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691.
The effect of temperature over the range ?196 to 150°C on the crosslinking of polyethylenes irradiated by electron beam has been investigated on the basis of gel content determination and Fourier transform infra-red (FTIR) spectroscopy. The crosslinking efficiency increases significantly with increasing irradiation does and at elevated irradiation temperature. The crosslinking rates of high density polyethylene (HDPE) and low density polyethylene (LDPE) samples above the melting point (TM) are much higher than those below Tm. The FTIR data give positive evidence: (i) that trans-vinylene double bonds in cross linked HDPE and LDPE samples increase with increasing irradiation dose temperature (ii) that vinyl double bonds in HDPE decrease rapidly with increasing irradiation dose and temperature, and (iii) vinylidene groups in LDPE decrease slowly with increasing temperature at the lower dose and are almost independent of the irradiation temperature at above room temperature and the higher dose of more than 100 kGy. Gas bubbles are observed in LDPE samples irradiated at 100 and 150°C with high dose (200 to 250 kGy). The size of the bubbles increases gradually at high temperatures. 相似文献
692.
Low resolution mass spectra of pyrrolidides of isomeric octadecadienoic acids and other polyunsaturated straight chain fatty acids are presented and discussed. The spectra of the pyrrolidides contain mainly ions from the polar part of the molecule and give spectra that are specific for each isomer. The interpretation follows, in most cases, the rule developed for monounsaturated fatty acid pyrrolidides. 相似文献
693.
The name “catatectic” is proposed for the reaction solid 1 ⇆ solid 2 + liquid, and a heating simple thermodynamic analysis
is presented to aid in predicting the existence of this feature in binary phase diagrams. In addition, a survey of available
phase diagrams shows that the reaction may occur much more commonly than has been suspected. 相似文献
694.
Bengt Sundén 《International Communications in Heat and Mass Transfer》1985,12(3):225-232
The problem of conjugate heat transfer from rectangular fins is treated numerically. Results are provided for the three Prandtl numbers (three fluids) 0.021, 0.7 and 5.0 and convection - conduction parameters meters in the range of 0 ≤ √Re kfL/ksb = CCP ≤ 5. The results indicated great effects of both CCP and Pr. Comparisons with the simple conventional fin theory show that concerning the fin efficiency, the simple theory yields acceptable results while the temperature variation and local heat flux distributions are not correctly predicted. 相似文献
695.
A deterministic approach is used to evaluate bounds for the frequency of the digital oscillator considering either roundoff or magnitude-truncation quantisation. With a proper choice of the number of significant digits, any degree of approximation for a specified sinusoidal oscillation can be achieved. 相似文献
696.
The first study of the entire liquid binary iron-tin is reported. The system exhibits ideal/Henrian behavior on the iron-rich
side, and pseudoregular behavior on the tinrich side. Near 1300°C the miscibility gap in the liquid is evident; at 1500°C
it cannot be ascertained by the mass spectrometric method. The center of the tendency for demixing is near xsn = 0.60. The
activity coefficients at 1537°C are in the range 0 < xsn < 0.41: γFe = 1 and γsn = 2.15; in the range 0.79 <xSn < 1-00: lnγFe = -0.41 + 2.31x2Sn and ln γsn = 2.36 x2Fe.
SIGURD WAGNER, formerly Postdoctoral Fellow, Department of Metallurgical Engineering, Ohio State University, Columbus, Ohio 相似文献
697.
Alex Z. Kattamis Noel Giebink I‐Chun Cheng Sigurd Wagner Stephen R. Forrest Yongtaek Hong Vincent Cannella 《Journal of the Society for Information Display》2007,15(7):433-437
Abstract— An active‐matrix organic light‐emitting diode (AMOLED) display driven by hydrogenated amorphous‐silicon thin‐film transistors (a‐Si:H TFTs) on flexible, stainless‐steel foil was demonstrated. The 2‐TFT voltage‐programmed pixel circuits were fabricated using a standard a‐Si:H process at maximum temperature of 280°C in a bottom‐gate staggered source‐drain geometry. The 70‐ppi monochrome display consists of (48 × 4) × 48 subpixels of 92 ×369 μm each, with an aperture ratio of 48%. The a‐Si:H TFT pixel circuits drive top‐emitting green electrophosphorescent OLEDs to a peak luminance of 2000 cd/m2. 相似文献
698.
Effects of dietary phenolic compounds on tocopherol, cholesterol, and fatty acids in rats 总被引:5,自引:0,他引:5
The effects of the phenolic compounds butylated hydroxytoluene (BHT), sesamin (S), curcumin (CU), and ferulic acid (FA) on
plasma, liver, and lung concentrations of α- and γ-tocopherols (T), on plasma and liver cholesterol, and on the fatty acid
composition of liver lipids were studied in male Sprague-Dawley rats. Test compounds were given to rats ad libitum for 4 wk at 4 g/kg diet, in a diet low but adequate in vitamin E (36 mg/kg of γ-T and 25 mg/kg of α-T) and containing 2 g/kg
of cholesterol. BHT significantly reduced feed intake (P<0.05) and body weight and increased feed conversion ratio; S and BHT caused a significant enlargement of the liver (P<0.001), whereas CU and FA did not affect any of these parameters. The amount of liver lipids was significantly lowered by
BHT (P<0.01) while the other substances reduced liver lipid concentrations but not significantly. Regarding effects on tocopherol
levels, (i) feeding of BHT resulted in a significant elevation (P<0.001) of α-T in plasma, liver, and lung, while γ-T values remained unchanged; (ii) rats provided with the S diet had substantially
higher γ-T levels (P<0.001) in plasma, liver, and lung, whereas α-T levels were not affected; (iii) administration of CU raised the concentration
of α-T in the lung (P<0.01) but did not affect the plasma or liver values of any of the tocopherols; and (iv) FA had no effect on the levels of
either homolog in the plasma, liver, or lung. The level of an unknown substance in the liver was significantly reduced by
dietary BHT (P<0.001). BHT was the only compound that tended to increase total cholesterol (TC) in plasma, due to an elevation of cholesterol
in the very low density lipoprotein + low density lipoprotein (VLDL+LDL) fraction. S and FA tended to lower plasma total and
VLDL+LDL cholesterol concentrations, but the effect for CU was statistically significant (P<0.05). FA increased plasma high density lipoprotein cholesterol while the other compounds reduced it numerially, but not
significantly. BHT, CU, and S reduced cholesterol levels in the liver TC (P<0.001) and percentages of TC in liver lipids (P<0.05). With regard to the fatty acid composition of liver lipids, S increased the n-6/n-3 and the 18∶3/20∶5 polyunsaturated
fatty acids (PUFA) ratios, and BHT lowered total monounsaturated fatty acids and increased total PUFA (n−6+n−3). The effects
of CU and FA on fatty acids were not highly significant. These results suggest some in vivo interactions between these phenolic compounds and tocopherols that may increase the bioavailability of vitamin E and decrease
cholesterol in rats. 相似文献
699.
Quantification of Phorbol Esters in Jatropha curcas by HPLC‐UV and HPLC‐ToF‐MS with Standard Addition Method
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Philipp M. Neu Sigurd Schober Martin Mittelbach 《European Journal of Lipid Science and Technology》2018,120(8)
700.
Bengt Turner 《Journal of Housing and the Built Environment》1993,8(1):61-66
Conclusions The Housing Indicators Program will generate a large data set, involving a number of countries where reliable data has not
yet been available. It will be most useful for the analysis of housing markets, especially in a comparative perspective.
My critical comments concerned on the relevance and reliability of the indicators to assess the housing situation in countries
with different housing objectives. I have also commented on possible missing indicators and warned against an uncritical use
of the outcomes of an indicator study. I do believe, however, that if the indicators are used in a responsible way, the program
has the potential of becoming a useful tool in the evaluation and implementation of housing policy.
Finally, the Indicators Program will help to put housing policy on the political agenda-which is where it belongs. 相似文献