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In this paper, we proposed an inverse gradient nanograined structure (IGNS) to improve the mechanical behavior of an austenitic stainless steel. Using high strain cold rolling and subsequent ultra-high-frequency electromagnetic induction heating, we successfully fabricated an IGNS layer on AISI 316L stainless steel, within which the grain size exponentially decreases from the micrometer scale in the surface to the nanometer scale in the inner center. Microstructure evolution was systematically characterized by transmission electron microscopy. The uniaxial tensile test result shows a superior strength–ductility synergy in the IGNS sample. It obtained a yield strength of 842 MPa and a uniform elongation of 16%. A linear relationship between yield strength and uniform elongation was exhibited in IGNS samples with different volume fractions. Effects of the IGNS layer on strength and ductility were examined. Additionally, the effect of recrystallized grain distribution on mechanical properties was discussed.

The multicomponent eutectic alloys (MCEAs) have demonstrated great potential applications in industrial fields owing to their excellent castability during solidification. The cast MCEAs can achieve a good strength-ductility synergy. However, they usually suffer from mechanical failure at surface due to high surface residual stress resulting from direct solidification. Here we introduce a surface treatment technique through electromagnetic induction heating (EMIH), by which the stress level at surface (−24 MPa) was significantly reduced compared to that of the base MCEA (+573 MPa) with a chemical composition of AlCrFe2(Ni0.85Co0.15)2. This EMIH treatment not only mitigates surface residual stress but also enhances tensile ductility by 30 % without sacrificing its yield strength. In contrast, surface gradient structure synthesized by surface mechanical grinding treatment (SMGT) exhibited a dual-phase nanostructure, together with a compressive residual stress that is an order of magnitude higher than that of the EMIH-processed MCEA. The SMGT-processed MCEA showed marginal improvement in its tensile ductility because of limited work hardening ability resulting from limited dislocation sources at surface. Our study envisages an approach to process MCEAs by surface treatment with relatively a low cost.

It has been demonstrated that self-organized InGaN nanotips can be vertically grown via metal-organic vapor phase epitaxy (MOVPE) and thermal annealing. It was found that typical height of these nanotips is 20 nm with an average width of 1 nm. It was also found that the local density of vertically grown self-organized InGaN nanotips could reach 1.6 times 1013 cm -2. Furthermore, the overall uniformity in both height and width of nanotips were also demonstrated. These small sized vertical nanotips are potentially useful for field emission devices, blue light emitters and near-field microscopy.

Dissolved inorganic phosphorus (DIP), dissolved organic phosphorus (DOP), particulate phosphorus (PP) and sedimentary phosphorus (SP), were determined in northern Taiwan's Tanshui Estuary and one of its tributaries. Concentrations of DIP and PP (w/v) in the upper estuary were 15–20 times higher than those in the freshwater of the upper reaches in its tributaries, suggesting that the Tanshui Estuary is a seriously phosphorus-polluted environment. The fraction of DIP generally accounted for more than 85% of the total dissolved phosphorus (TDP, DIP plus DOP) within the salinity c . 70% in the lower estuary (salinity >30). The fraction of PP accounted for about 60% of total phosphorus (TDP plus PP) in the salinity 30). The logarithm of distribution coefficient, log (K D ), ranged from 4·36 to 5·61 within the whole estuary and was independent of the salinity. The total concentration of sedimentary phosphorus (TSP) ranged from 328 mg kg −1 to 1240 mg kg −1 within the estuary, and the inorganic form of phosphorus accounted for 87–97% of TSP. The distribution of DIP in the Tanshui Estuary showed slight addition in the upper estuary, removal in the mid-estuary and conservation in the lower estuary. The addition and removal of P appeared to be related to desorption from and adsorption onto PP. The concentrations of PP(w/w) and TSP exhibited addition in the salinity 5–10 region, strongly suggesting the removal of DIP onto the sediment. This removal of DIP probably resulted from co-precipitation or adsorption by Fe oxides/hydroxides. The upstream input of total P in the Tanshui River system was generally less than 0·3 tP day −1 and the phosphorus flux from the discharge of domestic sewages input to the upper estuary was approximately 6·0 tP day −1 during the study periods. A 2-D steady-state multi-box model was employed to calculate the phosphorus sedimentary and estuarine export fluxes. The calculated results showed that approximately 4·0 tP day −1 deposited in the upper estuary, and that the estuary also exported about 2·0 tP day −1 to the coast.

A substantial support effect exists for the interaction of N 2 and H 2 with supported Rh. Infrared spectroscopy was used to show that the interaction of N 2 with Rh/TiO 2 (average ΔH = −5.0 kcal mol −1 ) was stronger than that of N 2 with Rh/Al 2 O 3 (average ΔH = −2.2 kcal mol −1 ). It was also demonstrated that H 2 dissociates to a greater extent over Rh/TiO 2 than over Rh/Al 2 O 3 to produce H 2 O on the support. Low coverages of RhH (Θ=0.1–0.2) on the supported Rh caused an enhanced interaction of N 2 with Rh for both supports which was evident in enhancement of the intensity of the NN stretching mode for the RhN 2 surface species. Both weakly bound and strongly bound forms of hydrogen were thought to be involved in the enhanced N 2 interaction with Rh. The interaction mechanism probably involves an electronic effect transmitted between H and N 2 through the Rh metal centers, causing increased surface coverage of RhN 2 and possibly an increase in the NN vibrational mode extinction coefficient.

Ab initio theoretical computations have been performed for RhN2, Rh+N2, Rh(N2)2, and Rh+(N2)2 species. The computed vibrational frequencies and binding-energy trends are in qualitative accord with prior FTIR studies of N2 interacting with supported Rh films. Computations of the type described herein should be useful in aiding the assignment of observed infrared bands to specific surface species in future work.

The paper is concerned with the problem of tracking a manoeuvring target. The error monitoring and recovery technique of the perception net is utilised to improve the tracking performance for a highly manoeuvring target. The interacting multiple model (IMM) filter is well known as being the most cost-effective hybrid-state estimation scheme. Both the detection of a manoeuvring target and the compensation of the estimated state can be achieved by employing a properly implemented error monitoring and recovery technique. IMM and full IMMPDA filters which employ an error monitoring and recovery technique show a better tracking performance compared with the conventional IMM and IMMPDA filters for a highly manoeuvring target, even in a clutter environment. They also reduce the peak values of the estimation errors when manoeuvring starts and finishes. The effectiveness of the proposed method is validated through simulations by comparing it with a conventional IMM filter. A similar evaluation is performed for a conventional IMMPDA filter.