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设计并合成了一种基于喹诺酮衍生物的双极绿色磷光主体材料1-甲基-3-[4-(9-咔唑基)苯基]-4-苯基喹啉-2(1 H)-酮.计算发现,化合物的HOMO轨道的电子云位于咔唑基团,LUMO轨道的电子云位于喹诺酮基团,是一种良好的双极材料.化合物的磷光发射峰为515 nm(2.41 eV),符合绿色磷光主体材料的基本要求(>2.4 eV).热失重和差热分析结果表明,该化合物具有较高的热稳定性,分解温度和玻璃化转变温度分别为312℃和105℃.研究结果表明:该新型化合物是一种潜在的具有双极特性的绿色磷光主体材料. 相似文献
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助推段导弹有高温、大面积的尾焰,根据尾焰光谱特征可准确识别导弹。将其应用到天基预警系统能够使导弹防御系统趋于完善,但光谱信息数据量庞大,从获取光谱信息到识别光谱信息需要耗费大量时间。为此,寻找能够代表导弹尾焰光谱的特征光谱,使用模糊算法对特征光谱进行数据处理,以达到准确、快速识别的目的。利用已有的红外图像和大气、云层、导弹及飞机尾焰光谱数据进行特征光谱图像拟合,经信噪比分析后可知,特征光谱图像比全波段红外光谱图像的信噪比高。分别使用模糊算法和光谱角测度对拟合图像进行处理,结果表明模糊算法的实时性和准确性优于光谱角测度。 相似文献
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设计并合成了一种由咔唑和噁二唑基团构成的,具有双极载流子传导特性的新型主体材料C1PBD。通过对C1PBD的光物理和电化学性能进行研究,证明这种新型的双极主体材料可以用作为蓝色荧光器件的主体材料.利用传统蓝色荧光掺杂材料TBPe,制备了C1PBD作为主体材料的器件,并对其性能进行了表征,器件开启电压约为3.2 V,最大电流效率达到2.26 cd/A,器件表现出稳定的蓝色发光,CIE值稳定在(0.14,0.14),展现了C1PBD作为主体材料的良好性能. 相似文献
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Unipolar memristive devices are an important kind of resistive switching devices. However, few circuit models of them have been proposed. In this paper, we propose the SPICE modeling of flux-controlled unipolar memristive devices based on the memristance versus state map. Using our model, the flux thresholds, ON and OFF resistance, and compliance current can easily be set as model parameters. We simulate the model in HSPICE using model parameters abstracted from real devices, and the simulation results show that the proposed model caters to the real device data very well, thus demonstrating that the model is correct. Using the same modeling methodology, the SPICE model of charge-controlled unipolar memristive devices could also be developed. The proposed model could be used to model resistive memory cells, logical gates as well as synapses in artificial neural networks. 相似文献
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本文介绍了对ARCH/GARCH模型的两种估计方法:准极大似然估计和极小绝对偏差估计,并提出了一种基于自助法(Bootstrap)对估计方法的选择。在厚尾程度不同的情况下进行了模拟分析,表明对于一个具体的数据,该选择法能够自动选择较优的估计方法。并用该方法对上海证券交易所A股和B股的股价指数进行了分析,印证了上海股市B股收益率的尾部厚于A股收益率尾部。 相似文献
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The Higgs decay H →γγ due to the virtual W-loop effect is revisited in the unitary gauge by using the symmetry-preserving and divergent-behavior-preserving loop regularization method,which is realized in the fourdimensional space-time without changing original theory.Though the one-loop amplitude of H →γγ is finite as the Higgs boson in the standard model has no direct interaction with the massless photons at tree level,it involves both tensor-type and scalar-type divergent integrals which can in general destroy the gauge invariance without imposing a proper regularization scheme to make them well-defined.As the loop regularization scheme can ensure the consistency conditions between the regularized tensor-type and scalar-type divergent irreducible loop integrals to preserve gauge invariance,we explicitly show the absence of decoupling in the limit M W /M H → 0 and obtain a result agreeing exactly with the earlier one in the literature.We then clarify the discrepancy of the earlier result from the recent one obtained by R.Gastmans,S.L.Wu and T.T.Wu.The advantage of calculation in the unitary gauge becomes manifest in that the non-decoupling arises from the longitudinal contribution of the W gauge boson. 相似文献
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Analysis and modeling of resistive switching mechanism oriented to fault tolerance of resistive memory based on memristor 下载免费PDF全文
With the progress of the semiconductor industry, resistive memories, especially the memristor, have drawn increasing attention. The resistive memory based on memrsitor has not been commercialized mainly because of data error. Currently, there are more studies focused on fault tolerance of resistive memory. This paper studies the resistive switching mechanism which may have time-varying characteristics. Resistive switching mechanism is analyzed and its respective circuit model is established based on the memristor Spice model. 相似文献