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As a part of continuous efforts to systematically understand the morphological development in water‐assisted injection molding, high density polyethylene with different molecular weights was molded in this study. Unexpectedly, it was found that shish kebab with high lamellar and molecular orientations was formed in the sample with a lower molecular weight (LMW) rather than in the higher one, especially in the water channel layer. Present finding is obviously inconsistent with the general consensus, that is, higher molecular weight (HMW) polymer is much easier to form preferential orientation in flow field than LMW one. Such anomalous phenomenon is explained by the fact that even though melts experienced the same processing, lower shear rate is practically achieved in HMW sample due to its high viscosity. The result indicates that the flow history in industrial processing method is far from that in laboratory one. Copyright © 2012 John Wiley & Sons, Ltd.

Iron(iii) oxide ultrafine powders have been synthesized by laser-induced vapour-phase reaction using an IR pulsed COP laser as light source and a mixture of Fe(CO),-0, as reactant without adding any sensitizer. The optimum experimental conditions were presented. A single laser pulse can initiate an explosive reaction provided that the total Fe(CO),-0, pressure exceeds 5 kPa and the 0,-Fe(CO), partial pressure ratio is 3 1 . The reaction results in the complete disappearance of iron carbonyl and the energy consumption is very low compared with the conventional chemical process. The maximum quantum efficiency is ca. 1 02, suggesting that the explosive reaction may proceed according to a chain reaction mechanism. The relationships between the total pressure and the quantum efficiency and laser fluence threshold were both derived. IR, XRD, TEM and XPS were used to characterize the powders. The experimental results showed that the powders consisted of both crystalline y-Fe203 and amorphous Fe,03. The former phase is 50-100 nm in diameter while the latter is 5-12 nm in diameter. This is the first time that crystalline y-Fe203 prepared in this way has been found to be present as regular polyhedra and not spherical particles.

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The infiltration types of film hole irrigation (FHI) can be divided into film hole free infiltration (FHFI) and film hole interference infiltration (FHII). Numerical simulations were carried out with HYDRUS to investigate the influence of soil texture (ST), film hole diameter (D), film hole spacing (S) and water depth above the film hole (H) on the cumulative infiltration under two infiltration types of FHFI and FHII. The results showed that the amount of FHII was reduced significantly compared to that of FHFI. ST, D and S are the dominant factors affecting the infiltration reduction volume (ΔI). The relationship between ΔI and the time after interference (t À t 0 ) is a proportional function (R 2 ≥ 0.96), and its proportional coefficient has a good power function relationship with D and S. The power function coefficients have large differences for different ST, and the range of variation is 0.1-191, whereas there is little difference between the power function index of D and S; the average values were 2.6 and À2.5, respectively. A simplified calculation model of infiltration reduction was established, and the estimation accuracy was high (RMSE = 0.017 L, EF = 0.980). This research can provide a reference for the calculation of the irrigation water volume of the FHI.