Advanced Materials Research Vols. 610-613

Abstract: Fe-modified ZSM-5 and β zeolites were prepared by adopting liquid ion-exchange method and their catalytic performance was studied in the N₂O decomposition reaction. The state of Fe loaded on Fe-zeolites was investigated by means of UV-vis diffuse spectra, infrared spectroscopy, EPR and H2-TPR. The results of IR of hydroxyl stretching and UV-vis investigation_{Subscript text}s indicated that part of the iron-ions was introduced into zeolites at the charge-balancing sites. The results of EPR and H₂-TPR investigations showed that the same iron species were loaded on ZSM-5 and β zeolites. However, the results of IR of the perturbed anti-symmetric T-O-T vibrations of iron-ions indicated that different types of ZSM-5 and β zeolites resulted in different distributions of charge-balancing iron cations. The iron-ions could replace Brönsted acid protons at the straight channel wall (α sites), intersection of straight and sinusoidal channels (β sites), and sinusoidal channel wall (γ sites) within the ZSM-5 zeolite. In the case of Fe-β zeolites, iron-ions mainly located in the straight channels. We observed that the catalytic activity of the iron ions located on the α sites of ZSM-5 zeolites was better than those of iron ions located on β and γ sites in N₂O direct decomposition, since the former was the most easily reduced from Fe3⁺ to Fe²⁺ in H₂. Furthermore, it was found that Fe-β zeolite showed higher catalytic activity than Fe-ZSM-5 zeolite. This difference was attributed to the active sites located almost exclusively in the straight zeolite channels.

Abstract: G1.0 (Generation1.), G2.0, G3.0, G4.0 polyamidoamine (PAMAM) dendrimers-supported Na₅Co^II(H₂O)PW₁₁O₃₉ (PW11Co) were prepared by co-precipitation method. They were characterized by UV-Vis, XPS, XRD, and TEM. It is suggested that as the generation of the PAMAM dendrimers increased, the interaction between PW11Co and PAMAM dendrimer enhanced and the particle size of PW11Co decreased. The catalytic activities for the oxidation of isobutyraldehyde (IBA) to isobutyric acid (IBAc) by PW11Co-PAMAM(G1.0, G2.0, G3.0, G4.0) were examined.

Abstract: The molecular structures, electron affinities, and dissociation energies of the C₆F₆ molecule have been determined using seven hybrid and pure density functional theory (DFT) methods and the DZP++ basis set. Three different types of the neutral-anion energy separations reported in this work are the adiabatic electron affinity (EA_ad), the vertical electron affinity (EA_vert), and the vertical detachment energy (VDE). The most reliable adiabatic electron affinities, obtained at the B3PW91 and B3LYP levels, are 0.59 and 0.69 eV, respectively. The first dissociation energies D_e (C₆F5-F) for the neutral C₆F₆ predicted by the DFT metho_{Subscript text}ds except BHLYP are 5.195.44 eV. Compared with the limited experimental dissociation energies, our theoretical predictions of the B3LYP and B3PW91 methods are fairly reasonable.

Abstract: Green tides outbreak frequently around Lianyungang surrounding waters in recent years. In order to understand the nutrient response relationship with the typical Enteromorpha species, the experiment investigated uptake kinetics of NO3-N, NH4-N and PO4-P with Michaelis-Menten equation. It was found that the Ks values of Enteromorpha linza are lower than that of Enteromorpha prolifera, which indicated E. linza have a better ability to adapt low nutrient environment. Vmax for various nitrogen species followed the order of NO3-N > NH4-N, indicating ammonia absorption can inhibit the uptake of nitrate. The study provided a theoretical basis for exploring the Enteromorpha outbreak mechanism and marine ecological effects assessment.

Abstract: The distribution and activity of cell receptors, which are key factors of baculovirus-insect cell interactions, may be attributed to cell cycle. In fact, the virtual difference in time of infection is the difference in cell cycle distribution. In this work, the effects of cell cycle on cell activity and baculovirus production were investigated. Sf9 cells were infected with baculovirus at the different cycle phases. It was found that G1 phase plays a substantial role in cell activity and competence for the baculovirus replication. Sf9 cells have the highest succinate dehydrogenase activity and are most sensitive for the baculovirus replication when the proportion of G1 phase in cell population reaches a maximum. On the hand, cell activity is at the lowest when G2/M percentage reaches its maximum. These results provide a guidance in developing the baculovirus infection dynamics model and controlling the expression of useful foreign genes when cell cycle is taken into account.

Abstract: In this study the toxicity of malachite green (MG) to aquatic plants (rice seeds) and impact by Aldrich humic acid (HA, used as model dissolved organic matter) were investigated with the germination rate of rice seeds. Results showed that germination rate was decreased from 77% to 1% with the increasing concentration of MG (0-2000 mg L-1), and the obvious dose-response relationship was observed. At the same time, the germination rate was improved from 33% to 50% after the addition of HA (1-500 mg L-1) at the fixed concentration of MG (1000 mg L-1).

Abstract: The gene fesod encoding iron superoxide dismutase from Magnetospirillum AMB-1 with a calculated 22kDa was cloned and efficiently expressed in Escherichia coli BL21 (DE3). The open reading frame of 597 nucleotides encoded a protein of 199 amino acids without the signal peptide sequence. Recombinant enzyme fesod was purified by IMAC (Ni2+) in a single step to electrophoretic homogeneity presented as a single protein band on SDS-PAGE. The recombinant enzyme displayed maximum activity at 25 °C, which was stable in the pH range from 5.4 to 8.2 and at temperature from 25 to 45 °C. These results suggest that fesod may have very attractive applications in cosmetics industry as an anti ageing protein in a moderate temperature range.

Abstract: The continuous dosing and discharge of water soluble redox mediators such as biologically recalcitrant compounds will result in the secondary contamination. The immobilized redox mediator prepared by incorporation of anthraquinonedisulphon-ate (AQDS) during the electropolymerization of pyrrole monomer on active carbon felt (ACF), AQDS/PPy/ACF, was used for catalyzing bioreduction of 2,4-dinitrotoluene(2,4-DNT) in this study. The results showed that the morphology of the PPy films deposits on ACF are characterized by some globular structure; AQDS/PPy/ACF exhibited good catalytic activity and stability for 2,4-DNT, the enhanced reduction rates obtained in the incubations with AQDS/PPy/ACF was about 5 times that without AQDS/PPy/ACF, the corresponding first-order reduction rate constant k reached 0.045 h-1; 2,4-DNT was reduced to be 2,4-diaminotoluene via 2-amino-4-nitrotoluene and 4-amino-2-nitrotoluene in the system.

Abstract: Based on field experiment, the yield and water use efficiency (WUE) of tobacco under different nitrogen levels were studied in Hunan province, China. The results show that the evaportranspiration (ET) of flue-cured tobacco dealt with N2 (90kg N fertilizers per ha) gets to the maximum. In addition, the vigorous period has the maximum ET due to the critical period of water requirement. The linear relationship is established among fertilization, yield and water use efficiency. Reasonable fertilizer application can increase water use efficiency and flue-cured tobacco yield.

Abstract: The blossom-end rot (BER) induced by calcium deficiency will cause a great impact on tomato yield and quality. Aimed at the tomato physical barriers caused by calcium deficiency, the composite micro-organisms (EM) fermentation technology was applied to configure biological active calcium preparations of different calcium concentrations, with raw materials of calcium sulfate, lime and gypsum. The active calcium preparation with calcium concentration of 1 ‰ was sprayed on the fruits during the fruit development period in the field experiment. The results show that lime with highest solubility is the best raw material for the fermentation of EM active calcium preparations with the consideration of higher calcium concentration, reasonable pH and EC value, and the lowest cost. It also shows the incidence of blossom-end rot of the experimental group is 35.36 % lower than that of CK.