Advanced Materials Research Vols. 532-533

Abstract: TiNbTaZr alloy is potential medical biomaterials, due to its high strength, low elastic modulus, superelasticity, superplasticity, and many other excellent performances. TiNbTaZr rolling samples under solid solution state and deformation state were characterized by TEM and XRD technologies. The results show that the alloy has the grain size of 42mm, straight of grain boundaries, intragranular no significant defects after solution heat treatment at 1063K. When the deformation reaches 40% in the rolling process, the local zones in intragranular appears high density of dislocations and a small amount of twinning. When the rolling is to 92%, the high density of dislocation cells forms nano subgrain block in sample with {100} plate texture and the texture axis of {100} plate under density of 2.29.

Abstract: Si/carbon nanofibers (Si/CNFs) composite used as the anode materials of lithium-ion battery have been prepared via electrospinning and calcinations treatment. Hydrofluoric acid is used to remove surface oxides of Si particles. SEM observation indicates that silicon particles are uniformly embedded in the carbon nanofibers. X-ray diffraction (XRD), energy dispersive x-ray spectroscopy (EDX) and Raman scattering have been used to analysis the composition and phase of the composite materials. The first reversible capacity of the Si/CNFs composite is 1004 mAh/g, and 390 mAh/g has been remained after 100 cycles. Such Si/CNFs composite could be a promising anode material in lithium ion batteries.

Abstract: Fluorene derivatives are typical semiconductor materials. The electronic structures of Fluorene derivatives were successfully investigated by density functions theory (DFT). Furthermore, the HOMO and LUMO energy levels will be changed owing to the introduction of some aliphatic chains in the fluorene. So through theoretical investigation of electronic structure and molecule orbit by the DFT method, the variational UV-vis absorption spectra of fluorene derivatives due to variational levels were explained.

Abstract: By using floret silk/cotton blended yarn, high-tech knitting technology and strict technical procedure, we designed and produced knitted sports socks. We had a series of test of socks' wearing capabilities, including tensile, burst, wear-resistant, air breathable, moisture permeable, anti-pilling property. Testing results showed that floret silk/cotton sports socks were comfortable and durable enough to wear.

Abstract: The researches of non-oriented silicon steel are mainly focused on the effect of main processing parameters on the microstructure and magnetic properties, but there have been few studied about its flow stress until now. In this paper, the hot deformation of non-oriented silicon steel 50A1300 is studied by thermal-mechanical simulation method. The hot deformation behavior of the steel is explored and the flow stress prediction of the steel is established based on a kind of BPA ANN. A piecewise method is proposed in this paper, and the prediction with this new method has good accuracy.

Abstract: To investigate the wounding effects in human on the basis of the similarity theory, by taking the temporary cavity as the research object, through the analysis on the forming of cavity and its physical process, main influencing factors effecting temporary cavity are obtained, which can provide a good theoretical basis for similarity research in wounding ballistics in the future, and the killing effect of the high speed steel ball is more deeply described.

Abstract: Rude ores, which were collected from two lead-zinc oxide ore deposits in Sichuan province, are very difficult to process with low grade and uneven mineral dissemination. It is very difficult to separate valuable minerals from gangue minerals, especially for the recovery of lead and zinc minerals. On the basis of mineral characteristic study, author studied flotation technology on lead-zinc mineral, and gained satisfactory concentrate indicator by stage-grinding: the lead concentrate with a grade of 52.45 percents and a recovery of 79.30 percents and the zinc concentrate with a grade of 35.26 percents and a recovery of 87.57 percents .

Abstract: An approach of preparing single polymer composites (SPCs) by injection molding was demonstrated. Polypropylene (PP) was used as a model system to investigate this method. The thermal properties of PP granules and PP fibers were analyzed by Differential Scanning Calorimeter (DSC) to determine the processing temperatures. The flexural test of PP SPCs showed that the flexural strength was obviously improved compared to the non-reinforced PP. The results also indicated that the injection pressure, holding pressure and nozzle temperature greatly affect the flexural strength of PP SPCs. The microstructure observation showed no gaps between fibers and the matrix by using Scanning Electron Microscopy (SEM). The matrix melt was able to penetrate into fiber webs and the two materials had good interfacial compatibility.

Abstract: The deliming experiment of limed pelt for leather-making was carried out by means of formic acid, sulfosalicylic acid, citrate acid, Nylon acid, gluconic acid and other nitrogen-free materials. The impacts of the pH of deliming liquid and the content of calcium ion in the deliming liquid on the deliming effect were investigated. In order to further improve the deliming effect of the material, the nitrogen-free organic acids above were subjected to composite research, wherein the results thereof showed that the deliming values of sulfosalicylic acid, formic acid and citrate acid were relatively high, the deliming abilities were relatively strong, but the buffer during the deliming process was not obvious; the deliming values of Nylon acid and gluconic acid were not relatively high, but the deliming process had a certain buffer; and the deliming effect of composite formic acid and gluconic acid was very good. Compared with the conventional deliming agent (NH₄)₂SO₄, the composite deliming agent not only could remove the pollution caused by ammonia nitrogen in the deliming wastewater and greatly reduce the S^2- in the wastewater, but also could effectively reduce COD_Cr and BOD₅ of the deliming effluent.

Abstract: Ni-doped diamond-like carbon coatings were deposited on silicon wafer by magnetron sputtering. The Ni content was controlled by changing the Ni target current. The Ni content, mechanical properties and tribological properties of the coatings were systematically studied by Raman spectroscopy, nano-indentation and ball-on-disc tester. The highest hardness and internal stress are obtained at the Ni content of 2.3%. The friction coefficient and wear rate lower with the decreased of the Ni content, which may be responsible for the excellent tribological properties.