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ABSTRACT: It's elemental! β-Rhombohedral boron was investigated as an elemental photocatalyst. Boron crystals were found to be photocatalytically active in the generation of (.) OH radicals under irradiation with visible light; however, the presence of an amorphous oxide layer on the surface of the crystals impaired their photocatalytic activity.
Angewandte Chemie International Edition 04/2013; · 13.45 Impact Factor
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ABSTRACT: Anatase TiO2 nanocrystals doped with nitrogen and sulfur, where substitutional N and S atoms for lattice O, respectively, locate in the bulk and the surface layer of the crystals, were designed and prepared. As a result of remarkably lowered electronic resistance, the N/S doped TiO2 shows a superior high rate lithium storage capability to that of reference TiO2 nanocrystals, though the former has a larger particle size.
Chemical Communications 03/2013; · 6.17 Impact Factor
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ABSTRACT: Increasing visible light absorption of wide-bandgap photocatalysts (for example, ZnO and TiO2) plays a pivotal role in improving their photocatalytic activity. In this work, we show that substitutional nitrogen doping can be realized in semi-crystalline zinc oxide (ZnO) nanoparticles but fails for highly crystalline ZnO by heating the ZnO at a temperature of 400°C in gaseous ammonia atmosphere. The results suggest that substitutional nitrogen for lattice oxygen is strongly dependent on the crystallinity of ZnO. The nitrogen doped ZnO obtained shows an improved visible light photocatalytic activity in the degradation of organic dyes due to its increased visible light absorption. The origin of the increased visible light absorption is theoretically attributed to the formed N 2p localized states in the bandgap.
Journal of Colloid and Interface Science 03/2013; · 3.07 Impact Factor
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ABSTRACT: We report the template-free synthesis of Ta3N5 nanorod array films grown on Ta foil by a combination of a vapor-phase hydrothermal process and subsequent nitriding. The Ta3N5 nanorod array film modified with Co(OH)x when used as a photoanode in a photoelectrochemical cell for water splitting yields a stable photocurrent density of 2.8 mA cm-2 at 1.23 VRHE under AM 1.5G simulated sunlight. The incident photon-to-current conversion efficiency at 480 nm is determined to be 37.8%.
Chemical Communications 03/2013; · 6.17 Impact Factor
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ABSTRACT: Four novel asymmetrical diarylethenes with a pyrrole and a variable aryl unit have been synthesized. Their crystal structures and photochromic performance were systematically studied to elucidate the effects of the aromatic stabilization energy (ASE) of aryl units. Experimental results showed that their thermal stability as well as cyclization quantum yield, photoconversion ratio, fluorescence modulation efficiency, and fatigue resistance exhibited a strong correlation with ASE.
Organic Letters 03/2013; 15(5):980-3. · 5.86 Impact Factor
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ABSTRACT: Seeking visible-light-active photocatalysts for efficient solar-energy conversion has become an intensifying endeavor worldwide. In this concept paper, general requirements for finding new visible-light-active photocatalysts are briefly introduced, and recent progress in exploring elemental photocatalysts for clean-energy generation and environmental remediation are reviewed. Finally, opportunities and challenges facing elemental photocatalysts are discussed.
ChemPhysChem 02/2013; · 3.41 Impact Factor
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ABSTRACT: To compare the quality of life at baseline and at 6 months after coronary artery bypass grafting (CABG) and investigate the related risk fators.
The prospective study included 210 consecutive patients undergoing CABG between November 2008 and March 2010, who met inclusion criteria and completed short form-36 (SF-36) health status survey at baseline and at 6 months after CABG. Change of quality of life and influencing factors on quality of life were analyzed.
Eight domains including physical functioning, role-physical, bodily pain, general health, vitality, social functioning, role-emotional and mental health and two component summaries including physical component summary (PCS) and mental component summary (MCS) of SF-36 were significantly improved at 6 months following CABG (all P<0.01). Moreover, the improvement on PCS was significantly higher compared to MCS (80.0% vs. 68.6%, P<0.01). Advanced age (P<0.05) and lower PCS score (P<0.01) prior to CABG were independent predictors of low PCS after CABG, while MCS could not be predicted by pre-CABG status (P>0.05).
The findings demonstrate quality of life is significantly improved at 6 months post CABG. Advanced age and lower PCS score prior to CABG are linked with low PCS after CABG.
Zhonghua xin xue guan bing za zhi [Chinese journal of cardiovascular diseases] 06/2012; 40(6):492-6.
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ABSTRACT: A photoelectrode of single-crystal rutile TiO(2) pillars with well-developed facets shows a 2.5 times higher capability of water splitting at 0.3 V than a conventional anatase TiO(2) nanotube array electrode. The improvement is attributed to the synergistic effects of the high crystallinity of single-crystal rutile pillars, the exposed high-energy {011} and {111} as the reactive facets of water oxidation reaction and the extended light absorption range by ca. 23 nm.
Nanoscale 06/2012; 4(13):3871-4. · 5.91 Impact Factor
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ABSTRACT: We show that in contrast to conventional compound photocatalysts, α-sulfur crystals of cyclooctasulfur (S(8)) are a visible-light-active elemental photocatalyst. The α-S crystals were found to have the ability not only to generate ·OH radicals but also to split water in a photoelectrochemical process under both UV-vis and visible-light irradiation. Although the absolute activity obtained was low because of the large particle size and poor hydrophilicity of the α-S crystals studied, there is great potential for increasing the activity with the assistance of known strategies such as surface modification, nanoscaling, doping, and coupling with other photocatalysts.
Journal of the American Chemical Society 05/2012; 134(22):9070-3. · 9.91 Impact Factor
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ABSTRACT: Full-field hard X-ray tomography could be used to obtain three-dimensional (3D) nanoscale structures of biological samples. The image of the fission yeast, Schizosaccharomyces pombe, was clearly visualized based on Zernike phase contrast imaging technique and heavy metal staining method at a spatial resolution better than 50 nm at the energy of 8 keV. The distributions and shapes of the organelles during the cell cycle were clearly visualized and two types of organelle were distinguished. The results for cells during various phases were compared and the ratios of organelle volume to cell volume can be analyzed quantitatively. It showed that the ratios remained constant between growth and division phase and increased strongly in stationary phase, following the shape and size of two types of organelles changes. Our results demonstrated that hard X-ray microscopy was a complementary method for imaging and revealing structural information for biological samples.
Microscopy Research and Technique 05/2012; 75(5):662-6. · 1.79 Impact Factor
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ABSTRACT: Here we show that B(2)O(3-x)N(x) nanoclusters can be formed on the surface of WO(3) particles by a combination of thermal oxidation of tungsten boride (WB) in air and the subsequent nitriding process in gaseous ammonia. The resultant nanoclusters are found to play an apparent role in improving the photocatalytic oxygen evolution of WO(3) by promoting the surface separation of photoexcited charge-carriers.
Nanoscale 02/2012; 4(4):1267-70. · 5.91 Impact Factor
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ABSTRACT: A novel framework using a Bayesian approach for content-based phishing web page detection is presented. Our model takes into account textual and visual contents to measure the similarity between the protected web page and suspicious web pages. A text classifier, an image classifier, and an algorithm fusing the results from classifiers are introduced. An outstanding feature of this paper is the exploration of a Bayesian model to estimate the matching threshold. This is required in the classifier for determining the class of the web page and identifying whether the web page is phishing or not. In the text classifier, the naive Bayes rule is used to calculate the probability that a web page is phishing. In the image classifier, the earth mover's distance is employed to measure the visual similarity, and our Bayesian model is designed to determine the threshold. In the data fusion algorithm, the Bayes theory is used to synthesize the classification results from textual and visual content. The effectiveness of our proposed approach was examined in a large-scale dataset collected from real phishing cases. Experimental results demonstrated that the text classifier and the image classifier we designed deliver promising results, the fusion algorithm outperforms either of the individual classifiers, and our model can be adapted to different phishing cases.
IEEE Transactions on Neural Networks 11/2011; · 2.95 Impact Factor
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ABSTRACT: Single crystalline anatase TiO(2) rods with dominant reactive {010} facets are directly synthesized by hydrothermally treating Cs(0.68)Ti(1.83)O(4)/H(0.68)Ti(1.83)O(4) particles. The nanosized rods show a comparable conversion efficiency in dye-sensitized solar cells (DSSCs), and a superior photocatalytic conversion of CO(2) into methane to the benchmark P25 TiO(2) nanocrystals.
Chemical Communications 06/2011; 47(29):8361-3. · 6.17 Impact Factor
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Advanced Functional Materials 03/2011; 21(9):1717 - 1722. · 10.18 Impact Factor
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ABSTRACT: The paper is about mobile Stream Control Transmission Protocol (mSCTP) and the problems related to simultaneous mobility. Simultaneous mobility is when the both endpoints of a communication session are mobile and they move at about the same time. mSCTP works well in the case of non-simultaneous mobility where the SCTP association is established between a mobile endpoint and a stationary one. In the case of simultaneous mobility however, the probability of broken association may become high because both endpoints may suffer from losing address binding update. This is a consequence of the fact that the targeted addresses become unreachable. In this paper, we suggest a solution based on Host Name Address (HNA), together with pro-active Name Server, Address Handling Function (AHF) and Simultaneous Mobility Detection Function (SMDF) to eliminate this problem. Our preliminary results show that the performance of our solution is as good as for non-simultaneous mobility situation in terms of packet loss rate for low rate stream. On the other hand, the drawback is that some modifications to the current standard mSCTP are needed.
New Technologies, Mobility and Security (NTMS), 2011 4th IFIP International Conference on; 03/2011
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ABSTRACT: A new photochromic compound 1-[2-methyl-5-(4-methyl-phenyl)-3-thienyl]-2-[2-methyl-5-(4-fluor-phenyl)-3-thienyl]perfluoroyclopentene (1a) was synthesized, its photochromic properties were examined, the result indicated that the color of the compound 1a changed from colorless to a blue one upon irradiation with 297 nm UV light, a new absorption maxima were observed at 577 and 581 nm in hexane and PMMA film, respectively. This new photochromic compound also exhibited remarkable optical storage character.
Journal of Physics Conference Series 03/2011; 276(1):012116.
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ABSTRACT: A novel photochromic diarylethene was synthesized and its photochromic, fluorescence and kinetics properties were investigated detail. This compound exhibited remakable photochromism, changing from colorless to blue after irradiation with UV light both in solution and in PMMA amorphous film. In hexane, the kinetic experiments showed that the cyclization /cycloreversion process of the compound was determined to be the zeroth/first reaction, respectively. Finally, The results demonstrated that the diarylethene compound had attractive properties for high density optical storage.
Journal of Physics Conference Series 03/2011; 276(1):012191.
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ABSTRACT: Crystal facet engineering of semiconductors has become an important strategy for fine-tuning the physicochemical properties and thus optimizing the reactivity and selectivity of photocatalysts. In this review, we present the basic strategies for crystal facet engineering of photocatalysts and describe the recent advances in synthesizing faceted photocatalysts, in particular TiO(2) crystals. The unique properties of faceted photocatalysts are discussed in relation to anisotropic corrosion, interaction dependence of adsorbates, photocatalytic selectivity, photo-reduction and oxidation sites, and photocatalytic reaction order. Ideas for future research on crystal facet engineering for improving the performance of photocatalysts are also proposed.
Chemical Communications 03/2011; 47(24):6763-83. · 6.17 Impact Factor
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Angewandte Chemie International Edition 02/2011; 50(9):2133-7. · 13.45 Impact Factor
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ABSTRACT: A fully integrated 60 GHz frequency down-converter with divided LO output for external PLL is presented in this paper. The circuit is realized in a 0.8 μm SiGe HBT process with f<sub>T</sub>/f<sub>max</sub> of 80 GHz. It consists of a 60 GHz down-conversion mixer, a VCO at half the LO frequency, a frequency doubler and a divide by 32 frequency divider. With the VCO tuned to 33.8 GHz, the down-converter achieves a conversion gain of 0 dB at 60 GHz input and a 3 dB IF bandwidth of 12 GHz. The input 1-dB compression point is around -5 dBm. The output power of the divided LO signal is approximately -3 dBm, the measured phase noise at 1 MHz offset is -117 dBc/Hz. The complete down-converter draws 136 mA from a 4 V supply.
Microwave Conference Proceedings (APMC), 2010 Asia-Pacific; 01/2011
