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51.
52.
Alexey A. Roenko Vladimir V. Lukin Igor Djurović Xu Zhengguang 《Signal, Image and Video Processing》2009,3(2):157-170
A novel adaptive clipping technique for filtering a constant amplitude frequency modulated (FM) signal embedded in non-Gaussian
noise is proposed. It is based on the analysis and processing of the estimate of probability density function of a FM signal
realization. As a result, modifications of two robust estimators of FM signal amplitude are proposed. It is shown that these
estimators can be used for Gaussian and non-Gaussian heavy-tail environments. The proposed clipping technique can exploit
one or another obtained robust estimate of the signal amplitude for adaptive setting a threshold. Analysis of signal estimate
accuracy for different noise environments is carried out. Comparative analysis of the obtained methods and known approaches
based on scanning window nonlinear filtering and optimal robust L-DFT form is performed. It is demonstrated that the usage
of clipping-based technique leads to the considerable improvement of the FM signal filtering efficiency in comparison to the
aforementioned known approaches for different noise environments and a wide range of input SNR values. 相似文献
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54.
Joseph Berry Tonio Buonassisi David A. Egger Gary Hodes Leeor Kronik Yueh‐Lin Loo Igor Lubomirsky Seth R. Marder Yitzhak Mastai Joel S. Miller David B. Mitzi Yaron Paz Andrew M. Rappe Ilan Riess Boris Rybtchinski Oscar Stafsudd Vladan Stevanovic Michael F. Toney David Zitoun Antoine Kahn David Ginley David Cahen 《Advanced materials (Deerfield Beach, Fla.)》2015,27(35):5102-5112
55.
Emine Kaplanoglu Igor Kolotilin Rima Menassa Cam Donly 《International journal of molecular sciences》2022,23(7)
Plant-mediated RNA interference (RNAi) holds great promise for insect pest control, as plants can be transformed to produce double-stranded RNA (dsRNA) to selectively down-regulate insect genes essential for survival. For optimum potency, dsRNA can be produced in plant plastids, enabling the accumulation of unprocessed dsRNAs. However, the relative effectiveness of this strategy in inducing an RNAi response in insects using different feeding mechanisms is understudied. To investigate this, we first tested an in vitro-synthesized 189 bp dsRNA matching a highly conserved region of the v-ATPaseA gene from cotton mealybug (Phenacoccus solenopsis) on three insect species from two different orders that use leaf-chewing, lacerate-and-flush, or sap-sucking mechanisms to feed, and showed that the dsRNA significantly down-regulated the target gene. We then developed transplastomic Micro-tom tomato plants to produce the dsRNA in plant plastids and showed that the dsRNA is produced in leaf, flower, green fruit, red fruit, and roots, with the highest dsRNA levels found in the leaf. The plastid-produced dsRNA induced a significant gene down-regulation in insects using leaf-chewing and lacerate-and-flush feeding mechanisms, while sap-sucking insects were unaffected. Our results suggest that plastid-produced dsRNA can be used to control leaf-chewing and lacerate-and-flush feeding insects, but may not be useful for sap-sucking insects. 相似文献
56.
Multifunctional iron-carbon nanocomposites through an aerosol-based process for the in situ remediation of chlorinated hydrocarbons 总被引:1,自引:0,他引:1
Zhan J Kolesnichenko I Sunkara B He J McPherson GL Piringer G John VT 《Environmental science & technology》2011,45(5):1949-1954
Spherical iron-carbon nanocomposites were developed through a facile aerosol-based process with sucrose and iron chloride as starting materials. These composites exhibit multiple functionalities relevant to the in situ remediation of chlorinated hydrocarbons such as trichloroethylene (TCE). The distribution and immobilization of iron nanoparticles on the surface of carbon spheres prevents zerovalent nanoiron aggregation with maintenance of reactivity. The aerosol-based carbon microspheres allow adsorption of TCE, thus removing dissolved TCE rapidly and facilitating reaction by increasing the local concentration of TCE in the vicinity of iron nanoparticles. The strongly adsorptive property of the composites may also prevent release of any toxic chlorinated intermediate products. The composite particles are in the optimal range for transport through groundwater saturated sediments. Furthermore, those iron-carbon composites can be designed at low cost, the process is amenable to scale-up for in situ application, and the materials are intrinsically benign to the environment. 相似文献
57.
Igor Luisetto Simonetta Tuti Elisabetta Di Bartolomeo 《International Journal of Hydrogen Energy》2012
Co/CeO2 (Co 7.5 wt.%), Ni/CeO2 (Ni 7.5 wt.%) and Co–Ni/CeO2 (Co 3.75 wt.%, Ni 3.75 wt.%) catalysts were prepared by surfactant assisted co-precipitation method. Samples were characterized by X-Ray diffraction, BET surface areas measurements, temperature programmed reduction and tested for the dry reforming of methane CH4 + CO2 → 2CO + 2H2 in the temperature range 600–800 °C with a CH4:CO2:Ar 20:20:60 vol.% feed mixture and a total flow rate of 50 cm3 min−1 (GHSW = 30,000 mL g−1 h−1). The bimetallic Co–Ni/CeO2 catalyst showed higher CH4 conversion in comparison with monometallic systems in the whole temperature range, being 50% at 600 °C and 97% at 800 °C. H2/CO selectivity decreased in the following order: Co–Ni/CeO2 > Ni/CeO2 > Co/CeO2. Carbon deposition on spent catalysts was analyzed by thermal analysis (TG-DTA). After 20 h under stream at 750 °C, cobalt-containing catalysts, Co/CeO2 and Co–Ni/CeO2, showed a stable operation in presence of a deposited amorphous carbon of 6 wt.%, whereas Ni/CeO2 showed an 8% decrease of catalytic activity due to a massive presence of amorphous and graphitic carbon (25 wt.%). 相似文献
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59.
Anastasiya N. Mikhailova Galina P. Kayukova Igor P. Kosachev Irina I. Vandyukova Alexey V. Vakhin Georgy A. Batalin 《Petroleum Science and Technology》2018,36(17):1382-1388
Character of conversion of organic matter from Domanic rocks of Pervomaiskoye field (Tatarstan) of Semiluki horizon of upper Devonian deposits in the hydrothermal-catalytic system at temperature of 300?°C in carbon dioxide medium was studied with the application of complex of oil-soluble precursors of catalysts containing Fe, Co, and Cu. In presence of catalysts complex, content of organic extract increases, in which content of hydrocarbon fractions, saturated and aromatic hydrocarbons, increases 1.5 times, while resins content decreases by two times. As result of kerogen destruction in products of experiments, the content of asphaltenes and carbonaceous substances such as carbenes and carboides increase. 相似文献
60.
Igor Lashkevych J. E. Velázquez Oleg Yu. Titov Yuri G. Gurevich 《Journal of Electronic Materials》2018,47(6):3189-3192
A comprehensive study of the mechanisms of heating and cooling originating from an electrical current in semiconductor devices is reported. The variation in temperature associated with the Peltier effect is not related to the presence of heat sources and sinks if the heat flux is correctly determined. The Thomson effect is commonly regarded as a heat source/sink proportional to the Thomson coefficient, which is added to the Joule heating. In the present work, we will show that this formulation of the Thomson effect is not sufficiently clear. When the heat flux is correctly defined, the Thomson heat source/sink is proportional to the Seebeck coefficient. In the conditions in which the Peltier effect takes place, the temperature gradient is created, and, consequently, the Thomson effect will occur naturally. 相似文献