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511.
Axel Schindler Jochen Brill Norbert Fruehauf James P. Novak Zvi Yaniv 《Physica E: Low-dimensional Systems and Nanostructures》2007,37(1-2):119
We have investigated two possible fields of application for carbon nanotube (CNT) networks in flexible displays. Transparent and conductive layers of CNTs were spray coated onto glass and plastic substrates. The spectral transmission of the produced layers is almost even for all wavelengths in the visible regime. A sheet resistance of 400 Ω/□ at a transmittance of 80% was achieved.Thin-film transistors (TFT) were created on silicon wafers and glass substrates using low-density CNT networks as a semiconducting layer. The process used for device fabrication on glass substrates is fully compatible to application on plastic foils. The transistors reach on/off ratios of more than five orders of magnitude and show device charge carrier mobilities in the order of 1 cm2/Vs. These values promise an application in active matrix liquid crystal displays (AMLCD). Issues that need to be addressed are the homogeneity and reproducibility of the device properties. 相似文献
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513.
In this paper, we give a comprehensive error analysis for an approximate solution method for the generalized eigenvalue problems arising for instance in the context of electronic structure computations based on density functional theory. The solution method has been demonstrated to excel as compared to established solvers in both computational effort and scaling for parallelization. Here we estimate the improvement provided by our proposed subspace method starting from the initial approximations for instance provided in the course of the self-consistent field iteration, showing that in general the approximation quality is improved by our method to yield sufficiently accurate eigenvalues. 相似文献
514.
515.
Bai Z Bolton T Brown JS Bunnell KO Burchell M Burnett TH Cassell RE Coffman D Cook V Coward DH DeJongh F Dorfan DE Drinkard J Dubois GP Eigen G Eisenstein BI Freese T Gatto C Gladding G Grab C Heusch CA Hitlin DG Izen JM Kim PC Labs J Li A Lockman WS Mallik U Matthews CG Mincer AI Mir R Mockett PM Nemati B Odian A Parrish L Partridge R Pitman D Richman JD Sadrozinski HF Scarlatella M Schalk TL Schindler RH Seiden A Simopoulos C Stockdale IE Toki W Tripsas B Villa F Wang MZ Wasserbaech S 《Physical review letters》1991,67(8):1011-1014
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517.
Sander O Henss A Näther C Würtele C Holthausen MC Schindler S Tuczek F 《Chemistry (Weinheim an der Bergstrasse, Germany)》2008,14(31):9714-9729
Detailed mechanistic studies on the ligand hydroxylation reaction mediated by a copper bis(imine) complex are presented. Starting from a structural analysis of the CuI complex and the CuII product with a hydroxylated ligand, the optical absorption and vibrational spectra of starting material and product are analyzed. Kinetic analysis of the ligand hydroxylation reaction shows that O2 binding is the rate-limiting step. The reaction proceeds much faster in methanol than in acetonitrile. Moreover, an inverse kinetic isotope effect (KIE) is evidenced for the reaction in acetonitrile, which is attributed to a sterically congested transition state leading to the peroxo adduct. In methanol, however, no KIE is observed. A DFT analysis of the oxygenation reaction mediated by the micro-eta2:eta2 peroxo core demonstrates that the major barrier after O2 binding corresponds to electrophilic attack on the arene ring. The relevant orbital interaction occurs between the sigma* orbital of the Cu2O2 unit and the HOMO of the ligand. On the basis of the activation energy for the rate-limiting step (18.3 kcal mol(-1)) this reaction is thermally allowed, in agreement with the experimental observation. The calculations also predict the presence of a stable dienone intermediate which, however, escaped experimental detection so far. Reasons for these findings are considered. The implications of the results for the mechanism of tyrosinase are discussed. 相似文献
518.
In multibody systems, two alternative approaches exist to compute contact forces between bodies. The unilateral constraint contact and the unilateral regularized contact do not take into account the influence of the deformation due to other contacts on a body using rigid body dynamics. In this paper, a third alternative, i.e. the Maxwell-Contact, is derived coupling the deformations of different contacts on one body quasi-statically. An academic example validates the fundamental properties of the contact model and the application in a simulation of a pushbelt CVT shows improved results. (© 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
519.
Masoud Amirkhani Nicola Berger Mohamed Abdelmohsen Frank Zocholl Manuel Rodrigues Gonçalves Othmar Marti 《Journal of Polymer Science.Polymer Physics》2011,49(20):1430-1436
The Breath‐Figure technique was employed to imprint honeycomb structures in the polymer films via the condensation of water vapor on the surface of an evaporating polymer solution. Generally, the condensed water droplets can be stabilized by an end‐functional polymer or by particles added to the polymer solution. In this study, we carried out a systematic experiment on the effect of different stabilizers on the porous honeycomb structure under identical physical conditions. The end‐functional polymer produced a large area of regular spherical bubbles, whereas adding particles to the polymer solution leads to smaller arrays of the flattened bottom bubbles. The separation length between pores was larger for polymer/particle sample than that of the end‐functional polymer films. In the regular area of polymer/particle film many bubbles were not decorated by particles. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 49: 1430–1436, 2011 相似文献
520.
Schindler A Heindl C Balázs G Gröger C Virovets AV Peresypkina EV Scheer M 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(3):829-835
Treatment of the pentaphosphaferrocene [Cp*Fe(η5‐P5)] with CuI halides in the presence of different templates leads to novel fullerene‐like spherical molecules that serve as hosts for the templates. If ferrocene is used as the template the 80‐vertex ball [Cp2Fe]@[{Cp*Fe(η5‐P5)}12{CuCl}20] ( 4 ), with an overall icosahedral C80 topological symmetry, is obtained. This result shows the ability of ferrocene to compete successfully with the internal template of the reaction system [Cp*Fe(η5‐P5)], although the 90‐vertex ball [{Cp*Fe(η5:η1:η1:η1:η1:η1‐P5)}12(CuCl)10(Cu2Cl3)5{Cu(CH3CN)2}5] ( 2 a ) containing pentaphosphaferrocene as a guest is also formed as a byproduct. With use of the triple‐decker sandwich complex [(CpCr)2(μ,η5‐As5)] as a template the reaction between [Cp*Fe(η5‐P5)] and CuBr leads to the 90‐vertex ball [(CpCr)2(μ,η5‐As5)]@[{Cp*Fe(η5‐P5)}12{CuBr}10{Cu2Br3}5{Cu(CH3CN)2}5] ( 6 ), in which the complete molecule acts as a template. However, if the corresponding reaction is instead carried out with CuCl, cleavage of the triple‐decker complex is found and the 80‐vertex ball [CpCr(η5‐As5)]@[{Cp*Fe(η5‐P5)}12{CuCl}20] ( 5 ) is obtained. This accommodates as its guest [CpCr(η5‐As5)], which has only 16 valence electrons in a triplet ground state and is not known as a free molecule. The triple‐decker sandwich complex [(CpCr)2(μ,η5‐As5)] requires 53.1 kcal mol?1 to undergo cleavage (as calculated by DFT methods) and therefore this reaction is clearly endothermic. All new products have been characterized by single‐crystal X‐ray crystallography. A favoured orientation of the guest molecules inside the host cages has been identified, which shows π???π stacking of the five‐membered rings (Cp and cyclo‐As5) of the guests and the cyclo‐P5 rings of the nanoballs of the hosts. 相似文献