Advanced Materials Research Vols. 233-235

Abstract: A series of 4-dihydroquinolinone derivatives were fully optimized by density functional theory (DFT), Hartree-Fock (HF) and Configuration Interaction Singlet (CIS) approaches. Absorption spectra, emission spectra and two-photon absorption cross sections were calculated by using time-dependent density functional theory and few-state model. Calculations were performed in the presence of solvent by using Conductor polarizable continuum model (CPCM). The molecular geometries, absorption spectra, emission spectra were in good agreement well with those experiment values. The absorption and emission peak red-shifted as a result of the extension of the conjugated structures. The introduction of heteroatoms such as F, Cl and Br gave rise to intramolecular transfer and the blueshift of the absorption and the emission spectra. The introduction of O or S atoms in two sides of molecules propelled the redshift of the absorption and emission maximum.

Abstract: In this paper, a sizing agent applied in papermaking was synthesized via emulsion polymerization using styrene (St), methyl acrylic acid (MAA), methyl methacrylate (MMA) and butyl acrylate (BA) as monomer. In this process, potassium persulfate (KPS) was used as a initiator and sodium lauryl sulfate (SDS) and OP-10 were used as the emulsifier or no emulsifier was used, while NB_2B was used as a protective atmosphere for the reaction system. The product of emulsion polymerization with St and BA has a good comprehensive properties and a certain sizing effectiveness. Furthermore, the microwave irradiation could not only produce emulsions with small diametric particles but also shorten the polymerized time greatly.

Abstract: The solubility of different commercially available sodium salts was measured at 120°C for the potential use in the production of sodium metal by electrochemical processes in Ionic liquids (ILs) at relatively moderate temperatures. The results showed that the anion, cation, and substituents on the cation of the IL have a great effect on the solubility of the salts. It was found that the solubility of the salts in some ILs is higher than the value required in the production of sodium metal. An electrochemical method was used to measure the electrical conductivity of the selected ILs. Moreover, the effect of sodium salts on the conductivity of the ILs was studied. The conductivity of IL increased with the dissolution of sodium salts. In general, the conductivity of the studied ILs with/without sodium salts was suitable for the use in the production of metal sodium.

Abstract: Al-Ca master alloy was prepared by molten salt electrolysis method, using a mixed molten salt system of CaCl_2-CaF₂ and feeding CaO as electrolysis material. The technological parameters such as back electromotive force (BEMF), cell voltage, and current were measured by testing device of molten salt electrolysis. The effects of current density, CaO addition, electrolysis time and feeding period on the back electromotive force in the electrolysis process are studied. The results indicate that back electromotive force increases with current density increasing, the feeding period is 30min measured by potential control method. Finally, the Al-Ca alloy with the Ca content of 11.6wt% can be obtained by electrolyzing for 1h at the current of 7A and at 740.

Abstract: Powder of Ti-46at%Al alloy was synthesized through mechanical activation (MA) and then sintered and concurrently consolidated in a short sintering time of 900 s by using spark plasma sintering (SPS) process. The XRD and SEM profiles show that the microstructures of TiAl alloys contained γ TiAl and small amount α-2 Ti₃Al phase, whose amount can be controlled by the sintering temperature. The compacts retained the original fine-grained fully densified bodies by avoiding an excessively high sintering temperature. The alloys sintered at higher temperature with this process showed a coarser microstructure. So it is possible to produce dense nanostructured TiAl alloys by mechanically activated spark plasma sintering (MASPS) within a very short period of time.

Abstract: Focuses on the dynamical collapse of large-span spatial structure, this paper uses giant magnetostrictive material as the main component to design a kind of new GMM actuator, which could used in active vibration control of large-span spatial structure. The genetic algorithm has been used to optimize the position of actuators in large-span spatial structure, and the optimization of the results has been analyzed by numerical simulation. The research shows that the GMM actuator has fine actuator effectiv.

Abstract: The PVC composite was prepared by extrusion melt using a new plasticizer octodecyl acyl tributyl citrate and PVC resin. Influence on mechanical and resistance to cold properties of PVC was studied by tensile and low temperature impact tests. The thermal behavior, texture and mechanism of plasticizing of OTBC plastifying PVC were supported by TG, DSC and SEM. The result indicated that the glass transition temperature of plastifying material was about 36°C, breaking strength was 25.3MPa, elongation at break was 250% and, plasicizing efficiency was 0.88, resistance to cold property better than plastifying material of DOP’s, domains between two phases of micro-texture were small and distributed homogeneously when OTBC content in PVC resin was 30%.

Abstract: Shocking temperature rise of the shaped charge with porous liner before collapse was calculated based on the Herrman equation of state. Shaped charges with 36mm charge diameter were used to fire at the 603 armor steel target, the penetration-standoff curves(P-S) of the shaped charge liner with 88.6% and 90.3%T.D were measured and compared. It is shown that proper porosity is helpful to lengthen the jet break up time and penetration depth，which is of significance for the application of porous liner.

Abstract: Temperatures of the carbide tip's surface when turning Carbon-Fiber-Reinforced Plastics (CFRP) composites with a sharp worn main cutting edge tool is investigated. The frictional forces and heat generated in the basic cutting tools are calculated by using the measured cutting forces and the theoretical cutting analysis. The heat partition factor between the tip and chip is solved by using the inverse heat transfer analysis, which utilizes temperature on the carbide tip’s surface measured by infrared as the input. The tip’s surface temperature is determined by finite element analysis (FEA) and compared with temperatures obtained from experimental measurements. Good agreement demonstrates the accuracy of the proposed model.

Abstract: Recently, it has been observed that surface modification of carbon nanotubes（CNTs）influences on CNT’s distribution among epoxy resin and affects the mechanical properties and electrical conductivities of CNTs. Owing to above-mentioned effects, carbon nanotubes treated with oxidizing in organic acids, a kind of surface modification, generates functional groups on the surface of CNTs taht is a major investigation in this study to enhance mechanical properties and electrical conductivities of CNTs. The influence of the different proportion contents of CNTs added into epoxy resin on mechanical properties and electrical conductivities of composites was investigated, and strength of material tested under different temperature environments was observed. Moreover, the creep behavior of carbon fiber（CF）/epoxy resin thermosetting composites tested under different temperature and stress were also concerned to be analyzed. The resulting creep behavior consists of only two stages, including primary creep and steady-state creep. The effects of creep stress, creep time, different humidity treatment on the various temperature creep of composites containing different proportion contents of CNTs were investigated. It is believed that the increased creep strains can be attributed to higher applied stresses, longer creep times, higher humidity, higher temperature and lower hardnesses. The test results also exhibit that mechanical strength and electrical conductivity increase with the increase of CNTs content added into composites. In the influence of temperature effect on specimen, because of different coefficient of expansion among matrix, fiber and CNTs, the overexpansion of matrix caused by high temperature results in crack occurred among matrix. From observation of the fracture surface by SEM image, the debonding occurs and longitudinal fibers are pulled out due to poor interfacial bonding of fiber and matrix, which also results in entire strength degeneration.