Applied Mechanics and Materials Vols. 198-199

Abstract: According the test, this paper discussed the relationships among nano SiO₂ content of nano SiO₂ cement concrete ,air content, water-cement ratio and frost resistance property.Meanwhile, the relationship among the bubble parameter, structure of holes and the frost resistance is primarily discussed. The results show that the concrete mixed with some nano SiO₂, with the increase of impervious holes in hardened cement paste, compared with ordinary concrete,both the ability of freezing-thawing resisting and compression strength will have an improvement. What’s more, when mixed with the air-entraining agent, freezing-thawing cycles number will have an obvious increase.When water-cement ratio is 0.35-0.39, the ability of frost resisting is very high but when water-cement ratio is larger than 0.39, freezing-thawing resisting performance is substantial decline.

Abstract: Little is known about the potential behavior and ecotoxicity of nanoparticles to aquatic organisms. The cytotoxicity and immunotoxicity of NiO-Nanoparticles and Chlamydomonas reinhardtii. It shown that the mitochondrial activity was gradually reduced significantly at the different exposure concentrations for NiO nanoparticles. NiO nanoparticles had a similar effect on membrane integrity as that observed for inhibition of cellular metabolic activity, with a significant reduction in membrane integrity. The NiO nanoparticles exhibited a significantly higher degree of BOD compared to the control group. NiO nanoparticles induced increases in MDA levels with incubation time. A significantly higher percent of cells with mitochondrial depolarization was observed when cells were exposed NiO nanoparticles. NiO nanoparticles significantly elevated ROS levels more than four fold at the highest concentration and the lysozyme activity was significantly increase at all the exposure concentrations and incubation times.

Abstract: The situations of smelting SPHD were analyzed for 150t converter in TangSteel. Based on the analysis of dephosphorization process and the thermodynamic conditions in converter, the operation of dephosphorization was optimized. The industrial tests for dephosphorization were carried out, and the results were analyzed. The results were shown that the distribution coefficient would be the highest value, when the alkalinity of slag was 3.5 and the FeO content was 21% in making SPHD steel. The distribution coefficient would reduce, when the temperature was increased, especially more than 1700°C, so end point temperature should be best less than 1700°C.

Abstract: Acoustic emission (AE) monitoring is the primary technology used for the identification of different types of failure in composite materials. Tensile test were carried out on twill-weave composite specimens, and acoustic emissions were recorded from these tests. AE signals were decomposed into a set of Intrinsic Mode Functions(IMF) components by means of Empirical Mode Decomposition(EMD) , the Fast Fourier Transform (FFT) of each IMF component was performed, it was shown that the event peak frequency of each IMF component could be directly related to the materials damage modes.

Abstract: To minimize interfacial power losses, thin layers of NiO, a p-type oxide semiconductor, are inserted between the active organic layer, poly(3-hexylthiophene) (P3HT) [6,6]-phenyl-C61 butyric acid methyl ester (PCBM), and the ITO (tin-doped indium oxide) anode of bulk-heterojunction ITO/P3HT:PCBM/Al solar cells. The interfacial NiO layer is deposited by radio frequency (RF) magnetron sputtering deposition directly onto cleaned ITO, and the active layer is subsequently deposited by spin-coating. Insertion of the NiO layer affords cell power conversion efficiencies as high as 2.5% and enhances the fill factor to 56% and the open-circuit voltage (Voc) to 605 mV versus ones without NiO buffering layer control device. The value of such hole-transporting/electron-blocking interfacial layers is clearly demonstrated and should be applicable to other organic photovoltaics.

Abstract: Laser cladding technology was adopted to fabricate hydroxyapatite(HAP) and calcium phosphate compound coating according to the feature that a metallurgical bonding can be formed by laser cladding process. Compared with CO₂ laser, Nd-YAG laser has different wavelength(the former is 1.06μm and the latter is 10.06μm). Metal and ceramic material has quite different absorbance ability towards them and thus they can generate different laser cladding products by these two laser surface processings with different wavelength. This paper presents a new process and mechanism analysis to obtain bioceramic composite coating on Ti6Al4V substrate by Nd-YAG laser cladding. A bioceramic composite coating including HAP，Ca₂P₂O₇，Ca₃(PO₄)₂ and calcium titanates and was successfully obtained by Nd-YAG laser cladding with pre-depositing mixed powders of CaHPO₄•2H₂O and CaCO₃ directly on Ti6Al4V substrate. Nd-YAG laser transmits mixed powders of CaHPO₄•2H₂O and CaCO₃ and the laser power is absorbed by Ti6Al4V substrate to produce a thin layer of molten region. There are mainly two kinds of chemical reaction systems in the coating during laser cladding processing. When CaHPO₄•2H₂O and CaCO₃ react together, they make calcium phosphate bioceramic products; The microstructure of the bioceramic composite coating is even and minute because of the rapid solidification in laser processing. A chemical metallergical bonding is formed between the boceramic composite coating and Ti6Al4V substrate. It can also be expected that Nd-YAG laser cladding technology can be used as a further modification procedure to enhance HAp/metal interface property.

Abstract: In recent years there has been increasing interest concerning the synthesis of hollow materials in nanometer to micrometer dimensions. Hollow hydroxyapatite(HAP) microspheres with pores on their surfaces were prepared by a Li-Ca-B glass in situ immersion conversion process in an aqueous phosphate solution at 37°C. The chemical reaction ability of the Li-Ca-B glass was studied by immersing the glass in SBF solution, and the phases of the reaction product were identified by the XRD method. The morphology, composition, phases and thermal property of the hollow HAP microspheres were investigated using by chemical analysis, SEM ,and XRD . The microphere wall consisted of calcium deficient hydroxyapatite (CDHAP) crystals only. Furthermore, the formation mechanism of the hollow HAP microsphere was also discussed.

Abstract: Normal load can affect the wear performance of the materials. with the normal load increased, friction coefficient is firstly increases and then decreases, when the normal load is 80N, the minimum friction coefficient is 0.916; rotating speed can effect the wear performance of the materials with the change of rotating speed, the faster the speed, the bigger the friction coefficient When the speed is 60 rad/min, the minimum friction coefficient is 0.918.The content of VC can influence greatly for wear-resisting performance, when the content of VC was 55%, the wear performance of material is better, the friction coefficient is 0.916-0.918.The results show that: the microstructure analysis can judged that, in the wear process, iron is off first, then the particle phase, so VC grain can intensify the wear resistance.

Abstract: The goal of this paper was to study the micro-morphology and mineral composition of PM10 in Nan jing typical areas were studied using scanning electronic microscopy and energy dispersive spectrometer (SEM/EDS). Samples were collected as PM10 for 24 h using high-volume air sampler from Dachang and Shanxilu area. The SEM/EDS analysis showed that mineral particles with regular shapes were popular in PM10 in Dachang District, and mineral particles with irregular shapes were popular in PM10 in Shanxilu area respectively. The composition of mineral particles with regular shapes were mainly carbon ates, sulphates, and aluminosilicates, while mineral particles with irregular shapes were mainly soot aggregates, biomass and primitive minerals.

Abstract: In this paper，the organo-montmorillonite (OMMT) was prepared by cation exchange reaction, using sodium montmorillonite (Na+-MMT) and cetyltrimethylammonium bromide(CTAB) as all intercalation agent under precision microwave organic synthesis system. The structure of the montmorillonite was characterized by X-ray diffraction (XRD)、infrared spectrum (IR)、thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The results show that the intercalation is successful, the CTAB as a organic modifier introuduced into lattice layers of montmorillonite by cation-exchange reaction and the surface morphology of OMMT is complete exfoliation, the distance between the lattice layers of montmorillonite has been greatly increased.