Explaining the different efficiency behaviors of PHOLEDs with/without a hole injection barrier at the hole transport layer/emitter layer interface

In this work we investigate the different efficiency behaviors of the devices with and without hole injection barrier, utilizing in our investigation the archetypical 4,4′-bis(carbazol-9-yl)biphenyl:Tris(2-phenylpyridine)iridium(III) host–guest PHOLEDs system. The results show that the recombination of electrons and holes on the host material generally leads to higher device efficiency in comparison to the case where recombination happens on the guest material. The results also show that in devices where a hole injection barrier between the HTL and the host material in the EML exists, the emission mechanism gradually changes from one based on host e–h recombination to one based on guest e–h recombination as the guest concentration is increased. When host e–h recombination is dominant, although it tends to produce higher device efficiency, host e–h recombination is generally also associated with significant efficiency roll-off; the latter arises from quenching of the host triplet excitons primarily due to host–host TTA. As the concentration of the guest molecules increases and the creation of host triplet excitons subsides (since most e–h recombination occurs on the guest) host–host TTA decreases, hence also the efficiency roll-off. In such case, quenching is mostly caused by polarons residing on guest sites. At optimum guest concentrations (∼8% Vol.), a balance between host e–h recombination and guest e–h recombination is reached, and thus also minimal TTA and Triplet-Polaron Quenching. On the other hand, in devices where hole injection barrier between the HTL and the host in the EML is insignificant, emission mechanism is always based on host e–h recombination irrespective of the guest concentration, and therefore have higher efficiency and the efficiency does not depend on guest concentration. The absence of the injection barrier in these devices results in a wider recombination zone, and hence a lower exciton concentration in general, which in turn reduces host–host TTA and thus lowers efficiency roll-off. In contrast, guest–guest TTA is not found to play a significant role in device efficiency behavior.     

Fast,compact and symmetric modular exponentiation architecture by common-multiplicand Montgomery modular multiplications

In this paper, the primitive common-multiplicand Montgomery modular multiplication is developed for modular exponentiation. Together with Montgomery powering ladder, a fast, compact and symmetric modular exponentiation architecture is proposed for hardware implementation. The architecture consists of one group of processing elements along the central line and two symmetric groups of accumulation units on two sides. The central elements perform modular reductions, while the symmetric units on both sides accumulate the modular multiplication results. A feedforwarding architecture is employed to decrease the latency between processing elements, in parallel with the word-based accumulation units, which are also pipelined. Meanwhile, due to the symmetric architecture and Montgomery powering ladder, the modular exponentiation is immune from fault and simple power attacks. Implemented in FPGA platform, the performance of our proposed design outperforms most results so far in the literature.     

Java多线程机制及其应用

对Java多线程的通信机制、同步机制进行了分析，说明了Java多线程的应用，并介绍了Java多线程机制的实现方法，给出了在多用户远程协同工作系统中，运用Java多线程机制实现Senrer端和Client端交互信息的实时处理。     

场发射显示器(FED)荧光粉的研究进展

场发射显示器(FED)是一种新发展起来的平板显示器。它在亮度、视角、响应时间、工作温度范围、能耗等方面具有优良的特性。文章首先简要地介绍了FED发展历史和现状、工作原理以及对荧光粉的要求，然后介绍了FED荧光粉的研究历史和发展现状以及有关FED荧光粉激发和发光机理的相关研究工作。最后就FED荧光粉的研究提出了一些建议。     

Direct evidence for the electron–hole pair mechanism by studying the organic magneto-electroluminescence based on charge-transfer states

Organic magneto-electroluminescence (MEL) based on the charge-transfer (CT) states was investigated to clarify the electron-hole (e-h) pair mechanism for the organic magnetic field effects. The CT state is an ideal object because its emission is a direct intermolecular recombination process without forming intramolecular exciton. We found that the MEL of the CT states is not only greater than that of the exciton, but also exhibits almost no high-field decrease at low temperatures. Our results directly prove the e-h pair mechanism. Meanwhile, the transient electroluminescence measurements with and without magnetic fields confirm that magnetic field has no effect on the charge mobility but on the charge recombination process, implying the charge mobility-related mechanisms may be less dominant above the turn-on voltage.     

基于移动代理和信任机制的网格作业管理

介绍了网络计算环境下的作业管理,引入了移动代理技术和信任机制,并进行了深入分析,对所用到的关键技术进行了详细的解释,说明了基于移动代理和信任机制的网格作业管理运行步骤.     

基于VCG-Kelly机制的钢铁企业能源分配的研究

钢铁企业能源中心的主要目标是确保生产用能的稳定供应和动态调配。为了抑制二级厂自私性行为,提出了基于VCG-Kelly机制的能源分配机制。该机制具有占优策略激励兼容特性,且只需一维竞价信息。仿真结果表明,本文所提出的分配机制通过有效的价格惩罚,使自私二级厂主动地选择真实的能源需求策略,抑制其说谎的动机,进而使能源能得到合理的分配。     

近场光学中成象衬度机制的研究

本文从理论上研究了收集式近场光学显微镜中的成角衬度问题。采用三维时域有限差分法计算了光学近场区域亚波长尺度的电磁场分布。计算表明;利用ｐ偏振光成象可以得到样品的形貌衬度,而利用ｓ偏振光成象可以得到样品形貌的边缘象。该结果为近场光学显同镜中的图像解释及新仪器的开发提供了理论依据。     

Electrical characteristics of Ge MOS device on Si substrate with thermal SiON as gate dielectric

Metal-oxide-semiconductor (MOS) devices, using a Si substrate and a thermal SiON film as the gate dielectric on a Ge layer, have been physically and electrically characterized. The small frequency dispersion and negligible hysteresis demonstrate very few oxide traps. The efficiency of Ge surface passivation is evidenced by the acceptable interface trap density of 7.08 × 10¹¹ cm⁻² eV⁻¹ close to midgap, which is critical for the enhancement of the carrier mobility in MOSFET devices. On the other hand, for the thermal SiON film, a higher permittivity of 4.86 can be achieved by NH₃ nitridation and a subsequent N₂O treatment of an as-grown SiO₂ film without compromising its leakage current. The conduction mechanism is confirmed to be Fowler-Nordheim (F-N) tunneling with extracted electron barrier height of 2.71 eV. Combining with these promising properties, the SiON film shows a great potential to further boost the performance of Ge MOSFETs. Most importantly, without using a Ge substrate, the SiON film on a Ge layer can be formed by the process fully compatible with incumbent ultra-large-scale integration (ULSI) technology, and hence, providing an economic way of fabricating high-performance Ge MOSFETs.     

中高磨床偏心式中高形成机构理论计算公式的推导

从设计角度介绍了中高磨床偏心式中高形成机构的结构、工作原理及理论计算的推导过程，以及根据中高值求解调整偏心量的理论计算公式。