be represented in two-component notation, xLiFePO4·y Li3V2(PO4)3 (LFVP), has been evaluated as electrodes in lithium cells.
Abstract: A series of mechanical mixture of lithium–iron–vanadium–phosphate compositions that can be represented in two-component notation, xLiFePO4·y Li3V2(PO4)3 (LFVP), has been evaluated as electrodes in lithium cells for x:y = 0:1, 1:1, 5:1, 10:1, and 1:0, in which an olivine component, LiFePO4 (LFP), and a monoclinic component, Li3V2(PO4)3 (LVP), coexisted Powder X-ray diffraction (XRD) patterns show that the end members and the electrochemical profiles of cells with these electrodes are consistent with those expected for the olivine LiFePO4(x = 1, y = 0) and for monoclinic Li3V2(PO4)3 (x = 0, y = 1) XRD data and the changes of cell parameters indicate that there existed some V- and Fe-doping in the composite xLiFePO4·y Li3V2(PO4)3, resulting with a good performance compared with single LiFePO4 and Li3V2(PO4)3 Electrochemical characteristics were evaluated by using cyclic voltammetry and electrochemical impedance spectroscopy The results show that the electron transfer activity and the lithium ion diffusion rate in LFVP are better than single LFP and LVP
54 citations
15 Jan 2009-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this article, the plastic deformation characteristics of 42CrMo steel in upsetting process and find out the feasibility of using computer simulation to analyze and research the upsetting process of the 42crMo billet, by means of commercial and professional plastic forming software DEFORM-3D, was simulated.
Abstract: In order to study the plastic deformation characteristics of 42CrMo steel in upsetting process and find out the feasibility of using computer simulation to analyze and research the upsetting process of the 42CrMo billet, by means of commercial and professional plastic forming software DEFORM-3D, the forging process of 42CrMo billet was simulated. It is concluded that (1) the changes of the temperatures, stresses and strains at the different regions of the billet were simulated during the entire forging process, (2) based on the stress and strain distributions of the forged billet, the forming defects analyze was proceeded and it is concluded that some forging defects or flaw may occur near the head surface or around the side edge during the plastic deformation process.
TL;DR: In this article, a scheelite structure was used to obtain a green fluorescent lamp phosphor (LaPO4:Ce,Tb), which exhibited strong green light centered at 545 nm under ultraviolet light excitation.
TL;DR: In this paper, a modified solution combustion method was used to prepare nanophosphors and submicron phosphors with sizes of 17.6-80 nm and 300 nm, respectively.
Abstract: Ultrafine Y2O3:Eu3+ phosphors were prepared by a modified solution combustion method. The as-prepared samples with sizes of 17.6–80 nm (nanophosphors) and 300 nm (submicron phosphors) were characterized by x-ray diffraction, transmission electron microscope, scanning electron microscopy, selected area electron diffraction, and energy dispersive x-ray spectroscopy. The emission spectra of the samples are unchanged in comparison with that of standard material. The excitation spectra show a redshift in the charge-transfer-state band and a blueshift in the host gap band. In relation to commercial sample, the relative luminescence intensities of nano- and submicron phosphors are increased sufficiently to 64.4% and 93.6%, respectively. Higher quenching concentration of the activator Eu3+ ion was observed in the nanophosphor than that in the phosphor synthesized by solid state reaction.
TL;DR: In this article, the authors investigated the transition to amplitude death in scale-free networks of nonlinear oscillators and found that, as the coupling strength increases, the network will undergo three different stages in approaching the state of complete amplitude death.
Abstract: Transition to amplitude death in scale-free networks of nonlinear oscillators is investigated both numerically and analytically. It is found that, as the coupling strength increases, the network will undergo three different stages in approaching the state of complete amplitude death (CAD). In the first stage of the transition, the amplitudes of the oscillators present a 'stair-like' arrangement, i.e. the squared amplitude of an oscillator linearly decreases with the number of links that the oscillator receives (node degree). In this stage, as the coupling strength increases, the amplitude stairs are eliminated hierarchically by descending order of the node degree. At the end of the first stage, except for a few synchronized oscillators, all other oscillators in the network have small amplitudes. Then, in the second stage of the transition, the synchronous clusters formed in the first stage gradually disappear and, as a consequence, the number of small-amplitude oscillators is increased. At the end of the second stage, almost all oscillators in the network have small but finite amplitudes. Finally, in the third stage of the transition, without the support of the synchronous clusters, the amplitudes of the oscillators are quickly decreased, eventually leading to the state of CAD.
TL;DR: In this article, a mild solvothermal route for preparation of cubic-like CuInS2 crystals was developed by using benzyl alcohol as the reaction medium and In(NO3)3·9H2O, CuCl2·2H 2O and thiourea as the precursors.
TL;DR: A model to investigate the dynamics of attractive and repulsive couplings, which give rise to rich phenomena, especially for amplitude death (AD), is proposed.
Abstract: Together with attractive couplings, repulsive couplings play crucial roles in determining important evolutions in natural systems, such as in learning and oscillatory processes of neural networks. The complex interactions between them have great influence on the systems. A detailed understanding of the dynamical properties under this type of couplings is of practical significance. In this paper, we propose a model to investigate the dynamics of attractive and repulsive couplings, which give rise to rich phenomena, especially for amplitude death (AD). The relationship among various dynamics and possible transitions to AD are illustrated. When the system is in the maximally stable AD, we observe the transient behavior of in-phase (high frequency) and out-of-phase (low frequency) motions. The mechanism behind the phenomenon is given.
TL;DR: In this article, the dissolution rates of Ni, Co and Mn with hydrochloric acid as leachant are all over 95% under the optimal conditions of initial HCL of 6 mol/L, particle size of 120 μm, molar ratio of H2O2 to MeS of 2, leaching temperature about 60 °C, ratio of liquid to solid of 8, and leaching time of 2 h.
TL;DR: In this article, poly (lactic-co-glycolic acid) (PLGA) microspheres were incorporated into calcium phosphate cement (CPC) to impart macroporosity and maintain early strength.
01 Dec 2009
TL;DR: Through forecasting traffic flow at Hongqi crossroad in Ganzhou City, the result shows that this model has a considerable accuracy, which provides a new reliable and effective way of forecasting short term traffic flow of crossroads in urban road network.
Abstract: Estimation of traffic flow with reasonable accuracy is essential for successful implementation of an Intelligent Transportation System (ITS) Crossroads are important part of urban traffic system, whose flow prediction on each direction is one of the most extraordinary key functions in the urban ITS Some forecasting models have been developed, but these methods' precision usually can't meet with practical requirement In this article, a neural network model is presented for foreccasting crossroads traffic flow using Backpropagation (BP) Neural Network Through forecasting traffic flow at Hongqi crossroad in Ganzhou City, the result shows that this model has a considerable accuracy, which provides a new reliable and effective way of forecasting short term traffic flow of crossroads in urban road network
TL;DR: LiCoO2 recovery technology for Li-ion batteries was studied in this article, where Li2CO3 was removed from the Al foil with dimethyl acetamide (DMAC), and then polyvinylidene fluoride (PVDF) and carbon powders in the active material were eliminated by high temperature calcining.
12 Dec 2009
TL;DR: In weighted mean squares error (WMSE) function, each sample error multiplies a weighting coefficient, then it can make noise error have a smaller proportion in the cost function, even the outliers can’t affect the learning of the neural networks by tuning the smooth parameter, which enhances the anti-noise ability of neural networks.
Abstract: In weighted mean squares error (WMSE) function, each sample error multiplies a weighting coefficient, then it can make noise error have a smaller proportion in the cost function, even the outliers can’t affect the learning of the neural networks by tuning the smooth parameter , which enhances the anti-noise ability of neural networks. If the samples don’t have noise samples, weighted mean squares error function can make neural networks avoid over-fitting. When the neural networks are linear models, the new cost function turns into a realization of weighted least squares method, the simulation results show the advantages and application conditions of the weighted squares error function.
TL;DR: In this paper, the authors proposed the technology route, ideas and some quantitative assessment results for analyzing the ecology and environment cumulative effects impacts based on field theory, and proposed the method to analyze the coal exploitation activities have strong characteristics of time persistency, space scalability, long development cycle, more forms of mining area environment system perturbation, wide impacts source and complex mechanism.
TL;DR: In this article, the ordered double-perovskite La2NiMnO6 films were successfully deposited on LaAlO3 substrate by chemical solution deposition method and the X-ray diffraction and Raman scattering spectroscopy are used to characterize all the films, it is found that all films are single phase with highly (0 − 0 l)-oriented.
TL;DR: In this article, the synthesis and crystal structure of two new complexes (Zn and Mn) containing tetrazolyl ligands are described, which are shown to exhibit strong blue fluorescent emissions at λmax ǫ ≥383 nm for 1 and 411 nm for 2 respectively in the solid state at room temperature.
TL;DR: In this paper, the effects of mixed rare earth oxides and CaCO3 on the microstructure of an in-situ Mg2Si/Al-Si hypereutectic alloy composite were investigated by optical microscope, scanning electron microscope, and energy dispersive spectrum analysis.
TL;DR: In this paper, a broad emission band ranging from the violet to visible can be observed at room temperature with the excitation wavelength at 201-nm and their centers are situated at 357 and 456-nm, respectively.
01 Jan 2009
TL;DR: In this paper, a fuzzy set theory was used to decrease subjective preferences of decision makers as well as fuzzy and uncertain factors in reliability allocation process, and the mathematical model of fuzzy reliability allocation for engine was constructed based on the analysis of influential factors to engine reliability allocation.
Abstract: A fuzzy reliability allocation method for engine was proposed based on multi-field experts' knowledge.In this method,fuzzy set theory was used to decrease subjective preferences of decision makers as well as fuzzy and uncertain factors in reliability allocation process.The mathematical model of fuzzy reliability allocation for engine was constructed based on the analysis of influential factors to engine reliability allocation.A fuzzy evaluation matrix method was proposed to determine the weights of the influential factors in which the triangular fuzzy numbers were utilized to substitute the scaling scheme of conventional analytic hierarchy process.Experts' opinions and the risk index of the product development process were also taken into account in the method.An application example was used to verify effectiveness and feasibility of the proposed method.
18 Nov 2009
TL;DR: Experimental results show that this wavelet digital watermarking algorithm can get a watermarked image with perceptual invisibility and is robust to typical watermark attacks such as: noise adding, image filter, cropping and JPEG compression.
Abstract: In this paper, a wavelet digital watermarking algorithm based on human visual system and watermarking capacity analysis was proposed. Firstly, watermark was scrambled through Arnold transform. Then, the frequency, texture and luminance masking factor of the improvement just noticed difference threshold model can be exploited to compute the watermark embedding intension in wavelet domain. And, with the watermarking capacity analysis, adaptive wavelet coefficients were chosen to embed the watermark. Finally, the watermark embedding intensions further adjust by watermark attack analysis. Experimental results show that this algorithm can get a watermarked image with perceptual invisibility. Moreover, the algorithm is robust to typical watermark attacks such as: noise adding, image filter, cropping and JPEG compression.
TL;DR: In this article, the structural and phase stabilization of β -La 2−− x L x Mo 2 O 9 (L = Gd, Sm, Nd and Bi) and β −La 2 Mo 2− ǫ y M y o 9 (M = Cr, W) was studied in terms of the empirical parameter, bond valence sums (BVS).
TL;DR: In this article, the fractal dimensions of primary phase morphology in semi-solid A356 alloy prepared by low superheat pouring and slightly electromagnetic stirring were calculated, and the effect of pouring temperature on fractal dimension of primary phases was researched.