Advanced Materials Research Vols. 228-229

Abstract: Based on the process reuse, a great number of process chains in a computer aided process planning (CAPP) system can form into a large process network as a collection of process collaborations with a large weight and processes with a larger strength. This paper aims to study the topological structure, weighted connectivity and assortativity, and configurability analysis of a realistic turbine process network. The empirical analysis indicates that the nonequilibrium weight distribution reveals a decaying power-law behavior, whereas the weight assignment of process collaborations behaves randomly, and has an assortative relationship with degrees of quite a few processes. In this paper, an evaluation method of configurability of process couples is proposed based on assortativity, and then the process configurability can be classified into the strong and weak ones.

Abstract: Tungstic oxide is prepared with pure ammonium paratungstate in the air. And then Tungsten powder is obtained with tungstic oxide through deoxidation in the hydrogen gas (Rate of purity: 99.99 %, dew point: -40 °C), and tungsten powder is oxidized in the air. Tungstic oxide is reduced into tungsten powder in the hydrogen gas. The above routes are repeated. The samples are characterized by the laser particle size distribution measuring instrument and the electron probe scan instrument. The results show that submicron tungsten powder is obtained through circulatory oxidation twice and reductiuon three times. The volume percentage of the particle size distribution of submicron tungsten powder between 0.1 μm and 0.5 μm is 94.81 %.

Abstract: The nanometer YSZ can be synthesized by a hydrothermal method. The experimental results of XRD, BET and TEM showed that the hydrothermal powder is pure cubic phase of Y2O3 stabilized ZrO2 with the crystallite size less than 10nm. Using the slurry directly, the YSZ film can be deposited on anode substrate by a dip-coating technique. The Field Emission Scanning Electron Microscope photographs approved that the film has been densified after sintered at 950°C for 5h. The pore diameter distribution experiment confirmed that there not exist aggregates in green film. The nanometer sized crystallite and no aggregates existence endow the YSZ green film with excellent sintering ability. Consequently, the YSZ film can be sintered below 1000°C for the first time.

Abstract: The paper presents an integration method of artificial neural network (ANN) and empirical mode decomposition (EMD) to identify fault severity in rolling bearing. A test apparatus is established, in which the rolling bearings with different faults and defect sizes are tested. Fault severity is divided into four grades of normal, light, middle and severe based on the defect size. Vibration signals are collected from the test rig. Due to the complexity of the signals, EMD has been exploited to decompose the signals into a series of intrinsic mode functions (IMFs). Then an ANN with one hidden layer is designed to diagnose the fault type and severity. The virtual values of first eight IMFs of a signal form the input vector of ANN. The output vector of ANN represented the fault severity with two binary digits. Appling the ANN to test the signals with unknown defect sizes, the diagnosis capability can arrive to about 95%. The results demonstrate that the integration method is successful in machine fault severity diagnosis.

Abstract: This paper is an overview of research about variable intake manifold in the past 12 years. First, a brief introduction to the basic principle of the variable intake is given.Then, the research of variable intake manifold in these years is presented and discussed, and the important studies are described in detail. Finally, the paper gives a summary of the research status and prospects of variable intake manifold.

Abstract: SPHB tests of concrete under different temperatures and various loading conditions are completed, and high-temperature dynamical behavior of concrete is obtained. Dynamical mechanical behavior of concrete with high temperature is affected by not only the strain rate effect, but also the high temperature weakening effect, and the strain rate hardening effect is coupled with high temperature weakening effect, but the latter has greater influence. Concrete failure evolution is described on basis of the damage factor, the intercoupling strain rate hardening effect and temperature weakening effect are simply set as mutually independent factors, each parameter is respectively fitted with test data, finally, concrete constitutive equation under high-temperature dynamical conditions is established, and comparative analysis with test data are conducted, indicating good coincidence with test results.

Abstract: A three-dimensional “fin-groove” composite structure copper current collector was fabricated by micro-ploughing process. 3D and common 2D carbon anodes for lithium- ion batteries were prepared. The electrochemical properties of these electrodes were studied by linear sweep cyclic voltammetry (CV) and charge-discharge (C-D) test. 2D anode showed high contact resistance, high coulombic efficiency but poor cycle performance. In contrast, 3D anode showed the structure superiority in reinforcing bonding force between active materials and copper substrate, improving the conductive environment and alleviating volume changes. It was believed that 3D anode can keep high coulombic efficiency and improve the cycle performance of lithium- ion batteries.

Abstract: There are close relationships between the surface micrograph and element contents of birch and its heating-up temperature. By using the scanning electron microscope (SEM) and the X-ray energy dispersive spectrometer (EDS), the surface micrograph and element contents of birch carbonizations prepared in the simulating fires with different heating-up temperatures were observed and compared. The results show that as the heating-up temperature rises, the surfaces of tracheids gradually become smoother, and the cross sections of tracheids change from circular or ovate shape to polygon. The external films of tracheid fibers are damaged and bordered pits are exposed gradually with the increasing of heating-up temperature. At high temperature, bordered pits change from flat eye-like pores to circular pits, at the same time, the carbon content increases from 52.46% to 90.96%, and the oxygen content decreases from 47.34% to 8.31%, while the potassium and calcium content increase. Thus, the study of connecting wood surface micrographs and element contents with heating-up temperature is useful in fire trace and evidence identification, and the result is meaningful to fire investigation.

Abstract: Paper discusses that water content of emulsion has effects on the surface quality of cold-rolled aluminum alloy 5052 and higher concentration of emulsion gave thicker lubrication film and better surface quality of aluminum strip. When the speed of rolling reaching a critical speed, thickness of emulsion film will decrease with time. Film forming of emulsion shows that when rolling speed is low, properties of emulsion is similar to that of oil, while when speed reaching a critical value, mechanism of lubrication in rolling work zone will change from plate-out model suitable for low rolling speed to starvation model suitable for high rolling speed .This paper also discusses friction model for cold-rolling, and explains that the contact length of work zone and strip and forward slip get greater with rolling reduction increasing , which easily result in lubrication failure in the work zone.

Abstract: The most important part of ITS (Intelligent Technology System) is the forecasting of dynamic traffic information reporting in a timely manner. Based on the results of past empirical studies, this article is presenting and analyzing two models based on Grey Theory and the BP (Back propagation) Neural Network. In accordance with the advantages and disadvantages of these two models, we established a new combination model. This article also presents the calculation of dynamic traffic stream volumes based on the application of two models (Grey Theory and BP Neutral Network).The results predicted an increase in the overall prediction accuracy of road traffic volume.