Advanced Materials Research Vols. 430-432

Abstract: This paper presents a new permanent magnet synchronous motor (PMSM) drive technique using adaptive state estimator for high-performance motion control to estimate the instantaneous speed, position and disturbance load torque. In the proposed algorithm, the model reference adaptive control (MRAC) method is incorporated to identify the variations of inertia moment, and the identified inertia is used to adapt the extended Kalman filter (EKF), which is an optimal state estimator to provide good estimation performance for the rotor speed, rotor position and disturbance torque with low precision quadrature encoder in a random noisy environment. In addition, the disturbance–rejection ability and the robustness to variations of the mechanical parameters are discussed and it is verified that the system is robust to the modeling error and system noise. Simulation and experimental results confirm the validity of the proposed estimation technique.

Abstract: Studying on the mechanism and device for high-melting-point metals droplets deposition technology are imperfect. In our research, a pneumatic driven droplet generator was developed to generate mono-sized copper droplets. Experiments were conducted to investigate the influence of spray pressure and pulse width on the size of droplets. Droplet was stably ejected while spray pressure was between 30kPa and 35kPa and pulse width was between 600μs and 900μs. The droplet size increased as the spray pressure increased. However the pulse width had no significant impact on the droplet size. At last a copper column was fabricated to certify the stability of the system and the reproducibility of the parameters.

Abstract: As is with general industries, Internet of Things industry also follows life cycle theory in the long run. However, in the short term, its high-tech industrial property will bring with it an inevitable outbreak growth at growth stage. The internal mechanism of explosive growth is that the whole networking industry chain achieves linkage development between supply and demand. Currently, Internet of Things industry in China faces a "quake lakes dilemma", which makes the linkage unrealized. Therefore, to get out of the "quake lakes dilemma" and further accelerate the evolution of Internet of Things, it is vital to make major breakthroughs in technologies, standards bottlenecks and remove cost barriers.

Abstract: The nanosized Al/AlN powder was immersed in deionized water to investigate their hydrolysis behavior from 40 °C to 80 °C. The Al/AlN powder hydrolysis behavior was observed by measuring the pH of the suspension, whereas XRD and TEM analyses were employed for the characterization of the hydrolytic products. The hydrolysis at the higher temperature was different from that at the lower temperature. The nanofibrous crystalline boehmite was formed mainly over 80 °C, while the bayerite (Al (OH₃)) coexisted with the boehmite predominantly below 70 °C. The hydrolytic product showed the higher specific surface area at 70 °C than that of the hydrolytic product at other temperatures. The highest specific surface area of hydrolytic product was 145.84m²/g.

Abstract: A composite of TiO2 and HZSM-5 zeolite was used for adsorption and photocatalytic degradation of Active Brilliant Red X-3B. The composite was prepared by solid state dispersion method. Decoloration rate increased with increasing TiO2 content to the maximum value of 80% at TiO2 content of 10%. After that, decoloration rate declined as continuing increase of TiO2 content. Adsorption of ABR X-3B on the composite had very small change and the maximum adsorption rate was not more than 5% with the variation of TiO2 content. Photocatalytic degradation varied drastically with change of TiO2 content. The optimum TiO2 content was 10% as under consideration of its adsorption and photocatalytic degradation activity.

Abstract: Taking into consideration of the boundary conditions in fluid-solid interactions, the author built the FSI large rectangle aqueduct model of dynamic analysis according to the equation dynamic performance of the fluid-solid coupling system. Large aqueduct of the dynamic properties were analyzed with asymmetric eigenvalue method, dynamic properties rules were calculated by changing the depth of the water in the aqueduct. Aqueduct, also called elevated canal, is usually built over valley, lower land or river for conducting water from a distance or even for shipping.The aqueduct is one of the most important hydraulic structures in Yindaruqin Irrigation Project. After aqueduct is built, all kinds of reasons get its degree of safety descent so as to affect its ordinary running with the time going. Based on fluid-solid coupling system, a FSI analysis model of the aqueduct structure is established.

Abstract: Cloud barycenter evaluation method is applied to battle damage assessment for air base on basis of the establishment of the evaluation index system and damage level classification. The index system of battle damage assessment for air base is established and the application step of cloud barycenter evaluation method to air base damage evaluation is analyzed. The battle damage level of air base is achieved using weighted deflection degree which is used to demonstrate the deflection degree between battle damage and its perfect state. The correctness and validity of the proposed method is verified by the calculating result, which provide an efficient way for battle damage assessment.

Abstract: This paper presents a mold cavity surface subdivision method by using image boundary detection technology to realize high efficiency NC machining. From the new perspective of image processing, the method constructed an optimal cutting direction angle field image in the u-v system of parameters according to the relationship between maximum cutting bandwidth and cutting direction in the theory of iso-scallop height firstly, and then fuzzy c - means clustering method was applied for subdivision surface boundary detection. Experimental results demonstrate good performance of the proposed method in distinguishing and extracting boundary points of surface subdivision.

Abstract: In this paper, a chemical plant of chromium salt was selected as the typical chromium slag contaminated site. The range and level of chromium in soil were tested by way of digestion and leaching in order to investigate the pollution of chromium slag. Speciation of chromium in soil was simultaneously analyzed by way of Tessier. The results showed that soil around the residue piling yard was polluted by Cr. Concentrations of Cr (VI) and total chromium in soil were both higher than the background value. Speciation analysis indicated that Cr in contaminated soil was mainly in the residual fraction. The data of investigation display chromium slag diffusion rule in horizontal direction is accord with particulate matter non-point source diffusion model.

Abstract: The method to avoid the formation of hot cracking in hot charging process is analyzed in this paper. The microstructure evolution of Nb containing steel during hot charging process was investigated by simulation with a HT-1600 pipe furnace. The results indicate that the microstructure varied from γ→γ+α→α+P with the charging temperature decrease from 950°C to room temperature, and the duplex phase of austenite and ferrite appeared at 750°C. Microstructure of the specimen at the beginning of rough rolling is austenite and the grain size is similar when the reheated temperature is above 850°C. Furthermore, severe mixed grain structure with coarse grain is apparent during the hot charging temperature from 750°C to 650°C. The hot charging temperature close to A₁ and hot charging at 550°C is appropriate for saving energy and avoiding slab surface cracking in heating furnace.