Abstract: Lead-free (1-x)(Na0.5K0.5)NbO3-x(Na0.5Bi0.5)TiO3 (x=0.02, 0.04, 0.06, 0.08, and 0.10) ceramics have been prepared by the conventional mixed oxide process. For 0.98(Na0.5K0.5)NbO3-0.02(Na0.5Bi0.5)TiO3 ceramics, the electromechanical coupling coefficients of the planar mode kp and the thickness mode kt reach 0.33 and 0.62, respectively, after sintering at 1100°C for 5 h. The ratio of the thickness coupling coefficient to the planar coupling coefficient is 1.88. Our results show that 0.98(Na0.5K0.5)NbO3-0.02(Na0.5Bi0.5)TiO3 solid solution ceramics are promising lead-free ceramics for high-frequency electromechanical transducer applications.
Abstract: For saving much workload of calculation and avoiding some computation mistakes, order-flexibility method is presented in this paper.
Abstract: During water-exit of underwater vehicle, the high pressure， which the local cavity collapse of underwater vehicle causes, poses a great challenge to the vehicle structure. The cavity collapse during vertical water exit of an underwater vehicle is simulated by a viscous flow solver with homogeneous multiphase flow model. The shrinkage and collapse of cavity zone and violent changes of the pressure field have been captured during the simulation. The changes of cavity shape and pressure field at different water exit velocity have been analyzed. It has been concluded that higher velocity may cause the delay of cavity total collapse and the max pressure point to transfer backwards.
Abstract: There are some differences between traditional fine blanking and closed extruding fine blanking in stress, separation process and change of material's performance. The article researched the micro-state's characteristics and deformation law in closed extruding fine blanking process, through observing the closed extruding fine blanking parts' metallographic, flow lines of deformation zone and analyzing the micro-hardness.
Abstract: Flotation is a conventional way for treating low grade metal oxide ore which has some advantages such as high efficiency and low cost. In order to recover the zinc from a low grade complex zinc oxide ore in which the grade of Zn is 13 wt.%, this paper presents a preliminary investigation of this type of ore by flotation method. In the experiments, the effects of different parameters such as grinding fineness, amount of Na2SiO3, amount of Na2S and amount of octadecylamine were investigated in relation to the metal contents of concentrates. The results show that about 35% of initial Zn content was obtained with 70% -200 mesh grinding fineness, 1000g/t Na2SiO3, 2000g/t Na2S and 500g/t octadecylamine. It is clear that the preliminary flotation tests with the ore sample indicated that there was no selectivity in terms of zinc recovery. Almost 65% zinc remained in the tailings and could not be recovered by flotation due to its complicated mineralogical structure. Therefore, application of metallurgical processes is proposed for zinc recovery from the tailings in the following investigations.
Abstract: This template takes the 30 completely state-owned and the scale above the manufacturing industry professions as the object of study, has surveyed the manufacturing industry entire essential factor productivity index, the technology advancement index and the technology efficiency index with the Malmquist productivity exponential method. The conclusion believed that Manufacturing industry showed continued growth in total factor productivity trends, mainly due to the raising level of technological progress, while the scale efficiency and pure technical efficiency was manifested as decreased.
Abstract: In this paper aerobic process was applied in an anaerobic baffled reactor to form an innovative Hybrid Baffled Reactor (HBR), which was used to investigate the treatment effect of livestock and poultry farming wastewater. Biofilm cultivation, the influence of Hydraulic Retention Time (HRT) and treatment effect in three tanks were also discussed. The study result showed that good COD and NH4+-N removal efficiency was achieved in the reactor. When the influent COD concentration, NH4+-N concentration and HRT were 900 mg/L, 200 mg/L and 24 h, the concentrations of COD and NH4+-N in the outlet were smaller than 100 mg/L and 70 mg/L, and COD removal efficiency and nitrification rate were 90% and 70% respectively.
Abstract: The purpose of this study is testing the force of green energy lift mechanism and analyzes its result to get the key technology for green energy (saving force and energy). At first, the green energy lift mechanisms on the market are surveyed, then the mechanism are analyzed in this study. The force balance system of the mechanism is used to save force and energy. The position limitation of saving force and energy for the force balance system will be investigated. Universal testing machine is used to test the driving force by the different loads during the lift mechanism moving downward. The tested results of the driving force will be estimated. The study results show that the loads influence significantly the driving force. The angle between pulley and wire is the key factor of the driving force.
Abstract: Full scale Ningxia super high-rise steel TV tower (NXTVT) model is established in the numerical simulation to investigate the flow field around it. And then, the UDF program of mean wind section plane, turbulence kinetic energy and turbulence dissipation rate were compiled. The flow fields under these two typical inflow conditions, 30 degree is chosen as the field measurement data. The results show that both the RNG model and the Realizable model can simulate the distribution rule and similarity. Both can give reasonable turbulence kinetic energy distribution in the region of windward sharp edge, where flow separation occurs. Subsequently, the mean pressure field with certain precision can be obtained in the highly turbulent negative pressure region.
Abstract: Depolymerization of thermosetting epoxy resin with environmental-friendly heteropolyacid catalyst at temperatures between 270°C-350°C in H2O medium. The effect of the factors catalyst, temperature and time on the depolymerization was researched. UV spectrum was used to characterize the thermal stability of heteropolyacid catalyst. The products of depolymerization were analysed qualitatively and quantitatively by means of GC/MS and GC. The results indicated that the main depolymerized products were phenol, p-isopropylphenol and bisphenol-A (BPA). The results showed adding heteropolyacid contribute to enhancing the rate of depolymerization and increasing the yield of BPA. Also, the depolymerization kinetics of epoxy resin was researched and the activation energy was calculated.