Advanced Materials Research Vol. 904

Abstract: PbTe nanocrystals (NCs) have been synthesized by a novel method at low temperature. Pb acetate being solved in glycerol and Te in TOP solution were used as the precursors for the preparation of PbTe nanocrystals. The as-prepared products were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), UVvis absorption, Fourier transform infrared spectroscopy (FTIR). These data, together with analysis of the absorption spectra, allowed us to observe the size dependence of the peaks in the absorption spectrum. The size-dependent optical spectra of the PbTe nanocrystals exhibits wide tunable band gap energies varying from UV visible range to near IR region, which corresponds to a huge blue shift of 3.0 eV in comparison to the bulk counterpart. Keywords: 1. PbTe nanocrystals, 2. optical properties, 3. wide tunable band gap, 4. microstructure

Abstract: The aim of this article is to research the characteristics of corrosion pit on 2xxx aluminum alloys in different environments (3.5wt% NaCl solution, water in fuel tank and wet air). Measure the area of corrosion pit, the depth of corrosion pit in different environments. The results show that in 3.5wt% NaCl solution: the initiation of surface corrosion pits mainly occur in 24h, with time increasing ,the depth of corrosion pit rises indistinctively; in water in fuel tank : during 24h-120h, with the extension of corrosion time, the maximum depth of corrosion pits changed a little, the maximum corrosion area became a little smaller than that in 3.5wt% NaCl solution; in wet air: the corrosion damage was smaller than that in 3.5wt% NaCl solution and water in fuel tank, the depth of the corrosion pit was about 20μm, the biggest size of corrosion pit area was about 0.5 x10⁴μm².

Abstract: Multi-functional CoNiAu nanoparticles were successfully synthesized via nanoemulsion method with the use of PEO-PPO-PEO as the surfactant, C₁₄H₂₉CH(OH)CH₂OH as the reducing agent, Ni (acac)₂, Co (acac)₂ and Au (ac)₃ as precursors. The characterization of the CoNiAu nanoparticles was performed using X-ray powder diffraction (XRD), fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), vibrating sample magnetometry (VSM) and UV-vis near IR spectrophotometer (UV-vis). The XRD and TEM analysis confirm the formation and structure of the nanoparticles. The UV-vis and VSM measurements display the optical and magnetic properties of the CoNiAu nanoparticles at the room temperature. The CoNiAu nanoparticles with the well defined optical and magnetic properties are promised for optical, magnetic, catalytic and biomedical applications.

Abstract: In this paper, the low cycle fatigue (LCF) behavior of Q345b steel was experimentally investigated in fully reversed cyclic axial configurations at room temperature. The strain range of 0.3%, 0.4%, 0.5%, 0.6% and 0.7% at constant strain rate of 0.005 s^-1 was adopted. Cyclic stress-strain curve and strain life relationship were analyzed according to the Ramberg-Osgood relationship and Coffin-Manson relationship respectively. Suitable parameters were obtained showing good agreements with the experimental fatigue data.

Abstract: A new coumarin derivative L was synthesized and characterized by ¹H NMR, ¹³C NMR, IR and mass spectrum. UV-Vis and fluorescence emission spectra of L without or with different anions (NO₂, F, Cl, HSO₃, HSO₄, AcO or NO₃) or metal ions were measured, which showed while addition of anions or metal ions Mg²⁺, Zn²⁺, Ca²⁺, Cu²⁺, Ni²⁺, Co²⁺, Fe³⁺ or Al³⁺ led to decrease in intensity of the maximum emission peak at about 480 nm, addition of Hg²⁺ ions caused increase in intensity of the maximum emission peak, suggesting that L may act as a fluorescent probe for detection of Hg²⁺ ions.

Abstract: Fe-20wt%Cu-Al braking materials were prepared by induction heating sintering method combined with the Copper cladding iron matrix with various aluminum elements. Effects of Aluminum on surface morphology, Mechanical and frictional properties of Cu-Fe-based Braking Material were analyzed by Scanning Electron Microscope (SEM), machine test and friction-wear test. Lastly suitable parameters of the process are decided. Meanwhile, wear mechanisms were discussed. The results showed that the prepared shaking materials with aluminum content of 3wt%, silicon carbide content of 5wt%, manganese and chromium content of 5wt% and copper cladding iron power content of 87wt% had excellent performance.

Abstract: Abstract. Iron oxide particles with spherical, date-pit like, or polyhedron morphology were obtained by hydrothermal method. The morphology, thermal analysis, crystal structure of the products was characterized by FESEM, thermogravimetry (TG), X-ray diffraction (XRD), respectively. The measured results reveal that the product of three different shapes is hematite (α-Fe₂O₃).

Abstract: A novel PPy/P(BA-co-AA)-g-PMMA-GMA (terpolymer) composites were prepared and the preparation conditions, characterization and properties of the composites were investigated. The results indicate that the oxidant types, molar ratio of oxidant/monomer, polymerization time, PPy content affect greatly the conductivity of the PPy/terpolymer composites. The ultimate elongation of composites decreases with increasing PPy content,while high PPMM content brings forth high tensile strength.

Abstract: This paper analyzes the whole deterioration process of the concrete structural performance caused by reinforcement corrosion, and given the three setting conditions which are corrosion cracking conditions and collapsed condition, and the corresponding performance function for such structural durability limit state. The relevant content can provide a reference for the design of structural durability and related specifications.

Abstract: The recent dramatic progress in the printed electronics and flexible electronics, due to the universality of the substrates including the foldable and stretchable substrates, has opened a new prospect in the field of future electronics. In this paper, silver nanospheres in large-scale are synthesized, the nanosilver ink with 63.88% silver content are prepared and a new type of highly conductive and far identify distance RFID tags are manufactured. Especially there are no resin and other additives containing in our conductive ink which satisfy the rheological characteristics and process of screen printing. The tags exhibit the best radiation performance own to there is no high temperature sintering in need. The surface resistance of the tags could be 80 mΩ/, and the identify distance reach to 6.0m. Keywords:silver nanoparticles, conductive ink, RFID tags