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111.
Channel length dependence of field-effect mobility and source/drain parasitic resistance in pentacene thin-film transistors with a bottom-gate, bottom-contact configuration was investigated. Schottky barrier effect such as nonlinear behaviors in transistor output characteristics appeared and became more prominent for shorter channel length less than 10 μm, raising some concerns for a simple utilization of conventional parameter extraction methods. Therefore the gate-voltage-dependent hole mobility and the source/drain parasitic resistance in the pentacene transistors were evaluated with the aid of device simulation accounting for Schottky contact with a thermionic field emission model. The hole mobility in the channel region shows smaller values with shorter channel length even after removing the influence of Schottky barrier, suggesting that some disordered semiconductor layers with low carrier mobility exist near the contact electrode. This experimental data analysis with the simulation enables us to discuss and understand in detail the operation mechanism of bottom-gate, bottom-contact transistors by considering properly each process of charge carrier injection, carrier flow near the contact region, and actual channel transport. 相似文献
112.
The enantiomeric composition of the monounsaturated triacylglycerols (TG) from cocoa butter was estimated. The monounsaturated
TG were separated into three fractions by reversed-phase high-performance liquid chromatography (HPLC), and each fraction
was subjected to the stereospecific analysis with chiral-phase HPLC. The results indicated that the major TG consisted of
equal amounts of 1-stearoyl-2-oleoyl-3-palmitoyl-sn-glycerol (SOP-sn-TG) and POS-sn-TG (47 mol%), 1,3-distearoyl-2-oleoyl-glycerol (SOS-TG) (33 mol%), and POP-TG (19 mol%). The contents of SOP-sn-TG and POS-sn-TG are 1.30 times that of the POP-TG content, and the SOS-TG content is 1.302 times that of the POP-TG content. The term “priority factor” is proposed for the ratio of the stearoyl group/palmitoyl group,
1:30 at thesn-1 andsn-3 or 1(3)-position. It shows a distinct specificity for particular fatty acids or their Coenzyme A esters in random esterification
at each position of the glycerol moiety in the biosynthesis of cocoa butter TG. 相似文献
113.
In this paper, a new design scheme of multiloop predictive self‐tuning PID controllers is proposed for multivariable systems. The proposed scheme first uses a static precompensator as an approximately decoupling device in order to roughly reduce the interaction terms of the controlled object. The static matrix precompensator is adjusted by an on‐line estimator. Furthermore, by regarding the approximately decoupled system as a series of single‐input single‐output subsystems, a single‐input single‐output PID controller is designed for each subsystem. The PID parameters are calculated on‐line based on the relationship between the PID control and the generalized predictive control laws. The proposed scheme is numerically evaluated on a simulation example. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 147(3): 63–71, 2004; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10284 相似文献
114.
The diversity of human immunodeficiency virus (HIV) in vivo has been reported. In this article, we propose a cellular automata
(CA) model describing the interactions between the immune system and HIV, and examine the effect of the diversity of these
interactions. The novel aspects of our CA model are that it not only considers four states (HIV, virgin, dead, infect) but
also the diversity exhibited by both HIV and T cells. We simulated maximum diversities for these states by simulating CA on
a computer. The model revealed that increased diversity had the effect of increasing the HIV population and simulation steps.
In addition, we observed that the CA model accurately reflects the occurrence of infection, incubation period, and the development
of AIDS. The CA model demonstrated that the diversity of the virus is the major factor affecting the success rate of the escape
of HIV from the immune response.
This work was presented in part at the 10th International Symposium on Artificial Life and Robotics, Oita, Japan, February
4–6, 2005 相似文献
115.
Wen‐xue Zhang Zong‐wei Qiao Toru Shigematsu Yue‐qin Tang Cheng Hu Shigeru Morimura Kenji Kida 《Journal of the Institute of Brewing》2005,111(2):215-222
Denaturing gradient gel electrophoresis (DGGE) and 16S rRNA gene analysis were carried out to analyze the bacterial community in Zaopei during production of Chinese Luzhou‐flavor liquor. Primers PRBA338F and PRUN518R were used for DGGE. Polymerase chain reaction (PCR) for clone analysis was preformed with primers EU27F and 1490R. The results by DGGE showed that with increasing fermentation time the diversity of bacteria in Zaopei decreased and after one week, only one bacterium phylotype was dominant. Gene clone libraries (16S rRNA) containing 55 clonal sequences were constructed. The bacterial diversity shift observed by DGGE was also shown by the clone library analysis. Bacteria closely related to Lactobacillus acetotolerans appeared to play a key role during Chinese liquor fermentation. 相似文献
116.
A procedure for micro stereospecific analysis of triacyl-sn-glycerols (TGs) by high-performance liquid chromatography (HPLC) on a chiral column is presented. TGs were partially hydrolyzed
with ethyl magnesium bromide, and total products were immediately converted to 3,5-dinitro-phenylurethane derivatives. Each
of the 1- and 2-monoacylglycerol (MG) derivatives was isolated by HPLC on a silica column. The 1-MGs were resolved intosn-1 andsn-3 MG fractions by HPLC on a Sumichiral OA-4100 column (Sumitomo Chemical, Osaka, Japan). Fatty acid methyl esters obtained
from thesn-1,sn-2 andsn-3 MG fractions were analyzed by gas-liquid chromatography on a capillary column. Analyses of standard TGs showed that, even
with 1 mg of sample, accuracy was comparable to that obtained with 100-mg samples. Applying this procedure to the stereospecific
analysis of 5 mg of jujube pulp, TGs revealed the positional distribution of the (n-5) series of monounsaturated fatty acids
they contained.
Honored Student Award Address presented at the 83rd AOCS Annual Meeting held in Toronto, Canada, May 10–14, 1992. 相似文献
117.
Fountain flow for isothermal viscoelastic fluids is simulated by a numerical method based on a combination of a finite element method and a finite volume method. For the treatment of moving free surfaces, a fringe element generation method is used. Circulating flow and elongation in the transverse direction at the melt front are simulated well. Numerical results also suggest that circulation in fountain flow and viscoelastic retardation may give rise to symmetric V-shaped patterns of birefringence between the center-plane and wall. Such information on molecular orientation in fountain flow is important for physical properties of thick molded products. 相似文献
118.
Tantalum powder production by magnesiothermic reduction of tantalum pentachloride (TaCl5) through an electronically mediated reaction (EMR) has been examined. Feed material, TaCl5, and reductant magnesium alloy were charged into electronically isolated locations in the molten salt (e.g. NaCl–KCl–MgCl2) at 1073 K. After providing external path for electron flow, the current flow between the feed and the reductant locations was monitored. A large current, more than 1 A, was detected during the reaction and tantalum powder with low nickel and silver content was obtained, although liquid Mg–Ag–Ni alloy was used as the reductant. This clearly demonstrates that tantalum powder can be produced by electronically mediated reaction (EMR) without direct physical contact between the feed (TaCl5) and the reductant (magnesium). The feasibility of tantalum reduction using Dy2+ ions dissolved in molten salt has also been demonstrated by utilizing molten salt containing DyCl2 as a reaction mediator. The mechanism of magnesiothermic reduction of TaCl5 in the molten salt is discussed using isothermal chemical potential diagrams. 相似文献
119.
Fumi Osawa Toshio Fujii Takehisa Nishida Nobuki Tada Toru Ohnishi Osamu Kobayashi Toshihiro Komeda Satoshi Yoshida 《Yeast (Chichester, England)》2009,26(9):485-496
Industrial production of L ‐lactic acid, which in polymerized form as poly‐lactic acid is widely used as a biodegradable plastic, has been attracting world‐wide attention. By genetic engineering we constructed a strain of the Crabtree‐negative yeast Candida boidinii that efficiently produced a large amount of L ‐lactic acid. The alcohol fermentation pathway of C. boidinii was altered by disruption of the PDC1 gene encoding pyruvate decarboxylase, resulting in an ethanol production that was reduced to 17% of the wild‐type strain. The alcohol fermentation pathway of the PDC1 deletion strain was then successfully utilized for the synthesis of L ‐lactic acid by placing the bovine L ‐lactate dehydrogenase‐encoding gene under the control of the PDC1 promoter by targeted integration. Optimizing the conditions for batch culture in a 5 l jar‐fermenter resulted in an L ‐lactic acid production reaching 85.9 g/l within 48 h. This productivity (1.79 g/l/h) is the highest thus far reported for L ‐lactic acid‐producing yeasts. DDBJ/EMBL/GenBank nucleotide database with Accession Nos. AB440630 and AB440631. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
120.
Ralph A. Dalla Betta James C. Schlatter David K. Yee Daniel G. Loffler Toru Shoji 《Catalysis Today》1995,26(3-4):329-335
A catalytic combustion system has been developed which feeds full fuel and air to the catalyst but avoids exposure of the catalyst to the high temperatures responsible for deactivation and thermal shock fracture of the supporting substrate. The combustion process is initiated by the catalyst and is completed by homogeneous combustion in the post catalyst region where the highest temperatures are obtained. Catalysts have been demonstrated that operate at inlet temperatures as low as 320°C at 11 atm total pressure and conditions typical of high performance industrial gas turbines. The ignition temperature is shown to correlate with the specific catalytic activity of the washcoat layer over a rather broad range of activities. A reaction model has been developed that can predict ignition behavior from the measured catalytic activity. 相似文献