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471.
We present a realization of untwisted vertex operators in terms of operations on Schur functions. Calculations of matrix elements and traces of products of vertex operators are performed using results from the classical theory of symmetric functions. The concepts of compound, composite and supersymmetric Schur functions naturally appear in this context. Furthermore, a trace formula for a product of vertex operators turns out to be a generalization of a MacDonald identity reformulated in terms of Schur functions.  相似文献   
472.
473.
In this paper, the averaging method is used to analyse the performance of second subharmonically injection locked Gunn oscillator. Some useful expressions such as the locking range, output response, output impedance of nonlinear device in fundamental and subharmonic frequency are obtained. a W — band subharmonically locked Gunn oscillator is developed and experimental result demonstrates the validity of this analysis.  相似文献   
474.
475.
Bioethanol was produced using polysaccharide from soybean residue as biomass by separate hydrolysis and fermentation (SHF). This study focused on pretreatment, enzyme saccharification, and fermentation. Pretreatment to obtain monosaccharide was carried out with 20% (w/v) soybean residue slurry and 270 mmol/L H2SO4 at 121 °C for 60 min. More monosaccharide was obtained from enzymatic hydrolysis with a 16 U/mL mixture of commercial enzymes C-Tec 2 and Viscozyme L at 45 °C for 48 h. Ethanol fermentation with 20% (w/v) soybean residue hydrolysate was performed using wild-type and Saccharomyces cerevisiae KCCM 1129 adapted to high concentrations of galactose, using a flask and 5-L fermenter. When the wild type of S. cerevisiae was used, an ethanol production of 20.8 g/L with an ethanol yield of 0.31 g/g consumed glucose was obtained. Ethanol productions of 33.9 and 31.6 g/L with ethanol yield of 0.49 g/g consumed glucose and 0.47 g/g consumed glucose were obtained in a flask and a 5-L fermenter, respectively, using S. cerevisiae adapted to a high concentration of galactose. Therefore, adapted S. cerevisiae to galactose could enhance the overall ethanol fermentation yields compared to the wild-type one.  相似文献   
476.
477.
Twisted bilayer graphene, in which interlayer interaction plays a critical role in this coupled system, is characterized for its angle‐dependent electronic and optical properties. Here, we present a systematic Raman study of single‐crystal twisted bilayer graphene grains, with the spectra of each bilayer graphene precisely correlated to its twist angle using combined transmission electron microscopic technique. Van Hove singularities develop as a result of band rehybridization at the crossing Dirac cones of the two layers, giving rise to a critical twist angle that determines the energy separation between the saddle points in the band structure and the resonance Raman spectra accordingly. The 2D mode becomes sensitive to the twist angle, showing the angle‐dependent position, peak width, and intensity. Our results interpreted in the framework of angle‐dependent double resonance scattering provide an important experimental perspective in understanding the coupled bilayer graphene system. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   
478.
In this paper the endurance characteristics and trap generation are investigated to study the effects of different postdeposition anneals(PDAs) on the integrity of an Al2O3/Si3N4/SiO2/Si memory gate stack. The flat-band voltage(Vfb)turnarounds are observed in both the programmed and erased states of the N2-PDA device. In contrast, this turnaround is observed only in the erased state of the O2-PDA device. The Vfbin the programmed state of the O2-PDA device keeps increasing with increasing program/erase(P/E) cycles. Through the analyses of endurance characteristics and the low voltage round-trip current transients, it is concluded that in both kinds of device there are an unknown type of pre-existing characteristic deep traps and P/E stress-induced positive oxide charges. In the O2-PDA device two extra types of trap are also found: the pre-existing border traps and the P/E stress-induced negative traps. Based on these four types of defects we can explain the endurance characteristics of two kinds of device. The switching property of pre-existing characteristic deep traps is also discussed.  相似文献   
479.
In this paper the endurance characteristics and trap generation are investigated to study the effects of different postdeposition anneals (PDAs) on the integrity of an Al2O3/Si3N4/SiOz/Si memory gate stack. The flat-band voltage (Vfb) turnarounds are observed in both the programmed and erased states of the N2-PDA device. In contrast, this turnaround is observed only in the erased state of the O2-PDA device. The Vfb in the programmed state of the O2-PDA device keeps increasing with increasing program/erase (P/E) cycles. Through the analyses of endurance characteristics and the low voltage round-trip current transients, it is concluded that in both kinds of device there are an unknown type of pre-existing characteristic deep traps and P/E stress-induced positive oxide charges. In the O2-PDA device two extra types of trap are also found: the pre-existing border traps and the P/E stress-induced negative traps. Based on these four types of defects we can explain the endurance characteristics of two kinds of device. The switching property of pre-existing characteristic deep traps is also discussed.  相似文献   
480.
In their reactions with phosphines, cyclic sulfates 9, 10, 11, and 12 afforded corresponding olefins by way of phosphonium sulfate salts whereas sugar cyclic sulfates 21 and 22 gave anhydrosugar 23.  相似文献   
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