Bragg scattering of nonlinear surface waves over a wavy bottom is studied using two-dimensional fully nonlinear numerical wave tanks (NWTs). In particular, we consider cases of high nonlinearity which lead to complex wave generation and transformations, hence possible multiple Bragg resonances. The performance of the NWTs is well verified by benchmarking experiments. Classic Bragg resonances associated with second-order triad interactions among two surface (linear incident and reflected waves) and one bottom wave components (class I), and third-order quartet interactions among three surface (linear incident and reflected waves, and second-order reflected/transmitted waves) and one bottom wave components (class III) are observed. In addition, class I Bragg resonance occurring for the second-order (rather than linear) transmitted waves, and Bragg resonance arising from quintet interactions among three surface and two bottom wave components, are newly captured. The latter is denoted class IV Bragg resonance which magnifies bottom nonlinearity. It is also found that wave reflection and transmission at class III Bragg resonance have a quadratic rather than a linear relation with the bottom slope if the bottom size increases to a certain level. The surface wave and bottom nonlinearities are found to play opposite roles in shifting the Bragg resonance conditions. Finally, the results indicate that Bragg resonances are responsible for the phenomena of beating and parasitic beating, leading to a significantly large local free surface motion in front of the depth transition.

Extreme wave runup around a simplified representative floating production, storage and offloading vessel hull with a vertical bow is studied using computational fluid dynamics, complemented by experimental and diffraction analysis. This is a highly nonlinear system involving large vessel motions and extreme surface waves, and the behaviour is important for offshore design and operations. A separation method based on phase manipulation is carried out to facilitate the extraction of harmonics associated with the Stokes expansion of nonlinear waves. The separation method is applied to numerical and experimental data, and found to work well even for a highly nonlinear wave field scattered from a freely floating ship-shaped body. It is found that both low- and high-frequency second harmonic components can lead to wave runup at significantly higher levels than predicted by a linear analysis, while the vessel motions are very close to linear. The nonlinearity in the local wave field rather than vessel motion is key for the excitation of nonlinear extreme runup.

In the present paper, four cDNAs encoding the alpha and gamma subunits of elongation factor 1 (EF-1) were cloned and sequenced from Nilaparvata lugens, named NlEF-1α, NlEF-1γ, and its yeast-like symbiont (YLS), named YsEF-1α and YsEF-1γ, respectively. Comparisons with sequences from other species indicated a greater conservation for EF-1α than for EF-1γ. NlEF-1α has two identical copies. The deduced amino acid sequence homology of NlEF-1α and NlEF-1γ is 96 and 64%, respectively, compared with Homalodisca vitripennis and Locusta migratoria. The deduced amino acid sequence homology of YsEF-1α and YsEF-1γ is 96 and 74%, respectively, compared with Metarhizium anisopliae and Ophiocordyceps sinensis. Reverse transcription-quantitative polymerase chain reaction (RT–qPCR) analysis revealed that the expression level of NlEF-1α and NlEF-1γ mRNA in hemolymph, ovary, fat body and salivary glands were higher than the midgut and leg tissue. YsEF-1α and YsEF-1γ was highly expressed in fat body. The expression level of NlEF-1α was higher than that of NlEF-1γ. Through RNA interference (RNAi) of the two genes, the mortality of nymph reached 92.2% at the 11th day after treatment and the ovarian development was severely hindered. The RT–qPCR analysis verified the correlation between mortality, sterility and the down-regulation of the target genes. The expression and synthesis of vitellogenin (Vg) protein in insects injected with NlEF-1α and NlEF-1γ double-stranded RNA (dsRNA) was significantly lower than control groups. Attempts to knockdown the YsEF-1 genes in the YLS was unsuccessful. However, the phenotype of N. lugens injected with YsEF-1α dsRNA was the same as that injected with NlEF-1α dsRNA, possibly due to the high similarity (up to 71.9%) in the nucleotide sequences between NlEF-1α and YsEF-1α. We demonstrated that partial silencing of NlEF-1α and NlEF-1γ genes caused lethal and sterility effect on N. lugens. NlEF-1γ shares low identity with that of other insects and therefore it could be a potential target for RNAi-based pest management.

Extended abstract of a paper presented at Microscopy and Microanalysis 2013 in Indianapolis, Indiana, USA, August 4 – August 8, 2013.

Ce-containing MCM-41 mesoporous materials with large surface area and ordered pore structure system have been possible to be synthesized through a surfactant-assisted approach. The textural properties and structural regularity of the materials varied with the Si/Ce molar ratio. It is found that the band at 970 cm-1 in the FTIR spectrum of the Ce-MCM-41 mesoporous materials might be used as an indicator of the formation of the Ce-O-Si bond and its intensity as a measure of a degree of cerium ion substitution in the framework of Si-MCM-41. When Ni was loaded on the Ce-MCM-41 support, the Ni/Ce-MCM-41 catalysts show high catalytic activity which has strong temperature dependence. The methane conversion over these catalysts reached 60-75 % with a 100 % selectivity towards hydrogen.

Although studies in Caucasian populations have reported the beneficial effects of intakes of fruit and vegetables on bone mass, limited data are available in the Asian populations. We examined the association of the intake of fruits and vegetables with bone mineral density (BMD) in a population-based cross-sectional study of 670 postmenopausal Chinese women aged 48–63 years. Habitual dietary intakes were assessed using a food frequency questionnaire. BMD at the whole body, lumbar spine and left hip were measured with dual-energy X-ray absorptiometry. Univariate regression analyses showed that the total intake of fruits and vegetables was significantly associated with greater BMD at the whole body, lumbar spine (L1–L4), total hip, trochanter and intertrochanter. An independently positive association between fruit and vegetable intake and BMD at the whole body (P=0·005), lumbar spine (P<0·001) and total hip (P=0·024) remained even after adjusting for age, years since menopause, body weight and height, dietary energy, protein and Ca, and physical activities. A daily increase of 100 g fruit and vegetable intake was associated with 0·0062 (95 % CI 0·0019, 0·0105) g/cm2, 0·0098 (95 % CI 0·0041, 0·0155) g/cm2 and 0·0060 (95 % CI 0·0011, 0·0109) g/cm2 increases in BMD at the whole body, lumbar spine and total hip, respectively. In conclusion, greater fruit and vegetable intake is independently associated with better BMD among postmenopausal Chinese women.

We have studied the effects of external growth parameters during the deposition of the i-layers of a-Si p-i-n solar cells using dc plasma decomposition of silane-hydrogen mixtures at growth rates of up to 3A/s. The loss of initial performance with increasing growth rate is mainly due to a loss of short-circuit current. The relative degradation of efficiency upon extended light soaking also increases with growth rate, and is mainly due to a decrease in the fill factor. Systematic comparisons of the performance and its degradation with changes in growth conditions reveal that these two components of the total degradation have distinct origins.

The downward accelerated e− in the “unfavorable” zone, like that in the “favorable” one, will emit γ-photons, which in turn convert into e± pairs in some places near the surface of stars. But what happens, which is different from that in the “favorable” zone, is that some γ-photons will travel through a long distance before their conversion. This makes it possible that some γ-photons arrive at the “diode” district in the “favorable” zone. The magnetic conversion of pairs is much easier to happen than that occured in the “favorable” zone, where the γ-photons are created by the primary e− beam. The existence of dense e± plasma near the surface of stars makes the E, vanish at places where such plasma is present.