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991.
AbstractNitric oxide (NO) plays a critical role in the regulation of a wide variety of physiological processes. It is a potent inhibitor of platelet adhesion and aggregation, inhibits bacterial adhesion and proliferation, is implicated in mediating the inflammatory response toward implanted devices, plays a role in tumor growth and proliferation, and is a neurotransmitter. Herein, we describe the synthesis and NO-release properties of a modified polydimethylsiloxane that contains S-nitroso-N-acetyl-D-penicillamine covalently attached to the cross-linking agent (SNAP–DMS). Light from a C503B-BAN-CY0C0461 light-emitting diode (470 nm) was used as an external trigger to allow precise control over level and duration of NO release ranging from a surface flux of zero to approximately 3.5×10?10 mol cm-2 min-1. SNAP–PDMS films stored in the dark released NO after 297 days, indicating the long-term stability of SNAP–PDMS. 相似文献
992.
戴孟良 《有色冶金设计与研究》2012,33(1):21-23
介绍韶冶在氧化物料对工厂生产经营和现场环境造成不利影响的条件下,通过设备、工艺两方面的研究,提高氧化物料处理能力,从而增强烧结工艺对原料的适应性,使干精矿含硫降低,烧结机产能大幅度提升,烧结块质量保持较高水平,年创效益约2 500万元。 相似文献
993.
Nonvolatile rewritable organic memory devices based on poly(3,4-ethylene dioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and nitrogen doped multi-walled carbon nanotube (NCNT) nanocomposites were fabricated on glass and PET substrates.Organic memory devices with bistable resistive switching were obtained using very low NCTN concentration (∼0.002 wt%) in the polymeric matrix. The memory devices exhibited a good ON/OFF ratio of approximately three orders of magnitude, a good retention time of 104 s under operating voltages ≤ |4V| and a few hundredths of write-read-erase-read cycles. The bistable resistive switching is mainly attributed to the creation of oxygen vacancies. These defects are introduced into the thin native Al oxide (AlOx) layer on the bottom electrode during the first voltage sweep. The well-dispersed NCNTs immersed in PEDOT:PSS play a key role as conductive channels for the electronic transport, hindering the electron trapping at the AlOx-polymer interface and inducing a soft dielectric breakdown of the AlOx layer. These PEDOT:PSS + NCNTs memory devices are to easy to apply in flexible low-cost technology and provide the possibility of large-scale integration. 相似文献
994.
In this paper, the thermoelectric properties of ZnO doped with Al, Bi and Sn were investigated by combining experimental and theoretical methods. The average Seebeck coefficient of Bi doped ZnO over the measured temperature range is improved from −90 to −497 μV/K. However, segregation of Bi2O3 in ZnO:Bi sample, confirmed by FESEM, lead to enormous grain growth and low electrical conductivity, which makes Bi is not a good dopant to improve ZT value of ZnO. As a 4+ valence cation, Sn doping actually show an increase in carrier concentration to 1020 cm−3, further enhancing the electrical conductivity. Unfortunately, the Seebeck coefficient of ZnO:Sn samples is even lower than pure ZnO sample, which lead to a low ZT value. As for ZnO:Al sample, with nearly no change in lattice thermal conductivity, electrical conductivity and Seebeck coefficient were both enhanced. Threefold enhancement in ZT value has been achieved in ZnO:Al sample at 760 °C compared with pure ZnO. 相似文献
995.
《Organic Electronics》2014,15(4):871-877
Transition metal oxides (TMOs) on organic semiconductors (OSs) structure has been widely used in inverted organic optoelectronic devices, including inverted organic light-emitting diodes (OLEDs) and inverted organic solar cells (OSCs), which can improve the stability of such devices as a result of improved protection of air sensitive cathode. However, most of these reports are focused on the anode modification effect of TMO and the nature of TMO-on-OS is not fully understood. Here we show that the OS on TMO forms a two-layer structure, where the interface mixing is minimized, while for TMO-on-OS, due to the obvious diffusion of TMO into the OS, a doping-layer structure is formed. This is evidenced by a series of optical and electrical studies. By studying the TMO diffusion depth in different OS, we found that this process is governed by the thermal property of the OS. The TMO tends to diffuse deeper into the OS with a lower evaporation temperature. It is shown that the TMO can diffuse more than 20 nm into the OS, depending on the thermal property of the OS. We also show that the TMO-on-OS structure can replace the commonly used OS with TMO doping structure, which is a big step toward in simplifying the fabrication process of the organic optoelectronic devices. 相似文献
996.
《Food Control》2014
Zinc oxide (ZnO) nanoparticles have been proven to have strong antibacterial activity against food borne pathogens. The practical applications of different concentrations (0, 1, 3, 5 and 8 mM) of ZnO suspensions containing 0.3% citric acid were investigated against the pathogenic bacteria like, Listeria monocytogenes, Escherichia coli, Staphylococcus aureus and Bacillus cereus. Zinc oxide suspensions (0, 1, 3, 5 and 8 mM) containing citric acid have shown a significant inhibitory effect on the growth of all strains during 12 h of incubation. Our results have also shown that 5 and 8 mM suspensions of ZnO were the most effective on all strains. These data suggested that the antibacterial activity of ZnO was concentration dependent. Thus 5 mM and 8 mM ZnO were selected for further studies, carried out in mango juice, as they showed a significant growth inhibition in TSB. ZnO NPs were more capable of reducing initial growth counts of all the above stated strains in mango juice. Results have also exhibited that ZnO and citric acid had inhibitory effect on the growth of all strains during 24 h culture period in mango juice, as compared to the control experiment, which was further confirmed in liquid culture. This is the first report, describing the antibacterial activity of ZnO NPs in mango juices that showed the potential of these nanoparticles for use as an antibacterial agent in the food industry. 相似文献
997.
《Materials at High Temperatures》2013,30(2):211-216
AbstractIn order to develop an improved oxidation-limited lifetime model, experiments are being conducted to assess the critical factors that affect the rate of Al loss from Fe-base alumina-forming alloys during cyclic oxidation. Both wrought and dispersion strengthened ferritic and intermetallic Fe–Al±Cr alloys are being investigated at exposure temperatures from 1100–1300°C. Higher temperatures, thinner specimens and cycle frequency are used to accelerate degradation during oxidation. However, the effects of these experimental choices often have not been critically assessed in prior work. Electron probe microanalysis has been used to measure the residual Al content under various conditions and at various stages of life. For 0.5–2mm thick specimens, lifetime repeatedly showed a linear relationship to thickness. Increasing the oxidation temperature appears to be the most viable strategy to accelerate the evaluation of oxidation resistance for comparing and developing alloys. 相似文献
998.
We investigated the size dependent ferromagnetism in dodecyl amine capped zinc oxide nanoparticle. X-ray diffraction and X-ray photoelectron spectroscopy analysis demonstrated that density of oxygen vacancies was enhanced due to an increase in compressive strain concomitant with the decrease in particle size. Magnetic measurements showed increased ferromagnetic ordering in ZnO nanoparticles with reduced particle size. It was also found that the increase in coercive field, saturation magnetization and magnetic hysteresis loop area were invariably associated with increased oxygen defect population. The observed ferromagnetism in organic capped zinc oxide nanocrystals has therefore been assigned to defect induced phenomena. Results of sample characterization using optical absorption spectroscopy, photo luminescence spectroscopy and high resolution transmission electron microscope have also been presented. 相似文献
999.
Harnessing power from sea water using nano material as photocatalyst and solar energy as light source: the role of hydrocarbon as dual agent
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D. DeepanPrakash V. Premnath C. Raghu S. Vishnukumar S.S. Jayanthi D. Easwaramoorthy 《国际能源研究杂志》2014,38(2):249-253
The splitting of water in the presence of ordinary and nano TiO2 was carried out using hydrocarbon as a dual agent and solar energy as a light source for these experiments. The hydrogen gas evolved was tested and measured using downward displacement of water. The observed results show that more hydrogen was evolved when nano TiO2 was used as catalyst due to the larger surface area of the nano material. The splitting of sea water yields more hydrogen compared with ordinary water due to the presence of electron donating sodium ions in water. The added hydrocarbon plays a dual role as electron donor and as a trapping agent, which enhances the production of hydrogen to a greater extent compared with the regular donors such as olefin. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
1000.
Issei Fujimoto Nini Wang Rie Saito Yugo Miseki Takahiro Gunji Kazuhiro Sayama 《International Journal of Hydrogen Energy》2014
We report on the improvement in the water splitting efficiency of a WO3/BiVO4 composite photoelectrode by the application of an improved auto-combustion method to the preparation of porous BiVO4 thin films. The unique feature of this preparation method is the addition of both NH4NO3, as a strong oxidizing agent, and an organic additive into BiVO4 precursor solution. The local decomposition heat of the organic additive and oxidizing agent created a porous film with small, highly crystalline BiVO4 particles. The photoelectrode has many advantages over existing ones, such as the high light-harvesting efficiency (LHE), a single BiVO4 phase, the facile access of the holes to the photoelectrode/electrolyte interface, and the ease of water and oxygen diffusion. The maximum incident photon-to-current efficiency (IPCE) was estimated to be 64% (at 440 nm, 1.23 V vs. RHE) and the applied bias photon-tocurrent efficiency (ABPE) reached as high as 1.28%. This ABPE value is highest among all oxide semiconductor photoelectrodes reported previously, except for the case of a stacking photoelectrode system. 相似文献