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Benjamin Kupfer Koushik Majhi David A. Keller Yaniv Bouhadana Sven Rühle Hannah Noa Barad Assaf Y. Anderson Arie Zaban 《Liver Transplantation》2015,5(1)
Co3O4 is investigated as a light absorber for all‐oxide thin‐film photovoltaic cells because of its nearly ideal optical bandgap of around 1.5 eV. Thin film TiO2/Co3O4 heterojunctions are produced by spray pyrolysis of TiO2 as a window layer, followed by pulsed laser deposition of Co3O4 as a light absorbing layer. The photovoltaic performance is investigated as a function of the Co3O4 deposition temperature and a direct correlation is found. The deposition temperature seems to affect both the crystallinity and the morphology of the absorber, which affects device performance. A maximum power of 22.7 μW cm?2 is obtained at the highest deposition temperature (600 °C) with an open circuit photovoltage of 430 mV and a short circuit photocurrent density of 0.2 mA cm?2. Performing deposition at 600 °C instead of room temperature improves power by an order of magnitude and reduces the tail states (Urbach edge energy). These phenomena can be explained by larger grains that grows at high temperature, as opposed to many nucleation events that occur at lower temperature. 相似文献
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Mutualistic relationships between vertebrates and plants apart from the pollen and seed-dispersal syndromes are rare. At first view, carnivorous pitcher plants of the genus Nepenthes seem to be highly unlikely candidates for mutualistic interactions with animals, as they form dimorphic terrestrial and aerial pitchers that trap arthropods and small vertebrates. Surprisingly, however, the aerial pitchers of Nepenthes rafflesiana variety elongata are poor insect traps, with low amounts of insect-attractive volatile compounds and low amounts of digestive fluid. Here, we show that N. rafflesiana elongata gains an estimated 33.8 per cent of the total foliar nitrogen from the faeces of Hardwicke's woolly bats (Kerivoula hardwickii hardwickii) that exclusively roost in its aerial pitchers. This is the first case in which the faeces-trapping syndrome has been documented in a pitcher plant that attracts bats and only the second case of a mutualistic association between a carnivorous plant and a mammal to date. 相似文献
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Junyong Zhang Yonghui Deng Dong Gu Shutao Wang Lan She Renchao Che Zhong‐Sheng Wang Bo Tu Songhai Xie Dongyuan Zhao 《Liver Transplantation》2011,1(2):241-248
A novel ligand‐assisted assembly approach is demonstrated for the synthesis of thermally stable and large‐pore ordered mesoporous titanium dioxide with a highly crystalline framework by using diblock copolymer poly(ethylene oxide)‐b‐polystyrene (PEO‐b‐PS) as a template and titanium isopropoxide (TIPO) as a precursor. Small‐angle X‐ray scattering, X‐ray diffraction (XRD), transmission electron microscopy (TEM), high‐resolution scanning electron microscopy, and N2‐sorption measurements indicate that the obtained TiO2 materials possess an ordered primary cubic mesostructure with large, uniform pore diameters of about 16.0 nm, and high Brunauer–Emmett–Teller surface areas of ~112 m2 g?1, as well as high thermal stability (~700 °C). High resolution TEM and wide‐angle XRD measurements clearly illustrate the high crystallinity of the mesoporous titania with an anatase structure in the pore walls. It is worth mentioning that, in this process, in addition to tetrahydrofuran as a solvent, acetylacetone was employed as a coordination agent to avoid rapid hydrolysis of the titanium precursor. Additionally, stepped evaporation and heating processes were adopted to control the condensation rate and facilitate the assembly of the ordered mesostructure, and ensure the formation of fully polycrystalline anatase titania frameworks without collapse of the mesostructure. By employing the obtained mesoporous and crystallized TiO2 as the photoanode in a dye‐sensitized solar cell, a high power‐conversion efficiency (5.45%) can be achieved in combination with the N719 dye, which shows that this mesoprous titania is a great potential candidate as a catalyst support for photonic‐conversion applications. 相似文献
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In the last 10 years, biodegradable aliphatic polyesters, such as poly(lactic-co-glycolic acid) (PLGA), have attracted increasing attention for their use as scaffold materials in bone tissue engineering because their degradation products can be removed by natural metabolic pathways. However, one main concern with the use of these specific polymers is that their degradation products reduce local pH, which in turn induces an inflammatory reaction and damages bone cell health at the implant site. Thus, the objective of the present in vitro study was to investigate the degradation behavior of PLGA when added with dispersed titania nanoparticles. The results of this study provided the first evidence that the increased dispersion of nanophase titania in PLGA decreased the harmful change in pH normal for PLGA degradation. Moreover, previous studies have demonstrated that the increased dispersion of titania nanoparticles into PLGA significantly improved osteoblast (bone-forming cell) functions (such as adhesion, collagen synthesis, alkaline phosphatase activity, and calcium-containing minerals deposition). In this manner, nanophase titania-PLGA composites may be promising scaffold materials for more effective orthopedic tissue engineering applications. 相似文献
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Saquib Ahmed Aurelien Du Pasquier Tewodros Asefa Dunbar P. Birnie III 《Liver Transplantation》2011,1(5):879-887
TiCl4 surface treatment studies of porous electrode structure of TiO2 aggregates synthesized using an acidic precursor and CTAB as a templating agent are carried out in order to understand and improve upon recombination kinetics in the photonanode film matrix, together with enhancing the intrinsic light scattering. The key beneficial features of the photoanode included high surface roughness, necessary for superior dye adsorption, nanocrystallite aggregates leading to diffuse light scattering within the film matrix, and a hierarchical macro‐ and mesopore structure allowing good access of electrolyte to the dye, thereby assisting in dye regeneration (enhanced charge transfer). Pre‐treatment of the TiO2 electrodes reduced recombination at the fluorine‐doped tin oxide (FTO)/electrolyte interface. The post‐treatment study showed enhanced surface roughness through the deposition of a thin overlayer of amorphous TiO2 on the film structure. This led to a notable improvement in both dye adsorption and inherent light scattering effects by the TiO2 aggregates, resulting in enhanced energy harvesting. The thin TiO2 overlayer also acted as a barrier in a core‐shell configuration within the porous TiO2 matrix, and thereby reduced recombination. This allowed the hierarchical macro‐ and mesoporosity of the film matrix to be utilized more effectively for enhanced charge transfer during dye regeneration. Post‐treatment of the aggregated TiO2 matrix resulted in a 36% enhancement in power conversion efficiency from 4.41% of untreated cells to 6.01%. 相似文献
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H. STEPHAN H. D. FRAHM G. BARON 《Journal of Zoological Systematics and Evolutionary Research》1987,25(3):205-211
The large size of the hippocampus in the papillose bat (Kerivoula papulosa) (see Part I) is paralleled by a structural differentiation of area CA 1 which is unique among Vespertilionids, and possibly Chiroptera in general. CA 1 of the papillose bat has a very thick band of cells which fills about 2/3 of the whole thickness of CA 1, in contrast to a maximum of 1/3 in other Vespertilionids. As in primates, the cells are dispersed over the whole stratum oriens and reach the alveus. Unlike in primates, however, the cells seem to migrate also in the direction of the periphery, i. e. into the sub-stratum radiatum of the molecular layer. Only a relatively small outer cell-poor band remains (1/4 of the whole thickness versus more than 1/2 in primates; Table 2). In K. papulosa the cell band of CA 1 is clearly thicker than that of the adjacent neocortex, separated by the lateral ventricle (Fig. 4). So far we have no strong arguments to correlate this very specific structural character with any particular behavior in K. papulosa. 相似文献
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