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排序方式: 共有1115条查询结果,搜索用时 31 毫秒
141.
Nicolas Cocherel Cyril Poriel Dr. Joëlle Rault‐Berthelot Dr. Frédéric Barrière Dr. Nathalie Audebrand Dr. Alexandra M. Z. Slawin Prof. Dr. Laurence Vignau Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2008,14(36):11328-11342
New routes to ladder‐type phenylene materials 1 and 2 are described. The oligomers 1 and 2 , which possess a “3π‐2spiro” architecture, have been synthesized by using extended diketone derivatives 3 and 10 as key intermediates. The physicochemical properties of the new blue‐light emitter 2 were studied in detail and compared with those of the less‐extended 1 . Owing to the recent development of fluorenone derivatives and their corresponding more conjugated analogues as potential electron‐transport materials in organic light‐emitting diodes (OLEDs) and as n‐type materials for photovoltaic applications, we also report herein the thermal, optical and electrochemical behavior of the key intermediates, diketones 3 and 10 . Finally, the application of dispiro 2 as a new light‐emitting material in OLEDs is reported. 相似文献
142.
We introduce and discuss a combination of methods and options that aim at the aerodynamical optimization of a flow around an arbitrary aircraft shape. The flow is governed by the Euler equations, discretized by a mixed element-volume method on a fixed unstructured tetrahedrization. The shape parametrization relies on the skin of the above mesh through a hierarchical representation. Descent-type and one-shot algorithms are devised and adapted to the solution of a few model problems. 相似文献
143.
Howard Alper Nathalie Hamel James B. Woell David J.H. Smith 《Tetrahedron letters》1985,26(19):2273-2274
Esters are isolated in fine yields from the rhodium(I) catalyzed reaction of benzyl chlorides with borate esters and carbon monoxide, in the presence of potassium iodide. 相似文献
144.
Luis Bel Thibaut Damour Nathalie Deruelle Jesus Ibanez Jesus Martin 《General Relativity and Gravitation》1981,13(10):963-1004
Using a fast-motion approximation method we obtain the second-order gravitational field and equations of motion for two pointlike objects in algebraically closed form. A regularization procedure is used which is shown to guarantee the consistency of the approximation scheme. The equations of motion are then transformed within the framework of relativistic predictive mechanics into a system of ordinary differential equations. 相似文献
145.
146.
Emilie Groison Salim Adjili Alice Ferrand Frdric Lortie Daniel Portinha Nathalie Sintes‐Zydowicz 《Macromolecular rapid communications》2011,32(6):491-496
This contribution presents a new strategy for preparing nanocapsules with a shell made of a supramolecular polymer which repeating units are held together by reversible interactions rather than covalent bonds. These nanocapsules were prepared in classical miniemulsion through interfacial addition reaction of a diisocyanate (IPDI) and a monoamine (iBA), forming low‐molecular weight bis‐ureas moieties which are strong self‐complementary interacting molecules through hydrogen‐bonding. The nanocapsules present a diameter around 100 nm, and MALDI‐TOF MS and 1H NMR analyses confirm the expected molecular characteristics for the shell. This strategy opens the scope of a new type of nanomaterials exhibiting stimuli‐responsiveness due to the reversible interaction linking the repeating units.
147.
Bruneval F Vast N Reining L Izquierdo M Sirotti F Barrett N 《Physical review letters》2006,97(26):267601
State-of-the-art theoretical methods fail in describing the optical absorption spectrum, band gap, and optical onset of Cu(2)O. We have extended a recently proposed self-consistent quasiparticle approach, based on the GW approximation, to the calculation of optical spectra, including excitonic effects. The band structure compares favorably with our present angle-resolved photoemission measurements. The excitonic effects based on these realistic band structure and screening provide a reliable optical absorption spectrum, which allows for a revised interpretation of its main structures. 相似文献
148.
The role of the lithium ion environment is of fundamental interest regarding transport and conductivity in lithium polymer electrolytes. X-ray crystallography has been used to characterize the lithium environment in completely crystalline poly(ethylene oxide) (PEO) electrolytes, but this approach cannot be used with dilute PEO electrolytes. Here, using solid-state NMR data collected with the rotational-echo double-resonance 13C[7Li] (REDOR) pulse sequence, we have been able to characterize the crystalline microdomains of a PEO-lithium triflate sample with an oxygen/lithium ratio of 20:1. Our data clearly demonstrates that the lithium crystalline microdomains are nearly identical to those of a completely crystalline 3:1 sample, for which the crystal structure is known. 相似文献
149.
Guennoun Z Piétri N Couturier-Tamburelli I Aycard JP 《The journal of physical chemistry. A》2006,110(24):7738-7743
Laboratory experiments involving ultraviolet (UV) irradiation of dicyanoacetylene (C(4)N(2)) trapped in water ice at 10 K have been conducted and monitored by infrared spectroscopy (FTIR). By the support of isotopic experiments and theoretical calculations, the irradiation of a DCA/H(2)O ice mixture at lambda > 230 nm has been found to be a possible source of NH(4)(+)HCO(3)(-) (ammonium bicarbonate) and NH(4)(+)HCOO(-) (ammonium formate). These latter compounds can arise from a proton-transfer reaction between H(2)O and the CN radical, which is issued from photolyzed C(4)N(2). 相似文献
150.