Advanced Materials Research Vols. 912-914

Abstract: In this paper, the hollow or porous carbon nanofibers based on the PAN with high molecular weight were manufactured through concentric electrospinning. The PAN terpolymers with the viscosity-average molecular weight of 30 kDa were synthesized via aqueous precipitation polymerization. Then the prepared PAN was dissolved in DMF to afford the shell. Two kinds of solutions, silicone oil and the 10% PVP DMF solution, were used as the core. After the concentric electrospinning, the obtained core-shell PAN nanofibers exhibit the different morphology. Compared with the 10% PVP DMF solution as the core, the silicone oil as the core led to the greater and more uneven in diameter. After the oxidative stabilization and carbonization, the PAN based carbon nanofibers (CNFs) showed the obvious hollow cores no matter the silicone oil or 10% PVP DMF solution is in core. When the silicone oil is in core, the profiles of the PAN based CNFs reveal the better fibrous shape and thinner diameter. Furthermore, a mixture of PAN and PMMA with the molecular ratio of 1:1 in shell and the 10% PVP DMF solution in core were also concentrically electrospun. FESEM reveals that the addition of PMMA made the nanofibers more even and thinner diameters. After carbonization, the resulted PAN based CNFs show the porous cross-section.

Abstract: Low-temperature fuel cells have been attracting more and more attentions for the direct conversion of chemical energy into electricity. Efficiencies of fuel cells to a great extent depend on the activity of the catalytic platinum and its alloys. Increasing the reaction surface area and decreasing the diameter of platinum particles can enhance the activity of the platinum. In this paper, we report a platinum catalyst supported on porous carbon nanofibers. Two kinds of PAN terpolymers with various molecular weights of 15 kDa (PAN-1) and 30 kDa (PAN-2) were first prepared by aqueous precipitation polymerization. The mixtures of PAN with various molecular weights and PMMA were then electrospun, stabilized and carbonized to provide the porous carbon nanofibers. It was found that the PAN with lower molecular weight results in the even fibrous surface and thick diameter, indicating a stable spinning process. Moreover, the PAN-based carbon nanofibers were immersed into a platinum complex solution to support the platinum positive ions. After calcination, the platinum ions deposited on the carbon nanofibers were converted into nanoplatinum particles to provide the platinum catalyst supported on the porous carbon nanofibers.

Abstract: Fe₃O₄@β- cyclodextrin magnetic functional nanometerials have been successfullysynthesized and developed as a magnetic solid phase extraction for thedetermination of trace Cu(II) in environmental water samples. The resultsindicate that:adsorption rate is effeceed by pH、temperature、time and capacity .And at pH of 7 and 55°C,the adsorption rate ofβ-cyclodextrin Fe₃O₄ magnetic microspheres to Cu(II) canup to 97%, and static adsorption capacity was 28.51mg/g.Besides,someenvironmrntal samples’s results were satisfacting as recovery is in the rangeof 95.9%-102%.

Abstract: Diamond-Like Carbon (DLC) films were deposited on quartz substrates by using a gas mixture of hydrogen-methane-oxygen in the Star-Shape Microwave Plasma enhanced Chemical Vapor Deposition (MPCVD) reactor. The pretreatment parameters include the pretreatment methods and the pretreatment time was optimized. Results showed that ultrasonically abrasive in the acetone solution with nanocrystalline diamond powder in it was an efficient pretreatment method to advance the deposition of DLC films, and 10 minute turned to be the most appropriate time for this pretreatment. The Fourier Transform Infrared spectrometer (FTIR) showed that the DLC films synthesized by the optimized technics have high transparence fit for optical applications. These indicated that the Star-Shape MPCVD reactor was the perfect equipment for the volume-produce of DLC films for its unique big reactive cavity.

Abstract: cooler failures and accidents by about 60% due to the cooling equipment for corrosion and leakage Suozhi bundle . Rational use of cooling equipment for bundle material for cooling equipment for corrosion , corrosion in different environments , using different strategies to reduce corrosion , and achieved good results and significant economic benefits.

Abstract: Since Menggulin reservoir fully been developed in1990, profile control technique is widely used for improving water swept volume. After multiple rounds and large-scales of polymer flooding by materials mixed with sol-gel and Yellow River clay, the formation damage such as depth blockage and stemming become more and more serious.According to statistics, in 2012 there are respectively 10 and 11 water injection wells happened with back flow of profile control agent and wells pressure higher than fracture pressure that without injection. The original reservoir permeability is good, and individual well production has the capacity of 40 to 50m³/d. Yet recently several oil wells almost have fewer even no liquid output due to the blockage and stemming. Estimated by a typical well group,the speed of sol-gel drive increased from 10 m/year to 50~60 m/year, and average water injection pressure were up to 16MPa which almost double original pressure while the only 2MPa pressure corresponding to oil wells. Hence, it show that the severe depth blockage of the formation exactly exit in Menggulin reservoir.

Abstract: The Cylinder liner is one of the working environment of the worst parts in internal combustion engine ,it is required to have good wear resistance, corrosion resistance, resistance to high temperature and high pressure shock, etc. After tests showed, better comprehensive mechanical properties of cylinder liner is got by using Plasma Spray composite ceramic nanometer coating technology, and after laser remelting treatment.

Abstract: Nanotechnology decides the ability of human manipulation of the atoms and molecules, the goal is to master the ability to create new material and design to create the desired application products, and nanomaterials is the basis of the integration of a variety of nanotechnology. The connotation and development prospect of nanotechnology are introduced. The present status and the research emphasis in every stage of the nanomaterials are pointed out and nanomaterials are classified according to the different way. The characteristics of all kinds of nanomaterials and applications in all fields are analyzed.Key words: Nanomaterials; Nanotechnology; Fullerenes; Graphene; Carbon nanotubes

Abstract: Rapid prototyping and the silicone mold are more and more widely used in the process of new product development, it has become the hotshot in this field. With the method of single factor experiment and using rapid prototyping based on FDM technology as a master pattern,several main factors influence the dimensional precision molding products is analyzed and the redeem measures are put forward during silica gel mold casting process. The study has importance in guiding the practical application of the silicone mold casting products and provides the experimental basis on research and development to silicon mold technology.

Abstract: The Experiment studies onthe welding technology and the process phenomenon of zirconium 702. The resultsshow that it can obtain high-quality weld seam to strictly clean before welding,to use the special tooling for being protected by high- purity argon, to selectthe reasonable technologicalparameters of tungsten argon arc welding,and to reasonably process groove forms.After welding, thetest plates are all qualified in the visual inspection,PT, RT, mechanical property test, the macro-metallographic test and corrosiontest.