Forest canopies are dynamic interfaces between organisms and atmosphere, providing buffered microclimates and complex microhabitats. Canopies form vertically stratified ecosystems interconnected with other strata. Some forest biodiversity patterns and food webs have been documented and measurements of ecophysiology and biogeochemical cycling have allowed analyses of large-scale transfer of CO, water, and trace gases between forests and the atmosphere. However, many knowledge gaps remain. With global research networks and databases, and new technologies and infrastructure, we envisage rapid advances in our understanding of the mechanisms that drive the spatial and temporal dynamics of forests and their canopies. Such understanding is vital for the successful management and conservation of global forests and the ecosystem services they provide to the world.

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Hollow nestlike α-Fe(2)O(3) spheres were successfully synthesized via a facile template-free, glycerol-mediated hydrothermal process employing microwave heating. The product was characterized using X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, and nitrogen adsorption measurements. The as-prepared product was found to consist of hierarchically nanostructured spheres assembled of nanorod subunits. The effect of the relative amount of glycerol in the reaction system on the composition and morphology of the products was systematically studied, and a possible formation mechanism of the hollow nestlike spheres was proposed. Because of their large surface area and unique mesoporous structure, we investigated the potential application of the hollow α-Fe(2)O(3) spheres in water treatment. With maximum removal capacities of 75.3, 58.5, and 160 mg g(-1) for As(V), Cr(VI), and Congo red, respectively, these novel nanostructures have the potential to be used as low-cost and efficient adsorbent materials for the removal of toxic metal ions and organic pollutants from water.

Visible-light driven ordered mesoporous metal ion doped anatase TiO 2 photocatalysts were synthesized via a hard-template chemical route. The effects of metal ion doping on the band energy level, surface area, pore volume, pore diameter, and photocatalytic properties of the ordered mesoporous anatase TiO 2 were systematically investigated. X-Ray photoelectron spectra and UV-vis absorption spectra indicate that the W and Mn ions enter into the lattice of anatase TiO 2 in the presence of W 6+ and Mn 3+ /Mn 4+ , resulting in a band gap transition with a red shift from the ultraviolet to the visible range, preventing the recombination rate of electron-hole pairs, therefore the photocatalytic activity can be greatly enhanced in the visible region. There exists an optimal doping level of 5 mol% W and 0.5 mol% Mn, respectively, with 95% MB and 82% MB being photocatalytically decomposed within 70 min under the visible light for 5% W and 0.5% Mn doped mesoporous anatase TiO 2 , respectively. Importantly, W ion doped TiO 2 displays much higher photocatalytic efficiency than Mn ion doped TiO 2 , which can be attributed to the presence of much higher Lewis surface acidity of W 6+ doped TiO 2 surface with a higher affinity for chemical species having unpaired electrons than Mn doped TiO 2 . In addition, the W doping induced grain refinement, highly crystalline state, large surface area and large pore size additionally contribute to the improved photocatalytic activity of the mesoporous W-doped TiO 2 samples. The enhanced ability to absorb visible light makes the ordered mesoporous metallic ion doped TiO 2 an effective photocatalyst for solar-driven applications. IntroductionBecause of its superior photocatalytic activity, chemical stability, low cost, and nontoxicity, TiO 2 has attracted much attention due to its potential applications as a photocatalyst, 1 electrode 2 and gas sensor 3 for its unique electronic and optical properties. A variety of TiO 2 nanostructured materials have been especially attracting increased attention in the realm of photocatalysis. [4][5][6][7][8] Ordered mesoporous materials, since their first discovery in 1992, 9 have found various applications such as adsorption, catalysis, energy storage and biosensors due to their high specific surface area, pore volume, and controlled pore structure. Due to their high surface areas and greatly organized pore structures, mesoporous materials can further enhance the photocatalytic activity and find potential applications in many fields. The fabrication techniques to mesoporous TiO 2 include soft template and hard template methods. The synthesis route using surfactants (P123, 10 F127, 11 etc.) as soft templates usually causes amorphous oxides because the soft template cannot tolerate the high crystallization temperature. On the other hand, mesoporous crystalline TiO 2 can be synthesized using hard templates (CMK-3, 12 SBA-15, 13 KIT-6, 14 etc.), which can resist high temperature, and the hard templates be easily removed. Therefore, the hard template method is m...

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Mg-Al-layered double hydroxide (LDH) coatings were fabricated by a combined co-precipitation method and hydrothermal process on an AZ31 alloy substrate. The characteristics of the coatings were investigated using SEM, XRD, FT-IR and EDS. The corrosion resistance of the LDH coatings was studied using potentiodynamic polarization and electrochemical impedance spectrum. The results demonstrated that the LDH coatings, characterized by nanoplates stacked vertically to the substrate surface and ion-exchange ability, possess excellent corrosion resistance.

Aqueous phase catalytic upgrading of phenolic monomers to hydrocarbons have been explored using Pd/C combined with HZSM-5 zeolite catalysts in the presence of H 2. 2-Methoxyl-4-allylphenol (eugenol), which consists of methyl ether bond, hydroxyl group, aromatic ring and propyl olefin bond, was chosen as a classic lignin model compound. This research focuses on the relationship between the acidity of zeolites and the deoxygenation activities basis on the hydrodeoxygenation (HDO) of eugenol. The results indicated that the decrease of Si/Al ratio resulted in the increase of the acidity of the zeolites, which significantly influenced their catalytic performance for product distributions. Over the HZSM-5 (Si/Al = 12.5) catalyst, the 2-methoxyl-4-propylphenol conversion of 86.5% and the hydrocarbon selectivity of 73.4% were obtained with the HDO of eugenol under 513 K and 5 MPa hydrogen pressure. Owing to the lower selectivity of hydrocarbon with HZSM-5 (Si/Al = 50) as acidic catalyst, the pore treatment was used to enlarge the outer surface of zeolite. After modified by alkali-treatment, much more acid active sites were provided for feasible accessibility of oxygenated reactants. The selectivity of hydrocarbons was improved by the alkaline treatment of HZSM-5 zeolite with 0.3 mol L −1 sodium hydroxide solution.

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