Coupling experimental with simulation studies into the impact factors and reaction mechanism of sawdust char pressured hydrogasification on K-modified transition metal composite catalysts.

The utilization of biomass char was hindered by the low gasification activity due to thick ring structures and unclear gasification mechanism. Herein, the mechanism was elucidated by experimental and DFT to improve the activity. The results demonstrated that temperature increased the gasification activity but did not changed the order of gasification activity of samples. Pressure dominated the position of the highest point of instantaneous CH4 yield, and high pressure enhanced carbon conversion by 81.72 % and 7.32 times. Moreover, KNi exhibited an uppermost catalytic activity with the instantaneous CH4 yield 1.89 times higher than that of raw char at 750 °C. The formation of the CxNi structure lowered the activation barrier for the ring opening reaction. Possible transformation pathways of Ni species were as follows: Ni(NO3)2·6H2O â†’ NiO â†’ Ni. KNi changed the reaction pathways and the most energy-consuming step. The study could shed light on the hydrogasification reaction mechanism.

Topography-specific isotropic tunneling in nanoparticle monolayer with sub-nm scale crevices.

Material used in flexible devices may experience anisotropic strain with identical magnitude, outputting coherent signals that tend to have a serious impact on device reliability. In this work, the surface topography of the nanoparticles (NPs) is proposed to be a parameter to control the performance of strain gauge based on tunneling behavior. In contrast to anisotropic tunneling in a monolayer of spherical NPs, electron tunneling in a monolayer of urchin-like NPs actually exhibits a nearly isotropic response to strain with different loading orientations. Isotropic tunneling of the urchin-like NPs is caused by the interlocked pikes of these urchin-like NPs in a random manner during external mechanical stimulus. Topography-dependent isotropic tunneling in two dimensions reported here opens a new opportunity to create highly reliable electronics with superior performance.

Proteomic analysis of salt-responsive proteins in oat roots (Avena sativa L.).

BACKGROUND: Oat is considered as a moderately salt-tolerant crop that could be used to improve saline and alkaline soil. Previous studies have focused on short-term salt stress exposure (0.5-48 h), while molecular mechanisms of salt tolerance in oat remain unclear. RESULTS: Long-term salt stress (16 days) increased the levels of superoxide dismutase activity, peroxidase activity, malondialdehyde content, putrescine content, spermidine content and soluble sugar content and reduced catalase activity in oat roots. The stress also caused changes in protein profiles in the roots. At least 1400 reproducible protein spots were identified in a two-dimensional electrophoresis gel, among which 23 were differentially expressed between treated vs control plants and 13 were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. CONCLUSION: These differentially expressed proteins are involved in five types of biological process: (1) two fructose-bisphosphate aldolases, four alcohol dehydrogenases, an enolase, a UDP-glucuronic acid decarboxylase and an F1-ATPase alpha subunit related to carbohydrate and energy metabolism; (2) a choline monooxygenase related to stress and defense; (3) a lipase related to fat metabolism; (4) a polyubiquitin related to protein degradation; (5) a 14-3-3 protein related to signaling. © 2015 Society of Chemical Industry.

Electrical conduction of nanoparticle monolayer for accurate tracking of mechanical stimulus in finger touch sensing.

A flexible strain gauge is an essential component in advanced human-machine interfacing, especially when it comes to many important mobile and biomedical appliances that require the detection of finger touches. In this paper, we report one such strain gauge made from a strip of nanoparticle monolayer onto a flexible substrate. This proposed gauge operates on the observation that there is a linear relationship between electrical conduction and mechanical displacement in a compressive state. Due to its prompt temporal response, the gauge can accurately track various mechanical stimuli running at the frequencies of interest. Experiments have confirmed that the proposed strain gauge has a strain detection limit as low as 9.4 × 10(-5), and its gauge factor can be as large as 70, making this device particularly suitable for sensitive finger touch sensing. Furthermore, negligible degradation in the gauge's output electrical signal is observed even after 9000 loading/unloading cycles.