Advanced Materials Research Vol. 787

Abstract: As a kind of high performance concrete material in the construction of structure engineering, the concrete containing nanoparticles has been paid more and more attention to and used in the field of high and long span buildings because of good mechanical performance and durability performance. In order to in-depth understand the characteristic of the concrete containing nanoparticles and promote the application of the concrete containing nanoparticles in practical engineering, a series of research works on the mechanical properties and durability of the concrete containing nanoparticles were summarized based on the current study results. Furthermore, the research trend of the concrete containing nanoparticles was presented.

Abstract: CdS has been synthesized electrochemically on multi walled carbon nanotubes paste electrode (MWCNPE) from aqueous solutions consists of Cd²⁺ and S₂O₃^2- at40°C, using potentiostatic technique.Cyclic voltammetric response of thiosulfateand Cd²⁺ individually and together has been investigated. The optimum conditions of CdS electrodeposition were determined. Interesting data were obtained and discussed in this work. The mechanism of CdS electrodeposition was suggested. Moreover, the electrodeposited CdS is of n-type semiconductor. Ithas been investigated by the Mott-Schotky test, and also the concentrations of donors (N_D) were determined.

Abstract: A microsphere trapped by optical tweezers moves according to the Brownian motion law, which can be described by the Langevin equation. Based on it, a quadrant photodiode (QD) is used to track the displacement of the microsphere with a diameter of 2.5um trapped by holographic optical tweezers, and power spectrum method is adopted to obtain radial trap stiffness. Experiments show that the trap stiffness increases with the increase of the laser power, and decreases as the distance between the optical trap and the inside bottom surface of the sample cell increases.

Abstract: We report the synthesis of ZnO nanowires grown on glass using a two-step process: (a) preparation of the seed layer, and (b) growth of the nanostructures. First step:solutions of zinc acetate dehydrate and 1-propanol of 10 mM concentrationwere spin coated on glass at 2000 rpm for 58 s. A seed layer was obtained after three layers of spin coating. Second step: vertical ZnO nanowires were grown by dipping the substrate in a 25 mMequimolarsolution of zinc nitrate hexahydrate and hexamethylenetetramine. Subsequently, films were thermally treated with a commercial microwave oven at different power settings (350 and 700 W) for 5, 20 and 35 min. The ZnO nanowires obtained were characterized optical and morphologically. Scanning electron microscopy analysis showed that the size of ZnO nanowires was less than 50 nm in diameter and around 500 nm in length. XRD patterns revealed that when low power in the microwave oven was utilized, the presence of Zn (OH)2 on the films is observed. The ZnO nanowires bandgap energy was obtained from optical transmission spectra.

Abstract: Emulsion electrospinning is a novel and straightforward tequnique to fabricate core-shell structured nanofibers on the basis of conventional electrospinning method. In this paper, the emulsion electrospunnanofibers were electrospun, and further characterized by scanning electron microscopy (SEM), Laser confocal scanning microscopy (LCSM) and water contact angle. The drug release property of emulsion electrospunnaofibers up to 28 days were recorded and analyzed. The biocompatibility of the emulsion electrospunnanofibers were evaluated and confirmed by MTS assay.

Abstract: The static characteristic of a horizontal composite mooring system for wave measuring buoy is studied using 3D potential theory and catenary theory. The 3D hydrodynamic model is built for surface pontoon and wave measuring buoy to calculate the mean steady drift forces and response amplitude operators. Combined with extreme environmental conditions and catenary theory, static analysis of the mooring system is done, obtaining the results of line tension, catenary shape and safety factor etc. The research results show that the horizontal composite mooring system meets the design requirements and it is proven to be an effective mooring method for the sea area with large current velocity.

Abstract: The structure and processing of double chamber throttle valve body castings were analyzed. Die-casting molding process scheme was established. The design of mold includes three core-drawing mechanisms. Considering the large parts surface area and the relatively small wall thickness and the requirement of parting, the gate was arranged on the casting bottom surface. For economy and die easy maintenance considerations, die-casting machine, mold, and mold standard parts should be standard parts. The designs of mold gating system and non-standard pieces were completed. Proved by actual production, the mold operated smoothly, without clamping stagnation, and the production of die castings meet delivery requirements.

Abstract: Shooting nails are mainly applied to fix thin reinforced concrete and steel plate, so the nails should have high hardness and high toughness. Unreasonable heat treatment process could possibly cause too high hardness and decreased toughness, leading to nail cracking and fracture in the course of production and use. Research on heat treatment process through experimental study on the nail determines the reasonable heat treatment process of nail. The feasible quenching heating temperature was 847~840 °C, and the temperature of salt bath during isothermal cooling was 292 °C. Its resultant hardness was 680HV, meeting the requirements of the use of nails. The shoot nail cracking and fracture in the course of use can be avoided effectively. The microstructure of shooting nails after heat treatment showed lower bainite, which contributed to good mechanical properties.

Abstract: A three-dimensional dynamic simulation model of the molten iron flow field was presented in the paper with Fluent simulation software. Different operating parameters combinations, including different oxygen lance locations, oxygen pressures and oxygen flows, different arrangements of bottom blowing holes, hole sizes, nitrogen pressures and nitrogen flows were studied. It is shown that the relative optimum value of the distance from top-blow gun to the molten iron surface is 1500 mm, and bottom blowing hole diameter is 20mm, there is no significant difference of the blowing effects found when comparing single ring arrangement with double rings arrangement of 8 bottom blowing holes with only bottom-blow, and the bottom-blow of inner ring is disturbed by top-blow when top and bottom combined blow. Optimized design results have been applied to the design and manufacture of the actual converter, the converter has been successfully used in plant. The actual production results indicate that the desiliconization precision can reach 0.05%, the content of Cr₂O₃ in the slag after reduction can be less than 2%, better than the technical requirements of 3%, and improve the recovery rate of the chromium. Compared with traditional desiliconization method by iron gutter and iron ladle, desiliconization by converter does not use compression residue agents and reduce the amount of desiliconization agents and slag, and improve the desiliconization efficiency and productivity.

Abstract: This paper demonstrates a design of double-layer copper sheet suitable for RFID tags antenna called extended double-layer flexible strip dipole antenna. RFID tag antenna is widely used with different surfaces. The result found that RFID tag antenna can be bended or curved responding to the cylinder shape of the objects. Our proposed extended double-layer flexible strip dipole antenna has been technically designed to make changes on itself to obtain the result in increasing resonance frequency when it is being bended. The key concept of the study is the designed antenna which can freely change inside each layer when applying itself on curved object. The result of this design reveals that antenna has better performance than modern antenna. The extended double-layer flexible strip dipole antenna for RFID tags was designed for resonance frequency of 2.45 GHz. Consequently, the analysis of antennas efficiency will be affected by thickness. The designed antenna there will be considered and discussed to find out the relative value in order to use creating the design for the antenna that is suitable for the further study.