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41.
Effects of Y incorporation in TaON gate dielectric on electrical performance of GaAs metal–oxide–semiconductor capacitor 下载免费PDF全文
In this study, GaAs metal–oxide–semiconductor (MOS) capacitors using Y‐incorporated TaON as gate dielectric have been investigated. Experimental results show that the sample with a Y/(Y + Ta) atomic ratio of 27.6% exhibits the best device characteristics: high k value (22.9), low interfacestate density (9.0 × 1011 cm–2 eV–1), small flatband voltage (1.05 V), small frequency dispersion and low gate leakage current (1.3 × 10–5A/cm2 at Vfb + 1 V). These merits should be attributed to the complementary properties of Y2O3 and Ta2O5:Y can effectively passivate the large amount of oxygen vacancies in Ta2O5, while the positively‐charged oxygen vacancies in Ta2O5 are capable of neutralizing the effects of the negative oxide charges in Y2O3. This work demonstrates that an appropriate doping of Y content in TaON gate dielectric can effectively improve the electrical performance for GaAs MOS devices.
42.
Large-scale ultrasonic cleaning system: Design of a multi-transducer device for boat cleaning (20kHz) 总被引:1,自引:0,他引:1
Mazue G Viennet R Hihn JY Carpentier L Devidal P Albaïna I 《Ultrasonics sonochemistry》2011,18(4):895-900
The present study is part of a global project which consists in the development of an automatic cleaning station for immersed boats (cockle, ninepin, etc.) in a self-service mode, associating an innovative ultrasonic device for cleaning with a specific water treatment. The originality of the process is that cleaning is performed by three transducers operating simultaneously at low frequency and moving along the surface, thanks to programmable logic controllers, and that it includes a suction to collect the dirt removed. Therefore, the time required for boat maintenance is shortened, ensuring high quality cleaning without the need for dry docks and avoiding additional pollution in the harbor areas. One of the key points was the evaluation of washing efficiency, as it is really hard to give a quantitative estimation of the dirt removed. To obtain the first design laws, feasibility tests have been carried out on dirty cockle samples and on real boat hulls with a laboratory ultrasonic device. The influence of a large number of parameters was tested such as transducer-probe distance, displacement speed and transmitted power. The obtained data allowed us to design an optimized cleaning device combining high efficiency and speed. 相似文献
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α-n-amylcinnamaldehyde (jasminaldehyde) was obtained with 82 % yield by solid-liquid phase transfer catalysis without solvent within 3 days at room temperature. By use of domestic microwave irradiation, the same yield was obtained within 1 minute at a power of 600 W. 相似文献
44.
Mathieu Gaudin Maï Panchal Sophie Ayciriex Erwan Werner Alain Brunelle David Touboul Claire Boursier‐Neyret Nicolas Auzeil Bernard Walther Charles Duyckaerts Olivier Laprévote 《Journal of mass spectrometry : JMS》2014,49(10):1035-1042
The development of ‘omics’ sciences offers new opportunities for the study of neurodegenerative diseases but increases at the same time the sample demand on brain banks that collect and store valuable human post‐mortem tissue. Our study aims to evaluate in lipidomics the potential of formalin‐fixed tissue compared with the cryopreservation method, considered as the gold standard for biochemical research. Two complementary liquid chromatography/mass spectrometry analytical platforms were used on the basis of hybrid quadrupole time‐of‐flight and triple quadrupole mass spectrometers. Untargeted fingerprinting, semitargeted profiling of specific lipid classes and targeted monitoring of lipid species were performed in formalin‐fixed and cryopreserved samples to provide detailed information at the molecular level on the formalin‐induced alterations of the brain tissue. In vitro incubations of lipid standards were also performed to further describe the degradation processes induced by formaldehyde. Phospholipid compounds were found to be extensively hydrolysed, whilst the sphingolipid ones were preserved. N‐methylation and N‐formylation of amine‐containing phospholipids have also been evidenced. These findings show that the potential detrimental effect of formalin on the analytes of interest must be taken into account when analysing formalin‐fixed samples. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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Laura Pop Pierrik Lassalas László Csaba Bencze Monica Ioana Toşa Botond Nagy Florin Dan Irimie Christophe Hoarau 《Tetrahedron: Asymmetry》2012,23(6-7):474-481
Stereoselective preparative enzymatic acylation and hydrolysis/methanolysis of various C-substituted rac-thiazol-2-yl-methanols were achieved for the preparation of enantiopure or enantiomerically enriched, naturally occurring 2-hydroxymethylthiazoles. The absolute configurations of the resulting secondary alcohols were determined by a detailed 1H NMR study of Mosher’s derivatives. 相似文献
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2-(l-acetoxyethyl) acrylonitrile 1 can be stereoselectively converted into 2-ethylidene -3-aminonitriles 4 in good yields in the presence of primary or secondary arnines in THF at room temperature. 相似文献