Showing papers by "Henan Normal University published in 2011"
TL;DR: In this article, nano-structured ZnO and Sn-doped ZnOs with high sunlight photocatalytic activity were successfully synthesized through the decomposition of zinc acetate and glucose by microwave heating.
Abstract: In the present study, nano-structured ZnO and Sn-doped ZnO photocatalysts with high sunlight photocatalytic activity were successfully synthesized through the decomposition of zinc acetate and glucose by microwave heating. The prepared ZnO and Sn-doped ZnO photocatalyst were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence spectrum (PL), UV–vis absorption spectrum (UV–vis), N 2 adsorption and UV–vis diffuse reflectance spectra (DRS). The results showed that the doping greatly changed the microstructure, morphology and optical properties of ZnO, which may contribute to the enhancement of photocatalytic activity. The sunlight photocatalytic activity of the prepared pure ZnO and Sn-doped ZnO photocatalyst was investigated by the degradation of Methylene Blue (MB) solution under sunlight irradiation. Compared with pure ZnO, 13% higher decolorization rate and 29–52% higher mineralization efficiency were obtained by the Sn-doped ZnO. The results indicated that Sn-doped ZnO had a higher photocatalytic activity and Sn dopant greatly increased the photocatalytic activity of ZnO.
194 citations
TL;DR: In this paper, a diffusive logistic equation with a free boundary in higher space dimensions and a heterogeneous environment was studied, and the spreading-vanishing dichotomy established in Du and Lin (2010) [10] still holds in the more general and ecologically realistic setting considered here.
176 citations
TL;DR: In this article, the effect of anionic structure on solubility of chitosan and the possible dissolution mechanism in ionic liquids was investigated, and it was shown that in the ionic liquid investigated, [C4mim][CH3COO] is the most efficient liquid for the dissolution of chitsan.
145 citations
TL;DR: This work provides valuable information on the selectivity of lattice vacancy in trapping metal atoms, which would be vital for the atomic-scale design of new metal-carbon nanostructures and graphene-based catalysts.
Abstract: The binding of a single metal atom (Pt, Pd, Au, and Sn) nearby a single-vacancy (SV) on the graphene is investigated using the first-principles density-functional theory. On the pristine graphene (pri-graphene), the Pt, Pd, and Sn prefer to be adsorbed at the bridge site, while Au prefers the top site. On the graphene with a single-vacancy (SV-graphene), all the metal atoms prefer to be trapped at the vacancy site and appear as dopants. However, the trapping abilities of the SV-graphene are varied for different metal atoms, i.e., the Pt and Pd have the larger trapping zones than do the others. The diffusion barrier of a metal atom on the SV-graphene is much higher than that on the pri-graphene, and the Pt atom has the largest diffusion barrier from the SV site to the neighboring bridge sites. On the SV-graphene, more electrons are transferred from the adatoms (or dopants) to the carbon atoms at the defect site, which induces changes in the electronic structures and magnetic properties of the systems. This work provides valuable information on the selectivity of lattice vacancy in trapping metal atoms, which would be vital for the atomic-scale design of new metal-carbon nanostructures and graphene-based catalysts.
124 citations
TL;DR: In this paper, the authors demonstrated that exogenous hydrogen peroxide (H2O2) was able to improve the tolerance of wheat seedlings to salt stress by decreasing the concentration of malondialdehyde (MDA), increasing the activity of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidation (APX).
Abstract: Hydrogen peroxide (H2O2), an active oxygen species, is widely generated in many biological systems and mediates various physiological and biochemical processes in plants. In this study, we demonstrated that exogenous H2O2 was able to improve the tolerance of wheat seedlings to salt stress. Treatments with exogenous H2O2 for 2 days significantly enhanced salt stress tolerance in wheat seedlings by decreasing the concentration of malondialdehyde (MDA), the production rate of superoxide radical (O2
−), and increasing the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX), and the concentration of glutathione (GSH) and carotenoids (CAR). To further clarify the role of H2O2 in preventing salt stress damage, CAT and ascorbate (AsA), the specific H2O2 scavengers, were used. The promoting effect of exogenous H2O2 on salt stress could be reversed by the addition of CAT and AsA. It was suggested that exogenous H2O2 induced changes in MDA, O2
−, antioxidant enzymes and antioxidant compounds were responsible for the increase in salt stress tolerance observed in the experiments. Therefore, H2O2 may participate in antioxidant enzymes and antioxidant compounds induced tolerance of wheat seedlings to salt stress. The results also showed that exogenous H2O2 had a positive physiological effect on the growth and development of salt-stressed seedlings.
123 citations
TL;DR: A simple, sensitive, and viable method for the determination of bisphenol A, 4-n-nonylphenol and 4-tert-octylphenol in water samples using temperature-controlled ionic liquid dispersive liquid-phase microextraction coupled to high performance liquid chromatography-fluorescence detector is described.
123 citations
TL;DR: The results showed that the coexisting ions containing in water samples had no obvious negative effect on the determination of lead and the proposed method was excellent for the future use and satisfied spiked recoveries.
121 citations
TL;DR: The results show that when NH(4)(+) and NO(2)(-) coexist in the aquatic environment, the inhibiting effect on the photodegradation diclofenac is less than the sum of the partial inhibiting effects.
105 citations
TL;DR: The X(1835), which was previously observed by BESII, is confirmed with a statistical significance that is larger than 20σ, and the angular distribution of the radiative photon is consistent with expectations for a pseudoscalar.
Abstract: With a sample of (225.2 +/- 2.8) x 10(6) J/psi events registered in the BESIII detector, J/psi -> gamma pi(+)pi(-)eta' is studied using two eta' decay modes: eta' -> pi(+)pi(-)eta and eta' -> gamma rho(0). The X(1835), which was previously observed by BESII, is confirmed with a statistical significance that is larger than 20 sigma. In addition, in the pi(+)pi(-)eta' invariant-mass spectrum, the X(2120) and the X(2370), are observed with statistical significances larger than 7.2 sigma and 6.4 sigma, respectively. For the X(1835), the angular distribution of the radiative photon is consistent with expectations for a pseudoscalar.
104 citations
TL;DR: In this article, the authors studied the behavior of finite Morse index solutions of the equation − Δ u = | x | α | u | p − 1 u in Ω ⊂ R N, where p > 1, α > − 2, and Ω is a bounded or unbounded domain.
100 citations
TL;DR: In this article, a green strategy was proposed to construct Ag/ZnO metal-semiconductor nanocomposites with hierarchical micro/nanostructure and enhanced photocatalytic activity.
TL;DR: It is suggested that the solvophobic parameter, characterized quantitatively by Gibbs energy of transfer of hydrocarbon from gas into a given solvent, can be used to account for the effect of organic additives on the formation and growth of the ionic liquid aggregates in water.
Abstract: Material preparation in ionic liquids and environmental pollution control by ionic liquids are often closely dependent on the aggregation behavior of ionic liquids in solution. In the present work, conductivity, fluorescence probe, and dynamic light scattering techniques have been used to study the effect of organic solvents on the aggregation behavior of 1-dodecyl-3-methylimidazolium bromide in water. It was shown that the critical aggregation concentration (CAC), the ionization degree of the aggregates (α), and the standard Gibbs energy of aggregation (ΔGm°) of the ionic liquid increase, while its aggregation number (Nagg) and aggregates’ size decrease with increasing concentration of organic additives in water. These results have been discussed from the favorable interactions of alkyl chain of the ionic liquid with the mixed solvents. It is suggested that the solvophobic parameter, characterized quantitatively by Gibbs energy of transfer of hydrocarbon from gas into a given solvent, can be used to acco...
TL;DR: In this article, the excess molar volume (V m E ) and excess logarithmic viscosity ((ln ǫ)E) for binary mixtures of 1-hexyl-3-methylimidazolium tetrafluoroborate ([C6mim][BF4]) with butanone, ethyl acetate, butylamine, and tetrahydrofuran have been determined from density and viscoity measurements in the whole composition range at the temperature of 298.15 k.
TL;DR: In this paper, the authors show that neutralino dark matter can be as light as a few GeV and its scattering rate off the nucleon can reach the sensitivity of XENON100 and CoGeNT.
TL;DR: In this article, residues of HCHs and DDTs in surface water and suspended particulate matter (SPM) from upper reach of the Huaihe River, East China, were investigated.
TL;DR: In this article, the authors compared three different supersymmetric models, namely, the minimal super-symmetric standard model (MSSM), the next-to-minimal super-substance model (NMSSM) and the nearly minimal supersymmymmetric super-standard model (nMSSMs), and obtained the following observation in the allowed parameter space: (i) In the MSSM the signal rate is always suppressed, but in a tiny corner of the parameter space it can be enhanced (maximally by a factor of 2);
TL;DR: In this paper, a spin-polarized density functional theory has been used to study the effects of vacancy defects on the magnetic properties of graphene, and a relation between the vacancy-induced magnetic moment and the size and shape of the vacancy clusters in graphene sheet was formulated.
Abstract: Spin-polarized density functional theory has been used to study the effects of vacancy defects on the magnetic properties of graphene. Structural optimization shows that introducing a carbon vacancy cluster into a graphene sheet changes the spatial distribution of the neighbor atoms, particularly those located around the vacancy. From spin-polarized DOS and LPDOS calculations, we find that only vacancies containing unpaired electrons show magnetism. These results lead us to formulate a relation between the vacancy-induced magnetic moment and the size and shape of the vacancy clusters in graphene sheet.
TL;DR: The experimental results indicated that modified TiO(2) nanotube arrays demonstrated an excellent merit on the preconcentration of PAHs, and there were excellent linear relationships between peak area and the concentration ofPAHs in the range of 0.2-100 μg L(-1) and 1.0-100μ-SPE.
TL;DR: In this paper, a model based on band-gap alignment was proposed to elucidate the underlying mechanism of the enhanced UV emission and photocatalytic activity of these unique heterostructures.
Abstract: ZnO–ZnS heterostructures were fabricated via using ZnO rods as template in different Na2S aqueous solutions. These heterostructures are 5–6 μm in length and formed by coating ZnO rod with a layer of porous ZnS shell comprising primary crystals about 10 nm in diameter. Subsequently, intact ZnS polycrystalline tubes were obtained by removing the ZnO cores with 25% (wt) ammonia. The as-prepared products were characterized by scanning electronic microscopy (SEM), transmission electronic microscopy (TEM), X-ray diffraction (XRD), energy-dispersive X-ray analysis (EDX), Fourier transform infrared (FT-IR), and electrochemical impedance spectroscopy (EIS). It was found that the electron transfer between ZnS shell and ZnO core strongly affect the photoluminescence and photocatalytic performances of these heterostructures. The rapid transfer of photo-induced electrons from the ZnS shell to the ZnO core leads to enhanced ultraviolet emission. However, if this correlation was destroyed, then the corresponding heterostructure exhibits improved photocatalytic efficiency due to the reduced volume recombination of the charge carries and the multiple reflection effect. Finally, a model based on band-gap alignment was proposed to elucidate the underlying mechanism of the enhanced UV emission and photocatalytic activity of these unique heterostructures.
TL;DR: The surface molecularly imprinted polymer presented here may find useful application as a solid phase absorbent to separate trace imidazole in environmental water samples and form the basis for the research program on the preparation and application of alkyl-imidazolium imprinted polymers.
TL;DR: Purine is utilized as a new directing group for the Pd-catalyzed monoarylation of 6-arylpurines with simple aryl iodides via C-H bond activation in good yields, providing a complementary tool for the modification of6- Darylpurines (nucleosides).
TL;DR: In this paper, a detailed interpretation of the infrared spectra of the title compound was reported, and the theoretical spectrograms for FT-IR spectra were constructed by using the MOLVIB program.
TL;DR: In this paper, a special air bubbling photo-reactor, with a perfect photon utilizing of an only 6 W, UV-C light source, was employed and a promising hybridized homogeneous AOP, as: UV/S 2 O 8 2− /Fe 2+ /H 2 O 2, under initial natural pH of 6.0, was introduced.
TL;DR: In this article, a novel sensor for hydrogen peroxide (H2O2) was fabricated using β-MnO2 nanorods on a glassy carbon electrode (GCE).
Abstract: A novel sensor for hydrogen peroxide (H2O2) was fabricated using β-MnO2 nanorods on a glassy carbon electrode (GCE). The nanorods were obtained by a hydrothermal method and characterized by scanning electron microscopy and X-ray diffraction. Cyclic voltammetry was used to evaluate the electrochemical performance of the modified GCE. The sensor exhibits excellent catalytic activity toward the oxidation of H2O2 and displays a rather wide linear range (from 2.5 μM to 42.9 mM), high sensitivity (21.74 μA·mM−1), a low detection limit (2.45 μM at an S/N of 3), and a response time of <5 s.
TL;DR: Hollow PdCu alloyed nanocubes were synthesized by a novel one-pot template-free strategy through tuning the surface energy difference of the crystal planes by alloying to exhibit superior electrocatalytic activity and stability for formic acid oxidation.
TL;DR: It is shown that electric field effects may be functional for the natural redox processes of cytochrome c in the respiratory chain, as well as for the switch from the redox to the peroxidase function, one of the key events preceding apoptosis.
Abstract: Most of the biochemical and biophysical processes of proteins take place at membranes, and are thus under the influence of strong local electric fields, which are likely to affect the structure as well as the reaction mechanism and dynamics. To analyse such electric field effects, biomimetic interfaces may be employed that consist of membrane models deposited on nanostructured metal electrodes. For such devices, surface-enhanced resonance Raman and IR absorption spectroscopy are powerful techniques to disentangle the complex interfacial processes of proteins in terms of rotational diffusion, electron transfer, and protein and cofactor structural changes. The present article reviews the results obtained for the haem protein cytochrome c, which is widely used as a model protein for studying the various reaction steps of interfacial redox processes in general. In addition, it is shown that electric field effects may be functional for the natural redox processes of cytochrome c in the respiratory chain, as well as for the switch from the redox to the peroxidase function, one of the key events preceding apoptosis.
TL;DR: In this paper, the decays of gamma chi(cJ) and gamma v (V = phi, rho(0), omega) were studied with a sample of (1.06 +/- 0.04) X 10(8)psi' events collected with the BESIII detector.
Abstract: The decays chi(cJ) -> gamma V ( V = phi, rho(0), omega) are studied with a sample of radiative psi' -> gamma chi(cJ) events in a sample of (1.06 +/- 0.04) X 10(8)psi' events collected with the BESIII detector. The branching fractions are determined to be: B(chi c1 -> gamma phi) = 25.8 +/- 5.2 +/- 2.3 X 10(-6), B(chi(c1) -> gamma rho(0)) = (228 +/- 13 +/- 22) X 10(-6), and B(chi(c1) -> gamma omega) = (69.7 +/- 7.2 +/- 6.6) X 10(-6). The decay chi(c1) -> gamma phi is observed for the first time. Upper limits at the 90% confidence level on the branching fractions for chi(c0) and chi(c2) decays into these final states are determined. In addition, the fractions of the transverse polarization component of the vector meson in chi(c1) -> gamma V decays are measured to be 0.29(-0.12-0.09)(+0.13+0.10) fo chi(c1) -> gamma phi, 0.158 +/- 0.037(-0.014)(+0.015) for chi(c1) -> gamma rho(o), and 0.247(-0.087-0.026)(+0.090+0.044) for chi(c1) -> gamma omega, respectively. The first errors are statistical and the second ones are systematic.
TL;DR: In this article, a possible formation mechanism of the hollow superstructures has been proposed and the optical properties of these ZnO structures were investigated in some detail, which showed high photocatalytic activity towards Congo Red under ultraviolet (UV) irradiation.
Abstract: With the introduction of mannite, hollow flower-like complex superstructures assembled by ZnO nanorods have been successfully constructed via a simple hydrothermal method. The results reveal that the mannite-directed hydrothermal process is essential for the final products. The morphologies of the ZnO products could be easily tuned by adjusting the molar ratios of mannite to zinc ion, the amount of ammonia, the reaction time and temperature. A possible formation mechanism of the hollow superstructures has been proposed and the optical properties of these ZnO structures were investigated in some detail, which showed high photocatalytic activity towards Congo Red under ultraviolet (UV) irradiation.
TL;DR: A zinc-based ionic liquid ([CHCl][ZnCl2]2] was found to be an excellent reaction medium for the direct nucleophilic substitution reactions of alcohols as discussed by the authors.
TL;DR: A novel 4-amino-1,8-naphthalimide with two different metal cation receptors connected at 4-AMino or imide nitrogen positions respectively was designed and prepared and several logic gate operations, such as OR, NOR and INHIBIT, can be achieved.
Abstract: A novel 4-amino-1,8-naphthalimide (NDI) with two different metal cation receptors connected at 4-amino or imide nitrogen positions respectively was designed and prepared. Significant internal charge transfer (ICT) as well as photoinduced electron transfer (PET) from the receptors to NDI is revealed by the shifted UV-vis absorption spectra and significant fluorescence quenching. Both Zn2+ and Cu2+ can coordinate selectively with the two cation receptors in this molecule with different affinities. The coordination of Zn2+ with the receptor at imide nitrogen hindered the PET process and accordingly restored the quenched fluorescence of NDI. But the coordination of Zn2+ at 4-amino position blocked the ICT process and caused significant blue-shift on the absorption peak with the fluorescence intensity unaffected. Similarly, coordination of Cu2+ with the receptor at imide nitrogen can block the PET process, but can not restore the quenched fluorescence of compound 3 due to the paramagnetic properties of Cu2+, which quench the fluorescence significantly instead. With Cu2+ and Zn2+ as two chemical inputs and absorption or fluorescence as output, several logic gate operations, such as OR, NOR and INHIBIT, can be achieved.