Showing papers by "Nanchang University published in 2004"
TL;DR: The present review focuses on the antioxidant activity, chemical types, sampling and sample processing procedures, and separation using various chromatographic and electrophoretic techniques.
391 citations
TL;DR: N-Benzamido-N'-phenylthioureas represent a new generation of neutral thiourea-based anion receptors that show substantially improved anion binding performance important for anion sensing and recognition.
Abstract: A series of neutral N-(substituted-benzamido)-N‘-phenylthioureas (substituent = p-OC2H5, p-CH3, m-CH3, H, p-Cl, p-Br, m-Cl, and p-NO2) were designed as anion receptors, in which the thiourea binding site was attached to the benzamido moiety via an N−N bond. The absorption spectra of these N-benzamidothioureas in acetonitrile peaked at ca. 270 nm were found to show unprecedented red shifts by 7 373 to 14 325 cm-1 in the presence of anions such as AcO-, F-, and H2PO4-. Under the same conditions, the classic neutral thiourea receptors, N-(substituted-phenyl)-N‘-phenylthioureas, showed absorption spectral shifts in most cases of less than 800 cm-1 with one exception of 6501 cm-1. Control experiments, effects of protic solvent, and 1H NMR titration confirmed the formation of hydrogen-bonding complexes between the new N-benzamidothiourea receptors and anions. The binding constants with AcO-, for example, are at 105−107 mol-1 L order of magnitude, which are 13 to 590 times those of the corresponding classic N-ph...
140 citations
TL;DR: In this article, the photocatalytic activity of the doped TiO2 was evaluated by hydrogen production, and it was found that Be2+ can enter into the interstitial site of theTiO2 lattice, and therefore, it depends on the doping method, when the doping ions were in the shallow surface, the doping was beneficial; while in the deep bulk, it was detrimental.
89 citations
TL;DR: CaPKR-like was the first identified fish gene most similar to mammalian PKRs, and was suggested to be mediated possibly by newly produced CAB IFN, which was further supported by using cycloheximide, a potent inhibitor of protein synthesis.
87 citations
TL;DR: In this article, a differential pulse stripping voltammetry method (DPSV) is proposed for the determination of parathion-methyl (PTM), fenitrothion (FT), and parathions (PT) at a hanging mercury drop electrode (HMDE).
82 citations
TL;DR: In this article, a low dielectric constant nanocomposites of polyimides with grafted methacrylate side chains containing polyhedral oligomeric silsesquioxane (POSS) were successfully synthesized by thermally initiated free-radical graft copolymerization of MA-POSS with the ozone-preactivated poly(amic acid), followed by thermal imidization.
76 citations
TL;DR: In this article, a combination of NaOH treatment and homogenization was used as a pretreatment to enhance the enzymatic hydrolysis of corn stover, which was found to maximize the economic benefit of the pretreatment.
Abstract: Corn stover, the most abundant agricultural residue in the U.S., is a potential feedstock for production of bioethanol
because of its high content of carbohydrates, but an efficient pretreatment is required prior to enzymatic hydrolysis. In
this study, a combination of NaOH treatment and homogenization was used as a pretreatment to enhance the enzymatic hydrolysis
of corn stover. The combined pretreatment increased the enzymatic hydrolysis of corn stover five times compared to the
control. The effectiveness of such pretreatment was found to be a function of NaOH concentration and particle size. Within
the NaOH concentration range of 0.1 to 1.0 N, best performance of this combined pretreatment was achieved at 0.3 N NaOH.
There is a significant cross effect of homogenization and NaOH treatment. Among the three particle sizes tested (the particle
size was not directly measured; it passed through screens with openings of 2 mm, 0.707 mm, and 0.25 mm respectively), 2 mm
was found to maximize the economic benefit of the pretreatment.
76 citations
TL;DR: In this article, the authors presented five new lanthanide coordination polymers with 2-aminoterephthalic acid (H2atpt) and 1,10-phenanthroline (phen), [Ln(atpt),1.5(phen)2]n·1.75nH2O (5), prepared by hydrothermal reactions and structurally characterized.
Abstract: This paper presents five new lanthanide coordination polymers with 2-aminoterephthalic acid (H2atpt) and 1,10-phenanthroline (phen), [Ln(atpt)1.5(phen)(H2O)]n
[Ln = La (1); Eu (2)], [Ln2(atpt)3(phen)2(H2O)]n
[Ln = Tb (3); Er (4)] and [Yb2(OH)(atpt)2.5(phen)2]n·1.75nH2O (5), prepared by hydrothermal reactions and structurally characterized. 1 and 2 are isostructural, in which all the Ln3+ ions are eight-coordinated. 3 and 4 are also isostructural and have two types of lanthanides; Ln(1)
(Ln = Tb, Er) is seven-coordinated and Ln(2)
(Ln = Tb, Er) is eight-coordinated in the asymmetric unit. 1–4 are two-dimensional rhombus-like grids constructed by bridging atpt ligands, and further form 3-D supramolecular architectures via hydrogen bonds and π–π stacks between phen molecules. Complex 5, in which there are two eight-coordinated Yb3+ ions linked by one hydroxyl group and one atpt ligand in the asymmetric unit, exhibits an interpenetrated 3-D network with a brick structure. In 1–4 one atpt ligand is coordinated to three or four Ln3+ ions (Ln = La, Eu, Tb, Er) in bridging modes and in 5 one atpt ligand is coordinated to two or three Yb3+ ions by double chelating or chelating-bridging mode. The high-resolution emission spectrum of 2 shows only one Eu3+ ion site in 2, which is in agreement with the results of the X-ray diffraction. The thermal stabilities of the supramolecular compounds 2, 4 and 5 show that the presence of amino groups induces formation of hydrogen bonds that are responsible for the increase in the thermal stability.
71 citations
TL;DR: The propagation of coherent and partially coherent light pulses through a one-dimensional photonic crystal ( 1DPC) is investigated and the effect of the coherence of the pulses on the propagation properties are discussed.
Abstract: The propagation of coherent and partially coherent light pulses through a one-dimensional photonic crystal ( 1DPC ) is investigated. The dependence of the evolution of the pulses inside the 1DPC on incident angles and the effect of the coherence of the pulses on the propagation properties are discussed. The evolution of a pulse inside the 1DPC is affected by the coherence of the pulse. As the coherence decreases, superluminal proprogation changes to subluminal propagation.
68 citations
TL;DR: In this paper, the preparation of nano-sized CeO 2 powder by mechanochemical reaction of hydrate cerium carbonate with sodium hydroxide and subsequent heat treatment was studied using X-ray diffraction, differential thermal and thermo gravimetric analyses, and transmission electron microscopy.
58 citations
TL;DR: In this paper, a method for the simultaneous determination of the pesticides, carbofuran, isoprocarb and propoxur in fruit and vegetable samples has been investigated and developed.
TL;DR: In this article, the electrical conductivity and its temperature dependence for all the materials used in the simulation were determined under consistent electric field strength as the simulated ohmic heating processes, and the model predictions yielded good agreement with the MRI temperature maps.
Abstract: Mathematical modeling of ohmic heating of liquid–particulate mixtures allows insight into the heating behavior, but model verification that uses only a selected number of points in an ohmic heating system is inadequate because of the unknown temperature distribution within the heated food materials, including the locations of hot and cold spots. In this study, ohmic heating of liquid–particulate mixtures was simulated using the finite-element analysis with the commercial software FEMLAB, and the model predictions were verified against temperature maps obtained using magnetic resonance imaging (MRI). A factor ignored by the previous modeling works, the electricity-to-heat conversion efficiency, was considered in the model, resulting in an improved model performance. The electrical conductivity and its temperature dependence for all the materials used in the simulation were determined under consistent electric field strength as the simulated ohmic heating processes. Other factors/parameters affecting model prediction, such as the boundary conditions and heat transfer coefficients, were also determined in situ for an accurate parametric input. The model predictions yielded good agreement with the MRI temperature maps. Results showed that the electrical conductivity of the materials is the most critical factor causing heating rate variations between the particulate phase and the liquid phase. The heating rate variations could be overcome by adjusting the electrical conductivity of the food materials before ohmic heating. This modeling procedure can be used for designing and controlling ohmic heating processes to ensure thermal sterilization and safety of ohmically heated food products.
TL;DR: The basic balance equations of MRP theory, using input–output analysis together with the Laplace transform, are used and conclusions are derived in the form of conditions for when commonality is recommended, and when not.
TL;DR: The perovskite-like La 2− x Sr x CoO 4± λ (x = 0.0-1.0) mixed oxides of K 2 NiF 4 structure were prepared by the polyglycol gel method and used successfully for CO and C 3 H 8 oxidation; these samples were investigated by using the XRD, IR, TEM, BET, TPD and iodometry methods.
Abstract: The perovskite-like La 2− x Sr x CoO 4± λ ( x =0.0–1.0) mixed oxides of K 2 NiF 4 structure were prepared by the polyglycol gel method and used successfully for CO and C 3 H 8 oxidation; these samples were investigated by using the XRD, IR, TEM, BET, TPD and iodometry methods; and the effects of coefficient x on their structure and catalytic activities of these samples were studied for the first time. The results show that La 2 CoO 4 has orthorhombic K 2 NiF 4 -type structure, when La 3+ is substituted by Sr 2+ , whose ionic radius ( r Sr 2+ =0.1310 nm) is larger than that of La 3+ ( r La 3+ =0.1216 nm), the structure factor increases, and this leads to the structure change from orthorhombic (O) system to tetragonal (T) system; in addition, these catalysts possess different catalytic activities towards the oxidation of CO and C 3 H 8 , and the catalytic activity of LaSrCoO 4 is better than that of other samples in oxidation reaction, this is explained in terms of their structure: mobile lattice oxygen, content of Co 3+ , particle sizes and BET surface areas.
TL;DR: It can be concluded that various chromatographic retention mechanisms are responsible for the separation of above compounds on CABS, such as hydrophobic interaction, hydrogen bonding interaction, and pi-pi interaction.
TL;DR: In this paper, a voltammetric method aided by chemometrics was developed for the simultaneous determination of paracetamol and phenobarbital in pharmaceuticals, which gave well defined oxidation peaks in the Britton-Robinson buffer (pH 5.72) when analyzed by differential pulsestripping voltammetry (DPSV) at a glassy carbon electrode.
Abstract: A voltammetric method, aided by chemometrics, was developed for the simultaneous determination of paracetamol and phenobarbital in pharmaceuticals. Both of these analytes gave well‐defined oxidation peaks in the Britton–Robinson buffer (pH 5.72) when analyzed by differential pulse‐stripping voltammetry (DPSV) at a glassy carbon electrode. The experimental conditions were optimized: 200 mV—deposition potential, 160 s—deposition time, 4 mV—increment potential, 50 mV—amplitude, and 60 ms—pulse width. Under these selected conditions, the oxidation current had a linear relationship with concentration of paracetamol [ranges: 0.09–0.93 mg l−1 (r 2 = 0.999) and 0.9–11.7 mg l−1 (r 2 = 0.999)], and phenobarbital [1.0–22.0 mg l−1 (r 2 = 0.999)]. Due to the overlapping voltammograms from the two analytes, two chemometrics methods, partial least squares (PLS), and principal component regression (PCR), were used for building calibration models from voltammograms of mixtures. These models were applied for predi...
TL;DR: It can be concluded that the high selectivity of CABS for aromatic carboxylic acids ascribes to various interactions between CABS and the analytes, such as hydrophobic interaction, hydrogen bonding interaction, pi-pi interaction and inclusion interaction.
TL;DR: The chromatographic data indicated that CABS was superior to ODS in the routine fast separation of nucleosides and bases and hydrophobic interaction, hydrogen-bonding interaction, and dipole-dipole interaction are mainly responsible for the retention behavior.
TL;DR: In this paper, two uniform ZnO thin film samples made by MOCVD were treated with hydrogen peroxide (H 2 O 2 ) solution and oxygen, respectively, and it was observed that the UV emission peak (3.30 eV) becomes stronger, the green emission peak becomes weaker, and the green peak shifts from 525 eV to 500 eV.
TL;DR: In this article, a formula for the e.ective elastic tensor of an orthorhombic aggregate of cubic crystallites by the perturbation method was derived, in which quadratic texture dependence was shown.
Abstract: Herein we obtain a formula for the e.ective elastic sti.ness tensor C e. of an orthorhombic aggregate of cubic crystallites by the perturbation method.The e.ective elastic sti.ness tensor of the polycrystal gives the relationship between volume average stress and volume average strain. Under Voigt’s model, Reuss’ model and Man’s theory, the elastic constitutive relation accounts for the e.ect of the orientation distribution function (ODF) up to terms linear in the texture coe7cients.However, the formula derived in this paper delineates the e.ect of crystallographic texture on elastic response and shows quadratic texture dependence.The formula is very simple. We also consider the in:uence of grain shape to elastic constitutive relations of polycrystals. Some examples are given to compare computational results of the formula with those given by Voigt’s model, Reuss’s model, the ;nite element method, and the self-consistent method.In Section 3, we also present an expression of the perturbation displacement ;eld, in which Green’s function for an orthorhombic aggregate of cubic crystallites is included. ? 2004 Elsevier Ltd.All rights reserved.
TL;DR: In this paper, an aligned multiwalled carbon nanotubes (CNTs) have been obtained on an anodic aluminum oxide (AAO) template by chemical catalytic vapor deposition at 650 °C.
TL;DR: A quantitative differential pulse voltammetric method for determination of maleic hydrazide was developed on the basis of studies involving the reduction of the compound at a hanging mercury drop electrode.
TL;DR: In this paper, a supported amorphous NiB/CNTs catalyst was prepared by impregnation, following the chemical reduction with KBH4 solution, and the gas-phase benzene hydrogenation was used as a probe reaction to evaluate the catalytic activity.
TL;DR: A new ptert-butyl-calix[4]arene−bonded silica gel stationary phase (C4BS) was prepared via breaking ring reaction of 3−glycidoxypropyltrimethoxysilane used as coupling reagent for high performance liquid chromatography (HPLC).
Abstract: A new p‐tert‐butyl‐calix[4]arene‐bonded silica gel stationary phase (C4BS) was prepared via breaking ring reaction of 3‐glycidoxypropyltrimethoxysilane used as coupling reagent for high performance liquid chromatography (HPLC). The structure of the new stationary phase was characterized by Fourier transform infrared (FTIR) spectroscopy, elemental analysis, and thermal analysis. Its chromatographic property was evaluated by using neutral, acidic, and basic solutes as probes. Meanwhile, several bonded phases, such as a p‐tert‐butylphenyl‐ether‐bonded stationary phase (PEBS, the monomer‐bonded phase), a p‐tert‐butyl‐calix[8]arene‐bonded phase (C8BS), and ODS were also used for the comparative study of C4BS, under the same chromatographic conditions. The results show that C4BS is an excellent reversed‐phase packing with versatile chromatographic performance. The hydrogen bond, π–π and synergistic interactions between the calix[4]arene ligand of C4BS and solutes can be observed, which result in that t...
TL;DR: In this paper, the primary structure of a tea polysaccharide and its configuration in the aqueous solution were investigated utilizing a combination of classical chemical methods and modern instrumental techniques including GC-MS, Proton NMR, UV and CD.
Abstract: The monosaccharide composition of a tea polysaccharide (TGC) was determined by GC-MS method. Furthermore, the primary structure of tea polysaccharide and its configuration in the aqueous solution were investigated utilizing a combination of classical chemical methods and modern instrumental techniques including GC-MS, Proton NMR, UV and CD. The results indicate that TGC consists of 6 monosaccharides: Rha, Ara, Xyl, Glu, Man and Gal. The configuration of TGC in water solution is proposed to be an ordered helix. The possible primary structure of TGC was outlined as below: the basic structure of the main chain consists of Rha, Glu and Gal units. All three monosaccharides can potentially be connected to branch chains consisting of mainly Ara, and the linkages could be in β1 → 2, β 1 → 3, β 2 → 3 forms. When branch chain is absent in the basic structure of the main chain the linkage consists of only β 1 → 3; Xyl exists at the terminal end of either the main chain or the branch chain with β 1 → linkage.
TL;DR: In this paper, the authors applied the Butterworth low-pass filter to inertial navigation system (INS) data processing, which was used to examine the correction of the results made by Guo and Wang.
Abstract: This article tries to apply the Butterworth low-pass filter to inertial navigation system (INS) data processing. A set of INS heading data of a practical example has been calculated and the filtering tested. This filtering method is used to examine the correction of the results made by Guo and Wang. Based on the discrete Fourier transformation and the digital filter design technique, a Butterworth low-pass digital filter has been designed and performed to process INS heading raw data. The design of a special Butterworth filter includes determination of the technical specification of the filter and of the response function in the time domain or the frequency domain (determination of the order and cutoff frequency of the digital filter). For the high-frequency noise of INS raw data, a Butterworth low-pass filter has been designed to obtain a more accurate INS heading. The choice of the parameters and orders of the filter is also discussed in the paper. Finally, an example of INS heading data calculation is presented. The signal-processing TOOLBOX of MATLAB software is used for calculating and mapping the results. The result (RMS) is at the level of 0.01 degrees. The method described here is simpler than Kalman filtering or the smoothing method and has sufficient accuracy for INS processing. It also provides ideas for some other series of raw data with high-frequency noise.
TL;DR: In this article, the authors studied the blue luminescence at about 2.9 eV in unintentional doped GaN films, which were grown on (0 0 0 1) oriented sapphire substrates by MOCVD.
TL;DR: In this paper, the growth properties of well-aligned carbon nanotube arrays are studied as a function of synthesis conditions, and it is found that 750℃ and 10 nm Fe film are suitable conditions for the growth of wellaligned CNT arrays.
Abstract: The growth of well-aligned carbon nanotube (CNT) arrays using a heat chemical vapor deposition system on silicon substrates is reported. The growth properties of CNT arrays are studied as a function of synthesis conditions. It is found that 750℃ and 10 nm Fe film are suitable conditions for the growth of well-aligned CNT arrays. CNT arrays with a uniform diameter, thick tube wall and firm cohesion to the Si substrate can be grown for C2H2 concentration of 27%. Based on the experiment, the processes of improving the alignment of CNT arrays and cohesion between CNT arrays and Si substrates are discussed.
TL;DR: In this article, the feasibility of using ozone (O3) to replace sulfur dioxide (SO2) in corn steeping was evaluated, and an ozone-aided steeping (OAS) process had starch yields as high as conventional SO2 steeping.
Abstract: The present research evaluated the feasibility of using ozone (O3) to replace sulfur dioxide (SO2) in corn steeping. Traditionally, steep water contains 0.1–0.2% sulfur dioxide to promote starch-protein separation and high starch yields, and to control microbial growth. However, residual SO2 in starch products affects product quality and jeopardizes the “organic products” claims. Also, SO2 discharged to the environment pollutes water and air. Ozone is a strong oxidant and disinfectant with a capability to control the growth of putrefactive microorganisms in steeping systems, and to break down the endosperm protein matrix and, hence, improve starch release. This study demonstrates that an ozone-aided steeping (OAS) process had starch yields as high as conventional SO2 steeping. OAS processes can be conducted at a lower temperature (20°C vs. 50°C) and for shorter times (36 hr vs. 48 hr) than the conventional SO2 processes, suggesting significant energy savings and increased productivity. We have fo...
TL;DR: In this article, perovskite-like LnSrCoO4 (Ln=La, Sm) mixed oxides of K2NiF4 structure were synthesized by the polyglycol gel method and used successfully for CO and C3H8 oxidation for the first time.
Abstract: Perovskite-like LnSrCoO4(Ln=La, Sm) mixed oxides of K2NiF4 structure were synthesized by the polyglycol gel method and used successfully for CO and C3H8 oxidation for the first time. The structure was characterized by means of XRD, TEM, BET, O2-TPD and CO2-TPD, respectively. An oxidation mechanism over LnSrCoO4is proposed.