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排序方式: 共有193条查询结果,搜索用时 15 毫秒
31.
To understand deeply the structural,elastic and thermodynamic characteristics of Al 2 X (X= Sc,Y) compounds in C15 type (space number 227) Cu 2 Mg structure,we have performed ab-initio density functional theory within the local density approximation (LDA) and the generalized gradient approximation (GGA).The thermodynamic properties of the considered structures are obtained through the quasi-harmonic Debye model.We have presented the results on the basic physical parameters,such as the lattice constant,bulk modulus,pressure derivative of bulk modulus,second-order elastic constants,Zener anisotropy factor,Poisson s ratio,Young s modulus,and isotropic shear modulus.In order to gain further information,the pressure-and temperature-dependent behaviour of the volume,bulk modulus,thermal expansion coefficient,heat capacity,entropy,Debye temperature and Gru¨neisen parameter were also evaluated over a pressure range of 0-20 GPa for Al 2 Sc and 0-17 GPa for Al 2 Y compound and a wide temperature range of 0-2000 K for both compounds.The obtained results were compared with the other reported values. 相似文献
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Sahan Yasemin Gurbuz Ozan Goncagul Gulsen Kara Ali Ozakin Cuneyt 《Food science and biotechnology》2017,26(4):1123-1128
Food Science and Biotechnology - Polyethylene glycol (PEG) and polyethylene glycol–polylactic acid (PEG–PLA) have an organic structure and no negative effect on human health. The... 相似文献
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The purpose of this study is to explore the role of target costing in managing product costs while promoting quality specifications that will meet customer requirements. In addition, it aims to develop a target costing module that will simplify implementation of target costing especially in small and medium enterprises (SMEs). Tools of operations management such as quality function deployment (QFD) and value engineering (VE) have been considered and evaluated in terms of their integration into the target costing. In order to investigate the total effect, an implementation of the QFD deployment–target costing process (QFD–TC process) was conducted in a small manufacturing company. Previous studies on target costing were mostly conducted in lead companies. This study focuses on implementation of the QFD–TC process in SMEs. Overall, it was found that the QFD–TC process was an essential technique in managing the costs of both a product and the overall production process. Combining target costing with QFD and VE techniques provides companies with a competitive cost advantage. 相似文献
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We examined the development of self-esteem in adolescence and young adulthood. Data came from the Young Adults section of the National Longitudinal Survey of Youth, which includes 8 assessments across a 14-year period of a national probability sample of 7,100 individuals age 14 to 30 years. Latent growth curve analyses indicated that self-esteem increases during adolescence and continues to increase more slowly in young adulthood. Women and men did not differ in their self-esteem trajectories. In adolescence, Hispanics had lower self-esteem than Blacks and Whites, but the self-esteem of Hispanics subsequently increased more strongly, so that at age 30 Blacks and Hispanics had higher self-esteem than Whites. At each age, emotionally stable, extraverted, and conscientious individuals experienced higher self-esteem than emotionally unstable, introverted, and less conscientious individuals. Moreover, at each age, high sense of mastery, low risk taking, and better health predicted higher self-esteem. Finally, the results suggest that normative increase in sense of mastery accounts for a large proportion of the normative increase in self-esteem. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
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Antioxidant activities of organic grape, pomace, juice, must, wine and their correlation with phenolic content 总被引:2,自引:0,他引:2
Hatice K. Yldrm Yasemin D. Akçay Ulgar Güvenç Ahmet Altndili & Eser Y. Sözmen 《International Journal of Food Science & Technology》2005,40(2):133-142
The highest values of antioxidant activity (AOA), inhibition of low‐density lipoproteins (LDL‐diene, LDL‐MDA) and total phenols were determined in pomace (82.30 and 82.60%), grapes (68.91%) and must [2750 mg L?1 gallic acid equivalents (GAE)], respectively. For all parameters (AOA, iLDL‐diene, iLDL‐MDA, total phenols) the highest values were obtained in Cabernet Sauvignon and Merlot grape varieties. Positive correlations were determined between AOA and iLDL‐diene (r = 0.809); AOA and total phenols (r = 0.528); total phenols and iLDL‐diene (r = 0.451) with significance of P < 0.005. The results of principal component analysis demonstrated that the location of iLDL‐diene and AOA is the same for pomace, must and red wines. The total phenols are found in the same place in red wines, red grapes, pomace and must. The results emphasize the importance of must, pomace and red wine for inhibiting LDL‐oxidation. 相似文献
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Saliha Ilican Yasemin Caglar Mujdat Caglar Mutlu Kundakci Aytunc Ates 《International Journal of Hydrogen Energy》2009
CdxZn1−xO films have been deposited by sol–gel spin-coating method onto glass substrates. The Cd/Zn ratio in solution was changed from 0 to 1. Zinc acetate dehydrates, cadmium acetate dehydrates, 2-methoxyethanol and monoethanolamine were used as a starting material (zinc and cadmium), solvent and stabilizer, respectively. The crystal structure and orientation of the films were investigated by X-ray diffraction (XRD) patterns. XRD patterns show that the films are polycrystalline nature. As x varies from 0 to 1, it was observed that the crystal structure changed from wurtzite (ZnO) to cubic (CdO) structure. The optical properties of these films have been investigated by means of the optical transmittance and reflectance spectra. A significant change in optical absorption edge, optical band gap and optical constant with variation in composition was observed. 相似文献
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Seval Aksoy Yasemin CaglarSaliha Ilican Mujdat Caglar 《International Journal of Hydrogen Energy》2009
CdO film has been deposited by sol–gel spin coating method on the glass substrate and then the film has been annealed at 400, 500, 600 °C for 1 h. Effect of annealing temperature on the structural and optical properties of the film has been investigated. The crystal structure and orientation of the as-grown and annealed CdO films have been investigated by X-ray diffraction method. Annealed CdO films are polycrystalline with (111) preferential orientation. The information on strain and grain size is obtained from the full width-at-half-maximum (FWHM) of the diffraction peaks. Texture coefficient and lattice constant have been calculated. The surface morphology of the films has been analyzed. The optical band gap value decreased with increasing the annealing temperatures. 相似文献