Advanced Materials Research Vols. 295-297

Abstract: A more accurate simulation of the response to the structure under seismic load action can be generated through taking bi-directional seismic motion input into consideration. The commonly used four calculation methods of bi-directional input are adopted in this paper to compare the different dynamic responses of mega steel-frame structure to seismic load action. The paper also provides a method for choosing Raleigh damping coefficients applicable to the dynamic analysis of mega steel-frame structure.

Abstract: Comparing with the traditional welding technology, laser welding of the diamond core drill bit has much merit that easy to realize automatic control and the production efficiency is high. It is the important direction of originality innovation on the diamond tool. Aim at the characteristics that more specification, higher accuracy and bad welding of diamond core drill bit, the laser welding technology was designed by “uniform design”. The technological parameter of experiment was presented by uniform design software and abundant experience. The experiments show that the welding seam is smooth and the flexural strength is 2000 N/mm² which is higher as the European Designing Standard for the same product, and it is better than others in reliability safety and stabilization, when the welding speed is 1600 mm/min and the welding power is 1700 W. The study has significance of guiding and reference to the industrial production of diamond core drill bit.

Abstract: According to the analysis of a six-story reinforced concrete masonry building model with the methods of nonlinear time history analysis, the seismic performance of structure has been studied in this paper. The interstory shear-deformation and stiffness of linear elastic model is established. The availability of the analysis model, hysteretic model and relevant parameters adopted and the computation program developed are verified. The longitudinal deformation of structure is bigger than the lateral deformation under different earthquake waves, from this it can be showed that longitudinal seismic performance is smaller than lateral wall; for seven-story concrete block building with core-and tie-columns, the requirement of the seismic fortification intensity can be met. The analysis of this paper provides a reference for reinforced concrete block buildings.

Abstract: The poly(o-toluidine)/BaFe₁₀Al₂O19 (POT/BFA) composites were synthesized by in-situ polymerization of o-toluidine in the presence of BaFe₁₀Al₂O₁₉ particles. The structure, composition and morphology and electromagnetic property of the obtained samples were characterized by means of modern testing techniques. The results indicated that BFA particles were coated effectively by POT polymer chain and some interactions between POT and BFA particles were existed in the composites. The conductivity and saturation magnetization of POT/BFA composites were smaller than those of pure polymers and pure BFA respectively. The POT/BFA composites had excellent magnetic loss (μ′′) and dielectric loss (ε′′) in the range of 1 MHz~3 GHz because of their intrinsic properties and synergistic effect between components. Hence, they could be recommended as candidates for electromagnetic wave absorption and shielding materials.

Abstract: Fe-28Al and Fe-28Al-10Ti alloys were prepared by mechanical alloying and hot pressed sintering. The mechanical properties and wear resistance were studied. The results show that Fe-28Al bulk material is mainly characterized by the low ordered B2 Fe₃Al structure with some dispersed Al₂O₃ particles. The mechanical properties such as the hardness and strength of Fe-28Al-10Ti are significantly improved compared with Fe-28Al, which is attributed to the grain refinement and solid solution reinforcing with the addition of Ti element. The fracture mode is mainly the intergranular fracture. Fe-28Al-10Ti exhibits more excellent wear resistance than Fe-28Al, especially after long distance sliding wear test. There is difference in wear mechanisms of Fe-28Al and Fe-28Al-10Ti alloys. Under the load of 100N, there is obvious plastic deformation on the worn surface of Fe-28Al. Micro-crack and layer splitting occur on the surface of Fe-28Al. The main wear performance of Fe-28Al-10Ti is particle abrasion, the characteristics of which are micro cutting and micro furrows.

Abstract: For the purpose of combining the properties of polymethylsiloxane and fluorinated compound, hexafluorobutyl mathacrylate (HFBMA) was grafted to polymethylhydrosiloxane (PMHS) by hydrosilylation reaction in the presence of Karstedt’s catalyst. The prepared polymethylsiloxane with pendant fluorocarbon side chains (PMHS-g-HFBMA) was characterized by FTIR, ¹H NMR and TGA. The results showed that the expected product was successfully formed. The surface property and solubility of the product were also investigated.

Abstract: Carbon matrix/Carbon fibre reinforced composite(C/C composite) has many special characteristics such as high strength, high elastic modulus, high temperature resistance and ablation resistance. So it is used to manufacture rocket engine nozzle in aerospace filed. But its security will be seriously effected during rocket engine working due to the manufacturing defects. Based on analyzing defect types and structure characteristic of C/C composite, the ultrasonic and infrared testing methods on C/C composite are further studied in this thesis. And effective defect detection has been achieved.

Abstract: In this note, a class of gun control system of tank is considered with all uncertainties, such as unknown constant parameters, unlinearly parts, unparameterized parts, unmodeled parts, unknown external disturbance and so on. An robust adaptive control law is designed with backstepping technique. Compared to exist results on tank gun control problem , our control scheme combine the robust control and the adaptive estimator of unknown constant parameters and can compensate all uncertainties Accurately. The stability of closed loop system and the tracking performance can be guaranteed by this control law. Simulation studies show that this controller is effective.

Abstract: Two new conjugated copolymers, PFPh and PFTDP, comprised of alternating 9,9-dioctylfluorene and phthalimide (Ph) or thieno [3, 4-c] pyrrole-4,6-dione (TPD) have been synthesized via Suzuki coupling reaction. Polymeric light-emitting diodes (PLED) were fabricated with an ITO/PEDOT: PSS/PVK/Polymer/BCP/Alq/Ca:Ag configuration. The maximum brightness and maximum current efficiency of PLED are 2600cd/m² and 2.52 cd/A for PFPh, and 2300cd/m² and 1.13 cd/A for PFTDP, respectively, which are significantly improved compared with the reported alternating fluorene-unsubstituted phenylene/thiophene systems.

Abstract: The aim of this paper is to discuss the application of ethanol-dissolved lignin in preparing high value products. Lignin was extracted from wheat straw by ethanol and used to prepare water-based UV-curable polyurethane. The preparation of water-based UV-curable polyurethane was completed by a three-step reaction. Besides lignin, toluene- 2, 4- diisocyanate (TDI), dimethylolpropionic acid (DMPA), 2-hydroxyethyl acrylate (HEA) and polyether glycol (PPG) were used. The effect of lignin content on the synthesis process was studied. The prepared lignin polyurethane was neutralized with tertiary amine (TEA) and dispersed in water. The properties of the final product, for example, rheological property, average particle size, UV-curing ability and mechanical property, etc. were characterized. Results indicated that the lignin polyurethanes could cure quickly and the presence of lignin with a proper proportion during the synthesis had a positive effect on the tensile strength of cured film.