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671.
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
672.
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
673.
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
674.
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
675.
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
676.
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
677.
Elisabeth Smolle Valentin Taucher Martin Pichler Edgar Petru Sigurd Lax Johannes Haybaeck 《International journal of molecular sciences》2013,14(5):9536-9555
Ovarian carcinoma (OC) is the most lethal gynecological malignancy. Response to platinum-based chemotherapy is poor in some patients and, thus, current research is focusing on new therapy options. The various histological types of OC are characterized by distinctive molecular genetic alterations that are relevant for ovarian tumorigenesis. The understanding of these molecular pathways is essential for the development of novel therapeutic strategies.
Purpose
We want to give an overview on the molecular genetic changes of the histopathological types of OC and their role as putative therapeutic targets.In Depth Review of Existing Data
In 2012, the vascular endothelial growth factor (VEGF) inhibitor, bevacizumab, was approved for OC treatment. Bevacizumab has shown promising results as single agent and in combination with conventional chemotherapy, but its target is not distinctive when analyzed before treatment. At present, mammalian target of rapamycin (mTOR) inhibitors, poly-ADP-ribose polymerase (PARP) inhibitors and components of the EGFR pathway are in the focus of clinical research. Interestingly, some phytochemical substances show good synergistic effects when used in combination with chemotherapy.Conclusion
Ongoing studies of targeted agents in conjunction with chemotherapy will show whether there are alternative options to bevacizumab available for OC patients. Novel targets which can be assessed before therapy to predict efficacy are needed. The assessment of therapeutic targets is continuously improved by molecular pathological analyses on tumor tissue. A careful selection of patients for personalized treatment will help to reduce putative side effects and toxicity. 相似文献678.
This article reports on an investigation on numerical prediction of thermal characteristics of a certain type of duct. The ducts considered have rib turbulators to enhance the heat transfer rate. The calculation method consists of a low Re number turbulence model and two methods for determining the turbulent Reynolds stresses, namely, a simple eddy viscosity model (EVM) [1] and an explicit algebraic stress model (EASM) [2]. The model development is carried out to make the original EASM consistent with the low Re number k- epsilon turbulence model applied. A certain method is developed to deal with the decoupling of the velocity and Reynolds stress fields inthe collocated grid arrangement that is chosen in this study. The SIMPLEC algorithm handles the pressure-velocity coupling. The computations are performed with the assumption of fully developed periodic conditions. These models are used to predict the convective turbulent forced convection in different test cases and the results are compared with experiments. A ribbed duct with two ribs on opposite walls is chosen and the obtained results including the mean thermal characteristics of the considered duct are compared with an experimental correlation. Two further duct configurations, identical to an experimental setup, are then computed. These experimental cases are chosen because detailed thermal-hydraulic information is available and then local comparisons between the two prediction models and experimental results are possible. The calculated mean and local thermal-hydraulic values are compared with corresponding experimental data and the prediction capabilities of the two turbulence models (EVM and EASM) are discussed. Theresults show that the EASM has some superiority over the EVM in the prediction of the velocity field structure, but the mean thermal predictions are not very different. There are also some important features of the flow field, whichare not revealed by theEVM calculations. However, the required CPU times are considerably higher for the EASM case. 相似文献
679.
Fengli Zhang Bengt Sundén Weihong Zhang 《Numerical Heat Transfer, Part A: Applications》2013,63(10):1087-1105
Based on the Constructal Theory, parallel-flow and counterflow microchannels heat sinks with bifurcations are put forward to manage the temperature nonuniformity and further reduce the temperature of microchannel heat sinks bottom plates. Several models with different lengths of bifurcations are designed, and the corresponding laminar fluid flow and heat transfer of all models have been investigated through numerical simulations. The pressure, velocity, temperature distributions, and averaged Nusselt numbers are analyzed in details, and then the overall thermal resistances and overall thermal performance are compared. The results show that the thermal performance of counterflow microchannel heat sinks is better than that of parallel-flow heat sinks for the same geometry, and bifurcation can improve the thermal performance for all cases. It is suggested that a proper design of the length of bifurcation counterflow microchannel can be employed to improve the overall thermal performance of microchannel heat sinks. The study complements and extends previous works. 相似文献
680.
Instead of the traditional trial-and-error process, a genetic algorithm (GA) is successfully applied to thermal design of fin-and-tube heat exchangers (FTHEs). The design method uses a GA to search and optimize structure sizes of FTHEs. The minimum total weight or total annual cost of FTHEs is taken as the objective function in the GA, respectively. Seven design parameters are varied for the optimization objectives. The implementation of the design method consists of a GA routine and a thermal design routine. In the GA routine, binary coding for tournament selection, uniform crossover, and one-point mutation is adopted. In the thermal design routine, thermal design of the FTHE is carried out according to the conditions of the structure sizes that the genetic algorithm generated, and the log-mean temperature difference method is used to determine the heat transfer area under the combined structure sizes for a given heat duty. Optimization shows that it is possible to achieve a great reduction in cost or weight, whenever such objectives have been chosen for minimization. The method is universal and may be used for thermal design and optimization of FTHEs under different specified duties. 相似文献