Emission properties of thin films of electroactive doped polymers

We have studied the effect of the intensity of the exciting radiation and the temperature on the emission properties of two kinds of thin-film samples based on blends of two types of organic electroactive materials: polyfluorene + iridium triphenylpyridinate and polyepoxypropylcarbazole + zero-th order PAMAM dendrimer with eosin. We have shown that an increase in the excitation intensity leads to an increase in the intensity of the luminescence of the polymer matrices and the iridium complex up to a power density of 300 kW/cm², and the emission of the dendrimer is rapidly saturated and does not return to the initial value when the excitation level decreases. Heating up to 170°C followed by cooling causes an increase in the intensity for all the components except the dendrimer. The data obtained show that annealing is an important method for improving the emission efficiency of the proposed thin-film structures, due to a change in the packing of the activator molecules in the polymer matrix leading to more efficient transfer of the excitation energy. Molecules of the studied dendrimer are not stable when exposed to optical radiation and temperature. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 6, pp. 820–825, November–December, 2007.     

Kinetic energy release for the collision-induced dissociation of CO<Superscript>+</Superscript>

The kinetic energy release distributions (KERDs) of C⁺ and O⁺ fragments arising from 5 keV collision-induced dissociation (CID) of CO⁺ ions with helium have been measured. The KERDs of C⁺ and O⁺ exhibit different features corresponding to the states that participate in CID processes. We have identified groups of dissociative and predissociative states, and compare them with theoretical and experimental values.     

Vibrational excitation of molecules in a lattice due to shock induced molecular deformation

A simple formalism is developed to calculate the rate of internal vibrational excitation of a molecule in a lattice due to abrupt deformation of the bonds of the molecule as a result of the application of a shock pulse to the lattice. The excitation rate is calculated as a function of rise time of the pulse and peak pressure for the case of 1,3,5-trinitro, 1,3,5-triazocyclohexane. It is shown that large vibrational excitation rates can be achieved if the rise time of the shock pulse is in the order of the period of vibration of the bond. The possible role of this process in shock induced chemical reactions in solids is considered.     

小型全内腔脉冲Ar~＋激光管的研制

介绍一种小型全内腔脉冲Ａｒ＋激光管的设计和结构。并对不同阴极，放电管直径，激励电压及Ａｒ气压等对输出功率及激光管寿命的影响作了一系列的实验，试制出结构简单，使用方便，价格便宜的有一定实用价值的小型全内脏脉冲Ａｒ＋激光管。     

Rate processes on fractals: Theory,simulations, and experiments

Heterogeneous kinetics are shown to differ drastically from homogeneous kinetics. For the elementary reaction A + A products we show that the diffusion-limited reaction rate is proportional tot ^– h[A]² or to [A]^x, whereh=1- d _s/2, X=1+2/d _s =(h-2)(h-1), andd _s is the effective spectral dimension. We note that ford = d _s =1, h =1/2 andX = 3, for percolating clustersd _s = 4/3,h = 1/3 andX = 5/2, while for dust ds <1, 1 >h > 1/2 and >X > 3. Scaling arguments, supercomputer simulations and experiments give a consistent picture. The interplay of energetic and geometric heterogeneity results in fractal-like kinetics and is relevant to excitation fusion experiments in porous membranes, films, and polymeric glasses. However, in isotopic mixed crystals, the geometric fractal nature (percolation clusters) dominates.     

Spectral characteristics of luminescence of solutions of complex molecules under conditions of electronic excitation transfer to a saturable acceptor in the case of inhomogeneous broadening of electronic energy levels

Spectral characteristics of solutions of complex molecules under conditions of inhomogeneous broadening of energy levels are considered in the case when the nonlinear dependence of the population of molecular states on the excitation intensity is determined not by saturation of molecular levels but by exchange of the electronic excitation energy with the environment. Calculations have shown that the dependence of the position of the fluorescence spectrum on the excitation frequency is nonmonotonic in solutions of the type and varies substantially with the excitation intensity. Belarusian State University, 4, F. Skorina Ave., Minsk, 220072, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 2, pp. 164–168, March–April, 1997.     

感应耦合等离子体中原子发射光谱的非局部热平衡 Ⅰ.非玻尔兹曼分布

本文叙述了在感应耦合等离子体中,原子激发过程可以用台阶式模型来近似,从而证实了激发态粒子数的局部非玻尔兹曼分布是等离子体光学薄性质的必然结果。从理论上讨论了局部非玻尔兹曼分布公式以及分布曲线弯曲时的拐点能量。     

Study on Pair Correlation Energies of Isoelectronic Systems F~-,HF and H_2F~+

IntroductionAsawell knownfact ,thecalculationofelectroncor relationenergyisabottleneckprobleminthecalculationsofmolecularpropertiesandchemicalreactionsinquantumchemistry .1Ithasattractedgreatattentionoftheoreticalchemists.NumerousdifferentmethodshavebeenusedtocalculatethecorrelationenergysinceL wdin2 givethedef initionofelectroncorrelationin 195 9.In 196 0s ,Sinanoˇglu3,4 definedtheexactelectronpaircorrelationen ergyanddevelopedmany electrontheoryofatomsandmoleculesinwhichthetotalcorrelation…     

纳米钙钛矿型LaFe1-xNixO3(x=0~1.0)的制备及其在紫外光激发下的电化学性能

本文采用溶胶-凝胶法制备了LaFe1-xNixO3(x=0,0.2,0.4,0.6,0.8,1.0)纳米晶粉末,利用XRD、TEM和电化学测试方法对LaFe1-xNixO3材料的相结构、形貌、成分组成和其在碱液中的充放电性能以及电化学动力学性能等方面进行了表征和分析,同时对电极受紫外光激发前后的电化学行为进行了对比研究。XRD和TEM分析表明,用硝酸盐作为原材料和溶胶-凝胶方法可制备出单一相结构的纳米晶钙钛矿型LaFe1-xNixO3复合氧化物,随Ni替代量x的增大,LaFe1-xNixO3的相结构由正交结构向菱面体结构转变,其分子体积和晶粒尺寸呈现减小的趋势。电化学研究结果表明,紫外光激发前,LaFe1-xNixO3电极的放电容量随x的增加而逐渐增大;光激发后,电极的放电容量和交换电流Io与未激发前相比显著提高,当x=0.4时其放电容量具有最大值483.1mAh·g-1,Io值由光激发前的3.54～11.58 mA·g-1大幅增加至激发后的8.37～40.11 mA·g-1。