22,784 research outputs found
Facile synthesis of ginsenoside Ro
No full textTwo concise synthetic routes, being different in the glycosylation sequence, toward ginsenoside Ro (1) are developed. These syntheses feature the elaboration of the glucuronide residue at a later stage via the TEMPO-mediated selective oxidation and the installation of AZMB as a benzoylic neighboring participating group capable of being selectively removed afterward
Where Visual Speech Meets Language: VSP-LLM Framework for Efficient and Context-Aware Visual Speech Processing
No full textAnalytical drain thermal noise current model valid for deep submicron MOSFETs
No full textIn this paper, a physics-based MOSFET drain thermal noise current model valid for deep submicron channel lengths was derived and verified with experiments. It is found that the well-known muQ(inv)/L-2 formula, previously derived for long channels, remains valid for short channels. Carrier heating in the gradual channel region was taken into account implicitly with the form of diffusion noise source and then impedance field method taking velocity saturation effect was used to calculate the external drain thermal noise current. The derived model was verified by experimental noise for devices with channel lengths down to 0.18 mum. Excellent agreement between measured and modeled drain thermal noise was obtained for the entire V-GS and V-DS bias regions
Anomalous cyclic fatigue-crack propagation behavior of small cracks in monolithic, grain-bridging ceramics
No full textCyclic fatigue properties of two monolithic, high-toughness SIC ceramics were examined, with emphasis placed on differences between long- (>3 mm) and small-crack (<250 mu m) behavior. Studies were performed on two microstructures in which sintering additives were systematically varied. Small cracks were initiated with Vickers indents placed on the tensile surfaces of beams, and crack extension was monitored optically under an applied cyclic load. For small cracks, high growth rates which exhibited a negative dependence on the farfield driving force were observed. Such behavior was rationalized both in terms of indent-induced residual stresses and the relative size of cracks compared to bridging zone lengths. (C) 2000 Elsevier Science Ltd and Techna S.r.l. All rights reserved.Work on the Al, B, C-based SiC was supported by the
Director, Oce of Energy Research, Oce of Basic
Energy Sciences, Materials Sciences Division of the US
Department of Energy under Contract No. DE-AC03-
76SF00098. Additional support to facilitate collaboration
between the Korean and U.S. groups on the Al2O3/
Y2O3-based SiC was provided by the U.S. National
Science Foundation through their Division of Interna-
tional Programs under Grant No. INT-9507653. Thanks
are also due to Mr. Q. Tran for experimental assistance
Cyclic Fatigue-Crack Propagation Behavior in Silicon Carbide: Long- and Small-Crack Behavior
No full textCyclic fatigue properties of high-toughness SiC with additives of Al2O3 and Y2O3 were examined, with a focus on differences between long- (>3 mm) and small-crack (<200 <mu>m) behavior. Small cracks were initiated with Vickers indents placed on the tensile surfaces of beams, and crack extension was monitored optically under cyclic load. For small cracks, high growth rates which exhibited a negative dependence on the far-field driving force were observed. Such behavior was explained by both indent-induced residual stresses and the relative size of cracks compared with bridging zone lengths
Fluorescence Properties of 6-Aryl-2´-deoxy-furanouridine and –pyrrolocytidine and their derivatives
No full text2'-deoxyfuranouridine derivatives presenting various aryl groups have been synthesized through Cu(I)-catalyzed intramolecular cyclizations. Moreover, corresponding pyrrolo-dC derivatives have been synthesized and both families of compounds thoroughly characterized using UV/vis and fluorescence spectroscopy as well as time-dependent density functional theory calculations. The photophysical characterization, show that our newly synthesized derivatives of the important pyrrolo-dC family have high fluorescence quantum yields (QYs) and brightness values. Pyrrolo-dC derivative, 3a, shows an environment sensitive QY of up to >60% and brightness of almost 3000, in low polarity solvents and excitation and emission maxima between 365-381 nm and 479-510 nm, respectively, in solvents of different polarities. Two other derivatives, 3b and 3c, show high QYs and brightness values of up to 3300 that are fairly insensitive to their microenvironment. These promising photophysical features suggest future applicability as fluorescent nucleobase analogs.11Nsciescopu
Malicious content filtering based on semantic features
No full textThis paper proposes a method to filtering malicious contents using semantic features. In conventional content based approach, low-level features such as color and texture are used to filter malicious contents. But, it is difficult to detect them because of semantic gaps between the low-level features and global concepts. In this paper, global concepts are divided into several semantic features. These semantic features are used to classify the global concept of malicious contents. We design semantic features and construct semantic classifier. In experiment, we evaluate the performance to filter malicious contents by comparing low-level features and semantic features. Results show that our proposed method has better performance than the method using only low-level features
Complete high-frequency thermal noise modeling of short-channel MOSFETs and design of 5.2-GHz low noise amplifier
No full textTaking a velocity saturation effect and a carrier heating effect in the gradual channel region, complete thermal noise modeling of short-channel MOSFETs including the induced gate noise and its correlation coefficients is presented and verified extensively with experimentally measured data. All of the four noise models have excellently predicted experimental data with maximal error less than 10% for the deep-submicron MOSFETs. Using these models and a simultaneous matching technique for both optimal noise and power, a low noise CMOS amplifier optimized for 5.2-GHz operation has been designed and fabricated. Experiments using an external tuner show that both NF50 and NFmin are very close to 1.1 dB, which is an excellent figure of merit among reported LNAs
Dataset to support the article "High-resolution 𝜙-OFDR using phase unwrap and nonlinearity suppression"
No full textThis dataset is used for realizing high resolution of phase-sensitive Optical Frequency Domain Reflectometer. It is associated with the research paper:
Guo Z, Yan J, Han G, Yu Y, Greenwood D and Marco J (2023) "High-Resolution φ-OFDR Using Phase Unwrap and Nonlinearity Suppression". Journal of Lightwave Technology, 41 (9), 2885-2891. (https://doi.org/10.1109/JLT.2023.3236775).
The data is presented as an excel file:
High_resolution_OFDR_using_phase_unwrap_and_nonlinearity_suppression.xlsx
This work was funded by High Value Manufacturing Catapult and the Engineer and Physical Sciences Research Council - EPSRC EP/V000624/1. The author Gaoce Han would like to acknowledge the China Scholarship Council for sponsoring.</span
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