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101.
K. Kakushima K. Okamoto M. Kouda T. Kawanago P. Ahmet K. Tsutsui T. Hattori 《Microelectronics Reliability》2010,50(3):356-359
The chemical bonding states and electrical characteristics of SrO capped La2O3/CeOx gate dielectric have been examined. Angle-resolved X-ray photoelectron spectroscopy measurement has revealed that Sr atoms diffuse into silicate layer to form SrLa-silicate after annealing. Owing to the incorporation of Sr atoms into silicate layer, a transistor operation with an equivalent oxide thickness (EOT) below 0.5 nm has been demonstrated. A strongly degraded effective electron mobility of 78 cm2/V s at 1 MV/cm has been obtained, which fit well with the general trend in small EOT range below 1 nm. Although process optimization is needed to improve the performance of transistors, Sr capping technique can be useful for EOT scaling. 相似文献
102.
Ekrem Köksal Ercan Bursal İlhami Gülçin Mustafa Korkmaz Cüneyit Çağlayan Ahmet C. Gören 《International Journal of Food Properties》2017,20(3):514-525
Like tea, the leaves of Turkish thyme (Thymus vulgaris) can be boiled in water to produce an extract. This is widely used as syrup for the treatment of coughs and bronchitis at alternative medicine clinics in many parts of the world. In the current study, we assessed the phenolic content and antioxidant activity of thyme. The antioxidant activities of both ethanol and aqueous extracts of thyme were determined using various in vitro methods. The total phenolic and total flavonoid contents were determined to be a gallic acid equivalent and a quercetin equivalent, respectively. Finally, the quantities of the phenolic compounds were detected using high-performance liquid chromatography and tandem mass spectrometry. The total phenolic compounds in the aqueous extract and ethanol extracts of Turkish thyme were 256.0 μg gallic acid equivalent/mg dried extract and 158.0 μg gallic acid equivalent/mg dried extract, respectively. Conversely, the total flavonoid compounds in both extracts were 44.2 μg and 36.6 μg quercetin equivalent/mg dried extract, respectively. For the first time, we determined phenolic contents and investigated the antioxidant potential of thyme. The results indicate that Turkish thyme is a good dietary source with phenolic properties. 相似文献
103.
Medine Güllüce Münevver Skmen Fikrettin ahin Atalay Skmen Ahmet Adigüzel Hakan
zer 《Journal of the science of food and agriculture》2004,84(7):735-741
The in vitro antimicrobial and antioxidant activities of the essential oil and methanolic extract of Micromeria fruticosa ssp serpyllifolia as well as the composition of the essential oil were examined. The essential oil exhibited activity against 14 bacteria, three fungi and a yeast, with minimal inhibitory concentration (MIC) values ranging from 31.25 to 125 µl ml?1, whilst the methanolic extract was inactive. Antioxidant activity was measured by two methods, namely scavenging of the free radical DPPH and inhibition of linoleic acid oxidation. The methanolic extract exhibited significant antioxidant activity in both assays, providing 50% inhibition at 70.9 ± 0.5 µg ml?1 concentration in the DPPH assay and inhibiting linoleic acid oxidation to 59% at 2 mg ml?1 concentration, whilst the essential oil showed activity only at higher concentrations. The gallic acid equivalent total phenolic content of the methanolic extract was found to be 55.2 ± 2.00 µg mg?1 dry weight extract (5.5% w/w). The chemical composition of the hydrodistilled essential oil was analysed by means of GC/MS. Twenty‐nine constituents were identified, the main ones being piperitenone (50.61%) and pulegone (29.19%). Copyright © 2004 Society of Chemical Industry 相似文献
104.
The production of pure powder samples of boron-rich ternary Al–B–C phases was investigated in vacuum at temperatures between 1400 °C and 1600 °C, using a range of different starting powders. Compacted powder mixes of B–AlB2–B4C, Al–B–C, Al–B–B4C, B–C–AlB2, B–AlB2 and Al–B were heated for 1–2 h under vacuum in a carbon resistance furnace and the products characterised by X-ray diffraction. It was found impossible to produce significant quantities of C4AlB24 under these conditions, but >95% pure samples of α-AlB12, AlB12C2 and Al3B48C2 were obtained. This study is a precursor to further research aimed at producing dense B4C-type materials which might offer the advantages of easier densification and fabrication as compared with B4C itself. 相似文献
105.
F. Melda Patan Alper Ahmet T. Ince Maria Aiordachioaiei 《International Journal of Thermophysics》2011,32(1-2):505-512
Calibration of thermometers in the temperature range from ?80 °C to 550 °C requires liquid baths; alcohol, water, silicon oil, salt baths and dry block furnaces. In this study, the use of salt baths outside of their usual range of 250 °C to 540 °C for calibrating thermometers in the range between 175 °C and 250 °C is proposed. The calibration range from 150 °C to 250 °C is usually covered by an oil bath, but utilizing a salt bath saves calibration time and resources, improves stability and homogeneity, allows longer term usage of the liquid, and reduces hazardous chemical vapors evaporated at temperatures above 175 °C. This proposal is based on a study of the uncertainty contributions at varying salt bath temperatures in the range from 175 °C to 540 °C which was carried out in this study. Results achieved and analyzed in this study indicate that the implementation of salt baths in this lower temperature range provides opportunities to calibrate reference and/or working thermometers with an uncertainty below 30 m°C, almost the same as the oil-bath uncertainty in the range of 175 °C to 250 °C. The main components of uncertainty contributed by a salt bath over this temperature range are discussed in this study. 相似文献
106.
HIV-1 protease has been the subject of intense research for deciphering HIV-1 virus replication process for decades. Knowledge of the substrate specificity of HIV-1 protease will enlighten the way of development of HIV-1 protease inhibitors. In the prediction of HIV-1 protease cleavage site techniques, various feature encoding techniques and machine learning algorithms have been used frequently. In this paper, a new feature amino acid encoding scheme is proposed to predict HIV-1 protease cleavage sites. In the proposed method, we combined orthonormal encoding and Taylor’s venn-diagram. We used linear support vector machines as the classifier in the tests. We also analyzed our technique by comparing some feature encoding techniques. The tests are carried out on PR-1625 and PR-3261 datasets. Experimental results show that our amino acid encoding technique leads to better classification performance than other encoding techniques on a standalone classifier. 相似文献
107.
Ali Erdoğmuş Mahmut Durmuş Ahmet Lütfi Uğur Oğuzhan Avciata Ulvi Avciata Tebello Nyokong 《Synthetic Metals》2010,160(17-18):1868-1876
The synthesis, photophysical and photochemical properties of soluble 3,4-(methylendioxy)-phenoxy substituted oxo-titanium(IV) phthalocyanines (4–6) are reported for the first time. The new compounds have been characterized by elemental analysis, FT-IR, 1H NMR spectroscopy, electronic spectroscopy and mass spectra. General trends are described for fluorescence lifetimes and fluorescence, photodegradation and singlet oxygen quantum yields, of these compounds in dimethylsulfoxide (DMSO) and toluene. The effects of the position of the substituents and solvent effect on the photophysical and photochemical parameters of the oxo-titanium(IV) phthalocyanines (4–6) are also reported. The fluorescence of the substituted oxo-titanium(IV) phthalocyanine complexes (4–6) is effectively quenched by 1,4-benzoquinone (BQ) in both DMSO and toluene. 相似文献
108.
109.
In this paper, a coupled finite and infinite element system is used to study the effects of canyon-shaped topography and geotechnical
characteristics of the soil on the dynamic response of free surface and of 2-D soil-structure systems under ground motion.
A parametric study is carried out for canyon-shaped topographies. It is concluded that topographic conditions may have important
effects on the ground motion along the canyon. Geotechnical properties of the soil also have significant amplification effects
on the whole system motion, which cannot be neglected for design purposes. Thus, the dynamic response of both free surface
and a soil-structure system are primarily affected by surface shapes and geotechnical properties of the soil. Location of
the structure is another parameter affecting the whole system response. 相似文献
110.
Zafer Odabaş İmran Koç Ahmet Altındal Ali Rıza Özkaya Bekir Salih Özer Bekaroğlu 《Synthetic Metals》2010,160(9-10):967-977
The new mono-nuclear FeII 2 and ball-type homo-dinuclear FeII–FeII 3 phthalocyanines have been synthesized from the corresponding 4,4′-(1a,8b-dihydronaphtho[b]naphthofuro[3,2-d]-furan-7,10-diyl)bis(oxy)diphthalonitrile 1 while ball-type hetero-dinuclear FeII–CoII phthalocyanine 4 was synthesized from 2. The compounds have been characterized by elemental analysis, UV–vis, IR and MALDI-TOF-mass spectroscopies. The redox behaviours of the complexes were identified by controlled-potential coulometry, cyclic voltammetry and differential pulse voltammetry measurements on Pt in dimethylsulfoxide containing tetrabutylammonium perchlorate. The assignments of the redox processes and the understanding of the interactions between the metal phthalocyanine units in 3 and 4 were achieved by the combined evaluation of the voltammetric and in situ spectroelectrochemical outcomes. Complex 3 showed ring-based mixed-valence behaviour as a result of the considerable interaction between the phthalocyanine rings. On the other hand, the interactions between the two metal phthalocyanine units of 4 were found to be much weaker than those in 3. The potential application of molecular organic semiconductors needs the control adjustment of conductivity. Ac and dc conductivity measurements were performed with the applied external electric filed. At high frequency, the conduction follows the universal power law and conduction mechanism can be explained by classical hopping barriers mechanism for the system. 相似文献