Highly Efficient,Solution‐Processed,Single‐Layer,Electrophosphorescent Diodes and the Effect of Molecular Dipole Moment

A new family of highly soluble electrophosphorescent dopants based on a series of tris‐cyclometalated iridium(III) complexes (1–4) of 2‐(carbazol‐3‐yl)‐4/5‐R‐pyridine ligands with varying molecular dipole strengths have been synthesized. Highly efficient, solution‐processed, single‐layer, electrophosphorescent diodes utilizing these complexes have been prepared and characterized. The high triplet energy poly(9‐vinylcarbazole) PVK is used as a host polymer doped with 2‐(4‐biphenylyl)‐5‐(4‐tert‐butyl‐phenyl)‐1,3,4‐oxadiazole (PBD) for electron transport. Devices with a current efficiency of 40 cd A^?1 corresponding to an EQE of 12% can thus be achieved. The effect of the type and position of the substituent (electron‐withdrawing group (CF₃) and electron‐donating group (OMe)) on the molecular dipole moment of the complexes has been investigated. A correlation between the absorption strength of the singlet metal‐to‐ligand charge‐transfer (¹MLCT) transition and the luminance spectral red shift as a function of solvent polarity is observed. The strength of the transition dipole moments for complexes 1–4 has also been obtained from TD‐DFT computations, and is found to be consistent with the observed molecular dipole moments of these complexes. The relatively long lifetime of the excitons of the phosphorescence (microseconds) compared to the charge‐carrier scattering time (less than nanoseconds), allows the transition dipole moment to be considered as a “quasi permanent dipole”. Therefore, the carrier mobility is sufficiently affected by the long‐lived transition dipole moments of the phosphorescent molecules, which are randomly oriented in the medium. The dopant dipoles cause positional and energetic disorder because of the locally modified polarization energy. Furthermore, the electron‐withdrawing group CF₃ induces strong carrier dispersion that enhances the electron mobility. Therefore, the strong transition dipole moment in complexes 3 and 4 perturbs both electron and hole mobilities, yielding a reduction in exciton formation and an increase in the device dark current, thereby decreasing the device efficiency.     

飞思卡尔触摸传感器实现新的应用

概述 有了接近式触摸传感器,按字面意思理解就是没有按压操作了.因为它们是触摸式按钮,而不是按压式按钮.在任何情况下,接近式触摸传感器都没有移动部件.没有弹簧,没有敲击,没有跳动的键帽.而且,它们可以满足任何空间要求.没有任何突出的东西,因此开发人员可以将它们直接安装在设计轮廓上.     

The Loss of Hydrophobic Polypeptides during Fermentation and Conditioning of High Gravity and Low Gravity Brewed Beer

The object of this study was to investigate the loss of hydrophobic polypeptides, which are important for foam quality and stability in finished beer. Loss of hydrophobic polypeptide due to fermenter foaming occurs during transfer of fermented wort since a gradient of hydrophobic polypeptides towards the surface is created during fermentation. Due to higher polyphenol levels in high gravity (20°Plato) wort, more hydrophobic polypeptides are lost due to cold break (cold trub) precipitation compared to low gravity (12°Plato) wort. Another important factor affecting the loss of hydrophobic polypeptides could be proteinase A activity during fermentation, especially in high gravity fermentation where the yeast is exposed the higher stress. During high gravity fermentation, where osmotic pressures are higher, ethanol levels become greater, and nitrogen‐carbohydrate ratios are lower, more proteinase A is released by the yeast. This release of proteinase A into fermenting wort could have implications for the foam stability of the finished product.     

Reprocessing of thermally oxidized aluminum arsenide (AlAs) in epitaxial multilayers without delamination

Annealing or processing of AlAs that has been subjected to a wet thermal oxidation process can result in severe delamination of material at the oxidation front. This paper reports a procedure for preventing this delamination and presents a possible cause for the delamination.     

Dynamic mechanical properties of polymer melts: The effect of molecular weight distribution on the temperature dependence of viscoelastic properties

An experimental investigation of the dynamic mechanical response of molten polymers was performed using the Maxwell Orthogonal Reheometer. One purpose of the study was to evaluate the effect of molecular weight distribution on the temperature dependence of viscoelastic properties. Data were obtained over a range of temperatures for both monodisperse and polydisperse materials which indicate that viscoelasticity is highly temperature dependent only for monodisperse polymers. On a molecular basis the reduction in temperature sensitivity for polydisperse materials logically can be attributed to the influence of the low molecular weight species present in a distribution on the relaxation spectrum. Since the relaxation spectrum largely determines all viscoelastic functions, the observations made from th dynamic data shown in this paper can be generalized to all viscoelastic experiments.     

Correlates of social status among mildly handicapped learners in self-contained special classes.

Studied the contributions of perceived cognitive competence and misbehavior to the variance in the sociometric status of 222 educable mentally retarded (EMR) and 65 educationally handicapped (EH) children in self-contained special classes. Teachers and peers rated Ss on academic competence and misbehavior. Results indicate that the combined teacher ratings of these 2 dimensions accounted for the most variance in both acceptance and rejection of EMR Ss, whereas ratings of academic competence were associated with both acceptance and rejection of EH Ss. Results are discussed in terms of differential factors associated with social status of mildly handicapped learners in special classes vs regular classes. In addition, the data suggest the importance of differences in the characteristics of children doing the rating of both independent and dependent variables. (9 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Personal adjustment and academic predictability among college freshmen.

The objective of this study was to investigate whether the prediction of academic achievement is influenced by personal emotional adjustment as found by Hoyt and Norman in 1954. Samples consisted of 1,465 arts college freshmen from which were selected three "adjustment" groups (normal, one-peak, and maladjusted) according to arbitary cut-off points on the clinical scale of the MMPI. Correlations between grade point average (GPA) and predictor variables were determined. For the arts college, no significant differences were found between the adjustment groups for the correlation of GPA with either of the predictors high school rank or the Minnesota Scholastic Aptitude Test. 11 predictor variables were used for the engineering freshmen, only one of which yielded statistically significant differences between the adjustment groups. In contrast to the findings of Hoyt and Norman, it was concluded that the predicton of academic achievement is not influenced by personal adjustment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Acquired retinal folds in the cat

Retinal folds were found in 5 cats. The apparent cause of the folding was varied: in 1 cat the folds appeared after a localized retinal detachment; in 2 cats the condition accompanied other intraocular abnormalities associated with feline infectious peritonitis; 1 cat had active keratitis, and the retinal changes were thought to have been injury related; and 1 cat, bilaterally affected, had chronic glomerulonephritis.     

Fatal systemic mycotic infections in the burned child

Two cases of systemic phycomycotic burn wound infection occurred in severely burned children. Both patients, although treated aggressively, died after systemic colonization through the burn wound by fungi. Modern burn therapy has increased survival of many severely burned children but opportunistic fungal infection remains as an ominous threat. Early recognition, wide excision or amputation, and systemic antifungal agents comprise the current clinical armamentarium against systemic fungal invasion of burn wounds.