查看更多>>摘要：This paper presents a case study on an ultra-deep diaphragm wall with a depth of 110 m constructed in Ningbo City.The in-situ application shows that using Bauer BC40 cutter machine in conjunction with cutter wheels specified for different strata would be qualified for constructing the 110 m diaphragm wall with high efficiency and precision given that the quality of slurry and poured concrete can be guaranteed.The ground settlement can be effectively controlled by using the overlapping construction method.Sliding failure as a whole characterized by pronounced lateral deformation is likely to occur in the upper muddy clay layer due to its high compressibility and sensitivity.In contrast,local collapse of trench walls tends to happen in the sandy silt strata.Furthermore,careful attention should be paid to sandy silt during the entire construction period as the vertical displacement of the sandy silt continues to develop even after concrete pouring.
查看更多>>摘要：To improve the oxidation resistance and corrosion resistance of Zr-4 alloy,titanium nitride (TiN) coatings were prepared on the Zr-4 alloy with a TiN ceramic target with different ratios of N2.Microstructure and high-temperature properties of the TiN coated samples were studied by scanning electron microscopy (SEM),energy dispersive spectrometer (EDS),X-ray diffraction meter (XRD),X-ray photoelectron spectroscopy (XPS),heat treatment furnace and autoclaves,respectively.The x value of the TiN coatings (TiNx) ranges from 0.96 to 1.33.After the introduction of N2,TiN coating exhibits a weak (200) plane and a preferred (111) orientation.The coating prepared with an N2 flow ratio of 15％ shows an optimal oxidation resistance in the atmospheric environment at 800 ℃.In either 1 200 ℃ steam environment for one hour,or deionized water at 360 ℃ and a pressure of 18.6 Mpa for 16 d,the opitimized TiN coated samples have no delamination or spallation;and the gains in the masses of samples are much smaller than Zr-4 alloy.These results demonstrate the effectiveness of the optimized TiN coating as the protective coating on the Zr-4 alloy under extreme conditons.
查看更多>>摘要：Motion simulator usually appears the phenomenon of false cues and the workspace is limited in the process of washout.The proposed washout algorithm combines fuzzy logic control with the vestibular system to design the tilt coordination fuzzy adaptive filter,in order to minimize the vestibular sensory error below the human perception threshold.Owing to tilt coordination angular velocity limiter,the loss of low-pass acceleration must be compensated by the acceleration transform model.The translational channel decreases the possibility of the workspace beyond limitation and expands the scope of motion platform simulating input acceleration by using third-order filter.The simulation results show that the proposed algorithm can effectively overcome the phase retardation of classical washout algorithm,and then prevent the produce of false cues,decrease the displacement of motion platform simultaneously;in addition,white Gaussian noise simulates large variations in acceleration.The proposed washout algorithm can have maximal extreme value of acceleration and accurate simulating performance in general.It also proves that the proposed washout algorithm has a strong adaptability and reliability,which can effectively improve the dynamic fidelity for motion simulator.
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