Advanced Materials Research Vol. 496

Abstract: Novel uniform nano/micron-sized ZnO spheres assembled from the aggregation of nano-particles have been synthesized by hydrothermal method. It was observed that ZnO spheres with controllable diameter were obtained when various volume ratios of triethanolamine (TEA) to H2O were used. Increasing the volume ratio of TEA to H2O could result in the formation of loosely packed ZnO spheres. The UV-visible absorption spectra show that the absorption peak red-shifts with the increasing average diameter of the spheres.

Abstract: There are the four types of defects during remote laser welding of zinc coated sheet metal. The root cause of all these defects is the explosion or ejection of molten weld metal caused by the escape of trapped high pressurized zinc vapor. Zinc removal is one of the methods used to solve the defects. We have researched the full penetration zinc removal method for remote laser welding with coupons of zinc coated sheet metal. The result shows that the full penetration zinc removal method works at the cost of high heat input and low welding speed

Abstract: Taking modified na-bentonite as matrix, PEG-20000 and NaHA are added to form composite briquette binder, while its influence on the properties of the prepared briquette is studied. The result indicates when the dosage of the composite briquette binder consisting of 0.8Kg Sodium bentonite, 0.08Kg PEG-20000 and 0.12Kg NaHA is 7% of the coal sample mass, briquette with relatively higher compressive strength, good thermal stability and desirable humidity resistance can be prepared.

Abstract: An improved accurate speckle projection method is used for study the mechanical properties of the composite material film in the paper. A system for deformation measurement is developed with the telecentric lenses, in which such conventional lens’ disadvantages such as lens distortion and perspective error will be diminished. Experiments are performed to validate the availability and reliability of the calibration method. The system can also be used to measure the dynamic deformation and then results are also given.

Abstract: Cr-substituted mesoporous aluminophosphate molecular sieve (Cr-MAP) was prepared and characterized. Cr-MAP is a typical mesoporous molecular sieve with long-range ordered structure, providing effective molecular sieve for fabricating acetophenone by selectively oxizing ethylbenzene with tertiary butyl hydro peroxide (TBHP). When the reaction is at 100 °C for 8 h, using chlorobenzene as solvent and TBHP as oxidant, ethylbenzene conversion, acetophenone selectivity and acetophenone yield reach 72.8 %, 85.4 %, and 62.2 %, respectively.

Abstract: We experimentally demonstrate a tunable fiber ring laser with narrow linewidth and fine tuning resolution based on Er³⁺-doped fiber(EDF) laser material. A tunable fiber Bragg grating(FBG) filter is used in the system as the frequency selecting element, and a stepping motor together with a single chip acts as the precise tuning mechanism. The fiber ring laser has a narrow linewidth of ~0.07nm, a tuning resolution of ~1.5pm/pulse, an output power of ~25 mW, and a slope efficiency of ~17.9%.

Abstract: The synthesis, structure and luminescent properties of a cyclometalated iridium (ΙΙΙ) complex are reported. The cyclometalated ligand and auxiliary ligand are 2-(2-fluorophenyl)-benzothiazole (F-BT) and acetylacetone (Hacac), respectively. The complex (F-BT)2Ir(acac) exhibits bright photoluminescence (PL) at room temperature with a high solution PL quantum efficiency of 0.62. Organic electroluminescent (EL) devices are fabricated employing (F-BT)2Ir(acac) as an emissive dopant in 4,4′-N,N′-dicarbazole-biphenyl (CBP) host. EL efficiency shows weak dependence on doping concentration and current density. While the optimized device exhibits a peak efficiency of 28.5 cd/A and a maximum brightness of 49880 cd/m2. An efficiency of 22.7 cd/A at 100 mA/cm2, 80% of the maximum, can be achieved.

Abstract: Monodisperse iron oxide and quantum dots were synthesized via high-temperature decomposition. Hydrophobic iron oxide was transferred into water and then encapuslated into vesicle interior of liposomes with hydrophilic quantum dots within the phospholipid bilayer. The formed magnetic-fluorescent liposomes with embedded structure can be used for both magnetic resonance imaging and fluorescent imaging in biological field.

Abstract: This paper carries out the research on using the toughening mechanism of phase transition of ZrO₂ to inhibit the WC grain and improve the toughness of the hard alloys. WC–ZrO2–8wt%Co hard metals was mixed with 0-2 wt% nano-ZrO₂ and prepared by conventional sintering (CS) for 2 h at 1440oC to see whether the addition of ZrO₂ could improve densification behavior, the microstructure and mechanical properties of the samples. Experimental results showed that the use of ZrO₂ nanoparticles could decrease the relative density because of the worse wetting effects; it could also inhibit the growth of the grains of WC-Co hardmetal to enhance the hardness of the alloy. The fracture toughness of sample has an increasing tendency as a whole because of the phase transition during the sintering process.

Abstract: A new non-contact sensor with three magnetic pole based on magnetoelastic effect was designed, and its operation principle and mathematical model of induced voltage output were given. The output characteristic of the sensor affected by field current intensity, frequency, and the gap between the probe of the sensor and the surface of the material tested was analyzed by testing. The calculation result based on the output model found by the paper accord basically with the test result. The results of the test have showed that the measuring precision and sensitivity of the sensor can meet the demands of the general practical application.