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991.
Sabrina Niesar Rui N. Pereira Andre R. Stegner Nadine Erhard Marco Hoeb Andrea Baumer Hartmut Wiggers Martin S. Brandt Martin Stutzmann 《Advanced functional materials》2012,22(6):1190-1198
Freestanding silicon nanocrystals (Si‐ncs) offer unique optical and electronic properties for new photovoltaic, thermoelectric, and other electronic devices. A method to fabricate Si‐ncs which is scalable to industrial usage has been developed in recent years. However, barriers to the widespread utilization of these nanocrystals are the presence of charge‐trapping defects and an oxide shell formed upon ambient atmosphere exposure hindering the charge transport. Here, we exploit low‐cost post‐growth treatment routes based on wet‐etching in hydrofluoric acid plus surface hydrosilylation or annealing enabling a complete native oxide removal and a reduction of the defect density by up to two orders of magnitude. Moreover, when compared with only H‐terminated Si‐ncs we report an enhancement of the conductivity by up to a factor of 400 for films of HF etched and annealed Si‐ncs, which retain a defect density below that of untreated Si‐ncs even after several months of air exposure. Further, we demonstrate that HF etched and hydrosilylated Si‐ncs are extremely stable against oxidation and maintain a very low defect density after a long‐term storage in air, opening the possibility of device processing in ambient atmosphere. 相似文献
992.
ALD functionalized nanoporous gold: thermal stability, mechanical properties, and catalytic activity
Biener MM Biener J Wichmann A Wittstock A Baumann TF Bäumer M Hamza AV 《Nano letters》2011,11(8):3085-3090
Nanoporous metals have many technologically promising applications, but their tendency to coarsen limits their long-term stability and excludes high temperature applications. Here, we demonstrate that atomic layer deposition (ALD) can be used to stabilize and functionalize nanoporous metals. Specifically, we studied the effect of nanometer-thick alumina and titania ALD films on thermal stability, mechanical properties, and catalytic activity of nanoporous gold (np-Au). Our results demonstrate that even only 1 nm thick oxide films can stabilize the nanoscale morphology of np-Au up to 1,000°C, while simultaneously making the material stronger and stiffer. The catalytic activity of np-Au can be drastically increased by TiO(2) ALD coatings. Our results open the door to high-temperature sensor, actuator, and catalysis applications and functionalized electrodes for energy storage and harvesting applications. 相似文献
993.
S.J. Rose J.N. Wilson N. Capellan S. David P. Guillemin E. Ivanov O. Méplan A. Nuttin S. Siem 《Annals of Nuclear Energy》2011,38(11):2619-2624
The multi-recycling of innovative uranium/thorium oxide fuels for use in the European Pressurized water Reactor (EPR) has been investigated. If increasing quantities of 238U, the fertile isotope in standard UO2 fuel, are replaced by 232Th, then a greater yield of new fissile material (233U) is produced during the cycle than would otherwise be the case. This leads to economies of natural uranium of around 45% if the uranium in the spent fuel is multi-recycled. In addition we show that minor actinide and plutonium waste inventories are reduced and hence waste radio-toxicities and decay heats are up to a factor of 20 lower after 103 years. Two innovative fuel types named S90 and S20, ThO2 mixed with 90% and 20% enriched UO2 respectively, are compared as an alternative to standard uranium oxide (UOX) and uranium/plutonium mixed oxide (MOX) fuels at the longest EPR fuel discharge burn-ups of 65 GWd/t. Fissile and waste inventories are examined, waste radio-toxicities and decay heats are extracted and safety feedback coefficients are calculated. Finally, we discuss the economics of such strategies. 相似文献
994.
995.
Ekaterina I. Lesnova Olga V. Masalova Kristina Yu. Permyakova Vyacheslav V. Kozlov Tatyana N. Nikolaeva Alexander V. Pronin Vladimir T. Valuev-Elliston Alexander V. Ivanov Alla A. Kushch 《International journal of molecular sciences》2021,22(13)
Hepatitis C virus (HCV) is one of the main triggers of chronic liver disease. Despite tremendous progress in the HCV field, there is still no vaccine against this virus. Potential vaccines can be based on its recombinant proteins. To increase the humoral and, especially, cellular immune response to them, more effective adjuvants are needed. Here, we evaluated a panel of compounds as potential adjuvants using the HCV NS5B protein as an immunogen. These compounds included inhibitors of polyamine biosynthesis and urea cycle, the mTOR pathway, antioxidants, and cellular receptors. A pronounced stimulation of cell proliferation and interferon-γ (IFN-γ) secretion in response to concanavalin A was shown for antioxidant N-acetylcysteine (NAC), polyamine biosynthesis inhibitor 2-difluoromethylornithine (DFMO), and TLR9 agonist CpG ODN 1826 (CpG). Their usage during the immunization of mice with the recombinant NS5B protein significantly increased antibody titers, enhanced lymphocyte proliferation and IFN-γ production. NAC and CpG decreased relative Treg numbers; CpG increased the number of myeloid-derived suppressor cells (MDSCs), whereas neither NAC nor DFMO affected MDSC counts. NAC and DFMO suppressed NO and interleukin 10 (IL-10) production by splenocytes, while DFMO increased the levels of IL-12. This is the first evidence of immunomodulatory activity of NAC and DFMO during prophylactic immunization against infectious diseases. 相似文献
996.
Caspers MP Schuren FH van Zuijlen AC Brul S Montijn RC Abee T Kort R 《Food microbiology》2011,28(2):245-251
Failure of food preservation is frequently caused by thermostable spores of members of the Bacillaceae family, which show a wide spectrum of resistance to cleaning and preservation treatments. We constructed and validated a mixed-species genotyping array for 6 Bacillus species, including Bacillus subtilis, Bacillus licheniformis, Bacillus pumilus, Bacillus sporothermodurans, Bacillus cereus and Bacillus coagulans, and 4 Geobacillus species, including Geobacillus stearothermophilus, Geobacillus thermocatenulatus, Geobacillus toebii and Geobacillus sp., in order to track food spoilage isolates from ingredient to product. The discriminating power of the array was evaluated with sets of 42 reference and 20 test strains. Bacterial isolates contain a within-species-conserved core genome comprising 68-88% of the entire genome and a non-conserved accessory genome comprising 7-22%. The majority of the core genome markers do not hybridise between species, thus they allow for efficient discrimination at the species level. The accessory genome array markers provide high-resolution discrimination at the level of individual isolates from a single species. In conclusion, the reported mixed-species microarray contains discriminating markers that allow rapid and cost-effective typing of Bacillus food spoilage bacteria in a wide variety of food products. 相似文献
997.
Sudeshna Saha Duygu Kocaefe Yaman Boluk Andre Pichette 《Progress in Organic Coatings》2011,70(4):376-382
Heat-treated wood is a value-added product but its exposure to various environmental factors leads to discoloration of wood surface due to the photochemical reactions. Discoloration has become an important economic problem for wood industries since product specifications are now more demanding. In addition, stricter environmental legislations necessitate the development of environmentally friendly transparent coatings with minimal use of chemicals which balances aesthetic and protection. In this study, the acrylic polyurethane coating was improved with the addition of natural antioxidant (bark extract) and lignin stabilizer alone or in combination to enhance the resistance of this coating to different weathering factors. An accelerated aging test was conducted with the aim of comparing the acrylic polyurethane coatings containing different additives with the commercially available pigmented solvent borne coating used by industry and organic UV absorbers. The modifications in chemical structure of coatings were characterized by ATR–FT-IR analysis. The color change data showed that the coating containing bark extract was the most effective and performed better than the industrial coating. However, the visual assessment showed that the coating containing bark extract and lignin stabilizer had the best performance. FT-IR analyses suggested that the chain scission reaction took place throughout the weathering but its effect was not significant for any of the coatings. 相似文献
998.
On the basis of new research by the Sapozhnikov method (State Standard GOST 1186), as well as data on the yield of volatiles (State Standard GOST 6382) and the petrological characteristics, new definitions are proposed in assessing the clinkering and coking of coal for bed coking. Under that proposal, clinkering properties and coking properties would refer exclusively to samples of individual coals; clinkering ability and coking ability would apply to coal blends and coal batch. As is shown, data for the petrographic composition and vitrinite reflection coefficient permit assessment of the genetic compatibility of coal, which may be used as a behavioral characteristic of coal in batch for blast-furnace coke production. 相似文献
999.
This article describes tests of nonwoven antimicrobial filter materials from viscose fibre (rayon) containing the antimicrobial
preparations catamin AB and desant. Wide-ranging tests of antimicrobial filter materials have been carried out to determine
the aerodynamic characteristics, dust content and dust penetrability, weather tolerance, resistance to saprophytic (mold)
fungi, etc. The tests and function-based classification of antimicrobial filter materials comply with GOST R 51251. Investigations
were carried out at the microbiological laboratories of I. V. Michurin All-Russia Scientific Research Institute of Orcharding,
Center of Hygiene and Epidemiology in the Moscow Region, and FGU “Mendeleevskii TsSM” to determine the efficiency of air purification
from microorganisms by antimicrobial filter materials made of viscose fibre containing the preparations catamin AB and desant
employing a specially designed equipment. Performance tests of various types of air filters having filter elements from filter
materials containing desant and catamin AB have been carried out. The efficiency of air purification from the microorganisms
Staphylococcus aureus, Micrococcus falvus, Bacillus subtilis, etc. that infect patients in medical institutions has been determined. 相似文献
1000.
Yu. F. Ivanov V. E. Gromov S. V. Gorbunov S. V. Vorob’ev S. V. Konovalov 《The Physics of Metals and Metallography》2011,112(1):81-89
Optical and scanning and transmission electron microscopy have been used to study structural and phase states of steel 08Kh18N10T
failed under fatigue conditions. Structural factors that reduce the fatigue life of a material have been revealed. To increase
the fatigue life of the steel, it is recommended to treat the surface of the material by concentrated energy fluxes. 相似文献