Abstract: The comprehensive failure analysis was taken to investigate the leakage initiation of spiral plate heat exchanger. The micro appearance of cracks in spiral plates, chemical composition, metallographic structure, crack fracture and tensile properties were analyzed. The results show that the failure of spiral plates is most likely due to the non-standard design and manufacture combined with alternating load caused by alkali washing.
Abstract: EVA was added into PC/PLA blends as a modifier for improving the impact strength of blends, and meanwhile the thermal properties and rheological properties of blends should also be influenced. PC/PLA/EVA blends were prepared by melt blending and the catalyst DBTO was added into the blends in blending process to catalyze the transesterification of PC and EVA for improving the compatibility of blends. The effects of blend composition and transesterification on the thermal and rheological properties of blends were investigated. The results showed that the addition of EVA could improve the crystallinity of PLA in PC/PLA/EVA blends but had little influence on the thermal stability of blends,and the transesterification was beneficial to both the crystallization of PLA and thermal stability of blends. The addition of EVA and the transesterification of PC and EVA increased the apparent viscosity of blends, while the apparent viscosity of blends decreased drastically and the pseudo-plasticity characteristic of blend melts was weakened obviously with increasing PLA content and rising temperature.
Abstract: Most metal materials tend to produce brittle fracture at low temperature. Nominal stress of producing brittle fracture is low, generally lower than yield limit. By use of this property, the machinability of the workpiece, tool life and workpiece surface quality can be improved. Classification and application of low temperature machining was introduced in the paper. Tests of low temperature machining were carried out. The test results show low temperature machining is superior to the cutting in normal temperature for the aspects of tool life and the roughness of workpiece surface.
Abstract: Applying elastic-hydrodynamic lubrication theory, oil film thickness of tooth surface was studies in accordance with the quasi-steady state. This paper focused on the influence of gear parameters such as gear ratio, module and center distance on the thickness of oil film of tooth flank. The results show, as speed ratio increases, oil film thickness increases significantly. When the number of teeth is fixed, oil film thickness increases significantly with the increase of module. When center distance is fixed, oil film thickness declines greatly with the increase of module in both into meshing and out of meshing points. Therefore when center distance is fixed, less module and more teeth are selected，on the condition that gear intensity is met. By results analyzing, the minimal oil film thickness may occur in the single tooth meshing area and into meshing or out of meshing points.
Abstract: Owing to the complex operating environment of underwater vehicles, many uncertainties of sensors data, big noises of sensors , low precision and high rate of wild points of underwater acoustic sensors, data processing of motion sensors data for underwater vehicle navigation system becomes extremely important. The integrated navigation system of autonomous underwater vehicle based on dead-reckoning is introduced. An modified adaptive Kalman filter is adopted for underwater vehicle sensors information data processing. Experimental results show that the modified self-adaptive Kalman filter(SAKF) is effective, and can meet the underwater robots perform a variety of tasks in the navigation and positioning accuracy..
Abstract: We reported our detailed investigation of the microstructure and surface chemistry of nanoporous black Si layers using transmission electron microscopy techniques such as HRTEM, EDS, and EELS. We found that a one-step nanoparticle-catalyzed liquid etch creates deep conical nanovoids. The cones provide the density-graded surface that suppresses reflection. The surface of the as-etched nanoporous black Si is an amorphous Si suboxide (SiOx) produced by the strongly oxidizing nanocatalyzed etch. The c-Si/suboxide interface is rough at the nanometer scale and contains a high density of point defects.
Abstract: Starting with features of production in Sequential Manufacturing industries, this paper integrated the four stages -modeling, execution, management, and optimization- of Business Process Management (BPM) into related links of production in Sequential Manufacturing. Therefore, a BPM model orienting to Sequential Manufacturing (SMBPM) was constructed, and then applied into a Chemical Enterprise. Consequently， remarkable achievements was gained in aspects of business process combing, bottleneck analysis and its optimization, etc. At last, with the support of the YAWL, the automatic execution of BPM in sequential manufacturing was explored.
Abstract: The acetochlor residue in the tobacco cultivated soils was inclined to affect the growth of tobacco. In this study, regarding the acetochlor as the inorganic salt medium with the sole carbon source, we obtain the acetochlor-degrading bacteria from the tobacco cultivated soil through isolation and screening, numbering as CSUFTM78. Under the view of the microscopy, the bacteria has a rod shape and no spore with the size of 0.8 ~ 1.5 × 0.4 ~ 0.6μm; in the medium, the colonies are opaque, white, round, convex with neat edge and moist and shiny surface. Then determine the concentration of acetochlor which was directly added into the liquid medium and the phote-absorbance of strain number using UV spectrophotometer. The results indicate that the strain CSUFTM78 can grow in the inorganic salt medium which regards quinclorac as the sole carbon source; besides, the degradation rate was up to 38%. By determining the 16S sequence of CSUFTM78 strain, the homology of GENBANK in BLAST reaches more than 99% with Stenotrophomonas maltophilia (HQ185399). By constructing a phylogenetic tree, strain CSUFTM78 and S. maltophilia were integrated into one with the confidence of 100%. Combined with the morphological characteristics of strains, we identify the CSUFTM78 as S.maltophilia and the results can provide both strains and theoretical basis for degrading the acetochlor residual in tobacco cultivated soil using microorganism.