Advanced Materials Research Vols. 160-162

Abstract: Spinel LiMn2O4 powders have been prepared at 500 for 5h by solution combustion synthesis in water or ethanol system, using lithium and manganese acetate as raw materials and no fuels. The structure and morphology of the products have been analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The electrochemical performance has been charged or discharged in coin-type battery. XRD analysis indicates that the purity and crystallinity of the product prepared in ethanol are much better than these of the product prepared in water. SEM investigation indicates that the particles of the product prepared in ethanol are smaller and more dispersed than these of the products prepared in water. The product prepared in ethanol also exhibits better electrochemical performance than that of the product prepared in water. The initial discharge capacity of the product prepared in ethanol is 120mAh/g, and remains 110mAh/g after 20 cycles, at a current density of 50mA/g and in the voltage range of 3.2-4.35V.

Abstract: A method for material fragmentation based on Lagrangian FEM with the concept of nodes separation is proposed. This method is consisted of nodes separation mechanism and elements distortion erosion. In the simulation the nodes of failure elements are separated to form crack and distorted elements are detected and eliminated to prevent singularity. Nodes separation method can greatly improve the energy loss disadvantage in the failure erosion method. Based on LS-dyna secondary development the method is implemented. Hypervelocity impact problem of satellite protective structure is simulated and compared to experimental data for calibration. The performance of multi layer aluminum mesh shield under hypervelocity impact is also evaluated. The results show the high efficiency and applicability of nodes separation method in practical problems.

Abstract: From the perspectives of modularization disassembly, the influence of entity structure, function, motion and other factors of product brought to disassembly efficiency is elaborated. A way to improve design facing modularization disassembly is proposed. The time and cost of disassembly are checked by the proposed method through examples. Comparisons of disassembly evaluation before and after improvement are conducted based on the results. The general method to improve design is summarized. In terms of differences of repair probability of key parts in maintenance process, the improvement design criterion is put forward in the method, which improves the maintenance efficiency, reduces the maintenance cost and difficulty of disassembling operation and avoids data explosion of disassembly sequence because of too many parts.

Abstract: For high strength LTWBs used widely in light-weigh auto body production, warm forming process has become an effective solution to improve their forming performance and reduce springback. While the flow-stress model of LTWB warm forming is vital to determine reasonable warm forming process scheme, and predict precisely LTWB forming status and springback. In the present work, aimed to 1mm thickness DP steel LTWB (B340/590DP), a warm tension flow-stress model is proposed based on KS function and bi-linear interpolation by analyzing characters of the stress-stain curve obtained from warm tension test. Via comparing the model prediction results with those of other existing flow-stress models and experiment data, it is verified that the proposed model can not only give more closely the stress-strain relationship than other models during uniform plastically deforming and plastic yielding, but also can indicate the occurrence of necking phenomenon.

Abstract: The structural, electronic and optical properties of a tantalum doped rutile-phased stannic oxide were investigated by ab initio calculations. The Ta dopant doesn’t change the lattice symmetry of rutile phase, but brings about a smaller volume expansion comparing with Sb:SnO2, a increase in thermal stability, a semiconductor-metal transition in electronic structure and a red shift in the optical spectrum. The intra-band excitation caused by Ta dopant leads to to a remarkable enhancement of optical peaks in the infrared region, while the stability of optical spectrum in the visible light region supports the preservation of high visible transparency of Ta:SnO2 with dopant concentration as high as 4.17 at.%.

Abstract: We investigated that the bioefficacies of cinnamon oil and insecticide based on the mixture of porous starch and cinnamon oil. They were evaluated for their insecticidal activities and their mortality on adults of Sitophilus zeamais. Fumigant toxicity assayed by hanging in glass jars showed that these chemicals caused significant mortality of the test insect. Cinnamon oil evoked high repellent action and high fumigant toxicity (LD50 = 0.030μL/cm3) against adults of Sitophilus zeamais. The two concentrations of the new insecticide 0.030μL/cm3 (LD50) and 0.040μL/cm3 (the highest) lose their insecticidal activity after a minimum of 144h and 168h, respectively. These results suggest that cinnamon oil starch powder is the most effective insecticide, and could increase its efficacy for use as an alternative to synthetic insecticides.

Abstract: In recent years, the trend of eutrophication appeared in Erhai and the phenomena of small-scale algae outbreak has already happened. Erhai Lake pollution caused by many reasons.As an important factor of Erhai lake eutrophication, superabundant manure stacking at random in rural areas of Erhai Lake Basin and transference of the manure nitrogen and phosphorus into waterbody have attracted much attention of environmental researchers eutrophication of Erhai lake. The nitrogen and phosphorus contentes of livestock manure in the process of naturally composting were mensurated and the transference characteristics of the manure nitrogen and phosphorus were analysed. As a result, the regular pattern and loss type of livestock manure were advanced and advices about developing solid waste treatment facilities were brought forword.

Abstract: In order to investigate the supramolecular assembly and intermolecular hydrogen bonding of special amphiphiles, two bolaform amphiphilic Schiff bases (GN1 and GN2) with different hydrophilic spacers were designed, and their supramolecular assembly and interaction properties were investigated by spectral measurements. It was found that both the Schiff bases showed hydrogen bonding interaction with barbituric acid. In addition, it was interesting to note that the spacer groups of the molecules had effect on the molecular ratio in the hydrogen-bonded complexes. Due to the directionality and strong matching of hydrogen bond, one barbituric acid molecule can be encapsulated into the intramolecular area of GN1, while two barbituric acid molecules were trapped into the GN2 molecule through intermolecular H-bonds for GN2 due to the long spacer and flexible structure. A rational complex mode was proposed.

Abstract: Zinc silicate-based (Zn2SiO4:Eu3+) long afterglow phosphors were produced by solid state reaction method. The effects of borax and Eu2O3 additive on the properties of fabricated products have been studied. The results show that, there is not much difference in phase compositions within the borax additive amount; however, their SEM morphologies are different. Borax additive can increase the grain size of the product. Some sintering phenomena could be observed in the sample with Eu2O3 addition. The fluorescence spectroscopy results indicate that, the emission peak of the sample with Eu3+ additive located at 612nm, which may be a good candidate for red phosphor applications. The luminescent mechanism of Zn2SiO4:Eu3+ is also discussed.

Abstract: The dynamic constitutive model could show the dynamic characteristics of soil, so it was essential in ground motion in earthquake safety evaluation and seismic response analysis of soil, and it had great influence on research and analysis of seismic performance of soil and the stability of the foundation. Sandy pebble soil distributed abroad in Sichuan, so it was widely used in engineering construction. Based on the test results of dynamic triaxial non-drain consolidation test，this paper studied the dynamic constitutive model of saturated sandy pebble soil to provide reference for the future use.