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991.
S. Cecchi T. Etzelstorfer E. Müller A. Samarelli L. Ferre Llin D. Chrastina G. Isella J. Stangl J. M. R. Weaver P. Dobson D. J. Paul 《Journal of Electronic Materials》2013,42(7):2030-2034
Ge/SiGe multiple quantum wells are presented as efficient material for room-temperature thermoelectric generators monolithically integrated onto silicon. We have deposited and characterized 10-μm-thick heterostructures engineered for lateral devices, in which both heat and current flow parallel to the multilayer. In this paper we investigate in detail the structural and interface quality by means of x-ray diffraction and transmission electron microscopy. Thermoelectric measurements, giving a figure of merit of 0.04 to 0.08, together with mobility spectra and defect analysis suggest possibilities of even higher efficiency. Nevertheless, the high power factor of 2 mW/K2m to 6 mW/K2m is promising for applications. 相似文献
992.
Transition zones between structures as bridges or box culverts frequently present higher degradation rates compared to the remaining railway. This paper presents a numerical model for the dynamic loads on the ballast caused by trains passing a transition. The model was validated with field data obtained from an extensive field survey conducted in two transition zones in the Netherlands. Results show that the forces on the ballast vary significantly both in time and space on a transition, especially with the appearance of voids under the sleepers. Implications of the results on the long-term behaviour of transition zones are presented. 相似文献
993.
994.
Wasylyshyn Christina; Verhaeghen Paul; Sliwinski Martin J. 《Canadian Metallurgical Quarterly》2011,26(1):15
A meta-analysis of 26 published articles (with 36 independent participant groups) was conducted to analyze the relationship between task-switching effects and aging. Latency served as the dependent measure. Multilevel modeling was used to test for additive and multiplicative complexity effects in local and global switch costs. Global task switching was found to add 1 or more stages to processing and resulted in a marked age deficit. Local task-switching costs, on the other hand, showed a multiplicative complexity effect but no specific attention-related age deficits. Cueing or switch predictability did not affect age differences. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
995.
996.
997.
Christian J. Cyron Jean-Jacques Marigo Paul Sicsic 《International Journal of Fracture》2014,187(1):51-75
This paper studies the initiation of cohesive cracks in the thermal shock problem through a variational analysis. A two-dimensional semi-infinite slab with an imposed temperature drop on its free surface is considered. Assuming that cracks are periodically distributed and orthogonal to the surface, at short times we show that the optimum is a distribution of infinitely close cohesive cracks. This leads us to introduce a homogenized effective behavior which reveals to be stable for small times, thanks to the irreversibility. At a given loading cracks with a non-cohesive part nucleate. We characterize the periodic array of these macro-cracks between which the micro-cracks remain. Finally, for longer times, the cohesive behavior converges towards that from Griffith’s evolution law. Numerical investigations complete and quantify the analytical results. 相似文献
998.
Cord Henrik Surberg Paul Stratton Klaus Lingenhöle 《BHM Berg- und Hüttenm?nnische Monatshefte》2010,155(9):425-429
For a tool steel AISI D2 (1.2379) and a case hardening steel (1.7131) the opportunity of reduction processing time and improvements of final properties and dimensional stability using deep cold treatments were investigated. Hardened blocks were subjected to various combinations of single and multiple tempering steps (520 °C and 540 °C for 1.2379 and 180 °C for 1.7131 respectively) and short- as well as long-time deep cold treatments (-90 °C, -120 °C and -150 °C). The greatest dimensional stability was achieved by deep cold treatments at the lowest temperature (-150 °C) and was independent of the deep cold treatment time. 相似文献
999.
Gibbons Mary Beth Connolly; Crits-Christoph Paul; Barber Jacques P.; Wiltsey Stirman Shannon; Gallop Robert; Goldstein Lizabeth A.; Temes Christina M.; Ring-Kurtz Sarah 《Canadian Metallurgical Quarterly》2009,77(5):801
The goal of this article was to examine theoretically important mechanisms of change in psychotherapy outcome across different types of treatment. Specifically, the role of gains in self-understanding, acquisition of compensatory skills, and improvements in views of the self were examined. A pooled study database collected at the University of Pennsylvania Center for Psychotherapy Research, which includes studies conducted from 1995 to 2002 evaluating the efficacy of cognitive and psychodynamic therapies for a variety of disorders, was used. Patient samples included major depressive disorder, generalized anxiety disorder, panic disorder, borderline personality disorder, and adolescent anxiety disorders. A common assessment battery of mechanism and outcome measures was given at treatment intake, termination, and 6-month follow-up for all 184 patients. Improvements in self-understanding, compensatory skills, and views of the self were all associated with symptom change across the diverse psychotherapies. Changes in self-understanding and compensatory skills across treatment were predictive of follow-up symptom course. Changes in self-understanding demonstrated specificity of change to dynamic psychotherapy. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
1000.
Codruţa Ignea Cristina Mihaela Dorobanţu Christopher Paul Mintoff Norica Branza-Nichita Michael R. Ladomery Panagiotis Kefalas Veronica Sanda Chedea 《Food chemistry》2013
Grape seed extracts (GSEs) were investigated in yeast cells harbouring defects in their antioxidant system (regarding the cellular growth and growth recovery from H2O2 insult). GSEs antioxidant activity was detected in wild-type and mutant strains Δcta1, Δgsh1 and Δoye2glr1, while pro-oxidant activity in Δsod1 cells was seen. Assessment of proliferation of prostate cancer PC3 and HBV-replicating HepG2 2.2.15 cells treated with GSEs has shown higher cytotoxicity of red grape seed extract (RW) than white grape seed extract (WW) subjective to dose and period of administration. No antiviral effect was detected by measuring the secreted virion particles in HepG2 2.2.15 cells treated with GSEs. The GSEs play a dual antioxidant/pro-oxidant role in vivo according with the cellular antioxidant system deficiencies and exhibit cytotoxic properties in PC3 and HepG2 2.2.15 cell lines, but no antiviral action against HBV. 相似文献