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991.
Romaner L Heimel G Gruber M Brédas JL Zojer E 《Small (Weinheim an der Bergstrasse, Germany)》2006,2(12):1468-1475
Density functional theory (DFT) calculations based on band structure are used to investigate the electromechanical properties of a molecular junction consisting of a dithiolbenzene molecule sandwiched between two gold slabs. This represents a prototypical system for the field of molecular electronics; such a system has previously been studied in break-junction measurements and electron-transport calculations. The stretching and breaking behavior of the junction is analyzed for different geometric conformations, and it is found that the breakage occurs through dissociation of one of the sulfur-gold bonds with a maximum force of 1.25 nN. The molecular electronic states shift during stretching, and, at the point of highest stress in the junction, the highest occupied molecular orbital (HOMO) of the molecule is located exactly at the Fermi level. 相似文献
992.
Consumption of green or black tea has been inversely associated with the development and progression of cardiovascular diseases. In this review, the current knowledge about protective effects of tea and tea constituents, particularly flavonoids, on the cardiovascular system is summarized. Underlying mechanisms for the beneficial effects of tea include vasculoprotective, antioxidative, antithrombogenic, anti-inflammatory, and lipid-lowering properties of tea flavonoids. Although promising experimental data on beneficial effects of tea in various cardiovascular diseases are available, results of clinical studies in humans are not uniform. A number of factors are discussed which may contribute to inconsistent data in humans. Overall, tea represents a promising tool for the prevention and treatment of cardiovascular disorders. 相似文献
993.
Valenzuela M. A. Bentley J. M. Lorenz R. D. 《Industry Applications, IEEE Transactions on》2010,46(1):108-120
994.
Raca D. Garcia P. Reigosa D. D. Briz F. Lorenz R. D. 《Industry Applications, IEEE Transactions on》2010,46(1):167-178
995.
Dariusz Burnat Andre Heel Lorenz Holzer Eugenio Otal Dariusz Kata Thomas Graule 《International Journal of Hydrogen Energy》2012
Chemical interactions between common electrolyte materials and various La doped strontium titanates (LST), which are redox-stable candidates for SOFCs anodes, were thoroughly investigated. The reactions of nanosized reagents were studied by SEM/EDX microscopy and XRD with subsequent Rietveld refinement. It was found that all A-site deficient LSTs promoted a reaction with Sc and Y stabilized zirconia, whilst stoichiometric LST was chemically stable. Detected structural and microstructural changes were solely assigned to high mobility of Ti. Diffusion of Ti into the zirconia structure promoted formation of tetragonal structures with p42/nmc-type space groups. The results indicate that the reduction of oxygen partial pressure during sintering and application of Sc-containing electrolyte material are successful strategies to hinder or even avoid reactivity. 相似文献
996.
997.
Nina M. Keil Marc Pommereau Antonia Patt Beat Wechsler Lorenz Gygax 《Journal of dairy science》2017,100(2):1353-1362
Confined goats spend a substantial part of the day feeding. A poorly designed feeding place increases the risk of feeding in nonphysiological body postures, and even injury. Scientifically validated information on suitable dimensions of feeding places for loose-housed goats is almost absent from the literature. The aim of the present study was, therefore, to determine feeding place dimensions that would allow goats to feed in a species-appropriate, relaxed body posture. A total of 27 goats with a height at the withers of 62 to 80 cm were included in the study. Goats were tested individually in an experimental feeding stall that allowed the height difference between the feed table, the standing area of the forelegs, and a feeding area step (difference in height between forelegs and hind legs) to be varied. The goats accessed the feed table via a palisade feeding barrier. The feed table was equipped with recesses at varying distances to the feeding barrier (5–55 cm in 5-cm steps) at angles of 30°, 60°, 90°, 120°, or 150° (feeding angle), which were filled with the goats' preferred food. In 18 trials, balanced for order across animals, each animal underwent all possible combinations of feeding area step (3 levels: 0, 10, and 20 cm) and of difference in height between feed table and standing area of forelegs (6 levels: 0, 5, 10, 15, 20, and 25 cm). The minimum and maximum reach at which the animals could reach feed on the table with a relaxed body posture was determined for each combination. Statistical analysis was performed using mixed-effects models. The animals were able to feed with a relaxed posture when the feed table was at least 10 cm higher than the standing height of the goats' forelegs. Larger goats achieved smaller minimum reaches and minimum reach increased if the goats' head and neck were angled. Maximum reach increased with increasing height at withers and height of the feed table. The presence of a feeding area step had no influence on minimum and maximum reach. Based on these results, the goats' feeding place can be designed to ensure that the animals are able to reach all of the feed in the manger or on the feed table with a relaxed posture, thus avoiding injuries and nonphysiological stress on joints and hooves. A feeding area step up to a maximum of 20 cm need not be taken into account in terms of feeding reach. However, the feed table must be raised at least 10 cm above the standing area to allow the goats to feed in a species-appropriate, relaxed posture. 相似文献
998.
Natalio F Kashyap A Lorenz S Kerschbaumer H Dietzsch M Tahir MN Duschner H Strand S Strand D Tremel W 《Nanoscale》2012,4(15):4680-4686
A convenient and simple strategy for preparing water soluble, photoluminescent functionalized silica nanoparticles (M-dots) in the absence of fluorophores or metal doping is demonstrated. These M-dots can be used for bioimaging using one and two-photon microscopy. Because of their high photostability, low toxicity and high biocompatibility compared with Lumidot? CdSe/ZnS quantum dots, functionalized silica particles are superior alternatives for current bioimaging platforms. Moreover, the presence of a free amine group at the surface of the M-dots allows biomolecule conjugation (e.g. with antibodies, proteins) in a single step for converting these photoluminescent SiO(2) nanoparticles into multifunctional efficient vehicles for theragnostics. 相似文献
999.
1000.