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91.
Chun‐Teh Li Renbo Yang Minliang Shih Chuh‐Yung Chen Lien‐Te Hsieh 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2003,78(7):817-823
A radio frequency (RF) plasma system has been used to decompose 1,2‐dichloroethane (DCE). Final products were identified by a Fourier transform infrared (FTIR) spectrometer. The main products of DCE decomposition in O2/Ar plasma were CO2, CO, and HCl. Other minor chlorinated products were CCl4, C2HCl3, C2H3Cl, C2Cl4, CHCl3, C2HCl5, and COCl2. Nonchlorinated products were C2H2, C2H4, C2H6, and HCOOH. The plasma reactor with a brass electrode had a higher decomposition fraction of DCE [η, (Cin ? Cout)/Cin × 100%] than that obtained with other materials (Au, Ni, and Cr). Different electrode configurations (inner and outer) were also evaluated for the decomposition of DCE. Argon plus oxygen was found to be the most suitable carrier/auxiliary gas for DCE decomposition. In addition, operational parameters for DCE decomposition in RF plasma including concentration, operational pressure, and total gas flow rate were evaluated. Copyright © 2003 Society of Chemical Industry 相似文献
92.
Docosahexaenoic acid (DHA, 22∶6n-3) and arachidonic acid (AA, 20∶4n-6) serve important roles in perinatal visual and neural
development. A neonatal pig model was used to determine if dietary supplementation with DHA and AA at slightly greater concentrations
than normally found in human milk would influence fatty acid accretion in retina. One-day-old piglets were assigned to one
of four diets (n=5/group): (i) STD, standard diet containing fat similar to infant formula; (ii) STD+DHA, 0.7% of fatty acids
as DHA; (iii) STD+AA, 0.9% as AA; and (iv) STD+BOTH, 0.8% as DHA plus 1.0% as AA. After 25 d, fatty acids in retina phosphatidylcholine
(PC) and phosphatidylethanolamine (PE) were determined. Supplementation with DHA resulted in approximately twofold increases
(P<0.05) in PC-DHA (4.88% in STD vs. 10.03% in STD+DHA and 9.47% in STD+BOTH). Similarly, AA supplementation increased PC-AA
1.3–1.4-fold (4.47% in STD vs. 6.19% in STD+AA and 5.70% in STD+BOTH). For PE, supplementation with either fatty acid or in
combination resulted in no significant increases, except for a 1.2-fold increase in DHA for STD+BOTH (32.66%) vs. STD (28.38%).
Thus, PC responded to dietary supplementation, with addition of DHA, AA, or BOTH, resulting in increases in respective fatty
acids; PE was less responsive, with only STD+BOTH resulting in increased DHA. No significant competition between DHA and AA
in incorporation into phospholipids was observed. In conclusion, consumption of a combination of DHA and AA by neonatal pigs
supported accretion of DHA in retina phospholipids, while simultaneously supplying the AA necessary for membrane phospholipids
and eicosanoid biosynthesis.
Based on a presentation at the AOCS Annual Meeting & Expo in San Antonio, Texas, May 7–11, 1995. 相似文献
93.
Solution‐Processed High‐Performance Tetrathienothiophene‐Based Small Molecular Blends for Ambipolar Charge Transport 下载免费PDF全文
Sureshraju Vegiraju Chih‐Yu Lin Pragya Priyanka Deng‐Yi Huang Xian‐Lun Luo Hsiang‐Chi Tsai Shao‐Huan Hong Chia‐Jung Yeh Wei‐Chieh Lien Chien‐Lung Wang Shih‐Huang Tung Cheng‐Liang Liu Ming‐Chou Chen Antonio Facchetti 《Advanced functional materials》2018,28(28)
Four soluble dialkylated tetrathienoacene ( TTAR) ‐based small molecular semiconductors featuring the combination of a TTAR central core, π‐conjugated spacers comprising bithiophene ( bT ) or thiophene ( T ), and with/without cyanoacrylate ( CA ) end‐capping moieties are synthesized and characterized. The molecule DbT‐TTAR exhibits a promising hole mobility up to 0.36 cm2 V?1 s?1 due to the enhanced crystallinity of the microribbon‐like films. Binary blends of the p‐type DbT‐TTAR and the n‐type dicyanomethylene substituted dithienothiophene‐quinoid ( DTTQ‐11 ) are investigated in terms of film morphology, microstructure, and organic field‐effect transistor (OFET) performance. The data indicate that as the DbT‐TTAR content in the blend film increases, the charge transport characteristics vary from unipolar (electron‐only) to ambipolar and then back to unipolar (hole‐only). With a 1:1 weight ratio of DbT‐TTAR DTTQ‐11 in the blend, well‐defined pathways for both charge carriers are achieved and resulted in ambipolar transport with high hole and electron mobilities of 0.83 and 0.37 cm2 V?1 s?1, respectively. This study provides a viable way for tuning microstructure and charge carrier transport in small molecules and their blends to achieve high‐performance solution‐processable OFETs. 相似文献
94.
Terahertz (THz) radiation probes intermolecular interactions through crystal lattice vibrations, allowing the characterization of solid materials. Thus, THz spectroscopy is a promising alternative to mainstream solid-state analytical tools such as X-ray diffraction or thermal analysis. The method provides the benefits of online measurement, remote sampling and three-dimensional imaging, all of which are attractive for quality control and security applications. In the context of pharmaceutical solids, THz spectroscopy can differentiate and quantify different forms of active pharmaceutical ingredients. Here, we apply this technique to monitor a dynamic process involving two molecular crystals. In particular, we follow the mechanochemical construction of a two-component cocrystal by grinding together phenazine (phen) and mesaconic acid (mes). To rationalize the observed changes in the spectra, we conduct lattice dynamics calculations that lead to the tentative assignment of at least one feature in the cocrystal THz spectrum. 相似文献
95.
The recently described gastrointestinal glutathione peroxidase (GI-GPx) is the fourth member of the family of the selenoenzymes glutathione peroxidases (GPx). In contrast to the more uniform distribution of, for example, the classical glutathione peroxidase (cGPx), it is expressed exclusively in the gastrointestinal tract and has, therefore, been suggested to function as a primary barrier against alimentary hydroperoxides. In order to get an idea of its relative importance we investigated its position in the hierarchy of selenoprotein expression. The selenium-dependent expression of GI-GPx was analyzed in comparison with that of other GPx types at the level of mRNA and protein in HepG2 and CaCo-2 cells. Furthermore, the selenocysteine insertion sequence (SECIS) efficiencies of GI-GPx, phospholipid hydroperoxide glutathione peroxidase (PHGPx) and cGPx in response to selenium were determined by a reporter-gene assay in human hepatoma cells and baby hamster kidney cells. GI-GPx mRNA levels increased during selenium deficiency, whereas cGPx mRNA levels decreased and PHGPx mRNA levels remained almost unaffected. In cells grown in selenium-poor media, all GPx-types were low in both activity and immunochemical reactivity. Upon selenium repletion immunoreactive GI-GPx protein reached a plateau after 10 h, whereas cGPx started to be expressed at 24 h and did not reach its maximum level before 3 days. SECIS efficiencies decreased in the order PHGPx > cGPx > GI-GPx. The augmentation of SECIS efficiencies by selenium was highest for cGPx and intermediate for PHGPx, whereas it was marginal for GI-GPx. The high mRNA stability under selenium restriction, the speed of biosynthesis upon selenium repletion and the marginal effect of selenium on the SECIS efficiency indicate that of the GPx isotypes, GI-GPx ranks highest in the hierarchy of selenoproteins and point to a vital role of GI-GPx in the gastrointestinal tract. 相似文献
96.
Despite the potential use of long-chain polyunsaturated fatty acid (LCPUFA) supplementation to promote growth and neural development
of the infant, little is known about potential harmful effects of the supplementation. The present study determined whether
supplementation with arachidonic acid (AA) and/or docosahexaenoic acid (DHA) in rat milk formula (RMF) affects saturation
of pulmonary surfactant phospholipids (PL). Beginning at 7 d of age, infant rats were artificially fed for 10 d with RMF supplemented
with AA at 0, 0.5, and 1.0% of total fatty acid, or supplemented with DHA at 0, 0.5, and 1.0%, or cosupplemented with AA and
DHA at levels of 0∶0, 0.5∶0.3, and 1.0∶0.6% of the fat blend. Lung tissue PL contained 43 weight percent palmitate (16∶0)
of total fatty acids in infant rats fed the unsupplemented RMF. The supplementation with AA at both 0.5 and 1.0% decreased
the weight percentage of 16∶0 and stearate (18∶0), indicating a decrease in saturation of PL. The observed decreases were
accompanied by increases in AA and linoleic acid (18∶2n−6). Surfactant phosphatidylcholine (PC) consisted of 71 weight percent
16∶0 in the unsupplemented group, and this highly saturated PC was not altered by the cosupplementation with AA and DHA although
there was a slight increase in DHA. Similarly, the cosupplementation did not change fatty acid composition of surfactant PL
when compared with the unsupplemented group. The cosupplementation slightly decreased the weight percentage of 16∶0 with a
proportional increase in 18∶0 leading to an unchanged weight percentage of total saturated fatty acids. These results suggest
that, unlike lung tissue PL, the composition of saturated fatty acids in surfactant PL, particularly PC, is resistant to change
by dietary AA and DHA supplementation. This, together with the unchanged concentration of total fatty acids in surfactant
PC, indicates that LCPUFA cosupplementation causes no effect on pulmonary surfactant. 相似文献
97.
98.
Cellulose crystallite sizes of naturally green and brown cottons as well as of white undyed and dyed cotton were studied by using X‐ray diffractometry. Data were analyzed both by a peak stripping method using the program WinFit and by whole profile matching using the FullProf program. The fit obtained with WinFit agreed with the results from the FullProf except for a small difference centered on the 002 reflection. Crystallite sizes of white and colored cottons were estimated by the full‐width‐at‐ half‐minimum (FWHM) method, and the results showed that compared to the white cotton, the crystallite sizes of green and brown cottons based on the 101 and 002 reflections were found to be comparable, whereas smaller 101¯ crystallite sizes were observed. After dyeing, the crystallite size of dyed brown cotton displayed a slight increase in the 002 crystallite size compared to that of the undyed white cottons. The average crystallite size of 101, 101¯, and 002 for each cotton determined by the WinFit program was comparable to that estimated by the FullProf program. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 1466–1471, 2000 相似文献
99.
Yueh‐Heng Li Yung‐Sheng Lien Yei‐Chin Chao Derek Dunn‐Rankin 《Progress in Photovoltaics: Research and Applications》2009,17(5):327-336
Combustion‐driven thermophotovoltaic (TPV) systems have obtained increasing attention in recent decades, but most studies have focused on developing narrowband photovoltaic cells and selective emitters. In terms of the heat source, conventional combustion configurations and light gaseous fuels are extensively utilized in macro‐ or meso‐scale TPV power systems to simplify thermal management and mechanical fabrication. As far as miniaturization is concerned, however, fuelling these systems with liquid hydrocarbons would provide inherent advantages of high energy density and low volatility. Liquid fuels also promise easy and safe fuel recharging for small‐scale power systems. In this paper, a central porous‐medium combustor was employed in a small scale TPV power system. The combustor incorporated an emitting chamber wall and a heat recuperator. The radiant efficiency and overall efficiency were compared using different liquid hydrocarbon fuels in the system. The electric output characteristics of the combustion driven TPV system have been investigated to demonstrate the feasibility of a GaSb cell‐based TPV power system and to provide design guidance for mesoscale liquid‐burning TPV systems. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
100.
Bert De Schoenmaker Annelies Goethals Lien Van der Schueren Hubert Rahier Karen De Clerck 《Journal of Materials Science》2012,47(9):4118-4126
Nanofibres can be processed into several high-end applications due to their unique characteristics, especially when based
on a diversity of polymers with specific properties. This, however, requires that the nanofibrous structures are produced
in a highly reproducible way. The article gives focus to polyamide (PA) 6.9, a less exploited PA though with interesting properties
such as a very low moisture absorption. To trace and understand the dominant parameters that allow for the aimed reproducible
characteristics, the influence of the solution parameters on the steady state behaviour during electrospinning as well as
the resultant fibre morphology is followed by scanning electron microscopy and differential scanning calorimetry. Results
show a significant effect of the amount of non-solvent acetic acid, added to the solvent formic acid, on the steady state
behaviour and the fibre morphology. The non-solvent acetic acid broadens the steady state window by making the electrospin
solutions more suitable to obtain uniform and reproducible nanofibrous structures with a narrow nanofibre diameter distribution.
The mixture of the solvent formic acid and the non-solvent acetic acid strongly contributes to the future potentials of PA
6.9 nanofibres, with its leading to a smaller fibre distribution and moreover highly reproducible in time. 相似文献