Mixed host structure

Enhancement in the performance of OLEDs can be achieved by balanced charge injection and charge transport. The charge transport is related to the drift mobility of charge carriers. Liu et al. [166] reported blue emission from OLED based on mixed host structure. A mixed host structure consists of two different hosts NPB and 9,10-bis(2 -naphthyl)anthracene (BNA) and one dopant 4,4 -bis(2,2-diphenylvinyl)-l,l -biphenyl (ethylhexyloxy)-l,4-phenylene vinylene (DPVBi) material. They reported significant improvement in device lifetime compared to single host OLEDs. The improvement in the lifetime was attributed to the elimination of heterojunction interface and prevention to formation of fluorescence quenchers. Luminance of 80,370 cd/m2 at 10 V and luminous efficiency of 1.8 cd/A were reported. 

Loeb has reported a series of pseudorotaxanes [84,85] and rotaxanes [86,87] where C-H- 0 hydrogen bonding interactions (together with N+- -O attractive forces) play an important contribution in templating the formation of the interlocked species. In particular, the formation of a pseudorotaxane was observed when equimolar amounts of [pyCH2CH2py]2+ and the crown ether 20 were mixed. The structural characterization of the resulting host-guest complex... 

Centrosymmetric crystals can be transformed into chiral or polar mixed crystals and this enables us to obtain novel means for absolute asymmetric synthesis. The principle is based on selective introduction of a guest molecule into a centrosymmetric host structure, thus reducing the symmetry of the mixed crystal. Crystallization of (E)-cinnamamide (space group P2i/c) in the presence of (E)-... 

The dimensionally stable anode in this system is composed of an electrically conductive substrate of titanium, having a coating of a defect solid solution containing mixed crystals of precious metal oxides. These substitutional solid solutions are both electrically conductive, electrocatalytic, and dimensionally stable. Within the aforementioned solid-solution host structures the valve metals include titanium, tantalum, niobium, and... 

To understand the behavior of the mixed host-probe films, it is essential to understand the behavior of the pure films of both components. We previously investigated in detail the behavior of the pure films of 12-nitrox-ide stearate [2-( 10-carboxydecyl)-2-hexyl-4,4 -dimethyl-3-oxazolidinyloxyl] including its extraordinary temperature dependence (7, 8, 16). In this paper we extend our investigations to the pure films of other nitroxide stearic acid (and methyl ester) probes where the oxazolidine ring is attached to various carbon atoms of the stearic acid (or ester) hydrocarbon chain. This series of spin-label probes is one of those most extensively used to study cell membrane structure. It was used to define, among other things, an order parameter establishing the fluidity (17) and polarity profiles (18) of lipid bilayers. 

Kim, S. H., Jang, J., Lee, J. Y. et al. 2007. Relationship between host energy levels and device performances of phosphorescent oi anic tight-emitting diodes with triplet mixed host emitting structure. Appl. Phys. Lett. 91 083511. 

Consequently, most of the intercalation compounds are mixed-conductors, i.e., electronic and ionic to some extent, in which the charge transfer occurs between the intercalant species and the host structure. The tendency for this charge transfer process is the main driving force for the intercalation reaction and it is one of the basic properties that make the host framework a suitable cathode material. Intercalation is crucial in the working cycle of modem batteries and supercapacitors it involves complex diffusion processes along and across the layers. 

Inspection of Table 13-1 shows that the number of water molecules required to form the hydrate increases with the size of the guest molecule to be captured. Hydrates are classified into simple and mixed hydrates depending on whether one or more host or guest molecules compose the compound. They also exhibit different structures. 

Contrary to the structure similarity of the pheromones secreted by taxonomical related moths, some differences are necessary for their sexual communication systems to play an important role in their reproductive isolation. In addition to further modifications of the various structures, diversity of the lepidopteran sex pheromones is generated by blending multiple components. Innumerable pheromone blends are based not only on combinations of different components but also on variations in the mixing ratio. A pioneer study with Adoxophyes spp. (Tortricidae Tortricinae) had already proposed this concept in the early 1970s. While the smaller tea tortrix (A. honmai) and the Japanese summerfruit tortrix (A. oranafasciata) had been considered to be variant strains with different host preferences in the same species, Tamaki et al. found that females of the former pest insect in the tea garden secreted Z9-14 OAc and Zll-14 OAc in a ratio of 7 4 but females of the latter defoliator of apple trees secreted them in a ratio of 13 4 [127,128]. Furthermore, two other components (Ell-14 OAc and MelO-12 OAc) were subsequently identified from the former species [129]. 

There are multiple ways of deciding between the two former scenarios, and in particular to try to see if pollution might indeed have played an important role in increasing the metal content of the planet host stars relative to their non-planet host counterparts. Probably the most clear argument is based on stellar internal structure. Material falling into a star s surface would induce a different increase in [Fe/H] depending on the depth of its convective envelope, where mixing can occur. However, no correlation is found between the metallicity of the planet host stars and their convective envelope mass (e.g. [16,21]). 

When tripropylamine or tributylamine is used instead of the corresponding Alk N salt, ZSM-5/11 mixed phases (intergrowths ) are formed, suggesting that the Alk N species are less efficient in directing a specific structure. Unexpectedly, Bu N yields essentially a ZSM-5-rich phase while ZSM-11-rich phases are preferentially obtained with Pr N (XRD data). When an organic molecule acts as template towards (alumino)silicate species to form an ordered zeolitic framework, the latter is supposed to organize itself around the host organic species in such a way that a complete... 

The isopod I. baltica is adapted to use F. vesiculosus as food as shown by its capability to grow and reproduce when fed with this alga alone. I. baltica prefers F. vesiculosus as a structural host and feeds readily on it. However, F. vesiculosus is not the best single-host diet species growth of this herbivore on a sole F. vesiculosus diet was inferior to many other hosts and to a mixed diet (Jormalainen et al. 2001 Hemmi and Jormalainen 2004a). Phlorotannins from F. vesiculosus were harmful to the performance of this herbivore Increasing concentrations of phlorotannins in extracts from F. vesiculosus decreased both the total... 

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