Applied Mechanics and Materials Vols. 675-677

Abstract: The catalytic selective reduction of NO_x with CO over Pd/Al₂O₃ and Pd/TiO₂/Al₂O₃ under lean conditions (called SCR-deNO_x in simple way) was studied here. The performance of the catalysts with different Pd loadings for deNO_x was investigated. The results showed that the 2.0 wt.% Pd/TiO₂/Al₂O₃ and 1.5 wt.% Pd/Al₂O₃ catalysts displayed optimum deNO_x activities of 46% and 20% at 200°C, respectively. TEM, XRD, XPS and SEM were utilized to characterize the catalysts. Metallic palladium is thought to be the active site which highly dispersed on the catalyst supports. The synergy between TiO₂ and Al₂O₃ or Pd is thought to be the reason for the obvious improvement in deNO_x process.

Abstract: The performance of various noble metal based catalysts for the NO_x reduction in the CO-rich conditions of simulated post Euro-IV diesel emissions at low temperature was investigated in this paper. Pd loaded catalyst showed higher catalytic activity than Ir or Rh loaded catalysts. Titania, as one of the support material, clearly promoted the deNO_x process due to the synergy with alumina and Palladium. The TiO₂ loading was optimized subsequently. As a result, Pd/TiO₂/Al₂O₃ catalyst with Pd loading of 2.0 wt.% and TiO₂ loading of 10 wt.% showed the NO_x conversions of 25~46% in the temperature range of 200~250°C.

Abstract: Chrome doped nanoTiO₂ transparent hydrosol was synthesized by a complexation-controlled hydrolysis method at room temperature. The absorbance spectrum and phase structure of samples were characterized by UV-Vis spectrophotometer, and X-ray diffraction, respectively. The photocatalytic activity by degradating acid red 3R dye was studied, and the results indicated that when nanoparticle doped with 0.5% Cr, the degradation rate exceeded 96% for 60 min under the sunlight.

Abstract: To explore the possibility of simultaneously adsorptive treating polluted water containing both organics and heavy metals, multifunctional polymeric resin NDA-1500 was prepared through chemically modification of chloromated polystyrene with salicylic acid. The FT-IR, BET surface area measurements and sodium capacity measurement were applied to characterize the properties of NDA-1500. The adsorption properties toward 4-chloro-phenol and heavy metals such as Pb²⁺, Cu²⁺ and Ni²⁺ ions were studied respectively. The adsorption data of the NDA-1500 toward 4-chloro-phenol fit well with Langmuir model. The adsorption capacity of NDA-1500 toward 4-chloro-phenol was higher than that of unmodified NDA-150 and adsorption capacity decreased with increase of temperature suggesting the exothermic process. The removal efficiencies of metal ions by NDA-1500 were also 2-3 times higher than that of NDA-150 and the metals were recovered completely with 0.2 mol/L hydrochloric acid.

Abstract: Algogenic organic matters (AOM) generate from two parts, that are extracellular organic matters (EOM) and intracellular organic matters (IOM). This paper compared the structural characteristics of IOM and EOM originated from Microcystis aeruginosa using techniques including ultra violet-visible spectrum (UV-VIS), Fourier infrared spectrum (FT-IR) and three-dimensional excitation emission matrix (EEM) fluorescence spectroscopy. The results demonstrated that concentrations of the organic matter in EOM were less than that in IOM. EOM has less characteristic absorption peaks. There were more aromatic ring compounds, more protein and amino acids in IOM than EOM.

Abstract: Polycyclic aromatic hydrocarbon (PAHs), espically benzopyrene (BaP),are the most popular pollutants in surface water,and the adverse effects on male reproductive function have aroused more and more attention. The objective of this study is to confirm BaP regulates testosterone (T) in adult rat Leydig cells and then deserve the effect of BaP on Cx43 between Leydig cells, in order to explore whether the influence of Bap on Leydig cells is via its effect on Cx43. Established the primary culture system Leydig cell, Primary cultured Leydig cells were incubated in the different concentrations (1;10;50ug/ml) of BaP, and DMSO control group. After culturing 24h, the expression of Cx43 on cell membrane were investigated with immunofluorescence and the total Cx43 were evaluated by Western blotting.. The results indicate: comparing with the control group, the expression of Cx43 are suppressed by Bap in a dose-response relationship.

Abstract: The second Songhua River has severe organic contamination due to domestic sewage and industrial wastewater. It is important to determine its genotoxic activity, which is a potential hazard for human health. The micronucleus assay and lymphocytes SCGE assay were employed to examine the genotoxic activity of organic extracts of water samples taken from upstream, midstream and downstream in Jilin City section of the second Songhua River in dry season and in wet season, respectively. Micronucleus assay results showed that there were significant increases in water samples at doses of 25L/kg and 50L/kg. The genotoxicity seemed to be less when compared with the results from dry season to wet season and to be strong from upstream to downstream. A similar result was also obtained in DNA damage on lymphocytes by SCGE assay. These results indicate that the organic extracts of water samples taken from the Songhua River show genotoxic activity. The risks of potential harm for human health in the Songhua River should be studied further.

Abstract: By applying the OECD soil column method, the leaching behavior of chlorpyrifos and it main metabolite, 3,5,6-trichloro-2-pyridinol (TCP), in five types of saturated soil was compared. The results show the following: (1) Chlorpyrifos can be retained in the five types of saturated soil, and the rate of chlorpyrifos residues in the five types of soil columns are 86.9% (Black soil), 80.3% (Red soil), 77.9% (Limestone soil), 74.7% (fluvo-aquic soil) and 68.9% (Purple soil) of the application amount; (2) No chlorpyrifos was found in the leachate; (3) TCP could fully migrate in the five types of 30-cm-long soil columns and the TCP residues in these columns are 34.4% (Black soil), 29.6% (Red soil), 24.8% (Limestone soil),14.1% (fluvo-aquic soil) and 10.3% (Purple soil) of the application amount; (4) The average concentrations of TCP in the 400 mL leaching solution were from 0.31 μg·mL^-1 to 0.23 μg·mL^-1; and (5) The K_oc and GUS values of the TCP in the five types of soil showed that TCP has a great leaching risk compared with its parent compound of chlorpyrifos.

Abstract: An ultrasound-assisted ionic liquid based dispersive liquid-liquid microextraction (UA-IL-DLLME) was developed for the determination of four plant hormones (6-benzyladenine (6-BA), kinetin (6-KT), 2, 4-dichlorophenoxy acetic acid (2, 4-D) and uniconazole (UN)) in soil, using high performance liquid chromatography (HPLC)-diode array detection (DAD). Several important parameters including the type and volume of extraction solvent, the volume of disperser solvent, ultrasound time, pH of the solution and salt effect were studied and optimized. Under optimum conditions, the limits of detections (LODs) for the target analytes were in the range of 0.002-0.01 μg g^-1. And satisfactory recoveries of the target analytes in the soil samples were 79.3-96.7 %, with relative standard deviations (RSD, n=5) that ranged from 4.3 to 6.7%.

Abstract: High filling and excavation of loess landslide happens more frequently, which serious impact on security of the project, but formation mechanism of the landslide is still not perfect, therefore this paper analyze from damage characteristics and influence factors of slope stability to evaluate its stability and summary such failure mode. Conclusion: ① The root cause of the formation of class landslide: the lithology of compacted layer is different from upper loose soil, and the clay is unevenly distributed, which lead to local shear strength lower ② Rainfall is the main predisposing factors of slope instability, which infiltrates slope, the weak surface throughout the entire slope.③ Failure mode is similar to the general loess landslide, but the position of slipping surface is more regular